Branched long-chain bases from the bivalve Corbicula sandai. Long-chain bases were liberated from a crude mixture of sphingolipids from whole tissue of the fresh-water bivalve C. sandai, and conversion of the bases into N-acetyl-0-trimethylsily derivatives was accomplished. The derivatized bases were analyzed by combined gas-liquid chromatography and mass spectrometry. A portion of the sphingolipids was subjected to catalytic hydrogenation from whch saturated long-chain bases (sphinganines) were obtained. The saturated bases were oxidized with lead tetra-acetate and the aldehydes produced were analyzed by gas-liquid chromatography. The aldehydes were further oxidized to acids with silver oxide, the resulting fatty acids methylated and also analyzed by gas-liquid chromatography. By these analyses, altogether five long-chain bases were identified, consisting of hexadeca-4-sphingenine (15%), heptadeca-4-sphingenine (2%), iso-octadeca-4-sphingenine (13%), octadeca-4-sphingenine (39%) and anteiso-noadeca-4-sphingenine (31%). So far no branches have been found in shellfish spingolipid long-chain bases.


Mass spectral fragmentation of 5alpha-hydroxysteroids. The mass spectra of a number of C-4alpha- and C-4beta-alkylated cholestan-3beta, 5alpha-diols have been found to contain an intense ion at m/e 332. the corresponding 6beta-alkylated (R) cholestan-3beta, 5alpha-diols exhibit an abundant ion at m/e 331 + R. The mass spectra of cholestan-5alpha-ol and cholestan-3beta, 5alpha-diol also show an ion at m/e 332 which, however, is of relatively low abundance. The ion in question appears to arise from fragmentation processes which are characteristics of 5alpha-hydroxysteroids. A similar fragmentation has been found to occur in cases of C-4 and C-6beta-alkylated 5alpha-hysroxy-cholestan-3-ones. The results of isotopic labeling, high resolution and metastable ion defocusing studies are discussed in terms of the origin of several of the ions in the spectra of the various compounds.


Synthesis of DL-2,3-diacyloxypropylphosphonyl-cholines from DL-2,3-diacyloxyiodopropanes. The chemical synthesis of racemic diacyloxypropylphosphonylcholines having octanoyl, myristoyl, oleoyl and stearoyl groups is described. The route involved reaction of dioactanoyloxy-dimyristoyloxy-dioleoyloxy-, and distearoyloxpropyliodide with tris (trimethylsilyl) phosphite to yield the corresponding bis (trimethylsilyl) phosphonate. Removal of the trimethylsilyl groups by neutral aqueous hydrolysis gave the free diacylpropylphosphonic acids, which, when treated with choline toluenesulfonate, yielded the desired dioctanoyloxy-, dimyristoyloxy-, dioleoyloxy-, and distearoyloxypropylphosphonylcholines. The paper also describes the synthesis of 2-octadecyleicosylphosphorylcholine.


Diesters of alkane diols and 2-hydroxy fatty acids: identification and discrimination of isomers with the aid of NMR spectroscopy. High resolution nuclear magnetic resonance spectroscopy has been shown to be extremely useful for the identification and discrimination of naturally occurring diesters of 1,2- and 2,3-alkanediols as well as for fatty alkyl esters of acylated 2-hydroxy fatty acids. A comparison of 220 MHz spectra of 1,2 and erythro- 2,3-alkanediol diesters exhibits the following distinguishing features: (1) two non-equivalent methylene protons from the glycol group of 1,2-alkanediol diesters resonate at 3.87 ppm and 4.17 ppm respectively while these resonances are completely absent in the spectrum of 2,3-isomer; (2) methylene protons adjacent to esther carbonyl groups appear as two overlapping triplets at 2.22 ppm in 1,2-alkanediol diesters while the corresponding protons in the 2,3-isomer are displayed as two partially overlapping triplets centered at 2.15 ppm and 2.2 ppm respectively; and (3) methyl protons adjacent to glycol group in 2,3-isomer appear as downfield doublet at 1.13 ppm; this downfield doublet is not shown by 1,2-alkanediol diesters. Erythro- and threo-2,3-alkanediol diesters have also been distinguished from each other; two alpha-methylenes in erythro isomers appear as partially overlapping triplets while these protons in threo isomer display an apparent quartet centered at 2.22 ppm. Fatty alkyl esters of acylated 2-hydroxy fatty acids display a triplet at 4.79 for 2-position methylene proton, a distinguishing feature not shown by diacyl alkanediols. A distinction between diester lipids and other classes of neutral lipids has also been achieved by the study of nuclear magnetic resonance spectra, particularly in the region of 3-6 ppm.


The tilting of the hydrocarbon chains in a single bilayer of phospholipid. The tilt angle of the hydrocarbon chains to the planes of a dipalmitoryl lecithin single bilayer and multilayers were estimated by the asymmetry of the electron diffraction patterns of respective hydrated specimens. The chains in a single bilayer were found to be perpendicular to the bilayer plane, whereas the chains in the multilayers were found to be tilted with respect to the normal of the plane. Thermal analysis data also supported this conclusion.


Reflex suppression of renin secretion during distention of cardiopulmonary receptors in dogs. We studied the effect of brief periods of left atrial-pulmonary vein distention on the rate of renin secretion in sodium-restricted dogs anesthetized with chloralose and breathing spontaneously. Series 1 consisted of 32 trials in seven dogs with intact renal nerves and intact vagi. Renin secretion, calculated as the product of renal venous minus arterial renin activity (radioimmunoassay) times renal plasma flow (electromagnetic flowmeter), was depressed to 56% of control during atrial distention despite no change in arterial pressure, central venous pressure, or renal blood flow. Series 2 consisted of 58 trials in 12 dogs which had undergone unilateral renal denervation several days prior to the studies. Simultaneous, bilateral determinations indicated that renin secretion from the innervated kidney was depressed to 58% of control during atrial distention; secretion from the denervated kidney was unchanged. Series 3 consisted of 30 trials in six dogs with bilateral cervical vagotomy. Atrial distention evoked no changes in renin secretion. We conclude that left atrial distention reflexly reduces the rates of renin secretion via vagal afferent and renal sympathetic efferent pathways.


Effects of activation sequence on the local recovery of ventricular excitability in the dog. We measured refractory periods at ventricular sites in the dog heart during drive from ventricular test sites and during combined drive from the test sites and other ventricular sites or the atrium. We found that ventricular activation sequence caused significant alterations on refractory period. Combined drive from two sites which resulted in fusion complexes was associated with shorter refractory periods at the test sites than those observed during drive at the test sites only. Our findings are explicable because earlier excitation and consequent earlier recovery of surrounding areas during fusion beats exerts an electrotonic influence on test sites.


Effect of thoracic blood volume changes on steady state cardiac output. We have investigated the extent to which shifts of blood volume out of or into the thoracic  region influence the steady state cardiac output. The systemic circulation of anesthetized dogs was replaced with an artificial circuit which stimulated the pertinent mechanical characteristics of an intact circulation. As in the normal animal, the steady state venous return was proportional to the pressure gradient for venous return (i.e, mean systemic minus right atrial pressure). Cardiac function was altered either by administration of epinephrine or by changes in left ventricular afterload. At a constant mean aortic pressure of 100 mm Hg, epinephrine administration increased the steady state cardiac output by 55%. Half of this increase resulted from the lowered mean right atrial pressure (caused by improved cardiac function); the remainder resulted from an increased mean systemic pressure (caused by the volume shift to the systemic circulation). Increases in afterload transferred sufficient volume to the heart-lung compartment to reduce significantly the mean systemic pressure and, hence, the steady state venous return. Our results indicate that the heart-lung compartment contains a significant volume which is under cardiac control. In addition to being able to alter the right atrial pressure, the heart can modulate the steady state cardiac output by adjusting the mean systemic pressure. To this degree the heart can adjust its own venous return.


Relationships between pressure and flow in the umbilical and uterine circulations of the sheep. We studied the relationship of fetal and maternal vascular pressures to umbilical and uterine blood flow in the unanesthetized ewe and in the sheep fetus in utero by placing electromagnetic flow transducers around both the common umbilical and uterine arteries. Reductions in umbilical arterial pressure or elevations in umbilical venous pressure decreased umbilical blood flow without affecting either the uterine arterial blood flow or other maternal cardiovascular variables which were studied. Elevations in uterine venous pressure or reductions in uterine arterial pressure decreased uterine arterial flow but these interventions had no effect on umbilical blood flow until fetal hypoxemia and bradycardia occurred. When the bradycardia of the fetal hypoxic response was inhibited by atropine, alterations in maternal vascular pressure had no effect on umbilical arterial flow. These data do not support the presence of a "sluice" or "waterfall" effect in the umbilical-placental circulation of the sheep fetus in utero.


The vascular basis for acute renal failure in the rat. Preglomerular and postglomerular vasoconstriction. Myohemoglobinuric acute renal failure (ARF) was induced in dehydrated, salt-deficient, salt-loaded, and untreated rats by intramuscular injection of glycerol, and the renal vasculature was studied after 24 hours. Kidneys were prepared for examination by rapid freezing in vivo to -160 degrees C and freeze substitution in -80 degrees C alcohol, and by perfusion fixation with 1% glutaraldehyde in Ringer's solution at 120 mm Hg. Frozen kidneys were examined by light microscopy after paraffin and epoxy resin embedding. Techniques used in examining the perfusion-fixed kidneys were: (1) vascular injection with silicone rubber and clearing in glycerol, (2) electron microscopy, and (3) morphometric evaluation of lumen to wall area ratios of glomerular arterioles. Kidneys of all rats with ARF showed renal cortical arterial and glomerular arteriolar (afferent and efferent) vasoconstriction. The degree of constriction, estimated by lumen to wall ratios, correlated with the degree of azotemia (r = -0.71; P less than 0.001). Differences between all ARF groups and respective controls were highly significant (P less than 0.001). Vasoconstriction was maximal in the dehydrated group, intermediate in the untreated and Na-deficient rats, and lowest in the salt-loaded animals. Glomerular and peritubular capillaries were patent and free of endothelial swelling or thrombi. Glomerular basement membranes and epithelial foot processes showed no morphological alterations. The observations suggest that marked pre- and postglomerular vasoconstriction occurs in established myohemoglobinuric ARF, that it is related to azotemia, and that mechanical vascular obstruction does not play a major role in this experimental model.


Length-induced changes in activation during contraction. A study of mechanical oscillations in strontium-mediated contractions of cat and frog heart muscle. The plateau phase of prolonged Sr-mediated contractions of preparations of cat and frog heart muscle was used to study the transient response to abrupt changes in load or length. An oscillatory response (total amplitude equal to or less than 5% Lmax) was obtained. Isotonic oscillations were less damped than their isometric counterparts, implying positive feedback and thus a causal role of the perturbation in length. Oscillation frequency was 2-3 HZ at 29 degrees C (Q 10, 2-3); it could be increased by epinephrine or caffeine, independently of their effects on extent of shortening; it otherwise changed as a generally constant function of the length at which the oscillation occurred, whether this was altered by changes in extracellular [Sr], frequency of contraction, or load (independent of the direction and magnitude of the preceding load step). Similar oscillatory responses were induced during Sr- or Ca-mediated contractures. Cat muscles showed an additional slower component to the oscillatory response. Transient augmentation of the velocity-length relationship after abrupt reduction in load, previously described for twitch contractions under certain conditions, appears to be analogous to the first phase of the oscillatory response studied here. Our findings indicate that the oscillation is not attributable to any mechanism intrinsic to myofilament interaction, but rather that it involves length-induced changes in the level of activation, probably mediated by Ca2+ or Sr2+. We conclude that length influences the level of activation during contraction of heart muscle.


The pumping ability of the left heart and the effect of coronary occlusion. In  an isolated preparation of cat heart we studied the pumping capacity of the left heart while left atrial filling pressure was kept constant. We used the source impedance concept to quantify the pumping capacity. In this source impedance concept the relation between left ventricular output and left ventricular pressure is given by the formula (see article) where Zs = source impedance, Plv = left ventricular pressure, Iao = flow in the ascending aorta, and omega = 2pif, f being frequency.. The pressure obtained at zero flow is called the hydromotive pressure (HMP). Only the mean values of pressure and flow were studied. We studied the behavior of 10 hearts in three different experimental situations and in the following sequence: (1) control conditions, (2) after ligating a part of the left coronary arterial system, and (3) after restoring left ventricular output to control level by raising left atrial filling pressure. It was found that source resistance was not significantly different in the three situations but that mean hydromotive pressure (HMP) was significantly lower after ligation of a part of the left coronary arterial system. It was concluded that the decrease in pumping capacity of the left heart after infarction can be compensated for almost completely by an increase in left atrial filling pressure. This compensating mechanism therefore seems to be very efficient.


Electrophysiological and antiarrhythmic effects of propranolol in canine acute myocardial ischemia. To correlate the antiarrhythmic and electrophysiological effects of propranolol in acute myocardial ischemia, we examined the effects of temporary (15-minute) ligations of the left anterior descending coronary artery in studies on 15 dogs. We recorded bipolar electrograms and monophasic action potentials from the ischemic and normal zones and measured the intervals from the onset of QRS in a standard electrocardiogram lead to the major deflection of electrograms recorded from the ischemic and normal zones. We also determined monophasic action potential duration (APD) and effective refractory period (ERP). Data for control ligations were compared to those during which propranolol, 40 mug/kg, was administered intravenously immediately after ligation. Propranolol reduced the mean number of ventricular beats per minute (from 15 to 6) (P less than 0.01). Propranolol slowed conduction in the ischemic zone (by 10 msec at peak effect, P less than 0.01) and had no or only a very slight effect (by 1-msec at 15 minutes, P less than 0.05) on conduction in the normal zone. Propranolol also prolonged APD in the ischemic (32-msec) and normal (14-msec) zones (P less than 0.01), prolonged ERP in the ischemic (41-msec) and normal (20-msec) zones (P less than 0.01), and reduced the APD/ERP ratio in the ischemic (1.62 to 1.47) (P less than 0.01) and normal (1.62 to 1.55) (P less than 0.05) zones. During the control ligation, APD in the ischemic zone was 25 msec shorter than in the normal zone (P less than 0.01), but with propranolol the difference was not significant. The effects of propranolol in slowing conduction in the ischemic zone, in prolonging refractoriness, in reducing APD/ERP, and in reducing the disparity in APD between ischemic and normal zones may explain its demonstrated antiarrhythmic effects in acute myocardial ischemia.


Effects on myocardial contractility of blood-borne material released from the feline small intestine in simulated shock. There is a pronounced derangement in cardiovascular function in the cat after a 2- or 3-hour period during which shock is simulated in the small intestine by regional hypotension (BP = 30-35 mm Hg) during activation of vasoconstrictor nerve fibers. It has been proposed that these effects are caused by blood-borne cardiode-pressant substance(s) released from the "shocked" small intestine. To obtain further evidence for this hypothesis we performed a study on two heart preparations in vitro. Rabbit papillary muscles or isolated beating rat hearts were exposed to intestinal venous plasma obtained from control cats and from cats subjected to simulated intestinal shock for 2 or 3 hours. while control plasma induced only a slight depression of myocardial contractility, plasma from "shocked" intestine caused a significant decrease in peak isometric tension of the papillary muscles or a fall in systolic pressure of the rat hearts. Since the experiments on papillary muscle indicated that time to peak tension was largely unaffected by the plasma samples, we conclude that the feline intestine in shock releases material into blood that exerts a negative inotropic effect on the myocardium.


Blood pressure and plasma angiotensin II concentration after renal artery constriction and angiotensin infusion in the dog. (5-Isoleucine)angiotensin II and its breakdown fragments in dog blood. We measured arterial plasma angiotensin II concentration, renal blood flow, and arterial blood pressure in six conscious dogs during intravenous infusion of angiotensin II (5, 10, and 20 ng/kg per min). The same measurements were made on a different occasion in the same six animals, while they were conscious, before and during constriction of a main renal artery. Arterial blood pressure and plasma angiotensin II rose and renal blood flow decreased in both experiments. The similarity of regressions for plasma angiotensin II concentration and arterial blood pressure in the two experiments strongly suggests that the rise of circulating angiotensin II after renal artery constriction is sufficient to account for the hypertension by its direct pressor action. As discussed, a different mechanism seems likely to be involved in the later stages of renal hypertension. Angiotensin II is more likely to be in the 5-isoleucine form than in the 5-valine form in the dog. In contrast to the rat, plasma concentrations of the heptapeptide (angiotensin III), hexapeptide, and pentapeptide fragments of angiotensin II are low in the dog.


The role of arterial baroreceptors in mediating the cardiovascular response to a cardiac glycoside in conscious dogs. To determine the role of the arterial baroreceptor reflex in mediating the cardiovascular response to a cardiac glycoside, we examined the effects of ouabain (G-strophanthin), 17.5 mug/kg, iv, on direct and continuous measurements of left ventricular diameters, pressures, velocity of shortening, (dP/dt)/P, arterial pressure, cardiac output, and total peripheral resistance. These studies were conducted on healthy conscious dogs before and after total arterial baroreceptor denervation (TABD). Maximal pressor effects were observed in the first 3-5 minutes; mean arterial pressure increased by 11 +/- 1 mm Hg in normal dogs compared to 33 +/- 4 mm Hg in denervated dogs. In intact dogs at this time heart rate decreased by 18 +/- 2 beats/min and cardiac output fell by 18 +/- 3%; these values gradually returned toward control over 15-30 minutes. When heart rate was kept constant, cardiac output did not fall after injection of ouabain. In contrast, heart rate and cardiac output did not change significantly after ouabain in dogs with TABD. The maximal effects on the contractile state of the heart occurred between 15-30 minutes and were similar in both groups. Arterial baroreceptor reflexes appear to be responsible for the reduction in heart rate and cardiac output caused by administration of ouabain to the intact dog. They exert an important buffering action on the vasopressor effect but a less important action on the inotropic response.


Report of the Inter-Society Commission for Heart Disease Resources. Optimal resources for vascular surgery--a supplement. This supplement is an updated and expanded planning and optimal resource guideline for vascular surgery. Activities relating to examination and certification in vascular surgery are reviewed and hospital resource requirements are identified for different categories of vascular operations. There is a detailed summary of results of common vascular operations as reported by leading vascular surgeons. The statement will be of value in planning and organizing vascular surgery programs and in assessing the results of vascular operations locally.


The contribution of tricuspid valve closure to the first heart sound. An intracardiac micromanometer study. The sound-pressure correlates of the second high frequency component of a split first heart sound (S1) were investigated in 27 patients. An external phonocardiogram was recorded with high fidelity sound and pressure from the left and right atria in 21 patients, from the pulmonary artery in 14 of these, and from the central aorta in 11. In the remaining six patients, high fidelity recordings from the central aorta and right-sided chambers were obtained with an external phonocardiogram. The external component of S1 that coincided with a left atrial C wave and "internal sound" was defined as M1. In those cases where the left atrial pressure was not recorded, this component could be identified by a low frequency transient in the central aortic pressure trace. The other external high frequency component of S1 that was synchronous with a separate right atrial C wave and "internal sound" was defined as T1; with two exceptions, M1 preceded T1. The two exceptions which caused reversal of this order, so that T1 preceded M1, were due to chronic left bundle branch block and mitral stenosis. In both cases, T1 was shown to be distinctly separated from the upstroke of pressure rise in the central aorta. This finding was also demonstrated in three cases of right bundle branch block and one case with aortic valvular disease. The usual asynchrony of ventricular contraction was altered by induction of ventricular premature systoles; the separation of externally identifiable M1 and T1 components and their internal markers was predictably altered by this maneuver. The occurrence of T1 was variable in relation to the upstroke of the pulmonary artery pressure, which suggests that it is not related to pulmonic ejection. It is concluded that micromanometrically recorded right and left atrial C waves can serve as markers for externally recordable M1 and T1 components of the first heart sound. In addition, T1 is frequently an externally recordable and audible event.


Familial atrial septal defect with prolonged atrioventricular conduction. This report describes a family with frequent recurrence of congenital heart disease in multiple generations. Eight members had atrial septal defect (ASD) of the fossa ovalis type and seven members had other forms of congenital heart disease. One branch of the pedigree showed a predominance of ASD with prolonged atrioventricular (A-V) conduction and initially suggested an autosomal dominant gene effect. A variety of other forms of congenital heart disease were found in several first degree relatives of those with ASD as well as in more distant relatives. The variability of congenital heart disease in this pedigree is compatible with the polygenic mode of inheritance. Definition of the inheritability of congenital heart disease in a specific family has important consequences in the determination of the recurrence risks for all family members.


Electrophysiologic evaluation of sinus node function in patients with sinus node dysfunction. Twenty patients of mean age 66.2 years, with suspected sinus node dysfunction, underwent extensive electrophysiologic study. Sinus bradycardia (18), sinus pauses (3), and sinoatrial block (1) were identified in their ECGs prior to study. Also 11 patients had some abnormality of atrioventricular nodal and/or intraventricular conduction prior to study. At the time of electrophysiological study, 10/20 patients (50%) had a mean cycle length exceeding 1000 msec, and mean P-V interval exceeded 210 msec in 7/20 (35%). The estimated "sinoatrial conduction time" exceeded 215 msec in 6/16 (38%) patients. The maximum first escape cycle following pacing at six different rates exceeded a value equal 1.3 X the mean value of the control cycle length + 101 msec (slope of regression line + Y intercept + 1 SD) in 13/9 (68%) patients. Nineteen patients received 1 mg atropine intravenously and mean cycle length decreased by 19%, from 891 +/- 175.8 msec to 718 +/- 182.9 msec. Graded infusion of isoproterenol was employed in 19 patients; four patients required an infusion rate greater than 28.3 ng/kg/min to produce a 20% decrease in spontaneous sinus cycle length. These data would indicate that a variety of interventions are required to characterize the disturbance of sinus node automaticiy and sinoatrial conduction in patients with sinus node dysfunction.


Concealed intraventricular conduction in the His bundle electrogram. Multiple areas of concealed intraventricular conduction are deduced on the basis of aftereffects observed in His bundle recordings. Electrocardiograms and His bundle recordings are presented from two patients with unstable bilateral bundle branch block, the instability of which depended on the interval at which ventricular depolarization was initiated by sinus or paced impulses. This circumstance allows postulation of 1) concealed transseptal retrograde penetration of the left bundle branch system; 2) concealed transseptal retrograde penetration of the right bundle branch system; 3) alternate beat Wenckebach phenomenon with two areas of block in the bundle branch system with concealed penetration of the proximal area; 4) concealed re-entry in the right bundle branch system during an H-V Wenckebach cycle with resetting of the sequence of 2:1 H-V block and return of the re-entry wave to the A-V node causing subsequent A-H block; 5) proximal 2:1 block and distal Wenckebach block producing only two consecutively blocked beats; and 6) infrahisian Wenckebach block with changes both in A-V conduction and QRS contour.


Incidence and significance of left anterior hemiblock complicating acute inferior wall myocardial infarction. The hospital course and serial vectorcardiograms of 56 consecutive patients with acute inferior wall myocardial infarction were reviewed. Left anterior hemiblock (LAH) complicating inferior wall myocardial infarction was diagnosed by vectorcardiographic criteria. Seven patients (12.5%) developed LAH between the first and third hospital day, while 49 patients did not. There was no significant difference between these two groups when compared for age, sex, incidence of congestive heart failure, atrial and ventricular arrhythmias, atrioventricular (A-V) block, hospital mortality, and previous hypertension, diabetes mellitus, and myocardial infarction. We conclude that LAH is a relatively common complication of acute inferior wall myocardial infarction, with no apparent effect on the clinical course.


Protection of the sinus node in Mustard's operation. The occurrence of dysrhythmias after the Mustard operation for transposition of the great arteries was compared in 70 patients operated upon before and 58 patients operated upon after January 1972 when surgical modifications aimed at preserving the sino-atrial node and its arterial supply were initiated. The surgical modifications included changing the site of the superior vena cava (SVC) cannulation away from the SVC-right atrial junction, incision into the right atrial wall anterior to the sulcus terminalis, and sewing of the superior part of the baffle patch away from the sino-atrial node area. A significant decrease in the incidence of dysrhythmias occurred in the group of patients operated upon after the surgical modifications. The modifications in surgical technique have reduced but not avoided dysrhythmias.


Effects of vasodilator therapy for severe pump failure in acute myocardial infarction on short-term and late prognosis. Forty-three patients with severe pump failure complicating acute myocardial infarction were treated with vasodilators (nitroprusside (40) and phentolamine (3)) for four hours to 27 days. Cardiac index, stroke volume index, and stroke work index (SWI) increased while the left ventricular filling pressure (LVFP) decreased during vasodilator therapy. Twenty-four of the 43 patients (56%) survived. Of patients with initial SWI between 11-20 gm-m/m2 and LVFP less than 15 mm Hg, 68% survived. In contrast only 18% of patients with SWI of 10 gm-m/m2 or less and LVFP greater than 15 mm Hg survived. Of the 17 patients with clinical shock, 8 (47%) survived. All 24 patients discharged from the hospital were followed for at least 12 months. Fourteen patients died one to 25 months (average 9.2 months) after discharge and the cause of death was pump failure in ten of them (71%). The ten survivors at last follow-up had been followed for 15 to 32 months (average 24 months). The cumulative survival at 24 months was 28%. Thus, despite improvement in short-term prognosis with vasodilator therapy in patients with severe pump failure complicating acute myocardial infarction, the prognosis for long term survival remains unfavorable, possibly due to severe intrinsic cardiac damage.


Left ventricular function and adrenergic hyperactivity before and after saphenous vein bypass. Forty patients with severe angina pectoris were studied before and two weeks after saphenous vein bypass surgery (SVG) in order to assess the effect of this operation on left ventricular performance as judged by systolic time intervals (STI). The patients were divided into two groups: group I included 29 patients in whom no postoperative infarction occurred and group II was composed of 11 patients with postoperative infarction. For group I the PEP/LVET was 0.39 +/- 0.01 preop and slightly but significantly increased at 0.42 +/- 0.004 (P less than 0.025) two weeks postop. The mean preop PEP/LVET was 0.33 +/- 0.01 for group II and dramatically increased to 0.54 +/- 0.02 (P less than 0.001) after surgery. Another striking abnormally was a marked shortening of electromechanical systole (QS2I), which was uniformly present in the postoperative studies. Follow-up studies in 16 patients and urinary catecholamine determination in five patients suggested excessive adrenergic activity was responsible for the abbreviated QS2I. This phenomenon must be considered when interpreting the results of SVG on left ventricular function.


Regional myocardial perfusion during atrial pacing in patients with coronary artery disease. Regional myocardial perfusion (RMP) was measured with 133xenon and a multiple-crystal scintillation camera at rest and during atrial pacing in 24 patients with normal coronary arteriograms or less than 50% lesions, Group I, and in 24 with significant (greater than 50% lesions) left coronary artery disease (CAD), Group II. Pacing induced increases in the double product (DP) of heart rate and systolic blood pressure, an index of myocardial oxygen consumption, were not different for Groups I and II. In Group I average mean LV perfusion rate was subnormal at rest but rose from 49 to 73 ml/100 g-min during pacing to 150/min without angina. A response index (RI), (deltaMP X 10(3)/deltaDP), averaged 2.93. Twenty patients in Group II developed angina during pacing. The average mean LV perfusion rose less than in Group I, from 48 to 64 ml/100 g-min (P less than 0.05) and the average RI, 1.76, was lower (P less than 0.01). In 19 of these patients, average RMP distal to the major coronary lesion increased from 46 to 58 ml/100 g-min; this increase during pacing was significantly less than in the remainder of the LV of 48 to 66 ml/100 g-min (P less than 0.05). Average regional RIs were 1.39 and 2.18, respectively. In three patients the presence of collaterals termed adequate by radiological criteria was not associated with preferential decreases in the distal regional RI. The data support the hypothesis that in some patients with CAD, angina pectoris results when an obstructive coronary lesion restricts the total or regional myocardial blood flow response to an increased rate of myocardial oxygen consumption.


Influence of dobutamine on regional myocardial blood flow and ventricular performance during acute and chronic myocardial ischemia in dogs. The data from this study document that dobutamine is a powerful inotropic agent in anesthetized dogs with acute myocardial ischemia and in awake, unsedated ones with chronic myocardial infarction. Dobutamine significantly increases heart rate at relatively small doses in anesthetized dogs with acute myocardial ischemia but considerably larger amounts of dobutamine are required to significantly increase heart rate in awake, unsedated dogs with myocardial infarction. Dobutamine also significantly increases regional myocardial blood flow to all areas of the heart at 20mug/kg/min in both anesthetized dogs with acute myocardial ischemia and awake, unsedated ones with myocardial infarction. However, in anesthetized dogs 20mug/kg/min of dobutamine significantly increases epicardial ST-segment elevation during acute myocardial ischemia. Propranolol prevents the inotropic and chronotropic effects of dobutamine in both anesthetized and awake, unsedated dogs. This study suggests that during experimental acute myocardial ischemia dobutamine given at doses that significantly increase heart rate and contractility may increase the extent of myocardial damage. The data also suggest that this agent should be of value in the setting of severe myocardial depression without associated severe coronary artery disease to increase cardiac contractility at doses that do not markedly alter heart rate. The hemodynamic and coronary blood flow effects of dobutamine in patients with and without severe coronary artery disease should be evaluated.


Effects of isometric exercise on the end-diastolic pressure, volumes, and function of the left ventricle in man. Changes induced in left ventricular (LV) hemodynamics by isometric exercise were analyzed in 43 patients: 30 with coronary heart disease (CAD), four with noncoronary heart disease, nine normal. Volumes were angiographically determined and correlated with left ventricular end-diastolic pressure (LVEDP) both at rest and during the fifth minute of 30% sustained handgrip (HNG). All normals and eight with CAD improved LV function during HNG. LVEDP decreased or remained constant, end-diastolic volume (EDV) decreased, end-systolic volume (ESV) decreased, as ejection fraction (EF) remained constant. None of these eight CAD cases altered their regional LV contraction pattern during HNG. Twenty-five patients, 21 CAD and four nonCAD, showed diminished LV function during HNG. LVEDP increased, EDV decreased, ESV increased, as EF declined. In these 21 CAD patients, at least one major coronary vessel was narrowed 70% or more and, with but two exceptions, was not supported by adequate collaterals. In 18, new asynergic zones developed in previously normally contracting areas or pre-existing asynergic zones extended during HNG.


Myocardial reperfusion in acute experimental ischemia. Beneficial effects of prior treatment with steroids. To test the hypothesis that prior steroid administration may enhance the mechanical and metabolic response to myocardial reperfusion, regional myocardial function (Hg-in-silastic length gauges), transmyocardial lactate balance and K+ difference were measured in 12 control and 13 treated (30 mg/kg methyl-prednisolone, 30 to 60 min postocclusion) dogs. At three hours of ischemia, systolic shortening in the ischemic segment was greater in treated dogs (40.6% vs. 12%, P less than 0.05), while both lactate balance and K+ arteriovenous difference became positive. Lactate balance and K+ difference remained negative in the untreated animals. After three hours of occlusion and one hour of reperfusion, recovery of shortening was significantly greater in the treated animals (75.9 vs. 31.6%, P less than 0.05). In addition, while lactate balance remained negative among the control dogs, it further improved in the treated dogs. Thus, steroid administration during experimental coronary occlusion impedes the progression of ischemia and is additive to reperfusion in reversing ischemic dysfunction.


Effect of intra-aortic balloon counterpulsation on the motion and perfusion of acutely ischemic myocardium. An experimental echocardiographic study. The effect of intra-aortic balloon counterpulsation (IABC) on the motion and perfusion of ischemic left ventricular posterior myocardium was studied in 30 open-chest dogs, using ultrasound to register motion and 7-10 mu radioactive microspheres to determine perfusion. Circumflex coronary artery ligation produced acute aneurysmal bulging during isovolumetric contraction and diminished ischemic wall velocity during systolic ejection. Myocardial perfusion was determined in five dogs; perfusion of the area supplied by the ligated coronary artery fell from a control value of 72.9 +/- 13.8 (SE) to 30.0 +/- 2.3 cc/100 g/min (P less than 0.05) at 5 minutes after coronary occlusion. IABC was then administered for one hour, with a fall in aortic systolic pressure (112 +/- 6 to 105 +/- 7 mm Hg, P less than 0.05) and rise in peak aortic diastolic pressure (94 +/- 6 to 102 +/- 7 mm Hg, P less than 0.05). Despite this the ischemic area showed no change in perfusion (measured at the same time): 30.0 +/- 2.3 to 28.0 +/- 2.4 cc/100 g/min. Little change in wall motion occurred: aneurysmal bulging decreased modestly (4.5 +/- 0.3 to 3.6 +/- 0.3 mm, P less than 0.05), but ischemic wall velocity did not increase. After cessation of counterpulsation and one hour of coronary reperfusion aneurysmal bulging disappeared and wall velocity improved. The addition of norepinephrine (eight dogs) or nitroprusside (seven dogs) to intraaortic balloon counterpulsation did not cause a significant further improvement in the response of the dyskinesis during the period of ischemia. We conclude that IABC has little effect on ischemic dyskinesis, probably due to its failure to improve perfusion of the acutely ischemic myocardium.


Echocardiographic assessment of left ventricular function in aortic valve disease. Echocardiography was used to study left ventricular size and contraction in 128 patients with isolated aortic valve disease -45 patients with aortic stenosis, 25 with mixed aortic valve disease and 58 with aortic regurgitation. Left ventricular measurements included the end-diastolic internal dimension (LVIDd), mural thickness (PWTd), an index of circumferential myocardial contraction-fractional shortening (FS=[(LVIDd-LVIDs)/LVIDd] X 100)--and stroke volume (LVSV). In the absence of left ventricular failure, measurements in aortic stenosis were characteristic of pressure overload with normal LVIDd and FS and an increase in PWTd related to the severity of stenosis; in aortic regurgitation, there was volume overload with increases in LVIDd and PWTd which were related to the severity of regurgitation, while FS was slightly reduced. In mixed aortic valve disease there was evidence of both pressure and volume overload. When left ventricular failure was associated with aortic stenosis, mixed aortic valve disease and chronic aortic regurgitation, FS was usually reduced. By contrast, in a recent patient with acute severe aortic regurgitation, FS was normal despite left ventricular failure, suggesting pump rather than myocardial failure.


Echocardiographic assessment of left ventricular function in mitral valve disease. Echocardiography was used to study left ventricular size and contraction in 90 patients with isolated mitral valve disease--47 patients with mitral stenosis, 26 with mixed mitral valve disease and 89 with mitral regurgitation. Left ventricular measurements included the end-diastolic internal dimension (LVIDd), mural thickness (PWTd), an index of circumferential myocardial contraction--fractional shortening (see article)--and stroke volume (LVSV). The left ventricle was abnormally small only when mitral stenosis was severe. Reduced myocardial contraction was common in patients with rheumatic valvular heart disease but was rarely severe. In mitral regurgitation without left ventricular failure, measurements were characteristic of volume overload with increases in LVIDd, LVSV and PWTd which were related to the severity of regurgitation. In other diseases, left ventricular failure is usually associated with reduced myocardial contraction (FS) but in mitral regurgitation with failure, myocardial contraction (FS 32%) did not differ significantly from normal (34%). The reduction in afterload caused by mitral regurgitation probably increases myocardial contraction and may lead to underestimation of the severity of myocardial impairment. Also potentially misleading was severe mitral regurgitation with normal values for LVIDd and LVSV (three patients). When the distinction between cardiomyopathy with secondary mitral regurgitation and primary mitral regurgitation was difficult clinically, echocardiography could usually make the distinction by demonstrating severe reduction of myocardial contraction with a slight or moderate increase in LVSV.


The determinants of onset of mitral valve prolapse in the systolic click-late systolic murmur syndrome. The onset of mitral valve prolapse and its close correlate, the time of systolic click, vary considerably with different physiologic and pharmacologic interventions. In order to explain the mechanism responsible for these alterations, the effects of tilt and amyl nitrite inhalation on left ventricular dynamics and the time of the systolic click were studied by analyzing echocardiograms and simultaneously recorded phonocardiograms in 14 patients with mitral valve prolapse and mid-systolic  click. The patients were studied in the supine position, with 40-60 degrees head-up tilt and after amyl nitrite inhalation. Computer analysis of the recordings was used to measure the left ventricular end-diastolic diameter, the click diameter (left ventricular diameter at the time of mid-systolic click), the maximal velocity of circumferential fiber shortening (max VCF), and the time interval between the first heart sound and systolic click (S1-X). With tilt and amyl nitrite, shortening of the S1-X interval b y an average of 44 and 87 msec, respectively, was observed. The click diameter, however, remained virtually constant with both maneuvers. Earlier prolapse after tilt was due to a decrease in the end-diastolic diameter from 5.03 +/- 0.74 to 4.50 +/- 0.68 cm (P less than 0.001) with no change in max VCF. Immediately after amyl nitrite, earlier prolapse was due to an increase of VCF in the preprolapse period, with max VCF increasing from 2.15 +/- 0.27 to 3.06 +/- 0.40 circ/sec (P less than 0.001), there being no change in the end-diastolic diameter up to this time. The constant click diameter indicates that the abnormal valve motion in this syndrome occurs at a critical left ventricular chamber size. Variations in the onset of prolapse are caused by changes in left ventricular end-diastolic dimensions and the velocity of circumferential fiber shortening in the preprolapse period.


Hemodynamic consequences of afterload reduction in patients with chronic aortic regurgitation. Nitroprusside was used to reduce afterload in 13 patients with isolated, severe aortic regurgitation. The drug significantly lowered mean aortic pressure, pulse pressure, left ventricular end-diastolic pressure and left ventricular volume. Total ventricular, or angiographic, cardiac index was generally unaffected, but forward cardiac index was improved significantly in 8 of 13 patients. Augmentation of forward cardiac index was seen in patients with subnormal resting forward cardiac index, in patients with decidedly elevated end-diastolic pressure, and in those with depressed resting ejection fractions. Regurgitant fraction fell with nitroprusside in six patients and remained unchanged in seven. Total stroke work index was diminished in all patients. These data show that afterload reduction in patients with severe aortic regurgitation may improve hemodynamics by reducing aortic regurgitation or by improving ventricular pump function. The lowered total stroke work, reduced ventricular size and improved forward cardiac index imply that afterload reduction may benefit left ventricular failure and delay progressive ventricular dysfunction in patients with aortic regurgitation.


Right and left ventricular volume characteristics in children with pulmonary stenosis and intact ventricular septum. Right (RV) and left ventricular (LV) volume variables were calculated in 27 patients with pulmonary stenosis (PS) during routine cardiac catheterization. These included 21 patients with isolated PS (group I) and seven studies in six patients (group II) with PS and right-to-left atrial shunt. Right and left ventricular volumes were calculated according to Simpson's rule and the area length methods respectively. In group I, right ventricular end-diastolic volume (RVEDV) was not different from normal, RVEF (0.70 +/- 0.02) was significantly higher than normal, and right ventricular stroke index (RVSI) (4.36/L/min/M2 +/- 0.23) was normal. The RVEDV/LVEDV ratio was significantly less than normal (P=0.001). Multiple regression analysis indicated that RVEDV (% of normal) decreased with both age and severity of RV outflow obstruction (r=0.77). In group II, RVEDV and RVSI were both less than normal (P less than 0.001), while RVEF was normal. LVEDV in the group was slightly higher than normal (P=0.026) while LVEF was less than normal (P=0.027) and resulted in normal LVSI. The data suggest that RV and LV function in children with isolated PS are normal, and that knowledge of the RV volume variables is not essential for the management of these patients. In contrast, hearts of patients with PS and right-to-left interatrial shunt have evidence that suggest depressed ventricular function, and the quantitation of RV volume may be helpful in the management of these patients.


The lateral chest film as an unreliable indicator of azygos continuation of the inferior vena cava. Recognition of azygos continuation of the inferior vena cava (AC-IVC) is necessary to prevent unnecessary surgery, to modify the approach to right heart catheterization and to avoid potentially fatal azygos ligation at the time of thoracic surgery. Absence of the inferior vena cava (IVC) shadow on the lateral chest film has been claimed to be an important feature of AC-IVC. Our findings, however, indicate that AC-IVC is frequently associated with a normal appearing IVC shadow on lateral chest film study. When the findings on frontal chest film examination suggest AC-IVC, a caval shadow on the lateral view does not exclude the diagnosis. There persists a need for further radiographic evaluation and, if necessary, angiographic confirmation. The lateral chest film does not provide reliable evidence for or against the diagnosis of azygos continuation of the inferior vena cava.


Uremic pericarditis as a cause of cardiac tamponade. Uremic pericarditis may complicate either acute or, more commonly, chronic renal failure. When dialysis is not employed, uremic pericarditis is usually a preterminal event and is characterized by a serofibrinous exudation of an amount inadequate to cause cardiac tamponade. Nevertheless, cardiac tamponade may uncommonly be observed in nondialyzed patients. Cardiac tamponade, which may be life-threatening, is more common in dialyzed than in nondialyzed patients with chronic renal failure. The primary causes of cardiac tamponade in uremic pericarditis in order of decreasing frequency are (1) pericardial effusion, usually of the serosanguineous type, (2) massive hemorrhage into the pericardial sac and (3) collagenization of pericardial exudate. From pathologic evidence, the following forms of therapy appear appropriate to manage uremic pericarditis that has reached the stage of causing cardiac tamponade. For effusion, pericardiocentesis or parietal pericardiectomy are logical procedures. Massive hemorrhage into the pericardial sac is usually attended by clotting and requires pericardiotomy and evacuation of clot. Collagenization of exudate yields an encasing, fibrous shell over the heart and requires decortication, as is practised in classical constrictive pericarditis.


Re-entry due to manifest and concealed. His bundle ectopic systoles. Report of a case. Concealed (C) His bundle ectopic systoles (H') have been shown in man to give rise to first and second degree atrioventricular (A-V) block and to simulate nonconducted atrial premature beats (P'). This report outlines a hitherto undescribed electrophysiologic consequence of H' in a 69-year-old man with arteriosclerotic heart disease and a Wenckebach type second degree A-V block in the His-Purkinje system. During a His bundle study, H' were shown to conduct either to the atria and ventricles with varying relationships to P' and QRS, or to conduct only to the atria, simulating nonconducted P' or atrial fusion beats. Both types of H' could initiate a re-entrant arrhythmia during retrograde conduction. Of particular interest are late coupled H' that failed to conduct to the ventricles and also failed to activate the atria because of prior capture by the sinus impulse (CH'). These CH' could also initiate re-entry by conducting retrogradely to engage the subatrial re-entry circuit. Evidence is presented to suggest re-entry occurs by way of a retrograde concealed accessory pathway and antegrade conduction in the atrioventricular node.


Cord-like aortic valve vegetation in bacterial endocarditis. Demonstration by cardiac ultrasonography. Report of a case. The ultrasonic features in a case of bacterial endocarditis in which a highly mobile, cord-like vegetation, attached to the noncoronary cusp of the aortic valve, are reported. The echocardiogram demonstrated abnormal echo patterns in the left ventricular outflow tract in diastrole which were continuous with similar echoes in the aortic root. While these findings did not differ from the previously reported manifestations in cases of flailing aortic valve leaflets, the cardiac ultrasonogram distinguished this vegetative growth. Cardiac ultrasonography revealed a cord-like characteristic, showed the movement of the entire growth into the left ventricular outflow tract in diastole and into the aorta in systole, and allowed estimation of the size of the vegetation. We conclude that cardiac ultrasonography can help in differentiating aortic valve leaflet flail and vegetations in endocarditis.


The use of o-dianisidine for serum haptoglobin electrophoresis using cellulose acetate. 1. Due to the carcinogenicity of benzidine, a method by which o-dianisidine is used to stain serum haptoglobin is described. Serum haptoglobin is determined by electrophoresis using cellulose acetate as the medium. 2. A comparison of the two staining systems demonstrates good agreement. 0-Dianisidine can be substituted for benzidine without loss of specificity.


A modified procedure for determining metanephrines in urine. We have modified the procedure for determining total metanephrines in urine described by Gupta, Price and Keane(1) to shorten the time necessary for completion while allowing the technician time to perform other tests. The modification involves the extraction of interfering substances from urine. Instead of having to extract 3 individual tubes for each patient, we have developed an extraction that can be performed in a single tube per sample. This allows the number of tubes handled in the first portion of the procedure to be reduced by 66% and a reduction in analysis time of 25%. Day-to-day precision of the method is 8.7%. The modified procedure was compared to the original procedure by running 38 different patients by each method. The mean for the original and modified method were 1.1 mg/24h and 1.1 mg/24h respectively. The correlation coefficient was 0.9051. The t-test (p = 0.05) indicated that there was no significant difference in the means of the methods and the F-test (p = 0.05) indicated that there was no significant difference in the precision of the methods.


Future education and training requirements of clinical biochemists. In order for clinical chemistry to attain full stature as a profession, and clinical biochemistry to become front rank as a discipline, the future education and training of clinical biochemists will require (i) that we achieve recognition and support from our Universities and Hospitals and, where possible, the establishment of Chairs in Clinical Biochemistry, (ii) that we have the resources to attract appropriately qualified physicians and scientists to the staff, (iii) that good courses are developed  on the "bio-chemistry of human diseases", "analytical clinical chemistry" and "laboratory administration and management", as a minumum, (iv) that we have the capacity to attract good students for graduate research experience and postgraduate students (both MD and PhD) for professional training and (v) that funds are made available to support these students.


Comparison of serum gastrin radioimmunoassay kits. 1. Two commercially available kit procedures for gastrin measurement were investigated. 2. While the precision of both kits appeared comparable, discrepancies were observed in both accuracy and parallel studies and in the comparison of kit standards and patients' samples.


The reduction of oxo-acids by human tissue extracts. The reduction of pyruvate, 2-oxobutyrate, hydroxy-pyruvate and glyoxylate under optimal conditions at 37 degrees by extracts of human heart, kidney, pancreas, skeletal muscle and liver has been examined. The ratios of reduction rates, particularly of glyoxylate and 2-oxobutyrate reveal a capacity to differentiate the isoenzyme composition of the tissue extracts.


A new automated procedure for serum inorganic phosphorus. 1. The method of Parekh and Jung for determination of inorganic phosphorous in serum has been adapted for automation. One of the assets of the method is its unusually stable reagents. The automated procedure is highly accurate, sensitive, rapid and economic. Its other advantages are discussed in light of the literature.


Performance of "kits" used for clinical chemical analysis of GOT (aspartate aminotransferase). Forty-three kits for clinical chemical analysis of GOT (aspartate aminotransferase) were evaluated. The reference method was the kinetic method performed on the Abott ABA-100 Bichromatic Analyzer. Specific data are tabulated for each kit and include ease and speed of testing and performance data. Most kits failed to provide completely adequate labelling information. Reproducibility CV for the kits varied widely (4.20 to 21.26 for the normal pool and 1.57 to 20.51 for the high pool). Many kits gave significant numbers of false positive and false negative results on patient samples. There is a need for manufacturers to either derive their own normal ranges or to establish exact equivalency values with the method used to establish the normal values. No difference was demonstrated between performance by two skilled technologists. However, we did detect lot-to-lot variation and differences in performance between narrow bandpass and wide bandpass spectrophotometers.


Bilirubin quantitation with lipemic plasma. 1. In the presence of lipemia, the estimation of BR by diazo method is variable and hence unreliable. 2. The estimation of BR in lipemic plasma by the use of the A-O bilirubinometer yielded BR levels which were consistently lower than theoretical values. 3. By regression analysis of the percent error in BR estimation, (using the A-O bilirubinometer) and TG Concentrations, a straight line is obtained. Based upon this line, a correction factor for plasma BR concentration in the range of 5-25 mg/dl can be obtained if the degree of lipemia is known.


Triglyceride assay using the ABA-100.

Triglyceride assay using the ABA-100. 1. A fast, simple, accurate method for the assay of triglycerides on the ABA-100 is described. 2. The Abbott A-Gent Triglyceride kit, Calbiochem Triglyceride Stat-Pack reagent and the Smith Kline French Eskalab Triglyceride reagent were evaluated for use with this method. The reagents were all found to be satisfactory, but the Abbott A-Gent Triglyceride kit was found to be less stable than the other reagents.


Radioimmunoassay of bile acids in serum. We developed four radioimmunoassay procedures for the determination of glycine-conjugated bile acids in serum. Antibodies to two primary bile acids, cholylgycine and chenodeoxycholylglycine, and to two secondary bile acids, sulfolithocholylglycine and deoxycholylglycine, were raised in rabbits after the acids were covalently linked to albumin by use of the carbodiimide reaction. Assay sensitivity for each of these bile acids is in the picomole range with the standard curve extending from 10-80 pmol. The concentration of bile acids in serum increased in various states of liver disease and its measurement appears to be an extremely sensitive indicator of liver function.


Kinetic determination of serum lipase activity with the Abbott ABA-100. A turbidimetric procedure for lipase has been adapted for use on the Abbott Bichromatic Analyzer (ABA-100). The method is rapid and results compared well with those by the more traditional method of Cherry and Crandall [Am. J. Physiol. 100, 266 (1932)]. Advantages of this method include shorter incubation time (2 min), smaller sample size (50 mul), neglible interference from bilirubin, and greater dynamic range (to eightfold normal).


Gas-liquid chromatographic profile of neutral and acidic metabolites in cerebrospinal fluid from newborns and infants. A profile (chromatographic pattern) of the neutral and acidic metabolites present in cerebrospinal fluid from newborns and infants was obtained by gas-liquid chromatography. The metabolites are those extracted with ethyl acetate and diethyl ether. They are converted to trimethylsilyl ether derivatives, and chromatographed on a column containing 5% silicone OV-101 (methyl) packed on Chromosorb W. Several substances were tentatively identified from their methylene unit values. We established a control profile for infants, and compared profiles for infants and adults. Noteworthy qualitative and quantitative differences from the control were seen for cerebrospinal fluid from subjects with neurological disorders of infections. The technique may be of use in neurological diagnosis.


Improved determination of prostatic acid phosphatase (sodium thymolphthalein monophosphate substrate). We have modified a previously described method for determining acid phosphatase, with thymolphthalein monophosphate as substrate, to increase its sensitivity. We assessed effects of serum on variables influencing acid phosphatase activity as measured by this method. The method is shown to be not completely specific for prostatic acid phosphatase. The importance of standardizing methodology in measurement of enzyme activities is demonstrated.


The anion gap: its use in quality control. Because the anion gap is useful in classifying acid-base disorders, quantitative information on this variable should be readily available. Three populations were studied and means and central 90% ranges were determined for the anion gap, calculated as sodium-(chloride + bicarbonate). In 1047 hospitalized patients the mean was 12 mEq/liter, 86 faster volunteers had a mean of 13 mEq/liter with a 90% range of 9--17 mEq/liter, and 203 plasmaphoresis donors had a mean of 11 mEq/liter with a 90% range of 7--16 mEq/liter. Most of this variability can be accounted for by analytical rather than physiological variation. This quantitation of the anion gap is useful for interchecking electrolyte values as an additional and inexpensive means of laboratory quality control. In 73 of 75 abnormal anion gaps, for which the data were verified to be correct, the clinical information provided a reasonable explanaation for the abnormality.


Decreased radioassay values for folate after serum extraction when pteroylglutamic acid standards are used. Radoiassay values for folate in protein-denautured (extracted) sera are compared with values obtained by individual serum blank correction. Lower folate values are reported for sera extracted at pH 1.3, 7.6, 10.5, and 12.4 when pterolyglutamic acid (PGA) calibration standards are used. The results are unchanged when ascorbate added to the sera is increased from 1 to 20 g/liter and when [3H]PGA is substituted for 125I-labeled PGA. However, a higher mean value for extracted serum is reported when N-5-methyltetrahydrofolic acid calibration standards are substituted for PGA. Because both patients' samples and assay calibrators were subjected to the same extraction methods, our results suggest that serum folate behaves differently from PGA during the extractions.


Technical pitfalls in measurement of venous plasma NH3 concentration. Measurement of venous plasma NH3 in normal subjects by the ion-exchange method of Forman [Clin. Chem. 10, 497 (1964)] in a hospital clinical laboratory gave a mean value of 640 mug/liter (range, 300-1320 mug/liter; intraassay, intra-individual, and inter-individual coefficients of variation, 8, 47, and 47%, respectively). The following conditions adversely affect the reproducibility of the test: pollution of laboratory atmosphere and glassware by NH3-containing detergents; smoking by patient or analyst; delay, turbulence, or use of heparin lock in venipuncture; delay or warming of plasma above degrees C before mixing it with resin; and delay in colorimetric analysis of resin eluate. When these sources of error were eliminated, the mean value for normals was reduced to 330 mug/liter, the range was narrowed to 220-470 mug/liter, and the above-mentioned CV's were 5, 16, and 17%, respectively. With the precautions cited, furthermore, the intra-assay and intra-individual CV's for fasting NH3 concentration in cirrhotic patients were similarly reduced. An NH3 tolerance test was done by administering a standard dose of NH4Cl to patients and measuring venous plasma NH3 at 0, 15, 30, 60, and 90 min; the NH3 tolerance was quantified from the area under the curve relating concentration to time (mug - min/liter). As measured in the clinical laboratory, NH3 tolerance of cirrhotic patients showed intra-assay and intra-individual CV's of 50 to 90%. When the tolerance tests were repeated in the same subjects with the laboratory precautions listed above, these CV's were reduced to 8-15%.


Interference of fatty acids in the competitive protein-binding assay for serum thyroxine. An increase in apparent thyroxine values obtained by competitive protein-binding assay on storage of sera is well documented. We find that the major source of this positive bias is probably the unsaturated nonesterified fatty acids. Nonesterified fatty acids cause a positive basis in the competitive protein-binding assay for serum thyroxine because they inhibit the binding of radioactive thyroxine by the serum-binding reagent (probably thyroxine-binding globulin). This inhibition by fatty acids may be due to the formation of a fatty acid/thyroxine complex. The degree of inhibition caused by the fatty acids depends on the length of the carbon chain of the fatty acid and the degree of saturation. Short-chain fatty acids are more potent inhibitors of thyroxine binding than those with a longer chain, and unsaturated fatty acids are more potent inhibitors of thyroxine binding than are saturated fatty acids. The polyunsaturated fatty acid, arachidonic acid, was the most potent inhibitor of all the fatty acids tested. Triglycerides (triacylglycerols) insignificantly inhibit thyroxine binding in this assay.


Specificity and reproducibility of acetone precipitation in identifying surface-active phosphatidylcholine in amniotic fluid. We show the thoretical and actual variability in the amount of surface-active lecithin precipitated in the acetone-precipitation step of determining lecithin/sphingomyelin (L/S) ratios in the clinical laboratory. Lecithins precipitated may range from 60 to 90% of the total surface-active lecithins present. The range is sufficient to account for the occasional "immature" L/S ratios (less than 2/1) found in amniotic fluid from women bearing mature fetuses.


Four commercial urease reagents and a laboratory-prepared reagent compared for analysis of blood urea nitrogen with the Beckman analyzer. Three laboratory-prepared urease reagents were compared with a commercial preparation supplied for routine use on the Beckman Blood Urea Nitrogen Analyzer. There were discrepancies in results for urea nitrogen among the four urease reagents when matching serum and the corresponding oxalate/fluoride treated plasma were compared as measured with the Beckman Analyzer and continuous-flow (AutoAnalyzer) method. All four urease preparations were affected by fluoride, but to different extents. We believe that an effective laboratory reagent can be prepared in the laboratory at significantly lower cost.


Use of blood specimens collected on filter paper in screening for abnormal hemoglobins. Both cellulose acetate electrophoresis and citrate agar electrophoresis were performed on 834 blood samples collected on filter paper in Jamaica and shipped for testing to the National Hemoglobinopathy Standardization Laboratory at the U.S. National Center for Disease Control. Additionally, 30 blood samples collected locally were stored on filter paper, in microhematocrit capillary tubes, and as whole blood specimens; at selected times the samples were tested for stability to determine the best sample-collection technique for hemoglobin electrophoresis. Results were most nearly accurate when both cellulose acetate electrophoresis and citrate agar testing were used. The methods are easy to perform, but results are unreliable if the blood samples on filter paper are stored at 4 degrees C for longer than two weeks before they are tested.


Quantitation of glycine in plasma and urine by chemical ionization mass fragmentography. A new technique has been developed for rapid and precise quantitation of glycine in micro samples of biological fluids. Glycine is measured as the n-butyl N-trifluoroacetyl (TAB) derivative by chemical ionization mass fragmentography, using both methane and isobutane as carrier/reagent gases, with the analogous derivative of 2,2-dideuterioglycine added as the internal standard. This technique is also readily applicable, with sensitivity to the femtomole level, to determinations of other amino acids, as, for example, in studies of congenital errors of metabolism.


Purification of thyroxine and triiodothyronine for radioassay with sephadex. The use of [125I] thyroxine in the determination of dialysable thyroxine (free T4) places very high demands on the purity of the reagent. Less than 5% dissociated radioactive iodine (as iodide) is enough to influence the results [1]. For this reason several workers have developed methods for the purification of iodo amino acids used in radioassay for thyroid hormones. Two techniques have been used mainly, namely dialysis of incubated tracer-serum mixture [1,2], and adsorption chromatography on dextran gels in strongly basic buffers [3-5]. In this laboratory we have developed an adsorption chromatography method using bovine serum albumin for the separation of [125I] thyroxine from contaminating compounds.


[Studies on the accuracy and precision of total serum cholesterol in regional interlaboratory trials (author's transl)]. The between-run precision of the Liebermann-Burchard reaction modified by Watson was, in our laboratory, 2-3%, the within-run coefficient of variation was 1-2%. The between-run precision of the enzymatic test was 3-4%, the within-run coefficient of variation was 3%. The regression analysis of 92 serum specimens from patients was y = -17.31 + 1.04 chi, the coefficient of regression was r = 0.996. Interlaboratory trials of serum cholesterol were studied in the normal and pathological range. Lyophilized samples of serum prepared commercially and from fresh specimens from patients were analysed by the method of Liebermann-Burchard as well as by the enzymatic procedure. Acceptable results estimated by Liebermann-Burchard were obtained in the different laboratories after using a common standard of cholesterol. The coefficient of variation of the enzymatic test in the interlaboratory trial was higher in comparison to the Liebermann-Burchard reaction. Methodological difficulties of the Liebermann-Burchard reaction are discussed and compared with the specific, enzymatic assay.


Stereospecific distribution of fatty acids in human plasma triglycerides. Because of a biological difference between both primary hydroxylgroups of glycerol there are three distinct hydroxylgroups esterified with fatty acids in triglycerides. The distribution of fatty acids in the three distinct positions of triglycerides can be investigated by a combination of partial hydrolysis of triglycerides by pancreatic lipase, phosphorylation of the diglycerides formed and the stereospecific action of phospholipase A on phosphatides. Plasma triglycerides from normal and hyperlipemic humans are analysed. Human plasma triglycerides are highly asymmetric. The 1-position contains more than twice as much palmitic acid as the 3-position. Statistically significant differences are found between normal and hyperlipemic humans for palmitic and linoleic acid at the 2-position, and for oleic and linoleic acid at the 3-position.


Interference of sodium azide with the quantitation of serum cholesterol: a comparative study. Interference of sodium azide (employed widely as a preservative for serum) with six different cholesterol methods and two modified procedures is analyzed and compared. Sodium azide is shown to lower the serum cholesterol values of the iron-cholesterol methods from 5 to 50% at 0.1 g% azide, and from 60 to 95% at 1.0 g% azide concentration, depending on the method employed. This inhibition is independent of serum cholesterol concentration. Increased serum to reagent (v/v) ratio, i.e., increased azide concentration, caused increased depression of serum cholesterol values. Appropriate choice of low serum-to-reagent (v/v) ratio thus decreases the magnitude of the azide interference in the iron-cholesterol reaction to 3-10% for the precipitation procedures, and to 25% for the non-precipitation procedure at 0.1 g% azide concentration in serum.


Continuous in vivo measurement of creatine kinase variations in man during an exercise. In order to obtain information concerning the CPK turnover during exercise, we have elaborated a technique to measure its activity continuously in vivo. A colorimetric method has been adapted to total blood. CPK was measured continuously in 5 physically fit athletes exercised on an ergometric bicycle for 30 min. There was practically no increase in enzymatic activity. The starting level was very high, corresponding perhaps to a "permanent state of enzyme release"; the exercise was not hard enough because of the fitness of the athletes or the maximal increase did not occur immediately after the exercise.


The influence of thyroxine on the serum free triiodothyronine concentration. By means of measurement of the serum free triiodothyronine fraction (%FT3) by equilibrium dialysis, the influence of varying serum concentrations of thyroxine (T4) on %FT3 was studied in conditions associated with lack or excess of serum T4 and in serum enrichment with T4 in vitro. The enrichment of pooled serum with T4 caused significant increases of %FT3 with T4 was added to elevate its T4 content between 10 and 25 mug/dl. In 4 subjects with primary hypothyroidism treated with T3 (25 mug once daily for two weeks, twice daily thereafter), progressive increases of serum T3 were observed while their T4, free T4 and T3 fractions remained unchanged. Consequently, the serum free T3 and thyrotropin concentrations became normal after the serum T3 concentrations became hypernormal. When comparisons of the serum thyroid hormone levels were made between 6 subjects with T3 toxicosis and 8 with a usual variety of hyperthyroidism matched for serum T3 concentration, the former sub-group of hyperthyroidism showed significantly lower serum free T3 concentration (0-51 +/- 0.22 ng/dl versus 0.79 +/- 0-21 ng/dl, p less than 0.05). The amount of T4 in serum is considered to affect its free T3 concentration by virtue of sharing serum-binding proteins.


On the mechanism of 5-oxoproline overproduction in 5-oxoprolinuria. The primary metabolic defect in 5-oxoprolinuria (pyroglutamic aciduria) is the lack of glutathione synthetase. The mechanism of the concomitant overproduction of 5-oxoproline was studied using cell-free extracts of erythrocytes from control individuals and from patients with 5-oxoprolinuria. Such extracts catalyzed the synthesis of 5-oxoproline from L-glutamate. Addition of ATP, Mg ions and alpha-aminobutyrate was needed for optimal activity. The conversion of glutamate to 5-oxoproline occurred in two steps, catalyzed by gamma-glutamyl-cysteine synthetase and gamma-glutamyl cyclotransferase, respectively. Extracts of erythrocytes from control subjects and patients with 5-oxoprolinuria had identical capacity to synthesize 5-oxoproline. The conversion of glutamate to 5-oxoproline was markedly inhibited by reduced glutathione, which exerted its effect on the gamma-glutamyl-cysteine synthetase step. The following mechanism is postulated for the overproduction of 5-oxoproline in 5-oxoprolinuria: the deficiency of glutathione synthetase causes a lack of glutathione which is an essential feed-back inhibitor in the initial step of its biosynthesis. Therefore gamma-glutamyl-cysteine is produced in excessive amounts and it is subsequently converted to 5-oxoproline (and cysteine) by gamma-glutamyl cyclotransferase. This overproduction of 5-oxoproline exceeds the capacity of the 5-oxoprolinase and 5-oxoproline accumulates in body fluids.


Enzyme-linked immunoassay of thyrotropin. A method was developed for immunoassay of thyrotropin after its conjugation with alkaline phosphatase using the double antibody technique. The dilution of serum resulted in curves parallel to those obtained for standard thyrotropin. The mean recovery of thyrotropin (TSH) added to serum was 97%, and values for serum TSH determined by this method correlated well with those determined by radioimmunoassay. The coefficients of variation were 2 to 7% (within assay) and 10 to 15% (between assay). The method requires minimal equipment, and is less expensive than radioimmunoassay, so it should be useful as a screening test for primary hypothyroidism in cases with above the maximum normal serum TSH level (10 muH/ml).


A method for the estimation of total calcium in serum or heparinized plasma. A simple titrimetric method for the determination of total calcium in serum or heparinized plasma is described. After removing interfering substances with an ion-exchange resin, calcium is reacted with glyoxalbis (2-hydroxyanil), GBA, and the resulting red colour titrated with ethylenediaminetetra-acetic acid in the presence of a methanol/glycerol mixture. No special equipment is used, deproteinization is not necessary and only 0.2 ml of sample is required.


Congenital adrenal hyperplasia caused by defect in steroid 21-hydroxylase. Establishment of definitive urinary steroid excretion pattern during first weeks of life. The steroid excretion of two female infants with congenital adrenal hyperplasia due to 21-hydroxylase deficiency has been studied during the first weeks of life. The techniques used were gas chromatography on an open-tubular column and combined gas chromatography-mass spectrometry using selected ion recording. During the first days of life 3beta-hydroxy-5-ene steroids predominate and the levels found were considerably greater than those found in normal infants. Selected ion recording mass spectrometry permitted detection of pregnanetriol and 11-oxo-pregnanetriol several days before these steroids could be determined with accuracy by conventional gas chromatography. Pregnanetriol and 11-oxo-pregnanetriol were first detected on the third day of life. The results of this investigation demonstrate that 21-hydroxylase deficiency may be indicated during the first week of life by an increased 3beta-hydroxy-5-ene steroid excretion, but the definitive excretion pattern required for firm diagnosis may not develop for several days. The amounts of the definitive steroids excreted may not be sufficient to be detected by the more usual methods for several weeks.


Measurement of angiotensin II in human plasma: technical modifications and practical experience. This paper presents our experience in measurement of plasma angiotensin II concentration according to the method described by Düsterdieck, G. and McElwee, G. (1971) Eur. J. Clin. Invest. 2, 32-38. Certain technical modifications of the procedure have been worked out. For each individual plasma sample, the recovery across extraction and elution steps is determined by addition of radio-iodinated angiotensin II. A time-saving recycling elution procedure is described. Evidence for the clinical applicability of the modified method is presented.


Conversion of sorbitol to mannitol when used parenterally. Conversion of sorbitol to mannitol was shown by the unexpected discovery of the urinary excretion of mannitol when urinary levels were being measured in connection with the surveillance of patients suffering from malnutrition or head injury and receiving total parenteral nutrition: glucose, sorbitol, amino acids and soya oil. The presence of mannitol in thr urine would appear to result from a secondary catabolism through a physiological pathway for the fructose produced by the metabolism of sorbitol not broken down during glycolysis.


Defective erythrocyte pyruvate kinase.

Defective erythrocyte pyruvate kinase. A defective pyruvate kinase (EC 2.7.1.40) is described. The abnormal PK is characterized by a shift in the R in equilibrium T equilibrium to the T-state. The Ko.5 for the substrate phosphoenol pyruvate is about 6 times higher than for the normal enzyme, while the KM value for the positive effector Fru-1, 6-P2 is increased. In agreement with a shift to the T-state is the increased affinity of the abnormal enzyme for the negative effectors ATP and alanine. The results are discussed in relation to other abnormal pyruvate kinases.


Effect of cotrimoxazole on the response to phenylalanine loading in man. Cotrimoxazole impairs the L-phenylalanine tolerance of control subjects as judged by the time course of the plasma phenylalanine concentration and the plasma ratios [phenylalanine]/[tyrosine] after oral and intravenous loading with phenylalanine. These subjects are presumed not to be heterozygous for any of the abnormal recessive genes which cause hyperphenylalaninaemia when they are present in the homozygous state. Patients with classical phenylketonuria did not show this effect. Cotrimoxazole did not affect the renal clearance of phenylalanine. The effect appears to be virtually entirely due to the trimethoprim component as opposed to the sulphamethoxazole component of cotrimoxazole.


[A two-step determination of plasma total cholesterol and free cholesterol by gas-liquid chromatography. Suggestion for a reference method (author's transl)]. A technique for the determination of free and esterified plasma cholesterol by gas-liquid chromatography is proposed as a reference method. After a critical examination of all the stages to prove its validity, the method is compared to the usual techniques. Such a comparison confirms that colorimetric methods are more accurate after a lipidic extraction and with a purification step by liquid-solid chromatography.


A simple method for the determination of free cortisol in plasma, with normal levels in men and women, including women taking low oestrogen contraceptives. A small scale equilibrium dialysis method for the measurement of the non-protein bound cortisol in plasma is described. Dialysis is carried out in PTFE cells against an isosmolar Hepes buffer, equilibration occurring within 18 hours. Inter-assay variation was found to be approximately 6%. Samples taken from normal males and females and from oestrogen-treated females were analysed and the results compared with published levels. A significant difference in both the total and free cortisol levels was found between the normals and oestrogen-treated females.


Comparison of plasma progesterone assay in women by competitive protein binding (CPB) and radioimmunoassay (RIA). Plasma progesterone levels during the follicular and luteal phases were compared when measured simultaneously by competitive protein binding (using guinea pig sera as binding agent) and radioimmunoassay (antiserum against progesterone-11-alpha-succinyl bovine serum albumin in rabbits), the values obtained were significantly different within each technique, depending on whether previous thin-layer chromatographic purification of the extracts was employed or not. No significant differences were noticed between CPB and RIA when the chromatographic step was used, but when it was omitted, CPB was greater than RIA at the follicular but not at the luteal phase.


Increased excretion of N-carbamoyl compounds in patients with urea cycle defects. Increased urinary levels of N-carbamoyl-beta-alanine, and also, on occasions, of N-carbamoylaspartate, were observed in patients with ornithine carbamoyl-transferase (EC 2.1.3.3) deficiency, argininosuccinate synthetase (EC 6.3.4.5) deficiency and argininosuccinate lyase (EC 4.3.2.1)deficiency, but not in a patient with carbamoylphosphate synthase deficiency. The relevance of these findings to the diagnosis of urea cycle defects is discussed.


A new reference method for the determination of the oxygen content of blood. To be able to determine the slight differences between the theoretical and the actual O2-binding capacity of human haemoglobin, a highly accurate method has been developed for measuring the O2 content of blood samples. It is an adaptation of an established O2 determination in organic microanalysis. The bound O2 of the blood is set free by conversion of HbO2 to Hi, and the O2 stripped from the blood is converted to CO by contact with granular carbon at 1120 degrees C. The CO is then converted to CO2 using CuO at 300 degrees C and the CO2 titrated in a solution of BaCl2, using NaOH of known strength. The measuring system was checked by analysis of 36 samples of air, yielding an O2 content of 20.93 +/- 0.06%. The coefficient of variation calculated from 62 duplicate determinations of samples of human blood was 0.65%.


Photodynamic effects of protoporphyrin on cholesterol and unsaturated fatty acids in erythrocyte membranes in protoporphyria and in normal red blood cells. The protoporphyrin-induced photodynamic damage of erythrocytes is caused by photooxidation of a cellular target, localized in the red cell membrane. In model experiments it appeared that some amino acid residues of membrane proteins, unsaturated fatty acid side chains of phospholipids and cholesterol are sensitive to photooxidation, induced by protoporphyrin. In previous studies it has been shown that the membrane damage cannot be attributed to photooxidation of unsaturated fatty acid side chains. Photosensitized peroxidation of cholesterol was studied in model systems, in red cell ghosts and in intact cells. Although cholesterol appeared to be sensitive to protoporphyrin-induced photooxidation in model systems and in red cell ghosts, it could be shown that photohemolysis of red blood cells of patients with erythropoietic protoporphyria cannot be rationalized on the basis of a cholesterol peroxidation.


The chemistry of human neonatal femoral epiphyseal cartilage. The estimation of cartilage constituents such as hydroxyproline and hexosamine may be used to detect gross changes in the total amount of collagen and matrix. This simple approach, which can only be regarded as a "screening" procedure prior to more exhaustive analysis, has been applied to samples of neonatal human cartilage. It is suggested that this method would be useful in analysis cartilage biopsies, especially from patients with bone dysplasias.


Microdetermination of methylmalonic acid and other short chain dicarboxylic acids by gas chromatography: use in prenatal diagnosis of methylmalonic acidemia and in studies of isovaleric acidemia. We have developed a sensitive gas-chromatographic method for the determination of methylmalonic acid and other short chain dircarboxylic acids in biological samples. The method is based on the isolation of the short chain dicarboxylic acid fraction by Dowex 3 X 4 column chromatography followed by gas-chromatography analysis of these acids as methyl esters. 2-n-Pentyl-malonic acid is used as an internal standard. With this method, methylmalonic, succinic and methylsuccinic acids were consistently detected and accurately measured in urine and serum from normal subjects; the identity of these acids being verified by mass spectroscopy. The method's sensitivity permitted its used in the prenatal diagnosis of methylmalonic acidemia by measuring methylmalonic acid in urine and amniotic fluid from three pregnant heterozygous women at risk. One affected (vitamin B-12 responsive type) and two unaffected fetuses were correctly diagnosed prenatally as judged by postnatal investigations. The amount of methylmalonic acid in urine and amniotic fluid was distinctly increased (2 to 14 times normal) in the former and consistently normal in the latter two cases during the third trimester of pregnancy. Effect of prenatal therapy with large doses of vitamin B-12 was closely followed in the first case using analyses of multiple maternal urine specimens. Urinary methylsuccinic acid excretion was studied in two cases with isovaleric acidemia. It was normal in a sample from a patient in remission but was increased seven fold over control during an episode of ketoacidosis.


Toxicology of methyl methacrylate: the rate of disappearance of methyl methacrylate in human blood in vitro. 1. The rate of disappearance of methyl methacrylate in blood has been determined using an isotope dilution technique. 2. At a concentration of 10(-4) mol dm(-3), methyl methacrylate disappears with pseudo first order kinetics. 3. The half-life of methyl methacrylate in blood at 37 degrees C lies in the range 20--40 min. 4. The half-life showed no dependence on the age or sex of the blood donor. 5. A major, possibly the only, pathway of metabolism is by hydrolysis to methacrylic acid.


Contributions of other sterols to the estimation of cholesterol. The responses of 5alpha-cholestan-3beta-ol, 5alpha-cholest-7-ene-3beta-ol and cholesta-5,7-dien-3beta-ol, normally found in human serum, were examined by: (1) the Liebermann-Burchard reaction, (2) the Zak (ferric chloride) reaction, (3) an enzymatic cholesterol method monitored by estimating the amount of hydrogen peroxide produced, (4) an enzymatic cholesterol method monitored by observing the change in absorbance at 240 nm, and (5) gas chromatography. The results show that none of these methods is specific for cholesterol; contributions from the sterols examined range from zero to more than 150% relative to cholesterol. For the first four methods contributions depend on the conditions under which each test is performed.


Plasma cholesteryl esters turnover in man: comparison of in vivo and in vitro methods. The rate of formation of plasma cholesteryl esters was determined by both in vivo and in vitro methods in 15 subjects. In vivo production of plasma cholesteryl esters was calculated from the specific activity slopes of plasma free and esterified cholesterol after an intravenous injection of [3H] mevalonic acid or [3H] cholesterol incorporated in plasma lipoproteins. In vitro production of cholesteryl esters was estimated by measuring lecithin:cholesterol acyltransferase activity in plasma. Lecithin:cholesterol acyltransferase was estimated by incubating the subjects' own plasma for 1 h at 37 degrees C. The plasma sample used for incubation was collected 2 h after the injection of radioactive precursor (when radioactivity of esterified cholesterol was very low relative to that in free cholesterol and the specific activity of free cholesterol in all of the major plasma lipoprotein classes was identical). The mean value for the production of plasma cholesteryl esters obtained by in vivo method was 126.2 +/- 41.9 mg/h, and it was not significantly different from the mean of 110.5 +/- 25.5 mg/h calculated from the results of in vitro method. The values obtained by the two methods in all 15 subjects had an excellent correlation (r = 0.93). It was found that in normotriglyceridemic subjects the values obtained by the two methods wwere essentially identical, but in hypertriglyceridemic subjects the values obtained by the in vitro method were consistently somewhat lower than the obtained by the in vivo method.


Isoelectric focussing of normal human erythrocyte pyruvate kinase (PK) and PK variants with abnormal electrophoretic patterns. Isoelectric points of normal human erythrocyte pyruvate kinase (PK) and PK variants with abnormal electrophoretic patterns, were obtained by means of isoelectric focussing. The obtained isoelectric points of normal, PK Nagasaki, PK Tokyo II, PK Ube, and case T.S. were 7.36, 7.38, 7.05, 6.90, and 7.04, respectively, at 6 degrees C. All of the PKs collected after isoelectric focussing were shown to be not of the L-type PK but to be the erythrocyte PK (by means of thin-layer-polyacrylamide gel electrophoresis). The PKs with fast migration had isoelectric points that were shifted to the acidic side as compared with those of the normal subjects. The PK with slow migration had an isoelectric point that was shifted to the alkaline side, demonstrating that the isoelectric points obtained by isoelectric focussing were consistent with the electrophoretic patterns of the crude hemolysates. Isoelectric focussing also revealed the existence of PK variants with abnormal electric net charge, just as well as thin-layer-polyacrylamide gel electrophoresis.


Cardio-cutaneous syndrome (the "LEOPARD" syndrome). Review of the literature and a new family. Numerous reports of familial cardiac disorders associated with abnormalities of cutaneous pigmentation have appeared in the literature. In some of these there have been other somatic malformations including retardation of growth and anomalous development of the genitalia. In this paper we review the literature and describe another family with multiple lentigines occurring in six members out of eight examined. They were reported to occur in 10 other members not seen by us. The trait showed an autosomal dominant mode of inheritance and appeared to be transmitted by affected fathers. In previous reports transmission has usually been through an affected mother. In five of the six patients examined, only skin abnormalities were detected, but in the propositus the lentigines were associated with retardation of growth, hypertelorism, abnormal genitalia and complete atrioventricular block. The possible explanations for the lack of pleomorphy in other members of the family are discussed.


A genetic study of facial clefting in Northern England. A family is reported of 500 facial cleft index cases, attendees for plastic surgery review at hospitals in northern England. Cases displaying malformation syndromes (29 cases, 5.8% of series) were excluded from analysis, after which CL +/- P and CP pedigree data were examined for evidence of polygenic inheritance. The frequencies of affected among parents, aunts and uncles, and first cousins of 324 CL +/- P index cases are respectively 21, 6 and 4 times the population incidence. The sex ratio among index cases increases with severity of defect. Both of these findings are in good agreement with the polygenic mode of inheritance favored for this condition. The frequencies of affected among parents, aunts and uncles, and first cousins of 147 CP index cases are respectively 30, 5, and 9 times the population incidence. Since syndrome-associated clefts have been excluded from analysis, this elevated incidence in first cousins favors the suggestion that multiple genetic forms of CP may exist.


Hypospadias in successive generations - possible dominant gene inheritance. Two families were ascertained with multiple cases of hypospadias. In one family, four generations were reported to be affected and this was proven in three generations. In the second family, a father and two sons were affected. We suggest that dominant gene inheritance may be responsible for a small number of hypospadias cases. The incidence of hypospadias in British Columbia is 1 per 250 live male births and, using Edwards' formula, this gives a theoretical empiric recurrence risk of about 6%.


A new chromosome deletion syndrome. Report of a patient with a 46,XY,8p- chromosome constitution. A mentally retarded boy with narrow cranium, high forehead, epicanthic folds, flat nasal bridge, low-set but normal ears, retrognathy, short neck and broad chest with wide-set nipples is described. The routine chromosome and banding analyses revealed a 46,XY,8p- chromosome constitution. The parents had normal chromosomes. On the basis of measurements on reflectodensitometer tracings and of measurements of the individual G-bands directly on photographic prints of the normal and abnormal chromosome 8, an intercalary deletion of band p22 seemed most probable. The clinical features of the patient are compared with the 8p- case of Lubs & Lubs (1973) as well as with four other cases of short arm deletion of an unidentified C-autosome. The clinical features of one of these cases were very similar to those of the boy described. An attempt was made to delineate the clinical characteristics of this new chromosomal deletion syndrome.


Re-evaluation of the effect of spray adhesives on human chromosomes. The possible effects of spray adhesives on human chromosomes were re-examined in several ways by three different laboratories. A total of 3,382 metaphases were analyzed in a blind-coded fashion. The proportion of abnormal cells, including gaps, was similar in both the control (8.2%) and exposed (8.3%) samples. Our findings do not confirm the original investigation in which the proportion of abnormal cells was found to be significantly higher in the exposed group (8.99%) than in the control group (1.65%). In the earlier study, however, blind-coded slides were not employed. These and other studies show no positive evidence of an effect of spray adhesives on human chromosomes.


Recurrence risks in a consecutive series of congenitally malformed children dying in the perinatal period. During a 4 1/2-year period a special study of 207 consecutive perinatal deaths, including clinical, genetical, roentgenological and autopsy investigations, was undertaken with the aim of identifying inherited malformations with a high risk of recurrence to subsequent sibs. Fifty-three of the children dying perinatally were malformed. In 13 cases the cause of the malformation was purely genetic; 11 were caused by mutant genes of large effect, and two by chromosomal aberrations. Information from such a study provides a good basis for genetic counselling of the family.


Familial spastic paraplegia with distal muscle wasting in the Old Order Amish; atypical Troyer syndrome or "new" syndrome. The Troyer syndrome was found by Cross & McKusick (1967) in 20 members of 12 Old Order Amish families in Holmes County, Ohio; it is a form of hereditary spastic paraplegia combined with distal muscle wasting, i.e. signs of involvement of lower motor neurons. The condition usually begins at 1 to 2 years and progresses at variable rates. Further manifestations include growth retardation, delayed speech development with dysarthria and drooling, and cerebellar signs; mental functions are usually not affected but severe emotional lability is a common finding. Brothers in a Wisconsin Old Order Amish family are reported with spastic diplegia, mental retardation, behavioral disorder and shortness of stature; the condition apparently is not progressive, and may be a "new" syndrome but could also represent a variant of the Troyer syndrome. Autosomal recessive inheritance is most likely, although consanguinity of the parents could not be proven. Another child in this family suffers from focal scleroderma (morphea) which is not related to the neurological syndrome.


Autosomal recessive syndrome of pseudogliomantous blindness, osteoporosis and mild mental retardation. We report a sibship of three sisters and two brothers who showed osteoporosis of variable severity; the propositus has incapacitating deformities following numerous fractures. Four of the sibs, including three with frequent fractures, were blind from infancy ("pseudogliomatous blindness"). In addition, two were mentally retarded. The osteoporosis-pseudoglioma syndrome is inherited as an autosomal recessive trait; similar reports from the literature support this assumption.


The position of the external ear in Turner's syndrome. The cephalometric roentgenograms of persons with the syndrome of XO gonadal dysgenesis and its variants, and of those with Noonan's syndrome, were compared with a control sample of unaffected females matched for age. Posterior craniofacial relationships differ between XO and normal individuals, particularly in the region of the external auditory meatus, which is located relatively more inferiorly and anteriorly in XO gonadal dysgenesis subjects than in chromosomally normal persons. Individuals who are mosaics, and those with Noonan's syndrome, do not differ from the unaffected population to the same extent. Although the position of the auricle often changes appreciably with growth when judged by clinical criteria alone, cephalometric analysis of relative ear position may still support the diagnosis of "low-set" ears.