Incorporation of [32P]-orthophosphate into total and individual plasma phospholipids in patients with polycythemia vera. Incorporation of [32P]-orthophosphate into plasma phospholipids was investigated in 11 patients with polycythemia vera. The specific activity of phospholipid radioactive precursors (TCA-extract) was maximal 1 hour after the delivery of radioactive phosphorus and dropped to less than 20 per cent of maximal value after 24 hours. The peak of total phospholipid specific activity was observed 48 hours after the administration of [32P]-orthophosphate in 10 patients, and after 24 hours in one, and decreases regularly afterward. The half-life of the lipid-bound phosphorus in the plasma of investigated patients, determined during the decrease of their specific activity was 252+/-60 hours. Concentration of total plasma phospholipids and the pattern of individual phospholipid found in patients with polycythemia vera were similar to those reported for normal individuals. The rate of incorporation of the labeled phosphorus into phosphatidylethanolamine and phosphatidic acid was much more rapid than into lysophosphatidylcholine, sphingomyelin, or phosphatidylcholine.


Properties of glycerol-75Se-triether: A lipid-soluble marker for the estimation of intestinal fat absorption. The properties of a 75Se-labeled glycerol triether were investigated in rat experiments designed to test this substance as a nonabsorbable marker for the assessment of intestinal fat absorption. After oral administration of 75Se-triether, the radioactivity was excreted almost completely with the feces. Amounts in excess of the quantity required tor clinical use did not interfere with overall fat absorption. No evidence for toxicity of 75Se-triether was observed. 131l-triolein was used as tracer fat and fat absorption was calculated by the following methods: (1) isotope balance method-oral intake minus fecal excretion of 131L; (2) isotope ratio method-comparison of the 131L to 75Se ratios in the test dose and in a stool sample. Results obtained from the isotope ratio method were in close agreement with those of the isotope balance method over a range of fat absorption of 80 to 95 per cent, thus indicating that the marker and the radioactive fat pass the gastrointestinal tract at the same rate under these experimental conditions. These results show that 75Se-triether possesses several of the properties of an ideal marker for fat absorption studies. Its advantages over other proposed markers for fat absorption studies are discussed. Simultaneous administration of 131L-TRIOLEIN AND 75Se-triether in a single dose may provide a reliable, rapid, and simple method to estimate intestinal fat absorption in man.


Chromosomal abnormalities in progressive systemic sclerosis (scleroderma) with consideration of radiation effects. An increased frequency of cytogenetic aberrations was observed in 63 patients with progressive systemic sclerosis (PSS, scleroderma). The most striking finding was the appearance of compound aberrations (chromosomal fragments and rearrangements) in PSS patients, while none were found in the control subjects. The aberrations were nonspecific in nature. The frequency of aberrations in the PSS patients was elevated above that of other patients receiving similar diagnostic radiation exposure (less than 1 R to greater than 10 R), but showed no relation to the amount of irradiation. The dose-response relation may have been obscured by the narrow range of exposures or by a "breakage factor" newly reported in such patients. It appears that in PSS patients the increased chromosomal breakage is not associated with an elevated frequency of leukemia or other neoplasms such as has been reported to be associated with other nonspecific breakage syndromes.


Altered in vitro functions of platelets prepared by the Haemonetics blood processor. The function and ultrastructure of platelets collected by the Haemonetics blood processor were investigated. Aggregability, release ability, and morphology of these platelets were compared with platelets of the same donors before plateletpheresis was instiuted. Data of a group of 15 normal donors were pooled and analyzed. Our results showed that Haemonetics-isolated platelets had the following altered in vitro functions. Adenosine diphosphate-induced aggregation was markedly reduce, and epinephrine-induced aggregation was often absent. Collagen-induced aggregation was characterized by prolongation of the aggregation time and, sometimes, also by reduction of aggregation. Increase of adenosine diphosphate or collagen concentration resulted in improvement of aggregation of Haemonetics-collected platelets; increase of epinephrine concentration had no effect. Exogenous CaCL2, pre-Haemonetics platelet-rich or platelet-poor plasma failed to correct the abnormal aggregation of post-Haemonetics platelets. Release of labeled serotonin induced by spinephrine and collagen was reduced. However, the ultrastructure of post-Haemonetics platelets was normal.


Blood cell structure-function studies: light transmission and attenuation coefficients of suspensions of blood cells and model particles at rest and with stirring. The Beer-Lambert law of light transmission was found valid for suspensions of blood platelets, erythrocytes, and leukocytes, as well as similarly sized model particles (latex spheres and flat guanine crystals), for a DB-G double-bean photometer at 605 and 710 mg, and a Payton aggregometer with red filter (660 to 750 mu). Attenuation coefficients (K) showed a similar dependence on a particle "equivalent sphere" radius as data reported for a "zero-degree photometer," for particles at rest. Size distribution, degree of aggregation, state of contamination, and effects of aldehyde fixation of the cell suspensions, well as optical geometry, were related to the measured K values. Particle optical efficiencies (K) for asymmetric particles were similar whether calculated from cross-sectional areas derived from "equivalent spheres" or from geometric cross-sections accounting for orientation distributions at rest. Appropriate cell and latex models were identified for the erythrocytes (E) and platelets (P) at rest on the basis of similar K,k values. The biphasic change in K occurring with stirring of these asymmetric blood cells (E, HP) was partly explainable by the known variations of K with shear-induced particle alignment to the optic axis. No such effects were observed with spherical particles or "sphered" cells, even when polydisperse as to size an aggregates. This investigation begins to quantitate ongoing light transmission studies of blood cell shape/aggregation changes.


Temporal relationships between dietary, plasma, hepatic, and adipose tissue lipids after short-term feeding of safflower oil to rats. The objectives of this research were to study effects of dietary neutral fat on the concentration and the fatty acid composition of triglyceride (TG) and other lipid classes in plasma, liver, and adipose tissue and, particularly, to study the temporal and precursor-product relationship among those various lipid pools. Accordingly, male rats were administered 1.5 ml. of safflower oil by gastric intubation at 0, 4, and 8 hours after a 16-hour fast. Samples of plasma, liver, and adipose tissue were collected from groups of rats before fat feeding (0 time, controls), during the period of feeding (4 and 8 hours), and at several times thereafter up to 36 hours (28 hours after the last meal). The esterified lipids in all lipid fractions of liver and plasma became enriched with linoleic acid (18:2) during the experiment. The enrichment of plasma and hepatic TG, and of plasma FFA with 18:2 was substantial, reaching a maximum 8 hours after the third meal, whereas only a modest enrichment of adipose tissue TG was observed. The enrichment with 18:2 of various lipid fractions proceeded in the following sequence: total plasma TG became enriched first with 18:2 of chylomicron TG fatty acids during the period of active absorption of fat. Second, plasma FFA were enriched with 18:2 derived presumably from metabolism of chylomicron TG. Subsequently, enrichment of hepatic TG with 18:2 was observed. After maximum enrichment was attained, the percentage of 18:2 in these various lipid pools decreased in the following order. The percentage of 18:2 in plasma FFA fell rapidly, followed by a slower decrease of the 18:2 content of plasma TG and, finally, by an even slower decline of the 18:2 content of hepatic TG. All lipid fractions except plasma FFA contained an increased content of 18:2 even 28 hours following the last fattly meal. It can be deduced from these temporal relationships that plasma TG is derived indirectly from dietary TG long after active absorption of dietary fat has ceased. The composition of hepatic TG is altered by dietary neutral fat, through the intermediary uptake of plasma FFA derived from metabolism of chylomicron TG; this hepatic TG, which reflects dietary fat, is a significant precursor pool of the plasma TG in the postabsorptive state.


Dialysance and clearance measurements during clinical dialysis-a plea for standardization. Mass transfer and dialysance measurements were determined using (1) whole blood solute concentrations with blood flow rates, (2) plasma solute concentrations with plasma flow rates, and (3) plasma solute concentrations with whole blood flow rates by standard formulas during 30 clinical hemodialyses. Resulting values by these three methods were compared for potassium, urea, and creatinine. The three techniques yield significantly different values and, accordingly, the type of measurement must be specified before such clinical measurements of solute transport are interpretable. Multiple mechanisms to account for the differences are suggested and include minimal or no immediate effect of a single coil blood transit on intracellular solute concentrations for all solutes studied.


Evaluation of the plasma kinin system in dengue hemorrhagic fever. The role of the plasma kinin system in the pathogenesis of dengue hemorrhagic fever (DHF) ws explored by simultaneously measuring factor XLL (Hageman), prekallikrein, kallikrein inhibitors, bradykinin, and complement (C3) in the blood of Thai children with DHF and acute febrile illnesses other than dengue. Prekallikrein, factor XII, and C3 levels were significantly lower in DHF patients compared to fever control patients with the lowest mean levels found in dengue patients with shock. However, bradykinin concentrations were not elevated and mean activity levels of kallikrein inhibitors were not depressed in dengue patients. Two dengue patients first studies at least 2 days before onset of shock had falling C3 levels which were more closely related temporally to the onset of shock than were their rising levels of prekallikrein. The results fail to provide convincing evidence ofr activation of the plasma kinin system leading to free bradykinin or a significant role for bradykinin in the immunopathogenesis of DHF. By contrast, the results refocus attention on complement as a potentially important humoral mediator of the dengue shock syndrome.


Endotoxin, thrombin, and the Limulus amebocyte lysate test. The Limulus amebocyte lysate, a proteinaceous composite isolated from the hemolymph cells of the horseshoe crab (Limulus polyphemus) is sensitive to picogram quantities of Gram-negative bacterial lipopolysaccharides. However, a controversy currently exists as to whether the Limulus amebocyte lysate is specifically sensitive to Gram-negative bacterial endotoxins as a result of a recent report that the blood coagulation protease, thrombin, can mimic endotoxins in the Limulus amebocyte lysate test. Experiments including those employing two highly purified fractions isolated from the Limulus lystae have provided us with evidence that thrombin per se is unable to mimic endotoxin.


The influence of serum calcium and parathyroid hormone upon glucose metabolism in uremia. The alterations in carbohydrate metabolism which attend the uremic syndrome have been recognized for some time. Recently, an interaction between hyperparathyroidism and these alterations in intermediary metabolism has been postulated. To further define any such interaction, 6 stable dialysis patients with significant secondary hyperparathyroidism were studied prior to and after subtotal parathyroidectomy. Glucose utilization and insulin secretion were estimated by use of a standard intravenous glucose tolerance test and the resistance of peripheral tissues to exogenous insulin was evaluated by insulin tolerance testing. All of peripheral tissues to exogenous insulin was evaluated by insulin tolerance testing. All patients were studied under baseline conditions, as well as induced hyper- and hypocalcemia, prior to and at least 2 months after surgery. Parathyroidectomy, per se, had no significant effect upon glucose utilization, insulin secretion, or the resistance of peripheral tissues to the action of exogenous insulin. Both induced hyper- and hypocalcemia, on the other hand, significantly diminished glucose utilization as judged by a reduced glucose disappearance rate during intravenous glucose tolerance testing. Hypocalcemia was associated with a markedly reduced insulin secretory response and normal tissue insulin sensitivity, while hypercalcemia was associated with a normal insulin response but reduced tissue sensitivity. The data suggest that calcium ion concentration may affect both glucose utilization and insulin secretion. As such, it must be adequately controlled in furture metabolic studies.


Morphological, biochemical, and functional changes in human platelets subjected to shear stress. Thromboembolic complications associated with cardiovascular prostheses are thought to result from activation of coagulation factors or platelets by surface contact and/or by certain physical forces generated at the interface between the foreign material and blood. Studies of the effects on human platelets of one of these physical forces, shear stress, were made. A rotational viscometer was used to apply graded levels of shear stress to platelet-rich plasma. Very low shear stress (50 dynes per square centimeter) resulted in the liberation of small amounts of ATP, ADP, and serotonin and subsequent platelet aggregation. Stresses of 100 dynes per square centimeter or more resulted in the appearance in plasma of nonstorage nucleotides, indicating cell lysis, and shear stresses of 250 dynes per square centimeter or more resulted in the fragmentation of platelets. Shear-induced platelet aggregation was partially reversible but only those samples subjected to low levels of shear stress recovered their ability to aggregate to the subsequent addition of ADP. These studies indicate that platelets are extremely sensitive to shear stress and raise the possibility that thrombus formation and/or accelerated platelet turnover in patients with rheumatic valvular disease or who possess artificial heart valves or other cardiac prosthetic devices could result from the effects of this physical force on circulating platelets.


Apparently normal pituitary-adrenal suppressibility in Cushing's syndrome: dexamethasone metabolism and plasma levels. In this study, we evaluated the responses of the pituitary-adrenal axis to the suppressive action of dexamethasone by relating plasma dexamethasone (Dex) and cortisol (F) levels in normal subjects and patients with Cushing's syndrome. Various doses of Dex were ingested at midnight as a single dose or at 6-hour intervals for 2 days beginning at 8 A.M. A nomogram was prepared by plotting the 8 A.M. plasma F concentration as a function of the plasma Dex value. Two patients with Cushing's syndrome had normal responses to Dex suppression as assessed by conventional tests. With the nomogram, we found that all patients with Cushing's syndrome, including these two, exhibited abnormally high plasma F values at some time during our evaluation. A decreased metabolic clearance rate of Dex appears to explain why one showed normal suppression. Another patient with bilateral adrenal hyperplasia showed sequentially over 13 months abnormal, normal, and abnormal suppression, which could not be attributed to an abnormality of Dex metabolism. We conclude that relating plasma Dex and F provides the investigator with a reliable index for evaluating resistance of the pituitary-adrenal axis to the suppressive effect of Dex.


Distribution of storage iron as body stores expand in patients with hemochromatosis. The relative distribution of storage iron between bone marrow and liver has not been adequately studied in patients with iron-loading disorders. To help clarify this we assessed iron metabolism in patients with iron overload and in control subjects with cirrhosis but no excess body iron. In 4 patients with advanced iron overload studied late in the course of their illness, excess hemosiderin was present in both bone marrow and liver, as expected. In contrast, 2 patients with idiopathic hemochromatosis whose excess iron had been depleted by phlebotomy subsequently developed progressive hepatic parenchymal and reticuloendothelial (RE) deposition of iron, yet marrow hemosiderin remained sparse. Moreover, surface radioactivity over the liver after an oral dose of 59Fe. These results suggest that during the initial stages of hemochromatosis there is a dissociation in the rate of iron accumulation between the bone marrow and liver. Excess hemosiderin appears to be deposited predominantly and preferentially in hepatic storage sites until the later stages of the disease.


The source of Na+ and Cl- activities on the skin surface. Experiences with electrode measurements in children. We have used ion-specific electrodes in an attempt to map the sodium and chloride activities on the skin under differing surface conditions. The range of values and the standard deviations are so wide that a baseline for the untreated dry skin is precluded. In patients with cystic fibrosis, a wide range of values is also found. For this group, measurements on dry skin taken immediately after washing were in the same low range as for healthy subjects. The range of measurements on the dry skin of newborn infants was similar for full-term infants with reactive sweat glands and for premature infants who failed to show sweating responsiveness to natural reflex stimulation as well as local glandular stimulation with sudorific drugs. For only two conditions have measurements of sodium and chloride activities on the surface of the skin been of value: (1) on the sweat-covered skin for the detection of the high values encountered in cystic fibrosis, and (2) on the dry skin surface, deprived of autonomic innervation (spinal paraplegia), extremely low sodium and chloride activities reflect absent gland activity.


Drug-induced inhibition of myeloid colony growth: protective effect of colony-stimulating factor. The effect of some potentially myelotoxic drugs on the growth of colony-forming cells in mouse marrow in vitro was examined. Among the drugs tested chloramphenicol, thiamphenicol, and chlorpromazine were inhibitory in therapeutic concentrations, a finding consistent with the common occurrence of a dose-dependent leukopenia from these drugs. The degree of drug-induced inhibition of colony growth was inversely proportional to the concentration of colony-stimulating factor in the medium. It is postulated that the concentration of colony-stimulating factor in the cell milieu in vivo may play a significnat role in determining the occurrence or degree of leukopenia from thses drugs.


A simple radioimmunoassay for unconjugated estriol in pregnancy plasma. A simple and specific radioimmunoassay (RIA) for the measurement of plasma or serum unconjugated estriol (E3) in pregnancy is described for general laboratory use. Two different antibodies utilized had low cross-reaction to estrone (E1) and estradiol-17 beta (E2). With either of these antibody reagents, a method was designed that requires only an extraction step using a specific solvent mixture of ethyl acetate and n-hexane (3:2, v/v), one-hour incubation with working antibody, and separation of bound from free E3 by ammonium sulfate. Standard curves useful in the range of 0 to 2,000 pg. were obtained. This assay, requiring only 0.05 ml. of plasma, can be completed within 4 hours. The sensitivity of this RIA was 10 pg. The intra- and interassay coefficients of variation (CV) were 5.0 and 9.4 per cent, respectively. When E3 determinations by this method are compared with RIA values by a more complicated technique using Celite column chromatography, the results are not significantly different. There was a good correlation between our RIA and a standard urine E3 determination (n = 137, r = 0.82, p less than 0.001). Using our simplified method, the mean plasma E3 during pregnancy were 1.0 +/- 0.6 ng. per milliliter at 10 weeks, 2.3 +/- 0.6 ng. per milliliter at 20 weeks, 6.5 +/- 1.4 ng. per milliliter at 30 weeks, and 16.5 +/- 5.1 ng. per milliliter at term. Since the serum RIA reflects changes in free E3 which has a shorter half-life than conjugated E3, this rapid and simple method is attractive as an approach to monitor fetal-placental function.


Interlaboratory reproducibility of gastrin measurements by radioimmunoassay. A collaborative study was conducted to determine interlaboratory variations in the measurement of gastrin by radioimmunoassay (RIA). A kit containing reagents for a communal RIA method, as well as test samples containing different amounts of human synthetic gastrin (SHG I) and test samples of serum from a fasting normal patient admixed with varying volumes of serum from a patient with the Zollinger-Ellison syndrome, was sent to each collaborating investigator. Each investigator was requested to measure the gastrin concentrations in test samples by means of the communal RIA method, as well as the RIA method utilized in his or her laboratory. Use of the communal RIA method resulted in no significant interlaboratory variation in the determination of gastrin concentration in SHG I test samples and a maximum two- to threefold variation in determination of gastrin serum test samples. In contrast, when individual RIA methods were used to measure gastrin concentrations, the amount of SHG I in test samples reported by one laboratory was significantly different than that reported by the other three. In addition, use of different RIA methods resulted in a 2- to 19-fold interlaboratory variation in serum gastrin measurements and the maximum variation was found when the gastrin in normal fasting serum was measured. Increased variations in results, when different RIA methods were used, may be due to differences in preparation and purification of labeled antigen, to differences in separation of bound from free hormone, and to differences in the antibodies themselves.


Microchromatography of hemoglobins. IV. An improved procedure for the detection of hemoglobins S and C at birth. Substitution of CM-cellulose for CM-Sephadex had yielded a superior microchromatographic method for distinguishing the AS, AC, SS, SC, and CC conditions at birth. On the translucent columns of CM-Sephadex, the hemoglobin zones are somewhat diffuse. However, the compact, well-defined zones on the CM-cellulose column facilitate the interpretation of the results even though the amount of sample is only 20 per cent as great. The CM-cellulose method is as simple and rapid as the original CM-Sephadex procedure.


Jamshidi bone marrow needle modification. A modification of the Jamshidi bone marrow biopsy needle is described. Modification includes designing a removable handle and changes to the obturator. These modifications allow for more precise use, prevention of instrument breakage, and greater convenience for the operator.


Measurement of triiodothyronine in unextracted urine. A radioimmunoassay procedure to measure triiodothyronine (T3) in unextracted urine is described, and the results are compared with those obtained with different assays by others. It is assumed that the radioimmunoassayable T3 in urine represents free T3. Euthyroid subjects excreted 1.0 +/- 0.3 mug (mean +/- S.D.) in 24 hours. Similar values were obtained in pregnant women, sick patients without thyroid disease, and euthyroid patients receiving antithyroid agents. Values were about 3 times normal in patients with hyperthyroidism and about one-third of normal in patients with hypothyroidism. Estrogen, salicylate, or diphenylhydantoin therapy did not significantly alter the values. Radioimmunoassayable T3 increased after acid hydrolysis, suggesting that a fraction of the T3 in urine is present as an acid-hydrolyzable conjugate. However, it cannot be excluded that at least part of the T3 found after hydrolysis derives from monodeiodination of T4. This hydrolyzable fraction was about 25 per cents of the total T3 in urine. Measurements of T3 in urine are reliable and easy to perform. These measurements have little significance as a clinical test of thyroid function, but the assay may allow a new approach to understanding thyroid hormone metabolism and action, provided that deiodination of T4 during the procedure can be rigorously controlled and that the urinary T3 conjugates can be determined quantitatively.


Personality tests in Ménière's disorder. The personality of patients with Ménière's disorder has been evaluated using the Eysenck Personality Inventory and the Middlesex Hospital Questionnaire. The most notable finding was an elevated obsessionality score in the patients with Ménière's disorder as compared with other groups. There was no significant difference between the personality of subgroups of patients complying with rigid definitions of Ménière's disorder and those complying with a more liberal definition. The results of most scales decreased with increasing severity of the disorder, although the obsessionality scores do not follow this tendency.


Exposure to asbestos and laryngeal carcinoma. One hundred and nineteen male patients with squamous carcinoma of the larynx and 119 matched controls with various non-malignant diseases were questioned about their exposure to asbestos. Thirty-three patients and three controls had experienced an important degree of exposure to asbestos. The difference between the two groups was statistically highly significant.


Laryngeal and tracheal stenosis: an adapted speaking aid tracheostomy tube. A 41-year-old male patient with post-diphtheritic laryngeal deformity and an extensive upper tracheal stenosis is presented. Previous surgical attempts at repair of the tracheal stenosis had been unsuccessful and further surgery is not contemplated at the present time. A permanent speaking-aid tracheostomy tube must therefore be worn at all times and an adaptation to this tube to allow some expiratory escape past the valve is described.


Otoscleroma.

Otoscleroma. Otoscleroma is a new term used by us to describe the occurrence of scleroma in the middle ear. Although no cases have been reported in the literature, we describe here two cases.


Ventricular activation process in minipigs. Because the form of QRS from the body surface of pigs is different from that of carnivores or ungulates, and because that form is dependent upon pathways of ventricular activation, this study was designed to study pathways of ven tricular activation in pigs. Twelve pigs were anesthetized and right or left hemithoracotomies were performed to expose the heart. Contiguous bipolar electrograms were recorded from button electrodes on the epicardium and from both faces of the interventicular septum, and from multipolar plunge electrodes introduced into the intramural regions of both ventricles. Electrograms were recorded simultaneous with the Z-axis ECG at 625 mm/sec paper speed on a photographic oscillograph. Times of arrival of waves of activation at numerous points in the ventricle were referenced to the peak of the R-wave in the Z-axis ECG. During the initial 10 msec of QRS, the apical-third of the interventricular septum is activated from left to right. During the next 40 msec of QRS, waves of activation originating at the cranial portion of the right ventricle and the caudal portion of the left ventricle engulf the epicardium toward the interventricular septum and slightly in an apico-basilar direction. Activity begins slightly earlier at the caudal aspect of the left ventricular free-wall and terminates on the pulmonary conus region. During the terminal 30 msec of QRS, the basilar third of the interventricular septum is activated in a general apico-basilar direction. Through regions of either right or left ventricular free-walls was a general endocardial to epicardial activation observed. These pathways of ventricular activation may be explained by the rather complete penetration of Purkinje fibers through both ventricular free-walls in a manner similar to that of ungulates but different from carnivores and primates.


A cellular model for the simulation of activation in the ventricular myocardium. A digital computer model of cardiac activation was used to investigate the relationship between cellular orientation and conduction and propagation of the ventricular activation wave front. The results of the simulation for  a single cycle initiated in fully recovered tissue under normal and simplified pathological conditions (ischemia and infaraction) indicate (a) that the conduction velocity of the cellular action potential in ventricular cardiac tissue may be several (3-5) times greater than is normally considered to be the case, (b) that the ventricular activation wave front propagates transmurally from endocardium to epicardium despite fiber orientation parallel to these surfaces, without the need for assuming the existence of either lateral contacts between adjacent cells or fibers with a transmural orientation, (c) the wave front of activation propagates through ventricular cardiac tissue with an anisotropic phase velocity, (d) the presence of ischemia and infarction gives rise to tangential spread of activation, and (e) small subendocardial infarcts should not be considered to be electrically silent.


The QRS phasic characteristics of right ventricular hypertrophy in precordial leads. The QRS apparent phase in some electrocardiograms (ECGs) progresses in opposite directions in the two halves of the precordial leads. The genesis of the waveforms leading to such bidirectional phase properties may be given in terms of the particular shapes of the horizontal vector loops. Such phasic properties associate themselves with right ventricular hypertrophy (RVH) of type A and type C although the reverse is not necessarily true. Schematic diagrams are generally used in this article for clarity in illustration, but the method has been tried on some well-documented cases of RVH, reported by Chou and Helm, 3 with promising results.


Determination of the locus of the heart vector from body surface measurements: model experiments. Based on the Gabor-Nelson equations a technique is described for measuring the location of the resultant heart dipole (locus-cardiogram). The technique uses three rows of eight electrodes, a head and a foot lead. Experiments with a male and a female human torso model showed good agreement between actual andmeasured dipole locations. The presence of intrathoracic electricla inhomogeneities shifts theapparetn locus of the dipole toward the highly conductive mass. The conductivity of the volume conductor and the dipole monent value do not introduce any error into the computed locus of the dipole. It is concluded that the technique is accurate and simple enough to be used for experimental and clinical observation.


The normal electrocardiogram of the domestic pony. Twelve-lead electrocardiograms (ECGs) were recorded from 52 resting mature female domestic grade ponies. Evaluation of the 50 ECG's ultimately selected for analysis revealed numerous differences from accepted normal values of horses. Among these differences are shorter durations of the P and QRS complexes as well as P-R and Q-T intervals and a lower amplitude of the P wave. Pony ECG's displayed a lower incidence of wandering pacemaker and complete absence of second degree atrioventricular block, in contrast to the relatively routine occurrence of these phenomena in the horse. The existence of significant differences between the ECG of the pony and horse must be recognized and considered in future clinical and research applications of electrocardiography in the domestic pony.


Case studies: Significance of episodic painless ST segment elevation at rest in ischemic heart disease. The occurrence of episodic painless ST segment elevation at rest was documented by continuous electrocardiographic monitoring in four patients with ischemic heart disease who did not conform to the classic description of Prinzmetal's variant angina. The degree of ST segment elevation in the absence of pain was generally similar to that seen with painful episodes. Clincopathological correlation was available in three of these patients: two were found to have severe coronary artery disease and one had a 70% obstructive lesion in the right coronary artery only. Three patients subsequently developed a myocardial infarction. Our observations suggest that transient painless ST segment elevation at rest is a serious finding reflecting severe ischemia and more likely to be "preinfarctional" than "variant" angina. Long term monitoring is useful in detecting silent severe ischemia that may sometimes occur with potentially lethal arrhythmias as demonstrated in one case.


Direct and imcomplete concealed Wenckebach phenomena in the left bundle-branch system. A case is reported showing a tachycardia dependent Wenckebach phenomenon in both the A-V node and the left bundle branch system. Pacing from the His bundle region induced manifest (direct) and imcompletely concealed (indirect) types of Wenckebach phenomenon within the left bundle branch system.


Complete heart block with normal QRS duration occurring distal to the his bundle in acute inferior myocardial infarction. A patient with acute inferior myocardial infarction developed on the second day complete heart block with normal QRS duration, and the block was found to be distal to the His bundle. To our knowledge, this is the first such documented case in the English literature. Failure of the preceding Wenckebach periods and of complete heart block to respond to intravenous atropine may be a clinical clue to the nature of this type of heart block. The implications and possible explanations are discussed in the light of recent knowledge concerning the nature of heart block in inferior wall myocardial infarction.


Mid-systolic click, late systolic murmur syndrome associated with complete heart block. A 60 year old woman is presented who had the mid-systolic click, late systolic murmur syndrome, documented by phonocardiogram and left ventricular angiography. During an episode of non-anginal chest pain, advanced heart block was demonstrated and permanent transvenous pacemaker therapy was subsequently instituted. The association of the mid-systolic click, late systolic murmur syndrome and heart block is reviewed. It is suggested that 24-hour continuous electrocardiographic monitoring, as well as exercise stress testing, be included in the evaluation of patients with this syndrome.


The reliability of pacemaker electrode-leads. Extensive experience has been obtained with Medtronic pacemakers, in Glasgow where over 400 patients have received their primary implant. In this review, which covers a period of seven and a half years ending December 31, 1973, the technical reliability of electrode-leads is considered in terms of failed implant lifetimes and incomplete implant lifetimes. Too few myocardial electrode-leads have been used to reach firm conclusions about its reliability, but the incidence of failures with the endocardial bipolar electrode-lead (Type 5818) has so far been small and it is evidently more reliable than its predecessor (Type 5816). More time must elapse, however, before it can be claimed with confidence that the present design of bipolar catheter will match the theoretical implant lifetimes of generators with the long-life power sources. Insulation failures are usually of no immediate clinical significance whereas any broken conductor is hazardous. The use of multistranded conductors is therefore advocated. All pacemakers should be retrieved after the deaths of patients.


The relative risk of spontaneous complete atrioventricular block in elderly patients with impaired intra-ventricular conduction. We reviewed 144 consecutive patients with symptomatic high grade atrioventricular block. Cases due to congenital heart disease, acute myocardial infarction, cardiac surgery or digitalis toxicity were excluded. Of the remaining, we chose 71 patients in whom atrioventricular conduction was observed either intermittently during complete heart block (CHB) or in electrocardiograms taken within two years prior to documentation of CHB. The mean age was 69 years, with the peak incidence in the seventh decade in 43 men and eight decade in 28 women. Bundle branch block (BBB) was present in 76% of patients as follows: 47% had right BBB (20% with normal QRS axis, 20% with left axis deviation and 7% with right axis deviation), 17% had left BBB (11% with normal QRS axis and 6% with left axis deviation) and 12% had either alternating BBB, right BBB with alternating axis deviation or atypical BBB. "Trifascicular block" patterns accounted for 21% of the total group of CHB. We also studied the prevalence of various patterns of BBB in a group of 2000 random hospital patients of comparable age and sex exclusive of those with acute myocardial infarction and heart surgery. The risk of CHB for the various patterns of BBB was calculated relative to normal intraventricular conduction. All patterns of BBB carried a considerably increased relative risk of CHB, (P smaller than .01). The relative risk was highest for RBBB with left axis deviation and lowest for LBBB with normal or left axis deviation. In the men, 74% had QRS patterns of "bifascicular" or "trifascicular" block during atrioventricular conduction. By contrast, 71% women had atrioventricular beats showing either no BBB or right BBB with normal QRS axis. QRS pattern during CHB was unchanged from that during atrioventricular conduction in 52% if cases (rabge 38%-76% with different QRS patterns) suggesting idiojunctional pacemaker. CHB in these cases was thought to be due probably to coexistent disease in the AV node or His bundle. Although the concept of uni-, bi- and trifascicular block patterns has been useful in identifying patients at greater risk of CHB, the predictability of the electrocardiogram has obvious limitations, particularly in women.


Effects of electrical stimulation of the neurohypophysis on labour in the rat. Labour was studied in 69 primiparous and multiparous rats by continuous observation and by the recording of intra-uterine activity. The effect of electrical stimulation of the neurohypophysis with stimulation parameters selected to create a pulsatile release of oxytocin was investigated. Stimulation was applied to the neurohypophysis through chronically implanted electrodes every 5 min, in 45 min sessions, from noon on Day 21 of gestation and at 3 h intervals thereafter. Electrical stimulation successfully promoted (or induced) the onset and facilitated the course of labour. Stimulation at 12.00 h on Day 21, or at a subsequent stimulation session 3, 6, 9 or more hours later, promoted an immediate increase in the frequency and amplitude of uterine contractions. Overt signs of abdominal straining followed within 5-30 min and the first pup was delivered shortly thereafter. These 'induced' deliveries were almost identical to those displayed by control rats; labour continued to completion despite the termination of the stimulation session after 45 min. By contrast, one third of the stimulated animals displayed an interrupted pattern of labour in which events virtually ceased for 30-60 min when stimulation was terminated. Stimulation, however, only advanced labour by 1-2 h in relation to control animals; this was not statistically significant. Stimulation accelerated the delivery of the first 5 pups in each litter. In both stimulated and control animals, the birth intervals declined over these first few deliveries to reach the lowest values of 5-6 min throughout the remainder of labour. The most common litter size was 12 pups. The distribution of labour on Day 21 and 22 was bimodal. Seventy per cent of the animals gave birth between 12.00 and 18.00 h on Day 21, a few gave birth during the following night and the remainder formed a second peak on Day 22. All litters of less than 6 pups were born during this later period. The implications of these results in the context of spontaneous labour are discussed. We conclude that endogenous oxytocin (with perhaps other neurohypophysial hormones) released in pulses of 1-3 mu. every 5 min can promote a pattern of labour on Day 21 of gestation that is almost indistinguishable from that which occurs naturally.


Reversal by progesterone of phenobarbitone blockade of ovulation in the prepubertal rat primed with pregnant mare serum gonadotrophin. In immature female rats injected with PMSG at 30 days of age (day 30), ovulation occurs between the hours of 02.00 and 03.00 on day 33. If progesterone is injected at 10.00 h on day 32, the onset of ovulation is advanced by 1-2 h. In rats that were not given progesterone, ovulation was blocked by phenobarbitone sodium administered on day 32 before 13.50 h. However, pretreatment with progesterone at 10.00 h caused ovulation to occur in spite of phenobarbitone treatment at 13.50 h. An early release of ovulatory gonadotrophin from the anterior pituitary gland cannot completely account for progesterone's capacity to reverse the blockade of ovulation by phenobarbitone, because when phenobarbitone treatment was advanced by 2-4 h, ovulation still occurred in most progesterone-treated rats.


Responsiveness of the ovary to gonadotrophins in pre- and perinatal life: oestrogen secretion in tissue and organ cultures. Secretion of oestrogen by the ovaries of foetal (15-19 days of gestation) and newborn rats in organ and tissue culture was not detectable by fluorometry when the ovary was taken from foetuses before folliculogenesis had occurred. In organ cultures of ovaries, the time of folliculogenesis corresponded with the normal timing of folliculogenesis in vivo. In tissue cultures the process of formation of follicles was delayed. Oestrogens were present in the medium when folliculogensis was fully established in the cultured foetal ovaries. Secretion began spontaneously and did nto depend on the addition of gonadotrophins to the medium. The addition of gonadotrophins the the culture medium did not effect the level of oestrogen secreted by the foetal and newborn rat ovaries during the period of incubation (2-3 weeks).


Lipids in the mouse uterus during early pregnancy. Lipids in the uterine endometrium of mice during early pregnancy were investigated by histochemical techniques. Three groups of animals were studied: (1) on days 1-8 inclusive of the first pregnancy, (2)on days 1-9 after mating at the post-partum oestrus and suckling seven or eight young from their first pregnancy, (3) on days 1-6 after delivery of the first litter but with no access to males. Day 1 was that on which a seminal plug appeared in the vagina or (group 3) after birth of a litter during the previous night. In post-partum mice, only the areas between the former implanation sites were studied. Epithelial lipids are sparse during the first 24 h. On day 2 and early day 3 in nulliparous mice, and for a longer period in post-partum mice, the presence of lipid in epithelium and stroma seems mainly a degenerative phenomenon associated with cell breakdown and consequent tissue disruption. During late day 3 and on day 4 the increase in lipid droplets giving staining reactions characteristic for triglycerides may represent the storage in this form of fatty acids no longer needed for phospholipid synthesis or as energy sources, once the intense mitotic proliferation of these cells dies down. Triglycerides also predominated in the necks of the glands, but in the deeper parts, the sparse droplets often gave staining reactions for acidic lipids. In differentiating decidual cells during day 5 and early day 6 in nulliparous mice, histochemical reactions suggest that fatty acids accumulate. Some of these are probably utilized in synthesis of the increasing amounts of phospholipids which were particularly prminent later on day 6 and during day 7, while others appeared to be temporarily stored during that period as triglycerides The phased deposition and removal of triglyceride proceeds centrifugally through the decidua and is slightly in advance of glycogen deposition and removal in the same cell; its time-course correlated well with that which other workers have described from chemical assay. Histochemical tests appeared to reveal activity of a lipase-esterase (fatty acid ester hydrolase) which strengthened and spread through the decidua in parallel with the disappearance of lipid droplets. In lactating mice, as long as the blastocysts remained in diapause, epithelial lipid resembled that on day 4; in the stromal cells, lipid droplets were plentiful in areas close to the former placental sites but were few or absent elsewhere. Once the delayed implantation had started no abnormalities were detected. Alterations in lipids are discussed in the context of the known changes in the levels of ovarian hormones. Lipids within uterine macrophages are also discussed.


Dynamics of insulin release by perfused hamster )Mesocricetus auratus) pancreases: effects of hypophysectomy, bovine and human growth hormone, and prolactin. The hamster exhibits a biphasic pattern of insulin secretion; however, the dynamic response differs qualitatively from that of the rat in that there is a steady-state second release phase. A marked attenuation of insulin secretion as a result of hypophysectomy was observed after 3 weeks, but not after 2 weeks. This depression of insulin secretion was restored to near or above normal levels by bovine growth hormone, human growth hormone, and prolactin.


Discrepancy between radioimmunoassay and radioligand-receptor assay of luteinizing hormone released in vitro by pituitary tissue from male rats of different ages. Anterior pituitary glands from male rats aged 21, 40, 60 or 95 days were incubated in medium containing 0, 2 or 20 ng luteinizing hormone-releasing hormone (LH-RH)/ml. Incubates were assayed for LH by radioimmunoassay (RIA), by the radioligand-receptor assay (RLA) using testicular homogenates as the source of receptor and, in some instances, by the ovarian ascorbic acid depletion assay (OAAD). Irrespective of the dose of added LH-RH, glands from rats aged 40 and 60 days always showed a higher release of LH, as determined by RLA, than glands from animals aged 21 or 95 days. Measurement by RIA showed a similar pattern to RLA in the basal release of LH, but in the presence of LH-RH showed little difference in LH release by glands from rats aged 40, 60 or 95 days. The LH release caused by the higher concentration of LH-RH was always greater when measured by RLA than by RIA. Assay of comparable incubates by OAAD showed close agreement with RLA estimates in four incubations (mean index of discrimination 1.07; range 0.86-1.18) and consistent disagreement with RIA estimates (1.64; range 1.38-1.99). In contrast to the results with incubates, homogenates of pituitary glands from male rats of various ages showed close agreement of estimates by RLA, RIA and OAAD. These results suggest that RIA underestimates the LH-RH-stimulated release of LH in vitro from the male rat pituitary during some stages of sexual maturation.


Metabolic effects of testosterone in the chequered water-snake, Natrix piscator. In the water-snake, Natrix piscator, the following are depressed by orchidectomy and restored to normal by testosterone treatment: glucose, free and esterified fatty acids and triglycerides in plasma, hepatic triglycerides, and total esterified fatty acids. The increase in hepatic free fatty acids and muscle glycogen was also reduced to the level found in intact snakes. Moreover, although castration had no effect, testosterone caused a significant increase in liver weight and plasma protein, and a significant decrease in free plasma cholesterol. Except for an increase in triglyceride content by high doses of the hormone, neither castration nor the administration of 5 mg testosterone had any significant effect on the free fatty acid and triglyceride content of the adipose tissue of the snakes.


Maternal and foetal corticosterone levels during late pregnancy in rats. Adrenal and plasma corticosterone levels were determined in rat foetuses and in intact or adrenalectomized mothers during late pregnancy. Foetal adrenal and plasma corticosterone concentrations reached a peak on day 19 of pregnancy, while maternal plasma corticosterone increased on day 18 and remained high until parturition. From day 18, mothers adrenalectomized on day 14 had corticosterone levels similar to those of intact pregnant rats. At every stage of gestation (except day 21) plasma corticosterone levels were higher in the foetuses than in the mothers. The corticosterone concentration in the maternal plasma correlated with the number of live foetuses during the last 3 days of gestation. These results suggest that corticosterone can cross the placenta from foetus to mother as early as day 18 and that the foetus contributes to the maternal corticosterone pool after day 18.


The proliferative response of the coagulating gland of the castrated mouse under continuous androgen stimulation: an experimental and computer simulation model. The proliferative response of the coagulating gland of the castrated male mouse has been examined during continuous treatment with testosterone propionate. Fourteen days after castration, s.c. daily injections of testosterone propionate were begun. Mitotic (Im) and labelling (IL) index values were obtained at 3 h intervals for up to 100 h after the initial injection. These showed a biphasic response, in which IL reached a maximum at 30 and 70 h, and Im at approximately 45 and 75 h. Fraction-labelled mitoses (FLM) curves were begun 24, 48, and 72 h after the first androgen injection. In each curve the first wave of labelled mitoses rose to 100% and showed a square form indicating little spread in the durations of the G2 and S phases. Values of 7.5, 1.3 and 0.7 h were obtained for the durations of DNA synthesis (ts), the post-synthetic period (tG2) and of mitosis (tm) respectively. In none of the FLM curves was it possible to demonstrate a second wave of labelled mitoses and direct measurement of the cell cycle time (Tc) was not obtained. Continuous tritiated thymidine labelling indices revealed that after a latent period of 25 h, DNA synthesis began and labelling rose rapidly to 80% by 45 h and then more slowly to 95% by 97 h. Cell population changes during androgen stimulation estimated from measurements of total glandular DNA indicated that the number of cells present in the glands remained constant during the first 30 h after stimulation and thereafter increased to approximately 2-3 times the original value. The data are compared with a mathematical model which assumes that the cell population of castrated mice when stimulated passes from a GO compartment through successive waves of DNA synthesis and mitosis. After each cell division the cells may leave or remain in the proliferative cycle. This model has been subjected to computer simulation using the cell cycle parameters obtained in the kinetic experiments. There was good agreement between the stimulation and experimental results in the Im and IL curves, continuous labelling, and total cell number experiments. The simulation of FLM curves was less successful. Although the first wave of labelled mitoses was clearly seen the model predicts a distinct second wave of labelled mitoses. It is concluded that this does not appear because of variation in the duration of G1.


Androgenic regulation of rapidly synthesized RNA in the rat ventral prostate. The influence of castration on the incorporation of nucleotide precursors into RNA of isolated prostatic tissue has been investigated. Castration brought about an apparent increase of incorporation by increasing the specific activity of the uridine nucleotide pool and not by an enhancement in synthesis of rapidly labelled RNA. An actual decrease in this reaction was shown by dividing the radioactivity incorporated into RNA by the specific activity of the uridine nucleotide. Administration of testosterone brought about enhanced synthesis of RNA in the prostates of rats castrated for 3 days as early as 4 h after injection, reaching maximum effect at 8 h. No significant difference was found between the turnover rates of rapidly labelled RNA from castrated, androgen-treated castrated and intact rats. The increased prostatic permeability to nucleosides as an early action of androgens in this organ is discussed.


A comparison of changes in the peripheral plasma concentrations of luteinizing hormone and follicle-stimulating hormone in the rat. Plasma FSH concentrations in rats have been determined by radioimmunoassay under a variety of experimental conditions to see whether any evidence could be obtained of an acute divergence in LH and FSH secretion rates which would support the idea of separate, specific hypothalamic releasing factors for these two hormones. During the normal ovarian cycle and after the administration of progesterone to female rats on the morning of the day of pro-oestrus increased secretion of both LH and FSH began simultaneously but FSH concentrations were later maintained or increased slightly while LHING EARLY PREGNANCY FSH concentrations were higher than at the corresponding stage of the cycle at a time when LH concentrations had been shown to be lower. Progesterone injected at the dioestrous stage of the cycle reduced both LH and FSH concentrations though the effect on LH was more marked. After ovariectomy at any stage of the oestrous cycle or on day 4 of pregnancy there was a rapid and significant increase in plasma FSH concentration which was quite different from the delayed increase in LH concentration observed in these animals. In contrast, the early increase in FSH concentration in male rats after castration was less than the increase in LH concentration. The final FSH concentration in castrated males was only about four times the basal level in contrast to the 10- to 15-fold increase in LH in males and both LH and FSH in females. Anovulatory adult females that had received 1-25 mg of testosterone propionate on day 4 of postnatal life showed the rapid and sustained increase in plasma FSH after ovariectomy that was seen in normal females. None of these results strongly support the idea that separate and specific hypothalamic releasing factors for LH or FSH are secreted in the rat although the differences in the early response to gonadectomy could be explained on this basis.


Evidence for a possible foetal control of prostaglandin release from the pregnant rat uterus in vitro. The release of prostaglandin-like material and these spontaneous contractions of individual horns from the pregnant rat uterus in vitro have been studied on day 22 of pregnancy - the expected day of delivery. Removal of foetuses (retaining placentae in utero) from one or both uterine horns on day 16 or 17 significantly reduced prostaglandin F release and spontaneous activity. Rats which had been made unilaterally pregnant after ligation of one uterine horn, exhibited a decrease in prostaglandin F output from both horns. Uterine activity and prostaglandin release were increased in quiescent uteri by the addition of arachidonic acid (5 mug/ml) or phospholipase A (160 mu./ml); the effects were abolished by indomethacin (20 mug/ml). However, the stimulation of uterine activity by PGF2alpha (30-60 ng/ml) was not affected by indomethacin. It is concluded that the release of prostaglandins from the pregnant rat uterus in vitro at term is related to the presence of viable foetuses.


Morphogenesis in Micrasterias. II. Patterns of morphogenesis. The final form of the polar lobe and lateral wings of developing semicells of M. rotata results from combined action of three growth processes: tip growth, branching and lobe broadening. Tip growth unaccompanied by branching or broadening occurs during normal development in M. radiata, but is observed only under abnormal conditions (e.g. raised temperature) in M. rotata. When branching and broadening do occur, they occur together and for this reason may be causally related. Autoradiograms demonstrate that specific patterns of cell wall incorporation can be associated with each of the three processes in M. rotata. Autoradiographic patterns found in the polar lobe differ from those found in wings. The growing polar lobe also responds to laser irradiation differently from the wings; lasings occasionally cause duplication of the polar lobe.


The development of trophoblast in vitro from blastocysts containing varying amounts of inner cell mass. When intact mouse blastocysts are cultured in vitro in medium supplemented with foetal calf serum, trophoblast cells proliferate and undergo giant cell transformation such as occurs in vivo. If the amount of inner cell mass in the blastocyst is decreased by culture with [3H]-thymidine then giant cell transformation occurs normally but proliferation is reduced. In the absence of inner cell mass no proliferation occurs, and giant cell transformation is more rapid than in undamaged blastocysts.


Experimental cardiac morphogenesis. I. Development of the ventricular septum in the chick. An experimental technique utilizing microfiber markers and radioautography was used to study the morphogenesis of the ventricular septum in the ckick embryo heart from stages 22 to 33 of Hamburger & Hamilton (1951). Fibers placed in the myocardium of the primitive ventricles of 4-day-old embryos within 250 mum to each side of the future site of the ventricular septum resulted in shortening of the distance between the two fibers until both were found within the myocardium of the septum at 7 days. The fibers coated with tritiated thymidine labeled the myocytes of the trabeculae immediately adjacent to where the fibers were placed and showed that when trabeculae were labled within the 400-500 mum width centered on the ventricular septum, they aggregated together. The labeled myocytes in the trabeculae were found from the smooth crest to the most apical portion of the septum. These findings suggest that the muscular ventricular septum is formed by aggregation and coaptation of trabeculae and is of a single developmental origin.


Local autonomy of gastrulation movements after dorsal lip removal in two anuran amphibians. The time-course of the remaining gastrulation movements has been investigated after removal of the dorsal lip, the presumptive foregut endoderm and the anterior mid-dorsal mesoderm as a plug-shaped mass of cells from beginning gastrulae of Xenopus laevis and Bombina orientalis. This embryonic region has been previously studied in its role as an organizer, when grafted into a host gastrula marginal zone. There is usually no effect of the removal of these cells, the first morphogenetically active ones, either upon rate of subsequent completion of the external aspects of gastrulation, or upon the internal evolution of the presumptive mesodermal mantle. This finding is discussed in connexion with results of a previous paper on pattern formation in early Xenopus development, since it may help to distinguish between possible types of explanation for those results.


Demonstration of cytoplasmic processes in Millipore filters permitting kidney tubule induction. The presence of cytoplasmic material inside thin Millipore filters between interacting mouse metanephric mesenchyme and spinal cord was investigated using different fixation methods. The transmission of induction was studied from sections of Zenker-fixed paraffin-embedded explants. Formation of kidney tubules was taken as evidence for induction. Filters with 0.8 and 0.22 mum pores permitted induction, whereas only 6 out of 31 filters with 0.1 mum pores did so. Glutaraldehyde-fixed Epon-embedded explants were used for study of cytoplasmic penetration into filters. In thick sections, filters with large pores were seen to contain cytoplasmic material at all levels. Filters with 0.1 mum pores usually showed only shallow ingrowth, but those which had permitted passage of induction contained material at least half way from the spinal cord and shallow ingrowth from the mesenchyme. With 0.8 mum filters the ingrowths from both sides met first after 18 h of transfilter cultivation. This has previously been shown to be the minimum time needed for induction to take place in this system. In electron microscopy cytoplasmic processes were seen deep inside the 0.8 and 0.22 mum filters regularly permitting induction. In small pores such material was only preserved by certain glutaraldehyde fixatives. Diffusion studies did not reveal major differences between induction-permitting 0.22 mum filters and induction-preventing 0.1 mum filters. Thus in the kidney tubule induction system this and our previous work speak in favor of a mechanism based on close apposition of cells rather than on long-range diffusion of inductive substances or on matrix interaction.


Sex chimaerism and germ cell distribution in a series of chimaeric mice. 1. Of 30 mice born from aggregation of embryos from a multiple recessive strain with F1 embryos carrying the contrasting alleles, 4 females and 20 males proved to be overtly chimaeric. 2. Three XX/XX females, five XY/XY males and eight XY/XX males were identified by chromosome analysis. Thus 50% of the population analysed were sex chimaeras, and all of these developed as phenotypic males, though one showed evidence of hermaphroditism. 3. In seven XY/XX chimaeras that bred, the genetic component undergoing spermatogenesis coincided in every case with the component identified by chromosome morphology as XY. 4. The F1 component predominated in metaphase plates derived from cultured blood cells. Comparison with direct preparations from bone marrow suggested selection in favour of F1 cells, either through differential proliferation of stem cells in vivo or differential response to phytohaemagglutinin in vitro. 5. In XY/XX males, the percentage of XX cells detected varied from 1% to 98% in blood, and from 0% to 80% in bone marrow. 6. Of eight 'single-sex' chimaeras progeny-tested (three XX/XX, five XY/XY), only one showed evidence of a mixed population of germ cells. The proportion of the two types of progeny varied significantly from litter to litter, but was unrelated to the age of the male.


Reconstitutive ability of axial tissue in early rat embryos after operations and culture in vitro. Longitudinal incisions have been made in the axis of 10-day-old rat embryos (post-neurula stage with 5-10 pairs of somites) at mid-trunk levels, dividing the axis into right and left halves. The embryos have then been cultured in vitro by New's method and their ability to reconstitute tissues in each half has been studied. After 20 h culture at 37 degrees C, there was no longer any external sign of the division of the axis. Histological studies showed that in nearly all cases, however, the neural tube was duplicated in the operated region. The two neural tubes lay in close contact in the midline, and ventral to them the gut was single. Apart from four cases in which the gut roof was slightly broadened and forked, all other tissues were normal. The reconstitutive ability of the neural and gut tissue has been compared with that of amphibian and avian embryos, as observed in 'twinning' experiments by other workers. The apparent delay in axial rotation in the operated rat embryos, as compared with controls, is attributed to the inability of the two separated halves of the somite series to co-ordinate their contractions. Further details of the rotation process in operated embryos will be the subject of a future study.


Structural basis of the functional development of the retina in the cichlid Tilapia leucosticta (teleostei). The differentiation of retinal cells has been studied with special reference to the formation of functionally important structures. Three phases could be revealed: from day 3 to day 6 retinal cells in the mostly advanced central part show signs of general cell differentiation (formation of ribosomes, endoplasmic reticulum, mitochondria). In the second phase from day 6 to day 9 characteristic nerve cell structures appear (neurites, dendrites, synapses, receptor outer and inner segments). In the last phase from day 9 to day 12 these special structures attain their final, mature appearance, synapses seem ready for function, dendritic invaginations and synaptic ribbons are formed, twin cones become arranged in mosaic patterns. This developmental order conforms to a gradient running from the ganglion cells to the receptors. Neurites and dendrites appear in the ganglion cells on day 3, in the intermediate neuron layer not before day 4. The horizontal cells are the last ones to differentiate out of the intermediate neurons. The inner plexiform layer synapses are structurally mature before those from the outer plexiform layer. The receptor inner and outer segments differentiate from the 5th day up to the time the young fish is able to see (day 13). The last structures to appear are dendritic invaginations and synaptic ribbons in the receptor terminals, and the twin cone mosaic. It is assumed that the ability to see is achieved only when these structures have been formed.


Differentiation in vitro of sympathetic cells from chick embryo sensory ganglia. This study was carried out in order to determine what factors control the differentiation of certain neural crest cells in the chick embryo. Emphasis was placed on the morphologically and biochemically divergent sensory and sympathetic pathways of differentiation. Embryos were precisely stage according to Hamburger & Hamilton (1951) and it was observed that sensory ganglia with somites, explanted at stages 21-24, gave rise to cells showing formaldehyde-induced fluorescence in more than 25% of explants. These cells were identical in properties to the fluorescent cells of the sympathetic system of embryos of similar age, and appeared by 12 days in vitro. These fluorescent cells did not appear when somites and sensory ganglia explants were maintained separately. The incidence of fluorescent cells in combined explants was considerably reduced or absent when cultures were maintained for 7 days or less, or when the explants were obtained from stage 25-26 embryos. Furthermore, when neural tube was also included in the cultures, the appearance of fluorescent cells was markedly inhibited. The requirement for somitic tissue to induce fluorescent cells in combined explants can be repalced by forelimb-bud tissue. The origin of these cells and the factors that control their differentiation in vitro are discussed with reference to the neural crest origin of the sensory ganglion, and the possible conditions pertaining in vivo in this region.


Quantitative studies of germ plasm and germ cells during early embryogenesis of Xenopus laevis. The germ plasm in the egg is paritioned between the first four blastomeres by the first two cleavage planes. Although the blastomeres divide 10-11 times through the rest of cleavage, as shown by reduction in their size, the number of presumptive primordial germ cells (p.p. germ cells) does not increase significantly. During and as a result of the formation of the first two cleavage planes, the germ plasm aggregates together and moves towards and along the cleavage furrows. At subsequent mitoses, the germ plasm is localized at one of the poles of the spindle and hence is segregated to only one of the daughter cells, thus explaining how mitosis occurs without increase in the number of cells with germ plasm. Early in gastrulation, the germ plasm moves to a perinuclear position, therefore ensuring that as mitosis continues, both daughter cells receive germ plasm and the number of p.p. germ cells increases. Direct counts of the number of p.p. germ cells and measurements of their volume suggest that they divide twice between early gastrula and the stage at which they leave the endoderm. The p.p. germ cells behave similarly to the adjacent endodermal cells until they begin to migrate to the gonad, an event which may represent the first overt signs of differentiation. Measurements of the volume of germ plasm suggest that there is no change through cleavage. The general conclusion is drawn that during cleavage, the morphogenetic determinant germ plasm is segregated to a few cells by the normal processes of cleavage and that subsequently these cells undergo a small number of cloning divisions which are contemporaneous with the first signs of differentiation.


Organogenesis in Cephalopoda: further evidence of blastodisc-bound developmental information. The basic mechanisms of organ differentiation in the Cephalopod embryo (telolecithal egg, discoidal cleavage) are studied. The results of ligation experiments, performed in early cleavage stages, confirm earlier conclusions of the author, drawn from transplantation/explantation and heat-shock experiments. The developmental information for cellular differentiation is shown to reside in the blastodisc; the yolk syncytium, in which a large part of the original egg cortex is incorporated, acts as as nutritive substrate for the cellular material involved in organogenesis. On the basis of these results, Arnold's induction model supposing an undisplaceable determining informational pattern laid down in the uncleaved egg cortex must be rejected.


Determination in regenerating tissues of Dugesia dorotocephala: the influence of nerve cord grafts. Lateral fragments which contained no nerve cord were isolated from the postpharyngeal body section of Dugesia dorotocephala and fused with nerve cord grafts soon after isolation and at daily intervals through 8 days of regeneration. Fragments fused soon after isolation formed "headless" regenerates but had normal body proportions. If the lateral cordless fragment was allowed to regenerate for 1 day or longer before fusion with the nerve cord fragment, the head always developed and the body proportions were normal. Therefore, head structures become determined in the lateral fragment within the first 24 h of regeneration; during this time these tissues can also respond to the head-inhibiting influence of the nerve cord. The competence to form particular structures of the postcerebral body regions must emerge after head-forming competence is lost, that is about 24 h after isolation; however, it persists at least through the first 8 days of regeneration. Normal body proportions can be induced by nerve cord grafts throughout the first 8 days of regeneration. Lateral fragments fused at any time after isolation with another fragment containing no nerve cord developed head structures but failed to differentiate tissues of the postcerebral regions. This confirms that the nerve cord is responsible for inhibition of head structures and induction of differentiation of body regions and normal body proportions.


The functional significance of the haemoglobin in a marine nematode, Enoplus brevis (Bastian). An animal chamber and a simple microspectrophotometer for investigating the in vivo oxygenation of the haemoglobin of E. brevis are described. The in vivo absorption peaks of this haemoglobin occur at similar wavelengths to those of other nematodes. Mean values, given with their corresponding standard errors, occur at 577.6 plus or minus 0.6 nm, 543.6 plus or minus 0.5 nm and 421.7 plus or minus 1.9 nm for oxyhaemoglobin, and 555.2 plus or minus 0.9 nm and 432.2 plus or minus 1.3 nm for the deoxygenated pigment. The percentage of oxyhaemoglobin in the pharynx of E. brevis decreased at external oxygen tensions of less than 20 Torr, and the pigment was completely deoxygenated at 5 Torr. Stimulation of individuals in aerated sea water for 1-2 min caused a partial deoxygenation of the haemoglobin; the pigment reloaded soon after this period of increased activity had ended. The functional significance of the haemoglobin of E. brevis is disucssed.


Convergence of olfactory inputs from both antennae in the brain of the honeybee. Electrical activities of the olfactory neurones in the brain of the honeybee were investigated. Odorous stimuli were given to each antenna separately or to both simultaneously. The inputs from the antennae affected both the impulse frequency and the latency of the olfactory interneurones in the protocerebrum. The predominant response was to the stimulation of the ipsilateral antenna. Input from the contralateral antenna produced mainly excitatory effects, although a few inputs gave inhibitory effects. No particular relationships between the loci of the units in the brain and the types of responses produced were found. Most of the units were located in the protocerebral lobe and in the central commissure. The units in the deutocerebrum responded only to the stimulation of the ipsilateral antenna, and the magnitude of response and the latency were not different with respect to unilateral or bilateral stimulation of the antennae. Differences in latency between unilateral and bilateral stimulation were observed in some of the units in the protocerebrum. Neural models which explain these phenomena are postulated.


Water balance across the cuticle of a soil insect. 1. The water regime in soil commonly approaches equilibrium of water potential with the insects living there. 2. Even under these conditions, non-equilibrium processes have a significant effect on water movement through the cuticle of soil insects. 3. Measurements of water potential on either side of the cuticle of Costelytra zealandica larvae showed that equilibrium is not reached while the insect is alive. There is an active outward flow of water by thermoosmosis associated with the flow of heat from the insect.


Eye movements in Daphnia pulex (De Geer). 1. The various types of eye movement exhibited by the cyclopean eye of Daphnia pulex were studied using high speed motion photography. 2. This rudimentary eye, which consists of only 22 ommatidia, can move through approximately 150 degrees in the sagittal plane and 60 degrees in the horizontal plane. 3. Four classes of eye movement were found: (1) a high speed tremor at 16 Hz with an amplitude of 3-4 degrees, which resembles physiological nystagmus, (2) a slow rhythmic scanning movement at 4 Hz, and 5-6 degrees amplitude, (3) large fast eye movements similar to saccadic eye movements and (4) optokinetic nystagmus produced by moving striped patterns. 4. Where the fast tremor occurred concurrently with the slow rhythmic scan, a Fourier analysis revealed that the former was the fourth harmonic of the latter.


Excretory role of the midgut in larvae of the tobacco hornworm, Manduca sexta (L.). Caterpillars of Manduca sexta use two distinct transport mechanisms for the excretion of dyes. One pump (Type A) has a high affinity for acid (anionic) dyes and occurs in the midgut and medial Malpighian tubules. Acid dyes accumulate rapidly in the lumen of the midgut while the Malpighian tubules appear to play only a minor role in the excretion of these dyes. The other pump (Type B) excretes basic (cationic) dyes and is located primarily in the proximal Malpighian tubules. Evidence is presented that hippuric acid competes with acid dyes for excretion by both midgut and Malpighian tubules. After the final-instar larva purges its gut the ability of the midgut and Malpighian  tubules to excrete dyes gradually decreases. Sixty hours after the purge only the Malpighian tubules retain some dye excreting activity.


Sodium and lithium movements and axonal function in cockroach nerve cords. Exposure to sodium-deficient (tris) saline caused an appreciable decline in the sodium content of intact connectives in the absence of equivalent reduction in the amplitude of the recorded action potentials. Return of sodium-depleted connectives to normal saline resulted in a rapid recovery of axonal function despite only a partial (less than 70%) recovery in sodium content. Replacement of sodium ions by those of lithium in the bathing medium resulted in a substantial accumulation of this cation. Lithium movements exhibited a marked asymetry, no significant decline in concentration being observed upon return to normal saline. These results are tentatively interpreted in terms of an exchangeable glial sodium fraction and are discussed in relation to extra-axonal sodium regulation.


Applicability of hydrodynamic analyses of spermatozoan motion. This paper investigates the applicability of a simple hydrodynamics theory due to Gray & Hancock (1955), and extended by Brokaw (1970), to the analysis of the motions of sea urchin, rabbit, and bull spermatozoa. Experimental procedures for filming and analysing the swimming motions are presented. A detailed discussion of the agreement between the experimental and theoretical results is given, and the limitations of the theory in analysing the motion of mammalian spermatozoa are discussed.


The length-tension relationship of the dorsal longitudinal muscle of a leech. The length-tension relationship of a preparation of the dorsal body wall of the leech Haemopis sanguisuga was determined. Passive tension is low except at very long lengths of the preparation, when it rises steeply. It is due mainly to the epidermis present in the preparation. The active tension curve is very flat, with tension being reduced only at very short and very long lengths. This shape is explained in the context of the myofilament arrangement of the muscle fibres. It may be that thin filaments can form cross-bridges with different thick filaments at different lengths of the preparation.


Multiple individual and cross-specific indiotypes on 13 levan-binding myeloma proteins of BALB/c mice. 13 leven-binding myeloma proteins (LBMP) of BALB/c origin were classified into two groups with different binding specificities; one group of 11 proteins bound beta2 leads to 1 fructosans, a second group of two proteins bound fructosans probably of beta2 leads to 6 linkage. Anti-idiotypic sera prepared to 10 of the proteins in the appropriate strains of mice identified numerous idiotypic determinants. Each protein used for immunization had its own unique individual idiotypic specificities (IdI) and in addition most of the proteins carried two-nine cross-specific or shared idiotypes (IdX) that were found only among LBMP, and not found in 106 non-LBMP. Most of the IdX determinants and only four of the IdI determinants of the beta2 leads to 1 fructosan binding group were located in the antigen-binding site. The multiplicity of antigenic differences in this functionally related group of immunoglobulins reveals an unexpected degree of heterogeneity in V-regions that appears to be unrelated to binding.


The permeability of glomerular capillaries of aminonuceoside nephrotic rats to graded dextrans. Graded dextrans were used as tracers to study glomerular permeability in nephrotic rats. Two narrow range fractions were used, one which was approximately the same size as albumin (62,000 mol wt) and one which was considerably larger (125,000 mol wt). Nephrosis was induced with daily injections of an aminonucleoside of puromycin, and the animals examined after 7 days, when proteinuria is minimal, or after 10 days, when proteinuria has almost reached a maximum. At both stages and with both dextran fractions the following results were obtained: (a) dextran was retained for up to 3 h (the longest interval studied) in the plasma at high concentration; (b) there was a sharp drop in the concentration of tracer between the inner, looser portions of the basement membrane (lamina rara interna) and its outer denser portions (lamina densa), (c) accumulation of dextran was seen in the mesangial areas with time; and (d) no accumulation of dextran was seen in the slits at any time. These results are the same as those reported earlier in normal animals, and they demonstrate that in nephrotics the basement membrane still behaves as the main filtration barrier retaining most of the plasma proteins. Certain differences from the findings in normals were also noted in that increased amounts of the tracer were present on the epithelial side of the basement membrane: (a) in the urinary spaces; (b) in the subepithelial portions of the basement membrane; and (c) within lysosomes (protein absorption droplets) in the epithelial cytoplasm. In addition areas of thinning of the dense portions of the basement membrane (lamina densa) were seen which were accompanied by a corresponding widening of the less dense, subendothelial and subepithelial layers (lamina rara interna and externa, respectively). The presence of increased quantities of dextran on the epithelial side of the basement membrane indicates that the filter, i.e. the basement membrane, is leaky and allows increased passage of dextrans and therefore plasma proteins.


Blocking and overshadowing in two species of fish. In Experiment 1, a mixed blocking-overshadowing effect of color on an auditory discrimination was demonstrated in goldfish. In Experiment 2 (with lines differing in color and angle), blocking of angle by color and of color by angle was demonstrated in goldfish, In Experiment 3 (again with lines differing in color and angle), overshadowing of angle by color was demonstrated in carp, but the same animals (like goldfish in a previous study) failed to show greater intradimensional than extradimensional transfer. These results are consistent with the hypothesis that blocking and overshadowing are general phenomena of vertebrate learning. They suggest also that the processes responsible for blocking and overshadowing are different from those which produce the dimensional transfer effect.


Effects of neophobia and habituation on the poison-induced avoidance of exteroceptive stimuli in the rat. Two experiments on the role of neophobia in poison-induced aversions to exteroceptive stimuli are reported. In Experiment 1, rats were given either 10 or 25 days of habituation to the test situation prior to conditioning. Those animals with the longer habituation period avoided a complex of novel exteroceptive stimuli while those with the shorter habituation period did not. In Experiment 2 rats initially avoided the more novel of two containers, but gradually came to eat equal amounts from both. A single pairing of toxicosis with consumption from either the novel or the familiar container reinstated the avoidance of the novel container in both cases. The results were discussed in terms of an interaction between habituation and conditioning procedures. It was suggested that previously reported differences between interoceptive and exteroceptive conditioning effects may have been influenced by the differential novelty of the two classes of stimuli in the test situation. It was further suggested that non-contingently poisoned control groups should routinely be included in poison avoidance conditioning studies.


Reinstatement of fear to an extinguished conditioned stimulus. Four experiments are reported which demonstrate the ability of an unconditioned stimulus (UCS) presentation following extinction to partially reinstate the conditioned response. These experiments are interpreted in terms of the strengthening of an extinction-reduced UCS representation. The first two experiments address alternative interpretations in terms of sensitization, reinstating the stimulus conditions of acquisition, conditioning of background cues, and stimulus generalization. Experiment 3 suggests that reinstatement is possible with a UCS qualitatively different from that used in conditioning. Experiment 4 explores an alternative extinction procedure which especially preserves the conditioned stimulus-unconditioned stimulus association while encouraging modification of the UCS representation. The results are discussed both in terms of related empirical phenomena, such as spontaneous recovery and sensory preconditioning, and in relation to the general role of the UCS representation in conditioning.


Disordered labor: objective evaluation and management. Simplified techniques for analyzing the graphic patterns of dilatation and descent allow the practitioner to define aberrant labor using objective criteria for diagnosis. Six major disorders of labor are readily characterized. Once diagnosed, details concerning etiologic factors, efficacy of modalities of treatment, and prognostic outlook can be readily evolved. Programs of management are presented for each group of dysfunctional patterns based on such data. Introduction of the graphic analytic technique for diagnosing and managing labor adds a significant new dimension to our diagnostic potential and therapeutic capabilities.


Protocol management of dysuria, urinary frequency, and vaginal discharge. A proctocol to be administered by nurses for the management of dysuria, frequent urination, and vaginal discharge was validated. In a randomized, controlled trial, 146 women were seen by both nurse and physician and then assigned to either the nurse-proctocol treatment plan or the physician treatment plan. The clinical data collected by the nurse showed no important differences from the physicians' data. The protocol recommended that 89 percent of the patients be sent home without seeing the physician. The physicians agreed with the protocol-recommended disposition in all but two cases. All patients with complications were appropriately referred to the physician. In follow-up, more than 95 percent of both groups reported symptomatic improvement, and repeat urine cultures were negative. We conclude that the protocol can be accurately administered, makes sound recommendations, is safe, and efficiently saves physician time.


Types of family practice teachers and residents: a comparative study. A study of personality types using the Myers-Briggs Type Indicator was performed on family practice teachers and residents. The combined group was found to be different from the general medical population. There was a larger percentage of persons who tended to be practical, realistic, present-oriented, organized, and able to deal effectively with factual information. The majority were persons who enjoy seeing immediate results of actions and can made decisions quickly and effectively using whatever information is available. These personality types are similar to those found in the older field of general practice. The residents and faculty were similar in the above respects but a higher percentage of the residents tended to make judgments using impersonal logic and a factual basis for reaching decisions. The faculty, however, had a significantly higher percentage of types who make judgments by considering human values and understanding of people.


Medical student's perspective on preceptors in family practice. Preceptorships have become an important means by which medical students are exposed to family practice. In order for a preceptor to be successful in nurturing student interest in family practice, he must have a good understanding of certain characteristics of today's medical students. Important differences exist between preclinical and clinical students, and the preceptorship must be designed accordingly. Unless preceptors are carefully selected and trained, they may have a negative influence on student interest in family practice.


A method for evaluating patient care and auditing skills of family practice residents. A system of chart review is presented which develops both auditing skills and patient care skills. The model suggested is a flexible one, applicable at various levels of training in both inpatient and outpatient settings. Its application to family practice resident training is shown by comparing the performances of residents at the beginning and end of a demonstration period.


Medical records-their medico-legal significance. This article discussed the physician's obligations in record-keeping and current judicial attitude towards the patient's medical record. Physicians are required, both medically and legally, to maintain a current, adequate record for each patient. This established the physician's continuity of care, but it also requires his vigilance and diligence through constant review and surveillance. In the past, the record was exclusively the property of the health care provider. Of late, jurisdictions are decreeing that the health care provider has an absolute right to possession and ownership of the original record only, and the right to the information in the record belongs absolutely to the patient. The physician is liable for the proper maintenance, custody, and storage of the record for the required statutory period. Although the patient can custimarily obtain his record by court order, the courts have also recognized the concept of professional discretion under which a physician may deny the patient access to his medical record if in the physician's judgment he believes it would be to the patient's detriment.


The common anemias.

The common anemias. Anemia is a common clinical problem requiring precise diagnosis of its underlying etiology in order to provide effective therapy. Most common anemias are characterized by discrete hematologic patterns. The most useful laboratory studies in most instances are red cell indices, blood film, reticulocyte count, platelet count, serum iron and total iron binding capacity. This paper presents simple guidelines for the rational use of common laboratory tests in the diagnostic assessment of anemia.


Liquid nitrogen cryotherapy in the treatment of benign skin lesions. This article summarizes the use of liquid nitrogen as a cryotherapeutic modality in the treatment of various bening skin lesions. Deep cryosurgery also has been effectively instituted for the treatment of malignant cutaneous lesions, but this article will not describe the latter in detail. Liquid nitrogen is equally as effective as other conventional modalities. Superiority of this treatment is attributed to the simplicity of its application and lack of disfigurement and scarring.


Systematic analysis of explosive residues. A scheme for systematic analysis of explosive residues is presented and demonstrated by test explosions using commercial, military, and homemade explosives.  The significance of reaction product identification is demonstrated.


The distribution of natural stable isotopes of carbon as a possible tool for the differentiation of samples of TNT. TNT samples from different countries are shown to have different 13C/12C ratios. The delta13C spread (against the PDB standard) is about 6.5%. 13C/12C ratios can therefore be utilized in order to correlate or discriminate between samples of TNT.


Differentiation of bullets by spark source mass spectrometry. A study has been made to demonstrate the capability of spark source mass spectrometry (SSMS) for differentiating bullets on the basis of elemental composition.  Twenty-six elements are commonly found in bullet lead at the 0.1-ppm level and above.  Only twelve of these prove to be generally useful for quantitative characterization.  The precision of analysis with SSMS using photographic detection is about 10% relative standard deviation.  The accuracy obtained in this study is considerably worse than this, about 30% average error.  In spite of such large errors, SSMS is shown to be far superior to the more precise method of neutron activation analysis.  The reason, of course, is the large number of elements determined by SSMS.  Bullets do not have uniform elemental compositions within a box or lot.  Instead, there are usually two or three distinct groups of bullets within a given box.  Three Winchester boxes representing lots manufactured a few weeks apart showed common groups among them.  All other  boxes had unique groups of bullets, indicating that the method is a promising alternative to the conventional method of identifying bullets by physical markings.


A new serial number marking system applicable to firearms identification. A new system for physically recording serial numbers on individual items is proposed.  Each serial number is converted to a unique array of points, and this array is recorded on the item by drilling a set of holes having the arrangement of the array into the item.  Laser drilling can be used to produce holes of small diameter for the array.  The identifying marks extend into the item and cannot be readily removed as surface stampings.  In some cases the serial number can be marked in a critical area, so that its removal would destroy the usefulness of the item.  This system is particularly suitable for the marking of firearms.


A semiautomated radioimmunoassay for mass screening of drugs of abuse. A rapid, semiautomated radioimmunoassay system for detection of morphine, barbiturates, and amphetamines is described. The assays are applicable to large drug abuse screening programs. The heart of the system is the automatic pipetting station which can accomplish 600 pipetting operations per hour. The method uses 15 to 30 mul or urine for the morphine and barbiturate assay and 100 mul for the amphetamine and combined morphine/barbiturate assays. A number of other drugs were tested for interference with the assays and the results are discussed.


Report of a fatal, acute tripelennamine intoxication. A death resulting from tripelennamine overdose in a 19-year-old male Caucasian is reported. The patient died 7 h after ingesting approximately twenty 50-mg tripelennamine tablets. A concentration of 1.0 mg/100 ml was found in the blood. All tissue concentrations were measured by ultraviolet spectroscopy and verified by gas-liquid chromatography. Significant findings included pulmonary edema and multiple small petechial hemorrhages in the soft tissue of the scalp.


Death associated with fluorocarbon inhalation: report of a case. This case documents postmortem tissue concentrations of fluorocarbons in an individual whose inhalation of cooking spray vapors was well documented.  The data presented here should contribute to the information base which will assist the pathologist in determining the cause of death in cases related to inhalation of these fluorocarbons.


Identification of street drugs by thin-layer chromatography and a single visualization reagent. TCBI has been shown to be an extremely sensitive visualizer that gives a wide variety of colors with the drugs of abuse.  The combination of TCBI as a visualization reagent and manual TLC, using flexible silica gel sheets, can provide a rapid means for the preliminary identification of street drugs.


GC-quandrupole mass fragmentography of heroin. Quantitative analysis by quadrupole mass fragmentography is a rapid and accurate method for assay.  Its advantage is fundamentally the requirement for very small sample sizes.  One must allude to the disadvantage of these techniques in the preparation of a deuterated internal standard (if not commercially available) and operator experience with sophisticated instrumentation.  By extrapolating the signal intensities to the baseline intersection (no response) assuming optimal gas chromatographic conditions, 0.5 ng of heroin injected on column appears to be the limit of detection by the above-referenced equipment.


SCUBA tank corrosion as a cause of death. Corrosion of compressed air breathing tanks may result in dangerous oxygen depletion.  In every SCUBA mishap the residual air should have, as one of the tests, a measurement of oxygen content.  The tank should also have a visual inspection.  All compressed air breathing tanks should have a routine visual inspection on a regular basis, even if the tank is made or lined with corrosion resistant material.


Action spectra and chromatic mechanisms of cells in the median ocelli of dragonflies. Spectral sensitivities were recorded intracellulary in median ocelli of Anax junius, Aeschnatuberculifera, and Libellulapulcella. All cells had peak sensitivities at 360 and 500 nm while UV-blue+green cells found only in Anax had a third peak sensitivity at 440 nm. Ratios of UV-to-green sensitivities varied from cell to cell in each ocellus, but no UV-only or green-only cells were recorded. Half of the cells tested had a reverse Purkinje shift: They were more sensitive in the green at low illuminations but more sensitive in the UV at high illuminations; their intensity-response curves at 370 and 520 nm crossed but became parallel for large responses. Wave-lengths 420 nm and shorter elicited a family of low intensity-response curves with one slope; wavelengths 440 nm and longer elicities a family of curves with another slope. Orange-adapting lights selectively adapted sensitivity in the green, but UV-adapting lights had little selective effect. Amounts of log-selective adaptation were proportional to log orange-adapting intensity. It is concluded that two spectral mechanisms can be recorded from each cell, possibly by coupling of UV and green cells or possibly because each cell contains two visual pigments. Selective chromatic adaptations may provide the ocellus with a kind of "authomatic color control," while the reverse Purkinje shift could extend the ocellus' sensitivity to prevailing skylight.