Prostaglandin synthesis in rat adrenocortical cells. The biosynthesis of prostaglandins by isolated rat adrenocortical cells has been studied by determinations of products formed during incubations with labeled arachidonic acid and by radioimmunoassays. Analysis by thin-layer chromatographic separation of silicic acid column fractions indicated that PGE2, PGA2, (B2) and PGF2 alpha were the predominant prostaglandins formed by rat adrenocortical cells. Approximately 75% of the incorporated isotope was associated with the prostaglandins of the PGE pathway [PGE2 + PGA2 (B2)]. This was a consistent finding whether cells were incubated directly with arachidonic acid or with cells prelabeled with the substrate prior to study. ACTH did not affect the uptake or oxidation of [1-14C]-arachidonate, but did significantly increase incorporation of labeled substrate into [14C]prostaglandins. Of the ACTH-induced increase, 92% was accounted for by an increase in prostaglandins of the E pathway. Studies with prelabeled cells indicated that 77% of the prostaglandins synthesized in both control and ACTH-stimulated adrenocortical cells was released into the incubation medium during the 2-hr study. These had the same composition [88% PGE2 + PGA2 (B2)] as did the intracellular prostaglandins. Analysis by radioimmunoassays gave comparable data on the distribution of E- and F-type prostaglandins in control cells and cells incubated with ACTH or dibutyryl cyclic AMP. Thus, with these techniques, 88-92% of the increased prostaglandin synthesis due to ACTH or cyclic AMP was produced by the PGE2 rather than the PGF2 alpha pathway.


The effect of glucagon, norepinephrine, and dibutyryl cyclic AMP on cholesterol efflux and on the activity of 3-hydroxy-3-methylglutaryl CoA reductase in rat hepatocytes. Incubation of rat hepatocytes for 3 hours in a sterol-free medium containing 1.5% albumin resulted in efflux of cellular sterol into the medium and an increased activity of 3-hydroxy-3-methylglutaryl CoA reductase. The secretion of cholesterol was inhibited when cells were incubated with glucagon, norepinephrine, or dibutyryl cyclic AMP. Glucagon and dibutyryl cyclic AMP also inhibited the induction of HMG-CoA reductase. Norepinephrine treatment resulted in a decrease in the synthesis and secretion of proteins but caused an increase in reductase activity. Insulin treatment had no effect either on reductase activity or on sterol efflux from rat hepatocytes.


Low density lipoprotein metabolism and lipoprotein cholesterol content in southwestern American Indians. The prevalence of ischemic heart disease is significantly lower in southwestern American Indians than in Caucasians. To investigate this difference, the metabolism of low density lipoprotein apoprotein (apo-LDL) and plasma lipoprotein cholesterol composition were studied in 10 southwestern American Indians and 5 Caucasian controls. The plasma concentration of LDL cholesterol in American Indians was 88 +/- 5 mg/dl (mean +/- SEM) and 111 +/- 7 mg/dl in Caucasians. The corresponding values of apo-LDL concentrations were 53 +/- 3 mg/dl and 77 +/- 4 mg/dl, respectively. Conversely, high density lipoprotein cholesterol (HDL) concentrations were significantly higher in American Indians (56 +/- 4 mg/dl) than in Caucasians (37 +/- 3 mg/dl). There were no statistically significant differences in the biological half-life of apo-LDL, calculated from the second exponential of the plasma die-away curve (3.06 +/- 0.15 days vs. 3.45 +/- 0.11 days), the fractional catabolic rate of apo-LDL (0.432 +/- 0.01 vs. 0.411 +/- 0.01), or the fraction of total exchangeable apo-LDL in the intravascular space (70 +/- 1 vs. 67 +/- 3%). As derived from the absolute catabolic rate under steady-state conditions, the synthetic rate of apo-LDL in American Indians was, however, significantly lower than in Caucasians (334.6 +/- 7.8 mg/m(2) per day vs. 507.2 +/- 6.7 mg/m(2) per day; P < 0.001). These data indicate that the lower levels of plasma LDL cholesterol and apo-LDL in American Indians are due to a reduced rate of apo-LDL synthesis rather than to differences in fractional catabolic rates. These differences, in combination with higher HDL cholesterol levels, may contribute to the lower prevalence of ischemic heart disease in American Indians.


Study of the atherogenic dyslipoproteinemia induced by dietary cholesterol in rhesus monekys (Macaca mulatta). Hypercholesterolemia was induced in adult male rhesus monkeys with a high-fat diet containing an elevated cholesterol level (0.5%). Plasma lipoproteins were chromatographically separated into four size populations (regions) that were subdivided by density until fractions with single electrophoretic mobilities were obtained. The region III lipoproteins (LDL) contained 80% of plasma cholesterol and were present in the highest concentration of all fractions. Their molecular weight was increased over that of controls so that each particle averaged 1.8 times the number of cholesteryl ester molecules as did control LDL. Region II lipoproteins, a heterogeneous group, were present in next highest concentration. Most were cholesteryl ester-rich, beta-migrating lipoproteins that overlapped the VLDL and LDL density ranges; apoB was the predominant apoprotein. One region II subfraction had pre beta 2 migration and the density range. 1.050 less than d less than 1.10. Another subfraction, cholesteryl ester-rich VLDL including only about 1% of plasma cholesterol, had pre beta 1 migration and apoB and apoC as the predominant apoproteins with no apoprotein E. Region I lipoproteins were larger sized, slow beta-migrating cholesteryl ester-rich VLDL that included 5% of plasma cholesterol. ApoB and apoE were the predominant apoproteins. Region IV lipoproteins (HDL) contained 4% of the plasma cholesterol; their concentration was decreased to about 1/3 of the control level. Atherogenic features of the diet-induced dyslipoproteinemia included the increased plasma concentrations and cholesteryl ester contents of the region I, II, and III lipoproteins in addition to the decreased HDL concentration.


The cholesterol turnover, synthesis, and absorption in two sisters with familial hypercholesterolemia (type IIa). To explore the mechanisms of the profound plasma cholesterol elevations in familial homozygous hypercholesterolemia (type IIa), cholesterol turnover, sterol balance, cholesterol absorption, and low density lipoprotein studies were carried out under controlled dietary conditions in two sisters (aged 13 and 16). Cholesterol turnover was prolonged. The half-life of the first exponential of the plasma cholesterol specific activity decay curve was double that of normal adults. The rate constants for the removal of cholesterol from pool A (KAA = 0.0652) and for the excretion of cholesterol from the system (Kaa = 0.0197) were less than half of normal. The production rates of cholesterol were low, only 6.30 and 6.86 mg/kg per day as measured by cholesterol turnover and sterol balance techniques, respectively. Fecal neutral steroid and bile acid excretion were 5.22 and 1.64 mg/kg per day, which is remarkably low in comparison to those of normal and heterozygous children. Cholesterol absorption was within the upper limit of the values reported for normal adults. THE HDL cholesterol values were extremely low (27 mg/dl) in contrast to profoundly elevated LDL levels. The fractional catabolic rate of LDL (0.127 per day) and the rate of synthesis and catabolism of apo-LDL (15 mg/kg per day) were low in comparison to previously reported values in homozygotes. These composite data indicated that the definable metabolic defects of these two sisters with homozygous familial hypercholesterolemia were the sluggish clearance of cholesterol from the body coupled with low total body synthesis of cholesterol.


Quantitation of different cells in the epididymal fat pad of the rat. To determine the number of adipocytes and cells developing into adipocytes (preadipocytes) in the epididymal fat pad of normal Sprague-Dawley rats, two methods were developed. Liberation of all cells from the tissue was obtained by a combination of lytic enzymes and mechanical treatment with only a limited loss of cell integrity; with large tissue masses, an initial perfusion was necessary. These cells were cultured in medium 199 supplemented with serum, glucose, insulin, a triglyceride emulsion, and methyl cellulose to form a culture medium with high viscosity in which it has been shown that the cells do no multiply. In this medium some of the cells developed into adipocytes and could be recognized and counted. The results show that there are about twice as many preadipocytes as mature adipocytes in the smallest rats examined (about 50 g). With increasing weight and age the mature adipocytes increased while the number of preadipocytes seemed to be constant up to a weight of about 150 g, after which they continuously diminished and could not be found in rats weighing more than 300 g. Here the number of mature fat cells had reached a constant level. These results are consistent with the formation of new preadipocytes up to a rat weight of about 150 g. In normal rats these cells successively fill up with triglyceride and disappear at a body weight of about 300 g when they have been transformed into mature adipocytes. The results are also consistent with the concept that no new adipocytes are formed spontaneously in the adult Sprague-Dawley rat. It was shown, however, that in media without methyl cellulose, isobutylmethylxanthine probably could induce the formation of new adipocytes in the cells isolated from all rats, including the heaviest (oldest). This finding shows that the potential of cells to develop into adipocytes also seems to exist in the adult rat under certain circumstances.


Essential fatty acid deficiency and adrenal cortical function in vitro. Adrenocortical cells were prepared from rats maintained on essential fatty acid-deficient diets and control litter mates. Cells from control rats had high concentrations of essential fatty acids in the cholesteryl ester fraction of which approximately 22% was arachidonate. In contrast, cells from EFA-deficient rats had only 2.5% arachidonate in the cholesteryl esters, even though the total esterified cholesterol level was comparable to that of controls. In place of the essential fatty acids, the cholesteryl esters of these cells were rich in 20:3(n--9) and 22:3(n--9). When cells from EFA-deficient rats were incubated with ACTH or dibutyryl cyclic AMP, the output of corticosterone was the same as in controls. Also sterol esters were hydrolyzed to the same extent as in controls despite the unusual composition of the fatty acid esters. The phospholipids in both control and EFA-deficient cells contained high levels of arachidonate but were not hydrolyzed in either type of cell during incubation with ACTH or dibutyryl cyclic AMP. The results indicate that high levels of the prostaglandin precursors, namely linoleate and arachidonate, are not a sine qua non for the steroidogenic action of ACTH or cyclic AMP.


Distribution of cholesterol and apolipoprotein A-I and A-II in human high density lipoprotein subfractions separated by CsCl equilibrium gradient centrifugation: evidence for HDL subpopulations with differing A-I/A-II molar ratios. The purpose of this experiment was to characterize the high density lipoproteins (HDL) as a function of hydrated density. HDL was subfractionated on the basis of hydrated density by CsCl density gradient centrifugation of whole serum or the d 1.063-1.25 g/ml HDL fraction isolated from three men and three women. Apolipoprotein A-I and A-II quantitation by radial immunodiffusion showed that the A-I/A-II ratio varied with the lipoprotein hydrated density. The A-I/A-II molar ratio of HDL lipoproteins banding between d 1.106 and 1.150 g/ml was nearly constant at 2.2 +/- 0.2. In the density range 1.151-1.25 g/ml the A-I/A-II ratio increased as the density increased. On the other hand, in the density range between 1.077 and 1.105 the A-I/A-II ratio increased as the density decreased, ranging from 2.8 +/- 0.5 for the d 1.093-1.105 g/ml fraction to 5.6 +/- 1.3 for the d 1.077-1.082 g/ml fraction. The d 1.063-1.076 g/ml fraction and the d 1.077-1.082 g/ml fractions had comparable A-I/A-II ratios. Serum and the d 1.063-1.25 g/ml HDL fraction exhibited similar trends. The cholesterol/(A-I + A-II) ratio decreased as the density increased in all 12 samples (six serum and six HDL) examined. Gradient gel electrophoresis of the density gradient fractions showed that as the density increased from 1.063 to 1.200 g/ml the apparent molecular weight decreased from 3.9 x 10(5) to 1.1 x 10(5). HDL subfractions with the same hydrated densities had comparable molecular weights and A-I/A-II and cholesterol/(A-I + A-II) ratios when isolated from men or women. HDL contains subpopulations that differ in the A-I/A-II molar ratio.-Cheung, M. C., and J. J. Albers. Distribution of cholesterol and apolipoprotein A-I and A-II in human high density lipoprotein subfractions separated by CsCl equilibrium gradient centrifugation: evidence for HDL subpopulations with differing A-I/A-II molar ratios.


Changes in plasma very low density and low density lipoprotein content, composition, and size after a fatty meal in normo- and hypertriglyceridemic man. Four subfractions of plasma VLDL characterized by decreasing Sf value and LDL were isolated by density gradient preparative ultracentrifugation from normotriglyceridemic (NTG) and hypertriglyceridemic (HTG) (type IV) subjects in the fasting state and after a fatty meal. Chemical analysis and computation of numbers of particles in each fraction showed that the hyperlipidemia of type IV subjects was accounted for by an increase in total numbers of VLDL and a shift in the distribution of VLDL towards particles of larger diameter. Postprandial hyperlipidemia was due to the presence of chylomicron remnants rather than intact chylomicrons, and was accounted for by an increase in particle diameter of the largest VLDL subfraction rather than by an increase in particle numbers. Postprandial hyperlipedemia was accompanied by a shift in the distribution of VLDL towards particles of larger diameter in both NTG and HTG subjects, probably because of competition for the triglyceride-depletion process between chylomicrons and hepatic VLDL. Most chylomicron remnants were removed from the circulation without degradation to smaller VLDL or to LDL, but some remnants were sufficienty small to contribute to smaller VLDL subfractions. The LDL of type IV subjects contained more apoprotein B than those from NTG subjects, and this difference was associated with increases in diameter, molecular weight, density, and the ratio of protein: phospholipid in LDL from type IV subjects. Defective degradation of large VLDL to small VLDL, and of VLDL to LDL may be related to this alteration in apoprotein B content of the lipoproteins in type IV subjects.


Ontogeny of glycerolipid biosynthetic enzymes in swine liver and adipose tissue. Enzymes associated with glycerolipid biosynthesis were examined in microsomal fractions of liver and adipose tissue obtained from swine of various ages. Generally, liver glycerophosphate acyltransferase, phosphatidate phosphohydrolase, diglyceride acyltransferase, and choline phosphotransferase activities were substantial at birth but increased 2- to 3-fold by day 14 postpartum, decreased at day 25, then increased at the oldest ages studied (up to 155 days postpartum). In adipose tissue, enzyme activities were low at birth and developed through day 25 in a pattern generally similar to that observed in liver. In contrast to liver, the adipose enzymes were depressed immediately postweaning (day 32) with subsequent recovery. The observed decline in adipose tissue enzyme activities expressed on a tissue basis at older ages was primarily the result of increased adipocyte size, since the activities expressed on a cell basis did not decline as rapidly. In both liver and adipose tissue, phosphatidate was the major glycerolipid synthesized by the microsomal glycerophosphate acyltransferase enzymes at all ages (generally greater than 75%). The ratio of neutral lipids to phospholipids produced by acylation of glycerophosphate was increased when a microsomal--cytosolic preparation was used as a source of enzyme in contrast to a microsomal preparation.


Changes in the concentration of plasma lipoproteins and apoproteins following the administration of Triton WR 1339 to rats. Changes in whole plasma and lipoprotien apoprotein concentrations were determined after a single injection of Triton WR 1339 into rats. Concentrations of apoproteins A-I (an activator of lecithin:cholesterol acyl transferase), arginine-rich apoprotein (ARP), and B apoprotein were measured by electroimmunoassay. The content of C-II apoprotein (an activaor of lipoprotein lipase) was estimated by the ability of plasma and lipoprotein fractions to promote hydrolysis of triglyceride in the presence of cow's milk lipase and also by isoelectric focusing on polyacrylamide gels. Apoproteins C-II and A-I were rapidly removed from high density lipoprotein (HDL) after Triton treatment and were recovered in the d 1.21 g/ml infranate fraction. A-I was then totally cleared from the plasma within 10--20 hr after injection. Arginine-rich apoprotein was removed from HDL and also partially cleared from the plasma. The rise in very low density lipoprotein (vldl) apoprotein that followed the removal of apoproteins from HDL was mostly antributed to the B apoprotein, although corresponding smaller increases were observed in VLDL ARP and C apoproteins. The triglyceride:cholesterol, triglyceride:protein, and B:C apoprotein ratios of VLDL more closely resembled nascent rather than plasma VLDL 10 hr after Triton injection. These studies suggest that the detergent may achieve its hyperlipidemic effct by disrupting HDL and thus removing the A-I and C-II proteins from a normal activating environment compirsing VLDL, HDL, and the enzymes. The possible involvement of intact HDL in VLDL catabolism is discussed in relation to other recent reports which also suggest that abnormalities of the VLDL-LDL system may be due to the absence of normal HDL.


Characterization of the specific binding of prolactin to binding sites in the seminal vesicle of the rat. The binding of ovine prolactin to the seminal vesicles of the rat has been characterized and found to be a saturable process, dependent upon time, temperature, protein concentration of the seminal vesicle and divalent ions. Its specificity was similar to that reported for prolactin binding to other organ preparations. Time and temperature studies of the specific binding revealed that equilibrium was reached after 16 h at 5 degrees C or 4 h at 19 degrees C. Nonspecific binding was also dependent on time and temperature. This parameter has been reported to comprise up to 70% of the total binding to various organ-binding sites, but it fell to below 20% after 48 h at 19 degrees C, thus demonstrating the high degree of specificity required of target organ receptors. From degradation studies it was evident that no damage occurred to the free hormone during incubation for up to 70 h at 5 degrees C or 16 h at 19 degrees C. However, there seems to be a difference in the susceptibility of bound and free ovine prolactin to damage during incubation: after 40 h at 19 degrees C the hormone in the supernatant fraction had lost 85% of its binding ability, whereas a high level of specific binding was evident in the pellet. A Scatchard plot of competitive binding studies revealed two classes of binding sites, of which the high-affinity, low-capacity site was similar to that reported previously and consistent with a physiological receptor for prolactin in the seminal vesicle of the rat.


Acetylcholine stimulates growth hormone secretion, phosphatidyl inositol labelling, 45Ca2+ efflux and cyclic GMP accumulation in bovine anterior pituitary glands. Acetylcholine (25 micromol/l) in the presence of the choline esterase inhibitor physostigmine (67 micromol/l) increased the release of growth hormone and efflux of 45Ca2+ from perifused bovine pituitary slices; the time taken for the maximal response to occur was the same. In batch incubations, acetylcholine (1 micromol/l--1 mmol/l) increased pituitary cyclic GMP concentrations in the pituitary gland within 2 min, and increased incorporation of [3H]inositol and [32P]phosphate into pituitary phosphatidyl inositol within 15 min. Cyclic AMP concentrations were not significantly changed 2 or 5 min after acetylcholine addition. All the tissue responses were inhibited by prior exposure of the tissue to atropine (1 micromol/l) but not by tubocurarine (10 micromol/l--1mmol/l), indicating that the responses were mediated by receptors of the muscarinic type. The similarities between these responses and those to known hypothalamic hypophysiotrophic hormones are discussed.


Evidence that both long-acting thyroid stimulator and long-acting thyroid stimulator-protector stimulate the human thyroid gland. Thyroid-stimulating immunoglobulins were prepared from two potent sera, one contained long-acting thyroid stimulator (LATS) and the other contained both LATS and LATS-protector (LATS-P). The potencies of the immunoglobulin G (IgG) preparations were estimated in the McKenzie assay. The accumulation of cyclic AMP in mouse thyroid lobes was stimulated only by LATS--IgG; LATS-P--IgG was inactive. In contrast, both LATS-IgG and LATS-P--IgG were equally effective in slices of human thyroid.


Ontogeny and control of prolactin receptors in the mammary gland and liver of virgin, pregnant and lactating rats. Prolactin receptors were identified and partially characterized in the mammary gland of the rat. The binding of 125I-labelled ovine prolactin to a subcellular particulate fraction of rat mammary gland decreased between days 30 and 100 of age. Over the same period, binding to the liver increased and there was a significant negative correlation between prolactin binding in the two tissues. Binding to the mammary gland was low during pregnancy, increased in early lactation and declined after the litters were weaned. Binding to the liver was lower during lactation than during pregnancy or the period after weaning suggesting that tissue-specific factors may operate in the control of this receptor. In virgin rats, prolactin binding by the mammary gland was increased by oestrogen. This effect was blocked by hypophysectomy and partially restored by replacement therapy with prolactin. Hypothyroidism and treatment with progesterone also reduced the response to oestrogen. The maintenance of prolactin binding by the mammary gland of lactating rats depends on the presence of the ovaries and pituitary, thyroid and adrenal glands. Examination of the ratio epithelium: stroma suggests that prolactin acts by increasing the number of epithelial cells in the mammary gland and that thyroid, adrenal and ovarian hormones modulate the number of receptors per cell.


Suppression of serum levels of luteinizing hormone by short- and long-loop negative feedback in ovariectomized women. The suppressive effects of short- and long-loop negative feedback on serum levels of LH were assessed after administration of human chorionic gonadotrophin (HCG) and conjugated oestrogens. Fourteen ovariectomized women were injected intravenously with 5 mg conjugated oestrogens, eight of these patients were also given an intramuscular injection of 10,000 i.u. HCG 8 h later, while the other six patients were given a control injection of 0.9% saline. The serum levels of LH decreased by similar amounts in both groups of women. Thirteen other ovariectomized women were initially injected with 10,000 i.u. HCG, i.m., seven of these patients were also given an i.v. ijection of 5 mg conjugated oestrogens 8 h later, while the remaining six patients received a control injection of 0.9% saline. The results showed that conjugated estrogens could further supress the serum level of LH which had been reduced by prior HCG treatment. In six ovariectomized women who received i.m. saline injections at the start of the experiment and 8 h later, the serum levels of LH did not change significantly. It is concluded that the suppression of the serum concentrations of LH by long-loop negative feedback after administration of 5 mg conjugated oestrogens is greater than that by short-loop negative feedback after treatment with 10,000 i.u. HCG.


A rapid and specific method for separation of bound and free antigen in radioimmunoassay systems. This communication reports a method for increasing the speed of separation of bound and free antigen in radioimmunoassay systems with no loss in the specificity of binding. The technique uses a mixture of second antibody and polyethylene glycol. It is not species or antibody specific, and systems using specific first antibodies from rabbit, goat or sheep are all functional. Results for the assay of parathyrin, calcitonin and corticotropin are described here, although the system has been shown to work for triiodothyronine, thyroxin, thyrotropin, thyroxine binding globulin and transferrin. The time taken for the reaction between first and second antibody is in the order of seconds, and the stability of the complex is unchanged over a period of hours.


4-Aminopyridine and the early outward current of sheep cardiac Purkinje fibers. We have studied the effects of the potassium-blocking agent 4-aminopyridine (4-AP) on the action potential and membrane currents of the sheep cardiac Purkinje fiber. 4-AP slowed the rate of phase 1 repolarization and shifted the plateau of the action potential to less negative potentials. In the presence of 4-AP, the substitution of sodium methylsulfate or methanesulfonate for the NaCl of Tyrode's solution further slowed the rate of phase 1 repolarization, even though chloride replacement has no effect on the untreated preparation. In voltage clamp experiments, 4-AP rapidly and reversibly reduced the early peak of outward current that is seen when the Purkinje fiber membrane is voltage-clamped to potentials positive to -20 mV. In addition, 4-AP reduced the steady outward current seen at the end of clamp steps positive to -40 mV. 4-AP did not appear to change the slow inward current observed over the range of -60 to -40 mV, nor did it greatly change the current tails that have been used as a measure of the slow inward conductance at more positive potentials. 4-AP did not block the inward rectifying potassium currents, IK1 and IK2. A phasic outward current component that was insensitive to 4-AP was reduced by chloride replacement. We conclude that the early outward current has two components: a chloride-sensitive component plus a 4-AP-sensitive component. Since a portion of the steady-state current was sensitive to 4-AP, the early outward current either does not fully inactivate or  4-AP blocks a component of time-independent background current.


Thyroid thermogenesis in adult rat hepatocytes in primary monolayer culture: direct action of thyroid hormone in vitro. We have studied the effect of 3,5,3'-triiodothyronine (T3) on the respiration of adult rat hepatocytes in primary monolayer culture prepared from hypothyroid rat liver. After addition of T3 to the culture medium at a concentration of 2 x 10(-7) M, oxygen consumption of the cultured cells increased detectably at 24 h and was maximal at 72--96 h, relative to control cultures (38.0 +/- 1.8 vs. 25.0 +/- 1.5 microliter/h.mg protein). The thyroid-responsive enzymes, Na+ + K+-activated adenosine triphosphatase (NaK-ATPase) and alpha-glycerophosphate dehydrogenase (GPD), each exhibited increased activity in response to T3, in parallel with the change in oxygen consumption, whereas the activity of Mg-dependent ATPase was unaffected. These responses to T3 were dose dependent over similar concentration ranges, the half-maximal response for each occurring at ca 8 x 10(-10) M. In thyroid-treated cells, the observed increase in respiration was almost completely (90%) inhibited after addition of ouabain (10(-3) M) to the culture medium. It was found also that a 4-h exposure of the cultured hepatocytes to T3 was sufficient to elicit a significant thermogenic response, measured at a time (48 h later) when T3 was no longer present in the medium. The response to T3 occurred in fully defined culture medium and was independent of the presence or absence of hypothyroid rat serum, corticosterone, or insulin, and cellular ATP was unaffected by T3 in concentrations up to 2 x 10(-7) M. The findings document that adult rat hepatocytes in primary monolayer culture respond directly to thyroid hormone; the increases in respiration and NaK-ATPase activity elicited by T3 were cotemporal and apparently coordinate.


Phagolysosome formation, cyclic adenosine 3':5'-monophosphate and the fate of Salmonella typhimurium within mouse peritoneal macrophages. Salmonella typhimurium did not inhibit fusion of lysosomes with the phagocytic vacuoles in infected macrophages and caused no increase in cyclic adenosine 3':5'-monophosphate. Glutaraldehyde-killed bacteria showed rapid ultrastructural degeneration within the phagolysosomes. In contrast, untreated bacteria were resistant to digestion by lysosomal enzymes. Intracellular survival of this species appears to depend on resistance to, and not evasion of, lysosomal enzymes.


Phagosome-lysosome fusion and cyclic adenosine 3':5'-monophosphate in macrophages infected with Mycobacterium microti, Mycobacterium bovis BCG or Mycobacterium lepraemurium. When ingested by mouse peritoneal macrophage monolayers, live Mycobacterium microti caused a sustained increase in monolayer cyclic AMP content and fusion of lysosomes with the bacterium-containing phagosomes was impaired. Ingested live M. bovis BCG caused a transient increase in cyclic AMP and the defect in phagolysosome formation was less pronounced. Dead mycobacteria and live M. lepraemurium neither enhanced monolayer cyclic AMP content nor inhibited phagolysosome formation. Mycobacterium microti and BCG exceeded M. lepraemurium in cyclic AMP-synthesizing activity in vitro but the question of whether bacterial cyclic AMP contributed substantially to the increments in infected macrophages was not resolved. Antibody-coated BCG retained the ability to synthesize cyclic AMP and to enhance monolayer cyclic AMP but lost the ability to inhibit phagolysosome formation in macrophages, The observations are discussed in terms of possible control of phagolysosome formation by cyclic nucleotides.


Anatomical relationships between the ventral mesencephalic tegmentum--a 10 region and the locus coeruleus as demonstrated by anterograde and retrograde tracing techniques. We have searched for anatomical connections between the ventral mesencephalic tegmentum (VMT), including the dopaminergic cell group A10 and the locus coeruleus (LC) region. Tritiated leucine (120--220 nl) and horseradish peroxidase delivered by electrophoresis were injected in the VMT-A10 region. We have demonstrated, on the one hand bilateral projections from the VMT-A10 region to LC, and on the other hand a possible contralateral projection from LC to VMT-A10 region. These relationships, reported for the first time may have some important functional significance.


Contribution of the locus coeruleus to the adrenergic innervation of the rat spinal cord: a biochemical study. The possible existence and magnitude of a noradrenergic innervation from the locus coeruleus (LC) to the spinal cord was investigated in the rat with various techniques. Horseradish peroxidase, injected into the lumbar spinal cord produced heavy labelling of presumably noradrenaline (NA)-containing neurons in the ventral region of the LC, while cells in the dorsal region of the LC were only lightly labelled. The effects of electrothermic destruction and electrical stimulation of the LC on levels of NA in various parts of the spinal cord, the cerebral cortex and the hippocampus were studied. Fourteen days after unilateral destruction of the LC there were decreases in NA levels of about 85% in the cerebral cortex and hippocampus and of about 15% in the cervical and thoracic segments of the spinal cord (ipsilateral versus contralateral). Fourteen days after bilateral lesioning of the LC significant decreases (about 25%) in NA levels were observed in all spinal cord segments. Unilateral stimulation in or near the LC induced decreases of NA levels in all areas of the central nervous system investigated. In this experiment the levels of NA in the spinal cord were significantly lowered in the ipsilateral cervical (16%), thoracic (12%) and lumbar/sacral (15%) segments of the spinal cord. These findings together indicate that a small part (no more than 30%) of the NA levels in the rat spinal cord are dependent upon the integrity and activity of NA-containing neurons of the predominantly ipsilaterally localized LC.


Neuropathy, amyloidosis, and monoclonal gammopathy. Three cases of neuropathy with monoclonal gammopathy and amyloid deposits in peripheral nerves are described. They appeared to present a benign gammopathy because of the duration of the neuropathy in the absence of any clinical or biological sign of myeloma or macroglobulinaemia. The pathological abnormality found in the sural nerves of the three patients was characterised by a marked loss of myelinated and unmyelinated nerve fibres because of active axonal degeneration with Wallerian degeneration. The most striking feature in all three cases was the finding of deposits identified as an accumulation of microfibrils.


Effect of temperature on neuromuscular transmission in the Eaton-Lambert syndrome. A patient with the Eaton-Lambert syndrome is described in whom no associated condition was discovered. There was clinical and electrical evidence that the defect in neuromuscular transmission became more severe as local temperature was raised.


Multiple sclerosis-associated agent. Failure of MS brain and serum to depress the polymorph count in normal mice and mice inoculated with cells containing C/type particles. The groups that originally reported and confirmed the demonstration of a multiple sclerosis associated agent (MSAA) are now, along with others, unable to reproduce this effect. In view of this confusion and the potential importance of this work for multiple sclerosis (MS) we have done a strict double-blind trial using larger groups of mice (10) and counting more cells (900) than in previous reports to offset the high variability of mouse polymorphonuclear neutrophil (PMN) counts. Sera from 5 active MS patients and 4 normal subjects were tested in mice, half of which had previously been injected with PAM line cells (containing C-type particles and subject to reduced cell yield when cultured with MS brain extract). No significant PMN depression was found in either MS or normals on any basis of comparison. However, a significant depression was seen following PAM cell injection irrespective of serum origin. Higher counting accuracy did not reduce PMN variability. A single MS brain specimen was also without effect. consequently we have been unable to confirm the existence of an MSAA as defined by PMN depression in mice.


Analysis of the major lipid classes in human peripheral nerve biopsies. Age group differences and abnormalities of ganglioside level in perhexiline maleate therapy. We report here the results of a simple and reproducible technique which can be used in semi-routine analysis of peripheral nerve biopsy specimens, so as to have a quantitative analysis of the major lipid classes, i.e. cholesterol, cerebrosides, ethanolamine phospholipids, phosphatidyl-choline, phosphatidyl-serine + phosphatidylinositol, sphingomyelin and gangliosides. Glycolipid hexoses, cholesterol and total phospholipids have been compared in different age groups. Although all lipid classes increased from the younger to the older age group, the molar ratio of cholesterol to phospholipid differed less than the glycolipid to phospholipid ratio. Both increased significantly, even between age group 10--16 and older patients (36, 54, 61, 68, 72 and 73 years old). Although individual variations in lipid content are noteworthy, it must be emphasized that evolution with age of the lipid composition must be taken into account. Furthermore, this study confirms and extends earlier findings of increased ganglioside levels in some cases of peripheral neuropathies observed during perhexiline maleate therapy where characteristic lipid-like polymorphous inclusions have been demonstrated.


Short-term effects of prednisolone on neuromuscular transmission in normal rats and those with experimental autoimmune myasthenia gravis. Electrophysiological investigations of the effects of bath-applied prednisolone at the neuromuscular junction were performed in muscles from normal rats and rats with experimental autoimmune myasthenia gravis (EAMG). In muscles from both groups, prednisolone reversible and significantly depressed the amplitudes of minature end-plate potentials (MEPPs), end-plate potentials (EPPs) and indirectly elicited action potentials (APs) without affecting resting membrane potentials. Prednisolone also caused a significant reduction in EPP rise time to peak and half-decay time while markedly increasing MEPP frequency and AP rise time to peak and duration. These effects were shown to be dose-dependent. The percentage decrease in amplitude after prednisolone perfusion was similar for EPPs and MEPPs, indicating that the depressive effect of prednisolone at the junction is postsynaptic. In all of the parameters studied, the percentage effect of prednisolone was the same in EAMG and normal preparations. No stimulus-linked repetitive EPPs or APs were observed after prednisolone. It is concluded that prednisolone has a depressive effect on neuromuscular transmission, but that this occurs only at high concentrations of the drug which are not achieved during the treatment of myasthenia gravis.


Monovalent cation transport in myotonic dystrophy. Na-K pump ratio in erythrocytes. Myotonic dystrophy is a dominantly-inherited disorder which affects skeletal muscle in combination with several other systems. Because of abnormalities in red blood cells, a universal membrane defect has been proposed as the primary disturbance. Erythrocyte cation pump ratios have also been reported to be abnormal. Hyperinsulinemia and glucose intolerance are present in a large number of patients. Since dramatic effects of insulin on membrane cation transport have been shown in several tissues, notably skeletal muscle, we wished first to confirm reports of altered pump ratio in these patients and then to evaluate the effects of insulin on cation fluxes. However, in our experiments myotonic dystrophy patients had normal pump ratios when compared with disease controls.


Transketolase inhibition and uremic peripheral sensory neuropathy. The relationships between predialysis and postdialysis erythrocyte transketolase activities and symptoms of uremic peripheral neuropathy were studied prospectively for 21 months in 19 chronic hemodialysis patients. In all patients the predialysis activity was observed to be sometimes greater and sometimes less than the postdialysis activity. These observations were interpreted as indicating the coexistence in uremic blood of stimulatory and inhibitory substances which influence the enzyme independently. After enzyme stimulation was assumed to be a constant feature of uremia, the expected stimulated activity in erythrocytes of predialysis blood was found to be variably inhibited up to about 55% in these patients. The occurrence of paresthesiae was closely correlated with prolonged erythrocytes transketolase inhibition which in most cases reached a level of about 40%. Our conclusion is that the magnitude of erythroycte transketolase inhibition above a certain minimum level, together with its duration, is associated with symptoms of sensory peripheral neuropathy in the uremic patient. It is therefore predicted that such measurements may be usefully applied in ascertaining the extent of hemodialysis needed to prevent the development of this pathological state.


Pathogenesis of visna. IV. Spinal fluid studies. Visna is a persistent retrovirus infection of sheep which produces a chronic progressive paralytic disease after an incubation period lasting from months to years. The cerebrospinal fluid (CSF) was repeatedly sampled in a group of Icelandic sheep which were infected intracerebrally and followed up to 42 months. Minimal levels of infectious virus were isolated from the cerebrospinal fluid (CSF) up to 4 months after infection after which CSF neutralizing antibodies appeared in many sheep. These antibodies varied in titer and in some animals exceeded serum antibody levels which were moderate to high. CSF antibody is apparently produced within the CNS by local proliferation of B cell clones, and is accompanied by the appearance of considerable numbers of plasma cells in the neural parenchyma. Some sheep raised serum antibody to a second serotype of visna virus and in a number of these animals heterotypic antibody was also found in the CSF. An increase in CSF leukocytes often occurs within 1 to 3 months following infection and may then persist or wane. A persistent high level of CSF cells is an indicator of progressive CNS disease and such animals are more likely to yield virus, have higher CSF antibody levels, more severe CNS lesions, and an enhanced risk of clinical illness (progressive paralysis). CSF cells are predominantly macrophages and lymphocytes, with a consistent minority of plasma cells.


Derangement of neuronal migration in a child with multiple congenital anomalies, two congenital neoplasms, without apparent chromosomal abnormalities. A live-born male infant with multiple severe abnormalities, two congenital neoplasms, a neuroblastoma and nephroblastoma, and without apparent chromosomal abnormalities, is described. The neuropathologic findings were a holoprosencephalic type defect with disturbance of neuronal migration to the cortical plate. Comparison of the overall findings with cases presenting similar multiple congenital abnormalities indicates that this case either demonstrates previously unrecognized features of these syndromes, or is unique.


Effects of vitamin E deficiency on the activities of lipid-requiring enzymes in rabbit liver and muscle. The effects of vitamin E deficiency on membrane integrity were studied by examining the temperature dependence of membrane-bound enzyme activities in liver mitochondria and microsome and in muscle sarcoplasmic reticulum. In vitamin E-deficient rabbits, the specific activities at 37 degrees of mitochondrial oligomycin-sensitive ATPase (EC 3.6.1.3), beta-hydroxybutyrate dehydrogenase (EC 1.1.1.30), and microsomal glucose-6-phosphatase (EC 3.1.3.9) were increased, whereas those of microsomal NADH cytochrome C reductase (EC 1.6.99.3) and sarcoplasmic reticulum Ca-ATPase were reduced in comparison to control rabbits. Arrhenius plots of activity against temperature yielded a linear plot over the range 10 to 40 degrees in the case of beta-hydroxybutyrate dehydrogenase, NADH cytochrome C reductase and Ca-ATPase, and multiple discontinuities for glucose-6-phosphatase and oligomycin-sensitive ATPase. In control rabbits, all five enzymes showed a single discontinuity in the Arrhenius plot over the range 16 to 19 degrees. These results reflect changes in the microenvironment of membrane-bound enzymes as a consequence of vitamin E depletion.


A classification of dysplastic forms of dentin. Considerable effort has been made in the past to describe the morphologic changes in dentin which characterize various developmental disturbances of teeth. However, there appears to be no previous attempt to describe the spectrum of changes which may be exhibited by abnormal dentin. This paper presents a classification of dysplastic forms of dentin with definitions and illustrations of each abnormality. The classification was derived from reviewing the literature and from a study of 82 odontomas, examples of specific developmental disorders of dentin, regional odontodysplasia, and systemic conditions affecting dentin.


Granular cell tumors of the head and neck. Forth-two granular cell tumors of the head and neck were collected and studied with light and electron microscopy. Granular cells were found in four odontogenic tumors, two congenital epulides of newborn infants, and 36 myoblastoma lesions of the skin and mucous membranes. Support is presented for the hypothesis that granular cells represent an unusual nonspecific degenerative process and that nonodontogenic granular cell tumors develop from undifferentiated mesenchymal cells that subsequently undergo autophagocytosis.


Analysis of postsurgical neurologic alteration in the trigeminal nerve. Neurologic alteration in 36 patients who had received either a sagittal split osteotomy, an intraoral vertical ramus osteotomy, or a mandibular vestibuloplasty was evaluated by questionnaire, detailed neurosensory examination, and personality testing. Subjective sensory alteration was reported by 69.4% of the entire group; neurosensory examination showed demonstrable neuropathy in 54% of the 72 nerve divisions that were examined, with the greatest incidence, 84.6%, in the group that had received sagittal split osteotomies. Personality testing indicated that dysesthetic patients experienced greater degrees of neuroticism and depression than did patients without pain.


Adrenergic and serotonergic receptor binding in rat brain after chronic desmethylimipramine treatment. The effects of chronic administration of the tricyclic antidepressant agent desmethylimipramine (DMI) on brain adrenergic and serotonergic receptor binding processes were studied. We examined the kinetic properties of alpha adrenergic, beta adrenergic and serotonergic receptor binding sites in cortical and subcortical brain regions of rats treated chronically for various time periods with DMI(6 mg/kg i.p. daily). After 1 week of daily injections, beta receptor binding density in the cortex was significantly decreased. The reduced density of the cortical beta receptors was evident throughout a 12-week administration period. It was not until after 6 weeks of DMI administration that a significant reduction in the subcortical beta receptors was evident. Compared to saline-injected controls, chronic DMI administration  lowered [3H]dihydroalprenolol binding in the hippocampus but not in the striatum. After 12 weeks of DMI we detected no differences in alpha adrenergic binding characteristics in the cortex or subcortical forebrain using [3H]dihydroergocryptine as the binding ligand. There was no consistent alteration in the cortical serotonin receptor densities throughout the 12 weeks of DMI administration, and DMI had no effect on the serotonergic binding characteristics in the subcortical forebrain region. We conclude that chronic DMI administration selectively decreases the density of beta adrenergic receptors in rat brain.


Naloxone and naltrexone: actions and interactions at an opiate drug receptor on frog skeletal muscle fibers. Extracellular and intracellular microelectrode studies were conducted to test the actions and interactions of naloxone and naltrexone, two supposedly "pure" opiate antagonists. Both were shown to depress excitability and action potential production when applied in relatively high concentrations. Low naltrexone concentrations antagonized the depression produced by naloxone, but low naloxone concentrations did not antagonize the depression produced by high naltrexone concentrations. Naltrexone also depressed the stimulus-induced increase in potassium conductance (gK) which naloxone did not do. Thus, the naloxone depression is mediated via an opiate drug receptor, whereas naltrexone in high concentrations produces a "local anesthetic-like" depression not involving the opiate drug receptor.


Pan uveitis and retinitis in neonatal herpes simplex infection. Neonatal infection with herpes simplex virus is, in recent years, a more frequently recognized complication of maternal genital herpes infection. Chorioretinitis has been described in approximately 16 cases. A case report is presented in which clinical photographs of the intraocular lesions are presented.


Aicardi's syndrome: a report of four cases and review of the literature. Four patients with Aicardi's syndrome (infantile flexion spasms, agenesis of the corpus callosum, and ocular anomalies) are reported, along with photographs of their characteristic fundus abnormalities. The etiology of the syndrome is unclear, but its occurrence exclusively in female patients suggests the possibility of a genetic factor. The ocular abnormalities of Aicardi's Syndrome are distinguishable from, but may be confused with, those of congenital toxoplasmosis and cytomegalic inclusion disease. The syndrome can be identified clinically with a high degree of certainty. Ophthalmologists who are familiar with the syndrome may be helpful in the differential diagnosis.


Changes in total and quantal release of acetylcholine in the mouse diaphragm during activation and inhibition of membrane ATPase. 1. Acetylcholine (ACh) released from mouse diaphragm was gel filtrated and estimated by bio-assay and compared with electrophysiologically measured quantal release, expressed either as frequency of miniature end-plate potentials or quantum content of end-plate potentials. 2. Activation of Na+-K+-dependent membrane ATPase (membrane ATPase) in Na+-loaded muscles lowered the total amount of ACh released at rest to one tenth of the control value, but quantal release remained unchanged. 3. Inhibition of membrane ATPase by 2 X 10(-5) M-ouabain or by K-free solution led to an increase in total release and to a delayed progressive increase in quantal release. When Ca2+ was removed only the total release was enhanced. 4. Depolarization of the diaphragm by 8, 11 and 14 mM-K increased both total and quantal release only in the presence of Ca2+ in the perfusion medium. When Ca2+ was removed, no significant increase in release was observed. 5. The total and quantal release in response to 2 Hz stimulation of the preparation was increased 1.4 and 45 times, respectively. It is concluded that the total amount of ACh released at rest consists of two fractions, quantal and non-quantal, the former representing about 1% of the total release.


Direct inhibition of gastric secretion and mucosal blood flow by arachidonic acid. 1. Gastric acid and pepsin secretion stimulated almost maximally by i.v. infusion of histamine, the mucosal blood flow, and the immunoreactive prostaglandin E (PGE) content have been measured following arachidonic acid administration either intra-arterially or topically to the mucosa of the fundic portion of a stomach kept in a Lucite chamber. 2. Arachidonic acid administered directly to the stomach produced a marked and significant inhibition of histamine-induced gastric secretion accompanied by a reduction in mucosal microcirculation and a rise in the immunoreactive PGE content in the gastric juice. 3. These secretory and circulatory changes induced by arachidonic acid were prevented by pretreatment of the gastic mucosa with indomethacin, a potent inhibitor of the prostaglandin synthetase system. 4. Arachidonic acid infused intra-arterially in graded doses resulted in a dose-dependent reduction in gastric acid secretion, mucosal blood flow and cyclic AMP mucosal content. 5. These studies indicate that arachidonic acid applied directly to the stomach causes a marked gastric secretory inhibition, probably due at least in part to the enzymic transformation of arachidonic acid to prostaglandins and possibly other active lipids responsible for the changes in the gastric mucosal microcirculation and cyclic AMP mucosal content.


Normal distribution and denervation changes of neurotransmitter related enzymes in cholinergic neurones. 1. The activities of choline acetyltransferase (CAT) and acetylcholinesterase (AChE) were assayed in adult pigeon ciliary ganglia, in the post-synaptic ciliary and choroid nerves, and in ciliary nerve iris terminals isolated from control birds and from animals from which the oculomotor nerve was previously transected. Enzyme activity levels were also measured in the iris terminals after surgical section of the ciliary nerves. From differences in enzyme activity between control and 3-day denervated tissues, the localization of CAT and AChE in pre- and post-synaptic elements of the ganglia and at the iris neuromuscular junctions was estimated. The fate of the preganglionic nerve terminals after denervation was investigated by electron microscopic examination of ganglia after surgical section of the oculomotor nerve.2. The CAT activity in the ganglion was distributed as follows: 60% in presynaptic elements, 31% in cell somas, and 9% in intraganglionic post-synaptic axons; in the iris junctions, 98% of the activity was present in the ciliary nerve terminals. For AChE: 20% was present in the preganglionic terminals, 69% in ganglion cell somas and the remaining 11% in post-ganglionic axons; at the neuromuscular iris junctions, 20% was found in the ciliary nerve terminals and 80% in the iris striated muscle.3. The first changes in the fine structure of the nerve terminals were observed 14 hr after surgery, and by 24 hr marked alteration of the synaptic structure were clearly recognized. No preganglionic endings were found in 3 day-old denervated ganglia.4. There was a positive correlation between CAT activity in the control iris nerve terminals and in ganglia. After denervation, when the activity of the enzyme decreased in ganglion cell somas, there was a corresponding decrease in the post-synaptic nerves. These two findings suggest that CAT slow axoplasmic transport is related to its perikarial concentration.5. There was a 60% reduction of CAT activity in the post-synaptic elements, assayed in the 10-day denervated ganglia, which was accompanied by a 30% decrease in activity in the iris nerve terminals. Similarly, post-synaptic AChE decreased approximately 30% in the ganglion and approximately 30% in the iris 10 days after section of the oculomotor nerve. At the same time, CAT activity also decreased in the nerve trunks, 70% at the ciliary nerve and 40% at the choroid; for AChE there were smaller changes.6. In contrast to CAT and AChE, there were no differences in ganglionic protein content, or lactate dehydrogenase (LDH), co-enzyme A (CoA) and monoamine oxidase (MAO) levels between short-term (3 days) and long-term (10 days) denervated ganglia.7. The later decrease of CAT and AChE activity in the cell somas, axons and nerve terminals after long-term preganglionic transection suggests that the activity of these enzymes is regulated across the synapses. It is postulated that the AChE regulation is part of a general ;trophic interaction' between neurones, but that the trans-synaptic modulation of CAT is specific for cholinergic cells.


The influence of corticosteroids on the secretion of corticotrophin and its hypothalamic releasing hormone. 1. The effects of stress, adrenalectomy and corticosterone treatment on the functional activity of the hypothalamo-pituitary-adrenocortical system have been studied using highly sensitive and precise bio-assay methods for the determination of ACTH and CRH.2. Adrenalectomy resulted in a rise and corticosterone treatment a fall in the hypothalamic CRH content and the plasma ACTH concentration.3. Stress caused a fall followed by a rise in the hypothalamic CRH content, a rise in the pituitary and plasma ACTH concentrations and an increase in the plasma corticosterone concentration.4. The stress-induced changes in hypothalamic CRH content and pituitary and plasma ACTH were exaggerated in adrenalectomized rats but normal in adrenalectomized rats treated with corticosterone. They were also normal in animals injected I.P. with corticosterone 15 min before the stress but inhibited in those similarly treated 60 min previously.5. The ability of adenohypophyses and hypothalami to synthesize and release in vitro ACTH and CRH respectively in response to trophic stimuli was exaggerated in glands removed from adrenalectomized rats and reduced in those removed from corticosterone-treated rats.6. Addition of corticosterone to the pre-incubation medium reduced the capacities of adenohypophyses and hypothalami removed from untreated rats to synthesize and release ACTH and CRH respectively.


The effect of nutritional state on neuromuscular transmission in the rat. 1. Evoked end-plate potentials (e.p.p.s) were recorded in phrenic nerve-hemidiaphragm preparations from rats which had been subjected to periods of dietary restriction. 2. The mean quantum content of the first e.p.p. of trains of e.p.p.s was significantly increased after 1 week of dietary restriction in 30-day-old but not in 110-day-old rats. 3. The mean quantum content of plateau e.p.p.s elicited at a frequency of 10 Hz was not significantly affected by brief periods of dietary restriction in either 30-day-old or 110-day-old rats. 4. In the younger animals there was found to be a decrease in the safety factor of neuromuscular transmission following dietary restriction when this parameter was calculated using previously reported values for the amplitude of spontaneous miniature end-plate potentials (m.e.p.p.s) after such a restricted diet. 5. Such rapid changes in neuromuscular transmission following brief periods of dietary restriction indicate that great care is required in the choice of adequate control animals when food intake is altered by experimental procedures.


Signal transmission from red cones to horizontal cells in the turtle retina. 1. Intracellular recordings were made from L-type horizontal cells in the retina of the turtle Pseudemys scripta elegans. The responses were evoked by 500 msec pulses of 'white' light. 2. L-type horizontal cells were classified as either, 'small receptive field' s.r.f. or 'large receptive field' l.r.f. based upon (1) receptive field size and (2) kinetics of responses to test flashes covering small and big spots. 3. Constant illumination of the entire receptive field, with any intensity studied, evoked a response that reached a peak and then slowly sagged back to a steady-state level that was about half the peak response. 4. Termination of backgrounds resulted in a very fast recovery of the membrane potential that overshot the dark-adapted potential. This 'off' response had faster kinetics in horizontal cells than in red cones. 5. The intensity-response curve measured around any background intensity was shifted along the log intensity axis toward higher test intensities. The curves obtained under light-adapted conditions were sharper than the curve measured in the dark-adapted state. 6. The photoresponses of red cones and s.r.f. horizontal cells were compared under similar states of adaptation. In the dark-adapted state of the gain, expressed as the millivolt change in the horizontal cell per millivolt change in the cone, was not linearly related to cone potential, and was highest for dim stimuli. Light-adaption modified the synaptic transmission to make the horizontal cells most sensitive to light modulation around the background illumination. 7. The mechanisms by which signal transmission can be modified by light-adaptation are discussed in terms of transmitter release by the presynaptic terminals and its binding to post-synaptic sites.


The effect of theophylline and dibutyryl cyclic AMP on the uptake of radioactive calcium and phosphate ions by boar and human spermatozoa. Radioactive calcium uptake by suspensions of washed boar and human spermatozoa was inhibited by the mitochondrial uncoupling agent carbonylcyanide-p-trifluoromethoxy-phenylhydrazone (FCCP). Theophylline + dibutyryl cyclic AMP also inhibited calcium uptake in the presence or absence of FCCP. Uptake of low concentrations of calcium (0 . 1 mM) was inhibited by the calcium ionophore A23187, but at high calcium concentrations the ionophore stimulated calcium uptake. These observations are explained in terms of a mechanism for the regulation of calcium uptake in spermatozoa based on competing mitochondrial and plasma membrane pumps. Uptake of 32P was also inhibited. These effects provide evidence that cyclic AMP plays a role in the transport of ions across the plasma membrane of spermatozoa.


Regulation of cyclic nucleotide phosphodiesterase activity in myometrium from pregnant and spayed rhesus monkeys. The activities of myometrial cyclic nucleotide phosphodiesterases (PDEs) and the sensitivity of these enzymes to the effector molecules, cGMP and cAMP, were determined in the 100,000 g supernatant of homogenates from pregnant and spayed rhesus monkeys. The specific activities (per mg nitrogen) of the myometrial cyclic nucleotide PDEs in the supernatant from spayed monkeys were higher than those from pregnant monkeys at all substrate levels studied. However, when calculated on the basis of the DNA content of the myometrium, which was 8 times higher in the spayed than in the pregnant animals, the specific activities were lower in the tissue from spayed animals. At substrate levels of 2 . 5 micron-cAMP, low levels of cGMP (0 . 1-1 . 0 micron) caused the same percentage increase in cGMP-PDE activity in both tissues. At high substrate levels of 100 micron-cAMP, 1 micron-cGMP inhibited only the cAMP-PDE from spayed monkeys, and the enzyme from spayed monkeys was more effectively inhibited by 10 and 40 micron-cGMP than was the enzyme from pregnant animals. The cGMP-PDE activity was inhibited by cAMP (1 . 0-50 . 0 micron), and the percentage inhibition with increasing levels of cAMP appeared to be similar in the two series. The levels of cGMP and cAMP that modify the rate of hydrolysis of the other nucleotide in rhesus myometrium seem to be within the physiological range for these compounds in situ. It therefore appears possible that cAMP and cGMP are each involved in regulating the degradation of the other nucleotide in rhesus myometrium.


Conjugated and unconjugated oestrogens in fetal and maternal fluids of the cow throughout pregnancy. The changes in concentration of oestrone, oestradiol (-17alpha and -17beta), oestrone sulphate and the oestradiol sulphates have been measured in allantoic and amniotic fluids and in maternal peripheral plasma throughout gestation. Oestrone sulphate was the major oestrone present in all of the fluids. It was measurable in allantoic fluid before Day 52 and reached a peak concentration of 475 ng/ml around Day 133. A lower peak occurred in the amniotic fluid around Day 110. The changes in oestradiol sulphates in allantoic fluid were similar to those of oestrone sulphate but at a much lower level. Considerable fluctuation was observed in the oestradiol sulphate concentrations in amniotic fluid. The ratio of oestradiol-17alpha sulphate to oestradiol-17beta sulphate was considerably higher in amniotic fluid than in allantoic fluid. Consistent changes in the levels of oestrone and the oestradiols were found in amniotic fluid but not in allantoic fluid during the second half of pregnancy. In maternal peripheral plasma oestrone sulphate was measurable before Day 72. In the limited number of samples analysed no difference in oestrogen concentration due to the sex of the fetus was evident in any of the fetal or maternal fluids.


Studies of oligoadenylate formation on a poly (U) template. We have studied a variety of condensation reactions involving poly (U) as template and isomeric adenosine dinucleotides as substrates. We find that [3'-5']-linked dinucleotides such as A3pA and pA3pA are better acceptors than the corresponding [2'-5']-linked compounds, while ImpA2pA is a better donor than ImpA3pA. The reaction between A2pA and ImpA3pA, for example, yields only 4% of product while the reaction of A3pA with ImpA2pA yields 86% of product. The more efficient condensation reactions of dimers are about as efficient as the self-condensation of ImpA. They yield a few percent of material in which five or more substrate molecules are linked together. The percentage of the natural [3'-5']-linkage in the product varies greatly, from as little as 1% to as much as 45%.


Women's vaginal responses during REM Sleep. Eight female subjects underwent vaginal photoplethysmographic recordings while asleep. Results demonstrated consistent findings of decreases in relative blood volume and increases in relative pulse pressure within the vagina during REM periods. Thes vascular changes indicate that females undergo phasic shifts in vascular blood flow in the vagina during REM sleep, similar to the phasic shifts of blood flow in the male's penis during REM sleep.


Spinal cord compression from metastatic breast carcinoma: treatment by radiation therapy alone. There are few reports in the medical literature of treatment of compression of the spinal cord by the use of radiation therapy alone. Laminectomy has been the standard procedure to relieve compression of the spinal cord and should be performed within 48 hours of initial symptoms. In this patient, radiation therapy was the only modality used. It was supplemented by diethylstilbestrol in the course of follow-up. The result of radiotherapy so far has been excellent. The authors emphasize that radiotherapy was begun three months after development of paraplegia, which makes this an interesting case for presentation.


Adenoid cystic carcinoma of breast with metastasis: a case report and review of the literature. Adenoid cystic carcinoma of the breast is a rare tumor having a favorable prognosis. At this writing, less than 100 cases have been reported. A review of the literature discloses only six well-documented cases with associated distant metastases. The characteristic biological behavior of this tumor appears to be the development of distant metastasis without prior detectable invasion of axillary lymph nodes.


Treatment of calcium urolithiasis with diphosphonate: efficacy and hazards. The effect of treatment of renal stone formation with 5 to 20 mg./kg. per day oral disodium ethane-1-hydroxy-1,1-diphosphonate for up to 30 months was examined in 12 patients with active renal (calcium) stone disease. The over-all incidence of stone passage decreased from 17.8 stones per year per patient before treatment to 7.7 stones per year per patient during therapy. Of the 12 patients 7 passed fewer stones or no stones during treatment. However, the incidence of stone passage was not changed substantially by disodium ethane-1-hydroxy-1,1-diphosphonate in 5 patients. Symptoms of muscle weakness and pain in the back, hips and shoulders occurred in 3 patients during treatment, 2 patients had an increase in serum alkaline phosphatase and 1 patient had a decrease in bone density. Although disodium ethane-1-hydroxy-1,1-diphosphonate may be clinically useful to manage calcium urolithasis in certain patients its over-all use is limited because of its ineffectiveness in some patients and owing to its potential to induce osteomalacia.


Adult Wilms tumor treated with radiotherapy and chemotherapy: a case report. A 24-year-old man underwent a left radical nephrectomy for a mass that was found to be a Wilms tumor. The postoperative course, consisting of combined radiotherapy and chemotherapy, is discussed and the recent literature is reviewed.


Vertical transmission of mouse hepatitis virus infection in mice. Transplacental infection with mouse hepatitis virus, JHM strain was studied by intravenous inoculation of pregnant dams. Inoculation on day 9 or 12 of gestation brought about the death of more than 50% of the fetuses at 4 days postinfection while inoculation on day 6 or 15 of gestation effected the death of 12% of fetuses or neonates. Inoculation of day 12 of gestation resulted in markedly higher virus titers. At 72 h postinfection in the placentas, fetal membranes and fetuses than in the maternal livers and blood. Virus-specific antigen and virus particles were noted in the placentas, visceral yolk sac and fetal livers by immunofluorescence and electron microscopy. Histopathology revealed degenerative and necrotic changes in these tissues and in the fetal bone marrow.


Nasopharyngeal carcinoma in an Alaskan Eskimo family: report of three cases. Nasopharyngeal carcinoma (NPC) has been reported to occur in Alsaka Natives (Eskimos, Indians, and Aleuts) at a rate greater than 15 times the rate for U.S. whites. At least 3 cases of NPC have occurred in close relatives of a Northern Alaskan Eskimo family. All 3 patients had poorly differentiated tumors and have died. Blood groups, HLA antigens, and antibodies to Epstein-Barr virus (EBV) were studied in the family members. EBV titers were elevated in the 1 NPC patient tested and in 1 of 15 other family members tested. All family members studied except 1 were of blood group A, Rh-positive, and HLA types AW24, CW3, CW40/A2, CW2 and B27. This was the first report of more than 2 cases of NPC in a single family in the United States.


Extraction of soluble antigens of Epstein-Barr virus, Herpesvirus salmirl, and Herpesvirus ateles with the use of glycine. For extraction of soluble antigen from cells infected with Epstein-Barr virus, Herpesvirus salmirl, and H. ateles, 0.1 M glycine (pH 9.5) was used. This method yielded increased amounts of the antigen containing much less cell debris. Lymphoblastoid cells infected with Epstein-Barr virus could maintain up to 50% viability after the extraction procedure. These cells could be used again after an appropriate interval in culture. The usefulness of this technique is discussed.


Preferential inhibition by quercetin of mitogen-stimulated thymocyte glucose transport. The ATPase inhibitor quercetin, which inhibits tumor glycolysis, was shown to be a glucose transport inhibitor like the chemically related compound phloretin. Rat thymocyte glucose transport stimulated by the mitogens concanavalin A or ionophore A 23187 was more sensitive than unstimulated transport to quercetin inhibition. The partial inhibition of Na+-, K+- ATPase activity by quercetin observed in tumor cells was confirmed in thymocyte plasma membranes. The specific Na+-, K+- ATPase inhibitor ouabain did not mimic the effect of quercetin on mitogen-stimulated glucose transport but did reduce the effectiveness of concanavalin A as a stimulator of mitochondrial pyruvate oxidation. The results support the idea that glycolytic flux and the activity of plasma membrane ATPase are related but suggest that glucose transport, rather than the Na+-, K+-ATPase, is the  rate-limiting reaction in lymphocytes.


Inability of antiserum active in antibody-dependent cellular cytotoxicity and arming tests to protect against simian virus 40 tumor cell challenge. Previous studies have shown that simian virus 40 (SV40) hamster tumor cells that were pretreated with antiserum from syngeneic hosts sensitized to SV40 were killed following exposure to nonsensitized spleen cells. In this study preincubation of nonadherent spleen or lymph node cells with SV40 antiserum rendered the cells specifically cytotoxic for the SV40-transformed fibroblasts. The capacity of a particular antiserum to "arm" (i.e., to be made specifically cytotoxic) was comparable with its ability to mediate antibody-dependent cellular cytotoxicity (ADCC). Experiments were performed to determine if the SV40 antiserum had prophylactic activity. Two hours after passive transfer of serum, cytotoxic effector cells could be demonstrated in the blood, spleen, and mesenteric lymph node, and the recipients' sera were active in ADCC tests. Nevertheless, such hosts were not resistant to challenge with small numbers of SV40 tumor cells that were given intradermally or intracardiacly, nor was tumor growth suppressed by addition of normal lymph node cells to the antiserum-pretreated tumor cell inoculum. Thus SV40 antiserum, active at high titer in ADCC and arming assays, did not prevent or delay growth of SV40 tumor isografts.


Risk of radiation-related subsequent malignant tumors in survivors of Ewing's sarcoma. Twenty-four long-term survivors of Ewing's sarcoma were identified as being at risk for a second primary tumor. Among this group of patients followed from 3 to 22 years, 4 new bone tumors were observed, whereas 1.2 x 10(-3) were expected. All new tumors arose in heavily irradiated areas. The risk associated with radiation after 3 years was 7.2 cases/million person-years per rad. The cumulative cancer risk over 10 years for irradiated patients was 35% (SE, 15.1%). Intensive chemotherapy (cyclophosphamide and vincristine administered in five or more courses) seemed to exert an enhancing effect, increasing the rate of development of new tumors.


Seroepidemiologic studies of bovine papillomavirus infections. Bovine and human sera were analyzed for the presence of antibodies against bovine papillomavirus types 1 and 2 (BPV 1 and 2) and human papillomavirus type 1 (HPV 1) in a solid-phase radioimmunoassay. Human sera did not react with BPV antigens, and bovine sera showed no evidence of antibodies against HPV 1. In contrast, 19% of all bovine sera tested reacted with BPV 1 and 2 antigens, and 35% of human sera revealed antibodies against HPV 1. No serologic evidence was obtained for heterologous infections of persons exposed preferentially to cattle (farmers, butchers, and patients with Q-fever).


Morphologic characterization of proliferative cells and virus particles in turkeys with lymphoproliferative disease. The tumors found in turkeys having lymphoproliferative disease (LPD) are histologically characterized by a pleomorphic population of cells of the lymphoid series. Electron microscopy has shown that, despite marked differences in shape and size, the proliferating cells share basic ultrastructural features, indicating their lymphoid origin. Virus particles morphologically and morphogenetically characteristic of type C oncorna-viruses of Retraviridae were found in different organs and plasma samples of diseased or infected turkeys with LPD. This LPD type C virus resembled members of the reticuloendotheliosis virus group but not members of the avian sarcoma virus group.


[Effect of strophanthin and cytochrome C on myocardial contraction and the incidence of shock and ventricular fibrillation in experimental myocardial infarct]. High ligation of the interventricular artery caused ventricular fibrillation in the first 2--4 minutes in 20% of cats. In the remaining animals myocardial contractility diminished to half its initial value. After that, contractility increased gradually. In cardiosclerosis myocardial contractility reduced by 20--30%. Ligation of the interventricular artery on the background of cardiosclerosis induced cardiogenic shock in half of the animals. Cytochrome C does not reduce the diminution of myocardial contractility after ligation and has a marked antifibrillatory effect. Strophantin does not affect the diminution of contractility of a healthy myocardium but reduces the decrease in contractility of a sclerosed myocardium and also promotes the development of ventricular fibrillation following ligation of the interventricular artery.


[Total cholesterol, triglyceride and alpha-lipoprotein cholesterol levels in the blood of 40- to 59-year-old men in Moscow and Leningrad]. A population survey of 6.990 males 40--59 years of age living in Moscow and Leningrad was conducted to determine the level of lipids in blood plasma by means of automatic standard biochemical methods. Curves were built of the distribution of the concentration of total cholesterol, triglycerides and alpha-lipoprotein cholesterol, and the average content, the upper levels of the norm (and the lower level of the norm for alpha-lipoprotein cholesterol too) were determined from them. The average content of total cholesterol was 217 mg/100 ml, that of triglycerides 100 mg/100 ml, and that of alpha-lipoprotein cholesterol 50 mg/100 ml. The upper norm levels for total and alpha-lipoprotein cholesterol found by cutting off 10% of the higher values were 270 and 75 mg/100 ml, respectively; the upper norm level for triglycerides (cutting off 5% of the higher values) was 250 mg/100 ml. The lower norm level for alpha-lipoprotein cholesterol (cutting off 10% of the lower values) was 35 mg/100 ml.


Cyclic nucleotide phosphodiesterases in glomeruli of rat renal cortex. The presence and properties of cyclic 3',5'-adenosine monophosphate phosphodiesterase (cAMP-PDIE) and cyclic 3',5'-guanosine monophosphate phosphodiesterase (cGMP-PDIE) were studied in glomeruli isolated from rat renal cortex by sieving and density gradient centrifugation. The specific activity of cGMP-PDIE was higher than the specific activity of cAMP-PDIE in glomeruli; in tubules and renal cortical slices, the specific activity of cAMP-PDIE was higher than that of cGMP-PDIE. In homogenates, X 100,000g supernate of homogenate (cytosol) and X 100,000g pellet (membrane fraction) from glomeruli, the specific activity of cGMP-PDIE was significantly higher than it was in analogous preparations from tubules or renal cortical slices. Cyclic 3',5'-GMP (10(-6)M to 10(-5)M) stimulated glomerular cAMP-PDIE, but it was without effect on cAMP-PDIE from tubules. Structural analogs of cyclic 3',5'-GMP or 5'-GMP did not stimulate glomerular cAMP-PDIE. Cyclic 3',5'-AMP slightly inhibited cGMP-PDIE from both glomeruli and tubules. N6-,2'-0-dibutyryl cyclic 3',5'-AMP inhibited cAMP-PDIE, but not cGMP-PDIE. The addition of calcium increased the activity of cGMP-PDIE, mainly in tubules, but was without effect on cAMP-PDIE. These results suggest the predominance of cyclic 3',5'-GMP catabolism in glomeruli in comparison with other cortical structures, and they demonstrate that both the specific activities and regulatory properties of cyclic nucleotide phosphodiesterase in glomeruli differ markedly from tubules or unfractionated renal cortical tissue.


Studies of respiratory disease in random-source laboratory dogs: viral infections in unconditioned dogs. A prospective study was conducted to identify the viruses causing respiratory diseases in unconditioned, random-source dogs. During the quarantine period, respiratory disease occurred in 86 of 167 (52%) dogs, and 34 (21%) died. Most affected dogs had a distemper-like illness which required extensive and prolonged care. Histopathologic studies confirmed the diagnosis of canine distemper in 10 of 12 (83%) fatal infections examined. Sixty-seven of 91 (74%) dogs which arrived without canine distemper antibody became ill, and 30 (32%) died. In contrast, only 16 of 67 (24%) dogs with canine distemper antibody had respiratory disease, and only 3 (4%) died. Parainfluenza SV5 and canine adenovirus--type II were recovered from 27 of 54 and 22 of 54 sick dogs, respectively. Canine herpesviruses, canine coronaviruses, and canine parvoviruses were less frequently isolated. Increased antibody titers to SV5 were found consistently, and rises in titer to the other viruses were demonstrated. Many of the sick dogs were infected with two or more viruses. Although several viral agents were detected during these epizootics, prevention of canine distemper appeared to be the key to controlling severe, prolonged, and often fatal respiratory disease.


Isolation of a cytomegalovirus from salivary glands of white-lipped marmosets (Saguinus fuscicollis). Minced salivary glands from seven white-lipped marmosets (Saguinus fuscicollis and Saguinus nigricollis) and one cotton-topped marmoset (Saguinus oedipus) were cocultivated with marmoset cell cultures. A viral agent, designated SSG, was isolated from two Saguinus fuscicollis. Slowly progressing foci of rounded, vacuolated, refractile cells were first observed at 40-43 days incubation. Electron microscopy revealed intranuclear herpesvirus nucleocapsids and intracytoplasmic and extracellular enveloped particles. Infected cells stained with hematoxylin and eosin contained eosinophilic intranuclear and cytoplasmic inclusion bodies. SSG could be passaged in cell cultures only using viable whole cells; infectious cell-free virus was not detected in either culture supernatants or cell lysates. SSG replicated in marmoset fibroblastic but not in marmoset epithelioid or human fibroblastic cell cultures. Plasma antibodies to SSG were detected by indirect immunofluorescence assays in 16 of 56 (28.6%) adult wild-caught marmosets but were absent in 40 colony-born, hand-reared marmosets. Antigenic cross-reactivity of SSG with a rhesus monkey (Macaca mulatta) cytomegalovirus (bidirectional) and with a human cytomegalovirus (unidirectional) was also demonstrated by indirect immunofluorescence assays. SSG was identified as a herpesvirus by morphology and was classified as a cytomegalovirus by its site of isolation, biologic properties in vitro, and antigenic characteristics.


Spontaneous liver tumors in aged germfree Wistar rats. Liver tumors, ranging from benign nodules to carcinomas, developed spontaneously in 115 (87%) of 132 germfree Wistar rats beyond the age of 30 months. In addition, the rats developed a high incidence of benign adenomas of endocrine glands and of the breasts.


Requirement for guanosine triphosphate in the activation of adenylate cyclase by cholera toxin. The activation of adenylate cyclase in lysed pigeon erythrocytes requires, among several cofactors, a nucleotide which may be ATP, GTP, or many other triphosphates. However, after removal of endogenous nucleotides by gel filtration or by adsorption onto charcoal the requirement can be met only by GTP, or an analog of GTP. The GTP is required during the activation of the cyclase by toxin even if GTP is also included during the subsequent adenylate cyclase assay, conducted without toxin. In the presence of GTP it is possible to assay for the cytosolic protein that is also required for the action of cholera toxin. By gel filtration, its apparent molecular weight is 15,000--20,000.


Gap junctions and ACTH sensitivity in Y-1 adrenal tumor cells. Initial studies of adrenocorticotropin-sensitivity (ACTH-sensitive) and ACTH-insensitive Y-1 adrenal cortical tumor cell lines suggest a relationship between responsiveness to ACTH and the presence of gap junctions. An ACTH-sensitive clone of Y-1 cells possesses gap junctions and these junctions appear to enlarge with ACTH treatment. GAP junctions have not been observed, however, in an ACTH-insensitive clone of Y-1 tumor cells even when stimulated to produce cyclic adenosine monophosphate and steroids with cholera toxin.


Pseudo-chondrosarcoma: solitary osseous metastases from atypical bronchogenic carcinoma. A patient with bronchogenic carcinoma with a solitary metastases to the femur in whom the clinical, radiologic, and pathologic setting suggested that the primary tumor was the bone lesion (chondrosarcoma) and the pulmonary lesion was a solitary metastasis is presented. This case is added to the limited literature indicating that mucin-secreting tumors metastatic to bone may simulate primary bone tumors radiographically.


Human carcinoma-associated precursor antigens of the NM blood group system. Blood group NM specificities occur in healthy, benign and carcinomatous breast glands and those of the gastrointestinal (G.I.) tract, but the precursors in their biosynthesis, T (Thomsen-Friedenreich) and Tn, are found in adenocarcinomata and not in benign or healthy tissues. T- and Tn-antigenic specificities are thus human carcinoma-associated. All humans possess anti-T and anti-Tn antibodies. Patients with breast or G.I. tract carcinoma show statistically significant alteration of anti-T titer levels when compared to patients with benign disease and to healthy controls. Breast carcinoma patients but not healthy people showed cellular immunity to T antigen in vitro and in vivo. Most striking was the delayed-type hypersensitivity reaction, which was positive in over 90% of ductal breast carcinoma patients tested and negative in all presumably healthy individuals. T antigen is readily prepared from healthy human red blood cells in uncontaminated form, and free of HL-A and Au antigens. T antigen and anti-T antibodies may be useful in combating some human adenocarcinomata.


Surgical treatment of recurrent primary malignant tumor of the left atrium. A young woman presented with a tumor in the left atrium resembling a left atrial myxoma. After simple excision of the tumor the diagnosis of primary malignant fibrous histiocytoma of the heart was made. A course of radiation therapy was given. Four subsequent recurrences were treated by cardiotomy and resection of the left atrial wall. At the third, fourth, and fifth operations fulguration of the left atrial wall was performed. Subsequent chemotherapy failed to control the tumor. The patient was admitted 6 weeks after the last resection and died. Postmortem examination revealed a large recurrent tumor obstructing the left atrium with no metastases. The clinical course, cardiac catherization data, and postmortem examination are presented. Palliation was achieved by repeated resection of a radiation-resistent primary sarcoma of the heart.


New oncogenic human papovaviruses.

New oncogenic human papovaviruses. Human papovaviruses of the polyoma-SV40 subgroup are common infectious agents. The clinical picture of the primary infection of these viruses is unknown, but one of the viruses, the JC virus, is associated with and probably causes progressive multifocal leukoencephalopathy. These viruses cause tumours and transform cells of several species of laboratory animals. Current results seem to rule them out as a major aetiollogical factor in human cancer. However, their relationship to human tumours requires further study, especially in immunologically compromised patients showing activation of a latent infection.


[Benign tumors of the petrous bone].

[Benign tumors of the petrous bone]. 41 benign tumor of the temporal bone are reported. 33 glomustumors, originating from the middle ear or from the lower temporal bone. According to their origin they present different surgical problems. Neurinomas are less common. Surgery is the therapy of choice. Symptoms and properties of these tumors are discussed briefly.


High density lipoproteins, 1978 -- an overview. High density lipoproteins (HDL) have come of age. For years it has been fashionable to study HDL as an approach to understanding lipoprotein structure and lipid binding. Available in abundant amounts from normal human plasma, readily separable into its individual lipid and soluble apolipoprotein components, HDL has provided much information for lipoprotein model building. Suddenly it has been thrust center stage clinically by a host of convincing epidemiologic studies that clearly establishes an inverse relationship between HDL levels and coronary vascular events. Biochemists, clinicians, cardiologists and epidemiologists are simultaneously focusing attention on HDL. Familial High Density Lipoprotein Deficiency (Tangier Disease) has been well described but is poorly understood as a clinical syndrome complex. We have suddenly become aware of how little we understand about HDL's normal ultracentrifugal and apoprotein heterogeneity, about its functional role(s) or the determinant(s) of its concentration in plasma. The relative contributions of the two sites of HDL origin, the liver and intestine, are yet to be determined as are the site(s) of degradation. Awareness of a problem and its importance is the first step toward the solution(s) of the problem.


The evidence for the antiatherogenicity of high density lipoprotein in man. It has long been recognized that patients with clinical coronary heart disease (CHD) have, on average, higher concentrations of plasma very low density and low density lipoproteins than do healthy subjects. The same studies clearly demonstrated that coronary victims tend also to have low plasma concentrations of high density lipoprotein (HDL). It is only recently, however, that the possible significance of this second observation has been examined. Direct evidence for an inverse relationship between HDL cholesterol concentration and the prevalence of clinical CHD, independent of other plasma lipoproteins, has been provided by the Honolulu Heart and Cooperative Lipoprotein Phenotyping Studies. The Tromsø Heart and Framingham Studies subsequently demonstrated that this relationship precedes the clinical manifestation of coronary disease. More recently, angiographic studies have confirmed that the severity of existing coronary atherosclerosis is inversely related to HDL cholesterol concentration. Other investigations have shown that coronary victims also have low mean concentrations of apolipoproteins AI and AII (the major protein components of HDL), although the reduction of apoAI concentration may be less marked that that of HDL cholesterol, and preliminary findings from Tromsø have suggested that apolipoprotein AI may be less powerful that HDL cholesterol as a predictor of CHD. Such observations have supported the porposal that HDL may exert a protective effect against coronary atherosclerosis. Final comfirmation (or otherwise) of this hypothesis, however, must await the results of carefully controlled animal experiments and of regression studies in patients with angiogrphically defined atherosclerosis.


Ultrastructure of serum high density lipoproteins: facts and models. The complexity of the structure of plasma high density lipoproteins (HDL) has invited numerous approaches which have been directed at the study of the intact particles, their apolipoproteins and reassembled complexes. Parameters such as flotation and sedimentation coefficients, size and molecular weight have been determined and in addition, through scattering techniques, an understanding has been obtained on the long range organization between core (cholesteryl esters and triglycerides) and surface components (unesterified cholesterol, phospholipids and apoproteins). In the case of the apolipoproteins, the knowledge of their primary structure has facilitated the study of their physicochemical properties in solution and at the air-water interface and has also permitted realistic predictions of the two dimensional organization, not only of their alpha-helical segments but also of the beta-pleated sheets, random coil and beta-turns, all of which have amphipathic properties. When all of the information from the physical and chemical studies is put together, the various HDL can be described as spherical structures having a liquid core of radius, r - 20.2 A, surrounded by a monolayer of cholesterol and phospholipids with closely packed hydrophobic ends on the surface of the core. The organization of the apoproteins at the lipoprotein interface is comparatively less understood. However, reasonable predictions can be made on secondary structure considerations and on their behavior at the air-water interface. The emerging overall structural information can be translated into a space-filling model that not only provides a useful representation of HDL, but, more importantly, a basis for planning future studies on the elucidation of the structure of these particles on a molecular level.


Plasma, apolipoprotein, A-I and A-II levels in hyperlipidemia. Some of the component moieties of high density lipoproteins (HDL) were analyzed in normal subjects and in patients with hyperlipidemia. Apoproteins A-I and A-II were quantified by radioimmunoassay, HDL cholesterol and triglycerides were assessed on heparin-MnCl2 supernates of fasting plasmas. We found that HDL is enriched in triglycerides in all forms of hyperlipidemia, while the proportion of ApoA-II is unaltered and the proportion of ApoA-I is decreased. Thus, the composition of HDL is altered in hupertirglyceridemia. The molecular associations of ApoA-I and ApoA-II in plasma were also examined by assaying the apoprotein contents of plasma fractions prepared by ultracentrifugation and by gel filtration column chromatograpy. The ApoA-I contents of d smaller than 1.063 fraction increased in hyperlipidemia from smaller than 0.5% to approximately 2%, but the ApoA-I contents of the d greater than 1.21 fraction remained at less than 12% of total plasmas with triglyceride levels smaller than 1500 mg/dl. d greater than 1.21 ApoA-I rose to 23% in one plasma with a triglyceride level of greater than 1700 mg/dl. On column chromatography, ApoA-I eluted with the lipoproteins and also in a fraction whose molecular weight (MW) appeared to be approximately 50,000 daltons. The proportion of plasma ApoA-I which eluted in the 50,000 MW peak was positively correlated with plasma triglyceride levels, but at triglyceride levels of less than 1500 mg/dl, less than 20% of ApoA-I was in the 50,000 MW peak. Between levels of approximately 2000 and 12,000 mg/dl, the percentage "50,000 M.W. ApoA-1" was 20-25%. The ApoA-II contents of d smaller than 1.063 fractions were also increased in hyperlipidemia, but greater than 95% of ApoA-II was found in the HDL fractions in both normal and hyperlipidemic plasma both by column chromatography and ultracentrifugation. Thus, the molecular association of ApoA-I appears to be altered in hyperlipidemia.


The effect of exercise on plasma high density lipoproteins. The influence of vigorous activity in man on plasma lipids and lipoproteins is reviewed, with particular emphasis on high density lipoproteins. Both cross sectional and longitudinal (or training) studies have been reported, many of them of less than ideal design. Nonetheless, a consistent pattern emerges in which increased exercise levels lead to lower plasma concentrations of triglycerides and very low density lipoproteins, and of low density lipoproteins. High density lipoprotein levels increase. Sometimes, but not uniformly, plasma total cholesterol level falls as the result of these changes. The increase in plasma high density lipoprotein appears to be the result largely of an increase in the less dense HDL2 subfraction. Plasma apolipoprotein A-I levels (but not apo-A-II levels) seem to increase concomitantly. The precise biochemical mechanism responsible for these changes has not been elucidated; but the recent finding of increased lipoprotein lipase activity in adipose tissue and muscle of endurance runners suggests that increased lipolytic rate of triglyceride-rich lipoproteins may be an initial step in a sequence of events leading to higher plasma levels of HDL-2.


A review of the unique features of HDL apoproteins. The human plasma high density lipoproteins (HDL) are a heterogeneous ensemble of five proteins associated with both neutral and polar lipids. The sequence of all five proteins are known. ApoA-I and apoA-II are the major protein components; apoC-I, apoC-II and apoC-III are the minor protein components. All these apoproteins spontaneously recombine with phospholipids to give stable lipid-protein complexes and freely exchange between the two major HDL subclasses, HDL2 and HDL3. In addition, ApoC-I, apoC-II, and apoC-III exchange between HDL and very low density lipoproteins. Furthermore, certain HDL apoproteins are activators for plasma enzymes that are important in lipid metabolism. ApoA-I and apoC-I activate lecithin/cholesterol acyltransferase; apoC-II is an activator of lipoprotein lipase. The regions of apoC-I and apoC-II that are involved in the activation of these enzymes have been localized with synthetic peptides. Studies of synthetic and native fragments of apoA-II, apoC-I, apoC-II, and apoC-III as well as model lipid-binding peptides have identified specific regions with structural features common to lipid-binding proteins. These special properties, which include helical potential, sequences with a critical amphipathic length, and high hydrophobicity of the nonpolar side of the amphipathic helix, are the determinants of HDL structure and metabolism.


Organization and expression of a two-gene cluster in the arginine biosynthesis of Saccharomyces cerevisiae. In Saccharomyces cerevisiae, argB and argC define two adjacent and complementing loci, with mutants defective in two consecutive steps of arginine biosynthesis: N-acetylglutamate kinase (AG-kinase) and N-acetylglutamyl-phosphate reductase (AGPreductase). These enzymic activities are readily separated by ammonium sulfate fractionation or Sephadex G-200 chromatography. This suggests that each activity is carried in vivo by a different protein. The synthesis of the two enzymes is coordinately regulated, with an 85-fold difference in specific activities between fully repressed and fully derepressed cells. Missence mutations of the argB locus are defective in AGkinase only. Nonsense mutations in the argB locus are defective in both activities. Missense and nonsense mutations in the argC locus are defective in AGPreductase, with a few alleles also showing a reduced level of AGkinase. These data are best explained by assuming that argB and argC are two genes transcribed as a single messenger from argB to argC. This messenger produces in vivo two distinct proteins corresponding to the argB and argC gene products, either because translation can be initiated at the beginning of both genes, or because a large polypeptide is specifically cut in vivo to yield the gene products of argB and argC.


Spontaneous production of a C-type RNA virus in a cell line derived from rat glioma. The spontaneous production of a rat C-type RNA virus (ACV) in a cultured cell line (AC cells) established from a chemically induced rat glioma was studied. The characteristics of ACV were: morphology typical of C-type RNA virus; buoyant density of 1.15 g/ml in a sucrose density gradient; RNA directed DNA polymerase activity; viral core with a density of 1.28 to 1.30 g/ml; 70S RNA with dimer structure; and structural protein composed of mainly four polypeptides. Kinetical analysis of DNA-DNA hybridization revealed that DNA sequences homologous to DNA transcripts of RNA of ACV were present in rat cells. RNA directed DNA polymerase of ACV partially cross-reacted with antiserum to the polymerase of Rauscher murine leukemia virus. These data suggest that ACV is an endogenous C-type RNA virus of rat origin.