Showing papers by "Saint Louis University published in 1972"
TL;DR: When actin molecules form “rigor complexes” with nucleotide-free myosin, tropomn binds calcium with greater affinity and in a cooperative response the remaining actin molecule not cornplexed with myOSin are “turned on” even though calcium is absent.
Abstract: When actin molecules form “rigor complexes” with nucleotide-free myosin, tropomn binds calcium with greater affinity and in a cooperative response the remaining actin molecules not cornplexed with myosin are “turned on” even though calcium is absent.
673 citations
TL;DR: The purpose of this paper is to show that current interpretations of the status of vitamin E nutrition from blood level data are inadequate, and to suggest a means of remedying the situation.
Abstract: The purpose of this paper is to show that current interpretations of the status of vitamin E nutrition from blood level data are inadequate, and to suggest a means of remedying the situation. It has been known for some time that the serum level of cholesterol can be related to the level of the total tocopherol in the s e ~ u m . ~ ~ More recently, the relationship of serum tocopherol to serum lipoproteins and other lipid fractions has been reported by several laboratories." Since changes not related to the amounts of vitamin E ingested can occur in the blood levels of the tocopherols when other factors such as age, pregnancy, protein deficiency, and a variety of disease states cause changes in the blood lipids, one is faced with the fact that a determination of the serum tocopherol may give erroneous information about the level of tocopherol in the tissues. Furthermore, since only about 1% of the total body tocopherol may be in the blood, and the peroxide hemolysis test is largely dependent on the level of tocopherols in the blood, even this test of the relative susceptibility of the erythrocyte to oxidation may lose its usefulness unless the blood lipid levels are known. This report will confirm and examine those aspects of the serum lipid-tocopherol relationships that provide information from which a numerical statement of relative tocopherol nutrition may be derived. The data presented are divided into five sections. First, data from a previous study, designed for a different purpose, will show the changes that occurred when patients who were fed diets in which their tocopherol intake were controlled were given triiodothyronine (T3). The second section describes experiments with rats whose lipids were increased by a combination of drugs and dietary means, in order to determine how much one can elevate the serum levels of tocopherol by increasing the blood lipid levels. A third section illustrates the changes observed during studies of infants recovering from protein-calorie malnutrition while they were fed controlled diets that contained relatively low levels of tocopherol. The fourth section includes data on the analysis of plasma from a variety of patients, at various ages from birth to maturity, to illustrate the range of data that can be obtained. The fifth section compares the data obtained from mother and child at the time of birth.
473 citations
TL;DR: An infant with ileal atresia and a postoperative short bowel syndrome was maintained intermittently for the first 8 1/2 months of life by total parenteral nutrition when she developed signs of copper deficiency which responded promptly to copper supplementation.
278 citations
TL;DR: The results support the proposal that renal prostaglandins function in an intrarenal negative feedback control system which regulates antidiuretic and vasoconstrictor systems.
Abstract: 1. The concentrations of prostaglandin E(PGE)- and prostaglandin F(PGF)-like substances in renal venous blood were determined by parallel bioassay of extracts of renal venous effluent before and during adrenergic stimulation of the kidney and were related to simultaneous measurements of renal blood flow and urine flow. 2. When noradrenaline was infused continuously into the renal artery, its initial vasoconstrictor and antidiuretic effects diminished on seven of eight occasions in six dogs. Rapid recovery of renal blood flow and urine flow was invariably associated with increasing concentration in renal venous blood of a substance having the physicochemical, chromatographic and biological properties of a prostaglandin of the E series. In the one instance when rapid early recovery of renal blood flow was not observed the concentration of PGE-like substance was not increased. 3. In contrast, during renal nerve stimulation early rapid recovery of renal blood flow and urine flow did not occur and the concentration of a PGE-like substance in renal venous blood did not increase. The concentration of a PGF-like substance in renal venous effluent did not increase in response to either stimulus. 4. Since PGE 2 , unlike PGF 2α , is a potent renal vasodilator and diuretic, the intrarenal release of this substance by noradrenaline in concentrations similar to those determined for a PGE-like substance (>0·50 ng/ml assayed as PGE 2 equivalents) would account for the changes in renal blood flow and urine flow in these experiments when the renal actions of noradrenaline were attenuated. 5. These results support the proposal that renal prostaglandins function in an intrarenal negative feedback control system which regulates antidiuretic and vasoconstrictor systems.
160 citations
TL;DR: A critical appraisal of information about the possible involvement of sarcoplasmic reticulum in various muscle diseases such as cardiac failure, muscular dystrophy, myotonia, and denervation atrophy is discussed.
Abstract: Publisher Summary This chapter discusses a critical appraisal of information about the possible involvement of sarcoplasmic reticulum in various muscle diseases such as cardiac failure, muscular dystrophy, myotonia, and denervation atrophy. Because of the singular concentration of attention on the role of sarcoplasmic reticulum in the regulation of sarcoplasmic Ca 2+ concentration, conspicuous gaps developed in the knowledge regarding other possible functions of sarcoplasmic reticulum such as its involvement in the energy metabolism of muscle cells. Recent evidence indicates that the sarcoplasmic reticulum may represent a compartment for hexokinase, glyceraldehydephosphate dehydrogenase, and phosphofructokinase activities. Other metabolic functions of sarcoplasmic reticulum include the synthesis of phospholipids and proteins, as suggested by their turnover in Sarcoplasmic reticulum membrane. Finally, a detailed biochemical analysis of the function of transverse tubular system and the triad may soon become possible. The distribution of sarcoplasmic reticulum in the muscle cell and its relationship to the myofibrils, surface membranes, and the T-system tubules bear considerable importance in relation to its physiological function.
95 citations
TL;DR: All ten RNA tumor viruses contained ribonuclease H activity which degraded the RNA of both the calf thymus hybrid and poly(A)-poly(dT), whereas only the ribonUClease H in the Moloney strain of murine sarcoma-leukemia virus and in RD-feline leukemia virus hydrolyzed the RNA strand of poly(U)- poly(dA).
Abstract: Ten ribonucleic acid (RNA) tumor viruses grown in five different host cell species and three non-oncogenic viruses from three different virus groups have been examined for ribonuclease H content. Three different substrates were used to assay ribonuclease H: calf thymus [3H]RNA-deoxyribonucleic acid (DNA) hybrid prepared with denatured calf thymus DNA and Escherichia coli DNA-directed RNA polymerase, 3H-polydenylic acid [3H-poly(A)] complexed to polydeoxythymidylic acid [poly(dT)], and 3H-polyuridylic acid [3H-poly(U)] complexed to polydeoxyadenylic acid [poly(dA)]. All ten RNA tumor viruses contained ribonuclease H activity which degraded the RNA of both the calf thymus hybrid and poly(A)-poly(dT), whereas only the ribonuclease H in the Moloney strain of murine sarcoma-leukemia virus and in RD-feline leukemia virus hydrolyzed the RNA strand of poly(U)-poly(dA). No appreciable ribonuclease H activity was detected in influenza, Sendai, or vesicular stomatitis virus. The ribonuclease H and RNA-directed DNA polymerase activities in Moloney murine sarcoma-leukemia virus were inseparable by phosphocellulose chromatography or glycerol gradient centrifugation, but appeared to be partially separated by diethylaminoethyl-cellulose chromatography.
89 citations
TL;DR: Fungus were over 100 times more susceptible than animal cells to the effects of amphotericin B, and these observations might have clinical application.
Abstract: Amphotericin B was found to potentiate the antifungal effects of mycophenolic acid glucuronide, tetracycline, and actinomycin D by increasing the penetration of these antibiotics through the fungal cytoplasmic membrane. Because the fungi were over 100 times more susceptible than animal cells to these effects of amphotericin B, these observations might have clinical application.
79 citations
TL;DR: Single-stranded 35S and 20S viral RNA species are synthesized in virus-producing mouse and rat cells transformed by the murine sarcoma virus.
Abstract: Single-stranded 35S and 20S viral RNA species are synthesized in virus-producing mouse and rat cells transformed by the murine sarcoma virus. A transformed hamster cell line that does not produce virus synthesizes 35S, but not 20S viral RNA.
75 citations
71 citations
TL;DR: In this paper, the physical processes occurring within a perennial snow cover and at its surface are discussed with particular emphasis on monthly variations in Antarctic snow, and results of a one-year simulation of physical processes In snow are compared with 1958 data at Mirny and Pionerskaya, Antarctica.
Abstract: The physical processes occurring within a perennial snow cover and at its surface are discussed with particular emphasis on monthly variations in Antarctic snow. Results of a one-year simulation of physical processes In snow are compared with 1958 data at Mirny and Pionerskaya, Antarctica. The simulation demonstrates the following: first, solar radiation is effective to a depth of 50 cm or so, but longwave radiation cools the surface alone, causing the “greenhouse” effect first observed in snow at least four decades ago. Highest summertime temperature and initial snowmelt thus occur not at the surface but roughly 10 cm below It. Second, the percolation of meltwater with eventual refreezing during the subsequent winter is the most efficient mechanism for modifying the temperature profile at depths of several meters of more. Third, concerning the surface energy budget, at temperatures below −20C, atmospheric sensible heat flux approximately compensates net radiation throughout the year. When the te...
60 citations
TL;DR: The trypanosomatid Crithidia fasciculata contains a single bifurcated mitochondrial organelle, and a method is described for its isolation as a relatively intact structure that carries out oxidative phosphorylation and shows respiratory control with succinate as substrate.
TL;DR: The total biosynthesis of ubiquinone-9 from p-hydroxy[U-14C]benzoate has been demonstrated in mitochondria isolated from rat liver slices preincubated with mevalonic acid and partial reactions were demonstrated, suggesting that the inner membrane of liver mitochondria is capable of the hydroxylation and methylation of aromatic precursors of ubiqu inone.
TL;DR: It is concluded that the avian uterus is more responsive to prostaglandins than the mammalian myometrium and thus may serve as a highly sensitive model for further studies.
TL;DR: It is established that the 5′-end of poliovirus RNA is pAp, which is mainly labeled pAp in viral RNA labeled in vivo with 32 P.
TL;DR: It is postulated that liberation of acetylcholine secondary to hypo-magnesaemia leads to cholinergic symptoms and neuromuscular hyperirritability and Histamine liberation is greatest in the neonatal period and when the body temperature and blood-sugar are lowest; this might explain the highest incidence of S.U.G.D. in the first months of life in the early morning hours of winter.
TL;DR: During the winter and spring of 1970 to 1971, an epidemic of measles occurred in the St. Louis area, and acute-phase measles HAI antibody titers in the recipients of live vaccines were greater than those of killed vaccine recipients, whereas the converse was true of the convalescent-phase serum titers.
Abstract: During the winter and spring of 1970 to 1971, an epidemic of measles occurred in the St. Louis area. During a study of this epidemic, 12 children had clinical illnesses suggesting the "atypical measles" syndrome, but six of these children had received only live attenauted measles vaccines. The illnesses in these six children were qualitatively similar to those in the six children who had been immunized with killed measles vaccines, but they were quantitatively less severe. Acute-phase measles HAI antibody titers in the recipients of live vaccines were greater than those of killed vaccine recipients, whereas the converse was true of the convalescent-phase serum titers.
TL;DR: It appears that, for both hamster and mouse rRNA, when the chromosomes of one species constituted the majority of the chromosome of a hybrid, a disproportionately higher percentage of rRNA of that species was present in the hybrid.
Abstract: The ribosomal RNA (rRNA) of a series of hamster-mouse somatic cell hybrids was studied. Mouse 28S rRNA was separated from its hamster counterpart by a two-step procedure involving sucrose gradient centrifugation of ribosomes and polyacrylamide gel electrophoresis of rRNA. Both hamster and mouse types of rRNA were synthesized in the 11 hybrids tested, including hybrids containing only about one-half the haploid number of either mouse or hamster chromosomes. It appears that, for both hamster and mouse rRNA, when the chromosomes of one species constituted the majority of the chromosomes of a hybrid, a disproportionately higher percentage of rRNA of that species was present in the hybrid. Some hybrid clones, having a majority of mouse chromosomes, had a mouse rRNA cell concentration approximately four to five times higher than the concentration expected from linear extrapolation of the value found for the mouse parental cell line.
TL;DR: High-molecular-weight cell-derived polypeptides with the same mobilities as those detected in the immunoprecipitate of intracellular proteins were found in virions released from cells after a 10-min pulse, and two possible interpretations are that they have a turnover rate higher than that of the major virion polypePTides or are cleaved proteolytically from the virions during long incubation in the culture media.
Abstract: Antibodies to disrupted murine sarcoma-leukemia virus (MSV[MLV]) were used to study the synthesis of viral polypeptides in the transformed, virus-producing rat cell line 78A1. When cultures were labeled for 10 min with radioactive amino acids, about 9% of the total labeled proteins were precipitated with antiserum against purified MSV(MLV), and 3 to 4% were precipitated with the same antiserum after it had been absorbed with an extract from uninfected rat cells. The difference is due to the presence in the unabsorbed antiserum of antibodies to cellular proteins that are present in purified virus preparations. Intracellular viral proteins labeled with radioactive amino acids were isolated by immunoprecipitation and analyzed by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. The mobilities of intracellular viral polypeptides were identical to those of the purified virion. However, labeled polypeptides having electrophoretic mobilities lower than that of the major virion polypeptide, the group-specific antigen of molecular weight 31,000, were present in higher proportion in the total cell extract and in the membrane fraction than in the virion. These polypeptides appear to be of cellular origin for they were present only in minute amounts in the immunoprecipitates obtained with the absorbed serum. After a 10-min labeling period, radioactive proteins were assembled into extracellular virions rapidly for the first 4 hr followed by a slower rate. More than 2% of the total proteins of the cell labeled in a 10-min pulse were assembled into virions at the completion of a 24-hr chase. The high-molecular-weight polypeptides with the same mobilities as those detected in the immunoprecipitate of intracellular proteins were found in virions released from cells after a 10-min pulse. A larger proportion of these high-molecular-weight proteins was detected in virions released after short chase periods (30-120 min) than after longer chase periods (6-24 hr). Two possible interpretations of these data are that the high-molecular-weight cell-derived polypeptides (i) have a turnover rate higher than that of the major virion polypeptides or (ii) are cleaved proteolytically from the virions during long incubation in the culture media.
TL;DR: Results indicate that PGE1 is a potent GH secretagogue and is accompanied by elevated plasma FFA and glucose levels without a significant change in insulin concentrations.
TL;DR: Comparisons among the four experiments manifested different patterns of pauses and rate across the two languages and age brackets.
Abstract: Three groups of 40 Ss (German adolescents and American adults and adolescents) read two passages and retold them. In confirmation of O'Connell Kowal, and Hormann (1969) for German adults, a number of pause and rate measures were significantly different for semantically ordinary or unusual passages. Comparisons among the four experiments manifested different patterns of pauses and rate across the two languages and age brackets.
TL;DR: The thyroid tissue demonstrated lack of peroxidase activity in the tyrosine iodinase, triiodide, guaiacol, and p-hydroxyphenylpyruvic acid (HPPA) assays.
Abstract: The spectrum of familial goiter due to iodide organification defect includes goitrous cretins, Pendred's syndrome, and goiter with euthyroidism and normal hearing. One female example of the latter group, now age 16, with goiter since age 6 and 50% perchlorate discharge, underwent thyroidectomy. The thyroid tissue demonstrated lack of peroxidase activity in the tyrosine iodinase, triiodide, guaiacol, and p-hydroxyphenylpyruvic acid (HPPA) assays. An inhibitor,of doubtful significance, was detected in the tissue in both triiodide and guaiacol assays using a soluble bovine thyroid peroxidase as enzyme source. No inhibition was found in the tyrosine iodinase or HPPA assays. Preincubation of the inactive enzymatic preparation from the goiter with hematin restored activity in the tyrosine iodinase assay to normal levels, while activity in the triiodide assay remained negligible. Using other human thyroid peroxidase preparations as controls, it was observed that the reconstructed enzyme from the goiter was more ...
TL;DR: The findings suggest that smokers have trouble quitting the habit because of their relatively little or lack of control of external events which personally affect them.
TL;DR: Late after adenovirus 2 infection (18 hr), nearly all newly synthesized polysomal messenger ribonucleic acid (mRNA) is viral specified and bound selectively by utilizing membrane filtration at high ionic strength.
Abstract: Late after adenovirus 2 infection (18 hr), nearly all newly synthesized polysomal messenger ribonucleic acid (mRNA) is viral specified. Large amounts of adenovirus mRNA have been purified by utilizing membrane filtration at high ionic strength. With this procedure, molecules that contain polyadenylic acid [poly (A)] tracts are bound selectively, and ribosomal RNA can be separated from the viral mRNA which contains poly(A). Polysomal RNA synthesized 18 hr after infection was labeled in the presence of 0.02 mug of actinomycin D per ml and extracted at pH 9.0. This RNA annealed 40% to 3 mug of adenovirus 2 deoxyribonucleic acid; the RNA selected by membrane filtration bound 80% under the same conditions. The RNA eluted from membrane filters was 80 to 90% greater than 18S and contained species migrating as 31, 27, and 24S. Binding of polysomal RNA to individual membrane filters was linear, using as much as 300 mug of RNA per membrane. A 1.1-mg amount of viral RNA was prepared from 17.7 mg of polysomal RNA that had been purified by extraction at pH 9.0.
TL;DR: Rapid kinetic analysis of the rate of development of difference spectrum after the addition of ATP or ADP to H-meromyosin indicates, that blocking of the S 1 and S 2 SH groups of H-MERomyOSin decreases both the formation and the dissociation rate constants of the substrate complex.
TL;DR: It seems clear that a humoral mechanism is responsible for the hepatic and hematopoietic alterations, but the nature of the mechanism remains to be demonstrated.
Abstract: Although first described in 1961, the association of renal carcinoma with hepatosplenomegaly, hepatic dysfunction, and thrombocytosis remains unexplained and is still not widely recognized. Among the most recent 50 patients with renal carcinoma treated at the St. Louis University Hospitals, five had this constellation of findings. The median age, 59 years, was the same for patients with or without the syndrome; the lesions were histologically identical to renal carcinomas without hepatic dysfunction. None of the five patients had evidence of metastasis to the liver at the time of operation, and the liver was histologically normal in one patient from whom a biopsy was taken. The hepatic dysfunction, hepatomegaly, and thrombocytosis disappeared postoperatively in the four patients who underwent nephrectomy. It seems clear that a humoral mechanism is responsible for the hepatic and hematopoietic alterations, but the nature of the mechanism remains to be demonstrated.
TL;DR: Functionally, polysomes from progesterone-treated ovariectomized rats had a low capacity to incorporate amino acids which corresponded closely with the capacity residing in polySomes from sham-operated pregnant subjects; animals in full lactation provided polysome which were 2 to 3 times more active.
Abstract: The hypothesis that progesterone is the sole hormone suppressing lactation during pregnancy in the rat has been tested in several ways in these experiments. At the dose frequently administered to rats (6 mg/24 hr) this steroid prevented the appearance of casein in the mammary gland, and greatly diminished the incorporation of 32PO4-2 into RNA of mammary tissue of ovariectomized rats. One effect of progesterone was to prevent the formation of RNA of both subunits of the ribosomes. Tissue from ovariectomized animals treated with this steroid had polysome profiles very similar to that obtained from mammary tissue from sham-operated pregnant rats. Functionally, polysomes from progesterone-treated ovariectomized rats had a low capacity to incorporate amino acids which corresponded closely with the capacity residing in polysomes from sham-operated pregnant subjects; animals in full lactation provided polysomes which were 2 to 3 times more active. Chronic infusion of low levels (12–48 μg/hr) of progesterone into...