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Biomedical subjects

G Wilson

Publications and source records attributed to G Wilson.

At least 289 records · Page 16Linked to original sources
PubMed1982

Prenatal counseling: a statewide telephone service.

The University of Michigan has provided a statewide prenatal counseling service for obstetricians and pregnant patients since 1974. Using a toll-free telephone hot line, 5204 inquiries have been made, relating to genetic conditions, exposure to potential teratogens, and obstetric or medical complications during early pregnancy. Up-to-date and accurate information has been supplied by a team of nurses and physicians with backgrounds in genetics or maternal-fetal medicine. Calls were taken by perinatal nurse counselors and referred to the appropriate medical specialist. The number of inquiries has increased from 3 per week in 1974 to 30 per week in 1981. Genetic amniocenteses, performed in response to 46% of all inquiries, provided financial support for the project. The authors consider the statewide use of this self-supported prenatal counseling service to be encouraging and recommend that this format be used at other institutions.

Adult↗
PubMed1981

Site of synthesis of the mitochondrial cytochromes in hepatocyte cultures.

The biosynthesis of mammalian mitochondrial cytochromes was explored in primary hepatocyte cultures. When these were pulsed with [35S]methionine in the presence of cycloheximide, eight discrete mitochondrial polypeptides were detected by fluorography after their resolution under denaturing conditions by polyacrylamide gel electrophoresis. Since the pulse labeling of the polypeptides was sensitive to chloramphenicol, an inhibitor of mitochondrial translation, they must be translated on mitochondrial ribosomes. Three were identified as the largest subunits of cytochrome oxidase by their immunoprecipitation with antibody directed against purified rat liver cytochrome oxidase. Another (Mr = 28,000) was identified as one of eight subunits of purified rat liver cytochrome b-c1 complex by its immunoprecipitation with antibody directed against bovine heart b-c1 complex. Since cytochrome b apoprotein is the only product of the mitochondrial genome in the yeast cytochrome b-c1 complex (Krieke, J., Bechmann, H., van Hemert, F. J., Schweyan, R. J., Boer, P. H., Kaudewitz, F., and Groot, G. S. P. (1979) Eur. J. Bio-chem. 101, 607-617), the results strongly suggest that the Mr = 28,000 subunit of liver b-c1 complex is cytochrome b apoprotein. Thus the contribution of the mitochondrial translation system to the cytochrome complexes in liver is identical to that of yeast and Neurospora, and there appears to be no deletion or transfer to the nuclear genome of structural genes for mitochondrially synthesized cytochromes during eukaryotic evolution.

Animals↗
PubMed1981

Measuring corneal recovery from osmotic and anoxic stress.

Halos indicate an important change in vision performance which can occur in contact lens wearers. Experimentally, halos occur when the cornea id deprived of atmospheric oxygen or bathed with hypotonic solutions. Pachometry is the accepted technique for measuring changes in the cornea, yet there is little evidence that measurement of overall corneal thickness is a sensitive indicator of structural changes in the epithelium, such as those causing halos. There is a need for a technique which is responsive to changes in the epithelium. This paper describes a new technique for quantifying changes in the epithelium by measuring halo brightness. Halos were produced by osmotic and anoxic stress, and recovery was monitored using measurements of corneal thickness and halo brightness. We found that the time course of halo recovery could be measured successfully on a naive subject. The technique provides information not available from pachometry and should be of considerable value in studies on the human cornea of factors which alter the optical integrity of the epithelium.

Contact Lenses↗
PubMed1981

3-Hydroxy-3-methylglutaryl coenzyme A lyase deficiency. Follow-up of first described case.

We report the progress of a child with a defect in leucine metabolism due to a deficiency of 3-hydroxy-3-methylglutaryl Coenzyme A lyase activity. This child was reported briefly in 1976 when the abnormality was first suspected at which time he was 7 months old. He is now aged 4 years 7 months and appears to be well and developing satisfactorily. His diet has been difficult to control and the biochemical defect is extremely sensitive to small amounts of leucine in the diet.

Amino Acid Metabolism, Inborn Errors↗
PubMed1981

Non-uniform swelling properties of the corneal stroma.

The swelling properties of the anterior and posterior stroma of bovine and rabbit corneas were examined by three different methods. The results show that the posterior stroma can swell more than the anterior stroma. Also, at a given swelling pressure, the posterior stroma is more hydrated than the anterior stroma. In a third experiment it is demonstrated that the posterior stroma is also more hydrated in the living eye. It is concluded that the stroma is not a homogeneous structure. The superficial stroma has different physiological properties from the deep stroma. These differences must be taken into account in theoretical models of corneal deturgescence.

Animals↗
PubMed1981

The effect of anoxia on the human corneal epithelium.

After 6 hr of oxygen deprivation, the human corneal epithelium had not swollen. Over the first hour of recovery from anoxia, the epithelium shrank by up to 20% before returning toward its predeprivation thickness. No fluorescein staining of the epithelium was seen during these experiments, but some subjects were able to discern halos immediately after deprivation. We conclude that homeostasis is maintained in the corneal epithelium for up to 6 hr of anoxia, but the intercellular spaces may be altered.

Adult↗
PubMed1980

Chromatin conjugate protein A24 is cleaved and ubiquitin is lost during chicken erythropoiesis.

The content of protein A24, an adduct of histone 2A and ubiquitin, was studied during chicken erythropoiesis. The amount of protein A24 was negligible in transcriptionally inactive mature chicken erythrocyte nuclei and 6-fold higher in the transcriptionally active nuclei of erythroid cells from phenylhydrazine-treated chickens. The decreased amount of protein A24 in the mature cells was offset by the relatively increased amount of histone 2A. A loss of free ubiquitin was also noted. In contrast, the amounts of high mobility group proteins 1,2, and E were essentially constant. Inasmuch as cleavage of the ubiquitin---histone 2A bond of protein A24 and loss of ubiquitin accompanied transcriptional shutdown during erythropoiesis, the presence of protein A24 and ubiquitin in premature polychromatic erythrocytes may reflect the presence of potentially active and transcribing chromatin structures.

Animals↗
PubMed1980

Assay of a placental protein to determine fetal risk.

Plasma concentrations and total amounts of pregnancy associated plasma protein A were determined in 272 patients at 34 weeks' gestation by immunoelectrophoretic assay. The mean plasma concentration and mean total amount of this protein were closely related (r = 0.9643) and were significantly raised in patients who subsequently developed pre-eclampsia (28 patients), went into premature labour (12), or suffered from antepartum haemorrhage (10). Mean values in all patients delivering growth-retarded babies were also raised, but when the results for such patients who also had other complications were excluded there were no differences between the sets of means. The assays were easily performed, and they may be a useful technique for screening pregnant women to detect those at risk of developing pre-eclamptic toxaemia, although the full potential of these assays cannot be realised until the protein's function is known.

Female↗
PubMed1980

The galactose-specific recognition system of mammalian liver: the route of ligand internalization in rat hepatocytes.

We have used two electron microscopic tracers, asialoorosomucoid covalently coupled to horseradish peroxidase (ASOR-HRP) and lactosaminated ferritin (Lac-Fer), to investigate the internalization of proteins bound by the asialoprotein receptor of rat hepatocytes. Both ligands are cleared rapidly from the circulation of rats, are retarded in their clearance by an excess of ASOR and accumulate principally in the liver. Morphological examination of the livers of rats after injection of the probes confirmed that the hepatocyte is the principal liver cell involved in the clearance of galactose-terminating proteins. Internalization occurred via coated pits and coated vesicles of 1000 A diameter. At 30 sec to 2 min the tracers began to accumulate in a complex arrangement of larger smooth-surfaced vesicles and tubular structures at the sinusoidal periphery of the cell. Fluid phase pinocytosis did not appear to account for any of the uptake into larger vesicles. The particulate tracer, Lac-Fer, was closely apposed to the membrane of coated pits and vesicles, but was found scattered throughout the lumen of the larger vesicles, possibly indicating dissociation of the ligand from its receptor. Although occasional lysosomes were detected cytochemically in the cell periphery, vesicles containing Lac-Fer showed no demonstrable aryl sulfatase activity. At 5 min, the tracers began to appear in Golgi-lysosome regions of the hepatocyte and were present in small vesicles of <2000 A in diameter, larger irregular vesicles and tubules. Serial sectioning indicated that tubular structures in Golgi-lysosome regions were often interconnected to the larger vesicles, but that tubules in the peripheral cytoplasm were only occasionally connected to larger structures. Some of the Lar-Fer-containing vesicles in Golgi-lysosome areas at 15 min after injection were found to contain aryl sulfatase reaction product, indicating fusion with lysosomes.

Animals↗
PubMed1980

Molecular evidence for genetic exchanges among ribosomal genes on nonhomologous chromosomes in man and apes.

We have found that human and ape ribosomal genes undergo concerted evolution involving genetic exchanges among nucleolus organizers on nonhomologous chromosomes. This conclusion is based upon restriction enzyme analysis of the ribosomal gene families in man and five ape species. Certain structural features were found to differ among (but not within) species even though the ribosomal genes have a multichromosomal distribution. Genetic exchanges among nucleolus organizer regions may be related to the well-known phenomenon of acrocentric chromosome associations observed in man and apes. Length variation in a region of the nontranscribed spacer was found in both chimpanzee species we examined. The nature of this length variation was found to be identical to that previously described in man. The origin of the length variation and its polymorphism within these three species might be explained by unequal alignment and unequal cross-over among the ribosomal genes. An especially surprising finding was a nucleotide sequence polymorphism present in each individual human and ape we examined. Some ribosomal genes of each individual have a HindII site in the 28S gene about 800 base pairs from the EcoRI site in this gene. The remaining 28S genes lack this HindII site. The presence of this polymorphism within individuals of every species we examined suggests that it has been maintained by natural selection.

Animals↗
PubMed1980

Thickness of the corneal epithelium during anoxia.

Thickness changes in the epithelium and stroma of the cornea of a living rabbit eye were observed with the specular microscope. Previous experiments on the excised cornea using this technique have failed to show any thickening of the corneal epithelium due to anoxia at the anterior surface. In the living eye, the same result was obtained. The results confirm that corneal edema due to anoxia is caused almost entirely by swelling of the stroma, the epithelium undergoing very little thickness change.

Animals↗
PubMed1980

Tests of fetal wellbeing in the third trimester of pregnancy.

Five different products secreted by the fetoplacental unit into the maternal circulation were measured in 272 patients when they were 34 weeks pregnant. The most useful indicator of present pathology or future complications of pregnancy was a placental protein, pregnancy associated plasma protein. A which was raised in pre-eclamptic toxaemia, antepartum haemorrhage and premature labour. The highest values were recorded in pre-eclampsia before any signs of the disease were evident. Schwangerschafts protein 1 was also raised in pre-eclampsia and antepartum haemorrhage but only after the disease had presented. Placental lactogen was also raised in pre-eclampsia and its measurement may have some predictive value. Total oestriol was lowered in fetal growth retardation and the unconjugated steroid raised in pre-eclampsia and lowered in retarded fetal growth.

Estriol↗