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Biomedical subjects

C Hall

Publications and source records attributed to C Hall.

At least 343 records · Page 19Linked to original sources
PubMed1982

The polyadenylated RNA directing the synthesis of the rat myelin basic proteins is present in both free and membrane-bound forebrain polyribosomes.

Free and membrane-bound polyribosomes were isolated from the forebrain of actively myelinating 24-day-old rats. The poly(A)+ RNA (polyadenylated RNA) extracted from both fractions was translated in vitro in reticulocyte lysates [Hall & Lim (1981) Biochem. J. 196. 327-336] in the presence or absence of a heterologous microsomal membrane fraction from dog pancreas. The rat myelin basic proteins synthesized in vitro were isolated by CM-cellulose chromatography and by immunoprecipitation with purified anti-(myelin basic protein) antibody. The large (mol.wt. 18 500) and small (mol.wt. 16 000) myelin basic proteins were translational products of poly(A)+ RNA from both free and membrane-bound polyribosomes. The identity of the myelin basic proteins was verified by analysis of peptides generated by the cathepsin D digestion of the immunoprecipitated proteins synthesized in vitro, in comparison with authentic rat myelin basic proteins. Although several other translational products of membrane-bound polyribosomal poly(A)+ RNA were modified when microsomal membranes were present during translation, molecular weights of the myelin basic proteins themselves were unchanged. The myelin basic proteins synthesized in vitro also did not differ significantly in size from the authentic myelin basic proteins, indicating that these membrane proteins are unlikely to be synthesized as substantially larger precursor molecules. The presence of the specific mRNA species on both free and membrane-bound polyribosomes is compatible with the extrinsic location of the myelin basic proteins on the cytoplasmic surface of the myelin membrane.

Animals↗
PubMed1982

Analysis of human cytomegalovirus nucleoprotein complexes.

When chromatin was isolated from cells infected with human cytomegalovirus, the virus DNA remained with the chromatin fraction. If deproteinized virus DNA was added to either isolated nuclei or chromatin, the DNA was lost during the chromatin isolation. When isolated chromatin from cytomegalovirus-infected cells was banded in isopycnic metrizamide gradients, a single peak with a density of 1.18 g/cm3 was present. Analysis of this peak in isopycnic neutral CsCl gradients indicated that it contained both human cytomegalovirus and human embryonic lung cell DNAs. When infected nuclei were treated with micrococcal nuclease, 11S subunit particles which cosedimented with cell nucleosomes and contained virus DNA were isolated.

Chromatin↗
PubMed1982

Two clinical variants of spondylo-epiphysial dysplasia congenita.

Seventeen patients with congenital spondylo-epiphysial dysplasia from six centres in Britain have been investigated and two variants delineated. There is wide clinical and radiological variability in each group with overlap between them, but 12 of the patients had very short stature and grossly disorganised hips with severe coxa vara, and the five remaining patients were less seriously affected with height only a little below the third percentile and only mild coxa vara. Both groups can be diagnosed at birth but the two cannot be differentiated on clinical and radiological grounds until after the age of three to four years when the developing severe coxa vara and difference in stature become apparent. All cases were sporadic with the exception of a concordant twin-pair.

Abnormalities, Multiple↗
PubMed1982

Adenocarcinoma in Barrett's oesophagus. Two case reports and discussion.

Two cases of adenocarcinoma in columnar epithelium-lined oesophagus are reported. Two discrete carcinomas were found in one case, and areas of epithelial atypia were demonstrated in regions devoid of tumour in both. Similar observations in the literature together with statistical evidence indicate that Barrett's oesophagus should be regarded as a premalignant condition. Its clinical implications are outlined.

Adenocarcinoma↗
PubMed1982

Safety assessment of new anticancer compound, mitoxantrone, in beagle dogs: comparison with doxorubicin. II. Histologic and ultrastructural pathology.

Beagle dogs received either doxorubicin hydrochloride (1.75 mg/kg) or mitoxantrone (0.125 or 0.25 mg/kg) iv once every 3 weeks. These doses were equivalent to 36.05 mg/m2 of doxorubicin and 2.58 or 5.15 mg/m2 of mitoxantrone. Sequential endomyocardial biopsies were performed approximately 2 weeks after the fourth (or fifth), seventh, and ninth doses in order to monitor histopathologic and ultrastructural changes during the study. Myocardial lesions that progressed with time and dose were observed in heart samples from dogs that received doxorubicin, but not in dogs that received mitoxantrone. The myocardial lesions induced by doxorubicin were observed with cumulative doses as low as 144 mg/m2. Myocardial changes, which did not progress with time and cumulative dose, were observed in dogs that received either dose of mitoxantrone. The earliest observable evidence of doxorubicin-associated cardiotoxicity was seen morphologically in biopsy material before clinical signs of cardiotoxicity. No evidence of cardiotoxicity, either morphologic or clinical, was seen in dogs treated with the maximum tolerated dose of mitoxantrone during the course of treatment. The dog appears to be a suitable model for studying the chronic cardiotoxic effects of anthracyclines and for monitoring effects of compounds such as mitoxantrone, which show a spectrum of activity and mechanism of action similar to that of anthracycline compounds.

Animals↗
PubMed1982

The relationship between clinical stereotests.

The stereo-thresholds of 67 normal binocular subjects and two smaller groups of nonbinocular and temporarily occluded subjects were measured using three clinical stereotests and a laboratory two-needle test. The Titmus, Frisby and two-needle tests were found to give a much lower mean threshold than the TNO test. It was found that there is low, but significant, correlation between most pairs of the tests. This suggests they all measure the same underlying function of stereopsis, but other factors must also influence performance in these tests. The non-binocular subjects performed slightly better than the occluded subjects in some of the stereotests.

Adolescent↗
PubMed1981

Astrocyte cell lineage. I. Astrocyte progenitor cells in mouse neopallium.

The astrocyte cell lineage during postnatal development of the neopallium of Swiss mice was studied, using a colony culture assay method in which dissociated neopallial cells form discrete colonies in culture. It was found that immature epithelial-like cells that from type A colonies in culture come primarily from the subventricular zone but also from other regions of the neopallium. In culture, cells of type A colonies from type C colonies consisting of cells, which although still epithelial like, differ morphologically from the type A colony-forming cells. In the presence of dibutyryl cyclic adenosine monophosphate (dBcAMP) the type C colonies form cells rich in glial fibrillary acidic protein (GFAP) and stainable with Cajal's gold chloride sublimate, a stain specific for astrocytes. Therefore, it is proposed that type A colony-forming cells are astrocyte progenitor cells resembling the "pale" cells found in the subventricular zone (Blakemore and Jolly, '72), the "large glioblasts" (Sturrock, '76) and the free subependymal cells (Privat, '70; Paterson et at., '73) in the corpus callosum. The sequence of the lineage, i.e., cells forming type A colonies give rise to cells forming type C colonies which eventually differentiate into astrocytes, takes place in situ as well as in culture. As postnatal development of the neopallium progresses the number of colony-forming cells decreases in the subventricular zone and in other parts of the neopallium. The astrocyte progenitor cells migrate from the subventricular zone to other parts of the neopallium and progress through the lineage of differentiation in all regions of the neopallium.

Animals↗
PubMed1981

A/USSR and B/Hong Kong vaccine. Field experiences during an A/Brazil and an influenza B epidemic.

Young adults vaccinated in late spring of 1978 with one dose of vaccine containing either 7 microgram or 20 microgram of A/USSR (H1N1) hemagglutinin, followed by a dose of trivalent (A/USSR, A/Texas, B/Hong Kong) vaccine, were observed through an epidemic of A/Brazil influenza in the winter of 1978-1979, and of influenza B in 1979-1980. Influenza infection was diagnosed by virus isolation or serological titer rises between the spring seasons of 1978, 1979, and 1980. During the A/Brazil epidemic, rates of reported influenza-like illness and serologically confirmed H1N1 influenza infections were similar for all vaccine groups and two control groups. Naturally acquired antibody, but not vaccine-induced hemagglutination-inhibiting antibodies (HAI), appeared protective. During the influenza B epidemic, a lower rate of serologically confirmed infections was observed in the 1978 vaccine cohort than in one control group.

Adolescent↗
PubMed1981

Chromatin organization in the rat hypothalamus during early development.

The organization of chromatin in neuronal and glial nuclei isolated from different brain regions of rats during development was studied by digestion of nuclei with micrococcal nuclease. A short chromatin repeat length (approx. 176 base-pairs compared with that of glial nuclei from foetal cerebral cortex (approx. 200 base-pairs) was present in hypothalamic neurons throughout the ages studied, which was similar to the repeat length of cortical neurons from 7- and 25-day-old animals (approx. 174 base-pairs). Whereas in cortical neurons the chromatin repeat length shortened from approx. 200 base-pairs in the foetus to approx. 174 base-pairs in the first postnatal week, the short chromatin repeat length of hypothalamic neurons was already present 2 days before birth, indicating that hypothalamic neurons differentiate earlier than cortical neurons during brain development.

Animals↗
PubMed1981

Developmental changes in the composition of polyadenylated RNA isolated from free and membrane-bound polyribosomes of the rat forebrain, analysed by translation in vitro.

Free and membrane-bound polyribosomes were isolated from the rat forebrain during its development. Polyadenylated RNA [poly(A)+ RNA] was isolated from both fractions, by using oligo(dT)-cellulose chromatography, and its composition studied by translating the poly(A)+ RNA in vitro in reticulocyte lysates. Electrophoretic analysis of the translation products showed that both free and membrane-bound polyribosomal poly(A)+ RNA gave many common components, but that there were also distinct differences in the protein composition of the products of the two fractions. Several proteins, of mol.wts. 39 000, 37 000, 31 000, 27 000 and 17 000, appeared to be products predominantly of free polyribosomal poly(A)+ RNA, whereas others, of mol.wt. 47 000, 33 000, 24 000 and 21 000 were specific to the membrane-bound polyribosomal poly(A)+ RNA fraction. More developmental changes were observed in the translational products of the membrane-bound poly(A)+ RNA fraction. Proteins of mol.wts. 33 000 and 21 000, which were predominant components of the translational products of this fraction when isolated from 10-day and older rats, were not present in translational products derived from preparations isolated from 3-day-old rats. The developmental appearance of these proteins as translational products of the membrane-bound poly(A)+ RNA suggests the appearance of new mRNA species. These transcriptional changes are discussed in relation to processes involved in brain differentiation, including myelination.

Animals↗
PubMed1981

Hypothalamic neurons in dissociated cell culture: the mechanism of increased survival times in the presence of non-neuronal cells.

Rat hypothalamic neurons were cultured in the presence of fluorodeoxyuridine to inhibit nonneuronal cell proliferation. Under these conditions, neuronal cell survival was dependent on contact with homologous nonneuronal cells. This phenomenon did not seem to be due to the release of diffusable trophic factors, since neither growth on polylysine in the close proximity of nonneuronal cells nor the use of preconditioned medium significantly increased neuronal survival. However, metabolically active cell layers were required, since growth on heat-killed or fixed homologous nonneuronal cells did not increase neuronal survival. The increased survival of neurons seen here in the presence of homologous nonneuronal cells therefore appears to be due to metabolic co-operation mediated by specific, direct cell-cell contact.

Animals↗