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Biomedical subjects

D G Morgan

Publications and source records attributed to D G Morgan.

At least 127 records · Page 7Linked to original sources
PubMed1979

The incorporation of intrastriatally injected [3H]fucose into electrophoretically separated synaptosomal glycoproteins. II. The influence of passive avoidance training.

Following intrastriatal injections of [3H]L-fucose, male albino rats served as (a) trained subjects in a step-down passive avoidance task, (b) stress controls receiving inescapable shock or (c) handled controls. At a series of time points after treatment the animals were sacrificed and the P2 fraction of the injected neostriatum was isolated. This tissue was electrophoresed on SDS-polyacrylamide gels and radioactivity profiles were constructed from 1 mm gel slices. The profiles of trained subjects were compared to shocked and handled control subjects from the same time point group. No differences in total [3H]fucose incorporation into neostriatal glycoproteins were detected as a result of the behavioral treatment used, nor was an incorporation into the majority of electrophoresed peaks altered. Three radioactive gel peaks were significantly altered as a function of experience. At the one day time point, trained subjects exhibited a significant increase in the tritium content of a 70,000 dalton fucosyl-glycoprotein peak. At the 5 day time point, increased label was detected in a 180,000 dalton peak in both trained and shocked subjects, while a significant increase in a 140,000 dalton peak was observed only in trained animals. The relation of the present findings to perviously reported training related differences in glycoprotein metabolism are discussed.

Animals↗
PubMed1979

Site of Epstein-Barr virus replication in the oropharynx.

Cells and cell-free material in saliva, parotid secretions, and throat washings from patients with acute infectious mononucleosis and patients undergoing tonsillectomy were assayed for the presence of infectious Epstein-Barr (EBV) virus. The agent was invariably present in cell-free form in saliva; neither infectious virus nor viral antigens were found in the cells. Tonsillar lymphocytes from eight patients were also free of EBV. In 10 of 40 patients virus was recovered in secretions from parotid-gland orifices or ducts. These findings suggest that the salivary glands are the site of EBV production in the oropharynx.

Acute Disease↗
PubMed1979

Down syndrome due to 21;21 translocation in a male twin.

A spontaneous 21;21 translocation resulting in features consistent with Down syndrome is reported in the first born of male fraternal twins. No history of twinning or chromosomal abnormalities in the family was noted. Any association between dizygous twinning and Down syndrome due to de novo translocation remains speculative until a sufficient pool of published data is available from study of such families.

Chromosomes, Human, 21-22 and Y↗
PubMed1977

Acute respiratory distress in the dog associated with paraquat poisoning.

An acute respiratory distress syndrome in 10 adult dogs was usually preceded by vomiting, anorexia and lethargy followed, after a short interval, by dyspnoea. The dyspnoea became increasingly severe, despite oxygen therapy, and cyanotic respiratory failure ensued. All 10 dogs died or were killed after illnesses lasting between one and eight days. Necropsies revealed pulmonary congestion, oedema, collapse and haemorrhage with loss of alveolar epithelial cells. Early alveolar fibrosis was also found. Paraquat was identified in post mortem samples from four of the 10 dogs.

Animals↗
PubMed1977

Sequential immunofluorescence and infectivity studies on the replication of Herpesvirus saimiri in owl monkey kidney cells.

Methods are described for the preparation and authentication of a highly specific antiserum against herpesvirus saimiri (HVS) capsid antigens. The antiserum was used in immunofluorescence tests to follow the development of capsid antigens in HVS-infected owl monkey kidney cells throughout the virus replication cycle in parallel with sequential titrations of virus infectivity in both cells and medium. Fluorescence was detected as a round or oval, bright green area of staining at the centre of the nucleus which was similar in outline to the Cowdry type A inclusion seen in HVS-infected cells stained by haematoxylin and eosin. The first detection of fluorescence towards the end of the eclipse phase of the virus growth cycle, and its abolition by the treatment of infected cultures with cytosine arabinoside confirmed the identity of HVS capsid antigens as late antigens. The failure to detect fluorescence in the cytoplasm of HVS-infected cells has brought to light a conflict between the site of accumulation of virus capsid antigens as determined by immunofluorescence and the finding, by electron microscopy, of cytoplasmic immature particles in intact cells during the early stages of the virus replication cycle. The significance of this discrepancy is discussed in relation to its possible existence for other members of the herpesvirus group.

Animals↗
PubMed1977

Observations on the antigenic relationships between Epstein-Barr virus and herpesvirus saimiri.

The antigenic relationships between Epstein-Barr (EB) virus and herpesvirus saimiri (HVS) have been investigated in comparative immunofluorescence, microimmunodiffusion and serum neutralization tests. No similarity was detected between the structural antigens of the two herpesviruses but the results of microimmunodiffusion tests showed that they shared a non-structural, virus-determined antigen. The implications of this finding are discussed in relation to the importance of HVS and its monkey lymphoma as a model system of herpesvirus oncogenesis.

Antigens, Viral↗
PubMed1976

Morphological observations on the replication of herpesvirus saimiri in monkey kidney cell cultures.

Owl and African green monkey kidney cell cultures have been infected with 1 p.f.u./cell of herpesvirus saimiri and sample cultures have been taken for examination by electron microscopy at 3 to 6 hourly intervals over a period of 7 days; the experiments were repeated several times. The peculiarly slow replication cycle of Herpesvirus saimiri has enabled distinct cytoplasmic and nuclear phases in virus maturation to be clearly distinguished; the overall fine structural features were similar in both cell types. Immature particles were first detected in the nucleus and cytoplasm 63 h after infection. Thereafter, abundant cytoplasmic immature particles matured by budding through cytoplasmic membranes until about 100 h, whereas nuclear immature particles budded through the inner nuclear membrane or intranuclear invaginations of it later, from about 100 h until cytolysis was complete at 160 h. Morphological differences were also observed between particles budding at cytoplasmic membranes and the nuclear envelope. At the former site the membrane overlying the bud showed an electron opaque thickening which imparted to the mature particle an asymmetrical appearance. Such thickenings of the envelope were not observed in mature particles of nuclear origin. Unusual tubular and laminated nuclear structures were seen towards the end of the replicative cycle corresponding with the phase of nuclear virus maturation by budding; the morphology of the latter structures is described.

Animals↗
PubMed1973

Unusual intranuclear tubular structures associated with the maturation of Herpesvirus saimiri in monkey kidney cell cultures.

Unusual intranuclear tubules have been observed in cultures of both African green monkey and owl monkey kidney cells infected with Herpesvirus saimiri; the material was studied in thin sections with the electron microscope. The tubules were seen in about 10% of virus-containing cells at the stage when the virus matured by budding at the nuclear membrane, measured 160-180 nm in diameter and up to 3.6 μm in length, were bounded by an outer "membrane" and contained beneath this an electron dense repeating structure arranged either as a coil or a series of evenly spaced rings. The morphology and significance of the tubules are discussed.

Animals↗