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Biomedical subjects

D E Onions

Publications and source records attributed to D E Onions.

66 records · Page 4Linked to original sources
PubMed1983

Ferrokinetic and erythrocyte survival studies in healthy and anemic cats.

Erythrocyte survival and ferrokinetic studies were adapted to the cat. For 5 clinically healthy 4- to 9-month-old cats, mean 51Cr-labeled erythrocyte survival was 144 hours, and mean plasma 59Fe-labeled transferrin disappearance halftime was 51 minutes. Erythrocyte use of radioiron was rapid and efficient, with 50% to 80% of labeled iron incorporated into the erythron by 100 hours after injection into the cat. Six cats with feline leukemia virus infection were studied. For 2 cats with erythroid aplasia associated with C subgroup of feline leukemia virus, erythrocyte survival times were similar to those determined for the healthy cats, but plasma radioiron disappearance half time and erythrocyte use of radioiron were markedly diminished.

Anemia↗
PubMed1980

Polypeptides of feline leukaemia virus: identification of p15(E) and p12(E).

Antiserum to the p15(E) polypeptide of Rauscher murine leukaemia virus (R-MuLV) precipitated two proteins from purified virions of feline leukaemia virus (FeLV) with apparent mol. wt. of 18500 and 155000 on SDS-polyacrylamide gels. These proteins have been designated p15(E) and p12(E), in line with the nomenclature for MuLV proteins. Like the analogous protein of MuLV, FeLV p15(E) was found to be disulphide-linked to the virion glycoprotein, gp70. FeLV p15(E) was sensitive to digestion of intact virus particles with the proteolytic enzyme, bromelain, indicating that this protein is on the outer surface of the virion. An analysis of cat sera for precipitating activity for FeLV p12(E) showed this only in sera from cats which had recovered from FeLV infection and had virus-neutralizing activity.

Animals↗
PubMed1978

Leukocyte migration inhibition responses in canine lymphosarcoma.

The leukocyte migration inhibition (LMI) responses of 16 cases of canine lymphosarcoma were assessed at several stages of a combined chemotherapy immunotherapy regime. Pooled allogeneic lymphosarcoma cells used in treatment together with other allogeneic lymphosarcoma cells and autochthonous tumour cells were employed as antigens. Positive inhibitions were detected at all stages of treatment when medium controls were used but were not detected in five normal dogs with the same control. There was no association between relapse and remission and LMI response. When a normal lymph-node cell control was used only four dogs produced positive responses, all of which occurred after allogeneic cell administration. These positive responses could not be completely accounted for by sensitization to histocompatibility antigens but as they occurred both in remission and in relapse, including very advanced cases necessitating euthanasia, they were of no value in determining prognoses.

Animals↗
PubMed1975

Cultures of pig macrophages.

Freshly collected blood from pigs was defibrinated with glass beads. The white cells were collected on a Ficoll-Hypaque mixture and grown in RPMI 1640 medium containing 20 per cent fetal calf serum. Monocytes adhered to the plastic or glass flasks and the erythrocytes and lymphocytes remained in suspension. The adherent cells assumed the appearance of macrophages and the mean cell size at eight days was 40 mum. Phagocytosis was demonstrated and, in the first few days, incorporation of tritiated thymidine occurred. Cells remained viable in culture for more than eight weeks. Histo-chemical studies and the appearance of the cells under the electron microscope are described.

Animals↗
PubMedDate not supplied

Transgenic science.

The ability to manipulate the genome of the whole animal has, for the past 10 years, provided researchers with an alternative route of inquiry into many complex biological processes. Transgenic animals have numerous applications, encompassing a wide range of different disciplines, but they have proved especially useful in the investigation of gene regulation and gene function within the context of the living animal. This review describes the different techniques which have been used to produce transgenic animals and highlights advances which have been achieved using the transgenic approach.

Animals↗
PubMedDate not supplied

Feline leukaemia viruses: molecular biology and pathogenesis.

The feline leukaemia virus (FeLV) group represents one of the most important viral pathogens of the domestic cat. In addition, this virus - host system is one of the major experimental models for retroviral pathogenesis. Under natural conditions, the virus is horizontally transmitted through the cat population. The outcome of infection depends on a variety of factors including the virus does encountered and the age and immune status of the host. FeLVs can establish persistent infection, either overt or latent. Degenerative diseases of the haemopoietic system are the most common result of persistent infection and immunosuppression with secondary infection accounts for more deaths than does neoplastic disease. However, more is known about the molecular mechanisms of oncogenesis in this system and there are now numerous examples of field case tumours where FeLV has transduced an oncogene or acted as an insertional mutagen. The factors affecting the relative frequency of these mechanisms are considered as is the possibility that recombinant env gene recombinants play a role in FeLV pathogenesis.

Animals↗