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Biomedical subjects

L Bishop

Publications and source records attributed to L Bishop.

10 recordsLinked to original sources
PubMed1989

Reconstitution of a bacterial periplasmic permease in proteoliposomes and demonstration of ATP hydrolysis concomitant with transport.

The histidine periplasmic permease of Salmonella typhimurium has been partially purified and reconstituted into proteoliposomes. In this in vitro preparation, transport activity is completely dependent on the presence of all four permease proteins (HisJ, HisQ, HisM, and HisP) and on internal ATP. The reconstituted system shows initial rates of transport that are comparable to those obtained with right-side-out membrane vesicles and it establishes a 100-fold concentration gradient for histidine. Proteoliposomes also transport histidine when GTP replaces ATP. Proteoliposomes do not catalyze significant ATP hydrolysis until histidine transport is initiated by addition of substrate along with HisJ, the water-soluble histidine-binding protein. Both initially and throughout the course of substrate transport there is a concomitant hydrolysis of ATP, with an apparent stoichiometry (ATP/histidine) of 5:1. These experiments demonstrate directly that ATP is the source of energy for periplasmic permeases, thus resolving previous controversies on this topic.

ATP-Binding Cassette Transporters↗
PubMed1989

Fine-structure genetic map of the maltose transport operon of Salmonella typhimurium.

We have constructed a fine-structure genetic map of the maltose transport operon in Salmonella typhimurium. We have isolated mal mutants by using indicator plates, penicillin selection, or a proton suicide technique. Mutants were obtained as spontaneous events or were induced by chemical mutagenesis and transposon insertion. Tn10 and Mu d(lac Ap)1 insertion mutations were used to create deletions. Mutations were also obtained in a gene that is equivalent to lamB in Escherichia coli, which codes for the lambda bacteriophage receptor. The gene products in the mutants were characterized by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis and immunoblotting. Our data indicate that the location of this operon on the Salmonella chromosome as well as the gene order and its orientation are the same as those in E. coli. This map will be useful in studying the mechanism of periplasmic transport in S. typhimurium.

ATP-Binding Cassette Transporters↗
PubMed1986

Ultrastructural investigations of cardiomyopathy in the dog.

Eight dogs of the giant breeds with congestive cardiomyopathy were studied at necropsy and samples taken for examination with the electron microscope. Of the 8 dogs, 6 were male. There were 4 Irish Wolfhounds, 2 Great Danes, one Pyrenean and one Saint Bernard. Ages ranged from 6 months to 7 years and if the atypical 6-month-old is removed, the average age was 5 and a third years. Ultrastructural examination of myocardium from abnormal animals showed increases in intermyofibrillar spaces, lipofuscin granules, fat droplets and myelin figures, mitochondrial hyperplasia, disruption of myofibrils and thickening of Z bands. Although all the ultrastructural changes noted were non-specific, the degree of degeneration in cases of congestive cardiomyopathy appeared to be greater than that reported in cases with heart failure caused by other conditions. However, there was no obvious correlation between the length or severity of illness and the degree of ultrastructural damage in dogs with congestive cardiomyopathy. Similarly, there was no correlation between the duration of illness and the severity of the hypertrophy (measured by Z band thickening). As in man, no characteristic features peculiar to this condition were established.

Animals↗
PubMed1986

Monoclonal antibodies to human osteosarcoma-associated antigen(s).

Monoclonal antibodies (MoAbs) against human osteosarcoma cells were obtained by the production and cloning of hybrids resulting from the fusion of mouse myeloma cells P3 X 63Ag8.653 with spleen cells from partially purified, osteosarcoma-associated antigen (OSAA)-immunized BALB/c mice. OSAAs were isolated from the spent culture medium of a human osteosarcoma cell line (TE-85). Five hybrid clones were established and designated as OSA1, OSA2, OSA3, OSA4, and OSA5. OSA1 and OSA2 had similar activity. All 5 MoAbs reacted strongly with most osteosarcoma cell lines and with all osteosarcoma tissues tested but not with 10 tumor cell lines and 2 tumor tissues from other cancers. OSA3, OSA4, and OSA5 cross-reacted with a fibrosarcoma cell line, a colon cell line, and fibrosarcoma, respectively, as well as with a melanoma cell line. None of the MoAbs were reactive with activated normal human peripheral blood mononuclear cells (PBMC). Immunoprecipitation of membrane protein isolated from LM cells and TE-85 cells with the MoAbs OSA1 and OSA2 conjugated with Staphylococcus aureus yielded a molecule with molecular weight of approximately 92,000. No detectable membrane protein was precipitated when 125I-labeled membrane protein from pooled activated human PBMC and tumor cells of other histologic types were used in the immunoprecipitation.

Animals↗
PubMed1979

Parasite-related lesions in a bearded seal, Erignathus barbatus.

A free-ranging adult male bearded seal (Erignathus barbatus) killed by polar bears was salvaged and examined at necropsy. Significant findings included diffuse intrahepatic bile duct fibrosis and chronic cholangitis; multiple nodules of chronic fibrosing pancreatitis; and gastric ulcers. Trematode eggs (Family Campulidae) were found in the pancreatic nodules. These eggs and the trematodes that produced them probably caused the pancreatic and liver lesions. Phocanema decipiens and Contracaecum osculatum were found in the stomach lumen; several P. decipiens were attached to gastric ulcers. Sarcocystis sp. is reported for the first time in a bearded seal.

Animals↗
PubMed1979

Chronic active hepatitis in dogs associated with leptospires.

Chronic active hepatitis was diagnosed in five American Foxhounds from one kennel. Spirochetes were demonstrated in the liver in four of the dogs. A rising titer to Leptospira interrogans serovar grippotyphosa was found in the fifth dog, although spirochetes were not demonstrated in tissues. A serologic survey at the kennel revealed evidence of exposure of 6 of 13 dogs to grippotyphosa. This is the first report of an association between chronic active hepatitis leptospiral infection in any species.

Animals↗
PubMed1978

Intracranial teratoma in a domestic rabbit.

A solid and cystic suprasellar teratoma was found in a rabbit killed because of incoordination. The tumor consisted of neural cells, cysts lined by various types of epithelium, respiratory mucosa, gastric mucosa, mucous and mucoserous glands, collagenous connective tissue, cartilage and fat.

Animals↗
PubMed1977

A case of chancroid.

After a visit to Hong Kong, a 27-year-old salesman developed penile ulceration which failed to respond to three weeks' penicillin therapy. He then presented to hospital with acute paraphimosis. A clinical diagnosis of chancroid was confirmed by isolation of Haemophilus ducreyi. The ulcers healed after sulphonamide and streptomycin therapy. Although chancroid is an uncommon venereal disease in Australia, its incidence is still high in many tropical countries. It should be considered as a possible cause of genital ulceration in patients who have travelled overseas.

Adult↗