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Biomedical subjects

J R Baker

Publications and source records attributed to J R Baker.

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

Subcellular localization of 111In in human and rabbit platelets.

In order to examine the subcellular distribution of 111In in 111In-oxine-labeled human and rabbit platelets, we employed a hypothetical grain technique of EM autoradiography analysis. The results indicate that in the rabbit 111In was concentrated within the platelet dense bodies, particularly when the platelets had been labeled in a plasma-free system. Under comparable conditions of labeling, human platelets appeared to accumulate almost all the radiolabel within the cytosol. Using inhibitors of 5-hydroxytrptamine (5-HT) uptake, i.e., cloimipramine, ouabain, sodium fluoride, p-chloromercuribenzoate, and reserpine, we were unable to demonstrate an active uptake process in either species. Both collagen and thrombin were able to cause dose-dependent release of radioactivity from the labeled rabbit platelets only. In the case of collagen, this mimicked endogenous 5-HT release and was inhibited by indomethacin. These results and their implications are discussed.

Animals↗
PubMed1981

Diabetic home blood glucose monitoring using a direct reading glucose sensitive test strip.

The aim of this study was to assess the performance of the BM Test Glycemie 20-800. Twelve diabetic patients were studied using the BM Test Glycemie 20-800, compared with one of the commonly available reflectance meters. The correlation coefficient for the BM 20-800 strip versus reference blood glucose result was significantly better than the reflectance meter (p = 0.01). In a separate study, laboratory staff tested both methods and achieved results which were similar to those of the patients using the BM Test Glycemie 20-800, but better than those of the patients using the reflectance meters. The BM Test Glycemie 20-800 is a cheap, reliable and acceptable method for the measurement of blood glucose levels.

Adolescent↗
PubMed1981

The C1q inhibitor in serum is a chondroitin 4-sulfate proteoglycan.

An inhibitor of human C1q has been purified from serum and identified as a chondroitin 4-sulfate proteoglycan. A typical preparation contained 22% uronic acid, 20% hexosamine, 12% sulfate, and 9% protein. When chromatographed on Sepharose CL-2B, the proteoglycan was eluted as a broad peak with a mean Kav of 0.6, which indicates that it is polydisperse and has an average Mr = approximately 175,000 (range, 45,000-750,000). Unlike the major species of cartilage proteoglycans, the serum proteoglycan did not form a complex with hyaluronic acid. Additional evidence for the noncartilaginous origin of C1q inhibitor is that its glycosaminoglycan chains totally lack chondroitin 6-sulfate isomers. Furthermore, the glycosaminoglycan component of C1q inhibitor was eluted from Sepharose CL-6B with a Kav of 0.52, indicating that these polysaccharide chains are considerably larger than those of human articular cartilage proteoglycan. The interaction between the proteoglycan and C1q was clearly evident in 0.15 M NaCl, as demonstrated by a radial immunodiffusion technique. The interaction decreased with increasing ionic strength but was not entirely abolished even at 0.3 M NaCl. These findings suggest that the interaction between C1q and the C1q inhibitor may occur under physiological conditions and may be of importance in modulating C1q activity in vivo.

Amino Acids↗
PubMed1981

Trypanosoma (Schizotrypanum) dionisii as a model for chemotherapeutic studies related to Chagas's disease.

Cultivated trypomastigotes of Trypanosoma (Schizotrypanum) dionisii were added to cultures of buffalo lung (BL) cells at 37 degrees C in a ratio of 500 parasites per cell. More than 60% of the cells became infected with amastigotes and the system was used to test trypanosomicidal activity and cytotoxicity of possible chemotherapeutic agents for use in Chagas's disease. Three nitroheterocyclic compounds known to be active against T. cruzi in cell cultures (nifurtimox, benznidazole and SQ 18506) were active at similar levels against intracellular T. dionisii (1, 10 and 0.1 microgram ml-1 respectively); concentrations of 10, 10 and 1 microgram ml-1 respectively were cytotoxic. Other substances, not regarded as active against T. cruzi (metronidazole, pentamidine and pentostam, had little or no trypanosomicidal effect even at 100 microgram ml-1. A recently developed nitroheterocyclic compound (MK 436) was active, and not cytotoxic, at 10 microgram ml-1 and possibly warrants further investigation Tetraethylthiuram disulphide, an inhibitor of threonine dehydrogenase which prevents growth of extracellular T. cruzi and T. dionisii in vitro at 1 microgram ml-1, was only slightly trypanosomicidal to intracellular T. dionisii at this dose; it was also somewhat cytotoxic.

Animals↗
PubMed1981

A survey of post mortem findings in 480 horses 1958 to 1980: (1) causes of death.

The causes of death recorded in 480 consecutive post mortem examinations of horses performed at the department of pathology, Veterinary Field Station, University of Liverpool, between February 1958 and February 1980, are reported. The alimentary, locomotor and nervous systems were those most frequently diseased. The most common specific entities were those associated with grass sickness, fractures and endoparasitism.

Animals↗
PubMed1981

A survey of post mortem findings in 480 horses 1958 to 1980: (2) disease processes not directly related to the cause of death.

Disease processes not directly related to the cause of death recorded in 480 consecutive post mortem examinations of horses performed at the department of pathology, Veterinary Field Station, University of Liverpool, between February 1958 and February 1980 are reported. The alimentary, cardiovascular, respiratory and locomotor systems were those most frequently diseased. The most common specific entities were those associated with endoparasitism and its associated vascular lesions, pneumonia and fractures.

Animals↗
PubMed1980

Immunological determinants of proteoglycans. Antibodies against the unsaturated oligosaccharide products of chondroitinase ABC-digested cartilage proteoglycans.

Bovine nasal cartilage proteoglycan monomer which had been digested with chondroitinase ABC to form the keratan sulfate-protein core was injected into rabbits. High titer antiserum was obtained as judged by the binding of 125I-labeled keratan sulfate-protein core. Native proteoglycan did not inhibit the interaction of the antiserum with labeled keratan sulfate-protein core. However, the disaccharide obtained from chondroitin 4-sulfate by the action of chondroitinase ABC, 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose, inhibited the interaction 50% at a concentration of 500 microM. The corresponding 6-sulfated and nonsulfated disaccharides at the same concentration gave 15% and 10% inhibition, respectively. Chondroitinase-digested proteoglycan from Swarm rat chondrosarcoma was strongly inhibitory, while the hyaluronidase-digested chondrosarcoma proteoglycan exhibited no detectable inhibition. Evidently, the antiserum raised against chondroitinase ABC-digested bovine nasal cartilage proteoglycan contains antibodies which recognize the unsaturated uronic acid residue linked to N-acetylgalactosamine 4-sulfate. These antibodies will be valuable for identifying and quantitating chondroitin 4-sulfate-containing proteoglycans in tissues.

Animals↗
PubMed1980

A clinical and immunopathological study of Brucella abortus strain 19--induced arthritis in cattle.

From a series of 11 calves presenting with a clinical unilateral gonitis (inflammation of the stifle), six were subjected to serological examination for titres against Brucella abortus and to subsequent post mortem examination. Tissues from five calves studied showed similar clinical and radiological features with post mortem examination confirming the presence of characteristic arthritic lesions in the affected stifle and other joints. The immune studies indicated the presence of B abortus strain 19 antigenic material within the cells of the stifle, synovial membrane and the drainage lymph nodes. Attention is drawn to the apparent absence of intact brucella organisms and to the incompatibility between some of the serum agglutination titres and the results of the immune studies. It is concluded that the absence of an elevated serum agglutination titre to B abortus is not an indication of the absence of B abortus antigenic material and that B abortus strain 19 under certain circumstances is pathogenic to calves causing a characteristic and serious clinical syndrome.

Animals↗
PubMed1980

A survey of causes of mortality in budgerigars (Melopsittacus undulatus).

Lesions found in 257 post mortem examinations of budgerigars (Melopsittacus undulatus) are recorded. The commonest disease was neoplasia, principally of the gonads, kidneys and fat. Hepatitis and focal hepatic necrosis, thyroid dysplasias and septicaemias were also common. A great variety of other disease processes occurred; each affected only a few birds.

Animals↗