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Biomedical subjects

J H Martin

Publications and source records attributed to J H Martin.

At least 109 records · Page 6Linked to original sources

Glycocalyceal bodies and microvillous core rootlets: their value in tumor typing.

An ultrastructural study of the cell surface of lumen-forming tumors was carried out to determine the distribution of two morphologic markers seen in relation to the microvilli. These are membrane-bound glycocalyceal bodies and microvillous filament cores that penetrate the underlying cytoplasm as rootlets. They were found (especially when in combination) to be valuable in identifying tumors of what is referred to as intestinal-type epithelium, and could be seen in cases in which brush borders were absent. They have been demonstrated in intestinal-type carcinomas of the stomach and gallbladder, in adenocarcinomas of the small and large intestines and pancreatic ducts, in mucin-forming bronchiolar carcinomas, and in certain mucinous ovarian and endocervical tumors. Other tumors, whether mucin-producing or not, have been found to consistently lack these structures.

Adenocarcinoma↗

Calcium localization in normal rachitic, and D3-treated chicken epiphyseal chondrocytes utilizing potassium pyroantimonate-osmium tetroxide.

Normal, rachitic, and vitamin D3-replete chicken growth plates were studied utilizing the potassium pyroantimonate-osmium tetroxide procedure. A marked membrane and mitochondrial calcium was revealed in all specimens in the maturing and early hypertrophic zones which disappeared as heavy matrix mineralization began. The most significant difference shown in the specimens was in the marked intracellular lipid content of chondrocytes in all zones of the rachitic and D3-replete growth plates. There was negligible lipid present in normal specimens. It is suggested that as most of the mechanisms postulated as necessary for calcification are present in rachitic chicks, perhaps the increased intracellular lipid pool results from the formation of abnormal lipids for insertion into the plasma membrane and thus prevents normal calcium transport. Chains of intracellular vesicles were also visualized in maturing and hypertrophic chondrocytes. These were more often seen in rachitic growth plates and in increased numbers in the early D3-replete specimens. The etiology is unknown at the present time.

Animals↗

Interposition left gastric-caval shunt using internal jugular vein autograft in the treatment of portal hypertension.

The selective left gastric-caval shunt is, in theory, one of the better procedures in the surgical treatment of portal hypertension. We have performed a modification of the previously described technique utilizing an internal jugular vein autograft in 4 patients who had had more than one major haemorrhage from oesophageal varices 3-12 months before operation. There were no post-operative deaths. All 4 patients are still alive 3 months to 4 years after shunting, with no episodes of bleeding. On radiological and endoscopic follow-up, the oesophagogastric varices were noted to be markedly smaller in size than before shunting.

Humans↗

Glycocinnamoylspermidines, a new class of antibiotics. II. Isolation, physiocochemical and biological properties of LL-BM123beta, gamma1 and gamma2.

LL-BM123beta, gamma1 and gamma2 are three new antibiotics produced by fermentation of an unidentified species of Nocardia. These strongly basic, water soluble compounds were isolated from the culture filtrate by CM-Sephadex ion-exchange and carbon chromatography. All three antibiotics are active against both gram-positive and gram-negative bacteria. A mixture of LL-BM123 gamma1 and gamma2 is more active than the beta component but generally less active than gentamicin.

Animals↗

Estimating demographic characteristics using the ratio-correlation method.

Studies of the relative accuracy of methods of estimating the population at the substate level have generally found that the greatest degree of accuracy is provided by the ratio-correlation, or regression, method. This paper reports on research aimed at evaluating the effectiveness of this method in estimating the age and race composition of populations at the substate level. In addition to the basic multiple regression equation variants such as stratification and the averaging of estimates from simple regression equations are also tested. Surprisingly, for Virginia localities the most satisfactory results are generated by the nonstratified multiple regression equation.

Demography↗

Persistence of antibiotics in milk from cows treated late in the dry period.

Nineteen cows were treated via intramammary infusion at various times prior to calving with one of two dry cow antibiotic preparations (cloxacillin or penicillin). Milk samples from these cows after calving were analyzed for antibiotic residues by the Sarcina lutea cylinder plate method. Eight cows were treated with cloxacillin was detected in the milk of only two cows after calving and then for only one milking, so no problem should exist with cloxacillin if the manufacturer's recommendations are followed. Penicillin residues were not detected in milk samples taken from cows treated more than 9 days prior to calving with the dry cow penicillin preparation. However, seven of nine cows treated with penicillin up to 9 days prior to calving had detectable penicillin residues in the milk from treated quarters after calving. Only one cow had detectable penicillin residues longer than the manufacturer's recommended milk withholding time of 96 h, and this cow was treated only 3 days prior to parturition. Normal routine on a dairy farm and adherence to manufacturer's recommendations should result in no antibiotic residue problems in milk from cows treated during the dry period for mastitis control with either cloxacillin or penicillin.

Animals↗

Fatty acids of vegetative cells and spores of Bacillus licheniformis.

Lipids were extracted from vegetative cells and spores of Bacillus licheniformis. Vegetative cells were grown in nutrient broth and spores on nutrient agar. Total lipid approximated 2.89% of the dry weight of vegetative cells and 2.09% of the dry weight of spores. The fatty acids were prepared as methyl esters and analyzed by gas chromatography and mass spectrometry. There were six fatty acids in concentrations greater than 5% of the total lipid in both spores and vegetative cells, but only palmitic acid was common to both. Fatty acids from vegetative cells in quantities of 5% or more of the total lipid material were lauric, myristic, palmitic, palmitoleic, and linoleic acids. Fatty acids from spores in concentrations greater than 5% of the total lipid were isopentadecylic, palmitic, Carbon-17 iso, and three other long or branched chain fatty acids which were not identified. Spores contained more long and branched chain fatty acids with odd numbers of carbon atoms than did vegetative cells.

Bacillus↗