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Biomedical subjects

J Martin

Publications and source records attributed to J Martin.

At least 919 records · Page 51Linked to original sources
PubMed1983

Mucosal lesions in the rat associated with the attachment of Moniliformis (Acanthocephala).

By means of scanning electron microscopy, aspects of the attachment of Moniliformis dubius (Acanthocephala) to the intestinal wall of the rat are described together with various changes in the structure and form of the mucosa. Attachment of the parasite results in the formation of a distinct pit around the everted proboscis and a crater around the neck. Contact between the anterior region of the trunk of the worm and the intestine of the host appears to lead to villous fusion so that characteristic grooves are formed in the mucosal tissue. Evidence was also obtained to suggest that host goblet cells may become exhausted during the course of an infection with Moniliformis.

Acanthocephala↗
PubMed1983

Estimation of the numbers and infectivity of Nippostrongylus larvae.

Experimental investigations of the subcutaneous infection of third-stage larvae of Nippostrongylus brasiliensis reveal discrepancies between the actual and intended inoculum, and also variability between replicate inocula. Emphasis is thus placed on the importance of obtaining accurate estimates of the level of confidence associated with inoculum size. Under specified laboratory conditions, the retention of infectivity of N. brasiliensis larvae was found to be age-dependent, with a maximum of between 120 and 156 days. The motility of the larvae was not found to be indicative of their ability to complete migration and to become established in the small intestine of the host following subcutaneous inoculation.

Animals↗
PubMed1983

Nematodirus battus: structure of the body wall of the adult.

Males of Nematodirus battus have a body wall composed of a longitudinally ridged cuticle made up of 8 layers, a hypodermis and a layer of longitudinal muscle cells which are divided into 4 sectors by the hypodermal cords. There is a characteristic cephalic inflation of the cuticle in both sexes. The structure of the body wall in the anterior half of the female is similar to that of the male. In the posterior half of the female the cuticle is not ridged and has 7 layers; the longitudinal muscles are reduced in number and the lateral hypodermal cords increasingly extend dorsally and ventrally along the length of the posterior part of the nematode and come to occupy most of the lateral sectors of the body. The possible significance of these modifications in the structure of the female nematode are discussed.

Animals↗
PubMed1983

Amphotericin B selection of mutant Chinese hamster cells with defects in the receptor-mediated endocytosis of low density lipoprotein and cholesterol biosynthesis.

This paper describes a rapid and efficient two-step procedure for the isolation of mutant cells with defects in receptor-mediated endocytosis. The procedure takes advantage of two fungal metabolites, compactin (ML236B), a potent inhibitor of cholesterol biosynthesis, and amphotericin B, a polyene antibiotic that forms toxic complexes with sterols in membranes. Mutagen-treated Chinese hamster ovary cells were preincubated overnight in a medium containing mevalonate, low density lipoprotein (LDL), and compactin (Mev/LDL/Com). At the end of the preincubation period, wild-type cells were cholesterol replete while mutant cells that could not utilize the cholesterol in LDL were cholesterol deficient. Subsequent incubation with amphotericin B for 6 hr killed most of the wild-type cells. After a second round of Mev/LDL/Com-amphotericin B selection, endocytosis-defective clones appeared at a frequency of approximately equal to 2.6 X 10(-5). Some of these clones expressed LDL receptor-defective phenotypes and fell into one of two previously defined classes of mutation. Sensitivity of the mutants to infection by vesicular stomatitis virus suggested that the mutations do not disrupt the coated pit-coated vesicle pathway of endocytosis. Minor modifications in the Mev/LDL/Com-amphotericin B selection permit the isolation of cholesterol auxotrophs and might allow the isolation of conditional-lethal mutations. Because LDL can be coupled to ligands that bind to receptors other than the LDL receptor, Mev/LDL/Com-amphotericin B selection may permit the isolation of mutant cells with defects that specifically disrupt other endocytic pathways.

Amphotericin B↗
PubMed1983

Constipation in long-stay elderly patients: its treatment and prevention by lactulose, poloxalkol-dihydroxyanthroquinolone and phosphate enemas.

37 long-stay geriatric patients were studied. All had 80% transit time (TT) in excess of 6 days. Only an average of 23% of markers were passed by day 6 and 30% of patients still had markers in situ after 2 weeks. Three daily enemas had no effect on TT and three daily enemas together with a laxative for 6 days normalized TT in 40% only. A further 3 weeks of laxatives did not prevent constipation from getting worse. The effectiveness of lactulose and poloxalkol-dihydroxyanthroquinolone, respectively, were the same and better than no treatment.

Aged↗
PubMed1983

Peripheral neuropathy in hypothyroidism--an association with spurious polycythaemia (Gaisbock's syndrome).

The neurological complications of hypothyroidism, including dementia, cerebellar ataxia, myopathy and entrapment neuropathy, are well recorded, but peripheral neuropathy has rarely been documented (Swanson et al. 1981). In this paper two patients are described who developed myxoedema and peripheral neuropathy. The first patient had a very rapid onset of myxoedema, and during observation he developed spurious polycythaemia (Gaisbock's syndrome) over a period of nine days.

Female↗
PubMed1983

The carcinogenicity of 1-methyl-3(p-bromophenyl)-1-nitrosourea (Br-MPNU).

In long-term experiments with Hooded rats the carcinogenic potential of 1-methyl-3(p-bromophenyl)-1-nitrosourea (Br-MPNU) could be demonstrated for the first time. Br-MPNU is formed also endogenously after combined administration of 1-methyl-3(p-bromophenyl)-urea (Br-MPU) and sodium nitrite. After repeated intragastric administration of 0.33 mmol Br-MPU and 0.73 mmol NaNO2 per kg b.w. papillomas and carcinomas of the forestomach developed in 83%. After repeated administration of 0.28 mmol Br-MPNU per kg b.w. these neoplasms were observed in 88%. The comparison of results obtained in similar experiments with 1-methyl-3-phenyl-1-nitrosourea shows that bromine substitution led to a reduction of the carcinogenic activity. The present paper is part of a complex program studying the interrelationships between structure, physico-chemical properties, mutagenicity and carcinogenicity of nitrosoureas.

Administration, Oral↗
PubMed1983

[Prognostic nutritional index in digestive surgery].

It is difficult to select and combine the nutritional parameters most useful in predicting the outcome of major gastrointestinal surgery. The aim of this study was to define retrospectively a multifactorial prognostic nutritional index adapted to this purpose. Seventy-eight patients on whom one or more total or partial visceral resection were performed in nonemergency conditions were included in this study. Statistical analysis was carried out to determine correlations between the preoperative nutritional parameters and the postoperative complications such as: a) wound rupture and anastomotic leakage; b) severe sepsis; c) death. Delayed hypersensitivity, assessed as normal or abnormal, together with plasmatic albumin and transferrin levels, the thresholds of which were respectively determined at 35 g/l and 2.2 g/l, were selected as the factors with the greatest predictive value. For the prognosis of postoperative severe complications and death, the sensitivity and specificity of an index using the association of these three parameters were respectively 82.7 p. 100 and 51 p. 100 with positive and negative predictive values of 50 p. 100 and 83.3 p. 100.

Adolescent↗