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Biomedical subjects

A Leonard

Publications and source records attributed to A Leonard.

At least 91 records · Page 5Linked to original sources
PubMed1977

The chromosomal radiosensitivity of lymphocytes from the chimpanzee (Pan troglodytes).

The yield of chromosomal aberrations induced by exposure to X-irradiation in vitro was studied in the lymphocytes of the chimpanzee (Pan troglodytes), a hominoid ape phylogenically and chromosomally closely related to man. In agreement with the similarity of the chromosome characteristics, no significant difference was observed between man and chimpanzee with respect to the incidence of dicentrics and fragments. It is obvious that the nuclear area, which apparently constitutes the most evident difference between the nuclei of man and chimpanzee lymphocytes, did not play an important role in the yields of aberrations.

Animals↗
PubMed1977

Cytogenic investigations on leucocytes of cattle intoxicated with fluoride.

Cattle which grazed in the vicinity of a plant manufacturing enamel and which displayed signs of chronic fluoride poisoning such as osteosclerosis and mottled enamel or dental fluorosis were investigated for the presence of structural chromatid and chromosome aberrations. Venous blood was incubated for 48 h, and 100 cells were analyzed for each animal. No statistical difference in the incidence of such anomalies was observed between the controls and the intoxicated animals.

Animals↗
PubMed1977

Hereditary anophthalmia in the progeny of an X-irradiated female rat.

Inherited anophthalmia was observed in the progeny of a female rat irradiated with 50 R of X-irradiation at 17 days of age. Observations on the inheritance of the condition indicated that this anophthalmia can be considered as the result of polygenic factors with incomplete penetrance.

Animals↗
PubMed1976

Irreversible acute renal failure in idiopathic nephrotic syndrome.

In five adult patients (aged 44 to 74 years) with idiopathic nephrotic syndrome, irreversible acute renal failure developed. Prior renal disease, associated systemic illness or occlusion of major renal vasculature was not present. All patients continued to excrete large amounts of proteins (8.6 to 15 g/24 hours) despite a minimal glomerular filtration rate and severe oliguria. One patient died after five months without recovering renal function. Four patients have required hemodialysis for a period of 12 to 58 months. The failure to recover renal function could not be explained by the light microscopic findings. It is suggested that the irreversibility of the renal failure may be related to either permanent alterations in renal blood flow or ultrastructural changes, or to both. Clinically, adult patients in whom acute renal failure develops during the course of idiopathic nephrotic syndrome seem to have a grave prognosis. Protracted oliguria or irreversible renal failure can be expected to occur.

Acute Kidney Injury↗
PubMed1976

The radiosensitivities of lymphocytes from pig, sheep, goat and cow.

Dose-effect curves for X-irradiation in vitro were determined on cultured blood lymphocytes of four mammalian species-cow, goat, sheep and pig-having approximately the same number of chromosome arms, the same nuclear volume and the same DNA content. The data from cow, but not those from the other species, exhibited significant inhomogeneity between the experiments. On inspection the numerical yields appear not to differ greatly in the lower dose range. Evaluation of the parameters according to the quadratic law and the power law, however, demonstrate significant differences. Pig differs from the other species regardless of which presentation is chosen. For the power law a significant difference is also found between goat and sheep.

Animals↗
PubMed1976

Action of lead on early divisions of the mouse embryo.

The number of cells in mouse embryos 48 h after mating was studied in normal and lead-treated females (0.125, 0.25, 0.5, 1% of lead in the diet). The percentage of embryos in the 4-cell stage compared to those in the 8-cell stage increased after 0.125, 0.25 and 0.5% of dietary lead. After the highest dose an increase in nondivided eggs was also seen which occurred at the expense of 4-cell embryos. The different possibilities, delay of all divisions, delay of only the first division and action of lead on only a part of the embryonic population, are discussed.

Animals↗
PubMed1976

[Chromosome modifications induced in mouse spermatogonia through exposure to high-energy neutrons].

The incidence of reciprocal translocations induced in mouse spermatogonia has been studied in CBA mice given X-ray or neutron exposure. Analysis of dividing spermatocytes at diakinesis-first metaphase stage of meiosis shows that in X-irradiated mice there is a linear dose-response relationship. After exposure to fast neutrons the yield of translocations follows a humped curve with a maximum of chromosome exchanges after exposure to 100 rad.

Animals↗
PubMed1976

[Study of chromosome characteristics of artificially-induced ascite tumors].

Some ascite tumours have been induced in rat by intraperitoneal injection of RadLV and in mouse by intraperitoneal injection of RadLV, or of protozoa such as Trypanosoma brucei and Toxoplasma gondii. Cytological examination of the resulting ascite tumours has shown that chromosome aberrations were associated with the presence of C and A viral particles.

Animals↗
PubMed1975

Subdural hematoma in regularly hemodialyzed patients.

Thirteen of 394 (3.3%) regularly dialyzed patients of the Regional Kidney Disease Program developed subdural hematoma. The following factors contributed to formation of subdural hematoma: head trauma, ultrafiltration to control excessive accumulation of fluid and hypertension, anticoagulants, and frequent vascular access infection and clotting. Neurologic symptoms and signs, which may be similar to dialysis disequilibrium, aid only in signifying the presence, not the ultimate localization, of subdural hematoma. Our experience underscores the frequency of bilateral disease, irrespective of neurologic findings. Skull films, lumbar puncture, and electroencephalography were of little diagnostic help. Although valuable and safe, brain scanning was not as useful as desired due to occurrences of false-negative studies and failure to identify bilaterality of lesions. Cerebral angiography was always diagnostic. Surgical intervention yielded disappointing results, and only 2 patients (15%) survived. A review of 9 other patient reports is included.

Adult↗