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Biomedical subjects

J F Nelson

Publications and source records attributed to J F Nelson.

At least 109 records · Page 6Linked to original sources
PubMed1977

Fibrous dysplasia of the mandible and sphenoid bones: report of case.

A case of fibrous dysplasia of the mandible has been presented in which further diagnostic procedures showed the presence of a second and potentially more dangerous lesion. The literature was reviewed with the purpose of bringing attention to the still confused state of fibro-osseous lesions of the jaws and skeleton. The relationship of the ossifying fibroma and fibrous dysplasia was explored in relative depth. Fibrous dysplasia is a usually benign fibro-osseous abnormality of bone that may occur as monostotic, polyostotic, or craniofacial disease or as a part of a syndrome. Its nosology is confusing and its etiology is still unknown.

Adolescent↗
PubMed1976

Blood corticosteroids in Australian marsupial and placental mammals and one monotreme.

Peripheral blood corticosteroid levels were determined in nine species of Australian marsupial (Eastern grey kangaroo, black-tailed, Bennett's and pademelon wallabies, quokka, wombat, koala and Western native and tiger cats), one species of monotreme (echidna) and one placental Australian mammal (dingo). Animals were obtained or bled with minimal disturbance and came from areas considered to have adequate sodium content of the vegetation. Aldosterone, corticosterone, cortisol, 11-deoxycorticosterone and 11-deoxycortisol were measured and levels found to be similar to five introduced eutherian species (sheep, cow, dog, fox and man) with the exception of the koala and the wombat. Cortisol was the predominant corticosteroid, except in the koala, which produced corticosterone in relatively the greatest quantity, and the wombat which produced more 11-deoxycortisol. Steroid levels were generally low in the wombat. ACTH administered to the koala changed its pattern of corticosteroid secretion from predominantly corticosterone to cortisol. In the dingo, administration of ACTH caused rises in corticosteroid levels similar to those seen in most other eutherian mammals.

Adrenal Cortex Hormones↗
PubMed1975

The role of ACTH and adrenal glucocorticoids in the salt appetite of wild rabbits (Oryctolagus cuniculus (L)).

The selective appetites of wild rabbits for 500 mEq/1 solutions of NaC1, KC1, MgC1(2), and CaC1(2) were studied in intact and adrenalectomized rabbits during daily treatment with either 4 IU long acting ACTH, 1.0 or 2.5 mg cortisol acetate, or 2.5 mg corticosterone. The animals were individually caged and external sodium balances performed. In intact rabbits, cortisol or corticosterone produced a significant stimulation of NaC1 appetite. The response to concurrent dosage of cortisol and corticosterone was less than half of that obtained with ACTH which produced a comparable alteration of blood glucocorticoid levels but a 10-fold increase in NaC1 intake. CaC1(2) intake was increased in intact rabbits by cortisol treatment but not by corticosterone or ACTH. Adrenalectomized rabbits maintained on daily steroid replacement therapy of 0.1 mg deoxycorticosterone acetate and 0.75 mg cortisone acetate showed a normal pattern of electolyte, food, and water intake. Under these conditions ACTH produced a 4-fold increase in NaC1 intake. Further addition of cortisol and corticosterone to steroid replacement therapy produced an increase in NaC1 intake comparable to their effect on normal rabbits. Thereupon supplementation with ACTH resulted in an increase to a level at least as great as that found in ACTH treated, normal rabbits. The effects of ACTH and glucocorticoids on NaC1 appetite were synergistic. Sodium balance showed that increases in NaC1 intake were not the result of the treatment initially producing a body sodium deficit, which was then corrected by increased intake. The results provide further evidence for the hypothesis that NaC1 appetite may be hormonally regulated, and demonstrate that ACTH is capable of stimulating NaC1 intake by a previously unsuspected non-adrenal pathway.

Adrenalectomy↗
PubMed1975

Plasma testosterone levels in C57BL/6J male mice: effects of age and disease.

Plasma testosterone (T) was measured by radioimmunoassay in both healthy and diseased, mature (8-11 months) and senescent (29-31 months) C57BL/6J male mice. Pathological lesions in diseased mice included reticulum cell sarcoma and enlarged mesenteric lymph nodes. In healthy mice neither plasma T nor testicular weight differed between age groups. Median levels and 95 percentiles of plasma T in ng/ml were 1.12 (0.19-12.18) in mature mice and 1.17 (0-7.31) in senescent mice. In diseased mice testicular weight and the range of values of plasma T were significantly reduced. The marked decreased in plasma T and testicular weight in diseased senescent mice illustrates the importance of distinguishing between disease-related changes and effects of aging, per se.

Aging↗
PubMed1975

Myoepithelioma of minor salivary gland origin. Light and electron microscopical study.

A gingival tumor that invaded the anterior maxilla was removed from a 14-year-old boy and studied by light and electron microscopy. The tumor was composed exclusively of myoepithelial cells and appeared to be malignant. By light microscopy, the tumor appeared to be a poorly differentiated epithelial neoplasm of undetermined origin; however, electron microscopical examination showed myoepithelial differentiation, indicative of a salivary gland origin. To our knowledge, the present case represents the only confirmed myoepithelioma that shows features indicative of malignant potential. Myoepitheliomas may be related to mixed tumors of salivary glands.

Adolescent↗