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Biomedical subjects

J Edmondson

Publications and source records attributed to J Edmondson.

15 recordsLinked to original sources
PubMed1998

"A satellite primer on tuberculosis:" a collaboration in distance education.

"A Satellite Primer on Tuberculosis" was offered as a distance-based certificate course on tuberculosis (TB) fundamentals to a national audience of over 5,000 individuals. The course was a collaborative effort of a school of public health, a state health department, and the Centers for Disease Control and Prevention. Instruction was provided through print-based self-study modules that were complemented by live, interactive satellite conferences. Course completers, over 70 percent of whom were nurses and employees of public health departments, scored significantly higher on a course posttest than on a pretest, and the vast majority felt the course provided valuable training.

Curriculum↗
PubMed1996

Visualizing an olfactory sensory map.

We have developed a genetic approach to visualize axons from olfactory sensory neurons expressing a given odorant receptor, as they project to the olfactory bulb. Neurons expressing a specific receptor project to only two topographically fixed loci among the 1800 glomeruli in the mouse olfactory bulb. Our data provide direct support for a model in which a topographic map of receptor activation encodes odor quality in the olfactory bulb. Receptor swap experiments suggest that the olfactory receptor plays an instructive role in the guidance process but cannot be the sole determinant in the establishment of this map. This genetic approach may be more broadly applied to visualize the development and plasticity of projections in the mammalian nervous system.

Animals↗
PubMed1996

Influence of dietary protein, fat, and fiber on growth, blood chemistry, and tumor incidences in Fischer 344 rats.

Composition of diets may influence growth, diseases, tumor rates, and responses to chemical treatment. For two years, Fischer 344 rats were fed the NIH-07 open-formula nonpurified diet (approximately 23% protein, approximately 5% fat, and approximately 3.5% fiber) and nonpurified experimental diets (NTP-90, NTP-91, and NTP-92) containing lower protein and higher fat and fiber (14.6-15.3% protein, 7.2-8.5% fat, and 9.4-14% fiber) than the NIH-07 diet. Rats were evaluated for growth patterns, survival, hematology, serum chemistry, nephropathy, and tumor incidences. Growth patterns were similar in rats fed the experimental diets and in those fed the NIH-07 diet. However, in rats fed the experimental diets, the adult body weights were significantly (6-9%) lower and the survival at 110 weeks of age was significantly higher (15-20%) than in rats fed the NIH-07 diet. Lower protein content of experimental diets decreased the severity of nephropathy. Higher fat content of experimental diets appears to have decreased the incidence or delayed the development of leukemia and associated mortality in males. Higher fiber content of experimental diets appears to have delayed the development of mammary tumors and associated mortality in females. Higher fat and/or fiber of the experimental diets decreased the incidence of pheochromocytomas in males. The lower protein and higher fat and fiber contents of the experimental diets decreased the spontaneous tumor burden in two-year studies. These studies indicate that diets for rats in long-term studies could be modified to decrease the severity of nephropathy and to decrease/delay the development of spontaneous tumors.

Animals↗
PubMed1993

Influence of dietary protein concentration on severity of nephropathy in Fischer-344 (F-344/N) rats.

Nephropathy is an age-related spontaneous disease of most rat strains, and protein content of diet may affect the severity. The purpose of this study was to determine the effect of a 15% protein nonpurified diet on body weight and severity of nephropathy in comparison to a 23% protein NIH-07 diet. Groups of 25 male and 25 female Fischer-344 (F-344) rats, 6 wk of age, were fed the 23 or 15% protein diet ad libitum for 2 yr. Rats were weighed at 1-4-wk intervals, and mean body weights were determined. Water consumption measurements and urinalysis were done at approximately 3-mo intervals during the second year of the study. At the end of the 2-yr study, kidneys from all rats, including those that died or were euthanatized after the eightieth week of the study, were examined by light microscopy and graded for severity of nephropathy as grades 1-4 (minimal, mild, moderate, marked). Growth patterns and the maximum body weights attained by each sex fed the 23 or 15% protein diet were not significantly different. The severity of nephropathy in male rats was significantly higher when fed the 23% protein diet (2.8 moderate to marked) compared to the 15% protein diet (1.3 minimal to mild). The severity of nephropathy in female rats increased slightly when fed the 23% protein diet (1.5 minimal to mild) compared to the 15% protein diet (1.0 minimal).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Monoclonal antibodies to periodontal ligament cells.

Ten mouse monoclonal antibodies were prepared against cultured bovine periodontal ligament cells to be used as reagents for the study of periodontal disease and wound healing. Using standard immunohistochemical methods, these antibodies were found to recognize cell surface antigens in formalin-fixed bovine periodontium. Three of the 10 monoclonal antibodies (i.e., PDL-1, PDL-2, and PDL-10) cross-reacted with cells found in primate periodontium. While the isolated monoclonal antibodies appeared to distinguish subpopulations of cells located in the supporting tissues of teeth, immunohistological examination of other organs (dermis, kidney, skeletal muscle, thyroid, and parotid gland) indicated that a number of cell types of mesenchymal origin share an antigen(s) found on periodontal cells. The monoclonal antibodies described in this report should prove to be useful in studies of periodontal disease and guided tissue regeneration by providing both analytical reagents and immunochemical methods for isolating selected cell populations of the periodontium.

Animals↗
PubMed1990

Tissue reaction to an implantable identification device in mice.

Long-term toxicity and carcinogenicity studies require positive identification of animals. Due to the unreliability of traditional methods, it was necessary to investigate more dependable identification methods that can be read directly or by electronic means. A two-year study to determine the stability of and tissue reaction to a microchip glass-sealed device implanted in subcutaneous tissue of mice was conducted. Seventy B6C3F1 mice of each sex were anesthetized and implanted with the microchip. The devices were read by an electronic detector and palpated at periodic intervals. Ten mice of each sex were necropsied at 3 months and at 15 months with the remaining animals necropsied at 24 months. Of the 140 devices implanted, 3 were lost and 4 failed during the 24-month study. Devices were palpable and appeared to be fixed at one location with no obvious swelling due to inflammation or palpable masses around the implants for 24 months. At the 3, 15, and 24 month necropsies, implants were encapsulated by connective tissue. Light microscopic evaluation indicated that the capsule around the implants was thin and composed of fibrocytes and mature collagen fibers, with minimal to mild inflammation and occasional granulomatous reaction. Neoplastic changes were not observed in the tissue around the glass-sealed devices with polypropylene cap for up to 24 months.

Animal Identification Systems↗
PubMed1989

Influence of viral infections on body weight, survival, and tumor prevalence of B6C3F1 (C57BL/6N x C3H/HeN) mice in carcinogenicity studies.

Sendai virus (SV), mouse hepatitis virus (MHV), and pneumonia virus of mice (PVM) are common viral infections of mice. Influence of these viral infections on the prevalence of liver tumors, lung tumors, and lymphoma is of concern in chemical carcinogenicity studies. Body weight, survival, and tumor prevalence of B6C3F1 mice with and without viral infections in 33 male and 34 female untreated control groups and 32 male and 32 female low- and high-dose groups of 2-year chemical carcinogenicity studies were evaluated. In male mice, the SV infection was associated with significantly (p less than 0.05) higher survival of control, low-dose, and high-dose groups, and higher prevalence of liver tumors and lymphoma. The increases in tumor prevalence are possibly due to an increase in the survival of male mice that had SV infection. However, when interlaboratory variability and time-related effects were taken into account, the number of significant effects was consistent with the expected false-positive rate inherent to the statistical procedures. The MHV and PVM infections did not cause consistent changes in body weight, survival, and tumor prevalences in the control and chemical treatment groups of male mice. Viral infections did not cause consistent increases or decreases in body weight, survival, or tumor prevalence in the control and chemical treatment groups of female B6C3F1 mice.

Animals↗
PubMed1989

Influence of viral infections on body weight, survival, and tumor prevalence in Fischer 344/NCr rats on two-year studies.

Sendai virus (SV), pneumonia virus of mice (PVM), and rat coronavirus/sialodacryoadenitis virus (RCV/SDAV) were common viral infections of rats in the National Cancer Institute-National Toxicology Program (NCI-NTP) studies from 1977 to 1983. Influence of these viral infections on body weight, survival, and prevalences of spontaneous tumors in the F344/NCr rats of 28 diet control groups at five different laboratories were evaluated. Tumor prevalences evaluated in this investigation included the following: leukemia and tumors of the anterior pituitary, lungs, salivary glands and Harderian glands in both sexes; adrenal pheochromocytomas in male rats; and mammary tumors in female rats. SV and PVM but not RCV/SDAV infections were associated with significant (P less than 0.05) decreases in body weights of male and female rats. Male rat groups with PVM infection had a lower prevalence of leukemia and male rat groups with RCV/SDAV infection had a higher prevalence of anterior pituitary tumors than the corresponding uninfected groups. Female rat groups with SV infection had greater survival and a higher prevalence of lung tumors than groups without SV infection. However, none of the tumor prevalence and survival differences were statistically significant when interlaboratory variability and time-related effects were taken into account.

Animals↗
PubMed1984

Location of the binding site in subcomponent C1q for plasma fibronectin.

Previous studies on the interaction of fibronectin with C1q have yielded apparently conflicting results since both the globular head regions (produced by collagenase digestion) and the collagen-like domains (produced by limited pepsin digestion) have been reported to bind to fibronectin. In this study, the binding of 125I-labelled fibronectin to either intact C1q, or the collagenase or pepsin digestion products, immobilised on plastic microtitre plates was examined. Inhibition of the C1q-fibronectin interaction by the C1q digestion products was also examined. The results confirmed that both globular 'head' region preparations and collagen-like region preparations, can interact with fibronectin. Since the fragments used in these studies share a section of common amino acid sequence from the C1q molecule it can be concluded that the binding site, on C1q for fibronectin, is located in a region formed from the residues 81-97 of each of the three chains of the C1q molecule.

Amino Acid Sequence↗
PubMed1981

Feasibility of low doses of I-131 for thyroid ablation in postsurgical patients with thyroid carcinoma.

The feasibility of using low doses of I-131 (30 mCi) for ablation of thyroid remnants following surgery for papillary and follicular thyroid carcinoma was examined in 21 patients. Six weeks following near-total thyroidectomy and three days following intramuscular thyroid-stimulating hormone (10 IU), patients were given 30 mCi of I-131 and scans were performed 24 to 72 hours later. Remaining thyroid tissue was identifiable in the thyroid bed in 19 patients, and two patients also had evidence of cervical metastases. Patients with metastases received an additional 100 mCi of I-131. Follow-up I-131 scans were performed at nine to 15-month intervals in ten patients who initially received 30 mCi of I-131, and only one patient showed complete ablation of the residual thyroid tissue, whereas the remaining nine patients had persistent uptake of I-131 in the same regions in which the uptake was seen in the initial postoperative scans. One of the nine patients had evidence of a cervical metastasis as well. It is therefore apparent that total or near-total thyroidectomy rarely removes all thyroid tissue and that an "out-patient" dose of I-131 is not adequate for ablation of postoperative thyroid remnants.

Adenocarcinoma↗
PubMed1975

Demonstration of a diurnal variation in serum parathyroid hormone in primary and secondary hyperparathyroidism.

It had been reported previously that there is a diurnal variation in serum parathyroid hormone (PTH) in normal subjects but not in patients with primary hyperparathyroidism. Studies were performed to determine whether there is a diurnal variation in serum PTH in primary or secondary hyperparathyroidism and whether the nocturnal increase in serum PTH, if present, could be prevented by induced hypercalcemia. Serum PTH and calcium were measured in five normal subjects, two patients with pseudohypoparathyroidism, and fourteen patients with primary hyperparathyroidism, twelve of whom were subsequently found to have parathyroid adenomas. In the normals, there was a mean decline in serum PTH of 0.07 ng/ml before noon and a mean increase of 0.04 ng/ml after 8 PM. In primary hyperparathyroidism there was a mean decline in serum PTH before noon of 0.11 ng/ml and a mean increase of 0.11 ng/ml after 8 PM. In both groups, the lowest mean serum calcium values were noted between midnight and 6:00 AM. Patients with pseudohypoparathyroidism showed a nocturnal increase in serum PTH. In each of two normal subjects, two patients with primary hyperparathyroidism, and two patients with pseudohypoparathyroidism, calcium, 4 mg/kg body weight per hour for 4 hours (8:00 PM to 12 midnight), produced hypercalcemia and prevented the nocturnal increase in serum PTH. We have concluded that a diurnal variation in serum PTH often occurs in both normal subjects and in patients with primary or secondary hyperparathyroidism and that nocturnal increases in serum PTH can be prevented by induced hypercalcemia.

Adult↗