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Biomedical subjects

R A French

Publications and source records attributed to R A French.

29 records · Page 2Linked to original sources
PubMed1996

Dual expression of p80 type I and p68 type II interleukin-I receptors on anterior pituitary cells synthesizing growth hormone.

Interleukin-1 alpha (IL-1 alpha) and IL-1 beta bind to either the p80 type I IL-1 receptor (IL-1RI) or the p68 type II IL-1R (IL-1RII) on both T and B lymphocytes. We and others have previously shown that the anterior pituitary gland also has specific high affinity binding sites for IL-1 alpha (Kd = approximately 1 nM) and expresses transcripts for both isoforms of the IL-1R. However, the identity of cells in the anterior pituitary gland that express the IL-1R and whether different populations of adenohypophyseal cells express different isoforms of the IL-1R remain unknown. Here we have used a combination of immunohistochemistry and histochemistry to localize IL-1RI and IL-1RII to specific target cells in the mouse anterior pituitary gland. Perfusion-fixed, paraffin-embedded sections of anterior pituitary gland were immunolabeled with well characterized monoclonal antibodies to either IL-1RI or IL-1RII and counterstained using a modified Gomori's method to document acidophils and basophils. Immunolabeling demonstrated that both IL-1RI and IL-1RII were abundantly expressed on a single population of anterior pituitary gland cells and that these cells could be classified on the basis of histochemical staining as a subpopulation of acidophils. The distribution, morphology, and proportion of cells immunolabeled for IL-1RI and IL-1RII were consistent with GH-synthesizing cells. To confirm this hypothesis, a modified indirect avidin-biotin complex, sequential peroxidase/alkaline phosphatase technique was used to label anterior pituitary gland cells with antibodies to IL-1RI followed by antibodies to IL-1RII, GH, PRL, or ACTH. The IL-1RI-positive cells predominately coexpressed IL-1RII and GH, but very little, if any, PRL or ACTH. These data establish that the predominant cell population in the murine anterior pituitary gland that constitutively expresses IL-1R stain as acidophils histochemically, is round to oval with dense granular cytoplasm and eccentric nuclei, synthesizes GH, and simultaneously expresses IL-1RI and IL-1RII isoforms.

Animals↗
PubMed1994

Degenerative myeloencephalopathy in two llamas.

Degenerative myeloencephalopathy of unknown cause was diagnosed in 2 mature llamas. One llama had ataxia and paresis of the left limbs; whereas, the other developed tetraplegia that was not preceded by obvious ataxia or paresis. Results of cranial nerve examinations were unremarkable in both llamas. Cerebrospinal fluid from both llamas was normal, and hematologic and serum biochemical abnormalities were attributed to concurrent conditions and not to the myeloencephalopathy. Results of cervical spinal radiography and myelography in 1 llama were normal. In each llama, the diagnosis of degenerative myeloencephalopathy was made at necropsy after the llama failed to respond to treatment for other neurologic or muscular disorders. Lesions of degenerative myelopathy were found bilaterally in the white matter of all spinal cord segments, but were most pronounced in the thoracic segments. The dorsal and dorsolateral funiculi were most severely affected. The most prominent lesion was axonal sheath dilatation, with swelling or loss of axons. Dilated axon sheaths contained cellular and myelin debris, and accumulation of gitter cells was prominent. In the gray matter of 1 llama, a few degenerate neuronal cell bodies were seen in addition to axonal swelling. Degenerate neurons were identified in the brain stem of both llamas.

Animals↗
PubMed1991

Efficacy of ivermectin chewable tablets and two new ivermectin tablet formulations against Dirofilaria immitis larvae in dogs.

One hundred four heartworm-free Beagles less than 1 year old were studied to determine the efficacy of ivermectin chewable tablets and of 2 other ivermectin tablet formulations against heartworm larvae. At 30 days after SC inoculation of dogs with infective Dirofilaria immitis larvae, all ivermectin formulations were given orally at dosage of 6 micrograms/kg of body weight. The ivermectin chewable tablets also were given orally at dosage of 2 and 6 micrograms/kg at 30 and 45 days, respectively, after injection of larvae. Replicates of 6 or 8 dogs in each study were formed on the basis of gender and body weight and, within replicates, were randomly allocated to treatment groups. At 30 days after injection of larvae, the additional dogs (in replicates of 8) were assigned to the control group and to the group given ivermectin chewable tablets at dosage of 6 micrograms/kg. All dogs were housed individually. Necropsy was performed approximately 5 or 6 months after larvae were administered. In both trials, all control dogs had heartworms at necropsy (University of Illinois--geometric mean, 35.0; Florida--geometric mean, 26.1). In both trials, the ivermectin chewable tablet (6 micrograms/kg) and both tablet formulations (6 micrograms/kg) given at 30 days after larval injection, and the chewable formulation (6 micrograms/kg) given at 45 days after larval injection were 100% effective (P less than 0.01) in preventing development of induced infection with D immitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Partnership for the consumer: a personal view of joint planning.

Since 1974 health authorities and local authorities have been required to undertake joint planning. It is widely held though, that results have been disappointing, and that difficulties have increased in recent years. Roger French examines the reasons for this and proposes some actions which should lead to better performance.

Health Planning Organizations↗
PubMed1987

Youth cancer education through a combined American Cancer Society-Boy Scouts of America pilot program.

A pilot cancer education program for Boy Scouts in grades six through nine was developed. Motivation to complete requirements was provided by awarding a "Cancer Awareness Patch." Content of the program included health issues related to smoking and tobacco use, diet, and sun exposure, plus education about the practice of testicular self-examination, and sunscreen usage. Retention of factual material was good up to 18 months post-program. Participants developed positive attitudes toward lifestyle development and volunteerism. The program is recommended for supplementation of school health promotion curricula.

Adolescent↗
PubMed1986

AIDS in Kansas.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Clinical and immunohistochemical characterization of thymic lymphosarcoma in a heifer.

A 2-year-old Holstein heifer with a swollen brisket, jugular vein distention, muffled heart sounds, tachycardia, and free gas bloat was examined. Thymic lymphosarcoma was suspected based on a negative agar gel immunodiffusion test for bovine leukemia virus, presence of atypical lymphocytes in pleural fluid, and detection of a mass in the thoracic inlet. Right-sided cardiac catheterization was performed, and markedly increased jugular venous pressures (41 mm Hg) with a pressure gradient of 29 mm Hg immediately cranial to the heart indicated constriction of the cranial vena cava. Immunohistochemical staining of formalin fixed, paraffin-embedded tissue sections of the tumor using a rabbit antihuman T cell, CD3 polyclonal antibody confirmed that the neoplastic lymphocytes were of thymic origin.

Animals↗
PubMedDate not supplied

Feather folliculoma in a captive-bred barn owl (Tyto alba).

Proliferative cutaneous lesions are frequently encountered in examination of avian species. Tumors of the skin have been reported in many bird species, although comparatively less is known about the incidence of integumentary neoplasia in nondomesticated species than in production or companion species. An adult male, 9-yr-old, captive-bred barn owl (Tyto alba) was presented for examination of a proliferative skin mass of several months' duration on the left wing. An excisional biopsy was performed, and the owl recovered uneventfully. Light microscopic examination of tissue sections of the mass revealed a focal, unencapsulated, well-demarcated, multiloculated mass that consisted of variably sized cystic spaces lined by stratified squamous epithelium and containing concentric laminations of keratin and foci of feather differentiation. A histopathologic diagnosis of feather folliculoma was made. This neoplasm has not previously been described in owls. Its incidence and documentation are significant in that this neoplasm should be considered as a differential diagnosis of proliferative skin lesions in this raptorial species.

Animals↗