Biomedical subjects

R S Redman

Publications and source records attributed to R S Redman.

101 records · Page 6Linked to original sources

PubMedDate not supplied

Response of rat salivary glands to mastication of pelleted vitamin A-deficient diet.

Interpretation of previous studies of the effects of hypovitaminosis. A on salivary glands is confounded by the atrophic effects of liquid or powdered diets. The purpose of this study was to reevaluate the effects of vitamin. A deficiency on the morphology and function of rat salivary glands using a pelleted diet that promotes physiological levels of masticatory stimulation. Profound vitamin A deficiency resulted in a marked decrease in stimulated parotid secretion. Histological evaluation demonstrated the development of squamous metaplasia in the ducts of parotid, submandibular and sublingual salivary glands; however, atrophy was observed only in serious salivary glands. In the parotid gland the degree of atrophy corresponded to the decrease in stimulated secretion. Mild hypovitaminosis A (before the development of squamous metaplasia in ducts) was associated with distinctly different effects. The parotid gland was moderately enlarged. There was also a significant increase in stimulated secretion, which was not explained by changes in gland size, muscarinic receptor number or affinity, or receptor-mediated calcium signalling.

Animal Feed↗

PubMedDate not supplied

Oral hairy leukoplakia: an ultrastructural study and review of the literature.

A 39-year-old, homosexual, Caucasian man with a 9-month history of acquired immunodeficiency syndrome by reduced CD4 lymphocyte count alone was found to have extensive, asymptomatic, nonremovable, corrugated, white patches on the lateral borders and ventral aspects of the tongue typical of oral hairy leukoplakia (OHL). Histologically, irregular hyperparakeratosis, acanthosis, and clusters of ballooned keratinocytes in the stratum spinosum were present in the biopsied lateral tongue. Some of the superficial ballooned keratinocytes had peripherally beaded nuclei, whereas others had ground glass intranuclear inclusions. Ultrastructurally, the ballooned keratinocytes had three important findings of diagnostic significance. First, frequent herpesvirus nucleocapsids were largely confined to superficial ballooned keratinocytes having marginated and condensed chromatin. In searching for herpesvirus nucleocapsids, the marginated and condensed chromatin was an invaluable marker for cells harboring the virions. Second, the marginated and condensed chromatin frequently had a distinctive punched-out or cribriform appearance. Third, the ground glass intranuclear inclusion bodies consisted of central, medium electron-dense, finely granular material containing frequent herpesvirus nucleocapsids and partially surrounded or capped by prominent, clumped chromatin. The patient died with progressive multifocal leukoencephalopathy 24 months after OHL was diagnosed.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Histological and biochemical characterization of von Ebner's glands in the Syrian hamster; comparison with rat von Ebner's glands.

We report here for the first time a morphological description and observations on some of the secretory proteins of the von Ebner's lingual salivary glands (VEG) of the Syrian hamster. Hamster VEG were macroscopically less distinct, but histologically similar to rat VEG. VEG extracts of hamster and rat were assayed for lipase, alpha-amylase and peroxidase activities. Unlike rat VEG, which is rich in lipase activity, hamster VEG extract had no detectable lipase activity and did not react with antibodies to either rat lingual lipase or human gastric lipase in Western blots. Immunohistochemical reactions with the anti-rat lingual lipase antibody were very weak in hamster VEG and strong in rat VEG. Moderate alpha-amylase enzyme activities and immunohistochemical reactions were demonstrated in both hamster and rat VEG. Peroxidase activity was negligible in the VEG, unlike the high activity in the submandibular glands of both species. An 18 kDa von Ebner's gland protein (VEGP), a member of the lipocalin superfamily of hydrophobic ligandbinding proteins, was abundant in rat VEG, but not detected in hamster VEG. Thus, hamster VEG differs from rat VEG in macroscopic appearance and the absence of lipase and VEGP. It is similar to rat VEG histologically and with regard to the presence of alpha-amylase and absence of peroxidase.

Animals↗

PubMedDate not supplied

Primary culture of polarized human salivary epithelial cells for use in developing an artificial salivary gland.

Therapeutic irradiation for head and neck cancer, and the autoimmune disease Sjogren's syndrome, lead to loss of salivary parenchyma. They are the two main causes of irreversible salivary gland hypofunction. Such patients cannot produce adequate levels of saliva, leading to considerable morbidity. We are working to develop an artificial salivary gland for such patients. A major problem in this endeavor has been the difficulty in obtaining a suitable autologous cellular component. This article describes a method of culturing and expanding primary salivary cells obtained from human submandibular glands (huSMGs) that is serum free and yields cells that are epithelial in nature. These include morphological (light and transmission electron microscopy [TEM]), protein expression (immunologically positive for ZO-1, claudin-1, and E-cadherin), and functional evidence. Under confocal microscopy, huSMG cells show polarization and appropriately localize tight junction proteins. TEM micrographs show an absence of dense core granules, but confirm the presence of tight and intermediate junctions and desmosomes between the cells. Functional assays showed that huSMG cells have high transepithelial electrical resistance and low rates of paracellular fluid movement. Additionally, huSMG cells show a normal karyotype without any morphological or numerical abnormalities, and most closely resemble striated and excretory duct cells in appearance. We conclude that this culture method for obtaining autologous human salivary cells should be useful in developing an artificial salivary gland.

Artificial Organs↗

PubMedDate not supplied