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Biomedical subjects

L L Rife

Publications and source records attributed to L L Rife.

9 recordsLinked to original sources

Immunohistochemical identification of androgen receptors in human lacrimal glands.

PURPOSE: Androgens are thought to play a role in the regulation of the human lacrimal gland. Androgen receptor mRNA has been isolated from human lacrimal tissue; however, it is not known which cell(s) in human lacrimal tissue may contain androgen receptors. This study is an immunohistochemical investigation of the location and distribution of androgen receptors in human lacrimal tissue. METHODS: Formalin-fixed, paraffin-embedded human lacrimal gland tissues were subjected to established antigen retrieval techniques. This was followed by routine immunohistochemical staining, employing one of two anti-human androgen receptor monoclonal antibodies, each specific for a different antigenic epitope within the receptor molecule. RESULTS: The two anti-human androgen receptor monoclonal antibodies demonstrated similar staining patterns in adjacent tissue sections from the same human lacrimal gland specimens. Specific staining for androgen receptors was observed in the nucleus and cytoplasm of lacrimal acinar cells, as well as in lacrimal duct cells. Both the intensity of staining and the number of cells demonstrating staining varied among specimens. We also observed staining for androgen receptors in interstitial and inflammatory cells distributed between lacrimal acinar units in some specimens. CONCLUSIONS: Androgen receptors are located in human lacrimal gland acinar cell nuclei as observed in other animals. However, the detection of androgen receptors in lacrimal interacinar interstitial and inflammatory cells suggests that androgens may play a role in modulating the activities of cells other than lacrimal cells within the human lacrimal gland.

Adolescent↗

Anterior segment prosthesis development: retinal function following anterior segment removal.

Replacement of the entire anterior segment of the eye is a very ambitious and complex endeavor and it is not known whether the retina remains functional when the anterior structures have been removed. We used routine histo-pathologic evaluation and electroretinographic measurements to determine the structural and functional status of rabbit retinas following surgical removal of the internal anterior structures (iris, ciliary body, and lens) and replacement of the vitreous with silicone oil. In some cases, we were able to record both a scotopic and a photopic electroretinographic response as long as 15 weeks after complete removal of the internal anterior segment structures. Although many hurdles remain and more efficacious surgical techniques and biomaterials need to be developed, our results suggest that, in the rabbit, the retina may continue to function in the absence of critical anterior segment structures.

Animals↗

Anterior segment prosthesis development: evaluation of expanded polytetrafluoroethylene as a sclera-attached prosthetic material.

To further the development of a sclera-attached anterior segment prosthesis we investigated the biocompatibility of expanded polytetrafluoroethylene following its surgical implantation into the rabbit sclera. Thin sheets (250 microns) of expanded polytetrafluoroethylene were cut into pieces measuring either 2 x 2, 2 x 4, 2 x 8, or 4 x 8 mm. The pieces were sterilized and placed individually within surgically prepared pockets in the sclera of rabbit eyes. Animals were sacrificed for routine histopathologic evaluation and transmission electron microscopic study of the eyes at 7 days, 14 days, 1 month, and 4 months following surgical implantation. The implants demonstrated excellent compatibility with the sclera and, by 14 days following implantation surgery, exhibited histiocytes, fibroblasts, and blood vessels infiltrating the internodal spaces of the highly porous material. The number of cells and the amount of extracellular matrix material deposited in the implants appeared to increase with time. Transmission electron microscopic studies revealed deposition of collagen within the implants. Our results suggest that expanded polytetrafluoroethylene has potential for use in the development of a sclera-attached prosthetic device.

Animals↗

Chronic anaerobic bacterial endophthalmitis in pseudophakic rabbit eyes.

Experimental anaerobic bacterial endophthalmitis was produced in pseudophakic and aphakic rabbits by using anterior chamber inoculation of 2.5 x 10(6) Propionibacterium acnes organisms. Clinical inflammation was more intense and prolonged in operated eyes with an intraocular lens in place. The presence of an intraocular lens favors the development of chronic low-grade P. acnes-related inflammation.

Animals↗

Anaerobic bacterial endophthalmitis in the rabbit.

Anaerobic bacterial endophthalmitis was studied in rabbits following intravitreal injection of live Fusobacterium necrophorum. Clinical response, bacterial recovery, and histopathology were studied. An inoculum of approximately 50 organisms produced endophthalmitis in 59% of injected eyes, while 1000 or more organisms produced endophthalmitis in 100% of injected eyes. The course and severity of disease seemed to be independent of the concentration of bacteria above a minimal inoculum size. Affected eyes showed progressive endophthalmitis. Histopathologic changes corresponded to the clinical gradation of endophthalmitis, including progressive retinal necrosis.

Animals↗

Compartmentalized growth of hemopoietic stem cells within mouse Friend leukemic spleens.

A dose of 4000 rads (r) to the central portion of mouse spleens followed by Friend erythroleukemic virus infection created independent compartments where hemopoietic stem cells exhibited distinct growth kinetics. Rather than suggesting autonomous proliferation, the stem cell kinetics were indicative of the control exercised by the local microenvironment upon stem cell growth within each compartment.

Animals↗

Hemopoietic stem growth on a capillary stage.

A hollow fibre capillary stage was used for the maintenance and renewal of hemopoietic stem cells in extra corporeal conditions. The partial success of this technique is due to the preservation of cell-cell contacts and interactions within the tissue sections.

Capillaries↗