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Biomedical subjects

P Nagarajan

Publications and source records attributed to P Nagarajan.

6 recordsLinked to original sources

Strobilocercus fasciolaris infection with hepatic sarcoma and gastroenteropathy in a Wistar colony.

Tapeworm cysts were identified in liver of Wistar rats and it induced fibrosarcoma in liver and gastroenteropathy in stomach and intestine. The tapeworm larva was confirmed as Strobilocercus fasciolaris by PCR linked mitochondrial DNA sequencing. Light microscopy, special staining (masson trichrome) and immunoflouresence supported the diagnosis of fibrosarcoma. Infiltration of plasma cells, macrophages and eosinophils were observed in the liver section. Gastric mucosal hyperplasia, dilation of gastric glands with secretion, intestinal mucosal cell hyperplasia, proliferation of duodenal submucosal glands were confirmed by light microscopy and supported by PAS, AB staining. The concomitant development of hepatic sarcoma and gastroenteropathy by larvae of Taenia taeniaeformis (S. fasciolaris) infection is very rare and is the first reported case in Wistar rats to our knowledge.

Animals↗

Follicle-stimulating hormone-independent functions of primate Sertoli cells: potential implications in the diagnosis and management of male infertility.

CONTEXT: FSH is known to augment the production of essential germ cell (Gc) survival factors, lactate and estradiol, by Sertoli cells (Sc) of 18-d-old pubertal rats. However, the failure of gonadotropin and androgen treatment to initiate spermatogenesis in testis of some infertile men bearing Sc and Gc is intriguing. The role of FSH in regulation of lactate and estradiol production by primate Sc is currently unknown. OBJECTIVE: The objective of the study was to determine the role of FSH in regulating lactate and estradiol production by primate Sc. METHODS: Gc differentiation was initiated in male juvenile rhesus monkeys by pulsatile administration of GnRH for 4-5 wk. Sc from these pseudopubertal monkeys and pubertal rats were cultured. Production of lactate and estradiol in response to FSH and 8-bromoadenosine-cAMP was evaluated. Inhibin-betaB expression, cAMP production, and cell proliferation were also assayed. RESULTS: Unlike Sc from pubertal rats, Sc from pseudopubertal monkeys constitutively aromatized testosterone to estradiol and produced large amounts of lactate without FSH stimulation. Increasing doses of recombinant monkey FSH or 8-bromoadenosine-cAMP failed to augment lactate production, although they significantly augmented proliferation of Sc. Production of cAMP and expression of inhibin-betaB mRNA were also remarkably augmented by recombinant monkey FSH. CONCLUSIONS: These results suggest that lactate and estradiol production by monkey Sc is not governed by FSH, as previously thought based on studies of rat Sc. Thus, in a clinical situation, assessment of such gonadotropin-independent functions of Sc may be obligatory for the diagnosis and management of certain forms of idiopathic male infertility.

Animals↗

Granulosa theca cell tumor with luteoma in the ovary of a bonnet monkey (Macaca radiata).

A mass was identified on the left caudal region of the abdomen in a 13-year-old bonnet monkey (Macaca radiata). The mass was excised and diagnosed as granulosa theca cell tumor accompanied with luteoma based on the microscopic findings. Morphologically it appeared pink, round, firm multilobulated measured approximately 5 x 3 x 2.5 cm in dimension. Histologically the luteoma composed of polyhedral cells with pale strained vacuolated cytoplasm, centrally located nuclei with distinct cytoplasmic borders. Granulosa theca cell tumor appeared as densely packed spindle shaped fusiform cells arranged in interlacing bundles and whorled pattern with neoplastic cells appearing irregular shaped solid sheets. The concomitant development of granulosa theca cell tumor with luteoma in a single ovary is very rare and is the first reported case in a bonnet macaque to our knowledge.

Animals↗

Sebaceous gland adenoma in a rhesus monkey (Macaca mulatta).

A tumor mass was identified below the shoulder region of a 5-year-old male rhesus monkey (Macaca mulatta). The mass was excised and diagnosed as sebaceous gland adenoma based on the microscopic findings. Morphologically it appeared as an elevated, dome-shaped, circumscribed mass of 3.6 x 2.8 x 3.2 cm in dimension with tan speckled color. Histologically, the tumor was composed of mature, sebaceous cells (sebocytes), basal cells arranged in a mass of irregular shapes and sizes, with a characteristic appearance of poly or multilobular structure. Sebocytes were well differentiated with foamy cytoplasm in the center of the lobules and poorly or undifferentiated densely staining basal cells in the periphery of the lobules. Cellular changes in the adjacent lymph node included hyperplasia of plasma cells, macrophages and lymphoid elements with typical mitosis.

Adenoma↗

Differential expression of putative transbilayer amphipath transporters.

The aminophospholipid translocase transports phosphatidylserine and phosphatidylethanolamine from one side of a bilayer to another. Cloning of the gene encoding the enzyme identified a new subfamily of P-type ATPases, proposed to be amphipath transporters. As reported here, mammals express as many as 17 different genes from this subfamily. Phylogenetic analysis reveals the genes to be grouped into several distinct classes and subclasses. To gain information on the functions represented by these groups, Northern analysis and in situ hybridization were used to examine the pattern of expression of a panel of subfamily members in the mouse. The genes are differentially expressed in the respiratory, digestive, and urogenital systems, endocrine organs, the eye, teeth, and thymus. With one exception, all of the genes are highly expressed in the central nervous system (CNS); however, the pattern of expression within the CNS differs substantially from gene to gene. These results suggest that the genes are expressed in a tissue-specific manner, are not simply redundant, and may represent isoforms that transport a variety of different amphipaths.

Adenosine Triphosphatases↗