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Biomedical subjects

J Garancis

Publications and source records attributed to J Garancis.

5 recordsLinked to original sources

Effects of complement depletion on glomerular eicosanoid production and renal hemodynamics in rat nephrotoxic serum nephritis.

The role of complement in mediating the changes in renal hemodynamics and glomerular eicosanoid synthesis after the administration of heterologous antibody against rat glomerular basement membrane (AGBM) was studied in Munich-Wistar rats. AGBM serum decreased glomerular filtration rate (GFR) and increased glomerular thomboxane B2 (TxB2) production without associated changes in glomerular prostaglandin E2 (PGE2) or PGF2 alpha production. Pretreatment of rats with cobra venom factor to deplete complement blocked the fall in GFR produced by AGBM without altering the increment in glomerular TxB2 production. In these animals, glomerular PGE2 synthesis was elevated. The results indicate that the salutary effects of complement depletion in nephrotoxic serum nephritis are not mediated by changes in the glomerular production of the vasoconstrictor TxA2. An enhanced production of PGE2 may participate in preventing the fall in GFR after AGBM administration in the complement-depleted rats.

Animals

BSS Plus: a potential irrigating solution for neurosurgery.

BSS Plus is a pH-stable balanced salt solution similar to glutathione bicarbonate Ringer's solution. Extensively used in ophthalmology, it is of potential value in neurosurgery. In comparative tests of its effectiveness, 28 cats underwent bilateral irrigation of the surface of the cerebral cortex with normal saline on one side and BSS Plus on the other. After 2 hours, a marked decrease was seen in the surface pH of the hemisphere irrigated with normal saline but not of the hemisphere treated with BSS Plus. Blood-brain barrier changes (measured with Evans blue dye techniques) were more evident following saline irrigation. Somatosensory evoked potentials and cerebral blood flow were not significantly altered. Conventional light microscopy using three standard stains did not reveal a significant difference. Transmission electron microscopy studies were performed in 14 animals and scanning electron microscopy in six. In five animals both transmission and scanning electron microscopy studies were conducted after irrigation with both agents without a cottonoid cover and with immediate harvest of superficial layers from the living brain and immersion-fixation in glutaraldehyde. Tissue preservation was superior on the BSS Plus side in all studies. This agent may represent an improved irrigation solution for neurosurgery, but further studies are required.

Animals

Chemodectoma involving the cavernous sinus and semilunar ganglion.

This paper reports a case of paraganglioma involving the cavernous sinus and semilunar ganglion. The origin of the tumor cells, from paraganglia in this region, is also discussed. Recognition of paraganglia in this area may aid the clinician and pathologist in the differential diagnosis of tumors in this region.

Aged

"Milwaukee shoulder"--association of microspheroids containing hydroxyapatite crystals, active collagenase, and neutral protease with rotator cuff defects. II. Synovial fluid studies.

Hydroxyapatite crystals in spheroid-shaped masses 1.9-15.6 micrometer in diameter were found in 12 of 13 synovial fluids obtained from the shoulder joints of 4 patients with rotator cuff tears and glenohumeral osteoarthritis. Two of 16 control joint fluids also showed these particles. Collagen types I, II and III were identified in the joint fluid pellets from 3 of the 4 patients, and fibers with typical collagen periodicity were also seen on transmission electronmicroscopy. Collagenase and neutral protease activities were found in fluids from 5 joints in 3 patients, whereas active collagenase was found in only 1 of 10 fluids from rheumatoid arthritis patients and in none of 3 fluids from patients with osteoarthritis. Neutral protease activities were present in several rheumatoid joint fluids. These findings are compatible with the hypothesis of an enzymatic release of hydroxyapatite crystals from the synovium and endocytosis by synovial macrophage-like cells with subsequent crystal-stimulated release of collagenase and neutral protease into the joint fluid, completing a pathogenetic cycle.

Aged