Renal histomorphology in dogs with pyometra and control dogs, and long term clinical outcome with respect to signs of kidney disease

<p>Abstract</p> <p>Background</p> <p>Age-related changes in renal histomorphology are described, while the presence of glomerulonephritis in dogs with pyometra is controversial in current literature.</p> <p>Methods</p> <p>Dogs with pyometra were examined retrospectively for evidence of secondary renal damage and persisting renal disease through two retrospective studies. In Study 1, light microscopic lesions of renal tissue were graded and compared in nineteen dogs with pyometra and thirteen age-matched control bitches. In Study 2, forty-one owners of dogs with pyometra were interviewed approximately 8 years after surgery for evidence ofclinical signs of renal failure in order to document causes of death/euthanasia.</p> <p>Results</p> <p>Interstitial inflammation and tubular atrophy were more pronounced in dogs with pyometra than in the control animals. Glomerular lesions classified as glomerular sclerosis were present in both groups. No unequivocal light microscopic features of glomerulonephritis were observed in bitches in any of the groups.</p> <p>Two bitches severely proteinuric at the time of surgery had developed end stage renal disease within 3 years. In five of the bitches polyuria persisted after surgery. Most bitches did not show signs of kidney disease at the time of death/euthanasia.</p> <p>Conclusion</p> <p>Tubulointerstitial inflammation was observed, but glomerular damage beyond age-related changes could not be demonstrated by light microscopy in the dogs with pyometra. However, severe proteinuria after surgery may predispose to development of renal failure.</p

Chemiluminescence in activated human neutrophils

Human neutrophils (PMNs) suspended in Hanks' balanced salt solution (HBSS), which are stimulated either by polycation-opsonized streptococci or by phorbol myristate acetate (PMA), generate nonamplified (CL), luminol-dependent (LDCL), and lucigenin-dependent chemiluminescence (LUCDCL). Treatment of activated PMNs with azide yielded a very intense CL response, but only a small LDCL or LUCDCL responses, when horse radish peroxidase (HRP) was added. Both CL and LDCL depend on the generation of Superoxide and on myeloperoxidase (MPO). Treatment of PMNs with azide followed either by dimethylthiourea (DMTU), deferoxamine, EDTA, or detapac generated very little CL upon addition of HRP, suggesting that CL is the: result of the interaction among H 2 O 2 , a peroxidase, and trace metals. In a cell-free system practically no CL was generated when H 2 O 2 was mixed with HRP in distilled water (DW). On the other hand significant CL was generated when either HBSS or RPMI media was employed. In both cases CL was markedly depressed either by deferoxamine or by EDTA, suggesting that these media might be contaminated by trace metals, which catalyzed a Fenton-driven reaction. Both HEPES and Tris buffers, when added to DW, failed to support significant HRP-induced CL. Nitrilotriacetate (NTA) chelates of Mn 2+ , Fe 2+ , Cu 2+ , and Co 2+ very markedly enhanced CL induced by mixtures of H 2 O 2 and HRP when distilled water was the supporting medium. Both HEPES and Tris buffer when added to DW strongly quenced NTA-metal-catalyzed CL. None of the NTA-metal chelates could boost CL generation by activated PMNs, because the salts in HBSS and RPMI interfered with the activity of the added metals. CL and LDCL of activated PMNs was enhanced by aminotriazole, but strongly inhibited by diphenylene iodonium (an inhibitor of NADPH oxidase) by azide, sodium cyanide (CN), cimetidine, histidine, benzoate, DMTU and moderately by Superoxide dismutase (SOD) and by deferoxamine. LUCDCL was markedly inhibited only by SOD but was boosted by CN. Taken together, it is suggested that CL generated by stimulated PMNs might be the result of the interactions among, NADPH oxidase, (inhibitable by diphenylene iodonium), MPO (inhibitable by sodium azide), H 2 O 2 probably of intracellular origin (inhibitable by DMTU but not by catalase), and trace metals that contaminate salt solutions. The nature of the salt solutions employed to measure CL in activated PMNs is critical.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44510/1/10753_2004_Article_BF00918987.pd

Consequences of transcellular biosynthesis of leukotriene C4 on organ function

Formation of eicosanoids is a special mode of cell communication whereby production of eicosanoids by mixed cell populations differs from that expected from each individual cell. Transcellular biosynthesis of leukotriene C4 occurs via transfer of the reactive intermediate leukotriene A4 from neutrophils to vicinal acceptor cells devoid of 5-lipoxygenase activity such as platelets or vascular cells. Evidence for the in vivo relevance of transcellular eicosanoid metabolism results from experiments using the isolated beating rabbit heart perfused with activated neutrophils. The resultant leukotriene C4 synthesis is timely related to the pressor response of the coronary arteries and inflammatory damage of the heart by edema formation and neutrophil infiltration into the organ. Blockade of leukotriene C4 synthesis by 5-lipoxygenase inhibitors or leukotriene C4 actions by respective receptor antagonists facilitated significant protective effects. Further confirmation of the potential role of LTC4 in myocardial ischemia comes from in vivo studies in the rabbit