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Proximal Convoluted Tubules (proximal + convoluted_tubule)
Selected AbstractsMurine glutathione S -transferase A1-1 in sickle transgenic miceAMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2007Yelena Z. Ginzburg Patients with sickle cell anemia exhibit mild to moderate renal and liver damage. Glutathione S -transferase A1-1 is produced during kidney and liver damage. We hypothesized that cellular damage in sickle transgenic mice would lead to increased serum and urine murine glutathione S -transferase A1-1 levels. Levels of murine glutathione S -transferase A1-1 in the serum and urine of S+S-Antilles, NY1DD, and control mice were measured by ELISA, which revealed that the serum of S+S-Antilles mice, relative to controls, had elevated levels of murine glutathione S -transferase A1-1 (P = 0.005) as did NY1DD mice (P = 0.02, baseline vs. 2-day hypoxia). Serum liver enzymes, such as aspartate amino transferase and alanine amino transferase, as well as lactate dehydrogenase were increased in S+S-Antilles mice relative to controls (P = 0.000006, P = 0.0003, and P = 0.029, respectively). Urine murine glutathione S -transferase A1-1 of S+S-Antilles mice, as well as NY1DD mice under hypoxic stress, was not significantly different from controls. Murine glutathione S -transferase class-mu was measured by ELISA in the urine of sickle transgenic mice and control mice to define the location of tubular damage at the proximal convoluted tubule; murine Glutathione S -transferase class-mu was below the limit of detection. These findings suggest that elevated levels of murine glutathione S -transferase A1-1 in the serum reflect release during liver damage and that proximal tubular damage does not lead to appreciable urinary murine glutathione S -transferase A1-1. Am. J. Hematol. 82:911,915, 2007. © 2007 Wiley-Liss, Inc. [source] Clinical and pathological effects of short-term cyanide repeated dosing to goatsJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2005B. Soto-Blanco Abstract The purpose of this work is to determine and describe the effects of subacute cyanide toxicity to goats. Eight female goats were divided into two groups. The first group of five animals was treated with 8.0 mg KCN kg,1 body weight day,1 for seven consecutive days. The second group of three animals was treated with water as controls. Complete physical examination, including observation for behavior changes, was conducted before and after dosing. One treated animal was euthanized immediately after dosing. Later, two of the remaining treated animals and a control goat were euthanized after a 30-day recovery period. Euthanized animals were necropsied and tissues were collected and prepared for histologic studies. Clinical signs in treated goats were transient and included depression and lethargy, mild hyperpnea and hyperthermia, arrhythmias, abundant salivation, vocalizations, expiratory dyspnea, jerky movements and head pressing. Two goats developed convulsions after day 3 of treatment. One animal developed more permanent behavioral changes as she became less dominant and aggressive. Histologic changes included mild hepatocellular vacuolation and degeneration, mild vacuolation and swelling of the proximal convoluted tubules of the kidneys and spongiosis of the white matter (status spongiosis) of the cerebral white tracts, internal capsule, cerebellar peduncles, spinal cord and peripheral nerves. In summary, sub-lethal cyanide intoxication in goats resulted in behavioral changes, and during the treatment period animals showed delayed signs of toxicity. Significant histologic lesions in goats were observed and need to be characterized further. Copyright © 2005 John Wiley & Sons, Ltd. [source] Relative contribution of V-H+ATPase and NA+/H+ exchanger to bicarbonate reabsorption in proximal convoluted tubules of old ratsAGING CELL, Issue 5 2006Mariana Fiori Summary With aging, the kidney develops a progressive deterioration of several structures and functions. Proximal tubular acidification is impaired in old rats with a decrease in the activity of brush border Na+/H+ exchange and a fall of H-ion flux measured with micropuncture experiments. In the present work we evaluate the contribution of 5-N-ethyl-n-isopropyl amiloride- (EIPA) and bafilomycin-sensitive bicarbonate flux () in proximal convoluted tubules of young and aged rats. We performed micropuncture experiments inhibiting the Na+/H+ exchanger with EIPA (10,4 M) and the V-H+ATPase with bafilomycin (10,6 M). We used antibodies against the NHE3 isoform of the Na+/H+ exchanger and the subunit E of the V-H+ATPase for detecting by Western blot the abundance of these proteins in brush border membrane vesicles from proximal convoluted tubules of young and old rats. The abundance of NHE3 and the V-H+ATPase was similar in 18-month-old and 3-month-old rats. The bicarbonate flux in old rats was 30% lower than in young rats. EIPA reduced by 60% and bafilomycin by 30% in young rats; in contrast, EIPA reduced by ,40% and bafilomycin by ,50% in old rats. The inhibited by bafilomycin was the same in young and old rats: 0.62 nmol · cm,2· s,1 and 0.71 nmol · cm,2· s,1, respectively. However, the EIPA-sensitive fraction was larger in young than in old rats: 1.26 nmol · cm,2· s,1 vs. 0.85 nmol · cm,2· s,1, respectively. These results suggest that the component more affected in bicarbonate reabsorption of proximal convoluted tubules from aged rats is the Na+ -H+ exchanger, probably a NHE isoform different from NHE3. [source] Acute inorganic mercury vapor inhalation poisoningPATHOLOGY INTERNATIONAL, Issue 3 2000Sigeyuki Asano Abstract Mercury contamination is a serious environmental problem worldwide. Two primary sources of contamination are dumping of large quantities of inorganic mercury and exposure in the mining industry. Although the actual fatal level of mercury vapor is not known, exposure to more than 1,2 mg/m3 of elemental mercury vapor (Hg0) for a few hours causes acute chemical bronchiolitis and pneumonitis. Two hours after exposure, lung injury appears as hyaline membrane formation, and finally, extensive pulmonary fibrosis occurs. Clinical findings correlate with the duration of exposure, the concentration of mercury, and the survival time after exposure. There is no correlation between pathological findings and the concentration of mercury in the tissues. Necrosis of proximal convoluted tubules may be attributed to the disruption of the enzyme systems of Hg2+ -sulfhydryl compounds. Metallothionein protein (MT), induced by the accumulation of Hg2+ in the kidneys, may play an important role in detoxication after it forms a non-toxic Hg2+ -MT compound. Despite the deposition of mercury in the brain, compared with organic mercury, inorganic mercury did not seem to damage the neurons. Drugs such as chelating agents and corticosteroids appear to effectively decrease the inflammation and delay pulmonary fibrosis. [source] Altered expression of aquaporin-2 in human explants with chronic renal allograft dysfunctionBJU INTERNATIONAL, Issue 7 2005Kossen M.T. Ho OBJECTIVE To investigate the distribution of aquaporins, a recently discovered family of transmembrane water channels, in human renal explants, with specific reference to chronic renal allograft dysfunction (CRAD). MATERIALS AND METHODS Immunohistochemistry for aquaporin-1 and -2 was used in 11 explants, of which five had clinically and histologically confirmed CRAD. Controls were taken from the six explants unaffected by CRAD and from histologically normal areas of six kidneys excised for renal tumours. RESULTS In the renal tumour control group, aquaporin-1 immunoreactivity was detected in the glomerular endothelium, Bowman's capsule, the proximal convoluted tubules and the thin limb of the loop of Henle, whereas immunoreactivity for aquaporin-2 was detected in the collecting ducts only. Of the explants without CRAD, where architecture was preserved, immunoreactivity for aquaporin-1 and -2 was the same as in the renal tumour controls. In the two explants with no CRAD and loss of collecting ducts, there was no aquaporin-2 immunoreactivity. In five explants with CRAD, immunoreactivity for aquaporin-2 was decreased or absent from the medulla to the cortex. The apparent decreased immunoreactivity of aquaporin-1 in this group was secondary to a decrease in the number of viable proximal tubules. CONCLUSION There was less aquaporin-2 immunoreactivity in human renal explants diagnosed with CRAD, starting from the medullary region. In explants with no CRAD and viable collecting ducts, or in normal controls, aquaporin-2 immunoreactivity remained unchanged. Aquaporins might be useful as markers for CRAD. [source] | ||||||||||