scholarly journals Carcinogenesis in female C57Bl/6J mice chronically exposed to sodium arsenate (Asv) in drinking water for 2 years

Author(s):  
M. Krishnamohan ◽  
A. A. Seawright ◽  
M. R. Moore ◽  
J. C. Ng
1995 ◽  
Vol 14 (6) ◽  
pp. 475-483 ◽  
Author(s):  
G. García-Vargas ◽  
ME Cebrián ◽  
A. Albores ◽  
CK Lim ◽  
Francesco De Matteis

1 A time-course study was carried out in mice subchroni cally exposed to As III (as sodium arsenite) or As V (as sodium arsenate), via drinking water, relating the pattern of urinary porphyrin excretion to the renal and hepatic enzyme activities of porphobilinogen deaminase (PBGD), uroporphyrinogen III synthetase (URO III-S), uropor phyrinogen decarboxylase (URO-D) and coproporphyrino gen oxidase (COPRO-O), as well as to the hepatic por phyrin accumulation in the treated animals. 2 A time-dependent, wave-like porphyric response was found in mice exposed to As V, and the increases seen in total urinary porphyrins (at 3 weeks of exposure) corre sponded to an increased activity of PBGD and Uro III-S in liver. 3 Significant decreases in renal URO-D and hepatic and renal COPRO-O activities were found in treated mice; these inhibitions were more pronounced in animals exposed to As III. 4 The combination of these enzymic effects may explain the time-dependent porphyric response of mice subchroni cally exposed to As. Finally, the relative magnitudes of URO-D and COPRO-O inhibitions may determine the pat tern of porphyrin concentration observed in urine and tis sues. 5 The decrease in renal URO-D activity may help to explain the inversion in the coproporphyrin/uroporphyrin ratio previously reported in humans chronically exposed to As; however, there were differences between the uri nary porphyrin profiles found in both species. The possi ble reasons for the similarities and differences are briefly discussed.


Author(s):  
Jack C. Ng ◽  
Alan A. Seawright ◽  
Lixia Qi ◽  
Corinne M. Garnett ◽  
Barry Chiswell ◽  
...  

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).


Author(s):  
Elsie M. B. Sorensen

The detoxification capacity of the liver is well documented for a variety of substances including ethanol, organic pesticides, drugs, and metals. The piscean liver, although less enzymatically active than the mammalian counterpart (1), contains endoplasmic reticulum with an impressive repertoire of oxidizing, reducing, and conjugating abilities (2). Histopathologic changes are kncwn to occur in fish hepatocytes following in vivo exposure to arsenic (3); however, ultrastructural changes have not been reported. This study involved the morphometric analysis of intracellular changes in fish parynchymal hepatocytes and correlation with arsenic concentration in the liver.Green sunfish (Lepomis cyanellus, R.) were exposed to 0, 30, or 60 ppm arsenic (as sodium arsenate) at 20°C for 1, 2, or 3 week intervals before removal of livers for quantification of the arsenic burden (using neutron activation analysis) and morphometric analysis of ultrastructural alterations. Livers were cut into 1 mm cubes for fixation, dehydration, and embedding.


1983 ◽  
Vol 17 (9) ◽  
pp. 394-394 ◽  
Author(s):  
JGMM Smeenk

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