Biotin-deficient rats were raised on a purified ration containing raw egg white plus avidin. Urea synthesis and excretion were compared between the biotin-deficient and the pair-fed control rats. 24hrurinary urea excretion and the specific activities of carbamylphosphate synthetase, ornithine transcarbamylase, and arginase in the liver mitochondria fraction were no different between these two groups. The net urea production in the liver slice and in the isolated perfused liver of the biotin-deficient rats was similar to that of the pair-fed control. Thus the conclusion must be that biotin is not in urea in mea biosynthesis in the rat.
Animal ; Avitaminosis/metabolism ; Biotin* ; Liver/metabolism* ; Rats ; Urea/biosynthesis* ; MH - ; Substances: ; Urea ; Biotin

Idiopathic retroperitoneal fibrosis (IRF) is a rare human disease characterized by non-neoplastic fibroblastic proliferation associated with chronic inflammatory cells; its pathogenesis is obscure. We undertook an immunohistochemical study for the expression of HLA-DR antigens and other immune-related markers by retroperitoneal proliferating fibroblasts and inflammatory cells from 2 IRF patients. Patterns of immunoreactivity were compared with those expressed by human nodular fasciitis (NF) and granulation tissue. In IRF, most fibroblasts immunostained strongly for HLA-DR antigens, whereas fibroblasts in NF and granulation tissue did, not immunostain at all. The fibroblasts did not immunostain for interleukin 2 receptor, C3b receptor, CD-4, CD-8, or Leu-M1 in any of the tissue studied. Most macrophages and lymphocytes in IRF and NF immunostained Strangly for HLA-DR antigens. In IRF, the CD-4 and CD-8 immunostained T-lymphocytes appeared equally distributed. The expression of HLA-DR antigens by fibroblasts in IRF indicates that this rare disease may indeed be an immune-associated hypersensitivity disorder.
Adult ; Aged ; MH - ; Biological Markers ; Fasciitis/pathology ; Fibroblasts/*immunology/pathology ; Granulation Tissue/pathology ; HLA-DR Antigens/*analysis ; Humans ; Male ; Middle Aged ; Retroperitoneal Fibrosis/*immunology/pathology

To investigate the earlier cellular alterations(Glucose-6-Pase activity and morphologic features) caused by a hepatotoxin, thioacetamide (TAA), a single dose of the agent (200mg per kg of body weight) was given intraperitoneally to mice, which were sacrificed at intervals of 4, 8 or 16 hours after corresponding treatments. For histochemical study of glucose-6-phosphatase (G6Pase) activity, unfixed frozen sections were incubation of the Wachstein and Meisel medium and stained. The smallest pieces of liver tissue were fixed in glutaraldehyde and osmic acid, and stained by the routine electron-microscopic techniques. Some pieces of liver were fixed in 10% formalin, embedded in paraffin, and stained with hematoxylin and eosin. There was a rapid and progressive loss of G6Pase activity, in an orderly time sequence, in the experimental group. There were also morphologic changes: loss of cytoplasmic basophilia, cell infiltration and necrosis in the centrilobular and intermediate zones, and an increase of sER, small vesicles and ribosomes in the cytoplasm of hepatocytes, the marked changes of nuclei and nucleoli, and a slight increase of lipid droplets in the cytoplasm at 16 hours after intoxication. The correlation between these cellular alterations was discussed in view of mechanisms in the hepatotoxic action.
Acetamides/adverse effects* ; Animal ; Glucose-6-Phosphatase/metabolism* ; Liver/drug effects* ; Liver/enzymology ; Liver/ultrastructure ; Male ; Mice ; Thioacetamide/adverse effects* ; MH - ; Substances: ; Acetamides ; Thioacetamide ; Glucose-6-Phosphatase

To investigate the earlier cellular alterations(Glucose-6-Pase activity and morphologic features) caused by a hepatotoxin, thioacetamide (TAA), a single dose of the agent (200mg per kg of body weight) was given intraperitoneally to mice, which were sacrificed at intervals of 4, 8 or 16 hours after corresponding treatments. For histochemical study of glucose-6-phosphatase (G6Pase) activity, unfixed frozen sections were incubation of the Wachstein and Meisel medium and stained. The smallest pieces of liver tissue were fixed in glutaraldehyde and osmic acid, and stained by the routine electron-microscopic techniques. Some pieces of liver were fixed in 10% formalin, embedded in paraffin, and stained with hematoxylin and eosin. There was a rapid and progressive loss of G6Pase activity, in an orderly time sequence, in the experimental group. There were also morphologic changes: loss of cytoplasmic basophilia, cell infiltration and necrosis in the centrilobular and intermediate zones, and an increase of sER, small vesicles and ribosomes in the cytoplasm of hepatocytes, the marked changes of nuclei and nucleoli, and a slight increase of lipid droplets in the cytoplasm at 16 hours after intoxication. The correlation between these cellular alterations was discussed in view of mechanisms in the hepatotoxic action.
Acetamides/adverse effects* ; Animal ; Glucose-6-Phosphatase/metabolism* ; Liver/drug effects* ; Liver/enzymology ; Liver/ultrastructure ; Male ; Mice ; Thioacetamide/adverse effects* ; MH - ; Substances: ; Acetamides ; Thioacetamide ; Glucose-6-Phosphatase