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41.
1. The kinetic properties of the 5'-nucleotidase (EC 3.1.3.5) present in the cytosol of rat liver were investigated in relation to the conversion of adenine nucleotides into uric acid, with particular reference to the stimulation of this process by fructose. The enzyme was assayed by the release of Pi and by a new and more sensitive radiochemical procedure. 2. When IMP was used as substrate, the partially purified enzyme displayed almost hyperbolic kinetics (h = 1.1) with S0.5 = 1.2 mM. Similar kinetics were observed with GMP and other nucleoside 5'-monophosphates, except AMP. 3. Vmax. of the enzyme for AMP was about the same as for IMP, but the kinetics were sigmoidal (h = 1.6) with S 0.5 = 10 mM. 4. The hydrolysis of IMP was inhibited competitively by GMP. IMP, at concentrations up to 0.5 mM, had a paradoxical stimulatory action on the hydrolysis of 2-5 mM-AMP and was inhibitory at higher concentrations. 5. The activity of the enzyme towards AMP and IMP was stimulated by ATP and GTP, and inhibited by Pi. Activators and inhibitor approximately cancelled each others' effects. At pH 7.4, the enzymic activity with 0.2 mM-AMP was undetectable under physiological conditions. 6. It is concluded that, in the liver cell, AMP is not hydrolysed by the soluble 5'-nucleotidase, but that its degradation requires prior deamination to IMP. 相似文献
42.
Summary A polymalformed newborn with partial monosomy for the long arm of chromosome 16 is presented. Karyotype 46,XX,del(16)(q21). 相似文献
43.
Summary A malformed male newborn with partial trisomy for the distal part of the long arm chromosome 14 (14q2314qter) is described. This anomaly arose as a segregation product of a balanced t(14q-, 11q+), translocation in the father. 相似文献
44.
Interleukin-6 administration has no acute hemodynamic or hematologic effect in the dog 总被引:4,自引:0,他引:4
J C Preiser D Schmartz P Van der Linden J Content P Vanden Bussche W Buurman W Sebald E Dupont M R Pinsky J L Vincent 《Cytokine》1991,3(1):1-4
To investigate the possible hemodynamic effects of interleukin-6 (IL-6), a single dose of 15 mcg/kg of recombinant IL-6 isolated from Escherichia coli was injected intravenously in six pentobarbital-anesthetized dogs. After 30 min, saline infusion was performed to maintain the pulmonary artery balloon-occluded pressure at baseline level. The animals were observed for up to 5 hours. No other hemodynamic alteration was observed than a gradual decline in cardiac output attributed to anesthesia. Hematologic variables, blood glucose, and total serum proteins were also constant. IL-6 levels were markedly elevated in the blood, but no tumor necrosis factor activity was detected. Thus a primary role for IL-6 in the early cardiovascular alterations associated with septic shock seems unlikely. 相似文献
45.
John P. Vanden Heuvel Benedict I. Kuslikis Marc J. Van Rafelghem Richard E. Peterson 《Journal of biochemical and molecular toxicology》1991,6(2):83-92
The elimination, tissue distribution, and metabolism of [1-14C]perfluorooctanoic acid (PFOA) was examined in male and female rats for 28 days after a single ip dose (9.4 μmol/kg, 4 mg/kg). A sex difference in urinary elimination of PFOA-derived 14C was observed. Female rats eliminated PFOA-derived radioactivity rapidly in the urine with 91% of the dose being excreted in the first 24 hr. In the same period, male rats eliminated only 6% of the administered 14C in the urine. The sex-related difference in urinary elimination resulted in the observed difference in the whole-body elimination half-life (t1/2) of PFOA in males (t1/2 = 15 days) and females (t1/2 < 1 day). Analysis of PFOA-derived 14C in tissues showed that the liver and plasma of male rats and the liver, plasma, and kidney of female rats were the primary tissues of distribution. The relatively high concentration of PFOA in the male liver was further examined using an in situ nonrecirculating liver perfusion technique. It was shown that 11% of the PFOA infused was extracted by the liver in a single pass. The ability of the liver to eliminate PFOA into bile was examined in rats whose renal pedicles were ligated to alleviate sex differences in the urinary excretion of PFOA. In a 6-hr period following IP administration of PFOA, there was no apparent difference in biliary excretion, where both males and females eliminated less than 1% of the PFOA dose via this route. We hypothesized that the sex difference in the persistence of PFOA was due to a more rapid formation of a PFOA-containing lipid (i.e., a PFOA-containing mono-, di-, or triacylglycerol, cholesteryl ester, methyl ester, or phospholipid) in the male rat. Also, the increased urinary elimination of PFOA in females may have been due to increased metabolism to a PFOA-glucuronide or sulfate ester. However, no evidence that PFOA is conjugated to form a persistent hybrid lipid was obtained, nor were polar metabolites of PFOA in urine or bile detected. In addition, daily urinary excretion of fluoride in male and female rats before or after PFOA treatment were similar, suggesting that the parent compound is not defluorinated. Thus, the more rapid elimination of PFOA from female rats is not due to formation of a PFOA metabolite. 相似文献
46.
A Kleczkowska J P Fryns P Moerman K Vandenberghe H Van den Berghe 《Annales de génétique》1990,33(2):111-112
In this report we present a female fetus with hemilobar holoprosencephaly and 46,XX,der(7)t(7;8)(q36.1;p12) mat karyotype. The holoprosencephaly-sequence is apparently related with the distal 7(q36.1----qter) deficiency. 相似文献
47.
In this report we present a 3-year-old girl with partial trisomy of the long arm of chromosome 16 due to a direct duplication 16q11.1----q13 (karyotype: 46, XX, dir dup(16) (pter----cen----q11.1----q13::q11.1----q13::q13----qter]. She presented moderate mental retardation and severe hyperkinetic behaviour. Slight dysmorphic stigmata but no internal anomalies were found. 相似文献
48.
J. P. Fryns M. Haspeslagh E. Vandenbussche P. Goddeeris E. Eggermont H. Van den Berghe 《Human genetics》1980,56(2):225-226
Summary An XX/XY mosaicism was detected in two phenotypically male newborns with perinatal death. The importance of chromosome studies at the paediatric necropsy and the significance of the present findings are discussed. 相似文献
49.
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