Serum cholesterol esterifying and cholesteryl ester hydrolyzing activities in liver diseases: relationships to cholesterol, bilirubin, and bile salt concentrations

Patients with acute hepatitis and chronic alcoholic liver disease had decreased net serum cholesterol esterifying activity (CEA) which correlated positively with the percentages and concentrations of cholesteryl esters in their serum. These cholesterol parameters also correlated negatively with serum bilirubin concentrations, but bilirubin added to sera in vitro failed to influence CEA. The decreased net CEA in the patients was not due to its inhibition by serum bile salts. The sera from five patients catalyzed a net hydrolysis of cholesteryl esters rather than a net esterification of free cholesterol. Since serum cholesteryl ester hydrolase activity may also have been present in the patients with decreased CEA, net CEA cannot be equated with the activity of lecithin-cholesterol acyl transferase (LCAT) in patients with liver disease. The relative contributions of LCAT and cholesteryl ester hydrolase activities to CEA in disease states remain to be evaluated by mutually independent assays. Nevertheless, the correlations found between net CEA and the concentrations and percentages of cholesteryl esters support the concepts that serum cholesterol esterifying activity is physiologically important in the formation of serum cholesteryl esters and that decreased CEA is one mechanism for the decreased level of cholesteryl esters seen in patients with liver diseases.     

Complication of insulin-dependent diabetic pregnancies by preeclampsia and/or chronic hypertension: analysis of outcome

The significance of hypertensive complications of insulin-dependent diabetic pregnancies (IDDP) has not been well examined since the early reports of Pedersen, which demonstrated an increased risk of neonatal death in women with pregnancy induced hypertension (PIH). To assess the effect of both PIH and chronic hypertension (CH) on outcome of IDDP managed using contemporary obstetrical and diabetic management, we reviewed the records of all 199 IDDP delivered at our institution over a 7-year period. Patients were classified as having PIH (Group 1, n = 37), CH (Group 2, n = 18) or both (Group 3, n = 4) on the basis of standard clinical criteria. All other IDDP were placed in the control group (Group 4, n = 140). Comparing all groups, significant differences were found for maternal age (P less than .0001) and distribution among White's Classes (P less than .0001). There was no significant difference in estimated gestational age (EGA) at delivery, birthweight, Apgar scores, hypoglycemia, hyperbilirubinemia, or congenital anomalies. Intrauterine fetal death (IUFD) was no more common in Groups 1, 2 or 3 than in Group 4; however, IDDP with CH were significantly more likely to have had previous stillbirths than IDDP with PIH (P = .011) or control IDDP (P = .017). Contrary to common clinical belief, the "stress" of CH and PIH did not offer protection to the newborn in the development of RDS or HMD. In fact, Group 3 infants had a higher rate of HMD than control infants (P = .024).(ABSTRACT TRUNCATED AT 250 WORDS)     

Nucleotide degrading enzymes in Neurospora crassa

Considerable amounts of GTP, GMP, adenosine, guanine, and adenine accumulated in Neurospora crassa when a culture grown on low phosphate (0.01%) medium was transferred to a high phosphate (1%) medium. The levels of alkaline phosphatase, nucleotidase, and nucleosidase decreased by 2.4, 5.4, and 3 folds, respectively, in cultures grown on high phosphate medium. Substrate kinetics of these enzymes revealed that: (1) alkaline phosphatase isolated from the organism grown on low phosphate medium demonstrates nonlinear reciprocal plots with two distinct apparent Km values for β-glycerophosphate compared to one apparent Km value (associated with 32% decrease in the apparent V_max value) obtained with that grown on high phosphate medium; (2) nucleotidases and nucleosidases isolated from organisms cultivated on low phosphate and high phosphate media showed the same apparent Km values, 0.25 mM for nucleotidase and 0.909 mM for nucleosidase. There was, however, >3 times decrease in the catalytic activity of the latter enzymes isolated from organisms grown on high phosphate medium as compared to those grown on low phosphate. Inclusion of inorganic phosphate in standard assay mixtures of the three enzymes resulted in a considerable inhibition in the catalytic activities of all of them. High levels of phosphate in the medium caused marked repression of three out of six of alkaline phosphatase, two out of three of nucleotidase, and one out of two of nucleosidase isozymic forms detected in the low phosphate grown culture.