Data from a chromosome examination of 14,069 consecutive newborn infants is presented. Successful karyotypes were obtained on 13,939 babies using short-term blood cultures and conventional staining methods. Of those, 13,645 babies had normal chromosomes; 64 (0.46%) had a major chromosome abnormality; and 230 (1.65%) had a marker chromosome; giving a total of 294 (2.11%) babies with a major chromosome abnormality or distinctive marker chromosomes. Six male babies with sex chromosome abnormalities had a 47,XXY and four a 47,XYY karyotype, and three were mixoploids. Five female babies had a 47,XXX karytotype and two were mixoploids. There were three babies with ambiguous external genitalia, all with normal karyotypes. Fourteen babies had 21-trisomy; there were three 18-trisomics and one 13-trisomic. The mother of one 18-trisomy baby had a balanced (18;21) translocation. Twenty-four infants had a balanced chromosome rearrangement. Eleven of these were reciprocal and thirteen were Robertsonian translocations. One baby had an unbalanced derivative chromosome resulting from an 18;11 insertion. Two infants with additional unidentified fragments were detected. Two hundred and thirty babies (1:60) carying distinctive chromosome variants were detected. The commonest variant was the Yq+ among males (0.89%). Other common variants involved the short arms of the D and G groups (0.32% and 0.57%, respectively) 16q+ (0.09%), and 1q+ (0.04%). The results of the present study when combined with five other comparable studies, thus comprising a total of 46,150 newborn infants, indicates that the frequency of major chromosome abnormalities is between 1:150 and 1:200 live-born babies. This represents a small proportion of all conceptuses with chromosome abnormalities, which has been estimated as being approximately 1:20. It is thus clear that chromosome abnormalities form a major part of the genetic load carried by the human population. The development of chromosome banding techniques already has increased, and with further increase, the complexities of human cytogenetics and may reveal many additional rearrangements undetectable by conventional methods.

Canada↗

PubMed1975

Correlation of plasma propranolol concentration with therapeutic response in patients with angina pectoris.

The therapeutic response to propranolol was evaluated in patients with documented coronary artery disease at doses varying from 40 to 320 mg/day. Therapeutic response was quantified by evaluating exercise performance on a treadmill and then related to plasma propranolol concentration. Plasma propranolol was defined in terms of beta-adrenergic blockade by comparison with dose (concentration) response curves in normal subjects. Individual therapeutic benefit occurred at doses which averaged 144 +/- 21 mg/day and at concentrations which averaged 30 +/- 7 ng/ml. There was a wide variation between both dose and concentration among the patients at maximum therapeutic response, but when the plasma propranolol was related to pharmacologic activity, the maximum therapeutic response was observed between 64 to 98% of total blockade. Despite the increased exercise performance in these patients, the double product of heart rate and systolic blood pressure was always less, suggesting either an alteration of the relation between myocardial oxygen consumption and the double product during propranolol or a reduction on oxygen delivery to the myocardium as the result of beta-adrenergic blockade of the coronary vasculature.

Administration, Oral↗

PubMed1975

The effect of chlordiazepoxide hydrochloride on the isolated perfused rat liver.

The effects of chlordiazepoxide-hydrochloride (CDZ) on the isolated perfused rat liver were examined. CDZ administration decreased bile flow, biliary excretion of sulfobromophthalein (BSP) and hepatic uptake of BSP. The addition of CDZ to the perfusate of livers obtained from phenobarbital (Pb) pretreated rats led to 50% greater reductions in bile flow, concentration of BSP in bile and hepatic uptake of BSP. The adverse effects of CDZ on BSP excretion per g liver, however, did not appear to be enhanced by Pb pretreatment. The complex nature of the interrelationship of the effects of Pb and of CDZ on the control liver prevented differentiation of the role of CDZ from that of a metabolite on the adverse effect on liver function.

Animals↗

PubMed1975

The composition and biosynthesis of milk fat.

Explore the source record for details and available documents.

Adrenal Cortex Hormones↗

PubMed1975

Lipogenesis in rabbit adipose tissue.

Previous reports that rabbit adipose tissue does not synthesize fatty acids at significant rates led us to study in detail the pathways of lipogenesis and glyceroneogenesis in this tissue. We found that rabbit adipose tissue has a low capacity for denovo fatty acid synthesis from glucose but a high capacity for synthesis from pyruvate and acetate. The tissue can also convert pyruvate to glyceride-glycerol via the dicarboxylic acid shuttle and gluconeogenic pathways. Experiments with hydroxycitrate, a potent inhibitor of citrate cleavage enzyme, demonstrated that this is an obligatory enzyme in lipogenesis from pyruvate. The lipogenic system of rabbit adipose tissue resembles that of a ruminant in that it is adapted to utilize acetate rather than glucose. However, in contrast to ruminant tissues, the limited ability to convert glucose to fatty acid results not from a deficiency in the enzymes concerned with the transport of acetyl units out of the mitochondria but from a block prior to the level of pyruvate, most likely at the hexokinase and pyruvate kinase reactions.

Acetates↗

PubMed1975

Fatty acid synthetase from a mouse mammary adenocarcinoma.

Fatty acid synthetase was isolated from transplantable mammary adenocarcinomas carried by C3H mice. Comparison of physicochemical and immunological properties of this enzyme with those of the fatty acid synthetase isolated from normal glands of lactating C3H mice indicates that the enzymes are similar in all respects. The products of the purified fatty acid synthetase from normal and neoplastic tissues were the same, mainly long-chain fatty acids. The normal gland was found to contain 30 times more enzymes per g tissue than did the neoplasm; this may account in part for the relatively low rat of fatty acid synthetase found previously in this neoplasm.

Adenocarcinoma↗

PubMed1975

Calcium uptake and ATPase activity of microsomes from heterotopically transplanted rabbit heart.

Heterotopic cardiac transplantation was performed in rabbits. The calcium uptake and ATPase activities of microsomal fraction were studied in three groups (group I, normal controls; group II, early transplants; group III, late transplants) during severe rejection as characterized histologically and electrocardiographically. Group III showed a significant decrease in calcium uptake but no difference in ATPase activity compared with groups I or II. The results demonstrate that in the rejecting transplanted hearts there is an uncoupling of microsomal calcium uptake from this ATP splitting function.

Adenosine Triphosphatases↗

PubMed1974