Effect of a quinazolinone derivative on the metabolism of Streptococcus faecalis--R (ATCC-8043)

2-methyl-3(3'-methyl-2'-pyridyl)-4 (3H) quinazolinone (SRC-820) and methaqualone inhibited the growth of Streptococcus faecalis-R (ATCC-8043). Phosphoenolpyruvate formation from 3-phosphoglycerate by an enzyme extract of S. faecalis was inhibited by SRC-820. With edetate or fluoride, an additive inhibitory effect by SRC-820 was observed.

Inbreeding among some Brahman populations of Tamil Nadu

A statewide survey of four endogamous Brahman populations of Tamil Nadu reveals a low level of inbreeding in three of them. In the fourth population, the Thengalai, the level is higher, but not as high as in other social castes. The Tamil Brahmans rank next to the Telugu and the Kanarese Brahmans in this respect. Uncle-niece marriages also occur as in Telugu-speaking populations, and these exceed in the two Ayyangar populations in comparison to the Ayyar. A decline of first-cousin marriages and an increase of uncle-niece marriages are detected in the first two living generations in each population.

FURTHER STUDY OF NITINOL WIRE AS CONTRACTILE ARTIFICIAL MUSCLE FOR AN ARTIFICIAL HEART

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A study of serum lipoproteins and angiographic evidence of coronary artery disease

Extensive serum lipid analyses, with specific emphasis on the concentration of serum beta and pre-beta-lipoproteins, were made on 93 patients who had a clinical diagnosis of angina pectoris and were undergoing coronary angiographic studies. Those individuals with abnormal angiographic evidence of obstructive coronary artery disease, including a group with a prior myocardial infarction, have almost uniformly elevated serum beta-lipoprotein levels when related to an arbitrary division based on the mean values for a "normal" adult population at a similar age level. Compared to serum cholesterol and serum triglycerides, the serum lipoprotein concentrations, specifically beta-lipoproteins, appear to be a more useful parameter for predicting the existence of coronary artery disease. Further studies relating clinical risk factors to coronary artery disease might be better approached by using angiography of coronary vessels rather than myocardial infarction or sudden death from coronary artery disease as an endpoint of morbid data.

Thromboresistance of glass after glow discharge treatment in argon

Glow discharge treated (GDT) inorganic materials are sterile and free of all organic contaminants. Such materials implanted in the canine inferior vena cava often demonstrate significant thromboresistance. Standard Pyrex glass tubing was GDT in argon to provide a surface free energy above 70 dynes/cm, slight surface negativity, and other surface-physical modifications of its interface. Chromic acid cleaned lengths of the same tubing, and short segments whose edges were not fire-polished were used as controls. Upon canine implantation, the in vivo results were similar in independent surgical laboratories. The glass was implanted as 1.4 cm long rings or as 5 cm long tubes in separate medical centers according to different protocols. GDT specimens remained patent; all controls accumulated thrombi. A remarkably pure, low critical surface tension, labile protein coating covered all cylindrical lumens after 2 hr in vivo. This coating diminished within 2 weeks and was essentially absent after 480 days, eeven though scanning EM showed evidence of a micron thick luminal film, probably eroding glass. No emboli were found in the implant animal's kidney or lungs at any stage.

Effects of Co60 gamma radiations on the conduction properties of frog sciatic nerves

The effect of Co60 gamma radiations on the amplitude, detection period and duration of the action potential of sciatic nerves of Rana Tigrina frogs have been studied. Dose levels of up to 120 KR were employed. Irradiation of the nerves with dose levels upto 30 KR does not seem to affect the action potential profiles. The amplitude falls rapidly therafter, registering less than 5% of the orginal value after irradiation by a dose of 120 KR. Qualitatively similar behaviour is seen in the case of detection period and duration of action potential. These results are examined in the light of the authors' data (11) on the effect of Co60 gamma rays on the enzyme acethlcholinesterase (AchE). Portions of this paper have already been communicated (12).

Effect of eltroxine and neomercazol on monoamine oxidase from rat tissues

The paper describes the effect of two drugs, (Eltroxine and Neomercazol) on the nature and activity of monoamine oxidase (MAO) in albino rats. Four organs namely liver, kidney, brain and heart were examined from this point of view. Biological activity measurements were done using tyramine hydrochloride as the substrate. The liver MAO from normal as well as the drug treated rats were subjected to DEAE gel filtration studies. These investigations show that there is a significant difference in the biological activity as well as in the actual nature of the enzyme as a result of treatment with the drugs mentioned above.

Nonthrombogenic ac polarized copper prosthesis

In previous studies from our laboratories, it was shown that metals and alloys which register negative potentials in blood vs the normal hydrogen electrode tend to be antithrombogenic while those with positive potentials are invariably thrombogenic. The present paper deals with a novel approach of maintaining an implanted metallic prosthesis at a negative potential. A copper vascular prosthesis in a dog was maintained at cathodic potentials by a small amplitude (+/- 10 mV) high-frequency ac (100 kHz) on the prosthesis. The prostheses were removed after 2 hours, 6 hours, 1 day, and 42 days, with subsequent visual and scanning electron microscopic examination of the prostheses completed. All tubes were free of thrombus deposits. Minimal junctional thrombi were found, probably due to differences in physicochemical characteristics of the vascular prostheses and recipient vessels. The results are compared with those in the control group (copper tubes with no current) and dc polarized copper tubes. While the control tubes occluded in 2 to 6 hours, the dc and ac polarized tubes remained patent. Of the ac and dc polarized tubes, the former tubes lasted up to 6 weeks with less thrombus deposit. The mechanism of operation of the ac polarized copper prosthesis is not fully understood.

Earlobe attachment, hand clasping and arm folding among Tamil Brahmans in relation to cultural and ethnic affiliations

The traits, earlobe attachment, hand clasping and arm folding, are found to show a high degree of homogeneity in the Tamil Brahmans. The latter appear to be closest to the Bengali Brahmans, with respect to all three traits, and differ significantly from other Brahman populations, with respect to earlobe.

Adrenal cells in tissue culture the effects of choleragen and ACTH on steroid and cyclic-AMP metabolism

Primary cultures of mouse adrenocortical tumors provide a sensitive system for investigating the effects of the enterotoxin of the V. cholerae (choleragen) on cyclic-AMP metabolism in the intact cell. Like ACTH, the toxin stimulates the synthesis and release of steroids from these cells but its mode of action differs from that of ACTH. The steroidogenic response to ACTH is immediate and of limited duration. The initial rate of steroidogenesis is the highest. In contrast, the steroidogenic response to choleragen is preceded by a 30-240 minute lag period which is inversely related to the concentration of the toxin. Whereas prolongation of the response to a single dose of ACTH requires hormone concentrations above those producing maximal initial steroidogenic activity, persistent steroidogenesis is induced at all levels of the toxin. Steroidogenic responses are detectable with 10 pg/ml of choleragen or less. The respective effects of ACTH and choleragen on cyclic-AMP synthesis and release into the medium parallel those on steroidogenesis. Intracellular cyclic-AMP levels in ACTH-treated cells reach a peak within 20-30 minutes and decline to normal levels within 2-4 hours. In choleragen-treated cells, after the lage period, the levels of intracellular cyclic-AMP remain above control levels indefinitely. The effects of ACTH and choleragen on cyclic-AMP biosynthesis are additive at all levels of the two compounds. The effects of choleragen are blocked by prior treatment of the toxin with a five-fold molar excess of ganglioside GM1, a presumed constituent of the toxin-binding site.

Hormonal steroids: effects on the vascular system

An increase in the incidence of thromboembolic disorders has been associated with oral contraceptive use, though the causative mechanisms remain unclear. Our studies indicate that the contraceptive steroids, irrespective of the intermediary metabolic processes involved, cause changes in the surface charge characteristics of the blood vessel wall and blood cells in the following cases: (i) in experiments using dogs, the hormonal steroids result in a greater reduction in the pore surface charge of veins than in arteries; (ii) in rats, the current induced mesenteric occlusion times are significantly lowered following administration of combined contraceptives steroids; (iii) in humans, the electrophoretic mobilities of erythrocytes and platelets from women taking Ovral and Demulen are lower than in controls, and (iv) there is no significant alteration of plasma coagulation times of women who are on injectable progestin therapy. Demulen and Ovral appear to result in a slight decrease in activated partial thromboplastin times compared to controls.

The role of electrochemical surface properties in thrombosis at vascular interfaces: cumulative experience of studies in animals and man

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A note on the stability of conjugated diene absorption of rat liver microsomal lipids after carbon tetrachloride poisoning

Liver microsomal lipid peroxidation has been observed in fatal human CCl(4) poisoning, in rats with fatty livers induced by CCl(4) or by yellow phosphorus, and in mice poisoned with 1,1,2,2-tetrachloroethane. These observations suggest the possibility that other instances of toxic liver injury may involve lipid peroxidation. Cases of acute, fatal, toxic liver injury (e.g., from halothane anesthesia) are not likely to occur at or near laboratories equipped to determine whether any lipid peroxidation might have taken place. The data presented indicate that rat livers may be stored frozen for at least 7 days with no demonstrable diminution in CCl(4)-induced conjugated diene absorption of liver microsomal lipids.