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S Jenkins

Publications and source records attributed to S Jenkins.

11 recordsLinked to original sources

Lack of effect of maternal cocaine administration on myometrial electromyogram and maternal plasma oxytocin concentrations in pregnant sheep at 124-146 days' gestational age.

Although cocaine abuse during human pregnancy is associated with an increased incidence of preterm labor, there are few reports on the effects of cocaine on myometrial activity during pregnancy in experimental animals. Cocaine (0.5, 1, or 2 mg/kg) or vehicle was randomly administered intravenously to 15 pregnant ewes between 124-146 days' gestation (term is 147 days). Neither cocaine nor vehicle administration altered total myometrial electromyographic activity from pre-dose levels 1 or 6 hours after administration. Maternal arterial plasma oxytocin did not change during the study. Using a positive control, we confirmed observations of other investigators that administration of 2 mg/kg cocaine significantly increases maternal arterial blood pressure. The results indicate that cocaine does not stimulate myometrial contractility significantly in late pregnancy in sheep.

Animals

Formation of lentivirus particles by mammalian cells infected with recombinant fowlpox virus.

Recombinant fowlpox viruses (FPV) containing the env or gag-pol genes of simian immunodeficiency virus from macaques (SIVmac) were constructed. The env, gag, and pol-encoded polypeptides were efficiently expressed and processed in avian cells productively infected with FPV as well as in mammalian cells, in which FPV infection is abortive. In addition, the recombinant FPV expressing the gag-pol genes directed the formation of defective, lentivirus-like particles which were released into the culture medium of infected cells. Coinfection of cells with the env and gag-pol recombinant viruses resulted in the generation of particles containing SIVmac envelope glycoprotein. The applications of this system to vaccine development are discussed.

Animals

Triclosan and sodium lauryl sulphate mouthrinses. (II). Effects of 4-day plaque regrowth.

Toothpastes have been shown to exert some plaque inhibitory effects probably due to the action of detergents such as sodium lauryl sulphate (SLS). Recently the antimicrobial, triclosan, has been added to experimental and commercial toothpaste products to enhance activity against plaque. There is, however, little information as to the plaque inhibitory effects alone of ingredients such as SLS and triclosan. This investigation compared the effects on 4-day plaque regrowth of a 1% SLS, 0.2% triclosan and 0.2% chlorhexidine rinse with a 0.9% saline rinse. The study was single blind, latin square, four-period crossover design, balanced for residual effects and employing 16 healthy dentate volunteers. During each period, normal oral hygiene ceased and plaque regrowth from a zero baseline was measured by score and area after 2 x daily rinses with 10 ml volumes of each rinse. Washout was a minimum of 60 h. Plaque scores and areas were significantly lower with chlorhexidine than the other preparations and significantly higher with saline. There were no significant differences between SLS and triclosan. The results were essentially consistent with the similar substantivity of SLS and triclosan demonstrated from the salivary bacterial count investigation. Taste acceptability may, however, explain the small reverse trends noted between the two studies. It is concluded that both SLS and triclosan would individually confer plaque inhibitory properties to toothpaste formulations. However, when combined in a single formulation, their effects may not be additive.

Adult

Interaction of pneumococcal antigens with complement in rats.

Complement activation with pneumococcal antigens was studied both in vitro and after injection of the antigens into rats. Whole pneumococci of various serotypes activated C3-C9 in rat serum treated with ethyleneglycol-bis (beta-aminoethyl ether)-N,N'-tetraacetic acid, although serotypes differed greatly in the extent of activation. Some purified pneumococcal capsular polysaccharides also activated C3-C9 in rat serum, but only when the antigens were present in concentrations of 500 to 1,000 mug/ml. Much of the activation with capsular polysaccharides was eliminated by the use of ethyleneglycol-bis (beta-aminoethyl ether)-N,N'-tetraacetic acid. Activation of C3-C9 by capsular polysaccharides did not correlate with the level of reactivity observed with whole organisms of the same serotypes. After injection of 5 x 10(9) pneumococci (type 3 or type 4) intravenously into rats, there was a transient decline in serum C3-C9 activity, but there was no decline in C3-C9 levels after intravenous injection of 1,000 mug of type 3 or type 4 capsular polysaccharides. As determined by immunofluorescence, circulating capsular polysaccharide was deposited in several tissues, including the vascular endothelium and glomerular mesangium of the kidney. C3 was not detectable in these deposits, and there was no histological evidence of an inflammatory response. Capsular polysaccharides appear to be only weak activators of complement. Other pneumococcal antigens may be more important in the pathogenesis of hypocomplementemia in pneumococcal infection.

Animals

Diagnostic delay in neoplastic disease.

It may be possible to measure quality of care in general practice by selecting a single criterion of care such as the delay in the recognition of neoplastic disease. Seven general practitioners reported on 55 new cases and the results are analysed according to age, sex, and diagnostic category. An attempt is made to quantify ;quality' by comparing the theoretical ;ideal' delay (retrospectively assessed) with the ;actual' delay. The wider implications of the study are discussed.

Adolescent

Left ventricular endomyocardial biopsy. III: ultrastructural characteristics of cardiomyopathy and cardiac hypertrophy with good or poor ventricular function.

Left ventricular endomyocardial biopsies have been obtained from patients with cardiomyopathy and hypertrophy due to aortic valve disease. These biopsies have been examined by electron microscopy and the ultrastructural abnormalities compared. In congestive cardiomyopathy no specific abnormalities were found although myofibrillary degeneration and membrane-bound vacuoles were more commonly present. Crossing of whole groups of sarcomeres was found only in asymmetric septal hypertrophy, but was not present in all cases. Amyloid deposits were demonstrated easily by electron microscopy in patients with restrictive cardiomyopathy. In the patients with hypertrophy due to aortic valve disease, no specific features were found and ultrastructural abnormalities did not differentiate between normal and impaired left ventricular functions.

Aortic Stenosis, Subvalvular

Children of divorce.

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Counseling