Storage of audiometric data - online - with a small computer

Between 1968 and 1977 there were 4 113 109 primary smallpox vaccinations in France. There were 30 deaths but no deaths occurred after re-vaccination. The mortality can be analysed as follows: -- proven or probable cases: 1.5 death/million vaccinations; -- proven, probable or possible cases 2.9/million vaccinations; -- proven, probable, possible or doubtful 7.3 cases/million vaccinations. The risk of death is 3 to 4 times greater under the age of one year and an overall death rate of 6/million vaccinations in reasonably accurate.     

Renin-dependent renovascular hypertension in infant with abdominal aortic atresia

A newborn infant was seen with severe and progressive arterial hypertension, congenital atresia of the abdominal aorta, and a renal venous renin activity ratio greater that 1:1.5 (1:3.1). Preoperative studies indicated that the renin-angiotensin axis was responsible for the production and maintenance of the severe hypertensive process. Right nephrectomy cured the arterial hypertension both above and below the area of coarctation. The possible roles of the pathogenic mechanism are discussed.     

Medium-chain-length poly(beta-hydroxyalkanoate) synthesis from triacylglycerols by Pseudomonas saccharophila

Pseudomonas saccharophila NRRL B-628 is capable of utilizing agricultural lipids for growth. The organism exhibited good growth with triacylglycerol substrates that contained saturated fatty acyl moieties such as coconut oil (CO; C10-12 fatty acids) and tallow (T; C16-18 fatty acids). Electron micrographs of the triacylglycerol-grown cells showed the presence of intracellular granules indicative of poly(beta-hydroxyalkanoate) (PHA) production. Cells grown in a 250-ml CO-containing medium produced ca. 0.2 g of medium-chain-length (mcl)-PHA. Gas chromatographic analysis showed that beta-hydroxyoctanoic acid (30%), beta-hydroxydecanoic acid (40%), and beta-hydroxydodecanoic acid (16%) were the major monomer repeat-units of the CO-derived polymer. The estimated mean molecular mass of the CO-derived mcl-PHA as determined by gel permeation chromatography was 13.1 x 10(4) g/mol with a polydispersity of 3.16.     

Characterization of an intrinsically fluorescent gonadotropin-releasing hormone receptor and effects of ligand binding on receptor lateral diffusion

The GnRH receptor (GnRHR) is a G protein-coupled receptor expressed by gonadotropes in the anterior pituitary gland. In the past several years, much has been learned about the structure-function relationships that exist in this receptor with regard to ligand binding and signal transduction. However, the lack of specific antibodies has precluded any analyses of the behavior of the unbound form of this receptor. We have constructed a functional GnRHR in which enhanced green fluorescent protein is fused to the carboxyl-terminus of the murine GnRHR. This fusion receptor was expressed diffusely throughout the cell, with approximately 38% of the fusion receptors colocalized with a plasma membrane marker in the gonadotrope-derived alphaT3 cell line, and approximately 82% of the fusion receptors colocalized with a membrane marker in Chinese hamster ovary cells. Furthermore, the fusion receptor displayed a Kd of 0.8 nM for iodinated des-Gly10,D-Ala-6-GnRH N-ethyl amide in Chinese hamster ovary cells, which was similar to the Kd of the native GnRHR expressed in alphaT3 cells. The surface mobility of the fusion protein was examined by fluorescence photobleaching recovery methods. In the unbound state the majority of the receptors were laterally mobile and displayed a lateral diffusion rate of 1.2-1.6 x 10(-9) cm2/sec. Binding of GnRH reduced the rate of lateral diffusion over 3-fold and reduced the fraction of mobile receptors from approximately 76-91% to 44-61%. Like GnRH, the competitive GnRH antagonist antide slowed the rate of receptor diffusion approximately 3-fold. In contrast to GnRH, antide had no effect on the fraction of mobile receptors. Thus, an intrinsically fluorescent GnRHR is trafficked to the plasma membrane of mammalian cells, is capable of ligand binding and signal transduction, and allows direct observation of the GnRHR in the nonligand-bound state. Furthermore, fluorescence photobleaching recovery analysis of the GnRHR-green fluorescent protein fusion reveals fundamental differences in the membrane dynamics of the GnRHR induced by the binding of an agonist vs. that induced by the binding of an antagonist.     

Degradation of HMG-CoA reductase in vitro. Cleavage in the membrane domain by a membrane-bound cysteine protease

We have recently shown that the endoplasmic reticulum (ER) membrane protein, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, is cleaved in isolated membrane fractions enriched for endoplasmic reticulum. Importantly, the cleavage rate is accelerated when the membranes are prepared from cells that have been pretreated with mevalonate or sterols, physiological regulators of the degradation process in vivo (McGee, T. P., Cheng, H. H., Kumagai, H., Omura, S., and Simoni, R. D. (1996) J. Biol. Chem. 271, 25630-25638). In the current study, we further characterize this in vitro cleavage of HMG-CoA reductase. E64, a specific inhibitor of cysteine-proteases, inhibits HMG-CoA reductase cleavage in vitro. In contrast, lactacystin, an inhibitor of the proteasome, inhibits HMG-CoA reductase degradation in vivo but does not inhibit the in vitro cleavage. Purified ER fractions contain lactacystin-sensitive and E64-insensitive proteasome activity as measured by succinyl-Leu-Leu-Val-Tyr-7-amino-4-methylcoumarin hydrolysis. We removed the proteasome from purified ER fractions by solubilization with heptylthioglucoside and observed that the detergent extracted, proteasome-depleted membrane fractions retain regulated cleavage of HMG-CoA reductase. This indicates that ER-associated proteasome is not involved in degradation of HMG-CoA reductase in vitro. In order to determine the site(s) of proteolysis of HMG-CoA reductase in vitro, four antisera were prepared against peptide sequences representing various domains of HMG-CoA reductase and used for detection of proteolytic intermediates. The sizes and antibody reactivity of the intermediates suggest that HMG-CoA reductase is cleaved in the in vitro degradation system near the span 8 membrane region, which links the N-terminal membrane domain to the C-terminal catalytic domain of the protein. We conclude that HMG-CoA reductase can be cleaved in the membrane-span 8 region by a cysteine protease(s) tightly associated with ER membranes.