Marijuana use and social networks in a community outbreak of meningococcal disease.

Background: We examined the role of social networks and marijuana smoking in a community outbreak of infections due to Neisseria meningitidis.

Methods: We interviewed all patients and their contacts. Isolates were tested by pulsed field electrophoresis and multilocus enzyme electrophoresis.

Heterogeneous tissue distribution of a mitochondrial DNA polymorphism in heteroplasmic subjects without mitochondrial disorders.

Context: Several maternally inherited point mutations of the mitochondrial genome cause mitochondrial disorders, but the correlation between genotype and phenotype remains obscure in many cases. The same mutation may cause various diseases, probably because of a different tissue distribution.

Objective: To assess the role of random somatic segregation in generating interperson differences by analysis of an apparently neutral polymorphism.

Creutzfeldt-Jakob disease after receipt of a previously unimplicated brand of dura mater graft.

Background: Iatrogenic Creutzfeldt-Jakob disease (CJD) transmission via dura mater grafts has been reported in many countries. In September 1998, a 39-year-old Colorado woman was reported as having suspected CJD after receiving a dura mater graft 6 years earlier.

Methods: An investigation was initiated to confirm the diagnosis of CJD and assess the possible source of CJD transmission.

Treatment of severe acute respiratory distress syndrome: a final report on a phase I study.

Adult respiratory distress syndrome (ARDS) has a high mortality. Its only effective treatment is respiratory therapy. If this fails mortality is probably 100 per cent.

Comprehensive community effectiveness of health care. A study of malaria treatment in children and adults in rural Burkina Faso.

Malaria is one of the most important causes of morbidity and mortality in children in sub-Saharan Africa, yet community effectiveness of treatment is not well understood. This study presents a quantitative estimate of community effectiveness of malaria treatment in Burkina Faso, based on population surveys, observational studies of health services and user surveys. Analysis of seven steps in the process of treating malaria reveal the following: (1) 21% of people with malaria attend health centres; (2) 31% of them have a sufficient history taken; (3) 69% receive a complete clinical examination; (4) 81% receive the correct dosage of drugs prescribed; (5) 91% purchase the drugs; (6) 68% take the drugs as prescribed; (7) the drugs are estimated to be 85% effective.

A new flux-orientated concept to derive critical levels for ozone to protect vegetation.

The current European critical levels for ozone (O3) to protect crops, natural and semi-natural vegetation and forest trees are based on a relative small number of open-top chamber experiments with a very limited number of plant species. Therefore, the working group "Effects of Ozone on Plants" of the Commission on Air Pollution Prevention of the Association of German Engineers and the German Institute of Standardization reanalysed the literature on O3 effects on European plant species published between 1989 and 1999. An exposure-response relationship for wild plant species and agricultural crops could be derived from 30 experiments with more than 30 species and 90 data points; the relationship for conifer and deciduous trees is based on 20 experiments with nine species and 50 data points.

Functional rescue of the nephrogenic diabetes insipidus-causing vasopressin V2 receptor mutants G185C and R202C by a second site suppressor mutation.

Mutations in the gene of the G protein-coupled vasopressin V2 receptor (V2 receptor) cause X-linked nephrogenic diabetes insipidus (NDI). Most of the missense mutations on the extracellular face of the receptor introduce additional cysteine residues. Several groups have proposed that these residues might disrupt the conserved disulfide bond of the V2 receptor.

Peptide leucine arginine, a potent immunomodulatory peptide isolated and structurally characterized from the skin of the Northern Leopard frog, Rana pipiens.

On the basis of histamine release from rat peritoneal mast cells, an octadecapeptide was isolated from the skin extract of the Northern Leopard frog (Rana pipiens). This peptide was purified to homogeneity using reversed-phase high performance liquid chromatography and found to have the following primary structure by Edman degradation and pyridylethylation: LVRGCWTKSYPPKPCFVR, in which Cys(5) and Cys(15) are disulfide bridged. The peptide was named peptide leucine-arginine (pLR), reflecting the N- and C-terminal residues.

Brain ischemia and reperfusion: molecular mechanisms of neuronal injury.

Brain ischemia and reperfusion engage multiple independently-fatal terminal pathways involving loss of membrane integrity in partitioning ions, progressive proteolysis, and inability to check these processes because of loss of general translation competence and reduced survival signal-transduction. Ischemia results in rapid loss of high-energy phosphate compounds and generalized depolarization, which induces release of glutamate and, in selectively vulnerable neurons (SVNs), opening of both voltage-dependent and glutamate-regulated calcium channels. This allows a large increase in cytosolic Ca(2+) associated with activation of mu-calpain, calcineurin, and phospholipases with consequent proteolysis of calpain substrates (including spectrin and eIF4G), activation of NOS and potentially of Bad, and accumulation of free arachidonic acid, which can induce depletion of Ca(2+) from the ER lumen.

Can quality circles improve hospital-acquired infection control?

It is a fundamental principle of continuous quality improvement (CQI) that processes should be the objects of quality improvement. The objective of this study was to improve process quality concerning the prevention of hospital-acquired infections in surgical departments and intensive care units by a continuous quality improvement (CQI) approach based mainly on quality circles. This approach was evaluated in a prospective controlled intervention study in medium-size acute care hospitals (four intervention and four control hospitals).

Requirement of specific intrahelical interactions for stabilizing the inactive conformation of glycoprotein hormone receptors.

Systematic analysis of structural changes induced by activating mutations has been frequently utilized to study activation mechanisms of G-protein-coupled receptors (GPCRs). In the thyrotropin receptor and the lutropin receptor (LHR), a large number of naturally occurring mutations leading to constitutive receptor activation were identified. Saturating mutagenesis studies of a highly conserved Asp in the junction of the third intracellular loop and transmembrane domain 6 suggested a participation of this anionic residue in a salt bridge stabilizing the inactive receptor conformation.

Comparative analysis of CD137 and LPS effects on monocyte activation, survival, and proliferation.

CD137 (ILA/4-1BB), a member of the TNF receptor family, regulates activation, survival and proliferation of primary human monocytes. Here we compare the activities of lipopolysaccharide (LPS), a classical and potent monocyte activator to that of CD137. LPS is a more potent activator of monocytes, as evidenced by a stronger induction of the proinflammatory cytokine IL-8.

Effects of the 5-HT3 antagonist cilansetron vs placebo on phasic sigmoid colonic motility in healthy man: a double-blind crossover trial.

Aims: 5-hydroxytryptamine3 receptor antagonists act antiemetically and slow colonic transit. This study evaluated effects of the high-affinity 5-HT3 antagonist, cilansetron, on fasting, meal-and anticholinesterase-stimulated phasic contractile activity of the human sigmoid colon as well as on bowel habits and stool consistency.

Methods: Five female and seven male healthy volunteers received, during three 7 day periods separated by 7 day wash-out periods, 4 mg cilansetron, 8 mg cilansetron or placebo three times daily orally under random, double-blind, crossover conditions.

From diagnosis to drug taking: staff compliance with guidelines and patient compliance to prescriptions in Burkina Faso.

Objective: We studied compliance with guidelines and prescriptions for six steps of the health care process to identify the step with the greatest need for improvement.

Design: In a cross-sectional study we used hidden observation in health centres and counting of remaining drugs in home visits. We assessed provider compliance with guidelines for medical history, physical examination, drug choice, and explanation of drug dosing, and patient compliance for drug buying and drug taking.

Cysteine scanning mutagenesis of helices 2 and 7 in GLUT1 identifies an exofacial cleft in both transmembrane segments.

Cysteine scanning mutagenesis in conjunction with site-directed chemical modification of sulfhydryl groups by p-chloromercuribenzenesulfonate (pCMBS) or N-ethylmaleimide (NEM) was applied to putative transmembrane segments (TM) 2 and 7 of the cysteine-less glucose transporter GLUT1. Valid for both helices, the majority of cysteine substitution mutants functioned as active glucose transporters. The residues F72, G75, G76, G79, and S80 within helix 2 and G286 and N288 within helix 7 were irreplaceable because the mutant transporters displayed transport activities that were lower than 10% of Cys-less GLUT1.

Molecular and conformational features of a transport-relevant domain in the C-terminal tail of the vasopressin V(2) receptor.

We have previously shown a conserved glutamate/dileucine motif ((335)ELRSLL(340)) in the intracellular C terminus of the vasopressin V(2) receptor (V(2) receptor) to be essential for receptor transport from the endoplasmic reticulum (ER) to the Golgi apparatus. The motif may represent a transport signal that is recognized by a component of ER to Golgi vesicles. Alternatively, it may be necessary for transport-competent receptor folding to pass the quality-control system of the ER.

Spontaneous and chemically induced point mutations in HPRT cDNA of the metabolically competent human lymphoblastoid cell line, MCL-5.

Thioguanine-resistant clones of the human lymphoblastoid cell, MCL-5, which carries two recombinant plasmids expressing xenobiotic metabolizing enzymes, were obtained spontaneously and after treatment with 0.1 microgram/ml benzo[a]pyrene (BaP), 1.0 microgram/ml 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), and 10 micrograms/ml cigarette smoke condensate (CSC).

Rationality of drug prescriptions in rural health centres in Burkina Faso.

The objective of this study is to investigate the quality of drug prescriptions in nine health centres of three districts in rural Burkina Faso. 313 outpatient consultations were studied by methods of guided observation. Additionally interviews were held with the health care workers involved in the study.

Effects of solar ultraviolet radiation on the potential efficiency of photosystem II in leaves of tropical plants.

The effects of solar ultraviolet (UV)-B and UV-A radiation on the potential efficiency of photosystem II (PSII) in leaves of tropical plants were investigated in Panama (9 degrees N). Shade-grown tree seedlings or detached sun leaves from the outer crown of mature trees were exposed for short periods (up to 75 min) to direct sunlight filtered through plastic or glass filters that absorbed either UV-B or UV-A+B radiation, or transmitted the complete solar spectrum. Persistent changes in potential PSII efficiency were monitored by means of the dark-adapted ratio of variable to maximum chlorophyll a fluorescence.

Structural requirements for V2 vasopressin receptor proteolytic cleavage.

The ligand-induced proteolytic cleavage of the V2 vasopressin receptor transiently expressed in COS cells was investigated. After incubation of the cell membranes with a photoreactive ligand possessing full agonistic properties for V2 receptors, approximately 90% of the porcine and bovine V2 vasopressin receptors were cleaved in the upper part of transmembrane helix 2 at a heptapeptide sequence conserved in both vasopressin and oxytocin receptors. The oxytocin receptor was completely resistant to proteolysis after binding the same photoreactive ligand, which is only a partial agonist for this receptor.

Effect of body weight on phosphorus digestibility and efficacy of a microbial phytase in young pigs.

The effect of body weight on P digestibility and on efficacy of supplemental Aspergillus niger phytase was studied in two experiments with young growing pigs. Excreta were collected quantitatively. All diets contained 2.

Solution structure of the receptor tyrosine kinase EphB2 SAM domain and identification of two distinct homotypic interaction sites.

The sterile alpha motif (SAM) is a protein interaction domain of around 70 amino acids present predominantly in the N- and C-termini of more than 60 diverse proteins that participate in signal transduction and transcriptional repression. SAM domains have been shown to homo- and hetero-oligomerize and to mediate specific protein-protein interactions. A highly conserved subclass of SAM domains is present at the intracellular C-terminus of more than 40 Eph receptor tyrosine kinases that are involved in the control of axonal pathfinding upon ephrin-induced oligomerization and activation in the event of cell-cell contacts.

Insulin induces dephosphorylation of eukaryotic initiation factor 2alpha and restores protein synthesis in vulnerable hippocampal neurons after transient brain ischemia.

Brain reperfusion causes prompt, severe, and prolonged protein synthesis suppression and increased phosphorylation of eukaryotic initiation factor 2alpha [eIF2alpha(P)] in hippocampal CA1 and hilar neurons. The authors hypothesized that eIF2alpha(P) dephosphorylation would lead to recovery of protein synthesis. Here the effects of insulin, which activates phosphatases, were examined by immunostaining for eIF2alpha(P) and autoradiography of in vivo 35S amino acid incorporation.