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Database Study (database + study)
Selected AbstractsImpairment due to cannabis and ethanol: clinical signs and additive effectsADDICTION, Issue 6 2010Jørgen G. Bramness ABSTRACT Aims Studies have shown that the impairing effects of ,-9-tetrahydrocannabinol (THC) are dose-related. Cannabis intake increases the risk of traffic accidents. The purpose of this study was to see how different clinical tests and observations were related to blood THC concentrations and to determine whether the combined influence of THC and ethanol was different from either drug alone. Design A retrospective cross-sectional forensic database study. Setting Drivers apprehended by the police suspected of driving under the influence of alcohol other drugs. Participants We investigated 589 cases positive for THC only. In addition, 894 cases with THC and ethanol were included. A comparison was made with 3480 drivers with only ethanol in their blood and 79 drivers who tested negative. Measurements Data were analytical results of blood samples and the 27 clinical tests and observations included in the Norwegian clinical test for impairment (CTI). Findings No relationship was found between blood THC concentration and most of the CTI tests. Blood THC concentration was, however, related to conjunctival injection, pupil dilation and reaction to light and to the overall risk of being judged impaired. When THC and ethanol were detected together the risk of being judged impaired was increased markedly. Conclusions This study demonstrates that cannabis impairs driving ability in a concentration-related manner. The effect is smaller than for ethanol. The effect of ethanol and cannabis taken simultaneously is additive. Conjunctival injection, dilated pupils and slow pupil reaction are among the few signs to reveal THC influence. [source] Cross talking of network motifs in gene regulation that generates temporal pulses and spatial stripesGENES TO CELLS, Issue 11 2005Shuji Ishihara Gene regulatory networks contain several substructures called network motifs, which frequently exist throughout the networks. One of such motifs found in Escherichia coli, Saccharomyces cerevisiae, and Drosophila melanogaster is the feed-forward loop, in which an effector regulates its target by a direct regulatory interaction and an indirect interaction mediated by another gene product. Here, we theoretically analyze the behavior of networks that contain feed-forward loops cross talking to each other. In response to levels of the effecter, such networks can generate multiple rise-and-fall temporal expression profiles and spatial stripes, which are typically observed in developmental processes. The mechanism to generate these responses reveals the way of inferring the regulatory pathways from experimental results. Our database study of gene regulatory networks indicates that most feed-forward loops actually cross talk. We discuss how the feed-forward loops and their cross talks can play important roles in morphogenesis. [source] Rationalization of the stereochemistry of an addition of dialkyl phosphites to certain chiral aldimines: The experimental and theoretical approachHETEROATOM CHEMISTRY, Issue 2 2002Ryszard B. Nazarski The absolute configuration of an ,-P stereogenic center in two diastereomeric O,O-dialkyl ,-aminophosphonates (3), arising from an induced 1,3-asymmetric phosphite addition to the CN bond of furfural-derived Schiff bases (1), was established from single product 1H NMR data. Such spectra were interpreted with anisotropic shielding in relation to the AM1 and MNDO/d structures of 3; the former ones turned out to be closer to the obtained experimental results (1H NMR spectra of 3, crystallographic database study). Since favored 3-21G geometries of starting imines 1 were modeled as well, it was inferred that a stereochemical outcome of this reaction is governed by Cram selectivity. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:120,125, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10005 [source] Matched case,control study to evaluate risk factors for hyperlactataemia in HIV patients on antiretroviral therapyHIV MEDICINE, Issue 4 2003D Datta Background Lactic acidosis is a life-threatening event during antiretroviral therapy (ART). Hyperlactataemia may be a prelude to acidosis. Our database study suggested that female gender, intercurrent illness and didanosine (ddI)-based regimens may increase risk of lactic acidosis. The aim of this matched case,control study was to identify risk factors for hyperlactataemia requiring screening. Methods Cases were defined as patients with two consecutive lactate samples ,3.5 mmol/L taken more than 1 week apart. Cases were matched to two controls on gender, use of ddI and total duration of therapy using a 6-month window on either side. Controls never had raised lactate >2.5 mmol/L. A conditional logistic regression analysis using the PHREG procedure in SAS (SAS Institute Inc, Cary, NC) was performed with a discreet logistic model stratified by matching variables. Results Twenty-one cases were matched to 42 controls. In the univariate model, current use of stavudine (d4T), total cholesterol >5.3 mmol/L and glucose levels ,5.2 mmol/L gave increased likelihood of persistent hyperlactataemia. The multivariate model showed current use of d4T to be a significant independent predictor of persistent hyperlactataemia. Conclusions The results of this case,control study indicate that, when controlling for ddI use, d4T use is an additional risk factor for hyperlactataemia. [source] Greater Prevalence and Incidence of Dementia in Older Veterans with Posttraumatic Stress DisorderJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2010[See editorial comments by Dr. Soo Borson, pp 1797-1798] OBJECTIVES: To explore the association between posttraumatic stress disorder (PTSD) and dementia in older veterans. DESIGN: Administrative database study of individuals seen within one regional division of the Veterans Affairs healthcare network. SETTING: Veterans Integrated Service Network 16. PARTICIPANTS: Veterans aged 65 and older who had a diagnosis of PTSD or who were recipients of a Purple Heart (PH) and a comparison group of the same age with no PTSD diagnosis or PH were divided into four groups: those with PTSD and no PH (PTSD+/PH,, n=3,660), those with PH and no PTSD (PTSD,/PH+, n=1,503), those with PTSD and a PH (PTSD+/PH+, n=153), and those without PTSD or a PH (PTSD,/PH,, n=5,165). MEASUREMENTS: Incidence and prevalence of dementia after controlling for confounding factors in multivariate logistic regression. RESULTS: The PTSD+/PH, group had a significantly higher incidence and prevalence of dementia than the groups without PTSD with or without a PH. The prevalence and incidence of a dementia diagnosis remained two times as high in the PTSD+/PH, group as in the PTSD,/PH+ or PTSD,/PH, group after adjusting for the confounding factors. There were no statistically significant differences between the other groups. CONCLUSION: The incidence and prevalence of dementia is greater in veterans with PTSD. It is unclear whether this is due to a common risk factor underlying PTSD and dementia or to PTSD being a risk factor for dementia. Regardless, this study suggests that veterans with PTSD should be screened more closely for dementia. Because PTSD is so common in veterans, this association has important implications for veteran care. [source] Competition of hydrogen-bond acceptors for the strong carboxyl donorACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2001Thomas Steiner A database study on the competition of hydrogen-bond acceptors for the strong carboxyl donor in crystals is reported. The relative success in attracting this donor is determined for 34 types of acceptor (O, N, S, halogen and , acceptors), and a correlation between the success in competition and the average hydrogen-bond distance is established. [source] New pseudopolymorphs of 5-fluorocytosineACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009Maya Tutughamiarso In order to better understand the interaction between the pharmaceutically active compound 5-fluorocytosine [4-amino-5-fluoropyrimidin-2(1H)-one] and its receptor, hydrogen-bonded complexes with structurally similar bonding patterns have been investigated. During the cocrystallization screening, three new pseudopolymorphs of 5-fluorocytosine were obtained, namely 5-fluorocytosine dimethyl sulfoxide solvate, C4H4FN3O·C2H6OS, (I), 5-fluorocytosine dimethylacetamide hemisolvate, C4H4FN3O·0.5C4H9NO, (II), and 5-fluorocytosine hemihydrate, C4H4FN3O·0.5H2O, (III). Similar hydrogen-bond patterns are observed in all three crystal structures. The 5-fluorocytosine molecules form ribbons with repeated R22(8) dimer interactions. These dimers are stabilized by N,H...N and N,H...O hydrogen bonds. The solvent molecules adopt similar positions with respect to 5-fluorocytosine. Depending on the hydrogen bonds formed by the solvent, the 5-fluorocytosine ribbons form layers or tubes. A database study was carried out to compare the hydrogen-bond pattern of compounds (I),(III) with those of other (pseudo)polymorphs of 5-fluorocytosine. [source] | |||||||||||||