Monoclinic form I of clopidogrel hydrogen sulfate from powder diffraction data.

The asymmetric unit of the title compound, C(16)H(17)ClNO(2)S(+)·HSO(4) (-), (I) [systematic name: (+)-(S)-5-[(2-chloro-phen-yl)(meth-oxy-carbon-yl)meth-yl]-4,5,6,7-tetra-hydro-thieno[3,2-c]pyridin-5-ium hydrogen sulfate], contains two independent cations of clopidogrel and two independent hydrogensulfate anions. The two independent cations are of similar conformation; however, this differs from that observed in ortho-rhom-bic form (II) [Bousquet et al. (2003 ▶).

Hibernator Citellus undulatus maintains safe cardiac conduction and is protected against tachyarrhythmias during extreme hypothermia: possible role of Cx43 and Cx45 up-regulation.

Background: Most mammals experience cardiac arrest during hypothermia. In contrast, hibernators remain in sinus rhythm even at body temperatures of 0 degrees C.

Objectives: The purpose of this study was to quantify electrical activity and connexin expression in the heart of hibernating Siberian ground squirrel Citellus undulatus.

Effect of intramolecular interactions on circular dichroism of ortho-substituted 1-phenethylamines.

The synthesis of ortho-substituted (S)-1-phenethylamines via ortho-lithiation of its N,N-dimethyl derivative followed by reactions with different reagents is described. Circular dichroism spectra of synthesized compounds were measured. It is shown that the observed short-wave Cotton effects greatly depend on the existence of cyclic structure due to possible interactions such as hydrogen bond or electrostatic interaction.

Influence of serotonin on the development and migration of gonadotropin-releasing hormone neurones in rat foetuses.

This study used a pharmacological approach to evaluate the consequences of the metabolic perturbations of neurotransmitters on brain development. Pregnant rats received p-chlorophenylalanine (pCPA), an inhibitor of serotonin (5-hydroxytryptamine, 5-HT) synthesis, or saline (control) from the 11th day of gestation once or daily up to the 15th, 17th and 20th day, followed by processing of the forebrain and/or nasal cranium of foetal males and females for high-performance liquid chromatography of monoamines, radioimmunoassay of gonadotropin-releasing hormone (GnRH) and quantitative and semiquantitative immunocytochemistry for GnRH. The pCPA treatment resulted in a 50-70% depletion of 5-HT in the nasal crania and forebrains at any studied age.

Reduced aggregation and improved specificity of G-rich oligodeoxyribonucleotides containing pyrazolo[3,4-d]pyrimidine guanine bases.

Guanine (G)-rich oligodeoxyribonucleotides (ODNs) can form undesired complexes by self association through non-Watson-Crick interactions. These aggregates can compromise performance of DNA probes and make genetic analysis unpredictable. We found that the 8-aza-7-deazaguanine (PPG), a pyrazolo[3,4-d]pyrimidine analog, reduces guanine self association of G-rich ODNs.