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.

Minor groove binder-conjugated DNA probes for quantitative DNA detection by hybridization-triggered fluorescence.

Here we describe the properties of a novel class of oligonucleotide probes capable of sensitive hybridization-triggered fluorescence. These fluorogenic probes, known commercially as MGB Eclipse probes, are characterized by having a conjugated minor groove binder (MGB) ligand at the 5'-end and a fluorophore at the 3'-end. Additionally, they have an efficient quencher moiety at the 5'-end that is useful with a wide variety of fluorescent dyes.

Role of sex hormones in development of pituitary adenoma.

Role of sex hormones in the development of pituitary adenomas was investigated by analyzing the content of nuclear estradiol and testosterone receptors in different tumors of the anterior pituitary: prolactinomas, meningiomas, growth hormone-producing adenomas, astrocytomas, neurinomas, and ependymomas. The concentration of nuclear estrogen and androgen receptors in prolactin-secreting pituitary adenomas was much higher than in growth hormone-producing adenomas and other pituitary tumors.

Catalyzed asymmetric dialkylzinc addition to benzaldehyde in the presence of new chiral ligands--delta-(1-phenethyl)aminoalcohols.

A series of delta-aminoalcohols prepared from (S)- and (R)-N,N-dimethyl-1-phenethylamines was found to catalyze the enantioselective addition of diethylzinc to benzaldehyde to yield optically active 1-phenylpropanol with enantiomeric excess 60-85%.

Luteinizing hormone-releasing hormone in thymus and hypothalamus of rat fetuses: suppressing effect of antagonist and of antibodies on concanavalin A-induced proliferation of thymocytes.

The effect of endogenous luteinizing hormone-releasing hormone (LHRH) on the proliferation induced by concanavalin A (Con A) in rat fetal thymocytes was studied. A selective antagonist (2 microg per fetus) or antibodies to LHRH (20 microl per fetus) were injected in utero into 20-day-old rat fetuses, and this resulted in a two- or fivefold decrease in the Con A-induced proliferation of thymocytes, respectively. In combined culture of the antagonist (10-5-10-6 M) with fetal thymocytes, the proliferative response was not decreased.

A new method for the postsynthetic generation of abasic sites in oligomeric DNA.

The abasic site is the most common lesion in DNA and is thought to play a critical role in mutagenesis. However, a general chemical method for the site-specific generation of true abasic sites in oligodeoxynucleotides has been lacking. We now describe a procedure which permits the postsynthetic generation of abasic sites in single- or double-stranded DNA oligomers without regard to their base composition.

[Relationship between regulatory effects of serotonin and testosterone on the development of the LHRH producing system of the rat brain during the prenatal period of development].

We have performed radioimmunoassay of LHRH in rostral and septal-preoptic brain regions, as well as in mediobasal hypothalamus of male and female fetuses at day 21 of the prenatal period after the injection to pregnant females on days 11-20 of gestation of either p-chlorophenylalanine (PCPA) or of a combination of PCPA with ethane-1,2-dimethane sulfonate (EDS). Control animals received the injection of the same volume of physiological saline. In the control fetuses, both males and females, the level of LHRH in the rostral brain region was significantly lower than in the septal-preoptic region.

Neuroendocrine control of the gonadotropic function of the hypophysis in experimental diabetes.

The stability of the function of the reproductive system depends on a multitude of factors of the internal and external milieux. Serious disturbances in its function, with alterations in carbohydrate homeostasis, underlie such diseases as diabetes mellitus. Disturbances to the functional activity of the reproductive system in laboratory animals with diabetes are known to be associated not only with destructive changes in the gonads, but also with dysfunction of the hypothalamo-hypophyseal complex [9, 11].

[Phosphorus-containing inhibitors of penicillin acylase. 4. Irreversible inhibition of penicillin acylase from Escherichia coli by monoaryl esters of benzylphosphonic acid].

Monoaryl of benzylphosphonic acid have been synthesized and studied as the inhibitors of penicillin acylase. These compounds were found to be effective and selective irreversible inhibitors of the enzyme. The kinetic parameters of enzyme inactivation are determined, and possible mechanism of the inhibition is discussed.

[Development of the reproductive system in the progeny of rats with streptozotocin diabetes].

Specificities of functioning and development of the reproductive system and mechanism of its regulation with hypothalamic structures were studied in the progeny of rats with streptozotocin diabetes. For this purpose pituitary sensitivity was analyzed in mature animals, as was functional capacity of the feedback system mediating the hypothalamic regulation of gonadotropin secretion in rat males and females at the age when this system normally starts functioning in health. The hypothalamo-hypophyseo-gonadal system feedback mechanism was found to develop in the progeny of female rats with streptozotocin diabetes later than in health.

[Development of hypothalamic regulation of gonadotropic function of the pituitary in hypoinsulinemic rats].

Effects of temporary hypoinsulinemia induced by streptozotocin in neonatal age on the development of the mechanism of hypothalamic regulation of hypophyseal gonadotropic function in rats were studied. With this aim the authors analyzed the status and functional capacity of feedback system mediating hypothalamic regulation of gonadotropin secretion in female and male rats at the age when this system starts functioning in health. Streptozotocin injection in the neonatal age induced a reduction of estradiol concentration and of estradiol and progesterone-stimulated preovulatory peak of luteinizing hormone (LH) in 28-day-old females and a reduction of LH concentration in 28-day-old castrated males.

[Diastereomers of nonionic oligonucleotide analogs. VI. Isolation of diastereomers of ethyl phosphotriesters of the octanucleotide d(GCCAAACA) by high performance affinity chromatography].

Diastereomers of oligonucleotide ethyl phosphotriesters were separated by high-performance complementary (affinity) chromatography on a column with the immobilized complementary oligonucleotide. The elution buffer contained 0.18 M K2HPO4, pH 7.