Effects of vitamin C on the pharmacokinetics and pharmacodynamics of nimodipine in rats.

In recent years, researchers have shown a growing interest in the interactions between different pharmaceutical agents. An intriguing instance lies in the possible interaction between nimodipine and vitamin C. To investigate the pharmacokinetic and pharmacodynamic effects of vitamin C on nimodipine in rats, rats were randomly divided into a nimodipine only group and a combination group (nimodipine + vitamin C). The two groups were given intragastric administration and nimodipine blood concentrations were determined using high-performance liquid chromatography-tandem mass spectrum at different time points. Blood pressure and heart rate were measured via carotid artery cannulation. Pharmacokinetic differences were observed between the nimodipine only group and the combination group at the same dose. Compared with the nimodipine only group, the combination group's main pharmacokinetic parameters of peak concentration and area under the curve increased significantly, and the difference was statistically significant (p < 0.05); furthermore, the combination group exhibited a significant reduction in average blood pressure, while no significant effects on heart rate were observed. Vitamin C did not affect the activity of CYP450 in rat liver. The pharmacokinetic characteristics and pharmacodynamics of nimodipine were changed by vitamin C administration in rats.

Automatic self-focused and situation-focused reappraisal of disgusting emotion by implementation intention: an ERP study.

Detachment (self-focused) and positive reinterpretation (situation-focused) are two important forms of cognitive reappraisal during emotion regulation. Previous research shows situation-focused reappraisal to be more effective than self-focused reappraisal for intentional emotion regulation. How the two differ in emotional consequences as components of automatic emotion regulation is however unclear. In the current study, event-related potentials were recorded to clarify this problem, while participants passively viewed disgusting or neutral scenes or formed implementation intentions based on self-focused or situation-focused reappraisal. Behavioural results showed fewer negative emotions during self-focused reappraisal than during either situation-focused reappraisal or free viewing (which had similar emotion ratings). In addition, self-reported cognitive cost was not enhanced during the two forms of reappraisal compared to passive viewing. Late positive potential (LPP) amplitudes for disgusting stimuli were larger than those elicited for neutral stimuli, at both frontal and posterior-parietal regions. This amplitude enhancement effect, irrespective of whether frontal or parietal LPP were involved, was found to be weaker during self-focused reappraisal than when participants were engaged in situation-focused reappraisal or passive viewing. The latter two conditions showed similar amplitude enhancement. These findings suggest that automatic self-focused reappraisal by implementation intention produces more favourable emotion regulation than situation-focused reappraisal, without enhancing cognitive cost.

Halomonas alkalitolerans sp. nov., a novel moderately halophilic bacteriun isolated from soda meadow saline soil in Daqing, China.

A moderately halophilic bacterial strain 15-13(T), which was isolated from soda meadow saline soil in Daqing City, Heilongjiang Province, China, was subjected to a polyphasic taxonomic study. The cells of strain 15-13 were found to be Gram-negative, rod-shaped, and motile. The required growth conditions for strain 15-13(T) were: 1-23% NaCl (optimum, 7%), 10-50°C (optimum, 35°C), and pH 7.0-11.0 (optimum, pH 9.5). The predominant cellular fatty acids were C(18:1) ω7c (60.48%) and C(16:0) (13.96%). The DNA G+C content was 67.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that strain 15-13(T) clustered within a branch comprising species of the genus Halomonas. The closest phylogenetic neighbor of strain 15-13(T) was Halomonas pantelleriensis DSM 9661(T) (98.9% 16S rRNA gene sequence similarity). The level of DNA-DNA relatedness between the novel isolated strain and H pantelleriensis DSM 9661(T) was 33.8%. On the basis of the phenotypic and phylogenetic data, strain 15-13(T) represents a novel species of the genus Halomonas, for which the name Halomonas alkalitolerans sp. nov. is proposed. The type strain for this novel species is 15-13(T) (=CGMCC 1.9129(T) =NBRC 106539(T)).

Genome-wide analysis of microRNA and mRNA expression signatures in hydroxycamptothecin-resistant gastric cancer cells.

AIM: To investigate the involvement of microRNAs (miRNAs) in intrinsic drug resistance to hydroxycamptothecin (HCPT) of six gastric cancer cell lines (BGC-823, SGC-7901, MGC-803, HGC-27, NCI-N87, and AGS). METHODS: A sulforhodamine B (SRB) assay was used to analyze the sensitivity to HCPT of six gastric cancer cell lines. The miRNA and mRNA expression signatures in HCPT-resistant cell lines were then identified using DNA microarrays. Gene ontology and pathway analysis was conducted using GenMAPP2. A combined analysis was used to explore the relationship between the miRNAs and mRNAs. RESULTS: The sensitivity to HCPT was significantly different among the six cell lines. In the HCPT-resistant gastric cancer cells, the levels of 25 miRNAs were deregulated, including miR-196a, miR-200 family, miR-338, miR-126, miR-31, miR-98, let-7g, and miR-7. Their target genes were related to cancer development, progression and chemosensitivity. Moreover, 307 genes were differentially expressed in HCPT-resistant cell lines, including apoptosis-related genes (BAX, TIAL1), cell division-related genes (MCM2), cell adhesion- or migration-related genes (TIMP2, VSNL1) and checkpoint genes (RAD1). The combined analysis revealed 78 relation pairs between the miRNAs and mRNAs. CONCLUSION: Hierarchical clustering showed that the miRNA and mRNA signatures in our results were informative for discriminating cell lines with different sensitivities to HCPT. However, there was slightly lower correlation between the expression patterns of the miRNA and those of the predicted target transcripts.

Genome-wide microRNA profiling in human fetal nervous tissues by oligonucleotide microarray.

OBJECTS: Our objective was to develop an oligonucleotide DNA microarray (OMA) for genome-wide microRNA profiling and use this method to find miRNAs, which control organic development especially for nervous system. MATERIALS AND METHODS: Eighteen organic samples included cerebrum and spinal cord samples from two aborted human fetuses. One was 12 gestational weeks old (G12w) and the other was 24 gestational weeks old (G24w). Global miRNA expression patterns of different organs were investigated using OMA and Northern blot. CONCLUSION: The OMA revealed that 72-83% of miRNAs were expressed in human fetal organs. A series of microRNAs were found specifically and higher-expressed in the human fetal nervous system and confirmed consistently by Northern blot, which may play a critical role in nervous system development.