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The article investigates the effects of the use of nandrolone decanoate with vincristine sulphate in the brain and lipid peroxidation in rats. Results of the study indicate that lipid peroxidation increased with the isolated use of vincristine and nandrolone decanoate and with vincristine associated to the highest dose of the ester as well. This suggest that nandrolone when used with vincristine protect the organism from the damaging process involved in free radical production.

The aim of this study was to investigate functional and morphological alterations caused by oxidative stress in streptozotocin (STZ)-induced diabetic rats and to evaluate the antioxidant effect of quercetin (QUE) in this disease. One hundred and thirty male Wistar rats, it were randomly distributed in 10 different experimental groups, with ten animals per group: Control Saline (CS), Control Ethanol (CE), Control QUE 5 mg/kg (CQ5), Control QUE 25 mg/kg (CQ25), Control QUE 50 mg/kg (CQ50), Diabetic Saline (DS), Diabetic Ethanol (DE), Diabetic QUE 5 mg/kg (DQ5), Diabetic QUE25 mg/kg (DQ25), Diabetic QUE 50 mg/kg (DQ50). Therefore, hyperglycemia is directly involved in oxidative stress production, as well as in functional and morphological alterations caused by the excess of free radicals. QUE, specially at the dosage of 50 mg/kg, can act as an antioxidant and anti-inflammatory agent, becoming a promising adjuvant in the treatment of diabetes mellitus. [ABSTRACT FROM AUTHOR]

Cigarette smoke is a complex mixture of various toxic substances that are capable of initiating oxidative damage and promoting blood platelet alterations. In this study, we investigated the activities of the ectoenzymes NTPDase (ectonucleoside triphosphate diphosphohydrolase, CD39) and 5'-nucleotidase (CD73) in platelets as well as adenosine deaminase (ADA) in the plasma of rats exposed to aged and diluted sidestream smoke during 4 weeks. The rats were divided into two groups: I (control) and II (exposed to smoke). After the exposure period, blood was collected and the platelets and plasma were separated for enzymatic assay. The results demonstrated that NTPDase (with ATP as substrate) and 5'-nucleotidase (AMP as substrate) activities were significantly higher in group II (p < 0.05) as compared to group I, while no significant difference was observed for NTPDase with ADP as substrate. The ADA activity was significantly reduced in group II (p < 0.05) as compared with group I. Platelet aggregation was significantly increased in group II (p < 0.05) as compared with group I. We suggest that these alterations in the activity of enzymes from the purinergic system are associated with an increase in platelet aggregation. However, our study has demonstrated that the organism tries to compensate for this enhanced aggregation by increasing hydrolysis of AMP and reducing hydrolysis of adenosine, a potent inhibitor of aggregation and an important modulator of vascular tone.

Abnormalities of prefrontal cortical function are prominent features of schizophrenia and have been associated with genetic risk, suggesting that susceptibility genes for schizophrenia may impact on the molecular mechanisms of prefrontal function. A potential susceptibility mechanism involves regulation of prefrontal dopamine, which modulates the response of prefrontal neurons during working memory. We examined the relationship of a common functional polymorphism (Val(108/158) Met) in the catechol-O-methyltransferase (COMT) gene, which accounts for a 4-fold variation in enzyme activity and dopamine catabolism, with both prefrontally mediated cognition and prefrontal cortical physiology. In 175 patients with schizophrenia, 219 unaffected siblings, and 55 controls, COMT genotype was related in allele dosage fashion to performance on the Wisconsin Card Sorting Test of executive cognition and explained 4% of variance (P = 0.001) in frequency of perseverative errors. Consistent with other evidence that dopamine enhances prefrontal neuronal function, the load of the low-activity Met allele predicted enhanced cognitive performance. We then examined the effect of COMT genotype on prefrontal physiology during a working memory task in three separate subgroups (n = 11-16) assayed with functional MRI. Met allele load consistently predicted a more efficient physiological response in prefrontal cortex. Finally, in a family-based association analysis of 104 trios, we found a significant increase in transmission of the Val allele to the schizophrenic offspring. These data suggest that the COMT Val allele, because it increases prefrontal dopamine catabolism, impairs prefrontal cognition and physiology, and by this mechanism slightly increases risk for schizophrenia.

Background: Several methods for detection of single nucleotide polymorphisms (SNPs; e.g., denaturing gradient gel electrophoresis and denaturing HPLC) are indirectly based on the principle of differential melting of heteroduplex DNA. We present a method for detecting SNPs that is directly based on this principle., Methods: We used a double-stranded DNA-specific fluorescent dye, SYBR Green I (SYBR) in an efficient system (PE 7700 Sequence Detector) in which DNA melting was controlled and monitored in a 96-well plate format. We measured the decrease in fluorescence intensity that accompanied DNA duplex denaturation, evaluating the effects of fragment length, dye concentration, DNA concentration, and sequence context using four naturally occurring polymorphisms (three SNPs and a single-base deletion/insertion)., Results: DNA melting analysis (DM) was used successfully for variant detection, and we also discovered two previously unknown SNPs by this approach. Concentrations of DNA amplicons were readily monitored by SYBR fluorescence, and DNA amplicon concentrations were highly reproducible, with a CV of 2.6%. We readily detected differences in the melting temperature between homoduplex and heteroduplex fragments 15-167 bp in length and differing by only a single nucleotide substitution., Conclusions: The efficiency and sensitivity of DMA make it highly suitable for the large-scale detection of sequence variants.

Objective: To evaluate the relationship of the tryptophan hydroxylase (TPH) genotype to suicidality by the study of surviving monozygotic (MZ) cotwins of twins who committed suicide., Method: Twenty-four surviving Swedish MZ twins whose MZ cotwins had committed suicide were compared to 158 demographically sampled Swedish general population controls for TPH alleles. We also examined serotonin transporter alleles., Results: The living MZ cotwins of suicide victims had a significantly higher TPH 17 779C allele frequency than controls. No significant difference was observed for serotonin transporter alleles., Conclusion: These results, in a small sample, suggest the possibility that the 17 779C allele of the TPH gene may be associated with an increased risk of suicide. Further studies in larger samples are needed., (Copyright 2001 S. Karger AG, Basel)

Background: The heritability of interindividual variation in anxiety and other aspects of personality establishes that variants of genes influence these traits. A functional polymorphism in the promoter of the human serotonin transporter gene (SLC6A4*C) was identified and found to be linked to an anxiety-related personality trait, Neuroticism. The polymorphism affects gene transcription and, ultimately, gene function. We have attempted to confirm the role of SLC6A4*C in anxiety-related personality traits by sibpair analysis and association studies., Methods: Sibpair linkage analysis and association study were performed in 655 Finns. The index cases were 182 alcoholic criminal offenders, through which 258 relatives were ascertained to obtain 366 sibpairs. In addition, 215 unrelated population controls were collected. Each individual was psychiatrically interviewed, blind-rated for DSM-III-R diagnoses, and assessed with the Tridimensional Personality Questionnaire., Results: The sibpair analysis revealed a positive linkage between SLC6A4*C and the 2 anxiety-related subdimensions of Harm Avoidance: HA1 (Anticipatory Worry) and HA2 (Fear of Uncertainty) (P = .003). However, there was no consistent association between SLC6A4*C and any Tridimensional Personality Questionnaire trait., Conclusions: In the present study we replicated the relationship of SLC6A4*C to anxiety by sibpair linkage analysis but found no evidence of association, raising the question of whether SLC6A4*C locus is itself affecting anxiety or is linked to another still unknown functional variant.