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Reactive oxygen species (ROS) are produced within the body during oxygen metabolism and living organisms have developed several defense mechanisms to protect themselves from oxidative stress. Under normal conditions, ROS and antioxidant systems are in balance. Oxidative stress is caused by the imbalance between production of pro-oxidants and the antioxidant defenses. The defense mechanisms include antioxidant enzymes like superoxide dismutase (SOD) or glutathione peroxidase (GPX) and several no enzymatic free radical scavengers. It has been proposed that the progressive increase in ROS and consequent oxidative damage play the major role in neurodegenerative disorders. Learning and memory show an age-related decline and this age-associated impairment extends to spatial memory tasks. Furthermore, the neural circuits between the prefrontal cortex and striatum are also involved in spatial memory. In our previous studies, we have shown the facilitatory role of nicotine and cholinergic system in learning and memory processes. In the present study, we examined whether oxidative stress contributes to the memory deficits induced by muscarinic acetylcholine receptors (mAchRS) blocked by scopolamine. We also examined the effect of nicotine on oxidative stress, and also if nicotine could attenuated the learning and memory deficits induced by blocked of mAchRS. We observed that the levels of SOD and GPX decrease in rats mAchRS blockade by scopolamine (0.75 mg/kg body weight i.p.), and the level of malondialdehyde (MDA) increase in same rats, compared with saline-treated rats. Therefore, our results suggest that the oxidative stress contributes to the learning and memory deficits in rats.

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UNLABELLED: Breast and ovarian cancer are common pathologies in women, with increasing incidences worldwide. In hereditary breast and ovarian cancer (HBOC) families, a large percentage of cases are attributable to hereditary factors compatibles with dominant autosomal transmission of a major tumour suppressor gene with incomplete penetrance. Screening for BRCA1 mutations is now standard practice for HBOC cases in western world, and permits medical follow-up and genetic counselling. Over 300 BRCA1 germinal mutations are stored in the Breast Cancer Information Core (BIC) mutation database. MATERIAL AND METHODS: Estimates in different countries range from 5 to 15% the BRCA1 related cases of hereditary breast cancer due to copy number changes of one or more exons of this gene. Exon deletions and amplifications will usually not be detected by sequence analysis of the complete BRCA1 gene, therefore MLPA screening is needed. RESULTS: Here we describe Multiplex Ligation-dependent Probe Amplification technique (MLPA) implementation for BRCA1 large genomic rearrangements. CONCLUSIONS: We did not detect any BRCA1 mutation by analysis of 15 HBOC recruited patients.

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Methylglyoxal (MG) is an early glycation product which is implicated in genesis of diabetic complications either as a direct toxin or as a precursor for advanced glycation end products. It is metabolized via S-D-lactoylglutathione to D-lactate by means of the enzymes glyoxalase I and II, which depend on glutattione as cofactor. MG is highly reactive and can bind to and modify proteins by chemical interaction with cellular proteins, action on energy production, induce free radical generation and cell killing. That way MG play a role in the events of the development of diabetic complications.

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UNLABELLED: The oxygen, through his toxic effects, has determined the human organism to perfectionate multiple and efficient protection systems, especially the GSH-Px. OBJECTIVES: To study the activity of GSHPx activity in the 0, 14 and 28 days of the menstrual cycle in a group of women with psychiatric disorders. METHODS: The activity of GSH-Px was investigated in 24 women inpatients from the Psychiatric Department of Murgeni Hospital Vaslui. The GSH-Px level was determined in human serum using Fukuzawa method, modified in the Biochemistry Lab of the "Al. I. Cuza" University, Iasi. RESULTS: It has been no correlation between the type of psychiatric disorders and the level of GSHPx. This activity of GSHpx is in direct relationship with the concentration of sexual hormones, showing an hormone dependent enzymatic induction. A growth of the GSHPx activity from the day 0 to the 28th day of the menstrual cycle followed by a sudden decrease at menstruation time have been observed in all age groups. This fact demonstrated the existence of an enzymatic cycle.

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This article reports on the reaction of urease immobilization through its covalent bonding on carboxymethylcellulose. The reaction is activated by dicyclohexylcarbodiimide. The coupling reaction is influenced by the enzyme-support and activator-support ratios, as well as by duration. Starting from a rotating, composed experimental program of the second order, the function correlating the activity of the immobilized enzyme with the reaction parameters is established. Immobilized urease exhibits thermal stability higher than that of free enzyme, regarding both pH and the inhibiting action of some metal ions or organic substances. The stability over time of the immobilized urease is high, its enzymatic activity being maintained at over 85% of the initial value three months after synthesis.

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Using the technique of mechanical isolation of the medial hypothalamus from the rest of the CNS, it has been concluded--based on total serum protein content, protein fractions as well as total serum amino acids--that under resting conditions the hypothalamic influence upon protein metabolism is achieved through the control exerted upon endocrine system rather than by a direct neural mechanism. The authors' results show that aminoacidemia is not a determining factor in feeding behaviour.

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