State of the DNA incorporated by Escherichia coli "permeable" cells

MTHFR Ala222Val polymorphism and clinical characteristics confer susceptibility to suicide attempt in chronic patients with schizophrenia

Patients with schizophrenia (SCZ) exhibit higher suicide rates than the general population. However, the molecular mechanism responsible for the high rate of suicidal behavior in SCZ remains poorly understood. MTHFR Ala222Val (C677T; rs 1801133) polymorphism has repeatedly demonstrated to play a pathological role in numerous mental disorders, but none of these studies focused on the susceptibility of suicidal behavior in SCZ. In the present cross-sectional study, we recruited 957 chronic inpatients with SCZ and 576 healthy controls to assess the psychopathological symptoms of SCZ and compare the frequency of the MTHFR Ala222Val genotype in both suicide attempters and non-attempters. Our results demonstrated no significant differences in MTHFR Ala222Val genotype and allele distributions between the SCZ patients and controls (p > 0.05), but showed a statistical significance in the distribution of Ala/Val genotype between suicide attempters and non-attempters (p < 0.05). Further logistic regression analysis showed that MTHFR Ala222Val genotype, psychopathological symptoms, number of cigarettes smoked per day and drinking status were related to suicide attempts in SCZ (p < 0.05). Our study demonstrated that MTHFR Ala222Val polymorphism and some clinical characteristics might confer susceptibility to suicide in patients with SCZ.

Enhanced uptake of donor DNA by Ca2+ treated Escherichia coli cells

The first steps in E. coli transformation have been studied. It was found that the cells attain the ability of enhanced uptake of donor exogenous DNA upon Ca2+ treatment. At saturating DNA concentrations the cells were capable to take up irreversibly about 6-10(8) dalton of donor DNA per cell (if to assume that all the cells are competent). About 75% of this DNA was found to be attached to the cytoplasmic membrane. Employing Poisson approximation for distribution of the donor-marker DNA molecules on recipient cells it was found that the efficiency of a marker recombination and expression is about 2-10(-5). The first steps in E. coli transformation have been studied. It was found that the cells attain the ability of enhanced uptake of donor 0exogenous