Short-term sequential analysis of sex hormones and helper T cells type 1 (Th1) and helper T cells type 2 (Th2) cytokines during and after multiple sclerosis relapse.

Multiple sclerosis (MS) is an immune-mediated disease with a clear sex-bias that may be attributed to sex hormones, sex' linked genes or both. Here we sought to determine the evolution pattern of cortisol and sex hormones at MS relapse and 2-months later in 7 male patients with relapsing remitting MS, and whether there was a correlation with a specific Th1 and Th2 cytokine pattern. Our findings indicate the activation of the hypothalamic-pituitary-adrenal axis and the concomitant upregulation of pro- and anti-inflammatory cytokines during relapse.

Th1/Th2 cytokine balance and nitric oxide in cerebrospinal fluid and serum from patients with multiple sclerosis.

Tumor necrosis factor (TNF-alpha) and IL-10 are key regulators of the T helper (Th)1/Th2 balance, which is critically skewed in many pathological conditions including immune-mediated inflammatory diseases of central nervous system (CNS) such as multiple sclerosis (MS). Nitric oxide (NO) has been reported to have dual effects on CNS pathology, and to play an important role in MS. We performed a cross-sectional study in 17 randomly selected patients during MS flare-up, and compared levels of TNF-alpha, IL-10 and NO in serum and cerebrospinal fluid (CSF) with the serum values of these mediators in two different control groups, healthy subjects and HIV-infected untreated patients.

A hisT::Tn5 mutation affects production of microcins B17, C7, and H47 and colicin V.

A Tn5 insertion decreasing the production of microcin B17 was mapped to 50.2 min on the Escherichia coli chromosome map. Sequence analysis showed that the insertion disrupted hisT, the gene encoding pseudouridine synthase I, a tRNA-modifying enzyme.

An unusual mechanism for resistance to the antibiotic coumermycin A1.

Bacterial DNA gyrases are type II topoisomerases made up of two A subunits and two B subunits. Coumarins are carbohydrate-containing antibiotics that inhibit topoisomerases II by competing with ATP for binding to the enzymes. High resistance to coumarins is produced in bacterial species by mutations in gyrB, the gene encoding subunit B.

Molecular characterization of pmbA, an Escherichia coli chromosomal gene required for the production of the antibiotic peptide MccB17.

Microcin B17 (MccB17) is a peptide antibiotic produced by Escherichia coli strains harbouring plasmid pMccB17. We have isolated two mutations that strongly reduce the production of MccB17. These mutations, which map at 96 min on the E.