23 research outputs found

    Vitamin D status in the elderly: seasonal substrate deficiency causes 1,25-dihydroxycholecalciferol deficiency

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    The seasonal variation of 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol was analyzed in 240 elderly subjects (mean age: 78 yr) in Belgium. Serum 25-hydroxycholecalciferol was lowest from February until May (mean levels less than 25 nmol/L). Summer peak levels were, however, not higher than nadir levels in younger control subjects. A seasonal variation in total and free 1,25-dihydroxycholecalciferol concentrations was also observed in the geriatric population with a nadir in February and March (50 +/- 24 pmol/L). The peak values in summer (110 +/- 33 pmol/L) were not different from those of the younger controls. Serum calcium and phosphate were decreased whereas alkaline phosphatase and parathyroid hormone were increased throughout the year in the geriatric patients. Oral 25-hydroxycholecalciferol treatment rapidly normalized serum 1,25-dihydroxycholecalciferol concentrations in vitamin D-deficient subjects. Deficiency of both the vitamin D substrate and hormone is frequent in the elderly population in Belgium

    Discovery and Structure-Based Optimization of 2-Ureidothiophene-3-carboxylic Acids as Dual Bacterial RNA Polymerase and Viral Reverse Transcriptase Inhibitors

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    We are concerned with the development of novel anti-infectives with dual antibacterial and antiretroviral activities for MRSA/HIV-1 co-infection. To achieve this goal, we exploited for the first time the mechanistic function similarity between the bacterial RNA polymerase (RNAP) "switch region" and the viral non-nucleoside reverse transcriptase inhibitor (NNRTI) binding site. Starting from our previously discovered RNAP inhibitors, we managed to develop potent RT inhibitors effective against several resistant HIV-1 strains with maintained or enhanced RNAP inhibitory properties following a structure-based design approach. A quantitative structure-activity relationship (QSAR) analysis revealed distinct molecular features necessary for RT inhibition. Furthermore, mode of action (MoA) studies revealed that these compounds inhibit RT noncompetitively, through a new mechanism via closing of the RT clamp. In addition, the novel RNAP/RT inhibitors are characterized by a potent antibacterial activity against S. aureus and in cellulo antiretroviral activity against NNRTI-resistant strains. In HeLa and HEK 293 cells, the compounds showed only marginal cytotoxicity

    Risks and benefits in the trial of the European working party on high blood-pressure in the elderly

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    Hypertensive patients over the age of 60 years were admitted to a double-blind placebo-controlled trial. Patients in the actively treated group received a combined potassium-losing and -sparing diuretic (triamterene 50 mg plus hydrochlorothiazide 25 mg; n = 416); this dose could be doubled and methyldopa (up to 2 g, daily) was added in 35% of patients when blood pressure remained high. The placebo group (n = 424) received matching capsules and tablets. Adverse effects were assessed in the double-blind period of the trial by calculating the incidence of abnormal biochemical results, investigator reports of diseases and prescriptions of concomitant therapy and a self-administered symptom questionnaire completed by patients. In 1000 hypertensive subjects over 60 years of age, 1 year of active treatment would prevent 11 fatal cardiac events, 6 fatal and 11 non-fatal strokes and 8 cases of severe congestive heart failure. No unexpected adverse treatment effects were observed. A significant excess incidence rate (per 1000 person years) was found in the active group compared with placebo for: (1) impaired renal function, a serum creatinine > 180-mu-mol/l (2.0 mg/dl); (2) mild hypokalaemia, a serum potassium 0.52 mmol/l in men or > 0.46 in women. Elevated blood sugar and prescriptions for hypoglycaemic drugs tended to be more frequent in the actively treated group, but this difference was not statistically significant. In both groups, there was a low incidence (< 7 per 1000 person years) of anaemia and depression and diseases of the liver, gall bladder or pancreas. More patients reported a dry mouth, blocked nose and diarrhoea in the active treatment group compared with placebo (P < 0.05). Dry mouth and diarrhoea were associated with methyldopa rather than diuretic. We conclude that the adverse effects do not outweight the benefits of treatment in preventing stroke events, cardiac deaths and heart failure
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