Synthesis of 7 alpha- and 7 beta-spermidinylcholesterol, squalamine analogues.

Stereoselective synthesis of squalamine dessulfates analogues, 7 alpha and 7 beta-N-[3N-(4-aminobutyl) aminopropyl]aminocholesterol are reported, using 7 alpha and 7 beta-aminocholesterol as a key intermediate. It's the first example in which the position of spermidine is modified at the steroid ring. These molecules showed a comparable antibacteria and fungi activities to squalamine. Then, they have a cytotoxic activity on a human non-small cell bronchopulmonary carcinoma line (NSCLC-N6).

Composition and antimicrobial activity of the essential oil of Hypericum coris.

The volatile fraction of Hypericum coris aerial parts, consisting mainly of alpha-curcumene was screened for activity against five microbial strains. The maximum activity was against Saccharomyces cerevisiae.

Stereoselective synthesis of 7 alpha- and 7 beta-aminocholestanol as potent fungicidal drugs.

Potentially lymphotropic 7 alpha- and 7 beta-aminocholestanol were stereoselectively synthesized. In vitro bioassay studies have shown that these fungicidal lipidic derivatives possess strong antifungal activity against Candida spp resistant strains to amphotericin B, 5-fluorocytosine and azoles.

Concordance of eight kits for antithyroid peroxidase autoantibodies determination.

Numerous methods are proposed to quantify antithyroid peroxidase autoantibodies. No standardization exists but most assays use the standard MRC 66/387 with a calibration factor. Costs of the tests vary between the different kits. We evaluated the concordance of eight peroxidase autoantibodies assay kits in two centres, using a panel of sera from 269 subjects: controls (n=100), patients with autoimmune thyroid disease (n=77; Graves' disease, Hashimoto's thyroiditis), patients with non-autoimmune thyroid disease (n=69; nodular goiter, differentiated thyroid carcinoma) and individual sera with thyroglobulin antibodies only (n=23). The concordance between the eight methods was high, ranging from 88.3% to 98.8% with the total panel of sera. The majority of assays demonstrated high diagnostic performance. We encountered some false-positive results at borderline positive levels, and the nonrecognition of some sera by competitive assays.

Synthesis of 25-aminosterols, new antifungal agents.

25-aminolanostenol 1 and 25-aminocholesterol 2 were hemisynthesized from natural sterols and tested in vitro against Candida albicans. The biological activity of compound 1 was rather weak, whereas 2 exhibited in vitro antifungal activity with MIC value of 4 microM.

Synthesis and cytotoxicity of aminosterols: activity studies on a non-small-cell bronchopulmonary carcinoma line (NSCLC-N6).

Various new aminosterols were synthesized. The antiproliferative activity of these compounds (I-IV) was studied in vitro on a continuous human non small-cell bronchopulmonary carcinoma line (NSCLC-N6) at the cell cycle level. The histograms indicate cell blockage in Phase Gl (compound I-III) associated with a reduction in the number of cells phases S and G2M and appearance of cellular debris derived from cells in Phase G1.

Antifungal metabolites from the marine sponge Pachastrissa sp.: new bengamide and bengazole derivatives.

This paper reports the studies of components of an undescribed sponge in the genus Pachastrissa sp., collected along the Djibouti coast. The extract showed activity against Candida albicans. Six new bengazoles (1-6) and a new bengamide, named bengamide L (16), in addition to the known bengazoles (7-11), bengamides A (12), B (13), E (14), and F (15), and a lactone (17) are described in this paper. All structures were determined on the basis of spectroscopic studies.

Synthesis of 6(alpha, beta)-aminocholestanols as ergosterol biosynthesis inhibitors.

delta 7-5-Desaturase catalyses one of the last steps in ergosterol biosynthesis in fungi. Moreover delta 5-unsaturation is necessary for the sparking function. Synthesis of three pairs of C-6 epimeric cholestanol derivatives are described as potential growth inhibitors. Preliminary results suggest that 6 beta-aminocholestanol is a potent antifungal agent.

Antibacterial activity of 7-aminocholesterol, a new sterol.

A new sterol, 7-aminocholesterol, which inhibits growth of Saccharomyces cerevisiae, also displayed antibiotic activity against Gram-positive bacteria. The 50% growth inhibitory concentration against strains of Listeria innocua, L. monocytogenes, Staphylococcus aureus, Enterococcus hirae and Bacillus cereus was 3 microM.

Pulsatility of growth hormone secretion and its relation to growth.

84 short children were submitted to nocturnal spontaneous growth hormone (GH) secretion tests and to provocative insulin-arginine tests. Discrepancies between the GH peak under the provocative test (I-AP) and nocturnal GH maximal peak (PA) and mean concentration (MC) were frequently observed, despite significant statistical correlation between I-AP and PA (r = 0.47; p < 0.02) and between I-AP and MC (r = 0.42; p < 0.02). Night profiles were evaluated by time analysis: 31 fitted a theoretical model, consisting of a cosine function of time (modelizable profiles). Spectral analysis, from Fourier transformation, indicated predominant periods after cluster analysis. The major predominant period in modelizable (n = 9) and in nonmodelizable (n = 28) profiles was close to 180 min and a secondary period was on average 122 min in modelizable (n = 20) and 105 min in nonmodelizable (n = 23) profiles. Two modelizable and two nonmodelizable profiles escaped this classification. The general, auxological and GH secretory status did not differ significantly between patients with modelizable and nonmodelizable profils. Growth velocity correlated with GH mean concentration (r = 0.36; p < 0.001), but not with plasma insulin-like growth factor-I levels nor with any of the pulsatility indices: number of peaks, main period, and pulse height index = mean GH peak/mean GH concentration. The relevance of GH pulsatility to growth is, therefore, unclear in humans.

Immobilization and treatment of Streptococcus faecalis for the continuous conversion of arginine into citrulline.

Citrulline is one of the steps of the arginine dihydrolase system of Streptococcus faecalis. We have shown that the bacteria, immobilized in polyacrylamide gel and treated with Cetyl trimethyl ammonium bromide (CTAB) or heat, were able to convert arginine to citrulline. Used continuously in a column reactor, the entrapped cells have a stable enzymatic activity for at least 30 days at 45 degrees C.

Assessment of the reproducibility of nocturnal growth hormone secretion.

The reproducibility of measurements of nocturnal spontaneous secretion of growth hormone (GH) was assessed. The study population consisted of 15 short children with a variety of pathological conditions. Blood samples were taken every 20 min from each subject during sleep on two consecutive nights. The analysis of variance of matched series indicated a global reproducibility, but also demonstrated significant individual variabilities (with-in-subject effect) of both peak amplitude (p = 0.05) and mean concentration (p = 0.02). We did not find any link between the variation of the GH parameters and the variations of the clinical sleep score in 11 patients.