A review of polycystic ovarian syndrome in adolescents.

Polycystic ovary syndrome (PCOS) is a complex disorder, involving primarily ovarian hyperandrogenism in females and linked with insulin resistance in the majority of cases. Clinical features are widely variable and include a combination of menstrual irregularities, acne, hirsutism, and alopecia. Although it typically presents around puberty, several risk factors during childhood may help raise a high index of suspicion for the development of PCOS in adolescents. The pathophysiology of PCOS still remains unknown and likely includes a combination of genetic factors, insulin resistance, and environmental factors. A thorough diagnostic work up is required in suspected cases and several management modalities have been suggested. Since various long term complications and comorbidities are associated with PCOS, early diagnosis and therapeutic intervention is warranted in these cases.

Pentapeptides containing two dehydrophenylalanine residues--synthesis, structural studies and evaluation of their activity towards cathepsin C.

Synthesis, structural and biological studies of pentapeptides containing two DeltaPhe residues (Z and E isomers) in position 2 and 4 in peptide chain were performed. All the investigated peptides adopted bent conformation and majority of them could exist as two different conformers in solution. Only pentapeptides, containing free N-termini appeared to act as weak inhibitors of cathepsin C with the slow-binding, competitive mechanism of inhibition, free acids being bound slightly better than their methyl esters. Results of molecular modeling suggested significant difference between peptides, depending of the type of amino acid residue in position 5 in peptide chain. Dehydropeptides containing Gly residue in this position may act as competitive slow-reacting substrates and therefore exhibit inhibitory-like properties.

A phosphonamidate containing aromatic N-terminal amino group as inhibitor of leucine aminopeptidase-design, synthesis and stability.

Fully deprotected phosphonamidate dipeptides, predicted as effective inhibitors of cytosolic leucine aminopeptidase, showed unexpected instability in water solution at pH below 12. Their hydrolysis rate was strictly correlated with basicity of the N-terminal amino group. To improve this feature a phosphonamidate analogue containing less basic, aromatic 2-aminophenylphosphonate residue in P1 position of the inhibitor was designed. The target compound was synthesised starting from diethyl 2-nitrophosphonate in several step procedure. The decrease in basicity of the terminal amino moiety of the modified analogue in fact resulted in satisfactory improvement of hydrolytic stability of the P-N bond. The developed phosphonamidate was proved to be fully resistant to hydrolysis above pH 7. Surprisingly, tested in enzymatic assays towards leucine aminopeptidase (optimum pH 8.5), it did not exhibit inhibition activity up to milimolar concentration. The explanation could be that diminishing the basic character of the terminal amino group may result in a change of its affinity towards the zinc ions.

Synthesis of tetrapeptide p-nitrophenylanilides containing dehydroalanine and dehydrophenylalanine and their influence on cathepsin C activity.

Three dehydrotetrapeptides of rationally varying structure were prepared and tested as affectors of cathepsin C. These compounds appeared to be substrates of the enzyme, being equipotent with their classical counterparts. Thus, replacement of amino acid in a short peptide by corresponding dehydroamino acid does not prevent cathepsin C in recognizing dehydropeptide as its substrate.

Levels of aflatoxin B1, bacteria and fungi in feed and food in 1971 - 1987.

Totally 39% out of 8371 feed and their component samples were contaminated by aflatoxin B1. Mean contamination was 36µg/kg with maximum yield 10100 µg/kg. Contamination of samples by total count of organisms, mean contamination and maximum yield, respectively was: 1) bacteria 99%, 2.2×10(6), 2.4×10(8); 2) proteolytic bacteria 94%, 1.2×10(5), 3.0×10(6);3) moulds 98%, 1.3×10(5), 9.0×10(6); 4) yeasts 44 %, 3.3×10(4), 3.6×10(6). The samples were contaminated in 92 % byAspergillus spp, in 71% byAspergillus flavus, in 83% byPenicillium spp, and in 20% byFusarium spp with mean contamination 8.3×104, 1.1×10(3), 4.2×10(4), 5.0×10(3) , and maximum yield 6.8×10(6), 1.0×10(5), 5.0×10(6), 1.5×10(6), respectively. Totally 8.5% of strains were aflatoxinogenic and 4.4% of the strains were isolated from feed and 21 % of the strains from grain/nut.