Inhibition of platelet aggregation by S-nitroso-cysteine via cGMP-independent mechanisms: evidence of inhibition of thromboxane A2 synthesis in human blood platelets.

S-Nitroso-cysteine (SNC), a putative endothelium-derived relaxing factor, potently inhibited collagen- and arachidonic acid-induced platelet aggregation (IC50=100 nM) and thromboxane A2 (TxA2) synthesis of human blood platelets. ODQ, a selective inhibitor of the soluble guanylyl cyclase, inhibited SNC-induced formation of cGMP but did not reverse inhibition by SNC of collagen- and arachidonic acid-induced platelet aggregation. Combination of ODQ with SQ-29548, a specific platelet TxA2 receptor antagonist, did not modify the antiaggregatory action of SNC. Our study shows that SNC inhibits platelet aggregation by cGMP-independent mechanisms that may involve inhibition of TxA2 synthesis in human platelets.

Daily dietary intake of selenium in eastern Croatia.

Data on the selenium content in the soil and human milk in eastern Croatia indicate a possibility of inadequate Se status of people in the area. In order to determine the daily dietary intake of Se in eastern Croatia, a 7-day duplicate diet study was performed. There were 41 participants (18-53 years old; 14 males and 27 females). Selenium measurement was carried out in a HG-AAS. The average daily Se intake in the area is 27.3 micrograms. A significant difference (P < 0.05) exists between male (32.2 micrograms) and female (24.8 micrograms) participants. Percentage of optimum Se intake shows an inverse association with the increasing age of subjects (r = 0.43; P < 0.01). Relationship between Se intake and intakes of different foods (cereal products, milk and dairy products, meat, fish, etc.) was also examined. The sub-optimal Se intake (RDA is 55 micrograms/day for women and 70 micrograms/day for men) is a reflection of low Se levels in the environment, so supplementation of fertilizers with Se should be considered.

Analysis of cysteine and N-acetylcysteine in human plasma by high-performance liquid chromatography at the basal state and after oral administration of N-acetylcysteine.

A high-performance liquid chromatographic method for the determination of free reduced cysteine and N-acetylcysteine in human plasma at the basal state and after oral administration of N-acetylcysteine is described. The method is based on acid-catalysed conversion of plasma thiols to the corresponding S-nitroso derivatives by excess of nitrite and their subsequent cation-pairing RP-HPLC with detection at 333 nm. Recovery rates of cysteine and N-acetylcysteine added to human plasma were 94.6 and 99.6%, respectively. Inter- and intra-day precision were below 6%. In healthy humans (n = 5), free reduced cysteine was determined to be (mean+/-S.E.) 10.0+/-0.96 microM. No N-acetylcysteine was detected in plasma of these subjects above the limit of detection (e.g. 170 nM). The method was successfully applied to a pharmacokinetic study on orally administered N-acetylcysteine to healthy volunteers.

[Dysphagia due to cervical spine involvement in ankylosing spondylitis]. / Disfagija tijekom afekcije vratne kraljeznice u ankilozantnom spondilitisu.

Here we present a case of a patient with a massive ossification of annulus fibrosus and longitudinal ligament at the level C3-C4, C4-C5 and C5-C6, also called the Van Swaay bridge. One can observe a propulsion of the pharingeal tissue at the level of the massive Van Swaay bridge between C5 and C6 which caused pressure and dysphagia.

[Incorrect diagnosis of peripheral arthritis in ankylosing spondylitis]. / Pogresna procjena perifernog artritisa u ankilozantnom spondilitisu.

We present a case of female patient who's been treated 28 years, under the diagnosis of rheumatoid arthritis because of the symmetric polyarthritis. After 28 years radiography of sacro-iliac joints and thoracolumbar vertebra was taken and showed changes typical for ankylosing spondylitis with asymmetrical affection of peripheral joints and with irreversible changes only in knees joints. Rheumatoid factor in serum was always negative, and the patient has also an iridocyclitis. We conclude that the diagnosis is surely ankylosing spondilitis.

Antiviral and anti-invasive titers of human interferons.

The titers of preparations of human leukocyte and human fibroblast interferon were examined to determine their antiviral and anti-invasive activity. The examinations showed a very high correlation of these activities in human fibroblast interferon (r = 0.99), whereas the correlation for human leukocyte interferon was lower. These two interferons have also been found to differ in the relation between antiviral and anti-invasive titers. This difference is highly significant (p less than 0.001).