Large-scale phenotypic analysis--the pilot project on yeast chromosome III.

In 1993, a pilot project for the functional analysis of newly discovered open reading frames, presumably coding for proteins, from yeast chromosome III was launched by the European Community. In the frame of this programme, we have developed a large-scale screening for the identification of gene/protein functions via systematic phenotypic analysis. To this end, some 80 haploid mutant yeast strains were constructed, each carrying a targeted deletion of a single gene obtained by HIS3 or TRP1 transplacement in the W303 background and a panel of some 100 growth conditions was established, ranging from growth substrates, stress to, predominantly, specific inhibitors and drugs acting on various cellular processes. Furthermore, co-segregation of the targeted deletion and the observed phenotype(s) in meiotic products has been verified. The experimental procedure, using microtiter plates for phenotypic analysis of yeast mutants, can be applied on a large scale, either on solid or in liquid media. Since the minimal working unit of one 96-well microtiter plate allows the simultaneous analysis of at least 60 mutant strains, hundreds of strains can be handled in parallel. The high number of monotropic and pleiotropic phenotypes (62%) obtained, together with the acquired practical experience, have shown this approach to be simple, inexpensive and reproducible. It provides a useful tool for the yeast community for the systematic search of biochemical and physiological functions of unknown genes accounting for about a half of the 6000 genes of the complete yeast genome.

[The response to the hepatitis B virus vaccine in patients undergoing hemodialysis and peritoneal dialysis--personal experience]. / Odpowiedz na szczepienie szczepionka przeciw wirusowemu zapaleniu watroby typu B chorych hemodializowanych i dializowanych otrzewnowo-doswiadczenia wlasne.

In 55 hemodialyzed and 15 patients on CAPD the presence of hepatitis B and C markers was estimated before the beginning of the vaccination series against hepatitis B with Engerix B vaccine. The initial anti-H Bs antibody titres was also estimated in these patients. The patients without H Bs Ag who have the anti-Hbs titres below 10 IU/I were qualified for this vaccination. The vaccination was needed by 40% of hemodialyzed patients H Bs(-) and 93% patients on CAPD. After completing the half year lasting series of vaccinations, the serological answer in vaccinated patients was estimated. The protective antibody titres above 10 IU/I was produced by 62.5% of patients on hemodialysis and 64.4% of patients on CAPD. The presence of anti-HCV antibodies had insignificant influence on the ability of producing the protective antibody titres in vaccinated patients.

The effect of sulphinpyrazone and alpha-tocopherol on platelet activation and function in haemodialysed patients.

In 30 patients on chronic haemodialysis treatment the platelet activity and function were studied before and during antiplatelet therapy with alpha-tocopherol and sulphinpyrazone. In both kinds of treatment a significant decrease of ADP-induced and spontaneous aggregation was observed. Sulphinpyrazone exerts an inhibitory effect not only on platelet aggregation but also on platelet factor 3 and provokes a significant prolongation of the bleeding time.

Collagen-anti-collagen complexes in rheumatoid arthritis sera.

Immune complexes (IC) were detected in rheumatoid sera by means of anti-antibody (AA) neutralization tests. The sera with rheumatoid factor (RF) that did not agglutinate human Rh+ erythrocytes sensitized by incomplete Rh antibodies, Ripley, could be tested in an AA neutralization test without any further treatment. On the other hand, 'Ripley-positive' sera had to be treated with 2-mercaptoethanol or dithiothreitol in order to destroy RF. IC-containing sera were further studied for dispersion of IC by collagen. Surprisingly, roughly 50% of IC-containing sera were affected by collagen in that they lost AA-neutralizing activity completely or partially. Significantly, very similar results were obtained with collagen type I, collagen type II and denatured collagen type II. It was concluded that these sera contained IC formed by denatured collagen and its antibodies. Further experiments were devoted to the study of the effect of collagen on reactions of RF with Ripley-sensitized erythrocytes. In several sera, the addition of collagen eliminated the prozone. This was interpreted as deblocking of RF due to the dispersion of the blocking IC by an excess of collagen. In other sera, the addition of collagen seemed to remove or block RF. This blocking effect was interpreted as a neutralization of multispecific RF by collagen. An alternative explanation proposed that collagen formed IC with free anti-collagen antibodies and that these IC blocked the RF.

Immune complexes in syphilis sera.

Four hundred and forty-nine syphilis sera, positive in VDRL and FTA-ABS tests, were studied for the presence of circulating immune complexes (CIC) by means of anti-antibody (AA) neutralization test. Ninety-three (20.7%) sera had demonstrable CIC. Subsequently, dispersion of CIC by saline suspension of cardiolipin and by extract of rabbit testicular syphiloma was examined. Of 40 CIC-containing sera tested with cardiolipin, dispersion of CIC was noted in 16 instances; of 32 CIC-containing sera examined with syphiloma extract, dispersion was noted in 16 cases. Significantly, CIC that showed definite dispersion by cardiolipin were not dispersed by syphiloma extract and vice versa. Some studies were also performed on lepromatous leprosy and SLE. None of 27 cIC-containing lepromatous leprosy sera were affected by cardiolipin, but in 2 of 9 CIC-containing SLE sera, cardiolipin dispersed the complexes. Cardiolipin-anti-cardiolipin complexes that neutralized AA were frequently observed when cardiolipin was added to sera containing its corresponding antibodies but not CIC. Similar reactions were noted between the syphiloma extract and anti-treponemal antibodies.