[Influence of obstetric factors on the quality of cord blood units collected for allogeneic transplantation].

Umbilical cord blood (CB) as a source of haematopoietic stem cells for allogeneic transplantation has many advantages over bone marrow and peripheral blood, however, a main limitation to its use in clinical setting is cell numbers. This study aimed to assess the impact of mother/neonatal factors on the quality of CB units, collected for allogeneic transplantation. We analyzed 33 CB units collected in University Hospital of Obstetrics and Gynaecology "Maichin dom" and donated to the National public bank for stem cells, University Hospital "Alexandrovska", Sofia. A significant increase (p < 0.001) of total nucleated cell (TNC) values was found after CB processing. A trend of higher values of CD34+ cells was observed in CB units obtained from vaginal deliveries compared to Cesarian section births, and from female newborns compared to their male counterparts. CD34+ cell number positively correlated with CD34+ percentage and TNC count. Our preliminary data demonstrate the need of a large retrospective evaluation of different obstetric factors in order to establish criteria for appropriate selection in our country of umbilical cord blood donors for public banking.

ELISPOT assays provide reproducible results among different laboratories for T-cell immune monitoring--even in hands of ELISPOT-inexperienced investigators.

Measurements of antibodies in bodily fluids (e.g., by ELISA) have provided robust and reproducible results for decades and such assays have been validated for monitoring of B-cell immunity. In contrast, measuring T-cell immunity has proven to be a challenge due to the need to test live cells in functional assays ex vivo. Several previous efforts looking into the reproducibility of ex vivo T-cell assays between different laboratories, or even within the same laboratory, have provided rather discouraging results. The hypothesis we tested in this study is that those poor results are due to the lack of assay and data analysis standardization, rather than the inherent complexity of T-cell assays. In this study, 11 laboratories across Europe and the United States were provided identical reagents and were asked to follow the same protocol while testing aliquots of the same three cryopreserved peripheral blood mononuclear cells (PBMC) in an interferon-gamma (IFNgamma) ELISPOT assay measuring the antigen-specific T-cell response to a CMV peptide. All individuals performing the assays were ELISPOT novices. At their first attempt, while three of these individuals failed with the basic logistics of the trial, eight detected the peptide-specific CD8+ T-cells in frequencies approximating the values established by the Reference Laboratory. The data show that ELISPOT assays provide reproducible results among different laboratories when the assay procedure and data analysis is standardized. Since ELISPOT assays have been qualified and validated for regulated studies, they are ideal candidates for robust and reproducible monitoring of T-cell activity in vivo.

Experimental study of subacute oral, dermal and inhalation toxicity of bulmoscide preparation.

The purpose of this study is to give the toxicological characteristics of subacute oral, dermal and inhalation exposure of microbial preparation Bulmoscide, which is based on bacterium Bacillus thuringiensis, serotype H-14. The study was performed on sexually mature Wistar rats of both sexes. No significant changes in non-specific, clinico-laboratory and biochemical parameters as well as morphological examinations in any tested groups compared to the control groups were revealed. The doses 110 mg.kg-1 (1.32 x 10(9) sp.kg-1) at oral administration in duration of 90 days, 3000 mg.kg-1 (3.6 x 10(10) sp.kg-1) in 21 day dermal application and maximum attainable concentration of dust aerosol 18 mg.kg-3 (2.2 x 10(8) sp.m-3) during a 30 day inhalation exposure are "no toxic effect" levels. On the basis of the data, the selective bacterial insecticide Bulmoscide has been determined to be of low toxic and low hazardous preparation in compliance with the Hygiene Classification of pesticides.

Toxicological evaluation of agromet (Metalaxyl) preparation.

A complex toxicological study was carried out in relation to the hygienic standardization of the fungicide preparation Ridomil, whose forthcoming production in this country will be under the name Metalaxyl. The study was performed on sexually mature white rats of both sexes, at oral, dermal and inhalation exposure, acute, subacute and chronic experiments, according to the Bulgarian State Standard. Besides the routine toxicological studies were carried also studies for establishing the long-term effects of the preparation (gonadotropic, embryotoxic and teratogenic, cardiovascular). The results from the study permitted the Agromet preparation to be put in III class--moderately toxic according to limiting index LD50 oral. On the basis of data from the authors study on the general toxicity and long-term effects of Metalaxyl a temporary MAC 4 mg/m3 was proposed.