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Biomedical subjects

R Tsvetkova

Publications and source records attributed to R Tsvetkova.

7 recordsLinked to original sources
PubMed2002

Dopamine transporter gene (DAT1) VNTR polymorphism in major psychiatric disorders: family-based association study in the Bulgarian population.

OBJECTIVE: A 40-bp variable number tandem repeat in the 3'-UTR of dopamine transporter gene (DAT1) has been examined for association with major psychiatric disorders in several case-control studies. No significant results have been found. We used a new collection of parent-offspring trios to test for association with schizophrenia (SZ), bipolar 1 disorder (BPI) and schizoaffective (SA) disorder. METHOD: We genotyped trios from Bulgarian origin where the proband had SZ (178 trios), BPI (77 trios) and SA (29 trios). Alleles ranging from 5 to 11 repeats were observed. The results were analysed with the extended TDT (ETDT). RESULTS: No preferential transmission of alleles was observed for any diagnostic group. The presence of allele DAT*10 was associated with the severity and frequency of auditory hallucinations, however, this result is not significant if corrected for multiple testing. CONCLUSION: Our results are in agreement with previous reports of a lack of association between this polymorphism and major psychiatric disorders.

Adult↗
PubMed1990

[The dissociation of a mutant strain of Streptomyces levoris 41-08, a producer of ichthiomycin].

The population of Streptomyces levoris 41-08, producer of ichtiomicin, is established to be unhomogeneous and consisting of four types of morphologically different varieties: light grey, white, oligospore and asporogenous. The morphological varieties differ in their biochemical activity. The most promising for the ichtiomicine biosynthesis is the grey variant, some of whose representatives manifest up to 30% higher activity than the controls. The statistical processing of data shows that the oligospore and the asporogene variants with their limits of activity to 121.8 and 119.3% respectively are promising too, while the existence of white representatives in the population is not recommended since they are low-active minus variants.

Anti-Bacterial Agents↗
PubMed1987

[System of internal laboratory control over the quality of clinical biochemical research].

An analysis and testing of the system of on-laboratory control on the quality of biochemical investigations with the use of control cards, has been performed. The system provides for the working out of control cards, the carrying out of control investigations, the evaluation of the results, and the correction of the control cards. Data for the built-up of the cards has been obtained with the practice of as many as 30 replications with one and the same sample, under the same conditions, the values of the average quadratic deviation (S) being in compliance with Tonks criterion. The action of control is substantiated through doubling the study of 10 per cent of the samples of each batch for each analysis and evaluation of the differences with regard to S by a two-mark system. An average mark from 0.00 to 2.00 per batch of samples is formed for each analysis. Filled in control cards for the total calcium and inorganic phosphorus are presented as an example. The changes in the S values are followed up after the introduction of control cards for 9 indices. With 7 indices reproducibility has proved higher. A total of 90 series of analyses have been controlled and evaluated--54 series (60 per cent) have proved 'good' (from 1.5 to 2.00), 22 series (24.44 per cent)--'satisfactory' (from 1.00 to 1.49), and 14 series (15.56 per cent)--'bad' (from 0.00 to 1.00 or at differences greater than 2.5 S) which implied that the respective analyses of the series of samples had to be replicated. A total of 24 control cards for various indices have been built up.

Animals↗