Inhibition of protein tyrosine phosphatase activity by diamide is reversed by epidermal growth factor in fibroblasts.

Diamide (azodicarboxylic acid bis(dimethylamide] inhibits protein tyrosine phosphatase activity in fibroblasts without altering protein tyrosine kinase activity associated with the epidermal growth factor receptor. The loss of protein tyrosine phosphatase activity caused by diamide is reversed by 2-mercaptoethanol or epidermal growth factor.     

Development and testing of an enzyme immunoassay-based monoclonal test system for the detection of the Yersinia pestis V antigen

An enzyme immunoassay-based test system for Y. pestis V antigen detection was developed. The specificity and sensitivity of this system met the requirements for medical immunobiological preparations for the identification of causative agents of highly fatal diseases. The sensitivity of the test system was assessed, and its high specificity was also demonstrated: the test system did not detect bacterial cells of closely related (four Y. pseudotuberculosis strains) and heterologous microorganism strains. The test system developed was able to detect the V antigen at concentrations as low as 2.0 ng/mL in cells of nine experimental Y. pestis cultures. The obtained preparation can be recommended for use in laboratory diagnostics of plaque.     

Association of permanent arterial hypertension with the renin-angiotensin and kinin-bradykinin system genes in children

A new approach, based on scoring, was proposed for a more objective estimation of the contribution of several genetic variants to a multifactorial disease. Two variants of the approach—genotype scoring and unfavorable factor scoring—were tested by analyzing the polymorphisms of REN (I9–83G>A), AGT (M235T), ACE (I/D), AGTR1 (1166A>C), ATGR2 (3123C>A), and BKR2 (?58T>C and I/D) in children with arterial hypertension (AH). Each of the two variants reported that the genes of the renin-angiotensin and kinin-brady-kinin systems play an important role in permanent AH in girls.     

Population and Family Studies of the CAG Repeats in the IT-15Gene

A simple and effective method for typing of CAG repeats in the IT-15gene has been suggested. This method was applied for examination of the CAG allele distribution in Huntington's disease (HD) patients in five different populations from the Commonwealth of Independent States. A total of 21 normal alleles with the sizes ranging from 9 to 32 triplet repeats units were revealed. Moreover, alleles with the sizes ranging from 16 to 20 repeats predominated constituting from 54.4 to 74.6% of all alleles in different populations. The number of repeats in one allele in HD patients exceeded 38 units (43 triplets on average). In two families an increase in the CAG repeat units number in the mutant allele upon its paternal transmission was recorded.     

Matrix metalloproteinases’s association of polymorphisms of MMP3 and MMP9 with development of genital endometriosis

We present a comparative analysis of the allelic polymorphisms of the matrix metalloproteinase (MMP) gene family, including MMP3 (rs3025058), MMP7 (rs11568818), MMP9 (rs17576, rs2250889), MMP12 (rs2276109), and MMP13 (rs2252070), in patients with external genital endometriosis (EGE) and in a control group of healthy women proven to be free of disease by laparoscopic inspection. We found significant differences in the incidence of particular MMP3 and MMP9 alleles, which substantiate the role of matrix metalloproteinases in EGE pathogenesis. We used the Multifactor Dimensionality Reduction (MDR) analysis to show that 14 allelic combinations of the MMP containing MMP3 (rs3025058) × MMP7 (rs11568818) × MMP9 (rs17576) alleles showed a statistically significant association with an increased risk of EGE, while 10 other combinations correlated with a reduced risk of the disease. MDR analysis produced two statistically significant models for MMP allelic combinations involved in EGE progression, both with 100% penetrance and 83 and 78% accuracy.     

Analysis of Deletions in SMN1, SMN2, and NAIPGenes in Spinal Muscular Atrophy Patients from the Northwestern Region of Russia

Polymerase chain reaction with subsequent SSCP (single-strand DNA conformational polymorphism) and restriction (BselI restriction endonuclease) analyses were used to type the DNA samples of affected individuals and their relatives from 23 Russian families with high risk of spinal muscular atrophy (SMA) residing in the northwestern region of Russia. Deletions of exon 7 of the SMN1gene were found in 96% of the individuals examined. The frequency of homozygous deletion of exons 7 and 8 of the SMN1gene was 65%. The frequency of homozygous isolated deletion of the SMN1gene exon 7 among the SMA patients was 4.3%. Homozygous deletion of exon 5 of the NAIPgene was found in 22% of SMA patients. In SMA patients, a total of seven deletion types involving the SMN1, NAIP, and SMN2genes were detected. Deletion of exons 7 and 8 of the SMN1gene was the most common mutation associated with SMA in patients from the northwestern Russia.     

Frequency of the F508 deletion in cystic fibrosis patients from the European part of the USSR

Summary The frequency of the F508 deletion (F508) has been analyzed in 189 cystic fibrosis (CF) patients from the European part of the USSR, viz. 127 nothern Slavonians (Leningrad region), 30 southern Slavonians (the Ukraine), 10 central Slavonians (Moscow region), 14 Moldavians (Kishenev region) and 8 Lithuanians (Vilnius region). The distribution of CF⁺ chromosomes with and without F508 varied significantly in the different ethnic groups studied and correlated with the clinical manifestation of CF. The overall frequency of F508 in Slavonian patients is equal to 62.5%, approximately 90% of them being heterozygous or homozygous for this mutation. The frequency of the deletion among 99 Slavonian patients with severe disease manifestation (pancreatic insufficiency, PI) is equal to 67.5%, only 12 patients having pancreatic sufficiency (PS, 17.5%). The highest value of F508 (77.4%) is registered in PI/CF patients of the southern Slavonian group; it is much less frequent (about 57%) in relevant groups of Slavonians from the northern and central parts of the country. Unusually low frequencies (24% and 26%) of F508 are detected in a few samples of Lithuanian and Moldavian CF patients, respectively. All F508⁺CF-chromosomes of Slavonian origin are associated with haplotypes 2.2.2. defined by the restriction fragment length polymorphism sites KM19/PstI, CS.7/Hin6I and MP6d-9/MspI, although a high proportion (about 25%) of unknown mutations is associated with the same haplotype. Haplotype B (allele 1XV2c/TaqI; allele 2 KM19/PstI) accounts for 91% of F508⁺CF chromosomes. Our data are consistent with the hypothesis of a single origin and subsequent diffusion of this major CF mutation; however, its interpopulational dissemination in Eastern Europe does not follow the suggested south-east to north-west gradient in Western Europe. The significance of these data for prenatal diagnosis and carrier screening of CF mutations is briefly discussed.     

Peculiarities of the GSTM1 0/0 genotype in French heavy smokers with various types of chronic bronchitis

A homozygous gene deletion of the glutathione S-transferase M1 (GSTM1) locus of genomic DNA from blood spots was studied by the polymerase chain reaction in a group of French heavy smokers (n = 361), which included patients with severe chronic bronchitis (SCB; n = 87), moderate chronic bronchitis (MCB; n = 102) and hard smokers (HS) with no permanent clinical symptoms of chronic bronchitis (n = 172). The GSTM1 0/0 genotype was found in 71.3% and 65.7% of cases in SCB and MCB, respectively, compared with only 47.1% in the control HS group (P = 0.0002). This latter figure (47.1%) is consistent with the average GSTM1 deletion frequency in French Caucasians. Moreover, the results showed a significant difference in the distribution of the GSTM1 0/0 genotype for both the SCB and MCB groups against the control HS group, according to gender (SCB: P = 0.001; MCB: P = 0.005), age (SCB: P = 0.0001; MCB: P = 0.005) and smoking history (SCB: P = 0.0001; MCB: P = 0.005). Thus, individuals homozygous for the GSTM1 gene deletion, especially in the under-41 age group (SCB: P = 0.001; MSB: P = 0.04) with an average smoking history of 16–30 pack-years (SCB: P = 0.002; MSB: P = 0.01) are more prone to chronic lung diseases, such as SCB and MCB, than are GSTM1 +/+ or 0/+ subjects. Population screening of young people for the identification of GSTM1 0/0 subjects, with special emphasis on smoking habits, might be useful (1) for the early detection of individuals at high risk of lung complications caused by environmental toxins and pollutants and (2) in clinical practice, in order to prevent the development of chronic bronchitis, which is a common disease. Received: 4 November 1996     

Detection of three rare frameshift mutations in the cystic fibrosis gene in an African-American (CF444delA), an Italian (CF2522insC), and a Soviet (CF3821delT).

We have identified three new frameshift mutations in the CFTR gene in patients with cystic fibrosis (CF). The first one involves the deletion of an adenine nucleotide in exon 4 in an African-American patient (CF444delA), the second involves the insertion of a cytosine nucleotide in exon 13 in an Italian patient (CF2522insC), and the third results from the deletion of a thymidine nucleotide in exon 19 in a Soviet patient (CF3821delT). Each mutation is predicted to result in premature termination of the CFTR protein.