RESUMEN
Prenatal diagnostics of genetic diseases becomes more and more popular. Classic obstetric approach for diagnostics of numerous genetic diseases employs biopsy or amniotic liquid analyses. Good evidence now exists that polymerase chain reaction (PCR) is one of the most powerful tools of prenatal diagnostics. In contrast to ultrasound investigation PCR is absolutely safe for an embryo and is much more sensitive at early stage of gestation. PCR analysis can recognize male fetal DNA in mother blood and detect some gender-related genetic diseases. Using detection of Y-chromosome in peripheral blood we have analyzed a diagnostic value of some markers sites of Y-chromosome during gestation, type of blood sample (whole blood, plasma or serum) and varioations of the PCR-method (single-step PCR or nested PCR). Comparative analysis of DNA sequences using NCBI Blast we have found Y-chromosome sites (loci DYS14 and ZFY) suitable for PCR identification of male DNA. Blood plasma is the most optimal blood sample for PCR prenatal gender determination. Prenatal gender determination by PCR can be diagnosed at 4-6 weeks gestation.
Asunto(s)
Cromosomas Humanos Y/genética , ADN/sangre , Reacción en Cadena de la Polimerasa/métodos , Análisis para Determinación del Sexo/métodos , Femenino , Humanos , Masculino , Embarazo , Análisis de Secuencia de ADNRESUMEN
A new modification of DNA purification has been developed. It includes: 1) standard treatment of biological material with proteinase K followed by phenol-chlorophorm extraction; 2) subsequent sample purification using micro-columns packed with Dowex-50 and Sephadex G-50. Oligonucleotide primers often used for DNA typing in man by means of polymerase chain reaction have also been modified. These are VNTR (variable number of tandem repeats) loci of apoB and D17S5. The increase of stability and specificity of amplification of VNTR loci of apoB and D17S5 was achieved by increase of primer length and amplification cycle. The sensitivity of this mode of amplification is 2-4 ng DNA-template. Employment of the nested amplification for apoB locus increased sensitivity of this method up to a few copies of DNA.
Asunto(s)
ADN/química , ADN/aislamiento & purificación , Apolipoproteínas B/genética , Medicina Legal , Humanos , Reacción en Cadena de la Polimerasa/métodos , Secuencias Repetidas en TándemRESUMEN
The range of antisecretory preparations used by a gastroenterologist now includes a new reliable preparation. Nexium, which allows solving the problem of optimization of treatment of patients with acid-dependent diseases.
Asunto(s)
Ácido Gástrico , Gastropatías/tratamiento farmacológico , Quimioterapia Combinada , Antagonistas de los Receptores H2 de la Histamina/uso terapéutico , Humanos , Inhibidores de la Bomba de Protones , Gastropatías/fisiopatologíaRESUMEN
A strain producing 5-del-proinsulin was designed on the basis of an industrial strain producing human recombinant proinsulin. 5-Del-proinsulin is an analog of human recombinant proinsulin. The new strain contains a deletion of 5 amino acid residues in the C-end region of the B-chain and a residue of tyrosine at B25. A method of oligonucleotide-directed mutagenesis was applied. Comparison of the electrophoregrams of the inclusion bodies of the initial and resulting strains made it possible to conclude that the pattern of the proteins was the same and the electrophoretic mobility of the recombinant proteins was practically identical.
Asunto(s)
Eliminación de Gen , Proinsulina/genética , Receptor de Insulina/metabolismo , Tirosina/genética , Secuencia de Aminoácidos , Secuencia de Bases , Sitios de Unión/genética , Escherichia coli , Código Genético , Humanos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Oligonucleótidos/genética , Proteínas Recombinantes/genéticaAsunto(s)
Clonación Molecular , Eritromicina/biosíntesis , Genes Bacterianos , Familia de Multigenes , Streptococcus/genética , Secuencia de Bases , Southern Blotting , Farmacorresistencia Microbiana , Eritromicina/farmacología , Datos de Secuencia Molecular , Mapeo Restrictivo , Streptococcus/efectos de los fármacos , Streptococcus/metabolismoRESUMEN
The complete primary structure (1449 b. p.) of mobile genetic element ISH S1 from Halobacterium halobium has been elucidated using the dideoxy/M13 sequencing procedure. Computer analysis of the structure reveals similarity in overall structural organization of ISH S1 and other known transposable genetic elements of halobacteria and makes it possible to propose a hypothetical model of halobacterial promoter.
Asunto(s)
Archaea/genética , Bacterias/genética , Secuencia de Bases , Elementos Transponibles de ADN , Genes Bacterianos , Secuencias Repetitivas de Ácidos Nucleicos , Homología de Secuencia de Ácido Nucleico , Escherichia coli/genética , Datos de Secuencia Molecular , Regiones Promotoras GenéticasRESUMEN
BglII fragment of S. typhimurium DNA, containing rpoB gene coding for the RNA polymerase beta-subunit, was cloned. The nucleotide sequence of the rpoB gene EcoRI-C fragment (2873 b.p.) was determined.
Asunto(s)
ARN Polimerasas Dirigidas por ADN/genética , Genes Bacterianos , Salmonella typhimurium/genética , Secuencia de Aminoácidos , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , Enzimas de Restricción del ADN , ADN Bacteriano/genética , Desoxirribonucleasa EcoRI , Salmonella typhimurium/enzimologíaRESUMEN
Three new rif-r-mutations, obtained independently, were localized in the rpoB gene coding for the beta-subunit of DNA-dependent RNA polymerase of E. coli. Two of them led to identical Asp(516)-Asn amino acid substitution with relatively low resistance of corresponding E. coli strains to rifampicin. The third mutation affected the His 526 residue transforming it into Tyr and endowed the E. coli cells with a high resistance against rifampicin.
