Detection of streptomycin-resistance associated rpsL and rrs gene mutations in Mycobacterium tuberculosis by PCR-single-strand-conformational polymorphism / 中华临床感染病杂志

ObjectiveTo establish a novel rapid detection method based on PCR-single-strand-conformational polymorphism (PCR-SSCP) to determine mutation of streptomycin-resistance associated rpsL and rrs genes in isolates of Mycobacterium tuberculosis (MTB).MethodsStreptomycin-resistance of 112 MTB isolates was detected using the routine drug susceptibility test,and a special PCR-SSCP assay was established.The mutations of rpsL and rrs genes in streptomycin-resistant MTB isolates were detected by PCR-SSCP and PCR direct sequencing (PCR-DS) ; the results from two techniques were compared.Results All isolates had both rpsL and rrs genes.Fifty-two isolates (46.4％) were streptomycin susceptible,in which only 1 isolate showed abnormal PCR-SSCP fragments from rrs gene,and the specificity of PCR-SSCP was 98.1％ (51/52).Sixty isolates (53.6％) were streptomycin-resistant,in which 46 (76.6％) and 11 ( 18.3％ ) isolates presented the abnormal PCR-SSCP fragments of rpsL and rrs gene,respectively.One streptomycin-resistant isolate showed abnormal PCR-SSCP fragments from both rpsL and rrs genes.The sensitivity of PCR-SSCP was 93.3％ (56/60).ConclusionThe PCR-SSCP that established in this study is a specific and sensitive method for rapid detection of the streptomycin-resistance associated mutations in rpsL and rrs genes of MTB.

Triagem de mutações nos receptores de Angiotensina II, AGTR1 e AGTR2 e avaliação dos polimorfismos C573T e A1166C do gene AGTR1 em pacientes com adrenarca precoce idiopática / Mutation screening in Angiotensin II receptors, AGTR1 and AGTR2, and evaluation of AGTR1 polymorphisms C573T and A1166C in patients with premature adrenarche / Mutation screening in Angiotensin II receptors, AGTR1 and AGTR2, and evaluation of AGTR1 polymorphisms C573T and A1166C in patients with premature adrenarche

Pubarca precoce é o aparecimento de pêlos pubianos antes dos 8 anos em meninas e 9 anos em meninos, sendo sua etiologia mais freqüente a adrenarca precoce idiopática, a longo prazo, associada à síndrome metabólica. Dentre os fatores envolvidos na gênese da adrenarca precoce podemos citar a Angiotensina II (Ang II), a qual promove proliferação celular e esteroidogênese, podendo agir através de dois receptores, o tipo 1 (AT1) e o tipo 2 (AT2). Com o intuito de estudar mutações dos genes dos receptores da AngII, foram avaliadas 50 crianças com diagnóstico de adrenarca precoce idiopática e comparadas ao grupo controle de indivíduos normais. Não foram detectadas mutações dos genes AGTR1 e AGTR2, contudo dois polimorfismos foram identificados no gene AGTR1: o polimorfismo C573T (localizado no exon 5) e o A1166C (na região 3' não codificadora). A freqüência do alelo polimórfico T573 foi de 35 por cento nos pacientes e 38 por cento nos controles. O alelo polimórfico C1166 esteve presente em 24 por cento dos pacientes e em 26 por cento dos controles. Não houve diferença significante entre os grupos, assim como não houve correlação entre a freqüência dos polimorfismos C573T e A1166C e as variáveis clínicas e laboratoriais dos pacientes, ou com sua história familial de síndrome metabólica.

Precocious pubarche is the appearance of pubic hair before the age of 8 years in girls and 9 years in boys. The most frequent etiology is idiopathic precocious adrenarche, suggested, after long-term follow-up, to be associated with metabolic syndrome. One of the factors involved in the genesis of precocious adrenarche is Angiotensin II (Ang II), which promotes cell proliferation and steroidogenesis through type 1 (AT1) and type 2 (AT2) receptors. In order to study Ang II receptors mutations, 50 children with idiopathic precocious adrenarche were evaluated and compared to a control group of normal individuals. Mutations were not detected in the AGTR1 and AGTR2 genes; however, two polymorphisms were identified in the AGTR1 gene: the C573T (exon 5) and the A1166C (3' untranslated region). The polymorphic allele T573 was found in 35 percent of the patients and 38 percent of controls. The polymorphic allele C1166 was present in 24 percent of the patients and 26 percent of controls. There was no statistical difference between groups. There was also no correlation between the polymorphisms and clinical and laboratory findings, as well as their family history of metabolic syndrome.

Analysis of Enterovirus Genotypes Using Single-Strand Conformational Polymorphism / 대한임상미생물학회지

BACKGROUND: Epidemics of aseptic meningitis due to enteroviruses has occurred annually in the late spring and early summer season. The early detection of such epidemics is important for the prevention of further infection. Enteroviruses consist of 67 serotypes but one or two serotypes may be the causative agents of epidemics in the year and several different serotypes involve sporadic cases. In order to discriminate epidemics from sporadic infection, the serotype should be determined. We evaluated the significance of the single-strand conformational polymorphism (SSCP) of reverse transcription-polymerase chain reaction (RT-PCR) products of 5'-untranslated region (UTR) for the determination of serotypes. METHODS: The specimens of patients were cultured with RD cell and the RT-PCR was performed in case of the positive cytopathic effect. For the amplification of 153-bp of 5'-UTR, primers (EN1: 5'-CTC CGG CCC CTG AAT GCG GCT AAT-3'; EN2: 5'-ATT GTC ACC ATA AGC AGC CA-3') were used. The RT-PCR products were denatured with 95% formamide at 95degrees C for 5 min and SSCP was performed. 12.5% polyacrylamide gel (49/1 acrylamide/bis) was made by using Mighty SmallTM SE245 Dual Gel Caster (Hoefer Scientific Instruments Inc., USA). Electrophoresis was done at 10 mA for 1.5 h, and silver nitrate stain was performed. The SSCP patterns were compared with serotypes determined by sequence analysis of VP1 region. RESULTS: Coxsackievirus A9 (two strains), coxsackievirus A16 (10), coxsackievirus B2 (two), coxsackievirus B3 (two), echovirus 3 (two), echovirus 11 (two), echovirus 16 (seven), echovirus 19 (two), echovirus 30 (three), and enterovirus 71 (six) showed the different SSCP patterns according to their serotypes. The same pattern was observed in the same serotype, except echovirus 30 showing two different patterns. CONCLUSIONS: The SSCP of RT-PCR products of 5'-UTR may be helpful to determine the serotype and discriminate epidemics from sporadic cases. This has the advantage to be able to test the specimens directly without the viral culture. But the serotype should be determined by other method such as neutralization or sequence analysis in case of the first isolate in the epidemic season and the stains showing the new SSCP patterns.

Detection of Mutations in the Wilms' Tumor Gene (WT1) in Leukemias / 中国医师杂志

Objective To analyze mutations in the Wilms tumor gene (WT1) in Ieukemogenesis.Methods WT1 gene in peripheral blood was determined by PRC-SSCP technique,in 32 cases of acute leukemia,included 9 cases of acute granulocytic leukemia,8 cases of chronic granulocytic leukemia(mean age-33 years) and 16 specimens of normal subjects were also detected.Results Mutations in the WT1 gene in 3 of 32 leukemias were found .WT1 mutations were found in 11% of cases of acute lymphoblastic leukemia and in 13% of cases of acute myeloid leukemia,in which they were associtated with a poor response to chemotherapy.Conclusions The mutations in Wilms tumor gene WT1 are associated with leukemogenesis and its therapy,which WT1 transcripts may prove a significant tumor marker, as a MRD monitor in evaluating remission status and early relapse,and may be useful in prognosis of acute leukemia.

Molecular Diagnosis of Cutaneous T Cell Lymphoproliferative Diseases

It is often problematic to diagnose T-cell lymphoproliferative disorders of the skin because of the difficulty in establishing clonality in paraffin-embedded tissue. We used polymerase chain reaction single strand conformational polymorphism (PCR-SSCP) and heteroduplex analysis in paraffin embedded tissue to detect clonal rearrangement of T-cell receptor gamma (TCRgamma) gene in 17 T-cell lymphoproliferative disorders and 6 atypical lymphoproliferative diseases. We used polymerase chain reaction to detect TCR beta gene rearrangement in 8 of 17 cases which did not show TCRgamma gene rearrangement. Jurkat cell lines were used as monoclonal controls. DNA was extracted from 5 biopsies of T-cell lymphomas, 10 biopsies of mycosis fungoides, 2 biopsies of lymphomatoid papulosis, and 6 biopsies of atypical lymphoproliferative lesions. We detected monoclonality in 5 of 5 T-cell lymphoma cases, 2 of 2 lymphomatoid papulosis cases, 6 of 10 mycosis fungoides cases, and 2 of 6 atypical lymphoproliferative disease cases. We conclude that nonradioactive PCR-SSCP for TCR gene rearrangement analysis is a useful adjunct to routine histological and immunophenotypic methods in the diagnosis of cutaneous T cell lymphoproliferative disorders in paraffin embedded tissue.