Nueva reacción en cadena de la polimerasa múltiple para el diagnóstico específico de especies implicadas en la candidiasis humana / A new multiplex PCR for species-specific diagnosis of human candidiasis

RESUMEN Introducción. Las candidiasis son un grupo de infecciones oportunistas causadas por levaduras del género Candida. Candida albicans es la especie de mayor prevalencia en las infecciones superficiales y profundas. Sin embargo, en la última década, la frecuencia de especies diferentes a C. albicans ha aumentado y, por ende, su relevancia clínica, lo cual exige la utilización de técnicas diagnósticas que permitan su detección y el tratamiento adecuado de los pacientes afectados. Objetivo. Diseñar y optimizar una técnica de reacción en cadena de la polimerasa múltiple (PCR múltiple) considerando parámetros termodinámicos para la detección simultánea de cinco especies de Candida relevantes en la etiología de la candidiasis humana. Materiales y métodos. Para el diseño de los cebadores se consideraron restricciones físicas y termodinámicas que afectan la PCR múltiple, usando el programa Gene Runner y la herramienta Mult-PSOS. Como plantillas se utilizaron la región transcrita interna 2 (ITS2) (AJ249486.1) para C. albicans y la topoisomerasa II (TOPII) para C. parasilopsis (AB049144.1), C. krusei (AB049139.1), C. tropicalis (AB049141.1) y C. guillermondii (AB049145.1), y como moldes, extractos de ADN total obtenidos de cepas ATCC y de aislamientos clínicos de las especies de Candida. Resultados. Se diseñaron diez cebadores para la amplificación simultánea de las especies de Candida. Se obtuvo el siguiente patrón de bandas: C. albicans (206 pb), C. guillermondii (244 pb), C. tropicalis (474 pb), C. parasilopsis (558 pb) y C. krusei (419 pb). Conclusión. El ensayo diseñado de PCR múltiple permitió la amplificación simultánea y eficiente de todos los amplicones correspondientes a las especies estudiadas de Candida, así como su adecuada resolución en gel de agarosa al 1,3 %.

ABSTRACT Introduction: Candidiases is a group of opportunistic infections caused by yeasts belonging to the genus Candida. Candida albicans is the most prevalent species in both superficial and deep infections, however, the clinical importance of non-albicans Candida has increased during the last decade, driving an urgent need for diagnostic tests that allow for species-level resolution and selection of the optimum therapeutic approach. Objective: To design and to optimize a new multiplex PCR assay for the simultaneous identification of the five most relevant species of Candida involved in human candidiasis etiology. Materials and methods: For primers design, the physical and thermodynamic restrictions that affect multiplex PCR performance were analyzed using Gene Runner and Mult-PSOS. As templates, the internal transcribed region 2 (ITR2) was selected for C. albicans (AJ249486.1), and topoisomerase II (TOPII) for C. parasilopsis (AB049144.1), C. krusei (AB049139.1), C. tropicalis (AB049141.1), and C. guillermondii (AB049145.1). We used ATCC strains of all these five species and clinical isolates as templates. Results: We designed ten oligonucleotides for the simultaneous amplification of the Candida species. The electrophoresis band profile was: C. albicans (206 bp), C. guillermondii (244 bp), C. tropicalis (474 bp), C. parasilopsis (558 bp), and C. krusei (419 bp). Conclusion: The new multiplex PCR assay designed in this study allowed a simultaneous and efficient amplification of the amplicons corresponding to the five species of Candida under study, with an adequate resolution in standard agarose gel.

Effect of Nitric Oxide on the Expression of Matrix Metalloproteinase and Its Association with Migration of Cultured Trabecular Meshwork Cells

PURPOSE: To determine the effect of exogenous nitric oxide (NO) on the migration of trabecular meshwork (TM) cells and its association with expression of matrix metalloproteinases (MMPs). METHODS: Primary human TM cells treated with 1 or 10 microM S-nitroso-N-acetyl-penicillamine (SNAP) and examined for changes in adherence. TM cells were seeded onto transwell culture inserts, and changes in their migratory activity were quantified. Reverse transcription polymerase chain reaction was performed to determine the relative changes in mRNA expression of MMPs and tissue inhibitor of metalloproteinases (TIMPs). RESULTS: Treatment with SNAP did not significantly suppress TM cell adhesion or migration (p > 0.05). Treatment of TM cells with 10 microM SNAP decreased expression of MMP-2 and increased expression of membrane type MMP-1 and TIMP-2. Treatment with interleukin-1alpha triggered MMP-3 expression but did not exert significant effects on MMP-3 activation in response to SNAP. CONCLUSIONS: These data suggest that NO revealed no significant effect on the migration of TM cells because NO decreased MMP-2 and increased TIMP-2 expression. Although expression of certain MMPs and TIMPs change in response to NO donors, NO may modulate trabecular outflow by changing the cellular production of extracellular matrix without having a significant effect on the migration of TM cells.

Effect of Super-Oxidized Water, Sodium Hypochlorite and EDTA on Dentin Microhardness

The present study aimed to evaluate the influence of the following irrigating solutions on the microhardness of root canal dentin: 2% sodium hypochlorite (2NaOCl), 5% sodium hypochlorite (5NaOCl), super-oxidized water (400 ppm Sterilox - Sx) and 17% EDTA (E). Eighty roots from bovine incisors were randomly divided into 8 groups (n=10): 2NaOCl, 5NaOCl, Sx, and 2NaOCl + E, 5NaOCl + E, Sx + E (associated with E as final irrigant for 5 min), E solely and distilled water (dH2O) as the negative control. Root canal preparation was performed by hand instruments, using one of the irrigation protocols for 30 min. Then, 5 mm of the cervical root third were cut out from each sample and subjected to the Vickers microhardness test, at two points, one at approximately 500-1000 µm from the root canal lumen (distance 1), and the other at approximately 500-1000 µm from the external root surface (distance 2). Data were analyzed by Wilcoxon and Kruskal-Wallis tests at 5% significance level. Microhardness values at distance 1 were significantly lower than those at distance 2 for all groups, except 5NaOCl and 5NaOCl + E groups (p>0.05). EDTA showed the lowest microhardness values. However, no statistically significant difference was detected among groups at distance 1 and EDTA was significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness at the most superficial root canal dentin layer compared to the one found near the external root surface, except 5NaOCl and 5NaOCl + E; EDTA promoted lower microhardness values in comparison to Sterilox at this site.

O presente estudo teve como objetivo avaliar a influência das seguintes soluções irrigadoras na microdureza da dentina do canal radicular: hipoclorito de sódio a 2% (NaOCl2), hipoclorito de sódio a 5% (NaOCl5), água superoxidada (Sterilox(r) 400 ppm - Sx) e EDTA a 17% (E). Oitenta raízes de incisivos bovinos foram divididas aleatoriamente em 8 grupos (n=10): NaOCl2, NaOCl5, Sx e NaOCl2 + E, NaOCl5 + E, Sx + E (associados ao E como irrigante final por 5 min), E isolado e água destilada (H2Od), como controle negativo. O preparo dos canais radiculares foi realizado com instrumentos manuais, usando um dos protocolos de irrigação por 30 min. A seguir, 5 mm do terço cervical de cada amostra foram cortados perpendicularmente e submetidos ao teste de microdureza de Vickers, em dois pontos, um aproximadamente 500-1000 µm da luz do canal radicular (distância 1), e o outro aproximadamente 500-1000 µm da superfície externa da raiz (distância 2). Os dados foram analisados pelos testes de Wilcoxon e Kruskal-Wallis com um nível de significância de 5%. Os valores de microdureza na distância 1 foram significativamente menores do que na distância 2 para todos os grupos, exceto NaOCl5 e NaOCl5 +E (p>0,05). O EDTA mostrou os menores valores de microdureza. No entanto, não foi detectada diferença estatisticamente significativa entre os grupos na distância 1 e o EDTA foi significativamente diferente apenas do Sx na distância 2. Pode-se concluir que todas as soluções testadas mostraram menor microdureza na camada de dentina mais superficial do canal radicular em comparação aos valores encontrados próximo à superfície radicular externa, exceto NaOCl5 e NaOCl5 + E; o EDTA promoveu menor microdureza em comparação ao Sterilox(r) neste ponto.

In planta detection of Xanthomonas axonopodis pv. commiphorae using fyuA and rpoD genes.

Guggal is tapped for extraction of medicinally important oleo–gum–resin (guggul) by inoculating the stem bark with natural gum suspension containing pathogenic bacterium Xanthomonas axonopodis pv. commiphorae (Xac). The tree dies in the process. In absence of any specific medium for isolation of Xac, it is difficult to assess spread of the pathogen within the plant. A PCR based molecular detection technique using fyuA and rpoD gene specific primers is described here. The primers amplified products only from Xac and not from host tissues or common saprophytes. The method was sensitive enough to produce positive signals for up to 4.4 bacterial cells or 2 pg target DNA per reaction mixture. However, PCR inhibitors present in plant tissues drastically reduced the limit of detection. A simple overnight incubation of surface sterilised plant tissues in nutrient medium was introduced to increase pathogen titre and to overcome this problem. This technique was successfully used to measure spread of Xac in plant tissues away from the site of inoculation. The pathogen showed preference for acropetal movement and did not spread to 7–8 cm below the site of inoculation till 15 days after inoculation. This suggests possibility to manage the disease through plant surgery.

Frequency of FCGR3B Alleles in Thai Blood Donors

BACKGROUND: Human neutrophil antigens (HNAs) are involved in autoimmune and alloimmune neutropenia and transfusion-related acute lung injury. The HNA-1 system is important in immunogenetics, and allele frequencies have been described in different populations. This study investigated the frequency of FCGR3B alleles encoding HNA-1a, HNA-1b, and HNA-1c among Thai blood donors and compared these frequencies with those previously reported for other populations. METHODS: Eight hundred DNA samples obtained from unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok, and the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, were included. Samples were simultaneously typed for each FCGR3B allele using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. RESULTS: The frequencies of FCGR3B*1, FCGR3B*2, and FCGR3B*3 alleles in central Thai blood donors were 0.548, 0.452, and 0.004, respectively; only FCGR3B*1 and FCGR3B*2 alleles were found in northern Thai blood donors (0.68 and 0.32, respectively). Compared with other Asian populations, central Thais had higher frequencies of the FCGR3B*2 allele (P<0.001), while the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in northern Thais were similar to those previously reported in Taiwanese and Japanese populations. In contrast, the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in the northern Thai population were statistically different from those observed in central Thai, Korean, German, and Turkish populations. CONCLUSIONS: FCGR3B allele frequencies were significantly different between central and northern Thai blood donors. Our in-house PCR-SSP method is a simple, cost-effective, and convenient method for FCGR3B allele detection.

Application of Single-nucleotide Polymorphism and Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats Analyses to Clinical Mycobacterium tuberculosis Isolates from Korea / 대한진단검사의학회지

BACKGROUND: Single-nucleotide polymorphism (SNP) analysis is a powerful strategy for large-scale molecular population studies examining phylogenetic relationships among bacterial strains. Mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) can be easily digitized to share data among laboratories. This study applied SNP and MIRU-VNTR analyses for molecular strain typing of Mycobacterium tuberculosis isolates collected throughout Korea. METHODS: We studied 102 clinical M. tuberculosis isolates, including 6 paired strains, collected from 11 university hospitals in Korea in 2008 and 2009. SNPs were detected using hairpin primer assays, and then, MIRU-VNTR analysis was performed. RESULTS: Thirty-five SNPs contained polymorphisms that helped differentiate the 96 tested isolates. The isolates were classified into 15 clusters. The Beijing family strains were distributed within closely related clusters in the SNP dendrogram. For MIRU-VNTR analysis, the 96 isolates were divided into 12 groups. The discriminatory index in 8 of these groups (MIRU-10, -23, -26, and -31; ETR-A, -B, -C, and -F) was high (Hunter-Gaston diversity index > 0.6). Unlike the SNP method, MIRU-VNTR analysis did not identify any notable localizations of Beijing or non-Beijing family isolates in specific clusters. CONCLUSIONS: SNP and MIRU-VNTR analyses are surrogate molecular strain-typing methods for M. tuberculosis in Korea where Beijing family isolates are predominant.

Streptococcus pneumoniae Type Determination by Multiplex Polymerase Chain Reaction

The purpose of this study was to develop pneumococcal typing by multiplex PCR and compare it with conventional serotyping by quellung reaction. Pneumococcal strains used in this study included 77 isolates from clinical specimens collected from children at Seoul National University Children's Hospital from 2006 to 2010. These strains were selected as they represented 26 different serotypes previously determined by quellung reaction. Molecular type was determined by 8 sequential multiplex PCR assays. Bacterial DNA extracted from cultured colonies was used as a template for PCR, and primers used in this study were based on cps operon sequences. Types 6A, 6B, 6C, and 6D were assigned based on the presence of wciNbeta and/or wciP genes in 2 simplex PCRs and sequencing. All 77 isolates were successfully typed by multiplex PCR assays. Determined types were as follows: 1, 3, 4, 5, 6A, 6B, 6C, 6D, 7C, 7F, 9V, 10A, 11A, 12F, 13, 14, 15A, 15B/15C, 19A, 19F, 20, 22F, 23A, 23F, 34, 35B, and 37. The results according to the PCR assays were in complete concordance with those determined by conventional quellung reaction. The multiplex PCR assay is highly reliable and potentially reduces reliance upon conventional serotyping.

Clinico-Genetic Study of Nail-Patella Syndrome

Nail-patella syndrome (NPS) is an autosomal dominant disease that typically involves the nails, knees, elbows and the presence of iliac horns. In addition, some patients develop glomerulopathy or adult-onset glaucoma. NPS is caused by lossof- function mutations in the LMX1B gene. In this study, phenotype-genotype correlation was analyzed in 9 unrelated Korean children with NPS and their affected family members. The probands included 5 boy and 4 girls who were confirmed to have NPS, as well as 6 of their affected parents. All of the patients (100%) had dysplastic nails, while 13 patients (86.7%) had patellar anomalies, 8 (53.3%) had iliac horns, 6 (40.0%) had elbow contracture, and 4 (26.7%) had nephropathy including one patient who developed end-stage renal disease at age 4.2. The genetic study revealed 8 different LMX1B mutations (5 missense mutations, 1 frame-shifting deletion and 2 abnormal splicing mutations), 6 of which were novel. Genotype-phenotype correlation was not identified, but inter- and intrafamilial phenotypic variability was observed. Overall, these findings are similar to the results of previously conducted studies, and the mechanism underlying the phenotypic variations and predisposing factors of the development and progression of nephropathy in NPS patients are still unknown.

Mutations of KRAS and TP53 in a minor proportion of Opisthorchis viverrini-associated cholangiocarcinomas in a hamster model.

BACKGROUND/AIMS: KRAS oncogene and TP53 tumor suppressor gene have been known as common genes involving in many cancers including cholangiocarcinoma (CCC). Activation of these genes could lead to uncontrolled proliferation and cancer ultimately. The aim of this study was to investigate mutation of KRAS exon 1 and TP53 exon 5-8 in Opisthorchis viverrini (OV)-induced cholangiocarcinoma (CCA) in a hamster model. METHODS: Twenty-seven CCAs were obtained from Syrian golden hamsters induced by OV infection and N-nitrosodimethylnitrosamine (N-NDDM) administration. The tumor tissues were processed for histopathology. Genomic DNA extracted from paraffin sections by microdissection was amplified for KRAS exon 1 and TP53 exon 5-8 mutations by PCR-direct sequencing. RESULTS: Histopathologically, the tumors were classified into tubular (81.5%, 22/27), papillary (3.7%, 1/27), mucinous (3.7%, 1/27) and mixed types (11.1%, 3/27). Of the 27 CCAs, PCR-direct sequencing of KRAS showed G[see text]A transition at codon 37 exon 1 in one CCA sample (3.70%). Point mutations of p53 exon 6 (G[see text]C transversion at codon 119 and 218 and A[see text]C transversion at codon 217) were found in 3 CCA samples (11.1%). CONCLUSIONS: The results suggest that mutation of TP53 particularly at exon 6 may be involved in cholangiocarcinogenesis and a novel mutation of KRAS exon 1 was firstly reported in OV-induced hamster CCA.

PCR-based detection of microcystin-producing cyanobacterial blooms from Central India.

Microcystin synthetase-gene-specific primers were used to identify hepatotoxic microcystin producing genotypes in six Microcystis spp.-dominant water blooms. Four blooms gave positive PCR reaction. They produced microcystin-RR and -LR amounting to 0.037 to 0.095% of the dry mass.

Genetic evaluation of the HSP70 protein in the japanese quail (Coturnix japonica)

Heat stress is one of the main problems in modern aviculture, since it affects birds especially in the final phase of rearing, causing bird mortality and economic losses to the aviculturist. The quail, as most birds, has difficulties in dissipating heat. However, little is known about the mechanism that controls the responses of the organism to stressor agents. Therefore, the study of heat shock proteins (HSPs) in these birds is important. A 960-bp portion of HSP70 was amplified using oligonucleotide primers specific for chickens. The fragment was sequenced, since it was the same protein, although some modifications have been observed. It showed 98% homology with HSP70 stress protein in Gallus gallus and 99% homology with Numida meleageris.

Relationship between the expression of RASSF1A protein and promoter hypermethylation of RASSF1A gene in bladder tumor / 华中科技大学学报（医学）（英德文版）

To investigate the relationship between the expression of RASSF1A protein and promoter hypermethylation of RASSF1A gene, RASSF1A protein expression was measured by Western blotting in 10 specimens of normal bladder tissues and 23 specimens of bladder transitional cell carcinoma (BTCC). The promoter methylation in BTCC and normal bladder tissues was detected by methylation-specific PCR (MSP). The results showed that the expression level of RASSF1A protein was significantly lower in BTCC tissues than that in normal bladder tissues. However, it was not correlated with its clinical stages and pathological grades. The frequency of promoter methylation of RASSF1A gene was higher in BTCC tissues than that in normal bladder tissues. In 14 patients with the aberrant promoter methylation, 13 showed loss or low expression of RASSF1A protein. It is concluded that RASSF1A gene promoter methylation may contribute to the low level or loss of RASSF1A protein expression, the inactivation of RASSF1A gene and the genesis of BTCC. But, it may bear no correlation with its clinical stages and pathological grades.

Identification and distribution of the clinical isolates of imipenem-resistant Pseudomonas aeruginosa carrying metallo-beta-lactamase and/or class 1 integron genes / 华中科技大学学报（医学）（英德文版）

To investigate the distribution of the genes of two major metallo-beta-lactamases (MBL; i.e., IMP and VIM) and class 1 integrons (intI) in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates, from a university hospital in Sichuan between December 2004 and April 2005 were screened for MBL genes by PCR using primers specific for bla ( IMP-1 ), bla ( VIM ) and bla ( VIM-2 ) genes. The MBL-positive isolates were further assessed for class 1 integrons by PCR using specific primers. The nucleotide sequences of several PCR products were also determined. The results revealed that the bla ( VIM ) gene was found in 81.5% (53/65) of all isolates, bla ( VIM-2 ) gene was found in only 1 isolate and the intI gene was observed in 45.3% (24/53) of bla ( VIM )-positive isolates. One isolate carried simultaneously both bla ( IMP-1 ) and intI genes, and to the best of our knowledge this is the first report of such isolate in southwest China. These observations highlight that the genes for VIM beta-lactamase and class 1 integrons were predominantly present among the imipenem-resistant P. aeruginosa tested, confirming the current widespread threat of imipenem-resistant, integron-borne P. aeruginosa.

Functional characteristics and molecular identification of swelling-activated chloride conductance in adult rabbit heart ventricles / 华中科技大学学报（医学）（英德文版）

Outwardly rectifying swelling-activated chloride conductance (ICl,Swell) in rabbit heart plays a critical role in cardioprotection following ischemic preconditioning (IP). But the functional characterization and molecular basis of this chloride conductance in rabbit heart ventricular myocytes is not clear. Candidate chloride channel clones (e.g. ClC-2, ClC-3, ClC-4 and ClC-5) were determined using RT-PCR and Western blot analysis. Whole cell ICl,Swell was recorded from isolated rabbit ventricular myocytes using patch clamp techniques during hypo-osmotic stress. The inhibitory effects of 4,4' isothiocyanato-2,2-disulfonic acid (DIDS), 5-nitro-2(3-phenylroylamino) benzoic acid (NPPB) and indanyloxyacetic acid 94 (IAA-94) on ICl,Swell were examined. The expected size of PCR products for ClC-2, ClC-3 and ClC-4 but not for ClC-5 was obtained. ClC-2 and ClC-3 expression was confirmed by automated fluorescent DNA sequencing. RT-PCR and Western blot showed that ClC-4 was expressed in abundance and ClC-2 was expressed at somewhat lower levels. The biological and pharmacological properties of I(Cl,Swell), including outward rectification, activation due to cell volume change, sensitivity to DIDS, IAA-94 and NPPB were identical to those known properties of ICl,Swell in exogenously expressed systems and other mammals hearts. It was concluded that ClC-3 or ClC-4 might be responsible for the outwardly rectifying part of ICl,Swell and may be the molecular targets of cardioprotection associated with ischemic preconditioning or hypo-osmotic shock.

Efficient Cultivation Conditions for Human Limbal Epithelial Cells

To compare the stem niche in different culture conditions of limbal epithelial cells, the suspended human limbal epithelial cells (HLECs) were seeded on the 3T3-pretreated plates and the other suspended cells were plated on amniotic membranes (AMs) which were either cryo-preserved or freeze-dried. All were cultured for 10 to 12 days. Reverse transcription-polymerase chain reaction (RT-PCR) for ATP-binding casette, subfamily G, member 2 (ABCG2), p63, cytokeratin 12, and connexin 43 were performed in cultivated HLECs and their expression levels were compared. The mRNA expression of all markers examined showed no statistically significant differences between the cells on cryo-preserved and on freeze-dried AM. The expression of p63 and cytokeratin 12 in cultivated cells on AMs were significantly lower than those in 3T3-cocultured cells on RT-PCR and immunofluorescent staining. Cultivated HLECs on AMs showed reduced proliferation and differentiation while maintaining stem-property regardless of the preservative method of AM.

Deteção de Mycobacterium tuberculosis em amostras clínicas por reação em cadeia da polimerase utilizando primers baseados na região intergênica plcB-plcC / Using polymerase chain reaction with primers based on the plcB-plcC intergenic region to detect Mycobacterium tuberculosis in clinical samples

OBJECTIVE: To develop a system for the molecular diagnosis of tuberculosis by polymerase chain reaction (PCR), constructing primers based on the difference in gene organization of the intergenic region of phospholipase C (plcB-plcC region), which differentiates Mycobacterium tuberculosis from other mycobacteria. METHODS: A PCR product of the expected size (432 bp) was obtained from M. tuberculosis and M. africanum only. A total of 33 mycobacterial isolates and 273 clinical samples from patients suspected of having tuberculosis were examined. These were used in the comparative study of the PCR technique versus culture. RESULTS: For PCR versus culture, the data showed 93.8 percent accuracy (p < 0.0001), 93.1 percent sensitivity (CI: 88.7-96.0), and 96.4 percent specificity (CI: 96.1-99.4). The Kappa value (0.82) shows that there was a near-perfect concordance between the two tests. CONCLUSION: The use of the plcB-plcC region in PCR amplification was found to be an important and reliable tool for the specific diagnosis of tuberculosis in the samples analyzed.

OBJETIVO: Desenvolver um sistema para o diagnóstico molecular da tuberculose por reação em cadeia da polimerase, do inglês polymerase chain reaction (PCR), pela construção de primers baseados na diferença da organização de uma região intergênica da fosfolipase (phospholipase) C (região plcB-plcC), que diferencia Mycobacterium tuberculosis das outras micobactérias. MÉTODOS: Um produto de PCR com o tamanho esperado (432 pb) foi obtido somente de M. tuberculosis e M. africanum. Um total de 33 isolados micobacterianos e 273 amostras clínicas de pacientes com suspeita de tuberculose foram examinados. Estes foram submetidos ao estudo comparativo da técnica de PCR contra o cultivo. RESULTADOS: Os dados mostraram 93,8 por cento de exatidão para PCR contra o cultivo (p < 0,0001), 93,1 por cento de sensibilidade (IC: 88,7-96,0) e especificidade de 96,4 por cento (IC: 96,1-99,4). O valor de Kappa foi de 0,82, demonstrando um alinhamento perfeito para a verificação do grau de concordância entre os testes. CONCLUSÃO: O uso da região plcB-plcC para a amplificação por PCR é mostrado como uma ferramenta importante e de confiança para o diagnóstico específico de tuberculose nas amostras clínicas analisadas.

Evaluation of DNA extraction methods and real time PCR optimization on formalin-fixed paraffin-embedded tissues.

Formalin-fixed, paraffin-embedded (FFPE) tissues are the most invaluable source of diagnostic material for studying pathogenesis of cancer and a variety of other diseases. Unfortunately, DNA extracted from formalin fixed tissues is highly degraded due to cross-linking between nucleic acid strands. Real Time PCR has become the standard for gene copy as well as RNA transcript determination. Thus, optimum standardization of Real Time PCR is crucial for obtaining accurate quantification for both research as well as for clinical diagnosis. However there are various factors which have negative impact . The aim of our study was to establish a simpler method of extraction and Real Time PCR Optimization for FFPE extracted DNA. Five breast cancer tissues that were formalin fixed and paraffin embedded were used for DNA extraction with four different methods. Extracted DNA was amplified with different primer sets that gave amplimers of different size. Optimization of Real Time PCR for EMSY, cyclin D1 and beta-globin genes was carried out on DNA obtained using heat treatment protocol for annealing temperature, primer concentration and template concentration. Highest quantity of DNA was obtained without the use of expensive reagents and in short time frame. PCR positivity was observed in case of shorter amplimer up to 250 bp in length. Amplimers of higher length failed to amplify with paraffin extracted DNA. Optimum annealing temperature for EMSY, Cyclin D1 and beta-globin genes were 60 degrees C, 60 degrees C and 61 degrees C respectively. Good results were seen with a primer concentration of 300 nM and 5 ng of template DNA. This study indicates that DNA obtained from formalin fixed paraffin embedded tissue is highly fragmented and can be used for successful amplification of shorter amplification products up to 250 bp in length. Optimization of real time PCR is important, especially while using SYBR green dye chemistry.

Study of genetic divergence among wheat genotypes through random amplified polymorphic DNA

The degree of genetic divergence was estimated in seven wheat genotypes, six exotic genotypes and one local variety, through random amplified polymorphic DNA methodology. A total of 112 DNA fragments were generated by the 15 random primers, with an average of about 7.4 bands per primer. Among the 112, 50 fragments showed polymorphism among the seven wheat genotypes. Nei and Li’s similarity matrix ranged from 86.2 to 93.0%, which indicated a narrow genetic base among the genotypes. The maximum similarity, 93.0%, was observed between 12WLRG/1-12 and WL-43. The local variety, Chenab-70, showed the lowest similarity with the exotic types. We conclude that random amplified polymorphic DNA analysis can be used for the characterization and grouping of wheat genotypes; these results will be helpful in our wheat breeding program.

Evaluation of genetic diversity in a natural rosewood population (Dalbergia nigra Vell. Allemão ex Benth.) using RAPD markers

Dalbergia nigra (rosewood) is a long-lived leguminous species, which is endemic to the Brazilian Atlantic forest. Because of the high economic value of its wood, this species has been over-explored in recent years. Currently, rosewood is included in the IUCN Red List as vulnerable. We examined the genetic diversity of 87 specimens of D. nigra sampled from a continuous forest in the Veracel Reserve and Brazilwood Ecological Station, Porto Seguro, Bahia state, with random amplified polymorphic DNA markers. Grouping analyses were done using unweighted pair group method with arithmetic averages. Using the 16 most informative primers, 112 markers were obtained; 39% (44 bands) were polymorphic. A genetic similarity matrix was made based on the polymorphic bands. The dispersion graph and dendrogram analyses showed three distinct sub-populations. The degree of polymorphism was high, near that of other populations of similar species; however, it was considered low for the conservation of this species.

Molecular phylogeny of parasitic Platyhelminthes based on sequences of partial 28S rDNA D1 and mitochondrial cytochrome c oxidase subunit I

The phylogenic relationships existing among 14 parasitic Platyhelminthes in the Republic of Korea were investigated via the use of the partial 28S ribosomal DNA (rDNA) D1 region and the partial mitochondrial cytochrome c oxidase subunit 1 (mCOI) DNA sequences. The nucleotide sequences were analyzed by length, G + C %, nucleotide differences and gaps in order to determine the analyzed phylogenic relationships. The phylogenic patterns of the 28S rDNA D1 and mCOI regions were closely related within the same class and order as analyzed by the PAUP 4.0 program, with the exception of a few species. These findings indicate that the 28S rDNA gene sequence is more highly conserved than are the mCOI gene sequences. The 28S rDNA gene may prove useful in studies of the systematics and population genetic structures of parasitic Platyhelminthes.