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Bệnh lý rối loạn tăng cholesterol máu ở dạng có tính chất gia đình (FH) với nguyên nhân là sự xuất hiện đột biến tác động đến chức năng của gene APOB và LDLR. Nghiên cứu phân tích đặc điểm phân tử tập trung ở vùng trình tự exon 26 gene APOB và exon 4 gene LDLR trên người bệnh tăng cholesterol máu ở Việt Nam, bằng phương pháp PCR kết hợp với giải trình tự. Trên bộ mẫu bệnh phẩm máu (37 mẫu), nghiên cứu ghi nhận tỷ lệ đột biến trên gene APOB là 32.42%, gene LDLR là 35.10%, đột biến xuất hiện đồng thời trên gene APOB và LDLR có tỷ lệ 10.81% trong 37 mẫu tăng cholesterol máu. Một số dạng biến thể mới, đặc trưng xuất hiện trên DNA bộ gen người bệnh tăng cholesterol máu ở Việt Nam, cụ thể là c.10550C>G (p.A3517G), c.10575C>A (p.S3525R) và c.10560C> (p.Y3520*) ở gene APOB; c.21038C>T (p.P171L), c.21001A>T (p.T159S) và insC376 (c.ins20903C) ở gene LDLR. Kết quả nghiên cứu là cơ sở khoa học thực tiễn, hỗ trợ phát triển công cụ sàng lọc, chẩn đoán sớm bệnh lý tăng choleslesterol máu - bệnh FH ở Việt Nam.

Background: The objective of this study was to estimate the correlation between the Ecadherin (CDH1) promoter methylation and the risk of nasopharyngeal cancer. Methods: Based on previous online articles for the evaluation the hypermethylated status of CDH1 gene at the promoter region with nasopharyngeal carcinoma, two independent reviewers selected studies through databases on PubMed, Google Scholar from 2001 to 2014. The software MedCalc® version 18.11 was applied for calculating pooled odd ratios (OR) with levels of data heterogeneity by the fixed and random effects models. Results: Of a total of 99 articles, 12 studies with 508 clinical samples of nasopharyngeal carcinoma patients and 282 normal samples were selected in the systematic review for meta-analysis. Overall, the results demonstrated the highly significant association between CDH1 promoter methylation with nasopharyngeal carcinoma under the fixed effects model (OR = 16.155, 95% CI: 8.533 - 30.585, p

Purpose: Death-associated protein kinase (DAPK or DAPK1) is an important tumor suppressor protein that involved in the regulation of cell activities. The aberrant methylation of DAPK promoter has been reported in patients with cervical cancer. However, the association between of DAPK1 and cervical cancer was not always unification, in previous studies. Therefore, in current study, a meta-analysis was performed for association of between DAPK gene’s promoter hypermethylated and cervical cancer. Methods: A systematic literature analysis was conducted based on the previous studies published in PubMed, PubMed Central (NCBI), Google by using following keywords: cervical cancer, cervical carcinoma, Methylation, by the end of January, 2018. The association between DAPK promoter methylation and cervical cancer was evaluated by odds ratio (ORs) and 95% confidence intervals (CI). To evaluate the potential sources of heterogeneity, the meta-regression analysis and subgroup analysis were conducted. Results: A total of 21 case-control studies which relevant to the association between DAPK1 gene’s promoter methylation frequency and cervical cancer, that including 1600 cancer cases and 1011 control cases (non-cancerous cases). The analysis results indicated that the characteristic of candidate gene’s promoter methylation increased the cervical cancer risk through the calculation of OR value (OR = 21.25; 95% CI = 8.73 – 52.97; p < 0.001; Random effect model). The association between DAPK1 gene’s promoter hypermethylation was confirmed in all the subgroups analyses, including materials and assays methods, ethnicity. Furthermore, this association is higher in cervical squamous cell carcinoma than cervical adenocarcinoma and is a characteristic of late-stage disease. Conclusion: The hypermethylated DAPK1 gene’s promoter was also one of etiological factor, lead to the cervical tumorigenesis.

The association between promoter hypermethylation of Glutathione S-transferase P1 (GSTP1) and breast cancer has been investigated by much previous research worldwide. However, the results of the correlation between the epigenetic features of human genes with breast cancer varied from study to study. The purpose of this study, therefore, is to use a meta-analysis to identify how the GSTP1gene’s promoter hypermethylation and breast cancer correlate to each other. Accordingly, 19 case-control studies were conducted to evaluate the association between GSTP gene’ promoter methylation status and breast cancer, including 1910 cancer cases and 671 control cases. The findings showed that the status of gene promoter methylation increased the candidate’s breast cancer risk by calculating the OR value (OR = 10,497; 95%CI = 4.42 -24.94; P < 0.0001; Random-effect meta-analysis). In addition, the re-collection of 13 case-control studies, including 1247 cancer cases and 369 control case, also showed an increase in the OR value (OR = 13,642; 95%CI = 8.23 -22.60; P < 0,001, Fixed-effect meta-analysis model). The association value also increased. Then, the hypermethylation characteristic of the GSTP1 gene’s promoter was observed in both tissue and blood samples, and at this level, it should be detected by many methods such as Methylation Specific PCR, MS-MLPA, Methylight and QMSP compared to Bisulfite methylation-specific PCR. The hypermethylated GSTP1 promoter was higher in Europeans and Africans than in Asians. Moreover, the hypermethylated GSTP1gene’s promoter is also found in breast cancer patients with high histopathology, large tumor size, lymph node and HER2 and at the terminal stage of the disease. The hypermethylated GSTP1gene’s promoter also results in the reduced expression and activity of GSTP1 protein.

Food poisoning, caused by a bacterial infection, consequently led to a wide range of infections and endanger to public health, has been considered as a big concern in the world. Therefore, it is an urgent demand for the clinical laboratory to exactly identify infectious bacteria. In our previous study, we successfully published a protocol based on the PCR-Reverse Dot Blot (PCR-RDB) to determine simultaneously 12 bacterial intestinal pathogens, including Bacillus cereus, Clostridium botulinum, Clostridium perfringen, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157: H7, Salmonella spp., Shigella spp.., Vibrio cholerae, Vibrio parahaemolyticus, Yersinia enterocolitica and Brucella spp. In this study, we continuously developed our published protocol by designing additional probes: positive control probe, negative control probe, color control probe and background signal controller. Moreover, concerning the clinical demand, the supplement of two designed probes, which detected Campylobacter jejuni và Yersinia enterocolitica O:8 caused intestinal infected diseases mainly in children, was necessary. As a result, this completed PCR-RDB protocol can simultaneously detect a total of 14 intestinal bacterial pathogens within high specificity and the sensitivity of 102 copies/ml. For the protocol confirmation, it was tested by 30 fecal samples and the results completely match with the commercial kit PowerCheckTM 20 Pathogen Multiplex Real-time PCR Kit (Korea).

Intestinal infections which are the important public health concern worldwide, are caused by the bacterial intestinal pathogens. The aim at our study is to develop a simultaneous, rapid, sensitive and specific diagnostic assay by using a combined PCR-Reverse dot blot method for the identification of pathogen strains, including Bacillus cereus, Clostridium botulinum, Clostridium perfringen, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7, Salmonella spp., Shigella spp., Vibrio cholerae, Vibrio parahaemolyticus, Yersinia enterocolitica and Brucella spp. Based on the 16S and 23S DNA regions, the two sets of universal primers and twelve specific probes were obtained for amplification and specific detection of those twelve bacterial species. The initial experimental results using bacterial cultures and 50 clinical samples confirmed the in silico hypothesis that was previously established in universal primers and probes design as well as identified with some basic conditions for PCR and Reverse Dot Blot hybridization reactions. Thus, this procedure being further tested for the other kinds of samples such as fecal samples or foods.

Familial defective apolipoprotein B-100 (FDB) is an autosomal codominant disorder associated with hypercholesterolemia, caused by mutations in and around codon 3500 of the Apolipoprotein (Apo) B gene, which encodes Apo B-100. The first mutation occurred in Arginine codons to be described, and the most characterized, is caused by a G→A transition at nucleotide 10,708 and results in the substitution of Arginine by Glutamine at codon 3500 (ApoB R3500Q). In this study, we have identified 27 R3500Q mutations in known FDB patients using PCRSequencing method. As the result, most of the patients carried heterozygous mutation R3500Q. PCR-Sequencing method that we have applied in this study proved consistent and so easily identified mutations correctly.

Cervical cancer is the leading cause of cancer death in women in Vietnam. Virtually, cervical cancers are associated with infection of HPV (Human papilloma virus). In addition, inactivation of tumor suppressor genes (TSGs), leading by aberrant hypermethylation, an epigenetic mechanism, has been observed in cervical cancer development. Screening for early detection of cervical cancer is importantly increasing from Vietnam, therefore, in current study, we analyzed the aberrant methylation status of APC (Adenomatous polyposis coli) gene, its product has an important role in cell cycle control and maintenance of genomic stability, as the pattern of potential biomarker for cervical cancer in Vietnamese population. The liquid-based Pap test samples which were identified whether HPV-infected or low-risk HPV infected or nonHPV-infected were enrolled and analyzed by MSP (Methylation specific PCR). As the results, the hypermethylation of APC was reached to 75%, 12.5% and 30% in high-risk HPV genotype infected group, in low-risk HPV genotype infected group, and non-HPV genotype infection, respectively. Especially, the characteristic of high-risk HPV infection was also associated with the hypermethylation of candidate gene (p < 0.05). Moreover, the odds ratio and relative risk were found in the high value, counting for 10.5 (95%CI, 2.3 – 47.2) and 3.37 (95%CI, 1.3 – 8.3), respectively. In conclusion, these outcomes suggested that the aberrant hypermethylation of APC gene, which accessed in non-invasive samples, led to the potential biomarker and application in early prognosis and diagnosis to cervical cancer in Vietnamese population.

Insect-parastitic fungi, especially Cordyceps sinensis, parasitize larvae of insects, are used as traditional medicinal drugs in various Asian countries, including Vietnam. However, knowledge of taxonomy of these fungi is still limited, due to many factors such as the difficulties in the classification and identification. Recently, the identification of these fungi was improved by molecular and bioinformatic methods. In this preliminarystudy, first we want to establishthe protocol including DNA extraction, PCR, sequencing then proof-reading and phylogenetic tree construction. The target sequence used for this protocol is Internal transcribed spacer –ITS. The protocol is carried out using the sample set, in which the already identified results by morphology and molecular biology combined bioinformatics were in high corcordance. Therefore, this protocol will be applied in order to identifyinsect-parasitic fungi specimens collected from Langbian mountain, Dalat, Lamdong, Vietnam.

Recent publications showed that Lactic acid bacteria (LAB) are used extensively to inhibit growth of spoilage and pathogenic bacterial strains. That is being applied in food processing such as tradition fermented food or dairy, beverage and meat products. Lactic acid bacteria can produce a variety of antibacterial agents including bacteriocin, diacetyl, etc. Thus, the isolation, identification and taxonomical characterization of each new Lactobacillus sp. strain is being more and more required. However, the large number of species in the genus Lactobacillus almost have their high phenotypic and physiological similarity which easily leads to misidentification. The present study was aimed for isolation and reliable identification of Lactobacillus sp. strains from some traditional fermented foods by on the basis of phenotypic analysis and combination of PCR and sequencing of target sequences base on 16S-23S rRNA gene. Eight strains of LAB were isolated and characterized through morpholigical, physiological, biochemical and carbohydrate fermentation tests. All of them were determined as Lactobacillus sp. Moreover, the nucleotides sequences of 16S-23S rDNA of them was compared and phylogenetic analysis to those of Lactosbacillus species in GenBank and the results confirm that four strains: L1, L3, L4 and L7 belong to Lactobacillus platarum and four strains: L2, L5, L6 and L8 belong to species L. rhamnosus

The herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2) and varicella-zoster virus (VZV) can cause life-threatening infections of the central nervous system and lead to severe disease in newborns and immunosuppressed patients. In these cases, rapid diagnosis is crucial. We have successfully established a process to simultaneously detect of HSV and VZV by multiplex real-time PCR using Taqman probes based on primers/probe from the DNA polymerase genes of those viruses. The performance of these techniques was assessed by analyzing serial dilutions of DNA known concentrations and the lowest limit of detection was found to be 102 DNA copies/ml. Of the 83 clinical samples collected from Tropical Diseases Hospital in HoChiMinh city and National Dermatology Hospital, 8/83 samples were infected with HSV, 10/83 samples were infected with VZV and 1/83 sample was co-infected with both HSV and VZV. The PCR results were confirmed by DNA sequencing showing 100% specificity. The method will be further tested on larger number of samples before being put into clinical application.

Hepatitis B is caused by the hepatitis B virus (HBV) and may be either acute or chronic. Chronic hepatitis B virus (HBV) infection is the major global cause of chronic hepatitis, as a result, which leads to cirrhosis and increases the risk of liver cancer development (hepatocellular carcinoma). Recent advances in the diagnosis and treatment of hepatitis B have enormously contributed to reduce the side effects of this disease in which the real-time PCR technique had the significant contribution todiagnosis, monitoring and therapy. In the current study, therefore, our purpose is the application of real-time PCR method to detect hepatitis B viral load, genotypes as well as lamivudine (LAM) and adefovir (ADV) resistance in patients at Dong Thap Hospital. The results figured that the mean age of HBV patients was 37.0 ± 0.34, the proportion of male infected was 59.0%. In addition, our results also showed that the rate of the patients with the normal ALT level and HBeAg negative were 51.2% and 23.0%, respectively. Moreover, the patients who were not indicated for treatment were approximately 30.0%. Among the group of HBsAg positive, the rate of HBV-DNA positive was 82.0% and a majority rate of 59.1% was HBV genotype B. The group of high viral load in those samples was equal to or greater than 20,000 IU/ml (36.0%). The total rate resistant mutation occurred in 56.1%, the rate of LAM resistant mutations was the most value of 86.0% and ADV resistant mutations were 68.0%. LAM resistant mutation 204I occurred at 84.0%. ADV resistant mutation A181T was the highest rate of 68.0%. Resistance mutations often associated with a higher proportion of HBeAg positive and the high viral loads. Meanwhile, the influence of genotype infections on the clinical, para-clinical characteristics were not clear.

Currently, tuberculosis is still one of the most common infectious diseases, mainly caused by Mycobacterium tuberculosis bacterium infection. PCR is a molecular biology technique used to detect infectious agents, especially viruses or bacteria with slowly culture as in the case of Mycobacterium tuberculosis because of its fastness, accurateness and high sensitivity. We carried out this study in order to develop a protocol based on Realtime PCR using 16S rRNA gene as a target sequence which is extensively used in taxonomy, molecular evolution and medical diagnostics. We have succeeded in designing the primers/probes on the 16S rRNA gene to detect Mycobacterium tuberculosis by Realtime PCR; have identified the parameters of the specificity of the primers/probe, theoretically and experimentally; the sensitivity of the primers/probe in the Realtime PCR protocol reached to 102 copies/ml; the protocol was also tested on 30 samples given good results.

Abstract Background The engineering of fusion proteins has become increasingly important and most recently has formed the basis of many biosensors, protein purification systems, and classes of new drugs. Currently, most fusion proteins consist of three or fewer domains, however, more sophisticated designs could easily involve three or more domains. Using traditional subcloning strategies, this requires micromanagement of restriction enzymes sites that results in complex workaround solutions, if any at all. Results Therefore, to aid in the efficient construction of fusion proteins involving multiple domains, we have created a new expression vector that allows us to rapidly generate a library of cassettes. Cassettes have a standard vector structure based on four specific restriction endonuclease sites and using a subtle property of blunt or compatible cohesive end restriction enzymes, they can be fused in any order and number of times. Furthermore, the insertion of PCR products into our expression vector or the recombination of cassettes can be dramatically simplified by screening for the presence or absence of fluorescence. Conclusions Finally, the utility of this new strategy was demonstrated by the creation of basic cassettes for protein targeting to subcellular organelles and for protein purification using multiple affinity tags.