Application of HRM Analysis in Detection of PDGFRA Exon 10 Polymorphism in CML Patients with Imatinib Resistance

@#Introduction: Imatinib mesylate has been widely used as a standard treatment for chronic myeloid leukemia (CML). It acts as a selective competitive inhibitor of the BCR-ABL tyrosine kinase. Despite the excellent efficacy on CML treatment, some patients developed resistance to the treatment. Mutation in the PDGFRA may be one of the factors involved in the mechanism of resistance that affects the response to imatinib. The mutational status of PDGFRA is highly relevant for prognosis and treatment prediction in CML patients. Thus, this study is intended to establish and validate a High Resolution Melting (HRM) analysis for PDGFRA exon 10 c.1432 T>C polymorphism in CML patients. Methods: High resolution melting (HRM) analysis was used to identify the c.1432 T > C polymorphism in PDGFRA exon 10 (n =86; response = 43; resistance = 43). The results from HRM analysis were compared and validated with Sanger sequencing. The association between the polymorphism and treatment response was assessed by statistical analysis using binomial logistic regression analysis. Results: HRM analyses showed two different melt curves. One curve followed the shape of the reference, homozygous wild type (TT) and the other curve showed a different melting profile than the reference with the TC genotype (heterozygous variant). The results revealed that heterozygous variant (TC) genotype showed a high risk of acquiring resistance with an OR of 3.795; 95% CI: 1.502-9.591, with a statistically significant association, p = 0.005. HRM analysis also showed 100% sensitivity and specificity in the detection of PDGFRA exon 10. Conclusion: The HRM analysis of PDGFRA exon 10 c.1432 T>C was successfully established. The exon 10 c.1432 T>C polymorphism shows a higher risk for the development of resistance toward imatinib treatment.

Sensitivity comparison for the Leishmania spp. detection in different canine tissues using PCR-HRM

ABSTRACT Background: Leishmaniasis is a vector-borne disease caused by a parasite protozoon from the genus Leishmania. Among the molecular techniques applied for detecting these parasites, real-time PCR with High Resolution Melting (PCR-HRM) proved advantageous since it simultaneously determines both the presence and species of the pathogen in one step, through amplification and later analysis of curves generated by melting temperature. Methods: Based on this molecular technique, the goal of this study was to estimate the PCR-HRM sensitivity for Leishmania spp. detection in different canine tissues by evaluating biological samples obtained from popliteal, submandibular, and pre-scapular lymph nodes, from bone marrow and ear pinnae of 28 stray dogs captured in the metropolitan area of Asunción (Paraguay). Results: The rk39 immunochromatographic test showed that 25/28 tested dogs (89%) presented antibodies against L. infantum. In 20/25 dogs that tested positive for rk39 (80%), it was possible to detect Leishmania spp. by PCR-HRM and determine that the species corresponded entirely to L. infantum. Regarding the analysis of different tissues, the parasite was detected in all popliteal lymph node samples, followed by high detection in submandibular (at 95%) and pre-scapular lymph nodes (at 90%), bone marrow (at 85%), and ear pinnae (at 85%). Conclusions: This study demonstrated that the use of real-time PCR-HRM using the molecular marker hsp70 was a highly sensitive method for simultaneously detecting and identifying Leishmania species in different tissues taken from infected dogs. In addition, the usefulness of ear pinnae as easily accessible tissue for molecular diagnosis was emphasized.

Two Leishmania species separation targeting the ITS-rDNA and Cyt b genes by developing and evaluating HRM- qPCR

ABSTRACT Background: Incidence of Cutaneous Leishmaniasis as an infectious and neglected disease is increasing, for the diagnosis of which several traditional methods and conventional PCR techniques have been developed, employing different genes for species identification. Methods: Leishmania parasites were sampled, DNA was extracted, and new specific and sensitive primers were designed. Two ITS-rDNA and Cyt b genes were targeted by qPCR using the High- Resolution Melting method to identify Leishmania parasites. The standard curves were drawn, compared, and identified by high-resolution melting curve analysis. Results: Melting temperature and Cycle of Threshold of ITS-rDNA was higher than Cyt b but Cyt b was more sensitive than ITS-rDNA when Leishmania major and Leishmania tropica were analyzed and evaluated. By aligning melt curves, normalizing fluorescence curves, and difference plotting melt curves, each Leishmania species was distinguished easily. L. major and L. tropica were separated at 83.6 °C and 84.7 °C, respectively, with less than 0.9 °C of temperature difference. Developing sensitivity and specificity of real-time PCR based on EvaGreen could detect DNA concentration to less than one pmol. Conclusions: Precise identification of Leishmania parasites is crucial for strategies of disease control. Real-time PCR using EvaGreen provides rapid, highly sensitive, and specific detection of parasite's DNA. The modified High-Resolution Melting could determine unique curves and was able to detect single nucleotide polymorphisms according to small differences in the nucleotide content of Leishmania parasites.

Identificación de especies de Leishmania mediante PCR en tiempo real acoplada a curvas de fusión de alta resolución

RESUMEN Introducción: La leishmaniasis es una enfermedad causada por parásitos del género Leishmania. En Colombia se han informado 10 especies patógenas. El diagnóstico parasitológico tradicional basado en la observación de los parásitos no permite identificar la especie, por lo cual se deben emplear métodos moleculares, entre ellos la reacción en cadena de la polimerasa o PCR convencional, pero esta presenta algunas limitaciones y requiere extensos periodos de tiempo para la obtención de resultados, que en ocasiones no son concluyentes. Objetivo: Evaluar un método basado en PCR en tiempo real acoplado a curva de temperatura de desnaturalización media de alta resolución (PCR-HRM) que permita el diagnóstico y la identificación simultánea de parásitos del género Leishmania en muestras clínicas de humanos y en cultivos in vitro de manera sensible y específica. Métodos: Se estandarizó una PCR-HRM, mediante la cual se evaluaron 237 muestras clínicas, 98 clasificadas como positivas y 139 como negativas, parasitológicamente por directo y/o cultivo. Las tipificaciones fueron comparadas con los resultados en paralelo obtenidos de una variante de la PCR, realizando cortes al amplicon que generó un fragmento de restricción de longitud polimórfica o PCR-RFLP que había sido previamente estandarizada. Resultados: Se logró implementar una PCR-HRM para el diagnóstico e identificación de especies de Leishmania, logrando un 100 % de concordancia con las tipificaciones obtenidas por PCR-RFLP. Incluso, se logró detectar e identificar el parásito en muestras diagnosticadas como negativas por los métodos convencionales. Se encontró que con un porcentaje de confiabilidad superior al 95 %, se lograron tipificar 91 muestras de 98; de estas el 81,63 % de los casos fueron L. panamensis, el 11,22% L. braziliensis e indeterminadas el 7,14 % de los casos. Conclusiones: La PCR-HRM es un buen método que permite la identificación de las especies más prevalentes en Colombia, comparando temperaturas medias de desnaturalización específicas según la especie de Leishmania involucrada.

ABSTRACT Introduction: Leishmaniasis is a disease caused by parasites of the genus Leishmania. Ten pathogenic species have been reported in Colombia. Traditional parasite diagnosis based on observation of the parasites does not make it possible to identify the species. Therefore, it is necessary to use molecular methods, among them conventional polymerase chain reaction or PCR, but this test presents some limitations and requires long periods of time to obtain results which sometimes are not conclusive. Objective: Evaluate a method based on real time PCR coupled with high resolution mean denaturalization temperature curve analysis (HRM-PCR) for the diagnosis and simultaneous identification of parasites of the genus Leishmania in clinical samples from humans and in vitro cultures in a sensitive and specific manner. Methods: Standardization was performed of an HRM-PCR with which 237 clinical samples were evaluated, 98 classified as positive and 139 as negative, by direct parasitological examination and/or culture. The typing obtained was compared with parallel results from a PCR variant, making cuts on the amplicon that generated a restriction fragment length polymorphism or PCR-RFLP previously standardized. Results: An HRM-PCR could be implemented for the diagnosis and identification of Leishmania species, achieving 100% concordance with the typing obtained by PCR-RFLP. It was even possible to detect and identify the parasite in samples diagnosed as negative by conventional methods. Of the total 98 samples, 91 could be typed with a percentage of reliability above 95%. Of these, 81.63% of the cases were L. panamensis, 11.22% were L. braziliensis and 7.14 % were indeterminate. Conclusions: HRM-PCR is a good method to identify the species most prevalent in Colombia, comparing specific mean denaturalization temperatures according to the Leishmania species involved.

Correlation analysis between P73 gene G4C14-to-A4T14 polymorphism and lung cancer risk in Guangdong population / 公共卫生与预防医学

Objective To analyze the correlation between P73 gene G4C14-to-A4T14 double nucleotide polymorphism and the risk of lung cancer in Guangdong population. Methods Genotype analysis of P73 gene polymorphism in peripheral blood of 642 patients with lung cancers (including 450 NSCLC patients and 192 SCLC patients) and 354 normal controls was performed with HRM method (high-resolution fusion curve). Results HRM genotyping results showed that the distribution of P73 genotypes in 450 NSCLC patients was as follows: GC/GC 280 (62.3%), GC/AT 155 (34.4%), and AT/AT 15 (3.3%). P73 genotypes in 192 SCLC patients were 118 GC/GC (61.5%), 67 GC/AT (34.9%) and 7 AT/AT (3.6%). The P73 genotypes of 354 normal controls were 192 GC/GC (53.1%), 136 GC/AT (38.5%), and 26 AT/AT (8.4%). AT/AT homozygous genotypes significantly reduced the risk of NSCLC (OR=0.393；95% CI:0.037-0.873；P=0.001) and SCLC (OR=0.428；95%CI:0.050-0.880；P<0.001) compared with non-carriers. Conclusion The results of the present study indicated that the polymorphism of P73 G4C14-A4T14 may be a modification factor for the susceptibility of lung cancer in Guangdong province, and the increased GC content in the P73 gene may increase the risk of lung cancer.

Evaluation of High Resolution Melting Technique for Detection of JAK2-V617F Mutation in Formalin-Fixed Paraffin-Embedded Specimen from Myeloproliferative Neoplasm Cases

@#Introduction: Myeloproliferative neoplasm (MPN) is a group of myeloid disorders which leads to erythrocytosis, thrombocytosis and leucocytosis. MPN with BCR-ABL positive is chronic myeloid leukaemia (CML) while BCR-ABL negative MPN includes polycythaemia Vera (PV), essential thrombocytemia (ET) and primary myelofibrosis (PMF). One of the major criteria for diagnosis of BCR-ABL negative MPN is the presence of JAK2-V617F mutation which is positive in 95% of PV and around 60% of ET and MF. Beside peripheral blood specimen, formalin-fixed paraffin-embedded (FFPE) marrow specimen can be used for detection of this mutation. Unfortunately, FFPE produces low quality DNA that put a challenge for successful amplification of DNA. We aimed to evaluate the utility of High Resolution Melting (HRM) analysis for detection of JAK2-V617F mutation in FFPE specimen from MPN cases. Materials and Methods: This study is a descriptive crosssectional study. Forty FFPE marrow specimens were retrieved from the years 2014-2016. Bio-Rad Precision Melt Analysis software was used for analysis of HRM data. Allele-specific PCR was done for validation of results. Positive samples were subjected to Sanger sequencing. Results: JAK2-V617F mutation was positive in 13 out of 40 MPN cases. Level of agreement between HRM and AS-PCR was 97.5%. Conclusion: HRM is a rapid and powerful diagnostic assay which is suitable for detection of JAK2-V617F mutation in FFPE marrow specimen.

Development and Validation of High Resolution Melting Assays for High-Throughput Screening of BDNF rs6265 and DAT1 rs40184

@#Introduction: One of the commonly used techniques for mutation screening is High Resolution Melting (HRM) analysis. HRM is a post PCR method that relies on the detection of the fluorescent signals acquired due to the release of DNA intercalated dyes upon the melting of dsDNA to ssDNA. The method is simple, inexpensive and does not require post PCR-handling, making it suitable for high throughput screening. Methods: This study aimed to develop and validate HRM technique for the screening of two disease-associated single nucleotide polymorphisms (SNPs) namely BDNF rs6265 and DAT1 rs40184 using a total of 30 gDNA samples. The obtained results were confirmed and validated by sequencing. Results: HRM analysis showed that the predicted genotypes of BDNF rs6265 and DAT1 rs40184 among all the gDNA samples were in 100% concordance with the sequencing results, making it an accurate and sensitive method for the detection of SNPs. Conclusions: The application of HRM can accurately determine the genotype of BDNF rs6265 and DAT1 rs40184 SNPs, making it a promising tool for rapid and high-throughput screening of targeted SNPs in a large population study.

HLA-B*15:02 screening in epileptic patients using a high resolution melting-real time PCR (HRM-QPCR) method

Background: The HLA-B*15:02 polymorphism in epileptic patients is known to be associated with carbamazepine-induced Stevens-Johnson syndrome (SJS). The prevalence of HLA-B*15:02 polymorphism seemed to be ethnic-specific with a higher frequency of HLA-B*15:02 in Asian compared to the Europeans. This study was performed to determine the frequency of the HLA-B*15:02 polymorphism in epileptic patients at the Chancellor Tuanku Muhriz Hospital-UKM Medical Centre (HCTM-UKMMC) using high resolution melting-real time PCR (HRM-QPCR) method. Methods: We performed a fast and effective in-house high resolution melting-real time polymerase chain reaction method and compared it with the conventional multiplex-PCR method. The specificity and sensitivity of each test were also determined using DNA from saliva. Results: Using the conventional multiplex-PCR approach for screening, 25 out of 64 (39.1%) epileptic patients were positive for HLA-B*15:02. However, using the HRM-QPCR technique, 24/64 (37.5%) of the patients were positive. The one patient who tested positive by the multiplex-PCR but negative using the HRM-QPCR turned out to be negative by DNA sequencing. The HRM-QPCR and DNA sequencing showed 100% sensitivity and specificity. The multiplex-PCR showed 100% sensitivity and 98.4% specificity compared to both HRM-QPCR and DNA sequencing. The HRM-QPCR is also more cost-effective (<$16.40 USD/test) and less time-consuming when compared to the multiplex-PCR ($25.15 USD/test).Conclusion: Our result suggested that multiplex PCR, HRM-QPCR and Sanger sequencing can be used for detection of HLA-B*15:02. However, a qualitative method such as multiplex PCR should be confirmed with other quantitative methods such as HRM-QPCR and Sanger sequencing.

Microbial additives in the composting process / Aditivos microbianos no processo de compostagem

ABSTRACT Composting is the process of natural degradation of organic matter carried out by environmental microorganisms whose metabolic activities cause the mineralization and partial humification of substances in the pile. This compost can be beneficially applied to the soil as organic fertilizer in horticulture and agriculture. The number of studies involving microbial inoculants has been growing, and they aim to improve processes such as composting. However, the behavior of these inoculants and other microorganisms during the composting process have not yet been described. In this context, this work aimed to investigate the effects of using a microbial inoculum that can improve the composting process and to follow the bacterial population dynamics throughout the process using the high-resolution melt (HRM) technique. To do so, we analysed four compost piles inoculated with Bacillus cereus, Bacillus megaterium, B. cereus + B. megaterium and a control with no inoculum. The analyses were carried out using samples collected at different stages of the process (5th to 110th days). The results showed that the bacterial inocula influenced the process of composting, altering the breakdown of cellulose and hemicelluloses and causing alterations to the temperature and nitrogen levels throughout the composting process. The use of a universal primer (rDNA 16S) allowed to follow the microbial succession during the process. However, the design of a specific primer is necessary to follow the inoculum throughout the composting process with more accuracy.

RESUMO A compostagem é um processo de degradação natural da matéria orgânica realizado por microrganismos presentes no ambiente, levando a mineralização e humificação parcial das substâncias presentes na pilha, esse composto formado pode ser beneficamente aplicado ao solo como fertilizante orgânico na horticultura e agricultura. O número de estudos envolvendo inoculantes microbianos é crescente, os quais tem por objetivo a otimização de processos de compostagem. Contudo, o comportamento desses inoculantes e da microbiota ao longo do processo não tem sido caracterizado. Nesse contexto, este trabalho foi realizado com o objetivo de avaliar o efeito da utilização de um inóculo bacteriano que promova melhorias no processo de compostagem, bem como o de acompanhar a dinâmica populacional bacteriana ao longo de todo o processo através da técnica de High Resolution Melt (HRM). Para isso foram analisados quatro pilhas de compostagem inoculadas com Bacillus cereus, Bacillus megaterium, B. cereus + B. megaterium e o controle sem adição de inóculo. Foram realizadas análises químicas e moleculares (HRM) das amostras coletadas em diferentes períodos da compostagem (5º ao 110º dias). Os resultados mostraram que os inóculos bacterianos influenciaram no processo de compostagem com alteração na degradação de celulose, hemicelulose bem como alteração da temperatura e níveis de nitrogênio ao longo da compostagem. A utilização de um primer universal (rDNA 16S) permitiu acompanhar a sucessão bacteriana ao longo do processo, nos tratamentos. Contudo a construção de um primer específico é necessário para acompanhar de maneira mais precisa o inóculo durante o desenvolvimento da compostagem.

Rapid detection of isoniazid resistance in clinical Mycobacterium tuberculosis isolates by high-resolution melting curve analysis / 中国人兽共患病学报

We detected the isoniazid resistance in clinical Mycobacterium tuberculosis isolates by high-resolution melting (HRM) curve analysis and assessed the application value of the assay.The isoniazid resistance of 49 M.tuberculosis isolates preserved in laboratory was analyzed by the drug sensitivity test (traditional proportion method).Further analysis was made on the sequencing of the isoniazid resistance determining region in these test strains,and their mutation sites were screened.Specific primers used in the HRM curve analysis were designed based on the screened mutation sites,DNA mutations were assayed in the isoniazid-resistant gene determining region by the HRM curve analysis,and an assessment was made of the detection efficiency of the assay in isoniazid resistance in M.tuberculosis.Results of the drug sensitivity test (proportion method) showed that,of the 49 test strains,there were 20 isoniazid-resistant strains,29 isoniazid-sensitive strains.Results of the sequencing analysis showed that:1) KatG gene had four mutation patterns,i.e.,point mutations at site 234,at sites 234 and 315,at sites 234 and 463,and at sites 234,315 and 463;2) there were three mutations were detected in inhA gene,i.e.,mutations in inhA-8,-15 and-152.Analysis of gene mutation in drug-resistant strains found that of the 20 isoniazid-resistant strains,11 (55 ％) were mutated at codon 315 of KatG gene;6 (30％) were mutated in inhA-15 (4/20),-8 (1/20) and-153 (1/20) of inhA gene;two (10％) were mutated at codon 315 of KatG gene and in inhA-15;in one strain (5％),no mutation was detected in KatG and inhA genes.Through the gene mutation detection,the sensitivity and specificity of isoniazid resistance in M.tuberculosis were 95 ％ and 100 ％,respectively.Results of HRM curve analysis of drug-resistance gene mutations in test strains showed gene mutations were present in 18 strains and absent in 24 ones;referring to DNA sequencing results,the sensitivity and specificity of the assay were 94.7％ and 80％,respectively.Judged by mutations as drug-resistance via the HRM curve analysis,19 resistant and 24 sensitive strains were tested.With the drug sensitivity test results by the proportion method as controls,the sensitivity and specificity of the assay were 95 ％ and 82.76 ％,respectively.Use of the HRM curve in the detection of resistance of M.tuberculosis to isoniazid is characterized by good sensitivity and short time consuming,and has certain value in the rapid diagnosis of isoniazid-resistant tuberculosis.

ITS2 barcoding DNA region combined with high resolution melting (HRM) analysis of Hyoscyami Semen, the mature seed of Hyoscyamus niger / 中国天然药物

Hyoscyami Semen, the mature dried seed of Hyoscyamus niger L., has long been used as a traditional Chinese medicine to treat human diseases. Hyoscyami Semen is found in local markets in China. In markets, sellers and buyers commonly inadvertently mix the seeds of H. niger with the seeds of related species such as Hygrophila salicifolia (Vahl) Nees, Astragalus complanatus R. Br., Cuscuta australis R. Br., Cuscuta chinensis Lam., and Impatiens balsamina L. because of their similar morphologies or similar names. Thus, developing a reliable method for discriminating H. niger seeds from its adulterants is necessary to reduce confusion and ensure the safe use of Hyoscyami Semen. The present study was designed to evaluate the efficiency of high-resolution melting analysis combined with DNA barcoding (Bar-HRM) with internal transcribed spacer 2 to discriminate H. niger. Our results show that Bar-HRM successfully identified the adulterants and detected the proportion of H. niger DNA extract within an admixture. In particular, HRM detected H. niger DNA extract in A. complanatus DNA extract at concentrations as low as 1%. In conclusion, the Bar-HRM method developed in the present study for authenticating H. niger is rapid and cost-effective. It can be used in the future to guarantee the purity of Hyoscyami Semen for the clinical use.

Influence of ABCB1 gene polymorphisms on breast cancer with paclitaxel-based chemotherapy / 西安交通大学学报(医学版)

Objective To detect gene polymorphisms of ABCB1/MDR1 in breast cancer and to analyze the association between ABCB1 gene polymorphisms and curative effect of paclitaxel-based chemotherapy in breast cancer.Methods Genotyping of ABCB1exon12 (1236),exon21 (2677)and exon26 (3435)was determined by polymerase chain reaction (PCR)-high resolution melting (HRM)method in 146 cases of female stage IV breast cancer to explore the relationship between the efficacy of chemotherapy in breast cancer patients with paclitaxel chemotherapy.Results In 146 patients with stage IV breast cancer,C1236T CC genotype accounted for 15.86%, CT genotype 44.83%,TT genotype 44.83%,G2677T/A GG genotype 16.67%,GT genotype 45.83%,GA genotype 6.25%,TT genotype 28.47%,AT genotype 2.78%,C3435 CC genotype 22.22%,CT genotype 56.25%,and TT genotype 21.53%.ABCB1 gene polymorphisms did not significantly differ between patients of Hui and Han Nationalities (P>0 .0 5 ).Hardy-Weinberg genetic equilibrium testing showed that polymorphisms of C1236T,G2677T/A and C3435T had group representation (P>0.05).In 146 stage IV breast cancer patients who had received paclitaxel-based chemotherapy,CT/TT genotype of C3435T site had a better response rate (74.11%) (χ2 =12.556,P<0.05),better curative effect than CC genotype (OR=4.183,95% CI 1.838 -9.521,P<0.05),T allele carriers more efficient than C allele carriers with paclitaxel-based chemotherapy (χ2 =8 .5 0 7 ,P<0 .0 5 ). Conclusion Detection of ABCB1 C3435T gene polymorphisms has a significantly clinical value in predicting the efficacy of taxanes chemotherapy in breast cancer patients.

Study on the correlation between the seven single nucleotide polymorphisms and genesis of type 2 diabetes mellitus / 中国糖尿病杂志

Objective To investigate onthe correlation between the seven single nucleotide polymorphisms and genesis of T2DM. Methods High‐resolution melting (HRM ) curve technology was used to detect thegenotype of the seven SNPs in 202 T2DM patients and 200 healthy volunteers. The relationship between susceptible gene polymorphism and T 2DM was analyzed. Results The frequency of five SNP loci rs8050136 ,rs13266634 ,rs7578597 ,rs864745 and rs7961581 showed significant differences between T2DM patients and controls ( P1 ,while OR of rs7961581 was <1. There was no significant difference in rs10811661 and rs10923931 loci between T2DM patients and controls (OR=1). Conclusion The polymorphism of loci rs8050136 ,rs13266634 ,rs7578597 and rs864745 is associated with T2DM genesis in this study population , while rs10811661 and rs10923931 is not associated with T 2DM genesis ,and rs7961581 may be a protective factor for T2DM.

Correlation between the clinical symptoms of 30 cases achalasia of cardia and their high-resolution manometry parameters / 中华消化杂志

Objective To investigate the correlation between the clinical symptoms of patients with achalasia of cardia (AC) and high-resolution manometry (HRM) parameters.Methods The clinical data of 30 AC patients were retrospectively analyzed.The severe degree of symptoms was evaluated by Eckardt score questionnaires,and motility of esophagus was assessed by HRM parameters.According to Chicago classification,patients were divided into three types.Mann-Whitney U test was performed for non normal distribution quantitative data comparison.Spearman correlation was used to analyze the correlation between AC symptoms and the HRM parameters.Results The reflux symptom of type Ⅱ patients was more severe than that of type Ⅰ patients (2.50(1.00) vs 1.00(1.50),U=56.000,P＜0.05).The integrated relaxation pressure (IRP) was moderately correlated with total Eckardt score of all AC patients,the frequency of reflux and the degree of body weight loss (r=0.528,0.441 and 0.662,all P＜0.05),furthermore IRP was strongly correlated with the degree in weight loss in type Ⅰ AC patients (r =0.703,P＜ 0.05).Lower esophageal sphincter resting pressure was weakly correlated with the degree of weight loss in all AC patients (r=0.398,P＜0.05).Conclusions The degree of severity of symptoms may be different in different types of AC patients.HRM parameters,especially IRP,might play a role in the assessment of severity of AC symptoms.

Method validation of a high resolution melting analysis of a candidate genetic marker of hypertension / Journal of the ASEAN Federation of Endocrine Societies

Objectives@#The study aimed to validate a high resolution melting (HRM) – polymerase chain reaction (PCR) based method for analysis of ATP2B1 rs2681472, a candidate genetic marker for hypertension. Specifically, the study aimed to establish method accuracy, inter- and intra-day precision, instrument detection limits (IDL) and linearity. @*Methodology@#DNA samples from whole blood of selected respondents of the 2008 National Nutrition Survey (NNS) were analyzed for ATP2B1 rs2681472, following the HRM-PCR method. Analytical validation parameters such as method accuracy, inter- and intra-day precision, IDL and assay linearity were evaluated. @*Results@#The data obtained using HRM conformed to data obtained from the current gold standard, which is direct DNA sequence analysis. Precision of the method is shown in the low intra-day and inter-day coefficients of variation of 0.11% and 0.14% respectively. The IDL was found at 1x10-2 ng DNA. Correlation coefficient using the method has met the acceptance criteria for linearity that is equal to 0.98. @*Conclusion@#HRM-PCR was successfully applied for analysis of ATP2B1 rs2681472. HRM is a highly commendable tool that can identify existence of polymorphisms in a genome which may be related to or which may cause hypertension. The method was found to be accurate and precise.

Clinical application of PCR and high resolution melting analysis for rapid identification of Brucella isolates / 中国人兽共患病学报

The aim of this study is to develop a rapid and accurately species typing method for Brucella isolates by using High Resolution Melting (HRM ) analysis .Six pairs of primers were used according to the reference for the sequence of pur‐pose gene .Nineteen biotypes of six species Brucella standard strains were identified by PCR‐HRM analysis and this analysis was used to detect the 35 clinical isolates .Results showed Brucella amplified specific melting curves were different from con‐trasted strains with primer Bspp .The six species Brucella standard strains have own characteristic curve shape from each oth‐ers by PCR‐HRM analysis with five pairs of primers .Thirty‐five clinical isolates of Brucella have entirely consistent with PCR‐HRM curve shape with Brucella melitensis standard strains .So ,PCR‐HRM analysis methods can accurately identify Brucella strains ,especially clinical isolated Brucella melitensis ,and may be used in clinical microbiology laboratories .

Rapid screening of rpoB and katG mutations in Mycobacterium tuberculosis isolates by high-resolution melting curve analysis.

Background: Early detection of multidrug‑resistant tuberculosis (MDR‑TB) is essential to prevent its transmission in the community and initiate effective anti‑TB treatment regimen. Materials and Methods: High‑resolution melting curve (HRM) analysis was evaluated for rapid detection of resistance conferring mutations in rpoB and katG genes. We screened 95 Mycobacterium tuberculosis clinical isolates including 20 rifampin resistant (RIF‑R), 21 isoniazid resistant (INH‑R) and 54 fully susceptible (S) isolates determined by proportion method of drug susceptibility testing. Nineteen M. tuberculosis isolates with known drug susceptibility genotypes were used as references for the assay validation. The nucleotide sequences of the target regions rpoB and katG genes were determined to investigate the frequency and type of mutations and to confirm HRM results. Results: HRM analysis of a 129‑bp fragment of rpoB allowed correct identification of 19 of the 20 phenotypically RIF‑R and all RIF‑S isolates. All INH‑S isolates generated wild‑type HRM curves and 18 out of 21 INH‑R isolates harboured any mutation in 109‑bp fragment of katG exhibited mutant type HRM curves. However, 1 RIF‑R and 3 INH‑R isolates were falsely identified as susceptible which were confirmed for having no mutation in their target regions by sequencing. The main mutations involved in RIF and INH resistance were found at codons rpoB531 (60% of RIF‑R isolates) and katG315 (85.7% of INH‑R isolates), respectively. Conclusion: HRM was found to be a reliable, rapid and low cost method to characterise drug susceptibility of clinical TB isolates in resource‑limited settings.

Superoxide Dismutase 1 Inhibits Alpha-Melanocyte Stimulating Hormone and Ultraviolet B-Induced Melanogenesis in Murine Skin

BACKGROUND: Over the last decade, the incidence of ultraviolet B (UVB)-related skin problems has increased. Oxidative stress caused by UVB induces the secretion of melanocyte growth and activating factors from keratinocytes, which results in the formation of cutaneous hyperpigmentation. Therefore, increasing the antioxidant abilities of skin cells is thought to be a beneficial strategy for the development of sunscreen agents. Superoxide dismutase 1 (SOD1) is an antioxidant enzyme that is known to exhibit antioxidant properties. OBJECTIVE: The purpose of this study was to investigate the effect of SOD1 on alpha-melanocyte stimulating hormone (alpha-MSH) and UVB-induced melanogenesis in B16F10 melanoma cells and HRM-2 melanin-possessing hairless mice. METHODS: The inhibitory effect of SOD1 on tyrosinase activity was evaluated in a cell-free system. Additional experiments were performed using B16F10 melanoma cells to demonstrate the effects of SOD1 in vitro, and HRM-2 melanin-possessing hairless mice were used to evaluate the antimelanogenic effects of SOD1 in vivo. RESULTS: We found that SOD1 inhibited melanin production in a dose-dependent manner without causing cytotoxicity in B16F10 melanoma cells. SOD1 did not inhibit tyrosinase activity under cell-free conditions. The results indicate that SOD1 may reduce pigmentation by an indirect, nonenzymatic mechanism. We also found that SOD1 decreased UVB-induced melanogenesis in HRM-2 melanin-possessing hairless mice, as visualized through hematoxylin and eosin staining and Fontana-Masson staining. CONCLUSION: Our results indicate that SOD1 has an inhibitory effect on alpha-MSH and UVB-induced melanogenesis, indicating that SOD1 may be a promising sunscreen agent.

The detection and significance of AKAP12 methylation levels in peripheral blood in patients with lung cancer / 重庆医学

Objective To detect the levels of AKAP12 methylation by methylation‐specific high‐resolution melting curve(MS‐HRM ) in peripheral blood in patients with colorectal cancer and investigate its clinical significance .Methods We used MS‐HRM technology to detect the levels of AKAP12 methylation in peripheral blood in 60 lung cancer patients ,and analyzed the relationship between the levels of AKAP12 methylation and pathological parameters of lung cancer patients .Results 34(56 .7% ) of the 60 lung cancer patients were found to be methylated at the AKAP12 promoter region by MS‐HRM ,the methylation levels of 18 cases ranged between 1% -20% ,14 cases ranged between 20% -60% ,2 cases ranged between 60% -100% .There was no significant differences between the levels of AKAP12 methylation and lung cancer patients′age and gender(P>0 .05) .However ,it was signifi‐cantly higher in the patients with high pathological stage and differentiation degree (P<0 .05) .Conclusion AKAP12 promoter re‐gion methylation was related to tumor progression and malignant degree .

Identification of Human LRG1 Polymorphisms and Their Genetic Association with Rheumatoid Arthritis

Human leucine-rich alpha-2-glycoprotein 1 (LRG1 ) was first identified as a trace protein in human serum. The primary sequence of LRG1 includes repeated leucine residues and putative membrane-binding domains. But, there is no published information on the genetic variation of this gene. In this study, LRG1 was identified as one of several upregulated genes in RA patients. We examined the expression levels of LRG1 between an RA patient and a healthy control by RT-PCR and validated that LRG1 was highly expressed in RA patients compared with controls. We identified the possible variation sites and single nucleotide polymorphisms (SNPs) in the human LRG1 gene by direct sequencing and analyzed the association of genotype and allele frequencies between RA patients and a control group without RA. We further investigated the relationship between these polymorphisms and the level of RF or anti-CCP in RA patients. We identified a total of three SNPs (g.-678A> G, g.-404C>T and g.1427T>C) and two variation sites (g.-1198delA and g.-893delA) in the LRG1 gene. Our results suggest that polymorphisms of the LRG1 gene are not associated with the susceptibility of RA in the Korean population.