Detection of the Pandemic H1N1/2009 Influenza A Virus by a Highly Sensitive Quantitative Real-time Reverse-transcription Polymerase Chain Reaction Assay

A quantitative real time reverse-transcription polymerase chain reaction （qRT-PCR） assay with specific primers recommended by the World Health Organization （WHO） has been widely used successfully for detection and monitoring of the pandemic H1N1/2009 influenza A virus. In this study, we report the design and characterization of a novel set of primers to be used in a qRT-PCR assay for detecting the pandemic H1N1/2009 virus. The newly designed primers target three regions that are highly conserved among the hemagglutinin （HA） genes of the pandemic HlN1/2009 viruses and are different from those targeted by the WHO-recommended primers. The qRT-PCR assays with the newly designed primers are highly specific, and as specific as the WHO-recommended primers for detecting pandemic H1N1/2009 viruses and other influenza viruses including influenza B viruses and influenza A viruses of human, swine, and raccoon dog origin. Furthermore, the qRT-PCR assays with the newly designed primers appeared to be at least 10-fold more sensitive than those with the WHO-recommended primers as the detection limits of the assays with our primers and the WHO-recommended primers were 2.5 and 25 copies of target RNA per reaction, respectively. When tested with 83 clinical samples, 32 were detected to be positive using the qRT-PCR assays with our designed primers, while only 25 were positive by the assays with the WHO-recommended primers. These results suggest that the qRT-PCR system with the newly designed primers represent a highly sensitive assay for diagnosis of the pandemic HIN1/2009 virus infection.

Detection of Human Parvovirus B19 Nonstrutural Protein DNA by Nested-Polymerase Chain Reaction in Gravida Serum and Pregnant Tissues

A new nested-polymerase chain reaction （nested-PCR） assay was developed to detect human parvovirus B19 DNA corresponding to the nonstructural protein in clinical specimens in a routine diagnostic laboratory. The sensitivity of this highly specific assay was up to 0. 005 fg of B19 DNA. Parvovirus B19 was identified in sera of 20 pregnant women with abnormal pregnant outcome. Among these 20 cases, intrauterine parvovirus infection did exist in 7 pregnant women because parvovirus B19 DNA was detected in the pregnant tissues of them such as placenta tissues, chorionic villi, amniotic fluid, fetal spleen, liver and abdominal fluids.

Characteristics of hepatic nuclear-transcription factor-kappa B expression and quantitative analysis in rat hepatocarcinogenesis

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. We analyzed the expression of miclear-transcription factor-kappa B (NF-kappa B) during hepatocarcinogenesis in order to evaluate its dynamic expression and its clinical value in the development and diagnosis of HCC. METHODS: Hepatoma models were induced by oral administration of 2-acetamidoflurene (2-FAA) to male Sprague-Dawley rats. Morphological changes were observed after hematoxylin and eosin staining. The cellular distribution of NF-kappa B expression during different stages of cancer development was investigated by immunohistochemistry, and the level of NF-kappa B expression in liver tissues was quantitatively analyzed by ELISA. The gene fragments of hepatic NF-kappa B were amplified by nested-polymerase chain reaction assay. RESULTS: Hepatocytes showed vacuole-like degeneration during the early stages, then had a hyperplastic nodal appearance during the middle stages, and finally progressed to tubercles of cancerous nests with high differentiation. The NF-kappa B-positive material was buff-colored, fine particles localized in the nucleus, and the incidence of NF-kappa B-positive cells was 81.8% in degeneration, 83.3% in precancerous lesions, and 100% in cancerous tissues. All of these values were higher than those in controls (P<0.01). Hepatic NF-kappa B expression and hepatic NF-kappa B-mRNA were also higher during the course of HCC development (P<0.01). CONCLUSION: The NF-kappa B signal transduction pathway is activated during the early stages of HCC development, and its abnormal expression may be associated with the occurrence of HCC.

No evidence of HPV DNA in esophageal squamous cell carcinoma in a population of Southern Brazil

AIM:To investigate the association between human papillomavirus(HPV)and esophageal squamous cell carcinoma(ESCC)in southern Brazil.METHODS:We studied 189 esophageal samples from125 patients from three different groups:(1)102 biopsies from 51 patients with ESCC,with one sample from the tumor and another from normal esophageal mucosa distant from the tumor;(2)50 esophageal biopsies from 37 patients with a previous diagnosis of head and neck squamous cell carcinoma(HNSCC);and(3)37 biopsies from esophageal mucosa with normal appearance from 37 dyspeptic patients,not exposed to smoking or alcohol consumption.Nested-polymerase chain reaction(PCR)with the MY09/11 and GP5/6 L1primers was used to detect HPV L1 in samples fixed in formalin and stored in paraffin blocks.All PCR reactions were performed with a positive control(cervicovaginal samples),with a negative control(Human Genomic DNA)and with a blank reaction containing all reagents except DNA.We took extreme care to prevent DNA contamination in sample collection,processing,and testing.RESULTS:The histological biopsies confirmed the diagnosis of ESCC in 52 samples(51 from ESCC group and 1 from the HNSCC group)and classified as well differentiated(12/52,23.1%),moderately differentiated(27/52,51.9%)or poorly differentiated(7/52,13.5%).One hundred twenty-eight esophageal biopsies were considered normal(51 from the ESCC group,42 from the HNSCC group and 35 from dyspeptic patients).Nine had esophagitis(7 from the HNSCC and 2 from dyspeptic patients).Of a total of 189 samples,only 6 samples had insufficient material for PCR analysis:1 from mucosa distant from the tumor in a patient with ESCC,3from patients with HNSCC and 2 from patients without cancer.In 183 samples(96.8%)GAPDH,G3PDH and/orβ-globin were amplified,thus indicating the adequacy of the DNA in those samples.HPV DNA was negative in all the 183 samples tested:52 with ESCC,9 with esophagitis and 122 with normal esophageal mucosa.CONCLUSION:There was no evidence of HPV infection in different ESCC from southern Brazil.

Quantitative analysis of a panel of gene expression in prostate cancer——with emphasis on NPY expression analysis

Objective： To investigate molecular alterations associating with prostate carcinoma progression and potentially provide information toward more accurate prognosis/diagnosis. Methods： A set of laser captured microdissected （LCM） specimens from 300 prostate cancer （PCa） patients undergoing radical prostatectomy （RP） were defined. Ten patients representing ＂aggressive＂ PCa, and 10 representing ＂non-aggressive＂ PCa were selected based on prostate-specific antigen （PSA） recurrence, Gleason score, pathological stage and tumor cell differentiation, with matched patient age and race between the two groups. Normal and neoplastic prostate epithelial cells were collected with LCM from frozen tissue slides obtained from the RP specimens. The expressions of a panel of genes, including NPY, PTEN, AR, AMACR, DD3, and GSTP1, were measured by quantitative real-time RT-PCR （TaqMan）, and correlation was analyzed with clinicopathological features. Results： The expressions of AMACR and DD3 were consistently up-regulated in cancer cells compared to benign prostate epithelial cells in all PCa patients, whereas GSTP1 expression was down regulated in each patient. NPY, PTEN and AR exhibited a striking difference in their expression patterns between aggressive and non-aggressive PCas （P=0.0203, 0.0284, and 0.0378, respectively, Wilcoxon rank sum test）. The lower expression of NPY showed association with ＂aggressive＂ PCas based on a larger PCa patient cohort analysis （P=0.0037, univariate generalized linear model （GLM） analysis）. Conclusion： Despite widely noted heterogeneous nature of PCa, gene expression alterations ofAM,4CR, DD3, and GSTP1 in LCM-derived PCa epithelial cells suggest for common underlying mechanisms in the initiation of PCa. Lower NPY expression level is significantly associated with more aggressive clinical behavior of PCa; PTEN and AR may have potential in defining PCa with aggressive clinical behavior. Studies along these lines have potential to define PCa-associated gene expression alterations and likely co-regulation of genes/pathways critical in the biology of PCa onset/progression.

KLF6mRNA Expression in Primary Hepatocellular Carcinoma

Summary: To investigate the expression of KLF6mRNA in primary hepatocellular carcinoma (HCC), nomal liver tissues and the tissues adjacent to the cancers, reverse-transcription polymerase chain reaction (RT-PCR) was employed to investigate the expression of the KLF6 gene in HCC, the corresponding adjacent non-cancerous tissues and normal liver tissue. Our results showed that an amplified fragment of 427 bp DNA was detected in 18 of 19 (94.7 %) adjacent non-cancerous tissues and normal liver tissue, and in 12 (85.7 %) of 14 HCC. There were no significant differences in the levels of KLF6 mRNA between normal liver and liver tumors (P>0.05). It is concluded that KLF6 mRNA is generally expressed in HCC.