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Human DNA (human + dna)
Selected AbstractsDetection of bacterial DNA by PCR and reverse hybridization in the 16S rRNA gene with particular reference to neonatal septicemiaACTA PAEDIATRICA, Issue 2 2001S Shang Aim: The clinical diagnosis of sepsis is difficult, particularly in neonates. It is necessary to develop a rapid and reliable method for detecting bacteria in blood and cerebrospinal fluid (CSF) Polymerase chain reaction (PCR) and reverse hybridization of the 16S rRNA gene would permit fast and sensitive determination of the presence of bacteria and differentiate gram-positive bacteria from gram-negative ones in clinical specimens. Methods: We developed a pair of primers according to the gene encoding 16SrRNA found in all bacteria. DNA fragments from different bacterial species and from clinical samples were detected with PCR, and with reverse hybridization using a universal bacterial probe, a gram-positive probe and a gram-negative probe. Results: A 371 bp DNA fragment was amplified from 20 different bacterial species. No signal was observed when human DNA and viruses were used as templates. The sensitivity could be improved to 10T -12 g. All 26 culture-positive clinical samples (22 blood samples and 4 CSF samples) were positive with PCR. The gram-negative and gram-positive probes hybridized to clinical samples and to known bacterial controls, as predicted by Gram's stain characteristics. Conclusions: Our results suggest that the method of PCR and reverse hybridization is rapid, sensitive and specific in detecting bacterial infections. This finding may be significant in the clinical diagnosis of sepsis in neonates. [source] Comparison of three different PCR methods for detection of Brucella spp. in human blood samplesFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2002E Navarro In the diagnosis of human brucellosis, PCR could be a more sensitive technique than blood cultures and more specific than conventional serological tests. We compared three different PCR methods for the detection of Brucella spp. and we studied whether human genomic DNA affect the sensitivity of three primer pairs for the detection of Brucella DNA in a peripheral-blood PCR assay. These three pairs of primers amplified three different fragments included in: (i) a gene encoding a 31-kDa Brucella abortus antigen (primers B4/B5), (ii) a sequence 16S rRNA of B. abortus (primers F4/R2), and (iii) a gene encoding an outer membrane protein (omp -2) (primers JPF/JPR). The three primers assayed showed a difference in sensitivity for detecting purified Brucella DNA, ranging between 8 fg and 20 pg. However, the sensitivity of the primers F4/R2 and B4/B5 was affected by the presence of human DNA while the primers JPF/JPR were not. Therefore, although the sensitivity of PCR using primers F4/R2 is affected by human DNA, they are still the most sensitive and they could provide a useful tool for the diagnosis of human brucellosis. [source] Detection of human bocavirus in respiratory, fecal, and blood samples by real-time PCR,JOURNAL OF MEDICAL VIROLOGY, Issue 3 2009Sarah J. Tozer Abstract Human bocavirus (HBoV) has been detected worldwide in respiratory samples. Two real-time PCR assays, targeting the non-structural protein (NP-1) and viral protein (VP-1) genes, were designed and validated to detect HBoV in patients with respiratory disease, gastroenteritis, or systemic illness. Sensitivity of the NP-1 and VP-1 assays were equal to the conventional PCR assay previously described by Allander et al. [2005: Proc Natl Acad Sci USA 102: 12891,12896] being 100%, and giving specificity of 94% and 93%, respectively. There was no cross-reaction identified with unrelated respiratory agents, or to human DNA. The limits of detection were 10 copies of genomic DNA equivalents per reaction for both assays. The assays were used to screen three different sample populations, combined nose, and throat swabs (n,=,96) from children with acute respiratory disease, fecal samples (n,=,375) from adults, and children with gastroenteritis and whole blood (n,=,229) collected from 31 immunocompromised children taken over an 18-month period. In total 17 (18%) respiratory samples and 18 (4.8%) fecal samples were identified as having HBoV present. Of the pediatric whole blood specimens investigated, HBoV was detected in six (2.6%) samples from four patients. In summary, two real-time PCR assays targeting different genes were designed and validated for use as screening methods for the detection of HBoV. HBoV was found in three different specimen types: parent-collected combined nose,throat swabs, fecal samples collected from symptomatic individuals and whole blood from immunocompromised children. J. Med. Virol. 81:488,493, 2009. © 2009 Wiley-Liss, Inc. [source] Sequencing of human-viral DNA junctions in hepatocellular carcinoma from patients with HCV and occult HBV infectionJOURNAL OF MEDICAL VIROLOGY, Issue 4 2003Akihiro Tamori Abstract DNA of free hepatitis B viruses (HBV) has been detected in the liver of patients infected with hepatitis C virus (HCV). It is unknown whether HBV DNA is integrated into such livers; if so, it may affect hepatocarcinogenesis. Hepatocellular carcinomas (HCCs) from 34 patients without HBV surface antigen (HBsAg) and with anti-HCV, and from 7 patients with HBsAg and without anti-HCV as controls, were examined, using the cassette-ligation,mediated polymerase chain reaction and primers based on HBV DNA sequence. In the controls, HBV DNA had been integrated into human DNA of all HCCs. On the basis of HBV DNA in tumor tissue, 23 of the 34 patients with anti-HCV had occult infection. Junctions between human DNA and HBV DNA were detected in 10 of the 34 patients without HBsAg and with anti-HCV. HBV DNA was integrated into chromosome 11q in 4 of the 10 HCCs with junctions. The DNA to either side of the human-viral junctions was sequenced. Clinically, the mean tumor size of these 10 HCCs was 39 mm; that of the 24 HCCs without integrated HBV was 25 mm. The surrounding tissue was cirrhotic in 2 of the 10 former HCCs and in 16 of the latter 24 HCCs. In conclusion, integrated HBV was detected in some patients with HCV infection; in these patients, the integrated DNA was associated with accelerated hepatocarcinogenesis. J. Med. Virol. 69:475,481, 2003. © 2003 Wiley-Liss, Inc. [source] Age Dependence of the Human Skeletal Muscle Stem Cell in Forming Muscle TissueARTIFICIAL ORGANS, Issue 3 2006Ralf Schäfer Abstract:, Human skeletal muscle stem cells from healthy donors aged 2,82 years (n = 13) and from three children suffering from Duchenne Muscular Dystrophy (DMD) were implanted into soleus muscles of immunoincompetent mice and were also expanded in vitro until senescence. Growth of implanted cells was quantified by structural features and by the amount of human DNA present in a muscle. Proliferative capacity in vitro and in vivo was inversely related to age of the donor. In vitro, a decline of about two mean population doublings (MPDs) per 10 years of donor's age was observed. Muscle stem cells from DMD children were prematurely aged. In general, cell preparations with low or decreasing content in desmin-positive cells produced more MPDs than age-matched high-desmin preparations and upon implantation more human DNA and more nonmyogenic than myogenic tissue. Thus, a "Desmin Factor" was derived which predicts "quality" of the human muscle tissue growing in vivo. This factor may serve as a prognostic tool. [source] Overproduction, crystallization and preliminary crystallographic analysis of a novel human DNA-repair enzyme that recognizes oxidative DNA damageACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2004Viswanath Bandaru DNA glycosylases repair oxidative DNA damage caused by free radicals. Recently, NEIL1, a human homolog of Escherichia coli DNA glycosylase endonuclease VIII, has been identified and shown to exhibit broad substrate specificity for a variety of types of pyrimidine-base damage. An active C-terminal deletion construct of NEIL1 was overexpressed in E. coli and crystallized. The unliganded NEIL1 crystallizes in space group R3, with unit-cell parameters a = b = 132.2, c = 51.1,Å. Complete data sets were collected from native, selenomethionyl and iodinated NEIL1 to 2.1, 2.3 and 2.4,Å, respectively. [source] | ||||||||||