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Reverse Hybridization (reverse + hybridization)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Detection of bacterial DNA by PCR and reverse hybridization in the 16S rRNA gene with particular reference to neonatal septicemia

ACTA PAEDIATRICA, Issue 2 2001
S 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]

Genital Carriage of Human Papilloma Virus (HPV) DNA in Prepubertal Girls with and without Vulval Disease

PEDIATRIC DERMATOLOGY, Issue 3 2003
Jennifer Powell, M.R.C.P.
Our objective was to compare HPV in prepubertal girls with and without lichen sclerosus (LS). We compared the frequencies and types of HPV in girls with LS with those in children with non-LS vulval disease (vulval swab and urine) and in children with no known vulval disease (urine only). HPV DNA was detected using a nested polymerase chain reaction (PCR) with general and consensus primers amplifying a region of the L1 gene, and PCR amplicons were typed using reverse hybridization with labeled HPV type-specific probes. Specimens untypeable by this method were typed by DNA sequencing. In the cohort of children with LS, we recorded the presence of maternal anogenital warts or a dysplastic cervical smear within 3 years of the affected child's birth. We found that HPV was present in the urine and vulval swabs of 8 of 32 children with LS and in 2 of 31 children with non-LS vulval disease, but also in the urine of 7 of 29 controls. In those with LS, the frequency was not increased significantly, but the types were predominantly those commonly associated with dysplasia of the cervix, penis, vulva, and anus, as opposed to the broader spectrum of types found in the control group, not all dysplasia associated. Two of the 32 mothers reported warts, and 15 of 32 (46.9%) had an abnormal smear. (The national average of abnormal cervical smears is less than 10%.) We concluded that HPV appears to be common in all prepubertal girls, but children with LS carried types associated with dysplasia and their mothers had had a high incidence of dyskaryotic smears. [source]

Presence of beta human papillomaviruses in nonmelanoma skin cancer from organ transplant recipients and immunocompetent patients in the West of Scotland

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2009
L.J. Mackintosh
Summary Background, Nonmelanoma skin cancer (NMSC) has been linked to cutaneous human papillomaviruses of the genus beta (betaPV). Objectives, We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients. Methods, One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction,reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes. Results, In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples (P = 0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2,8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) (P < 0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin. Conclusions, A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis. [source]

Occurrence of human papillomavirus in pterygia

ACTA OPHTHALMOLOGICA, Issue 8 2009
Marta Piecyk-Sidor
Abstract. Purpose:, The aim of the study was to assess the occurrence of human papillomavirus (HPV) DNA in pterygium. Methods:, The study involved 89 patients undergoing surgical procedures at the Department of Ophthalmology, Medical University of Lublin, Poland. Group 1 included 58 patients with clinically diagnosed pterygium. Group 2 consisted of 31 individuals with normal conjunctiva. The material was collected during elective surgical procedures. The presence of HPV genome was determined using polymerase chain reaction (PCR). Once the presence of HPV DNA was confirmed, 28 HPV genotypes were determined using reverse hybridization. Results:, The determinations confirmed the presence of HPV DNA in pterygium. In the material collected from 58 cases of pterygium (group 1), HPV DNA was identified in 16 patients (27.6%). In the material from 31 diagnostic specimens of normal conjunctiva (group 2), the presence of HPV was demonstrated in three cases (9.7%). A statistically significant difference was found in the presence of HPV DNA between the patients from groups 1 and 2 (p = 0.041). HPV type 16 was most common and was demonstrated in 56% of HPV-positive cases of pterygium. HPV 16 and HPV 6 co-infections were found in 19% of cases, while HPV 18 and HPV 6 co-infections were observed in 13%. In group 2, all three patients with HPV showed HPV 18. Conclusion:, It seems that HPV is not necessary to induce pterygium; however, it might play a synergistic role in the multi-stage process of its development. [source]