Biomedical subjects

P Gravitt

Publications and source records attributed to P Gravitt.

6 recordsLinked to original sources

PubMed2000

A prospective study of human papillomavirus (HPV) type 16 DNA detection by polymerase chain reaction and its association with acquisition and persistence of other HPV types.

Human papillomavirus (HPV)-16 causes about half the cases of cervical cancer worldwide and is the focus of HPV vaccine development efforts. Systematic data are lacking as to whether the prevention of HPV-16 could affect the equilibrium of infection with other HPV types and thus alter the predicted impact of vaccination on the occurrence of cervical neoplasia. Therefore, the associations of HPV-16 detection with subsequent acquisition of other HPV types and with the persistence of concomitantly detected HPV types were examined prospectively among 1124 initially cytologically normal women. Preexisting HPV-16 was generally associated with an increased risk for subsequent acquisition of other types. HPV-16 did not affect the persistence of concomitant infections, regardless of type. These findings suggest that the prevention or removal of HPV-16 is not likely to promote the risk of infection with other types, a theoretical concern with current vaccination efforts.

Cohort Studies↗

PubMed1999

Nonisotopic detection and typing of human papillomavirus DNA in genital samples by the line blot assay. The Canadian Women's HIV study group.

The line blot assay, a gene amplification method that combines PCR with nonisotopic detection of amplified DNA, was evaluated for its ability to detect human papillomavirus (HPV) DNA in genital specimens. Processed samples were amplified with biotin-labeled primers for HPV detection (primers MY09, MY11, and HMB01) and for beta-globin detection (primers PC03 and PC04). Amplified DNA products were hybridized by a reverse blot method with oligonucleotide probe mixtures fixed on a strip that allowed the identification of 27 HPV genotypes. The line blot assay was compared to a standard consensus PCR test in which HPV amplicons were detected with radiolabeled probes in a dot blot assay. Two hundred fifty-five cervicovaginal lavage specimens and cervical scrapings were tested in parallel by both PCR tests. The line blot assay consistently detected 25 copies of HPV type 18 per run. The overall positivity for the DNA of HPV types detectable by both methods was 37.7% (96 of 255 samples) by the line blot assay, whereas it was 43. 5% (111 of 255 samples) by the standard consensus PCR assay. The sensitivity and specificity of the line blot assay reached 84.7% (94 of 111 samples) and 98.6% (142 of 144 samples), respectively. The agreement for HPV typing between the two PCR assays reached 83.9% (214 of 255 samples). Of the 37 samples with discrepant results, 33 (89%) were resolved by avoiding coamplification of beta-globin and modifying the amplification parameters. With these modifications, the line blot assay compared favorably to an assay that used radiolabeled probes. Its convenience allows the faster analysis of samples for large-scale epidemiological studies. Also, the increased probe spectrum in this single hybridization assay permits more complete type discrimination.

Cervix Uteri↗

PubMed1994

Long PCR.

Explore the source record for details and available documents.

DNA↗

PubMed1991

A direct comparison of methods proposed for use in widespread screening of human papillomavirus infections.

We obtained cervical swabs from 397 women participating in a human papillomavirus (HPV) prevalence study. Samples were assayed for HPV infection using ViraPap expanded cocktail (detecting HPV types 6, 11, 16, 18, 31, 33, 35, 42, 43, 44, 45, 51, 52 and 56), ViraType and PCR amplifications. Consensus primers from the L1 region were used with generic and type-specific oligonucleotide probes. Additionally, the generic amplifications were analysed with a novel restriction digest scheme. Samples positive by these methods were confirmed by PCR amplification using primers from the E5 region specific for HPV types 6, 16 and 18. The presence of human DNA in the samples was verified with amplification of the human KM-19 haplotyping primers. Our results confirm that the PCR reporter oligomer hybridization method is more sensitive than ViraPap/ViraType, but encompasses a narrower range of HPV types. This is particularly true of the higher number types in the expanded cocktail. The narrow range seems to occur as the result of the reporter oligomer used in hybridization, rather than the consensus amplimer pair used. Amplification of a broader range of HPVs is seen on gels or using the restriction digest as confirmation of HPV infection. Both ViraPap and PCR methods of detection gave about a 10% rate of uninterpretable results. PCR methods indicated about 1.7 times as many positives, while showing overall agreement of 77.6% with ViraPap. Agreement on types ranged from 67% to 100%. All methods indicated large fractions of untypable HPVs).

Base Sequence↗

PubMedDate not supplied

Determinants of genital human papillomavirus infection in low-income women in Washington, D.C.

OBJECTIVES: To confirm the risk factors for genital human papillomavirus (HPV) infection. GOAL OF THIS STUDY: To investigate risk factors for HPV detection independent of the correlated risk factors for cervical neoplasia, in a high-risk population. STUDY DESIGN: We investigated 404 cytologically normal women attending medical assistance clinics in the Washington, D.C. area. Risk factor information was obtained and a cervicovaginal lavage was collected and used for HPV detection and typing by a PCR-based technique. RESULTS: The point prevalence of HPV was 33.7%. This contrasts with the 17.7% and 44.3% observed in the companion reports published in this issue of the journal. HPV prevalence decreased with age and increased with greater numbers of sexual partners. Moreover, more recent sexual behavior was a better predictor of current HPV detection than lifetime number of sexual partners. Numbers of pregnancies and current pregnancy were positively associated with HPV prevalence and there was an indication that current oral contraceptive users had a higher prevalence of HPV compared to never users. Smoking was not associated with increased HPV prevalence. CONCLUSION: Findings support the sexual route of transmission of HPV and confirm the association of HPV detection with age, suggesting the host's ability to clear infection or the virus' ability to become latent.

Adolescent↗

PubMedDate not supplied

Human papillomavirus genotypes associated with cervical neoplasia in India.

The aim of this study was to determine the prevalence of human papillomavirus (HPV) genotypes in tissue with cervical neoplasias in patients from south and east India. Cross-sectional cervical tissue was obtained from 100 patients from south India and 30 patients from east India who had a biopsy for clinically invasive cervical cancer or cervical intraepithelial neoplasia (CIN) in a tertiary care hospital in India. DNA amplification was done with biotinylated PGMY 09/11 primers, and the line blot assay was used to determine the HPV genotype. HPV DNA was detected in 95% of invasive cancers (113/119) and 91% of CINs (10/11). A single HPV type was found in 100 women (77%), and mixed infections were found in 23 women (18%). HPV 16 (60%) and HPV 18 (14%) were the most frequent types, but 16 other types (26, 31, 33, 35, 42, 45, 51, 52, 53, 56, 58, 61, 62, 64, 81, and 82) were also identified. HPV 16 was present in 63% of patients from south India and in 50% of patients from east India, while HPV 18 was present in 12% and 20%, respectively. There are several high-risk HPV types associated with cervical neoplasias of which types 16 and 18 are the most common.

Adolescent↗