Biomedical subjects

Robert D Burk

Publications and source records attributed to Robert D Burk.

At least 37 records · Page 2Linked to original sources

PubMed2005

Natural history and possible reactivation of human papillomavirus in human immunodeficiency virus-positive women.

BACKGROUND: Little is known in human immunodeficiency virus (HIV)-positive women about how the combination of plasma HIV RNA level and CD4+ T-cell count is associated with the natural history of human papillomavirus (HPV) infection or about HPV reactivation--whether it occurs and with what frequency in HIV-positive women. METHODS: HIV-positive (n = 1848) and -negative (n = 514) women were assessed at semiannual visits (total person-years = 5661) for cervicovaginal HPV with polymerase chain reaction assays and for squamous intraepithelial lesions (SILs) by Pap smear. We studied the prevalent detection of HPV and SILs with generalized estimating equations and the incident detection and persistence of HPV and SILs with multivariable Cox models. All statistical tests were two-sided. RESULTS: We observed a strong interaction between the associations of CD4+ and plasma HIV RNA strata with both prevalent (P(interaction) = .002) and incident (P(interaction) = .001) detection of HPV. Indeed, the hazard ratio for incident HPV detection peaked between 4.0 and 5.0, with either a CD4+ count of less than 200 cells per mm3 or an HIV RNA level of more than 100,000 copies per mL. Although incident HPV detection in all women was associated with the number of recent sex partners (P(trend)<.001), 22% of sexually inactive HIV-positive women with a CD4+ count of less than 200 cells/mm3 also had at least one incidentally detected HPV type. The association between CD4+/HIV RNA strata and HPV persistence was statistically significantly smaller (P<.001) than for incident HPV detection. SIL prevalence, incident detection, and persistence had similar associations with CD4+/HIV RNA strata as HPV (above). CONCLUSION: In HIV-positive women, plasma HIV RNA level and CD4+ count in combination appear to have a strong and statistically interactive association with incident detection of HPV, some of which may reflect HPV reactivation (e.g., in sexually inactive women). The more moderate association between HIV coinfection and HPV persistence could partly explain why cervical cancer rates have not reached more epidemic proportions in HIV-positive women.

AIDS-Related Opportunistic Infections↗

PubMed2005

Variability of serum levels of tumor necrosis factor-alpha, interleukin 6, and soluble interleukin 6 receptor over 2 years in young women.

Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and soluble interleukin 6 receptor (sIL-6R) have been studied as risk factors of cardiovascular disease in longitudinal studies. However, it is unknown about their long-term intra-individual variations and whether single measurements of these cytokines and receptor are reliable biomarkers in epidemiological studies. In this study, serum levels of TNF-alpha, IL-6, and sIL-6R were assayed by ELISAs in 36 young, healthy women from whom three blood samples were collected at 12-month intervals over 2 years, and the intraclass correlation coefficients (ICC) were estimated. The ICC of 0.73 (95% CI=0.49-0.79) for TNF-alpha was comparable to those of other commonly used biomarkers, justifying its use in epidemiological studies. The ICC of 0.48 (95% CI=0.25-0.58) for IL-6 was not optimal. However, IL-6 has been demonstrated as a consistent risk factor for cardiovascular disease, suggesting it could still be a useful biomarker if its disease association is substantial. The ICC of 0.36 (95% CI=0.10-0.47) for sIL-6R was relatively low, and multiple samples would need to be collected in prospective studies for this receptor.

Adolescent↗

PubMed2005

Incidence of cervical squamous intraepithelial lesions associated with HIV serostatus, CD4 cell counts, and human papillomavirus test results.

CONTEXT: Recent cervical cancer screening guidelines state that the interval between screenings can be safely extended to 3 years in healthy women 30 years or older who have normal cytology results and have negative test results for oncogenic human papillomavirus (HPV) DNA. OBJECTIVE: To determine the incidence of squamous intraepithelial lesions (SILs) in HIV-seropositive women with normal cytology results, by baseline HPV DNA results. DESIGN, SETTING, AND PATIENTS: Participants were HIV-seropositive (n = 855; mean age, 36 years) and HIV-seronegative (n = 343; mean age, 34 years) US women with normal baseline cervical cytology who were enrolled in the Women's Interagency HIV Study (WIHS), a large, multi-institutional prospective cohort study. Since their recruitment during 1994-1995, WIHS participants have been followed up semi-annually with repeated Pap smears for a median of 7 years. MAIN OUTCOME MEASURE: The cumulative incidence of any SIL and high-grade SIL or cancer (HSIL+) was estimated according to baseline HPV DNA results, stratified by HIV serostatus and CD4 T-cell count. RESULTS: Development of any SIL in women with negative HPV results (both oncogenic and nononcogenic) at 2 years was as follows: in HIV-seropositive women with CD4 counts less than 200/microL, 9% (95% CI, 1%-18%); with CD4 counts between 200/muL and 500/microL, 9% (95% CI, 4%-13%); and with CD4 counts greater than 500/microL, 4% (95% CI, 1%-7%). The CIs for these estimates overlapped with those for HIV-seronegative women with normal baseline cytology who were HPV-negative (3%; 95% CI, 1%-5%), indicating that at 2 years, there were no large absolute differences in the cumulative incidence of any SIL between groups. Furthermore, no HPV-negative participants in any group developed HSIL+ lesions within 3 years. Multivariate Cox models showed that on a relative scale, the incidence of any SIL among HIV-seropositive women with CD4 counts greater than 500/microL (hazard ratio [HR], 1.2; 95% CI, 0.5-3.0), but not those with CD4 counts less than or equal to 500/microL (HR, 2.9; 95% CI, 1.2-7.1), was similar to that in HIV-seronegative women. CONCLUSION: The similar low cumulative incidence of any SIL among HIV-seronegative and HIV-seropositive women with CD4 counts greater than 500/microL and who had normal cervical cytology and HPV-negative test results suggests that similar cervical cancer screening practices may be applicable to both groups, although this strategy warrants evaluation in an appropriate clinical trial.

Adult↗

PubMed2005

Isolation and cloning of a papillomavirus from a North American porcupine by using multiply primed rolling-circle amplification: the Erethizon dorsatum papillomavirus type 1.

The complete genome of a novel papillomavirus was isolated from a cutaneous papillomatous lesion of a North American porcupine (Erethizon dorsatum) using multiply primed rolling-circle amplification (RCA). The nucleotide sequence, genome organization, and phylogenetic position of the Erethizon dorsatum papillomavirus type 1 (EdPV-1) were determined. EdPV-1 is only distantly related to other benign cutaneous papillomavirus sequences and is the first member of the novel Sigma papillomavirus genus.

Animals↗

PubMed2005

A study of the impact of adding HPV types to cervical cancer screening and triage tests.

Use of human papillomavirus (HPV) testing in cervical cancer prevention is increasing rapidly. A DNA test for 13 HPV types that can cause cervical cancer is approved in the United States for co-screening with cytology of women >or=30 years old and for triage of women of all ages with equivocal cytology. However, most infections with HPV are benign. We evaluated trade-offs between specificity and sensitivity for approximately 40 HPV types in predicting cervical intraepithelial neoplasia 3 and cancer in two prospective studies: a population-based screening study that followed 6196 women aged 30-94 years from Costa Rica for 7 years and a triage study that followed 3363 women aged 18-90 years with equivocal cytology in four U.S. centers for 2 years. For both screening and triage, testing for more than about 10 HPV types decreased specificity more than it increased sensitivity. The minimal increases in sensitivity and in negative predictive value achieved by adding HPV types to DNA tests must be weighed against the projected burden to thousands of women falsely labeled as being at high risk of cervical cancer.

Adult↗

PubMed2005

Coercive sexual experiences and subsequent human papillomavirus infection and squamous intraepithelial lesions in adolescent and young adult women.

PURPOSE: The purpose of this study was to examine the associations between coercive sexual experiences and subsequent human papillomavirus (HPV) infection and/or squamous intraepithelial lesion (SIL) in adolescent and young adult women, and to determine whether risk behaviors mediate and sociodemographic factors moderate any observed associations. METHODS: Data were obtained from a longitudinal cohort study of female university students (N = 608). chi2 and Wilcoxon rank-sum tests were used to determine associations between history of a coercive sexual experience and subsequent risk behaviors, and between risk behaviors and HPV or SIL. Logistic regression models were used to determine whether a coercive sexual experience was associated with HPV or SIL and whether the association was mediated by risk behaviors and/or moderated by sociodemographic factors. RESULTS: Twenty-two percent of participants reported a prior coercive sexual experience. Report of a prior coercive sexual experience was associated with a higher lifetime number of sexual partners (p < .0001), which in turn was associated with subsequent HPV infection (p < .0001) and SIL (p < .0001). In logistic regression models, coercive sexual experience was associated significantly with HPV (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.19-2.84) and at a marginal significance level with SIL (OR, 1.90; 95% CI, .97-3.70). When the number of sexual partners was included in the first model, the association between coercive sexual experience and HPV infection became nonsignificant and the beta coefficient decreased by 49%. Race and age did not appear to moderate the association between coercive sexual experience and HPV. CONCLUSIONS: The number of sexual partners is an important mechanism through which adolescent and young adult women who report a coercive sexual experience acquire HPV.

Adolescent↗

PubMed2005

Outcome after negative colposcopy among human immunodeficiency virus-infected women with borderline cytologic abnormalities.

OBJECTIVE: To estimate the risk of and risk factors for progression among human immunodeficiency virus (HIV)-seropositive women with abnormal cervical cytology but negative colposcopy. METHODS: In a prospective cohort study, 391 HIV-seropositive and 103 seronegative women with cervical cytology read as atypical squamous cells (ASC) or low-grade squamous intraepithelial lesion (LSIL) but negative colposcopy were followed up for a mean of 4.0 years with cytology at 6-month intervals. Colposcopy was prescribed for any epithelial abnormality. RESULTS: Progression to CIN2, CIN3, high-grade SIL/severe dysplasia, or cancer occurred in 47 (12%) HIV-seropositive women and 4 (4%) HIV-seronegative women (P = .02). Progression to CIN1 was seen in an additional 12 HIV-seropositive women and 1 seronegative woman. In multivariate analysis, high-risk but not low-risk HPV detection (hazard ratio [HR] 2.46-95% confidence interval [CI] 1.18-5.12, P = .02 for high risk, HR 1.41, 95% CI 0.62-3.21, P = .42 for low risk), satisfactory colposcopy (HR 2.01, 95% CI 1.11-3.65, P = .02), and non-Hispanic African-American ethnicity (HR 5.08, 95% CI 1.72-14.98, P = .003) were the only factors associated with progression, while HIV serostatus was marginally significant (HR 2.53, 95% CI 0.85-7.50, P = .09). CONCLUSION: Human immunodeficiency virus-seropositive women with negative colposcopy after borderline cytology face a higher risk of progression than seronegative women, but the absolute risk is low and becomes nonsignificant after controlling for HPV risk type, ethnicity, and colposcopic findings. Observation is appropriate. LEVEL OF EVIDENCE: II-2.

Adult↗

PubMed2005

Overlapping reading frames in closely related human papillomaviruses result in modular rates of selection within E2.

A core group of four open reading frames (ORFs) is present in all known papillomaviruses (PVs): the E1 and E2 replication/transcription proteins and the L1 and L2 structural proteins. Because they are involved in processes that are essential to PV propagation, the sequences of these proteins are well-conserved. However, sequencing of novel subtypes for human papillomaviruses (HPV) 54 (AE9) and 82 (AE2/IS39), coupled to analysis of four other closely related genital HPV pairs, indicated that E2 has a higher dN/dS ratio than E1, L1 or L2. The elevated ratio is not homogeneous across the length of the ORF, but instead varies with respect to E2's three domains. The E2 hinge region is of particular interest, because its hypervariability (dN/dS>1) differs markedly from the two domains that it joins: the transcription-activation domain and the DNA-binding domain. Deciphering whether the hinge region's high rate of non-synonymous change is the result of positive Darwinian selection or relaxed constraint depends on the evolutionary behaviour of E4, an ORF that overlaps E2. The E2 hinge region is contained within E4 and non-synonymous changes in the hinge are associated with a disproportionate amount of synonymous change in E4, a case of simultaneous positive and purifying selection in overlapping reading frames. Modular rates of selection among E2 domains are a likely consequence of the presence of an embedded E4. E4 appears to be positioned in a part of the HPV genome that can tolerate non-synonymous change and purifying selection of E4 may be indicative of its functional importance.

Adult↗

PubMed2005

Variants of human papillomaviruses 16 and 18 and their natural history in human immunodeficiency virus-positive women.

Highly oncogenic human papillomavirus (HPV) 16 and 18 variants might be expected to be particularly aggressive in HIV-positive women. The association of HPV16 and 18 variant lineages with race, human immunodeficiency virus (HIV) coinfection, CD4+ T-cell count, HIV-RNA level, time-to-clearance of HPV infection and presence of squamous intraepithelial lesions (SIL) among women in the Women's Interagency HIV Study was studied. Subjects were followed semi-annually with Pap smear and cervicovaginal lavage (CVL). HPV DNA was detected in CVLs using MY09/11 L1 PCR assay. Specimens positive for HPV16/18 underwent E6 PCR and sequencing to determine the variant present. Specimens from 195 HPV16- and 162 HPV18-positive women were classified into variant lineages based on sequencing results. African variants of HPV16 and HPV18 were significantly more prevalent among African-Americans than among Caucasians [42 versus 14 % (P=0.001) and 60 versus 13 % (P<0.001), respectively]. However, it was not possible to detect associations between the HPV16 or 18 variant lineages and other factors studied. African variants of HPV16/18 were more common in women of African descent living outside Africa, which could reflect mixing behaviours and/or immunogenetic factors. However, in a large population of HIV-infected women, the variant of HPV16 or 18 was unrelated to persistence of infection or presence of SIL. If non-European variants are more oncogenic, the effect may involve a late stage in cervical tumorigenesis.

AIDS-Related Opportunistic Infections↗

PubMed2005

Diversifying selection in human papillomavirus type 16 lineages based on complete genome analyses.

Human papillomavirus type 16 (HPV16) is the primary etiological agent of cervical cancer, the second most common cancer in women worldwide. Complete genomes of 12 isolates representing the major lineages of HPV16 were cloned and sequenced from cervicovaginal cells. The sequence variations within the open reading frames (ORFs) and noncoding regions were identified and compared with the HPV16R reference sequence. This whole-genome approach gives us unprecedented precision in detailing sequence-level changes that are under selection on a whole-viral-genome scale. Of 7,908 base pair nucleotide positions, 313 (4.0%) were variable. Within the 2,452 amino acids (aa) comprising 8 ORFs, 243 (9.9%) amino acid positions were variable. In order to investigate the molecular evolution of HPV16 variants, maximum likelihood models of codon substitution were used to identify lineages and amino acid sites under selective pressure. Five codon sites in the E5 (aa 48, 65) and E6 (aa 10, 14, 83) ORFs were demonstrated to be under diversifying selective pressure. The E5 ORF had the overall highest nonsynonymous/synonymous substitution rate (omega) ratio (M3 = 0.7965). The E2 gene had the next-highest omega ratio (M3 = 0.5611); however, no specific codons were under positive selection. These data indicate that the E6 and E5 ORFs are evolving under positive Darwinian selection and have done so in a relatively short time period. Whether response to selective pressure upon the E5 and E6 ORFs contributes to the biological success of HPV16, its specific biological niche, and/or its oncogenic potential remains to be established.

Adult↗

PubMed2005

Phylogenetic incongruence among oncogenic genital alpha human papillomaviruses.

The human papillomaviruses (HPVs) have long been thought to follow a monophyletic pattern of evolution with little if any evidence for recombination between genomes. On the basis of this model, both oncogenicity and tissue tropism appear to have evolved once. Still, no systematic statistical analyses have shown whether monophyly is the rule across all HPV open reading frames (ORFs). We conducted a taxonomic analysis of 59 mucosal/genital HPVs using whole-genome and sliding-window similarity measures; maximum-parsimony, neighbor-joining, and Bayesian phylogenetic analyses; and localized incongruence length difference (LILD) analyses. The algorithm for the LILD analyses localized incongruence by calculating the tree length differences between constrained and unconstrained nodes in a total-evidence tree across all HPV ORFs. The process allows statistical evaluation of every ORF/node pair in the total-evidence tree. The most significant incongruence was observed at the putative high-risk (i.e., cancer-associated) node, the common oncogenic ancestor for alpha HPV species 9 (e.g., HPV type 16 [HPV16]), 11, 7 (e.g., HPV18), 5, and 6. Although these groups share early-gene homology, including high degrees of similarity among E6 and E7, groups 9 and 11 diverge from groups 7, 5, and 6 with respect to L2 and L1. The HPV species groups primarily associated with cervical and anogenital cancers appear to follow two distinct evolutionary paths, one conferred by the early genes and another by the late genes. The incongruence in the genital HPV phylogeny could have occurred from an early recombination event, an ecological niche change, and/or asymmetric genome convergence driven by intense selection. These data indicate that the phylogeny of the oncogenic HPVs is complex and that their evolution may not be monophyletic across all genes.

DNA Viruses↗

PubMed2005

Plasma uric acid levels in women with cervical intraepithelial neoplasia.

The objective of this study was to determine the association of plasma levels of uric acid, an endogenous antioxidant, in women with cervical intraepithelial neoplasia (CIN), while controlling for the confounding effects of human papillomavirus (HPV) infection, age, smoking, and use of oral contraception. Plasma-reduced and oxidized uric acid levels were determined in 650 women by high-performance liquid chromatography, employing electrochemical technique. The findings demonstrated that 1) plasma-reduced uric acid (PRUA) levels in women with CIN (n = 311) were significantly lower (P < 0.05) compared with women in a control group (n = 339); 2) according to multiple logistic regression analysis, PRUA levels were negatively (P = 0.0113) and HPV infection were positively associated (P < 0.0001) with CIN, after controlling for the confounding effects of the studied factors; 3) according to multiple regression analysis, there was a 31% decrease in CIN risk for each incremental increase of 1mg/dl of PRUA; and 4) according to polychotomous logistic regression analysis, independent of HPV infection, PRUA level was inversely associated with the histopathological graded severity of CIN. We have previously reported decreased plasma levels of exogenous antioxidants, for example, vitamins C and E, in women with CIN independent of HPV infection. The data suggest that plasma deficiencies of several antioxidants in HPV-infected uterine cervical tissue may create an oxidative environment that renders the tissue susceptible to free radical damage. It may be speculated that chronic free radical-induced tissue damage in the context of persistent HPV infection may be involved in the pathogenesis of CIN.

Adult↗

PubMed2005

PCR testing of pooled longitudinally collected cervical specimens of women to increase the efficiency of studying human papillomavirus infection.

In large active cohort studies of women investigating human papillomavirus (HPV) and cervical neoplasia, many women will be HPV-negative at all time points and testing of all their cervical specimens is an inefficient use of laboratory resources. The aim of this pilot study was to evaluate whether pooling cervical specimens from the same woman might provide a useful pretest of specimens from women unlikely to have high-grade cervical neoplasia or significant HPV exposure. We selected women (n = 187) participating in the Guanacaste Project for whom we already had HPV testing data on all their specimens from multiple visits (median = 8 visits), who were HPV DNA-negative at enrollment and at their 5- to 7-year exit from the cohort, and had no evidence of high-grade cervical neoplasia. Equal aliquots of cervical specimens from these women were pooled to create a proportional pooled specimen. Aliquots of pooled specimens were tested in a masked fashion by MY09/11 L1 consensus primer PCR. Second aliquots of some pooled specimens (n = 83) were included to assess the reliability of pooled testing. Results were compared with the predicted (expected) results based on the obtained test results of the individual specimens collected at interim visits. There was good overall agreement between observed and expected HPV DNA positivity, with a kappa of 0.63 [95% confidence interval (95% CI), 0.51-0.75] and a percent agreement of 83.4% (95% CI, 77.3-88.5%) although the HPV DNA positivity in the pooled specimen was less than expected (P = 0.001). The agreement between observed and expected HPV DNA positivity was related to the number of aliquots pooled, suggesting that positivity was related to viral genome concentrations. The kappa and percent agreement for intra-batch reliability of testing pooled specimens were 0.68 (95% CI, 0.53-0.84) and 84.3% (95% CI, 74.7-91.4%), respectively. We conclude that pooling specimens and testing by PCR may be useful for discriminating HPV DNA-positive from completely negative specimen sets in women who are likely to have been HPV DNA-negative.>

Female↗

PubMed2004

Codetection of a mixed population of candHPV62 containing wild-type and disrupted E1 open-reading frame in a 45-year-old woman with normal cytology.

We have cloned, sequenced, and characterized the complete genome of a novel human papillomavirus (HPV), candHPV62. During cloning, 2 candHPV62 viral isolates were recovered from a single cervical sample; 1 had all anticipated HPV open-reading frames (ORFs) intact, whereas the other exhibited an E1 frame-shift mutation. Further experiments indicated that the 2 strains were equivalent in abundance. It appears that an early mutation occurred within the E1 ORF, which was transcomplemented by an intact E1 protein. A search of the HPV database identified disruption of the E1 ORF in the cloned reference isolates of HPV16, HPV53, HPV56, and HPV72. These data suggest that disruption of the E1 ORF in genital HPVs is not uncommon.

Base Sequence↗

PubMed2004

Highly active antiretroviral therapy and cervical squamous intraepithelial lesions in human immunodeficiency virus-positive women.

BACKGROUND: Women infected with human immunodeficiency virus (HIV) have an increased risk of persistent squamous intraepithelial lesions (SILs) of the cervix. We assessed the association between use of highly active antiretroviral therapy (HAART) and regression of SIL in HIV-infected women enrolled in the Women's Interagency HIV Study, a large, multicenter, prospective cohort study. METHODS: Of 2059 HIV-infected participants, 312 HIV-infected women had normal cervical cytology at baseline and were subsequently diagnosed during 7 years of follow-up with incident SIL. Pap smears, CD4+ T-cell counts, and information regarding use of HAART were obtained every 6 months. The outcome of interest was lesion regression, defined as two consecutive normal Pap smears 6 months apart. Incidence rates of SIL regression were computed among person-years at risk, both before and after HAART initiation. All statistical tests were two-sided. RESULTS: Of 312 women, 141 had lesions that regressed to normal cytology, with a median time to regression of 2.7 years. Overall, the incidence of regression increased (P(trend) =.002) over time after HAART was introduced. At incident SIL, median CD4+ T-cell counts were lower in women whose lesions did not regress than in women whose lesions regressed (230 versus 336 cells/microL; P<.01). Before HAART was introduced, the rate of lesion regression was 0.0% (95% confidence interval [CI' = 0.0% to 2.4%). After HAART was introduced, the rate was 12.5% (95% CI = 9.9% to 15.1%) and was related to post-HAART CD4+ T-cell counts (P(trend) =.002). CONCLUSIONS: HAART use was associated with increased regression of SIL among HIV-infected women, and among women who used HAART, increased CD4+ T-cell counts were associated with a greater likelihood of regression. However, the majority of cervical lesions among HIV-infected women, even among individuals who used HAART, did not regress to normal.

AIDS-Related Opportunistic Infections↗

PubMed2004

A population-based study of vaginal human papillomavirus infection in hysterectomized women.

We compared point prevalences and determinants of human papillomavirus (HPV) DNA detection by testing enrollment vaginal specimens from hysterectomized women (n=569) and enrollment cervical specimens from nonhysterectomized women (n=6098) >or=30 years old, using MY09/MY11 L1 consensus-primer polymerase chain reaction. The subjects were participating in a population-based cohort study (n=10,049) in Guanacaste, Costa Rica, that was initiated in 1993. Non-cancer-associated HPV types, especially types 61, 71, and 72, were detected more frequently in the vaginal specimens from hysterectomized women (23.7% [95% confidence interval [CI], 20.3%-27.4%]) than in the cervical specimens from nonhysterectomized women (16.7% [95% CI, 15.7%-17.6%]) (P=.0001). There was no difference between the prevalences of cancer-associated HPV types in hysterectomized women and those in nonhysterectomized women; in both groups, the prevalence of HPV DNA was greater in women with multiple lifetime sex partners. We infer from our data that the cervical transformation zone may not be needed for cancer-associated HPV infection but may be uniquely susceptible to HPV-induced carcinogenesis; we also infer that specific phylogenetic groups of HPV (i.e., A3/A4/A15) may have a predilection for vaginal epithelium.

Adult↗

PubMed2004

Low prevalence of HPV infection and its natural history in normal oral mucosa among volunteers on Miyako Island, Japan.

OBJECTIVE: To investigate the prevalence of human papillomavirus (HPV) infection in normal oral mucosa, and to observe the natural history in the oral cavity in oral swab samples collected from healthy volunteers on Miyako Island, Okinawa, Japan. STUDY DESIGN: The prevalence of HPV infection in oral buccal mucosa cell scrapes collected between 2000 and 2002 from a cohort of 668 healthy volunteers was determined. HPV DNA was detected by consensus polymerase chain reaction (PCR) using MY09/MY11 primers followed by direct cycle sequencing. Just over 2 years later the HPV-positive participants were reevaluated. RESULTS: Of the 668 subjects, 662 samples were analyzed for HPV. HPV DNA was detected in 4 (0.6%) specimens. HPV type 16 (HPV16), HPV53, and HPV71, mucosal types, and HPV12, a cutaneous type, were all identified by direct sequencing. In the follow-up survey, the HPV71- and HPV12-positive participants again tested positive, while HPV DNA was not detected in the HPV16- and HPV53-positive participants. CONCLUSION: The results of this study among healthy individuals from Miyako Island suggest that oral HPV infection is uncommon. In this cohort, HPV71 and HPV12 were persistent, while HPV16 and HPV53 were transient in normal oral mucosa.

Adolescent↗

PubMed2004

Lack of the canonical pRB-binding domain in the E7 ORF of artiodactyl papillomaviruses is associated with the development of fibropapillomas.

The L-X-C-X-E pRB-binding motif of papillomavirus (PV) E7 proteins has been implicated in the immortalization and transformation of the host cell. However, sequencing of the complete genomes of bovine papillomavirus type 3 (BPV-3), bovine papillomavirus type 5 (BPV-5), equine papillomavirus (EQPV) and reindeer (Rangifer tarandus) papillomavirus (RPV) supports the notion that the pRB-binding motif is not ubiquitous among E7 proteins in the PV proteome. Key among the animal groups that lack the pRB-binding domain are the artiodactyl PVs, including European elk PV (EEPV), deer PV (DPV), reindeer PV (RPV), ovine PVs types 1 and 2 (OvPV-1 and -2) and bovine PVs 1, 2 and 5 (BPV-1, -2 and -5). Whereas the presence of the pRB-binding domain is normally associated with papillomas, the artiodactyl PVs are marked by the development of fibropapillomas on infection. Previous studies emphasized the role of E5 in the pathogenic mechanism of fibropapilloma development, but correlation between the lack of an E7 pRB-binding domain and the unique pathology of the artiodactyl PVs suggests a more complicated mechanism and an early evolutionary divergence from a pRB-binding ancestor.

Amino Acid Sequence↗