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Biomedical subjects

K H Fife

Publications and source records attributed to K H Fife.

At least 19 recordsLinked to original sources
PubMed2006

Down-regulation of MHC class I is a property common to papillomavirus E5 proteins.

The E5 protein family of papillomaviruses comprises small hydrophobic proteins which are associated with the cell endomembrane compartments. The functions of the E5 proteins, particularly those of HPV, are still far from clear. We have reported that the E5 proteins of BPV-1, BPV-4, HPV-16 and HPV-6 down-regulate MHC class I, potentially helping the virus evade the host immune response. Others have described MHC class I down-regulation by HPV-2 E5. We report here that another E5 protein, HPV-83 E5, likewise down-regulates MHC class I and propose that interference with expression, assembly and/or transport of MHC class I is a common property of all E5 proteins evolved by the virus to circumvent host immunosurveillance and thus establish productive infection.

Cell Line↗
PubMed2006

The psychosocial impact of serological diagnosis of asymptomatic herpes simplex virus type 2 infection.

OBJECTIVES: To evaluate the impact of a positive herpes simplex virus type 2 (HSV-2) serological test on psychosocial functioning among people with no known history of genital herpes. METHODS: Individuals (age 14-30 years) without a history of genital herpes were recruited from an urban university setting and sexually transmitted diseases (STD), primary care, and adolescent clinics. Participants completed a questionnaire addressing psychological functioning, psychosocial adjustment, and perceived quality of sex and were offered free HSV-2 antibody testing. 33 HSV-2 positive people and 60 HSV-2 negative people demographically matched from the same source of recruitment were re-evaluated at a 3 month follow up visit. HSV-2 positive participants also completed a genital herpes quality of life (GHQOL) measure. RESULTS: Of the 33 who were HSV-2 seropositive, four did not recall their diagnosis. In comparing those who were HSV-2 positive with those who were negative, repeated measures analysis of variance indicated there were no significant differences over time on any of the measures. None the less, many HSV-2 positive individuals indicated that the diagnosis had a notable impact on their quality of life. Also, among the HSV-2 positive people, lower GHQOL at the 3 month follow up was predicted by higher interpersonal sensitivity (r = -0.44, p<0.05), lower social support (r = 0.40, p<0.05), and quality of sex (r = 0.62, p<0.01) at baseline. CONCLUSIONS: A diagnosis of asymptomatic HSV-2 infection does not appear to cause significant lasting psychological difficulties. Those for whom the diagnosis had the greatest impact were interpersonally vulnerable before the diagnosis. These results suggest that assessment of interpersonal distress may be important to include as part of pretest and post-test counselling.

Adaptation, Psychological↗
PubMed2001

Neutralization of human papillomavirus type 11 (HPV-11) by serum from women vaccinated with yeast-derived HPV-11 L1 virus-like particles: correlation with competitive radioimmunoassay titer.

Neutralization of human papillomavirus type 11 (HPV-11) has been demonstrated using serum and cervical secretions from primates vaccinated with virus-like particles (VLPs). Theoretically, neutralizing antibodies could protect women from HPV infection. The immunogenicity of a yeast-derived HPV-11 L1 VLP vaccine was tested in women. Serum specimens were evaluated for HPV-11 titer by competitive radioimmunoassay (cRIA) and for neutralization by use of the athymic mouse xenograft system. Analysis of serum from 104 subjects showed a dose response in HPV-11 cRIA titers and neutralization. Overall, 68 (82.9%) of 82 postimmunization serum specimens from VLP recipients were 100% neutralizing when used in the assay at a 1:50 dilution. Of 69 serum specimens, 63 (91.3%) with cRIA titers >200 milliMerck units per milliliter were neutralizing. Immunization with HPV VLPs elicits a vigorous serum immune response in a high percentage of women. The HPV-11 cRIA titer appears to be a surrogate marker for neutralization.

Adolescent↗
PubMed2001

Detection of multiple human papillomavirus types in the lower genital tract correlates with cervical dysplasia.

Some human papillomavirus (HPV) types, such as HPV 16, are clearly associated with cervical dysplasia; however, the role played by other HPV types occasionally found in dysplasia is less certain. In addition, most methods used to detect HPV in clinical specimens cannot easily distinguish among more than two or three HPV types in a single specimen. Therefore, the significance of infection with multiple HPV types is not known. To address this question, we analyzed cervicovaginal lavage specimens from three cohorts of women for HPV DNA using a PCR/reverse blot assay system that permits the detection and partial quantitation of 26 genital HPV types. As expected, 94.1% of women who had dysplasia (n = 34) and 71.4% of women who had atypical squamous cells of uncertain significance (ASCUS) (n = 21) on cytology had HPV DNA detected compared to 54.5% of age matched women with normal cytology. HPV 16 DNA was detected in 35% of dysplasia patients compared to 9% of cytologic normals (P = 0.0044). Dysplasia patients had a mean of 3.29 (range 0-10) different HPV types detected compared to 1.04 (range 0-7) HPV types among those with normal cytology (P < 0.0001). These data support a possible role for multiple HPV types in the development or progression of cervical dysplasia.

Adult↗
PubMed2001

Treatment of external genital warts in men using 5% imiquimod cream applied three times a week, once daily, twice daily, or three times a day.

BACKGROUND: Medical therapy for genital warts remains suboptimal. The topical interferon and cytokine inducer, imiquimod, has been proved effective for the treatment of external genital and perianal warts, but there is a substantial difference in the response rates between men and women. When 5% imiquimod cream is applied three times a week up to 16 weeks, approximately two thirds of women treated with imiquimod achieve complete clearance of genital warts, whereas only about one third of men clear completely. GOAL: This study was undertaken to determine whether more frequent application of topical imiquimod cream would improve the rate of genital wart clearance in men. STUDY DESIGN: A randomized treatment trial involving adult men with biopsy-proven genital warts was conducted at nine centers in the United States and Canada using four different application frequencies. RESULTS: Complete clearance rates during the 16-week treatment period were as follows for the different imiquimod treatment frequencies: three times a week (35 %), once daily (28 %), twice daily (24%), and three times a day (27%)(P = 0.88). The four treatment groups all showed comparable reductions in the total lesion area, with a median of more than a 90% reduction in the lesion area by the end of treatment. There was a significant increase in the incidence and severity of local skin reactions including erythema, vesicle formation, ulceration, and excoriation as the dosing frequency increased from three times a week to three times a day. CONCLUSIONS: In this study, the optimal dosage regimen was the approved three times a week regimen. More frequent application (up to three times a day) did not improve clearance and was associated with an increase in local adverse events.

Adult↗
PubMed2000

In vivo antagonism with zidovudine plus stavudine combination therapy.

Human immunodeficiency virus (HIV)-infected subjects receiving zidovudine were randomized either to add stavudine (d4T) or didanosine (ddI) to their current regimen or to switch to ddI or d4T monotherapy. After 16 weeks of therapy, the mean reduction in HIV RNA from baseline was 0.14 log(10) copies/mL in patients receiving d4T or zidovudine plus d4T. In subjects receiving ddI or ddI plus zidovudine, reductions were 0.39 and 0.56 log(10), respectively. CD4 cell counts remained stable or showed modest increases in all arms except the zidovudine plus d4T arm. Patients receiving zidovudine plus d4T showed progressive declines in CD4 cell counts with a median of 22 cells/mm(3) below baseline by 16 weeks. Examination of intracellular levels of d4T-triphosphate in 6 subjects was consistent with previous in vitro studies demonstrating pharmacologic antagonism between zidovudine and d4T. Analysis of these data suggests that zidovudine and d4T should not be prescribed in combination and that ddI provides greater antiviral activity than d4T in zidovudine-treated patients.

Adult↗
PubMed2000

The human papillomavirus type 11 E1E4 protein is phosphorylated in genital epithelium.

The most abundant viral transcript in human papillomavirus (HPV) 11-infected xenograft tissue has been shown to encode the E1(wedge)E4 protein. The function of E1(wedge)E4 protein has not been determined. Several potential phosphorylation sequence motifs were identified in the HPV 11 E1(wedge)E4 protein, including potential sites of phosphorylation by mitogen-activated protein kinase (MAPK), cAMP-dependent protein kinase (PKA), casein kinase II, and protein kinase C. To test phosphorylation of the HPV 11 E1(wedge)E4 protein, a soluble maltose binding protein (MBP) fusion was produced in Escherichia coli. Only MAPK and PKA phosphorylated the E1(wedge)E4 protein. Phosphoamino acid analysis showed that one or more threonine residues were phosphorylated by MAPK, and both serine and threonine residues were phosphorylated by PKA. MBP-E1(wedge)E4 mutant proteins were designed to delineate the E1(wedge)E4 phosphoacceptor residues. MAPK was shown to phosphorylate E1(wedge)E4 on threonine 53 within a MAPK consensus phorphorylation sequence motif. PKA was shown to phosphorylate E1(wedge)E4 at two residues: threonine 36 within a consensus motif and serine 44 within a variant of the PKA consensus phosphorylation sequence motif. HPV 11-infected human genital tissue grown as a xenograft in an athymic mouse was labeled with [(32)P]orthophosphate. Phosphoamino acid analysis of E1(wedge)E4 protein immunoprecipitated from (32)P-labeled tissue revealed that both serine and threonine residues were phosphorylated. Analysis by liquid chromatography-mass spectrophotometry was consistent with phosphorylation of residues within the PKA and MAPK phosphorylation sequence motifs. Expression of E1(wedge)E4 protein containing phosphorylation substitution mutations showed that the PKA mutant did not differ from wild-type E1(wedge)E4 protein in intracellular distribution. In contrast, the MAPK mutant did not localize exclusively to the cytoplasm nor did it colocalize with wild-type E1(wedge)E4 protein. We conclude that HPV 11 E1(wedge)E4 protein is phosphorylated in vitro and in vivo. Our data are consistent with phosphorylation of HPV 11 E1(wedge)E4 protein by MAPK and PKA in infected tissue.

Amino Acid Sequence↗
PubMed1999

Nucleotide sequence and characterization of human papillomavirus type 83, a novel genital papillomavirus.

Studies of human papillomaviruses (HPV) are hampered by the lack of a conventional culture system, because HPV completes its life cycle only in fully differentiated human tissue. To overcome this obstacle, the athymic mouse xenograft system has been used to study the pathogenesis of a limited number of HPV types. We recently reported the propagation of a novel HPV type in the mouse xenograft system and the cloning of its genome. Consensus primer PCR had previously identified this virus as MM7, LVX82, or PAP291. Here we report the nucleotide sequence of the 8104-bp genome of this virus, now called HPV 83. HPV 83 is most closely related to HPV 61 and HPV 72, placing it in the papillomavirus genome homology group A3. Based on limited epidemiological data, the histological appearance of infected human foreskin implants, and the structure of the predicted HPV 83 E7 protein, this virus is probably of at least intermediate cancer risk. Like other papillomaviruses, HPV 83 produces an E1 E4, E5 transcript, but the position of the splice acceptor differs from that of other HPVs. The presence of an E5 open reading frame in the HPV 83 genome is uncertain; the most likely candidate to be the HPV 83 E5 protein has some structural similarity to the bovine papillomavirus 1 E5 oncoprotein, and is unlike most other HPV E5 proteins. HPV 83 is a relatively prevalent genital papillomavirus that has the largest genome of any characterized HPV and several other novel structural features that merit further study.

Amino Acid Sequence↗
PubMed1999

Cervical human papillomavirus deoxyribonucleic acid persists throughout pregnancy and decreases in the postpartum period.

OBJECTIVE: Our goal was to determine the persistence of human papillomavirus infection of the cervix in a prospectively evaluated cohort of pregnant women observed from the first trimester until after delivery. STUDY DESIGN: A group of 232 women were enrolled in the first trimester of pregnancy and had cervico-vaginal lavage specimens collected for detection of the deoxyribonucleic acid of human papillomavirus. They underwent sampling again in the third trimester (146 patients available) and at 4 to 12 weeks after delivery (83 patients available). Human papillomavirus deoxyribonucleic acid was detected by means of the Hybrid Capture assay. RESULTS: In the first trimester of pregnancy, 31% of the patients had positive test results for human papillomavirus deoxyribonucleic acid, whereas 35.6% had positive results in the third trimester (P = 1.0). A comparison of first-trimester test results with postpartum results (paired data available from 83 patients) showed a decline from 39.8% positivity to 26.5% (P =.04). Comparing third-trimester results with postpartum results (paired data available from 74 patients) showed a decline from 35.1% to 25. 7% positivity (P =.12). When specimens positive for human papillomavirus were divided between those containing "high cancer risk" types (9 virus types often associated with dysplasia or malignancy) and "low cancer risk" types (5 types usually found in benign lesions), similar trends were seen, although not all comparisons were statistically significant. CONCLUSION: The increased prevalence, during pregnancy, of detectable human papillomavirus deoxyribonucleic acid, which was previously reported (Fife et al, Am J Obstet Gynecol 1996;174:1487-93), persists at a similar level throughout pregnancy but declines in the postpartum period. This observation is most consistent with activation of the virus by the physiologic changes of pregnancy.

Adult↗
PubMed1999

Detection of multiple human papillomavirus types in Condylomata acuminata lesions from otherwise healthy and immunosuppressed patients.

Condylomata acuminata, or genital warts, are proliferative lesions of genital epithelium caused by human papillomavirus (HPV) infection. HPV types 6 and 11 are most often detected in these lesions. Genital lesions consistent with exophytic condylomata acuminata were removed by excision biopsy from 65 patients, 41 of whom were otherwise healthy individuals (control group) and 24 of whom had conditions known to cause immunosuppression. Histologically, the majority of the lesions were typical condylomata acuminata. Three lesions removed from immunosuppressed individuals also contained foci of moderate to severe dysplasia (intraepithelial neoplasia grade II/III). A recently developed PCR and reverse blot strip assay was used to determine the specific HPV types present in the genital lesions. With a set of oligonucleotide primers based on the same primer binding regions used for the MY09 and MY11 primer pair, this PCR assay detects the presence of 27 HPV types known to infect the genital tract. All but two condylomata acuminata contained either HPV type 6 or 11. The predominant type in the lesions from control patients was HPV 6, while lesions from immunosuppressed types most often contained HPV 11. Condylomata acuminata from immunosuppressed patients contained significantly more overall HPV types than lesions from the control group. HPV types associated with an increased risk of dysplasia (high-risk types) were detected in 42 (64.6%) of the total of 65 specimens; 18 (43.9%) specimens were detected in the 41 otherwise healthy individuals, and 24 (100%) specimens were detected in the 24 immunosuppressed patients. HPV 16 was the most common high-risk type detected, found in 21 of 65 (32.3%) specimens. After HPV types 6 and 11, HPV types 53 and 54 were the most frequently detected low-risk HPV types. This study demonstrates that a high percentage of condylomata acuminata lesions contain multiple HPV types, including types associated with a high risk of dysplastic abnormalities. Further studies are needed to determine the influence these additional HPV types have on the epidemiology of genital tract HPV infections and the natural history of condylomata acuminata, especially in immunosuppressed patients.

Adolescent↗
PubMed1998

A human papillomavirus related to human papillomavirus MM7/LVX82 produces distinct histological abnormalities in human foreskin implants grown as athymic mouse xenografts.

Studies of human papillomaviruses (HPVs) are hampered by the lack of a conventional culture system because HPV completes its life cycle only in fully differentiated human tissue. To overcome this obstacle, the athymic mouse xenograft system has been used to study the pathogenesis of HPV 11 and to develop neutralizing assays for vaccine development. Recently, HPV 40 has been produced in this system, and HPV 16 has been produced using mice with severe combined immune deficiency. To identify and characterize additional genital HPV types for similar studies, condylomata acuminata lesions containing a high copy number of HPV and detectable L1 major capsid protein were used to prepare infectious virus stocks. Human foreskin fragments were infected with the virus preparations and implanted under the renal capsules of athymic mice. After 5 months of growth, implant tissue was removed and processed for studies to detect HPV infection. Evidence of HPV infection was noted in some of the implants, but in contrast to HPV 11-infected epithelium, the implants derived from the new virus preparations contained a lesser degree of acanthosis, less developed koilocytosis, and a reduced number of preserved nuclei in the hyperkeratotic material within the cyst lining. The L1 consensus region was amplified by polymerase chain reaction from implant DNA and sequenced. Alignment of the amplified sequences with those in the HPV sequence database showed that the 452-bp amplimer was closely related but not identical to HPV LVX82 and HPV MM7 (also called Pap 291). The entire 7.9-kb genome was amplified by polymerase chain reaction and cloned. The presence of virions of the new isolate (named HPV IU) in the implants was verified by immunohistochemical detection of L1 major capsid protein and by demonstration of virion particles by electron microscopy. A second extract was made from one of the new implants and used to successfully propagate HPV IU. These experiments demonstrate that experimental infection of human epithelium with the new isolate, HPV IU, is associated with histological abnormalities that differ in potentially important ways from the changes observed in experimental HPV 11 infection.

Animals↗
PubMed1998

The intracellular expression pattern of the human papillomavirus type 11 E1--E4 protein correlates with its ability to self associate.

The function of the human papillomavirus type 11 (HPV 11) E1--E4 spliced protein is not known. E1--E4 protein in HPV-infected tissue is detected in the cytoplasm of differentiated epithelial cells and as immunoreactive bands corresponding to potential monomers, dimers and trimers in immunoblots. The yeast two-hybrid system was employed to test for self association of the HPV 11 E1--E4 protein. To confirm the results of the yeast two-hybrid experiments, coimmunofluorescence studies of a green fluorescent fusion protein (GFP-E1--E4) and a T7 epitope-tagged E1--E4 protein were performed in C33a keratinocytes. E1--E4 protein was shown to self associate in the yeast two-hybrid system, and this result was confirmed by colocalization of GFP-E1--E4 and T7-E1(wedge)E4 proteins in keratinocytes. Analysis of E1--E4 mutants established that the C-terminus was required for self association and that sequences in the N-terminus influenced the intracellular localization of E1--E4 protein. The intracellular expression patterns of GFP-E1--E4 and GFP-E1--E4 mutants were correlated with E1--E4 binding in the yeast two-hybrid system. Those E1--E4 mutants that did not self associate in the yeast two-hybrid system were detected as diffuse cellular fluorescence when expressed as GFP fusions. In contrast, GFP-E1--E4 was detected as a perinuclear aggregate. All E1--E4 mutants capable of associating with E1--E4 in the yeast two-hybrid system were detected as aggregates when expressed as GFP fusion proteins in keratinocytes.

Animals↗
PubMed1998

Expression of the human papillomavirus type 11 E5A protein from the E1E4,E5 transcript.

The abundant human papillomavirus type 11 (HPV 11) E1E4,E5 transcript potentially encodes the E1E4,E5a and E5b proteins. It is not known if either of the E5 proteins are expressed from this transcript. For HPV 16, E5 is a single open reading frame (ORF), and the E5 protein is expressed from an unspliced E2,E5 transcript but not from the spliced E1E4,E5 transcript. This study was undertaken to determine if the HPV 11 E5a protein is expressed from the E1E4,E5 transcript. To detect E5a expression in eukaryotic cells, the green fluorescent protein (GFP) gene was fused to the 3' end of the E5a gene in the pEGFP-N1 vector. Several recombinant plasmid constructs were made to determine if E5a translation is influenced by upstream sequences present in the E1E4,E5 transcript. COS-7 cells were transfected with each construct, and flow cytometry was performed after 24 h of growth. The amount of E5a-GFP expressed from each construct was determined by the mean fluorescence of 2,000 transfected cells. Although the E5a-GFP fusion was expressed by all but one construct, the quantity of expressed E5a-GFP varied considerably. The most abundant expression was detected in cells transfected with the E1E4,E5a construct that lacked the 5' noncoding sequence between nucleotides (nts) 714 and 831 that is present in the authentic transcript. Other constructs expressed E5a-GFP in variable amounts, suggesting that sequences between nt 714 and the start of the E5a ORF affect expression of the E5a protein. An E2,E5a construct was made to compare the HPV 11 E5a expression to that of HPV 16. In contrast to HPV 16, no E5a-GFP was expressed from the HPV 11 E2,E5a construct. E1wedgeE4 protein was detected by immunofluorescence in COS-7 cells transfected with a construct that expressed E1E4 as a T7-epitope-tagged protein, and E5a as a GFP fusion. We conclude that the abundant HPV 11 E1E4,E5 transcript is a functional message that can support both E1E4 and E5a expression in eukaryotic cells.

Animals↗
PubMed1998

High-grade dysplasia in genital warts from two patients infected with the human immunodeficiency virus.

Cancer-associated human papillomavirus (HPV) types are detected in genital warts removed from immunosuppressed individuals more commonly than from those occurring in otherwise healthy individuals. The prognosis of genital warts containing cancer-associated HPV types is not known. Because it is assumed that genital warts are benign lesions, they are usually treated by destructive therapies without prior knowledge of histopathology. The aim of the present study was to determine whether genital warts from individuals with or without human immunodeficiency virus (HIV) contain high-risk HPV types or areas of dysplasia. The study design was a nonrandomized analysis of genital warts removed by excision biopsy from 15 HIV-infected patients and 15 HIV-negative patients. The tissue was analyzed for HPV DNA by hybrid capture, and microscopic sections of each biopsy were examined for areas of dysplasia. Genital warts from HIV-infected patients contained cancer-associated ("high risk") HPV types in 9 of 15 cases, including 1 that contained only a high-risk type. High-grade dysplastic abnormalities were present in 2 of the 15 lesions from this group, both of which contained high-risk HPV types. Four genital warts removed from HIV-negative patients contained high-risk HPV types, but none contained dysplastic abnormalities. It is concluded that genital warts from HIV-infected patients often contain high-risk HPV types. Such lesions may exhibit dysplastic changes. The frequency of dysplastic changes in genital warts from HIV-infected patients is not known. Biopsy of genital warts may be indicated prior to additional therapy in HIV-infected patients, and surgical removal should be considered as a preferred treatment option in these patients.

Anus Diseases↗