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Biomedical subjects

K H Fife

Publications and source records attributed to K H Fife.

At least 37 records · Page 2Linked to original sources
PubMed1998

Human papillomavirus vaccine development.

The greatest successes in combating important viral infections have been achieved using vaccines. A vaccine to prevent genital tract human papillomavirus (HPV) infections, especially those types associated with genital tract malignancy, could significantly reduce morbidity and mortality from cervical and other genital tract cancers. However, several barriers currently stand in the way of HPV vaccine development. The immunological response to natural HPV infection is incompletely understood and there is uncertainty about which viral antigen(s) should be included in a candidate vaccine. It is clear that immunization of several animal species with the L1 major capsid protein (usually in the form of virus-like particles) spurs the production of anti-HPV antibodies that are neutralizing in several assay systems. However, it is not clear if neutralizing antibody will be present in the genital tract in sufficient quantities to block infection. A second problem is the lack of a reliable serological assay for HPV. This is a major problem for clinical trials in which the identification of susceptible individuals, and incident infections, usually relies on serological diagnosis. Finally, there is also interest in the development of a vaccine that is used to treat individuals who are already infected--a therapeutic vaccine. It is likely that a therapeutic vaccine will need to target different or additional antigens to those comprising a prophylactic vaccine.

Animals↗
PubMed1997

Functional characterization of the C---C chemokine-like molecules encoded by molluscum contagiosum virus types 1 and 2.

Many viruses have evolved mechanisms for evading the host immune system by synthesizing proteins that interfere with the normal immune response. The poxviruses are among the most accomplished at deceiving their hosts' immune systems. The nucleotide sequence of the genome of the human cutaneous poxvirus, molluscum contagiosum virus (MCV) type 1, was recently reported to contain a region that resembles a human chemokine. We have cloned and expressed the chemokine-like genes from MCV type 1 and the closely related MCV type 2 to determine a potential role for these proteins in the viral life cycle. In monocyte chemotaxis assays, the viral proteins have no chemotactic activity but both viral proteins block the chemotactic response to the human chemokine, macrophage inflammatory protein (MIP)-1alpha. Like MIP-1alpha, both viral proteins also inhibit the growth of human hematopoietic progenitor cells, but the viral proteins are more potent in this activity than the human chemokine. These viral chemokines antagonize the chemotactic activity of human chemokines and have an inhibitory effect on human hematopoietic progenitor cells. We hypothesize that the inhibition of chemotaxis is an immune evasion function of these proteins during molluscum contagiosum virus infection. The significance of hematopoietic progenitor cell inhibition in viral pathogenesis is uncertain.

Amino Acid Sequence↗
PubMed1997

Human papillomavirus type 11 neutralization in the athymic mouse xenograft system: correlation with virus-like particle IgG concentration.

Neutralization of virus is likely to be necessary for development of an effective prophylactic vaccine against genital human papillomavirus (HPV) infection. Two New Zealand white rabbits were immunized with purified HPV type 11 (HPV 11) virions in Freund's adjuvant. An enzyme linked immunoassay (ELISA) was used to determine the quantity of IgG which recognized the HPV 11 major capsid protein (L1 protein) virus-like particles (VLPs) in the two anti-HPV 11 sera (serum A and serum B). The concentration of HPV 11 L1 VLP-specific IgG in the A and B sera were determined to be 37 and 90 micrograms per ml, respectively. The A and B sera were used in neutralization experiments in the athymic mouse xenograft system with known quantities of purified HPV 11 virions. The concentration of HPV 11 L1 VLP-specific IgG required to neutralize HPV 11 was determined for each antiserum. This concentration of IgG was approximately 700 to 900 ng per ml. This study demonstrates a positive correlation between the level of HPV 11 L1 VLP-specific IgG in animals immunized with HPV 11 virions and neutralization of HPV 11 in the athymic mouse model. Further studies are needed 1) to determine if sera or genital secretions from other species are neutralizing in the athymic mouse xenograft system, and 2) to determine if the VLP ELISA can be used as a reliable substitute for more cumbersome neutralization assays.

Animals↗
PubMed1997

Valaciclovir versus acyclovir in the treatment of first-episode genital herpes infection. Results of an international, multicenter, double-blind, randomized clinical trial. The Valaciclovir International Herpes Simplex Virus Study Group.

BACKGROUND AND OBJECTIVES: Valaciclovir, the L-valine ester prodrug of acyclovir, is much better absorbed than acyclovir and produces acyclovir exposures three to five times those attainable with the parent drug. GOALS: To determine whether the improved bioavailability of valaciclovir and a more convenient, less frequent dose regimen can maintain the clinical efficacy previously demonstrated for acyclovir. STUDY DESIGN: This was an international, multicenter, randomized, double-blind clinical trial comparing 10-day regimens of valaciclovir (1000 mg, twice daily) and acyclovir (200 mg, 5 times daily) in the treatment of 643 otherwise healthy adults (> or = 18 years of age) with first-episode genital herpes. Patients were evaluated clinically and lesions were staged and cultured on days 1, 2, 3, 5, 7, 10, 14, and then twice weekly until healed. Blood for herpes serology tests was obtained on days 1 and 14; hematology and chemistry toxicity screening was done on days 1 and 7. RESULTS: Valaciclovir and acyclovir did not differ significantly in efficacy with respect to duration of viral shedding (hazard ratio, 1.00; 95% confidence interval [CI], 0.84-1.18), time to healing (hazard ratio, 1.08; 95% CI, 0.92-1.27), duration of pain (hazard ratio, 1.0; 95% CI, 0.85-1.18), and time to loss of all symptoms (hazard ratio, 1.02; 95% CI, 0.85-1.22). Patients with primary genital herpes (no preexisting antibody to either herpes simplex virus type at enrollment with seroconversion at day 14) had longer times to healing and longer duration of viral shedding and pain than patients with nonprimary first genital episodes. Adverse experiences were generally infrequent and mild and were comparable in the two treatment groups. CONCLUSIONS: Twice-daily valaciclovir proved as effective and well tolerated in the treatment of first-episode genital herpes as five-times-daily acyclovir. Valaciclovir provides a useful alternative to acyclovir with the advantage of a more convenient dosing regimen and the potential for improved compliance.

Acyclovir↗
PubMed1997

Acceptability of genital herpes immunization. The role of health beliefs and health behaviors.

BACKGROUND AND OBJECTIVES: Little is known about the acceptability of vaccines for prevention of sexually transmitted diseases (STDs). The purpose of this study was to examine potential predictors of genital herpes simplex virus type 2 (HSV-2) vaccine acceptability. GOALS: To evaluate the relationship of health beliefs and health behaviors to HSV-2 vaccine acceptability. STUDY DESIGN: Three hundred twenty-one subjects participating in two phase III clinical trials for an HSV-2 vaccine completed surveys addressing health beliefs, health behaviors, and acceptability of hypothetical HSV-2 vaccines. RESULTS: Bivariate analyses found that perceived benefits of vaccination, seatbelt use, a healthy diet, and having had cholesterol levels checked were associated with higher acceptability. Perceived limitations of HSV-2 immunization, alcohol use, and exercise were associated with lower acceptability. Multiple regression analysis identified perceived benefits of vaccination, decreased exercise, and lower alcohol use as significant independent predictors of greater HSV-2 vaccine acceptability. CONCLUSIONS: In groups of high-risk individuals who had completed participation in HSV-2 clinical trials, health beliefs and health behaviors influenced acceptability of hypothetical HSV-2 vaccination. The findings support the need to understand determinants of acceptance of vaccines for HSV-2 and other STDs.

Adult↗
PubMed1996

Growth of molluscum contagiosum virus in a human foreskin xenograft model.

Molluscum contagiosum virus (MCV) is a common pathogen causing a troublesome skin condition in many immunocompetent individuals and a widespread, disfiguring affliction in many patients with AIDS. We have successfully infected human foreskin fragments with a patient-derived isolate of MCV. This was demonstrated by exposing the foreskin pieces to a patient lesion extract and implanting the tissue under the renal capsule of athymic mice. Light and electron microscopic examination of infected implants showed the presence of cytoplasmic inclusions containing typical poxvirus particles within 2-3 weeks of implantation. Replication of MCV was established by demonstrating that viable virus was required to produce the cytopathologic effects, and viral DNA replication was demonstrated by incorporation of bromodeoxyuridine into cytoplasmic inclusions. Four additional patient extracts (representing both described MCV types) were also used to successfully infect foreskin implants. A limited number of attempts to pass virus from one infected implant to another were not successful. This system is the most rapid and reproducible for growing MCV that has been reported to date.

Animals↗
PubMed1996

Virus-like particles and E1-E4 protein expressed from the human papillomavirus type 11 bicistronic E1-E4-L1 transcript.

Detection of E1-E4 protein in human papillomavirus (HPV 11)-infected tissue is tightly linked to detection of L1 major capsid protein. The only L1-containing transcript identified in HPV 11-infected tissue is the bicistronic E1-E4-L1 mRNA, potentially encoding both the E1-E4 and the L1 proteins. It has not been established that these proteins can be expressed from the E1-E4-L1 transcript. The HPV 11 E1-E4-L1 sequence was cloned by reverse transcriptase polymerase chain reaction into the p1393 vector to produce recombinant baculoviruses. Immunoblots of recombinant baculovirus-infected Sf9 cell lysates demonstrated both the E1-E4 and the L1 proteins. An ELISA was performed on infected Sf9 cells using a monoclonal antibody specific for nondenatured L1, demonstrating that 10 ng of native L1 protein was present per microgram of total nuclear protein. Electron microscopic analysis revealed 50- to 60-nm icosahedral virus-like particles. In vitro transcription/translation was performed using pSPORT constructs containing the E1-E4-L1 sequence or, as controls, monocistronic pSPORT-E1-E4 or L1 constructs. The pSPORT-E1-E4-L1 construct produced the E1-E4 and L1 proteins at a ratio of 17:1. For E1-E4 protein, expression was greater from the pSPORT-E1-E4-L1 construct than from the monocistronic pSPORT-E1-E4 construct. In contrast, more L1 protein was expressed from pSPORT-L1 than from pSPORT-E1-E4-L1. A mutant E1-E4-L1 construct containing no E1-E4 start codon expressed L1 protein in amounts nearly equal to that expressed from the pSPORT-L1 construct. Addition of an antisense oligonucleotide directed at the E1-E4 start codon region to in vitro reactions using pSPORT-E1-E4-L1 was associated with inhibition of E1-E4 protein synthesis and increased translation of L1 protein.

Animals↗
PubMed1996

Association of human papillomavirus type 11 DNA with squamous cell carcinoma of the tongue.

A 47-year-old man with a history of a benign papilloma of the tongue 5 years earlier was treated for a squamous cell carcinoma of the tongue with surgical resection. An analysis of the tumor DNA using several methods showed the presence of human papillomavirus (HPV) type 11 sequences that migrated with the high molecular weight cellular DNA, suggesting integration of viral DNA into the cellular genome. A segment of the HPV DNA was cloned from the lesion and shown to be similar to prototype HPV 11 DNA, except for some variability in the viral long control region. The proviral DNA contained part of the L1 region, all of the viral long control region, the entire E6 and E7 open-reading frames, and at least a portion of the E1 region; the E4 region appeared to be deleted. The integration sites of the HPV DNA could not be specifically identified. An analysis of the p53 tumor suppressor gene region of the tumor DNA showed no evidence of mutation. These results suggest that the HPV 11 DNA may have had a role in the origin of the cancer in this patient.

Blotting, Southern↗
PubMed1996

Temporal and histologic relationships of proliferating cell nuclear antigen and human papillomavirus type 11 in the mouse xenograft system.

Proliferating cell nuclear antigen (PCNA) is an accessory protein of DNA polymerase delta. This protein is associated with cell cycle progression and can be detected in the replicating cells of normal tissues. Condylomata acuminata are benign epithelial tumors caused by infection with human papillomaviruses and are characterized by abnormal cell proliferation. The athymic mouse xenograft model of HPV 11 infection was used to test the hypothesis that PCNA is induced early in the course of HPV 11 infection and to study the temporal and histologic relationships between detection of PCNA and HPV DNA. Human foreskin tissue was infected with HPV 11 and implanted under the renal capsules of 10 athymic mice. Pairs of mice were sacrificed every week beginning four weeks after implantation. HPV DNA was detected in sections of foreskin implants by in situ hybridization. PCNA was as or more abundant in implants removed at earlier time points than at later time points, whereas HPV DNA became increasingly more abundant with time. PCNA was detected only in basal cells in areas of histologically normal epithelium that were also negative for HPV DNA. In contrast, PCNA was present throughout the epithelium in regions that were HPV DNA-positive. HPV DNA was detected only in differentiated epithelial cells in implants removed at all five time points, but in HPV DNA-positive regions, PCNA was detected with equal intensity in differentiated and undifferentiated cells. The foci of PCNA-positive cells were well demarcated and were larger than, but included, the foci of HPV DNA-positive cells. PCNA may be induced maximally in differentiated epithelium by HPV 11 prior to significant HPV DNA replication.

Animals↗
PubMed1996

Human papillomavirus detection by hybrid capture in paired cervicovaginal lavage and cervical biopsy specimens.

Infection of the uterine cervix with human papillomavirus (HPV) is associated with dysplastic lesions that may progress to malignancy. Certain HPV types are associated with higher risk of cervical cancer than other genital HPVs. The goal of this study was to determine if cells obtained by cervicovaginal lavage contain similar HPV types as paired cervical biopsy in women referred because of abnormal cervical cytology. Thirty-four paired lavage and biopsy samples were analyzed for HPV DNA by hybrid capture, using "low risk" (HPV types 6. 11, and related types and "high risk" group (HPV types 16, 18, and related types) HPV. HPV was detected in 24 lavage samples and 18 biopsies. High risk types were predominant. In 14 of 18 HPV-positive biopsies, the paired lavage was also positive for the same HPV group. Four biopsies were HPV-positive at low levels, and the paired lavage was HPV-negative. The mean viral copy numbers of the biopsies from patients with positive and negative lavage samples were 2.7 and 0.1, respectively (P = .02). Ten low level HPV infections were detected by lavage that were not detected by biopsy. HPV detection by hybrid capture in cells obtained by cervicovaginal lavage reflects the results of HPV testing in cervical biopsies.

Cell Biology↗
PubMed1996

Cancer-associated human papillomavirus types are selectively increased in the cervix of women in the first trimester of pregnancy.

OBJECTIVE: Because of incomplete data in the current literature, we sought to determine whether pregnancy is an independent risk for the detection of human papillomavirus infection. STUDY DESIGN: Pregnant patients in their first trimester who are seen for routine care at an obstetrics clinic and nonpregnant patients receiving routine care at a sexually transmitted diseases clinic and a gynecology clinic were recruited. Cervical cells were collected by saline solution lavage, and deoxyribonucleic acid was extracted and tested for the presence of human papillomavirus deoxyribonucleic acid with the hybrid capture assay. This assay detects the deoxyribonucleic acid of five "low cancer risk" and nine "high cancer risk" human papillomavirus types with two separate pools of deoxyribonucleic acid probes. RESULTS: Results from 245 pregnant women, 248 patients from the sexually transmitted diseases clinics, and 246 gynecology clinic patients were analyzed. Human papillomavirus deoxyribonucleic acid was detected in samples from 31% of the pregnant patients compared with 17.7% and 18.6% of the sexually transmitted diseases clinic and gynecology clinic patients, respectively. There was no significant difference in positivity for the "low-risk" human papillomavirus types among the three groups (positivity rates from 8.9% to 12.7%), but the pregnant patients had a significantly higher positivity rate for the "high-risk" human papillomavirus types (24.9% compared with 13.3% and 11.4% for the sexually transmitted diseases and gynecology clinic patients, respectively; p < 0.001). A multiple logistic regression analysis showed that pregnancy was an independent predictor of a positive test result for a "high-risk" human papillomavirus type (odds ratio 1.79, 95% confidence interval 1.11 to 2.89) but not a positive test result for a "low-risk" type. CONCLUSIONS: Because sexual activity was not greater among the pregnant patients, we propose that the increased detection of "high-risk" human papillomavirus types among the pregnant patients represents a selective activation of these viruses by hormonal or immunologic factors associated with pregnancy.

Adult↗
PubMed1995

Human papillomavirus type 11 E1--E4 and L1 proteins colocalize in the mouse xenograft system at multiple time points.

The most abundant viral mRNA species in HPV 11-infected tissue consists of two exons, joining a segment of open reading frame (ORF) E1 to ORF E4, potentially encoding the E1--E4 protein. The L1 ORF encodes the major capsid protein of HPV. Our previous studies demonstrated colocalization of the HPV 11 E1--E4 and L1 proteins within the same cells of HPV 11-infected human foreskin implants grown in athymic mice (the mouse xenograft system) and removed 12 weeks after implantation. Prior studies have demonstrated E1--E4 transcripts early in infection and throughout the HPV 11-infected epithelium, while L1 transcripts are detected later, and in a subset of E1--E4 mRNA-positive differentiated epithelial cells. Therefore, E1--E4 protein may be produced at an earlier time point or in less differentiated cells than the L1 protein. To study these questions, athymic mice were implanted with HPV 11-infected human foreskin fragments. Mice were sacrificed at 1-week intervals beginning 2 weeks after implantation of tissue. The E1--E4 and L1 proteins colocalized to the same differentiated epithelial cells or to tight clusters of cells in differentiated epithelial layers of HPV 11-infected implants. The E1--E4 and L1 proteins were first detected 4 weeks after implantation. E1--E4 protein was detected in the region of the cell membrane and cytoplasm, and never in the nucleus. L1 protein was only detected in the nucleus. Both proteins were detected in implants containing high viral copy numbers. No specific histologic changes were uniformly associated with detection of these proteins. The tight coupling of the E1-E4 and L1 proteins at multiple time points suggests that expression of both proteins is necessary to complete the virus life cycle.

Animals↗
PubMed1995

Sequence determination of human papillomavirus type 6a and assembly of virus-like particles in Saccharomyces cerevisiae.

Human papillomavirus 6a (HPV6a), the most abundant HPV6 subtype, was detected in a vulvar condyloma acuminatum. The complete genome of HPV6a was cloned, and its DNA sequence was shown to be over 97% identical to the HPV6b sequence. Of the eight open reading frames (ORFs) of HPV6a, only the imputed amino acid sequence of the major capsid protein L1 was identical to the corresponding HPV6b sequence; all other HPV6a ORFs showed amino acid changes compared to the HPV6b ORFs. The HPV6a L1 or the L1 + L2 ORFs were expressed in the yeast Saccharomyces cerevisiae. Self-assembly of the L1 capsid protein into virus-like particles (VLPs) was demonstrated both in the L1 as well as L1 + L2 coexpressing yeast strains. Copurification of the L1 and L2 proteins showed complex formation of the L1 and L2 proteins in the yeast-derived VLPs of coexpressing strains.

Adult↗
PubMed1994

Recurrence and resistance patterns of herpes simplex virus following cessation of > or = 6 years of chronic suppression with acyclovir. Acyclovir Study Group.

Questions have arisen regarding the clinical outcome and the possible selection of resistant virus when patients with genital herpes discontinue prolonged chronic acyclovir; 239 immunocompetent patients with a history of frequently recurring genital herpes who stopped successful suppressive therapy after 6 years were studied. Of the patients, 85.8% had at least one recurrence and 75% had at least two recurrences in the subsequent year (median time to first and second recurrence, 68 and 180 days, respectively). Herpes simplex virus isolates recovered from these patients had a median acyclovir sensitivity of 0.79 micrograms/mL and 4 (3.5%) were resistant (> or = 3 micrograms/mL). These values are comparable to those of pretherapy isolates and to reported values of isolates from acyclovir-naive patients. Also, paired pre- and posttherapy isolates from 13 patients showed no trend toward development of resistance. Thus, even after 6 years of acyclovir suppression, most patients continue to have recurrences, but the selection of resistant virus has not been observed.

Acyclovir↗
PubMed1994

Detection of multiple human papillomavirus types in condylomata acuminata from immunosuppressed patients.

Using the hybrid capture method, condylomata acuminata from healthy patients (controls) and patients with altered cell-mediated immunity were analyzed for multiple human papillomavirus (HPV) DNA: 82.9% and 38.0% of lesions from 41 controls and 21 patients, respectively, were HPV DNA-positive only with probes for low-risk HPV types (P = .00035). Using probes for both low- and high-risk HPV types, 16.3% and 52.3% of lesions from 43 controls and 21 patients, respectively, were positive for both probes (P = .0038). Evidence of multiple HPV types was also found by Southern blot and in situ hybridization studies. The mean HPV copy number detected by either probe did not differ significantly among patient groups. Using sensitive techniques, such as hybrid capture, multiple HPV types, including those associated with genital malignancy, can be detected in condylomata acuminata. Serial biopsies demonstrate the dynamic nature of genital HPV infection and that changes in the predominant HPV types may be reflected in tissue pathology.

Biopsy↗
PubMed1994

The safety and efficacy of combination N-butyl-deoxynojirimycin (SC-48334) and zidovudine in patients with HIV-1 infection and 200-500 CD4 cells/mm3.

We conducted a double-blind, randomized phase II study to evaluate the safety and activity of combination therapy with N-butyl-deoxynojirimycin (SC-48334) (an alpha-glucosidase I inhibitor) and zidovudine versus zidovudine alone. Patients with 200 to 500 CD4 cells/mm3 who tolerated < or = 12 weeks of prior zidovudine therapy received SC-48334 (1000 mg every 8 h) and zidovudine (100 mg every 8 h) or zidovudine and placebo. Sixty patients received combination therapy and 58, zidovudine and placebo. Twenty-three patients (38%) and 15 (26%), in the combination and zidovudine groups, respectively, discontinued therapy (p = 0.15). The mean SC-48334 steady-state trough level (4.04 +/- 0.99 micrograms/ml) was below the in vitro inhibitory concentration for human immunodeficiency virus (HIV). The mean increase in CD4 cells at week 4 was 73.8 cells/mm3 and 52.4 cells/mm3 for the combination and zidovudine groups, respectively (p > 0.36). For patients with prior zidovudine therapy, the mean change in CD4 cells in the combination and zidovudine groups was 63.7 cells/mm3 and 4.9 cells/mm3 at week 8 and 6.8 cells/mm3 and -45.1 cells/mm3 at week 16, respectively. The number of patients with suppression of HIV p24 antigenemia in the combination and zidovudine groups was six (40%) and two (11%) at week 4 (p = 0.10) and five (45%) and two (14%) at week 24 (p = 0.08), respectively. Diarrhea, flatulence, abdominal pain, and weight loss were common for combination recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Deoxynojirimycin↗
PubMed1993

Analysis of human papillomavirus types in exophytic condylomata acuminata by hybrid capture and Southern blot techniques.

Exophytic condylomata acuminata of the external genitalia of 40 patients were analyzed for human papillomavirus (HPV) DNA by the Southern blot and hybrid capture methods. All lesions were initially analyzed by the Southern blot method by using a mixture of HPV type 6, 11, 16, and 18 whole genomic probes. Southern blots demonstrated characteristic PstI restriction patterns of HPV type 6, 11, or 16 in all but one lesion. HPV 6 subtypes accounted for 28 of 39 HPV-positive lesions. Twenty-seven of these 28 lesions contained HPV type 6a, and 1 lesion contained HPV type 6c. Eight lesions contained HPV type 11 and three contained HPV type 16. Two of the three condylomata acuminata containing HPV type 16 were obtained from solid-organ transplant recipients receiving immunosuppressive medications. The third lesion containing HPV type 16 was a typical exophytic condyloma acuminatum from a woman with previously resected vulvar carcinoma. The hybrid capture assay detected HPV DNAs in all lesions except the Southern blot-negative lesion. Twenty-five lesions were positive for the A probe only (HPV types 6 and 11 and related types). All of these lesions were found to contain HPV type 6 or 11 sequences in the Southern blot assay. The remaining 14 lesions were positive for both the A probe and the B probe (HPV types 16 and 18 and related types). The strongest signal in these 14 lesions by the hybrid capture assay was consistent with the result of the Southern blot assay in all but one case. We conclude that (i) HPV type 6a is the most common type found in these lesions, (ii) HPV type 16 may be present more often in exophytic condylomata acuminata from immunosuppressed individuals, (iii) hybrid capture is a useful tool for documenting the presence of HPV sequences in DNAs from exophytic condylomata acuminata, and (iv) in samples containing multiple HPV types, hybrid capture allows detection of minority HPV types.

Blotting, Southern↗