Biomedical subjects

K V Shah

Publications and source records attributed to K V Shah.

At least 127 records · Page 7Linked to original sources

PubMed1988

Identification of the human papillomavirus E2 protein in genital tract tissues.

A 27-kilodalton protein representing approximately 60% of the E2 open reading frame of human papillomavirus type 6 (HPV-6) was synthesized in a bacterial expression system. Affinity-purified polyclonal antibody to this protein detected the probable E2 gene product as a 50-kilodalton protein in most condylomas by Western blot (immunoblot) analysis. The E2-positive condylomas were associated with HPV-6, HPV-11, HPV-16, or unidentified HPVs.

Condylomata Acuminata↗

PubMed1988

Genital warts, papillomaviruses, and genital malignancies.

Human papillomavirus (HPV) infections of the genital tract are widespread and often subclinical. Of about a dozen genital tract HPVs, types 16 and 18 are strongly associated with squamous cell carcinoma of the cervix and of other sites in the lower genital tract. In invasive cervical cancers, the viral genomes are often integrated into the cellular DNA and are transcriptionally active. These viruses, with additional cofactors, play a role in genital tract malignancies.

Carcinoma, Squamous Cell↗

PubMed1988

Detection of human papillomavirus in normal and dysplastic tissue by the polymerase chain reaction.

Detection of human papilloma virus (HPV) types 16 and 18 in formalin-fixed, paraffin-embedded tissue by a new in vitro DNA amplification method, the polymerase chain reaction, was compared with detection with genomic DNA probes using in situ hybridization. The polymerase chain reaction replicates exponentially HPV DNA sequences present in a single 5- to 10-micron paraffin-embedded tissue section. The amplified sequences are detected with a DNA hybridization probe in a dot blot assay. The HPV polymerase chain reaction was able to detect on the average less than one HPV genome/cell as determined by tests of paraffin sections of cell pellets with known HPV genomic content. Cervical sections from 21 patients with HPV types 16, 18, or 31 as determined by in situ DNA hybridization were analyzed by the polymerase chain reaction. No disagreements between the two methods were detected. The sections comprising normal and dysplastic epithelium were further analyzed by the HPV polymerase chain reaction. The presence of virus correlated with the presence of dysplasia in the sections, though 3 of 10 normal sections contained HPV, and 1 of 21 sections with dysplasia lacked HPV 16 or 18. The polymerase chain reaction can specifically detect HPV 16 or 18 with high sensitivity from paraffin-embedded tissues.

Autoradiography↗

PubMed1987

BK virus specific humoral and cell mediated immunity in allogeneic bone marrow transplant (BMT) recipients.

BKV specific humoral and cell mediated immunity was examined weekly in 19 allogeneic BMT recipients and correlated with the occurrence of BKV shedding. Responses to staphylococcal antigen (SPL) and tetanus toxoid (TET) were measured as specificity controls. Responses and virus shedding were assayed weekly for up to 15 weeks after BMT. Fourteen of 19 patients enrolled in this study were immunized with TET on the day of transplant. Significant rises in TET specific IgG were observed in TET immunized, but not in unimmunized, subjects. Similarly, TET specific lymphoproliferative responses were observed only in TET immunized subjects when they emerged from aplasia 3 to 4 weeks later. In contrast, all subjects had positive lymphoproliferative responses to SPL, an antigen derived from a ubiquitous agent All subjects were assayed weekly for the presence of BKV in the urine as detected by ELISA. By 15 weeks, 11 (58%) of these patients shed detectable quantities of BKV antigen at least once. Subjects who excreted BKV (BKV+) maintained BKV specific IgG at pretransplant levels, whereas levels steadily declined in those who did not (BKV-) (p less than 0.001). Lymphoproliferative responses to BKV, TET, and SPL antigens were not significantly different across time or between excretion groups. The temporal relationship of BKV shedding and the expression of BKV specific immunity was investigated by examining average responses measured in 5-week intervals surrounding positive and negative antigen detection assays. Both BKV specific IgG and BKV specific lymphoproliferative responses were higher (1.8 fold, p less than 0.005 and 2.5 fold, p = 0.06, respectively) surrounding positive detection assays. These findings indicate a strong association between BKV excretion and the development of indicators of virus specific immunity following BMT.

Adolescent↗

PubMed1987

Detection of human papillomavirus type 6/11 DNA in conjunctival papillomas by in situ hybridization with radioactive probes.

Twenty-three conjunctival papillomas and 28 conjunctival dysplasias were examined for human papillomavirus (HPV)-DNA sequences by in situ hybridization with nick-translated 35S-labeled HPV probes. Adjacent paraffin sections were hybridized with HPV type 2, 6, 16, and 18 probes at Tm - 17 degrees C. Fifteen tissues, all papillomas, displayed positive hybridization with the HPV-6 probe. Infection with HPV-6 (or the closely related HPV-11) appeared to be responsible for most of the conjunctival papillomas of children and young adults. The presence of genital tract HPV-6 in these lesions suggests that some of the infections were acquired during passage through an infected birth canal. The lack of hybridization in adult conjunctival dysplasias indicates either that HPVs are not associated with this condition or that the probes and the technique utilized were not adequate for demonstration of this association.

Adolescent↗

PubMed1987

Epizootiology of Hantavirus infections in Baltimore: isolation of a virus from Norway rats, and characteristics of infected rat populations.

Rats trapped from 14 locations in Baltimore, Maryland, were shown to have antibody to Hantavirus. Antibody prevalence rates were higher in residential locations than in parks. Infected rats were obtained continuously over a six-year period from 1980-1985 at five locations, indicating the enzootic nature of this infection in urban rats in the United States. Prevalence of antibody and geometric mean titers increased with rat mass and sexual maturity, suggesting that infections in rats are acquired through age-related mechanisms. Three isolates of Hantavirus were obtained from rats. One of these isolates was shown by serologic tests and monoclonal antibody reactivity patterns to be similar, if not identical, to rat virus previously obtained from Philadelphia. The presence of rats in many urban settings and the high prevalence of Hantavirus infection in this species suggest that human exposure to this virus is occurring in the United States, although human disease from this exposure has not been recognized.

Animals↗

PubMed1987

Human papillomavirus-associated early vulvar neoplasia investigated by in situ hybridization.

Of 21 consecutive cases of early vulvar neoplasia studied at the Istituto Nazionale Tumori of Milan, 62% appeared to be related to papillomavirus infection. This conclusion is the result of the present study by in situ hybridization with DNA probes of human papillomavirus (HPV) 6/11, 16, and 18 and of previous ultrastructural and immunohistochemical investigations. The proportion of cases associated with HPV was 78.5% for those (11/14) with histologic evidence of viral infection and 33% for those without (2/6). HPV 16 was detected in all cases that were positive by in situ hybridization except for one, which showed HPV 6/11 DNA. In one case there was a mixed triple infection for HPV 6/11, 16, and 18. The patient who was positive for HPV 6/11 had a giant condyloma associated with an inguinal lymph node containing a metastatic well-differentiated squamous cell carcinoma. Three cases were positive for papillomavirus internal capsid species-nonspecific antigen (PV-Ag) (with ultrastructural evidence of virions in one of them) and were negative for HPV-DNA hybridization. They appeared to be infected with a type of HPV not identified by the available probes. Three cases, and two sites of two other cases with double infection, were HPV-DNA-positive and PV-Ag-negative. They illustrate the limitation of immunohistochemical investigation in cases with high-grade intraepithelial neoplasia. Six cases of verrucous carcinoma of the vulva were negative for HPV DNA by in situ hybridization.

Carcinoma, Papillary↗

PubMed1987

Characterization of human papillomavirus type 45, a new type 18-related virus of the genital tract.

DNA of human papillomavirus (HPV) type 45, a new HPV type 18-related papillomavirus of the genital tract, was cloned from a recurrent cervical lesion displaying mild to moderate dysplasia with koilocytosis. HPV-45 DNA was identified in paraffin sections of biopsies of both the initial and recurrent lesions of the patient, taken 7 months apart. HPV-45 DNA hybridized efficiently to that of many different HPV types under low and moderate stringency conditions (Tm - 37 degrees C to Tm - 25 degrees C) but with only HPV-18 DNA under high stringency conditions (Tm - 17 degrees C). HPV-45 DNA was distinguished from HPV-18 DNA by (i) differences in restriction enzyme digest patterns, (ii) lack of hybridization at Tm - 17 degrees C between HPV-18 and some fragments of HPV-45, (iii) a value of 25% in liquid reassociation kinetics between HPV-18 and HPV-45 and (iv) differences in intensities of hybridization with selected tissue DNAs. The prevalence of HPV-45 infection in the genital tract was low. In tests of over 600 tissue DNAs from female genital tract lesions, HPV-45 sequences were detected in three additional tissues, one each of invasive cervical carcinoma, condyloma, and normal cervical epithelium. HPV-45 is a newly recognized papillomavirus which rarely infects the genital tract and is associated with lesions across a wide histological spectrum.

Chromosome Mapping↗

PubMed1987

Identification of the human papillomavirus type 6b L1 open reading frame protein in condylomas and corresponding antibodies in human sera.

Genital warts (condylomata acuminata) are among the most frequent sexually transmitted infections. Human papillomavirus type 6 (HPV-6), which is etiologically related to a majority of these lesions, has not been propagated in tissue culture. We generated two forms of HPV-6 viral antigens: a chemically synthesized oligopeptide (referred to as the C-terminal synthetic peptide) corresponding to residues 482 to 495 of the 500-amino-acid-long L1 open reading frame (ORF), and a bacterially expressed 54-kilodalton (kDa) fusion protein containing the N-terminal 13 amino acids encoded by the lambda bacteriophage cII gene followed by one vector-insert junctional residue and 462 amino acids of the L1 ORF sequence (residues 39 to 500). The cII-L1 fusion protein was specifically recognized by an antipeptide serum directed against the N-terminal 13 amino acids derived from the cII gene, an antiserum raised against the C-terminal synthetic peptide, and a genus-specific serum prepared by immunization with disrupted viral capsids. The 54-kDa fusion protein was purified, and the sequence of its first 36 amino acids was determined and found to be as predicted by the DNA sequence. Both the genus-specific anticapsid serum and the antiserum raised against the fusion protein identified authentic L1 ORF proteins in HPV-1-induced (58 kDa) and HPV-6/11-induced (56 kDa) papillomas. The synthetic peptide antiserum recognized the 56- to 58-kDa protein in HPV-6-induced warts, but not in HPV-1- or HPV-11-infected specimens. Using the fusion protein as antigen in immunoassays, we were able to detect the corresponding antibodies in human sera.

Antibodies, Viral↗

PubMed1987

Multicentric human papillomavirus infections of the female genital tract: correlation of viral types with abnormal mitotic figures, colposcopic presentation, and location.

Human papillomavirus deoxyribonucleic acid (DNA) was identified by Southern blot hybridization in 21 of 24 patients with multicentric anogenital lesions and in 46 of 61 individual lesions. Type 6/11 was present in nine patients, type 16 in one, an undetermined type in one, and more than one type in ten patients. Mixed types were present in eight of 46 virus-positive individual lesions. Abnormal mitotic figures were found in 16, 87, and 75% of lesions associated with type 6/11, type 16, and mixed types, respectively. Colposcopic presentation or location of lesions was not predictive of viral types. The relatively high rate of mixed human papillomavirus types in multicentric lesions and in single lesions, and the lack of absolute correlation between viral types and abnormal mitotic figures, suggest that lesions should be removed to prevent viral transmission and possible progression to carcinoma.

Biopsy↗

PubMed1986

Association of BK viruria with hemorrhagic cystitis in recipients of bone marrow transplants.

Fifty-three recipients of bone marrow transplants were monitored prospectively for urinary excretion of human polyomaviruses by enzyme-linked immunosorbent assays of urinary supernatants and DNA hybridization assays of urinary cells. Excretion of BK virus was demonstrated in 47 percent of the transplant recipients and was the result of the reactivation of latent virus. Hemorrhagic cystitis of long duration (greater than or equal to 7 days) was associated with BK viruria. The disease occurred four times more frequently in patients who excreted BK virus than in those who did not, and the virus was identified in 55 percent of the urine specimens during episodes of cystitis as compared with 8 to 11 percent of the specimens during cystitis-free periods. BK viruria often preceded or coincided with the onset of the disease. Among 19 patients with BK viruria lasting seven days or longer, hemorrhagic cystitis occurred in 15. Occurrence of the disease was related to the source of marrow. The disease occurred in 50 percent of 38 recipients of allogeneic marrow and in 7 percent of 15 recipients of syngeneic or autologous marrow. Among recipients of allogeneic marrow, the disease was observed in 71 percent of the 21 patients excreting BK virus and in 24 percent of the 17 not excreting the virus. An association of BK virus with hemorrhagic cystitis was demonstrated in 16 of the 18 cases of the disease that were adequately characterized. We conclude that reactivation of BK virus may account for a substantial proportion of late-onset, long-lasting hemorrhagic cystitis in recipients of bone marrow transplants.

BK Virus↗

PubMed1986

Genital tract papillomavirus type 6 in recurrent conjunctival papilloma.

An infant boy born of a mother who had condylomata (genital warts) during pregnancy and at delivery developed recurrent conjunctival papillomas and papillomas on the soft palate and the false vocal cords. A conjunctival lesion was first noticed by the mother when the infant was 4 months old and was excised and histologically diagnosed as a papilloma when he was 11 months old. The DNA sequences of genital tract human papillomavirus type 6 (HPV-6) were identified in conjunctival papilloma tissue by Southern transfer hybridization of tissue DNA extracted from a lesion excised at 29 months of age as well as by in situ hybridization of paraffin sections of the diagnostic biopsy specimen obtained at 11 months of age. It is probable that the infant acquired conjunctival infection from the mother, very likely during passage through the infected birth canal.

Condylomata Acuminata↗

PubMed1985

Genetic heterogeneity of the human papovaviruses BK and JC.

We have examined the structure and infectivity of BKV and JCV genomes from prototype strains after cell culture passage and of BKV genomes from primary isolates. Genomic structures were determined by restriction endonuclease analysis of molecularly cloned DNA. Infectivity was determined by transfection of the cloned genomes into urine-derived epithelial cells and assaying for viral proteins and virus production. Prototype BKV DNA, which was cloned after 14 passages in three different cell lines, contained no alterations in restriction enzyme sites and was infectious. In contrast, prototype JCV acquired changes in the late region of the genome during passage in cell culture and the cloned DNA was not infectious. Urine-derived cells were used to isolate virus from the urine of two renal transplant patients and one asymptomatic individual. The genome of the virus isolated from the normal individual was indistinguishable from prototype BKV except for a 60-base pair deletion, which was localized between 0.62 and 0.72 map units. Two isolates from transplant patients differed from each other and from prototype BKV at a number of restriction enzyme cleavage sites located in the early region and were infectious. Genomes containing deletions from 100 to 600 base pairs were also cloned but were not infectious.

Chromosome Mapping↗

PubMed1985

Direct detection of the human papovavirus BK in urine of bone marrow transplant recipients: comparison of DNA hybridization with ELISA.

Urine specimens from bone marrow transplant (BMT) recipients and from controls were directly tested for BK virus (BKV) DNA sequences by dot hybridization and for BKV antigen by a double-antibody indirect ELISA. A total of 158 specimens from 55 BMT patients (57 collected prior to or at the time of transplantation and 101 in the posttransplant period) and single urines from 125 control subjects were examined by both methods. A molecularly cloned, 32P-labelled BKV probe was hybridized with urine sediments that were spotted directly on nitrocellulose filters and denatured in situ. BKV DNA sequences were detected in 1 (1.8%) pretransplant and 22 (21.8%) posttransplant urines of BMT patients, and in none of control urines. In ELISA of urine supernatants, BKV antigen was detected in 1 (1.8%) pretransplant and 21 (20.8%) posttransplant urines of BMT patients and in 1 (0.8%) of the control urines. The results of the two tests correlated as follows: 16 urines were positive and 253 urines negative by both methods; seven specimens were positive by DNA hybridization only and seven were positive by ELISA alone. Virus excretion in urine was demonstrated in 20 (36.4%) patients by DNA hybridization, in 19 (34.5%) patients by ELISA, in 15 (27.3%) patients by both methods, and in 24 (44%) patients by at least one of the two tests.

Adolescent↗

PubMed1985

Cell-mediated immune responses to BK virus in normal individuals.

A lymphoproliferative assay was developed to study cell-mediated immunity (CMI) to BK virus (BKV), a human papovavirus, in healthy volunteer subjects. Responses to ultraviolet-inactivated antigen prepared from BKV-infected fibroblasts were compared to those elicited against a mock antigen preparation and an unrelated control antigen (tetanus toxoid, TET). CMI to BKV and TET were contrasted with humoral immunity as measured by enzyme-linked immunosorbent assay (ELISA). Specificity of the assay was confirmed by absence of response to mock antigen in all subjects studied. Positive response to BKV antigen was observed in all of 15 seropositive individuals but not in 5 neonates or 1 seronegative child. Similarly, all TET seropositive (n = 13) but no seronegative subjects (n = 2) responded to TET. The magnitude of lymphoproliferation to either antigen did not correlate with antibody titer. Additionally, the frequency of peripheral blood BKV-specific proliferating lymphocytes was determined by limiting dilution analysis (LDA). The frequency was approximately tenfold less than that observed for TET in the same group of subjects (1/30,300 vs 1/2,700). This may be due to differences in route and frequency of antigen exposure, both of which are unknown, at present, for BKV.

Adult↗

PubMed1984

Genital warts and cervical cancer. VI. The relationship between aneuploid and polyploid cervical lesions.

Human papillomaviral infection is now widely implicated in the causation of cervical neoplasia. Genotype analysis provides the best guide to biologic outcome; most polyploid lesions regress and most aneuploid ones persist or progress. This prospective survey examined the relationships between cell ploidy and 24 objectively validated criteria of human papillomaviral infection or premalignant change in 52 biopsies from a dysplasia clinic. Histologic evidence of benign warty expression and human papillomaviral capsid antigen production decreased steadily as DNA content ranged from diploidy to polyploidy to aneuploidy. In contrast, premalignant change increased with progressive distortion of nuclear DNA content. No absolute discriminants were found between polyploidy and aneuploidy, as evidenced by the detection of human papillomaviral proteins in three of 21 aneuploid epithelia and the recognition of abnormal mitotic figures in five of 17 polyploid lesions. Polyploid and aneuploid lesions differed only in severity, and it appears that some polyploid epithelia may be transition forms between diploidy and aneuploidy.

Animals↗

PubMed1984

Genital warts and cervical cancer. V. The tissue basis of colposcopic change.

Histologic differences between subclinical papillomaviral infection and cervical intraepithelial neoplasia are quantitative rather than qualitative. Both entities are characterized colposcopically by acetowhite epithelium and aberrant surface capillaries. This study correlates five new colposcopic signs (variations in contour, thickness, color, vascular patterns, and iodine staining) with 12 histologic signs of human papillomaviral infection and 12 features of premalignant change. Acetowhitening and capillary abnormalities in minor colposcopic lesions are attributable to human papillomaviral disturbance of cell growth and maturation, seen histologically as parabasal layer proliferation, papillomatosis, koilocytosis , and dyskeratosis. Alteration in cell ploidy is usually minimal. Major colposcopic abnormalities reflect extensive disorganization of cell phenotype and tissue architecture, increased DNA content, and aneuploid stem cell populations. Intermediate colposcopic patterns generally denote polyploid lesions in which tissue changes are a composite of two reciprocal events: the extent of benign warty expression and the severity of premalignant change.

Animals↗

PubMed1984

Genital warts and cervical cancer. III. Subclinical papillomaviral infection and cervical neoplasia are linked by a spectrum of continuous morphologic and biologic change.

Human papillomaviral (HPV) infection is now widely advanced as an important etiologic factor in cervical cancer. This study was undertaken to clarify morphologic relationships within the biologic spectrum linking subclinical papillomaviral infection (SPI) to cervical intraepithelial (CIN). Two pathologists analyzed 72 colposcopic biopsies, using a semi-objective rating scheme that scored 24 different histologic criteria. Each individual criterion was checked for reproducibility, and validated against an objective measure of papillomaviral infection (immunoperoxidase staining) or premalignant change (microspectrophotometry). The individual criteria were then combined into histologic indices of benign warty change, presumed viral atypia, abnormal cell phenotype, and disturbed tissue maturation. Histologic expression of papillomaviral infection decreased with increasing degrees of premalignant change. Plotting the index of abnormal cell phenotype against that of disturbed tissue maturation produced a linear plot in which cases clustered into four diagnostic groups. The histologic indices of papillomaviral infection displayed significant curvilinear correlations with genotypic distortion, benign warty change being maximal in the CIN 1 range and presumed viral atypia in the CIN 2 range. Disturbance of nuclear DNA content also increased with worsening diagnosis; diploidy being most common in SPI (67%), polyploidy in CIN 1 (59%), and aneuploidy in CIN 2 (65%) and CIN 3 (82%). Conversely, capsid antigen production decreased from 36% in SPI to 9% in CIN 3. Three aneuploid epithelia were immunoperoxidase positive. These inverse relationships between late viral expression and nuclear distortion fit experimental models of viral oncogenesis. The gradual transition and morphologic overlap between diagnostic groups support the postulate that SPI and CIN are a single disease spectrum, in which differences are those of degree rather than of kind.

Adolescent↗