Biomedical subjects

P Mounts

Publications and source records attributed to P Mounts.

At least 19 recordsLinked to original sources

PubMed1992

Antibody response to human papillomavirus (HPV) type 11 in children with juvenile-onset recurrent respiratory papillomatosis (RRP).

We previously established, using an ELISA, the presence of specific antibodies directed at human papillomavirus (HPV) type 11 virions in the sera of patients with condylomata acuminata, mostly a disease of young adults that, like recurrent respiratory papillomatosis (RRP), is caused by two closely related HPVs, types 6 and 11. The present study was done to investigate if children with RRP can make viral-specific antibodies to an infection that is acquired at birth. Using the same ELISA, we studied the sera of 32 children with biopsy-documented juvenile-onset RRP and compared them to the sera of 31 control children. The median (and interquartile range) of the OD values in the controls and the cases was 0.078 (0.003, 0.101) and 0.230 (0.063, 0.725), respectively, a statistically significant difference (P = 0.001). Among the cases, there was no difference in seroreactivity between children with HPV-11-induced RRP and those with HPV-6-induced RRP (P = 0.31). Since HPV-11 viral particles do bind to the ELISA plate and remain intact and accessible to antibodies, we conclude that children with RRP, like adults with condylomata acuminata, develop antibodies directed at HPV-11 virions.

Antibodies, Viral↗

PubMed1991

Long-term response of recurrent respiratory papillomatosis to treatment with lymphoblastoid interferon alfa-N1. Papilloma Study Group.

BACKGROUND: We earlier reported that patients with recurrent respiratory papillomatosis responded to six months of treatment with lymphoblastoid interferon alfa-n1. Because another study of patients treated for one year with leukocyte interferon alfa-n3 found that the growth rate of papillomas was slowed in the first six months but returned to base line during months 7 through 12 despite persistent interferon treatment, we now report the long-term results in our original study patients who were followed for a median of four years after the original one-year crossover study. METHODS: After the patients in our study had completed the first study year, their physicians could continue or recommence treatment with lymphoblastoid interferon alfa-n1 in a dose of either 2 MU per square meter of body-surface area per day or 4 MU per square meter every other day. The extent of disease was measured by endoscopy when clinically indicated. RESULTS: Data on late-follow-up were obtained for 60 of the 66 patients. There were 22 complete remissions and 25 partial remissions; 13 patients had no response. The median duration of the complete remissions was 550 days, and 15 patients continued to be in complete remission. The median duration of partial remissions was 400 days and seven patients were still in partial remission. Thirteen of 28 patients responded to a second course of interferon after an interruption in treatment of at least one month. The rate of response in the 11 of 53 patients who had neutralizing antibody to interferon was the same as in the patients without the antibody. CONCLUSIONS: Patients with severe recurrent respiratory papillomatosis may have a sustained or repeated response to treatment with lymphoblastoid interferon alfa-n1. We recommend that patients with recurrent respiratory papillomatosis who require surgery every two to three months be given a six-month trial of interferon alfa-n1.

Adolescent↗

PubMed1991

Polymerase chain reaction identification of human papillomavirus DNA in CO2 laser plume from recurrent respiratory papillomatosis.

Human papillomavirus (HPV) DNA was identified in the plume produced during CO2 laser vaporization of respiratory tract papillomata. The plume produced from CO2 vaporization was collected on Gelfoam pledgets that were affixed to suction tips evacuating the vapor plume from the operative field. The Gelfoam pledgets were snap frozen in liquid nitrogen, processed, and examined for HPV-6 and HPV-11 DNA by a polymerase chain reaction technique. Tissue and vapor-plume specimens were collected from 22 patients undergoing CO2 laser excision of laryngeal lesions. Seven patients had adult-onset recurrent respiratory laryngeal papillomatosis (RRP), 12 had juvenile-onset RRP, two had laryngeal carcinoma, and one had nonspecific laryngitis. HPV-6 or HPV-11 was identified in 17 of 27 vapor-plume specimens from RRP and in none of three from non-RRP lesions. All but one RRP tissue specimen contained HPV-DNA, and none of the non-RRP tissues contained HPV-DNA. When HPV was present in vapor, the same HPV type was found in the corresponding tissue specimen. Identification of HPV-DNA in the laser plume raises concern regarding potential risks from exposure to the plume--particularly to the endoscopic surgeon and the operating team. The practical concerns and effectiveness of the plume scavenging systems are discussed.

Air Microbiology↗

PubMed1990

Transforming activity of E5a protein of human papillomavirus type 6 in NIH 3T3 and C127 cells.

Human papillomavirus type 6 (HPV-6) is the etiologic agent of genital warts and recurrent respiratory papillomatosis. We are investigating the mechanism by which this virus stimulates cell proliferation during infection. In this paper, we report that the E5a gene of HPV-6c, an independent isolate of HPV-11, is capable of transforming NIH 3T3 cells. The E5a open reading frame (ORF) was expressed under the control of the mouse metallothionein promoter in the expression vector pMt.neo.1, which also contains the gene for G418 resistance. Transfected cells were selected for G418 resistance and analyzed for a transformed phenotype. The transformed NIH 3T3 cells overgrew a confluent monolayer, had an accelerated generation time, and were anchorage independent. In contrast, E5a did not induce foci in C127 cells, but C127 cells expressing E5a did form small colonies in suspension. The presence of the 12-kilodalton E5a gene product in the transformed NIH 3T3 cells was shown by immunoprecipitation and was localized predominantly to nuclei by an immunoperoxidase assay. A mutation in the E5a ORF was engineered to terminate translation. This mutant was defective for transformation, demonstrating that translation of the E5a ORF is required for biological activity. This is the first demonstration of a transforming oncogene in HPV-6, and the differential activity of E5a in these two cell lines should facilitate future investigations on the mechanism of transformation.

Amino Acid Sequence↗

PubMed1989

Detection by antibody probes of human papillomavirus type 6 E5 proteins in respiratory papillomata.

We have demonstrated the expression of proteins arising from the E5a and E5b open reading frames (ORFs) of human papillomavirus type 6c (HPV-6c) in respiratory tract papillomata. Recombinant plasmids were constructed to express the ORFs in the bacterial vectors pATH and pRIT2T. Fusion proteins were purified and injected into rabbits to produce polyclonal antibodies. Characterized antibodies generated against these fusion proteins were used in immunoperoxidase assays to identify the presence and distribution of HPV-6 E5 proteins in biopsy specimens of respiratory tract papillomata. The results showed that the E5a and E5b proteins were distributed throughout the thickness of the epithelium in the papillomata but not in the basal layer. The proteins were found in nuclei and in the cytoplasm of koilocytotic cells. Positive reactivity with a similar distribution in the epithelium and subcellular location was obtained in papillomata induced by other HPV-6 subtypes. This cross-reactivity was not unexpected, since nucleotide and amino acid (aa) sequence comparisons between HPV-6c and -6e demonstrated 79% sequence identity with 15 aa substitutions in the 91 aa of E5a. The E5b ORF of HPV-6c has the potential to encode a protein of 74 aa that differed at 28 positions compared with the 72 aa of HPV-6e.

Amino Acid Sequence↗

PubMed1989

Structural analysis of human papillomavirus type 6c isolates from condyloma acuminatum and juvenile-onset and adult-onset laryngeal papillomata.

The human papillomavirus type 6c (HPV-6c) genome was molecularly cloned from biopsy specimens of a juvenile-onset and an adult-onset respiratory-tract papillomata and a condyloma acuminatum of the cervix. To determine if the genital-tract isolate and respiratory-tract isolates contain divergent sequences that may account for a difference in tissue trophism or for a difference in the age of onset of the disease, fine-structure mapping, heteroduplex analysis by electron microscopy, and nucleotide sequencing were used to examine the sequence relationship among these HPV-6c isolates. No differences were found in the digestion patterns with 23 restriction enzymes. Heteroduplex analysis among the three genomes demonstrated that they were colinear without apparent deletions or rearrangements and had greater than 90% sequence identity. In heteroduplex analyses with a different subtype (HPV-6e) that was molecularly cloned from a genital wart, the genomes were colinear with greater than 90% sequence identity over 90% of their length. The most divergent region had 75-80% sequence identity and was localized to the part of the genome containing the E5a and E5b open reading frames (ORFs). Comparison of the sequence of 1430 nucleotides in this region for two of the HPV-6c isolates did not identify any differences between them. Comparison with the published sequences of HPV-6b identified deletions/insertions and base changes with approximately 75% sequence identity, and comparison with HPV-11 identified only six base changes. Conservation of sequences in the E4-E5 region and similarity in the restriction enzyme maps demonstrated that HPV-6c and HPV-11 are independent isolates of the same HPV-6 subtype.

Base Sequence↗

PubMed1989

Heterogeneity in mRNA of human papillomavirus type-6 subtypes in respiratory tract lesions.

We have analyzed the structure of viral transcripts in six HPV-6c-induced respiratory tract lesions, which included four benign laryngeal papilloma, one benign nasopapilloma, and one malignant tumor, in four benign laryngeal papilloma induced by HPV-6e, and in one benign laryngeal papilloma induced by HPV-6f. Northern analysis and S1 nuclease digestion with subgenomic RNA probes demonstrated that the major exon of 1050 bases had a 5' end in the E4 open reading frame and a 3' end in E5B. Primer extension from a synthetic oligonucleotide in E4 was used to examine sequences 5' to the major exon. Differences were found in length, start sites, and relative abundance of the first exon in transcripts produced in HPV-6c-induced infections as compared to HPV-6e- and HPV-6f-induced infections. Primer extension in the presence of dideoxynucleotides facilitated sequence analyses of the first exon. HPV-6c transcripts contained common sequences from E1 that in different transcripts extended farther upstream in the 5' direction into E7 resulting in different lengths. All of the mRNAs had the same splice junction at nucleotide 847 in E1 and 3325 in E4. Similarly, the HPV-6e transcripts shared common sequences in the first exon that differed in length as a result of different starting points and had the same splice junction as the HPV-6c transcripts. No differences were found in the structure of viral transcripts in a malignant vs benign lesions, nor in those of nasopapilloma vs laryngeal papilloma when induced by the same HPV-6 subtype.

Autoradiography↗

PubMed1989

Sensitive detection of nucleic acids and protein of human papillomavirus type 6 in respiratory and genital tract papillomata.

We have developed a sensitive method to detect and localize HPV-6 viral DNA, mRNA and protein in biopsy specimens of genital and respiratory tract lesions by using in situ hybridization and immunoperoxidase assays on sections of plastic-embedded tissue. This modified in situ hybridization technique, using ultrathin sections and strand-specific 3H-labelled riboprobes, offers the advantages of superior morphological preservation and detection of viral genomes at low copy number with good resolution. This modified immunocytochemistry provides better sensitivity when compared to previous methods using paraffin-embedded materials. In respiratory tract lesions, immunoperoxidase assay detected only a few capsid antigen positive cells, while in the genital tract lesions, there were more capsid antigen positive cells. Southern transfer analyses and in situ hybridizations demonstrated the presence of more viral nucleic acids in genital tract papillomata than respiratory tract papillomata. Epithelial cells throughout the papillomata were infected by HPV-6 as evidenced by positive hybridization, with more viral DNA present in superficial cells. Our results suggest that genital tract epithelium is more permissive for HPV-6 replication than respiratory tract epithelium. Using stand-specific probes synthesized from subgenomic fragments of the HPV-6 genome in conjunction with nuclease digestions, we were able to demonstrate that HPV-6 transcripts specific to open reading frames (ORFs) E6, E7, E1, L1, and L2 occur in maturing superficial cells. In contrast, transcripts specific to ORFs E1, E2, E4, E5a, and E5b could be detected throughout the whole of the epithelium with more signals noted at the basal cell areas. In addition, the distribution of HPV-6 nucleic acids and protein in a carcinoma in situ of the larynx was analyzed. In comparison to benign respiratory tract papillomata, more viral DNA was found in the malignant lesion, but the pattern and distribution of transcription and capsid antigen was similar.

Antigens, Viral↗

PubMed1989

Method for cloning single-stranded oligonucleotides in a plasmid vector.

A method for cloning single-stranded oligonucleotides in a plasmid vector has been developed. The method relies on ligation of the oligonucleotide into suitable restriction enzyme sites of the cloning vector such that the site at the 5' end has a 5' overhang [for example, a Bgl II site (A decreases GATCT)], and the site at the 3' end has a 3' overhang [for example, a Sac I site (GAGCT decreases C)]. This arrangement allows the oligonucleotide to anneal to the single-stranded ends of the vector and to be covalently joined by T4 DNA ligase. The complementary strand can be synthesized in vitro to generate a double-stranded plasmid, or the partially single-stranded molecule can be used as a target for site-directed mutagenesis. The subsequent transfer of the oligonucleotide to test plasmids or excision for other manipulations, such as band shift experiments to identify protein binding sites, is facilitated by cloning of the oligonucleotide into a polylinker containing multiple restriction enzyme sites. For this purpose, the plasmid vector, pKP59, which is a 2.0 kB derivative of pBR322 lacking "poison sequences" and containing 16 cloning sites, has been the most satisfactory.

Biotechnology↗

PubMed1988

Randomized surgical adjuvant trial of interferon alfa-n1 in recurrent papillomatosis.

Sixty-six patients with recurrent respiratory papillomatosis of juvenile onset were treated for six months with interferon alfa-n1 (Wellferon) in a randomized crossover trial. Half received interferon alfa-n1 intramuscularly at a dosage of 5 megaunits per square meter daily for 28 days and then thrice weekly for five months, followed by six months of observation. The other half were observed for six months and then treated. Operations were performed every two months to assess disease extent by a scale developed for this purpose. The score for the patients during the first observation period was stable. There was a statistically significant lowering of score in patients receiving interferon alfa-n1 during both periods of drug administration. Eight of 57 patients with assessable airway disease achieved complete remission, as did one additional patient with disease limited to the nasopharynx. No patients achieved complete remission during six months of observation alone. This difference was statistically significant. Patients without tracheostomy were significantly more likely to achieve remission than those with a tracheostomy. The patients who were observed after discontinuation of the drug therapy showed a significant rise in score within four months. Symptoms of toxicity included transient fever, fatigue, nausea, and headache. Elevations in serum aspartate aminotransferase levels occurred in 64% of the patients. There was an inverse correlation between age and the ability to tolerate the medication. The dose studied may be close to the maximum tolerated dose. It appears that interferon alfa-n1 as an adjuvant to routine surgical management is effective in slowing the growth of respiratory papillomas.

Clinical Trials as Topic↗

PubMed1988

Interferon alpha-n1 (Wellferon) for refractory genital warts: efficacy and tolerance of low dose systemic therapy.

This multi-center trial compared two doses of parenterally administered interferon alpha-n1 (Wellferon) in men and women with recurrent/resistant genital warts. Patients received either 1 or 3 MU/m2 daily for 14 days, then 3 times weekly for 4 weeks; non-responders could receive an additional four weeks of treatment. A total of 107 patients were enrolled, and 102 were evaluable after six weeks of study. The principal dose comparison was in 57 women assigned alternately to the two doses. Median lesion measurements were reduced significantly from baseline at weeks 2, 4 and 6 in both groups. Statistical analysis showed no difference in response to 1 versus 3 MU/m2. The overall complete response (CR) plus partial response (PR) rate at week 6 was 69% for the two doses. Two additional groups of 21 women and 24 men were treated at the higher dose with CR plus PR rates of 75 and 50%, respectively. Week 10 disease evaluations for all groups showed 19 of 77 patients to be completely cleared. Of these 19, only one had recurrent disease at the end of the 6-month study period. Analysis of the incidence of symptomatic side effects showed a significantly higher frequency among women treated with 3 MU/m2 than among women treated with 1 MU/m2. Five dose reductions and two withdrawals for toxicity occurred, all in the high dose group. This study demonstrates that parenterally administered Wellferon produces clearance of resistant genital warts in many patients, and that rates of clearance do not appear to vary between groups receiving moderate or low dose therapy.

Adult↗

PubMed1988

Transcriptional activity of human papillomavirus type 6 in respiratory tract papillomata.

We have investigated the molecular basis for differences that we observed in the biological activities of genetically related but distinguishable human papillomavirus type 6 (HPV-6) subtypes. To analyse tissue-specific differences in replication and transcription, and to identify viral gene products important in the benign transformation of epithelial cells, we have modified procedures utilizing guanidinium isothiocyanate and density gradient centrifugation to facilitate the extraction of relatively undegraded DNA and RNA from 21 biopsy specimens of respiratory tract papillomata. Southern transfer analysis was used to characterize the viral genome, and to demonstrate that relative quantities of viral DNA in lesions varied but that the range was similar in lesions induced by HPV-6c, -6d, -6e and -6f. Dot blot analysis of the amount of viral RNA in comparison with the amount of 28S ribosomal RNA indicated that the relative level of viral RNA in each lesion varied considerably and that on average there was approximately twice as much viral RNA in HPV-6c-induced lesions as in HPV-6d-, -6e- or -6f-induced lesions. In dot blot and Northern analyses, hybridization of RNA from HPV-6c-induced lesions with HPV-6c DNA gave a stronger signal than hybridization of the same RNA with an HPV-6e probe, and vice versa. These differences in hybridization intensities with subtype-specific probes indicate that the most abundant RNA species are transcribed from parts of the genome that show sequence divergence between these two subtypes. Northern analysis demonstrated the predominant viral transcript to be about 1200 nucleotides in length in lesions induced by each of the four subtypes.

DNA, Neoplasm↗

PubMed1988

Transcriptional regulatory elements in the noncoding region of human papillomavirus type 6.

We have identified three elements in the noncoding region of human papillomavirus type 6 (HPV-6) that regulate transcription when assayed in recombinant plasmids containing the bacterial gene for chloramphenicol acetyltransferase. One was a silencer that reduced expression in both a species- and tissue-dependent manner. The second was an enhancer element that was tissue specific. The third was a weak promoter that showed some tissue specificity. These elements have been localized within the noncoding region by analysis of 5'-to-3' and 3'-to-5' deletions with two HPV-6 subtypes, HPV-6e and HPV-6g. HPV-6g differs from HPV-6e by the presence of an additional copy in tandem of a 136-base-pair (bp) sequence and by an 8-bp sequence containing a 3-bp deletion. Silencer activity, assayed in plasmids with the simian virus 40 minimum promoter which were transfected into NIH 3T3 cells, could not be overcome by the enhancer activity of the simian virus 40 72-bp repeats. The 413-bp fragment of A of HPV-6g showed silencer activity, while the corresponding HPV-6e fragment containing the 8-bp change did not. Enhancer activity of HPV-6g was localized to fragment C of 326 bp which contains the 136-bp repeat. Dot blot hybridizations reflected relative chloramphenicol acetyltransferase activities and demonstrated enhancer and silencer activities at the RNA level. Analysis of the interaction of these activities in naturally occurring variants should provide information on tissue specificity and regulation of gene expression of HPVs and may provide information on the mechanism of action of transcriptional regulatory elements in eucaryotic cells.

Animals↗

PubMed1988

Carcinoma ex-papilloma: histologic and virologic studies in whole-organ sections of the larynx.

A patient with adult-onset recurrent respiratory papillomatosis (RRP), initially diagnosed at age 28 years, was treated with radiation therapy due to the rapid regrowth of lesions. Following 6 years of apparently inhibited growth, papilloma recurred, and squamous carcinoma was diagnosed from a laryngeal biopsy. A spontaneous laryngocutaneous fistula developed, and laryngectomy was performed 14 years after irradiation. The laryngectomy specimen was snap frozen and representative tissues were stored frozen for viral studies. The larynx was whole-organ sectioned for histologic examinations; residual papilloma, as well as carcinoma, was observed. Koilocytosis and other virus-associated histologic changes were also found. HPV capsid antigen was present in papilloma, carcinoma, and clinically normal epithelium. HPV nucleic acids, conforming to HPV type 6, were present in keratin pearls and dysplastic cells. According to prior reports, carcinoma developing in preexisting papilloma arises from juvenile-onset RRP. Irradiated papilloma develop cancer at about 10 years, and the patients rarely survive. Nonirradiated cases develop cancer after 30 years, and some develop papilloma in the hypopharynx and trachea, but most patients survive. Irradiation is not an obligatory precursor for malignant transformation of cancer; however, until now there have been no case reports of favorable outcome after irradiation of papilloma.

Adult↗

PubMed1986

Demonstration of papillomavirus capsid antigen in human conjunctival neoplasia.

To investigate the association of human papillomavirus with conjunctival neoplasia, we identified 50 resected papillomas from 47 patients. Papillomas were composed of papillary or, less commonly, flat proliferations of predominantly nonkeratinizing squamous epithelium with admixed goblet cells. Koilocytosis was focally present in 30 tumors (60%). Atypia that ranged from mild to severe was present in ten lesions (20%). In addition, we examined specimens of conjunctival dysplasia or carcinoma from 61 patients. The lesions were predominantly flat proliferations of atypical epithelial cells. Twenty biopsies performed for suspected sarcoidosis were used as controls. Papillomavirus capsid antigen was demonstrated using an immunoperoxidase technique in nuclei of mature superficial epithelial cells of 23 papillomas (46%) and five dysplasias or carcinomas (8.2%) but not in the control biopsy specimens. These results suggest that papillomavirus may play a role in the etiology of conjunctival papilloma, dysplasia, and carcinoma.

Adult↗

PubMed1986

Efficacy of human lymphoblastoid interferon in the therapy of resistant condyloma acuminata.

The efficacy and tolerance of human lymphoblastoid interferon (Wellferon) were studied in an open label trial of 17 patients with resistant and persistent condyloma acuminata. Patients were treated intramuscularly with 5 X 10(6) U (5 MU)/m2 daily for 28 days followed by thrice weekly injections for two weeks. Sixteen patients were considered evaluable; eight experienced complete clearance, seven had significant reduction (greater than 50%) in lesion size, and one showed no response during the course of this trial. Biologic side effects of interferon occurred in all patients during initial dosing and diminished during thrice weekly therapy. Intramuscular injections and associated side effects were tolerated well. This study shows that systemic human lymphoblastoid interferon is active in treating severe recurrent genital warts in women with a history of recalcitrant disease.

Adolescent↗

PubMed1986

Isolation and restriction endonuclease analysis of mycobacterial DNA.

A method for the isolation of DNA from mycobacteria propagated in vitro is described that utilizes organic solvents to extract lipoidal components from the outer membrane, and digestion with a protease (nagarse) and lysozyme to penetrate the cell wall. The mycobacterial cells were lysed by the addition of detergent and the DNA was purified by digestion with pronase, sequential phenol and chloroform extractions, and digestion with RNAase A. The isolated DNA, which was obtained in good yields, was of a relatively high Mr and could be readily digested by restriction endonucleases. By this method, the genomes of Mycobacterium avium, M. intracellulare, M. lepraemurium, 'M. lufu', M. marinum, M. phlei, M. scrofulaceum, M. smegmatis and M. tuberculosis were isolated and the restriction endonuclease digestion patterns analysed. Each species could be distinguished by the digestion patterns, indicating that this approach can be used for identifying mycobacterial species. This approach is also sufficiently sensitive to differentiate strains since we were able to distinguish two independently isolated strains of M. tuberculosis, H37 and H4. In addition, no evidence was obtained for the presence of methylcytosine residues in the sequences 5'.CCGG.3',5'.CCCGGG.3',5'.CC(A/T) GG.3' or for methyladenine at 5'.GATC.3' in the DNA of the nine mycobacterial species examined using pairs of restriction enzymes that recognize and cleave at the same nucleotide sequence but differ in their sensitivity to 5-methylcytosine or 6N-methyladenine.

DNA Restriction Enzymes↗

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↗