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Biomedical subjects

H L Smits

Publications and source records attributed to H L Smits.

At least 37 records · Page 2Linked to original sources
PubMed1997

No evidence of known types of human papillomavirus in squamous cell cancer of the oesophagus in a low-risk area. Rotterdam Oesophageal Tumour Study Group.

Controversial results regarding the presence and role of human papillomavirus in the development of oesophageal squamous cell carcinoma have been published. We used multiple broad-spectrum polymerase chain reactions to identify HPV DNA in oesophageal carcinomas from a low-incidence area. Paraffin embedded- and snap-frozen specimens from oesophageal cancer tissues of 63 patients were examined with a PCR technique with several primer pairs, capable of detecting most known HPV types. In none of the oesophagus cancer tissues could HPV DNA be detected. The role of HPV in this type of carcinoma in a low incidence area remains unclear.

Adult↗
PubMed1997

LEPTO dipstick, a dipstick assay for detection of Leptospira-specific immunoglobulin M antibodies in human sera.

We studied a dipstick assay for the detection of Leptospira-specific immunoglobulin M (IgM) antibodies in human serum samples. A high degree of concordance was observed between the results of the dipstick assay and an IgM enzyme-linked immunosorbent assay (ELISA). Application of the dipstick assay for the detection of acute leptospirosis enabled the accurate identification, early in the disease, of a high proportion of the cases of leptospirosis. Analysis of a second serum sample is recommended, in order to determine seroconversion or increased staining intensity. All serum samples from the patients who were confirmed to be positive for leptospirosis by either a positive microscopic agglutination test or a positive culture but were found to be negative by the dipstick assay were also judged to be negative by the IgM ELISA or revealed borderline titers by the IgM ELISA. Some cross-reactivity was observed for sera from patients with diseases other than leptospirosis, and this should be taken into account in the interpretation of test results. The dipstick assay is easy to perform, can be performed quickly, and requires no electricity or special equipment, and the assay components, a dipstick and a staining reagent, can be stored for a prolonged period without a loss of reactivity, even at elevated temperatures.

Antibodies, Bacterial↗
PubMed1995

Multifocal vulvar intraepithelial neoplasia grade III and multicentric lower genital tract neoplasia is associated with transcriptionally active human papillomavirus.

BACKGROUND: The incidence of vulvar intraepithelial neoplasia Grade III (VIN III) is increasing and is diagnosed at a younger age than previously. VIN III is often multifocal and frequently coexists with multicentric dysplastic lesions in the cervix and vagina. Warty-type VIN III more often has been found to contain human papillomavirus (HPV) DNA than basaloid-type VIN III: The authors performed HPV DNA polymerase chain reaction (PCR) analysis in 48 VIN III biopsies and reverse transcriptase (RT)-PCR in 8 HPV-16 DNA-positive multifocal VIN III biopsies to detect E6/E7 transcripts. METHODS: Human papillomavirus DNA detection and histologic analysis were performed on alternating slides of paraffin embedded biopsies. Polymerase chain reaction was performed with consensus primers, and HPV typing was performed by direct sequencing. Total RNA was isolated from frozen biopsies by centrifuging a guanidinium thiocyanate (GTC) lysate through a cesium chloride (CsCl) cushion. The RT reaction was performed using a 3' primer, located just downstream of the E7 stop codon, and the PCR reaction was performed using the same 3' primer and a 5' primer located just downstream of the E6 start codon. RESULTS: The mean age of the 48 patients was 37.7 years. Eighty-one percent had multifocal VIN III: Sixty-six percent had multicentric neoplasia. Forty-six percent of the biopsies were warty-type, 17% basaloid-type, 35% mixed-type and 2% differentiated-type. Ninety-two percent were HPV-positive and 83% contained HPV-16 DNA. Human papillomavirus DNA was more often present in multifocal VIN III lesions than in unifocal VIN III lesions and also more often in VIN III lesions coexisting with other dysplastic multicentric lesions than in unicentric VIN III lesions. Warty-type VIN III more often contained koilocytes than basaloid-type VIN III: A correlation between different morphologic forms of VIN III and the presence of HPV DNA was not found. Both types of VIN III often coexist in one lesion. In all the RT-PCRs, a 593-base-pair fragment was detected, corresponding to the expected length of the major E6*-E7 mRNA. CONCLUSIONS: The observed high prevalence of transcriptionally active HPV DNA associated with multifocal and multicentric dysplasia suggests a role of HPV in the pathogenesis of these lesions. A positive correlation between different morphologic forms of VIN III and the presence of HPV DNA was not found.

Adult↗
PubMed1995

Absence of human papillomavirus DNA from esophageal carcinoma as determined by multiple broad spectrum polymerase chain reactions.

Strong evidence has implicated human papillomaviruses (HPV) in the pathogenesis of anogenital cancers and a number of other mucosal and cutaneous lesions. Data concerning the involvement of HPV in esophageal cancers are controversial. Different investigators have detected HPV types (mainly types 16 and 18) in biopsy specimens of esophageal cancers. A study was undertaken to determine whether responses to chemotherapy of advanced squamous cell carcinomas could be correlated with the HPV status. Polymerase chain reaction (PCR) amplification was used for the detection of HPV DNA in biopsies of esophageal squamous cell carcinomas treated with either surgical resection alone (n = 42) or chemotherapy followed by surgical resection (n = 21). Different general and consensus PCR primer sets, which allow the detection of most of the known as well as a number of not yet characterized HPV types, were used. HPV DNA was not detected in any of the 61 esophageal squamous cell carcinomas, suggesting that HPV infections are not likely to play a major role in the etiology of this neoplasm.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Health Care Financing Administration (HCFA) and reimbursement in telemedicine.

Telemedicine has real potential to improve the availability of services and advice of medical specialists to primary care practitioners and their patients. Use of the term "telemedicine" for the purposes of this article will refer to two-way, interactive video systems over which medical consultation takes place. This does not include the use of telecommunications technology to transport still images, particularly radiologic images, from one site to another. We are quite aware that teleradiology and telepathology is already in common use in many sites. We are currently exploring the question of quality standards for teleradiology in addition to other forms of telemedicine.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1995

Application of the NASBA nucleic acid amplification method for the detection of human papillomavirus type 16 E6-E7 transcripts.

Using a human papillomavirus type 16 (HPV-16) E6-E7 specific primer set in a nucleic acid sequence-based amplification (NASBA) reaction, detection of HPV-16 transcripts was accomplished in a single enzymatic reaction at 41 degrees C. The NASBA reaction product was visualized either by Northern bolt analysis with an HPV-16 E6-E7-specific 32P-labelled oligonucleotide probe or by a non-radioactive enzyme-linked gel assay (ELGA). In combination with a rapid nucleic acid extraction procedure this method appears to be very suitable for the sensitive and specific detection of HPV-16 transcripts on small amounts of HPV-16-expressing cells of various sources, including cervical smears.

Base Sequence↗
PubMed1995

High frequency of detection of epidermodysplasia verruciformis-associated human papillomavirus DNA in biopsies from malignant and premalignant skin lesions from renal transplant recipients.

Based on immunologic and epidemiologic data, it is plausible that skin cancer in renal transplant recipients is associated with human papillomaviruses (HPV). At present, conflicting evidence exists concerning the presence of HPV DNA in these cancers. We recently described a nested polymerase chain reaction method that enables the detection of all previously isolated epidermodysplasia verruciformis (EV)-associated HPVs. We now describe the detection of EV-associated HPV DNA in 49 (80%) of 61 biopsies from squamous cell carcinomas, in four (50%) of eight basal cell carcinomas, in 14 (93%) of 15 actinic keratoses, in two (40%) of five cases of Bowen's disease, and in four (57%) of seven keratoacanthomas. HPV DNA typing revealed that all detected HPV types belonged to the EV-associated HPV types. A wide spectrum of EV-associated HPVs was found, including six putative new HPV types. In a high percentage of the lesions more than one HPV type was detected. We often found the same HPV types in different skin biopsies from both malignant and premalignant lesions from the same patient. The high frequency of detection of EV-associated HPV types in biopsies from malignant and premalignant lesions is in agreement with the hypothesis that EV-associated HPVs are involved in the pathogenesis of skin cancer in renal transplant recipients.

Adult↗
PubMed1995

Intermethod variation in detection of human papillomavirus DNA in cervical smears.

In order to investigate the reliability of detection of human papillomavirus (HPV) DNA in cervical smears, we have compared the performance of two HPV PCR systems, the CPI/IIG and MY09/11 primer-mediated PCRs and the Hybrid Capture System HPV DNA detection test (hybrid capture assay), in detecting HPV DNA in cervical smears. We also included in our study the MY09/11B PCR plus SHARP (solution hybridization assay for PCR products) Signal System. This SHARP Signal System was recently developed to detect MY09/11B-generated biotinylated PCR products. The detection rate of the hybrid capture assay was lower than those of the CPI/IIG and MY09/11 PCRs and the MY09/11B PCR plus SHARP Signal System. The detection rates of the CPI/IIG PCR and the MY09/11B PCR plus SHARP Signal System were similar and higher than that of the conventional MY09/11 PCR system. The agreement beyond chance of the PCR methods was nearly perfect (kappa value between 0.82 and 0.84). The agreement beyond chance of the hybrid capture assay and the PCR methods was fair to good (kappa value between 0.64 and 0.70). The systems detected HPV DNA in different but overlapping sets of smears. Our results indicate that each of the detection methods alone underestimates the prevalence of HPV.

Analysis of Variance↗
PubMed1995

Nested PCR approach for detection and typing of epidermodysplasia verruciformis-associated human papillomavirus types in cutaneous cancers from renal transplant recipients.

The epidermodysplasia verruciformis (EV)-associated human papillomaviruses (HPVs) constitute a group of HPV genotypes isolated mostly from the cutaneous lesions of patients with the genetic disorder of EV. Broad-spectrum detection of EV HPVs in cutaneous lesions of non-EV patients was previously difficult because no EV HPV consensus PCR was available. We describe a nested PCR that enables the detection of all known EV HPV types at relatively low-copy-number levels. The deduced sequences of a 92-amino-acid stretch of the L1 open reading frames of all types are shown for convenient typing. The technique proved very valuable in viral studies of skin cancers from renal transplant recipients. A high prevalence (81%) of EV HPV types was found in skin cancer biopsies. A wide spectrum of EV HPV types that differed from HPV-5 and -8 was found to be involved. The technique also proved useful in detecting potentially novel EV HPV types in skin cancers. The relationship of these new types to known HPV types is demonstrated by phylogenetic tree analysis.

Amino Acid Sequence↗
PubMed1994

Graduate medical education consortia: expectations and experiences.

Graduate medical education (GME) consortia are formal associations of medical schools, teaching hospitals, and other organizations involved in residency training, with central support, direction, and coordination allowing members to function collectively. GME consortia are not well documented in the literature, although they are included in many GME reform proposals. Proponents expect consortia to improve the organizational structure and governance of residency training programs and, through local coordination and possibly the allocation of resources, to help members meet national workforce goals regarding both numbers and practice locations for generalist and specialist physicians. The authors contrast the expectations of educators and policymakers for the future performance of GME consortia with the experiences of 36 functioning consortia, gathered in a 1993 national survey conducted by the Maine Medical Center and the Association of American Medical Colleges. Respondents account for nearly 10% of all residency training programs and 17% of all residents nationwide. The participating consortia differ markedly in their structures, functions, and other features, although nearly 85% have been convened by medical schools and closely affiliated hospitals. Fewer than half function with governing boards; 40% offer a single integrated residency training program in each discipline; and 58% allocate resources. A common concern of consortium members was physician distribution by specialty, but only 31% identified "increasing the number of generalist physicians" as a major accomplishment to date. To improve their performance, consortium participants call for greater commitment and leadership from the medical school and university, better definition of the community's GME needs, more information about the flow of GME funds locally, greater authority to allocate resources, and incentives for shifting allegiances from individual institutions to the consortium community as a whole.

Data Collection↗
PubMed1994

Identification of a unique group of human papillomavirus type 16 sequence variants among clinical isolates from Barbados.

The naturally occurring sequence variation of human papillomavirus type 16 (HPV-16) was analysed by direct sequence analysis of the PCR products of the long control region (LCR), the E5 and E7 open reading frames (ORFs), a segment of the L2 ORF overlapping the early viral poly(A) signal and a small segment of the L1 ORF or clinical isolates from Barbados and The Netherlands. Despite the widely different geographical and ethnic origin of the two groups of specimens, sequence analysis revealed relatively few mutational differences. Analysis of the LCR and the E5 ORF appeared to be the minimum requirement for the correct positioning of these variants in the HPV-16 phylogenetic tree. Most of the Barbadian variants appeared to be located at a unique position in the HPV-16 phylogenetic tree, at the internal branch close to the point where the European and Asian branches diverge. In contrast, most of the Dutch samples were located on the European branch.

Asia↗
PubMed1994

Detection of epidermodysplasia verruciformis-like human papillomavirus types in malignant and premalignant skin lesions of renal transplant recipients.

To evaluate the putative role of human papillomaviruses (HPV) in the development of skin cancer in renal transplant recipients, a series of skin biopsies from premalignant and malignant skin lesions was analysed using the polymerase chain reaction. Four different consensus primer pairs were used. HPV DNA was detected in five of 24 cases of squamous cell carcinoma, in one of three cases of Bowen's disease, in none of four basal cell carcinomas, in two of seven cases of actinic keratosis and in one of five cases of keratoacanthoma. Typing by direct sequencing of the amplified HPV DNA was possible in seven of nine cases, and revealed epidermodysplasia verruciformis (EV)-associated HPV types, or HPV types related to EV-associated types. Hence, HPV DNA could be detected in a significant proportion of (pre)malignant skin tumours in renal transplant recipients. The finding that some of the detected HPV types were as yet uncharacterized EV-related types, suggests that HPV DNA could be present in a higher percentage of lesions, and might be detected with refinement of the techniques.

Base Sequence↗
PubMed1993

Vaccination with cytotoxic T lymphocyte epitope-containing peptide protects against a tumor induced by human papillomavirus type 16-transformed cells.

Cytotoxic T lymphocyte (CTL) peptide epitopes can be used for immunization of mice against lethal virus infection. To study whether this approach can be successful against virus-induced tumors we generated a B6 (H-2b) tumorigenic cell line transformed by human papillomavirus (HPV). This virus is detected in over 90% of all human cervical cancers. To identify vaccine candidates, we generated a set of 240 overlapping peptides derived from the HPV type 16 (HPV16) oncogenes E6 and E7. These peptides were tested for their ability to bind H-2Kb and H-2Db MHC class I molecules. Binding peptides were compared with the presently known peptide-binding motifs for H-2Kb and H-2Db and the predictive value of these motifs is shortly discussed. The high-affinity H-2Db-binding peptide and putative CTL epitope E7 49-57 (RAHYNIVTF) was used in vaccination studies against HPV 16-transformed tumor cells. Immunization with peptide E7 49-57 rendered mice insensitive to a subsequent challenge with HPV 16-transformed tumor cells in vivo, and induced a CTL response which lysed the tumor cells in vitro.

Amino Acid Sequence↗
PubMed1993

Detection of cutaneous and genital HPV types in clinical samples by PCR using consensus primers.

Two sets of consensus PCR primers consisting of a common 3' primer CP-I and two 5'-primers, CP-IIG (primer set A) and CP-IIS (primer set B), in the E1 open reading frame of the human papillomavirus (HPV) genome are presented. These two primer sets enabled the detection of a 188 base pair (bp) fragment of HPV 1, 2, 3, 4, 5, 6b, 7, 8, 9, 10a, 11, 12, 14a, 16, 17, 18, 19, 20, 21, 22, 24, 25, 31, 33, 36, 37, 38, 39 and 46. HPV types 15, 23, 49 and 50 were poorly amplified and HPV type 41 was not amplified. The method is suitable for the detection of HPV DNA sequences in clinical samples of both cervical and cutaneous lesions.

Base Sequence↗
PubMed1993

Regulation of human papillomavirus type 16 (HPV-16) transcription by loci on the short arm of chromosome 11 is mediated by the TATAAAA motif of the HPV-16 promoter.

The human papillomavirus type 16 (HPV-16) enhancer-promoter is virtually inactive in normal human diploid fibroblasts, but active in human fibroblasts with a deletion in the short arm of one chromosome 11 (del-11 cells). Since the HPV-16 enhancer with the simian virus 40 promoter is active in both cell types, the target for chromosome 11-regulated HPV-expression is likely to be located in the HPV-16 early promoter region (nucleotides 57 to 112). We show here that DNA-protein complexes formed with an HPV-16 promoter fragment are quantitatively different in del-11 cell and diploid cell extracts. This quantitative difference detected in band shift experiments disappeared upon mutation of the HPV-16 TATAAAA box to TATTTAT. This mutation also strongly reduced the activity of the HPV-16 enhancer-promoter in del-11 cells. These results indicate that TATA-binding proteins are involved in the chromosome 11-mediated regulation of HPV-16 gene expression.

Base Sequence↗
PubMed1993

Detection of oncogenic HPV DNA by a consensus polymerase chain reaction method in genital carcinomas in twenty women in Barbados.

Paraffinized tissue from Barbadian women with histologically proven genital carcinoma was subjected to a consensus polymerase chain reaction method. Nineteen patients had cervical and one, vaginal carcinoma. The histological types were 17 squamous cell carcinoma, 2 adenocarcinoma and 1 adenosquamous carcinoma. HPV DNA was detected in 18/20 (90%). HPV DNA type 16 in 13 (65%), type 33 and type 45 in 1 (5%) each and 3 (15%) could not be typed. HPV DNA, type 16, was detected in one (50%) of the two cases of adenocarcinoma and 12/17 (71%) cases of squamous cell carcinoma. DNA HPV, type 33, and type 45 were each detected in 1/17 (6%) cases of squamous cell carcinoma. No HPV DNA, type 18, was detected.

Adenocarcinoma↗