Search PubMed⌕ Search

Biomedical subjects

A Verhest

Publications and source records attributed to A Verhest.

At least 55 records · Page 3Linked to original sources
PubMed1994

Human papillomavirus type 16 associated with multifocal transitional cell carcinomas of the bladder in two transplanted patients.

This report describes two cases of rapidly progressive, multifocal transitional cell carcinomas of the bladder that developed in two patients after renal and cardiac transplantation, respectively. In both cases human papillomavirus (HPV) type 16 DNA was detected using the polymerase chain reaction DNA amplification method. To our knowledge, this HPV type has not been previously described in multifocal bladder transitional cell carcinoma in transplanted patients. Our findings suggest that HPV may play a major role in the development of rapidly progressive, multifocal transitional cell carcinoma in immunosuppressed patients.

Base Sequence↗
PubMed1994

Transitional cell carcinoma of the bladder: evaluation of the role of human papillomaviruses.

OBJECTIVES: The study evaluated the conflicting results of the role of human papillomavirus (HPV) in the development of bladder carcinoma. METHODS: We analyzed the frequency of HPV types 6, 11, 16, 18, and 33 by using polymerase chain reaction on formalin-fixed, paraffin-embedded specimens, from 75 cases of transitional cell carcinoma (TCC) of the bladder. Fifteen samples of normal urothelium adjacent to TCC (10) or from normal bladder obtained at autopsy (5) served as negative controls. RESULTS: HPV type 16 deoxyribonucleic acid (DNA) was detected in 2 (2.7%) of the 75 cases of TCC and in none of the normal urinary bladder cases. The 2 patients with HPV type 16 were immunosuppressed after undergoing renal and cardiac transplantation. CONCLUSIONS: These results strongly suggest that HPVs play a minor role in the development of TCC of the bladder in the general population, although they can act as oncogenic agents in predisposed patients, such as those who are immunosuppressed.

Apolipoproteins C↗
PubMed1994

[Plexiform fibrohistiocytic tumor of the hand. Late form].

Plexiform fibrohistiocytic tumours are very rare, apparently benign neoplasms of the superficial soft tissue: only two series and one case report have been described in the literature. Macroscopically located within the dermis or superficial subcutis, they seem to predominate in the upper limbs of children and young adults. Moreover their recurrence rate is relatively high. We report the case of a 56 year old male patient presenting such a plexiform fibrohistiocytic tumour of the hand, which was surgically excised after a progressive clinical evolution of approximately 5 years and in which no recurrence has been observed with a follow-up of more than 24 months.

Follow-Up Studies↗
PubMed1994

Transformation of common warts into squamous cell carcinoma on sun-exposed areas in an immunosuppressed patient.

We report one case of renal transplant recipient who developed widespread multiple verrucous skin lesions. Histologic examination revealed typical warts and, only from several sites exposed to sun (hands and face), a development of dysplasia within the warts and a transformation of some of them toward infiltrating squamous cell carcinoma (SCC). Human papillomavirus (HPV) testing for DNA by polymerase chain reaction DNA amplification identified HPV type 1 in both warts and SCC. Our findings suggest that classic warts may progress to high-grade lesions and that, in addition to the oncogenic potential of the virus alone, other factors including the host's immunosuppressed state and ultraviolet radiation seem to be essential to malignant transformation.

Adult↗
PubMed1994

[Sebaceous cutaneous carcinoma. Value of early cytological test].

Sebaceous carcinoma is a skin tumour which frequently metastases to the visceral organs. Needle biopsy is needed for rapid diagnosis. We observed a case in a 65-year-old patient who had a tumour formation below the right maxillary angle and homolateral justamandibular lymph node enlargement. Cytology of the needle biopsy showed a double cell population: small anaplastic cells and an agglutinated cell mass with peripheral maturation and sebaceous differenciation. Treatment was surgical with homolateral node dissection and secondary plasty. The tumour was large, non-encapsulated with local infiltration. On light microscopy, two cell populations were seen. Evident sebaceous differentiation was confirmed by histochemical staining. Immunolabelling confirmed the epithelial nature of the tumour. The clinical diagnosis of sebaceous carcinoma is difficult. Early cytology is needed to identify the two cell components when other cytological signs do not allow a positive diagnosis.

Aged↗
PubMed1993

Nuclear DNA content, proliferation index, and nuclear size determination in normal and cirrhotic liver, and in benign and malignant primary and metastatic hepatic tumors.

The distribution values of ploidy, of the proliferation index, of the percentages of diploid cells/case, of nuclear size, and DNA histogram type are described in a series of 92 liver samples from 87 patients. The 92 samples include normal (31 cases) and cirrhotic (14 cases) tissues, benign tumors (7 cases), well-differentiated hepatocellular carcinomas (HCCs, 13 cases), moderately and poorly differentiated HCCs (8 cases), and colorectal glandular metastatic tissues (19 cases). The samples are from either fine-needle aspiration biopsy (FNAB) or histologic imprint smears (HIS). Nuclear assessments were computed on Feulgen-stained nuclei by means of a cell image processor. The results show that the mean DNA index value, the mean nuclear area (NA) value, and the mean percentages of diploid cells per sample are significantly different in the three benign groups under study (normal and cirrhotic tissues and benign tumors) as compared with the mean parameter values from the three neoplastic liver groups (well-differentiated and poorly differentiated HCCs and colorectal metastases). None of these three parameters, however, makes it possible to discriminate clearly between these six histopathologic groups at the individual case level. The mean proliferation index values were significantly lower in the normal tissues and the benign tumors than in the four other histopathologic groups. Recognizing six DNA histogram types, ie, diploid, hyperdiploid, triploid, hypertriploid, tetraploid, and polymorphic, we observed that all the benign samples (the normal and cirrhotic tissues and the benign tumors) exhibited a diploid and/or tetraploid DNA histogram pattern, whereas the neoplastic samples exhibited the six DNA histogram patterns. The combination of the five computerized parameters into a cytologic score (CS) ranging from 5 to 15 permits clear-cut discrimination between nonneoplastic and neoplastic liver cases. The specificity and sensitivity, and the positive and negative predictive values relating to this score were as high as 100%, 95%, 100%, and 96%, respectively.

Biopsy, Needle↗
PubMed1993

Demonstration of human papillomavirus type 2 in a verrucous carcinoma of the foot.

This report describes one case of verrucous carcinoma of the foot containing human papillomavirus type 2 DNA which was detected by the polymerase chain reaction DNA amplification method. Our findings suggest that human papillomavirus type 2, which was classically associated with palmoplantar warts, may also play a role in the pathogenesis of peripheral verrucous carcinoma.

Carcinoma, Papillary↗
PubMed1993

DNA histogram typing in retinoblastomas and neuroblastomas.

The nuclear DNA content characterization was carried out by means of both DNA index and DNA histogram type assessments in a series of 21 retinoblastomas, 11 neuroblastomas, 1 ganglioneuroblastoma, and 4 medulloblastomas. These measurements were performed by means of the cytophotometric digital cell image analyses of Feulgen-stained nuclei. The results indicate that as far as nuclear DNA content is concerned, retinoblastomas seem to be very different from neuroblastomas. In fact, in terms of DNA index, retinoblastomas are significantly more aneuploid than neuroblastomas. The DNA histogram type shows that the high level of aneuploidy found in retinoblastomas corresponds to genotypically polymorphic tumors, and this could reflect a serious degeneration of the genomic material in retinoblastomas. This type of degeneration seems to be much less frequent in neuroblastomas, which basically seem to be either diploid or hypertriploid.

Adolescent↗
PubMed1993

Heterogeneity of DNA ploidy, proliferation index and nuclear size in human colorectal carcinomas.

Measurements of DNA ploidy, proliferation index and nuclear area were performed on 210 samples taken from 15 human colorectal tissues. The tissues were divided into four groups labeled G1, G2, G3 and C. For each of the 15 tissues 9 samples were taken from the so-called unaffected--i.e., marginal--mucosa (G1-G3 groups) and 5 from the tumor (C group). The 9 samples from the unaffected mucosa of each tumor were obtained at a distance of 10 cm (3 samples/tissue, G1 group), 5 cm (3 samples/tissue, G2 group) and 1 cm (3 samples/tissue, G3 group) from the tumor. Computerized cell image analysis was carried out on Feulgen-stained cell suspensions obtained from paraffin-embedded, formalin-fixed tissues. The results revealed that four to five analyses are necessary to detect minor aneuploid cell nuclei populations in human colorectal tumors. A definite homogeneous diploid pattern was found in the G1-G3 samples. In contrast, proliferative activity varied widely between the normal and tumor samples, with such variations observed at both the sample-to-sample and tissue-to-tissue level. The nuclear area also varied markedly across the samples from a given tissue--i.e., both marginal and tumoral and across the tissues themselves. Finally, we observed that the diploid tumors, the nuclear sizes of which varied as widely as those of the aneuploid tumors, possessed a higher proportion of highly proliferating samples than did the aneuploid.

Aged↗
PubMed1992

Computerized morphonuclear characteristics and DNA content of adenocarcinoma of the pancreas, chronic pancreatitis, and normal tissues: relationship with histopathologic grading.

We report the morphonuclear characteristics of normal (13 cases), benign (ie, chronic) pancreatitis (six cases), and neoplastic (ie, ductal) adenocarcinoma (22 cases) tissues of the pancreas. This description is based on computerized cell image analysis, which permits the determination of parameters related to the morphometric (nuclear area), densitometric (nuclear DNA content), and chromatin texture features of Feulgen-stained nuclei from paraffin-embedded archival material. We observed that nuclear area discriminates between normal and benign (ie, chronic pancreatitis) as opposed to neoplastic cell nuclei. Morphonuclear parameters describing chromatin pattern characteristics made it possible to discriminate between grade I pancreatic carcinoma and normal and benign cell nuclei on the one hand, and grades I and III carcinoma on the other hand. The nuclear DNA content increased in a continuous manner from normal and benign through low-grade to high-grade neoplastic tissues of the pancreas. Combining the morphometric, densitometric, and textural parameters into one equation, we were able to calculate a score (ie, the malignancy level index) that showed a close relationship to conventional histopathologic grading. Thus, the computer-aided diagnosis of cytologic specimens from pancreatic lesions offers information of the same significance as that obtained by conventional histopathologic grading.

Adenocarcinoma↗
PubMed1992

Translocation (6;16) in a case of granulosa cell tumor of the ovary.

We performed a cytogenetic study of an ovarian granulosa cell tumor (GCT). Tumor cells showed a translocation (6;16); the full karyotype was 45,XX-6,dic(6;16)(q11;q22)/44,XX,-6,-22,dic(6;16)(q11;q22),-22/46,XX,- 6,dic(6;16)(q11;q22), +dic(6;16)(q11;q22). This is the second case of GCT with structural changes of chromosome 6 leading to loss of 6q material.

Adult↗
PubMed1992

Verrucous carcinoma of the penis: importance of human papillomavirus typing for diagnosis and therapeutic decision.

One case of penile verrucous carcinoma (Buschke-Löwenstein tumor) undergoing anaplastic transformation and containing human papillomavirus type 6 is presented. The viral genome is detected by in situ hybridization using biotin-labeled cDNA probes. The clinical, histological and virologic criteria of verrucous carcinoma are discussed in comparison to giant condyloma and highly differentiated squamous cell carcinoma. The importance of viral typing determination for further diagnostic and therapeutic procedures is emphasized.

Aged↗
PubMed1992

Modification of tumor ploidy level via the choice of tissue taken as diploid reference in the digital cell image analysis of Feulgen-stained nuclei.

We studied the influence of five cell nucleus populations taken as diploid standards with respect to the normalization of a human breast carcinoma. Four normal human tissues (lymphocytes, thyroid, liver, and bladder specimens) were taken as external standards, while the normal breast cells "contaminating" the tumor were taken as the internal diploid standard. Nuclear size and nuclear DNA assessments were performed by means of a cell image processor computing the parameters on Feulgen-stained nuclei from fresh imprint smears fixed in an ethanol-formalin-acetic acid mixture. Our results demonstrate that the choice of normal tissue as the diploid standard markedly influences the ploidy level of breast carcinoma. Normalization according to the lymphocytes led to our obtaining a major hyposextaploid G0-G1 DNA peak in the breast cancer. Using thyroid and liver cells as a standard, we obtained a major pentaploid and sextaploid G0-G1 peak, respectively. Using bladder cells or the normal contaminating breast cells within the tumor, we obtained a major tetraploid G0-G1 peak. Finally, the normalization of the normal bladder cells against the liver cells led to our obtaining a near triploid bladder specimen. The reverse feature was also observed, e.g., the obtaining of biologically nonsensical hypodiploid liver cells after normalization against the normal bladder cells. Such postnormalization variations in ploidy level depend upon the mean nuclear size and the mean nuclear DNA content of the normal tissue taken as diploid standard.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1992

Comparison of morphonuclear features in normal, benign and neoplastic thyroid tissue by digital cell image analysis.

We analyzed the morphonuclear features of thyroid cell nuclei from 10 normal tissues (10 multinodular goiters), 10 benign tissues (10 adenomas) and 10 neoplastic tissues (10 carcinomas--2 follicular, 2 medullary and 6 papillary). These morphonuclear features quantitatively described the nuclear size, DNA content and chromatin texture of 200-400 Feulgen-stained cell nuclei that were digitized by means of a cell image processor. Nuclear DNA estimations revealed that the benign thyroid tumors showed an aneuploidy level that was not different from that of the neoplastic tissues. Morphometric measurements showed a significant and positive correlation between an increase in nuclear area and the development of thyroid pathology--i.e., from normal to a neoplastic stage. We also observed a significant decrease in chromatin condensation and heterogeneity from normal to neoplastic thyroid tissue. In the specific case of thyroid tumors, such criteria were not found sufficient per se for a diagnosis of malignancy. More detailed data banks will be necessary for this purpose.

Adenocarcinoma↗