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Featured researches published by J. Haot.


The Journal of Urology | 1997

Possible Mechanisms of Action of Transurethral Needle Ablation of the Prostate on Benign Prostatic Hyperplasia Symptoms: A Neurohistochemical Study

Alexandre R. Zlotta; Gil Raviv; Marie-Odile Peny; Jean Christophe Noël; J. Haot; Claude Schulman

PURPOSE Transurethral needle ablation of benign prostatic hypertrophy (BPH) is a rapid, anesthesia-free outpatient procedure using low level radiofrequency energy that produces coagulative necrosis lesions at temperatures of approximately 100C. Clinically, significant improvement in objective and subjective parameters has been observed in BPH patients. Transurethral needle ablation has also been shown to be effective in relieving urinary retention. However, the precise mechanism of action of this procedure remains to be clarified. Ablation could produce its action on the dynamic component of the infravesical outlet obstruction. We analyzed the possible effects of transurethral needle ablation on the intraprostatic innervation. MATERIALS AND METHODS Histological sections from 10 open prostatectomy specimens (BPH) recovered 1 to 46 days after transurethral needle ablation were stained with hematoxylin and eosin and an immunohistochemical technique, using antibodies against S100 proteins and nonspecific enolase as specific nerve markers, and against anti-prostate specific antigen and anti-desmin for glandular and muscle cells, respectively. We used 5 BPH specimens as controls. RESULTS Microscopic examination of the treated areas showed necrotic lesions affecting epithelial and smooth muscle cells in the transition zone at a depth of 0.3 to 1.0 cm, from the preserved urethra. Nerve fibers in the control specimens and untreated prostatic areas were predominant in the urethral submucosal layer and in the stroma surrounding the epithelial nodules. No staining of any axon or isolated nerve cell was observed in any specimen treated by transurethral needle ablation, and there was a sharp and clear delineation between treated and untreated areas. CONCLUSIONS Our study demonstrated severe thermal damage to intraprostatic nerve fibers caused by transurethral needle ablation. A long-term denervation of alpha-receptors and/or sensory nerves could explain the clinical effects of transurethral needle ablation of the prostate. Theoretically, the best location to produce necrotic lesions should include submucosal and subcapsular nerve endings. Differences in the distribution of the adrenoreceptors and morphometry of the prostate transition zone could partly explain differences in clinical outcome observed after transurethral needle ablation of the prostate.


Cancer | 1996

Herpesvirus‐like DNA sequences and Kaposi's sarcoma: Relationship with epidemiology, clinical spectrum, and histologic features

Jean Christophe Noël; Philippe Hermans; Josette André; Isabelle Fayt; Thierry Simonart; Alain Verhest; J. Haot; Arsène Burny

The evidence of an infectious agent other than human immunodeficiency virus (HIV) acting as a possible etiologic cause of Kaposis sarcoma (KS) has received considerable attention in the last years. Recently, DNA sequences from a new herpesvirus (HHV‐8) have been observed in several cases of KS. The discovery suggests that this virus may play a role in the pathogenesis of KS. To evaluate these results, we determined the frequency of HHV‐8 DNA sequences in 78 specimens of KS according to different epidemiologic origins (sporadic KS: 6, immunosuppressive drug‐associated: 11, and AIDS‐associated: 61), clinical forms (cutaneous: 69, mucocutaneous: 4 and visceral: 5) and histologic variants (early‐patch: 40, late‐plaque or nodular: 38).


Vibrational Spectroscopy | 1996

Breast cancer detection by Fourier transform infrared spectrometry

Marc Meurens; J. Wallon; Jiashu J. Tong; Henri Noël; J. Haot

Fourier transform infrared spectra of 75 biopsies from 55 cases of breast carcinoma were studied in comparison with histo-morphometry. The spectra of carcinomatous tissues are very different from those of normal tissues. There are evident correlations between the intensity of some infrared absorption bands and the volume density of malignant cells measured by optical microscopy [7]. Very high correlation coefficients are observed for phosphate monoester and phosphodiester bands; significant correlation coefficients are also observed for amide I and II bands.


Journal of Cancer Research and Clinical Oncology | 1997

Leukaemia and lymphoma of the appendix presenting as acute appendicitis or acute abdomen: Four case reports with a review of the literature

Gebhard G. Muller; Jean-Louis Dargent; Valérie H J M V. Duwel; Dominique D. D'Olne; J. J. Vanvuchelen; J. Haot; Jean Hustin

Abstract Leukaemic and lymphomatous infiltration of the appendix is rare and even rarer is acute appendicitis as the initial manifestation. From our routine biopsy material we collected four cases of haematological malignancies presenting as acute appendicitis or acute abdomen, caused or accompanied by tumoral infiltration of the appendix. Appendicitis was the initial manifestation that allowed diagnosis of the underlying disease. The clinical histories and histological examinations of the appendices and of one autopsy are described. We report the first detailed description of acute myeloid leukaemia involving the appendix, and three cases of lymphomatous infiltration of the appendix presenting with appendicitis, and give an overview of the literature. In these days of budgetary cuts in national health services, where one may be tempted not to have seemingly commonplace cases of appendicitis histologically verified, our cases emphasize that careful histopathological examination of all appendectomy specimens should be mandatory. Despite the fact that leukaemia and lymphoma of the appendix are rare, our cases illustrate that these must be included in the differential diagnosis of acute appendicitis and that physicians and surgeons have to be aware of these conditions.


Urology | 1994

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

Jean Christophe Noël; Lise Thiry; Alain Verhest; N. Deschepper; Marie-Odile Peny; Ahmed A. Sattar; Claude Schulman; J. Haot

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.


British Journal of Dermatology | 1995

Proliferating cell nuclear antigen distribution in verrucous carcinoma of the skin.

Jean Christophe Noël; Michel Heenen; Marie-Odile Peny; Isabelle Fayt; Jean Peny; Gilbert De Dobbeleer; J. Haot; Paul Galand

Verrucous carcinoma (VC) of the skin is a rare variety of well‐differentiated squamous cell carcinoma (SCC) characterized by aggressive local growth and a low metastatic potential. These tumours are known to have histological and virological features similar to classic warts or condylomata. The aim of the present study was to map the proliferative compartment in VC (n=7) in comparison with warts (n=10) and typical well‐differtntiated SCC (n=10). The proliferating cells were detected by immunostaining of proliferating cell nuclear antigen (PCNA) in formalin‐fixed, paraffin‐embedded tissue sections, using the commercially available anti‐PCNA monoclonal antibody PC10. Normal epidermis served as a positive control and reference. In VC and warts, the PCNA‐positive cells were principally located at the periphery of lesions, in the basal layer of the tumour islands. In some warts, however, stronger PCNA expressed was noted in the superficial layers, of the lesions corresponding to virus‐infected keratinocytes (koilocytotic cells). In contrast, in SCC, PCNA‐positive cells were randomly scattered throughout the tumours.


Applied Spectroscopy | 1994

Identification of Breast Carcinomatous Tissue By Near-infrared Reflectance Spectroscopy

J. Wallon; Shou He Yan; Jiashu Tong; Marc Meurens; J. Haot

NIR reflectance spectra of 110 cryostat sections of carcinomatous tissue and 114 cryostat sections of normal surrounding fibro-glandular tissue from 10 cases of breast cancer, identified by a classical pathology method, were scanned between 1100 and 2500 nm by a grating spectrometer in reflectance mode. Four wavelength intervals (1208–1242, 1746–1788, 2012–2048 and 2326–2368 nm) were found to be different for normal and carcinomatous tissues. In each interval, the second-derivative spectra of normal tissue showed a similar pattern with several characteristic peaks. In order to test the capacity of NIR spectroscopy in discriminating between normal and carcinomatous breast samples, 104 tissue sections from five additional cases were scanned prior to microscopic examination. The diagnostic prediction of NIR spectroscopy coincided exactly with the histology diagnosis for all the samples. Moreover, the presence of even a minute quantity of cancer infiltration can be detected by NIR spectroscopy, in total accordance with the microscopical observation. Therefore, the results of our experiments allow us to consider that NIR spectroscopy might become, with feasible improvements, an accurate, rapid, and reliable method for detecting breast cancer.


Histopathology | 2000

Overexpression of 27-kDa heat shock protein relates to poor histological differentiation in human oesophageal squamous cell carcinoma.

Marie-Alexandra Lambot; Marie-Odile Peny; Isabelle Fayt; J. Haot; Jean Christophe Noël

Various stress conditions such as heat, chemical and mechanical stresses are known to play a major role in oesophageal squamous cell carcinoma development. Our goal was to evaluate whether changes in stress‐induced 27‐kDa heat shock protein (HSP27) expression could be demonstrated during oesophageal carcinogenesis.


Dermatology | 1996

p53 Protein Overexpression in Verrucous Carcinoma of the Skin

Jean Christophe Noël; Marie-Odile Peny; G. De Dobbeleer; S. Thiriar; Isabelle Fayt; J. Haot; Michel Heenen

BACKGROUND Verrucous carcinoma is a rare variant of well-differentiated squamous cell carcinoma which is characterized by a marked local aggressivity and a poor metastatic potential. Until now, little has been known about the oncogenic mechanisms of this tumor. Recently, extensive investigations have shown that p53 protein, a nuclear protein with oncogene-suppressing activity, may play a crucial role in cell transformation and immunoreactivity for this protein is found in a wide variety of cancers. OBJECTIVE AND METHODS The aim of the present study is to examine the frequency of immunohistochemically detectable p53 protein by using two monoclonal antibodies (D07 and BP53-12) in 8 cases of formalin-fixed and paraffin-embedded specimens of verrucous skin carcinoma. RESULTS Overexpression of p53 protein was detected in 6 (75%) of the cases examined with the D07 antibody and in 5 (62.5%) cases with BP53-12. The p53 positivity was shown in a peripheral distribution affecting mainly the basal cell layers of tumoral islands. CONCLUSION In a high percentage of verrucous carcinoma, p53 immunoreactivity has not been previously described in the literature and our findings suggest that abnormal expression of p53 tumor suppressor protein is a common event in the pathogenesis of this tumor.


European Journal of Gastroenterology & Hepatology | 1999

Sporadic carcinoid of the stomach : a highly proliferative disease with a probable role for p53 protein dysregulation

Marie-Odile Peny; Vincent Donckier; Michel Gelin; J. Haot; Jean Christophe Noël

We describe here one case of sporadic carcinoid of the stomach, occurring in a 65-year-old man. It is a rare, recently recognized entity, with only few cases reported in the literature. We were able to detect strong MIB-1 and p53 expression in this tumour, with 86 and 80% of tumoral cells positive, respectively. These data suggest that gastric sporadic carcinoids are a highly proliferative entity probably induced by dysregulation of p53 function.

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Jean Christophe Noël

Université libre de Bruxelles

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Marie-Odile Peny

Université libre de Bruxelles

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Pj. Kestens

Université catholique de Louvain

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Claude Schulman

Université libre de Bruxelles

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Isabelle Fayt

Free University of Brussels

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J. Wallon

Catholic University of Leuven

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Henri Noël

Université catholique de Louvain

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Jacques Rahier

Cliniques Universitaires Saint-Luc

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Ahmed A. Sattar

Vrije Universiteit Brussel

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