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Biomedical subjects

A Le Duc

Publications and source records attributed to A Le Duc.

At least 73 records · Page 4Linked to original sources
PubMed1995

Tumour-associated trypsin inhibitor and renal cell carcinoma.

In the absence of a specific marker for renal cell carcinoma (RCC), we evaluated the tumour-associated trypsin inhibitor (TATI) in patients with RCC. Between November 1990 and November 1993, 63 patients with RCC and 23 patients with benign renal disease underwent a competitive radioimmunoassay of TATI. The cutoff value was defined on a series of serum samples of 96 healthy subjects (normal n < 20 micrograms/l, then 25 micrograms/l after April 1993). We related the value of TATI to the tumour stage and compared the sensitivities of TATI and other markers (CEA, CA 15-3, CA 125, CA 19-9, ferritin). In 24 patients the TATI assay was repeated 3-12 months after radical nephrectomy. 15 patients with benign disease had a normal value of TATI (specificity: 65%). 44 of the 63 patients had a value of TATI above the cutoff point (sensitivity: 69%). Sensitivities of CEA, CA 15-3, CA 125, CA 19-9 and ferritin were 5, 10, 13, 5, 35%, respectively. The TATI value was correlated with the stage of the disease. Among the 15 patients without metastasis, the mean preoperative value was 112 micrograms/l (14-760) versus 46 micrograms/l (24-180) postoperatively. In the 9 patients with metastasis, the preoperative mean value was 100 micrograms/l (20-434) versus 240 micrograms/l (22-544) postoperatively. TATI showed a better sensitivity than other markers for RCC but its specificity is limited. Nevertheless it can be useful for a postoperative follow-up. TATI remains one of the best serum markers for RCC.

Biomarkers, Tumor↗
PubMed1995

Accumulation of 5 alpha-reduced androgen glucosiduronates associated with impaired removal in young male hemodialysis patients.

Hypothalamic-pituitary gonadal function is commonly altered in dialysis patients. Even though an improvement in general status and well-being has been noted after recombinant human erythropoietin supplementation, no significant changes were observed in the sex hormone profile. Pituitary gonadal axis as well as 5 alpha-reduced androgen glucosiduronates (i.e. 5 alpha-androstane,3 alpha,17 beta-diol and androsterone) profiles were studied in 23 young male stable dialyzed patients and compared to an age-matched group of healthy subjects. 5 alpha-Reduced androgen glucosiduronates are products of peripheral testosterone (T) metabolism and seem to be a useful tool in assessment of the male androgen status. Their polarity facilitates their urinary excretion, and their clearance is similar to the glomerular filtration rate in healthy men. We observed 1) a pituitary-Leydig cell dysfunction supported by normal serum estradiol and T levels, low free T, and increased LH levels; 2) an alteration of the dehydroepiandrosterone (DHEA) sulfate-DHEA interconversion, reflected by a dramatic decrease in DHEA while DHEA sulfate levels remained in the normal range; 3) an accumulation of 5 alpha-reduced androgen glucosiduronates, whose removal was impaired as shown by their very low sieving coefficients (< 0.012). Taken together, the above observations are consistent with alteration of spermatogenesis with respect to dialysis duration in which earlier elevated baseline serum LH levels indicate a primary defect in Leydig cell function.

Adolescent↗
PubMed1995

Magnetic resonance imaging in patients with penile carcinoma.

The aim of the study was to determine the role of pre-operative magnetic resonance imaging (MRI), with and without contrast enhancement, in patients with penile carcinoma. Nine patients with a penile cancer were studied. The staging of the tumours was performed by clinical examination, MRI and surgery, according to the TNM classification. Six patients had primary tumours, of clinical stage T1 (n = 1) and T2 (n = 5). Three other patients had been previously treated and presented with a local recurrence of clinical stage T2. Surface-coil MRI was performed at 0.5 T with T1 weighted sequences before and after gadolinium-DOTA, and T2 weighted sequences. MRI results were compared with the clinical and surgical findings. T1 weighted sequences did not clearly demonstrate the margins of the tumours. T2 weighted sequences were the more useful in five patients, whereas contrast enhanced T1 weighted sequences allowed better delineation of the lesions in only three patients. Therefore, an imaging protocol should include spin echo T2 weighted sequences. Clinical examination correctly staged six of nine tumours; MRI, seven of nine tumours and the combination of both examinations, eight of nine tumours. MRI provided good evaluation of tumoral invasion into the penile shaft.

Adult↗
PubMed1995

[The role of the laser in urology].

There is currently a renewed interest in laser in the field of urology, essentially for the treatment of benign prostatic hypertrophy, as a result of recent developments in the field of fibres. Laser is light coherent in time and space emitted continuously or in pulses. Only its thermal and photochemical properties are used in urology. Endoscopic coagulation of superficial bladder tumours by Nd YAG laser does not seem to be better than classical endoscopic resection, at the present time, as although it is less haemorrhagic, it does not decrease the recurrence rate. Photochemotherapy of bladder carcinoma in situ still constitutes a complex treatment protocol reserved for specialized centres. Lastly, upper urinary tract tumours can be treated by Nd YAG laser coagulation, in rare indications which are the same as those of ureteroscopic or percutaneous resection. The recent development of lateral firing laser fibres and contact tip fibres has led to a renewed interest in laser in benign prostatic hypertrophy. Two different techniques have been proposed: Nd YAG laser coagulation under direct visual or ultrasound control (TULIP), which gives delayed objective results (two or three months) and contact tissue vaporization (Nd YAG, diode), whose effects are more immediate. In both cases, intraoperative bleeding is minimal and the length of hospital stay is decreased, but the duration of urine drainage remains to be defined. Endoscopic pulsed laser urinary lithotripsy (dye, Ho YAG), although effective and atraumatic, is not justified at the present time because of its high cost compared to mechanical percussion lithotripters. Lastly, laser treatment for urethral stricture has not been found to be superior to classical scalpel urethrotomy and laser tissue welding is still in the experimental stages. In conclusion, laser technology, especially fibers, has currently reached an important phase of development with applications for urological disease, essentially in the treatment of benign prostatic hypertrophy in order to reduce the morbidity of classical endoscopic resection. However, other urological applications of laser could be validated in the near future due to the development of less expensive lasers (diode) and/or with multiple functions (Ho YAG).

Humans↗
PubMed1995

[A clinical and endoscopic study of the treatment of benign prostatic hypertrophy using focused transrectal ultrasound].

OBJECTIVE: To evaluate the clinical and endoscopic effects of transrectal focal ultrasound (Sonablate) on benign prostatic hypertrophy. METHOD: This was a phase II study, performed in 13 patients with benign prostatic hypertrophy. Patients were evaluated before treatment, and 45 days and 90 days after treatment by means of a symptom score (1-PSS), uroflowmetry, estimation of prostatic volume by transrectal ultrasonography, and urethroprostatic endoscopy. A transducer with a focal length of 3.5 cm was used in 12 patients. One patient was treated with a transducer with a focal length of 3 cm. We used an acoustic energy level at the focal point of 1,680 W/cm2 for the last two patients. RESULTS: With a follow-up of 3 months, the symptom score was only moderately improved (decreasing from 20 +/- 7 to 14 +/- 9, p < 0.03), with no improvement of uroflowmetry and tissue destruction was not demonstrated on endoscopy in any of the patients. CONCLUSION: The therapeutic applications of focal ultrasound thermotherapy are potentially very vast, but, up until now, have only rarely exceeded the experimental stage. Our data emphasize that future developments are essential before this technology can be included in therapeutic alternatives for benign prostatic hypertrophy.

Ceramics↗
PubMed1995

[Carcinoma of Bellini's tubules].

Carcinoma of the papillary ducts of Bellini is a rare form of renal cancer. Patients are usually asymptomatic middle-aged men who frequently have metastatic disease at the time of diagnosis. The diagnosis is based on histological examination of the nephrectomy specimen with a precise immunohistochemical examination. Radical nephrectomy is the first-line treatment and adjuvant chemotherapy, recommended by certain authors, does not appear to improve the usually poor prognosis of these tumours.

Adenocarcinoma↗
PubMed1995

[Genetic alterations in localized cancers of the prostate: identification of a common region of deletion on the chromosome 18q].

Prostate cancer is one of the most common malignancies in men. Few authors have attempted to identify consistent genetic alterations at the molecular level in adenocarcinoma of the prostate, but those most frequently reported are loss of heterozygosity (LOH) involving chromosome arms 8p, 10q, 16q, and 18q and inactivation of the TP53 tumor suppressor gene. In order to determine if alterations frequently found in other adenocarcinomas (breast, ovarian, colorectal), including losses of genetic material from chromosome arms 1p, 3p, 7q, 8p, 11p, 17p, 17q, and 18q, are also involved in prostate cancer, we examined 20 localized early-stage prostate tumors. We detected no mutations of the TP53 gene. Allelic losses were found from 7q (33%), 8p (50%), 10q (20%), and 18q (33%). Furthermore, as the first step toward isolating tumor suppressor genes on 18q, we used six polymorphic markers and identified a small common deleted region between the chromosome 18 centromere and the D18S19 locus.

Aged↗
PubMed1995

[Pseudo-tumoral cystitis due to Toxoplasma in an patient with AIDS].

The authors report a case of cystitis due to Toxoplasma Gondii infection in a patient suffering from AIDS. Initial symptoms consisted of dysuria, extreme frequency and urgent micturition responsible for pseudo urinary incontinence. Urine culture was sterile. Pelvic computed tomography and pelvic MRI demonstrated thickening of the bladder wall and seminal vesicles. Cystoscopy confirmed the presence of an intravesical proliferation with a pseudoneoplastic appearance. The diagnosis of Toxoplasma cystitis was confirmed by the discovery of Toxoplasma cysts on histological examination of bladder biopsies. Toxoplasma cystitis is a rare cause of pseudoneoplastic bullous cystitis in HIV-seropositive patients.

AIDS-Related Opportunistic Infections↗
PubMed1994

Oncogene amplifications in early-stage human prostate carcinomas.

Oncogene amplifications are frequently found in solid tumours and are often associated with more aggressively growing forms of human cancer. The proto-oncogenes c-myc, c-erbB2/neu and the 11q13 band are the most frequently amplified regions in adenocarcinomas of various origins. The present study was undertaken to define whether c-myc, int2/FGF3 (11q13 region) and c-erbB2/neu genes are involved in prostate tumorigenesis. Tumours and peripheral lymphocyte DNA from 21 localized early-stage prostatic carcinomas were analysed by Southern-blot electrophoresis for amplification of the c-myc and c-erbB2/neu genes and the 11q13 region (int2/FGF3). We detected no amplification of these 3 oncogenes in our panel.

Biomarkers, Tumor↗
PubMed1994

[Practical management of localized prostate cancer: surveillance, surgery or radiotherapy].

The discovery of a localised prostatic cancer has become an increasingly frequent clinical reality (60%). At this stage, the cancer is theoretically curable by radical prostatectomy. However, a number of factors prevent this surgery in practice, which is why the clinician often has to choose either radiotherapy or watchful waiting. This latter option is justified by the slow course of prostatic cancer and the mean age of detection of this cancer (70-75 years). The therapeutic approach to localised prostatic cancers is still a controversial issue, especially in men between the ages of 70 and 75 years. Progress must be made in the assessment of the aggressiveness of the prostatic cancer before this controversy can be resolved.

Age Factors↗
PubMed1994

Genetic alterations in localized prostate cancer: identification of a common region of deletion on chromosome arm 18q.

Accumulation of mutations in oncogenes and tumor suppressor genes transforms a normal cell into a malignant cell by allowing it to escape from normal control of growth. In prostate tumorigenesis, the current model envisages specific mutations of the TP53 tumor suppressor gene and loss of loci, detected by loss of heterozygosity (LOH), on chromosome arms 8p, 10q, 16q, and 18q. In order to determine if alterations frequently found in other adenocarcinomas (breast, ovarian, gastric, colorectal), including losses of genetic material from chromosome arms 1p, 3p, 7q, 8p, 11p, 17p, 17q, and 18q, are also involved in prostate cancer, we examined 20 localized early-stage prostate tumors. We detected no mutations of the TP53 gene. Allelic losses were found from 7q (33%), 8p (50%), 10q (20%), and 18q (33%). Furthermore, as the first step toward isolating tumor suppressor genes on 18q, we used six polymorphic markers and identified a small common deleted region between the chromosome 18 centromere and the D18S19 locus.

Alleles↗
PubMed1994

Immunocytochemical comparison of cultured normal epithelial prostatic cells with prostatic tissue sections.

By analyzing a culture system of human prostatic epithelial cells (HPEC) and human prostatic fibroblasts (HPF) for expression of several determinants by immunocytochemistry, we have shown that long-term cultures are able to preserve the phenotypic characteristics of the normal tissue from which they are derived. The cytoskeletal elements, prostate-specific proteins, and steroid receptor profiles were compared to those of prostatic epithelium and stroma in situ. When cultured in low serum and low calcium medium, the adult HPEC grew as two layers of cells, the upper one of which retained the differentiation characteristics observed in the luminal fraction of normal prostatic epithelium. This cell type is the likely origin of prostatic neoplasia, with expression of CK8, 18, and 19 but not CK14. Androgen receptors, prostatic-specific antigen, and prostatic acid phosphatase are also expressed in vitro but at lower level than in situ. The lower cell layer expressed most of the same determinants but at a much lower level, suggestive of a stem-cell type. The HPF cultured in RPMI serum supplemented media retained the stromal pattern of the cells observed in situ. Culture systems which conserve the characteristics of their normal counterparts in vivo should provide useful models for studying in vitro genetic and epigenetic factors associated with differentiation and proliferation, but also with tumorigenic progression in the prostatic gland.

Biomarkers↗
PubMed1994

Distinct androgen 5 alpha-reduction pathways in cultured fibroblasts and immortalized epithelial cells from normal human adult prostate.

All androgen-sensitive peripheral tissues and cells, including the prostate, are commonly believed to possess the ability to metabolize testosterone. We report on the in vitro metabolism of tritiated testosterone performed in immortalized human adult normal prostatic epithelial cells and in human adult normal prostate fibroblastic cells (stromal cells). These two cell types were incubated separately with increasing testosterone concentrations (1 to 50 nM.) for 2 and 4 hours, after which the testosterone metabolic profile was analyzed. Data analysis provided evidence, for the first time, of the existence of two different 5 alpha-reduced metabolic pathways. Stromal cells preferred the androsterone pathway via the oxidative androstenedione formation, whereas epithelial cells preferred the reductive 5 alpha-dihydrotestosterone pathway. These two 5 alpha-reduced metabolites were produced in nearly equal quantities regardless of testosterone concentration or time of incubation. Since interactions between epithelial and stromal cells are involved in the development of the prostate, the availability of defined epithelial and stromal cells suitable for in vitro experiments provides a useful tool for the study of the contribution of androgens to these interactions. The model presented in this study would permit a better evaluation of the intraprostatic regulation of androgen metabolism and the contribution of the anti-5-alpha-reductase drugs to the management of benign prostate hyperplasia.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1994

Ureteral and bladder lesions after ballistic, ultrasonic, electrohydraulic, or laser lithotripsy.

Four techniques of intracorporeal lithotripsy are now available: ballistic, ultrasonic, electrohydraulic, and laser. Their therapeutic efficacies have generally been evaluated and compared, but very few data have been available on their relative risks of iatrogenic trauma to the urothelial wall. We conducted a comparative analysis of this risk by testing the pig ureteral and bladder wall with the EMS Lithoclast, Olympus ultrasonic lithotripter, Walz Lithotron EL 23, and Versa Pulse Ho:YAG Coherent Laser. We measured the number of shockwaves or the energy required to perforate the ureter and bladder by delivering shocks perpendicular to the walls. Ureteral perforation was impossible with the 1.0-mm Lithoclast transducer and the 1.5-mm ultrasound transducer. Perforation was induced after 250 shocks with the 0.8-mm Lithoclast transducer, after 110 shocks with the 3F electrohydraulic electrode, and after 0.02 kJ with the laser. Bladder perforation was impossible with the 2.0-mm Lithoclast device and the 3.4-mm ultrasound transducer but was induced after 0.04 kJ had been delivered with the laser. We evaluated the iatrogenic risk under normal conditions of use by delivering the shocks tangentially to the ureteral wall and perpendicular to the bladder wall. We sacrificed animals on days 0, 1, and 6. The immediate histologic lesions induced by the Lithoclast and the ultrasound lithotripter were similar, consisting of a moderate reduction of the epithelial layers or intraepithelial detachments. Electrohydraulic shocks induced almost complete abrasion of the urothelium, and the laser induced extensive lesions of partial or complete necrosis of the urothelial wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Exploration and endoscopic treatment of unilateral primary haematuria: is non-specific diffuse pyelitis a real entity?

Chronic unilateral primary haematuria is rare and raises difficult problems of diagnosis and treatment as most of the knowledge in this field has been based on a very limited number of patients. This clinical entity needs critical reevaluation as recent progress in endourological investigations has revealed that lesions other than the classical submucosal haemangioma are just as frequently responsible for unilateral primary haematuria. These endoscopic lesions have generally been poorly defined up to now and our data based on a retrospective review of 8 patients emphasises the persistent gaps in our understanding of the pathophysiology of this disease. Among the lesions responsible for unilateral primary haematuria, diffuse petachiae of the renal pelvis and cavities represent the most frequent endoscopic lesion described in our experience (50% of cases). Histologically, these diffuse lesions correspond to non-specific pyelitis, consisting of simple oedema of the lamina propria. In addition to its diagnostic role, endoscopy can also be used to effectively treat the lesions responsible for unilateral primary haematuria, using either electrocoagulation or nitrate cautery, provided a retrograde approach can be completed by a percutaneous approach, with an overall success rate of 75% of cases with a mean follow-up of 16 months.

Electrocoagulation↗
PubMed1994

Endourological treatment of lumbar and iliac ureteral stones. A comparative study of 49 cases.

The efficacy of the Lithoclast has been described extensively in the recent literature. However, to our knowledge, few articles have dealt with the safety of this technique. We present a retrospective study of 49 patients with stones of the lumbar and iliac ureter treated between 1989 and 1992 either by means of the Lithoclast (17 patients), by electrohydraulic shock waves (16 patients), or by trapping the stones in a wire stone basket (16 patients). The success rates were 88% for the Lithoclast and wire stone baskets and 62% for electorhydraulic shock waves. The mean dimensions of the stones were 10 mm for the Lithoclast and electrohydraulic shock wave groups, and 7 mm for the wire stone basket group. Complications consisted of 7 ureteral lesions (2 cases with the Lithoclast, 4 cases with electrohydraulic shock waves and 1 case with the wire stone basket) and 1 stripping of the lower ureter following stone extraction with a wire stone basket, which required open reimplantation. This study demonstrates the efficacy and safety of the Lithoclast for the treatment of large stones of the lumbar and iliac ureter.

Adolescent↗