PubMed HealthSearch

Biomedical subjects

A Le Duc

Publications and source records attributed to A Le Duc.

At least 19 recordsLinked to original sources

Anatomical bases of percutaneous surgery for calculi in horseshoe kidney.

Horseshoe kidney is a renal fusion which combines three anatomic abnormalities: ectopia, malrotation and vascular changes. These anomalies can be recognised separately to varying degrees in unfused kidneys. Necessary modifications of the standard technique for percutaneous nephrolithotomy (PNL) are directly deducible from analysis of the anatomic data of the imaging of horseshoe kidneys. We report our experience with 5 patients (7 kidneys) who underwent PNL for calculi in horseshoe kidneys. The percutaneous approach was performed under ultrasound and fluoroscopic monitoring. In situ disintegration by ultrasonic lithotripsy and nephrostomy drainage were necessary in all cases. Modifications of the standard PNL procedure are related to the anatomic changes. The lower abdominal position of a horseshoe kidney necessitates upper or middle calyceal puncture, while the malrotation necessitates a more posterior puncture. Monitoring of the puncture needle by fluoroscopy as it is advanced postero-anteriorly is more difficult and the risk of the surgeon's hand entering the radiation path is increased. The renal pelvis is deep and a long endoscope may be required. Aberrant segmental vessels may create potential hazards. The majority of problems in location can be avoided by use of an ultrasonically guided needle. Percutaneous nephrolithotomy is the treatment of choice for calculi in horseshoe kidneys for the following reasons: the high incidence of recurrent lithiasis in horseshoe kidney and the complexity of repeated surgical approaches diminish the acceptable results of open surgery; difficulties in focussing on the calculi and drainage problems militate against the success of extracorporeal shock wave lithotripsy (ESWL); PNL has a good success rate and the least morbidity.

Humans

[Prostatic growth factors and benign hypertrophy of the prostate. Current knowledge and perspectives].

The importance of growth factors in prostatic regulation has been demonstrated for several years. These "prostatic" growth factors are ubiquitous polypeptides which are not specific to the prostate. To date, three principal families of growth factors appear to be potentially involved in the development of benign prostatic hypertrophy: Epidermal Growth Factor (EGF), Fibroblast Growth Factor (FGF), Transforming Growth Factor beta (TGF beta). The FGF and TGF beta families probably play a central role in the pathogenesis of benign prostatic hypertrophy. A better definition of the respective roles of growth factors and androgens in the control of prostatic growth opens up prospects for the future in the field of basic treatment of benign prostatic hypertrophy.

Growth Substances

Immortalization of human adult normal prostatic epithelial cells by liposomes containing large T-SV40 gene.

Simian virus SV40 has been widely used to immortalize epithelial cells of mammalian origin. We report here, for the first time to our knowledge, the immortalization of normal adult prostatic epithelial cells in culture by transfection of a plasmid containing SV40 genome with a defective replication origin (SV40 ori-) encapsulated into liposomes. These cells (PNT1) have now been cultured for more than 12 months, and shown to contain the SV40 genome. They express large T protein, present the phenotype of differentiated luminal prostatic cells (positive with antibodies to cytokeratin 18, 19, weakly positive for prostatic acid phosphatase and prostatic specific antigen, negative with anticytokeratin 14 and KL2 antibody). PNT1 cells contain high affinity receptors for dihydrotestosterone. These cells provide a useful tool to study the biology and the pathology of adult prostatic epithelial cells, specially to understand the steps leading to prostatic transformation.

Acid Phosphatase

[Screening for cancer of the prostate using prostate-specific antigen].

Systematic screening for prostate cancer was carried out in 600 men over 50 years of age by the industrial medicine departments of four big companies in the Paris region. The exploratory methods included prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) assays, rectal palpation and two-dimensional transrectal ultrasonography. Biopsy of the prostate was performed either when the PSA level was above 5 ng/ml or when rectal palpation gave suspicious results, or when ultrasonography showed abnormal images. A total of 93 biopsies were performed, and 18 cases of cancer were detected. Eleven of these 18 patients underwent radical prostatectomy. The PSA assay, with an accepted limit of 5 ng/ml, detected 17 out of 18 cancers but was not very specific. The PAP assay had low sensitivity (only 5 positive results). Combined PAP assay and rectal palpation provided high sensitivity and good specificity. Transrectal ultrasonography was helpful only to determine the site of biopsy and the distribution of the lesions.

Acid Phosphatase

[Should fragments of stone expelled after extracorporeal lithotripsy always be analyzed?].

The morphological and constitutional analysis of renal stone fragments expelled after extracorporeal shock wave lithotripsy enables the structure and morphological type of stones to be reconstructed in 92.8 per cent of the cases as regards surface and section and in 74.5 per cent of the cases down to the core. A study of the molecular and crystalline composition of such fragments demonstrated the preponderance of whewellite in both sexes (men 85.4 per cent; women 72.4 per cent). The frequency of weddellite was 1.6 times higher in men (73.8 per cent) than in women (44.8 per cent), and the frequencies of struvite and ammonium urate were 2.8 and 2.6 times respectively higher in women than in men, despite a significant fall in frequency as compared to a previous series. Correlations between morphological type of stone and biochemical data (when available) could be established in 84 per cent of the cases. This made it possible to initiate treatments aimed at preventing recurrences, the cost of these treatments in the long term being lower than that of the curative urological treatments, including extracorporeal shock wave lithotripsy.

Adult

A multicenter, double-blind, placebo-controlled trial of the efficacy of prazosin in the treatment of dysuria associated with benign prostatic hypertrophy.

An 8-center, double-blind, placebo-controlled trial of 39 patients with benign prostatic hypertrophy was conducted to assess the effects of prazosin HCl treatment on functional urologic variables after a treatment period of 4 weeks. The randomized groups were comparable for demographic variables and symptoms, except for the mean residual urinary volume, which was significantly higher in the prazosin HCl group. Prazosin HCl elicited statistically significant improvements in the mean prostatic urethral pressure and prostate area (Mann-Whitney U test: p = 0.001 for both variables as compared with the placebo group). Functional bladder capacity also improved significantly in the group receiving the test drug (Mann-Whitney U test: p = 0.05, as compared with the placebo group). Clinical improvements were also observed in the mean maximum urinary flow, decreased nocturia frequency, and residual urinary volume. Patient preference significantly favored the prazosin HCl treatment (Mann-Whitney U test: p = 0.001). Seven patients on prazosin HCl and 5 receiving placebo reported one or more side effects during the trial phase; these were mild to moderate and disappeared or were tolerated. No statistically significant effects on blood pressure or heart rate were observed.

Double-Blind Method

[Detection of cancer of the prostate. A study of 600 cases].

A free screening consultation for carcinoma of the prostate was proposed to men over the age of 50 years working in different companies in the areas of Paris. This consultation included a digital rectal examination, a blood test for determination of serum acid phosphatase and prostatic specific antigen, and two dimensional trans-rectal ultrasonography of the prostate. 600 patients were seen. 575 were evaluable. Prostate biopsy was recommended in 152 men. Ninety-three prostate biopsies were performed. Eighteen prostatic cancers and 1 urothelial cancer invading the prostate were detected with an overall incidence of prostate cancer of 3.1%. Radical prostatectomies were performed in 10 of the 18 patients with a prostate cancer. Sensitivity of digital rectal examination ultrasonography and PSA were respectively 42.8%, 47.3% and 68.4% with an abnormal serum PSA level defined as being greater than 5 ng/ml. The predictive value of a positive ultrasonography (18.7%) contrasts with the predictive value of a positive digital rectal examination (30.7%) and serum PSA (30%). Digital rectal examination and determination of serum prostatic specific antigen seem to be the most useful tests for mass screening of prostate cancer. Transrectal ultrasonography is very useful for guided prostatic biopsy and for a better topographic evaluation of the tumor.

Aged

Radioimmunodetection of lymph node invasion in prostatic cancer. The use of iodine 123 (123I)-labeled monoclonal anti-prostatic acid phosphatase (PAP) 227 A F(ab')2 antibody fragments in vivo.

The therapeutic indications in prostatic cancer depend on the regional and distant extension of the cancer and are difficult to assess before lymphadenectomy. Radioimmunodetection of lymph node involvement with monoclonal anti-prostatic acid phosphatase (PAP) antibodies can be proposed as a noninvasive alternative to lymphadenectomy. Fifteen patients with various stages of histologically proven prostatic cancer were examined by immunolymphoscintigraphy (ILS) before treatment to detect lymph node metastases. These patients had Stage A (n = 7), Stage B (n = 3), Stage C (n = 2), and Stage D (n = 3) tumors. They received between 100 and 400 micrograms of monoclonal antibody 227 A in the form of F(ab')2 fragments labeled with iodine 123 (123I). The antibody was injected directly into the periprostatic area. ILS images were obtained after 1, 3, 6, and 24 hours. Three days later, each patient underwent a lymphadenectomy for histologic examination. The results of the histologic examination and ILS were compared. In ten patients, the examination did not show any images capable of being interpreted as lymphadenopathy and histologic examination confirmed the integrity of the nodes examined. In five cases, scintigraphy suggested the presence of lymph node invasion by prostatic cancer and this was confirmed by histologic examination in three of the five cases. Overall, in terms of lymphadenopathy, this examination had a sensitivity of 100% and a specificity of 83%. Therefore, ILS appears to be capable of detecting lymph node metastases in prostatic cancer.

Acid Phosphatase

[Culturing of normal and tumor cells of the human prostate].

Cell lines of neoplastic human prostate gland tissue are uncommon. We studied the condition of long term prostatic cell culture; 18 primary cultures of epithelial prostatic cells and 15 subcultures were maintained for several months. The optimum medium for primary prostatic cell cultures contains: little calcium, epithelial growth factor (EGF), phosphoethanolamine, spermine and cholera toxin, the cell characterisation for cultivation of normal, hyperplastic and neoplastic prostate gland tissue in subcultures uses monoclonal antibody against cytokeratin, prostatic acid phosphatase and prostatic specific antigen.

Adenocarcinoma

[Magnetic resonance imaging of cancer of the prostate. Preliminary study].

Twenty-two patients with prostatic carcinoma have been studied by magnetic resonance imaging (MRI). Twenty-three examinations have been done for 2 stage A, 11 stage B, 2 stage C and 7 stage D. Prostatic signal and locoregional extension have been compared with rectal examination and the 3 prostatectomies. Cancer looked homogeneous in 4 cases, heterogeneous in 10 cases with a nodule in 5 cases either with hyper of hyposignal compared to the normal prostate. Local extension in stages C and D is seen, especially to the periprostatic fat and seminal vesicles. MRI appears to be sensitive but poorly specific in the diagnosis of prostatic cancer. On the other hand, it is an interesting examination in the staging of prostatic cancer. These results must be confirmed with more comparisons of images and prostatectomy specimens.

Aged

[Leiomyoma of the urinary excretory tract].

Four cases of leiomyoma of the urinary tract are presented: 3 locations in the bladder and one location in the ureter. Leiomyomas of the urinary tract are rare. These benign mesothelial tumors require conservative resection. Small lesions can be managed with endoscopic techniques.

Female