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D K Chopin

Publications and source records attributed to D K Chopin.

At least 19 recordsLinked to original sources
PubMed2004

[Tissue engineering in urology].

Tissue engineering refers to the techniques that are aimed at regeneration of human tissues and organs. Two elements are necessary for these techniques: matrix and cells. Matrix is the scaffold where tissues may organise. Cells are either autologous cells stimulated to regenerate in vivo, aided by implantation of matrix ("guided tissue regeneration"), or autologous cells cultured outside the body (in vitro) and later returned as auto-transplants. All types of conventional tissue reconstructive surgery need tissue engineering. These techniques have been introduced recently into the clinical practice. One of the main limitations of reconstructive surgery in genitourinary tract is the lack of autologous tissue. Two autotransplants could be distinguished: coherent tissue structure or cell suspensions. The great number of studies published in this area emphasizes the importance of the future clinical implication in urology.

Animals↗
PubMed2004

Laparoscopic promontory sacral colpopexy: is the posterior, recto-vaginal, mesh mandatory?

OBJECTIVE(S): The aim of our retrospective study was to determine if systematic placement of a posterior mesh, in addition to an anterior vesico-vaginal mesh, is necessary for laparoscopic treatment of pelvic organ prolapse. METHODS: A laparoscopic promontory sacral colpopexy was performed in 108 patients, including 55 patients with a concurrent laparoscopic Burch procedure (50.9%). We compared 33 patients treated with a single anterior mesh (SAM) and 71 treated with a double, anterior and posterior, mesh (DM). RESULTS: The difference between the SAM and DM groups was statistically significant in terms of posterior compartment failure (rectocele and/or enterocele): 31.3% and 5.9%, respectively (p=0.0006). This significant difference persisted in the Burch (B) group (p=0.001), but not in the non-Burch (NB) group (p=0.98). Among the SAM group, this difference between the B and NB groups, was significant (57.1% versus 0%; p=0.0015) and above all not a single posterior failure was observed in the NB group. CONCLUSION(S): The placement of a posterior mesh, if highly effective, appeared unnecessary in the absence of an associated Burch procedure or a patent posterior prolapse. The posterior mesh also increased risk of postoperative complications and side effects.

Adult↗
PubMed2003

Complete solo laparoscopic radical prostatectomy: initial experience.

OBJECTIVES: To demonstrate the feasibility of "complete solo" (CS) laparoscopic radical prostatectomy (LRP) performed solely with robotic manipulation of the laparoscope and without any human assistant at all. A comparison was made between CS LRP and the standard technique to identify the advantages and drawbacks. METHODS: Sixteen consecutive patients undergoing CS LRP were compared with the last 16 patients undergoing standard LRP. The standard procedure was performed with five trocars and one human assistant. Therefore, the surgeon had three instruments immediately available and could switch quickly from one to another, while the assistant held the laparoscope and a retractor. The CS method used a voice-controlled robotic arm to manipulate the laparoscope and a mechanical arm for the assisting instrument. RESULTS: The mean operative time in the CS and standard groups was 324 and 347 minutes, respectively (P >0.5). An additional human assistant was required, for 1 hour, in 3 patients of each group. No significant difference was noted between the two groups in terms of catheterization time, hospital stay, positive margin rate, complications, short-term cancer control, or functional results. The CS method has been demonstrated to be highly cost-effective compared with the standard technique. CONCLUSIONS: The CS LRP is feasible and compares favorably with the standard technique. It offers unique advantages in terms of direct control of the operative view, standardization of the assistance, and higher stability of the laparoscope, thus greatly enhancing the surgeon's comfort. The diminished need for human operative assistance provides significant economic and organizational benefits.

Aged↗
PubMed2002

Functions of epidermal growth factor-like growth factors during human urothelial reepithelialization in vitro and the role of erbB2.

Transitional epithelium of the urinary bladder can be damaged during, for example, catheterization, overstretching due to obstructed voiding, or partial resection. The subsequent repair process can be stimulated by specific proteins such as epidermal growth factor (EGF) and transforming growth factor-alpha (TGFalpha). However, little is known about the role of EGF-like growth factors and their respective receptors in human urothelial repair. In this study, we examined the effects of EGF, TGFalpha, amphiregulin and heregulin-alpha (HRGalpha) on proliferation, wound closure, and the expression of their receptors c-erbB1-c-erbB4 in primary cultures of human urothelial cells in vitro. Under conditions representing intact urothelium, all EGF-like growth factors except HRGalpha induced proliferation. TGFalpha induced proliferation up to four times. Amphiregulin increased expression of c-erbB1. Treatment with either TGFalpha or amphiregulin resulted in higher c-erbB1 activation and c-erbB3 levels. None of the growth factors affected the constitutive expression of c-erbB2 and c-erbB4. In the repair model, both EGF and TGFalpha stimulated the wound closure most strongly. This was mainly achieved by increased cellular migration. Receptor expression was not affected by the addition of exogenous growth factor. The role of c-erbB2 in wound healing was further investigated with the use of antisense DNA. Wound closure could be delayed up to 50% by antisense c-erbB2 but not by mismatched or sense oligonucleotides. Excessive production (e.g. in bladder tumors) or application of EGF, TGFalpha or amphiregulin, but not HRGalpha may lead to either hyperplasia or a faster repair of damaged urothelium in vivo. These effects seem to be mediated not only via c-erbB1 but also via c-erbB2. Our results suggest that modified members of the EGF-EGFR family are potential targets for future therapies for bladder wound healing and malignancy.

Cells, Cultured↗
PubMed2002

[Classification, favorable characteristics, prevention and treatment of adverse side-effects associated with Bacillus Calmette-Guerin in the treatment of superficial bladder cancer].

The efficacy of Bacillus Calmette-Guérin (BCG) in the treatment of superficial bladder cancer was first reported by Morales in 1976. Several authors have since demonstrated the efficacy of BCG in the prophylaxis and treatment of high-risk superficial bladder tumors (pT1G3, CIS). Although BCG is now recommended as an adjunctive treatment for superficial bladder tumors, the optimal treatment schedule remains to be defined. Results reported by Lamm suggest that an initial induction cycle of six weekly intravesical BCG instillations is suboptimal unless maintenance therapy (three consecutive weekly instillations) is given 3, 6, 12, 18, 24, 30 and 36 months later. However, the use of maintenance therapy is hindered by troublesome adverse reactions. This article reviews adverse reactions associated with BCG treatment, proposed a classification and discusses their prevention and treatment.

Adjuvants, Immunologic↗
PubMed2002

[Arterial reconstruction with detubulated aortic patch in simultaneous kidney-pancreas transplantation].

Simultaneous pancreas kidney transplantation has become an accepted therapy for the treatment of patients with insulino-dependant diabetes and renal chronic failure. The arterial arrangement of the pancreatic graft is necessary in order to avoid surgical complications of vascular thrombosis. We reported three cases of simultaneous pancreas kidney, a simple procedure using aortic arterial patch preleved with the superior mesenteric artery and detubulated, than the splenic artery is directly anastomosed to the patch.

Adult↗
PubMed2002

[Prostatic adenocarcinoma revealed by disseminated intravascular coagulation and fibrinolysis].

Disseminated intravascular coagulation (DIC) revealing a prostatic adenocarcinoma is rare. Most of the case are limited to biological abnormalities. We report a case of a 73 year old man with metastatic prostatic carcinoma and CIVD. The patient consulted for epistaxis and ecchymosis with thrombocytopenia and low coagulate factors. The prostatic specific antigen was 2200 ng/ml and fine needle aspiration of bone marrow biopsy detected metastatic cells. The patients received hormonotherapy, heparine and antithrombine III with a good follow up. About this case, we discuss the management of the patient with metastatic prostatic cancer and CIVD.

Adenocarcinoma↗
PubMed2002

Outcome of radical cystectomy for bladder cancer according to the disease type at presentation.

OBJECTIVE: To examine whether the outcome of cystectomy for invasive transitional cell carcinoma (TCC) of the bladder was influenced by the type of disease at initial presentation. PATIENTS AND METHODS: The charts of 76 patients treated for TCC by radical cystectomy from 1987 to 1997 in our unit were reviewed. The patients were divided into three groups: group 1 comprised 43 patients with primary invasive disease; group 2 included 12 patients with progression of an initial superficial bladder tumour after failure of conservative treatment; and group 3 comprised 21 patients who had a radical cystectomy for superficial TCC, with a high risk of progression after attempts at conservative treatment. The pathological findings on transurethral resection and cystectomy specimens, cancer-specific survival and the time to progression were compared among the three groups. RESULTS: The rate of pT0 in cystectomy specimens was 16%, 41% and 24% in groups 1, 2 and 3, respectively. Under-staging occurred in 24% of cases in group 3. The 10-year cancer-specific survival rates were 48%, 47% and 82% in groups 1, 2 and 3, respectively. The cancer-specific survival rate and progression rate were not significantly different between groups 1 and 2, but were significantly lower/higher in these patients than in group 3 (P < 0.01). CONCLUSIONS: These data suggest that the prognosis of superficial TCC which progresses despite conservative management is no better than that of invasive TCC at initial presentation, despite the closer follow-up received by the former patients. Early identification of this group of patients may improve the cancer-specific survival, as early cystectomy for high-risk superficial TCC yields better results.

Aged↗
PubMed2002

Muscle precursor cell autografting in a murine model of urethral sphincter injury.

OBJECTIVE: To determine whether muscle precursor cells (MPCs) harvested from limb skeletal muscle can enhance the regeneration process of the striated urethral sphincter after injury. MATERIAL AND METHODS: Striated urethral sphincters of male mice were injured by an injection of a myotoxic substance (notexin). In the experimental group, 2 days after injury, MPCs were enzymatically harvested from striated muscles of the lower limbs and labelled with PKH 26, then immediately re-injected into the injured urethral sphincter of the same animal. In the control group, saline buffer was injected instead of MPCs. Animals were killed 7 days or 1 month after injury and the sphincters removed for histological study (the presence of PKH 26-labelled myofibres, measurement of myofibre diameter and total number of myofibres). RESULTS: MPC autografting accelerated sphincter muscle repair, as shown by a higher myofibre diameter (P = 0.03) and number (P = 0.01) in the experimental group than in the controls at 7 days. One month after their injection MPCs were still detectable in the regenerating sphincters and participated in the formation of new myofibres. CONCLUSION: This study provides the experimental basis for a new therapeutic approach to urethral sphincter insufficiency after surgical or obstetrical injury, based on MPC autografting.

Animals↗
PubMed2001

p15(INK4b) in bladder carcinomas: decreased expression in superficial tumours.

The p15 gene which encodes a cyclin-dependent kinase inhibitor, is located in the 9p21 chromosomal region that is frequently deleted in human bladder transitional cell carcinomas (TCCs). The aim of the present paper is to study the potential involvement of the p15 gene in the evolution of TCCs. p15 mRNA expression was investigated by semi-quantitative RT-PCR in a series of 75 TCCs, 13 bladder cell lines and 6 normal bladder urothelia by semi-quantitative RT-PCR. p15 was expressed in the normal urothelium but p15 mRNA levels were significantly decreased in 66% of the superficial (Ta-T1) TCCs (P = 0.0015). In contrast, in muscle-invasive (T2-T4) TCCs, p15 expression differed widely between samples. p16 mRNA levels were also studied and there was no correlation between p15 and p16 mRNA levels, thus indicating that the two genes were regulated independently. Lower p15 expression in superficial tumours did not reflect a switch from quiescence to proliferative activity as normal proliferative urothelial controls did not present decreased p15 mRNA levels relative to quiescent normal urothelia. We further investigated the mechanisms underlying p15 down regulation. Homozygous deletions of the p15 gene, also involving the contiguous p16 gene, were observed in 42% of the TCCs with decreased p15 expression. No hypermethylation at multiple methylation-sensitive restriction sites in the 5;-CpG island of p15 was encountered in the remaining tumours. Our data suggest that decreased expression of p15 may be an important step in early neoplastic transformation of the urothelium and that a mechanism other than homozygous deletions or hypermethylation, may be involved in p15 down regulation.

Carcinoma, Transitional Cell↗
PubMed2001

[Cancer of the prostate: influence of nutritional factors. General nutritional factors].

OBESITY: Studies attempting to establish an epidemiological link between body mass index and the risk of cancer of the prostate have been contradictory. ENERGY INTAKE: No straightforward relationship between energy intake and cancer of the prostate has been identified. FAR INTAKE: According to epidemiology studies, there is a correlation between high-fat diet and the incidence of cancer of the prostate. It has thus been demonstrated that men whose diet contains more than 30 to 40% fat have a higher risk of developing cancer of the prostate than those whose diet contains less than 30% fat. In addition, high-fat diets favor progression of tumors in elderly subjects. ROLE OF SATURATED FAT: Saturated fat has been implicated most often in the development of cancer of the prostate, high intake being correlated with shorter survival after diagnosis of cancer.

Age Factors↗
PubMed2001

[Cancer of the prostate: influence of nutritional factors. Vitamins, antioxidants and trace elements].

CANCER OF THE PROSTATE AND VITAMINS: Four vitamins have been studied, vitamins A, E, D and C. the results of these studies have been contradictory. Vitamin A and vitamin E would have a protective effect. ANTIOXIDANTS: Carotenes have an activity similar to that of vitamin A. Beta-carotene was positively associated with risk of cancer of the prostate in one study while two others were unable to demonstrate any relationship. Lycopene, the red color in fruits and vegetables, particularly tomatoes, would contribute to a lower risk of prostate cancer. TRACE ELEMENTS: Cadmium would increase the risk of cancer while selenium would have a protective effect. However studies concerning selenium carry certain methodological biases.

Aged↗
PubMed2001

[Cancer of the prostate: influence of nutritional factors. A new nutritional approach].

FIBERS: A group of vegetarian subjects have been shown to have a lower risk of cancer of the prostate than a control group. But the exact role of food fiber remains to be determined because plant foods also have an antioxidant effect on their own. PLANT PRODUCTS AND EXTRACTS: A compound called PD SPEC has been showed to have antitumor effects both in vitro and in vivo. Evaluated in patients with a cancer escaping hormone control, the clinical response was a lower level of prostate specific antigen (PSA). SOYBEANS: Several studies have demonstrated the interesting properties of soybeans. No study has however been able to demonstrate the optimal dose per day. A prospective study is currently under way using a 40 g/day dose. OVERALL NUTRITIONAL APPROACH: Several studies are being conducted using a proposed diet where 15% of the total energy intake comes from fat (associated with a low saturated/unsaturated ratio), high fiber content (18 g/100 kcal) and 40 g daily soybean protein. Although large-scale studies with rigorous methodology are lacking, an overall nutritional approach could be an interesting strategy for the management of cancer of the prostate.

Animals↗
PubMed2001

[Aspergillosis located on polycystic kidney treated with retroperitoneal nephrectomy].

We reported an uncommon case of 40 years old man, cardiac transplant recipient with chronic renal faillure who consulted for infected left polycystic renal. The serum creatinine level was 750 mmol/L, and urine culture isolated a E. Ecol germe. The abdominopelvic computed tomography showed a bilateral large polycystic renal cortex and suspected the infected cyst in lower pole of left kidney. The retroperitoneal laparoscopic nephrectomy was performed confirming a renal invasive aspergillosa. About this case we should have a high index of suspicion for fungal aetiology in kidney infection in transplant patients and the management of non functioning infected polycystic kidney can use laparoscopic retroperitoneal nephrectomy. This approach can offers a minimal morbidity and alternative to open surgery.

Adult↗
PubMed2001

[Laparoscopic excision of para-aortic lymphatic metastasis of malignant pheochromocytoma].

We report a laparoscopic lymph node resection of a patient who had malignant pheochromocytoma and underwent conventional transabdominal adrenalectomy for unilateral left malignant pheochromocytoma, followed by transperitoneal laparoscopic metastatic para-aortic lymph nodes six years later. The postoperative course was uneventful and the patient was cured of the metastasis. We believe that this procedure is minimally invasive, and metastatic extension can be diagnosed laparoscopic as well as ablation can be performed in most instances without recurrence.

Adrenal Gland Neoplasms↗
PubMed2001

Relationship between penile thermal sensory threshold measurement and electrophysiologic tests to assess neurogenic impotence.

OBJECTIVES: Erectile function is usually assessed by neurophysiologic tests such as the bulbocavernosus reflex or pudendal nerve somatosensory evoked potentials. These tests investigate only large nerve fibers, although erection depends on autonomic nerve fibers, which are of small diameter. Warm and cold sensory fibers have similar calibers as the autonomic nerve fibers, and their integrity can be reliably evaluated by the measurement of thermal sensory thresholds. We studied penile thermal sensory testing in parallel with standard electrophysiologic tests to assess their sensitivity in the diagnosis of penile neuropathy. METHODS: Twenty-five normal male subjects without erectile dysfunction or evidence of diffuse neuropathy (group 1) and 35 diabetic patients who complained of impotence (group 2) were studied. Erectile function was quantitated using the erectile dysfunction symptom score. Warm, cold, and vibratory sensory thresholds were assessed on the dorsal aspect of the penis. In addition, penile sympathetic skin responses and pudendal nerve somatosensory evoked potentials were recorded. RESULTS: We found a significant difference between the two groups in the erectile dysfunction symptom score (P <0.0001), cold threshold (P = 0.0007), and warm threshold (P = 0.0025), but not for the other parameters. The erectile dysfunction symptom score correlated with the penile warm and cold thresholds (P = 0.0006 and 0.002, respectively). CONCLUSIONS: Thermal thresholds assess small nerve fiber damage, which can indirectly reflect autonomic disturbances, particularly in the context of a diffuse neuropathy such as diabetic polyneuropathy. Penile thermal sensory testing correlated strongly with the clinical evaluation of erectile function and is a new and promising tool for the diagnosis of neurogenic impotence.

Adult↗
PubMed2001

Tolerability of bacille Calmette-Guérin maintenance therapy for superficial bladder cancer.

OBJECTIVES: To study the influence of adverse reactions on adherence to an immunotherapy maintenance schedule and the recurrence rate of bladder cancer. Bacille Calmette-Guérin immunotherapy has documented efficacy in the management of high-risk superficial bladder cancer. However, the optimal duration of intravesical bacille Calmette-Guérin therapy and the risk/benefit ratio of maintenance therapy are controversial. METHODS: From April 1996 to April 2000, 72 patients with superficial bladder cancer were treated with Immucyst (six consecutive weekly instillations of 81 mg) and then received maintenance therapy consisting of three consecutive weekly instillations 3, 6, 12, 18, 24, 30, and 36 months later. Adverse reactions, studied during 518 instillations, were classified in four categories using a scale based on the World Health Organization recommendations, and their impact on the adherence to therapy was analyzed. RESULTS: After an average follow-up of 24 months, a durable disease-free response was observed in 84.9% of the patients; 12.5% of patients had a relapse and 2.6% had disease progression. The response rate was similar in patients with and without adverse reactions. Only 14 patients (19%) received all the scheduled maintenance instillations. The dose was reduced in 41 patients (57%), and treatment was stopped in 28 patients (39%). In multivariate analysis, an adverse event score of 1.5 or greater during induction therapy was significantly associated with cessation or modification of maintenance therapy (P = 0.01). CONCLUSIONS: The scale developed in this study to monitor the adverse reactions to bacille Calmette-Guérin and their impact on the adherence to maintenance therapy may be helpful for tailoring maintenance regimens or implementing protective measures (dose reduction or treatment postponement).

Adjuvants, Immunologic↗