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Biomedical subjects

M Colombel

Publications and source records attributed to M Colombel.

At least 19 recordsLinked to original sources
PubMed2006

Nephron-sparing surgery for renal cell carcinoma: detailed analysis of complications over a 15-year period.

PURPOSE: To assess the incidence of complications of conservative renal surgery for renal cell carcinoma in both elective and imperative indications, and its evolution over a 15 year period. PATIENTS AND METHODS: From 1988 to 2003, 127 patients underwent partial nephrectomy or tumorectomy for renal cell carcinoma in our department. INDICATIONs were imperative in 42% (n = 53) and elective in 58% (n=74) of cases. Morbidity was retrospectively assessed according to four parameters: 1- Period of surgery: A, from 1988 to 1999 and B, from 2000 to 2003. 2- INDICATION: elective vs. imperative. 3- experience of surgeon: senior vs. junior. 4- Nature of complications: minor or major. Comparative analysis was conducted using Chi-square and Fischer exact tests. RESULTS: Global incidence of complications was 30.7% (n = 39) corresponding to 18.1% minor (n = 23) and 12.6% (n = 16) major complications. Results show a moderate decrease of complication rate during Period B: 28.1% versus 32.9% during period A (p = 0.69). Complications occurred more frequently in imperative indications (49.1%) than in elective indications (17.6%) (p = 0.002), mostly regarding major complications (respectively 28.3% and 1.4%. (p < 0.001)). Overall re-intervention rate was 15.7%: 22.6% in imperative and 10.8% in elective indications (p = 0.008). Mean length of hospital stay was 14.1 days and significantly longer during period A (p = 0.003) and in imperative indications (p = 0.009). CONCLUSION: In our study, conservative renal surgery has a significant rate of complications which is extremely variable regarding to different parameters. Most discriminating factor was indication: in imperative indications, we observed a high rate of major complications (28.3%) that we consider acceptable to prevent anephria in clearly informed patients. Major complications are exceptional in elective indications. Decreased incidence of complications during the later period (B) is modest, and the role played by systematic pedicular clampage is discussed. As results published in medical literature are difficult to compare, we agree with authors who recently proposed to standardize complications data analysis, using a gravity scale, in order to provide relevant information to patients about statistical risks before surgery.

Acute Kidney Injury↗
PubMed2004

Principles and results of high-intensity focused ultrasound for localized prostate cancer.

Focused ultrasound holds promise in a large number of therapeutic applications. It has long been known that high-intensity focused ultrasound (HIFU) can kill tissue through coagulative necrosis. However, it is only in recent years that practical clinical applications are becoming possible, with the development of high-power ultrasound arrays and noninvasive monitoring methods. In the last decade, HIFU have been adapted and used to treat localized prostate cancer and it is now commercially available in Europe. In this article, preclinical studies and clinical development of prostate HIFU as well as early clinical results from our center and international studies are reviewed. Early results demonstrated that prostate HIFU is efficient to obtain local control for low- and intermediate-risk localized prostate cancer; however, long-term follow-up is still needed to estimate the efficacy of prostate HIFU in terms of specific cancer mortality. This makes HIFU a viable alternative in patients not candidate for radical therapy.

Humans↗
PubMed2003

Detection of bladder dysplasia using 5-aminolaevulinic acid-induced porphyrin fluorescence.

OBJECTIVE: To report results of a clinical investigation on the detection of bladder dysplasia and in situ carcinoma by using fluorescence induced by 5-aminolaevulinic acid (ALA). PATIENTS AND METHODS: The study included 50 patients with a primary bladder lesion, who had a bladder instillation of 50 mL of 3% ALA solution >or= 1 h before transurethral resection of the tumour. Random biopsies were taken using white-light cystoscopy, then using blue light to induce fluorescence; positive zones were noted and biopsied. The primary lesion was then resected. The frequency of dysplasia detected by ALA-induced fluorescence was evaluated, as was the risk of recurrence with a follow-up of >or= 2 years. RESULTS: In all patients the tumours were positive; in 21 fluorescence distant from the tumour was detected. The pathological report of the biopsies showed 11 cases of dysplasia, six of carcinoma in situ and four of inflammatory lesions. In 29 patients there was no fluorescence and quadrant biopsies were normal in all but three with moderate dysplasia. Within the minimum follow-up patients with bladder dysplasia detected by ALA-induced fluorescence had a higher risk of recurrence. CONCLUSION: ALA-induced fluorescence of the bladder significantly enhanced the detection of dysplasia and in situ carcinoma. However, this technique requires further investigation using well-characterized instrumentation and study protocols to determine any effect on treatment choice.

Aminolevulinic Acid↗
PubMed2001

[Retroperitoneal foreign body mimicking pararenal tumor].

We report the case of a 48 year-old woman presently with a pararenal tumor, with a history of pyelotomy in 1978 for the extraction of a renal pelvic stones. Results of surgery showed a foreign body. The clinical and diagnostic aspects of retained surgical gauze have been discussed and the need for radio-opaque markers in them have been emphasized.

Diagnosis, Differential↗
PubMed2001

[Bilateral adrenal pheochromocytomas in von Hippel-Lindau disease].

The pheochromocytoma is a medullo-adrenal tumor which develops at the cost of the chromaffin cells. It appears in 11-19% of cases of von Hippel-Lindau's disease (VHL), is often bilateral, and the symptomatology is often crude: arterial hypertension is frequently isolated and unstable, and the classic triad of headache, palpitations and sweating is quite rarely observed. We report four observations of bilateral pheochromocytomas in patients with von Hippel-Lindau's disease (three with phenotype IIA and one with phenotype IIB). The tumor was bilateral during the diagnosis in three cases; in the fourth patient, the attack on the contralateral adrenal gland came two years after the first adrenalectomy. All the patients had undergone an adrenalectomy by open surgery after a short preparation of 48 hours; replacement therapy was begun in each patient. Morbidity was low, and the patients submitted to a prolonged follow-up in order to screen for the onset of future lesions of VHL.

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

[Emphysematous pyelonephritis: report of 3 cases].

Emphysematous pyelonephritis (EPN) is a rare form of renal suppuration defined by the presence of pus and gas or bacterial origin within the renal parenchyma. It is associated with a high mortality in the absence of rapid and effective treatment. Emergency nephrectomy constitutes the reference treatment. Percutaneous drainage associated with medical treatment is an alternative in patients with localized or bilateral lesions or in the case of solitary kidney. The authors report 3 cases of EPN treated by percutaneous drainage combined with medical treatment for a localized lesion in two cases and nephrectomy in one case of disseminated multilocular lesion with an uneventful course in all three cases.

Emphysema↗
PubMed2001

[Three cases of spontaneous intraperitoneal rupture of the bladder].

Spontaneous rupture of the bladder is a rare disease which raises real diagnostic and therapeutic problems. Based on three new cases of spontaneous rupture of the bladder in the absence of any trauma and a review of the literature, the authors discuss the various diagnostic, prognostic and therapeutic aspects of this unusual lesion, secondary to multiple aetiologies, predominantly inflammatory causes. Idiopathic rupture of the bladder is particularly serious compared to other forms of traumatic or iatrogenic rupture. Late diagnosis caused by the absence of pathognomonic signs and the generally insidious clinical course at least partly contribute to this severity. Neoplastic forms have a very poor prognosis.

Adult↗
PubMed2000

Induction of apoptosis and inhibition of cell proliferation by the lipido-sterolic extract of Serenoa repens (LSESr, Permixon in benign prostatic hyperplasia.

BACKGROUND: To determine the mechanism by which prostate volume increases during the development of BPH and to evaluate the effect of LSESr (Permixon), a phytotherapeutic agent, we investigated apoptosis and cell proliferation in the stroma and epithelium of normal prostate and of BPH tissues from patients treated with or without LSESr. METHODS: MIB-1 staining and the in situ end-labeling assay were used to evaluate the proliferative-apoptotic balance in normal prostates and in BPH tissues. Quantitative assessment was performed using an image analysis system. RESULTS: In normal prostates, there was no significant difference between apoptotic and proliferative indices. Cell numbers and proliferative indices were higher in BPH than in normal prostates, while apoptosis values were similar. In the BPH treated group, LSESr significantly inhibited proliferation and induced cell death in both epithelium and stroma. CONCLUSIONS: Induction of apoptosis and inhibition of cell proliferation are likely to be the basis for the clinical efficacy of LSESr.

Adult↗
PubMed2000

Bisphosphonates inhibit breast and prostate carcinoma cell invasion, an early event in the formation of bone metastases.

The molecular mechanisms by which tumor cells metastasize to bone are likely to involve invasion, cell adhesion to bone, and the release of soluble mediators from tumor cells that stimulate osteoclast-mediated bone resorption. Bisphosphonates (BPs) are powerful inhibitors of the osteoclast activity and are, therefore, used in the treatment of patients with osteolytic metastases. However, an added beneficial effect of BPs may be direct antitumor activity. We previously reported that BPs inhibit breast and prostate carcinoma cell adhesion to bone (Boissier et al., Cancer Res., 57: 3890-3894, 1997). Here, we provided evidence that BP pretreatment of breast and prostate carcinoma cells inhibited tumor cell invasion in a dose-dependent manner. The order of potency for four BPs in inhibiting tumor cell invasion was: zoledronate > ibandronate > NE-10244 (active pyridinium analogue of risedronate) > clodronate. In addition, NE-58051 (the inactive pyridylpropylidene analogue of risedronate) had no inhibitory effect, whereas NE-10790 (a phosphonocarboxylate analogue of risedronate in which one of the phosphonate groups is substituted by a carboxyl group) inhibited tumor cell invasion to an extent similar to that observed with NE-10244, indicating that the inhibitory activity of BPs on tumor cells involved the R2 chain of the molecule. BPs did not induce apoptosis in tumor cells, nor did they inhibit tumor cell migration at concentrations that did inhibit tumor cell invasion. However, although BPs did not interfere with the production of matrix metalloproteinases (MMPs) by tumor cells, they inhibited their proteolytic activity. The inhibitory effect of BPs on MMP activity was completely reversed in the presence of an excess of zinc. In addition, NE-10790 did not inhibit MMP activity, suggesting that phosphonate groups of BPs are responsible for the chelation of zinc and the subsequent inhibition of MMP activity. In conclusion, our results provide evidence for a direct cellular effect of BPs in preventing tumor cell invasion and an inhibitory effect of BPs on the proteolytic activity of MMPs through zinc chelation. These results suggest, therefore, that BPs may be useful agents for the prophylactic treatment of patients with cancers that are known to preferentially metastasize to bone.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Caverno-pudendal nervous communicating branches in the penile hilum.

Classically, the peripheral neural pathways for erection are proerectile, issuing from the parasympathetic sacral fibres, and antierectile from the thoracolumbar sympathetic trunk. The cavernous nerves as terminal branches of the pelvic plexus convey the parasympathetic fibres to the penis. The pudendal nerve conveys sensory fibres from the penis and somatic fibres to the bulbos-pongiosus and ischiocavernosus striated mm. In animals, it has been demonstrated that the dorsal nerve of the penis contains sympathetic fibres. These findings suggest that communicating branches exist between the cavernous nerves and the dorsal nerve. Our aim in this study was to demonstrate the presence of such connections in man. We dissected 20 fresh male cadavers. The pelvic plexus and pudendal nerves were dissected to identify their terminal branches and connections. Histologic study was performed. Our results showed evidence of communicating nervous branches between the cavernous nerves and the dorsal nerve of the penis. Several variants existed concerning the number and type of connections. The presence of such communicating branches proves that the supralevator and infralevator neural pathways communicate and suggest the possibility of a kind of plasticity of the nervous supply of penile erection. Further studies are needed to identify the nature of these communicating branches.

Adult↗
PubMed1999

Perineal approach to radical prostatectomy in kidney transplant recipients with localized prostate cancer.

Close urologic follow-up of renal transplant candidates and recipients often reveals prostate carcinoma at an early stage. Two patients who underwent renal transplantation for end-stage disease also underwent radical perineal prostatectomy for localized prostate carcinoma, 3 years after grafting in 1 patient and 4 years before grafting in the other. The perineal approach to prostatectomy may facilitate later renal transplantation and avoid allograft damage.

Adenocarcinoma↗
PubMed1999

Results of pyeloureterostomy after ureterovesical anastomosis complications in renal transplantation.

OBJECTIVES: The most frequent urologic complications after renal transplantation involve the ureterovesical anastomosis (ie, leakage, stenosis, and reflux), with a frequency of 1% to 30% in different series. We present the results of pyeloureterostomy using the recipient's ureter. METHODS: From 1988 to 1996, 570 cadaveric renal grafts were performed at our institution. A Lich Gregoir ureterovesical anastomosis was used in every case. Complications involving the anastomosis occurred in 19 cases (3.3%), with 10 stenoses (1.7%), 6 cases of leakage (1.1%), and 3 of reflux (0.5%). The mean donor age was 36.2 years, and the mean duration of cold ischemia was 29.4 hours. The mean recipient age was 41.3 years. Corrective surgery was performed 0.09 years (range 0.01 to 0.22) after transplantation for leakage, 1.13 years (range 0.14 to 5.11) for stenosis, and 5.55 years (range 0.51 to 9.71) for reflux. The recipient's ureter was stented with a ureteral catheter before median laparotomy, except in 3 cases of early leakage (less than 3 days). The recipient's ureter was cut, without the need for ipsilateral nephrectomy, and sutured to the graft pelvis. A nephroureterostomia stent (Gil Vernet stent) (12 cases) or a double J ureteral stent (7 cases) was used for urinary drainage. RESULTS: One graft was lost on day 1 through renal vein thrombosis. Percutaneous nephrostomy was performed on day 2 to clear an obstruction of the double J ureteral stent in one case, and a double J ureteral stent was inserted on day 2 because the nephrouretrostomia stent was incorrectly positioned in another case. Pyelographic controls on day 15 were normal in every case. The mean follow-up was 2.25 years (range 0.24 to 6.1) (2.9 years for leakage, 2.08 years for stenosis, and 1.44 years for reflux). One patient died with a functional graft 3 years after surgery. One graft was lost 4 years after surgery through chronic rejection. There were no complications affecting the ipsilateral kidney. No further ureteral complications occurred after surgery. The mean creatinine level 3 years after surgery was 1.59 mg/dL. CONCLUSIONS: Pyeloureterostomy is a safe and permanent treatment for complications of ureterovesical anastomosis and gives excellent results. The technique requires stenting of the recipient's ureter and graft drainage with a nephroureterostomia stent or a double J ureteral stent.

Adult↗
PubMed1999

Regulation of Apoptosis in the Prostate Gland by Androgenic Steroids.

The prostate gland requires androgenic steroids for its appropriate embryological formation and postpubertal growth and, once at adult size, remains dependent on a continuous supply of androgens for its vitality and function. A reduction of the levels of circulating androgens will rapidly induce apoptosis of the cells of the prostate, leading to extensive glandular regression. Studies of rodent models of prostate response to castration have shown that there are some remarkable changes in the gene activity of prostate epithelial cells leading up to apoptosis. There is now evidence for a critical cell signaling pathway, regulated by c-fos expression, necessary for castration-induced apoptosis, as well as evidence that this signaling initiates an abrupt and transient alteration in the synthesis of fas antigen, p53, bax and bcl-2 proteins in the androgen receptor-expressing prostate epithelial cells, the cellular compartment that appears to be the most affected by castration. However, more recent studies suggest that these castration-induced effects on the prostate epithelial cells might be, at least in part, an indirect response to a critical reduction in blood flow to the prostate gland that precedes the onset of epithelial cell apoptosis. The castration effects on blood flow to the prostate gland seem to be related to vascular degeneration associated with apoptosis of a subset of prostate endothelial cells.

Journal Article↗