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Biomedical subjects

G Karam

Publications and source records attributed to G Karam.

At least 19 recordsLinked to original sources
PubMed2006

[Should double J catheter be systematically considered in renal transplantation?].

Protection of urinary anastomoses using a ureteral catheter is a frequent option in urology but such use in a systematic manner remains debated in renal transplantation. Some consider that systematic insertion of a double J sound decreases the incidence of ureteral complications (fistula and stenosis). Others who prefer a selective use in some situations with a related risk consider that the implementation of a double J catheter cannot compensate a technical defect. It is even responsible for specific complications (infections, incrustation, haemorrhages); it increases implantation costs and is useless in more than 90% of the cases. This article analyses the risks related to systematic implementation of a double J catheter in Lich-Gregoir ureterovesical anastomoses for renal transplantation, together with the related costs and the infectious risk. The benefits in terms of prevention of ureteral complications are evaluated.

Catheterization↗
PubMed2006

Late ureteral stenosis following renal transplantation: risk factors and impact on patient and graft survival.

The aim of this retrospective study of a cohort of 1787 consecutive kidney transplantations was to analyze the risk factors associated with the occurrence of ureteral stenosis and the impact of ureteral stenosis on graft and patient survival. Between January 1990 and December 2002, 1787 renal transplantations were performed at our center. Only stenosis observed after the first month, were considered. Among the parameters studied were: donor age and serum creatinine before procurement; recipient age, cold ischemia time, delayed graft function (DGF), number of arteries and the presence of a double J stent. The follow-up parameters were the number and timing of acute rejection episodes, cytomegalovirus (CMV) infection, acute pyelonephritis, renal function and death. Ureteral stenosis occurred in 4.1% of patients and was correlated with donor age > 65 years (p = 0.001), kidneys with more than 2 arteries (p = 0.009) and DGF (p = 0.016). Ureteral stenosis did not affect 10-year patient and graft survival rates, which were respectively 90% and 64% for the stenosis group, 86% and 63% for the no-stenosis group (p = NS). These data suggest an important role for donor age, number of renal arteries and DGF for the occurrence of ureteral stenosis following renal transplantation.

Adult↗
PubMed2005

[Local guidelines and quality of antibiotic treatment in urinary tract infections: a clinical audit in two departments of a university hospital].

AIM: To assess the effect of local guidelines implemented at the Nantes University Hospital regarding antibiotic therapy for urinary tract infections. DESIGN: Before/after study of one medical ward and one urologic surgery ward. Quality was measured by two principal criteria: compliance with guidelines and medical justification in the specific clinical situation. Both criteria considered simultaneously the choice of drug, dose and duration of treatment. Deviations from the guidelines were described. RESULTS: 1086 UTI cases were identified over two 12-month periods, before and after the dissemination of guidelines (for prostatitis, pyelonephritis, indwelling catheter-associated UTIs, and other undefined UTIs). The guidelines were applicable in 313 (30%) cases. Overall, after implementation of the guidelines, the percentage of justified prescriptions did not change significantly (41.8% compared with 38.7%, p=0.299), but the percentage of correct (conforming) prescriptions fell (from 30.4% to 15.7%, p=0.0022). The percentages of correct and justified prescriptions differed in the medical (respectively 45.0% and 46.6%,) and surgical units (13.1% and 36.5%). CONCLUSIONS: Issuing guidelines does not necessarily improve the quality of antibiotic therapy for UTIs in hospitals.

Anti-Bacterial Agents↗
PubMed2005

[Adequate prescription of antibiotic therapy for urinary tract infections in hospital: identifying and correcting non-observance of guidelines].

OBJECTIVE: We analyzed the adequacy of antibiotic therapy prescribed for urinary tract infections (UTI): prostatitis, pyelonephritis, indwelling catheter-associated UTIs, or other undefined UTIs. DESIGN: The adequacy of prescriptions to local guidelines was assessed retrospectively in two wards (Internal Medicine and Surgical Urology) of the Nantes University Hospital. The principal criteria involved simultaneously: choice of the molecule, dose, and treatment duration. Non-observances of guidelines were major (non-adequacy of the molecule, prescription of a non-active molecule according to in vitro susceptibility tests, non-appropriate treatment abstention), or minor (non-justified treatment, non-justified bitherapy, no prescription of bitherapy when requested, no treatment adaptation when requested, too short or too long treatment length, dosage mistakes). RESULTS: One thousand eighty-six infections were collected over a 24-month period. The overall rate of adequate prescriptions was 40.1% (46.6% in Internal Medicine and 36.5% in Surgical Urology). In Internal Medicine (226 non observance among 389 prescriptions), the ratio of major non-observance of guidelines was 9.8%. Among them, 44.7% were non-appropriate treatment abstentions. In Surgical Urology (539 non observance out of 695 prescriptions), non-observance related to treatment length were the most frequent. The ratio of major non-observance was 19.9%. Among them, non-adequacy of the molecule reached 60.7%. Non-justified treatment and non-appropriate bitherapies were frequent. CONCLUSIONS: For both units, indwelling catheter-related UTIs and other UTIs accounted for more than 50% of the infections although not detailed in the local guidelines. Identifying and analyzing Non observance may lead to targeted correcting actions to improve prescription quality.

Adult↗
PubMed2005

[Anaesthesia and prostate surgery].

OBJECTIVES: To review the current data about anaesthetic management in prostate surgery with special regards on analysis and prevention of specific risks, appropriate anaesthetic procedure keeping with surgery and patient, recognition and treatment of adverse events. DATA SOURCES AND EXTRACTION: The Pubmed database was searched for articles (1990-2004) combined with references analysis of major articles on the field. DATA SYNTHESIS: It is strongly recommended to settle germfree urine in the preoperative period. The thromboembolic risk of radical retropubic prostatectomy for cancer parallels lower abdomen oncologic surgery and is prolonged. Preoperative evaluation of cardiovascular, respiratory, neurological and metabolic comorbidity is a source of prognostic information and an essential tool in the management of elderly patients with prostate disease. Extreme patient positioning applied in prostate surgery induces haemodynamic and respiratory changes and are associated with severe muscular and nervous injuries. The laparoscopic access for radical prostatectomy is a growing alternative to the open surgical procedure. Acute normovolaemic haemodilution is a consistent and cost-effective blood conservation strategy in reducing allogenic blood transfusion for radical retropubic prostatectomy. Whether open transvesical or transurethral prostatectomy for treatment of benign hypertrophy depends on the size of the gland: transurethral resection is safe up to 80 g. Intrathecal anaesthesia with a T9 cephalad spread of sensory block, produces adequate conditions for transurethral prostatectomy and allows a rapid diagnosis of irrigating fluid absorption syndrome. In spite of recommended preoperative antibiotic prophylaxis, bacteriemias are frequent during transurethral prostate resection.

Adenoma↗
PubMed2005

[Upper urinary tract: physiology, pathophysiology of obstructions and function assessment].

The urine is transported from the renal papilla to the bladder through the upper urinary tract which allows this transport to be safe and comfortable, i.e., without any risk or pain for the kidney. This active transport depends on the smooth muscle contractile properties. The upper urinary tract is totally autonomous; this feature allows the preservation of its function after renal transplantation. However, despite its accessory role, the autonomous nervous system can modulate its activity. Upper urinary tract obstruction involves adaptative mechanisms which are different depending on the type (acute, chronic, acquired or congenital) of obstruction. Functional evaluations of the upper urinary tract are aimed at identify the urine transport conditions and the relationship between obstruction and clinical conditions such as hydronephrosis, pain or impaired renal function.

Humans↗
PubMed2004

Loss of NOS1 expression in high-grade renal cell carcinoma associated with a shift of NO signalling.

In normal human kidney, NOS1 and soluble guanylate cyclase (sGC) are expressed in tubular epithelial cells, suggesting a physiological autocrine NO signalling pathway. Therefore, we investigated both NOS1 and sGC expressions in benign and malignant renal tumours. In addition, we examined the pattern of protein tyrosine nitration in normal and tumour tissue. NOS1 expression and activity were found to be downregulated, correlating with the tumour grade, as shown by immunohistochemistry, quantitative RT-PCR analysis, and histochemical detection of the NADPH-diaphorase activity of nitric oxide synthases (NOS). These results show that the autocrine NO signalling pathway is maintained in benign tumours and lost in malignant tumours. In contrast, sGC expression was maintained in renal tumours whatever the tumour type, a finding showing that tumour cells remain sensitive to the bioregulatory role of exogeneous NO(*). Finally, the staining pattern of protein tyrosine nitration, assessed by immunohistochemistry, parallelled that of NOS1 expression in normal renal parenchyma and benign tumours, supporting the concept that protein nitration was accounted for by NOS1 activity. In contrast, in malignant tumours, protein tyrosine nitration was accounted for by the production of reactive nitrogen oxide species by the inflammatory infiltrate. Altogether, these findings argue for a pattern of NO signalling similar in normal kidney and benign renal tumours, whereas it is completely different in malignant renal tumours.

Carcinoma, Renal Cell↗
PubMed2001

Contrast-enhanced MR imaging of experimental acute tubular necrosis.

PURPOSE: To demonstrate the involvement of the various renal structures in acute tubular necrosis (ATN). MATERIAL AND METHODS: In 15 rats, using a T1-/T2-weighted sequence, either gadodiamide alone, or gadodiamide in combination with sprodiamide (a susceptibility agent) were used to enhance the various anatomical substrates of the kidney. The results were compared to those of pathological verification. RESULTS: Experimentally induced ATN of the rat kidney causes profound changes in the medulla, leaving the cortex largely intact. The difference between the normal cortex and the partially necrotic outer medulla, on the one hand, and the papillary region, was significantly enhanced with the combination, whereas a larger region composed of the inner and outer medulla was enhanced after the gadolinium chelate alone. CONCLUSION: The results varied considerably between the two procedures; the double contrast demonstrated a clear difference between the inner and outer medulla, and the gadolinium chelate alone demonstrated a clear difference between the medulla and the cortex. These results demonstrated a clear difference in the compartmentalization between the inner and outer medullary regions, providing complementary information about the pathological condition of the kidney.

Animals↗
PubMed2001

[Accuracy of pressure measurements obtained with a new rectal balloon catheter].

UNLABELLED: The accuracy of measurements performed by a balloon catheter used to record abdominal pressure during urodynamic investigations was verified on a test bench. OBJECTIVE: To study the accuracy and precision of the pressure measurements obtained with a new rectal balloon catheter (ref. 95018 Laboratoires Vermed), designed to record abdominal pressure during urodynamic assessments. The clinical value of this catheter, using air for pressure transmission, is its simplicity, as there is no contamination of the perfusion circuit or transducer, no purging of the circuit, and artefacts related to movements of the tubing are eliminated. METHOD: The catheter was placed in a pressure chamber fitted with a precise, calibrated regulation system allowing programmed pressure variations from 10 to 150 cmH2O. Pressures recorded by the test catheter were compared to reference pressures applied to the chamber. The frequency of acquisition of pressure measurements was 100 Hertz and the resolution was 10 Hertz. This model was used to study the accuracy of pressure measurements and the response times of the catheter. Measurements were performed with a volume of 2 ml of air introduced into the catheter (volume recommended by the manufacturer), and the optimal volume was investigated by inflating the catheter until the best result was obtained. The evaluation was based on calculation of the mean difference observed between the two measurements and the scatter of the differences observed. RESULTS: When the catheter was filled with 2 ml of air, pressures measured by the catheter were overestimated an average of 1.1 cmH2O (standard deviation = 1), and 95% of the differences between the two measurements were within +/- 2.15 cmH2O. The optimal air volume was found to be 1.5 ml. With this air volume, no significant difference was observed between the two measurements. The mean observed difference was 0.2 cmH2O (SD = 1.2), which means that 95% of the differences were situated within the range of +/- 2.35 cmH2O. CONCLUSION: The pressure recording method with this new catheter is validated in terms of physical parameters.

Equipment Design↗
PubMed2001

[Lumbar pain and hydrocalyx].

The authors report the case of a patient presenting with disabling left lumbar pain. Complementary investigations confirmed the diagnosis of isolated hydrocalyx with no organic cause. Surgical treatment was conservative with caliceal plasty. The authors discuss the diagnostic and therapeutic management by analogy between this type of hydrocalyx and Fraley's syndrome.

Child↗
PubMed2000

Low incidence of kidney rejection after simultaneous kidney-pancreas transplantation after antithymocyte globulin induction and in the absence of corticosteroids: results of a prospective pilot study in 28 consecutive cases.

BACKGROUND: Recipients of simultaneous kidney-pancreas transplantation receive a combination of polyclonal antithymocyte globulin (ATG), cyclosporin or tacrolimus, mycophenolate mofetil (MMF) and corticosteroids (Cs). To avoid the side effects and adverse events associated with Cs, we investigated a new immunosuppressive regimen without Cs after simultaneous kidney-pancreas transplantation. METHODS: A total of 28 consecutive patients who underwent simultaneous kidney-pancreas transplantation were included in this study. All patients received ATG, cyclosporin, and MMF. RESULTS: All patients but one tolerated the ATG course well. MMF was definitively discontinued in three patients because of leukopenia. Cytomegalovirus infection was diagnosed in eight patients (28.5%). Only two patients (7%) required an antirejection treatment. Patient, kidney, and pancreas survival is currently 96.4, 96.4, and 75%, respectively. CONCLUSIONS: The combination of ATG, cyclosporin, and MMF, without Cs, was well tolerated. The unexpectedly low (7%) incidence of acute kidney rejection observed suggests that Cs may partially interfere with the immunosuppressive effect of ATG.

Adolescent↗
PubMed2000

Interaction of anti-HLA antibodies with pig xenoantigens.

BACKGROUND: Many patients with renal failure are condemned to long-term dialysis with little prospect of transplantation because they are highly sensitized with immunoglobulin G (IgG) directed against class I human leukocyte antigens (HLA) of virtually all donors. Xenotransplantation could represent an attractive solution providing their alloantibodies (alloAb) do not recognize porcine motifs. Hitherto there has been no in vivo demonstration of any cross-reactivity and the objective of this work was to investigate this problem using a technique of extracorporeal pig kidney perfusion as a model of clinical xenografting. METHODS: Pig kidneys were perfused ex vivo with plasma from both a group of highly sensitized patients and healthy individuals. Sequential plasma samples were analyzed for the titer of anti-Galalpha1-3Gal antibody (Ab) (major natural xenoreactive Ab) by enzyme-linked immunosorbent assay and anti-HLA class I Ab against a cell panel. At the end of perfusion, kidneys were perfused with a citric acid buffer to elute bound Ab. RESULTS: Galalpha1-3Gal Ab were shown to decrease rapidly in the plasma (in less than 10 min) and then reached a plateau. A fractional decrease in anti-HLA Ab was also found in some of the perfused plasma samples. Anti-Gal Ab were readily detected in all citric acid perfusates and anti-HLA Ab in 8 of 10. The HLA specificities of eluted Ab were mainly concordant with the originally designated specificities for each patient. CONCLUSION: Anti-HLA class I Ab presumably cross-react with pig class I homologues. However, some plasma samples did not cross-react, suggesting that negatively cross-matched pig kidneys could be identified in the pig population for xenotransplantation in these patients. Further studies are required to precisely describe these cross-reactivities and to understand their functional significance in xenotransplantation.

Animals↗
PubMed2000

Intermittent androgen suppression in the treatment of metastatic prostate cancer.

BACKGROUND: To assess the feasibility of intermittent androgen suppression in patients with metastatic prostate cancer and to quantify the improvement in the quality of life. METHODS: Forty-three patients with M1 b prostate cancer were treated by intermittent hormonal deprivation using luteinizing hormone-releasing hormone (LHRH) analogue alone (n = 11), or associated with an antiandrogen (n = 32). The prospective nonrandomized study required an initial therapy period of 12 months with a stable biological response during 6 months (PSA, testosterone). Treatment was resumed when the serum PSA value recovered to 20 ng/ml, or when local failure or new bone metastasis occurred. The assessment of quality of life was carried out using the EORTC QLQ-C30. RESULTS: The mean follow-up time was 43.7 months. After the initial 12 months of androgen suppression, one patient with a minimal disease was off-therapy with a follow-up of 18 months. For the 42 other patients, the mean off-therapy period was 6.7 months. In the second therapy period (9-12 months), 7 patients were hormono-independent and died with a mean survival time of 27 months; 35 patients were responders. The mean off-therapy length in the second cycle was short (3.8 months). After this time, androgen suppression therapy was reintroduced permanently, but 10 patients were hormono-independent. No difference was observed in the EORTC QLQ-C30 between therapy and off-therapy periods, only a rapid decrease in adverse events due to the hormonal deprivation was reported in all cases during the off-therapy period. CONCLUSIONS: Intermittent androgen suppression in patients with M1 b prostate cancer could be associated with a significant period off-therapy in the first cycle (55.8%), and with a chance of second hormone response. But in the second cycle, the off-therapy period length was short and required a careful follow-up.

Aged↗
PubMed1998

Influence of parasympathetic dysfunction and hyperinsulinemia on the hemodynamic response to an isometric exercise in non-insulin-dependent diabetic patients.

The handgrip test has long been used as a test for investigating cardiac autonomic neuropathy in diabetic patients. However, the factors involved in the hemodynamic response to the handgrip test have not been thoroughly studied. The aim of this study was to investigate blood pressure (BP) and heart rate (HR) responses to an isometric test in non-insulin-dependent diabetics (NIDDs) and to correlate the results with vagal function evaluated by three standardized tests and with plasma insulin levels. Fifty-five NIDDs, 35 of whom had one to three abnormal parasympathetic tests (PS+), were compared with 10 healthy control subjects. Fasting and postprandial plasma insulin levels were significantly higher in the PS+ than in the PS- patients. Resting HR correlated significantly with log fasting and postprandial insulin. In PS+ NIDDs, resting HR was significantly higher than in PS- patients. Age-matched comparisons also showed that resting systolic BP was significantly higher in PS+ patients than in controls. In PS- patients, the mean acceleration of HR was significantly higher than in the control group from the second to the fifth minute, and the BP response was also higher than in controls. These data suggest that (1) sympathetic response to an isometric exercise is increased in PS- NIDDs; (2) cardiac parasympathetic dysfunction is associated with a more severe insulin resistance; and (3) the subsequent higher plasma insulin level may contribute to the increase in resting HR and BP through sympathetic activation while limiting the hemodynamic response to an isometric exercise through its vasodilative effect.

Blood Pressure↗
PubMed1998

Early transition to oral antibiotic therapy for community-acquired pneumonia: duration of therapy, clinical outcomes, and cost analysis.

Our objective was to compare therapeutic outcome and analyse cost-benefit of a 'conventional' (7-day course of i.v. antibiotic therapy) vs. an abbreviated (2-day i.v. antibiotic course followed by 'switch' to oral antibiotics) therapy for in-patients with community-acquired pneumonia (CAP). We used a multicenter prospective, randomized, parallel group with a 28 day follow-up, at the University-based teaching hospitals: The Medical Center of Louisiana in New Orleans, LA and hospitals listed in the acknowledgement. Ninety-five patients were randomized to receive either a 'conventional' course of intravenous antibiotic therapy with cefamandole 1 g i.v. every 6 h for 7 days (n = 37), or an abbreviated course of intravenous therapy with cefamandole (1 g i.v. every 6 h for 2 days) followed by oral therapy with cefaclor (500 mg every 8 h for 5 days). No difference was found in the clinical courses, cure rates, survival or the resolution of the chest radiograph abnormalities among the two groups. The mean duration of therapy (6.88 days for the conventional group compared to 7-30 days for the early oral therapy group) and the frequencies of overall symptomatic improvement (97% vs. 95%, respectively) were similar in both groups. Patients who received early oral therapy had shorter hospital stays (7.3 vs. 9.71 days, P = 0.01), and a lower total cost of care ($2953 vs. $5002, P < 0.05). It was concluded that early transition to an oral antibiotic after an abbreviated course of intravenous therapy in CAP is substantially less expensive and has comparable efficacy to conventional intravenous therapy. Altering physicians' customary management of hospitalized patients with CAP can reduce costs with no appreciable additional risk of adverse patient outcome.

Administration, Oral↗
PubMed1998

Randomized comparison of triple therapy and antithymocyte globulin induction treatment after simultaneous pancreas-kidney transplantation.

BACKGROUND: The incidence of acute rejection is considered to be higher after simultaneous pancreas-kidney (SPK) transplantation as compared to renal transplant alone. Therefore, the majority of SPK transplant recipients commonly receive a combination of cyclosporine (CsA) or tracolimus, and azathioprine or mycophenolic mofetyl, corticosteroids and/or antilymphocyte preparations. This study was designed to compare two immunosuppressive protocols for the prevention of acute rejection in patients undergoing SPK transplantation. The primary end-point was the incidence of acute rejection during the first 12 months after transplantation METHODS: Fifty patients with type-I insulin-dependent diabetes and chronic renal failure were randomized to receive a triple drug immunosuppressive regimen including CsA, azathioprine and corticosteroids (N = 25), or the quadruple sequential combination of rabbit antithymocyte globulin (ATG) given for 10 days, azathioprine, corticosteroids and delayed CsA (N = 25). Maintenance immunosuppression (CsA and azathioprine, without corticosteroids) was similar in both arms. RESULTS: The average follow-up was 36 months in both groups (range 9 to 60 months). No patient was excluded from the study. Although the percentage of patients with adverse events was higher in the ATG group (80 vs. 40%, P < 0.01), none of them resulted in premature discontinuation of the drug. Patients receiving ATG experienced a lower incidence (36% vs. 76%, P < 0.01) and number (13 vs. 29, P < 0.05) of acute renal rejection episodes. However, no difference was observed in patient, pancreas and kidney survival rates between groups. No case of isolated pancreas rejection was observed. CONCLUSIONS: The quadruple sequential combination ATG, azathioprine, corticosteroid and CsA significantly reduced the one year incidence of acute renal rejection after SPK transplantation, compared to a triple immunosuppressive regimen.

Adrenal Cortex Hormones↗
PubMed1998

[Testicular tumor in renal and pancreatic transplantation].

The authors report the case of a 49-year-old, insulin-dependent diabetic man treated by double kidney-pancreas transplantation. A T3, N3, M0 testicular tumour was discovered at the 8th month and treated by inguinal orchidectomy and 2 courses of chemotherapy. Immunosuppressant treatment was decreased without any consequences for the transplants. Seven years later, the patient was cured but still treated by haemodialysis for chronic rejection of the renal transplant. The pancreatic transplant was still functional and the patient is waiting for a second renal transplantation.

Azathioprine↗