46 research outputs found

    A Comparison between Clinical and Pathologic Staging in Patients with Bladder Cancer

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    Purpose: To determine the accuracy of clinical staging methods of bladder cancer and TURBT results in estimating the pathologic stage of tumor.Materials and Methods: Thirty two patients who had undergone radical cystectomy were studied in this retrospective survey. The results of bimanual examination, cystoscopy, TURBT pathology report and the tumor contour in CT scan, (size, infiltrative deepness, pelvic lymph nodes involvement and hydronephrosis) were recorded. The type of surgery and pathologic report of cystectomy sample were analyzed as well. Then the results of bimanual examination, tumor size, hydronephrosis and CT scan findings including tumor infiltrative deepness, pelvic lymph adenopathy and TURBT findings were compared to pathologic results of cystectomy sample.Results: Seven patients were females and 25 were males. Their mean age was 62 (range 36 to 80) years. Gross hematuria and irritative urinary symptoms were the most common complaints. The duration between symptom manifestation and patient’s referral was 5 days to 72 months (mean 12 months). Bimanual examination in estimating the extravesical involvement of tumor had a specificity of 82%, sensitivity of 46%, positive predictive value of 70% and negative predictive value of 63%. The size of tumor in determining extravesical involvement had a specificity of 41%, sensitivity of 93%, and positive predictive value of 58% and negative predictive value of 87%. Hydronephrosis was present in 15 patients of whom, 14 (93%) had bladder muscle involvement. CT scan specificity was 70%, and sensitivity was 46% regarding pelvic lymph adenopathy and perivesical fat involvement. In TURBT report no muscle sample was observed in 11 cases, so that the interpretations of results were impossible. The reported grade of tumor was lower than pathologic sample of cystectomy in 4 patients.Conclusion: Clinical staging in invasive bladder cancers has not high accuracy regarding the involvement of bladder surrounding fats and pelvic adenopathies. A tumor sized more than 5 cm could be sensitive in estimating extravesical involvement. Positive predictive value of hydronephrosis is considerable regarding bladder muscle involvement. Tumor understaging by TURBT is happened in high percentage of patients with invasive bladder cancer.</p

    Microchimerism and Renal Transplantation: Doubt Still Persists

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    Objective: We sought to study microchimerism in a group of kidney transplant recipients. Materials and Methods: In this study, the peripheral blood microchimerism (PBM) after renal transplantation was retrospectively evaluated in 32 male-to-female recipients of living unrelated or cadaveric donor renal transplants. Using a nested polymerase chain reaction (PCR) amplification specific for SRY region of the Y chromosome, microchimerism was detected with a sensitivity of 1:1,000,000. Recipients were compared according to the presence of PBM, acute and chronic rejection episodes, type of allotransplant, recipient and donor age at transplantation, previous male labor or blood transfusion, allograft function (serum creatinine level), and body mass index. Results: Among 32 recipients, 7 (21.9) were positive for PBM upon multiple testing at various posttransplant times. All microchimeric recipients had received kidneys from living unrelated donors. No significant difference was observed with regard to other parameters. In addition the acute rejection rate in the microchimeric group was 3 (42) versus 4 (16) in the nonmicrochimeric recipients (not significant). Conclusion: Our results suggested better establishment of microchimerism after living donor kidney transplantation. However, doubt persists concerning the true effect of microchimerism after renal transplantation. It seems that microchimerism alone has no major protective role upon renal allograft survival. © 2007 Elsevier Inc. All rights reserved

    The risk factors of prostate cancer: A multicentric case-control study in Iran

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    Prostate cancer (PC), in Iran, is the third most frequently diagnosed visceral cancer among men and the seventh most common underlying cause of cancer mortality. We evaluated the relation between speculated factors and PC risk using data from a multicentric case-control study conducted in Iran from 2005 to 2007 on 130 cases of incident, clinicopathologically confirmed PC, and 75 controls admitted to the same network of hospitals without any malignant disease. Odds ratios(OR) and corresponding 95 confidence intervals (CIs) were estimated using conditional logistic regression models. The risk of PC was increased with aging (OR: 5.35, 95 CI: 2.17-13.19; P<0.0001), and with the number of sexual intercourse �2 times/week (OR: 3.14, 95 CI: 1.2-8.2; P=0.02). One unit elevation in serum estradiol and testosterone concentration was related to increase (OR: 1.04, 95 CI: 1.01-1.06; P=0.006) and decrease (OR: 0.79; 95 CI: 0.64-0.96; P=0.02) of PC risk, respectively. Cases were less likely to have a history of diabetes (OR: 0.34, 95 CI: 0.12-0.98; P=0.04). Increasing in dietary consumption of lycopene and fat was associated with declined (OR: 0.45, 95 CI: 0.09-2.12) and increased (OR: 2.38, 95 CI: 0.29-19.4) PC development, respectively. Other factors including educational level, marriage status, dietary meat consumption, vasectomy and smoking have not been shown to affect PC risk in the Iranian population. Ourstudy adds further information on the potential risk factors of PC and is the first epidemiologic report from Iran. However, justification of these results requires more well-designed studies with a larger number of participants

    Centralized Rescheduling Approach against Autonomous Control Approach in Dynamic Flexible Flow Shop in the Presence of Machine Breakdowns

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    Summary: In the current paper, we study the concept of dynamic scheduling in flexible flow Shop with limited carrier under stochastic machine breakdowns and processing time. In most flexible flow shop scheduling methods reported in the literature consider a determinist environment, where all data of the problem are known in advance. Most of these works focused on the development of methods to produce a feasible schedule of good quality in short time computing. However, real systems are stochastic and dynamic such that the initial generated schedule must deal with the presence of a variety of unexpected disruptions that may occur dynamically and cause deviations from the initial schedule. To cope with machine breakdowns and stochastic processing time, a centralized heuristic based on local search simulated annealing algorithm is used to implement the reactive scheduling for the dynamic scheduling problem. This centralized heuristic method will be compared with a decentralized autonomous approach. In order to evaluate the performance of the both developed approaches two performance measures, namely the average flow time and the makespan, were be used. Keywords: Meta-Heuristic, Autonomous Control, Flexible Flow Shop Scheduling, Simulation. General In recent years, scheduling problems have become the subjects of many studies about tasks allocation. Depending on availability of jobs prior to a schedule creation, scheduling systems can be classified into static and dynamic ones. In static scheduling, all jobs&apos; specifications are identified before creating the respective schedule and the production sequence does not change during processing. In dynamic scheduling, dynamic events like random job arrivals and machine breakdowns can be appeared, so that they affect the normal execution of the initially generated schedule. Therefore, a rescheduling is necessary to adapt the predefined schedule Dynamic Scheduling Dynamic scheduling in conventional centralized approach The problem of dealing with uncertainty and stochastic events is addressed in literature by dynamic scheduling. Three general approaches of scheduling in consideration o

    Application of learning pallets for real-time scheduling by use of artificial neural network

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    Generally, this paper deals with the problem of autonomy in logistics. Specifically here, a complex problem in inbound logistics is considered as real-time scheduling in a stochastic shop floor problem. Recently, in order to comply with real-time decisions, autonomous logistic objects have been suggested as an alternative. Since pallets are common used objects in carrying materials (finished or semi-finished), so they have the possibility to undertake the responsibility of real time dispatching jobs to machines in a shop-floor problem. By insisting on the role of pallets for this task, their sustainment's advantage in manufacturing systems motivated the idea of developing learning pallets. These pallets may deal with uncertainties and sudden changes in the assembly system. Here, among some intelligent techniques artificial neural network is selected to transmit the ability of decision making as well as learning to the pallets, as distributed objects. Besides, pallets make decisions based on their own experiences about the entire system and local situations. Consequently, the considered scheduling problem resembles an open shop problem with three alternative finished products. Finally, a discrete event simulation model is developed to solve this problem and defined the results of this transmission paradigm
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