336 research outputs found
Iranian model of paid and regulated living-unrelated kidney donation.
Since the 1980s, many countries have passed legislation prohibiting monetary compensation for organ donation. Organ donation for transplantation has become altruistic worldwide. During the past two decades, advances in immunosuppressive therapy has led to greater success in transplantation and to increased numbers of patients on transplant waiting lists. Unfortunately, the altruistic supply of organs has been less than adequate, and severe organ shortage has resulted in many patient deaths. A number of transplant experts have been convinced that providing financial incentives to organ sources as an alternative to altruistic organ donation needs careful reconsideration. In 1988, a compensated and regulated living-unrelated donor renal transplant program was adopted in Iran. As a result, the number of renal transplants performed substantially increased such that in 1999, the renal transplant waiting list was completely eliminated. By the end of 2005, a total of 19,609 renal transplants were performed (3421 from living related, 15,356 from living-unrelated and 823 from deceased donors). In this program, many ethical problems that are associated with paid kidney donation also were prevented. Currently, Iran has no renal transplant waiting lists, and >50 of patients with ESRD in the country are living with a functioning graft. In developed countries, the severe shortage of transplantable kidneys has forced the transplant community to adopt new strategies to expand the kidney donor pool. However, compared with the Iranian model, none of these approaches has the potential to eliminate or even alleviate steadily worsening renal transplant waiting lists
Source mechanisms of the 2004 Baladeh (Iran) earthquake sequence from Iranian broadband and short-period data and seismotectonic implications
The relative frequency, clinical and laboratory findings of adult glomerulonephritidies in Tehran
Background: Renal diseases information is population-based and has great geographic variability. Due to the lack of national renal data registry system, there is no information on the prevalence rate, and clinical and laboratory features of various glomerulonephritidies (GNs) in Iran. Methods: In a retrospective cross sectional study, we analyzed 462 adult renal biopsies in Hashemi Nejad hospital, Tehran, Iran. We determined the prevalence rate and the frequency of different clinical and laboratory findings in patients with different GNs. We also compared our results with the reports from other countries. Results: There were 267(57.8) males and 195(42.2) females. The mean age (± SD) was 33.6 ± 15.7 (range, 13-75) years old. After exclusion of 55 biopsies with pathologies other than GNs and in the remaining 407 biopsies, membranous glomerulopathy (MGN) was the most common GN (23.6), followed by IgAN (13.5), membranoproliferative GN (11.5), systemic lupus nephritis (10.6), focal segmental glomerulosclerosis (10.3), and minimal change disease (9.8). These 6 GNs comprised the majority (79.4) of all GNs. Conclusion: MGN is the most common form of GN, followed by IgAN, MPGN, SLE-GN, FSGS and MCD in adult patients in our study. The multi-center studies with a larger sample size are needed for more comprehensive data in Iranian population
Catheter associated infections in hemodialysis patients.
Hemodialysis catheter related infections (HCRI) are one of the major causes of increasing mortality, morbidity and cost of therapy in hemodialysis patients. Prevention of HCRI requires the identification of predisposing risk factors. To determine the frequency of HCRI risk factors, we studied 116 patients (54 male, mean age of 49.5+/-16 years) patients with HCRI between 2003-2004. Forty one percent of the patients were diabetic. There was a history of previous catheter placement and infection in 41 and 32 of patients, respectively. Pathogenic organisms isolated from blood cultures included Staphylococcus-aureus 42, Coagulase-negative Staphylococci 20, E. Coli 19, Enterococci 7, Streptococcus D 7, Pseudomonas aeruginosa 4, and Klebsiella 1. Bacterial resistance to vancomycin and amikacin was present in 7 and 4 of the cases, respectively. Hemodialysis catheter related blood borne infections comprised 67 of the total blood-borne infections in our hospital. No significant statistical association was found between HCRI and age, gender, diabetes mellitus, serum albumin level <30 g/L, leukocyte count, erythrocyte sedimentation rate, anatomical location of catheter, mean duration of antibiotic therapy, mean catheter duration, frequency of hemodialysis sessions, pathogenic organisms, and history of previous catheter infection. We conclude that the prevalence of pathogenic organisms of HCRI were similar to previous studies. However, bacterial resistance to antibiotics was low. The mean duration of catheter usage was longer than previously reported
Coupled Fixed-Point Theorems for Contractions in Partially Ordered Metric Spaces and Applications
Bhaskar and Lakshmikantham (2006) showed the existence of coupled coincidence points of a mapping F from X×X into X and a mapping g from X into X with some applications. The aim of this paper is to extend the results of Bhaskar and Lakshmikantham and improve the recent fixed-point theorems due to Bessem Samet (2010). Indeed, we introduce the definition of generalized g-Meir-Keeler type contractions and prove some coupled fixed point theorems under a generalized g-Meir-Keeler-contractive condition. Also, some applications of the main results in this paper are given
Macrosegregation Resulting from Directional Solidification Through an Abrupt Change in Cross-Sections
Simulations of the directional solidification of two hypoeutectic alloys (Al-7Si alloy and Al-19Cu) and resulting macrosegregation patterns are presented. The casting geometries include abrupt changes in cross-section from a larger width of 9.5 mm to a narrower 3.2 mm width then through an expansion back to a width of 9.5 mm. The alloys were chosen as model alloys because they have similar solidification shrinkages, but the effect of Cu on changing the density of the liquid alloy is about an order of magnitude greater than that of Si. The simulations compare well with experimental castings that were directionally solidified in a graphite mold in a Bridgman furnace. In addition to the simulations of the directional solidification in graphite molds, some simulations were effected for solidification in an alumina mold. This study showed that the mold must be included in numerical simulations of directional solidification because of its effect on the temperature field and solidification. For the model alloys used for the study, the simulations clearly show the interaction of the convection field with the solidifying alloys to produce a macrosegregation pattern known as "steepling" in sections with a uniform width. Details of the complex convection- and segregation-patterns at both the contraction and expansion of the cross-sectional area are revealed by the computer simulations. The convection and solidification through the expansions suggest a possible mechanism for the formation of stray grains. The computer simulations and the experimental castings have been part of on-going ground-based research with the goal of providing necessary background for eventual experiments aboard the ISS. For casting practitioners, the results of the simulations demonstrate that computer simulations should be applied to reveal interactions between alloy solidification properties, solidification conditions, and mold geometries on macrosegregation. The simulations also presents the possibility of engineering the mold-material to avoid, or mitigate, the effects of thermosolutal convection and macrosegregation by selecting a mold material with suitable thermal properties, especially its thermal conductivity
The Incidence and Risk Factors of Delayed Graft Function in 689 Consecutive Living Unrelated Donor Renal Transplantation
Due to the severe shortage of deceased donor kidneys, the number of renal transplantation from living-related and living-unrelated donors has increased worldwide. The incidence and risk factors of delayed graft function after deceased donor renal transplantation have been extensively studied. In this analysis, the incidence and predictors of delayed graft function was investigated in 689 living-unrelated kidney recipients. In 53 recipients, dialysis was needed within the first week after renal transplantation (7.7). The risk factors for delayed graft function upon univariate analysis models were: female gender of kidney donor (P = .027), renal allograft with multiple arteries (P = .005) and previous transplantation (P < .005). Upon multivariate analysis, the only risk factor for development of delayed graft function was retransplantation (P = .001). © 2007 Elsevier Inc. All rights reserved
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