Effect of renal transplantation on coronary artery calcification in hemodialysis patients.

OBJECTIVE: Vascular calcification is a strong predictor of cardiovascular and all-cause mortality. Coronary artery calcification is more frequent, more extensive, and progresses more rapidly among subjects with chronic kidney disease (CKD) than in the general population. It is also considered to be a marker of coronary heart disease, the main cause of increased morbidity and mortality among patients either on maintenance hemodialysis or after transplantation. The aim of this study was to evaluate the effect of renal transplantation on the calcium scores of coronary arteries among hemodialysis patients. PATIENTS AND METHODS: The study included 31 patients (17 males and 14 females) of age range 19 to 56 years (mean, 38.08 +/- 13.49 years) who had been hemodialyzed 3 times a week for 6 to 49 months (mean, 20 +/- 15.72 months) prior to renal transplantation. Homocysteine, intact parathyroid hormone (iPTH), calcium, phosphate, and indices of lipid metabolism such as total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides were measured before and at 6 months after transplantation. To evaluate coronary artery calcification, all patients underwent multidetector coronary computed tomography (MDCT) using the Agatston technique for calcium scoring (CS) and color Doppler ultrasound for IMT before and at 6 months after the procedure. RESULTS: The prevalence of coronary artery calcifications among dialysis patients was 96% with a total CS ranging from 0 to 198. It affected more than 2 vessels in >50% of subjects with higher calcium scores in the left anterior descending artery (LAD). Mean total CS decreased significantly from pre- (39.82 +/- 63.05) to postoperation (24.34 +/- 39.55; P < .001). CS decreased from pre- to postprocedure in the left main artery (7.4 +/- 13.03 to 4.3 +/- 8.54; P < .01) and in LAD (15.76 +/- 23.53 to 10.23 +/- 15.81; P < .01 and in the circumflex (7.8 +/- 14.98 to 5.1 +/- 9.57; P < .001) and in the right coronary artery (9.2 +/- 17.18 to 4.7 +/- 8.18; P < .01). The CS before the procedure correlated significantly with age (r = .39; P < .005), P (r = .33; P < .05), Ca x P product (r = .39; P < .05), iPTH (r = .43; P < .001), and IMT (r = .56; P < .0001). There was a linear, meaningful correlation between CS and iPTH and Ca x P product reduction after renal transplantation. CONCLUSIONS: Renal transplantation significantly reduced coronary artery calcification among dialysis patients. It linearly correlated with a decrease in iPTH and Ca x P product at an early period after renal transplantation.

Pathogenicity of some Rhizoctonia solaniz isolates associated with root/collar rots on the cultivars of bean in greenhouse.

One hundred and eighteen isolates of Rhizoctonia solani were gathered from infected roots and hypocotyls of bean (Phaseolus vulgaris L.) grown in the fields of Tehran Province, Iran. Two isolates of the collected samples belonged to binucleate and 81 isolates to multinucleate of R. solani. The multinucleate isolates showed different anastomosis groups as AG-4 (subg. AG-4 HGI, AG-4HGII), AG-6 and AG-2. In greenhouse, pathogenicity tests carried out on bean cv. Naz in randomized design with 4 replications and each replication (pots) with 5 seeds of bean. Infection was done with seeds of wheat which were infected to the fungus with pasteurized soil. Results showed that the highest disease severity was caused by AG-4 (Rs21) isolates, whereas AG-4 (Rs74) isolates were weakly pathogenic with 90% and 21% infection, respectively. In this test the major pathogenic isolates belonged to AG-4 and they caused seed rot and damping-off of bean and AG-6 isolates were non-pathogenic. Five isolates of the fungus with major pathogenicity (Rs7, Rs18, Rs21, Rs62 and Rs71) selected and used for the reaction with different cultivars of bean. In this test, the cultivars and lines of bean (Pinto, red, white, green) studied in factorial experiment as randomized block design with 4 replications (pots). Results showed that none of the cultivars was completely resistant, however green bean cv. Sanry and pinto cv. Shad with number 4.8 disease severities had the highest susceptibility to seed rot and damping-off and red bean cv. Goli with 2.58 had the lowest susceptibility to the infection. Reaction of the cultivars and lines to the isolates of R. solani was significantly different at 1% level. Isolates of the fungus, Rs7, Rs21 with 84%, 90% pathogenicity was more virulent than the others.

Identification of anastomosis group of Rhizoctonia solani, the causal agent of seed rot and damping-off of bean in Iran.

Bean is one of the major crops in Iran. Seed rot and damping-off caused by Rhizoctonia solani is the most important disease of bean. In this research, infected roots and seedlings of beans were collected from different fields of Tehran Province. The samples were sterilized with 10% sodium hypochloride (5% stock) and incubated on PDA surface in petri-dishes. The purified fungi kept on filter paper and identified, pathogenicity test of R. solani was carried out on 2 cultivars of bean (red bean cv. Naz and white bean cv. Dehghan) and it determined. For identification of the anastomosis groups, the discs of cultured media with 5 mm. diameter of standard AG placed on one side of microscopic slides covered with water agar (2%) of 1 mm. thick and the isolates of the fungus on another side of slide about 2 cm away from each other. Experiment carried out in 4 replications. The cultures were incubated in 25 +/- 1 degrees C incubator for 24 hours, then the mycelial contact stained with lactophenol, cotton blue and hyphal anastomosis looked for under the light microscope with 10 x 40 and 10 x 100 magnifications. As a result, anastomosis groups: AG4, AG4HGII, AG2-2-2B and AG6 determined, frequency of these groups were 64, 18, 2, 16%, respectively. The group AG6 and subgroups AG4HGII and AG2-2-2B are introduced as new anastomosis groups on bean in Iran.