Hyperleptinemia Is a Risk Factor for the Development of Central Arterial Stiffness in Kidney Transplant Patients.

BACKGROUND: Arterial stiffness could cause adverse outcomes in kidney transplant (KT) patients. Leptin has a role in influencing vascular smooth muscle that may contribute to atherosclerosis. The aim of this study was to evaluate the relationship between fasting serum leptin concentration and carotid-femoral pulse wave velocity (cfPWV) in KT patients. MATERIALS AND METHODS: Fasting blood samples were obtained from 55 KT patients and 65 subjects from the outpatient department were enrolled as the control group. The cfPWV values of >10 m/s were used to define as the high arterial stiffness group and <10 m/s as the low arterial stiffness group. The predictive ability of leptin for arterial stiffness of KT was assessed using receiver operating characteristic (ROC) curve and multivariate logistic regression analyses. RESULTS: Kidney transplant patients had lower hemoglobin, but higher blood urea nitrogen, creatinine, total cholesterol, diastolic blood pressure, intact parathyroid hormone levels, and leptin levels than controls. Although cfPWV levels were higher in KT patients, there is no difference of cfPWV levels between KT patients and control (P = .595). Fifteen KT patients (27.3%) were defined in the high arterial stiffness group, and serum leptin level was higher in the high arterial stiffness group compared with the low arterial stiffness group in KT patients (P < .001). Multivariate logistic regression analysis showed that leptin (odds ratio: 1.044, 95% confidence interval [CI]: 1.016-1.072, P = .002) was an independent predictor of arterial stiffness in KT patients. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve predicting arterial stiffness in KT patients were 73.33%, 87.5%, 68.7%, 89.7%, and 0.828 (95% CI: 0.703-0.917, P < .001), and the leptin cut-off value was 74.14 ng/mL. CONCLUSION: Serum fasting leptin level could predict the development of central arterial stiffness of KT patients.

Diagnostic performance of serum cystatin C and serum creatinine in the prediction of chronic kidney disease in renal transplant recipients.

BACKGROUND: Chronic kidney disease (CKD) has adverse impacts on mortality and morbidity of renal transplant recipients. Serum cystatin C (sCysC) is a novel marker in predicting the CKD. We therefore compare sCysC and serum creatinine (sCr) with the aim of improving the detection of CKD in renal transplant recipients. METHODS: We enrolled 106 renal transplant recipients and estimated glomerular filtration rates (GFR) using the Cockcroft-Gault (GFR(CG)) and the abbreviated Modification of Diet in Renal Disease (GFR(aMDRD)) formulae. We defined CKD as the presence of structural or functional kidney damage, irrespective of the diagnosis. Comparisons of sCysC and sCr in detecting CKD were analyzed. RESULTS: sCysC correlates with sCr significantly (r = 0.87; P < .001). The receiver operating characteristic curve demonstrates that sCysC has a better specificity and area under the curve, but less sensitivity than sCr in predicting CKD in renal transplant recipients if GFR is estimated by GFR(CG). Additionally, if GFR was estimated by GFR(aMDRD), the role of sCysC or sCr in prediction of CKD was comparable. CONCLUSION: sCysC may be better than sCr to detect CKD in renal transplant recipients using the GFR(CG).

Analysis of gene expression in Treponema denticola with differential display polymerase chain reaction.

Treponema denticola is an oral spirochete associated with the periodontal diseases. A great deal of the molecular components of T. denticola will be learned soon since its genome sequence project is on the way. One of the most important works after genome sequence is to analyze the function of these genes and their regulation. However, like many other oral pathogens, there are currently a very limited number of molecular and genetic tools available to study gene expression in T. denticola. In this article, we describe a method of adapting differential display polymerase chain reaction (ddPCR) for use in the T. denticola system. To test for effectiveness of this protocol, we used three different temperature conditions, 4 degrees C, 25 degrees C and 42 degrees C, to test for differential gene expression. With various ddPCR conditions, we found a number of genes that were expressed differentially. Some of these differentially expressed genes were cloned and sequenced and found to be homologous with the known temperature-regulated genes, including HtrA. The study indicates that the ddPCR method can be effectively used in T. denticola for analyzing gene expression under various conditions.

Population density-dependent regulation of the Bradyrhizobium japonicum nodulation genes.

The nodulation genes of Bradyrhizobium japonicum are essential for infection and establishment of a nitrogen-fixing symbiosis. Here, we demonstrate that plant-produced isoflavones induce nodulation gene expression in a population density-dependent fashion. Nodulation gene induction is highest at a low population density and significantly reduced in more dense cultures. A quorum signal molecule in the conditioned medium of B. japonicum cultures mediates this repression. Repression in response to the quorum signal results from the induction of NolA which, in turn, induces NodD2 leading to inhibition of nod gene expression. Consistent with this, nolA-lacZ and nodD2-lacZ expression increased with increasing population density. Unlike the wild type, the ability to induce nodY-lacZ expression did not decline with population density in a NolA mutant. Normally, nod gene expression is repressed in planta (i.e. within nodules). However, expression of a nodY-GUS fusion was not repressed in a NolA mutant, suggesting that quorum-sensing control may mediate in planta repression of the nod genes. Addition of conditioned medium to cultures significantly reduced nod gene expression. Treatment of inoculant cultures with conditioned medium also reduced the ability of B. japonicum to nodulate soybean plants.