Association of serum uric acid with graft survival after kidney transplantation: a time-varying analysis.

The association of serum uric acid (UA) with kidney transplant outcomes is uncertain. We examined the predictive value of UA during the first year posttransplant as a time-varying factor for graft survival after adjustment for time-dependent and independent confounding factors. Four hundred and eighty-eight renal allograft recipients transplanted from January 2004 to June 2006 and followed for 41.1 ± 17.7 months were included. Data on UA, estimated glomerular filtration rate (eGFR), tacrolimus level, mycophenolate mofetil (MMF) and prednisone doses, use of allopurinol, angiotensin-converting enzyme-inhibitor/angiotensin-receptor-blocker (ACEi/ARB) and diuretics at 1, 3, 6, 9 and 12 months were collected. Primary endpoint of the study was graft loss, defined as graft failure and death. Cox proportional hazard models and generalized estimating equations were used for analysis. UA level was associated with eGFR, gender, retransplantation, decease-donor organ, delayed graft function, diuretics, ACEi/ARB and MMF dose. After adjustment for these confounders, UA was independently associated with increased risk of graft loss (HR: 1.15, p = 0.003; 95% CI: 1.05-1.27). Interestingly, UA interacted with eGFR (HR: 0.996, p < 0.05; 95% CI: 0.993-0.999 for interaction term). Here, we report a significant association between serum UA during first year posttransplant and graft loss, after adjustment for corresponding values of time-varying variables including eGFR, immunosuppressive drug regimen and other confounding factors. Its negative impact seems to be worse with lower eGFR.

The Maryland aggregate pathology index: a deceased donor kidney biopsy scoring system for predicting graft failure.

Despite the common use of diagnostic pretransplant deceased donor kidney biopsy, there is no consensus on the prognostic significance of the pathologic findings. In order to assist clinicians with interpretation we analyzed 371 pretransplant biopsies and correlated the findings with graft failure. Glomerular pathology was assessed with percent glomerulosclerosis (GS), glomerular size and periglomerular fibrosis (PGF); vascular pathology with arterial wall-to-lumen ratio (WLR) and arteriolar hyalinosis and interstitial pathology with measurement of cumulative fibrosis and presence of scar. Using two-thirds of the study population as a model-development cohort, we found that biopsy features independently associated with an increased risk of graft failure were GS > or =15%, interlobular arterial WLR > or =0.5 and the presence of PGF, arteriolar hyalinosis or scar. The Maryland Aggregate Pathology Index (MAPI), was developed from these parameters and validated on the remaining one-third of the population. Five-year actuarial graft survival was 90% for kidneys with MAPI scores between 0 and 7, 63% for scores from 8 to 11 and 53% for scores from 12 to 15 (p < 0.001). We conclude MAPI may help transplant physicians estimate graft survival from the preimplantation biopsy findings, in clinical situations similar to this study population (cold ischemia over 24 h, GS < 25%).

Effect of light source and time on the polymerization of resin cement through ceramic veneers.

PURPOSE: The purpose of this study was to evaluate the efficiency of 3 different light sources to polymerize a light curing resin cement beneath 3 types of porcelain veneer materials. MATERIALS AND METHODS: A conventional halogen light, a plasma arc light, and a high intensity halogen light were used to polymerize resin cement (Variolink II; Ivoclar North America Inc, Amherst, NY) through disks of veneer materials. Equal diameter and thickness disks of feldspathic porcelain (Ceramco II; Ceramco Inc, Burlington, NJ), pressable ceramic (IPS Empress; Ivoclar North America Inc), and aluminous porcelain (Vitadur Alpha; Vident Inc, Brea, CA) were used as an interface between the curing light tips and the light polymerized resin cement. The resin cement/veneer combinations were exposed to 4 different photopolymerization time protocols of 5 seconds, 10 seconds, 15 seconds, and 20 seconds for high intensity light units (Apollo 95E [Dental Medical Diagnostic Systems Inc, Westlake Village, CA] and Kreativ 2000 [Kreativ Inc, San Diego, CA]), and 20 seconds, 40 seconds, 60 seconds, and 80 seconds for conventional halogen light (Optilux; Demetron Research Inc, Danbury, CT). A surface hardness test (Knoop indenter) was used to determine the level of photopolymerization of the resin through the ceramic materials with each of the light sources. The data were analyzed by one-way analysis of variance and a post-hoc Scheffe test (p < .05). RESULTS: The data indicates that the Variolink II Knoop Hardness Number values vary with the light source, the veneer material, and the polymerization time. For a given light and veneer material, Knoop Hardness Number increases with longer polymerization times. The Kreativ light showed statistically significant differences (p < .05) between all test polymerization times. Use of this light required a polymerization time of greater than 20 seconds to reach maximum resin cement hardness. For samples polymerized with the Apollo light, there were statistically significant (p < .05) differences in surface hardness between samples polymerized at all times, except for the 15-second and 20-second times. Samples polymerized with the halogen light showed no statistically significant (p < .05) differences in hardness between polymerization times of 60 seconds and 80 seconds. CONCLUSIONS: High intensity curing lights achieve adequate polymerization of resin cements through veneers in a markedly shorter time period than the conventional halogen light. However, the data in this report indicate that a minimum exposure time of 15 seconds with the Kreativ light and 10 seconds with the Apollo 95E light should be used to polymerize the Variolink II resin, regardless of the composition of the veneer. Conventional halogen lights required a correspondingly greater polymerization time of 60 seconds.

A simplified method for fabrication of a die holder.

A technique is described for fabricating a simple and inexpensive holder for dies to be used during the process of die spacer application.