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Biomedical subjects

P D Light

Publications and source records attributed to P D Light.

13 recordsLinked to original sources
PubMed2000

Within-center correlation in dialysis adequacy.

The purpose of this study was to determine whether patients with end stage renal disease treated with hemodialysis were correlated in dialysis adequacy within facilities. This was a retrospective analysis of dialysis adequacy based on urea reduction ratio (URR) values from 6969 patients dialyzed at 154 facilities. The within-center correlation was quantified using the between-center variation and the parameter p that was derived using ANOVA tables and mixed effects models. The variation in center means for URR was wider than expected for independent observations (52.9-76.1 versus 60.7-73.8, respectively). Furthermore, there was a significant within-center correlation in URR values across all facilities (p = 0.136, P<0.0001), which persisted after adjusting for patient specific covariates, facility characteristics, and state. In conclusion, there was a substantial within-center correlation in dialysis adequacy that reflected important center effects on the outcome of ESRD patients.

Blood Urea Nitrogen↗
PubMed1999

Significance of serum creatinine values in new end-stage renal disease patients.

The appropriate use of serum creatinine level as a surrogate for time in the course of renal failure when dialysis commences requires it to be a significant predictor of mortality in incident patients with end-stage renal disease (ESRD). This study evaluated factors that account for variations in creatinine level before the initiation of dialysis and whether incident creatinine level after controlling for these factors was a risk factor for mortality. This is a retrospective cohort study of patients from Maryland and Virginia who initiated dialysis between April 1, 1995, and December 31, 1996, with data ascertained from the Health Care Financing Administration Form 2728. Multivariate models were used to evaluate both the factors that predict incident serum creatinine level and the association between creatinine level and mortality. There were 5, 388 patients followed up for an average of 23.6 +/- 0.2 months. Mean creatinine level was 9.2 +/- 0.1 mg/dL, with case-mix factors most predictive of serum creatinine level and accounting for 9% of its variance. Hematocrit and blood urea nitrogen levels as additional surrogates for progression of renal disease accounted for 7.4% of the variance, whereas the nutritional parameters, body mass index, and albumin level only explained an additional 1% of the total variance in creatinine level. Creatinine level was inversely correlated with mortality risk, and this relationship was sustained both with transformation into an estimated glomerular filtration rate and multivariate adjustment for confounders (relative risk = 0. 96; P < 0.0001). Creatinine values from an incident ESRD population have a weak relationship with the timing of dialysis initiation but represent a strong measure of health status.

Adult↗
PubMed1998

Colonization with vancomycin-resistant enterococci in chronic hemodialysis patients.

Vancomycin-resistant enterococcus (VRE) has been identified with increased frequency in dialysis populations, but the risk factors for VRE colonization are not well defined in hemodialysis patients. Patients from a university-affiliated outpatient dialysis center had surveillance stool or rectal cultures for VRE during April 1994 and January 1996. The combined cohort of 168 patients was followed-up for all-cause mortality, subsequent hospitalization, and VRE infection. Demographic and risk factor information, including age, gender, race, diabetes, coronary artery disease (CAD), and human immunodeficiency virus (HIV) infection, were collected on all patients. Sixteen patients had surveillance cultures grow vancomycin-resistant Enterococcus faecium or E faecalis (VREF), and nine additional patients had clinical cultures positive for VREF. The median follow-up time for patients with positive surveillance or clinical cultures for VREF was 421 days versus 423 days for those without VREF. Patients with positive surveillance cultures for VREF had less time on hemodialysis before screening (median = 207 days v 822 days; P < 0.01), and more hospitalization in the year before screening (median = 19 days v 3 days, P < 0.01) compared with those without VREF. Patients with VREF colonization were more likely to develop infection with VREF (25% v 1%, P < 0.01) than those without VREF colonization. However, adjusting for age, diabetes, coronary artery disease, and acquired immune deficiency syndrome (AIDS) using Cox-proportional hazards models, the presence of VREF on screening culture was not associated with increased risk of death (RR = 1.1, P = 0.86). Thus after adjusting for other comorbidities, VREF colonization was not associated with increased mortality. Patients with end-stage renal disease (ESRD) on hemodialysis who are hospitalized are more likely to have VREF, but longer duration on hemodialysis was not associated with presence of this organism. This suggests that VRE transmission occurs predominantly in the inpatient setting.

Adult↗
PubMed1997

Hemodialysis-related amyloidosis of the sternoclavicular joint.

Amyloid deposition is an important cause of morbidity in long-term hemodialysis patients, but it has rarely been reported in the sternoclavicular joint, where the clinical picture may be consistent with an infection. The imaging features of one case are discussed. Biopsy with specific staining for the beta-2 microglobulin component of amyloid should be considered in the work up of a lesion of this joint in this clinical setting.

Amyloidosis↗
PubMed1986

Bacterial colonization of Hemasite access devices.

Vascular access ports (Hemasites) were recovered from patients in whom they had become foci of infection and were examined according to microbiologic and morphologic techniques. All were covered on their extraluminal surfaces by well-developed biofilms consisting of host material and bacteria and their extracellular products. One Hemasite from which Staphylococcus aureus and Streptococcus faecalis were cultured was covered by a biofilm that consisted of coccoid bacterial cells and occasional fungal cells. Another Hemasite from which Proteus mirabilis was cultured was covered by a polymicrobial biofilm consisting of at least six morphologically distinct bacterial types and their extracellular products. This direct observation of the biofilm mode of bacterial growth on these devices suggests that the colonizing organisms will not be completely recovered by routine microbiologic techniques and that bacteria in the biofilm will tend to resist both host clearance mechanisms and antibiotic therapy. Removal of the device, with its accretion of bacterial biofilm, should allow the resolution of the associated infection.

Arteriovenous Shunt, Surgical↗
PubMed1985

Enzyme-linked immunosorbent assay for serum renal tubular antigen in kidney transplant patients.

A mouse monoclonal antibody, specific for binding with the epithelial surface antigen in human renal proximal tubules, was produced by hybridoma culture. Using this antibody, an enzyme-linked immunosorbent assay was developed to measure the human renal tubular epithelial antigen (HRTE) concentrations in serum samples from 25 normal subjects and 66 consecutive renal allograft recipients. In 46 patients treated with azathioprine and prednisone, serum HRTE was elevated more than two-fold in 56 of 62 rejection episodes 2-5 days before the clinical diagnosis was made. Of the 56 rejection episodes, the antigen level fell to baseline after treatment in 44 steroid-responsive episodes, but it remained elevated in 8 steroid-resistant rejections, and it became undetectable 3-4 days after the initial elevation in 4 episodes in which allografts were lost to rejection. In 20 patients treated with cyclosporine and prednisone, all 25 rejection episodes demonstrated a greater than two-fold increase of serum HRTE 1-6 days prior to the diagnosis of rejection. The antigen level fell to baseline in 23 reversible rejection episodes, however serum HRTE remained elevated in 2 steroid-resistant patients whose grafts were lost to rejection. Cyclosporine nephrotoxicity without rejection was confirmed in 6 episodes, each of which demonstrated a more than two-fold increase in HRTE 2-4 days before toxicity was diagnosed. When the cyclosporine dose was reduced, the antigen level decreased as the serum creatinine declined. Serial determinations of serum HRTE in renal transplant recipients can provide valuable information for the early diagnosis and management of allograft rejection and cyclosporine nephrotoxicity.

Animals↗
PubMed1985

Alternative vascular access in patients lacking veins for standard arteriovenous fistulae.

We have evaluated the Hickman catheter and Hemasite access port as means to re-establish vascular access in patients lacking veins for conventional arteriovenous fistulae. The Hemasite is more convenient, but is also costlier, requires more surgical skill to implant, and is more frequently associated with major infections. One-half of the Hemasites have failed because of infection. As a result, the long-term survival rate is lower for Hemasite graft, although the differences noted have not yet reached statistical levels of significance.

Adult↗
PubMed1983

The therapeutic efficacy of hemodialysis in schizophrenia.

Prompted by previous reports of substantial clinical improvement in most schizophrenic patients given hemodialysis for their psychiatric condition, we studied the efficacy of hemodialysis in 15 schizophrenic outpatients, under double-blind, controlled conditions. The patients were randomly assigned to either a real-sham or sham-real sequence of dialysis treatment. Results of repeated measurement and other analyses of data on symptoms and behavior that were collected before study treatment, at crossover, and at the end of treatment revealed no difference between the effects of real and sham dialysis. These results provide important experimental evidence of the lack of therapeutic efficacy of hemodialysis in schizophrenia.

Adolescent↗
PubMed1983

Schizophrenia and dialysis.

Open-trial reports of substantial clinical improvement in most schizophrenic patients on hemodialysis for their psychiatric condition prompted the present study to determine the efficacy of hemodialysis under double-blind, controlled conditions. Fifteen schizophrenic outpatients were randomly assigned to either a real-sham or sham-real dialysis treatment sequence. Presented in detailed, graphic form, results of repeated measurement and other analyses of symptom and behavioral data collected initially, at crossover, and at the end of treatment revealed no differential effects between real and sham dialysis. These results provide important experimental evidence of the lack of therapeutic efficacy of hemodialysis in schizophrenia.

Adult↗
PubMed1979

Amyloid deposition in a renal allograft in a case of amyloidosis secondary to rheumatoid arthritis.

A case of amyloidosis secondary to rheumatoid arthritis is presented in which renal transplantation was performed. Five years after transplantation the patient died following an episode of acute pancreatitis. During the intervening period the rheumatoid arthritis was considered quiescent, but his course was marked by several infectious processes caused by unusual organisms. The allograft function remained normal. Apart from renal amyloid the autopsy showed extensive generalized amyloidosis, most marked in vessel walls and endocrine organs. Amyloid deposits were located exclusively in the vessel walls of the transplanted kidney.

Amyloid↗
PubMedDate not supplied

High patency rate of internal arteriovenous fistulae in non-uremic patients with normal veins.

Forearm arteriovenous (AV) fistulae were formed in seventeen patients with normal coagulation parameters as part of a controlled study of the effects of hemodialysis in schizophrenia. The 100% patency rate of AV fistulae in this group of patients compares favorably with the patency rates obtained with similar AV fistulae in renal failure patients, and it is significantly higher than the patency rates obtained for AV fistulae formed to improve venous access in patients with acute leukemia. The results suggest that uremic coagulopathy contributes little to the success of internal AV fistulae. Adequacy of forearm veins is thought to be of greater importance.

Adolescent↗