Antibacterial Activity of Pharmaceutical-Grade Rose Bengal: An Application of a Synthetic Dye in Antibacterial Therapies.

Rose bengal has been used in the diagnosis of ophthalmic disorders and liver function, and has been studied for the treatment of solid tumor cancers. To date, the antibacterial activity of rose bengal has been sporadically reported; however, these data have been generated with a commercial grade of rose bengal, which contains major uncontrolled impurities generated by the manufacturing process (80-95% dye content). A high-purity form of rose bengal formulation (HP-RBf, >99.5% dye content) kills a battery of Gram-positive bacteria, including drug-resistant strains at low concentrations (0.01-3.13 µg/mL) under fluorescent, LED, and natural light in a few minutes. Significantly, HP-RBf effectively eradicates Gram-positive bacterial biofilms. The frequency that Gram-positive bacteria spontaneously developed resistance to HP-RB is extremely low (less than 1 × 10-13). Toxicity data obtained through our research programs indicate that HP-RB is feasible as an anti-infective drug for the treatment of skin and soft tissue infections (SSTIs) involving multidrug-resistant (MDR) microbial invasion of the skin, and for eradicating biofilms. This article summarizes the antibacterial activity of pharmaceutical-grade rose bengal, HP-RB, against Gram-positive bacteria, its cytotoxicity against skin cells under illumination conditions, and mechanistic insights into rose bengal's bactericidal activity under dark conditions.

Comparison of Prescribed and Measured Dialysate Sodium: A Quality Improvement Project.

BACKGROUND: There is controversy regarding the optimal dialysate sodium concentration for hemodialysis patients. Dialysate sodium concentrations of 134 to 138 mEq/L may decrease interdialytic weight gain and improve hypertension control, whereas a higher dialysate sodium concentration may offer protection to patients with low serum sodium concentrations and hypotension. We conducted a quality improvement project to explore the hypothesis that prescribed and delivered dialysate sodium concentrations may differ significantly. STUDY DESIGN: Cross-sectional quality improvement project. SETTING & PARTICIPANTS: 333 hemodialysis treatments in 4 facilities operated by Dialysis Clinic, Inc. QUALITY IMPROVEMENT PLAN: Measure dialysate sodium to assess the relationships of prescribed and measured dialysate sodium concentrations. OUTCOMES: Magnitude of differences between prescribed and measured dialysate sodium concentrations. MEASUREMENTS: Dialysate sodium measured pre- and late dialysis. RESULTS: The least square mean of the difference between prescribed minus measured dialysate sodium concentration was -2.48 (95% CI, -2.87 to -2.10) mEq/L. Clinics with a greater number of different dialysate sodium prescriptions (clinic 1, n=8; clinic 2, n=7) and that mixed dialysate concentrates on site had greater differences between prescribed and measured dialysate sodium concentrations. Overall, 57% of measured dialysate sodium concentrations were within ±2 mEq/L of the prescribed dialysate sodium concentration. Differences were greater at higher prescribed dialysate sodium concentrations. LIMITATIONS: We only studied 4 facilities and dialysate delivery machines from 2 manufacturers. Because clinics using premixed dialysate used the same type of machine, we were unable to independently assess the impact of these factors. Pressures in dialysate delivery loops were not measured. CONCLUSIONS: There were significant differences between prescribed and measured dialysate sodium concentrations. This may have beneficial or deleterious effects on clinical outcomes, as well as confound results from studies assessing the relationships of dialysate sodium concentrations to outcomes. Additional studies are needed to identify factors that contribute to differences between prescribed and measured dialysate sodium concentrations. Quality assurance and performance improvement (QAPI) programs should include measurements of dialysate sodium.

Relationship between Health Literacy and Kidney Function.

AIM: Low health literacy (HL) may contribute to poor self-management of chronic kidney disease (CKD) and poor kidney function. This study aimed to assess the relationship between HL and estimated glomerular filtration rate (eGFR). METHODS: A cross-sectional observational study was conducted among consecutive eligible adult patients with CKD stages 1-4 attending an outpatient nephrology clinic. HL was assessed using Newest Vital Sign (NVS). eGFR was estimated using the Modification of Diet in Renal Disease equation. CKD self-management behaviour knowledge was assessed using a study instrument (CKD self-management knowledge (SMKT)). RESULTS: One hundred fifty patients participated in the study (83% participation rate). The prevalence of high likelihood of limited HL was 32.7%. Participants' eGFRs ranged from 17 to 152 mL/min / 1.73 m(2) , with over 80% of the eGFRs below 60 mL/min / 1.73 m(2) . HL was associated with eGFR after controlling for all demographics except age, race and gender (which are included in eGFR equation) (P = 0.05). Every unit increase in NVS score was associated with a 1.9% increase (95% confidence interval = 0 to 3.86%) in eGFR (model R square = 0.23, P = 0.002), which remained significant after controlling for CKD-SMKT (P = 0.05; model R square = 0.28, P < 0.001). The relationship was non-significant after controlling for age, although it remained significant after controlling for other demographics including gender and race. CONCLUSIONS: There is a small but significant association between HL and eGFR. Providers should use HL-tailored communication strategies in CKD patients. Larger multicentre studies are needed to substantiate this relationship.

Immunization in end-stage renal disease: opportunity to improve outcomes.

Infection is the second most common cause of death in patients with end-stage renal disease (ESRD), following cardiovascular causes. Immunization is a fairly simple, but underutilized, strategy for prevention of infectious morbidity and mortality in patients with kidney failure. It is imperative for nephrologists and primary care providers to have an understanding of immunization as an essential component of preventive healthcare measures in this high-risk population. Patients with ESRD represent a unique population due to their immunosuppressed state, dialysis-related exposures and suboptimal response to routine vaccines. While the Advisory Committee on Immunization Practices (ACIP) provides guidelines for vaccination of patients with renal disease against Hepatitis B, influenza and pneumococcal disease, the data on immunization against other commonly preventable infectious diseases are lacking. This article reviews the recent evidence on immunization in the ESRD population and synthesizes the related implications for maximizing prevention of infectious diseases in this high-risk population.

Antibacterial effect of rose bengal against colistin-resistant gram-negative bacteria.

Increasing drug resistance in Gram-negative bacteria presents significant health problems worldwide. Despite notable advances in the development of a new generation of ß-lactams, aminoglycosides, and fluoroquinolones, it remains challenging to treat multi-drug resistant Gram-negative bacterial infections. Colistin (polymyxin E) is one of the most efficacious antibiotics for the treatment of multiple drug-resistant Gram-negative bacteria and has been used clinically as a last-resort option. However, the rapid spread of the transferable gene, mcr-1 which confers colistin resistance by encoding a phosphoethanolamine transferase that modifies lipid A of the bacterial membrane, threatens the efficacy of colistin for the treatment of drug-resistant bacterial infections. Colistin-resistant strains of Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae often reduce their susceptibility to other anti-Gram-negative bacterial agents. Thus, drugs effective against colistin-resistant strains or methods to prevent the acquisition of colistin-resistance during treatment are urgently needed. To perform cell-based screenings of the collected small molecules, we have generated colistin-resistant strains of E. coli, A. baumannii, K. pneumoniae, P. aeruginosa, and S. enterica Typhimurium. In-house MIC assay screenings, we have identified that rose bengal (4,5,6,7-tetrachloro-2',4',5',7'-tetraiodofluorescein) is the only molecule that displays unique bactericidal activity against these strains at low concentrations under illumination conditions. This article reports the antibacterial activity of a pharmaceutical-grade rose bengal against colistin-resistant Gram-negative bacteria.

Awareness, self-management behaviors, health literacy and kidney function relationships in specialty practice.

AIM: To determine the relationship between chronic kidney disease (CKD) awareness (CKD-A), self-management behaviors (CKD-SMB) knowledge, performance of CKD-SMBs, health literacy (HL) and kidney function. METHODS: Participants were eligible patients attending an outpatient nephrology clinic. Participants were administered: Newest Vital Sign to measure HL, CKD self-management knowledge tool (CKD-SMKT) to assess knowledge, past performance of CKD-SMB, CKD-A. Estimated GFR (eGFR) was determined using the MDRD-4 equation. Duration of clinic participation and CKD cause were extracted from medical charts. RESULTS: One-hundred-fifty patients participated in the study. eGFRs ranged from 17-152 mL/min per 1.73 m2. Majority (83%) of respondents had stage 3 or 4 CKD, low HL (63%), and were CKD aware (88%). Approximately 40% (10/25) of patients in stages 1 and 2 and 6.4% (8/125) in stages 3 and 4 were unaware of their CKD. CKD-A differed with stage (P < 0.001) but not by HL level, duration of clinic participation, or CKD cause. Majority of respondents (≥ 90%) correctly answered one or more CKD-SMKT items. Knowledge of one behavior, "controlling blood pressure" differed significantly by CKD-A. CKD-A was associated with past performance of two CKD-SMBs, "controlling blood pressure" (P = 0.02), and "keeping healthy body weight" (P = 0.01). Adjusted multivariate analyses between CKD-A and: (1) HL; and (2) CKD-SMB knowledge were non-significant. However, there was a significant relationship between CKD-A and kidney function after controlling for demographics, HL, and CKD-SMB (P < 0.05). CONCLUSION: CKD-A is not associated with HL, or better CKD-SMBs. CKD-A is significantly associated with kidney function and substantially lower eGFR, suggesting the need for focused patient education in CKD stages 1.

Prevalence of CKD, Diabetes, and Hypertension in Rural Tanzania.

INTRODUCTION: Chronic kidney disease (CKD), diabetes, and hypertension play a disproportionate role in the growing public health challenge posed by noncommunicable diseases (NCDs) in East Africa. The impact of these NCDs may pose the greatest challenge in rural areas with limited screening and treatment facilities, although precise prevalence estimates of these conditions in rural Tanzania are lacking. METHODS: The prevalence of CKD, diabetes, and hypertension, were estimated from a probability sample of adults (n = 739) residing in 2 communities within Kisarawe, a rural district of Tanzania. Following consent, participants were studied in their homes. Random point-of-care (POC) measures of glycosylated hemoglobin and blood pressure, were obtained. Serum creatinine, drawn at the POC and measured at Muhimbili National University, was used to calculate estimated glomerular filtration rate with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. RESULTS: The median age was 35 years (interquartile range 25-45 years). Overall the pooled prevalence for CKD stages III, IV, and V was 12.4% (95% confidence interval [CI] = 10.2-14.8). Surprisingly, the prevalence of CKD stage V (3.0%; 95% CI = 2.1-4.4) was high among the youngest age group (18-36 years). The prevalence estimates for prehypertension and hypertension were 38.0% (95% CI = 34.6-41.5) and 19.9% (95% CI = 17.1-22.9), respectively. The prevalence estimates for prediabetes and diabetes were 25.7% (95% CI = 22.6-29.1) and 14.8% (95% CI = 12.4-17.6), respectively. CONCLUSION: Although this pilot study had a relatively small sample size, the prevalence estimates for CKD, diabetes, and hypertension were higher than we expected based on previous estimates from Tanzania. CKD was not significantly associated with diabetes or hypertension, suggesting the possibility of an alternative causality.

Chronic Nephropathy from Dietary Hyperoxaluria: Sustained Improvement of Renal Function after Dietary Intervention.

A 56-year-old man with stable chronic kidney disease (CKD) for two years following a single episode of calcium oxalate urolithiasis developed progressive elevation of his serum creatinine concentration. Urinalysis revealed pyuria and white cell casts, a few red blood cells, minimal proteinuria, and no crystals. Urine culture was sterile. Gallium scintigraphy was consistent with interstitial nephritis. Proton pump inhibitor intake was discontinued, and a short course of oral corticosteroids was initiated. Percutaneous kidney biopsy, performed because of the continued deterioration of renal function to a minimum estimated glomerular filtration rate (eGFR) value of 15 mL/min per 1.73 m2 and persistent pyuria, revealed deposition of oxalate crystals in the tubules and interstitium, pronounced tubular changes, and interstitial nephritis and fibrosis. Urinary oxalate excretion was very high, in the range usually associated with primary hyperoxaluria. However, investigations for primary or enteric hyperoxaluria were negative. He reported a diet based on various nuts high in oxalate content. Estimated oxalate content in the diet was, for years, approximately four times higher than that in the average American diet. The institution of a diet low in oxalates resulted in the rapid normalization of urinary oxalate excretion and urinary sediment and in the slow, continuous improvement of renal function to near normal levels (eGFR 59 mL/min/1.73 m2) before his death from a brain malignancy 3.5 years later. The manifestations of nephropathy secondary to dietary hyperoxaluria, including the urine findings, can be indistinguishable from other types of interstitial nephritis. The diagnosis of dietary hyperoxaluria requires careful dietary history and a kidney biopsy. Identifying dietary hyperoxaluria as the cause of CKD is important because the decrease in dietary oxalate intake without any other measures can lead to sustained improvement in renal function.

Epidemiology of hypertension in CKD.

Both hypertension (HTN) and CKD are serious interrelated global public health problems. Nearly 30% and 15% of US adults have HTN and CKD, respectively. Because HTN may cause or result from CKD, HTN prevalence is higher and control more difficult with worse kidney function. Etiology of CKD, presence and degree of albuminuria, and genetic factors all influence HTN severity and prevalence. In addition, socioeconomic and lifestyle factors influence HTN prevalence and control. There are racial and ethnic disparities in the prevalence, treatment, risks, and outcomes of HTN in patients with CKD. Control of blood pressure (BP) in Hispanic and African Americans with CKD is worse than it is whites. There are disparities in the patterns of treatment and rates of progression of CKD in patients with HTN. The presence and severity of CKD increase treatment resistance. HTN is also extremely prevalent in patients receiving hemodialysis, and optimal targets for BP control are being elucidated. Although the awareness, treatment, and control of HTN in CKD patients is improving, control of BP in patients at all stages of CKD remains suboptimal.

Design of the Blood Pressure Goals in Dialysis pilot study.

BACKGROUND: Cardiovascular disease (CVD) is markedly increased among hemodialysis (HD) patients. Optimizing blood pressure (BP) among HD patients may present an important opportunity to reduce the disparity in CVD rates between HD patients and the general population. The optimal target predialysis systolic BP (SBP) among HD patients is unknown. Current international guidelines, calling for a predialysis SBP < 140 mm Hg, are based on the opinion and extrapolation from the general population. Existing randomized controlled trials (RCTs) were small and did not include prespecified BP targets. METHODS: The authors described the design of the Blood Pressure in Dialysis (BID) Study, a pilot, multicenter RCT where HD patients are randomized to either a target-standardized predialysis SBP of 110 to 140 mm Hg or 155 to 165 mm Hg. This is the first study to randomize HD patients to 2 different SBP targets. RESULTS: Primary outcomes are feasibility and safety. Feasibility parameters include recruitment and retention rates, adherence with prescribed BP measurements and achievement and maintenance of selected BP targets. Safety parameters include rates of hypotension and other adverse and serious adverse events. The authors obtained preliminary data on changes in left ventricular mass, aortic pulse wave velocity, vascular access thromboses and health-related quality of life across study arms, which may be the secondary outcomes in the full-scale study. CONCLUSIONS: The data acquired in the pilot RCT will determine the feasibility and safety and inform the design of a full-scale trial, powered for hard outcomes, which may require 2000 participants.

Nephropathy in dietary hyperoxaluria: A potentially preventable acute or chronic kidney disease.

Hyperoxaluria can cause not only nephrolithiasis and nephrocalcinosis, but also renal parenchymal disease histologically characterized by deposition of calcium oxalate crystals throughout the renal parenchyma, profound tubular damage and interstitial inflammation and fibrosis. Hyperoxaluric nephropathy presents clinically as acute or chronic renal failure that may progress to end-stage renal disease (ESRD). This sequence of events, well recognized in the past in primary and enteric hyperoxalurias, has also been documented in a few cases of dietary hyperoxaluria. Estimates of oxalate intake in patients with chronic dietary hyperoxaluria who developed chronic kidney disease or ESRD were comparable to the reported average oxalate content of the diets of certain populations worldwide, thus raising the question whether dietary hyperoxaluria is a primary cause of ESRD in these regions. Studies addressing this question have the potential of improving population health and should be undertaken, alongside ongoing studies which are yielding fresh insights into the mechanisms of intestinal absorption and renal excretion of oxalate, and into the mechanisms of development of oxalate-induced renal parenchymal disease. Novel preventive and therapeutic strategies for treating all types of hyperoxaluria are expected to develop from these studies.