Fifty Years of Balkan Endemic Nephropathy: Challenges of Study Using Epidemiological Method

Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial disease associated with urothelial cancer, which affects people living in the alluvial plains along the tributaries of the Danube River. Challenges of studying BEN using the epidemiological method are multiple. The natural history from exposure to occurrence of the disease may take many years. The early stages of BEN are not easily detectable clinically, as the disease is asymptomatic until a significant decline in function occurs, and even then symptoms are usually non-specific. The natural history of BEN is complex, possibly with multiple risk factors operating both at the stage of initiation of renal damage and in its progression. In BEN, genetic susceptibility is due to multiple genes of small effects, gene-gene interactions, and gene-environment interactions of complex nature that are difficult to assess with current study designs. BEN is now kidney disease of the old people, and many risk factors for disease such as smoking, alcohol consumption, obesity, and diabetes could contribute to the kidney damage. Evidence is presented that environmental rather than genetic factors play a decisive role in the etiopathogenesis of BEN. Aristolochic acid, described as a culprit of BEN in 1959, is confirmed in 2007 by the molecular biology methods. Mycotoxins and polycyclic aromatic hydrocarbons, leached from lignites and found in the vicinity of endemic settlements, deserve further investigation. Despite advances in understanding the epidemiology of BEN, more research is needed on the patterns of BEN over time and between places, and on identifying the contributions of modifiable risk factors in initiating and hastening progression of BEN in order to improve the scope for preventing BEN. Primary prevention is still at the beginning. Knowledge accumulated in the fifty years of BEN research and new data about prevention and treatment of chronic kidney disease reveal several effective methods in secondary and tertiary prevention of BEN. Genetic epidemiology could establish the relative size of the genetic effect in relation to other sources of variation in disease risk (i.e., environmental effects such as intrauterine environment, physical and chemical effects, as well as behavioral and social aspects). Public health authorities in the several countries having aristolochic acid nephropathy should take immediate measures for reducing dietary exposure of residents to Aristolochia.     

Ocular and systemic factors associated with glaucoma in chronic kidney disease patients

The goal of this study was to examine, the relationship between chronic kidney disease (CKD) and glaucomatous optic disc neuropathy in a cohort of patients from the south-east Serbia and to determine whether limited screening for glaucoma in specific subgroups of patients with CKD is reasonable and justifiable. This cross-sectional study included 328 subjects with various stages of CKD. All patients had visited the Outpatient Department of the Nephrology Clinic, Clinical Center Nis, Serbia. All patients underwent routine ophthalmic examinations. Glaucoma diagnosis based on elevated intraocular pressure (IOP), the presence of excavation of the optic nerve head (C/D ratio), and characteristic glaucomatous visual field loss (MD—mean deviation, PSD—pattern standard deviation). CKD was defined as kidney damage or glomerular filtration rate (GFR) of <60 ml/min/1.73 m² for >3 months. A total number of 328 CKD patients, 33 (10.1 %) with primary open angle glaucoma and 28 (8.5 %) with ocular hypertension (OH), were included in the study. Patients with CKD and glaucoma had significantly higher mean values of C/D ratio (0.59), visual field mean deviations (dB)—MD (p < 0.001), and visual field pattern standard deviations (dB)—PSD (p < 0.001) than patients with CKD and OH. Stepwise multivariate linear regression analysis confirmed that the most significant factors related to IOP are age (p < 0.05), AHT (p = 0.01), and eGFR (p = 0.001). Multivariate regression analysis also confirmed that the most significant factors related to cup-to-disc ratio are number of years of smoking (p < 0.05), AHT, and sCr (p < 0.01). In conclusion, the prevalence of glaucoma among CKD patients in the cohort from south-east Serbia is 10.1 %. Patients with CKD and glaucoma, eGFR and current cigarette smoking are associated with IOP level, MD, and PSD of visual field and C/D ratio.     

Drug seeking behavior

CONCEPT: Drug seeking behavior (DSB) is often mixed in illicit drug diversion confounding legitimate attempts to control acute and chronic pain. OBJECTIVE: To review the literature of acute and chronic pain control against the medical and legal context of DSB. DESIGN: Retrospective literature review from National Library of Medical Computerized Data Base 1990--2004. PATIENTS: Preference to human prospective on retrospective clinical trials. RESULTS: Drug use and abuse have significant adverse consequences. Pain control is desirable and necessary with chronic pain syndromes more prone to DSB. This behavior can be accurately profiled and information used to assist recovery. CONCLUSION: It is desirable to address DSB stressing acceptance and a multidisciplinary approach to recovery.     

Wall tension is a potent negative regulator of in vivo thrombomodulin expression

Thrombomodulin (TM), a key component of the anticoagulant protein C pathway, is a major contributor to vascular thromboresistance. We previously found that TM protein expression is dramatically reduced in autologous vein grafts during the first two weeks after implantation, coincident to a local inflammatory response, and remains suppressed for at least 6 weeks. To determine the proximate cause of TM loss, in vivo gene expression was quantified by real-time PCR. TM gene expression in vein grafts declined >85% during the first postoperative week and remained suppressed >55% at 6 weeks, accounting for the observed changes in protein expression. The effects of vein graft inflammation were evaluated in animals rendered leukopenic with vinblastine before graft implantation. Abrogating the local inflammatory response affected neither TM protein nor gene expression. To determine how hemodynamic forces might modulate TM expression, the surgical protocol was modified to alter blood flow and pressure-induced vessel distension. TM protein and gene expression did not correlate to changes in shear stress but highly correlated to changes in wall tension, both acutely and over time. We conclude that the primary stimulus for altered TM expression in vein grafts is the exposure to arterial pressure. Furthermore, these data identify strain as a novel and important pathway for in vivo TM gene regulation.