Analysis of the Brinkman-Forchheimer equations with slip boundary conditions

In this work, we study the Brinkman-Forchheimer equations driven under slip boundary conditions of friction type. We prove the existence and uniqueness of weak solutions by means of regularization combined with the Faedo-Galerkin approach. Next we discuss the continuity of the solution with respect to Brinkman's and Forchheimer's coefficients. Finally, we show that the weak solution of the corresponding stationary problem is stable

Systolic and diastolic hypertension among patients on hemodialysis: Musings on volume overload, arterial stiffness and erythropoietin

Hypertension among patients on hemodialysis is predominantly systolic (either isolated or combined with diastolic hypertension), whereas the scenario of isolated diastolic hypertension is rare and more common in younger patients. Uncontrolled hypertension that persists despite aggressive antihypertensive drug therapy is a reflection of the volume overload that is a prominent mediator of systolic and diastolic BP elevation. Clinical-trial evidence supports the notion that dry-weight probing is an effective strategy to improve BP control, even when overt clinical signs and symptoms of volume overload are not present. Accelerated arterial stiffness influences the patterns and rhythms of interdialytic ambulatory BP and is a major determinant of isolated systolic hypertension in hemodialysis. Post-hoc analyses of the Hypertension in Hemodialysis patients treated with Atenolol or Lisinopril (HDPAL) trial, however, suggest that arterial stiffness does not make hypertension more resistant to therapy and is unable to predict the treatment-induced improvement in left ventricular hypertrophy. A combined strategy of sodium restriction, dry-weight adjustment and antihypertensive medication use was effective in improving ambulatory BP control regardless of the severity of underlying arteriosclerosis in HDPAL. Other non-volume-dependent mechanisms, such as erythropoietin use, appear to be also important contributors and should be taken into consideration, particularly in younger hemodialysis patients with diastolic hypertension. In this article, we explore the role of volume overload, arterial stiffness and erythropoietin use as causes of systolic versus diastolic hypertension in patients on hemodialysis. We conclude with clinical practice recommendations and with a call for a “volume-first” approach when managing hemodialysis hypertension

Role of Nrf2 Dysfunction in Uremia-Associated Intestinal Inflammation and Epithelial Barrier Disruption

Aims: To study the expression profile of inflammatory and tight junction proteins in the colon from CKD rats compared to healthy controls, and demonstrate the role of Nrf2 (transcription factor nuclear factor erythroid 2-related factor 2) using a potent Nrf2 activator

Low-Level Lead Exposure, Metabolic Syndrome, and Heart Rate Variability: The VA Normative Aging Study

BACKGROUND: Altered heart rate variability (HRV), a marker of poor cardiac autonomic function, has been associated with sudden cardiac death and heart failure. OBJECTIVE: We examined the association of low-level lead exposure measured in bone by K-X-ray fluorescence with alterations in HRV, and whether metabolic syndrome (MetS) or its individual components modify those associations. METHODS: HRV measures [power in high-frequency (HF(norm)) and low-frequency (LF(norm)) in normalized units, and LF/HF] were taken among 413 elderly men from the Normative Aging Study. MetS was defined as subjects having three or more of the following criteria: abdominal obesity, hypertriglyceridemia, low high-density lipoprotein, high blood pressure, and high fasting glucose. RESULTS: Of the subjects, 32% were identified as having MetS. Inverse but nonstatistically significant associations of both tibia and patella lead levels with HF(norm) and nonstatistically significant positive relations with LF(norm) and LF/HF were found in the entire cohort. There was a graded, statistically significant reduction in HF(norm) and increases in LF(norm) and LF/HF in association with an increase in patella lead as the number of metabolic abnormalities increased. We also observed that higher patella lead was consistently associated with lower HF(norm) and higher LF(norm) and LF/HF among subjects with MetS or its individual components. No statistically significant interaction between MetS and tibia lead was observed. CONCLUSION: The results suggest that elderly men with MetS were more susceptible to autonomic dysfunction in association with chronic lead exposure as measured in patella. The modification by MetS is consistent with a role for oxidative stress in lead toxicity on the cardiovascular system

Increased Lead Biomarker Levels Are Associated with Changes in Hormonal Response to Stress in Occupationally Exposed Male Participants

Background: Lead (Pb) exposure has been associated with a host of pathological conditions in humans. In rodents Pb exposure has been shown to alter the hypothalamic–pituitary–adrenal (HPA) axis function

Recommendations for Medical Management of Adult Lead Exposure

Research conducted in recent years has increased public health concern about the toxicity of lead at low dose and has supported a reappraisal of the levels of lead exposure that may be safely tolerated in the workplace. In this article, which appears as part of a mini-monograph on adult lead exposure, we summarize a body of published literature that establishes the potential for hypertension, effects on renal function, cognitive dysfunction, and adverse female reproductive outcome in adults with whole-blood lead concentrations < 40 μg/dL. Based on this literature, and our collective experience in evaluating lead-exposed adults, we recommend that individuals be removed from occupational lead exposure if a single blood lead concentration exceeds 30 μg/dL or if two successive blood lead concentrations measured over a 4-week interval are ≥ 20 μg/dL. Removal of individuals from lead exposure should be considered to avoid long-term risk to health if exposure control measures over an extended period do not decrease blood lead concentrations to < 10 μg/dL or if selected medical conditions exist that would increase the risk of continued exposure. Recommended medical surveillance for all lead-exposed workers should include quarterly blood lead measurements for individuals with blood lead concentrations between 10 and 19 μg/dL, and semiannual blood lead measurements when sustained blood lead concentrations are < 10 μg/dL. It is advisable for pregnant women to avoid occupational or avocational lead exposure that would result in blood lead concentrations > 5 μg/dL. Chelation may have an adjunctive role in the medical management of highly exposed adults with symptomatic lead intoxication but is not recommended for asymptomatic individuals with low blood lead concentrations

Telomere shortening occurs in Asian Indian Type 2 diabetic patients

Aim: Telomere shortening has been reported in several diseases including atherosclerosis and Type 1 diabetes. Asian Indians have an increased predilection for Type 2 diabetes and premature coronary artery disease. The aim of this study was to determine whether telomeric shortening occurs in Asian Indian Type 2 diabetic patients. Methods: Using Southern‐blot analysis we determined mean terminal restriction fragment (TRF) length, a measure of average telomere size, in leucocyte DNA. Type 2 diabetic patients without any diabetes‐related complications (n = 40) and age‐ and sex‐matched control non‐diabetic subjects (n = 40) were selected from the Chennai Urban Rural Epidemiology Study (CURES). Plasma level of malondialdehyde (MDA), a marker of lipid peroxidation, was measured by TBARS (thiobarbituric acid reactive substances) using a fluorescence method. Results: Mean (± SE) TRF lengths of the Type 2 diabetic patients (6.01 ± 0.2 kb) were significantly shorter than those of the control subjects (9.11 ± 0.6 kb) (P = 0.0001). Among the biochemical parameters, only levels of TBARS showed a negative correlation with shortened telomeres in the diabetic subjects (r = −0.36; P = 0.02). However, telomere lengths were negatively correlated with insulin resistance (HOMA‐IR) (r = −0.4; P = 0.01) and age (r = −0.3; P = 0.058) and positively correlated with HDL levels (r = 0.4; P = 0.01) in the control subjects. Multiple linear regression (MLR) analysis revealed diabetes to be significantly (P < 0.0001) associated with shortening of TRF lengths. Conclusions: Telomere shortening occurs in Asian Indian Type 2 diabetic patients