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Progressive intravascular, interstitial, and alveolar fluid overload underlies the transition from compensated to acutely decompensated heart failure and loop diuretics are the mainstay of treatment. Adverse effects and resistance to loop diuretics received much attention while the contribution of a depressed cardiac output to diuretic resistance was downplayed.Analysis of experience with positive inotropic agents, especially dobutamine, indicates that enhancement of cardiac output is not consistently associated with increased renal blood flow. However, urinary output and renal sodium excretion increase likely due to dobutamine-mediated decrease in renal and systemic reduced activation of sympathetic nervous- and renin-angiotensin-aldosterone system. Mechanical circulatory support with left ventricular assist devices ascertained the contribution of low cardiac output to diuretic resistance and the pathogenesis and progression of kidney disease in acutely decompensated heart failure. Diuretic resistance commonly occurs in acutely decompensated heart failure. However, failure to resolve fluid overload despite high doses of loop diuretics should alert to the presence of a low cardiac output state.

Background: Chronic kidney disease (CKD) has been associated with adverse clinical outcomes. Hyponatremia, a marker of illness severity and poor prognosis, is commonly exhibited in patients with CKD. Methods: This cross-sectional study included patients hospitalized due to heart failure (HF). We used stepwise logistic regression to investigate the independent association of cardiovascular drugs, markers of HF severity, and baseline clinical characteristics with hyponatremia in three subgroups ; normal renal function, mild-to-moderate CKD, and severe CKD. Results: Of the 1232 patients, 38.6% were hyponatremic. Patients with severe CKD, compared to those with normal renal function and mild-to- moderate CKD, were more likely to be hyponatremic (47.1%, 34.4% and 36.6%, respectively ; p

Background The co-administration of loop diuretics with thiazide diuretics is a therapeutic strategy in patients with hypertension and volume overload. The aim of this study was to assess the efficacy and safety of treatment with bumetanide plus chlorthalidone in patients with chronic kidney disease (CKD) stage 4–5 KDIGO. Methods A double-blind randomized study was conducted. Patients were randomized into two groups: bumetanide plus chlorthalidone group (intervention) and the bumetanide plus placebo group (control) to evaluate differences in TBW, ECW and ECW/TBW between baseline and 30 Days of follow-up. Volume overload was defined as ‘bioelectrical impedance analysis as fluid volume above the 90th percentile of a presumed healthy reference population. The study’s registration number was NCT03923933. Results Thirty-two patients with a mean age of 57.2 ± 9.34 years and a median estimated glomerular filtration rate (eGFR) of 16.7 ml/min/1.73 m2 (2.2–29) were included. There was decreased volume overload in the liters of total body water (TBW) on Day 7 (intervention: -2.5 vs. control: -0.59, p = 0.003) and Day 30 (intervention: -5.3 vs. control: -0.07, p = 0.016); and in liters of extracellular water (ECW) on Day 7 (intervention: -1.58 vs. control: -0.43, p p p = 0.073) and Day 30 (intervention: -26.1 vs. control: -10, p = 0.028) and in diastolic blood pressure on Day 7 (intervention: -8.5 vs. control: -2.25, p = 0.059) and Day 30 (intervention: -13.5 vs. control: -3.4, p = 0.018). Conclusion In CKD stage 4–5 KDIGO without renal replacement therapy, bumetanide in combination with chlorthalidone is more effective in treating volume overload and hypertension than bumetanide with placebo.

There is ongoing controversy regarding the association between loop diuretics (LD), especially in high doses, and adverse clinical outcomes in outpatients with heart failure (HF). We performed a systematic review of the evidence for LD in outpatients with HF. We searched MEDLINE, EMBASE, and Cochrane Clinical Trial Collection to identify controlled studies, evaluating the association between LD and morbidity and mortality in patients with HF. The primary endpoint was all-cause mortality and secondary endpoint HF hospitalizations. Quantitative analysis was performed by generating forest plots and pooling adjusted risk estimates across studies using random effects models. Between-study heterogeneity was assessed through Q and I2 statistics. Twenty-four studies with a total of 96,959 patients were included. No randomized studies were identified. Use of LD was associated with increased all-cause mortality compared with non-use (pooled adjusted risk estimates, 1.18; P = 0.001) and increased HF hospitalization rates (pooled adjusted risk estimates, 1.81; P

The mechanisms of the diuretic effect of sodium-glucose cotransporter 2 (SGLT2) inhibitor and its predictors in heart failure (HF) patients with coexisting type 2 diabetes mellitus (T2DM) remain under investigation. A total of 40 hospitalized HF patients with T2DM (68 ± 13 years old, male gender 63%) were prospectively enrolled and received ipragliflozin at a dose of 50 mg once daily after breakfast for at least 4 consecutive days. They underwent first-morning blood and urine tests, and 24-h urine tests before and after short-term ipragliflozin therapy. Daily urine volume significantly increased from 1365 ± 511 mL/day on day 0 to 1698 ± 595 mL/day on day 3 (P

Prescribing cascades are where a drug adverse reaction is wrongly attributed to the emergence of a new condition, which leads to further drug prescribing. This promotes polypharmacy, adverse drug reactions and therapeutic burden. An example of a prescribing cascade is the co-prescribing of loop diuretics to treat the peripheral oedema caused by calcium channel blocker (CCB) drugs. Although well recognised, this is still a combination of medications taken by millions of people worldwide. CCBs have no prognostic benefit in heart failure and have an absolute risk increase for oedema of around 8-18% (number needed to harm 6-13). In the treatment of hypertension, they also increase the risk of oedema and a new diagnosis of heart failure without having any major advantages over alternative drugs. The best way to manage the oedema caused by CCBs is to switch to an alternative medication. Only where this is not possible or fails to achieve therapeutic goals would the CCB-loop diuretic combination appear to be justified. In many cases, therapeutic practice could be improved by targeting people on CCB-loop diuretic combinations for medication review. This could improve quality of life and reduce polypharmacy, adverse drug reactions, therapeutic burden and financial costs for millions of people worldwide.

Aerosol furosemide may be an option to treat refractory dyspnea, though doses, methods of delivery, and outcomes have been variable. We hypothesized that controlled delivery of high dose aerosol furosemide would reduce variability of dyspnea relief in patients with underlying pulmonary disease. Seventeen patients with chronic exertional dyspnea were recruited. Patients rated recently recalled breathing discomfort on a numerical rating scale (NRS) and the multidimensional dyspnea profile (MDP). They then performed graded exercise using an arm-ergometer. The NRS was completed following each exercise grade, and the MDP was repeated after a pre-defined dyspnea threshold was reached. During separate visits, patients received either aerosol saline or 80 mg of aerosol furosemide in a randomized, double-blind, crossover design. After treatment, graded exercise to the pre-treatment level was repeated, followed by completion of the NRS and MDP. Treatment effect was defined as the difference between pre- and post-treatment NRS at end exercise, expressed in absolute terms as % Full Scale. “Responders” were defined as those showing treatment effect ≥ 20% of full scale. Final analysis included 15 patients. Neither treatment produced a statistically significant change in NRS and there was no significant difference between treatments (p = 0.45). There were four “responders” and one patient whose dyspnea worsened with furosemide; two patients were responders with saline, of whom one also responded to furosemide. No adverse events were reported. High dose controlled delivery aerosol furosemide was not statistically different from saline placebo at reducing exercise-induced dyspnea. However, a clinically meaningful improvement was noted in some patients.

Purpose To describe methodological and reporting issues in non-randomised comparative drug safety studies pooled in meta-analyses, with focus on confounding by indication. Methods All studies included in statistically significant meta-analyses in a recent publication investigating fall risk properties of cardiovascular drugs were reviewed. Study characteristics were extracted and assessed. Results Nine studies, including between 498 and 321,995 individuals, contributed data to the significant meta-analyses in which loop diuretics and beta-blockers were associated with falls, five published in 2015. Five individual studies reported a statistically significant association. In the five cohort studies, characteristics of exposed vs unexposed individuals were either not reported (n = 3) or differed substantially regarding morbidity (n = 2). Drug treatment was determined at baseline, and data on falls were collected for up to 2 years thereafter. Out of the four case-control studies, the cases and controls in only one study were matched for morbidity. Morbidity characteristics of fallers compared with non-fallers were either not reported (n = 2) or they differed (n = 1) or were reported according to the matched-for diseases (n = 1). Confounding by indication was explicitly discussed in two studies. None of the abstract conclusions considered causality issues or the possibility of confounding by indication. Conclusions Confounding by indication is a major issue in non-randomised comparative drug safety studies, a problem which may be concealed in meta-analyses. To enhance such research, compared groups need to be balanced regarding relevant factors including morbidities and characteristics adequately reported. Confounding by indication needs to be explicitly discussed and highlighted in the abstract conclusion.

Acute heart failure hospitalizations complicated by diuretic resistance are associated with worse outcomes. Yet, quantification of the frequency and accompanying risk from loop diuretic resistance is limited by the absence of a comprehensive definition with universal clinical application. Herein, we outline limitations of the current metrics used to identify and define diuretic resistance. We discuss the best available methods to identify and prognosticate outcomes in diuretic resistance. We propose a mechanism-based classification system of diuretic resistance by anatomical location as follows: pre-nephron resistance, pre-loop of Henle resistance, loop of Henle resistance, and post-loop of Henle resistance. Within this paradigm, we compare and contrast historical beliefs of resistance mechanisms with current literature specific to patients with heart failure. We recommend a treatment pathway to restore diuretic efficacy with a literature review of the various combination diuretic strategies and ongoing clinical trials that may impact current best practices.

Diuretic resistance is a common issue in patients with acute decompensation of advanced chronic heart failure (ACHF). The aim of this trial was to compare boluses and continuous infusion of furosemide in a selected population of patients with ACHF and high risk for diuretic resistance. In this single-centre, double-blind, double-dummy, randomized trial, we enrolled 80 patients admitted for acute decompensation of ACHF (NYHA IV, EF ≤ 30%) with criteria of high risk for diuretic resistance (SBP ≤ 110 mmHg, wet score ≥ 12/18, and sodium ≤ 135 mMol/L). Patients were assigned in a 1:1 ratio to receive furosemide by bolus every 12 h or by continuous infusion. Diuretic treatment and dummy treatment were prepared by a nurse unassigned to patients’ care. The study treatment was continued for up to 72 h. Coprimary endpoints were total urinary output and freedom from congestion at 72 h. 80 patients were enrolled with 40 patients in each treatment arm. Mean daily furosemide was 216 mg in continuous-infusion arm and 195 mg in the bolus intermittent arm. Freedom from congestion (defined as jugular venous pressure of

The majority of patients with chronic heart failure (HF) receive long-term treatment with loop diuretics. The comparative effectiveness of different loop diuretics is unknown. We searched PubMed, clinicaltrials.gov , the Cochrane Central Register of Controlled Trials and the European Union Clinical Trials Register for randomised clinical trials exploring the efficacy of the loop diuretics azosemide, bumetanide, furosemide or torasemide in patients with HF. Comparators included placebo, standard medical care or any other active treatment. The primary endpoint was all-cause mortality. Secondary endpoints included cardiovascular mortality, HF-related hospitalisation and any combined endpoint thereof. Hypokalaemia and acute renal failure were defined as additional safety endpoints. Evidence was synthesised using network meta-analysis (NMA). Thirty-four trials reporting on 2647 patients were included. The overall quality of evidence was rated as moderate. NMA demonstrated no significant differences between loop diuretics with respect to all-cause mortality, cardiovascular mortality or hypokalaemia. In contrast, torasemide ranked best in terms of HF hospitalisation, and there was a trend towards benefits with torasemide with regard to occurrence of acute renal failure. Sensitivity analyses excluding trials with a follow-up

The measurement of electric potential and resistance reflect the transport of sodium and chloride ions which take place in keratinocytes and is associated with skin response to stimuli arising from external and internal environment. The aim of the study was to assess changes in electrical resistance and the transport of chloride and sodium ions, under iso-osmotic conditions and following the use of inhibitors affecting these ions’ transport, namely amiloride (A) and bumetanide (B). The experiment was performed on 104 fragments of rabbit skin, divided into three groups: control (n = 35), A—inhibited sodium transport (n = 33) and B—inhibited chloride transport (n = 36). Measurement of electrical resistance (R) and electrical potential (PD) confirmed tissue viability during the experiment, no statistically significant differences in relation to control conditions were noted. The minimal and maximal PD measured during stimulation confirmed the repeatability of the recorded reactions to the mechanical and mechanical–chemical stimulus for all examined groups. Measurement of PD during stimulation showed differences in the transport of sodium and chloride ions in each of the analyzed groups relative to the control. The statistical analysis of the PD measured in stationary conditions and during mechanical and/or mechanical–chemical stimulation proved that changes in sodium and chloride ion transport constitute the physiological response of keratinocytes to changes in environmental conditions for all applied experimental conditions. Assessment of transdermal ion transport changes may be a useful tool for assessing the skin condition with tendency to pain hyperactivity and hypersensitivity to xenobiotics.

This review aims to summarize our current understanding and management strategies of acute cardiorenal syndrome (CRS). The definition of acute CRS remains debated, in part due to the lack of reliable insights into salt and water handling of the kidneys beyond impairment in glomerular filtration. Protocolized use of loop diuretics to ensure adequate delivery to their target of action, as well as segmental tubular blockade with adjunctive use of thiazide diuretics, acetazolamide, amiloride, or sodium-glucose transporter 2 (SGLT2) inhibitors, may result in more effective natriuresis in patients with acute CRS who exhibit diuretic resistance. Other strategies, such as modulating renal sodium avidity with the use of hypertonic saline, reduction of intra-abdominal pressure, or device-based salt and volume removal, are promising and warrant further investigation. Acute CRS remains a significant contributor of morbidity and mortality for the acute heart failure population. New strategies have challenged current dogmas in our understanding of its pathophysiology, which may lead to potential new treatment approaches.

Dysregulation of cation-chloride cotransporters NKCC1 and KCC2 expression was shown to be related to drug-resistant epilepsy. Previous studies suggested that bumetanide, an inhibitor of NKCC1, might have antiepileptic effects.The aim of this study was to investigate the safety and efficacy of bumetanide add-on therapy in patients with drug-resistant epilepsy and its relation to cation-chloride cotransporters NKCC1 and KCC2.We conducted an open-label, single-arm clinical trial in drug-resistant temporal lobe epilepsy (TLE) patients. This study consisted of three phases: pretreatment (3 months), titration (3 weeks), and active treatment (6 months). During the pretreatment phase, the dose of antiepileptic drugs was stabilized, and bumetanide was then added at an initial dose of 0.5 mg/day, increasing by 0.5 mg/week until a target dose of 2 mg/day was achieved. Bumetanide treatment was then continued for 6 months. Seizure frequency and adverse events were assessed at every monthly visit. Blood samples were collected from patients and 12 healthy controls were used for polymerase chain reaction and Western blot analyses. Primary clinical outcomes were drug safety and change in seizure frequency. Changes in NKCC1 and KCC2 expression were the non-clinical endpoints.A total of 30 patients were enrolled, 27 of whom completed the study. The mean duration of epilepsy was 16.5 years. Median seizure frequency per month was 9 [interquartile range (IQR) 7-14.5] at baseline, 3.67 (IQR 1.84-6.17) at the first 3 months, and 2 (IQR 0.84-4.34) at the last 3 months (p 0.001). Five adverse events were detected in six patients. The reported adverse events were anorexia in four patients, nausea and vomiting in two patients, and agitation, headache and increased seizure frequency in one patient each. The level of NKCC1 and KCC2 gene transcripts and KCC2 protein did not change significantly following treatment (p 0.05); however, we observed a significant reduction in NKCC1 protein levels (p = 0.042).Bumetanide might be an effective and relatively tolerable drug in patients with drug-resistant TLE. Downregulation of NKCC1 protein following bumetanide treatment may be responsible for its antiepileptic effects.IRCT 201012115368N1.

Diuretic resistance (DR) is common in patients with decompensated heart failure (HF), and is associated with adverse outcomes. To determine the prevalence of DR and its impact on survival among patients with decompensated HF, we prospectively evaluated the prevalence and influence on prognosis of DR (defined as persistent congestion despite ≥ 80 mg of furosemide per day) in a cohort of elderly patients from the Spanish HF registry (RICA) admitted for an acute decompensation of HF. Patients with new-onset HF were excluded. From the global cohort of 2067 patients, 435 (21%; 95% CI 19.3%-22.7%) patients met criteria for DR. Patients with DR had more comorbidities (hypercholesterolemia, diabetes mellitus, valvular disease, chronic kidney disease, and cancer) and a worse functional status compared to patients without DR. In addition, patients with DR had a higher proportion of ischemic etiology, more advanced functional class and lower left ventricular ejection fraction values. After 1 year of follow-up, all-cause mortality was higher in patients with DR with an adjusted hazard ratio of 1.37 (95% CI 1.06-1.79; p = 0.018). The prevalence of DR in a cohort of elderly patients admitted for acute HF decompensation is 21%. DR is an independent predictor of 1-year mortality.

We attempted to identify the difference in diuretic properties between tolvaptan (TLV) and furosemide (FUR) in congestive heart failure (CHF) patients with loop diuretic resistance and renal impairment. We investigated 81 CHF patients with loop diuretic treatment and renal impairment included in t he Kanagawa Aquaresis Investigators Trial of Tolvaptan on Heart Failure Patients with Renal Impairment (K-STAR). Predictive baseline factors and their changes during treatment periods were analyzed for correlation with percentage change in urine volume (%ΔUV) after additive introduction of TLV or increasing doses of FUR. Higher urine osmolality at baseline (β = 0.355; p = 0.033) in the TLV group and a lower ratio of blood urea nitrogen to serum creatinine (BUN/Cr, β = − 0.405; p = 0.020) in the FUR group were predictive of higher %ΔUV. Higher Δfree-water clearance (β = 0.667; p

Autism spectrum disorder is defined by two core symptoms: a deficit in social communication and the presence of repetitive behaviors and/or restricted interests. Currently, there is no US Food and Drug Administration-approved drug for these core symptoms. This article reviews the biological origins of the social function deficit associated with autism spectrum disorder and the drug therapies with the potential to treat this deficit. A review of the history of autism demonstrates that a deficit in social interaction has been the defining feature of the concept of autism from its conception. Abnormalities identified in early social skill development and an overview of the pathophysiology abnormalities associated with autism spectrum disorder are discussed as are the abnormalities in brain circuits associated with the social function deficit. Previous and ongoing clinical trials examining agents that have the potential to improve social deficits associated with autism spectrum disorder are discussed in detail. This discussion reveals that agents such as oxytocin and propranolol are particularly promising and undergoing active investigation, while other agents such as vasopressin agonists and antagonists are being activity investigated but have limited published evidence at this time. In addition, agents such as bumetanide and manipulation of the enteric microbiome using microbiota transfer therapy appear to have promising effects on core autism spectrum disorder symptoms including social function. Other pertinent issues associated with developing treatments in autism spectrum disorder, such as disease heterogeneity, high placebo response rates, trial design, and the most appropriate way of assessing effects on social skills (outcome measures), are also discussed.

Diuretic therapy is important in critically ill patients because fluid overload impairs organ function and increases mortality. Compared to intermittent administration, continuous infusion of loop diuretics is theoretically superior in terms of diuresis and electrolyte balance. However, the available evidence is susceptible to carryover diuretic effects and resistance in earlier crossover trials. Consequently, we conducted a systematic review and meta-analysis of parallel-group randomized controlled trials to compare these two strategies in adults with acute decompensated heart failure. We searched Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from their inceptions to May 26, 2018. We pooled the data using a random effects model. Our primary outcomes were all-cause mortality, length of hospital stay, and body weight reduction. We analyzed 12 parallel-group randomized controlled trials involving 923 patients. Compared with intermittent administration, continuous infusion of furosemide was not associated with an improvement in all-cause mortality (risk ratio 1.19; 95% confidence interval [CI], 0.65 to 2.16), length of hospital stay (weighted mean difference [WMD] - 0.88 days; 95% CI, - 2.76 to 1.01), or 24-h urine output (WMD 489.17 mL; 95% CI, - 183.18 to 1161.51), but was significantly associated with a greater body weight reduction (WMD 0.63 kg; 95% CI, 0.23 to 1.02). No differences in hypokalemia, hyponatremia, increased serum creatinine level, and hypotension were noted. Continuous infusion of furosemide, compared to intermittent administration, is associated with a greater body weight reduction and potential increase in 24-h urine output. The limited available evidence suggests no difference in adverse events between both strategies. Trial registration: PROSPERO (CRD42017083878).

Due to their daily involvement in mineral metabolism, nephrologists are often asked to consult on children with hypercalcemia. This might become even more pertinent when the hypercalcemia is associated with acute kidney injury and/or hypercalciuria and renal calcifications. The best way to assess the severity of hypercalcemia is by measurement of plasma ionized calcium, and if not available by adjusting serum total calcium to albumin concentration. The differential diagnosis of the possible etiologies of the disturbance in the mineral homeostasis starts with the assessment of serum parathyroid hormone concentration, followed by that of vitamin D metabolites in search of both genetic and acquired etiologies. Several tools are available to acutely treat hypercalcemia with the current main components being fluids, loop diuretics, and antiresorptive agents. This review will address the pathophysiologic mechanisms, clinical manifestations, and treatment modalities involved in hypercalcemia.

Background Acute kidney injury (AKI) is a major complication of acute myocardial infarction(AMI), which can significantly increase mortality. This study is to analyze the related risk factors and establish a prediction score of acute kidney injury in order to take early measurement for prevention. Methods The medical records of 6014 hospitalized patients with AMI in Beijing Anzhen Hospital from January 2010 to December 2016 were retrospectively analyzed. These patients were randomly assigned into two cohorts: one was for the derivation of prediction score (n = 4252) and another for validation (n = 1762). The criterion for AKI was defined as an increase in serum creatinine of ≥ 0.3 mg/dL or ≥ 50% from baseline within 48 h. On the basis of odds ratio obtained from multivariate logistic regression analysis, a prediction score of acute kidney injury after AMI was built up. Results In this prediction score, risk score 1 point included hypertension history, heart rate > 100 bpm on admission, peak serum troponin I ≥ 100 μg/L, and time from admission to coronary reperfusion > 120 min; risks score 2 points included Killip classification ≥ class 3 on admission; and maximum dosage of intravenous furosemide ≥ 60 mg/d; risks score 3 points only included shock during hospitalization. In addition, when baseline estimated glomerular filtration rate (eGFR) was less than 90 ml/min·1.73 m2, every 10 ml/min·1.73 m2 reduction of eGFR increased risk score 1 point. Youden index showed that the best cut-off value for prediction of AKI was 3 points with a sensitivity of 71.1% and specificity 74.2%. The datasets of derivation and validation both displayed adequate discrimination (an area under the ROC curve, 0.79 and 0.81, respectively) and satisfactory calibration (Hosmer–Lemeshow statistic test, P = 0.63 and P = 0.60, respectively). Conclusions In conclusion, a prediction score for AKI secondary to AMI in Chinese patients was established, which may help to prevent AKI early.

Background Loop diuretics are recommended by clinical practice guidelines to treat volume overload in acute decompensated heart failure (ADHF). The effectiveness of switching furosemide to torsemide versus optimizing the furosemide dose following ADHF has not yet been evaluated. Methods This retrospective observational study aimed to assess the impact of switching furosemide to torsemide versus optimizing the furosemide dose after ADHF on HF-related hospitalization within 1 month and 6 months of discharge. The study included patients previously on furosemide admitted with ADHF to the Heart Hospital in Qatar between January 1, 2016 and June 30, 2017. The study included 2 groups: (1) patients discharged on torsemide; and (2) patients discharged on an optimized furosemide dose. Cox proportional hazard regression analysis was used to determine the association between diuretic use and hospitalization. Results Of the 232 patients included, 45 received torsemide and 187 received an optimized furosemide dose upon discharge. The majority of patients included were males (54%) with a mean age of 67 ± 12 years, and presented with HF with reduced ejection fraction (57%) and had a history of coronary artery disease (68%). The 1-month and 6-month HF-related hospitalization did not differ between the torsemide and optimized furosemide groups (aHR = 0.72; 95% CI 0.23–2.3, p = 0.57; aHR = 0.94, 95% CI 0.45–1.8, p = 0.87), respectively. Conclusion Switching furosemide to torsemide after ADHF was not associated with reduced HF-related hospitalization compared to receiving an optimized furosemide dose. Larger prospective clinical trials are needed to confirm the findings of this study.

International audience; Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease in Western countries, and typically affects the elderly. BP is immunologically characterized by tissue-bound and circulating autoantibodies directed against either the BP antigen 180 (BP180, or BPAG2) or the BP antigen 230 (BP230, or BPAG1e), or even both, which are components of hemidesmosomes involved in the dermal-epidermal cohesion. Risk factors for BP include old age, neurologic diseases (dementia, Parkinson's disease, cerebrovascular disease), and some particular drugs, including loop diuretics, spironolactone and neuroleptics. The spectrum of clinical presentations is extremely broad. Clinically, BP is an intensely pruritic erythematous eruption with widespread blister formation. In the early stages, or in atypical, non-bullous variants of the disease, only excoriated, eczematous or urticarial lesions (either localized or generalized) are present. The diagnosis of BP relies on immunopathologic findings, especially based on both direct and indirect immunofluorescence microscopy observations, as well as on anti-BP180/BP230 enzyme-linked immunosorbent assays (ELISAs). BP is usually a chronic disease, with spontaneous exacerbations and remissions, which may be accompanied by significant morbidity. In the past decade, potent topical corticosteroids have emerged as an effective and safe first-line treatment for BP, but their long-term feasibility is still controversial. Newer therapeutic agents targeting molecules involved in the inflammatory cascade associated with BP represent future alternatives to classical immunosuppressant drugs for maintenance therapy.

Electrolyte imbalance is a common problem affecting the elderly. Increased number of comorbidities and frequent use of drugs may contribute to increased risk of hypokalemia in the elderly. This study was performed to investigate the prevalence of community-acquired hypokalemia (CAH), risk factors for its development, related factors with hypokalemia, and morbidities and all-cause mortality rates (MR) of CAH in the elderly patients. Total of 36,361 patients aged above 65 years were screened retrospectively. Group 1 consisted of 269 elderly patients with potassium level ≤3.5 mmol/L, and group 2 (control group) consisted of 182 subjects with potassium level between 3.6 and 5.5 mmol/L. Etiologic factors of CAH, presence of comorbidities, duration of hospital stay, hospital cost, and clinical outcomes were recorded. Prevalence of hypokalemia was found 3.24% in patients aged above 65 years. Duration of hospital stay, presence of ≥2 comorbid diseases, hospital cost, and MR were significantly higher in group 1 compared to group 2 (p

Traumatic brain injury (TBI) is not only a leading cause for morbidity and mortality in young adults (Bruns and Hauser, Epilepsia 44(Suppl 10):210, 2003), but also a leading cause of seizures. Understanding the seizure-inducing mechanisms of TBI is of the utmost importance, because these seizures are often resistant to traditional first- and second-line anti-seizure treatments. The early post-traumatic seizures, in turn, are a contributing factor to ongoing neuropathology, and it is critically important to control these seizures. Many of the available anti-seizure drugs target gamma-aminobutyric acid (GABAA) receptors. The inhibitory activity of GABAA receptor activation depends on low intracellular Cl−, which is achieved by the opposing regulation of Na+–K+–Cl− cotransporter 1 (NKCC1) and K+–Cl−–cotransporter 2 (KCC2). Up-regulation of NKCC1 in neurons has been shown to be involved in neonatal seizures and in ammonia toxicity-induced seizures. Here, we report that TBI-induced up-regulation of NKCC1 and increased intracellular Cl− concentration. Genetic deletion of NKCC1 or pharmacological inhibition of NKCC1 with bumetanide suppresses TBI-induced seizures. TGFβ expression was also increased after TBI and competitive antagonism of TGFβ reduced NKKC1 expression, ameliorated reactive astrocytosis, and inhibited seizures. Thus, TGFβ might be an important pathway involved in NKCC1 up-regulation after TBI. Our findings identify neuronal up-regulation of NKCC1 and its mediation by TGFβ, as a potential and important mechanism in the early post-traumatic seizures, and demonstrate the therapeutic potential of blocking this pathway. Electronic supplementary material The online version of this article (doi:10.1007/s00429-016-1292-z) contains supplementary material, which is available to authorized users.

In patients with congestive heart failure and renal dysfunction, high dose of diuretics are necessary to improve congestion, which may progress to renal dysfunction. We examined the efficacy of tolvaptan with reduction of loop diuretics to improve renal function in patients with congestive heart failure and renal dysfunction. We conducted a multicenter, prospective, randomized study in 44 patients with congestive heart failure and renal dysfunction (serum creatinine concentration ≥1.1 mg/dl) treated with conventional diuretics. Patients were randomly divided into two groups: tolvaptan (15 mg) with a fixed dose of diuretics or with reducing to a half-dose of diuretics for 7-14 consecutive days. We examined the change of urine volume, body weight, serum creatinine and electrolyte concentrations in each group. Both groups demonstrated significant urine volume increase (724 ± 176 ml/day in the fixed-dose group and 736 ± 114 ml/day in the half-dose group) and body weight reduction (1.6 ± 1.5 kg and 1.6 ± 1.9 kg, respectively) from baseline, with no differences between the two groups. Serum creatinine concentration was significantly increased in the fixed-dose group (from 1.60 ± 0.47 to 1.74 ± 0.66 mg/dl, p = 0.03) and decreased in the half-dose group (from 1.98 ± 0.91 to 1.91 ± 0.97 mg/dl, p = 0.10). So the mean changes in serum creatinine concentration from baseline significantly differed between the two groups (0.14 ± 0.08 mg/dl in the fixed-dose group and -0.07 ± 0.19 mg/dl in the half-dose group, p = 0.006). The administration of tolvaptan with reduction of loop diuretics was clinically effective to ameliorate congestion with improving renal function in patients with congestive heart failure and renal dysfunction.

Vesicoureteral reflux (VUR) is a frequent cause of chronic kidney disease (CKD) in children. Using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI), we measured cortical and medullary oxygenation in children with CKD due to VUR and compared the results to those obtained on healthy controls.The study population comprised 37 children (19 with CKD due to VUR and 18 healthy age-matched controls). BOLD-MRI was performed before and after furosemide treatment. MR images were analyzed with the region-of-interest (ROI) technique to assess the mean R2* values (=1/T2*) of the cortex and medulla of each kidney and with the concentric object (CO) technique that divides renal parenchyma in 12 equal layers.R2* values were significantly lower (corresponding to higher oxygenation) in the cortex and medulla of kidneys of children with CKD due to VUR than in those of the healthy controls (cortex 16.4 ± 1.4 vs. 17.2 ± 1.6 s(-1) , respectively; medulla 28.4 ± 3.2 vs. 30.3 ± 1.9 s(-1) , respectively; P 0.05), and furosemide-induced changes in medullary R2* were smaller in the former than in the latter (-5.7 ± 3.0 vs. -6.9 ± 3.4 s(-1), respectively; P 0.05). Similar results were found with the CO technique. In children with a history of unilateral reflux (n = 9), the non-affected contralateral kidneys presented similar R2* values as the diseased kidneys, but their response to furosemide was significantly larger (-7.4 ± 3.2 vs. -5.7 ± 3.0, respectively; P = 0.05).Chronic kidney disease due to VUR is not associated with kidney tissue hypoxia in children. The significantly larger furosemide-induced decrease in medullary R2* levels in the healthy group and unaffected contralateral kidneys of the VUR group points towards more intense renal sodium transport in these kidneys.

Background The effect of loop diuretic use in critically ill patients on vasopressor support or in shock is unclear. This study aimed to explore the relationship between loop diuretic use and hospital mortality in critically ill patients with vasopressor support. Methods Data were extracted from the Medical Information Mart for Intensive Care III database. Adult patients with records of vasopressor use within 48 h after intensive care unit admission were screened. Multivariable logistic regression and propensity score matching was used to investigate any association. Results Data on 7828 patients were included. The crude hospital mortality was significantly lower in patients with diuretic use (166/1469 vs. 1171/6359, p

Objective: Our objective was to assess the relationship between antihypertensive drugs, loop diuretics, and the risk of hospitalization for hip fracture (HF). Design: We conducted a population-based study in a cohort of 81,617 patients from Lombardy (Italy) aged 70–90years who were newly treated with antihypertensive agents or loop diuretics between 2005 and 2009. Cases were the 2153 patients who experienced the outcome (hospitalization for HF before 31 December 2012). For each case, up to three controls were randomly selected from the cohort to be matched for sex, age at cohort entry, and date of initial prescription. The case–control and case-crossover designs and the logistic regression for matched sets were used to measure the strength of the association between current use of an antihypertensive drug (within 30days before the HF hospitalization) and the risk of outcome. Results: Case–control and case-crossover odds ratios (ORs) for current use of loop diuretics were 1.67 (95% confidence interval [CI] 1.28–2.18) and 1.49 (95% CI 1.05–2.10), respectively. Among patients aged 81–90years, case–control and case-crossover ORs were 1.52 (95% CI 1.04–2.21) and 1.82 (95% CI 1.10–3.00) for current use of loop diuretics and 1.86 (95% CI 1.03–3.35) and 1.88 (95% CI 1.01–3.48) for α-blockers. No other agent was associated with the outcome. Conclusions: Evidence that loop diuretics and α-blockers are associated with a higher risk of HF was consistent in the two observational approaches. Clinicians should carefully consider the risk of falls in their selection of drugs for hypertension and in the clinical use of loop diuretics.

The present study was designed to investigate the antistress effect of furosemide (sodium potassium chloride co-transporter inhibitor) in immobilization and foot-shock stress-induced behavioral alterations in the mice. Acute stress was induced in Swiss albino mice either by applying electric foot shocks of 0.6-mA intensity of 1-s duration with 30-s inter-shock interval for 1 h or immobilizing for 150 min. The acute stress-induced behavioral changes were assessed by using actophotometer, hole board, open-field, and social interaction tests. Biochemically, the corticosterone levels were estimated in the serum as a biomarker of hypothalamus-pituitary-adrenal (HPA) axis. Acute stress resulted in the development of behavioral alterations and elevation of the corticosterone levels. Intraperitoneal administration of furosemide (25 and 50 mg/kg) significantly attenuated immobilization and foot-shock stress-induced behavioral changes along with normalization of the corticosterone levels. It may be concluded that furosemide produces beneficial effects in reestablishing the behavioral and biochemical alterations in immobilization and foot-shock-induced acute stress in mice.

Periventricular leukomalacia (PVL) is a major form of preterm brain injury. Na(+)-K(+)-Cl(-) 1 cotransporter (NKCC1) expression on neurons and astrocytes is developmentally regulated and mediates Cl(-) reversal potential. We hypothesized that NKCC1 is highly expressed on oligodendrocytes (OLs) and increases vulnerability to hypoxia-ischemia (HI) mediated white matter injury, and that the NKCC1 inhibitor bumetanide would be protective in a rodent PVL model.Immunohistochemistry in Long-Evans rats and PLP-EGFP transgenic mice was used to establish cell-specific expression of NKCC1 in the immature rodent brain. HI was induced on postnatal day 6 (P6) in rats and the protective efficacy of bumetanide (0.3 mg/kg/i.p. q12h × 60 h) established.NKCC1 was expressed on OLs and subplate neurons through the first 2 postnatal weeks, peaking in white matter and the subplate between P3-7. Following HI, NKCC1 is expressed on OLs and neurons. Bumetanide treatment significantly attenuates myelin basic protein loss and neuronal degeneration 7 d post-HI.Presence and relative overexpression of NKCC1 in rodent cerebral cortex coincides with a period of developmental vulnerability to HI white matter injury in the immature prenatal brain. The protective efficacy of bumetanide in this model of preterm brain injury suggests that Cl(-) transport is a factor in PVL and that its inhibition may have clinical application in premature human infants.

Loop diuretic use has been shown to be associated with an increased fracture risk, but the findings have been inconsistent. The present meta-analysis suggests that loop diuretics show a significant positive association with the overall risk of total fractures and, specifically, hip fractures. Despite being widely used, there is limited, prospective randomized trial evidence regarding the skeletal effects of loop diuretics. Previous observational studies have reported conflicting findings regarding the association between loop diuretic use and the risk of fractures. This meta-analysis of observational studies assessed the association between loop diuretic use and the risk of fractures. The PubMed, EMBASE, and OVID databases were searched for prospective cohort and case–control studies. Relative risks (RR) with 95 % confidence intervals (CI) were derived using random-effects models throughout the analysis. Thirteen studies (4 cohort studies and 9 case–control studies) were included, involving 842,644 participants and 108,247 fracture cases. Compared with non-users, people who had taken loop diuretics had an approximately 15 % higher risk of total fractures (95 % CI, 1.04–1.26; p

Although antihypertensive drugs are known to reduce mortality in individuals with hypertension, the effects of different cardiovascular pharmacotherapies on mortality among patients with hypertension and atrial fibrillation (AF) have been less thoroughly explored. To study mortality rates in men and women separately with hypertension and AF prescribed different cardiovascular pharmacotherapies. A cohort of men (n=2809) and women (n=2793) aged45 years diagnosed with hypertension and AF were selected using patient records. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using Cox regression, with all-cause mortality as the outcome. Analysis was performed on the whole population and after stratification by age and sex. Independent factors were prescribed pharmacotherapies. Adjustments were made for a propensity score comprising age, comorbidities, education and marital status. The higher the number of antihypertensive drugs prescribed, the lower the mortality rate (P-value for trend 0.005). Individuals prescribed 4-5 antihypertensive drugs had a lower risk of mortality than those prescribed 0-1 drugs (HR: 0.62; 95% CI: 0.45-0.86). The HRs for the following drug classes were: loop diuretics 1.39 (95% CI: 1.08-1.78), non-selective β-blockers 0.68 (95% CI: 0.53-0.88), angiotensin receptor blockers 0.75 (95% CI: 0.56-0.99) and statins 0.68 (95% CI: 0.53-0.88). AF patients with hypertension prescribed statins, non-selective β-blockers and angiotensin receptor blockers had low relative mortality risks, suggesting that these prescribed pharmacotherapies were beneficial. This needs to be further explored in other clinical settings.

The aim of this study was to determine the postnatal risk factors associated with hearing loss as well as the prevalence of hearing loss among high-risk preterm infants in newborn hearing screening (NHS). We performed a retrospective study of high-risk preterm infants born with a gestational age ≤32 weeks and/or a birth weight ≤1,500 g. A NHS procedure was performed by automated auditory brainstem response (AABR) and automated evoked otoacoustic emission (TEOAE). Infants who failed TEOAE or AABR or both tests were referred to a tertiary audiology center for diagnosis confirmation and management. Postnatal risk factors associated with hearing loss were evaluated and compared for preterm infants with and without hearing loss. 1,360 high-risk preterm infants were assessed. Permanent hearing loss was found in 19 (1.4%) infants. Multivariate analysis revealed that proven sepsis (p = 0.019), mechanical ventilation ≥5 days (p = 0.024), loop diuretics (p = 0.001), patent ductus arteriosus ligation (p = 0.018) and operation for retinopathy of prematurity (ROP) (p = 0.034) were significant related factors for the hearing loss. This study showed a low prevalence of hearing loss and an association between operation for ROP and hearing loss in preterm infants, which has not been defined previously. Our results suggest that every neonatal intensive care unit should determine their own risk factors and take precautions to prevent hearing loss for these high-risk preterm infants.

Background Astaxanthin is a carotenoid pigment that possesses potent antioxidative, anti-inflammatory, antitumor, and immunomodulatory activities. Previous studies have demonstrated that astaxanthin displays potential neuroprotective properties for the treatment of central nervous system diseases, such as ischemic brain injury and subarachnoid hemorrhage. This study explored whether astaxanthin is neuroprotective and ameliorates neurological deficits following traumatic brain injury (TBI). Results Our results showed that, following CCI, treatment with astaxanthin compared to vehicle ameliorated neurologic dysfunctions after day 3 and alleviated cerebral edema and Evans blue extravasation at 24 h (p

Intravenous loop diuretics are widely used to treat the symptoms and signs of fluid overload in acute heart failure (AHF). Although diuretic therapy is widely used and strongly recommended by most recent clinical guidelines, prospective studies and randomized clinical trials are lacking and so reliable evidence is missing about the best therapy in terms of doses and methods of administration. In addition, clinical efficacy and safety outcomes are often affected by the presence of contrasting evidence. The efficacy of loop diuretics is impaired by diuretic resistance characterized by a decreased diuretic and natriuretic effect. This review focuses on the current management of AHF with diuretic therapy. Continuous diuretic infusion seems to be a good choice, from a pharmacokinetic point of view, when fluid overload is refractory to conventional therapy. Some available evidence comparing bolus injection to continuous infusion of loop diuretics proved the latter to be an effective and safe method of administration. Continuous infusion seems to produce a constant plasmatic concentration of drug with a more uniform daily diuretic and natriuretic effect and a greater safety profile (fewer adverse events such as worsening renal failure, electrolyte imbalances, ototoxicity). The analyses of the published studies did not provide conclusive data about the effects on clinical outcomes (mortality, rate of hospital readmissions, length of hospital stay and adverse events). Furthermore, recent studies focus their attention on alternative strategies of fluid removal, such as vasopressin antagonists, adenosine antagonists and ultrafiltration but available data are often inconclusive.

The mainstay of treatment for acute decompensated heart failure (ADHF) is intravenous (IV) diuretic therapy either as a bolus or via continuous infusion. Despite being available for decades, few randomized trials exist to guide dosing and administration of these drugs. In 2011, the Diuretic Optimization Strategies Evaluation (DOSE) trial used a prospective, randomized design to compare bolus versus continuous infusion of IV furosemide, as well as high-dose versus low-dose therapy. The study found no difference in the primary end point for continuous versus bolus infusion. High-dose diuretics were more effective than low dose without clinically important negative effects on renal function. Although limited by patient selection criteria and protocol design, the study challenges long-held beliefs that continuous infusion is more effective than bolus dosing. The study also challenges the notion that high-dose diuretics carry clinically important renal toxicity risks for patients.

Cerebral edema is a common finding in a variety of neurological conditions, including ischemic stroke, traumatic brain injury, ruptured cerebral aneurysm, and neoplasia. With the possible exception of neoplasia, most pathological processes leading to edema seem to share similar molecular mechanisms of edema formation. Challenges to brain-cell volume homeostasis can have dramatic consequences, given the fixed volume of the rigid skull and the effect of swelling on secondary neuronal injury. With even small changes in cellular and extracellular volume, cerebral edema can compromise regional or global cerebral blood flow and metabolism or result in compression of vital brain structures. Osmotherapy has been the mainstay of pharmacologic therapy and is typically administered as part of an escalating medical treatment algorithm that can include corticosteroids, diuretics, and pharmacological cerebral metabolic suppression. Novel treatment targets for cerebral edema include the Na(+)-K(+)-2Cl(-) co-transporter (NKCC1) and the SUR1-regulated NC(Ca-ATP) (SUR1/TRPM4) channel. These two ion channels have been demonstrated to be critical mediators of edema formation in brain-injured states. Their specific inhibitors, bumetanide and glibenclamide, respectively, are well-characterized Food and Drug Administration-approved drugs with excellent safety profiles. Directed inhibition of these ion transporters has the potential to reduce the development of cerebral edema and is currently being investigated in human clinical trials. Another class of treatment agents for cerebral edema is vasopressin receptor antagonists. Euvolemic hyponatremia is present in a myriad of neurological conditions resulting in cerebral edema. A specific antagonist of the vasopressin V1A- and V2-receptor, conivaptan, promotes water excretion while sparing electrolytes through a process known as aquaresis.

The aim of the present study was to clarify the prognostic significance of upright T waves (amplitude > 0 mV) in lead aVR in patients with a prior myocardial infarction (MI). We retrospectively examined 167 patients with a prior MI. The primary end point was cardiac death or hospitalization for heart failure. During a follow-up period of 6.5 ± 2.8 years, 34 patients developed the primary end point. A Kaplan–Meier analysis showed a lower primary event-free rate in patients with upright T waves in lead aVR than in those with nonupright T waves in lead aVR (P = 0.001). Univariate Cox proportional hazards regression analyses showed that age, gender, chronic kidney disease, anterior wall MI, upright T waves in lead aVR, left ventricular ejection fraction, loop diuretic use, and spironolactone use were significantly associated with the primary end point. A multivariate Cox proportional hazards regression analysis selected age [hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.05–1.16, P < 0.001], upright T waves in lead aVR (HR 3.10, 95% CI 1.23–7.82, P = 0.017), and loop diuretic use (HR 4.61, 95% CI 1.55–13.67, P = 0.006) as independent predictors of the primary end point. In conclusion, the presence of upright T waves in lead aVR is an independent predictor of cardiac death or hospitalization for heart failure in patients with a prior MI. The analysis of T-wave amplitude in lead aVR provides useful prognostic information in patients with a prior MI.

Little is known about the genetic impact on loop diuretic effects. We newly investigated five genetic polymorphisms in 95 healthy volunteers, who had ingested bumetanide, frusemide and torsemide. The subjects excreted means of 20.2 g sodium chloride, 2.87 g potassium and 261 mg calcium over 24 h. Concerning sodium chloride, the subjects excreted 2.2 g less per two T-alleles of C825T in the G nucleotide β-subunit 3 (GNB3), 3.2 g less per two Met32-alleles of Val32Met in the atrial natriuretic peptide precursor (ANP) and 2.8 g more per two Arg152-alleles of Ter152Arg in ANP (P=0.007, 0.05 and 0.007). Concerning potassium, the subjects excreted 0.42 g more per two ANP Arg152-alleles (P=0.023). Concerning calcium, the subjects excreted 32 mg more per two deletion-alleles of the insertion/deletion polymorphism in the angiotensin-converting enzyme, 44 mg more per two Trp460-alleles of Gly460Trp in α-adducin (ADD1) and 42 mg less per two GNB3 T-alleles (P=0.006, 0.023 and 0.008). The common genetic impact together with three polymorphisms in the sodium chloride cotransporter and the epithelial sodium channel was 20, 15, 10 and 23% of the variation in the urinary excretion of sodium chloride, volume, potassium and calcium. This exceeded the fraction of variation explained by differences in the pharmacokinetics: 13, 10, 11 and 6%. Thus, genetic variation seems to be a stronger predictor of the loop diuretic drug response than pharmacokinetic variation.

Traditionally accepted management strategies for patients with heart failure include sodium and fluid restriction, neurohormonal blockade, and the use of loop diuretics to achieve and maintain euvolemia. Despite continued advances in medical and device therapy, fluid management remains a significant problem in patients with the cardiorenal syndrome (manifested as diuretic resistance and worsening renal function with more aggressive attempts at volume removal). This article examines the counterintuitive use of hypertonic saline as a potential therapy to facilitate diuresis in patients with decompensated heart failure and diuretic resistance. Low-volume hypertonic saline administration offsets counterproductive neurohormonal upregulation, transiently improves hemodynamics, and promotes renal sodium excretion with accompanied net water loss and preservation of renal function. This "new" therapeutic tool should be explored further as an adjunct to current medical therapies in the management of patients with refractory volume overload.

Gerbils aged in quiet show a decline of the endocochlear potential (EP) and elevated auditory nerve compound action potential (CAP) thresholds. However, establishing a direct relationship between an age-related reduction in the EP and changes in the activities of primary auditory neurons is difficult owing to the complexity of age-related histological changes in the cochlea. To address this issue, we developed a young gerbil model of "metabolic" presbyacusis that uses an osmotic pump to deliver furosemide into the round window niche for 7 days, resulting in a chronically reduced EP. In this model, the only major histopathologic changes were restricted to the hook region of the cochlea and consisted of loss of strial intermediate cells and massive edema in the lateral wall. The morphological and physiological evidence suggests that the cochlea can adapt to furosemide application over time. The morphology of spiral ganglion cells and hair cells appeared normal throughout the cochlea. CAP responses and EP values in this model are similar to those of quiet-aged ears. The spontaneous activity of single auditory fibers (n = 188) was assessed in 15 young gerbils treated with furosemide for 7 days. The percentage of recorded low-spontaneous rate (SR) fibers at characteristic frequencies (CFs)or = 6 kHz was significantly lower in furosemide-treated than in control ears. Recovery function tests of CAP responses after prior stimulation also showed a decline in activity of the low-SR population with CFsor = 6 kHz in the treated cochleas. A similar loss in the activity of low-SR fiber has been previously shown in quiet-aged gerbils. These results suggest that dysfunction of the cochlear lateral wall and subsequent chronic reduction in the EP can directly affect the activity patterns of primary auditory neurons in a manner similar to that seen in aged gerbils.

The Notch signaling pathway is known to have multiple roles during development of the inner ear. Notch signaling activates transcription of Hes5, a homologue of Drosophila hairy and enhancer of split, which encodes a basic helix-loop-helix transcriptional repressor. Previous studies have shown that Hes5 is expressed in the cochlea during embryonic development, and loss of Hes5 leads to overproduction of auditory and vestibular hair cells. However, due to technical limitations and inconsistency between previous reports, the precise spatial and temporal pattern of Hes5 expression in the postnatal and adult inner ear has remained unclear. In this study, we use Hes5-GFP transgenic mice and in situ hybridization to report the expression pattern of Hes5 in the inner ear. We find that Hes5 is expressed in the developing auditory epithelium of the cochlea beginning at embryonic day 14.5 (E14.5), becomes restricted to a particular subset of cochlear supporting cells, is downregulated in the postnatal cochlea, and is not present in adults. In the vestibular system, we detect Hes5 in developing supporting cells as early as E12.5 and find that Hes5 expression is maintained in some adult vestibular supporting cells. In order to determine the effect of hair cell damage on Notch signaling in the cochlea, we damaged cochlear hair cells of adult Hes5-GFP mice in vivo using injection of kanamycin and furosemide. Although outer hair cells were killed in treated animals and supporting cells were still present after damage, supporting cells did not upregulate Hes5-GFP in the damaged cochlea. Therefore, absence of Notch-Hes5 signaling in the normal and damaged adult cochlea is correlated with lack of regeneration potential, while its presence in the neonatal cochlea and adult vestibular epithelia is associated with greater capacity for plasticity or regeneration in these tissues; which suggests that this pathway may be involved in regulating regenerative potential.

Changes in the luminal NaCl concentration ([NaCl]) at the macula densa (MD) modulate the tubuloglomerular feedback (TGF) responses via an affect on the release of nitric oxide (NO). This study was performed in a newly established mouse macula densa cell line (NE-MD) to investigate the effects of lowering [NaCl] on the neuronal NO synthase (nNOS) protein expression and L-arginine (Arg)-induced NO release. Expression of nNOS protein and release of NO were evaluated by Western blot analysis and an NO-sensitive electrode, respectively. Intracellular pH (pH(i)) was monitored by the BCECF assay. Although there was weak staining of the nNOS protein expression, L-Arg-induced NO generation was negligible in normal (140 mM NaCl) solution. Both were significantly (P0.05) increased either in the presence of furosemide (12 microM), an inhibitor of the Na(+)-K(+)-2Cl(-) cotransporter, or in a low (23 mM) Cl(-) solution. Furosemide- and low Cl(-)-induced NO generation was completely inhibited by 50 microM 7-nitroindasole (7-NI), a nNOS inhibitor. Moreover, these increases were significantly (P0.05) inhibited by the addition of 100 microM amiloride, an inhibitor of the Na(+)/H(+) exchanger, or by its analogue 5-(N)-ethyl-N-isopropyl amiloride (EIPA), and also at a lower pH of 7.1. Furthermore, nNOS expression and NO release were not stimulated in as low as 19 mM Na(+) solution. In conclusion, low [Cl(-)], but not low [Na(+)] in the lumen at the MD, increased nNOS protein expression and NO generation. Changes in the luminal [NaCl] may modulate the TGF system via an effect on the NO generation from the MD.

Activity-induced long-term modification of glutamatergic synapses depends on the frequency of synaptic activation. We found that long-term modification of developing rat hippocampal GABAergic synapses that was induced by repetitive coincident pre- and postsynaptic spiking was also frequency dependent. Spiking at 20-50 Hz resulted in synaptic potentiation, whereas spiking at 5 Hz led to synaptic depression. The potentiation was abolished by blocking GABA(B) receptors (GABA(B)Rs), whereas the depression was independent of GABA(B)R activation and could be converted to potentiation by elevating GABA(B)R activity. The potentiation could be attributed to a local postsynaptic increase in Na(+)/K(+)/2Cl(-) co-transporter activity near activated synapses. The activity of postsynaptic Ca(2+)/calmodulin-dependent protein kinase II was necessary for long-term potentiation of these developing GABAergic synapses and its phosphorylation at Thr286 could be enhanced by activating GABA(B)Rs with baclofen. Together with our finding that activation of GABA(B)Rs is frequency dependent, these results indicate that postsynaptic GABA(B)R activation mediates frequency-dependent potentiation of developing GABAergic synapses.

The Na+/H+ exchanger has been the only unequivocally demonstrated H+-transport mechanism in the synaptosomal preparation. We had previously suggested that a Cl−–H+ symporter (in its acidifying mode) is involved in cytosolic pH regulation in the synaptosomal preparation. Supporting this suggestion, we now show that: (1) when synaptosomes are transferred from PSS to either gluconate or sulfate solutions, the Fura-2 ratio remains stable instead of increasing as it does in 50 mM K solution. This indicates that these anions do not promote a plasma membrane depolarization. (2) Based in the recovery rate from the cytosolic alkalinization, the anionic selectivity of the Cl−–H+ symporter is NO 3 − > Br− > Cl− >> I− = isethionate = sulfate = methanesulfonate = gluconate. (3) PCMB 10 μM inhibits the gluconate-dependent alkalinization by 30 ± 6%. (4) Neither Niflumic acid, 9AC, Bumetanide nor CCCP inhibits the recovery from the cytosolic alkalinization.

BACKGROUND: Drug-induced ototoxicity is a subject of interest because many diseases are treated with drugs that have potential toxic effects on the ear. There is evidence that both inner ear and kidney tissue are immunologically, biochemically and functionally related. It has been suggested that drugs that influence the transport of sodium and/or potassium change ionic homeostasis in the inner ear and, hence, induce functional disturbances such as hearing loss, tinnitus and vertigo. OBJECTIVES: To assess whether renal suspected adverse drug reactions (sADRs) have predictive value for ear and labyrinth adverse drug reactions (ADRs) and whether drug classes involved have influence ion transport systems. STUDY DESIGN: Data were obtained from the Netherlands Pharmacovigilance Centre Lareb. The study base comprised all reports of sADRs up until 1 January 2007. Cases were all sADRs for relevant renal disorders and all sADRs for relevant ear disorders. All other reported sADRs were selected as 'non-cases'. The relationship between drug classes and renal, ear and labyrinth sADRs was evaluated by calculating reporting odds ratios (RORs). An ROR > or = 1.50 was regarded as a cut-off value for an association. Drug classes were classified into four groups: (A) ROR kidney or = 1.50; (C) ROR kidney > or = 1.50 and ROR ear or = 1.50 and ROR ear > or = 1.50. For each group, we calculated odds ratios (ORs) for the association between the group classification and the effect on ion channels/ion transport systems in kidney and ear tissues. RESULTS: Of 193 drug classes with relevant ADRs for renal disorders, 120 drug classes also had reports on ototoxic reactions. Fourteen out of 120 drug classes had an ROR > or = 1.50 for the association between the drug class and both renal and ear sADRs. Among these drug classes were several with a well known ability to induce renal (adverse) effects and ear and labyrinth disorders, such as loop diuretics, aminoglycosides and quinine. We found that one mechanistic commonality of the drug classes mentioned in the reports was the ability to affect ion transport systems. The percentage of drugs having this property differed between the four groups. The ORs for groups D and B were significantly higher compared with the reference group (OR 12.2, 95% CI 3.0, 30.5 and OR 8.7, 95% CI 2.4, 18.7, respectively), whereas there was no association for group C. CONCLUSION: Our data suggest that renal sADRs as such are not a marker for drug-induced ear and labyrinth disorders. However, the ability of drugs to act on ion channels or ion transport systems and, therefore, have an influence on ionic homeostasis in the kidney and ear might be a predictor for the possible occurrence of drug-related ototoxicity.

The authors investigate the effect of bumetan ide, an inhibitor of NKCC1 and a loop diuretic, on the tone of human umbilical artery (HUA). Rings of HUA (n = 35) from vaginal deliveries were suspended for isometric tension recordings in organ baths. Cumulative concentration-response curves to serotonin, histamine, and KCl were performed in the absence (control) or in the presence of bumetanide. The relaxant effect of bumetanide was also evaluated in serotonin- and histamine-induced contractions. Bumetanide inhibited HUA tone in serotonin- and histamine-induced contractions with significant changes in the potency (pD(2)) and maximum contractile response (E(max)) values. However, only pD( 2) values for KCl-induced contraction significantly changed in the presence of bumetanide. Bumetanide caused concentration-dependent and sustained relaxations in serotonin-induced contraction; however, there was refractoriness in histamine-induced contraction. These findings raise the possibility that NKCC1 may play a role in the regulation of the umbilical artery tone.

Current goals in the acute treatment of heart failure are focused on pulmonary and systemic decongestion with loop diuretics as the cornerstone of therapy. Despite rapid relief of symptoms in patients with acute decompensated heart failure, after intravenous use of loop diuretics, the use of these agents has been consistently associated with adverse events, including hypokalemia, azotemia, hypotension, and increased mortality. Two recent randomized trials have shown that continuous infusions of loop diuretics did not offer benefit but were associated with adverse events, including hyponatremia, prolonged hospital stay, and increased rate of readmissions. This is probably due to the limitations of congestion evaluation as well as to the deleterious effects linked to drug administration, particularly at higher dosage. The impaired renal function often associated with this treatment is not extensively explored and could deserve more specific studies. Several questions remain to be answered about the best diuretic modality administration, global clinical impact during acute and post-discharge period, and the role of renal function deterioration during treatment. Thus, if loop diuretics are a necessary part of the treatment for acute heart failure, then there must be an approach that allows personalization of therapy for optimal benefit and avoidance of adverse events.

The renal collecting system (CS) is composed of segment-specific (SS) and intercalated (IC) cells. The latter comprise at least two subtypes (type A and non-type A IC). The origin and maintenance of cellular heterogeneity in the CS is unclear. Among other hypotheses, it was proposed that one subtype of IC cells represents a stem cell population from which all cell types in the CS may arise. In the present study, we tested this stem cell hypothesis for the adult kidney by assessing DNA synthesis as a marker for cell replication. SS and IC cells were identified by their characteristic expressions of sodium- (epithelial sodium channel, Na–K-ATPase), water- (aquaporin-2) and acid/base- (H⁺-ATPase, anion exchanger AE1) transporting proteins. Immunostaining for bromodeoxyuridine (BrdU) and for the proliferating cell nuclear antigen (PCNA) was used to reveal DNA synthesis in CS epithelium. BrdU- and PCNA-immunostaining as well as mitotic figures were seen in all subtypes of CS cells. Dividing cells retained the cell-type specific expression of marker molecules. Treatment of mice with bumetanide combined with a high oral salt intake, which increases the tubular salt load in the CS, profoundly increased the DNA-synthesis rate in SS and non-type A IC cells, but reduced it in type A IC cells. Thus, our data show that DNA synthesis and cell replication occur in each cell lineage of the CS and in differentiated cells. The replication rate in each cell type can be differently modulated by functional stimulation. Independent proliferation of each cell lineage might contribute to maintain the cellular heterogeneity of the CS of the adult kidney and may also add to the adaptation of the CS to altered functional requirements.

According to the rules of GABA(A) receptor (GABA(A)R) subunit assembly, alpha4 and alpha6 subunits are considered to be the natural partners of delta subunits. These GABA(A)Rs are a preferred target of low, sobriety-impairing concentrations of ethanol. Here we demonstrate a new naturally occurring GABA(A)R subunit partnership: delta subunits of hippocampal interneurons are coexpressed and colocalized with alpha1 subunits, but not with alpha4, alpha6 or any other alpha subunits. Ethanol potentiates the tonic inhibition mediated by such native alpha1/delta GABA(A)Rs in wild-type and in alpha4 subunit-deficient (Gabra4(-/-)) mice, but not in delta subunit-deficient (Gabrd(-/-)) mice. We also ruled out any compensatory upregulation of alpha6 subunits that might have accounted for the ethanol effect in Gabra4(-/-) mice. Thus, alpha1/delta subunit assemblies represent a new neuronal GABA(A)R subunit partnership present in hippocampal interneurons, mediate tonic inhibitory currents and are highly sensitive to low concentrations of ethanol.