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This study aimed to evaluate the discharge waters in the Nerodime River and the impact of the seasons on the quality of the surface waters in the Nerodime River. Research data were collected at six locations along the Nerodime River in three seasons of 2021. During this research, 14 physico-chemical parameters and total coliform bacteria were analyzed. Based on the study results, most of the tested parameters are above the maximum values allowed in conformity with the legislation in Kosova (Administrative Instruction (MMPH) No. 30/2014 and Administrative Instruction (MMPH) No. 16/2012). CCA (canonical correspondence analysis) indicates that Total coliform bacteria were in positive correlation with turbidity, color, chlorides, sulphates, and total coliform bacteria. This Poor quality is a consequence of anthropogenic activities including industrial water use and sewage discharge. [ABSTRACT FROM AUTHOR]

Introduction: Hypertonic saline is often used to treat patients with traumatic brain injury. It carries the undesired side effect of hyperchloremia, which has been linked to acute kidney injury (AKI). We sought to evaluate the relationship of hyperchloremia and AKI in this population and whether the absolute exposure to hyperchloremia, including maximal hyperchloremia and duration of hyperchloremia were associated with AKI. Methods: A retrospective study of severe traumatic brain injury patients who received hypertonic saline at a single academic institution. Demographics, head abbreviated injury scale, development of hyperchloremia (Cl ≥ 115), duration of hyperchloremia, highest chloride level, duration of hypertonic saline use, admission GFR, and administration of nephrotoxic medications were abstracted. The outcome of interest was the association between renal function and hyperchloremia. Results: A total of 123 patients were included in the study. Multivariable logistic regression analysis demonstrated that only duration of hyperchloremia (p = 0.014) and GFR on admission (p = 0.004) were independently associated with development of AKI. The number of days of hypertonic saline infusion (p = 0.79) without the persistence of hyperchloremia and highest serum chloride levels (p = 0.23) were not predictive of AKI development. Discussion: In patients with traumatic brain injury, admission GFR and prolonged hyperchloremia rather than the highest chloride level or the duration of hypertonic saline infusion were associated with the development of AKI. [ABSTRACT FROM AUTHOR]

The article presents a study for examining correlation between ivacaftor-induced cystic fibrosis transmembrane conductance regulator (CFTR) activation in airway epithelial cells and improved lung function. Topics discussed include concentration of chloride in sweat (SwCl) as a central biomarker to diagnose CF, cells in PneumaCult EX medium (Stemcell) supplemented with fluconazole and antibiotics targeting CF pathogens; and drug-induced chloride transport.

Background: Early studies have reported various electrolyte abnormalities at admission in patients who progress to the severe form of coronavirus disease 2019 (COVID-19). As electrolyte imbalance may not only impact patient care, but provide insight into the pathophysiology of COVID-19, we aimed to analyse all early data reported on electrolytes in COVID-19 patients with and without severe form.Methods: An electronic search of Medline (PubMed interface), Scopus and Web of Science was performed for articles comparing electrolytes (sodium, potassium, chloride and calcium) between COVID-19 patients with and without severe disease. A pooled analysis was performed to estimate the weighted mean difference (WMD) with 95% confidence interval.Results: Five studies with a total sample size of 1415 COVID-19 patients. Sodium was significantly lower in patients with severe COVID-19 (WMD: -0.91 mmol/L [95% CI: -1.33 to -0.50 mmol/L]). Similarly, potassium was also significantly lower in COVID-19 patients with severe disease (WMD: -0.12 mmol/L [95% CI: -0.18 to -0.07 mmol/L], I2=33%). For chloride, no statistical differences were observed between patients with severe and non-severe COVID-19 (WMD: 0.30 mmol/L [95% CI: -0.41 to 1.01 mmol/L]). For calcium, a statistically significant lower concentration was noted in patients with severe COVID-19 (WMD: -0.20 mmol/L [95% CI: -0.25 to -0.20 mmol/L]).Conclusions: This pooled analysis confirms that COVID-19 severity is associated with lower serum concentrations of sodium, potassium and calcium. We recommend electrolytes be measured at initial presentation and serially monitored during hospitalization in order to establish timely and appropriate corrective actions. [ABSTRACT FROM AUTHOR]

Objective: Dysregulation of γ-aminobutyric acidergic (GABAergic) transmission has been reported in lesional acquired epilepsies (gliomas, hippocampal sclerosis). We investigated its involvement in a developmental disorder, human focal cortical dysplasia (FCD), focusing on chloride regulation driving GABAergic signals.Methods: In vitro recordings of 47 human cortical acute slices from 11 pediatric patients who received operations for FCD were performed on multielectrode arrays. GABAergic receptors and chloride regulators were pharmacologically modulated. Immunostaining for chloride cotransporter KCC2 and interneurons were performed on recorded slices to correlate electrophysiology and expression patterns.Results: FCD slices retain intrinsic epileptogenicity. Thirty-six of 47 slices displayed spontaneous interictal discharges, along with a pattern specific to the histological subtypes. Ictal discharges were induced in proepileptic conditions in 6 of 8 slices in the areas generating spontaneous interictal discharges, with a transition to seizure involving the emergence of preictal discharges. Interictal discharges were sustained by GABAergic signaling, as a GABAA receptor blocker stopped them in 2 of 3 slices. Blockade of NKCC1 Cl- cotransporters further controlled interictal discharges in 9 of 12 cases, revealing a Cl- dysregulation affecting actions of GABA. Immunohistochemistry highlighted decreased expression and changes in KCC2 subcellular localization and a decrease in the number of GAD67-positive interneurons in regions generating interictal discharges.Interpretation: Altered chloride cotransporter expression and changes in interneuron density in FCD may lead to paradoxical depolarization of pyramidal cells. Spontaneous interictal discharges are consequently mediated by GABAergic signals, and targeting chloride regulation in neurons may be considered for the development of new antiepileptic drugs. Ann Neurol 2019; 1-14 ANN NEUROL 2019;85:204-217. [ABSTRACT FROM AUTHOR]

Three studies evaluated the effects of added dietary salt on growth performance of pigs weighing 7 to 10, 11 to 30, and 27 to 65 kg. In experiment 1, 325 pigs were used with 5 pigs per pen and 13 pens per treatment. Pigs were fed a diet (0.39% Na and 0.78% Cl) for 7 d after weaning, then randomly assigned to diets with either 0, 0.20, 0.40, 0.60, or 0.80% added salt for 14 d. All diets were corn-soybean meal-based with 10% dried whey. Calculated Na concentrations were 0.11, 0.19, 0.27, 0.35, and 0.43% and calculated Cl concentrations were 0.23, 0.35, 0.47, 0.59, and 0.70%, respectively. Increasing salt increased (linear, P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F). For ADG, the linear, quadratic polynomial (QP), and broken-line linear (BLL) models were competing with the breakpoint for the BLL at 0.59% salt. For G:F, the BLL reported a breakpoint at 0.33% while the QP indicated maximum G:F at 0.67% added salt. In experiment 2, 300 pigs were used in a 34-d trial with 5 pigs per pen and 12 pens per treatment. Pigs were weaned at 21 d of age and fed a phase 1 diet (0.50% Na and 0.67% Cl) for 11 d and then a phase 2 diet (0.35% Na and 0.59% Cl) for 14 d. Then pens of pigs were randomly assigned to corn-soybean meal-based diets containing 0.20, 0.35, 0.50, 0.65, or 0.80% added salt. Calculated dietary Na concentration were 0.10, 0.16, 0.22, 0.28, and 0.34% and calculated Cl concentrations were 0.23, 0.32, 0.41, 0.50, and 0.59%, respectively. Overall, ADG and G:F increased (quadratic, P < 0.07) with increasing added salt. For ADG, the QP and BLL had similar fit with the breakpoint for BLL at 0.51% added salt. For G:F, the BLL model predicted a break point at 0.35% added salt. In experiment 3, 1,188 pigs were used in a 44-d study with 27 pigs per pen and 11 pens per treatment. Pens of pigs were randomly assigned to corn-soybean meal-based diets containing 0.10, 0.33, 0.55, or 0.75% added salt. Calculated dietary Na concentrations were 0.10, 0.19, 0.28, and 0.36% and calculated Cl concentrations were 0.23, 0.36, 0.49, and 0.61%, respectively. Overall, there was no evidence to indicate that added salt above 0.10% of the diet affected growth. In conclusion, the BLL models suggested to maximize ADG for 7 to 10 and 11 to 30 kg pigs was 0.59% (0.34% Na and 0.58% Cl) and 0.51% added salt (0.22% Na and 0.42% Cl), respectively. There was no evidence that growth of 27 to 65 kg pigs was improved beyond 0.10% added salt (0.11% Na and 0.26% Cl). [ABSTRACT FROM AUTHOR]

Background/Aims: One potential pathomechanism how low nephron number leads to hypertension in later life is altered salt handling. We therefore evaluated changes in electrolyte and water content in wildtype (wt) and GDNF+/- mice with a 30% reduction of nephron number. Methods: 32 GDNF+/- and 36 wt mice were fed with low salt (LSD, 0.03%, normal drinking water) or high salt (HSD, 4%, 0.9% drinking water) diet for 4 weeks. Blood pressure was continuously measured by telemetry in a subgroup. At the end of the experiment and after standardized ashing processes electrolyte- and water contents of the skin and the total body were determined. Results: We found higher blood pressure in high salt treated GDNF+/-compared to wt mice. Of interest, we could not confirm an increase in total-body sodium as predicted by prevailing explanations, but found increased total body and skin chloride that interestingly correlated with relative kidney weight. Conclusion: We hereby firstly report significant total body and skin chloride retention in salt sensitive hypertension of GDNF+/-mice with genetically determined lower nephron number. Thus, in contrast to the prevailing opinion our data argue for the involvement of non-volume related mechanisms. [ABSTRACT FROM AUTHOR]

Background: Recurrent airway infections are common in patients with Down's syndrome (DS). Hence, ruling out Cystic Fibrosis (CF) in these patients is often required. In the past, the value of sweat testing - the gold standard to diagnose CF - has been questioned in DS as false positive results have been reported. However, these reports are based on measurements of sweat osmolality or sodium concentrations, not chloride concentrations. This study analyses sweat secretion rate and chloride concentration in sweat samples of patients with DS in comparison to healthy controls.Methods: We assessed sweat samples in 16 patients with DS and 16 healthy controls regarding sweat secretion rate (SSR) and sweat chloride concentration.Results: All measured chloride concentrations were within the normal range. The chloride concentrations were slightly, but not significantly lower in patients with DS (15,54 mmol/l (±4,47)) compared to healthy controls (18,31 mmol/l (±10,12)). While no gender gap in chloride concentration could be found, chloride concentration increased with age in both groups. Insufficient sweat was collected in 2 females with DS (12.5% of the study group) but not in an individual of the control group. A significant lower sweat secretion rate was found in the DS group (27,6 μl/30 min (± 12,18)) compared to the control group (42,7 μl/30 min (± 21,22)). In a sub-analysis, female patients produced significantly less sweat (20,8 ± 10,6 μl/30 min) than male patients with DS (36,4 ± 7,8 μl/30 min), which accounts for the difference between patients and controls. Furthermore, while the sweating secretion rate increased with age in the control group, it did not do so in the DS group. Once again this was due to female patients with DS, who did not show a significant increase of sweat secretion rate with age.Conclusions: Sweat chloride concentrations were within the normal range in patients with DS and therefore seem to be a reliable tool for testing for CF in these patients. Interestingly, we found a reduced sweat secretion rate in the DS group. Whether the last one has a functional and clinical counterpart, possibly due to a disturbed thermoregulation in DS patients, requires further investigation. [ABSTRACT FROM AUTHOR]

Rationale The association between CFTR genotype, sweat chloride and mortality has been inconsistent, but no previous analyses have examined the association stratified by individual genotypes. Objectives To evaluate the genotype-specific association between sweat chloride and mortality. Methods The CFF Patient Registry was assessed and included all patients in the registry between 1996 and 2012 with at least one F508del allele. We excluded patients without a documented genotype or plausible sweat chloride level. The primary outcome was time to mortality during the observation period. We examined 15 genotypes using the three most prevalent alleles in each of 5 classes. We compared subgroups of sweat chloride using Kaplan-Meier curves, log-rank tests, and multivariable Cox PH models. The overall predictive value of sweat chloride on mortality was assessed using area under the receiver operating characteristic curves. Measurements and main results 18,893 subjects met inclusion criteria. Sweat chloride distribution was similar across genotypes in patients with class 1 mutations, but was significantly different across genotypes in mutation classes 2–5. The R117H/F508del genotype patients demonstrated an association between sweat chloride and mortality (HR: 1.32 for every 10 mmol/L increase in sweat chloride [95% CI 1.12–1.54]. There were also significant associations in patients with F508del/F508del, I507del/F508del, G551D/F508del and 2789 + 5G → A/F508del genotypes, though the clinical relevance for these genotypes is unclear. Conclusions There is significant variability in sweat chloride distribution across CFTR class 2–5 genotypes. The relationship between sweat chloride and mortality varies by genotype with a relatively strong relationship in R117H/F508del patients. [ABSTRACT FROM AUTHOR]

Background Using sweat chloride as a biomarker for CFTR modifying drugs requires knowledge of analytical and biological variation. Methods 979 sweat chloride concentrations from 128 subjects enrolled in the placebo arm of 2 multicenter, investigational drug trials were analyzed to determine coefficients of variation (CV) as well as reference change value (RCV) and index of individuality (II). Results For these populations, calculated values for the two studies were: analytical variation (3.9, 4.1%); within-subject variation (4.4, 6.0%); between-subject variation (8.9, 7.0%); RCV (13.7, 17.0%) and II (0.7, 1.0). Sweat chloride variation was not affected by sex, collection site or sample weight; but was slightly affected by age in one of the two studies. Conclusion Through determination of analytical as well as between- and within-subject variation, and with a larger sample size, our data allows improved estimates of the RCV and II, and can contribute to future trials of CFTR modulators and inform the design and interpretation of n of 1 trials in both research and clinical settings. [ABSTRACT FROM AUTHOR]

This study aimed to use atomic force microscopy to compare effects of ultrasound bath, injecting calcium chloride solution and sodium chloride solution on the ultrastructure of muscle fibers and choose the preferred meat tenderizing method. The muscles fibers were tenderized and then scanned by atomic force microscopy. When meat was treated by ultrasound bath (50 W, 100 W, 250 W), CaCl2 injection (400 mM, 500 mM) and NaCl injection (100, 200, 300, 400, 500 mM), the sarcomere length was longer as compared with the control (P < 0.05). In consideration of the consumer demand and other palatability and quality traits of meat, the ultrasound bath could be applied to improve meat tenderness without detrimental effects. [ABSTRACT FROM AUTHOR]

Here, we are reporting a sensitive, simple and rapid method for the analysis of cyanidin chloride and pelargonidin chloride anthocyanins in cherry, sour cherry, pomegranate and barberry produced in Iran. The analytes were extracted with acetonitrile-hydrochloric acid (1% v/v) mixture under optimized pretreatment conditions. Clean-up of the extract from fruits was conducted by magnetic solid phase extraction using salicylic acid functionalized silica-coated magnetite nanoparticles (SCMNPs) as the adsorbent. The optimized conditions searched with central composite design. Working under optimum conditions specified as: SCMNPs modified with salicylic acid, sorbent contact time and sample 10 min, mechanical stirring time 57.3 min. HPLC with UV-detection was used for determination of the analytes. The limit of detection, LOD, obtained for the two anthocyanins were 0.02 and 0.03 μg g −1 , respectively. The ranges of the spiked recoveries were 80.0–97.6 and 72.9–97.2%, with the relative standard deviations (RSD) of 2.1 and 2.5%, respectively. [ABSTRACT FROM AUTHOR]

Background Hyperchloremia produces renal vasoconstriction and fall in glomerular filtration rate. In 90% of brain-dead organ donors, diabetes insipidus develops, characterized by inappropriate diuresis, hyperosmolality, and hyperchloremia. The aim of this study was to determine the relationship between the serum concentration of chlorides of the donor and the onset of the function of the kidney allograft in the recipient. Methods We retrospectively studied 213 donors and kidney allograft recipients. Serum creatinine concentrations and glomerular filtration rates on the 1st, 7th, and 30th days after transplantation of the recipients from hyperchloremic donors were compared with the recipients from normochloremic donors, as well as the incidences of acute tubular necrosis and delayed graft function. Results On the 1st day, serum creatinine concentrations of the recipients from hyperchloremic and normochloremic donors, respectively, were 448.2 ± 212.1 μmol/L and 502.2 ± 197.8 μmol/L ( P = .1), on the 7th day, 168.6 ± 102.6 μmol/L and 196.9 ± 120.6 μmol/L ( P = .13), and on the 30th day, 129.4 ± 43.3 μmol/L and 131.8 ± 43.6 μmol/L ( P = .73). The differences were statistically significant. The groups also did not differ significantly in glomerular filtration rates and incidences of acute tubular necrosis and delayed graft function. Conclusions In this study, no significant correlation between serum chloride concentrations of the organ donors and the onset of the function of kidney allografts in the recipients was found. [ABSTRACT FROM AUTHOR]

Stroke is one of the major causes of death and disability worldwide. The major type of stroke is an ischaemic one, which is caused by a blockage that interrupts blood flow to the brain. There are currently very few pharmacological strategies to reduce the damage and social burden triggered by this pathology. The harm caused by the interruption of blood flow to the brain unfolds in the subsequent hours and days, so it is critical to identify new therapeutic targets that could reduce neuronal death associated with the spread of the damage. Here, we review some of the key molecular mechanisms involved in the progression of neuronal death, focusing on some new and promising studies. In particular, we focus on the potential of the chloride co-transporter (CCC) family of proteins, mediators of the GABAergic response, both during the early and later stages of stroke, to promote neuroprotection and recovery. Different studies of CCCs during the chronic and recovery phases post-stroke reveal the importance of timing when considering CCCs as potential neuroprotective and/or neuromodulator targets. The molecular regulatory mechanisms of the two main neuronal CCCs, NKCC1 and KCC2, are further discussed as an indirect approach for promoting neuroprotection and neurorehabilitation following an ischaemic insult. Finally, we mention the likely importance of combining different strategies in order to achieve more effective therapies. [ABSTRACT FROM AUTHOR]

Introduction Sweat chloride concentration, a biomarker of CFTR function, is an appropriate outcome parameter in clinical trials aimed at correcting the basic CF defect. Although there is consensus on a cut-off value to diagnose CF, we have only limited information on the within subject variability of sweat chloride over time. Such information would be useful for sample size calculations in clinical trials. Therefore, we retrospectively analyzed repeated sweat chloride values obtained in patients with G551D mutation(s) assigned to placebo in an ivacaftor interventional trial. Methods In subjects with G551D at least 12 years of age, a pilocarpine sweat test using Macroduct collector was taken on both arms at 8 time points over 48 weeks. We explored 1062 pilocarpine sweat test values obtained in 78 placebo patients of the VX08-770-102 trial. Results Mean overall sweat chloride value (all patients, all tests, n = 1062) was 100.8 mmol/L (SD 12.7 mmol/L). Using a multilevel mixed model, the between-subject standard deviation (SD) for sweat chloride was 8.9 mmol/L (95% CI 7.4–10.6) and within-subject SD was 8.1 mmol/L (95% CI 7.5–8.7). Limits of repeatability for repeat measurements were − 19.7 to + 21.6 mmol/L using values from one arm, and − 13.3 to 11.8 mmol/L using mean of values obtained at 4 test occasions. Sample size calculations showed that the minimal treatment effect on sweat chloride concentration that can be demonstrated for a group of 5 patients is around 15 mmol/L, using a cross-over design and combinations of 4 tests for each phase of the trial. Conclusion Although the sweat test is considered a robust measure, sweat chloride measurements in patients with CF and a G551D mutation had an inherent biological variability that is higher than commonly considered. Further analyses of placebo group data are crucial to learn more about the natural variability of this outcome parameter. [ABSTRACT FROM AUTHOR]

Ivacaftor, a CFTR potentiator that enhances chloride transport by acting directly on CFTR to increase its channel gating activity, has been evaluated in patients with different CFTR mutations. Several previous analyses have reported no statistical correlation between change from baseline in ppFEV 1 and reduction in sweat chloride levels for individuals treated with ivacaftor. The objective of the post hoc analysis described here was to expand upon previous analyses and evaluate the correlation between sweat chloride levels and absolute ppFEV 1 changes across multiple cohorts of patients with different CF-causing mutations who were treated with ivacaftor. The goal of the analysis was to help define the potential value of sweat chloride as a pharmacodynamic biomarker for use in CFTR modulator trials. For any given study, reductions in sweat chloride levels and improvements in absolute ppFEV 1 were not correlated for individual patients. However, when the data from all studies were combined, a statistically significant correlation between sweat chloride levels and ppFEV 1 changes was observed (p < 0.0001). Thus, sweat chloride level changes in response to potentiation of the CFTR protein by ivacaftor appear to be a predictive pharmacodynamic biomarker of lung function changes on a population basis but are unsuitable for the prediction of treatment benefits for individuals. [ABSTRACT FROM AUTHOR]

Background The sweat test is the current gold standard for the diagnosis of cystic fibrosis (CF). CF is unlikely when sweat chloride (Cl sw ) is lower than 30 mmol/L, Cl sw > 60 is suggestive of CF, with intermediate values between 30 and 60 mmol/L. To correctly interpret a sweat chloride value, the biological variability of the sweat chloride has to be known. Methods Sweat tests performed in two centers using the classic Gibson and Cooke method were retrospectively reviewed (n = 5904). Within test variability of Cl sw was measured by comparing results from right and left arm collected on the same day. Between test variability was calculated from subjects with sweat tests performed on more than one occasion. Results Within test variability of Cl sw calculated in 1022 subjects was low with differences between − 3.2 (p5) and + 3.6 mmol/L (p95). Results from left and right arm were classified differently in only 3 subjects. Between test variability of Cl sw in 197 subjects was larger, with differences between − 18.2 mmol/L (p5) and + 14.1 mmol/L (p95) between repeat tests. Changes in diagnostic conclusion were seen in 55/197 subjects, the most frequent being changing from indeterminate to ‘CF unlikely’ range (48/102). Conclusion Variability of sweat chloride is substantial, with frequent changes in diagnostic conclusion, especially in the intermediate range. [ABSTRACT FROM AUTHOR]

Postoperative pain is a critical problem in clinical pain administration. Due to the unclear formation mechanism of postoperative pain, the treatment of postoperative pain is still in the symptomatic treatment stage and lacking satisfactory analgesic effect. Postoperative pain can be simulated by using a rat incision pain model. We observed changes in pain-related behavior of rats affected by the 5-hydroxytryptamine 2A receptor (5-HT2AR) agonist, TCB-2, and antagonist, ketanserin, through intrathecal delivery. The transcription and translation level of potassium-chloride cotransporter 2 (KCC2) in the spinal cord was also measured to investigate the role of the 5-HT2AR-KCC2 pathway in the mechanism of incision pain. Compared with the control group, rats in the incision pain group had decreased mechanical withdrawal threshold (MWT), with significant differences on day 1-7 after surgery, and significant decreases in thermal withdrawal latency (TWL) on days 1, 2, 3 and 6 (P<0.05). Compared with the incision + dimethyl sulfoxide (DMSO) group, MWT and TWL decreased in the incision + ketanserin group on day 1 and 2 (P<0.05). There was no significant difference detected in TWL of incision + TCB-2 group on day 1, while MWT increased significantly compared to the incision + DMSO group (P<0.05). Furthermore, the transcription and translation levels of KCC2 in the incision + ketanserin group decreased significantly in comparison to the incision + DMSO group (P<0.05), while an increase was detected in the incision + TCB-2 group (P<0.05). MWT and TWL decreased in the incision pain rats, accompanied with a decreased transcription and translation level of KCC2. Intrathecal delivery of the 5-HT2AR agonist, TCB-2, alleviated the decreased WMT and inhibited the decreased transcription and translation level of KCC2, while intrathecal delivery of the 5-HT2AR antagonist, ketanserin, aggravated the decreased WMT and transcription and translation levels of KCC2, suggesting the involement of the 5-HT2AR-KCC2 pathway in the formation mechanism of incision pain in rats. [ABSTRACT FROM AUTHOR]

The article discusses the use of fluid resuscitation with crystalloid solutions as common interventions for hospitalized patients. It highlights several side effects of saline including hyperchloremia, metabolic acidosis and increase mortality in at-risk patients. It also stresses the decrease of renal blood flow due to high-chloride solutions.

KCC2 is the central regulator of neuronal Cl− homeostasis, and is critical for enabling strong hyperpolarizing synaptic inhibition in the mature brain. KCC2 hypofunction results in decreased inhibition and increased network hyperexcitability that underlies numerous disease states including epilepsy, neuropathic pain and neuropsychiatric disorders. The current holy grail of KCC2 biology is to identify how we can rescue KCC2 hypofunction in order to restore physiological levels of synaptic inhibition and neuronal network activity. It is becoming increasingly clear that diverse cellular signals regulate KCC2 surface expression and function including neurotransmitters and neuromodulators. In the present review we explore the existing evidence that G-protein-coupled receptor (GPCR) signalling can regulate KCC2 activity in numerous regions of the nervous system including the hypothalamus, hippocampus and spinal cord. We present key evidence from the literature suggesting that GPCR signalling is a conserved mechanism for regulating chloride homeostasis. This evidence includes: (1) the activation of group 1 metabotropic glutamate receptors and metabotropic Zn2+ receptors strengthens GABAergic inhibition in CA3 pyramidal neurons through a regulation of KCC2; (2) activation of the 5-hydroxytryptamine type 2A serotonin receptors upregulates KCC2 cell surface expression and function, restores endogenous inhibition in motoneurons, and reduces spasticity in rats; and (3) activation of A3A-type adenosine receptors rescues KCC2 dysfunction and reverses allodynia in a model of neuropathic pain. We propose that GPCR-signals are novel endogenous Cl− extrusion enhancers that may regulate KCC2 function. [ABSTRACT FROM AUTHOR]

Fast synaptic inhibition relies on tight regulation of intracellular Cl − . Chloride dysregulation is implicated in several neurological and psychiatric disorders. Beyond mere disinhibition, the consequences of Cl − dysregulation are multifaceted and best understood in terms of a dynamical system involving complex interactions between multiple processes operating on many spatiotemporal scales. This dynamical perspective helps explain many unintuitive manifestations of Cl − dysregulation. Here we discuss how taking into account dynamical regulation of intracellular Cl − is important for understanding how synaptic inhibition fails, how to best detect that failure, why Cl − regulation is energetically so expensive, and the overall consequences for therapeutics. [ABSTRACT FROM AUTHOR]

Background. High serum sodium (sNa) concentrations may be associated with hypertension, which deteriorates kidney function. However, it is equivocal whether high sNa concentrations are associated with impaired kidney function independently of blood pressure (BP) or serum chloride (sCl). Therefore, we addressed this issue in an apparently healthy population. Methods. Clinical variables including estimated glomerular filtration rate (eGFR) were examined in 3603 men and women (aged 25–75 years) who underwent health-screening check-ups. sNa concentrations were classified into five categories. Results. Most parameters, including age and BP, increased with increasing sNa, whereas eGFR decreased. Logistic regression analysis showed that, compared with low–normal sNa (≤ 140 mEq/l), high sNa (≥ 144 mEq/l) was significantly associated with elevated BP (≥ 130/85 mmHg) even after adjustment for blood hematocrit, eGFR, serum potassium (sK) concentration and sCl. The highest sNa category was significantly associated with reduced eGFR (< 60 ml/min/1.73 m2) independently of elevated BP. Unlike adjustment for sK, adjustment for sCl strengthened the association between high sNa and elevated BP but attenuated the association between high sNa and reduced eGFR. Conclusions. These results suggest that high sNa concentrations, even within the normal range, are independently associated with elevated BP and impaired kidney function. These associations may be substantially modified by sCl. [ABSTRACT FROM AUTHOR]

PKC regulates TMEM16Amediated Cl secretion in human biliary cells. Am J Physiol Gastrointest Liver Physiol 310: G34 –G42, 2016. First published November 5, 2015; doi:10.1152/ajpgi.00146.2015.—TMEM16A is a newly identified Ca2-activated Cl channel in biliary epithelial cells (BECs) that is important in biliary secretion. While extracellular ATP stimulates TMEM16A via binding P2 receptors and increasing intracellular Ca2 concentration ([Ca]i), the regulatory pathways have not been elucidated. Protein kinase C (PKC) contributes to ATPmediated secretion in BECs, although its potential role in TMEM16A regulation is unknown. To determine whether PKC regulates the TMEM16A-dependent membrane Cl transport in BECs, studies were performed in human biliary Mz-cha-1 cells. Addition of extracellular ATP induced a rapid translocation of PKC from the cytosol to the plasma membrane and activation of whole cell Ca2 -activated Cl currents. Currents demonstrated outward rectification and reversal at 0 mV (properties consistent with TMEM16A) and were inhibited by either molecular (siRNA) or pharmacologic (PMA or Gö6976) inhibition of PKC. Intracellular dialysis with recombinant PKC activated Cl currents with biophysical properties identical to TMEM16A in control cells but not in cells after transfection with TMEM16A siRNA. In conclusion, our studies demonstrate that PKC is coupled to ATP-stimulated TMEM16A activation in BECs. Targeting this ATP-Ca2 -PKC signaling pathway may represent a therapeutic strategy to increase biliary secretion and promote bile formation. TMEM16A;

Synaptic inhibition plays a key role in processing somatosensory information. Blocking inhibition at the spinal level is sufficient to produce mechanical allodynia, and many neuropathic pain conditions are associated with reduced inhibition. Disinhibition of spinal neurons can arise through decreased GABAA/glycine receptor activation or through dysregulation of intracellular chloride. We hypothesized that these distinct disinhibitory mechanisms, despite all causing allodynia, are differentially susceptible to therapeutic intervention. Specifically, we predicted that reducing bicarbonate efflux by blocking carbonic anhydrase with acetazolamide (ACTZ) would counteract disinhibition caused by chloride dysregulation without affecting normal inhibition or disinhibition caused by GABAA/glycine receptor blockade. To test this, responses to innocuous tactile stimulation were recorded in vivo from rat superficial dorsal horn neurons before and after different forms of pharmacological disinhibition and again after application of ACTZ. Blocking GABAA or glycine receptors caused hyperresponsiveness equivalent to that caused by blocking the potassium chloride cotransporter KCC2, but, consistent with our predictions, only disinhibition caused by KCC2 blockade was counteracted by ACTZ. ACTZ did not alter responses of neurons with intact inhibition. As pathological downregulation of KCC2 is triggered by brain-derived neurotrophic factor, we also confirmed that ACTZ was effective against brain-derived neurotrophic factor-induced hyperresponsiveness. Our results argue that intrathecal ACTZ has antiallodynic effects only if allodynia arises through chloride dysregulation; therefore, behavioral evidence that ACTZ is antiallodynic in nerve-injured animals affirms the contribution of chloride dysregulation as a key pathological mechanism. Although different disinhibitory mechanisms are not mutually exclusive, these results demonstrate that their relative contribution dictates which specific therapies will be effective. [ABSTRACT FROM AUTHOR]

The authors discuss changes in maternal physiology which cause changes in electrolyte and acid-base status of pregnant women and the factors to consider in adopting pregnancy-specific reference intervals. Topics discussed include the role of pregnancy reference intervals in clinical biochemistry, pregnancy dating and defining partitions, and vascular and renal physiology changes during pregnancy. It also discusses analytes such as sodium, potassium and chloride.

Glutamate is the major excitatory neurotransmitter, but prolonged exposure even at micromolar concentrations causes neuronal death. Extracellular glutamate is maintained at nanomolar level by glutamate transporters, which, however, may reverse transport and release glutamate. If and when the reverse occurs depends on glutamate transport stoichiometry (GTS). Previously we found that in the presence of chloride, the coupled GLT-1 glutamate transporter current and its relationship to radiolabeled glutamate flux significantly decreased when extracellular glutamate concentration increased above 0.2 mM, which implies a change in GTS. Such high concentrations are feasible near GLT-1 expressed close to synaptic release site during excitatory neurotransmission. The aim of this study was to determine GLT-1 GTS at both low (19–75 μM) and high (300–1200 μM) glutamate concentration ranges. GTS experiments were conducted in the absence of chloride to avoid contributions by the GLT-1 uncoupled chloride conductance. Mathematical analysis of the transporter thermodynamic equilibrium allowed us to derive equations revealing the number of a particular type of ion transported per elementary charge based on the measurements of the transporter reversal potential. We found that GLT-1a expressed in COS-7 cells co-transports 1.5 Na+, 0.5 Glu-, 0.5 H+ and counter-transports 0.6 K+ per elementary charge in both glutamate concentration ranges, and at both 37°C and 26°C temperatures. The thermodynamic parameter Q10 = 2.4 for GLT-1 turnover rate of 19 s-1 (37°C, -50 mV) remained constant in the 10 μM–10 mM glutamate concentration range. Importantly, the previously reported decrease in the current/flux ratio at high glutamate concentration was not seen in the absence of chloride in both COS-7 cells and cultured rat neurons. Therefore, only in the absence of chloride, GLT-1 GTS remains constant at all glutamate concentrations. Possible explanations for why apparent GTS might vary in the presence of chloride are discussed. [ABSTRACT FROM AUTHOR]

Background/Aims: Nobiletin, a citrus flavonoid isolated from tangerines, alters ion transport functions in intestinal epithelia, and has antagonistic effects on eosinophilic airway inflammation of asthmatic rats. The present study examined the effects of nobiletin on basal short-circuit current (ISC) in a human bronchial epithelial cell line (16HBE14o-), and characterized the signal transduction pathways that allowed nobiletin to regulate electrolyte transport. Methods: The ISC measurement technique was used for transepithelial electrical measurements. Intracellular calcium ([Ca2+]i) and cAMP were also quantified. Results: Nobiletin stimulated a concentration-dependent increase in ISC, which was due to Cl- secretion. The increase in ISC was inhibited by a cystic fibrosis transmembrane conductance regulator inhibitor (CFTRinh-172), but not by 4,4'-diisothiocyano-stilbene-2,2'-disulphonic acid (DIDS), Chromanol 293B, clotrimazole, or TRAM-34. Nobiletin-stimulated ISC was also sensitive to a protein kinase A (PKA) inhibitor, H89, and an adenylate cyclase inhibitor, MDL-12330A. Nobiletin could not stimulate any increase in ISC in a cystic fibrosis (CF) cell line, CFBE41o-, which lacked a functional CFTR. Nobiletin stimulated a real-time increase in cAMP, but not [Ca2+]i. Conclusion: Nobiletin stimulated transepithelial Cl- secretion across human bronchial epithelia. The mechanisms involved activation of adenylate cyclase- and cAMP/PKA-dependent pathways, leading to activation of apical CFTR Cl- channels. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Hyperpolarizing synaptic inhibition through GABA A and glycine receptors depends on the presence of the neuronal cation-chloride-cotransporter protein, KCC2. Several transcriptional and post-transcriptional mechanisms have been shown to regulate KCC2 and thereby influence the polarity and efficacy of inhibitory synaptic transmission. It is unclear however whether regulation of KCC2 enables the transporter to attain different levels of activity thus allowing a neuron to modulate the strength of inhibitory synaptic transmission to its changing requirements. We therefore investigated whether phosphorylation can allow KCC2 to achieve distinct levels of [Cl − ] i in neurons. We generated a variety of KCC2 alanine dephosphorylation mimics and used NH 4 + -induced pH i shifts in cultured hippocampal neurons to quantify the rate of KCC2 transport activity exhibited by these mutants. To explore the relationship between KCC2 transport and GABA A receptor-mediated current amplitudes we performed gramicidine perforated-patch recordings. The correlation between E GABA and NH 4 + -induced pH i shifts enabled an estimate of the range of chloride extrusion possible by kinase/phosphatase regulation of KCC2. Our results demonstrate that KCC2 transport can vary considerably in magnitude depending on the combination of alanine mutations present on the protein. Transport can be enhanced to sufficiently high levels that hyperpolarizing GABA A responses may be obtained even in neurons with an extremely negative resting membrane potential and at high extracellular K + concentrations. Our findings highlight the significant potential for regulating the inhibitory tone by KCC2-mediated chloride extrusion and suggest that cellular signaling pathways may act combinatorially to alter KCC2 phosphorylation/dephosphorylation and thereby tune the strength of synaptic inhibition. [ABSTRACT FROM AUTHOR]

The concentration of chloride ions in the cytoplasm and subcellular organelles of living cells spans a wide range (5-130 mM), and is tightly regulated by intracellular chloride channels or transporters. Chloride-sensitive protein reporters have been used to study the role of these chloride regulators, but they are limited to a small range of chloride concentrations and are pH-sensitive. Here, we show that a DNA nanodevice can precisely measure the activity and location of subcellular chloride channels and transporters in living cells in a pH-independent manner. The DNA nanodevice, called Clensor, is composed of sensing, normalizing and targeting modules, and is designed to localize within organelles along the endolysosomal pathway. It allows fluorescent, ratiometric sensing of chloride ions across the entire physiological regime. We used Clensor to quantitate the resting chloride concentration in the lumen of acidic organelles in Drosophila melanogaster. We showed that lumenal lysosomal chloride, which is implicated in various lysosomal storage diseases, is regulated by the intracellular chloride transporter DmClC-b. [ABSTRACT FROM AUTHOR]

The article presents abstracts on physiology topics including "CD97 regulates intestinal chloride transport," by Gabriela Aust and colleagues, "Porcine small intestine to study drug transport," by Frank Runkel and colleagues, and "Barrier characteristics of rat Peyer's patches epithelium," by Salah Amasheh and colleagues.

Objectives Sweat chloride testing is the gold standard for diagnosis of cystic fibrosis (CF). Our objectives were to: 1) describe variables that determine sweat rate; 2) determine the analytic and diagnostic capacity of sweat chloride analysis across the range of observed sweat rates; and 3) determine the biologic variability of sweat chloride concentration. Methods A retrospective analysis was performed using data from all sweat chloride tests performed at St. Louis Children's Hospital over a 21-month period. Results A total of 1397 sweat chloride tests (1155 sufficient [≥ 75 mg], 242 insufficient [< 75 mg]), were performed on 904 individuals. The sweat weight collected from forearms was statistically greater than that collected from legs. There was a negligible correlation between sweat weight and chloride concentration (r = − 0.06). The mean individual biologic CV calculated from individuals with two or more sweat collections ≥ 75 mg was 13.1% (95% CI: 11.3–14.9%; range 0–88%) yielding a reference change value of 36%. Using 60 mmol/L as the diagnostic chloride cutoff, 100% of CF cases were detected whether a minimum sweat weight of 75, 40, or 20 mg was required. Conclusions 1) Collection of sweat from forearms is preferable to upper legs, particularly in very young infants; 2) sweat chloride concentrations are not highly dependent upon sweat rate; 3) a change in sweat chloride concentration exceeding 36% may be considered a clinically significant response to cystic fibrosis transmembrane receptor targeted therapy, and 4) sweat collections of less than 75 mg provide clinically accurate information. [ABSTRACT FROM AUTHOR]

An 11 months 22 days old girl presented with a history of watery diarrhoea since birth, failure to thrive, and developmental delay. Her diagnosis was congenital chloride diarrhoea (CCD) with raised level of chloride (>90 mmol/L) in stool in the absence of cystic fibrosis. Management of CCD included replacement of NaCl, KCl, and correction of dehydration. Diarrhoea of the patient was resolved with Captopril, which was initially provided to the patient for managing heart failure. To our knowledge, this is the first reported case of CCD that shows the beneficial effect of Captopril. Therefore, we suggest that further study is warranted as to the potential for Captopril as additional option in the treatment for CCD. We present this case report with the informed consent of the patient's guardian. [ABSTRACT FROM AUTHOR]

One hundred - eighty Arbor A cres broiler chicks 7 days old were used to determine the effect of different dietary chloride levels on Tibial Dyschondroplasia (TD) incidence, growth performance , carcass traits, blood constitutes and tibia mineralzation . Chicks were randomly distributed into six groups of 30 chicks each, the first group served as control group (T1) had strain recommendation of chloride while, reduced chloride level by 25% (T2), an d 50% (T3) or raised the chloride level by 25% ( T 4), 50% (T5) and 75% (T6). The study was lasted for 35 days. Results indicated that incidence of tibial dyschondroplasia was influenced by the different levels of dietary chloride. The highest levels of chloride (25%, 50% and 75% Cl - ) over the strain recommendation, also the control diet which contain chloride requirements had increased tibial dyschondroplasia incidence . However, the lowest levels ( - 25% and - 50% Cl - ) seemed to decrease TD incidence. Chloride levels did not affect significantly the growth performance or carcass parameters, while, all treatments was significantly reduced abdominal fat comparing to the control group. Blood calcium and phosphorus significantly increased by reducing dietary chloride. D iet s contained - 25% or - 50% chloride increased significantly red blood cells count and improved cellular immunity of broilers . The best tibia ash, calcium and phosphorus content were observed at - 50% chloride level . It could be concluded that reducing dietary chloride level up to 50% Cl - reduced the incidence of TD without negative effect on growth performance of Arbor Acres broiler chicks. [ABSTRACT FROM AUTHOR]

Recent studies suggest that primary changes in vascular resistance can cause sustained changes in arterial blood pressure. In this review, we summarize current knowledge about Cl homeostasis in vascular smooth muscle cells. Within vascular smooth muscle cells, Cl is accumulated above the electrochemical equilibrium, causing Cl efflux, membrane depolarization, and increased contractile force when Cl channels are opened. At least two different transport mechanisms contribute to raise [Cl] in vascular smooth muscle cells, anion exchange, and cation-chloride cotransport. Recent work suggests that TMEM16A-associated Ca-activated Cl currents mediate Cl efflux in vascular smooth muscle cells leading to vasoconstriction. Additional proteins associated with Cl flux in vascular smooth muscle are bestrophins, which modulate vasomotion, the volume-activated LRRC8, and the cystic fibrosis transmembrane conductance regulator (CFTR). Cl transporters and Cl channels in vascular smooth muscle cells (VSMCs) significantly contribute to the physiological regulation of vascular tone and arterial blood pressure. [ABSTRACT FROM AUTHOR]

Cystic Fibrosis (CF) is an autosomal recessive disorder affecting the chloride transport in mucus-producing epithelial cells. The disease is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR), which is responsible for trans-epithelial chloride transport. Approximately 1900 mutations and gene variants of the CFTR have been described. The spectrum of major White-European mutations includes F508del, G542X, G551D and N1303K. F508del is the most common CF-causing mutation, found in approximately 70% of all CF patients worldwide. The spectrum of CF mutations of Arab populations is under-investigated. However, initial molecular-epidemiological studies indicate the existence of specific CF mutation clusters within geographical regions in the Middle East, suggesting specific distributions of CF mutation carrying chromosomes in this part of the world. We showed that the world-wide rare CF mutation S549R is the predominant disease causing mutation in the Omani population. We reported that S549R, together with two other identified mutations, F508del and the rare private mutation V392G, are genetically linked to the exonic methionine polymorphism c.1408A>G; p.Met470Val at exon 10 and the intronic dimorphic 4-bp GATT 6-repeat at intron 6, c.744_33GATT[6_8]. We detected three haplotypes in 28 alleles of the Omani CF cohort and 408 alleles of our control cohort of unrelated and unaffected Omani volunteers. The CF disease associated haplotype consisting of an M allele and a 6-repeat expansion, occurred with an allele frequency of only 0.174 in the normal Omani population. The discriminative power of the haplotype was attributed to the intronic dimorphic 4-bp GATT 6-repeat. Furthermore, we found only one mutation, c.1733_1734delTA in the Omani CF cohort which deviated from the rule and shared the most common haplotype, a V allele and a 7-repeat extension, with the normal population. [ABSTRACT FROM AUTHOR]

The proto-oncogene c-Myc plays critical roles in human malignancies including chronic myeloid leukemia (CML), suggesting that the discovery of specific agents targeting c-Myc would be extremely valuable for CML treatment. Nitidine Chloride (NC), a natural bioactive alkaloid, is suggested to possess anti-tumor effects. However, the function of NC in leukemia and the underlying molecular mechanisms have not been established. In this study, we found that NC induced erythroid differentiation, accompanied by increased expression of erythroid differentiation markers, e. g. α-, ε-, γ-globin, CD235a, CD71 and α-hemoglobin stabilizing protein (AHSP) in CML cells. We also observed that NC induced apoptosis and upregulated cleaved caspase-3 and Parp-1 in K562 cells. These effects were associated with concomitant attenuation of c-Myc. Our study showed that NC treatment in CML cells enhanced phosphorylation of Thr58 residue and subsequently accelerated degradation of c-Myc. A specific group of miRNAs, which had been reported to be activated by c-Myc, mediated biological functions of c-Myc. We found that most of these miRNAs, especially miR-17 and miR-20a showed strong decrement after NC treatment or c-Myc interference. Furthermore, overexpression of c-Myc or miR-17/20a alleviated NC induced differentiation and apoptosis in K562 cells. More importantly, NC enhanced the effects of imatinib in K562 and primary CML cells. We further found that even imatinib resistant CML cell line (K562/G01) and CML primary cells exhibited high sensitivity to NC, which showed potential possibility to overcome imatinib resistance. Taken together, our results clearly suggested that NC promoted erythroid differentiation and apoptosis through c-Myc-miRNAs regulatory axis, providing potential possibility to overcome imatinib resistance. [ABSTRACT FROM AUTHOR]

SLC26A3, or downregulated in adenoma (DRA), plays a major role in mediating Cl- absorption in the mammalian intestine. Disturbances in DRA function and expression have been implicated in intestinal disorders such as congenital Cl- diarrhea and gut inflammation. We previously showed that an increase in DRA function and expression by Lactobacillus acidophilus and its culture supernatant (CS) might underlie antidiarrheal effects of this probiotic strain. However, the effects of Bifidobacterium species, important inhabitants of the human colon, on intestinal Cl-/HCO3- exchange activity are not known. Our current results demonstrate that CS derived from Bifidobacterium breve, Bifidobacterium infantis, and Bifidobacterium bifidum increased anion exchange activity in Caco-2 cells (~1.8- to 2.4-fold). Consistent with the increase in DRA function, CS also increased the protein, as well as the mRNA, level of DRA (but not putative anion transporter 1). CS of all three Bifidobacterium sp. increased DRA promoter activity (-1,183/+114 bp) in Caco-2 cells (1.5- to 1.8-fold). Furthermore, the increase in DRA mRNA expression by CS of B. breve and B. infantis was blocked in the presence of the transcription inhibitor actinomycin D (5 μM) and the ERK1/2 MAPK pathway inhibitor U0126 (10 μM). Administration of live B. breve, B. infantis, and B. bifidum by oral gavage to mice for 24 h increased DRA mRNA and protein levels in the colon. These data demonstrate an upregulation of DRA via activation of the ERK1/2 pathway that may underlie potential antidiarrheal effects of Bifidobacterium sp [ABSTRACT FROM AUTHOR]

Na+-dependent chloride cotransporters (NKCC1, NKCC2, and NCC) are activated by phosphorylation to play critical roles in diverse physiological responses, including renal salt balance, hearing, epithelial fluid secretion, and volume regulation. Serine threonine kinase WNK4 (With No K = lysine member 4) and members of the Ste20 kinase family, namely SPAK and OSR1 (Ste20-related proline/alanine-rich kinase, Oxidative stress-responsive kinase) govern phosphorylation. According to present understanding, WNK4 phosphorylates key residues within SPAK/OSR1 leading to kinase activation, allowing SPAK/OSR1 to bind to and phosphorylate NKCC1, NKCC2, and NCC. Recently, the calcium-binding protein 39 (Cab39) has emerged as a binding partner and enhancer of SPAK/OSR1 activity, facilitating kinase autoactivation and promoting phosphorylation of the cotransporters. In the present study, we provide evidence showing that Cab39 differentially interacts with WNK4 and SPAK/OSR1 to switch the classic two kinase cascade into a signal kinase transduction mechanism. We found that WNK4 in association with Cab39 activates NKCC1 in a SPAK/OSR1-in-dependent manner. We discovered that WNK4 possesses a domain that bears close resemblance to the SPAK/OSR1 C-terminal CCT/PF2 domain, which is required for physical interaction between the Ste20 kinases and the Na+-driven chloride cotransporters. Modeling, yeast two-hybrid, and functional data reveal that this PF2-like domain located downstream of the catalytic domain in WNK4 promotes the direct interaction between the kinase and NKCC1. We conclude that in addition to SPAK and OSR1, WNK4 is able to anchor itself to the N-terminal domain of NKCC1 and to promote cotransporter activation. [ABSTRACT FROM AUTHOR]

Highlights: [•] DIOA, an inhibitor of K+–Cl− cotransporter (KCC), induced an increase in cell volume. [•] DIOA induced a decrease in intracellular Cl− concentration. [•] DIOA inhibited cell proliferation with the G0/G1 phase arrest in MDA-MB-231 cells. [•] DIOA induced down-regulation of cyclin D1 and cyclin E2, and up-regulation of p21. [ABSTRACT FROM AUTHOR]

Abstract: Secretory diarrhoeal disease due to enterotoxins is thought to arise from the enhancement to pathologically high rates of normally occurring chloride ion and therefore fluid secretion from enterocytes. In support of this concept, many enterotoxins increase intestinal short-circuit current, regarded now as faithfully reflecting the increased chloride ion secretion. Contradicting this assumption, STa reduces absorption but does not cause secretion in vivo although short-circuit current is increased in vitro. There is therefore a mismatch between an assumed enterocyte mediated secretory event that should but does not cause net fluid secretion and an undoubtedly increased short-circuit current. It is proposed here that short-circuit current increases are not themselves secretory events but result from interrupted fluid absorption. A noteworthy feature of compounds that inhibit the increase in short-circuit current is that the majority are vasoactive, neuroactive or both. In general, vasodilator substances increase current. An alternative hypothesis for the origin of short-circuit current increases is that these result from reflex induction of electrogenic fluid absorption. This reflex enhances a compensatory response that is also present at a cellular level. An intestinal reflex is therefore proposed by which decreases in interstitial and intravascular volume or pressure within the intestine initiate an electrogenic fluid absorption mechanism that compensates for the loss of electrically neutral fluid absorption. This hypothesis would explain the apparently complex pharmacology of short-circuit current increases since many depressor substances have receptors in common with enterocytes and enteric nerves. The proposed alternative view of the origin of short-circuit current increases assumes that these do not represent chloride secretion from the enterocytes. This view may therefore aid the successful development of anti-diarrhoeal drugs to overcome a major cause of infant mortality worldwide, if short-circuit current data are being persistently misinterpreted. The putative but testable link between interstitial volume or pressure and fluid absorption also provides support for the alternative view of secretion; namely, that enhanced capillary and epithelial cell tight junctional permeability together with increased intracapillary pressure may cause secretion and not chloride exit from the enterocytes. [Copyright &y& Elsevier]

Two hundred sixty-eight strip loins were collected from heifers fed at Oklahoma State University in Stillwater, OK. In Exp. 1, heifers («=127) were assigned to 1 of 3 health management treatment groups: antimicrobial administrations were given based on standard feedlot protocol (SFP) or ruminai temperature (RT) or given a metaphylactic treatment of tulathromycin (MT) followed by visual assessment (VA). In Exp. 2, heifers («=155) were assigned to the same treatment groups as above and were supplemented zilpaterol hydrochloride (ZH) or control (CON). Three steaks were collected from each strip loin, 1 each for retail display, sensory evaluation, and Wamer- Bratzler shear force (WBSF). Color was evaluated from the retail display steak using a trained color panel and objectively using a HunterLab Miniscan XE. An Instron Universal Testing Machine with a Wamer-Bratzler head was used for evaluation of instrumental tenderness, and a trained sensory panel was used to assess palatability traits. Heifers treated by VA had the least number of antimicrobial administrations and lowest yield grade and also had the lightest HCW (P < 0.05) compared with the heifers treated by the other health management protocols. There were no subjective color attribute differences or sensory panel differences (P > 0.05) across all health management systems or antimicrobial administrations. There were no differences in carcass and performance traits for any antimicrobial administrations treatment groups (P > 0.05). Heifers who had 0 or 1 antimicrobial administrations had lower (P < 0.05) a* (redness/ greenness: positive values = red and negative values = green), and b* (yellowness/blueness: positive values = yellow and negative values = blue) values compared with those who had 2 antimicrobial administrations. In Exp. 2, heifers treated by VA had the least number (P < 0.05) of antimicrobial administrations when compared with MT and RT. Health management group did not have any other effects on carcass, sensory, or color attributes. Zilpaterol hydrochloride supplementation caused a decrease (P < 0.05) in internal fat and yield grade, but no interactions were observed between the number of antimicrobial administrations and ZH supplementation. With the supplementation of ZH, WBSF significantly increased (P < 0.05). At the end of retail display, the control group had a greater (P < 0.05) surface discoloration when compared with the ZH group. Treatment and detection of bovine respiratory diseases (BRD) is critical to the industry economically and results from this study show that different methods can be used to detect BRD without dramatically impacting carcass, sensory, and retail case life characteristics. [ABSTRACT FROM AUTHOR]

Background: Altered chloride homeostasis has been thought to be a risk factor for several brain disorders, while less attention has been paid to its role in liver disease. We aimed to analyze the involvement and possible mechanisms of altered chloride homeostasis of GABAergic neurons within the substantia nigra pars reticulata (SNr) in the motor deficit observed in a model of encephalopathy caused by acute liver failure, by using glutamic acid decarboxylase 67 - green fluorescent protein knock-in transgenic mice. Methods: Alterations in intracellular chloride concentration in GABAergic neurons within the SNr and changes in the expression of two dominant chloride homeostasis-regulating genes, KCC2 and NKCC1, were evaluated in mice with hypolocomotion due to hepatic encephalopathy (HE). The effects of pharmacological blockade and/or activation of KCC2 and NKCC1 functions with their specific inhibitors and/or activators on the motor activity were assessed. Results: In our mouse model of acute liver injury, chloride imaging indicated an increase in local intracellular chloride concentration in SNr GABAergic neurons. In addition, the mRNA and protein levels of KCC2 were reduced, particularly on neuronal cell membranes; in contrast, NKCC1 expression remained unaffected. Furthermore, blockage of KCC2 reduced motor activity in the normal mice and led to a further deteriorated hypolocomotion in HE mice. Blockade of NKCC1 was not able to normalize motor activity in mice with liver failure. Conclusion: Our data suggest that altered chloride homeostasis is likely involved in the pathophysiology of hypolocomotion following HE. Drugs aimed at restoring normal chloride homeostasis would be a potential treatment for hepatic failure. [ABSTRACT FROM AUTHOR]

Abstract: The SLC12 family encodes electroneutral cation-coupled chloride cotransporters that are critical for several physiological processes including cell volume regulation, modulation of intraneuronal chloride concentration, transepithelial ion movement, and blood pressure regulation. Members of this family are the targets of the most commonly used diuretic drugs, have been shown to be the causative genes for inherited disease such as Gitelman, Bartter and Andermann syndromes, and potentially play a role in polygenic complex diseases like arterial hypertension, epilepsy, osteoporosis, and cancer. [Copyright &y& Elsevier]

Congenital chloride diarrhea (CLD, OMIM#214700) is an autosomal recessive disorder caused by mutations in the solute carrier family 26 member 3 ( SLC26A3) gene, which encodes an intestinal chloride/bicarbonate exchanger. While more than 50 mutations have been identified throughout the world, there have been no data on the genetic characteristics of the patients of East Asian ethnic origin. In this study, we performed genetic analysis by direct sequencing of the 20 exons and parts of exon-intron boundaries of the SLC26A3 gene in eight patients of Korean origin with non-consanguineous parents. We identified three novel mutations, including two splice-site mutations (c.2063-1G>T in intron 18, c.1047+3 A>C in intron 12) and one missense mutation (p.Ser134Asn in exon 5). One previously identified mutation was also found (p.Pro131Leu in exon 5). The most common mutation was c.2063-1G>T, which was found in at least one allele of all patients. Conclusion: This is the first report to demonstrate the genetic background of CLD in a single ethnic group of East Asian descent. The c.2063-1G>T mutation could be suggested as a founder mutation in Korean population so that the targeting sequencing for the mutation would be a cost-efficient screening method to confirm a diagnosis of CLD in patients of Korean descent. [ABSTRACT FROM AUTHOR]

KCC2 is a neuron-specific K+-Cl- cotransporter that is essential for Cl- homeostasis and fast inhibitory synaptic transmission in the mature CNS. Despite the critical role of KCC2 in neurons, the mechanisms regulating its function are not understood. Here, we show that KCC2 is critically regulated by the single-pass transmembrane protein neuropilin and tolloid like-2 (Neto2). Neto2 is required to maintain the normal abundance of KCC2 and specifically associates with the active oligomeric form of the transporter. Loss of the Neto2:KCC2 interaction reduced KCC2-mediated Cl- extrusion, resulting in decreased synaptic inhibition in hippocampal neurons. [ABSTRACT FROM AUTHOR]

Aim: Sodium valproate (NaVP) defines a novel class of histone deacetylases (HDAC) inhibitors inducing differentiation of transfonned cells by their antitumor properties. Earlier we have showed that single doses of NaVP havse natriuretic, kaliuretic and chloriduretic effects in rats. The chloriduretic effect of repeated NaVP doses has not previously been investigated. The aim of the present study was to define the peculiarities of 24 h urinary chloride (Cl-) excretion in young adult Wistar rats and to evaluate the related effects of single and repeated NaVP doses in a 10-day treat-ment. Materials and methods: 24 h urinary Cl-, creatinine and pH levels were measured in 14 control intact Wistar male rats and 13 Wistar male rats after a single per os administration of 300 mg/kg NaVP (VP rats), 5 Wistar male rats after 10 days of the daily intragastric ad-ministration of 300 mg/kg NaVP (VP-10 rats) and 5 matched control male rats. 24 h urine was collected keeping a rat alone in a special diure-sis cage (Tecniplast, Italy) for 24 h with free access to tap water, without food, in the same temperature and light conditions. 24 h urinary Cl-, Na+ levels were analyzed with an EML-105 electrolyte analyzer (Radiometer, Den-mark). Urinary pH levels were measured with a pH/mV/ion meter (ION Meter pH 340/ION, Germany). Results: After a single dose and af-ter 10 days of NaVP administration, 24 h total diuresis and 24 h diuresis per 100 g of body weight were significantly higher in VP and VP-10 rats as compared with the respective control. 24 h urine CP excretion was significantly higher in VP and VP-10 rats than in matched controls. The study data shows that repeated NaVP doses enhance CP excretion with urine. Authors discuss the possible new mechanism of NaVP anticancer effects related to intracellular CP level changes. Conclusion: The understanding of the hypothesized NaVP mechanism may lead to the recognition of CP as an important mediator in tumor development and as a novel therapeutic target for cancer. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine the effects of zilpaterol hydrochloride mM supplementation (ZH; 8.3 mg/kg on a DM basis for 20 d) and calcium chloride injection [CaCl2, 200 at 5% (wt/wt) at 72 h postmortem] on palatability traits of beef (Bos taurus) strip loin steaks. Select (USDA) strip loins were obtained from control (no ZH =19) and ZH-supplemented carcasses (n = 20). Right and left sides were selected alternatively to serve as a control (no INJ) or CaCl2-injected (INJ) and stored at 4°C. Before injecting the subprimals (72 h postmortem), 2 steaks were cut for proximate, sarcomere length, and myofibrillar fragmentation index (MFI) analyses. At 7 d postmortem each strip loin was portioned into steaks, vacuum packaged, and aged for the appropriate period for Warner-Bratzler shear force (WBSF; 7, 14, 21, and 28 d postmortem), trained sensory analysis (14 and 21 d postmortem), purge loss (7 d), and MFI (3, 7, 14,21, and 28 d postmortem). Results indicated steaks from both ZH supplementation and INJ had reduced WBSF values as days of postmortem aging increased. The WBSF values of ZH steaks were greater (P < 0.05) than no ZH steaks at each postmortem aging period. The INJ steaks had lower WBSF values {P < 0.05) than non-injected steaks. A greater percentage (91 vs. 71%) of steaks had WBSF values < 4.6 kg from steers with no ZH supplementation at 7 d postmortem, but the percentage did not differ (P > 0.05) due to ZH at 14, 21, or 28 d or due to INJ at any aging period. Trained panelists rated tenderness less in ZH steaks than steaks with no ZH at 14 d and 21 d. However, INJ improved (P < 0.05) the tenderness ratings and flavor intensity of the trained panelists, compared with their non-injected cohorts at 21 d. Zilpaterol hydrochloride supplementation reduced (P < 0.05) MFI values, but INJ resulted in greater (P < 0.05) MFI values compared with no INJ. Subprimals from ZH and INJ showed greater purge loss (P < 0.05). Although no interactions were found with ZH and CaCl2, injecting USDA Select strip loins from ZH-fed cattle can help reduce the normal WBSF variation as it does in steaks from non-ZH-fed cattle. [ABSTRACT FROM AUTHOR]

Abstract: Seizures are thought to originate from a failure of inhibition to quell hyperactive neural circuits, but the nature of this failure remains unknown. Here we combine high-speed two-photon imaging with electrophysiological recordings to directly evaluate the interaction between populations of interneurons and principal cells during the onset of seizure-like activity in mouse hippocampal slices. Both calcium imaging and dual patch clamp recordings reveal that in vitro seizure-like events (SLEs) are preceded by pre-ictal bursts of activity in which interneurons predominate. Corresponding changes in intracellular chloride concentration were observed in pyramidal cells using the chloride indicator Clomeleon. These changes were measurable at SLE onset and became very large during the SLE. Pharmacological manipulation of GABAergic transmission, either by blocking GABAA receptors or by hyperpolarizing the GABAA reversal potential, converted SLEs to short interictal-like bursts. Together, our results support a model in which pre-ictal GABAA receptor-mediated chloride influx shifts EGABA to produce a positive feedback loop that contributes to the initiation of seizure activity. [Copyright &y& Elsevier]

Congenital chloride diarrhoea (CLD) is a rare autosomal recessive disease with chronic secretory diarrhoea and a need for lifelong salt replacement therapy. We describe a male newborn of consanguineous parents with CLD. Postnatally, frequent watery diarrhoea and electrolyte disturbances were noted from the day 8 of his life. At molecular level, a homozygous mutation was detected in the solute carrier family 26 member A3 gene ( SLC26A3), confirming the clinical diagnosis of CLD. Conclusion: The relatively late onset of persistent clinical and laboratory signs may demonstrate a new clinical course of CLD. These findings support the need of a tight follow-up and monitoring if such a diagnosis is considered. [ABSTRACT FROM AUTHOR]

The article discusses aspects of drug-induced hypokalaemia. It provides an overview of hypokalaemia with details on the risk factors. It tackles the drugs associated with high urine potassium excretion rate including sodium disorders, chloride disorders, and metabolic alkalosis and acidosis. It also discusses the best management for the drug-induced hypokalemia and importance of urine potassium excretion assessment.