Calcium-sensing receptor activator cinacalcet for treatment of cyclic nucleotide-mediated secretory diarrheas.

Cyclic nucleotide elevation in intestinal epithelial cells is the key pathology causing intestinal fluid loss in secretory diarrheas such as cholera. Current secretory diarrhea treatment is primarily supportive, and oral rehydration solution is the mainstay of cholera treatment. There is an unmet need for safe, simple and effective diarrhea treatments. By promoting cAMP hydrolysis, extracellular calcium-sensing receptor (CaSR) is a regulator of intestinal fluid transport. We studied the antidiarrheal mechanisms of FDA-approved CaSR activator cinacalcet and tested its efficacy in clinically relevant human cell, mouse and intestinal organoid models of secretory diarrhea. By using selective inhibitors, we found that cAMP agonists-induced secretory short-circuit currents (Isc) in human intestinal T84 cells are mediated by collective actions of apical membrane cystic fibrosis transmembrane conductance regulator (CFTR) and Clc-2 Cl- channels, and basolateral membrane K+ channels. 30 µM cinacalcet pretreatment inhibited all 3 components of forskolin and cholera toxin-induced secretory Isc by ∼75%. In mouse jejunal mucosa, cinacalcet inhibited forskolin-induced secretory Isc by ∼60% in wild type mice, with no antisecretory effect in intestinal epithelia-specific Casr knockout mice (Casr-flox; Vil1-cre). In suckling mouse model of cholera induced by oral cholera toxin, single dose (30 mg/kg) oral cinacalcet treatment reduced intestinal fluid accumulation by ∼55% at 20 hours. Lastly, cinacalcet inhibited forskolin-induced secretory Isc by ∼75% in human colonic and ileal organoids. Our findings suggest that CaSR activator cinacalcet has antidiarrheal efficacy in distinct human cell, organoid and mouse models of secretory diarrhea. Considering its excellent clinical safety profile, cinacalcet can be repurposed as a treatment for cyclic nucleotide-mediated secretory diarrheas including cholera.

Histidine dipeptides are key regulators of excitation-contraction coupling in cardiac muscle: Evidence from a novel CARNS1 knockout rat model.

Histidine-containing dipeptides (HCDs) are abundantly expressed in striated muscles. Although important properties have been ascribed to HCDs, including H+ buffering, regulation of Ca2+ transients and protection against oxidative stress, it remains unknown whether they play relevant functions in vivo. To investigate the in vivo roles of HCDs, we developed the first carnosine synthase knockout (CARNS1-/-) rat strain to investigate the impact of an absence of HCDs on skeletal and cardiac muscle function. Male wild-type (WT) and knockout rats (4 months-old) were used. Skeletal muscle function was assessed by an exercise tolerance test, contractile function in situ and muscle buffering capacity in vitro. Cardiac function was assessed in vivo by echocardiography and cardiac electrical activity by electrocardiography. Cardiomyocyte contractile function was assessed in isolated cardiomyocytes by measuring sarcomere contractility, along with the determination of Ca2+ transient. Markers of oxidative stress, mitochondrial function and expression of proteins were also evaluated in cardiac muscle. Animals were supplemented with carnosine (1.8% in drinking water for 12 weeks) in an attempt to rescue tissue HCDs levels and function. CARNS1-/- resulted in the complete absence of carnosine and anserine, but it did not affect exercise capacity, skeletal muscle force production, fatigability or buffering capacity in vitro, indicating that these are not essential for pH regulation and function in skeletal muscle. In cardiac muscle, however, CARNS1-/- resulted in a significant impairment of contractile function, which was confirmed both in vivo and ex vivo in isolated sarcomeres. Impaired systolic and diastolic dysfunction were accompanied by reduced intracellular Ca2+ peaks and slowed Ca2+ removal, but not by increased markers of oxidative stress or impaired mitochondrial respiration. No relevant increases in muscle carnosine content were observed after carnosine supplementation. Results show that a primary function of HCDs in cardiac muscle is the regulation of Ca2+ handling and excitation-contraction coupling.

The role of chronic muscle (in)activity on carnosine homeostasis: a study with spinal cord-injured athletes.

To examine the role of chronic (in)activity on muscle carnosine (MCarn) and how chronic (in)activity affects MCarn responses to ß-alanine supplementation in spinal cord-injured athletes, 16 male athletes with paraplegia were randomized (2:1 ratio) to receive ß-alanine (n = 11) or placebo (PL, n = 5). They consumed 6.4 g/day of ß-alanine or PL for 28 days. Muscle biopsies of the active deltoid and the inactive vastus lateralis (VL) were taken before and after supplementation. MCarn in the VL was also compared with the VL of a group of individuals without paraplegia (n = 15). MCarn was quantified in whole muscle and in pools of individual fibers by high-performance liquid chromatography. MCarn was higher in chronically inactive VL vs. well-trained deltoid (32.0 ± 12.0 vs. 20.5 ± 6.1 mmol/kg DM; P = 0.018). MCarn was higher in inactive vs. active VL (32.0 ± 12.0 vs. 21.2 ± 7.5 mmol/kg DM; P = 0.011). In type-I fibers, MCarn was significantly higher in the inactive VL than in the active deltoid (38.3 ± 4.7 vs. 27.3 ± 11.8 mmol/kg DM, P = 0.014). MCarn increased similarly between inactive VL and active deltoid in the ß-alanine group (VL: 68.9 ± 55.1%, P = 0.0002; deltoid: 90.5 ± 51.4%, P < 0.0001), with no changes in the PL group. MCarn content was higher in the inactive VL than in the active deltoid and the active VL, but this is probably a consequence of fiber type shift (type I to type II) that occurs with chronic inactivity. Chronically inactive muscle showed an increase in MCarn after BA supplementation equally to the active muscle, suggesting that carnosine accretion following ß-alanine supplementation is not influenced by muscle inactivity.

Kinetics of Muscle Carnosine Decay after ß-Alanine Supplementation: A 16-wk Washout Study.

PURPOSE: This study aimed to describe the kinetics of carnosine washout in human skeletal muscle over 16 wk. METHODS: Carnosine washout kinetics were studied in 15 young, physically active omnivorous men randomly assigned to take 6.4 g·d-1 of ß-alanine (n = 11) or placebo (n = 4) for 8 wk. Muscle carnosine content (M-Carn) was determined before (PRE), immediately after (POST), and 4, 8, 12, and 16 wk after supplementation. High-intensity exercise tests were performed at these same time points. Linear and exponential models were fitted to the washout data, and the leave-one-out method was used to select the model with the best fit for M-Carn decay data. Repeated-measures correlation analysis was used to assess the association between changes in M-Carn and changes in performance. RESULTS: M-Carn increased from PRE to POST in the ß-alanine group only (+91.1% ± 29.1%; placebo, +0.04% ± 10.1%; P < 0.0001). M-Carn started to decrease after cessation of ß-alanine supplementation and continued to decrease until week 16 (POST4, +59% ± 40%; POST8, +35% ± 39%; POST12, +18% ± 32%; POST16, -3% ± 24% of PRE M-Carn). From week 12 onward, M-Carn was no longer statistically different from PRE. Both linear and exponential models displayed very similar fit and could be used to describe carnosine washout, although the linear model presented a slightly better fit. The decay in M-Carn was mirrored by a similar decay in high-intensity exercise tolerance; M-Carn was moderately and significantly correlated with total mechanical work done (r = 0.505; P = 0.032) and time to exhaustion (r = 0.72; P < 0.001). CONCLUSIONS: Carnosine washout takes 12-16 wk to complete, and it can be described either by linear or exponential curves. Changes in M-Carn seem to be mirrored by changes in high-intensity exercise tolerance. This information can be used to optimize ß-alanine supplementation strategies.

Insulin does not stimulate ß-alanine transport into human skeletal muscle.

To test whether high circulating insulin concentrations influence the transport of ß-alanine into skeletal muscle at either saturating or subsaturating ß-alanine concentrations, we conducted two experiments whereby ß-alanine and insulin concentrations were controlled. In experiment 1, 12 men received supraphysiological amounts of ß-alanine intravenously (0.11 g·kg-1·min-1 for 150 min), with or without insulin infusion. ß-Alanine and carnosine were measured in muscle before and 30 min after infusion. Blood samples were taken throughout the infusion protocol for plasma insulin and ß-alanine analyses. ß-Alanine content in 24-h urine was assessed. In experiment 2, six men ingested typical doses of ß-alanine (10 mg/kg) before insulin infusion or no infusion. ß-Alanine was assessed in muscle before and 120 min following ingestion. In experiment 1, no differences between conditions were shown for plasma ß-alanine, muscle ß-alanine, muscle carnosine and urinary ß-alanine concentrations (all P > 0.05). In experiment 2, no differences between conditions were shown for plasma ß-alanine or muscle ß-alanine concentrations (all P > 0.05). Hyperinsulinemia did not increase ß-alanine uptake by skeletal muscle cells, neither when substrate concentrations exceed the Vmax of ß-alanine transporter TauT nor when it was below saturation. These results suggest that increasing insulin concentration is not necessary to maximize ß-alanine transport into muscle following ß-alanine intake.

"Despite being an athlete, I am also a human-being": Male elite gymnasts' reflections on food and body image.

Our aim was to investigate the prevalence of symptoms related to eating disorders, disordered eating and body image perception, and attitudes toward eating in a group of elite male artistic gymnastics. Seventeen athletes took part in this quali-quantitative, cross-sectional study. Presence of eating disorders symptoms, and body image perception and satisfaction were assessed using validated questionnaires. Focus groups were held to discuss their attitudes toward eating and body image perception in more detail. Little to no evidence of symptoms consistent with eating disorders was observed, and this was supported by the qualitative data. However, some concerning practices and attitudes were described. Negative emotional eating cycles appeared prevalent (e.g. feelings of anger, stress and anxiety creating a desire to eat "junk foods", followed by guilt and regret). Body image perception and attitudes toward body weight's influence on performance varied widely. Some athletes expressed a desire to lose weight and believed that this would positively impact their performance, while others believed weight to be irrelevant and focused on feeling strong and vital. Athletes believed their female counterparts experienced far greater pressure to maintain low body weight and described some very concerning practices. We conclude that eating disorders and disordered eating did not appear to be prevalent among these elite male artistic gymnastics. However, some concerning attitudes and practices were observed and should be addressed with nutritional support programmes encompassing psychological and behavioural aspects of eating. These programmes should be extended to support staff and significant others, in addition to athletes.

Efeitos adversos no tratamento da tuberculose / Adverse effects in the treatment of tuberculosis

Objetivo: Analisar ocorrências de efeitos adversos relacionados a medicamentos no tratamento de tuberculose e sua associação com variáveis clínicas e desfecho. Método: Estudo transversal com 63 casos de tuberculose tratados no Ambulatório de Tuberculose e Hanseníase de São José do Rio Preto, São Paulo, no período de 2010 a 2015. Utilizou-se análise de frequência e teste qui-quadrado com correção de Monte Carlo. Resultados: Os efeitos adversos iniciaram-se antes do terceiro mês de tratamento; efeitos menores foram mais frequentes, com predomínio de irritação gástrica. Houve associação entre conduta médica e efeitos adversos (p = 0,009). Conclusão: Efeitos adversos causados pelos medicamentos podem prejudicar o desfecho clínico devido ao risco de abandono do tratamento. Profissionais de saúde devem estar atentos aos sinais e sintomas relacionados aos efeitos adversos, implementando condutas necessárias para neutralizar ou diminuir as queixas, visando adesão ao tratamento e cura da doença. (AU)

Objective: To analyze occurrences of drug-related adverse effects in treatment of tuberculosis and its association with clinical variables and outcome. Method: Cross-sectional study with 63 cases of tuberculosis treated at Tuberculosis and Leprosy Outpatient Clinic of São José do Rio Preto, São Paulo, from 2010 to 2015. We used frequency analysis and chi-square test with Monte Carlo correction. Results: Adverse effects started before the third month of treatment; effects were more frequent, with predominance of gastric irritation. There was association between medical conduct and adverse effects (p=0.009). Conclusion: Adverse effects caused by medications may impair the clinical outcome due to risk of treatment withdrawal. Health professionals should be alert to signs and symptoms related to adverse effects, implementing the necessary behaviors to neutralize or reduce complaints, aiming adherence to treatment and cure of the disease. (AU)

Objetivo: Analizar los efectos adversos relacionados con medicamentos en tratamiento de la tuberculosis y su asociación con variables clínicas y desenlace. Método: Estudio transversal con 63 casos de tuberculosis tratados en Ambulatorio de Tuberculosis y Hanseniasis de São José Rio Preto, São Paulo, en período de 2010 a 2015. Se utilizó análisis de frecuencia y prueba chi-cuadrado con corrección de Monte Carlo. Los efectos adversos se iniciaron antes del tercer mes de tratamiento; los efectos menores fueron más frecuentes, con predominio de irritación gástrica. Se observó asociación entre conducta médica y efectos adversos (p=0,009). Resultados: Los efectos adversos causados por medicamentos pueden perjudicar el resultado clínico debido al riesgo de abandono del tratamiento. Conclusiones: Los profesionales de salud deben estar atentos a los signos y síntomas relacionados con efectos adversos, implementando conductas necesarias para neutralizar o disminuir las quejas, visando adhesión al tratamiento y cura de la enfermedad. (AU)

The molecular structure of ß-alanine is resistant to sterilising doses of gamma radiation.

ß-alanine is the rate-limiting point for the endogenous synthesis of carnosine in skeletal muscle. Carnosine has a wide range of implications for health, normal function and exercise performance. Whilst the physiological relevance of carnosine to different tissues remains enigmatic, ß-alanine administration is a useful strategy to investigate the physiological roles of carnosine in humans. Intravenous administration of ß-alanine is an interesting approach to study carnosine metabolism. However, sterilisation is mandatory due to the nature of the administration route. We evaluated whether sterilising doses of gamma radiation damages the molecular structure and leads to the loss of functional characteristics of ß-alanine. Pure ß-alanine was sterilised by gamma radiation in sealed glass vials using a 60Co multipurpose irradiator at a dose rate of 8.5 kGy.hour-1 totalising 10, 20, 25 30 and 40 kGy. The molecular integrity was assessed by X-ray Diffraction and changes in content were determined by High Performance Liquid Chromatography (UV-HPLC) and Triple Quadrupole Mass Spectrometer (HPLC/MS-MS). Sterility assurance was evaluated by inoculation assay. To examine whether functional properties were preserved, ß-alanine was infused in one participant, who rated the level of paraesthesia on the skin using a 0-3 scale. Urinary ß-alanine was quantified before and 24-h following ß-alanine infusion using HPLC-ESI+-MS/MS. Irradiation resulted in no change in the crystal structure of ß-alanine, no degradation, and no new peaks were identified in the dose range assayed. The inoculation assay showed the absence of viable microorganisms in all ß-alanine samples, including those that did not undergo irradiation. Intravenous infusion of ß-alanine resulted in paraesthesia and it detected in the urine as per normal. We conclude that gamma radiation is a suitable technique for the sterilisation of ß-alanine. It does not lead to degradation, damage to the ß-alanine structure, content or loss of function within the evaluated irradiation conditions.

Dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation.

This study investigates the influence of habitual caffeine intake on aerobic exercise-performance responses to acute caffeine supplementation. A double-blind, crossover, counterbalanced study was performed. Forty male endurance-trained cyclists were allocated into tertiles, according to their daily caffeine intake: low (58 ± 29 mg/d), moderate (143 ± 25 mg/d), and high (351 ± 139 mg/d) consumers. Participants completed three trials in which they performed simulated cycling time trials (TTs) in the fastest time possible following ingestion of the following: caffeine (CAF: 6 mg/kg body mass), placebo (PLA), and no supplement (CON). A mixed-model analysis revealed that TT performance was significantly improved in CAF compared with PLA and CON (29.92 ± 2.18 vs. 30.81 ± 2.67 and 31.14 ± 2.71 min, respectively; P = 0.0002). Analysis of covariance revealed no influence of habitual caffeine intake as a covariate on exercise performance (P = 0.47). TT performance was not significantly different among tertiles (P = 0.75). No correlation was observed between habitual caffeine intake and absolute changes (CAF - CON) in TT performance with caffeine (P = 0.524). Individual analysis showed that eight, seven, and five individuals improved above the variation of the test in CAF in the low, moderate, and high tertiles, respectively. A Fisher's exact test did not show any significant differences in the number of individuals who improved in CAF among the tertiles (P > 0.05). Blood lactate and ratings of perceived exertion were not different between trials and tertiles (P > 0.05). Performance effects of acute caffeine supplementation during an ~30-min cycling TT performance were not influenced by the level of habitual caffeine consumption.NEW & NOTEWORTHY There has been a long-standing paradigm that habitual caffeine intake may influence the ergogenicity of caffeine supplementation. Low, moderate, and high caffeine consumers showed similar absolute and relative improvements in cycling time-trial performance following acute supplementation of 6 mg/kg body mass caffeine. Performance effects of acute caffeine were not influenced by the level of habitual caffeine consumption, suggesting that high habitual caffeine intake does not negate the benefits of acute caffeine supplementation.

Twenty-four Weeks of ß-Alanine Supplementation on Carnosine Content, Related Genes, and Exercise.

INTRODUCTION: Skeletal muscle carnosine content can be increased through ß-alanine (BA) supplementation, but the maximum increase achievable with supplementation is unknown. No study has investigated the effects of prolonged supplementation on carnosine-related genes or exercise capacity. PURPOSE: This study aimed to investigate the effects of 24 wk of BA supplementation on muscle carnosine content, gene expression, and high-intensity cycling capacity (CCT110%). METHODS: Twenty-five active males were supplemented with 6.4 g·d of sustained release BA or placebo for a 24 wk period. Every 4 wk participants provided a muscle biopsy and performed the CCT110%. Biopsies were analyzed for muscle carnosine content and gene expression (CARNS, TauT, ABAT, CNDP2, PHT1, PEPT2, and PAT1). RESULTS: Carnosine content was increased from baseline at every time point in BA (all P < 0.0001; week 4 = +11.37 ± 7.03 mmol·kg dm, week 8 = +13.88 ± 7.84 mmol·kg dm, week 12 = +16.95 ± 8.54 mmol·kg dm, week 16 = +17.63 ± 8.42 mmol·kg dm, week 20 = +21.20 ± 7.86 mmol·kg dm, and week 24 = +20.15 ± 7.63 mmol·kg dm) but not placebo (all P > 0.05). Maximal increases were +25.66 ± 7.63 mmol·kg dm (range = +17.13 to +41.32 mmol·kg dm), and absolute maximal content was 48.03 ± 8.97 mmol·kg dm (range = 31.79 to 63.92 mmol·kg dm). There was an effect of supplement (P = 0.002) on TauT; no further differences in gene expression were shown. Exercise capacity was improved in BA (P = 0.05) with possible to almost certain improvements across all weeks. CONCLUSIONS: Twenty-four weeks of BA supplementation increased muscle carnosine content and improved high-intensity cycling capacity. The downregulation of TauT suggests it plays an important role in muscle carnosine accumulation with BA supplementation, whereas the variability in changes in muscle carnosine content between individuals suggests that other determinants other than the availability of BA may also bear a major influence on muscle carnosine content.

Percepção do enfermeiro sobre o cuidado prestado aos pacientes portadores de neoplasia / Nurses´ perception on the care given to patients with cancer

A presença do enfermeiro nos hospitais é diária e constante. Como conseqüência, o relacionamento entre enfermeiro e paciente adquire grande importância no processo de cuidar. A comunicação terapêutica é fundamental para promover afeto, carinho e atenção e, dessa forma, pode atender às necessidades psicológicas do paciente. Necessidades que se tornam ainda mais evidentes em pacientes oncológicos, que associam a doença à morte eminente devendo o enfermeiro, assim, proporcionar uma assistência holística, que privilegie o ser humano. Dessa forma, este estudo teve como objetivo compreender o significado que o enfermeiro atribui ao cuidado que dispensa ao paciente portador de neoplasia, considerando os aspectos biopsicossociais e a relevância do seu relacionamento terapêutico. Utilizou-se a abordagem qualitativa visando à busca da essência, particularidades e singularidades nesta questão. Foram incluídos nesta pesquisa onze enfermeiros do Hospital de Base de São José do Rio Preto, SP, atuantes em unidades que prestam assistência aos pac ientes portadores de neoplasia. Os dados foram coletados por meio de entrevistas semi-estruturadas,permitindo livres manifestações acerca do tema, gravadas e transcritas. A análise das entrevistas demonstrou a desvalorização do cuidar holístico e o afastamento dos profissionais em relação aos pacientes oncológicos.Além disso, indicou uma grande deficiência na compreensão de relacionamento terapêutico, como aspecto fundamental no cuidado. Apontou, ainda, inconsistências na percepção do enfermeiro em relação ao cuidado do paciente no mais amplo sentido, evidenciando a necessidade de dar maior importância ao relacionamento terapêutico nos cursos de graduação e educação permanente para os profissionais atuantes.

The nurses´ presence is daily and frequently in the hospitals. Consequently, the relationship between the nurse and the patient acquires a great importance in the care process, The therapeutics communication isimportant to promote warmth , loving and attention and, therefore, to promote measures toward the patient’spsychological needs. Needs that can be more noticed with patients with cancer, since they are susceptible inassociating the disease with an eminent death. The nurse should thus provide a holistic assistance, focusing the human being. Therefore, this study aimed at understanding the care significance that the nurses have been providing to the patients with cancer considering the biopsychosocial aspects and the importance of the their therapeutic relationship. Qualitative approach was used to search the essence, particularities and singularities regarding this issue. Eleven nurses from Hospital de Base, São José do Rio Preto, SP, were included in this research. They have been working in units that provide assistance to patients with cancer.Semi-structured interviews were used to collect data, thus allowing free manifestation about the theme.Afterwards, they were recorded and registered. The analysis of these interviews showed a holistic caredevaluation and the professionals distance in relation to the oncological patients. Moreover, it showed agreat gap in understanding the therapeutic relationship as an important aspect in the care process. It has alsopointed out the inconsistency in the nurses perception regarding the patient´s care, in a broadest sense;being evidence the necessity in giving greater importance to the therapeutic relationship during the graduationcourses and continuing education for the acting professionals.