Sodium Homeostasis, a Balance Necessary for Life.

Body sodium (Na) levels must be maintained within a narrow range for the correct functioning of the organism (Na homeostasis). Na disorders include not only elevated levels of this solute (hypernatremia), as in diabetes insipidus, but also reduced levels (hyponatremia), as in cerebral salt wasting syndrome. The balance in body Na levels therefore requires a delicate equilibrium to be maintained between the ingestion and excretion of Na. Salt (NaCl) intake is processed by receptors in the tongue and digestive system, which transmit the information to the nucleus of the solitary tract via a neural pathway (chorda tympani/vagus nerves) and to circumventricular organs, including the subfornical organ and area postrema, via a humoral pathway (blood/cerebrospinal fluid). Circuits are formed that stimulate or inhibit homeostatic Na intake involving participation of the parabrachial nucleus, pre-locus coeruleus, medial tuberomammillary nuclei, median eminence, paraventricular and supraoptic nuclei, and other structures with reward properties such as the bed nucleus of the stria terminalis, central amygdala, and ventral tegmental area. Finally, the kidney uses neural signals (e.g., renal sympathetic nerves) and vascular (e.g., renal perfusion pressure) and humoral (e.g., renin-angiotensin-aldosterone system, cardiac natriuretic peptides, antidiuretic hormone, and oxytocin) factors to promote Na excretion or retention and thereby maintain extracellular fluid volume. All these intake and excretion processes are modulated by chemical messengers, many of which (e.g., aldosterone, angiotensin II, and oxytocin) have effects that are coordinated at peripheral and central level to ensure Na homeostasis.

Effectiveness of Custom-Made Foot Orthoses vs. Heel-Lifts in Children with Calcaneal Apophysitis (Sever's Disease): A CONSORT-Compliant Randomized Trial.

The aim of the present research was to determine the effectiveness of relieving calcaneal apophysitis pain using "off-the-shelf" heel-lifts and custom-made orthotics. Two intervention modalities were evaluated and compared in a 12-week follow-up trial. Inclusion criteria included 9- to 12-year-old children diagnosed with calcaneal apophysitis. Children were randomly stratified into treatment A (custom-made polypropylene foot orthoses) and treatment B ("off-the-shelf" heel-lifts) groups. Treatment effectiveness was measured by algometry and the visual analogical scale (VAS). A total of 208 patients were included. The treatment A group showed an increase in threshold algometry of 53.4% (95% CI 47.1% to 59.7%) and a decrease in VAS of -68.6% (95% CI -74.5% to -62.7%) compared with the treatment B group (p < 0.001). Calcaneal apophysitis pain perception was improved in both groups, but children who used custom-made foot orthoses showed a greater improvement.

Locally linear embedding and plantar pressure-time graph selection in heel pain classification: An observational, case-control study.

Plantar heel pain mainly manifests during the gait cycle when the whole foot is in contact with the floor, which corresponds to the second rocker of the gait. This moment can be studied through the analysis of pressure-time graphs obtained using plantar pressure plate systems. However, these graphs are complex, and a dimensionality reduction method, such as locally linear embedding (LLE), greatly assists in their comprehension. This observational, case-control pilot study included 45 subjects divided into case (n = 21) and control (n = 24) groups, depending on the presence/absence of plantar heel pain. The second rocker pressure-time graphs of the 45 subjects were obtained using the Footwork Pro® plantar pressure plate system. These graphs were analyzed and defined as the dynamic simultaneity surfaces (DSSs). This complex structure was composed of four dimensions: the dynamic simultaneity time (DST), slope upward grade (α), slope downward grade (ß), and height (h), and were reduced into one dimension and classified into pathological and non-pathological subjects using the LLE method. All 45 DSSs were successfully reduced and classified to distinguish between the case (plantar heel pain) and control (non-plantar heel pain) subjects. This study is the first to use the LLE method for gait analysis. This method serves as a novel and promising tool for the study and classification of pathological and non-pathological gait cycles. This method opens the door for future research and analysis, with significant potential to assess diagnosis, treatment follow-up, and injury prevention in physical medicine consultations.

Animal models for diabetes insipidus.

The hormone arginine vasopressin (AVP) is a nonapeptide synthesized by hypothalamic magnocellular nuclei and secreted from the posterior pituitary into the bloodstream. It binds to AVP receptor 2 in the kidney to promote the insertion of aquaporin channels (AQP2) and antidiuretic responses. AVP secretion deficits produce central diabetes insipidus (CDI), while renal insensitivity to the antidiuretic effect of AVP causes nephrogenic diabetes insipidus (NDI). Hereditary and acquired forms of CDI and NDI generate hypotonic polyuria, polydipsia, hyperosmolality, and hypernatremia. The AVP mutant (Brattleboro) rat is the principal animal model of hereditary CDI, while neurohypophysectomy, pituitary stalk compression, hypophysectomy, and mediobasal hypothalamic lesions produce acquired CDI. In animals, hereditary NDI is mainly caused by mutations in AVP2R or AQP2 genes, while acquired NDI is most frequently induced by lithium. We report here on the determinants of the intake and excretion of water and mineral salts and on the different types of DI in humans. We then describe the hydromineral characteristics of these animal models and the responses observed after administration of hypertonic NaCl or when they are fed with low-sodium diets. Finally, we report on the effects of drugs such as AVP analogues and/or oxytocin, another neuropeptide that increases sodium excretion in animal models and humans with CDI, and sildenafil, a compound that increases the expression and function of AQP2 channels in animal models and humans with NDI.

Reliability and Repeatability of the Footwork Plantar Pressure Plate System.

BACKGROUND: Plantar pressure plate instruments are commonly used in clinical practice and biomechanical analysis and are useful to establish a relationship between gait disorders and foot pressure. The aim of this study was to verify the reliability and repeatability of the Footwork pressure plate system for static and dynamic conditions. METHODS: Forty healthy adults, without apparent gait pathology, were recruited. For the static condition, participants were asked to stand static on the Footwork pressure plate for 5 sec in natural position (arms on either side of the body, feet shoulder-width apart in a comfortable angle, and looking ahead). For the dynamic condition, subjects were told to step five times with each foot on the plate following the three-step protocol. Both conditions were performed in two testing sessions spaced by 1 week. RESULTS: Intrasession and intersession reliability for both conditions showed substantial to almost perfect intraclass correlation coefficient (ICC) values, and low coefficient of variation, low standard error measure, and low percentage error. Intrasession ICCs were 0.724 to 0.993 for static condition evaluation and 0.639 to 0.986 for dynamic condition evaluation. Intersession reliability ICCs ranged from 0.850 to 0.987 for the static condition and from 0.781 to 0.996 for the dynamic condition. Coefficient of variation values were below 8% in both cases and percentage error calculated from standard error measure were less than 10%. CONCLUSIONS: The present work demonstrates that the Footwork plantar pressure plate system is a reliable instrument for collecting plantar pressures in static and dynamic conditions. Reliability data were higher for the static trials, probably because of the individual physiologic fluctuations, which are larger during dynamic gait. Reliability for intersession and average intrasession trials were higher than single-test reliability. The results from the present work can be used as a starting point for future research and to establish a basis for sample sizes for investigations that would use the Footwork platform.

Effects of oxytocin administration on the hydromineral balance of median eminence-lesioned rats.

In the clinical setting, acute injuries in hypothalamic mediobasal regions, along with polydipsia and polyuria, have been observed in patients with cerebral salt wasting (CSW). CSW is also characterised by hypovolaemia and hyponatraemia as a result of an early increase in natriuretic peptide activity. Salt and additional amounts of fluid are the main treatment for this disorder. Similarly, experimental lesions to these brain regions, which include the median eminence (ME), produce a well-documented neurological model of polydipsia and polyuria in rats, which is preceded by an early sodium excretion of unknown cause. In the present study, oxytocin (OT) was used to increase the renal sodium loss and prolong the hydroelectrolyte abnormalities of ME-lesioned animals during the first few hours post-surgery. The objective was to determine whether OT-treated ME-lesioned animals increase their sodium appetite and water intake to restore the volume and composition of extracellular body fluid. Electrolytic lesion of the ME increased water intake, urinary volume and sodium excretion of food-deprived rats and also decreased urine osmolality and estimated plasma sodium concentration. OT administration at 8 hours post-surgery reduced water intake, urine output and plasma sodium concentration and also increased urine osmolality and urine sodium excretion between 8 and 24 hours post-lesion. From 24 to 30 hours, more water and hypertonic NaCl was consumed by OT-treated ME-lesioned rats than by physiological saline-treated-ME-lesioned animals. Food availability from 30 to 48 hours reduced the intake of hypertonic saline solution by ME/OT animals, which increased their water and food intake during this period. OT administration therefore appears to enhance the natriuretic effect of ME lesion, producing hydroelectrolyte changes that reduce the water intake of food-deprived animals. Conversely, the presence of hypertonic NaCl increases the fluid intake of these animals, possibly as a result of the plasma sodium depletion and hypovolaemic states previously generated. Finally, the subsequent increase in food intake by ME/OT animals reduces their need for hypertonic NaCl but not water, possibly in response to osmotic thirst. These results are discussed in relation to a possible transient activation of the ME with the consequent secretion of natriuretic peptides stored in terminal swellings, which would be augmented by OT administration. Electrolytic lesion of the ME may therefore represent a useful neurobiological model of CSW.

Association between the Foot Posture Index and running related injuries: A case-control study.

BACKGROUND: Novice runners are at significantly greater risk of running-related injuries than experienced recreational runners. To develop prevention strategies for this population, it is important to identify predisposing factors that contribute to the incidence of these injuries. This study aims to assess the relationship between running-related injuries, foot posture and other factors in novice runners. METHODS: Case-control study in 600 novice runners, classified as cases or controls based on incidence of running-related injuries. Participants' foot posture was measured using the Foot Posture Index, and we performed a descriptive analysis of the explanatory variables, comparing cases and controls. To assess the association between the injury and the presence of exposure and other explanatory variables, we performed a simple logistic regression for each variable and then fit a multivariable regression model. FINDINGS: Our regression model showed that high supination was associated with 76.8 times higher odds of injury than a neutral Foot Posture Index score (P < 0.001). High pronation was associated with 20-fold higher odds of injury than neutral foot posture (P < 0.001). Other variables such as running surface, number of shoes used, and body mass index were also associated with injury. The model showed an acceptable predictive capacity, with an area under the ROC curve of 0.7753. INTERPRETATION: If the association between Foot Posture Index and running-related injury is confirmed in large prospective studies, running programs for beginners should consider foot posture in efforts to prevent running-related injuries.

Fiabilidad de la cinemática angular de rodilla y tobillo de la carrera en el plano sagital medido con Younext Direct Motion Capture(R) / Reliability of the angular kinematic of knee and ankle during the running in the sagittal plane measured with Younext Direct Motion Capture(R)

En los últimos cuarenta años la popularidad de salir a correr o hacer running se ha incrementado notablemente. Su popularidad y el gran número de lesiones hace que el running sea la actividad física más estudiada por el área de la biomecánica. En la práctica clínica, se utilizan principalmente software de análisis de movimiento 2D para analizar la cinemática. Younext Direct Motion Capture(R) (Podoactiva S.L., Huesca) es un software que analiza los parámetros cinemáticos durante la carrera en el plano sagital. El objetivo general de este estudio fue determinar la fiabilidad y repetibilidad de la cinemática angular de la rodilla y del tobillo de la carrera en el plano sagital en población sana utilizando Younext Direct Motion Capture(R). Estudio piloto observacional de concordancia. 8 sujetos (5 varones y 3 mujeres) fueron filmados mientras corrían en una cinta de correr, obteniendo tres grabaciones del ciclo de la carrera de cada participante en la primera sesión. Se realizó una segunda sesión de grabaciones a los 7 días del primer registro para volver a grabar siguiendo el mismo protocolo. Se calculó el coeficiente de correlación intraclase (ICC) para determinar la fiabilidad intra-sesión e inter-sesión del software a la hora de medir la cinemática de la rodilla y del tobillo. Se obtuvo una fiabilidad intra-sesión e inter-sesión casi perfectas (ICC> 0,81) tanto para tobillo como para rodilla. Este estudio demostró que el software Younext Direct Motion Capture(R) es fiable para analizar la cinemática angular de la rodilla y del tobillo de la carrera en población adulta sana

The popularity of running has increased remarkably the past forty years. Its popularity and the large number of injuries make running the most studied physical activity in the area of biomechanics. In clinical practice, joint kinematics during running are primarily quantified by two-dimensional motion-analysis software. Younext Direct Motion Capture(R) (Podoactiva S.L., Huesca) is a software that analyzes the kinematic parameters during the running in the sagittal plane. The main goal of this study was to determine the reliability and repeatability of the angular kinematics of the knee and ankle in the sagittal plane in a healthy population using Younext Direct Motion Capture (R). Observational pilot study of concordance. 8 subjects (5 men and 3 women) were filmed while running on a treadmill, obtaining three recordings of the running cycle of each participant in the first session. A second session of recordings was made 7 days after the first recording to re-record following the same protocol. The intraclass correlation coefficient (ICC) was calculated to determine the intra-session reliability and inter-session reliability of the software when measuring the kinematics of the knee and the ankle. Very good intra-session and inter-session reliability (ICC> 0.81) were obtained for both ankle and knee measurements. This study showed that Younext Direct Motion Capture(R) software is reliable for analyzing the angular kinematics of the knee and ankle during running in a healthy adult population

Screening for latent tuberculosis infection in patients with inflammatory bowel disease: Can interferon-gamma release assays replace the tuberculin skin test?

BACKGROUND/AIMS: Screening for latent tuberculosis infection is mandatory before starting anti-tumor necrosis factor therapy. New assays based on interferon-γ (IFN-γ) release have recently become available and may be more accurate. The aim of this study was to compare QuantiFERON-TB and tuberculin skin test in screening for latent infection in patients with inflammatory bowel disease. MATERIALS AND METHODS: We prospectively screened 138 patients with inflammatory bowel disease for latent tuberculosis infection with chest X-ray, tuberculin skin test, and a third-generation QuantiFERON-TB test. The association of the results in both tests with immunosuppression or inflammatory activity was determined by logistic regression. RESULTS: The tuberculin skin test and QuantiFERON-TB were positive in 21.7% and 24.6% of the patients, respectively. Overall, 71% patients were receiving immunosuppressants. Concordance between the two tests was moderate (κ=0.59; 95% confidence interval (CI), 0.43-0.75) and was higher in immunosuppressant-naïve patients (κ=0.75; 95% CI, 0.52-0.97) than in immunosuppressed patients (κ=0.51; 95% CI, 0.30-0.72). In both the tests, disease activity and receiving immunosuppression were not associated with the test results. Nevertheless, QuantiFERON-TB was negatively influenced with two or more immunosuppressive drugs. CONCLUSION: Concordance between the two tests was moderate, and it appears lower with immunosuppression. QuantiFERON-TB alone may be appropriate in immunosuppressant-naïve patients. Both tests should be considered in immunosuppressed patients.

Aluminum foot insoles reduce plantar forefoot pressure and increase foot comfort for motorcyclists.

BACKGROUND:: Foot pain and paresthesia are common in cycling, due to plantar pressure and repetitive loading. OBJECTIVES:: The aim was to investigate the effect of foot insoles on plantar pressure of the foot in motorcycling, as well as self-reported comfort. STUDY DESIGN:: A randomized crossover clinical trial. METHODS:: A flexible foot pressure mat (GP MobilData WiFi® Gebiomized®) with different sizes was utilized. RESULTS:: Maximum pressure values occurred predominantly in the hallux with 4.90 ± 1.19 N/cm2, followed by second and third metatarsal areas with 4.57 ± 0.73 N/cm2, followed by the first metatarsal area with 4.30 ± 0.96 N/cm2, and followed by the fourth and fifth metatarsal areas with 3.22 ± 0.89 N/cm2 when using the control foot insole and using aluminum foot insole, which reduces maximum pressure to 1.55 ± 0.34, 1.56 ± 0.75, 1.09 ± 0.43, and 1.07 ± 0.59 N/cm2, respectively ( p < 0.001), with an effect size of 3.828, 4.067, 4.315, and 2.847, respectively. CONCLUSION:: The use of an aluminum foot insole significantly reduced maximum pressure during motorcycling. CLINICAL RELEVANCE: In this study, an aluminum insole in a motorcycling boot was shown to decrease maximum pressure on the foot. Comfort was significantly higher than that from ethylene vinyl acetate or commercial boot inserts. This increased comfort and decreased pressure should result in increased safety and control for motorcyclists.

Reticulocyte hemoglobin content (MCHr) in the assessment of iron deficient erythropoiesis in inflammatory bowel disease.

BACKGROUND: In conditions associated with inflammation, biochemical parameters alone could be inadequate for assessing iron status. We investigated the potential utility of mean reticulocyte hemoglobin content (MCHr) in the assessment of the erythropoiesis status in inflammatory bowel disease (IBD). METHODS: We recruited 124 anemic outpatients with IBD. Serum iron, transferrin and ferritin were tested. Complete blood counts were performed on a CELL-DYN Sapphire analyzer (Abbott Diagnostics). Differences among groups were assessed using analysis of variance, considering P < 0.05 to be significant. Receiver operating characteristic analysis was used to assess the diagnostic performance of MCHr for detecting iron deficient erythropoiesis. The reference used as an indicator of insufficient iron availability was transferrin saturation <20%. RESULTS: Overall, 47.6% of the patients had iron deficiency anemia (IDA) and 31.5% anemia of chronic disease (ACD), while the others (20.9%) had mixed anemia. Patients with ACD or mixed anemia showed functional iron deficiency: normal or high ferritin and low MCHr. The area under curve was 0.858 (95% CI 0.742-0.942), considering a cut off 30.3 pg, the sensitivity was 82.2%, specificity 83.3%. CONCLUSIONS: MCHr provides information on iron availability in IBD patients. It is a reliable test to assess iron supply for erythropoiesis.

Adalimumab treatment of anti-TNF-naïve patients with ulcerative colitis: Deep remission and response factors.

BACKGROUND: Adalimumab is the second tumour necrosis factor antagonist (anti-TNF) adopted for the treatment of ulcerative colitis. Clinical data from naïve patients are scarce. AIM: Examine the response to adalimumab in TNF-antagonist-naïve patients. METHODS: This multicentre, observational, prospective study was conducted using a cohort of consecutive patients with ulcerative colitis. Clinical remission, mucosal healing and deep remission were examined employing the Mayo Score and Mayo Endoscopic Score. Clinical response was assessed using the Partial Mayo Score. RESULTS: Of 53 individuals included in this study, 49.1% of patients were in clinical remission at week 8 and 60.3%, at week 52. Clinical response was observed in 84.9% and 69.8%, respectively. Mucosal healing was found in 62.3% and 67.9% of the patients, and 43.4% and 58.4% showed deep remission at week 8 and 52, respectively. After a year, 71.7% of the patients continued the adalimumab treatment. Adverse effects were observed in 28.3% of patients. Multivariate analysis showed that the long-term factor predictive of response at week 52 was the response in week 8 (expressed as Mayo Score; OR 0.66; 95% IC 0.1-0.67, p < 0.006). CONCLUSIONS: Adalimumab treatment of ulcerative colitis is effective; the results are better in clinical practice and in patients naïve to anti-TNF.

Relación de Lunge y Jack Test en la apófisis calcánea (Talalgia de Sever) en futbolistas jóvenes / Relationship of Lunge and Jack test in calcaneal apophysitis (sever´s disease) in young soccer players

La talalgia de Sever o apofisitis calcánea ocurre generalmente antes o durante el pico de crecimiento acelerado en niños y niñas. En ocasiones se presenta al practicar un nuevo deporte que implique desplazamientos y saltos como el fútbol. Fue descrita por el Doctor J. W. Sever, a causa de la detección de un dolor con sensibilidad localizada en la cara posterior del hueso calcáneo en jóvenes. El objetivo de este estudio es relacionar la incidencia de la talalgia de Sever con la restricción en los valores del Lunge test y con la incapacidad para activar el mecanismo de Windlass medido a través del test de Jack. Se realizaron los dos test a una muestra de 60 futbolistas jóvenes divididos en dos grupos (Sever = 30 jóvenes, de 10,84±0,79 años y 16,87±0,85 de IMC; No Sever = 30 jóvenes, de 10,87±0,80 y 17,58±1,41 de IMC). Los resultados muestran un test de Jack del pie derecho positivo en el 26,7% de los niños con Sever frente al 10,0% de los niños sin Sever (p=0,181). Mientras que, para el pie izquierdo, el 33,3% de los niños con Sever tiene el test de Jack positivo frente al 13,3% de los niños sin Sever (p=0,125). Por otro lado, el Lunge test para el pie derecho muestra una diferencia significativa (p< 0,01) entre los niños con Sever (32,2±3,6) y los niños sin Sever (40,5±4,1). Lo mismo ocurre para el pie izquierdo, niños con Sever (32,1±3,6) y sin Sever (39,2±4,4) con una diferencia significativa (p< 0,01). La restricción de la flexión dorsal (FD) de tobillo medida por medio del test de Lunge ha demostrado tener una relación significativa con la incidencia de la Talalgia de Sever. Mientras que el test de Jack no muestra una relación significativa (AU)

Sever´s Disease or calcaneal apophysitis occur before or during the early growth in children. Experienced after a new practice of psychical activity that involve running or jumping as soccer. It was described by Dr. J. W. Sever, due to detection of pain with localized sensitivity in the posterior area of the calcaneus bone in young people. The aim of the study is relate the Sever´s Disease incidence and restricted values of Lunge test. In the same way, the inability to activate the windlass mechanism measured through the Jack test related with Sever´s Disease incidence. We performed both test to 60 young soccer players divided in two groups (Sever = 30 young players, 10,84±0,79 years old and 16,87±0,85 IMC values; No Sever = 30 young players, 10,87±0,80 years old and y 17,58±1,41 IMC values). The results shows that a 26,7% of Sever´s Disease patient had a positive Jack test in right foot versus 10,0% of non Sever´s Disease patient (p=0,181). While for left foot, a 33,3% of Sever´s Disease patient had a positive Jack test versus 13,3% of non Sever´s Disease patient (p=0,125). On the other hand, Lunge test for right foot show a significant difference (p< 0,01) between Sever´s Disease patient (32,2±3,6) and non Sever´s Disease patient (40,5±4,1). At the same way, in left foot between Sever´s Disease patient (32,1±3,6) and non Sever´s Disease patient (39,2±4,4) with a significant difference (p< 0,01). The ankle dorsiflexion restriction measured by Lunge test is related with an incidence of Sever´s Disease. While, Jack test do not show a significant relationship (AU)

Reliability of the OptoGait portable photoelectric cell system for the quantification of spatial-temporal parameters of gait in young adults.

Determining progress in gait requires a reliable method. However, achieving standard assessment results in the clinical setting can be challenging. Searching for a reliable tool, we tested OptoGait, a tool that has floor-level, high-density photoelectric cells that can be used to determine patterns of spatial-temporal gait on the basis of 19 variables: step length, stride length, distance, total contact time, step time, walking speed, acceleration, progressive step time, cadence, gait cycle, stance phase, swing phase, heel contact phase, flatfoot phase, takeoff phase, single limb support, double limb support, load response phase, and pre-swing phase. The gait of 126 study participants (41 males, 85 females; 27.37±1.77 years) was assessed twice for each participant during 10 episodes of walking on a 10m walkway each 2 weeks apart. Intra-session and inter-session results were compared using data for each foot alone as well as both feet together. All variables resulted in a high consistency except for acceleration. The intra-session data showed substantial agreement; the intra-class correlation coefficient (ICC) ranged from 0.72-0.78 in the heel contact phase, 0.72-0.76 in the load response phase, and 0.76-0.85 in the pre-swing phase and a low SEM. The inter-session data for each foot alone and both feet together showed substantial agreement (0.77-0.79 in the load response phase) and slight agreement for acceleration (0.06-0.22) with a low SEM. Based on these results, we conclude that the OptoGait system can be used with confidence to evaluate spatial-temporal gait except for acceleration and progressive step time assessment.

Animal models of Central Diabetes Insipidus: Human relevance of acquired beyond hereditary syndromes and the role of oxytocin.

The aim of this study was to review different animal models of Central Diabetes Insipidus, a neurobiological syndrome characterized by the excretion of copious amounts of diluted urine (polyuria), a consequent water intake (polydipsia), and a rise in the serum sodium concentration (hypernatremia). In rodents, Central Diabetes Insipidus can be caused by genetic disorders (Brattleboro rats) but also by various traumatic/surgical interventions, including neurohypophysectomy, pituitary stalk compression, hypophysectomy, and median eminence lesions. Regardless of its etiology, Central Diabetes Insipidus affects the neuroendocrine system that secretes arginine vasopressin, a neurohormone responsible for antidiuretic functions that acts trough the renal system. However, most Central Diabetes Insipidus models also show disorders in other neurobiological systems, specifically in the secretion of oxytocin, a neurohormone involved in body sodium excretion. Although the hydromineral behaviors shown by the different Central Diabetes Insipidus models have usually been considered as very similar, the present review highlights relevant differences with respect to these behaviors as a function of the individual neurobiological systems affected. Increased understanding of the relationship between the neuroendocrine systems involved and the associated hydromineral behaviors may allow appropriate action to be taken to correct these behavioral neuroendocrine deficits.

Naloxone impairs concurrent but not sequential flavor aversion: Resorting to a flexible/explicit learning.

The role of opiate systems has been extensively studied in relation to learning and memory. Naloxone (Nx), an opiate antagonist, was administrated in concurrent (Experiment 1) and sequential (Experiment 2) flavor aversion learning (FAL) tasks. The outcomes demonstrate that Nx impairs the acquisition of concurrent but not sequential FAL. In the concurrent learning (7 trials), both control (vehicle) and Nx2 (treated with Nx only on the first 2 days) groups learned the task. Furthermore, these 2 groups retained the learning in a discrimination test without drug administration (Day 8) but failed a reversal test (Day 9). In contrast, the Nx group (7 trials with Nx) showed no concurrent learning but correctly performed the discrimination test (Day 8) and, critically, the reversal test. These results suggest that Nx blocks concurrent (implicit) learning in these experiments but induces animals to resort to new strategies that are flexible, a characteristic of explicit learning.

Opposite effects of oxytocin on water intake induced by hypertonic NaCl or polyethylene glycol administration.

Oxytocin (OT), a neurohormone, has been related to natriuretic and diuretic effects and also to water intake and sodium appetite. The objective of the present study was to determine the effect of subcutaneous OT administration on water intake and urine-related measures induced by the administration of hypertonic NaCl (experiment 1) or polyethylene glycol (PEG) (experiment 2). Experiment 1 showed that OT administration increases the urine volume, urinary sodium concentration, and natriuresis and reduces the water intake, water and sodium balances, and estimated plasma sodium concentration induced by hypertonic NaCl administration. Conversely, experiment 2 showed that OT administration increases the water intake and the antidiuretic response induced by PEG administration. These results show that the opposite effects of OT on the water intake induced by hypertonic NaCl or PEG administration are accompanied by differential regulatory effects, enhancing a natriuretic response in the first experiment and generating an antidiuretic reaction in the second experiment. This study suggests a differential regulatory effect of OT during states of intra- and extracellular thirst.

Inhibition of natriuresis in median eminence polydipsia: effects after intake of diets with different osmolalities and after hypertonic NaCl administration.

Lesions in the hypothalamic median eminence (ME) induce polydipsia and polyuria in male rats. A first experiment was designed to examine the effect of salt consumption (standard 0.25 percent Na+ vs. low-salt 0.04 percent Na+ diet) on the fluid-electrolytic balance (plasma sodium, urinary sodium excretion, urine osmolality) and water intake of ME polydipsic animals. In the first 6 h post-surgery, the natriuretic response was higher in ME-lesioned animals than in control groups. At 24 h post-surgery, however, less sodium was excreted by ME rats fed with a standard salt diet (ME/SS), despite showing no decrease in salt intake, and they evidenced an increase in plasma sodium concentration and water intake. Urine osmolality was significantly higher in control animals than in either ME-lesioned group. In experiment 2, hypertonic NaCl administration (2 ml/2M) increased the polydipsic behavior of ME-lesioned but not control rats (day 2). Animals deprived of food/salt showed a significant reduction (on day 2) in the initial (day 1) polydipsia, which increased on day 3 when the animals had access to a standard-salt diet. These results suggest that the reduced natriuretic response and the consequent sodium retention observed in ME animals may exacerbate the hydromineral imbalance of this polydipsic syndrome.

Breast imaging: how we manage diagnostic technology at a multidisciplinary breast center.

This paper discusses the most important aspects and problems related to the management of breast cancer imaging, at a center specialized in breast pathology. We review the established and emerging diagnostic techniques, their indications, and peculiarities: digital mammography, CAD systems, and the recent digital breast tomosynthesis, ultrasound and complementary elastography, molecular imaging techniques, magnetic resonance imaging, advanced sequences (diffusion), and positron emission mammography (PEM). The adequate integration and rational management of these techniques is essential, but this is not always easy, in order to achieve a successful diagnosis.

The D2/D3-receptor antagonist tiapride impairs concurrent but not sequential taste aversion learning.

Taste aversion learning (TAL) is a learning modality in which the animals reject a gustatory stimulus associated with the administration of noxious visceral substances. This learning can be established by concurrent or sequential procedures that involve different anatomical and functional mechanisms and may constitute distinct learning modalities. The dopaminergic system has been related to various learning processes and goal-directed behaviours. The present study examined the effect of the administration of tiapride, a D(2)/D(3) dopaminergic antagonist, on concurrent and sequential TAL. Results obtained showed that pre-treatment with tiapride blocks the acquisition of concurrent TAL but does not affect sequential TAL, including reversal learning tasks. These results demonstrate the involvement of the D(2)/D(3) dopaminergic receptors in the former but not the latter learning process. The dopaminergic system appears to participate in concurrent TAL, an "implicit" learning modality, but not in sequential TAL, which is considered a relational/explicit acquisition process.