Anterior Interhemispheric Approach for the Surgical Treatment of Azygos Anterior Cerebral Artery Aneurysms: A Case Series.

The azygos artery is an uncommon vascular variant of the anterior cerebral artery (ACA). This anomaly is associated in a high percentage with aneurysms. Management of azygos ACA aneurysms represents a surgical challenge. We present five patients who underwent microsurgical treatment for distal azygos ACA aneurysms with complex morphology. Four patients showed subarachnoid hemorrhage (SAH) and one complained of sentinel headache. Early preoperative digital subtraction angiography (DSA) or computerized tomography angiography (CTA) was performed. All patients were treated by surgical clipping via an anterior interhemispheric approach. During follow-up, all patients had a satisfactory outcome, with postoperative angiograms showing complete resolution of aneurysms.

Oral health services in prison settings: A global scoping review of availability, accessibility, and model of delivery.

This review aimed at evaluating the state of availability, accessibility and model of delivery of oral health services in prisons, globally. Five databases of peer-reviewed literature and potential sources of grey literature were systematically searched. Inclusion criteria encompassed oral health papers related to prisons globally, with exclusion of certain article types. Selection involved independent evaluations by two researchers, followed by quality assessment. Data on the availability of oral health interventions in prisons came from 18 countries, while information on the model of delivery of the services is scarce. In addition, two sets of individual and organizational barriers toward oral health service uptake in prisons were revealed and discussed in the text. Lack of oral health services in prisons affects people living in prisons and jeopardizes their reintegration. Urgent and concrete international actions are required to ensure the availability, accessibility, and quality of oral health services among people living in prisons.

Safety of benzodiazepines in patients with acute heart failure: A propensity score-matching study.

AIM: Benzodiazepines (BZDs) are one of the most used drugs to control symptoms in patients with acute heart failure (HF). However, the evidence on its safety is inconclusive. The objective was to describe the characteristics of patients admitted for HF and treated with BZDs and to assess the relationship of this treatment and mortality. PATIENTS AND METHODS: We performed a cross-sectional, multicentre (74 Spanish hospitals), cohort study. Patients admitted for HF were divided depending on whether they were treated with BZDs or not. Propensity score analysis matched patients in both groups in a 1:1 manner according to different factors. The primary outcome was mortality at day 7. Secondary outcomes were mortality at days 30 and 180, as well as readmissions and emergency room visits at 180 days. RESULTS: We included 1855 patients: 639 (34.4%) had prescribed BZDs treatment versus 1216 (65.6%) who had not been treated. Patients receiving BZDs had advanced heart disease, severe symptoms, need more HF intensive treatment and higher mortality. After propensity matching 381 balanced paired cases were included in each group. Treatment with BZDs was not associated with greater risk of mortality at day 7 of index hospitalization (7.6% vs 5.2%, adjusted OR 1.49, 95% CI 0.83-2.68, p = 0.186). There were also no differences between groups in terms of mortality at day 30 and 180, readmissions or visits to the emergency room. CONCLUSIONS: Our data support that benzodiazepines could be safely used for improving symptoms. in patients admitted for acute HF in terms of short-medium term mortality.

On-Chip Optical Anodic Stripping with Closed Bipolar Cells and Cathodic Electrochemiluminescence Reporting.

The aim of this work was to develop a simple, accessible, and point-of-use sensor to measure heavy metal ions in water in low-resource areas that cannot accommodate expensive or technical solutions. This report describes a new bipolar electrochemical sensor platform that reimagines conventional anodic stripping voltammetry in a wireless bipolar format with an optical electrochemiluminescent readout that can be quantified with any simple optical sensor like that found on most modern cell phone cameras. We call this technique as optical anodic stripping. Using a new nonlithographic fabrication process, devices could be produced rapidly and simply at <$1/sensor. The sensing scheme was developed, characterized, and optimized using electrochemical and optical methods. Quantitation of Pb2+ in both lab and natural water samples was rapid (2-3 min), accurate, precise, and highly linear in the 25-1000 ppb range and was shown to be sufficiently selective in the presence of other common heavy metal ions such as Cu2+, Cd2+, and Zn2+.

Few-Mode Field Quantization of Arbitrary Electromagnetic Spectral Densities.

We develop a framework that provides a few-mode master equation description of the interaction between a single quantum emitter and an arbitrary electromagnetic environment. The field quantization requires only the fitting of the spectral density, obtained through classical electromagnetic simulations, to a model system involving a small number of lossy and interacting modes. We illustrate the power and validity of our approach by describing the population and electric field spatial dynamics in the spontaneous decay of an emitter placed in a complex hybrid plasmonic-photonic structure.

Branching Ratio Method for Assessing Optically Thin Conditions in Laser-Induced Plasmas.

The branching ratio method is usually used to evaluate the optical thinness conditions in laser-generated plasmas, which are important for the application of analytical methods such calibration free laser induced breakdown spectroscopy (CF-LIBS). In this communication, we warn on the possibility that in some circumstances, the branching-ratio method might give results close to the one characterizing optically thin plasma conditions, even in the presence of a substantial self-absorption for the transitions considered.

[Primary hyperaldosteronism in a population of hypertensive patients]. / Hiperaldosterismo primario en una población de pacientes hipertensos.

The diagnosis of primary hyperaldosteronism (PHPA) has progressively increased over the last years and some authors consider it as the main cause of secondary hypertension. We studied the prevalence of PHPA in hypertensive patients followed at the Hypertension Unit from July 1999 to July 2017. A total of 2500 patients were included and diagnosis of PHPA was done in 79 of them (3.2%). It was more frequent in women (55.7%) with an increased incidence in the elderly, as compared to previous studies (27.8%). Initial diagnosis was suspected upon the presence of inappropriate kaliuria and metabolic alkalosis, associated to an aldosterone/plasma renin activity ratio > 30 (ng/dl)/(ng/ml/h). After confirmation of the presence of PA, imaging techniques to determine the etiology were performed. In this way, 29 cases (36.8%) of aldosterone-producing adenoma and 5 cases of bilateral adrenal hyperplasia with nodules were identified. Computed tomography identified the adenomas and hyperplasias with bilateral cortical nodules in all patients. Adrenalectomy and/or antialdosteronics were efficient in controlling blood pressure in 69.9% of cases. Of note in this series was the remission of stage 3 chronic renal failure in two cases, the high prevalence of hypercalciuric urinary lithiasis and a case of breast carcinoma after prolonged treatment with spironolactone.

El diagnóstico de hiperaldosteronismo primario (HPAP) aumentó en los últimos años y algunos autores lo consideran la principal causa de hipertensión arterial secundaria. Estudiamos la prevalencia de HPAP en el total de pacientes hipertensos atendidos en la Unidad de Hipertensión Arterial, en el período comprendido entre julio 1999 a julio 2017. Se incluyeron 2500 pacientes y en 79 se diagnosticó HPAP (3.2%). El HPAP fue más frecuente en mujeres (55.7%), observándose un incremento en la edad geriátrica con relación a estudios previos (27.8%). El diagnóstico se sospechó ante la presencia de kaliuria inapropiada y alcalosis metabólica, acompañada de un cociente aldosterona/actividad de renina plasmática superior a 30 (ng/dl)/(ng/ml/h). Tras su confirmación se realizaron estudios de imagen para determinar la etiología. Se detectaron así 29 casos (36.8%) de adenomas productores de aldosterona y 5 de hiperplasia bilateral suprarrenal con nódulos. La tomografía computarizada identificó el 100% de los adenomas y de las hiperplasias con nódulos corticales bilaterales. El tratamiento con suprarrenalectomía y/o antialdosterónicos resultó eficaz en el control de la presión arterial en el 69.9% de los casos. Se comentan aspectos particulares de esta serie, como la remisión de la insuficiencia renal, la elevada presencia de litiasis urinaria hipercalciúrica y la detección de un carcinoma de mama tras dosis prolongadas de espironolactona.

Hiperaldosteronismo primario en una población de pacientes hipertensos / Primary hyperaldosteronism in a population of hypertensive patients

El diagnóstico de hiperaldosteronismo primario (HPAP) aumentó en los últimos años y algunos autores lo consideran la principal causa de hipertensión arterial secundaria. Estudiamos la prevalencia de HPAP en el total de pacientes hipertensos atendidos en la Unidad de Hipertensión Arterial, en el período comprendido entre julio 1999 a julio 2017. Se incluyeron 2500 pacientes y en 79 se diagnosticó HPAP (3.2%). El HPAP fue más frecuente en mujeres (55.7%), observándose un incremento en la edad geriátrica con relación a estudios previos (27.8%). El diagnóstico se sospechó ante la presencia de kaliuria inapropiada y alcalosis metabólica, acompañada de un cociente aldosterona/actividad de renina plasmática superior a 30 (ng/dl)/(ng/ ml/h). Tras su confirmación se realizaron estudios de imagen para determinar la etiología. Se detectaron así 29 casos (36.8%) de adenomas productores de aldosterona y 5 de hiperplasia bilateral suprarrenal con nódulos. La tomografía computarizada identificó el 100% de los adenomas y de las hiperplasias con nódulos corticales bilaterales. El tratamiento con suprarrenalectomía y/o antialdosterónicos resultó eficaz en el control de la presión arterial en el 69.9% de los casos. Se comentan aspectos particulares de esta serie, como la remisión de la insuficiencia renal, la elevada presencia de litiasis urinaria hipercalciúrica y la detección de un carcinoma de mama tras dosis prolongadas de espironolactona.

The diagnosis of primary hyperaldosteronism (PHPA) has progressively increased over the last years and some authors consider it as the main cause of secondary hypertension. We studied the prevalence of PHPA in hypertensive patients followed at the Hypertension Unit from July 1999 to July 2017. A total of 2500 patients were included and diagnosis of PHPA was done in 79 of them (3.2%). It was more frequent in women (55.7%) with an increased incidence in the elderly, as compared to previous studies (27.8%). Initial diagnosis was suspected upon the presence of inappropriate kaliuria and metabolic alkalosis, associated to an aldosterone/plasma renin activity ratio > 30 (ng/dl)/(ng/ml/h). After confirmation of the presence of PA, imaging techniques to determine the etiology were performed. In this way, 29 cases (36.8%) of aldosterone-producing adenoma and 5 cases of bilateral adrenal hyperplasia with nodules were identified. Computed tomography identified the adenomas and hyperplasias with bilateral cortical nodules in all patients. Adrenalectomy and/o r antialdosteronics were efficient in controlling blood pressure in 69.9% of cases. Of note in this series was the remission of stage 3 chronic renal failure in two cases, the high prevalence of hypercalciuric urinary lithiasis and a case of breast carcinoma after prolonged treatment with spironolactone.

Resultados perinatales en gestantes con trastornos nutricionales por exceso / Perinatal outcomes in pregnant women suffering of excess nutritional disorders

Introducción: cada día aumenta el número de mujeres que inician su embarazo con trastornos nutricionales por exceso, lo que incrementa la morbilidad y mortalidad materna y perinatal.Objetivo: determinar los resultados perinatales en gestantes con sobrepeso y obesidad pregestacionales en Santa Cruz del Norte durante 2 años.Métodos: se realizó un estudio analítico observacional prospectivo entre julio de 2009 y junio de 2011 a partir de un universo de 109 embarazadas con sobrepeso y obesidad a la captación, se escogió una muestra al azar de 96 gestantes que conformó el grupo estudio; se dispuso de un grupo control de 219 pacientes normopeso en la captación, escogidas al azar de los consultorios médicos siguiendo múltiples criterios. Los datos se recolectaron mediante revisión de las historias clínica y obstétrica y se procesaron empleando medidas estadísticas descriptivas e inferenciales.Resultados: en las pacientes con sobrepeso y obesidad pregestacional se observó de manera significativa la preeclampsia-eclampsia en 17,7 porciento; diabetes gestacional en 7,3 porciento; ganancia exagerada de peso en 34,4 porciento; insuficiencia placentaria en 12,5 porciento; oligoamnios en 16,7 porciento; parto pretérmino en 5,2 porciento y parto instrumentado en 10,4 porciento; el distrés respiratorio y la hipoglicemia fueron las complicaciones significativas del recién nacido con 11,5 porciento y 13,5 porciento respectivamente, y el sangramiento posparto en las puérperas con 14,6 porciento.Conclusiones: los trastornos nutricionales por exceso al inicio de la gestación predisponen a resultados perinatales adversos, tanto para la salud madre, como del feto y del recién nacido, que contribuyen al incremento de la morbimortalidad materna y perinatal.

Introduction: every day the number of women starting their pregnancy with excess nutritional disorders increases along with maternal and perinatal morbidity and mortality.Objective: to determine the perinatal outcome in pregnant women with pre-pregnancy overweight and obesity in Santa Cruz del Norte for 2 years.Methods: a prospective observational analytic study was conducted from July 2009 to June 2011 in a universe of 109 overweight and obese pregnant women at the beginning of their pregnancy. A random sample of 96 pregnant women was chosen to form the study group; 219 normal weight patients were available the control group, who were randomly selected from the medical practices according to multiple criteria. Data were collected by reviewing the clinical and obstetric histories and they were processed using descriptive and inferential statistical measures.Results: pre-eclampsia- eclampsia was significantly observed in pre-pregnancy overweight and obese patients (17.7 percent); 7.3 percent patients had gestational diabetes, excessive weight gain in 34.4 percent; 12.5 percent had placental insufficiency; 16.7 percent had oligoamnios; 5.2 percent had preterm delivery, and 10.4 percent needed instrumental delivery. Respiratory distress and hypoglycemia were significant complications of newborns (11.5 percent and 13.5 percent respectively), and 14.6 percent had postpartum bleeding.Conclusions: nutritional disorders excess at the beginning of pregnancy predispose to adverse perinatal outcomes for mother health, the fetus and the newborn. These disorders contribute to increased maternal and perinatal morbidity and mortality.

Relaciones de equivalencia y estilo cognitivo: hallazgos de una relación no explorada / Equivalence relations and cognitive style: findings of an unexplored relationship

La formación de relaciones derivadas a partir de un entrenamiento en discriminaciones condicionales es un fenómeno ampliamente demostrado en humanos. Sin embargo, no es infrecuente que se observen algunos casos de pobre desempeño en las pruebas de equivalencia o dificultades en el aprendizaje de las relaciones entre los miembros de la clase. Este estudio examina si los tipos perceptuales de respuesta a las condiciones estimulativas de la tarea experimental (estilos cognitivos de sensibilidad al campo visual) están relacionados con la variabilidad en el desempeño en pruebas de equivalencia. A través de la prueba de figuras enmascaradas (EFT), se evaluó el estilo cognitivo de 32 participantes y se examinó su desempeño en pruebas de equivalencia después de un entrenamiento con el procedimiento de igualación a la muestra respondiente. Las frecuencias observadas en tablas de contingencia y los análisis correlacionales entre el desempeño en las pruebas de equivalencia y las puntuaciones en la prueba EFT indican una asociación positiva entre el estilo de dependencia-independencia del campo visual y la formación de relaciones derivadas.

The formation of equivalence classes derived from exposure to conditional discrimination training is a widely demonstrated phenomenon in human research. However, low performance in equivalence tests and difficulties in the acquisition of relations among class members are not infrequent. The present study examined whether types of perceptual response to the experimental stimulus (the cognitive style of visual field sensitivity) are related to the variability observed in equivalence tests. The masked figures test (MFT) was used to determine the cognitive styles of 32 participants who were also exposed to equivalence tests after conditional discrimination training trials with a respondent matching-to-sample procedure. Observed frequencies, as reported in contingency tables, and correlation coefficients between performance in equivalence tests and MFT scores suggested a positive association between the cognitive style of visual field dependence-independence and the formation of equivalence classes.

Resultados perinatales en gestantes con bajo peso pregestacional / Perinatal outcomes in pregnant women with low weight prior pregnancy

Introducción: la malnutrición por defecto es crítica en el período gestacional al traer consigo resultados adversos para la salud materna, fetal y del recién nacido.Objetivo: determinar los resultados perinatales en gestantes con bajo peso pregestacional en Santa Cruz del Norte durante 2 años.Métodos: se realizó un estudio analítico observacional prospectivo entre julio de 2009 y junio de 2011 a partir de un universo de 152 embarazadas con bajo peso en el momento de la captación. Se escogió una muestra al azar de 112 gestantes que conformó el grupo estudio; se dispuso de un grupo control de 219 pacientes normopeso en el mismo período, escogidas al azar de los consultorios médicos siguiendo múltiples criterios. Los datos se recolectaron mediante revisión de las historias clínica y obstétrica y se procesaron empleando medidas estadísticas descriptivas e inferenciales.Resultados: en las pacientes con bajo peso pregestacional se observó de manera significativa la amenaza de parto pretérmino en 20,5 porciento; rotura prematura de las membranas en 17,9 porciento; ganancia insuficiente de peso en 43,8 porciento; restricción del crecimiento en 14,3 porciento; malformaciones congénitas en 2,7 porciento; parto pretérmino en 6,3 porciento y bajo peso al nacer en 8,9 porciento; el distrés respiratorio fue la complicación significativa del recién nacido con 10,7 porciento y la endometritis y sepsis urinaria, en las puérperas con 16,1 porciento y 5,4 porciento respectivamente.Conclusiones: los trastornos nutricionales por defecto al inicio de la gestación traen consigo un aumento en la morbilidad materna y perinatal al incrementar el riesgo de afecciones obstétricas, fetales, puerperales y del recién nacido

Introduction: default malnutrition is critical in the gestational period since it results adversely for maternal, fetal and newborn health.Objective: to determine the perinatal outcome in pregnant women with low weight prior pregnancy in Santa Cruz del Norte for 2 years.Methods: we performed a prospective observational analytical study from July 2009 to June 201. Our universe was 152 pregnant women with low weight when recruiting, a sample of 112 pregnant women were chosen to formed the study group and a control group of normal-weight 219 patients was formed randomly from the medical practices following multiple criteria. The data were collected by the review of clinical and obstetric records and they were processed using descriptive and inferential statistics.Results: significantly, patients with low pre-pregnancy weight were observed to have preterm labor (20.5 per cent), premature rupture of membranes (17.9 per cent), insufficient weight gain (43.8 per cent), growth restriction (14.3 per cent), congenital malformations (2.7 per cent), preterm delivery (6.3 per cent), and low birth weight (8.9 per cent). Respiratory distress was a significant complication in newborns (10.7 per cent), and endometritis and urinary sepsis in the postpartum women (16.1 per cent and 5.4 per cent respectively).Conclusions: nutritional disorders at the beginning of pregnancy bring an increase in maternal and perinatal morbidity, since the risk of obstetrical, fetal, postnatal and newborn conditions increased

Evaluación de la habituación a las condiciones estimulativas del procedimiento de igualación a la muestra / Assessment of the effects of habituation to matching-to-sample procedure stimulating conditions

Los estudios sobre equivalencia en humanos con habilidades verbales generalmente utilizan el procedimiento de igualación a la muestra e incluyen estímulos arbitrarios. En la gran mayoría de los estudios publicados no se observa un desempeño superior al criterio en todos los participantes de los grupos evaluados. Los casos de bajo desempeño usualmente no se interpretan y se discute la variabilidad en la adquisición de relaciones derivadas en humanos pocas veces. El propósito del presente estudio es examinar si pueden explicarse al menos parcialmente los bajos desempeños por la habituación a las condiciones estimulativas del arreglo experimental. Se comparan los resultados en las pruebas de equivalencia de un grupo expuesto a un procedimiento de igualación a la muestra respondiente, y un grupo expuesto al mismo procedimiento pero con un requerimiento de respuesta de observación durante algunos de los ensayos de entrenamiento. La inspección visual de los datos muestra que un número mayor de participantes del segundo grupo obtuvo una ejecución superior al criterio. Se discuten algunas implicaciones teóricas y procedimentales a partir del análisis de los reportes verbales de los participantes.

Traditionally, research studies on the formation of equivalence classes in verbally able individuals are conducted using arbitrary stimuli and a matching-to-sample procedure. However, a higher-than-criterion performance in equivalence tests is not usually observed in all participants of these studies. These data are not often interpreted and the implied variability in the acquisition of derived relations in humans is seldom discussed. The purpose of this study is to examine whether habituation to the stimulating conditions of the experimental preparation may account - at least partially - for low performances observed in equivalence tests. Results of participants in a group exposed to a respondent matching-to-sample procedure were compared to those of a group exposed to a similar procedure with an added observation response requirement on some of the training trials. Visual inspection of the data shows that a higher number of participants in the second group obtained above-criterion performances. Some additional theoretical and procedural implications are discussed based on the analysis of participants' verbal reports.

Resurgencia de conductas simbólicas: una aproximación experimental / Resurgence of symbolic behavior: an experimental approach / Ressurgência de condutas simbólicas: uma abordagem experimental

El propósito de este estudio fue evaluar los efectos diferenciales del cambio de consecuencias (de contingencias de reforzamiento a contingencias de castigo) sobre el aprendizaje de discriminaciones condicionales y las relaciones derivadas de estímulos. Se entrenó a siete participantes para que discriminaran cuatro pares de estímulos a través del procedimiento de igualación a la muestra (primer entrenamiento), y se probaron las relaciones derivadas. Posteriormente, los conjuntos de pares fueron reorganizados para establecer las nuevas funciones discriminativas condicionales entre estímulos (segundo entrenamiento; incongruente respecto al inicial). Las respuestas relacionales consistentes con el segundo entrenamiento fueron castigadas en la siguiente fase. Finalmente, las funciones discriminativas condicionales (la entrenada directamente y la derivada) fueron probadas. Un alto número de participantes mostró el fenómeno de resurgencia, el cual es un patrón conductual consistente con el primer entrenamiento de relaciones entre estímulos. Los resultados pueden apoyar la idea de que la resurgencia de conductas es una alteración común tanto en la conducta moldeada por las consecuencias como en la conducta novedosa.

The purpose of this study was to assess the differential effects of consequence change (from reinforcement to punishment contingencies) upon conditional discrimination learning and derived stimulus relations. Seven participants were taught to discriminate four pair-sets of stimuli by means of a matching to sample procedure (early training) and were tested for derived stimulus relations. Later the pair-sets were reorganized in order to establish the new conditional discriminative functions between stimuli (later training, inconsistent with respect to early training). Novel responses were tested as well. Relational responses consistent with the later training received punishment in the following phase. Finally, the conditional discriminative functions (both the one directly trained and the derived one) were tested. A high number of participants showed the resurgence phenomenon, a behavioral pattern consistent with early training both of directly trained and derived stimulus relations. These results can support the idea that resurgence of behavior is a common alteration of contingency-shaped behavioral topographies and novel behavior.

Neste artigo foram avaliados os efeitos diferenciais da modificação de conseqüências (de contingências de reforço a contingências de castigo na aprendizagem de discriminações condicionais e as relações derivadas de estímulos. Sete participantes treinados discriminaram quatro pares de estímulos pela igualação à amostra (primeiro treinamento) e foram provados as relações derivadas. Depois, os conjuntos dos pares foram reorganizados para determinar as novas funções discriminativas condicionais entre estímulos. As respostas relacionais coerentes com o segundo treinamento foram castigadas na etapa seguinte. Ao fim, foram provadas as funções discriminativas condicionais (a treinada diretamente e a derivada). Um grande número de participantes mostrou o fenômeno da ressurgência, um padrão de conduta coerente com o primeiro treinamento de relações entre estímulos. Os achados podem sustentar a ideia de que a ressurgência de condutas é uma modificação comum tanto na conduta moldada pelas conseqüências quanto na conduta nova.

Elección y sustitución de estímulos entre el alcohol y el alimento en ratas: relación entre el incremento del costo de una alternativa y el cambio en la elección / Choice and substitution of stimuli between alcohol and food in rats: relationship between the increase in the cost of an alternative and the change in the choice

El propósito de este estudio fue evaluar el efecto de la variación del costode las alternativas sobre la conducta de elección entre sacarina y etanolen cuatro ratas Wistar ingenuas. Con ello se pretendió establecer si lasratas sustituyen bienes como el etanol que se encuentra inicialmente enlibre acceso, por el alimento sacarina en restricción en la medida en quese aumenta el precio del etanol. La investigación se desarrolló en tresfases: 1. moldeamiento de la respuesta operante, 2. línea de base o delibre acceso a los bienes y por último, 3. restricción, donde el etanolinicialmente estuvo en acceso libre y luego fue restringido, en contraste,la sacarina se mantuvo en restricción constante. Los resultados encontradosseñalan que las ratas sustituyeron el etanol por la sacarina en lamedida en que los precios de éste aumentaron a una razón fija 5 (RF5),aunque se haya presentado un mayor consumo de etanol en las sesionesiniciales en que se encontraba. Dicho comportamiento corrobora la posiciónde la economía conductual sobre la conducta de elección en función de loscostos de las alternativas.

The purpose of this study was to evaluate the effect of changes in the costof alternatives on the choice between saccharin and alcohol and to establishwhether the rats substitute goods such as alcohol (which is initially freeaccess and then restricted) by saccharine (which is constantly restricted). The study was conducted in three stages: (1) shaping of the operantresponse, (2) baseline or free access to goods and (3) restriction: whereasthe access to alcohol was initially free and then restricted, the access tosaccharin was constantly restricted. As expected, as the price for ethanolwas increased to a fixed ratio 5 (RF5), rats substituted ethanol by saccharine, even when there was a greater alcohol consumption during the initial phases.Such behavior is in agreement with behavioral economics concepts on choicebehavior as a function of the costs of the alternatives.

Acupuncture and rehabilitation of the painful shoulder: study protocol of an ongoing multicentre randomised controlled clinical trial [ISRCTN28687220].

BACKGROUND: Although the painful shoulder is one of the most common dysfunctions of the locomotor apparatus, and is frequently treated both at primary healthcare centres and by specialists, little evidence has been reported to support or refute the effectiveness of the treatments most commonly applied. According to the bibliography reviewed, physiotherapy, which is the most common action taken to alleviate this problem, has not yet been proven to be effective, because of the small size of sample groups and the lack of methodological rigor in the papers published on the subject. No reviews have been made to assess the effectiveness of acupuncture in treating this complaint, but in recent years controlled randomised studies have been made and these demonstrate an increasing use of acupuncture to treat pathologies of the soft tissues of the shoulder. In this study, we seek to evaluate the effectiveness of physiotherapy applied jointly with acupuncture, compared with physiotherapy applied with a TENS-placebo, in the treatment of painful shoulder caused by subacromial syndrome (rotator cuff tendinitis and subacromial bursitis). METHODS/DESIGN: Randomised controlled multicentre study with blind evaluation by an independent observer and blind, independent analysis. A study will be made of 465 patients referred to the rehabilitation services at participating healthcare centres, belonging to the regional public health systems of Andalusia and Murcia, these patients presenting symptoms of painful shoulder and a diagnosis of subacromial syndrome (rotator cuff tendinitis and subacromial bursitis). The patients will be randomised into two groups: 1) experimental (acupuncture + physiotherapy); 2) control (TENS-placebo + physiotherapy); the administration of rescue medication will also be allowed. The treatment period will have a duration of three weeks. The main result variable will be the change produced on Constant's Shoulder Function Assessment (SFA) Scale; as secondary variables, we will record the changes in diurnal pain intensity on a visual analogue scale (VAS), nocturnal pain intensity on the VAS, doses of non-steroid anti-inflammatory drugs (NSAIDs) taken during the study period, credibility scale for the treatment, degree of improvement perceived by the patient and degree of improvement perceived by the evaluator. A follow up examination will be made at 3, 6 and 12 months after the study period has ended. Two types of population will be considered for analysis: per protocol and per intention to treat. DISCUSSION: The discussion will take into account the limitations of the study, together with considerations such as the choice of a simple, safe method to treat this shoulder complaint, the choice of the control group, and the blinding of the patients, evaluators and those responsible for carrying out the final analysis.