Conductance heterogeneities induced by multistability in the dynamics of coupled cardiac gap junctions.

In this paper, we study the propagation of the cardiac action potential in a one-dimensional fiber, where cells are electrically coupled through gap junctions (GJs). We consider gap junctional gate dynamics that depend on the intercellular potential. We find that different GJs in the tissue can end up in two different states: a low conducting state and a high conducting state. We first present evidence of the dynamical multistability that occurs by setting specific parameters of the GJ dynamics. Subsequently, we explain how the multistability is a direct consequence of the GJ stability problem by reducing the dynamical system's dimensions. The conductance dispersion usually occurs on a large time scale, i.e., thousands of heartbeats. The full cardiac model simulations are computationally demanding, and we derive a simplified model that allows for a reduction in the computational cost of four orders of magnitude. This simplified model reproduces nearly quantitatively the results provided by the original full model. We explain the discrepancies between the two models due to the simplified model's lack of spatial correlations. This simplified model provides a valuable tool to explore cardiac dynamics over very long time scales. That is highly relevant in studying diseases that develop on a large time scale compared to the basic heartbeat. As in the brain, plasticity and tissue remodeling are crucial parameters in determining the action potential wave propagation's stability.

Treatment of anastomotic leaks with metallic stent after esophagectomies.

The diagnosis and the treatment of anastomotic leak after esophagectomy are the keys to reduce the morbidity and mortality after this surgery. The stent plays an important role in the treatment of the leakage and in the prevention of reoperation. We have analyzed the database of the section of the esophagogastric surgery of Donostia University Hospital from June 2003 to May 2012. It is a retrospective study of 113 patients with esophagectomy resulting from tumor, and 24 (21.13%) of these patients developed anastomotic leak. Of these 24 patients, 13 (54.16%) have been treated with a metallic stent and 11 (45.84%) without a stent. The average age of the patients was 55.69 and 62.45 years, respectively. All patients treated with and without a stent have been males. Eight (61.5%) stents were placed in the neck and five (38.5%) in the chest. However, among the 11 fistulas treated without a stent, 9 patients had cervical anastomosis (81.81%) and 2 patients (18.18%) had anastomosis in the chest. Twelve patients (92.30%) with a stent preserve digestive continuity, and 10 patients (90.90%) were treated without a stent. One patient died in the stent group and one in the nonstent group. The treatment with metallic stent of the anastomotic leak after esophagectomy is an option that can prevent reoperation in these patients, but it does not decrease the average of the hospital stay. The stent may be more useful in thoracic anastomotic leaks.

The descriptive epidemiology of rheumatoid arthritis in Catalonia: a retrospective study using routinely collected data.

Information on the epidemiology of rheumatoid arthritis (RA) in Southern Europe is scarce. We estimated the age- and gender-adjusted incidence and prevalence of RA in Catalonia using routinely collected primary care records. We identified incident (2009-2012) and prevalent (on 31 December 2012) cases of RA in the SIDIAP database using ICD-10 codes. SIDIAP contains anonymized data from computerized primary care records for about five million adults (>80 % of the population). We estimated age- (5-year groups) and gender-specific, and directly standardized incidence and prevalence of RA and confidence intervals (95% CIs) assuming a Poisson distribution. A total of 20,091 prevalent (among whom 5,796 incident) cases of RA were identified among 4,796,498 study participants observed for up to 4 years. Rates of RA increased with age in both genders, peaking at the age of 65-70 years. Age- and gender-standardized incidence and prevalence rates were 0.20/1,000 person-years (95% CI 0.19-0.20) and 4.17/1,000 (4.11-4.23) respectively. Rheumatoid factor was positive (≥10 IU/mL) in 1,833 (73.9 %) of 2,482 cases tested in primary care. The incidence and prevalence of RA in Catalonia are similar to those of other Southern European regions, and lower than those of northern areas. This data will inform health care planning and resource allocation.

Socio-economic status and the risk of developing hand, hip or knee osteoarthritis: a region-wide ecological study.

OBJECTIVE: To determine the association between socio-economic status (SES) and risk of hand, hip or knee osteoarthritis (OA) at a population level. DESIGN: Retrospective ecological study using the System for the Development of Research in Primary Care (SIDIAP) database (primary care anonymized records for >5 million people in Catalonia (Spain)). Urban residents >15 years old (2009-2012) were eligible. OUTCOMES: Validated area-based SES deprivation index MEDEA (proportion of unemployed, temporary workers, manual workers, low educational attainment and low educational attainment among youngsters) was estimated for each area based on census data as well as incident diagnoses (ICD-10 codes) of hand, hip or knee OA (2009-2012). Zero-inflated Poisson models were fitted to study the association between MEDEA quintiles and the outcomes. RESULTS: Compared to the least deprived, the most deprived areas were younger (43.29 (17.59) vs 46.83 (18.49), years (Mean SD), had fewer women (49.1% vs 54.8%), a higher percentage of obese (16.2% vs 8.4%), smokers (16.9% vs 11.9%) and high-risk alcohol consumption subjects (1.5% vs 1.3%). Compared to the least deprived, the most deprived areas had an excess risk of OA: age-sex-adjusted Incidence Rate Ratio (IRR) 1.26 (1.11-1.42) for hand, 1.23 (1.17-1.29) hip, and 1.51 (1.45-1.57) knee. Adjustment for obesity attenuated this association: 1.06 (0.93-1.20), 1.04 (0.99-1.09), and 1.23 (1.19-1.28) respectively. CONCLUSIONS: Deprived areas have higher rates OA (hand, hip, knee). Their increased prevalence of obesity accounts for a 50% of the excess risk of knee OA observed. Public health interventions to reduce the prevalence of obesity in this population could reduce health inequalities.

Advantage of four-electrode over two-electrode defibrillators.

Defibrillation is the standard clinical treatment used to stop ventricular fibrillation. An electrical device delivers a controlled amount of electrical energy via a pair of electrodes in order to reestablish a normal heart rate. We propose a technique that is a combination of biphasic shocks applied with a four-electrode system rather than the standard two-electrode system. We use a numerical model of a one-dimensional ring of cardiac tissue in order to test and evaluate the benefit of this technique. We compare three different shock protocols, namely a monophasic and two types of biphasic shocks. The results obtained by using a four-electrode system are compared quantitatively with those obtained with the standard two-electrode system. We find that a huge reduction in defibrillation threshold is achieved with the four-electrode system. For the most efficient protocol (asymmetric biphasic), we obtain a reduction in excess of 80% in the energy required for a defibrillation success rate of 90%. The mechanisms of successful defibrillation are also analyzed. This reveals that the advantage of asymmetric biphasic shocks with four electrodes lies in the duration of the cathodal and anodal phase of the shock.

Shell thickening and chambering in the oyster Crassostrea gigas: natural and anthropogenic influence of tributyltin contamination.

Abnormal thickening and chambering in Crassostrea gigas oysters have been adopted for many years as bioindicators of available tributyltin (TBT) in coastal waters. Nevertheless, since natural causes can also induce the formation of multiple chambers, a field study and laboratory experimentation has been conducted with 72 examples of C. gigas in successive culture media. This work has enabled differences to be established between natural fine sediment-induced characteristics and the influence of TBT on the shells. External shell deformities have been assessed using three biometric indices, shell thickness index, weight index and volume index. Internal differences have been observed in longitudinal sections of the shell: retraction of growth, stagnation of the adductor muscle scar and thinning of the chambers in the TBT-polluted shell secretion. A new index, the opening chambers index, has been proposed, with a value of less than 1 in the TBT-polluted environment and greater than 1 in shells secreted in an unpolluted production site. These conclusions should be borne in mind when C. gigas is used in biomonitoring programmes.

Fibromyalgia and psychiatric comorbidity: their effect on the quality of life patients.

Patients with fibromyalgia (FM) often have associated mental disorders. As well as being very prevalent, the two conditions also have sociodemographic and clinical similarities. If both of these clinical conditions lead independently to a limitation of the health-related quality of life (HRQL) of the patients, it may be thought that their conjunction could have a greater adverse effect on this parameter. Equally, it could be assumed that the factors that worsen the HRQL of patients with FM or with mental illness could have a more serious effect on the HRQL of those in whom the two clinical conditions coexist. Although this conclusion seems evident, as far as we know there have been no studies to assess how much or in what way psychiatric comorbidity affects the HRQL of patients with FM, or any studies to analyze the particular factors that may affect their HRQL. This study approaches the importance of psychiatric comorbidity in patients with fibromyalgia and analyzes the combined effect that these two conditions have on the overall HRQL of these patients.

Comorbilidad psiquiátrica y fibromialgia. Su efecto sobre la calidad de vida de los pacientes / Fibromyalgia and psychiatric comorbidity: their effect on the quality of life patients

Los pacientes con Fibromialgia (FM) con frecuencia presentan trastornos mentales asociados. Tanto la FM como los trastornos mentales, además de tener elevada prevalencia, presentan similitudes tanto sociodemográficas como clínicas. Si ambos cuadros conducen de forma independiente a una limitación de la Calidad de Vida Relacionada con la Salud (CVRS) de los pacientes, cabe pensar que la conjunción de ambos podría tener una mayor consecuencia sobre este parámetro. Así mismo, podría suponerse que los factores que empeoran la CVRS de los pacientes con FM o con enfermedad mental podrían afectar más intensamente la CVRS de aquellos en los que ambos cuadros coexiste. A pesar de que esta circunstancia parece evidente, no existen a nuestro conocimiento estudios que valoren cuánto o cómo afecta la comorbilidad psiquiatrica a la CVRS de los pacientes con FM, ni estudios que analicen los factores que pueden condicionarla. En este trabajo se aborda la importancia de la comorbilidad psiquiátrica en los pacientes con fibromialgia y se analiza el efecto conjunto de ambos procesos sobre la CVRS de los pacientes (AU)

Patients with fibromyalgia (FM) often have associated mental disorders. As well as being very prevalent, the two conditions also have sociodemographic and clinical similarities. If both of these clinical conditions lead independently to a limitation of the health-related quality of life (HRQL) of the patients, it may be thought that their conjunction could have a greater adverse effect on this parameter. Equally, it could be assumed that the factors that worsen the HRQL of patients with FM or with mental illness could have a more serious effect on the HRQL of those in whom the two clinical conditions coexist. Although this conclusion seems evident, as far as we know there have been no studies to assess how much or in what way psychiatric comorbidity affects the HRQL of patients with FM, or any studies to analyze the particular factors that may affect their HRQL. This study approaches the importance of psychiatric comorbidity inpatients with fibromyalgia and analyzes the combined effect that these two conditions have on the overall HRQL of these patients (AU)

Distribution of butyltin and derivatives in oyster shells and trapped sediments of two estuaries in Cantabria (Northern Spain).

Distribution of butyltin compounds (BTs) and derivatives (monobutyltin, MBT; dibutyltin, DBT and tributyltin, TBT) was analysed in Crassostrea gigas oyster shells and the sediments trapped in the shell chambers, from two different estuaries in Cantabria (Northern Spain), with very different environmental conditions, where previous data have not been reported. Inorganic tin analysis in oyster shells was performed in order to study the degradation of BTs. Shell thickening and losses in biological growth are related with the presence of TBT, and were determined using three morphological indexes. Total BTs concentrations, expressed as Sn, ranged from 18.0 ng g(-1) to 176.7 ng g(-1) in sediments, and from 2.4 ng g(-1) to 11.1 ng g(-1) in oyster shells. Total inorganic tin concentrations ranged from 1775.0 ng g(-1) to 4781.3 ng g(-1) in oyster shells. The amount of BTs in oyster shells has been associated with the concentrations in the sediments trapped in the shell chambers. Partition coefficients between oyster sediments and oyster shells show the affinity of BTs by the sediments and the higher inorganic tin in oyster shells does not seem to be related to the BTs pollution.

Antidepresivos: ¿cuándo son analgésicos y cuándo antidepresivos? / Antidepressant: where are they analgesics or antidepresant drugs?

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Prevalencia de infección por el virus de la hepatitis C en pacientes a las que se practicó cirugía obstétrica y ginecológica en un hospital de tercer nivel / Prevalence of hepatitis C virus infection in patients undergoing obstetric-gynecological surgery in a third level hospital

Introducción: La infección por el virus de la hepatitis C (VHC) es un importante problema de salud pública por su elevada incidencia, el curso progresivo de la enfermedad y su asociación con el carcinoma hepático. La transmisión nosocomial del VHC ha sido objeto de debate en nuestro medio. Este riesgo depende de la prevalencia de la infección en la población atendida y en el personal sanitario, de los procedimientos realizados y de la adecuación de las medidas de prevención. Objetivo: Determinar la prevalencia de la infección en las pacientes atendidas por un parto o intervenidas ginecológicamente en un hospital de tercer nivel, como parte de un estudio más amplio dirigido a estimar el riesgo de transmisión nosocomial del VHC. Material y métodos: Se incluyeron en el estudio 1.649 pacientes atendidas en estos servicios entre octubre de 1999 y mayo de 2001.Antes de la intervención, se realizó una encuesta epidemiológica sobre antecedentes y factores de riesgo de infección por VHC y una extracción sanguínea para el estudio serológico (técnicas de ELISA III y confirmación por RIBA III).Resultados: La prevalencia global de infección por el VHC fue del 0,97 por ciento (intervalo de confianza [IC] del 95 por ciento, 0,56-1,57), con cifras superiores en ginecología (1,75 por ciento; IC del 95 por ciento, 0,96-2,92) que en obstetricia (0,24 por ciento; IC del 95 por ciento, 0,03-0,84) (p = 0,004). La edad fue la variable más asociada a la presencia de infección. El 75 por ciento de los casos desconocían la presencia de la infección. Conclusión: La prevalencia de infección por VHC en las pacientes intervenidas en los servicios de ginecología y obstetricia en nuestro centro es similar a la de la población general. Se ha observado un infradiagnóstico importante de esta infección en la población atendida (AU)

Psychological and occupational predictive factors for back pain among employees of a university hospital in southern Spain.

OBJECTIVES: To identify the individual and occupational factors that are predictors for low back pain among the employees of a university hospital in southern Spain. METHODS: A transverse study was conducted in which the population used was the hospital employees who volunteered to participate. The information was obtained by using a questionnaire, which included demographic and anthropometric variables, habits, characteristics of the work done, and of any pain experienced. The mental health condition of subjects was measured using the GHQ-28, using a score of > or = 6 as the cut-off point. To study the variables associated with pain, crude odds ratios (ORs) were calculated (+/- 95% CI) and adjusted according to a logistic regression model. RESULTS: One thousand one hundred and four subjects participated in the study but only 890 of these completed the questionnaire in full (rate of response, 35.7% of total employees). The population studied was notable for the high proportion of women, for subjects > 41 years of age, and subjects who undertook little or no physical exercise. In addition, according to the GHQ-28 test, 29.9% of the total were 'probable psychiatric cases'. The crude ORs were high in all the occupational categories in comparison with the doctors, with the exception of the maintenance, cleaning, and catering group. They were also higher among women, among subjects with poor mental health, and among women with one or more children. The adjusted ORs showed that having a GHQ-28 score of > or = 6, and belonging to the auxiliary technician category, were independent risk factors for suffering low back pain. Being older than 41 years and in temporary employment were protective variables. CONCLUSIONS: The presence of probable mental illness is the variable most strongly associated with the presence of low back pain in the population studied. Its diagnostic confirmation and appropriate treatment could contribute to reducing the prevalence of vertebral pains in this occupational group.

[Multicenter drug surveillance of sublingual immunotherapy in allergic patients]. / Estudio multicéntrico de farmacovigilancia de inmunoterapia sublingual en pacientes alérgicos.

A study of pharmacovigilance has been performed in 522 patients suffering from allergic rhinitis and/or asthma. Sensitization was due to pollens and mites in ther majority of cases. The treatment consisted in biologically standardized glycerinated allergenic extracts for specific sublingual immunotherapy (SLIT) and, major allergens were also quantified, depending on the allergenic composition. The aims of the study were to assay the effect of the SLIT in a short-and-medium-term course and to know the adverse reactions most frequently appearing, as well as the unexpected side effects that are only possible to know through the study of a numerous sample of patients. We also evaluated the factors that can modify the tolerance of the treatment, such as the onset of patient's disease and its severity. All the patients had a clinical history of, at least, two years of evolution and positive skin-prick test to the allergen/s cause of their atopic disorder. Exclusion criteria were immunotherapy in the last two years, pregnancy and those situations in which the immunotherapy is contraindicated according to the EAACI requirements. In order to carry out the daily record of the SLIT as well as the possible appearance of symptoms, two diaries were given to each patient. Tolerance was evaluated by the physician at the end of the build-up phase (3 months) and when the maintenance phase finished (5 months later). Total administered doses were 44.021, the final number of patients who registered any adverse reaction in relation with SLIT was 41 (7.9%), with a number of 67 adverse reactions that means a 0.15% over the total administered doses.(ABSTRACT TRUNCATED AT 250 WORDS)

[Gastrointestinal hemorrhage secondary to heterotopic jejunal pancreas]. / Hemorragia digestiva secundaria a páncreas heterotópico yeyunal.

A case of heterotopic pancreas located in the small intestine is herewith presented. The 19-years male patient had been admitted three times since 1991 for an anemic syndrome secondary to melena. The origin of the hemorrhage was not determined with the studies performed (intestinal transit, opaque enema, esophagogastroscopy, colonoscopy and gammagraphy with technetium 99). On the last admission a vascular lesion low flow was observed on arteriography of the upper mesenteric artery on the mesenteric edge of the proximal jejunum. Following laparotomy a small tumor was found in the jejunum and 5 cm of the intestine including the tumor was resected. The anatomic pathologic results demonstrated a heterotopic pancreas.