In vitro mechanism of antibacterial action of a citrus essential oil on an enterotoxigenic Escherichia coli and Lactobacillus rhamnosus.

AIM: This study investigated the in vitro mechanism of action of a commercial citrus EO, Brazilian orange terpenes (BOT), on an enterotoxigenic Escherichia coli (ETEC) isolated from pig gut and on Lactobacillus rhamnosus. METHODS AND RESULTS: Firstly, bacteria were exposed sequentially to BOT every 3 h (three times) at sub-minimal inhibitory concentrations and results showed that sequential exposure to BOT provoked a higher reduction of bacteria viability than a single exposure and the reduction of ETEC viability was higher compared to that of L. rhamnosus. Then, evaluation of the BOT effects on the cell membrane permeability and integrity, indicated that BOT increased the membrane permeability and caused disruptive effects on the integrity of bacterial cells as reflected by an increase of the relative electric conductivity and the release of essential cell constituents. Interestingly, BOT effects were more pronounced on the ETEC than on L. rhamnosus. This was ratified by scanning electron microscopy, which showed more noticeable morphological damages and disturbances on ETEC cells than on the L. rhamnosus cells. Limonene was detected as the major compound in BOT by polar/nonpolar GC-MS (78·65%/79·38%). CONCLUSIONS: Results revealed that the probable mechanism of the selective antibacterial action of the citrus EO, BOT, can be described as altering more remarkable the permeability and integrity of the cytoplasmic membrane as well as the external structure of ETEC cells than L. rhamnosus cells. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides information about the mechanism of antibacterial action displayed by a citrus EO, a by-product of the citrus processing industry, as a natural alternative to antibiotics used in pig production sector to combat pathogens such as ETECs.

[Claudication, functional outcomes and quality of life in primary total hip arthroplasty with minimally invasive anterolateral approach]. / Claudicación, resultados funcionales y calidad de vida en artroplastía total de cadera primaria con abordaje anterolateral mínimamente invasivo.

INTRODUCTION: The coxarthrosis has incidence of 88 cases per 100,000 people/year and symptomatic prevalence of 16% men and 6% women aged 65-74 years and increases with age. It is a growing public health disease. Total hip arthroplasty (THA) has become the most successful procedure to increase the quality of life of patients with coxarthrosis. Our objective was to determine the claudication, quality of life and functional results of THA through minimal invasive approach in patients with primary coxarthrosis. MATERIAL AND METHODS: Prospective longitudinal study in patients with unilateral primary coxarthrosis postop of THA with minimally invasive approach from March 2015-February 2016, each patient was analyzed with quality of Life instrument (WOMAC), Functional test for coxarthrosis (HHS) and functional test in patients with hip surgery (OHS) with follow-up of one year. RESULTS: We included 21 patients, 17 female and 4 males corresponding to 80.95% and 19.05% respectively, average age of 59.95 years (ED = 9.64), with excellent functional results to one year according to HHS and OHS, quality of life high in 100% of cases according to WOMAC, with claudication rate of 4.76%. DISCUSSION: The minimal invasive approach is a reproducible surgical technique, with excellent functional results, low claudication rate and high quality of life in postoperative patients of primary ATC at only one year of follow-up.

INTRODUCCIÓN: La coxartrosis tiene incidencia de 88 casos por 100,000 personas/año y prevalencia sintomática de 16% para hombres y 6% para mujeres en edades de 65-74 años e incrementa con la edad. Representa una enfermedad de salud pública que va en aumento, la mujer es quien presenta padecimiento más grave. La ATC (artroplastía total de cadera) se ha convertido en el procedimiento más exitoso para mejorar la calidad de vida de pacientes con coxartrosis. OBJETIVO: Determinar la claudicación, calidad de vida y resultados funcionales de la ATC mediante abordaje mínimo invasivo en pacientes con coxartrosis primaria. MATERIAL Y MÉTODOS: Estudio longitudinal y prospectivo en pacientes con coxartrosis primaria unilateral postoperados de ATC primaria con técnica mínimamente invasiva en el período comprendido de Marzo de 2015 a Febrero de 2016, se analizó a cada paciente con somatometría, calidad de vida (WOMAC), funcionalidad en pacientes con coxartrosis (HHS) y funcionalidad en pacientes con cirugía de cadera (OHS) de manera prequirúrgica y postquirúrgica con seguimiento a un año. RESULTADOS: Se incluyeron 21 pacientes, 17 femeninos y cuatro masculinos que corresponde a 80.95 y 19.05%, respectivamente, edad promedio de 59.95 años (DE = 9.64), con resultados funcionales excelentes a un año, según escalas de HHS y OHS, calidad de vida alta en 100% de los casos según WOMAC, con índice de claudicación bajo de 4.76%. DISCUSIÓN: El abordaje mínimo invasivo es una técnica quirúrgica reproducible con resultados funcionales excelentes, índice de claudicación baja y alta calidad de vida en pacientes postoperados de ATC primaria durante el primer año de seguimiento.

[Installed Capacity Perception Survey for the Training of Residents Program in Orthopedics and Care Needs in Acute and Chronic Musculoskeletal Pathology in Mexico]. / Encuesta de Percepción en Capacidad Instalada para la Formación de Médicos Residentes en Ortopedia (Traumatología) y Necesidades de la Atención en Patología Musculoesquelética Aguda y Crónica en México. Primera Parte.

INTRODUCTION: It is essential that orthopaedic resident physicians be highly proficient in all aspects, considering the balance between supply, demand, need and context. Fundamental to identify the capacity and quality installed for their training in Mexico. MATERIAL AND METHODS: Observational Study, transverse, non-probabilistic sampling-conglomerates, in two phases. The instrument has 8 domains, 57 variables and 4,867 items. 60 graduate professors of 20 states, 50 hospital sites, 22 university programs. RESULTS: 1,038 years of experience (collective intelligence), 17 years of experience/teacher (01 to 50 years). Identified: acute pathology 30 (2 to 90%), chronic pathology 30 (5 to 96%), patients 15 years, 10 (3 to 30%), patients between 15 and 65 years, 47 (2 to 78%), patients 65 years, 20 (2 to 60%), number of beds/seat 20 (2 to 510), number of clinics 3 (1 to 48), number of surgical procedures/headquarters per year at the national level, was 960 (50 to 24,650). The national average per resident doctor is 362 surgeries/year with 1,450 surgical times/year. CONCLUSIONS: The needs and resources for the training of physicians specializing in orthopedics/traumatology are highly heterogeneous, so it should be adapted to the epidemiological needs of the region of influence, in an area of epidemiological transition. 62.2% expressed not having or have bad academic and scientific infrastructure at its headquarters, more than 50% without rotation overseas and 90% without regular scientific production.

INTRODUCCIÓN: Es fundamental que los médicos residentes de ortopedia (traumatología) sean altamente competentes en todos los aspectos, considerando el equilibrio entre la oferta, demanda, necesidad y contexto. Es primordial identificar la capacidad y calidad instalada para su formación en México. MATERIAL Y MÉTODOS: Estudio observacional, transversal, muestreo no probabilístico-conglomerados, en dos fases. El instrumento tiene ocho dominios, 57 variables y 4,867 ítems. Sesenta profesores de postgrado de 20 estados, 50 sedes hospitalarias, 22 programas universitarios. RESULTADOS: 1,038 años de experiencia (inteligencia colectiva), 17 años de experiencia/profesor (01 a 50 años). Se identificó: patología aguda 30 (2 a 90%), patología crónica 30 (5 a 96%), pacientes 15 años, 10 (3 a 30%), pacientes entre 15 y 65 años, 47 (2 a 78%), pacientes 65 años, 20 (2 a 60%), número de camas/sede 20 (2 a 510), número de consultorios 3 (1 a 48), el número de procedimientos quirúrgicos/sede al año a nivel nacional fue de 960 (50 a 24,650). La media nacional por médico residente es de 362 cirugías/año con 1,450 momentos quirúrgicos/año. CONCLUSIONES: Las necesidades y recursos para la formación de médicos especialistas en ortopedia/traumatología son en alto grado heterogéneos, por lo cual se debería adaptar a las necesidades epidemiológicas de la región de influencia, en un ámbito de transición epidemiológica. Sesenta y dos punto dos por ciento expresó no tener o tener deficiente infraestructura académica y científica en su sede, más de 50% sin rotación al extranjero y 90% sin producción científica regular.

The effect of electrical stimulation on post mortem myofibrillar protein degradation and small heat shock protein kinetics in bull beef.

This study aimed to determine the effect of electrical stimulation and ultimate pH (pHu) on shear force, myofibrillar protein degradation and small heat shock protein (sHSP) concentrations in M. longissimus lumborum (LL). The LL from both sides of carcasses (n=15) was excised with low voltage electrical stimulation (ES) applied to an LL muscle from one side, while the opposing LL muscle was not stimulated (NS). Muscles were categorised into low (pHu<5.8), intermediate (5.8≤pHu<6.2) and high pHu (pHu≥6.2) and aged for up to 28days post mortem at -1.5°C. High pHu meat tenderised faster which corresponded with the faster degradation of titin and desmin in this group compared with low and intermediate pHu meat. Electrical stimulation significantly affected the variable levels of αß-crystallin and HSP20 with higher concentrations of these sHSP in ES muscles at later ageing timepoints compared with NS muscles.

Beef quality of different portions of the biceps femoris muscle in Bos indicus cattle improved by tumbling with brine.

The effect of tumbling with brines on different portions of the biceps femoris muscle was evaluated for the quality of beef from cattle older than 30 mo. Six biceps femoris muscles were divided into portions: origin (OP), insertion 1(IP1), and insertion 2 (IP2). The portions were sliced into steaks and were treated with no tumbling (control), tumbling with brine (BR), and tumbling with brine and hydrolyzed soy protein (BR+HSP). The steaks were vacuum packaged and stored for 1 and 12 d and then analyzed for pH, yield, color, cooking loss, and shear force. The control steaks from the OP had higher (P < 0.05) pH and shear force values and lower (P < 0.05) L* values than the control steaks from IP2. The pH and a* and b* values increased (P < 0.05) and the L* values and cooking loss decreased (P < 0.05) when the steaks were tumbled with BR and BR+HSP. Overall, substantial variation was found for the variables among the different portions of the biceps femoris muscle. Based on the lower lightness (low exudation) and greater yellow and red intensity (less oxidation) of the meat, the tumbling with brines improved the meat quality. However, the hydrolyzed soy protein incorporated into the brine did not increase the effect compared with using the brine alone for most of the variables.

Implantación de un plan de calidad en un servicio de urgencias y su impacto en la satisfacción del paciente / Implementation of an emergency department health care quality plan and its impact on patient satisfaction

Objetivo: Analizar el impacto de la implantación de un plan de calidad para mejorarla gestión de la demanda de atención urgente, en la evolución de las reclamaciones de los usuarios y su grado de satisfacción. Método: Estudio longitudinal observacional descriptivo prospectivo. Periodo de estudio: enero 2007 a diciembre 2010. Líneas del plan de calidad: desarrollo del plan funcional, un plan dirigido a la información y seguridad clínica, un sistema de gestión por procesos, un plan de actuación en formación y docencia con el desarrollo de un cuadro de mandos y un sistema de autoevaluación para el análisis de resultados. Análisis estadístico: test t de Student para variables continuas y la ji al cuadrado para dicotómicas o el Test exacto de Fisher y la corrección de Yates como test no paramétricos. Variables: urgencias atendidas/mes, número de reclamaciones y sus motivos, tiempos de estancia media en urgencias y demora admisión-1ª atención médica, y encuestas de opinión. Resultados: Se han incluido 210 reclamaciones: 81 en 2007, 59 en 2008, 48 en2009 y 22 en 2010. El 76,2% de ellas han sido por demora asistencial, seguidas por aquellas relacionadas con la disconformidad con las normas de organización (7,1%).Hay una reducción progresiva del porcentaje de reclamaciones respecto al total de urgencias atendidas con un valor de la ji al cuadrado de tendencia lineal de 28,28(p < 0,01). Tras la implantación del programa de calidad en 2008, disminuyeron un73,5% las reclamaciones por demora y dejaron de producirse reclamaciones por falta de intimidad y por accidentes en el centro. Conclusiones: El análisis de las reclamaciones es una herramienta útil de monitorización de la calidad asistencial. La implantación de un sistema de gestión de la calidad, se convierte en esencial en la mejora de la atención urgente del paciente sin costes adicionales (AU)

Objective: To analyze the effect of a quality control plan for improving emergency deparment case management interms of complaints received and patient level of satisfaction. Methods: Longitudinal, descriptive, prospective observational study. Time frame: January 2007 to December 2010.The health care quality plan involved the development of a viable plan; a campaign to impart information on patient and staff safety; a management system based on processes; and procedures for training and education, including a balanced scorecard and a system for self assessment of results. Outcome measures: emergencies attended monthly, number of claims and reasons for them, mean stay in the emergency department, delay from admission to first physician visit, and a user satisfaction survey. Results: A total of 210 claims were studied; 81 were filed in 2007, 59 in 2008, 48 in 2009, and 22 in 2010. Delays motivated 76.19% of the claims; disagreements about organizational procedures motivated 7.14%. More claims are received during summer months. After the program was implemented in 2008, complaints about delays decreased by73.53% and no further complaints about lack of privacy and accidents within the hospital were received. Conclusions: Claims analysis is a useful tool for monitoring health care quality. A health care quality management program is essential for improving emergency care without generating additional costs (AU)

Gases and volatile compounds associated with micro-organisms in blown pack spoilage of Brazilian vacuum-packed beef.

UNLABELLED: This study correlated the composition of the spoilage bacterial flora with the main gaseous and volatile organic compounds (VOCs) found in the package headspace of spoiled, chilled, vacuum-packed meat. Fifteen chilled, vacuum-packed beef samples, suffering from blown pack spoilage, were studied using 16S rRNA clone sequencing. More than 50% of the bacteria were identified as lactic acid bacteria (LAB), followed by clostridia and enterobacteria. Fifty-one volatile compounds were detected in the spoiled samples. Although the major spoilage compounds were identified as alcohols and aldehydes, CO2 was identified as the major gas in the spoiled samples by headspace technique. Different species of bacteria contribute to different volatile compounds during meat spoilage. LAB played an important role in blown pack deterioration of the Brazilian beef studied. SIGNIFICANCE AND IMPACT OF THE STUDY: The data generated by this study provided useful information to correlate the microbial contamination of Enterobacteriaceae, lactic acid bacteria and Clostridium with the VOC and gaseous compound production to define, in a faster manner, not only the type of contamination, but also to prevent it.

Wine industry residues extracts as natural antioxidants in raw and cooked chicken meat during frozen storage.

The effect of Isabel (IGE) and Niagara (NGE) grape seed and peel extracts on lipid oxidation, instrumental colour, pH and sensory properties of raw and cooked processed chicken meat stored at -18°C for nine months was evaluated. The pH of raw and cooked samples was not affected by the addition of grape extracts. IGE and NGE were effective in inhibiting the lipid oxidation of raw and cooked chicken meat, with results comparable to synthetic antioxidants. The extracts caused alterations in colour, as evidenced by the instrumental (darkening and lower intensity of red and yellow colour) and sensory results of cooked samples. In the sensory evaluation of odour and flavour, IGE produced satisfactory results, which did not differ from synthetic antioxidants. These findings suggest that the IGE and NGE are effective in retarding lipid oxidation of raw and cooked chicken meat during frozen storage.

Predominio del genotipo G9 de rotavirus en Valencia y Castellón entre 2005 y 2007 / Predominance of G9 rotavirus in Valencia and Castellón between 2005 and 2007

Introducción: Las infecciones por rotavirus son la causa más frecuente de gastroenteritis aguda en la infancia. Existen disponibles vacunas para su prevención, pero su uso todavía es limitado y estos virus continúan infectando a la población infantil, principalmente en los meses fríos del año. Objetivos: Caracterizar los genotipos G (VP7) y P (VP4) de rotavirus detectados en niños con gastroenteritis aguda y determinar la prevalencia de las cepas de rotavirus con genotipo G9 en 3 departamentos de Salud Pública de la Comunidad Valenciana. Pacientes y métodos: Se estudiaron de forma prospectiva 541 muestras de heces de niños con gastroenteritis desde octubre de 2005 a septiembre de 2008. Se analizó la presencia de rotavirus por métodos de ELISA o inmunocromatografía y se identificaron los genotipos G y P de las cepas de rotavirus mediante transcripción inversa y amplificación en cadena de la polimerasa. Resultados: Se caracterizaron los genotipos G y P en un total de 525 muestras (97%), y resultaron predominantes las cepas G9P[8] (56,5%) y G1P[8] (29,9%). Durante el período de tiempo estudiado, G9P[8] fue la combinación G/P más frecuente en las temporadas 2005–2006 y 2006–2007, y se encontró en el 81,2 y en el 64,7% de las muestras, respectivamente. Sin embargo, en la temporada 2007–2008 fueron las cepas G1P[8] las más frecuentes (68,8%), y G9P[8] disminuyó a un 7,2%. Conclusiones: Las cepas de rotavirus G9P[8] se diseminaron rápida y ampliamente durante los períodos 2005–2006 y 2006–2007, y suplantaron a otros genotipos anteriormente predominantes (G1, G4) en nuestra área geográfica. Su incidencia descendió bruscamente en la temporada 2007–2008, en la que las cepas G1P[8] resultaron ser nuevamente las que se detectaron más frecuentemente (AU)

Introduction: Rotavirus is the leading cause of acute gastroenteritis in young children worldwide. Effective vaccines to prevent rotavirus infections are currently available, although their clinical use is still limited, and rotavirus still causes many episodes of infantile gastroenteritis, mainly during the winter seasons. Objective: To characterise G (VP7) and P (VP4) genotypes of rotaviruses causing acute gastroenteritis in children and to determine the prevalence of genotype G9 rotavirus in three public health areas in the provinces of Valencia and Castellon. Patients and methods: Five-hundred and forty-one stool samples were prospectively collected from infants and children with gastroenteritis in the period between October 2005 and September 2008. They were analysed for rotavirus by ELISA or by immunochromatography. G and P genotyping was performed by reverse transcription and PCR (RT-PCR). Results: G and P rotavirus genotypes were characterised in a total of 525 faecal samples (97%), resulting in a global predominance of strains G9P[8] (56.5%) and G1P[8] (29.9%). During the period of time studied, G9P[8] was the G/P combination most frequently detected during the rotavirus seasons 2005–2006 and 2006–2007, being present in 81.2% and 64.7% of the patients, respectively. However, during the 2007–2008 season, G1P[8] strains were the most frequently found (68.8%), with a sharp decrease in G9P[8] strains to 7.2% of the samples. Conclusions: Rotavirus G9P[8] have spread rapidly and widely during the 2005–2006 and 2006–2007 seasons, replacing other previously dominant genotypes (G1, G4) in our geographic area. Its incidence has declined sharply in 2007–2008, in which G1P[8] was again the predominating genotype (AU)

[Predominance of G9 rotavirus in Valencia and Castellón between 2005 and 2007]. / Predominio del genotipo G9 de rotavirus en Valencia y Castellón entre 2005 y 2007.

INTRODUCTION: Rotavirus is the leading cause of acute gastroenteritis in young children worldwide. Effective vaccines to prevent rotavirus infections are currently available, although their clinical use is still limited, and rotavirus still causes many episodes of infantile gastroenteritis, mainly during the winter seasons. OBJECTIVE: To characterise G (VP7) and P (VP4) genotypes of rotaviruses causing acute gastroenteritis in children and to determine the prevalence of genotype G9 rotavirus in three public health areas in the provinces of Valencia and Castellon. PATIENTS AND METHODS: Five-hundred and forty-one stool samples were prospectively collected from infants and children with gastroenteritis in the period between October 2005 and September 2008. They were analysed for rotavirus by ELISA or by immunochromatography. G and P genotyping was performed by reverse transcription and PCR (RT-PCR). RESULTS: G and P rotavirus genotypes were characterised in a total of 525 faecal samples (97%), resulting in a global predominance of strains G9P[8] (56.5%) and G1P[8] (29.9%). During the period of time studied, G9P[8] was the G/P combination most frequently detected during the rotavirus seasons 2005-2006 and 2006-2007, being present in 81.2% and 64.7% of the patients, respectively. However, during the 2007-2008 season, G1P[8] strains were the most frequently found (68.8%), with a sharp decrease in G9P[8] strains to 7.2% of the samples. CONCLUSIONS: Rotavirus G9P[8] have spread rapidly and widely during the 2005-2006 and 2006-2007 seasons, replacing other previously dominant genotypes (G1, G4) in our geographic area. Its incidence has declined sharply in 2007-2008, in which G1P[8] was again the predominating genotype.

Peritonitis por Saccharomyces cerevisiae en un paciente sometido a diálisis peritoneal ambulatoria / No disponible

No disponible

[Ten-year retrospective study of rotavirus infection in the province of Castellón (Spain)]. / Estudio retrospectivo de 10 años de la infección por rotavirus en la provincia de Castellón.

OBJECTIVE: To determine the percentage of rotavirus infection in children aged less than 14 years old and the epidemiology in area 02 of the province of Castellón (Spain). MATERIAL AND METHODS: We performed a retrospective study from January 1995 to December 2004 in which 14,068 stool samples from pediatric patients with acute gastroenteritis were analyzed. The variables analyzed were sex, age, origin, diagnosis of rotavirus, and date of diagnosis. Differences were considered statistically significant if p<0.05. RESULTS: Rotavirus was detected in 11.9% of the samples (1687 cases) in the 10 years of the study, 12.14 % corresponded to boys and 11.81% to girls (p=0.5459). The mean age of the population was 2.63 years. The highest percentage of cases occurred in the group aged 1- 4 years old (14.1%; p<0.001) and in outpatients (12.76%; p<0.05). In this geographical region, there was a significant tendency (p<0.001) for rotavirus to occur in the winter months. CONCLUSION: Rotavirus is one of the main causes of morbidity in children both in the hospital and the outpatient setting. Children aged less than 4 years old are most frequently affected, especially those aged 1 year. The infection appears mainly in winter.

Estudio retrospectivo de 10 años de la infección por rotavirus en la provincia de Castellón / Ten-year retrospective study of rotavirus infection in the province of Castellón (Spain)

Objetivo. El objetivo de este trabajo es conocer el porcentaje de la infección por rotavirus en niños menores de 14 años y su epidemiología en el área 02 de la provincia de Castellón. Material y métodos. Se realizó un estudio retrospectivo desde enero de 1995 hasta diciembre de 2004 en el que se analizaron 14.068 muestras de heces de pacientes pediátricos con gastroenteritis aguda. Las variables analizadas fueron: sexo, edad, procedencia, diagnóstico de rotavirus y fecha de diagnóstico. Se consideraron valores significativos p < 0,05. Resultados. El rotavirus fue detectado en el 11,9 % (1.687 casos) en los 10 años del estudio; el 12,14 % en varones y el 11,81 % en mujeres (p = 0,5459). La edad media de la población del estudio fue de 2,63 años. El grupo que presentó el mayor porcentaje de casos fue el de 1 a 4 años con el 14,1 % (p < 0,001) y pacientes ambulatorios con el 12,76 % (p < 0,05). En nuestra área, el rotavirus predomina significativamente (p < 0,001) en los meses de invierno. Conclusión. El rotavirus es una de las causas más importantes de morbilidad en la edad pediátrica en el hospital y en el ambulatorio. Afecta más frecuentemente a los niños menores de 4 años, y principalmente a los de 1 año. La infección se presentó de forma predominante en el invierno

Objective. To determine the percentage of rotavirus infection in children aged less than 14 years old and the epidemiology in area 02 of the province of Castellón (Spain). Material and methods. We performed a retrospective study from January 1995 to December 2004 in which 14,068 stool samples from pediatric patients with acute gastroenteritis were analyzed. The variables analyzed were sex, age, origin, diagnosis of rotavirus, and date of diagnosis. Differences were considered statistically significant if p < 0.05. Results. Rotavirus was detected in 11.9 % of the samples (1687 cases) in the 10 years of the study, 12.14 % corresponded to boys and 11.81 % to girls (p = 0.5459). The mean age of the population was 2.63 years. The highest percentage of cases occurred in the group aged 1- 4 years old (14.1 %; p < 0.001) and in outpatients (12.76 %; p < 0.05). In this geographical region, there was a significant tendency (p < 0.001) for rotavirus to occur in the winter months. Conclusion. Rotavirus is one of the main causes of morbidity in children both in the hospital and the outpatient setting. Children aged less than 4 years old are most frequently affected, especially those aged 1 year. The infection appears mainly in winter

Diadenosine tetraphosphate is co-released with ATP and catecholamines from bovine adrenal medulla.

Secretion of adenosine(5')tetraphospho(5')adenosine (Ap4A) and ATP from perfused bovine adrenal glands stimulated with acetylcholine or elevated potassium levels was measured and compared with that of catecholamines. We have found a close correlation between the release of Ap4A and catecholamines elicited with all the secretagogues used in the presence of either Ca2+ or Ba2+, suggesting co-release of both constituents from the chromaffin granules. By contrast, ATP secretion, as measured with luciferase, showed a significantly different time course regardless of the secretagogue used. ATP secretion consistently decreased after 1-2 min of stimulation at a time when Ap4A and catecholamine secretions were still increasing. Measures of degradation of injected [3H]ATP to the gland during stimulation showed little difference in the level of uptake or decomposition of ATP throughout the pulse. However, a reexamination of ATP secretion by monitoring its products of degradation (AMP, adenosine, and inosine) by HPLC techniques showed that Ap4A, ATP, and catecholamines are indeed secreted in parallel from the perfused adrenal gland.

Low dihydropyridine receptor density in vasa deferentia of castrated rats.

Radioligand binding studies in crude membrane preparations of vasa deferentia of normal rats, with the 1,4-dihydropyridine (+)-[3H]-PN200-110 (isradipine) showed typical saturation isotherms. The binding exhibited a KD of 259 +/- 60 pM and Bmax of 144 +/- 20 fmol mg-1 protein. The low KD and the stereoselective displacement of (+)-[3H]-PN200-110 binding by (+)- and (-)-PN200-110 and by nifedipine suggests that these tissues contain dihydropyridine receptors probably coupled to voltage-sensitive, L-type calcium channels. In membrane preparations from vasa deferentia from rats castrated 30 days previously the maximum specific binding was 25 +/- 10 fmol mg-1 protein, representing only 11% of total binding; thus, the calculation of reliable KD values was not feasible. These findings suggest that a testicular hormone, possibly testosterone, plays an important role in the regulation of dihydropyridine-sensitive, voltage-dependent calcium channels in the rat vas deferens.

Muscarinic receptors in separate populations of noradrenaline- and adrenaline-containing chromaffin cells.

We have performed binding experiments of (a)[3H]quinuclidinyl benzilate to partially purified membranes from noradrenaline- and adrenaline-containing chromaffin cells and (b) [3H]N-methyl-quinuclidinyl benzilate to acutely isolated, or 48-h cultured, chromaffin cells subpopulations. Using this approach, we obtained enough evidence to conclude (1st) that muscarinic receptors are present in both noradrenaline- and adrenaline containing cells; (2nd) that noradrenaline cells contain in fact 2-3 fold higher density of those receptors; and (3rd) that those receptors undergo plastic changes upon chronic culturing of the cells.

(+)-PN200-110 and ouabain binding sites in purified bovine adrenomedullary plasma membranes and chromaffin cells.

Bovine adrenal medulla plasma membranes were purified by a differential centrifugation procedure using sucrose and Urografin discontinuous density gradients; the membranes were enriched 10-12-fold in acetylcholinesterase activity and [3H]ouabain binding sites. Specific (+)-[3H]PN200-110 binding to these membranes amounted to 90% of total binding and was saturable and of high affinity (KD = 41 pM; Bmax = 119 fmol/mg of protein) with a Hill coefficient close to 1, a result suggesting the presence of a single, homogeneous population of dihydropyridine receptors. The association and dissociation rate constants were, respectively, 7.5 X 108 M-1 min-1 and 0.023 min-1. Unlabeled (+)-PN200-110 displaced (+)-[3H]PN200-110 binding with a potency 100-fold higher than (-)-PN200-110 (IC50,0.5 and 45nM, respectively). Although the two enantiomers of BAY K 8644 completely displaced (+)-[3H]PN200-110 binding, they exhibited no stereoselectivity (IC50, 69 and 83 nM,respectively). Whereas ( +/- )-nitrendipine very potently displaced (+)-[3H]PN200-110 binding (IC50 = 1.3 nM) verapamil and cinnarizine displaced the binding by only 30 and 40% at 1 microM, and diltiazem increased it by 20% at 10 microM. [3H]Ouabain bound to plasma membranes with a KD of 34 nM and a Bmax of 9.75 pmol/mg of protein, a figure 80-fold higher than the Bmax for (+)-PN200-110. [3H]Ouabain also bound to intact chromaffin cells with a Bmax of 244 fmol/10(6) cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization and N-terminal sequence of a heparan sulphate proteoglycan synthesized by endothelial cells in culture.

We have isolated from the conditioned medium of an established endothelial cell line a heparan sulphate proteoglycan whose involvement in the inhibition of the extrinsic coagulation pathway was reported in previous studies [Colburn & Buonassisi (1982) Biochem. Biophys. Res. Commun. 104, 220-227]. The proteoglycan was purified by gel filtration and ion-exchange chromatography, and appears to be free of contaminating proteins as determined by polyacrylamide-gel electrophoresis of the radioiodinated protein core before and after removal of the glycosaminoglycan chains by treatment with heparitinase. By this procedure the Mr of the protein core was estimated to be 22000. The N-terminal end was sequenced up to amino acid 25. The 21st residue is likely to be glycosylated. Analysis of the purified proteoglycan by gel-filtration chromatography yielded Kd values of 0.2 for the whole molecule and 0.35 for the glycosaminoglycan chains. The structure that emerges from these data is that of a heparan sulphate proteoglycan characterized by a relatively small protein core and few glycosaminoglycan chains.