Diagnóstico microbiológico de la COVID-19 / Microbiological diagnosis of COVID-19

El diagnóstico microbiológico de la infección por SARS-CoV-2 es de gran importancia por su repercusión clínica a nivel individual y para la elaboración de estrategias de salud pública para intentar frenar su propagación. Actualmente la reacción en cadena de la polimerasa con transcriptasa inversa (RT-PCR) es la técnica de elección para el diagnóstico microbiológico del paciente sintomático por COVID-19, detectando material genético del virus en el organismo. Requiere un adecuado manejo de las muestras y un laboratorio bien equipado. Otros métodos diagnósticos utilizados son la detección de anticuerpos generados por el individuo en contacto con el virus, son útiles para el estudio de infección pasada, estudios de vacunas o estrategias epidemiológicas; y la detección de antígenos del SARS-CoV-2 en muestras biológicas, de mayor rentabilidad, menor coste y gran especificidad, pero con altas tasas de falsos negativos en pacientes con baja carga viral. Es fundamental una correcta indicación e interpretación de las pruebas diagnósticas para su mayor rentabilidad

Microbiological diagnosis of SARS-CoV-2 infection is crucial due to its clinical repercussion at the individual level and for the development of public health strategies to try to stop its spread. Currently, reverse transcriptase polymerase chain reaction (RT-PCR) is the gold standard for microbiological diagnosis of symptomatic COVID-19 patients, detecting genetic material of the virus in the body. It requires proper sample handling and a well-equipped laboratory. Other diagnostic methods used are the detection of antibodies generated by the individual in contact with the virus, useful for the study of past infection, vaccine studies or epidemiological strategies; and the detection of SARS-CoV-2 antigens in biological samples, with greater profitability, lower cost and high specificity, but with high rates of false negatives in patients with low viral load. Correct indication and interpretation of diagnostic tests is essential for greater profitability

Ansiedad y depresión en pacientes ingresados por una exacerbación de EPOC / Anxiety and depression in patients admitted for a copd exacerbation

INTRODUCCIÓN: La enfermedad pulmonar obstructiva crónica (EPOC) se asocia frecuentemente con la presencia de trastornos del ánimo, que pueden pasar desapercibidos. El objetivo de este estudio es determinar la prevalencia de ansiedad y depresión en pacientes con EPOC y analizar su relación con las puntuaciones en la escala HADS (Hospital Anxiety and Depression Scale). PACIENTES Y MÉTODOS: Estudio prospectivo, observacional, con un seguimiento a 3 meses, en el que se recogen diversas variables, incluyendo características clínicas, cuestionarios de calidad de vida y tratamientos realizados. RESULTADOS: Se incluyeron en el estudio 143 pacientes con EPOC (88,9% varones), con una edad media de 72,76 ± 9,72 años. El valor medio del FEV1 fue de 47,23 ± 19,44%. El 8,6% presentaba un diagnóstico previo de depresión y el 3,3% de ansiedad. La puntuación media en la escala HADS fue 6,96 ± 6,50 puntos (3,55 ± 3,54 en la subescala de depresión y 3,41 ± 3,76 en la de ansiedad). Obtuvimos un 5,6% de casos probables en la subescala de depresión y un 4,9% en la de ansiedad. El 14,3% de los pacientes con HADS ≥ 11 presentaban diagnóstico previo de ansiedad y el 12,5% de depresión. CONCLUSIONES: El 8,6% de nuestros pacientes presentaba un diagnóstico previo de depresión y el 3,3% de ansiedad. Así mismo, en la escala HADS obtuvimos un 5,6% de casos probables en la subescala de depresión y un 4,9% en la de ansiedad. Por otro lado, un porcentaje destacable de pacientes con EPOC y ansiedad o depresión tenían una puntuación elevada en la escala HADS

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is frequently associated with the presence of mood disorders, which can go unnoticed. The objective of this study is to determine the prevalence of anxiety and depression in patients with COPD and to analyze its relationship with scores on the HADS scale (Hospital Anxiety and Depression Scale). PATIENTS AND METHODS: Prospective, observational study, with a 3-month follow-up, in which various variables are collected, including clinical characteristics, quality of life questionnaires and treatments performed. RESULTS: 143 patients with COPD (88.9% male) were included in the study, with a mean age of 72.76 ± 9.72 years. The mean FEV1 value was 47.23 ± 19.44%. 8.6% had a previous diagnosis of depression and 3.3% of anxiety. The mean score on the HADS scale was 6.96 ± 6.50 points (3.55 ± 3.54 in the depression subscale and 3.41 ± 3.76 in the anxiety subscale). We obtained 5.6% of probable cases in the depression subscale and 4.9% in the anxiety subscale. 14.3% of the patients with HADS> 11 had a previous diagnosis of anxiety and 12.5% ​​of depression. CONCLUSIONS: 8.6% of our patients had a previous diagnosis of depression and 3.3% of anxiety. Likewise, in the HADS scale we obtained 5.6% of probable cases in the depression subscale and 4.9% in the anxiety subscale. On the other hand, a remarkable percentage of patients with COPD and anxiety or depression had a high score on the HADS scale

Nocardiosis pulmonar en paciente con EPOC grave de fenotipo agudizador con enfisema / Pulmonary nocardiosis in a patient with severe COPD of an exacerbating phenotype with emphysema

La nocardiosis pulmonar es una entidad poco frecuente que afecta a pacientes inmunodeprimidos y a aquellos con patologías pulmonares previas, entre las que se incluyen la enfermedad pulmonar obstructiva crónica (EPOC). Tanto sus manifestaciones clínicas como las radiológicas son inespecíficas, pudiendo llegar a confundirse con otros procesos como la tuberculosis o determinados tumores. Debido a ello y a la lentitud con la que crece en los cultivos, puede producirse un retraso en su diagnóstico, llegando a alcanzar la mortalidad hasta el 40% de los casos. Presentamos un caso de nocardiosis pulmonar en una paciente con EPOC grave de fenotipo agudizador con enfisema, que presentó una buena evolución tras el tratamiento antibiótico que se le instauró

Pulmonary nocardiosis is a rare disease that affects inmmunocompromised patients and those with previous pulmonary pathology, including chronic obstructive pulmonary disease (COPD). Both, clinical and radiological manifestations are nonspecific, and it can be confused with other processes such as tuberculosis or tumors. Because of this and its slow growth in cultures, there may be a delay in its diagnosis, reaching mortality up to 40% of cases. We present a case of Pulmonary nocardiosis in a patient with severe COPD of an exacerbating phenotype with emphysema, who presented a good evolution with antibiotic treatment

Relevancia de la comorbilidad en la EPOC / Relevance of comorbidity in chronic obstructive pulmonary disease (COPD)

Las comorbilidades son frecuentes en la enfermedad pulmonar obstructiva crónica (EPOC). Producen un aumento del coste de la EPOC y constituyen un factor predictivo de mortalidad en los pacientes con dicha patología. Las más frecuentes son las enfermedades cardiovasculares (cardiopatía isquémica, insuficiencia cardíaca, arritmias o ictus), la hipertensión arterial, la diabetes mellitus, las infecciones respiratorias, el cáncer (en especial el de pulmón), la insuficiencia renal, la osteoporosis, los trastornos psiquiátricos (predominantemente la ansiedad y la depresión), la anemia, la enfermedad vascular periférica, la desnutrición y la sarcopenia. Existen métodos de valoración de la comorbilidad, entre los que se encuentran el índice de comorbilidad de Charlson y el índice de COTE (Comorbidity test)

Comorbidities are frequent in chronic obstructive pulmonary disease (COPD). They produce an increase in the cost of COPD and are a predictive factor of mortality in patients with this disease. The most frequent are cardiovascular disease (ischemic heart disease, heart failure, arrhythmias or stroke), high blood pressure, diabetes mellitus, respiratory infections, cancer (es-pecially lung cancer), kidney failure, osteoporosis, diseases psychiatric (predominantly anxiety and depression), anemia and peripheral vascular disease. There are methods of assessing comorbidity, among which are the Charlson comorbidity index and the COTE index (Comorbidity test)

Utilidad de una plataforma telemática para la prevención de reingresos en pacientes dados de alta por una exacerbación de su EPOC / Usefulness of a telematic platform for the prevention of readmissions in patients discharged due to an exacerbation of their COPD

Introducción. Las exacerbaciones de la enfermedad pulmonar obstructiva crónica (EPOC) tienen un impacto negativo en la salud y la calidad de vida de los pacientes con EPOC. Un porcentaje importante de pacientes dados de alta por una exacerbación de esta enfermedad requieren un reingreso. El objetivo de nuestro estudio fue valorar la utilidad de un programa de asistencia telefónica en la prevención de asistencias a urgencias y reingresos en pacientes dados de alta en nuestro servicio por exacerbación de EPOC. Pacientes y métodos. Los pacientes incluidos fueron aleatorizados en 2 grupos: a) grupo de intervención, en el que se realizó una llamada telefónica a los pacientes cada 15 días tras el alta hasta completar un periodo de seguimiento de 90 días, con la finalidad de llevar a cabo un control clínico; b) grupo de no intervención, en el que se efectuó una única llamada telefónica de control clínico a los 90 días del alta para registrar su situación clínica y las incidencias acaecidas durante dicho periodo. Resultados. En relación con la tasa de exacerbaciones, se objetivó una reducción no estadísticamente significativa en ambos grupos (grupo intervención: 4,33 ± 4,21 al inicio del estudio vs 0,55 ± 0,88 al final del estudio; grupo no intervención: 3,81 ± 2,08 al inicio del estudio vs 1,09 ± 1,22 al final del estudio). También se encontró una disminución no estadísticamente significativa de la tasa de ingresos hospitalarios (grupo intervención: 4,11 ± 3,58 vs 0,44 ± 0,72; grupo no intervención 3,72 ± 2,05 vs 0,63 ± 1,20). En cuanto al número de días de ingreso hospitalario, tampoco se encontraron diferencias estadísticamente significativas en los dos grupos (grupo intervención: 7,6 ± 3,47 al inicio del estudio vs 3,3 ± 3,05 al final del estudio; grupo no intervención: 7,45 ± 4,78 al inicio del estudio vs 9,4±15,63 al final del estudio). La mortalidad fue similar en ambos grupos (1 fallecido en cada grupo). Conclusiones. En nuestra muestra, la implantación de un programa de asistencia telemática a los pacientes con EPOC no ha conseguido reducir de una manera significativa la tasa de exacerbaciones, los ingresos hospitalarios o la mortalidad en el grupo intervención en comparación con el grupo no intervención

Introduction. COPD exacerbations have a negative impact on health and quality of life of COPD patients. A significant percentage of patients discharged due to an exacerbation of this disease require re-entry. The aim of our study was to assess the usefulness of a telephone assistance program in the prevention of emergency care and readmissions in patients discharged from our service due to exacerbation of COPD. Patients and methods. We included patients, randomized into 2 groups: a) intervention group, in which a telephone call was made every 15 days after discharge until completing a follow-up period of 90 days, in order to carry out a clinical control. b) non-intervention group, in which a single clinical control telephone call was made 90 days after discharge to record their clinical situation and the incidents that occurred during that period. Results. In the exacerbation rate, a non-statistically significant reduction was observed in both groups (intervention group: 4.33 ± 4.21 at the beginning of the study vs 0.55 ± 0.8 at the end of the study, non-intervention group: 3.81 ± 2.08 at the beginning of the study vs 1.09 ± 1.22 at the end of the study). We also found a non-statistically significant decrease in the hospital admissions rate (intervention group: 4.11 ± 3.58 vs 0.44 ± 0.72, non-intervention group 3.72 ± 2.05 vs 0.63 ± 1.20). In relation to the number of hospital admission days, no statistically significant differences were found in the two groups either (intervention group: intervention group: 7.6 ± 3.47 at the beginning of the study vs. 3.3 ± 3.05 at the end of the study; no intervention group: 7.45 ± 4.78 at the beginning of the study vs 9.4 ± 15.63 at the end of the study). Mortality was similar in both groups (1 death in each group). Discussion. In our sample, the implementation of a telematic assistance program for patients with COPD has not significantly reduced the rate of exacerbations, hospital admissions or mortality in the intervention group compared to the non-intervention group

Mortalidad y factores asociados al reingreso en los pacientes dados de alta por una exacerbación aguda de EPOC / Mortality and associated factors with readmission in patients discharged by acute exacerbation of COPD

Introducción. Un porcentaje significativo de pacientes ingresados por una exacerbación aguda de enfermedad pulmonar obstructiva crónica (EPOC) presentan una evolución desfavorable en un breve periodo de tiempo tras el alta. El objetivo de este estudio es analizar la mortalidad y los factores asociados a la rehospitalización en los pacientes ingresados por una exacerbación aguda de EPOC en nuestro hospital. Pacientes y métodos. Se incluyó en el estudio a pacientes diagnosticados previamente de EPOC que ingresaron en nuestro Servicio entre junio de 2014 y abril de 2016. Se recogieron, entre otras variables, características sociodemográficas, parámetros clínicos y tratamiento, tanto de la EPOC como de las comorbilidades. A los 3 meses del alta se revisó el estado de supervivencia y los reingresos durante este periodo de tiempo. Resultados. Se incluyeron en el estudio 143 pacientes, 88,9% varones, con una edad media de 72,76 ± 9,72 años y un volumen espiratorio forzado en el primer segundo (FEV1) medio de 47,23 ± 19,44%. La comorbilidad asociada más frecuente fue la hipertensión arterial (71%). Durante el seguimiento fallecieron 10 pacientes (6,99%) y reingresaron 49 (34,26%). Los factores asociados de forma independiente con el reingreso a los 3 meses fueron el FEV1 (OR 0,97; IC 95% 0,95-0,99) y la existencia de anemia (OR 7,24; IC 95% 1,40-37,42). Conclusiones. Más de una tercera parte de los pacientes dados de alta por una exacerbación de EPOC reingresan en los primeros 3 meses tras el alta, falleciendo el 6,99% de ellos. Los parámetros que se asocian de forma independiente con el riesgo de reingreso son el FEV1 y la presencia de anemia

Introduction. A significant percentage of patients admitted by acute exacerbation of chronic obstructive pulmonary disease (COPD) present an unfavorable evolution in a short period of time after discharge. The aim of this study is to analyze the mortality and associated factors with readmission in hospitalized patients hospitalized by acute exacerbation of COPD in our hospital. Patients and methods. COPD patients who were admitted to our service between June 2014 and April 2016 were included in the study. Sociodemographic characteristics, clinical parameters, and treatment of COPD and comorbidities were collected, among other variables. Three months after discharge, the survival status and readmissions during this period of time were reviewed. Results. 143 patients were included in the study, 88.9% male, with a mean age of 72.76 ± 9.72 years and a forced expiratory volume in the first second (FEV1) of 47.23 ± 19.44%. The most frequent associated comorbidity was arterial hypertension (71%). During follow-up, 10 patients died (6.99%) and 49 (34.26%) were readmitted. The factors associated independently with readmission at 3 months were FEV1 (OR 0.97, 95% CI 0.95-0.99) and the existence of anemia (OR 7.24, 95% CI 1.40 -37.42). Conclusions. More than a third of the patients discharged by acute exacerbation of COPD are readmited in the first 3 months after discharge, with 6.99% of them dying. The parameters that are associated independently with the risk readmission are FEV1 and the presence of anemia

Derrame pleural asociado a síndrome de Sjögren / Pleural effusion associated with Sjögren's syndrome

El derrame pleural es una manifestación infrecuente del síndrome de Sjögren, especialmente si se presenta de forma aislada en ausencia de otras enfermedades del tejido conectivo. Puede ser uni o bilateral. En la mayoría de las ocasiones se trata de un exudado de predominio mononuclear. Su diagnóstico requiere, además de unas características bioquímicas determinadas en el líquido pleural, un periodo de seguimiento para poder descartar otro origen. El tratamiento consiste en la administración de glucocorticoides y el pronóstico suele ser favorable. Presentamos el caso de un varón con derrame pleural bilateral, con predominio en el hemitórax izquierdo, que fue diagnosticado y tratado inicialmente como secundario a insuficiencia cardiaca y renal, con mala respuesta en el lado izquierdo. Tras revisar el caso, se llegó al diagnóstico de síndrome de Sjögren con derrame pleural, con buena evolución tras inicio de tratamiento con corticoides sistémicos

Pleural effusion is an infrequent manifestation of Sjögren’s syndrome, especially if it occurs in isolation in the absence of other connective tissue diseases. It can be unilateral or bilateral. In most cases it is a mononuclear predominant exudate. Its diagnosis requires, in addition to specific biochemical characteristics in the pleural fluid, a follow-up period in order to rule out another origin. The treatment consists in the administration of glucocorticoids and the prognosis is usually favorable. We present the case of a man with bilateral pleural effusion, predominantly in the left hemithorax, who was diagnosed and initially treated as secondary to heart and kidney failure, with a poor response on the left side. After reviewing the case, the diagnosis of Sjögren’s syndrome with pleural effusion was reached, with good evolution after beginning treatment with systemic corticosteroid

Hipertensión pulmonar tromboembólica crónica / No disponible

La hipertensión pulmonar tromboembólica crónica (HPTEC) se produce por la oclusión crónica de las arterias pulmonares debido a la presencia de trombos organizados. Se debe considerar la posibilidad de esta enfermedad en pacientes con antecedentes de enfermedad tromboembólica venosa y persistencia de disnea, así como en aquellos con datos ecocardiográficos de hipertensión pulmonar, ya que hasta el 25% de los pacientes con HPTEC no tiene antecedentes de evento tromboembólico previo. Si se sospecha hipertensión pulmonar con la ecocardiografía, debería realizarse a continuación una gammagrafía pulmonar de ventilación-perfusión. Si se evidencian signos sugestivos de HPTEC en dicha exploración, debería indicarse una angiografía por tomografía computarizada multidetector, un cateterismo cardiaco derecho y una arteriografía pulmonar para confirmar la hipertensión pulmonar, cuantificar su gravedad, definir la accesibilidad quirúrgica de las lesiones trombóticas y confirmar que un componente aceptable de la elevación de la resistencia vascular pulmonar se debe a la existencia de una enfermedad quirúrgicamente accesible y no corresponde a una obstrucción distal o a una arteriopatía secundaria. El tratamiento de elección es la tromboendarterectomía pulmonar (TEA). En los pacientes con HPTEC en los que no puede realizarse la TEA o que presentan hipertensión pulmonar residual tras la realización de este procedimiento, se puede indicar el tratamiento médico con riociguat o valorar la realización de una angioplastia con balón de las arterias pulmonares

Chronic thromboembolic pulmonary hypertension (CTPH) is caused by chronic occlusion of the pulmonary arteries due to the presence of organized thrombi. The possibility of this disease should be considered in patients with a history of venous thromboembolic and persistent dyspnoea, as well as in those with echocardiographic data of pulmonary hypertension, since up to 25% of patients with HPTEC have no previous history of thromboembolic event . If pulmonary hypertension is suspected with echocardiography, then a pulmonary ventilation-perfusion scan should be performed. If signs suggestive of HPTEC are evident in such examination, multidetector computed tomography angiography, right cardiac catheterization, and pulmonary arteriography should be indicated to confirm pulmonary hypertension, quantify its severity, define surgical accessibility of thrombotic lesions, and confirm that an acceptable component of elevated pulmonary vascular resistance is due to the existence of a surgically accessible disease and does not correspond to a distal obstruction or secondary arteriopathy. Pulmonary thromboendarterectomy (TEA) is the treatment of choice. In patients with CTPH who cannot undergo TEA or who have residual pulmonary hypertension after performing this procedure, medical treatment with riociguat may be indicated or balloon angioplasty of the pulmonary arteries may be assessed

Embolización pulmonar de material de cementación vertebral / No disponible

El embolismo pulmonar por cemento (EPC) es una complicación potencialmente fatal. La migración del material de cementación a la circulación pulmonar puede producirse por extravasación del mismo hacia el plexo venoso vertebral, el cual se encuentra conectado con el sistema ácigos, alcanzando por esta vía la vena cava y la circulación pulmonar. La estrategia terapéutica depende de la sintomatología clínica y la localización de los émbolos: observación, anticoagulación o embolectomía quirúrgica. Presentamos el caso de una mujer de 64 años que fue sometida a una artrodesis posterolateral intrumentada L2-S1 con tornillos canulados para cementación. En la TAC torácica realizada posteriormente se identificaron múltiples imágenes de densidad metálica en el interior de las arterias pulmonares

Pulmonary embolism due to cementum (CPS) is a potentially fatal complication. The migration of the cementing material into the pulmonary circulation can occur by extravasation of the same to the vertebral venous plexus, which is connected to the azygos system, thereby reaching the vena cava and pulmonary circulation. The therapeutic strategy depends on the clinical symptomatology and the location of the emboli: observation, anticoagulation or surgical embolectomy. We present the case of a 64-year-old woman who underwent an instrumented L2-S1 posterolateral arthrodesis with cannulated screws for cementation. In the thoracic CT performed later, multiple images of metallic density were identified inside the pulmonary arteries

Vanadate inhibits the calcium extrusion in rat pancreatic acinar cells.

Our objective was to evaluate the role of vanadate on calcium extrusion in Fura-2-loaded rat pancreatic acinar cells by digital microscopic fluorimetry and spectrofluorimetry. In the absence of extracellular calcium, perfusion of pancreatic acinar cells with 1 nM CCK-8 and 1 mM vanadate did not significantly affect the typical transient calcium spike induced by CCK-8, but the plateau phase of calcium in response to CCK-8 remained elevated. In addition, vanadate was able to inhibit calcium efflux evoked by CCK-8 when we determined directly calcium transport across plasma membrane using Calcium Green-5N hexapotassium salt (cell impermeant form) in cell populations. The effect of vanadate on calcium extrusion was strongly blocked by the sulfhydryl-reducing agent dithiothreitol (DTT). The present results demonstrate that vanadate is able to irreversibly inhibit the calcium extrusion. This effect of vanadate can be blocked using DTT, indicating that its action is probably mediated by oxidation of sulfhydryl groups of Ca2+-ATPases.

Effect of dephostatin on intracellular free calcium concentration and amylase secretion in isolated rat pancreatic acinar cells.

This study investigates the effects of dephostatin, a new tyrosine phosphatase inhibitor, on intracellular free calcium concentration ([Ca2+]i) and amylase secretion in collagenase dispersed rat pancreatic acinar cells. Dephostatin evoked a sustained elevation in [Ca2+]i by mobilizing calcium from intracellular calcium stores in either the absence of extracellular calcium or the presence of lanthanium chloride (LaCl3). Pretreatment of acinar cells with dephostatin prevented cholecystokinin-octapeptide (CCK-8)-induced signal of [Ca2+]i and inhibited the oscillatory pattern initiated by aluminium fluoride (AlF4), whereas co-incubation with CCK-8 enhances the plateau phase of calcium response to CCK-8 without modifying the transient calcium spike. The effects of dephostatin on calcium mobilization were reversed by the presence of the sulfhydryl reducing agent, dithiothreitol. Stimulation of acinar cells with thapsigargin in the absence of extracellular Ca2+ resulted in a transient rise in [Ca2+]i. Application of dephostatin in the continuous presence of thapsigargin caused a small but sustained elevation in [Ca2+]i. These results suggest that dephostatin can mobilize Ca2+ from both a thapsigargin-sensitive and thapsigargin-insensitive intracellular stores in pancreatic acinar cells. In addition, dephostatin can stimulate the release of amylase from pancreatic acinar cells and moreover, reduce the secretory response to CCK-8. The results indicate that dephostatin can release calcium from intracellular calcium pools and consequently induces amylase secretion in pancreatic acinar cells. These effects are likely due to the oxidizing effects of this compound.

Phenylarsine oxide evokes intracellular calcium increases and amylase secretion in isolated rat pancreatic acinar cells.

The effects of the thiol reagent, phenylarsine oxide (PAO, 10(-5)-10(-3) M ), a membrane-permeable trivalent arsenical compound that specifically complexes vicinal sulfhydryl groups of proteins to form stable ring structures, were studied by monitoring intracellular free calcium concentration ([Ca2+]i) and amylase secretion in collagenase dispersed rat pancreatic acinar cells. PAO increased [Ca2+]i by mobilizing calcium from intracellular stores, since this increase was observed in the absence of extracellular calcium. PAO also prevented the CCK-8-induced signal of [Ca2+]i and inhibited the oscillatory pattern initiated by aluminium fluoride (AlF-4). In addition to the effects of PAO on calcium mobilization, it caused a significant increase in amylase secretion and reduced the secretory response to either CCK-8 or AlF-4. The effects of PAO on both [Ca2+]i and amylase release were reversed by the sulfhydryl reducing agent, dithiothreitol (2 mM). Pretreatment of acinar cells with high concentration of ryanodine (50 microM) reduced the PAO-evoked calcium release. However, PAO was still able to release a small fraction of Ca2+ from acinar cells in which agonist-releasable Ca2+ pools had been previously depleted by thapsigargin (0.5 microM) and ryanodine receptors were blocked by 50 microM ryanodine. We conclude that, in pancreatic acinar cells, PAO mainly releases Ca2+ from the ryanodine-sensitive calcium pool and consequently induces amylase secretion. These effects are likely to be due to the oxidizing effects of this compound.

Oxidizing effects of vanadate on calcium mobilization and amylase release in rat pancreatic acinar cells.

The effects of vanadate were examined by monitoring intracellular free calcium concentration ([Ca2+]i) and amylase secretion in collagenase-dispersed rat pancreatic acinar cells. Vanadate increased [Ca2+]i by mobilizing calcium from agonist-releasable intracellular calcium stores, since this increase was observed in the absence of extracellular calcium and vanadate failed to increase [Ca2+]i after treatment with thapsigargin in calcium-free medium. Moreover, pretreatment of acinar cells with vanadate prevented the cholecystokinin octapeptide (CCK-8)-induced signal of [Ca2+]i, whereas co-incubation with CCK-8 potentiated the plateau phase of calcium response to CCK-8 without modifying the transient calcium spike. The effects of vanadate on calcium mobilization were reversed by the presence of the sulfhydryl reducing agent dithiothreitol. Vanadate also activated the calcium influx, since an additional enhancement of calcium influx induced by thapsigargin-evoked intracellular store depletion was observed and vanadate reversed the inhibitory effect of lanthanum (an inhibitor of calcium entry) into acinar cells. In addition, vanadate evoked a concentration-dependent release of amylase from pancreatic acinar cells and moreover, reduced the secretory response to CCK-8. We conclude that, in pancreatic acinar cells, vanadate releases calcium from the agonist-releasable intracellular calcium pool and consequently induces amylase secretion. These effects are likely due to the oxidizing effects of this compound.

Inhibitory and stimulatory effects of somatostatin on two human pancreatic cancer cell lines: a primary role for tyrosine phosphatase SHP-1.

Somatostatin (SS-14) and its structural analogue SMS 201-995 (SMS) are recognized as physiological inhibitors of multiple organs and tissue functions through specific membrane receptors (sst1-sst5). The effects of SS-14 and SMS in the growth control of the pancreatic cancer cell lines MIA PaCa-2 and PANC-1 were investigated to identify and clarify the intracellular events involved. In PANC-1 cells, SS-14 and SMS caused inhibition of their basal growth, and that stimulated by epidermal growth factor, with a maximal effect at 0.1-1 microM. To understand the inhibitory mechanisms, we investigated the effects of SS-14 and SMS on phosphotyrosine phosphatase (PTPase) activity and, more specifically, that of tyrosine phosphatase SHP-1 (PTP1C). SS-14 and SMS caused significant increases in total cellular PTPase activity, and particularly SHP-1, with maximal activation within 1 min. Inhibition of membrane tyrosine kinase and p42 MAP kinase activities was also observed, in response to SS-14 and SMS. In MIA PaCa-2 cells, SS-14 and SMS were associated with a positive growth response at 1-10 nM, after 4 days of culture in serum-free medium. Total cellular PTPase activity was slightly increased, but SHP-1 activity could not be detected; its absence in this cell line was confirmed by Western blot. Membrane tyrosine kinase activities were significantly increased by SS-14 and SMS at concentrations needed for maximal growth. p44/p42, which are constitutively active in this cell line, and p38 activities were not affected by somatostatin. In conclusion, somatostatin can exert different effects on human pancreatic cancer cell growth, depending upon the presence or absence of SHP-1. This enzyme can play a key role in the control of cell proliferation, and its cellular presence may determine the therapeutic potential of somatostatin in the control of cancer cell growth.

Growth effects of regulatory peptides and intracellular signaling routes in human pancreatic cancer cell lines.

The intracellular events involved in normal pancreatic growth have been extensively investigated in response to cholecystokinin. Recent data indicate that tyrosine kinase, phospholipase D, phosphatidylinositol 3-kinase, and p42/p44 MAPK are stimulated in rat pancreatic acinar cells. Although we begin to understand the intracellular signaling pathways activated in normal pancreas, such information is not yet available in pancreatic cancer cells. This study was undertaken to identify the growth factors and hormones involved in cell proliferation of two human pancreatic cancer cell lines of ductal origin, the MIA PaCa-2, and PANC-1 cells, and to establish the intracellular events involved in the control of their growth. We demonstrated that FGF-2, IGF-1, cerulein, and gastrin but not FGF-1, HGF, secretin, and PACAP, stimulated proliferation of MIA PaCa-2 and PANC-1 cells. Autocrine factors such as gastrin and IGF-1 were also responsible for their proliferation. In response to EGF, FGF-2, IGF-1, cerulein, gastrin and bombesin, tyrosine kinase, and tyrosine phosphatase activities were stimulated in both cell lines. The close relationship established between cell growth and tyrosine kinase activation results from the observation that maximal growth stimulation paralleled with maximal enzyme activation and that genistein, the tyrosine kinase inhibitor, blocked cell growth and enzyme activation. The implication of PLD in growth-stimulated processes is doubtful since all growth factors and hormones tested failed to stimulate an already very active PLD activity. We finally observed a constitutive activity of p44 MAPK in both cell lines and of p42 in MIA PaCa-2 cells. However, p38 and p42 were stimulated in MIA PaCa-2 and PANC-1 cells, respectively, by all growth factors and hormones.

Effect of basic fibroblast growth factor on cholecystokinin-induced amylase release and intracellular calcium increase in male rat pancreatic acinar cells.

Isolated rat pancreatic acinar cells were used to investigate the effect of basic fibroblast growth factor (bFGF) on both amylase secretion and intracellular free calcium concentration ([Ca2+]i) in response to the calcium-mobilizing secretagogue cholecystokinin-octapeptide (CCK-8). Our data show that bFGF inhibited CCK-8-induced amylase release in a concentration-dependent manner and decreased the CCK-8-induced rise in [Ca2+]i. This inhibitory effect of bFGF on both amylase secretion and [Ca2+]i increase in response to CCK-8 was reverted when acinar cells were pretreated with 100 microM tyrphostin A25, a tyrosine kinase inhibitor. Tyrphostin A25 also inhibited Ca2+ influx induced by CCK-8. These results show that bFGF inhibits CCK-8-induced pancreatic response by a tyrosine kinase-dependent mechanism. A role for tyrosine phosphorylation in capacitative Ca2+ entry is suggested.

Histamine does not potentiate cyclic AMP-mediated amylase secretion in the guinea-pig pancreatic acinar cells.

1. This study investigates the interaction between histamine and the adenylate cyclase systems involved in the secretion of amylase in isolated guinea-pig pancreatic acinar cells. 2. Histamine caused does-related enhancement of amylase release. Similarly, incubation of acini with increasing concentrations of vasoactive intestinal peptide (VIP) resulted in a typical dose-dependent increase in amylase output. 3. When pancreatic acinar cells were incubated with histamine in combination with VIP, amylase secretion did not differ statistically from secretion induced by histamine or VIP alone and was significantly lower than theoretical additivity. Additionally, amylase secretion in the presence of histamine plus forskolin was significantly less than additive. The action of histamine was equally effective as VIP in causing cyclic adenosine monophosphate (cAMP) increase. 4. These results indicate that histamine may exert its secretory effects via the cyclic AMP pathway in the exocrine guinea-pig pancreas.

Secretory activity and trophic effects of epidermal growth factor in the rat pancreas.

This study was to investigate whether epidermal growth factor (EGF) may induce any long-term effect on pancreatic exocrine function in vivo as well to evaluate the chronic effects of EGF on pancreatic growth in rats. Rats were treated with EGF (10 micrograms/kg) for 5 or 7 days. EGF infused intravenously (2 micrograms/kg/h) in anaesthetized and pretreated rats for 5 or 7 days with EGF caused a slight decline flow rate after 1 h of EGF infusion compared to control values. In contrast, EGF evoked a increase in amylase secretion. This stimulatory effect was much larger in EGF-pretreated rats for 7 days, whereas the total protein output was unchanged. The trophic parameters which include pancreatic weight, total protein and total contents of DNA and RNA relative to body weight were not significantly different in any treated group. Only the pancreatic amylase content was increased significantly after 7 days of treatment with EGF. The present study fails to observe a stimulatory role of EGF on pancreatic growth in rats, but may participate in the regulation of pancreatic exocrine function in vivo.

Histamine and the cAMP pathway in the guinea-pig pancreas.

This study investigates the interaction between histamine and the adenylate cyclase systems involved in the secretion of amylase from the guinea-pig pancreatic lobules. Histamine increased amylase release, reaching a maximum response at 10(-5) M. Similarly, vasoactive intestinal peptide (VIP) evoked significant increase in amylase release, though not in a dose-dependent fashion. When the pancreatic lobules were incubated with histamine in combination with VIP, forskolin or 3-isobutyl-1-methylxanthine (IBMX), amylase secretion was increased as compared to histamine alone. The stimulatory effect of VIP was also increased by the presence of forskolin or IBMX. These findings suggest that in guinea-pig pancreatic lobules, VIP, forskolin and IBMX, agents involved in the cyclic adenosine monophosphate (cAMP) pathway, potentiate histamine stimulated amylase release.