Nutrition education in medical schools (NEMS) project: Joining ESPEN and university point of view.

BACKGROUND & AIMS: Nutrition education is not well represented in the medical curriculum. The aim of this original paper was to describe the Nutrition Education in Medical Schools (NEMS) Project of the European Society for Clinical Nutrition and Metabolism (ESPEN). METHODS: On 19 January 2020, a meeting was held on this topic that was attended by 51 delegates (27 council members) from 34 countries, and 13 European University representatives. RESULTS: This article includes the contents of the meeting that concluded with the signing of the Manifesto for the Implementation of Nutrition Education in the Undergraduate Medical Curriculum. CONCLUSION: The meeting represented a significant step forward, moved towards implementation of nutrition education in medical education in general and in clinical practice in particular, in compliance with the aims of the ESPEN Nutrition Education Study Group (NESG).

[Late ischemic stricture following anterior rectal resection]. / Estenosis isquémica tardía tras resección anterior de recto.

A considerable incidence of colonic strictures after oncologic low anterior resections has been reported. The present paper describes a colonic stricture 5 years after the surgery, and not related to radiotherapy, that required a challenging differential diagnosis with local recurrence of rectal cancer. The role of endoscopy in the management of this condition is discussed.

Estenosis isquémica tardía tras resección anterior de recto / No disponible

Existe una incidencia no despreciable de lesiones de colon deorigen isquémico tras resecciones anteriores bajas por cáncer.Presentamos un caso de estenosis isquémica de colon, no relacionadacon radioterapia, a los 5 años de la cirugía. Se discute la dificultaddel diagnóstico diferencial con recidiva tumoral, así como elimportante papel que desempeña la endoscopia en el abordaje deestos pacientes

A considerable incidence of colonic strictures after oncologiclow anterior resections has been reported. The present paper describesa colonic stricture 5 years after the surgery, and not relatedto radiotherapy, that required a challenging differential diagnosiswith local recurrence of rectal cancer. The role of endoscopyin the management of this condition is discussed

[Animal models in glucose intolerance and type-2 diabetes]. / Modelos animales de intolerancia a la glucosa y diabetes tipo 2.

There stilla are many unknown facts about the pathogenic mechanisms of such a prevalente disease nowadays as i type-2 diabetes mellitus (DM2). The advances in diabetes prevention and management will greatly depend on the understanding of these mechanisms; therefore, it will be essential to keep on using animal models on which carrying out experiments that would be urethical in humans. DM2 represents a heterogeneous group of diseases characterized by an increase in insulin resistance at periphera tissues and a deterioration in insulin secretion by pancreatic beta-cells, both abnormalities being highly interweaved. The mentioned heterogeneity of DM2 is also reflected by the high diversity of useful animal models for its study. The main DM2 models are reviewed, classifying them by their mechanism of action in spontaneous or induced. Also, two categories in each one of them are distinguiseed: analogous models, which try to imitate the human disease, and intrinsic models, with which we pretend to answer specific questions about the disease. The decision about which model to case for a particular experiment usually is multifactorial. Ideally, the experiments should be carried out in several different models, taking into account that none of them completely reflects the complexity of human DM2 and that precautions should be taken when trying to extrapolate the findings to the clinical practice.

Modelos animales de intolerancia a la glucosa y diabetes tipo 2 / Animal model in glucose intolerance and type-2 diabetes

Aún persisten múltiples incógnitas acerca de los mecanismos patogénicos de una enfermedad tan prevalente hoy día como es la diabetes mellitus tipo 2 (DM2). El avance en la prevención y tratamiento de la misma dependerá en gran parte de la comprensión de estos mecanismos y para ello es imprescindible seguir utilizando modelos animales en los que realizar experimentos que serían éticamente inaceptables en humanos. La DM2 representa un heterogéneo grupo de enfermedades caracterizado por un aumento en la resistencia a la acción de la insulina en los tejidos periféricos y un deterioro en la secreción de dicha hormona por parte de la célula â pancreática, encontrándose ambas anomalías íntimamente imbricadas. La citada heterogeneidad de la DM2 se ve asi mismo reflejada en la gran diversidad de modelos animales útiles para su estudio. Se revisan los principales modelos de DM2, clasificándolos, según su mecanismo de producción, en espontáneos e inducidos. También se distinguen dos categorías en cada uno de ellos: modelos análogos, que intentan imitar a la enfermedad humana, y modelos intrínsecos, con los que se pretende contestar preguntas concretas de aspectos específicos de la misma. La decisión acerca del modelo a usar para un experimento en particular es a menudo multifactorial. De modo ideal, los experimentos deberían ser llevados a cabo en varios modelos diferentes, teniendo en cuenta que ninguno de ellos refleja por completo la complejidad de la DM2 humana y que se deben extremar las precauciones a la hora de hacer cualquier tipo de extrapolación a la clínica

There stilla are many unknown facts about the pathogenic mechanisms of such a prevalente disease nowadays as i type-2 diabetes mellitus (DM2). The advances in diabetes prevention and management will greatly depend on the understanding of these mechanisms; therefore, it will be essential to keep on using animal models on which carrying out experiments that would be urethical in humans. DM2 represents a heterogeneous group of diseases characterized by an increase in insulin resistance at periphera tissues and a deterioration in insulin secretion by pancreatic â-cells, both abnormalities being highly interweaved. The mentioned heterogeneity of DM2 is also reflected by the high diversity of useful animal models for its study. The main DM2 models are reviewed, classifying them by their mechanism of action in spontaneous or induced. Also, two categories in each one of them are distinguiseed: analogous models, which try to imitate the human disease, and intrinsic models, with which we pretend to answer specific questions about the disease. The decision about which model to case for a particular experiment usually is multifactorial. Ideally, the experiments should be carried out in several different models, taking into account that none of them completely reflects the complexity of human DM2 and that precautions should be taken when trying to extrapolate the findings to the clinical practice

Efficacy of albendazole against Anisakis simplex larvae in vitro.

BACKGROUND: The growing popularity in western countries of eating uncooked seafood has resulted in an increased incidence of anisakidosis. AIM: To study the in vitro activity of different concentrations of albendazole against Anisakis simplex larvae under different media pH. METHODS: A. simplex larvae were obtained from fresh hakes acquired from the fish market of Madrid. They were divided into groups and placed in culture dishes (15 larvae each) containing RPMI-1640, in the presence or absence of different concentrations of albendazole (300, 400 and 500 microg/mL). RESULTS: Albendazole dose-dependently reduced the survival of the larvae, its maximum activity being at 500 microg/mL when it killed almost all larvae at 48 h. Acidic medium pH significantly reduced the efficacy of albendazole. CONCLUSION: Albendazole is effective in killing A. simplex larvae at different pH in vitro, suggesting that this molecule could be useful in treating clinical manifestations of human anisakidosis.

[Body weight profile in acute mesenteric ischemia. Experimental study in New-Zealand rabbits]. / Perfil del peso corporal en la isquemia mesenterica aguda. Estudio experimental en conejos Nueva Zelanda.

INTRODUCTION AND OBJECTIVES: There are few investigation studies that relate acute mesenteric ischemia and body weight in animal experimentation. The aim is to studying whether initial weight loss is related to the magnitude of the aggression induced by clamps of the superior mesenteric artery for 30 and 60 minutes, and whether reperfusion ischemia may hinder weight recovery in surviving animals at the end of 11 weeks of experimental work with New Zealand rabbits through a valid experimental model. MATERIALS AND METHOD: 80 animals (rabbits) were distributed in four series of 20 each one: series I (control), animals were weighed for 11 weeks; series II (simulated surgery); series III (mesenteric ischemia for 30 minutes); series IV (mesenteric ischemia for 60 minutes). We induced ischemia by clamping the superior mesenteric artery. Animals from series II, III, and IV were weighed 24 hours before the surgical procedure and weekly after surgery along their survival, until completing 11 weeks. For weight analysis, an ANOVA test was used by confronting the percentage weight variation according to the series. All animals were necropsied to know the cause of death and histological lesions of the intestinal mucosa. RESULTS: Series I had a linear weight increase until the end of the observation period. Series II, III and IV had a significant initial decrease of the percentage weight during the first post-surgical week, with a recovery towards the end of the study, but significantly lower as compared to the control series. Significant differences have also been found in weight recovery at 11 weeks between series II and series III and IV, and between ischemic series. CONCLUSIONS: Animals in series II, III, and IV reached at the end of the study a percentage weight significantly lower to that obtained by series I. In the experimental animal mesenteric ischemia-reperfusion processes, the initial percentage weight loss in the postsurgical period is influenced not only by ischemia time but also by pre-and postsurgical manipulations; by contrast, the longer ischemia time is, the greater weight loss at the end of the study will be.

Perfil del peso corporal en la isquemia mesentérica aguda. Estudio experimental en conejos Nueva Zelanda / Body weight profile in acute mesenteric ischemia. Experimental study in New-Zealand rabbits

Introducción y objetivos:  Hay pocos trabajos de investigación que relacionen la isquemia mesentérica aguda y el peso corporal en la experimentación animal. Se pretende estudiar, si la pérdida de peso inicial, está relacionada con la magnitud de la agresión provocada por los clampajes de la arteria mesentérica superior durante 30 y 60 minutos, y si la isquemia reperfusión puede dificultar la recuperación ponderal del peso en los animales supervivientes, al final de las 11 semanas del trabajo experimental con conejos Nueva Zelanda, mediante un modelo experimental válido. Material y método: Se distribuyeron 80 animales (conejos) en cuatro series de 20: serie I (control), los animales fueron pesados durante 11 semanas; serie II (operación simulada), serie III (isquemia mesentérica 30 minutos) y serie IV (isquemia mesentérica 60 minutos). Provocamos la isquemia por pinzamiento de la arteria mesentérica superior. Los animales de las series II, III y IV fueron pesados 24 horas antes del procedimiento quirúrgico y semanalmente en el postoperatorio durante su supervivencia hasta completar 11 semanas. Para el análisis de los pesos, se aplicó un ANOVA enfrentando la variación del peso porcentual en función de la serie. Todos los animales fueron necropsiados para conocer la causa del fallecimiento y las lesiones histológicas de la mucosa intestinal Resultados: La serie control tuvo un incremento lineal del peso hasta el final del período de observación. Las series II, III y IV sufrieron un descenso proceinicial significativo del peso porcentual en la primera semana del postoperatorio, con una recuperación al final del estudio, pero significativamente menor con respecto a la serie control. También se han encontrado diferencias significativas en la recuperación del peso a las 11 semanas entre la serie II y las series III y IV, y entre las series isquémicas entre sí. Conclusiones: Los animales de las series II, III, y IV alcanzaron al final del estudio un peso porcentual significativamente inferior que el alcanzado por la serie I. En los procesos de isquemia reperfusión mesentérica experimental animal, la pérdida de peso porcentual inicial en el postoperatorio, está influenciada no sólo por el tiempo de isquemia, sino por las manipulaciones pre y postoperatorias; en cambio, la pérdida de peso al final del estudio es más acentuada, cuanto mayor es el tiempo de isquemia (AU)

Introduction and objectives: There are few investigation studies that relate acute mesenteric ischemia and body weight in animal experimentation. The aim is to studying whether initial weight loss is related to the magnitude of the aggression induced by clamps of the superior mesenteric artery for 30 and 60 minutes, and whether reperfusion ischemia may hinder weight recovery in surviving animals at the end of 11 weeks of experimental work with New Zealand rabbits through a valid experimental model. Materials and method: 80 animals (rabbits) were distributed in four series of 20 each one: series I (control), animals were weighed for 11 weeks; series II (simulated surgery); series III (mesenteric ischemia for 30 minutes); series IV (mesenteric ischemia for 60 minutes). We induced ischemia by clamping the superior mesenteric artery. Animals from series II, III, and IV were weighed 24 hours before the surgical procedure and weekly after surgery along their survival, until completing 11 weeks. For weight analysis, an ANOVA test was used by confronting the percentage weight variation according to the series. All animals were necropsied to know the cause of death and histological lesions of the intestinal mucosa. Results: Series I had a linear weight increase until the end of the observation period. Series II, III and IV had a significant initial decrease of the percentage weight during the first post-surgical week, with a recovery towards the end of the study, but significantly lower as compared to the control series. Significant differences have also been found in weight recovery at 11 weeks between series II and series III and IV, and between ischemic series. Conclusions: Animals in series II, III, and IV reached at the end of the study a percentage weight significantly lower to that obtained by series I. In the experimental animal mesenteric ischemia-reperfusion processes, the initial percentage weight loss in the postsurgical period is influenced not only by ischemia time but also by pre-and postsurgical manipulations; by contrast, the longer ischemia time is, the greater weight loss at the end of the study will be (AU)

Non-heart-beating donation: current state of the art.

The use of non-heart-beating donors (NHBD) helps us to deal with the problem of the organ shortage. In addition to difficulties with legal and ethical acceptability, there are concerns regarding medical safety, which prevent the widespread use of these donors. To make optimum use of this potential organ supply, the ischemic injury that occurs after a period of warm ischemia needs to be reversed. To minimize the warm ischemia time, once the subject is declared dead, most centers commence in situ cold perfusion via a femoral access or a rapid aortic cannulation. This usually occurs within minutes of arriving at the emergency department, before the next of kin have been notified of the patient's death. The European experience of kidney transplantation from NHBD shows promising results. The long-term outcomes are similar to HBD kidneys notwithstanding a higher rate of delayed graft function, which seems not to affect the long-term survival of these kidneys. In summary, NHBD may have an important impact on the large discrepancy that exists between the organ supply and the demand. Current data suggest that the results may be further improved by better patient selection and retrieval team organization.

Últimos avances en el campo del trasplante de islotes de Langerhans / Update in clinical islet transplantation

Las complicaciones tardías de la diabetes constituyen un importante problema de salud pública y hoy día está demostrado que se deben a que el tratamiento habitual con insulina inyectada proporciona un control inadecuado de la glucemia. En pacientes con diabetes tipo I, se puede conseguir un buen control glucémico mediante la terapia intensiva con insulina o mediante un trasplante de páncreas. La terapia intensiva con insulina no logra normalizar las cifras de hemoglobina glucosilada y presenta un riesgo considerable de crisis de hipoglucemia. El trasplante de páncreas proporciona un control metabólico excelente y, aunque sus resultados han mejorado espectacularmente durante la última década, continúa siendo un procedimiento invasivo y con una morbilidad significativa. El trasplante de islotes aislados representa la alternativa más lógica para el tratamiento de estos pacientes. En un estudio reciente, que utiliza un innovador régimen inmunosupresor, el trasplante de islotes se acompañó de una morbilidad irrelevante y logró en todos los pacientes un buen control metabólico con normalización de la hemoglobina glucosilada e independencia de la insulina mantenidas (AU)

Glucagon-like peptide-1(7-36) amide stimulates surfactant secretion in human type II pneumocytes.

To determine the influence of glucagon-like peptides on the secretion of human pulmonary surfactant, we used human type II pneumocytes. In these cells, GLP-1(7-36) amide and exendin-4 stimulated phosphatidylcholine secretion (PC) and cAMP formation in a concentration-dependent manner; these effects were reversed by exendin(9-39). No changes were observed with other related peptides. The mechanism by which GLP-1(7-36) amide exerts its stimulatory effect was investigated with various agents that are well known to be stimulators or inhibitors of PC secretion. Thus, 8-bromo-cAMP increased and both Rp-cAMPS and H-89, the latter an inhibitor of protein kinase A (PKA), reduced pulmonary surfactant secretion in type II pneumocytes. Also, GLP-1(7-36) amide and TPA exerted additive effects in stimulating PC secretion, and Calph C, a potent inhibitor of protein kinase C (PKC), blocked most of the effect of GLP-1(7-36) amide. By contrast, both the calcium ionophore A23187 and GLP-1(7-36) amide had additive effects in increasing PC secretion, and the specific inhibitor of Ca(2+)-calmodulin-dependent protein kinase (Ca-CM-PK), KN-62, inhibited the effect of A23187 but did not alter the stimulatory action of GLP-1(7-36) amide. Our findings suggest that both PKA and PKC are involved in the stimulatory effects of GLP-1(7-36) amide on PC secretion, whereas this peptide has no effect on PC secretion through a Ca-CM-PK mechanism.

Effect of surfactant protein A (SP-A) on the production of cytokines by human pulmonary macrophages.

Surfactant protein A (SP-A) is thought to play a role in the modulation of lung inflammation during acute respiratory distress syndrome (ARDS). However, SP-A has been reported both to stimulate and to inhibit the proinflammatory activity of pulmonary macrophages (Mphi). Because of the interspecies differences and heterogeneity of Mphi subpopulations used may have influenced previous controversial results, in this study, we investigated the effect of human SP-A on the production of cytokines and other inflammatory mediators by two well-defined subpopulations of human pulmonary Mphi. Surfactant and both alveolar (aMphi) and interstitial (iMphi) macrophages were obtained from multiple organ donor lungs by bronchoalveolar lavage and enzymatic digestion. Donors with either recent history of tobacco smoking, more than 72 h on mechanical ventilation, or any radiological pulmonary infiltrate were discarded. SP-A was purified from isolated surfactant using sequential butanol and octyl glucoside extractions. After 24-h preculture, purified Mphi were cultured for 24 h in the presence or absence of LPS (10 microg/mL), SP-A (50 microg/mL), and combinations. Nitric oxide and carbon monoxide (CO) generation (pmol/microg protein), cell cGMP content (pmol/microg protein), and tumor necrosis factor alpha (TNFalpha), interleukin (IL)-1, and IL-6 release to the medium (pg/microg protein) were determined. SP-A inhibited the lipopolysaccharide (LPS)-induced TNFalpha response of both interstitial and alveolar human Mphi, as well as the IL-1 response in iMphi. The SP-A effect on TNFalpha production could be mediated by a suppression in the LPS-induced increase in intracellular cGMP. In iMphi but not in aMphi, SP-A also inhibited the LPS-induced IL-1 secretion and CO generation. These data lend further credit to a physiological function of SP-A in regulating alveolar host defense and inflammation by suggesting a fundamental role of this apoprotein in limiting excessive proinflammatory cytokine release in pulmonary Mphi during ARDS.

Carbon monoxide contributes to the cytokine-induced inhibition of surfactant synthesis by human type II pneumocytes.

BACKGROUND: An increase in cyclic guanosine 3',5'-monophosphate (cGMP) due to nitric oxide generation is known to participate in the mediation of the tumor necrosis factor alpha (TNF-alpha) effect in type II cells. Because guanylyl cyclase can be activated also by carbon monoxide (CO), in this study we examined the ability of human type II pneumocytes to produce CO in the presence of cytokines and the relative contribution of this molecule to the TNF-alpha and interleukin 1 effects. DESIGN: Type II pneumocytes were isolated from cadaveric multiple-organ donors by enzymatic digestion, adherence separation of macrophages, and gradient purification. After preculture for 24 hours, cells were cultured for 24 hours in the presence or absence of TNF-alpha, interleukin 1, sodium nitroprusside, N(omega)-nitro-1-arginine, CO, hemin, zinc-protoporphyrin type IX, deferoxamine mesylate, S-adenosyl-L-methionine, alpha-tocopherol, methylene blue (a guanylyl cyclase inhibitor), 8-bromine-cGMP, and combinations of these reagents. Both CO (picomole per microgram of protein) and nitric oxide release to the medium and the cGMP (picomole per microgram of protein) content of the cells were measured. In a different set of experiments, D-glucose labeled with radioactive carbon (14C) was added to the medium, and the labeling of several lipid fractions was determined (picomole per microgram of protein). RESULTS: D-[14C]glucose incorporation into phosphatidylcholine, the main surfactant component, was selectively inhibited in the presence of cytokines, CO, sodium nitroprusside, or 8-bromine-cGMP. The inhibitory effect of TNF-alpha was partially reversed by N(omega)-nitro-L-arginine, deferoxamine, or alpha-tocopherol and totally reversed by methylene blue. Tumor necrosis factor alpha induced an increase in cGMP cell content and in the CO and nitric oxide release to the medium. Hemin increased CO and cGMP production and decreased phosphatidylcholine synthesis. Zinc-protoporphyrin type IX, an inhibitor of heme oxygenase, and all 3 antioxidants, which inhibited CO production, also antagonized the TNF-alpha effect on cGMP and phosphatidylcholine synthesis. CONCLUSIONS: Intracellular cGMP increase due to an endogenous generation of both CO and nitric oxide mediates the cytokine-induced inhibition of surfactant synthesis by type II pneumocytes. Both lipid peroxidation and heme oxygenase activity are sources for the observed CO production.

Local production of oxygen free radicals and nitric oxide in rat diaphragm during sepsis: effects of pentoxifylline and somatostatin.

OBJECTIVE: To investigate the effect of giving lipopolysaccharide (LPS) on lipid peroxidation, and myeloperoxidase (MPO), nitric oxide (NO) synthase, and phospholipase A2 (PLA2) activities in rat diaphragm, and see whether they could be modified by giving pentoxifylline (PTXF) or somatostatin. DESIGN: Randomised experimental study. SETTING: Teaching hospital, Spain. MATERIAL: 76 Wistar rats divided into 4 groups of 19: control (saline/saline), LPS/saline, LPS/PTXF and LPS/somatostatin. INTERVENTIONS: The LPS was given intraperitoneally either 30 minutes (early, n = 10 in each group) or 120 minutes (late, n = 9 in each group) before treatment with saline, PTXF (45 mg/kg) or somatostatin (200 microg/kg) given intraperitoneally. Rats were killed 120 minutes after treatment. MAIN OUTCOME MEASURES: Malondialdehyde (MDA) and conjugated dienes content, and MPO, NO synthase, and PLA2 activities in diaphragmatic tissue. RESULTS: Conjugated dienes and MDA content, as well as MPO, NO synthase, and PLA2 activities were significantly increased in the rats given LPS. Independently of the timing of treatment, both PTXF and somatostatin completely prevented these increases. CONCLUSION: It is possible that treatment with PTXF or somatostatin may reduce the risk of ventilatory failure and speed recovery in septic patients.

TNF-alpha-induced inhibition of PC synthesis by human type II pneumocytes is sequentially mediated by PGE2 and NO.

Tumor necrosis factor-alpha (TNF-alpha)-induced inhibition of surfactant synthesis participates in the pathogenesis of the acute respiratory distress syndrome. We examined the ability of human type II pneumocytes to produce nitric oxide (NO) in the presence of TNF-alpha as well as the role of NO and prostaglandin (PG) E2 in the transduction of the cytokine signal. Multiple organ donors were used as a source of lung tissue. After 24-h preculture, type II pneumocytes were cultured for 18 h in the presence or absence of additives. The D-[U-14C] glucose incorporation into phosphatidylcholine (PC) was selectively inhibited by TNF-alpha, PGE2, sodium nitroprusside (SNP), or 8-bromoguanosine 3',5'-cyclic monophosphate. The effect of TNF-alpha was attenuated by indomethacin, N omega-nitro-L-arginine methyl ester (NAME), or methylene blue (MB). The effect of PGE2 was attenuated by NAME, while that of SNP was reversed by MB but not by indomethacin. TNF-alpha induced an increase in PGE2 and guanosine 3',5'-cyclic monophosphate cell content and in the NO release to the medium. NAME did not affect PGE2 production, while indomethacin blunted NO generation. Our results suggest that NO generation, secondary to PGE2 production, is responsible for the TNF-alpha-induced inhibition of PC synthesis by human type II pneumocytes.

Influence of cryopreservation on the sensitivity of human islets to tumor necrosis factor.

Tumor necrosis factor (TNF alpha) has been shown to inhibit insulin release and it has been postulated to-be an important effector in islet rejection. We studied the effect of cryopreservation on glucose oxidation rate (GOR), lipid synthesis, hormone secretion (insulin, glucagon, somatostatin, thyrotropin-releasing hormone), and cyclic guanosine 3',5'-monophosphate (cGMP) content of human islets, in the presence or absence of TNF alpha, looking for changes that could explain a different susceptibility to rejection for cryopreserved islets. Islets were isolated from multiple organ donor pancreata by collagenase digestion. The islets were then cultured for 7 days, cryopreserved (-0.25 degrees C/min), and stored in liquid N2. After 24 h of culture, thawed islets were cultured for an other 24 h in the presence or absence of TNF alpha. Islets were then washed to remove the cytokine and incubated in Krebs-Ringer bicarbonate (5 or 20 mM glucose), and both the cGMP content of the islets and the hormone concentration in the medium were determined by radio-immunoassay. GOR was measured as the production of 14CO2 from 5 or 20 mM D-[U-14C]glucose, and de novo lipid synthesis was determined as D-[U-14C]glucose incorporation into different lipidic fractions. Cryopreservation did not significantly modify the hormone response to glucose but it partially reversed the TNF alpha-induced inhibitory effect on insulin release in the presence of 20 mM glucose. In addition, the inhibitory effect of TNF alpha on phosphatidylcholine labeling was attenuated in cryopreserved islets compared with noncryopreserved islets. TNF alpha significantly stimulated islet nitrite production and cGMP accumulation, both effects being of a similar magnitude in cryopreserved and noncryopreserved islets. Our results suggest that cryopreservation can modify the metabolic and hormone response of human islets to TNF alpha. This effect is not mediated by changes in the TNF alpha-induced islet nitric oxide production or cGMP accumulation.

S-adenosylmethionine protects hepatocytes against the effects of cytokines.

Cytokines are thought to play an important role in the hepatocellular dysfunction that occurs during sepsis. Some cytokines have been shown to increase lipogenesis and to induce toxicity in isolated hepatocytes. Oxygen free radicals have been implicated as mediators of some cytokine effects. In this study we investigate a possible protection action of S-adenosyl-L-methionine against the toxic effects of cytokines on isolated hepatocytes. Isolated rat hepatocytes were precultured for 24 hr and then cultured for 1, 2, 3, 6, 12, or 24 hr in the presence or absence of S-adenosyl-L-methionine (12 micromol/l0) and/or either tumor necrosis factor (100, 200, or 500 ng/ml) or interleukin-1 (30, 60, or 120 IU/ml). Lactate dehydrogenase (media), and malondialdehyde, reduced glutathione, and the incorporation of D-[U- 14 C] glucose into different lipid fractions (cells) were determined. Both cytokines significantly increased hepatocyte malondialdehyde content, lactate dehydrogenase release, and triacylglycerol synthesis. None of these effects were observed in the presence of S-adenosyl--L-methionine. In addition, S-adenosyl-L-methionine was able to attenuate the decrease in phosphatidylcholine labeling also induced by both cytokines, and to prevent the increase in free fatty acid synthesis induced by tumor necrosis factor. Incubation in the presence of S-adenosyl-L-methionine also increased hepatocyte glutathione content (7.1 +/- 0.7, after 24 hr, vs 3.6 +/- 0.3 nmole/mg protein, P < 0.01), and prevented the decrease in glutathione induced by tumor necrosis factor (5.4 +/- 0.2 vs 2.1 +/- 0.1 nmole/mg protein, 100 ng/ml TNF alpha at 24 hr, P < 0.01). Our results show that S-adenosyl-L-methionine has a protective effect on hepatocytes against the in vitro effect of cytokines.