Pneumomediastinum and pneumothorax during emergency tracheotomy under spontaneous ventilation: Macklin meets Müeller? / Neumomediastino y neumotórax en la traqueotomía urgente en ventilación espontánea. Cuando Macklin encontró a Müeller

Potentially serious complications associated to emergency tracheotomy continue being a matter of concern. We review the pathogenesis of gas leakage in this setting and discuss about the possible mechanisms involved in its cause. We present two cases of pneumomediastinum, subcutaneous emphysema and pneumothorax in the context of emergency tracheotomy under spontaneous ventilation, finally resolved by chest drainage. The combination of overly negative pleural pressures due to extreme inspiratory efforts in the context of an almost completely obstructed airway together with over-pressurized alveoli because of gaseous entrapment secondary to serious expiratory obstruction appears to be the most plausible primary cause of air leaks in our patients. Understanding the underlying mechanisms evolved in its production will help clinicians to suspect and diagnose this phenomenon (AU)

Las complicaciones graves asociadas a la traqueotomía urgente continúan siendo un desafío clínico. En este trabajo revisamos y discutimos la fisiopatología de la fuga aérea en el contexto de la traqueotomía urgente. Presentamos dos casos de neumomediastino, enfisema subcutáneo y neumotórax en el curso de sendas traqueotomías urgentes realizadas sobre pacientes en ventilación espontánea que se resolvieron tras inserción de drenaje pleural. Nuestra conclusión es que la combinación de presiones pleurales inspiratorias muy negativas por el esfuerzo inspiratorio contra una vía aérea obstruida junto con la presencia de alveolos hiper-presurizados por el atrapamiento gaseoso espiratorio constituyen la base etiopatogénica del proceso. La comprensión de los mecanismos que subyacen en la generación del neumotórax y neumomediastino en este contexto facilitará que los clínicos sospechen y diagnostiquen el cuadro (AU)

Creatine and the Liver: Metabolism and Possible Interactions.

The process of creatine synthesis occurs in two steps, catalyzed by L-arginine:glycine amidinotransferase (AGAT) and guanidinoacetate N-methyltransferase (GAMT), which take place mainly in kidney and liver, respectively. This molecule plays an important energy/pH buffer function in tissues, and to guarantee the maintenance of its total body pool, the lost creatine must be replaced from diet or de novo synthesis. Creatine administration is known to decrease the consumption of Sadenosyl methionine and also reduce the homocysteine production in liver, diminishing fat accumulation and resulting in beneficial effects in fatty liver and non-alcoholic liver disease. Different studies have shown that creatine supplementation could supply brain energy, presenting neuroprotective effects against the encephalopathy induced by hyperammonemia in acute liver failure. Creatine is also taken by many athletes for its ergogenic properties. However, little is known about the adverse effects of creatine supplementation, which are barely described in the literature, with reports of mainly hypothetical effects arising from a small number of scientific publications. Antioxidant effects have been found in several studies, although one of the theories regarding the potential for toxicity from creatine supplementation is that it can increase oxidative stress and potentially form carcinogenic compounds.

Clinical management guidelines for subarachnoid haemorrhage. Diagnosis and treatment.

OBJECTIVE: To update the Spanish Society of Neurology's guidelines for subarachnoid haemorrhage diagnosis and treatment. MATERIAL AND METHODS: A review and analysis of the existing literature. Recommendations are given based on the level of evidence for each study reviewed. RESULTS: The most common cause of spontaneous subarachnoid haemorrhage (SAH) is cerebral aneurysm rupture. Its estimated incidence in Spain is 9/100 000 inhabitants/year with a relative frequency of approximately 5% of all strokes. Hypertension and smoking are the main risk factors. Stroke patients require treatment in a specialised centre. Admission to a stroke unit should be considered for SAH patients whose initial clinical condition is good (Grades I or II on the Hunt and Hess scale). We recommend early exclusion of aneurysms from the circulation. The diagnostic study of choice for SAH is brain CT (computed tomography) without contrast. If the test is negative and SAH is still suspected, a lumbar puncture should then be performed. The diagnostic tests recommended in order to determine the source of the haemorrhage are MRI (magnetic resonance imaging) and angiography. Doppler ultrasonography studies are very useful for diagnosing and monitoring vasospasm. Nimodipine is recommended for preventing delayed cerebral ischaemia. Blood pressure treatment and neurovascular intervention may be considered in treating refractory vasospasm. CONCLUSIONS: SAH is a severe and complex disease which must be managed in specialised centres by professionals with ample experience in relevant diagnostic and therapeutic processes.

Design and field-scale implementation of an "on site" bioremediation treatment in PAH-polluted soil.

An "on site" bioremediation program was designed and implemented in soil polluted with polycyclic aromatic hydrocarbons (PAHs), especially naphthalene. We began by characterizing the soil's physical and chemical properties. A microbiological screening corroborated the presence of microorganisms capable of metabolizing PAHs. We then analyzed the viability of bioremediation by developing laboratory microcosms and pilot scale studies, to optimize the costs and time associated with remediation. The treatment assays were based on different types of biostimulants, such as a slow or fast-release fertilizer, combined with commercial surfactants. Once the feasibility of the biostimulation was confirmed, a real-scale bioremediation program was undertaken in 900 m(3) of contaminated soil. The three-step design reduced PAH contamination by 94.4% at the end of treatment (161 days). The decrease in pollutants was concomitant with the selection of autochthonous bacteria capable of degrading PAHs, with Bacillus and Pseudomonas the most abundant genera.

Effects of 7-weeks competitive training period on physiological and mental condition of top level judoists.

AIM: We examined hormonal and haematological parameters and the profile of mood states (POMS) in top level judoists undertaking a 7-week competitive training period in a real contest. METHODS: Participants were 10 top level judoists belonging to the Spanish National Team. Training load was calculated by multiplying the training session intensity by the duration of the training session. The judoists competed in two official events on weeks 3 and 6 of the study. RESULTS: Urinary catecholamines increased at the end of the competitive period. Serum cortisol increased during the weeks in which judoists competed, confirming the existence of and anticipatory cortisol response to exercise; although we failed to find serum testosterone increases. Because of leukocyte values did not change, except monocytes, we speculate that the intensity of training was not sufficiently high to evoke injury to muscle tissue. Anger, tension, and fatigue increased according with training load, suggesting that the training exercise led participants into a negative psychological state. CONCLUSION: Findings indicate that during competitive periods, judoists suffer hormonal and mood changes according to training load and competitive events. Results support the usefulness of monitoring biological and psychological markers during season in order to adjust training loads and periods of recovery.

C282Y hemochromatosis gene mutation and iron parameters in dialysis patients.

BACKGROUND: Hereditary hemochromatosis is an autosomal recessive condition causing excessive intestinal iron absorption related to C282Y hemochromatosis mutation gene. Dialysis patients receive intravenous iron supplements as treatment for anemia. The gene mutation frequency and its influence on iron deposits and intravenous iron response are unknown in these patients. STUDY DESIGN: Prospective observational. SETTING AND PARTICIPANTS: 290 dialysis patients in Gran Canaria, Spain. OUTCOMES AND MEASUREMENTS: The C282Y hemochromatosis mutation gene was studied. Other active players in iron metabolism have not been included in this study. Red cell parameters, serum iron, transferrin and ferritin concentrations were measured every 2 months for 2 years. RESULTS: No differences in allelic and genotypic frequencies between dialysis patients and the general population were detected. Baseline clinical or analytical parameters were similar in C282Y +/- and C282Y -/- patients. Among those who did not need intravenous iron treatment, C282Y+/- patients maintained constant serum ferritin (302.1 ± 216.7 vs. 319.5 ± 300.5 µg/l after 4 months), whereas C282Y-/- patients showed decreased levels during the same period (306.7 ± 212.2 vs. 221.6 ± 167.8 µg/l, p < 0.001). After 4 months of parenteral iron, serum ferritin increased more intensely in C282Y +/- patients than in C282Y -/- patients (934.2 ± 195.8 vs. 658.7 ± 259.9 µg/l, p < 0.001). A multivariance analysis identified the C282Y allele as the most important factor that explains this difference. CONCLUSIONS: Heterozygosity for the C282Y allele of the hemochromatosis mutation gene could be associated with differences in iron parameters in dialysis patients.

Entrenamiento en técnicas de relajaciónen pacientes sometidos a cirugía urológica / No disponible

La mayoría de los pacientes sometidos a cirugía de próstata y vejiga en el posoperatorio son portadores de sonda vesical, que en algunasocasiones, produce espasmos vesicales. Éstos producen cierto grado de dolor y muchas veces la analgesia o los lavados manuales soninefectivos. Además tenemos que sumar el estrés que produce la hospitalización y el nuevo estado de salud. Dada la visión holística delos profesionales de enfermería, hemos entrenado y enseñado a nuestros pacientes técnicas sencillas de relajación y se ha conseguido disminuirel dolor percibido por el paciente (AU)

Most of patients under prostate and bladder surgery at post-intervention are carrying vesicle catheter, which sometimes produces vesicalspasms. Those produce certain grade of pain and frequently, anaesthesic products or manual washouts are ineffective.Furthermore, we have to add stress produced by hospitalization and new health status. Given the holistic vision of nursing staff, we havetrained and taught our patients some relaxation techniques, and reduction on self-related pain was achieved (AU)

Evaluation of the potential protective effects of ad libitum black grape juice against liver oxidative damage in whole-body acute X-irradiated rats.

AIMS: The aim of this study was to evaluate the potential protective effects of ad libitum black grape (Vitis labrusca) juice against liver oxidative damage in whole-body acute X-irradiated rats. MAIN METHODS: Animals were fed ad libitum and drank voluntarily black grape juice or placebo (isocaloric glucose and fructose solution) for 6 days before and 15 days following a 6 Gy X-irradiation from a 200 kV machine. KEY FINDINGS: Irradiated animals receiving placebo showed a significant increase in the concentration of thiobarbituric acid-reactive substances (TBARS), a marker of lipid peroxidation, as well as a significant decrease in both Cu/Zn superoxide dismutase (Cu/ZnSOD) and glutathione peroxidase (GPx) activity and reduced glutathione concentration (GSH). Black grape juice supplementation resulted in a reversal of lipid peroxidation, Cu/ZnSOD activity, and GSH concentration, towards values not significantly differing from those in non-irradiated, placebo-supplemented rats. Poly(ADP-ribose) polymerase (PARP-1) and Cu/ZnSOD changes in protein expression were observed for irradiated rats. No change in p53 expression or DNA fragmentation was found. SIGNIFICANCE: Ad libitum black grape juice intake is able to restore the liver primary antioxidant system against adverse effects due to whole-body acute X-irradiation in rats after 15 days post-irradiation. The results support using antioxidant supplements as a preventive tool against radiation-induced harm.

Multimodal BCI-mediated FES suppression of pathological tremor.

Tremor constitutes the most common movement disorder; in fact 14.5% of population between 50 to 89 years old suffers from it. Moreover, 65% of patients with upper limb tremor report disability when performing their activities of daily living (ADL). Unfortunately, 25% of patients do not respond to drugs or neurosurgery. In this regard, TREMOR project proposes functional compensation of upper limb tremors with a soft wearable robot that applies biomechanical loads through functional electrical stimulation (FES) of muscles. This wearable robot is driven by a Brain Neural Computer Interface (BNCI). This paper presents a multimodal BCI to assess generation, transmission and execution of both volitional and tremorous movements based on electroencephalography (EEG), electromyography (EMG) and inertial sensors (IMUs). These signals are combined to obtain: 1) the intention to perform a voluntary movement from cortical activity (EEG), 2) tremor onset, and an estimation of tremor frequency from muscle activation (EMG), and 3) instantaneous tremor amplitude and frequency from kinematic measurements (IMUs). Integration of this information will provide control signals to drive the FES-based wearable robot.

Una experiencia de acompañamiento con doula a adolescentes en trabajo de parto / Doula support during labor: experience in a sample of pregnant teenagers

Objetivo: Comparar la percepción del dolor-temor durante el trabajo de parto y parto, y el grado de dificultad-satisfacción con la experiencia de parto, en un grupo de adolescentes acompañadas por doula y otro con atención habitual. Método: El grupo estudio comprendió 80 adolescentes del "Programa Emprende Mamá" que controlaron sus embarazos en centros de salud de la comuna de La Florida y con parto en el hospital Dr. Sótero del Río, acompañadas por una mujer familiar o amiga, elegida por la joven, con capacitación previa de 2 horas. El grupo control estuvo formado por 80 adolescentes no participantes del programa, que controlaron sus embarazos en los mismos centros de salud, con parto en el mismo período. Resultados: El grupo estudio refirió menor percepción de dolor durante el trabajo de parto y parto, menor temor durante el parto y lo percibió como más fácil. No se encontraron diferencias significativas en el nivel de satisfacción respecto de la experiencia total. Sin embargo, las adolescentes con doula señalaron estar satisfechas por aspectos positivos de la vivencia, mientras que el grupo control centra su satisfacción en la ausencia de expectativas negativas temidas. Conclusión: El acompañamiento por doula en el parto de la embarazada adolescente, es una intervención de bajo costo que permite mejorar cualitativamente su vivencia de parto.

Objective: To compare the effects of continuous doula support and standard hospital care on pain and fear perception, during labor and delivery, as well as perception of difficulty and satisfaction with the birth experience, in a sample of pregnant teenagers. Method: The study group was conformed by eighty pregnant teenagers participants in "Emprende Mama Program" attended in the outpatient clinics of La Florida county for their prenatal care and delivery at a public hospital. They received emotional support during labor by a 2 hour trained female relative or friend, previously chosen by them. The control group was conformed by eighty non participants teenagers attended at the same outpatient clinics and delivery in the same period. Results: Teenagers with doula support reported less pain and fear during labor and delivery and perceived their birth experience as less difficult. No significant differences were reported in relation to satisfaction with birth experience. Although teenagers with doula support reported satisfaction due to positive aspects with birth experience, meanwhile the control group felt mostly satisfied due the absence of negative feared expectations. Conclusion: Labor support given by doula, is a low cost intervention which improves quality perception of birth experience in the adolescent pregnant.

El ictus en el siglo XXI. Tratamiento de urgencia / Stroke in the XXI Century. Emergency care

La enfermedad vascular, una verdadera epidemia, es la primera causa de muerte en los países desarrollados, responsable de más de una cuarta parte de las muertes documentadas a nivel mundial y la primera causa de discapacidad grave en el adulto. Las tres cuartas partes de los ictus afectan a pacientes mayores de 65 años, y debido a las previsiones de población en las que España será en el 2050 de las poblaciones más envejecidas del mundo, se prevé un incremento de la incidencia de esta patología en los próximos años. Numerosos estudios describen el escaso conocimiento de la población, sobre los signos y síntomas de presentación del ictus. Se recomienda elaborar campañas informativas orientadas a la población general para aumentar su conocimiento sobre los factores de riesgo, facilitar la identificación de los signos y síntomas de alarma y fomentar entre los pacientes el concepto del ictus como urgencia neurológica. El Código Ictus permite un rápido proceso de identificación, notificación y traslado de los pacientes a los servicios de urgencia hospitalarios. Los avances tecnológicos en el diagnóstico y la aparición de medidas terapéuticas eficaces, trombolíticos, hacen necesaria la organización coordinada y multidisciplinar. La Unidad de Ictus es la aproximación más eficaz y eficiente en el manejo de la fase aguda del ictus isquémico o hemorrágico. Los progresos en la investigación permitirán disponer de nuevas y mejores oportunidades para el tratamiento agudo del ictus (AU)

Cerebrovascular diseases have reached epidemic proportions worldwide. They are the major cause of mortality in developed countries, accounting for over one-quarter of worldwide documented deaths, and the leading cause of severe disability in adults. Given that Spain will become one of the countries most affected by population ageing, an increase in the incidence of these diseases is expected in coming years. Several studies have reported that public levels of awareness of stroke warning signs, symptoms and risk factors are relatively low. Information campaigns aimed at increasing these levels of awareness and considering stroke as a neurological emergency are needed. The stroke code is a system which allows rapid identification, notification, and transfer of stroke patients to the emergency units. Technological advances in stroke diagnosis, and the development of effective therapeutic measures, such as thrombolytics, require a coordinated multidisciplinary approach. Treating patients in Stroke Units is the most effective and efficient approach in acute ischemic or hemorrhagic stroke management. In coming years research advances will provide new and better strategies in acute stroke treatment (AU)

[Effects of glutamine on antioxidants systems and hepatic detoxification in rats: influence of formulation]. / Influencia de la formulación de la glutamina en sus efectos sobre los sistemas antioxidantes y de destoxificación hepática en la rata.

GOALS: The goal of this study is to assess the effect that supplementing parenteral diets with L-glutamine or with L-alanyl-L-glutamine has on the balance of oxidants/antioxidants in the liver and on detoxification systems mediated by P-450 cytochrome in rats. MATERIAL AND METHODS: Central catheters were inserted in the animals (n = 60) and they were randomly assigned to one of the following groups: a control group (C) with oral feeding and I.V. infusion of saline solution, a total parenteral nutrition group without glutamine (TPN without GLN), a parenteral nutrition group with glutamine supplement (TPN GLN), and a total parenteral nutrition group with a supplement of alanine-glutamine dipeptide (20 g/L) (TPN ALA-GLN). The parenteral nutrition provided was all isocaloric and isonitrogenated, and the infusions were administered at a speed of 2 ml/h over 5 days. RESULTS: In the animals of the group without GLN, the liver concentration of glutathione was reduced while the levels of thiobarbituric acid reaction products (TBARS) increased. Supplementing with either glutamine or alanine-glutamine normalized the levels of glutathione but the TBARS levels only fell in the group with the dipeptide. This effect was parallel to the partial recovery of the antioxidant enzyme activities analyzed. The liver concentrations of P-450 cytochrome, P-450 cytochrome dependent mono-oxygenases and the clearance of antipyrine were not modified by the supplements of glutamine or alanine-glutamine. CONCLUSIONS: Our data suggest a greater protection by alanine-glutamine supplements against the injury produced by free radicals during TPN and the absence of any effect with either glutamine or alanine-glutamine supplements on the oxidative metabolism of the liver.

Influencia de la formulación de la glutamina en sus efectos sobre los sistemas antioxidantes y de destoxificación hepática en la rata / Effects of glutamine on antioxidants systems and hepatic detoxification in rats: influence of formulation

Objetivos: El objeto de este estudio es valorar el efecto que la suplementación de dietas parenterales con L-glutamina o con L-alanil-L-glutamina ejerce sobre el equilibrio oxidante/antioxidante hepático y sobre los sistemas de destoxificación mediados por el citocromo P-450 en ratas. Material y métodos: Los animales (n = 60) se cateterizaron centralmente y se asignaron aleatoriamente a uno de los siguientes grupos: grupo control con alimentación oral e infusión i.v. de solución salina (C), grupo de nutrición parenteral total sin glutamina (NPT sin GLN), grupo de nutrición parenteral suplementada con glutamina (NPT GLN) y grupo de nutrición parenteral total suplementada con dipéptido alanina-glutamina (20 g/L) (NPT ALA-GLN). Las nutriciones parenterales eran isocalóricas e isonitrogenadas y las infusiones se administraron a una velocidad de infusión de 2 ml/h durante 5 días. Resultados: En los animales del grupo sin GLN disminuyó la concentración hepática de glutatión y los niveles de los productos de reacción del ácido tiobarbitúrico (TBARS) se incrementaron. Tanto la suplementación con glutamina como con alanina-glutamina normalizaron los niveles de glutatión pero sólo en el grupo del dipéptido disminuyeron los niveles de TBARS. Este efecto era paralelo a la recuperación parcial de las actividades enzimáticas antioxidantes analizadas. La concentración hepática del citocromo P-450, de las monooxigenasas dependientes del citocromo P-450 y el aclaramiento de antipirina no se modificaron por la suplementación de glutamina o de alanina-glutamina. Conclusiones: Nuestros datos sugieren una mayor protección de la suplementación con alanina-glutamina contra el daño producido por radicales libres durante la NPT y una ausencia de efectos tanto de la suplementación con glutamina como con alanina-glutamina sobre el metabolismo oxidativo hepático(AU)

Goals: The goal of this study is to assess the effect that supplementing parenteral diets with L-glutamine or with L-alanyl-L-glutamine has on the balance of oxidants/antioxidants in the liver and on detoxification systems mediated by P-450 cytochrome in rats. Material and methods: Central catheters were inserted in the animals (n = 60) and they were randomly assigned to one of the following groups: a control group (C) with oral feeding and I.V. infusion of saline solution, a total parenteral nutrition group without glutamine (TPN without GLN), a parenteral nutrition group with glutamine supplement (TPN GLN), and a total parenteral nutrition group with a supplement of alanine-gluta-mine dipeptide (20 g/L) (TPN ALA-GLN). The parenteral nutrition provided was all isocaloric and isonitrogenated, and the infusions were administered at a speed of 2 ml/h over 5 days. Results: In the animals of the group without GLN, the liver concentration of glutathione was reduced while the levels of thiobarbituric acid reaction products (TBARS) increased. Supplementing with either glutamine or ala-nine-glutamine normalized the levels of glutathione but the TBARS levels only fell in the group with the dipeptide. This effect was parallel to the partial recovery of the antioxidant enzyme activities analyzed. The liver concentrations of P-450 cytochrome, P-450 cytochrome dependent mono-oxygenases and the clearance of antipyrine were not modified by the supplements of glutamine or alanine-glutamine. Conclusions: Our data suggest a greater protection by alanine-glutamine supplements against the injury produced by free radicals during TPN and the absence of any effect with either glutamine or alanine-gluta-mine supplements on the oxidative metabolism of the liver (AU)

[Glycine: a cell-protecting anti-oxidant nutrient]. / La glicina: un nutriente antioxidante protector celular.

For many researchers it is still difficult to accept that beneficial effects can be obtained in several disease states with the simplest amino acid, glycine. However, evidence is mounting in favour of this idea. It is now clear that dietary glycine protects against shock caused either by blood loss or endotoxin, reduces alcohol levels in the stomach and improves recovery from alcoholic hepatitis, diminishes liver injury caused by hepatotoxic drugs and blocks programmed cell death and reduces the nephrotoxicity caused by the drug cyclosporin A in the kidney, preventing hypoxia and free radical formation. It could be also useful in other inflammatory diseases since it diminishes cytokines production. We review some of the beneficial effects of glycine and their responsible mechanism, which could led to advice its use in the therapy of different diseases.

Dietary glycine inhibits activation of nuclear factor kappa B and prevents liver injury in hemorrhagic shock in the rat.

We investigated the effects of a glycine-containing diet (5%) on liver injury caused by hemorrhagic shock and resuscitation in rats. Anesthetized rats were bled to a mean arterial blood pressure of 35-40 mm Hg for 1 h and then resuscitated with 60% of shed blood and lactated Ringer's solution. Feeding the rats glycine significantly reduced mortality, the elevation of plasma transaminase levels and hepatic necrosis. The increase in plasma TNFalpha and nitric oxide (NO) was also blunted by glycine feeding. Hemorrhagic shock resulted in oxidative stress (significant elevations in TBARS and in the oxidized/reduced glutathione ratio) and was accompanied by a reduced activity of the antioxidant enzymes Mn- and Cu,Zn-superoxide dismutase, glutathione peroxidase and catalase, overexpression of inducible NO synthase (iNOS), and activation of nuclear factor kappa B (NF-kappaB). Glycine ameliorated oxidative stress and the impairment in antioxidant enzyme activities, inhibited NF-kappaB activation, and prevented expression of iNOS. Dietary glycine blocks activation of different mediators involved in the pathophysiology of liver injury after shock.

Dietary fats affect rat plasma lipoprotein secondary structure as assessed by Fourier transform infrared spectroscopy.

This investigation was undertaken to determine by Fourier transform infrared spectroscopy the effects of diets enriched with fish, sunflower or olive oils on the secondary structure of plasma HDL and LDL from rats, as well as the effects on lipid unsaturation and acyl chain lengths. Controls were fed a commercial diet. In HDL, random coil conformation was relatively high in rats fed the fish diet, probably due to the irregular geometry of polyunsaturated fatty acids interacting with apoproteins. Parallel structural behaviors were observed for rats fed control and olive oil diets. The lowest lipid unsaturation level was found in HDL of rats fed olive oil, and acyl chain lengths were slightly increased by the three fats. Rats fed olive oil had the lowest percentage of LDL beta-sheets and these were more abundant in rats fed the fish oil diet. The least lipid unsaturation in LDL was in rats fed the olive oil diet. No significant differences in acyl chain lengths were observed. Certain protein conformational changes and/or apoprotein composition differences due to dietary fat may affect the binding between lipoproteins and their receptors in cells.

Effects of parenteral nutrition supplemented with glutamine or glutamine dipeptides on liver antioxidant and detoxication systems in rats.

Our aim was to determine the effects of glutamine or alanyl glutamine parenteral supplementation on the liver oxidant/antioxidant balance and on cytochrome-P450-mediated detoxication in rats. Animals were infused for 5 d with standard total parenteral nutrition (TPN), glutamine-enriched TPN, or alanyl glutamine-enriched TPN. The hepatic concentration of glutathione was reduced, and the levels of thiobarbituric-acid-reactive substances (TBARS) were increased in animals receiving standard TPN. Both glutamine and alanyl glutamine supplementation normalized glutathione, but thiobarbituric-acid-reactive substance concentration was only decreased by ananyl glutamine. This effect was parallel to a partial recovery of the activity of antioxidant enzymes. Cytochrome-P450 liver content, cytochrome-P450-dependent monooxygenases, and antipyrine clearance were not modified by glutamine or alanyl glutamine. Our data suggest a better protection against free radicals by alanyl glutamine supplementation and an absence of effects of both glutamine and alanyl glutamine on liver oxidative metabolism.