Evaluation of Increasing Dietary Concentrations of a Multi-Enzyme Complex in Feedlot Lambs' Rations.

The objective of this study was to evaluate the effects of increasing levels of the M-E complex (xylanase, glucanase, cellulase, and invertase) Optimax E® on the performance of growing lambs, their digestibility, and their rumen microbiota, and to estimate NEm, NEg, and ruminal methane levels. Forty lambs (Katahdin x Dorset; 22.91 ± 4.16 kg) were randomly assigned to dietary concentrations of ME (0, 0.2, 0.4, and 0.8% DM) and fed individually for 77 days. Increasing M-E improved feed conversion (p < 0.05) as well as NEm and NEg (p < 0.05), which were associated with increased in vivo DM and NDF digestion (linear and quadratic p < 0.01). Few microbial families showed abundancy changes (Erysipelotrichaceae, Christensenellaceae, Lentisphaerae, and Clostridial Family XIII); however, the dominant phylum Bacteroidetes was linearly reduced, while Firmicutes increased (p < 0.01), resulting in a greater Firmicutes-to-Bacteroidetes ratio. Total Entodinium showed a quadratic response (p < 0.10), increasing its abundancy as the enzyme dose was augmented. The daily emission intensity of methane (per kg of DMI or AGD) was reduced linearly (p < 0.01). In conclusion, adding the M-E complex Optimax E® to growing lambs' diets improves their productive performance by acting synergistically with the rumen microbiota, modifying the Firmicutes-to-Bacteroidetes ratio toward more efficient fermentation, and shows the potential to reduce the intensity of greenhouse gas emissions from lambs.

Influence of a Polyherbal Choline Source in Dogs: Body Weight Changes, Blood Metabolites, and Gene Expression.

Choline chloride is used to provide choline in dog foods; however, in other domestic species, it has been replaced with a polyherbal containing phosphatidylcholine. A polyherbal containing Achyrantes aspera, Trachyspermum ammi, Citrullus colocynthis, Andrographis paniculata, and Azadirachta indica was evaluated in adult dogs through body weight changes, subcutaneous fat thickness, blood metabolites, and gene expression. Forty dogs (4.6 ± 1.6 years old) who were individually housed in concrete kennels were randomly assigned to the following treatments: unsupplemented diet (377 mg choline/kg), choline chloride (3850 mg/kg equivalent to 2000 mg choline/kg diet), and polyherbal (200, 400, and 800 mg/kg) for 60 days. Blood samples were collected on day 59 for biochemistry, biometry, and gene expression analysis through microarray assays. Intake, final body weight, and weight changes were similar for the two choline sources. Feed intake variation among dogs (p = 0.01) and dorsal fat (p = 0.03) showed a quadratic response to herbal choline. Dogs that received the polyherbal diet had reduced blood cholesterol levels (Quadratic, p = 0.02). The gene ontology analysis indicated that 15 biological processes were modified (p ≤ 0.05) with implications for preventing cardiovascular and metabolic diseases, cancer prevention, inflammatory and immune response, and behavior and cognitive process. According to these results that were observed in a 60 day trial, the polyherbal form could replace choline chloride in dog diets at a concentration of 400 mg/kg.

Exposure to Sub-Lethal Doses of Permethrin Is Associated with Neurotoxicity: Changes in Bioenergetics, Redox Markers, Neuroinflammation and Morphology.

Permethrin (PERM) is a member of the class I family of synthetic pyrethroids. Human use has shown that it affects different systems, with wide health dysfunctions. Our aim was to determine bioenergetics, neuroinflammation and morphology changes, as redox markers after subacute exposure to PERM in rats. We used MDA determination, protein carbonyl assay, mitochondrial O2 consumption, expression of pro-inflammatory cytokines and a deep histopathological analysis of the hippocampus. PERM (150 mg/kg and 300 mg/kg body weight/day, o.v.) increased lipoperoxidation and carbonylated proteins in a dose-dependent manner in the brain regions. The activities of antioxidant enzymes glutathione peroxidase, reductase, S-transferase, catalase, and superoxide dismutase showed an increase in all the different brain areas, with dose-dependent effects in the cerebellum. Cytokine profiles (IL-1ß, IL-6 and TNF-α) increased in a dose-dependent manner in different brain tissues. Exposure to 150 mg/kg of permethrin induced degenerated and/or dead neurons in the rat hippocampus and induced mitochondrial uncoupling and reduction of oxidative phosphorylation and significantly decreased the respiratory parameters state 3-associated respiration in complex I and II. PERM exposure at low doses induces reactive oxygen species production and imbalance in the enzymatic antioxidant system, increases gene expression of pro-inflammatory interleukins, and could lead to cell damage mediated by mitochondrial functional impairment.

Manejo de la Cetoacidosis Diabética en un hospital universitario de Montevideo en el período Junio - Setiembre de 2015

Resumen: Introducción: La cetoacidosis diabética es una complicación aguda frecuente y seria de la diabetes mellitus, suponiendo 5% de su mortalidad. Existe evidencia internacional que la adherencia a las guías de tratamiento de la cetoacidosis diabética, disminuye su morbimortalidad y que no existe un cumplimiento riguroso de dichas guías. El objetivo del trabajo fue evaluar la adecuación a las pautas de tratamiento de la cetoacidosis diabética de la American Diabetes Association, en la puerta de emergencia. Metodología: Se realizó un estudio observacional descriptivo del tratamiento realizado en la emergencia de un Hospital universitario de Montevideo a los pacientes con diagnóstico de cetoacidosis diabética, entre junio y setiembre de 2015. Se comparó la terapéutica aplicada con el protocolo de manejo propuesto por la American Diabetes Association en 2009. Resultados: Un total de 17 casos fueron incluidos en el análisis. El diagnóstico fue correcto en 9 pacientes, el tratamiento en la primera hora fue completo en 7 pacientes y la monitorización paraclínica en las primeras 6 horas fue completa en 3 pacientes. Conclusión: Se evidenció adecuación aceptable a las guías en la mayoría de los casos.

Abstract: Introduction: Diabetic ketoacidosis is a frequent and serious acute complication of diabetes mellitus, accounting for 5% of its mortality. There is international evidence that adherence to the treatment guidelines for diabetic ketoacidosis decreases its morbidity and mortality and that there is no rigorous compliance with these guidelines. The objective of the study was to evaluate the adequacy of the diabetic ketoacidosis treatment guidelines of the American Diabetes Association, at the emergency door. Methodology: A descriptive observational study was carried out on the treatment carried out in the emergency room of a Montevideo university hospital for patients diagnosed with diabetic ketoacidosis, between June and September 2015. The applied therapy was compared with the management protocol proposed by the American Diabetes Association in 2009. Results: A total of 17 cases were included in the analysis. The diagnosis was correct in 9 patients, the treatment in the first hour was complete in 7 patients and the paraclinical monitoring in the first 6 hours was complete in 3 patients. Conclusion: Acceptable adequacy to the guidelines was evidenced in most cases.

Resumo: Introdução: A cetoacidose diabética é uma complicação aguda frequente e grave do diabetes mellitus, sendo responsável por 5% de sua mortalidade. Há evidências internacionais de que a adesão às diretrizes de tratamento para cetoacidose diabética diminui sua morbidade e mortalidade e que não há conformidade rigorosa com essas diretrizes. O objetivo do estudo foi avaliar a adequação das diretrizes de tratamento da cetoacidose diabética da American Diabetes Association, na porta de emergência. Metodologia: Foi realizado um estudo observacional descritivo sobre o tratamento realizado no pronto-socorro de um hospital universitário de Montevidéu para pacientes com diagnóstico de cetoacidose diabética, entre junho e setembro de 2015. A terapia aplicada foi comparada com o protocolo de manejo proposto pela American Diabetes Association em 2009. Resultados: Um total de 17 casos foram incluídos na análise. O diagnóstico foi correto em 9 pacientes, o tratamento na primeira hora foi completo em 7 pacientes e o monitoramento paraclínico nas primeiras 6 horas foi completo em 3 pacientes. Conclusão: A adequação aceitável às diretrizes foi evidenciada na maioria dos casos.

Composition, Structure, and PGPR Traits of the Rhizospheric Bacterial Communities Associated With Wild and Cultivated Echinocactus platyacanthus and Neobuxbaumia polylopha.

The Queretaro semi-desert in central Mexico is the most southern extension of the Chihuahua desert. This semi-arid zone shelters a vast cactus diversity with many endemic species. Currently, two cacti species from this semi-desert namely, Echinocactus platyacanthus and Neobuxbaumia polylopha are under a threat to their survival. So far, there are no reports on the bacterial communities associated with these plants. In this study, we assessed the structure and diversity of the rhizospheric bacterial communities associated with Echinocactus platyacanthus and Neobuxbaumia polylopha growing in wild and cultivated conditions. Samples of E. platyacanthus were also approached with culture-based methods in search of isolates with plant growth promoting abilities. Metagenomic DNA was extracted from rhizospheric samples and used for Illumina sequencing of the 16S rRNA gene. α-diversity and amplicon sequence variant (ASV) richness were higher in both groups of E. platyacanthus samples. All samples accounted for 14 phyla, and the major 6 were common to all treatments. The dominant phyla in all four sample groups were Actinobacteria and Proteobacteria. Analysis at family and genus levels showed association patterns with the cultivated samples from both species grouping together, while the wild samples of each cactus species were grouping apart. High abundance values of Rubrobacteraceae (15.9-18.4%) were a characteristic feature of wild E. platyacanthus samples. In total, 2,227 ASVs were scored in all 12 rhizospheric samples where E. platyacanthus samples showed higher richness with 1,536 ASVs. Regarding the growing conditions, both groups of cultivated samples were also richer accounting for 743 and 615 ASVs for E. platyacanthus and N. polylopha, respectively. The isolates from E. platyacanthus rhizosphere were mainly assigned to Bacilli and Gammaproteobacteria. In total 35 strains were assayed for PGPR traits (IAA and siderophore production, phosphate solubilization, and fungal growth inhibition). Strains obtained from plants growing in the wild displayed better PGPR characteristics, stressing that naturally occurring wild plants are a source of bacteria with diverse metabolic activities, which can be very important players in the adaptation of cacti to their natural environments.

Dose-Dependent Behavioral and Antioxidant Effects of Quercetin and Methanolic and Acetonic Extracts from Heterotheca inuloides on Several Rat Tissues following Kainic Acid-Induced Status Epilepticus.

Kainic acid (KA) has been used to study the neurotoxicity induced after status epilepticus (SE) due to activation of excitatory amino acids with neuronal damage. Medicinal plants can protect against damage caused by KA-induced SE; in particular, organic extracts of Heterotheca inuloides and its metabolite quercetin display antioxidant activity and act as hepatoprotective agents. However, it is unknown whether these properties can protect against the hyperexcitability underlying the damage caused by KA-induced SE. Our aim was to study the protective effects (with regard to behavior and antioxidant activity) of administration of natural products methanolic (ME) and acetonic (AE) extracts and quercetin (Q) from H. inuloides at doses of 30 mg/kg (ME30, AE30, and Q30 groups), 100 mg/kg (ME100, AE100, and Q100 groups), and 300 mg/kg (ME300, AE300, and Q300 groups) against damage in brain regions of male Wistar rats treated with KA. We found dose-dependent effects on behavioral and biochemical studies in the all-natural product groups vs. the control group, with decreases in seizure severity (Racine's scale) and increases in seizure latency (p < 0.05 in the ME100, AE100, Q100, and Q300 groups and p < 0.01 in the AE300 and ME300 groups); on lipid peroxidation and carbonylated proteins in all brain tissues (p < 0.0001); and on GPx, GR, CAT, and SOD activities with all the treatments vs. KA (p ≤ 0.001). In addition, there were strong negative correlations between carbonyl levels and latency in the group treated with KA and in the group treated with methanolic extract in the presence of KA (r = -0.9919, p = 0.0084). This evidence suggests that organic extracts and quercetin from H. inuloides exert anticonvulsant effects via direct scavenging of reactive oxygen species (ROS) and modulation of antioxidant enzyme activity.

Static Magnetic Fields Modulate the Response of Different Oxidative Stress Markers in a Restraint Stress Model Animal.

Stress is a state of vulnerable homeostasis that alters the physiological and behavioral responses. Stress induces oxidative damage in several organs including the brain, liver, kidney, stomach, and heart. Preliminary findings suggested that the magnetic stimulation could accelerate the healing processes and has been an effective complementary therapy in different pathologies. However, the mechanism of action of static magnetic fields (SMFs) is not well understood. In this study, we demonstrated the effects of static magnetic fields (0.8 mT) in a restraint stressed animal model, focusing on changes in different markers of oxidative damage. A significant increase in the plasma levels of nitric oxide (NO), malondialdehyde (MDA), and advanced oxidation protein products (AOPP), and a decrease in superoxide dismutase (SOD), glutathione (GSH), and glycation end products (AGEs) were observed in restraint stress model. Exposure to SMFs over 5 days (30, 60, and 240 min/day) caused a decrease in the NO, MDA, AGEs, and AOPP levels; in contrast, the SOD and GSH levels increased. The response to SMFs was time-dependent. Thus, we proposed that exposure to weak-intensity SMFs could offer a complementary therapy by attenuating oxidative stress. Our results provided a new perspective in health studies, particularly in the context of oxidative stress.

Documentación filmográfica de la ventilación mecánica en un modelo animal / Filmed documentation of mechanical ventilation in an animal model

Introducción: el aprendizaje de la ventilación mecánica (VM) pediátrica requiere de tiempo y diversas estrategias educativas. En los últimos años se han utilizado los videopodcast para la educación médica. Objetivos: documentación filmográfica de los elementos básicos de la mecánica respiratoria durante la VM en un modelo animal. Creación de un videopodcast para la formación de recursos humanos especializados en VM pediátrica. Metodología: se prepararon diferentes secuencias de VM con ventilador y en forma manual. Se realizó exposición pulmonar mediante toracotomía y VM convencional en un cerdo. Se grabó simultáneamente lo monitorizado por el ventilador y la visualización in vivo del pulmón expuesto ante cada secuencia. Dos especialistas en cuidados intensivos pediátricos analizaron durante la edición las grabaciones y confeccionaron un guión explicativo de lo observado. Resultados: se editó un video con las diferentes secuencias previstas: VM basal, VM sin presión positiva teleespiratoria (PEEP), VM con niveles incrementales de PEEP, VM con bolsa autoinflable, aspiración de sonda endotraqueal con circuito cerrado y abierto durante VM con ventilador y manual con operador. Se editó un videopodcast con leyendas explicativas. Discusión: la utilización de recursos digitales para la enseñanza y divulgación de diversas especialidades médicas es cada vez más frecuente. El videopodcast se ha expandido como una nueva herramienta educativa. Se construyó un modelo para la capacitación de los recursos humanos en VM mediante este formato. La experiencia servirá para construir una videoteca universitaria dirigida a la enseñanza de cuidados críticos del niño y para la divulgación de experimentos biomédicos.

Introduction: learning about mechanical ventilation (MV) in pediatrics requires time and several educational strategies. In recent years, videopodcast has been used for medical training. Objectives: to prepare a filmed documentary of the basic elements in respiratory mechanics during MV in an animal model. To create a videopodcast to train human resources specialized in MV in pediatrics. Material: different sequences of MV with ventilator and manual ventilation were prepared. Lungs were accessed through thoracotomy and MV was started in a pig. Monitored data from the ventilator was simultaneously recorded, the same as the live visualization of the visible lung for each sequence. Two specialists in pediatrics intensive care analysed the recording while it was edited and composed a script explaining what was observed. Results: a video was edited with the different sequences expected: basal MV, MV with zero PEEP, increasing PEEP levels, MV with self-inflating bag, traqueal suction with open and closed traqueal suction systems and manual ventilation with an operator. A videopodcast with explanatory subtitles was edited. Discussion: digital resources are increasingly being used to train physicians and disseminate several medical techniques. Today, videopodcast constitutes a new educational tool. A model was designed to train human resources in MV under this format. This experience will be used to build up a new university video library to assist the training in pediatric critical care and to disseminate biomedical experiments.

Sleep loss as a factor to induce cellular and molecular inflammatory variations.

A reduction in the amount of time spent sleeping occurs chronically in modern society. Clinical and experimental studies in humans and animal models have shown that immune function is impaired when sleep loss is experienced. Sleep loss exerts a strong regulatory influence on peripheral levels of inflammatory mediators of the immune response. An increasing number of research projects support the existence of reciprocal regulation between sleep and low-intensity inflammatory response. Recent studies show that sleep deficient humans and rodents exhibit a proinflammatory component; therefore, sleep loss is considered as a risk factor for developing cardiovascular, metabolic, and neurodegenerative diseases (e.g., diabetes, Alzheimer's disease, and multiple sclerosis). Circulating levels of proinflammatory mediators depend on the intensity and duration of the method employed to induce sleep loss. Recognizing the fact that the concentration of proinflammatory mediators is different between acute and chronic sleep-loss may expand the understanding of the relationship between sleep and the immune response. The aim of this review is to integrate data from recent published reports (2002-2013) on the effects of sleep loss on the immune response. This review may allow readers to have an integrated view of the mechanisms involved in central and peripheral deficits induced by sleep loss.

Effect of selective serotonin reuptake inhibitors and immunomodulator on cytokines levels: an alternative therapy for patients with major depressive disorder.

Major depressive disorder (MDD) is a psychiatric illness that presents as a deficit of serotonergic neurotransmission in the central nervous system. MDD patients also experience alterations in cortisol and cytokines levels. Treatment with selective serotonin reuptake inhibitors (SSRIs) is the first-line antidepressant regimen for MDD. The aim of this study was to determine the effect of a combination of SSRIs and an immunomodulator-human dialyzable leukocyte extract (hDLE)-on cortisol and cytokines levels. Patients received SSRIs or SSRIs plus hDLE. The proinflammatory cytokines IL-1 ß , IL-2, and IFN- γ ; anti-inflammatory cytokines IL-13 and IL-10; and 24-h urine cortisol were measured at weeks (W) 0, 5, 20, 36, and 52 of treatment. The reduction in cortisol levels in the SSRI-treated group was 30% until W52, in contrast, the combined treatment induced a 54% decrease at W36. The decline in cortisol in patients who were treated with SSRI plus hDLE correlated with reduction of anti-inflammatory cytokines and increases levels of proinflammatory cytokines at the study conclusion. These results suggest that the immune-stimulating activity of hDLE, in combination with SSRIs, restored the pro- and anti-inflammatory cytokine balance and cortisol levels in depressed patients versus those who were given SSRIs alone.

Chronic deep brain stimulation of the hypothalamic nucleus in wistar rats alters circulatory levels of corticosterone and proinflammatory cytokines.

Deep brain stimulation (DBS) is a therapeutic option for several diseases, but its effects on HPA axis activity and systemic inflammation are unknown. This study aimed to detect circulatory variations of corticosterone and cytokines levels in Wistar rats, after 21 days of DBS-at the ventrolateral part of the ventromedial hypothalamic nucleus (VMHvl), unilateral cervical vagotomy (UCVgX), or UCVgX plus DBS. We included the respective control (C) and sham (S) groups (n = 6 rats per group). DBS treated rats had higher levels of TNF-α (120%; P < 0.01) and IFN-γ (305%; P < 0.001) but lower corticosterone concentration (48%; P < 0.001) than C and S. UCVgX animals showed increased corticosterone levels (154%; P < 0.001) versus C and S. UCVgX plus DBS increased IL-1ß (402%; P < 0.001), IL-6 (160%; P < 0.001), and corsticosterone (178%; P < 0.001 versus 48%; P < 0.001) compared with the C and S groups. Chronic DBS at VMHvl induced a systemic inflammatory response accompanied by a decrease of HPA axis function. UCVgX rats experienced HPA axis hyperactivity as result of vagus nerve injury; however, DBS was unable to block the HPA axis hyperactivity induced by unilateral cervical vagotomy. Further studies are necessary to explore these findings and their clinical implication.

Chronic stress induces structural alterations in splenic lymphoid tissue that are associated with changes in corticosterone levels in wistar-kyoto rats.

Major depressive disorder patients present chronic stress and decreased immunity. The Wistar-Kyoto rat (WKY) is a strain in which the hypothalamic-pituitary-adrenal axis is overactivated. To determine whether chronic stress induces changes in corticosterone levels and splenic lymphoid tissue, 9-week-old male rats were subject to restraint stress (3 h daily), chemical stress (hydrocortisone treatment, 50 mg/Kg weight), mixed stress (restraint plus hydrocortisone), or control treatment (without stress) for 1, 4, and 7 weeks. The serum corticosterone levels by RIA and spleens morphology were analyzed. Corticosterone levels as did the structure, size of the follicles and morphology of the parenchyma (increase in red pulp) in the spleen, varied depending on time and type of stressor. These changes indicate that chronic stress alters the immune response in the spleen in WKY rats by inducing morphological changes, explaining in part the impaired immunity that develops in organisms that are exposed to chronic stress.

A helminth cestode parasite express an estrogen-binding protein resembling a classic nuclear estrogen receptor.

The role of an estrogen-binding protein similar to a known mammalian estrogen receptor (ER) is described in the estradiol-dependent reproduction of the helminth parasite Taenia crassiceps. Previous results have shown that 17-ß-estradiol induces a concentration-dependent increase in bud number of in vitro cultured cysticerci. This effect is inhibited when parasites are also incubated in the presence of an ER binding-inhibitor (tamoxifen). RT-PCR assays using specific oligonucleotides of the most conserved ER sequences, showed expression by the parasite of a mRNA band of molecular weight and sequence corresponding to an ER. Western blot assays revealed reactivity with a 66 kDa protein corresponding to the parasite ER protein. Tamoxifen treatment strongly reduced the production of the T. crassiceps ER-like protein. Antibody specificity was demonstrated by immunoprecipitating the total parasite protein extract with anti-ER-antibodies. Cross-contamination by host cells was discarded by flow cytometry analysis. ER was specifically detected on cells expressing paramyosin, a specific helminth cell marker. Parasite cells expressing the ER-like protein were located by confocal microscopy in the subtegumental tissue exclusively. Analysis of the ER-like protein by bidimensional electrophoresis and immunoblot identified a specific protein of molecular weight and isoelectric point similar to a vertebrates ER. Sequencing of the spot produced a small fragment of protein similar to the mammalian nuclear ER. Together these results show that T. crassiceps expresses an ER-like protein which activates the budding of T. crassiceps cysticerci in vitro. To the best of our knowledge, this is the first report of an ER-like protein in parasites. This finding may have strong implications in the fields of host-parasite co-evolution as well as in sex-associated susceptibility to this infection, and could be an important target for the design of new drugs.

Evaluation of the effect of selective serotonin-reuptake inhibitors on lymphocyte subsets in patients with a major depressive disorder.

To date, only the effect of a short-term antidepressant treatment (<12 weeks) on neuroendocrinoimmune alterations in patients with a major depressive disorder has been evaluated. Our objective was to determine the effect of a 52-week long treatment with selective serotonin-reuptake inhibitors on lymphocyte subsets. The participants were thirty-one patients and twenty-two healthy volunteers. The final number of patients (10) resulted from selection and course, as detailed in the enrollment scheme. Methods used to psychiatrically analyze the participants included the Mini-International Neuropsychiatric Interview, Hamilton Depression Scale and Beck Depression Inventory. The peripheral lymphocyte subsets were measured in peripheral blood using flow cytometry. Before treatment, increased counts of natural killer (NK) cells in patients were statistically significant when compared with those of healthy volunteers (312+/-29 versus 158+/-30; cells/mL), but no differences in the populations of T and B cells were found. The patients showed remission of depressive episodes after 20 weeks of treatment along with an increase in NK cell and B cell populations, which remained increased until the end of the study. At the 52nd week of treatment, patients showed an increase in the counts of NK cells (396+/-101 cells/mL) and B cells (268+/-64 cells/mL) compared to healthy volunteers (NK, 159+/-30 cells/mL; B cells, 179+/-37 cells/mL). We conclude that long-term treatment with selective serotonin-reuptake inhibitors not only causes remission of depressive symptoms, but also affects lymphocyte subset populations. The physiopathological consequence of these changes remains to be determined.

Variations in circulating cytokine levels during 52 week course of treatment with SSRI for major depressive disorder.

Major depressive disorder (MDD) is a psychiatric condition characterized by hypercortisolism and variations in circulatory cytokines. Previously it has been reported that administration of selective serotonin reuptake inhibitors (SSRI) in MDD patients modify cortisol and cytokine levels but these studies only evaluated changes over a short time period. This work reports the long-term effects of administration of SSRI on the cortisol levels and pro-/anti-inflammatory cytokine profile in a group of MDD patients treated for 52 weeks. A total of 31 patients diagnosed with MDD received anti depressant treatment with SSRI. HDRS and BDI were administered over a year, and levels of interleukin IL-1beta, IL-10, IL-2, IFN-gamma, IL-4, IL-13, and 24-h urine cortisol were determined at weeks (W) 0, 5, 20, 36 and 52 of treatment. Before treatment we found high levels of cortisol, IL-4, IL-13 (Th2) and IL-10 in MDD patients when compared with healthy volunteers. At W20 psychiatric scales indicated a remission of the depressive episode concomitantly with increments in IL-2 and IL-1beta but without changes in cortisol. Towards the end of the treatment (W52) we observed a significant reduction (p<0.01) in cortisol levels, with an increment in IL-1beta and IFN-gamma and a decrease in Th2 cytokines. Our results suggest that depressed patients only reach a partial reestablishment of HPA axis function after the long-term administration of SSRI.

Concepto de equivalencia sustancial aplicado alimentos derivados de cultivos genéticamente mejorados / The concept of substantial equivalence as applied to foodstuffs derived from genetically-modified crops

El objetivo del presente artículo es describir la aplicación del concepto de equivalencia sustancial, el cual es utilizado y aceptado internacionalmente para realizar la evaluación de la inocuidad de un alimento nuevo derivado de cultivos genéticamente mejorados. La metodología utilizada fue revisión de literatura actualizada, considerando, información tanto de revistas nacionales como internacionales y documentos de la Organización Mundial para la Agricultura y la Alimentación, FAO, Organización Mundial de la Salud, OMS, Codex Alimentarius, Organización Económica de Cooperación y Desarrollo, OECD, la Food and Drug Administration, FDA y otras. El artículo presenta la tendencia mundial en la siembra de cultivos genéticamente mejorados, así como la situación actual en Costa Rica con respecto a la siembra de cultivos genéticamente mejorados para incremento de semilla. Además, se detalla el concepto de equivalencia sustancial y se describe el conjunto de características de calidad que se deben evaluar los procedimientos metodológicos a seguir para demostrar que un alimento, derivado de un cultivo genéticamente mejorado, adCGM, es seguro para el consumo humano y animal. Como conclusión el concepto de equivalencia sustancial es el grupo de técnicas y metodologías, vigentes y aceptadas internacionalmente para evaluar la inocuidad de un nuevo alimento desarrollado mediante biotecnología moderna.

The objective of this article is to describe the complete application of the concept of substantial equivalence, which is internationally accepted and widely used for food safety evaluation of new foods. The methodology consists of a literature review of current documents from several agencies such as the World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO), Organization for Economic Cooperation and Development (OECD), the Food and Drug Administration of the USA (FDA), and others. This article presents the global trends related to the planting of genetically modified crops, and the Costa Rican situation on planting genetically modified crops for increasing seed yield. The article introduces the concept of substantial equivalence, and discusses several tests that should be applied in order to demonstrate that a genetically modified food derived from a GM crop is safe for human and animal consumption. As conclusion, the concept of substantial equivalence is the internationallyand currently accepted criteria the food safety assessment of crops developed by modern biotechnology.

Vías de neuroinmunomodulación. Primera parte

resumen está disponible en el texto completo

Summary: Inflammation is a normal response caused by physical stress like infection, injury and trauma; and processive or psychological stress like in psychiatric diseases such as major depression, schizophrenia and posttraumatic stress. The host responds with a complex series of immune, endocrine and nervous reactions to face the stressful stimuli named neuroendocrine immune interaction. These interactions help us to maintain the homeostasis under stressful stimuli. Stress is a physicochemical or emotional process that induces tension. This process promotes the release of proinflammatory cytokines, hormones such as the corticotrophin-release hormone (CRH) and cortisol, and a wide number of neurotransmitters that are together responsible for some behavioral alterations. Both systemic and psychological stress elicits an equivalent response in an organism. Particularly, the onset of inflammation is characterized by release of pro-inflammatory mediators including tumor necrosis factor (TNF)-α, interleukin (IL)-1, adhesion molecules, vasoactive mediators, and reactive oxygen species. The early release of pro-inflammatory cytokines by a widely variety of immune and no-immune cells has a pivotal role in triggering the local inflammatory response. Apart from their involvement in local inflammation, TNF-α and IL-1β are signal molecules for activation of brain derived neuroendocrine and immunomodulatory responses. Excessive production of cytokines, such as TNF-α and IL-1β however can be more injurious than the inciting event, initiating diffuse coagulation, tissue injury, hypotension, and death. The inflammatory response is balanced by anti-inflammatory molecules like the cytokines IL-10 and IL-4, soluble TNF receptors, IL-1 receptor antagonists, and transforming growth factor (TGF)-β. Neuroendocrine pathways, such as the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic division of the Autonomic Nervous System (SNS) control the inflammation process by triggering anti-inflammatory balancing mechanisms. The brain can monitor immune status and sense peripheral inflammation through two main pathways: neural and humoral. The neural mechanism relies upon activation of vagus nerve afferent sensory fibers that signal the brain that inflammation is occurring. Stressful stimuli activate vagal afferents either directly by cytokines released from dendritic cells, macrophages, and other vagal-associated immune cells, or indirectly through the chemoreceptive cells located in vagal paraganglia. The transmission of cytokine signals to the brain through the vagal sensory neurons depends upon the magnitude of the stressful challenge. Subdiaphragmatic vagotomy inhibits the stimulation of the HPA axis and noradrenaline (NA) release in hypothalamic nuclei in response to intraperitoneal administration of endotoxin or IL-1β. Intravenous endotoxin administration induces expression of the neural activation marker c-Fos in the brainstem medulla, regardless of the integrity of the vagus nerve. Vagotomy fails to suppress high dose endotoxininduced. IL-1β immunoreactivity in the brain and increases blood corticosterone levels. It is likely that the vagal afferent neural pathway plays a dominant role in mild to moderate peripheral inflammatory responses, whereas acute, robust inflammatory responses signal the brain primarily via humoral mechanisms. By other hand, humoral pathway are supported by a large body of evidence, especially in cases of systemic immune challenge; circulatory cytokines like IL-1 β and TNF-α can cross the blood-brain barrier and enter cerebrospinal fluid and the interstitial fluid spaces of the brain and spinal cord by a saturable carrier mediated mechanism that may function only at very high plasma cytokine concentrations. Cytokines also can bind to receptors at the surface of the endothelium of the brain capillaries and can enhance the synthesis and release of soluble mediators such as prostaglandins and nitric oxide, which diffuse into the brain parenchyma and modulate the activity of specific groups of neurons. It has been suggested that prostaglandins mediate fever and HPA axis activation. Cytokine-to-brain communication also may occur via circumventricular organs that lack normal blood-brain barrier function. Among the circumventricular organs, the AP (area postrema) appears to represent the best candidate for such a transduction site. The AP is located in the floor of the caudal fourth ventricle and dendrites of neurons in the NTS (nucleus tractus solitarius) and DMN (dorsal motor nucleus) penetrate both the AP and floor of the fourth ventricle. The close proximity of AP to NTS and RVM (rostral ventrolateral medulla) and the existing neural connections provide a way of signaling the SNS and HPA axis. Cytokine-induced production of prostaglandins within the AP, NTS, and RVM may activate the catecholamine projections to the PVN, resulting in subsequent HPA axis activation. This is one possible interaction between the neural and humoral mechanisms of immune to brain communication through which the brain mediates anti-inflammatory responses. Apart from their function in signaling the brain for immunomodulatory responses, cytokines play a multifunctional role in brain injury and neurodegenerative diseases. Restoration of homeostasis as a logical resolution of inflammation does not always occur. For instance, a lack of adequate inflammatory responses may result in increased susceptibility to infections or cancer. On the other hand, excessive responses are associated with autoimmune diseases, diabetes, sepsis, psychiatric diseases with an important inflammatory response like major depression or schizophrenia and other debilitating conditions. When control of local inflammatory responses is lost, pro-inflammatory mediators can spill into the circulation, resulting in systemic inflammation that may progress to shock, multiple organ failure, and death. A recent discovery, showed that a novel neuroimmunomodulatory pathway that interface the brain and the immune system, referred as to the autonomic cholinergic anti-inflammatory pathway, mediate inhibitory responses during inflammation possibly by recruiting central mechanisms that modulate systemic or peripheral inflammatory responses. Still unclear, this neural circuit has been implicated in promoting sort of psychotherapeutical activities such as hypnosis, meditation, prayer, biofeedback, including acupuncture, but this mechanims still remain elusive. The sympathetic and parasympathetic parts of the Autonomic Nervous System rarely operate alone; autonomic responses represent the interplay of both parts. A link between the parasympathetic part of the Autonomic Nervous System and immunoregulatory processes was suggested, when alleviation of T-lymphocyte cytotoxicity by muscarinic cholinergic stimulation was described. Communication between the immune, nervous, and endocrine systems is essential for host defense and involves a variety of mediators including cytokines, neurotransmitters, hormones, and humoral factors. The influence of the brain on immune function and the mechanisms involved in these interactions have been elucidated over the past 3 decades, however, two important questions arise when describing the brain-derived immunomodulation: How is the specific brain initially signaled by cytokines to trigger corresponding neural and neuroendocrine responses?; and: How is immunomodulation achieved through these mechanisms? This review outlines brain-related control mechanisms of immune function in the regulation of inflammation.

Immune variations in bipolar disorder: phasic differences.

OBJECTIVES: To characterize the immunological variations of patients with a bipolar disorder (BD) diagnosis in manic (BDm) and depressive (BDd) phases, by the quantification of the serum levels of interleukin (IL)-1beta, -2, -4, -6 and tumor necrosis factor alpha (TNF-alpha). METHODS: Twenty physically healthy patients with a BD type I diagnosis and 33 matched controls were studied, after giving informed consent. The inclusion criteria included at least three weeks without any kind of psychopharmacological treatment, Young Mania Rating Scale score > or =20 for BDm (n = 10) and Hamilton Depression Rating Scale score > or =21 for BDd patients (n = 10). Exclusion criteria included any infectious diseases, allergies or any other kind of medical illness that required treatment with immunosuppressors, as well as any other diagnosis in Axis I. Physical and laboratory examinations were performed to rule out any clinical illness. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the serum cytokines concentration. RESULTS: BD patients, when compared to controls, showed significant differences (p < or = 0.05) in the serum levels of the measured cytokines. The sub-group of BDd patients showed an increase in IL-6 and TNF-alpha, as well as a decrease in IL-2 concentration. The BDm sub-group, on the other hand, showed an increase in TNF-alpha and IL-4 values, with a low concentration of IL-1 and IL-2. The comparison between both sub-groups suggests that there is a distinctive cytokine pattern for the specific phases of the disorder: for mania, we found a high IL-4 and low IL-1beta and IL-6 concentration, while in the depressive phase, the inverse pattern was found. CONCLUSIONS: Our results show the existence of phasic differences in the serum levels of cytokines in BD.

Melatonin induced cyclic modulation of vectorial water transport in kidney-derived MDCK cells.

BACKGROUND: Melatonin, newly synthesized by the pineal gland, is rapidly released to general circulation reaching a nanomolar concentration. Cyclic production of melatonin synchronizes body rhythms with the photoperiod. Moreover, changes in urine production and osmolarity have been observed in the kidney during the night. However, the precise mechanisms by which plasma-circulating melatonin modifies renal physiology are not clearly understood. METHODS: Madin-Darby canine kidney (MDCK) cell monolayers transport water vectorially from the apical to the basolateral side forming blisters or domes. Transport in epithelial cells is regulated by tight junction sealing, ion pumps and channels, and cytoskeleton organization, among other processes. MDCK cells were used to study vectorial water transport to determine the role of microfilament organization and protein kinase C (PKC) in dome formation in culture conditions that mimic the cyclic pattern of melatonin circulation in plasma. RESULTS: Melatonin cyclically increased dome formation by 50% and caused enlargement and thickening of stress fibers in cells surrounding the domes. Optimal increase in dome formation was observed at nanomolar concentrations of melatonin after 6 hours, concomitantly with a 28% decrease in the transepithelial electrical resistance, which remained low for up to 12 hours, without apparent change in fluorescein isothiocyanate (FITC)-dextran flux. A blockage in dome formation elicited by melatonin was observed in monolayers preincubated with the Na+-K+-ATPase or PKC inhibitors. CONCLUSION: The results obtained indicate that melatonin cyclically modifies the transepithelial permeability in kidney-derived cells through PKC activation and microfilament reorganization, and supports the hypothesis that melatonin may synchronize daily body rhythms through cyclic cytoskeletal rearrangements.