Caracterización de los casos de accidente ofídico atendidos por el Centro de Información y Estudio de Medicamentos y Tóxicos (CIEMTO) de Medellín, Colombia durante 2016 / Characterization of snakebite cases attended by the drug and poison research and information center ( CIEMTO) in Medellin, Colombia during 2016

RESUMEN Introducción: Las mordeduras de serpiente continúan siendo un problema de salud pública, especialmente en países tropicales como Colombia. Objetivo: Caracterizar los casos de accidente ofídico atendidos en un nuevo centro de asesoría toxicológica de Medellín, Colombia. Metodología: Se realizó un estudio descriptivo, retrospectivo, revisando la base de datos donde se registra la información relacionada con la asesoría brindada por dicho centro desde el 1 de enero hasta el 31 de diciembre de 2016. Resultados: Se registraron 117 casos de accidente ofídico, de los cuales 93 (79%) eran hombres y 24 (21%) mujeres, con una mediana de edad de 32 años (rango: 2 a 82 años). El seguimiento de los casos pudo lograse en 55 de los 117 accidentes (47%), y se describieron complicaciones en 18 de los 55 (33%) pacientes. La complicación descrita con mayor frecuencia fue brote maculopapular pruriginoso asociado con la administración del suero, sin que se identificaran diferencias entre las distintas marcas de suero antiofídico utilizado. Se documentó la muerte de un paciente (0,85%). El género Bothrops produjo la mayoría de los accidentes. Discusión: Los datos obtenidos coinciden con la bibliografía publicada.

ABSTRACT Introduction: Snakebites continue to be a public health problem, especially in tropical countries like Colombia. Objetive: To characterize the snakebite cases attended by a new poison center in Medellin, Colombia. Methodology: A descriptive, retrospective study was carried out, reviewing the information of the Center's database from January 1st to December 31st, 2016. Results: There were 117 cases of ophidian accidents, affecting 93 men (79%) and 24 women (21%), with a median age of 32 years (range: 2 to 82 years). The follow-up of the cases could be done in 55 of the 117 accidents (47%), and complications were described in 18 of those 55 (33%) patients. The most commonly reported complication was a pruritic maculopapular rash that was associated to serum administration, without differences between the several brands of anti-ophidian serum used. The death of one patient (0.85%) was documented. The genus Bothrops caused most of the accidents. Discussion: Our results agree with previously published data.

Metabolite profiles of rats in repeated dose toxicological studies after oral and inhalative exposure.

The MetaMap(®)-Tox database contains plasma-metabolome and toxicity data of rats obtained from oral administration of 550 reference compounds following a standardized adapted OECD 407 protocol. Here, metabolic profiles for aniline (A), chloroform (CL), ethylbenzene (EB), 2-methoxyethanol (ME), N,N-dimethylformamide (DMF) and tetrahydrofurane (THF), dosed inhalatively for six hours/day, five days a week for 4 weeks were compared to oral dosing performed daily for 4 weeks. To investigate if the oral and inhalative metabolome would be comparable statistical analyses were performed. Best correlations for metabolome changes via both routes of exposure were observed for toxicants that induced profound metabolome changes. e.g. CL and ME. Liver and testes were correctly identified as target organs. In contrast, route of exposure dependent differences in metabolic profiles were noted for low profile strength e.g. female rats dosed inhalatively with A or THF. Taken together, the current investigations demonstrate that plasma metabolome changes are generally comparable for systemic effects after oral and inhalation exposure. Differences may result from kinetics and first pass effects. For compounds inducing only weak changes, the differences between both routes of exposure are visible in the metabolome.

Inducción de células T reguladoras por estatinas: alternativa terapéutica para el control del asma extrínseca / Induction of regulatory T cells by statins: alternative therapy for the control of extrinsic asthma

El asma bronquial extrínseca se origina por una reacción inmunológica de hipersensibilidad tipo I, desencadenada principalmente por alérgenos ambientales. Clásicamente, la respuesta inmune mediada por células T CD4+ con perfil Th2 determina las principales características de esta enfermedad, con la infiltración de eosinófilos y basófilos que median la inflamación crónica de las vías aéreas. Se ha observado que las células T reguladoras pueden actuar como moduladores endógenos durante los procesos asmáticos, controlando la exacerbación de las crisis y disminuyendo el daño tisular. Aunque los glucocorticoides son el principal tratamiento para el asma, solo alivian temporalmente los síntomas y se asocian con efectos adversos y aparición de resistencia, lo cual ha incentivado el desarrollo de alternativas terapéuticas que modulen la respuesta inmune y controlen la inflamación crónica. Recientemente, se ha postulado que las estatinas podrían ser una alternativa promisoria para disminuir la respuesta inflamatoria y disminuir la morbilidad asociada a esta enfermedad, debido a su gran potencial inmunomodulador, entre los que se destaca la inducción de células T reguladoras(AU)

Extrinsic asthma is caused by an immunological type I hypersensitivity reaction triggered mainly by environmental allergens. Usually, immune response mediated mainly by CD4 + T cells with Th2 profile determines the main features of extrinsic asthma, including infiltration of eosinophils and basophils that mediate chronic inflammation of the airways. It has been observed that regulatory T cells may act as endogenous modulators during asthmatic processes, controlling crisis exacerbation and decreasing tissue damage. Although glucocorticoids are the main treatment for asthma, these only relieve symptoms temporarily and are associated with adverse effects and development of resistance, which has encouraged the development of alternative therapies that modulate the immune response and control chronic inflammation. Recently, it has been postulated that statins may be a promising alternative to reduce the inflammatory response and decrease the morbidity associated with this disease, due to its great immunomodulator potential, especially in the induction of regulatory T cells(AU)

Infección por el virus de la hepatitis B en individuos con factores de exposición en Quibdó y Apartadó, Colombia / Hepatitis B Infections in Individuals with Exposure Factors in Quibdo and Apartado, Colombia

Antecedentes: Colombia presenta un patrón de prevalencia heterogéneo para la infección por virus de la hepatitis B (VHB) con regiones de alta, moderada y baja prevalencia. Objetivo: identificar los casos de infección por VHB y caracterizar los genotipos virales en población con factores de exposición en las ciudades de Quibdó y Apartadó, Colombia. Materiales y métodos: la población del estudio correspondió a 768 individuos asintomáticos con factores de exposición a la infección por VHB. El primer análisis fue la detección del antígeno de superficie del VHB (HBsAg) por prueba rápida. En las muestras de individuos positivos para esta prueba, se confirmó la presencia del HBsAg por ELISA y se detectó el genoma del VHB por reacción en cadena de la polimerasa (PCR). El genotipo viral fue determinado por secuenciación y análisis filogenético. Resultados: se identificaron 17/768 individuos con infección por VHB (2,2%) según la detección del HBsAg por prueba rápida y por ELISA. Los análisis filogenéticos permitieron la identificación de los genotipos F, (subgenotipos F3 y F1a) y A en las muestras. Conclusiones: se reporta por primera vez la circulación del subgenotipo F1a en Colombia y se confirma la circulación del subgenotipo F3 y el genotipo A.

Introduction: Colombia has a varied geographical pattern of prevalence of hepatitis B virus (HBV) infections with regions of high, moderate and low prevalences. Objective: The objective of this study was to identify cases of HBV infection and characterize viral genotypes in population with factors of exposure in the cities of Quibdo and Apartado, Colombia. Materials and Methods: The study population included 768 asymptomatic individuals with factors of exposure to HBV infections. An HBV surface antigen (HBsAg) rapid detection test was the first test used. Samples from individuals who tested positive were tested with ELISA to confirm the diagnosis and with PCR to detect the HBV genome. Viral genotypes were determined by sequencing and phylogenetic analysis. Results: Seventeen individuals (17/768, 2.2%) were diagnosed with HBV infections by both the Rapid Test and Elisa. Phylogenetic analyses allowed identification of genotypes F (F3 and Subgenotype F1a) and A in the samples. Conclusions: We report for the first time the presence of the F1a subgenotype in Colombia and confirme the presence of subgenotype F3 and genotype A.

The sensitivity of metabolomics versus classical regulatory toxicology from a NOAEL perspective.

The identification of the no observed adverse effect level (NOAEL) is the key regulatory outcome of toxicity studies. With the introduction of "omics" technologies into toxicological research, the question arises as to how sensitive these technologies are relative to classical regulatory toxicity parameters. BASF SE and metanomics developed the in vivo metabolome database MetaMap®Tox containing metabolome data for more than 500 reference compounds. For several years metabolome analysis has been routinely performed in regulatory toxicity studies (REACH mandated testing or new compound development), mostly in the context of 28 day studies in rats (OECD 407 guideline). For those chemicals for which a toxicological NOAEL level was obtained at either high or mid-dose level, we evaluated the associated metabolome to investigate the sensitivity of metabolomics versus classical toxicology with respect to the NOAEL. For the definition of a metabolomics NOAEL the ECETOC criteria (ECETOC, 2007) were used. In this context we evaluated 104 cases. Comparable sensitivity was noted in 75% of the cases, increased sensitivity of metabolomics in 8%, and decreased sensitivity in 18% of the cases. In conclusion, these data suggest that metabolomics profiling has a similar sensitivity to the classical toxicological study (e.g. OECD 407) design.

Mechanistic analysis of metabolomics patterns in rat plasma during administration of direct thyroid hormone synthesis inhibitors or compounds increasing thyroid hormone clearance.

For identification of toxicological modes of action (MoAs) a database (MetaMap(®)Tox) was established containing plasma metabolome consisting of approximately 300 endogenous metabolites. Each five male and female Wistar rats per groups were treated with >500 reference compounds over a period of 28 days. More than 120 specific toxicity patterns of common metabolite changes associated with unique MoAs were established. To establish patterns predictive effects on the thyroid, animals have been treated with reference compounds directly acting on the thyroid hormone formation (such as methimazole, ethylenethiourea) as well as liver enzyme inducers leading to an increased excretion of thyroid hormones and therewith to a secondary response of the thyroid (such as aroclor 1254 and boscalid). Here we present the plasma metabolite changes which form the patterns for direct and indirect effects on the thyroid. It is possible to identify metabolites which are commonly regulated irrespective of an indirect or direct effect on the thyroid as well as groups of metabolites separating both MoAs. By putting the metabolite regulations in the context of affected pathways helps to identify thyroid hormone inhibiting MoAs even when the hormone levels are not consistently changed. E.g., direct thyroid hormone synthesis inhibitors affect some enzymes in the urea cycle, increase the ω-oxidation of fatty acids and decrease glutamate and oxoproline levels, whereas indirect thyroid hormone inhibiting compounds interact with the lipid mediated and liver metabolism.

Differential regulation of proliferation and neuronal differentiation in adult rat spinal cord neural stem/progenitors by ERK1/2, Akt, and PLCγ.

Proliferation of endogenous neural stem/progenitor cells (NSPCs) has been identified in both normal and injured adult mammalian spinal cord. Yet the signaling mechanisms underlying the regulation of adult spinal cord NSPCs proliferation and commitment toward a neuronal lineage remain undefined. In this study, the role of three growth factor-mediated signaling pathways in proliferation and neuronal differentiation was examined. Adult spinal cord NSPCs were enriched in the presence of fibroblast growth factor 2 (FGF2). We observed an increase in the number of cells expressing the microtubule-associated protein 2 (MAP2) over time, indicating neuronal differentiation in the culture. Inhibition of the mitogen-activated protein kinase or extracellular signal-regulated kinase (ERK) kinase 1 and 2/ERK 1 and 2 (MEK/ERK1/2) or the phosphoinositide 3-kinase (PI3K)/Akt pathways suppressed active proliferation in adult spinal cord NSPC cultures; whereas neuronal differentiation was negatively affected only when the ERK1/2 pathway was inhibited. Inhibition of the phospholipase Cγ (PLCγ) pathway did not affect proliferation or neuronal differentiation. Finally, we demonstrated that the blockade of either the ERK1/2 or PLCγ signaling pathways reduced neurite branching of MAP2+ cells derived from the NSPC cultures. Many of the MAP2+ cells expressed synaptophysin and had a glutamatergic phenotype, indicating that over time adult spinal cord NSPCs had differentiated into mostly glutamatergic neurons. Our work provides new information regarding the contribution of these pathways to the proliferation and neuronal differentiation of NSPCs derived from adult spinal cord cultures, and emphasizes that the contribution of these pathways is dependent on the origin of the NSPCs.

Differential gene expression in the nucleus accumbens and frontal cortex of lewis and Fischer 344 rats relevant to drug addiction.

Drug addiction results from the interplay between social and biological factors. Among these, genetic variables play a major role. The use of genetically related inbred rat strains that differ in their preference for drugs of abuse is one approach of great importance to explore genetic determinants. Lewis and Fischer 344 rats have been extensively studied and it has been shown that the Lewis strain is especially vulnerable to the addictive properties of several drugs when compared with the Fischer 344 strain. Here, we have used microarrays to analyze gene expression profiles in the frontal cortex and nucleus accumbens of Lewis and Fischer 344 rats. Our results show that only a very limited group of genes were differentially expressed in Lewis rats when compared with the Fischer 344 strain. The genes that were induced in the Lewis strain were related to oxygen transport, neurotransmitter processing and fatty acid metabolism. On the contrary genes that were repressed in Lewis rats were involved in physiological functions such as drug and proton transport, oligodendrocyte survival and lipid catabolism.These data might be useful for the identification of genes which could be potential markers of the vulnerability to the addictive properties of drugs of abuse.

Muscle-conditioned media and cAMP promote survival and neurite outgrowth of adult spinal cord motor neurons.

Embryonic spinal cord motor neurons (MNs) can be maintained in vitro for weeks with a cocktail of trophic factors and muscle-derived factors under serum-containing conditions. Here we investigated the beneficial effects of muscle-derived factors in the form of muscle-conditioned medium (MCM) on the survival and neurite outgrowth of adult rat spinal cord MNs under serum-free conditions. Ventral horn dissociated cell cultures from the cervical enlargement were maintained in the presence of one or more of the following factors: brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), a cell permeant cyclic adenosine-3',5'-monophosphate (cAMP) analog and MCM. The cell cultures were immunostained with several antibodies recognizing a general neuronal marker the microtubule-associated protein 2 (MAP2) and either one or more motor neuronal markers: the non-phosphorylated neurofilament heavy isoform (SMI32), the transcription factors HB9 and Islet-1 and the choline acetyl transferase. We found that treatment with MCM together with the cAMP analog was sufficient to promote selective survival and neurite outgrowth of adult spinal cord MNs. These conditions can be used to maintain adult spinal cord MNs in dissociated cultures for several weeks and may have therapeutic potential following spinal cord injury or motor neuropathies. More studies are necessary to evaluate how MCM and the cAMP analog act in synergy to promote the survival and neurite outgrowth of adult MNs.

Caracterización de adolescentes escolarizados con riesgo de suicidio, Medellín, 2006 / Characterization of school adolescent students with suicide risk in Medellin, 2006

OBJETIVO: explorar la posible asociación entre el riesgo de suicidio, depresión, consumo de psicoactivos y disfunción familiar en adolescentes escolarizados. METODOLOGÍA: se administró una encuesta de autoaplicación a una muestra aleatoria de 779 adolescentes para evaluar el riesgo de suicidio, depresión, consumo de sustancias psicoactivas y disfunción familiar; se utilizaron los instrumentos ISO-30, CDI-LA, CIDI-II y Apgar familiar respectivamente. Para el análisis se empleó la técnica del método casos y controles. RESULTADOS: la prevalencia del riesgo de suicidio se situó entre 23,0% y 26,5%. La depresión y la disfunción familiar se asociaron positivamente con el riesgo de suicidio, con una razón de disparidad de 4,3 y 2,0 respectivamente. CONCLUSIONES: los resultados muestran la magnitud de un problema que deben tener en cuenta las autoridades educativas, la administración municipal y los padres de familia. Es prioritario fortalecer los programas de detección de la depresión adolescente, como también exigir al Estado mejores tratamientos para depresión (no solo limitados al medicamento). Es necesario promover la estrategia de escuela de padres en instituciones educativas, hacer énfasis en temas referentes a la salud mental y resaltar la importancia en la comunicación, la cooperación, el afecto y el respeto entre los miembros de la familia.

OBJECTIVE: To explore the possible association between the risk of suicide, depression, consumption of psychoactive and family dysfunction in school adolescents. METHODOLOGY: It was administered a self-administered survey to a random sample of 779 adolescents to assess the risk of suicide, depression, psychoactive substance use and family dysfunction, the instruments were used ISO-30, CDI-LA-II CIDI and Family Apgar respectively. The analysis used the technique of case-control method. RESULTS: The prevalence of suicide risk was between 23.0% and 26.5%. Depression and family dysfunction were positively associated with suicide risk, with a disparity ratio of 4.3 and 2.0 respectively. CONCLUSIONS: The results show the magnitude of a problem that must take into account the educational authorities, the municipal administration and parents. A priority is to strengthen programs for adolescent depression screening, and also require to the State better treatments for depression (not just limited to the drug). We must promote the strategy of school parents in educational institutions, emphasizing issues related to mental health and stress the importance of communication, cooperation, affection and respect among family members.

Salermide, a Sirtuin inhibitor with a strong cancer-specific proapoptotic effect.

Sirtuin 1 (Sirt1) and Sirtuin 2 (Sirt2) belong to the family of NAD+ (nicotinamide adenine dinucleotide-positive)-dependent class III histone deacetylases and are involved in regulating lifespan. As cancer is a disease of ageing, targeting Sirtuins is emerging as a promising antitumour strategy. Here we present Salermide (N-{3-[(2-hydroxy-naphthalen-1-ylmethylene)-amino]-phenyl}-2-phenyl-propionamide), a reverse amide with a strong in vitro inhibitory effect on Sirt1 and Sirt2. Salermide was well tolerated by mice at concentrations up to 100 muM and prompted tumour-specific cell death in a wide range of human cancer cell lines. The antitumour activity of Salermide was primarily because of a massive induction of apoptosis. This was independent of global tubulin and K16H4 acetylation, which ruled out a putative Sirt2-mediated apoptotic pathway and suggested an in vivo mechanism of action through Sirt1. Consistently with this, RNA interference-mediated knockdown of Sirt1, but not Sirt2, induced apoptosis in cancer cells. Although p53 has been reported to be a target of Sirt1, genetic p53 knockdowns showed that the Sirt1-dependent proapoptotic effect of Salermide is p53-independent. We were finally able to ascribe the apoptotic effect of Salermide to the reactivation of proapoptotic genes epigenetically repressed exclusively in cancer cells by Sirt1. Taken together, our results underline Salermide's promise as an anticancer drug and provide evidence for the molecular mechanism through which Sirt1 is involved in human tumorigenesis.

Toluene and TCE decrease binding to mu-opioid receptors, but not to benzodiazepine and NMDA receptors in mouse brain.

In vitro and in vivo studies have shown that abused solvents affect different neurotransmitter systems, including the GABAergic, glutamatergic, and opioidergic. The first purpose of this study was to determine in mice whether an acute exposure to 4,000 ppm toluene or 12,000 ppm 1,1,1-trichloroethane (TCE) modifies receptor binding levels to: (a) DAMGO, a mu-opioid receptor selective agonist; (b) MK-801, a noncompetitive selective NMDA-receptor antagonist; and (c) flunitrazepam, a benzodiazepine binding site selective agonist. In addition, in separate groups of animals, nociceptive effects of toluene alone or co-administered with morphine were evaluated in the hot-plate test. Mice were exposed to toluene or TCE in static exposure chambers for 30 min, and their brains were removed 24 h later for autoradiography. Acute toluene inhalation produced a significant decrease in mu-opioid receptor binding levels in cingulate and piriform cortices, caudate putamen, thalamus, amygdala, and periaqueductal gray, whereas TCE significantly decreased mu-opioid receptor levels, but only in thalamus and periaqueductal gray. Both toluene and TCE decreased benzodiazepine receptor binding levels in discrete brain areas, but had no effect on NMDA receptor levels. In the hot-plate test, a single toluene exposure counteracted morphine antinociceptive response when the solvent exposure time was immediately followed by morphine treatment, but not when morphine was administered 24, 48, 72, and 96 h later. However, co-administration of morphine and toluene 24, 48, 72, and 96 h after the single solvent exposure resulted in morphine-induced analgesia blockade. Present results suggest that mu-opioid receptors are an important molecular target for organic solvents, and that the inhalation of these compounds may affect the analgesic properties of opioids.

Allelic diversity within the high frequency Mamu-A2*05/Mane-A2*05 (Mane-A*06)/Mafa-A2*05 family of macaque MHC-A loci.

Macaque species serve as important animal models of human infection and immunity. To more fully scrutinize their potential in both the analysis of disease pathogenesis and vaccine development, it is necessary to characterize the major histocompatibility complex (MHC) class I loci of Macaca mulatta (Mamu), Macaca nemestrina (Mane), and Macaca fascicularis (Mafa) at the genomic level. The oligomorphic Mamu-A2*05/Mane-A2*05 (previously known as Mane-A*06) family of macaque MHC-A alleles has recently been shown to be present at high frequency in both Indian rhesus and pig-tailed macaque populations. Using a locus-specific amplification and direct DNA typing methodology, we have additionally found that the locus encoding this family is very prevalent (75%) among a sampling of 182 Chinese rhesus macaques and has a high prevalence (80%) within a larger, independent cohort of 309 pig-tailed macaques. Interestingly, among the Chinese rhesus macaques, only six alleles previously identified in Indian-origin animals were observed, while three recently identified in Chinese-origin animals and 25 new alleles were characterized. Among the pig-tailed macaques, we observed 1 previously known (Mane-A*06) and 19 new alleles. Examination of the orthologous locus in a preliminary sampling of 30 cynomolgus macaques showed an even higher presence (87%) of Mafa-A2*05 family alleles, with 5 previously identified and 15 new alleles characterized. The continued discovery of novel alleles and thus further diversity within the Mamu-A2*05/Mane-A2*05/Mafa-A2*05 family indicates that this MHC-A locus, although highly conserved across the three species of macaques, has remained a dynamic entity during evolution.

Pulses of extracellular K+ produce two cytosolic Ca2+ transients that display different temperature dependence and carbonyl cyanide m-chlorophenyl sensitivity in SH-SY5Y cells.

In SH-SY5Y cells we have shown that stimulation with high extracellular K+ ([K+]e) evokes a transient increase in cytoplasmic Ca2+ ([Ca2+]cyt) (K+on) that is triggered by the opening of voltage-dependent Ca2+ channels and followed by Ca2+ -induced Ca2+ release from the endoplasmic reticulum (Xu, F., Zhang, J., Recio-Pinto, E. and Blanck, T.J., Halothane and isoflurane augment depolarization-induced cytosolic CA2+ transients and attenuate carbachol-stimulated CA2+ transients, Anesthesiology, 92 (2000) 1746-56). The removal of high-[K+]e results in a second transient increase in [Ca2+]cyt (K+off) that is independent of extracellular Ca2+ (Corrales, A., Montoya, G.J., Sutachan, J.J., Cornillez-Ty, G., Garavito-Aguilar, Z., Xu, F., Blanck, T.J. and Recio-Pinto, E., Transient increases in extracellular K+ produce two pharmacological distinct cytosolic Ca2+ transients, Brain Res., 1031 (2005) 174-184). In this study we further characterize the properties of K+off. We found that K+off was detectable at near physiological temperatures (34-36 degrees C) but, depending on the level of [K+]e, it was undetectable or highly diminished at room temperature. In contrast, K+on was increased by lowering the temperature. Extracellular Na+ -replacement with K+ did not affect K+off, indicating that K+off was not generated by osmolarity changes. Replacement of extracellular Na+ with choline+ did not affect K+off, indicating that K+off did not result from activity changes of the plasma membrane Na+/Ca2+ exchanger. Caffeine decreased K+on but not K+off. CCCP (carbonyl cyanide m-chlorophenyl), a protonophore uncoupler that decreases mitochondrial Ca2+ uptake, decreased K+on but not K+off. CGP37157, an inhibitor of the mitochondria Na+/Ca2+ exchanger, decreased K+off when added alone but not when added simultaneously with CCCP. Clonazepam had similar effects as CGP37157. These findings indicate that the generation of K+off is strongly temperature-dependent and its pharmacology is distinct from the [Ca2+]cyt changes observed previously at room temperature.

On the relevance of defining protein structures in cancer research

Are three-dimensional structures of proteins relevant in the study of cancer? The knowledge of the three-dimensional structure of a protein is crucial to gain a full understanding of its function, and structural determination has already shown its potential for guided drug design. The knowledge of the structures of proteins and their complexes with other biological macromolecules helps to elucidate functional networks and provide a better understanding of the functionally relevant behaviour of the molecular machinery of the cell. To study the cell, we must be able to work with proteins, to elucidate how they diffuse and move, to know their interacting partners, and to understand the changes induced by those interactions. Three-dimensional structures give us a picture of the protein and thereby the opportunity to introduce mutations that alter its affinity and specificity for other interactions helping us to understand the physico-chemical mechanisms that control their function. In turn these can lead to the development of novel therapies (AU)

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Pluronic F-127 affects the regulation of cytoplasmic Ca2+ in neuronal cells.

Fura-2 is one of the most widely used cytoplasmic Ca2+ ([Ca2+]cyt) sensors. In studies using isolated dorsal root ganglion (DRG) neurons, the loading of Fura-2 AM is often facilitated by the use of pluronic F-127. In preliminary studies, we detected that the use of pluronic F-127 appeared to be affecting the depolarization-evoked [Ca2+]cyt transient in DRG neurons. To determine whether this was the case, we conducted a systematic study. Adult rat DRG neurons were cultured, and their response to 50 mM KCl was measured in sister cultured cells (isolated on the same day) that were loaded with 5 microM Fura-2AM in the absence or in the presence of 0.02% pluronic F-127. In the absence of pluronic F-127, the KCl-evoked [Ca2+]cyt transient changed with time, being wider on day 1 than on day 2 after plating. On day 2, the KCl-evoked [Ca2+]cyt transient was wider in neurons Fura-2 loaded in the presence of pluronic F-127. These results indicate that pluronic F-127 significantly alters depolarization-evoked [Ca2+]cyt transients, which may reflect alteration in regulation of [Ca2+]cyt in neuronal cells.

Perfil bioquímico sanguíneo hepático y renal en el sajino (Tayassu tajacu) criado en cautiverio en la amazonía peruana / Blood biochemical profile in the liver and kidney peccary (Tayassu tajacu) raised in captivity in the Peruvian Amazon

The objective of this study was to establish reference serum values for bilirrubin (total and direct), alanine amino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase, cholesterol, total protein, albumin, urea, and creatinine in healthy collared peccary (Tayassu tajacu) kept under captivity in the Amazonian jungle of Peru (Loreto, Iquitos). A total of 28 adult animals (14 males and 14 females) were used. Blood samples (7 ml) were collected from the safen vein. Serum values were: Total bilirrubin: 0.7± 0.2 mg/dl; direct bilirrubin: 0.2 ± 0.1 mg/dl; ALT: 26.5 ± 9.1 UI/l; AST: 15.9 ± 8.4 UI/l; alkaline phosphatase: 27.5 ± 15.5 UI/l; cholesterol: 94.4 ± 20.2 mg/dl; total protein: 8.5 ± 1.1 g/dl; albumin: 4.4 ± 0.5 g/dl; urea: 58.1 ± 11.1 mg/dl; and creatinine: 2.2 ± 0.5 mg/dl. It was concluded that serum values were similar to other results reported in the literature and without statistical differences due to sex.

Transient increases in extracellular K+ produce two pharmacological distinct cytosolic Ca2+ transients.

Transient increases in extracellular K+ are observed under various conditions, including repetitive neuronal firing, anoxia, ischemia and hypoglycemic coma. We studied changes in cytoplasmic Ca2+ ([Ca2+]cyt) evoked by pulses of KCl in human neuroblastoma SH-SY5Y cells and rat dorsal root ganglia (DRG) neurons at 37 degrees C. A "pulse" of KCl evoked two transient increases in [Ca2+]cyt, one upon addition of KCl (K+on) and the other upon removal of KCl (K+off). The K+on transient has been described in many cell types and is initiated by the activation of voltage-dependent Ca2+ channels followed by Ca2+-evoked Ca2+ release from intracellular Ca2+ stores. The level of KCl necessary to evoke the K+off transient depends on the type of neuron, in SH-SY5Y cells it required 100 mM KCl, in most (but not all) of dorsal root ganglia neurons it could be detected with 100-200 mM KCl and in a very few dorsal root ganglia neurons it was detectable at 20-50 mM KCl. In SH-SY5Y cells, reduction of extracellular Ca2+ inhibited the K+on more strongly than the K+off and slowed the decay of K+off. Isoflurane (1 mM) reduced the K+on)- but not the K+off-peak. However, isoflurane slowed the decay of K+off. The nonspecific cationic channel blocker La3+ (100 microM) had an effect similar to that of isoflurane. Treatment with thapsigargin (TG) at a concentration known to only deplete IP3-sensitive Ca2+ stores did not affect K+on or K+off, suggesting that Ca2+ release from the IP3-sensitive Ca2+ stores does not contribute to K+on and K+off transients and that the thapsigargin-sensitive Ca2+ ATPases do not contribute significantly to the rise or decay rates of these transients. These findings indicate that a pulse of extracellular K+ produces two distinct transient increases in [Ca2+]cyt.

Estrogen receptor beta dinucleotide (CA) repeat polymorphism is significantly associated with bone mineral density in postmenopausal women.

Significant associations between the lengths of a highly polymorphic dinucleotide (CA) repeat located within the human estrogen receptor beta (ESR2) gene on chromosome 14, bone mineral density (BMD) and androgen levels have been reported previously in premenopausal women. We measured the size of this microsatellite repeat in 226 healthy women (60-98 years). After adjustment for age, body mass index, hormone replacement status, and other variables known to influence BMD, women with < 25 CA repeats had significantly higher BMD measured in the total skeleton, lumbar spine, and femoral neck when compared with women having longer alleles. Women with shorter alleles also had higher circulating estrone and estradiol levels that approached statistical significance as compared with women harboring longer alleles after appropriate adjustments were performed in linear regression models. Women having both short and long CA repeats had BMD values in all regions of the skeleton that were midway between those found in women homozygous for longer or shorter repeat sizes. Because the ESR2 CA repeat size was neither associated with change in BMD nor serum levels of biochemical markers of bone turnover, it is likely that ESR2 CA repeat genotype is significantly linked to the attainment of peak bone mass in women.