RESUMO
Salinization is of global concern, threatening freshwater biodiversity. Salinity tolerance is highly variable and therefore needs to be evaluated on a species-specific basis. An estuarine population of Chilina dombeiana, a freshwater gastropod endemic to Chile and classified as vulnerable, has been recently found in the Biobío River's mouth, suggesting some degree of tolerance to brackish waters. This study evaluated the survival, behaviour (medium preference) and physiology of C. dombeiana when exposed to salinities higher than freshwater, thus elucidating the potential mechanisms used to survive salinization. Chilina dombeiana belongs to the Pulmonate group;, so we evaluated oxygen uptake in air and water, aiming to evaluate emersion as a potential avoidance response to a progressive salinity increase. Complete embryo development was observed for salinities ≤ 16 PSU (practical salinity units) but hatching rates above 50% were only achieved in freshwater (0 PSU). It was also found that salinity had stage-specific effects during embryonic development. In adults, acute exposure to brackish water (12 PSU) caused a decrease in oxygen consumption (compared to freshwater), in the ammonium excretion rates and in the percentage of muscular water content. Although C. dombeiana was able to take up oxygen in both mediums, survival in air decreased over time (days), which correlates with the behavioural preference to remain submerged, even at elevated salinities. Considering the survival of adults and embryos decreased as salinity increased and the lack of an avoidance behaviour or a physiological ability to maintain homeostasis at salinities higher than freshwater, our results suggest this snail could be adversely affected by salinization in the long term. Furthermore, given the ability of C. dombeiana to uptake oxygen in both mediums, it should be considered as a facultative air breather snail, rather than a strictly aquatic species.
RESUMO
Feeding and digestion are metabolically demanding causing a rise on metabolic rate called Specific Dynamic Action (SDA). Although SDA has been vastly reported in fish, its potential consequences on the oxidative-antioxidant balance has not been evaluated to date in fish, a model with a long alkaline tide associated with feeding as well. Using rainbow trout (Oncorhynchus mykiss) as a model species, the aims of the present study were to: (1) assess potential oxidative damages and changes in oxidative defences after feeding on a single meal, and (2) identify the timescale of such changes over a 96 h post-feeding period. Oxidative damage in proteins and lipids and the activities of four enzymatic antioxidant defences: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were measured in gill, stomach, intestine and liver. DNA damage was measured in red blood cells. Fish were sampled before and after 1.5, 6, 24, 48, 72 and 96 h of ingestion of a 3% body mass ration. Trends of post-prandial damage were present in all tissues, but only protein oxidation varied significatively during digestion in the stomach. The intestine and stomach presented the highest enzymatic activities, likely due to the high metabolic action that these tissues have during digestion, with peaks during post-feeding: at 24 h of SOD in stomach and at 48 h of CAT in intestine. Observed GPx peaks during post-feeding in gills are likely due to the exacerbated demands for ion fluxes and/or oxygen during feeding. The differential response of the antioxidant system observed in tissues of rainbow trout during digestion indicates a coordinated and tissue-specific antioxidant defence.
Assuntos
Oncorhynchus mykiss , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Oncorhynchus mykiss/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismoRESUMO
Larval stages of pentastomids were collected from different organs of small mammals from the Peruvian Amazon. These parasitized mammals included: a western Amazonian oryzomys (Hylaeamys perenensis), an elegant oryzomys (Euryoryzomys nitidus), a lowland paca (Cuniculus paca), two kinkajous (Potos flavus), two silvery woolly monkeys (Lagothrix poeppigii) and a brown-mantled tamarin (Leontocebus fuscicollis). Pentastomids were found in the mesentery and parenchyma of the liver and lungs of these animals. All pentastomids were morphologically identified as nymphs of Porocephalus spp. Only the nymphs collected from select animals (the western Amazonian oryzomys, the elegant oryzomys and the brown-mantled tamarin) were analysed molecularly. Molecular analysis was performed amplifying the mitochondrial cytochrome c oxidase subunit I gene from select nymphs collected from the western Amazonian oryzomys, the elegant oryzomys and the brown-mantled tamarin. The nucleotide sequences exhibited 95.8-97.7% similarity between them. Also, these sequences showed an identity of 95.8-97.9% to Porocephalus crotali (GenBank accession numbers MG559647-MG559655). Molecular analysis indicated the presence of at least two Porocephalus species. These findings represent the first record of Porocephalus in these mammals, thus adding new intermediate hosts for this pentastomid genus. This work represents the first molecular data of Porocephalus in a Neotropical climate.
Assuntos
Mamíferos/parasitologia , Doenças Parasitárias em Animais/parasitologia , Pentastomídeos/anatomia & histologia , Vísceras/parasitologia , Animais , Feminino , Estágios do Ciclo de Vida , Fígado/parasitologia , Pulmão/parasitologia , Masculino , Ninfa/genética , Pentastomídeos/classificação , Peru , Clima TropicalRESUMO
The dramatic increase of microplastics (plastic fragments <5â¯mm) in marine environments is a problem that has attracted public attention globally. Within the different types of microplastics, microfibres are the least studied (size <1â¯mm). We examined 51 female scats from a population in Northern Patagonia. Our results showed no presence of microplastic particles, however 67% of them showed a remarkable abundance of microfibers, which until now had only been reported in animals fed in captivity. As a result of this work we propose that the examination of scats from South American Fur Seal and also other pinnipeds could be an efficient tool to monitor environmental levels of microfibres and maybe microplastics in the environment due to the easy recognition of the animals and their scats.
Assuntos
Monitoramento Ambiental/métodos , Otárias/metabolismo , Plásticos/análise , Resíduos/análise , Poluentes Químicos da Água/análise , Animais , Chile , Fezes/química , FemininoRESUMO
The need for upkeep and management of medical technology has fostered the creation of a large number of under graduate programs in the field of biomedical Engineering. In Latin America alone, there are over 85 programs dedicated to this. This contrasts with programs in other regions where most of the undergraduates continue on to pursue graduate degrees or work as research and development engineers in the biomedical industry. In this work we analyze the situation regarding curricular design in the 48 BME programs in Mexico and compare this to suggestions and classifications of programs according to needs and possibilities. We then focus on a particular institution, Universidad Autónoma Metropolitana and due to its characteristics and performance we propose that it should redefine its aims from the undergraduate program on, in order to not only generate research but also to provide a nurturing environment for a budding biomedical industry in Mexico.
Assuntos
Engenharia Biomédica/educação , Engenharia Biomédica/economia , Currículo , Humanos , México , Pesquisa , UniversidadesAssuntos
Criação de Animais Domésticos/métodos , Camelídeos Americanos , Escabiose/veterinária , Animais , Animais Domésticos , Animais Selvagens , Antiparasitários/administração & dosagem , Antiparasitários/efeitos adversos , Antiparasitários/uso terapêutico , Camelídeos Americanos/parasitologia , Esquema de Medicação/veterinária , Resistência a Medicamentos , Feminino , Ivermectina/administração & dosagem , Ivermectina/efeitos adversos , Ivermectina/uso terapêutico , Masculino , Peru/epidemiologia , Escabiose/tratamento farmacológico , Escabiose/epidemiologiaRESUMO
Oxfendazole (OFZ) is efficacious for porcine cysticercosis at 30 mg/kg. OFZ is not registered to be used at this dose. The assessment of the OFZ and metabolites [(fenbendazole sulphone (FBZSO2), fenbendazole (FBZ)] plasma pharmacokinetic and tissue residue profiles after its oral administration to pigs and the withdrawal period for human consumption were reported. Forty-eight pigs allocated into two groups received OFZ (30 mg/kg) orally as a commercial (CF) or as experimental formulation (SMF). Samples (blood, muscle, liver, kidney and fat) were collected over 30 days post-treatment and analyzed by HPLC. OFZ was the main compound recovered in plasma, followed by FBZSO2 and low FBZ concentrations. OFZ AUC0-LOQ (209.9±33.9 µg·h/ml) and Cmax (5.40±0.65 µg/ml) parameters for the CF tended to be higher than those for the SMF (AUC0-LOQ: 159.4±18.3 µg h/ml, Cmax: 3.80±0.35 µg/ml). The highest total residue (OFZ+FBZSO2+FBZ) concentrations were quantified in liver, followed by kidney, muscle and fat tissue. FBZSO2 residue levels were the highest found in muscle (0.68±0.39 µg/g) and fat (0.69±0.39 µg/g). In liver and kidney the highest residues corresponded to FBZ (5.29±4.36 µg/g) and OFZ (2.86±0.75 µg/g), respectively. A withdrawal time of 17 days post-treatment was established before tissues are delivered for human consumption.
Assuntos
Anti-Helmínticos/uso terapêutico , Benzimidazóis/uso terapêutico , Cisticercose/veterinária , Resíduos de Drogas/análise , Doenças dos Suínos/tratamento farmacológico , Tecido Adiposo/química , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/farmacocinética , Área Sob a Curva , Benzimidazóis/administração & dosagem , Benzimidazóis/farmacocinética , Cisticercose/tratamento farmacológico , Cisticercose/patologia , Relação Dose-Resposta a Droga , Feminino , Meia-Vida , Rim/química , Masculino , Músculo Esquelético/química , Suínos , Doenças dos Suínos/parasitologiaRESUMO
Taurine and zinc exert neurotrophic effects. Zinc modulates Na(+)/Cl(-)-dependent transporters. This study examined the effect of zinc (ZnSO(4)) ex vivo and zinc chelator N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN) in vivo on [(3)H]taurine transport in goldfish retina. The effect of TPEN in vivo on taurine and zinc levels was determined. Isolated cells were incubated in Ringer with zinc (0.1-100 microM). Taurine transport was done with taurine (0.001-1 mM) and 50 nM [(3)H]taurine. Zinc (100 microM) noncompetitively inhibited taurine transport. TPEN was administered intraocularly and retinas extracted 3, 5 and 10 days later. Taurine was determined by HPLC (nmol/mg protein) and zinc by spectrophotometry ICP (mg/mg protein). Taurine and zinc levels decreased at 3 days and increased at 10 days after TPEN administration. At 10 days after intraocular TPEN, taurine transport affinity increased (K (s) = 0.018 +/- 0.006 vs. 0.028 +/- 0.008 mM). Apparently, zinc deficiency affects the taurine-zinc complex and taurine availability. The increased taurine uptake affinity by TPEN was possibly associated with a response to maximize retinal taurine content at low zinc concentration.
Assuntos
Quelantes/química , Retina/metabolismo , Taurina/metabolismo , Zinco/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Etilenodiaminas/química , Carpa Dourada , Cinética , Espectrometria de Fluorescência , Zinco/químicaRESUMO
Lymphocytes possess transporters of serotonin and dopamine, and also contain monoamines. The objective of this work was to determine the presence of noradrenaline transporters, the turnover rate of noradrenaline and serotonin in lymphocytes of major depression patients, and to correlate the biochemical parameters with the severity of the disorder. Lymphocytes from peripheral blood were isolated by Ficoll/Hypaque, and noradrenaline transporter was studied by binding of [3H]nisoxetine: control group (29, age 31.52+/-1.08, 7 men) and major depression patients (35, age 36.68+/-1.69, 6 men), Hospital Vargas de Caracas. Diagnostic was done by criteria of the American Psychiatric Association and severity by Hamilton Scale for Depression. Levels of noradrenaline, serotonin, 3-methoxy-4-hydroxyphenylglycol and 5-hydroxyindoleacetic acid were determined by HPLC. Turnover rate was evaluated by the ratios of monoamines and metabolites. Correlations were done between the biochemical parameters and the severity of depression. The score of Hamilton for Depression was 22.77+/-0.51. There was a reduction in the number of transporters in lymphocytes of patients, 0.95+/-0.27 versus 4.06+/-1.67 fmol/10(6) cells. Levels of monoamines and metabolites did not significantly differ between patients and controls. However, there was a higher monoamine/metabolite ratio in lymphocytes of patients, indicating a reduction of metabolic turnover rate. Also there was a relative greater concentration of noradrenaline than serotonin in the lymphocytes of the patients, as indicated by the ratio noradrenaline/serotonin. Noradrenergic and serotonergic turnover is decreased in blood peripheral lymphocytes of major depression patients; the reduction in noradrenaline transporter could be related to changes in intracellular levels, and these modifications could result in functional changes of the immune system.
Assuntos
Transtorno Depressivo Maior/metabolismo , Linfócitos/metabolismo , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/sangue , Adulto , Plaquetas/metabolismo , Membrana Celular/metabolismo , Feminino , Fluoxetina/análogos & derivados , Fluoxetina/sangue , Humanos , Ácido Hidroxi-Indolacético/sangue , Masculino , Metoxi-Hidroxifenilglicol/sangue , Pessoa de Meia-Idade , Norepinefrina/antagonistas & inibidores , Norepinefrina/sangue , Serotonina/sangueRESUMO
Serotonin transporter, measured by the specific binding of [(3)H]paroxetine, has been reported to be reduced in circulating lymphocytes of patients with major depression. Due to this observation, the objective of the present report was to determine the levels of serotonin transporter mRNA in lymphocytes obtained from 29 major depression patients (4 men, age 33.10+/-1.63 years) and from 30 subjects included as a control group (4 men, age 37.54+/-2.18 years) using RT-PCR. The patients were diagnosed according to the criteria of the American Psychiatric Association, and had a severity of depression of 32.68+/-1.55 determined by the Hamilton Rating Scale for Depression. The DNA was submitted to polymerase chain reaction with primers for the 5' regulatory region of human serotonin transporter, which could show the long and the short allelic forms of the transporter gene for the 5 HTTLPR polymorphism. Semiquantitative analysis was performed using beta-actin as internal and external standard. Control subjects presented the two allelic forms in 9.09% and depressed patients in 8.69%. The long variant was present in 73% of controls and in 60% of patients, without significant differences. There was a significant reduction in mRNA in depressed patients expressing the long allele. The number of immunofluorescent lymphocytes, labeled with a specific antibody against serotonin transporter, was reduced in the patients, as well as CD3+ lymphocytes. Serotonin and 5-hydroxyindoleacetic acid in platelet-poor plasma or lymphocytes did not differ between depressed patients and controls. The reduction in lymphocyte serotonin transporter described in major depression might be due to a decrease in the level of its mRNA and in the number of cells expressing it. These observations might implicate that functional modifications are associated with nervous-immune interactions in depression.
Assuntos
Transtorno Depressivo Maior/genética , Linfócitos/metabolismo , Polimorfismo Genético , Isoformas de Proteínas/genética , RNA Mensageiro/análise , Adulto , Alelos , Biomarcadores/análise , Feminino , Imunofluorescência , Humanos , Ácido Hidroxi-Indolacético/análise , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Serotonina/análiseRESUMO
cAMP regulates immune responses, and modifications in cAMP signaling are involved in the pathophysiology and treatment of depression. In the present report, basal and forskolin-stimulated levels of cAMP were determined in mononuclear cells and lymphocytes from control individuals and major depression patients. Twenty-eight patients between 24 and 59 years old were diagnosed for a major depression episode according to the criteria of the Structural Clinical Interview for Disorders of Axis I of the American Psychiatric Association. These patients presented a score of 25 for severity as measured by Hamilton Rating Scale of Depression (HAM-D), and 23 for Beck Inventory of Depression (BID). Control and patient mononuclear cells were isolated by Ficoll/Hypaque gradients and their lymphocytes were separated from the total mononuclear population by differential adhesion to plastic surface. The basal concentration of cAMP was 50% lower in mononuclear cells and lymphocytes from the depressed patients compared with the control subjects. The response to forskolin was significantly smaller in lymphocytes of major depression patients than in the controls, but no difference was evident in the mononuclear cell preparations. There was a significant increase in cAMP produced by 5HT in mononuclear cells from the control group, but not in their lymphocytes. This effect on mononuclear cells was reduced by the antagonist of 5HT1A receptors, WAY-100,135. However, the simultaneous addition of a specific agonist of 5HT1A receptors, 8-hydroxy-(dipropylamino)tetralin (DPAT) and WAY-100,135 resulted in higher levels of cAMP than with the agonist alone. This effect probably indicates the blockade of 5HT1A receptors and action of 5HT1A agonist on the other subtypes of serotonin receptors expressed on human lymphocytes. This response was not observed in the patient's lymphocytes. In lymphocytes from major depression patients, serotonin and 8-hydroxy-(dipropylamino)tetralin significantly increased cAmp levels, which was slightly reduced by WAY-100,135. The present report indicates: (1) differential responses of immune cells from control individuals and depressed patients, with lower apparent adenylate cyclase activity in patient's cells; (2) variation in the population of cells, with responses to serotonergic agonists being lower in mononuclear cells and higher in lymphocytes from major depression patients; (3) increases of cAMP levels by serotonin and 5HT1A agonist in the patient's cells; and (4) evidence of impairment in serotonergic transduction systems in immune cells during depression.
Assuntos
AMP Cíclico/sangue , Transtorno Depressivo Maior/sangue , Leucócitos Mononucleares/metabolismo , Linfócitos/metabolismo , Serotonina/farmacologia , 8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Adulto , Colforsina/farmacologia , Feminino , Humanos , Técnicas In Vitro , Leucócitos Mononucleares/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Piperazinas/farmacologia , Serotonina/metabolismo , Agonistas do Receptor 5-HT1 de Serotonina , Antagonistas do Receptor 5-HT1 de Serotonina , Antagonistas da Serotonina/farmacologiaRESUMO
Los pacientes con RF positivo a titulos altos, tuvieron mayor discapacidad funcional medida por HAQ y mayor utilización de DMARD (medicamentos modificadores de la AR). Es importante titular siempre el FR.
Assuntos
Artrite Reumatoide , Fator Reumatoide , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
There are increasing evidences of cell markers present in the immune and the nervous systems. These include neurotransmitter receptors and transporters. Serotonin receptor subtypes are related to depression and also have been shown to be present in certain cells of the immune system. In the present report, we determined the presence of 5-HT(1A) receptors by the binding of the selective agonist 8-hydroxy-2-(di-n-propyl-amino)tetralin in lymphocytes of peripheral blood isolated by Ficoll/Hypaque gradients from controls and depressed patients. The capacity of these receptors was around 24 fmol/10(6) cells in both groups of subjects, without significant difference among them. The affinity was in the nM range and either differ between controls and patients. Serotonin, 5-hydroxyindoleacetic acid, dopamine and 3,4-dihydroxyphenylacetic acid were determined by HPLC with electrochemical detector. There were no significant differences between controls and major depression patients in the values obtained for rich and poor platelet plasma or in the isolated cells. However, there was a reduction in serotonin turnover rate indicated by an increase in the ratio serotonin/5-hydroxyindoleacetic acid, but not in that of dopamine, in lymphocytes of major depression patients. Thus, there is a serotonergic dysfunction in immune circulating cells of major depression patients, without changes in the number of 5-HT(1A) receptors, although the coupling of these receptors to transduction mechanisms could be affected and may be related to the alteration of 5-HT turnover rate.
Assuntos
Transtorno Depressivo/sangue , Dopamina/sangue , Linfócitos/química , Receptor 5-HT1A de Serotonina/sangue , Serotonina/sangue , Ácido 3,4-Di-Hidroxifenilacético/sangue , 8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Adolescente , Adulto , Cromatografia Líquida de Alta Pressão , Transtorno Depressivo/imunologia , Feminino , Humanos , Ácido Hidroxi-Indolacético/sangue , Masculino , Pessoa de Meia-Idade , Psiconeuroimunologia , Agonistas do Receptor de Serotonina/farmacologiaRESUMO
A chronic methanol (MeOH) intoxication scheme (2 g/kg/day ip for 2 weeks) was carried out in Sprague-Dawley rats, previously depleted of folates with methotrexate (MTX). beta-Alanine (beta-Ala), 5%, was also administered to some animals in the drinking water. Amino acids were determined in plasma, retina, optic nerve, hippocampus and posterior cortex by HPLC with fluorescence detection and monoamines in retina, hippocampus and posterior cortex by electrochemical detection. Beta-Ala administration reduced taurine (Tau) levels in plasma, hippocampus and posterior cortex, but not in retina and optic nerve. Aspartate (Asp) concentration in the optic nerve was increased in MTX-MeOH treated animals, and the administration of beta-Ala did not modify this elevation. The association of beta-Ala with MTX-MeOH produced an increase of threonine, and a decrease of 5-hydroxytryptamine (5-HT) in the retina without modifying 5-hydroxyindoleacetic acid, whereas in the hippocampus an elevation of asparagine was observed. We conclude that, in the retina, beta-Ala in combination with MTX-MeOH increased serotonin and decreased dopamine (DA) turnover rate, and resulted in changes in the amino acid balance, that could affect glycinergic activity. On the other hand, in the hippocampus, Asp metabolism could be affected by Tau depletion with beta-Ala.
Assuntos
Aminoácidos/análise , Monoaminas Biogênicas/análise , Encéfalo/efeitos dos fármacos , Metanol/toxicidade , Retina/efeitos dos fármacos , Taurina/deficiência , Aminoácidos/sangue , Animais , Asparagina/análise , Química Encefálica , Córtex Cerebral/química , Cromatografia Líquida de Alta Pressão , Dopamina/análise , Ingestão de Líquidos , Deficiência de Ácido Fólico/induzido quimicamente , Hipocampo/química , Ácido Hidroxi-Indolacético/análise , Masculino , Metanol/administração & dosagem , Metotrexato/administração & dosagem , Nervo Óptico/química , Nervo Óptico/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Retina/química , Serotonina/análise , Taurina/análise , Taurina/fisiologia , Treonina/análise , beta-Alanina/administração & dosagemRESUMO
Tryptophan is required in the pineal gland for the formation of serotonin, precursor of melatonin biosynthesis. The level of this amino acid in the serum and in the pineal gland of the rat undergoes a circadian rhythm, and reduced plasma tryptophan concentration decreases secretion of melatonin in humans. Tryptophan is transported into the cells by the long chain neutral amine acid system T and by the aromatic amino acid system T. The high affinity component of [(3)H]tryptophan uptake was studied in pinealocytes of the rat. Inhibition was observed in the presence of phenylalanine or tyrosine, but not in the presence of neutral amino acids, alanine, glycine, serine, lysine or by 2-aminobicyclo[2,2,1]-heptane-2-carboxylic acid, a substrate specific for system L. The transport of tryptophan was temperature-dependent and trans-stimulated by phenylalanine and tyrosine, but was energy-, sodium-, chloride-, and pH-independent. In addition, the sulphydryl agent N-ethylmaleimide did not modify the high affinity transport of tryptophan in pinealocytes. The kinetic parameters were not significantly different at 12:00 as compared to 24:00 h. The treatment with the inhibitor of tryptophan hydroxylase, p-chlorophenylalanine, produced an increase in the maximal velocity of the uptake and a reduction in the affinity at 12:00, but not at 24:00 h, probably indicating that during the day, the formation of serotonin in the pineal gland is favoured by elevating the uptake of tryptophan, whereas at 24:00 h other mechanisms, such as induction of enzymes are taking place. High affinity tryptophan uptake in the rat pineal gland occurs through system T and is upregulated during the day when the availability of serotonin is reduced.
Assuntos
Fotoperíodo , Glândula Pineal/citologia , Glândula Pineal/metabolismo , Triptofano/metabolismo , Animais , Transporte Biológico/fisiologia , Ritmo Circadiano/fisiologia , Inibidores Enzimáticos/metabolismo , Etilmaleimida/metabolismo , Concentração de Íons de Hidrogênio , Masculino , Concentração Osmolar , Fenilalanina/química , Fenilalanina/metabolismo , Ratos , Ratos Sprague-Dawley , Temperatura , Tirosina/metabolismoRESUMO
The clinical and electroretinographic features of chronic methanol intoxication are scarce, and neurotransmitter studies have not been conducted. In addition, most of the studies in the field include results after acute administration. In the present work, a chronic methanol intoxication scheme (2 g/kg/day ip for 2 weeks) was carried out in Sprague-Dawley rats previously depleted of folates with methotrexate. Taurine (2%) in drinking water was also administered in two groups of animals. Blood formate levels were increased in methotrexate-methanol-treated animals with respect to controls (0.98 +/- 0.09 and 0.30 +/- 0.03 mM, respectively). Amino acids and monoamines were determined in plasma and in retina, optic nerve, hippocampus, and posterior cortex by HPLC with fluorescence or electrochemical detection. The main finding was an increased aspartate content in the optic nerve in methotrexate methanol-treated animals. Methanol alone increased glutamate, aspartate, glutamine, taurine, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid levels in the hippocampus and 5-hydroxytryptamine in the retina. Taurine administration had no significant effect on changes induced by methanol treatment. We concluded that chronic methanol administration produced accumulation of aspartate, an excitotoxic amino acid, in the optic nerve. These findings contribute to the understanding of methanol neurotoxicity and might indicate a relationship between chronic methanol consumption and the development of optic neuropathies.
Assuntos
Aminoácidos/metabolismo , Monoaminas Biogênicas/metabolismo , Encéfalo/metabolismo , Metanol/intoxicação , Neurotransmissores/metabolismo , Nervo Óptico/metabolismo , Retina/metabolismo , Aminoácidos/sangue , Animais , Monoaminas Biogênicas/sangue , Encéfalo/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Formiatos/sangue , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Metanol/administração & dosagem , Metanol/toxicidade , Metotrexato/farmacologia , Nervo Óptico/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Retina/efeitos dos fármacosRESUMO
Streptococcus pneumoniae isolates were obtained from nasopharyngeal swabs taken from children living in a low socioeconomic area of Lima, Peru, to determine the rates of antimicrobial resistance and serotype distribution. A total of 146 nasopharyngeal isolates were collected from children from 3 to 38 months of age. Twenty-one clinical laboratory isolates from both sterile and nonsterile sites were obtained from a local hospital. Isolates with reduced susceptibilities to penicillin represented 15.1 and 42.9% of the nasopharyngeal and clinical isolates, respectively. For neither group of isolates did penicillin MICs exceed 1.5 micro g/ml, indicating only intermediate resistance. Thirty-two different serotypes were identified from the 146 nasopharyngeal isolates. The serotypes of the clinical isolates were represented among those 32 types. Isolates with reduced susceptibility to multiple antimicrobial agents were present in both settings. These findings indicate some of the highest rates of antimicrobial resistance in the region as well as a slightly different serotype distribution pattern from those of other South American countries. The 7-valent conjugate pneumococcal vaccines would only have a limited effect, providing coverage for about half of all isolates. Increasing rates of resistance in Peru necessitate an awareness of antimicrobial treatment practices and vaccination strategies.
Assuntos
Streptococcus pneumoniae/efeitos dos fármacos , Pré-Escolar , Farmacorresistência Bacteriana , Humanos , Lactente , Testes de Sensibilidade Microbiana , Nasofaringe/microbiologia , Sorotipagem , Fatores Socioeconômicos , Streptococcus pneumoniae/classificaçãoRESUMO
Several immune system modifications have been reported in pathological anxiety, such as generalized anxiety, panic and obsessive-compulsive disorders. Since serotonin transporter is a marker of peripheral blood lymphocytes and it is modified in major depression, the aim of the present work was to evaluate this transporter by the binding of [3H]paroxetine to membrane preparations of blood peripheral lymphocytes from control subjects and patients with generalized anxiety disorder. The number of transporters and the affinity for the ligand did not differ among the two groups. Serotonin and 5-hydroxyindoleacetic acid (5HIAA) were determined in platelet-rich and -poor plasma, and in lymphocytes. Nonsignificant changes were found in the patients as compared to controls. However, there was a significant positive correlation between serotonin concentration in platelet-poor plasma and in lymphocytes in the patients, but not in the controls. This finding might be an indication of a poor regulation of the transporter function by which serotonin plasma concentration might influence lymphocyte serotonin concentration. Previous results indicate that serotonin transporter is reduced in these cells in major depression disorder; however, in generalized anxiety disorder, the number of transporters was not modified, although the functional efficiency of serotonin transporter might be altered.
Assuntos
Transtornos de Ansiedade/sangue , Proteínas de Transporte/sangue , Ácido Hidroxi-Indolacético/sangue , Linfócitos/metabolismo , Glicoproteínas de Membrana/sangue , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Serotonina/sangue , Adulto , Sítios de Ligação/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas da Membrana Plasmática de Transporte de SerotoninaRESUMO
La búsqueda de niveles adecuados de protección de la salud humana, salud animal y protección vegetal en el caso del Acuerdo SPS, y el aseguramiento de la calidad del bien, protección del consumidor de prácticas que puedan inducir a error y protección de los intereses esenciales en materia de seguridad en el caso del Acuerdo OTC . deben considerarse como un derecho soberano de los países, pero condicionado a que no se utilice como obstáculo injustificado del comercio.
Assuntos
Medição de Risco , Medicina Veterinária , ComércioRESUMO
The presence of serotonin 5-HT1A receptors and their physiological role were further characterized in the goldfish retina. The effects of the 5-HT6/7 receptor antagonists pimozide, fluphenazine and amoxapine, the 5-HT1A receptor antagonist WAY-100,135, and the alkylating agent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, on the 5-HT1A receptor agonist [3H]8-hydroxy-2-(di-n-propylamino)tetralin binding to retinal membranes, were evaluated. In addition, the effects of serotonin, 8-hydroxy-2-(di-n-propylamino)tetralin, WAY-100,135, the adenylate cyclase inhibitors SQ22536 and MDL12330A, and the cyclic AMP analog 8-bromoadenosine-3':5' cyclic monophosphate were also studied on neuritic outgrowth from retinal explants. WAY-100,135 but not 5-HT6/7 receptor antagonists inhibited [3H]8-hydroxy-2-(di-n-propylamino)tetralin binding to retinal membranes N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline decreased [3H]8-hydroxy-2-(di-n-propylamino)tetralin binding sites up to 70%, while receptor turnover was similar to that reported in other tissues. Serotonin and 8-hydroxy-2-(di-n-propylamino)tetralin stimulated cyclic AMP production, both ex vivo and in vitro, and these increases were related to inhibition of neuritic outgrowth. The inhibitory effect was reduced by SQ22536 and by WAY-100,135, and was mimicked by 8-bromoadenosine-3':5'cyclic monophosphate. This study supports previous findings about the role of serotonin as a regulator of axonal outgrowth during in vitro regeneration of the goldfish retina and demonstrates that this effect is mediated, at least in part, by 5-HT1A receptors through a mechanism which involves an increase of cyclic AMP levels.