RESUMO
BACKGROUND: Depression is one of the major contributors to the global burden of diseases; however, population-based data in South America are limited. METHODS: We conducted a population-based cross sectional study with 7524 participants, aged 35-74 years old, recruited between February 2010 and December 2011 from randomly selected samples in 4 cities (Bariloche and Marcos Paz, Argentina; Temuco, Chile; and Pando-Barros Blancos, Uruguay). Major Depressive Episode (MDE) was assessed using the Patient Health Questionnaire (PHQ) - 9. RESULTS: The overall prevalence of MDE was 14.6% (95% CI: 13.6, 15.6). However, there was a geographical variability of up to 3.7 folds between different cities being 5.6% (95% CI: 4.6, 6.7) in Marcos Paz, Argentina; 9.5% (95% CI: 8.2, 10.9) in Bariloche, Argentina; 18.1% (95% CI: 16.3, 20.0) in Temuco, Chile, and 18.2 (95% CI: 16.3, 20.2) in Pando-Barros Blancos, Uruguay. The multivariate model showed that, adjusted by location, being female, being between 35 and 44 years old, having experienced at least one stressful life event, currently smoking, and having a history of chronic medical diseases were independently associated with an increased risk of MDE, while having higher education and being married or living with a partner reduced the risk of MDE. LIMITATIONS: These results are representative of the selected cities included in the study. As such extrapolation to the general populations of Argentina, Chile, and Uruguay should be done with caution CONCLUSIONS: This study showed a high prevalence and variability of MDE in the Southern Cone of Latin America.
Assuntos
Transtorno Depressivo Maior/epidemiologia , Adulto , Idoso , Argentina/epidemiologia , Chile/epidemiologia , Doença Crônica , Cidades , Estudos Transversais , Feminino , Geografia , Inquéritos Epidemiológicos , Humanos , América Latina , Masculino , Pessoa de Meia-Idade , Prevalência , Inquéritos e Questionários , Uruguai/epidemiologiaRESUMO
A drug-induced liver injury (DILI) is defined as a liver injury caused by exposure to a drug or a non-infectious toxic agent with a variable degree of organ dysfunction. A better understanding of DILI epidemiology has been obtained in recent years with the institution of international registries in the United States and Europe. Despite the advances in the understanding and characterization of the phenomenon, DILI remains an exclusion diagnosis so, probability scores and the analysis of literature reports are useful tools in dealing with a suspected DILI. Idiosyncratic DILI can be considered a relatively rare event but it is one of the leading causes of acute liver failure. Thus, proper management is essential to avoid serious consequences. Here, we present an updated review of diagnostic and classification criteria of DILI. Prognostic tools, and principles of management and therapy have also been briefly discussed.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Europa (Continente) , Humanos , Sistema de Registros , Fatores de Risco , Estados UnidosRESUMO
Porcine periweaning-failure-to-thrive syndrome (PFTS) is a condition that affects newly weaned piglets. It is characterised by a progressive debilitation leading to death, in the absence of infectious, nutritional, management or environmental factors. In this study, we present the first report of PFTS in South America and the results of a genome-wide association study to identify the genetic markers associated with the appearance of this condition in a crossbred swine population. Four chromosomal regions were associated with PFTS predisposition, one located on SSCX, one on SSC8, and the two other regions on SSC14. Regions on SSC8 and SSC14 harbour important functional candidate genes involved in human depression and might have an important role in PFTS. Our findings contribute to the increasing knowledge about this syndrome, which has been investigated since 2007, and to the identification of the aetiology of this disease.
Assuntos
Insuficiência de Crescimento/veterinária , Doenças dos Suínos/genética , Animais , Insuficiência de Crescimento/genética , Feminino , Estudo de Associação Genômica Ampla , Masculino , Suínos , DesmameRESUMO
The utilization of antimicrobials in animal production, causes selection of resistant bacteria. The objective of this study was to compare the utilization of alternatives in association with preventive antibiotic therapy in swine feed during the growing and finishing phases. 1,045 animals were used from 60 to 190 days of age and were subjected to six treatments with 16 repetitions as follows: 1) antibiotic free; 2) antibiotics; 3) prebiotic; 4) probiotic; 5) essential oils; and 6) organic acid. Animals were weighted, and clinical history was recorded including mortality and diarrhea. At the abattoir, pneumonia index and gastric ulcers were investigated. The cost for each treatment was discussed. No difference between treatments were observed (P>0.05) regarding feed conversion rate (2.64±0.03), overall average weight gain (107.06±0.9kg), average daily weight gain (856.49±7.7g) and carcass weight (92.4±0.7kg). The application injectable drugs in animals presenting clinical symptoms, represented US$ 0.56/intervention, without difference between the treatments (P>0.05). Furthermore, independently of the treatment, high frequency of pneumonia was observed (>0.90). No difference for the degree of gastric ulcer nor feces consistency were observed (P>0.05). The utilization of antibiotic therapy and alternatives to antibiotics in feed did not produce benefits to the production indices and sanitary performances of the animals.(AU)
A utilização de antimicrobianos na produção animal provoca seleção de bactérias resistentes. O objetivo do estudo foi comparar a utilização de alternativas associadas à antibioticoterapia preventiva na alimentação de suínos nas fases de recria e de terminação. Foram utilizados 1.045 animais de 60 a 190 dias de idade, submetidos a seis tratamentos com 16 repetições, como segue: 1) sem antibióticos; 2) com antibióticos; 3) prebióticos; 4) probióticos; 5) óleos essenciais; e 6) ácidos orgânicos. Os animais foram pesados, e a história clínica foi registrada, incluindo mortalidade e diarreia. No abatedouro, foram investigados índices de pneumonia e úlceras gástricas. O custo de cada tratamento foi discutido. Não houve diferença entre os tratamentos (P>0,05) em relação à taxa de conversão alimentar (2,64 ± 0,03), ao ganho de peso médio geral (107,06 ± 0,9kg), ao ganho de peso médio diário (856,49 ± 7,7g) e ao peso de carcaça (92,4 ± 0,7kg). A aplicação de medicamentos injetáveis em animais com quadro clínico representou US$ 0,56/intervenção, sem diferença entre os tratamentos (P>0,05). Além disso, independentemente do tratamento, foi observada alta frequência de pneumonia (>0,90). Não foi observada diferença para o grau de úlcera gástrica nem na consistência das fezes (P>0,05). A utilização de antibioticoterapia e de alternativas aos antibióticos na ração não trouxe benefícios aos desempenhos zootécnico e sanitário dos animais.(AU)
Assuntos
Animais , Suínos/crescimento & desenvolvimento , Probióticos/administração & dosagem , Prebióticos/administração & dosagem , Gestão de Antimicrobianos/métodos , Ração Animal/análise , Antibacterianos/administração & dosagem , Óleos Voláteis/uso terapêuticoRESUMO
In immortalized GnRH neurons, cAMP production is elevated by increased extracellular Ca2+ and the Ca2+ channel agonist, BK-8644, and is diminished by low extracellular Ca2+ and treatment with nifedipine, consistent with the expression of adenylyl cyclase type I (AC I). Potassium-induced depolarization of GT1-7 neurons causes a dose-dependent monotonic increase in [Ca2+]i and elicits a bell-shaped cAMP response. The inhibitory phase of the cAMP response is prevented by pertussis toxin (PTX), consistent with the activation of G(i)-related proteins during depolarization. Agonist activation of the endogenous GnRH receptor in GT1-7 neurons also elicits a bell-shaped change in cAMP production. The inhibitory action of high GnRH concentrations is prevented by PTX, indicating coupling of the GnRH receptors to G(i)-related proteins. The stimulation of cAMP production by activation of endogenous LH receptors is enhanced by low (nanomolar) concentrations of GnRH but is abolished by micromolar concentrations of GnRH, again in a PTX-sensitive manner. These findings indicate that GnRH neuronal cAMP production is maintained by Ca2+ entry through voltage-sensitive calcium channels, leading to activation of Ca2+-stimulated AC I. Furthermore, the Ca2+ influx-dependent activation of AC I acts in conjunction with AC-regulatory G proteins to determine basal and agonist-stimulated levels of cAMP production.
Assuntos
Adenilil Ciclases/metabolismo , Cálcio/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Neurônios/metabolismo , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Toxina Adenilato Ciclase , Adenilil Ciclases/efeitos dos fármacos , Animais , Agonistas dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Sinalização do Cálcio , Polaridade Celular/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Feminino , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Hipotálamo/citologia , Hipotálamo/metabolismo , Ionomicina/farmacologia , Isoenzimas , Camundongos , Neurônios/efeitos dos fármacos , Nifedipino/farmacologia , Toxina Pertussis , Potássio/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores do LH/efeitos dos fármacos , Receptores do LH/genética , Receptores do LH/metabolismo , Receptores LHRH/efeitos dos fármacos , Receptores LHRH/metabolismo , Fatores de Virulência de Bordetella/farmacologiaRESUMO
The GT1-7 cell line of immortalized GnRH neurons has been shown to express receptors for GnRH, LH, and prolactin, as well as a variety of other hormones and transmitters. Treatment of GT1-7 cells with hCG caused a dose-dependent increase in cAMP production, with a rapid increase during the first 15 min and a subsequent decrease that was prevented by pre-treatment with pertussis toxin. Furthermore, the stimulatory effect of cholera toxin on cAMP production was inhibited by hCG in a dose-dependent manner. These data indicate that the LH receptors expressed in GT1-7 cells are coupled to adenylyl cyclase both stimulatory (Gs) and inhibitory (Gi) proteins. In perifused cell cultures, treatment with forskolin and 8-bromo cAMP increased the amplitude of spontaneous GnRH release. However, treatment with nanomolar concentrations of hCG abolished pulsatile GnRH release from both GT1-7 cells and rat hypothalamic cells. The similarity of hCG action on pulsatile GnRH release to that of extracellular Ca2+ depletion and calcium channel antagonists, and its partial resistance to potassium-induced depolarization, suggest that it results from inhibition of plasma-membrane ion channel activity. It is probable that the inhibitory action of hCG on pulsatile GnRH release is responsible for initiation of the suppression of pituitary LH secretion during pregnancy.
Assuntos
AMP Cíclico/biossíntese , Hormônio Liberador de Gonadotropina/metabolismo , Neurônios/metabolismo , Neuropeptídeos/antagonistas & inibidores , Receptores do LH/metabolismo , Toxina Adenilato Ciclase , Animais , Sítios de Ligação , Ligação Competitiva , Linhagem Celular , Toxina da Cólera/farmacologia , Gonadotropina Coriônica/farmacologia , Colforsina/farmacologia , Relação Dose-Resposta a Droga , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hipotálamo/citologia , Hipotálamo/embriologia , Hipotálamo/metabolismo , Neurônios/efeitos dos fármacos , Neuropeptídeos/metabolismo , Toxina Pertussis , Fluxo Pulsátil , Ratos , Receptores do LH/efeitos dos fármacos , Fatores de Virulência de Bordetella/farmacologiaRESUMO
Cultured rat pituitary cells and immortalized pituitary gonadotrophs (alphaT3-1 cells) express specific messenger RNA transcripts for GnRH and exhibit positive immunostaining for the GnRH peptide. Each cell type released GnRH during both static culture and perifusion, albeit in lesser amounts than cultured hypothalamic cells and GT1-7 neurons. In perifused pituitary cells, exposure to a GnRH agonist stimulated the release of GnRH as well as LH. In contrast, treatment with a GnRH receptor antagonist or with GnRH antiserum decreased basal LH release. In pituitary cell cultures, a small proportion of gonadotrophs exhibited high amplitude and low frequency baseline Ca2+ oscillations in the absence of GnRH stimulation. Such spontaneous oscillations were comparable to those induced by picomolar concentrations of GnRH and could be abolished by treatment with a GnRH antagonist. These in vitro findings indicate that locally produced GnRH causes low level activation of pituitary GnRH receptors, induces spontaneous intracellular Ca2+ oscillations, and contributes to basal LH secretion in cultured pituitary cells. In vivo, such autocrine or paracrine actions of pituitary-derived GnRH could provide a mechanism for the maintenance of optimal responsiveness of the gonadotrophs to pulses of GnRH arising in the hypothalamus. The presence and actions of GnRH in the anterior pituitary gland, the major site of expression of GnRH receptors, suggest that local regulatory effects of the neuropeptide could supplement the primary hypothalamic mechanism for the control of episodic gonadotropin secretion.
Assuntos
Hormônio Liberador de Gonadotropina/fisiologia , Hipófise/fisiologia , Animais , Cálcio/metabolismo , Células Cultivadas , Feminino , Hormônio Liberador de Gonadotropina/agonistas , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hipotálamo/citologia , Hipotálamo/metabolismo , Imuno-Histoquímica , Hormônio Luteinizante/metabolismo , Neurônios/metabolismo , Hipófise/citologia , Gravidez , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Episodic hormone secretion is a characteristic feature of the hypothalamo-pituitary-gonadal system, in which the profile of gonadotropin release from pituitary gonadotrophs reflects the pulsatile secretory activity of GnRH-producing neurons in the hypothalamus. Pulsatile release of GnRH is also evident in vitro during perifusion of immortalized GnRH neurons (GT1-7 cells) and cultured fetal hypothalamic cells, which continue to produce bioactive GnRH for up to 2 months. Such cultures, as well as hypothalamic tissue from adult rats, express GnRH receptors as evidenced by the presence of high-affinity GnRH binding sites and GnRH receptor transcripts. Furthermore, individual GnRH neurons coexpress GnRH and GnRH receptors as revealed by double immunostaining of hypothalamic cultures. In static cultures of hypothalamic neurons and GT1-7 cells, treatment with the GnRH receptor antagonist, [D-pGlu1, D-Phe2, D-Trp(3,6)]GnRH caused a prominent increase in GnRH release. In perifused hypothalamic cells and GT1-7 cells, treatment with the GnRH receptor agonist, des-Gly10-[D-Ala6]GnRH N-ethylamide, reduced the frequency and increased the amplitude of pulsatile GnRH release, as previously observed in GT1-7 cells. In contrast, exposure to the GnRH antagonist analogs abolished pulsatile secretion and caused a sustained and progressive increase in GnRH release. These findings have demonstrated that GnRH receptors are expressed in hypothalamic GnRH neurons, and that receptor activation is required for pulsatile GnRH release in vitro. The effects of GnRH agonist and antagonist analogs on neuropeptide release are consistent with the operation of an ultrashort-loop autocrine feedback mechanism that exerts both positive and negative actions that are necessary for the integrated control of GnRH secretion from the hypothalamus.
Assuntos
Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Neurônios/metabolismo , Animais , Comunicação Autócrina , Células Cultivadas , Hipotálamo/citologia , Hipotálamo/embriologia , Ratos , Ratos Sprague-Dawley , Receptores LHRH/efeitos dos fármacos , Taxa SecretóriaRESUMO
Agonist activation of cholinergic receptors expressed in perifused hypothalamic and immortalized GnRH-producing (GT1-7) cells induced prominent peaks in GnRH release, each followed by a rapid decrease, a transient plateau, and a decline to below basal levels. The complex profile of GnRH release suggested that acetylcholine (ACh) acts through different cholinergic receptor subtypes to exert stimulatory and inhibitory effects on GnRH release. Whereas activation of nicotinic receptors caused a transient increase in GnRH release, activation of muscarinic receptors inhibited basal GnRH release. Nanomolar concentrations of ACh caused dose-dependent inhibition of cAMP production that was prevented by pertussis toxin (PTX), consistent with the activation of a plasma-membrane Gi protein. Micromolar concentrations of ACh also caused an increase in phosphoinositide hydrolysis that was inhibited by the M1 receptor antagonist, pirenzepine. In ACh-treated cells, immunoblot analysis revealed that membrane-associated G(alpha q/11) immunoreactivity was decreased after 5 min but was restored at later times. In contrast, immunoreactive G(alpha i3) was decreased for up to 120 min after ACh treatment. The agonist-induced changes in G protein alpha-subunits liberated during activation of muscarinic receptors were correlated with regulation of their respective transduction pathways. These results indicate that ACh modulates GnRH release from hypothalamic neurons through both M1 and M2 muscarinic receptors. These receptor subtypes are coupled to Gq and Gi proteins that respectively influence the activities of PLC and adenylyl cyclase/ion channels, with consequent effects on neurosecretion.
Assuntos
Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Neurossecreção , Receptores Muscarínicos/fisiologia , Acetilcolina/farmacologia , Animais , Células Cultivadas , AMP Cíclico/biossíntese , Feminino , Proteínas de Ligação ao GTP/fisiologia , Hipotálamo/citologia , Fosfatidilinositóis/metabolismo , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Platelets isolated from patients with hypercholesterolemia are more sensitive in vitro to various aggregating agents, including epinephrine, than those isolated from normocholesterolemic subjects. Increased platelet reactivity is one mechanism that may explain the enhanced risk of thromboembolism in hypercholesterolemia. This study assessed whether platelet hyperreactivity to epinephrine in hypercholesterolemia is associated with higher alpha 2-adrenergic receptor density or affinity for epinephrine. METHODS: Platelet aggregation and binding studies, with use of [3H]yohimbine as ligand, were performed on platelets isolated from 30 patients with type IIa hypercholesterolemia and 23 control subjects. RESULTS: Platelet aggregation in response to epinephrine was significantly higher in patients with hypercholesterolemia than in control subjects. A statistically significantly higher alpha 2-adrenergic receptor density was observed in a subgroup of 13 patients with hypercholesterolemia than in 13 sex- and age-matched control subjects (280 +/- 61 and 230 +/- 49 fmol/mg protein respectively; p < 0.03), but no difference was observed in receptor affinity for the ligand. In these subgroups plasma total and levels of low-density lipoprotein (LDL) cholesterol were inversely correlated with platelet aggregation but directly correlated with platelet receptor density. CONCLUSION: Platelet alpha 2-adrenergic receptor density is increased in hypercholesterolemia and directly correlates with plasma total and levels of LDL cholesterol, providing at least a partial explanation for the enhanced platelet response to epinephrine that is observed in hypercholesterolemia.
Assuntos
Epinefrina/fisiologia , Hipercolesterolemia/metabolismo , Hipercolesterolemia/fisiopatologia , Agregação Plaquetária , Receptores Adrenérgicos alfa 2/metabolismo , Antagonistas Adrenérgicos alfa/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Hipercolesterolemia/sangue , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Ioimbina/metabolismoRESUMO
OBJECTIVE: To analyse whether platelets from hypertensive patients have an increased responsiveness to aggregating agents during morning hours and whether these changes might be related to concurrent changes in platelet membrane alpha 2-adrenoceptor characteristics, plasma catecholamine and cortisol levels, and blood pressure values. DESIGN AND METHODS: Blood samples from 14 mild-to-moderate essential hypertensive males were collected in the morning (0700-0900 h) and the evening (1900-2100 h) to determine platelet aggregability responses to adrenaline and ADP, platelet alpha 2-adrenoceptor number and binding affinity to [3H]-yohimbine, plasma catecholamines and cortisol. During the same day patients underwent 24-h ambulatory blood pressure monitoring. RESULTS: The lowest concentration of adrenaline required to induce biphasic aggregation was significantly lower in the morning than in the evening, indicating an increased morning platelet aggregability to adrenaline; the minimum ADP concentration inducing aggregation was similar in morning and evening samples. There were no significant differences between morning and evening samples in platelet alpha 2-adrenoceptor number and binding affinity. Plasma adrenaline, noradrenaline and cortisol levels were higher in the morning than in the evening, but no correlation was observed between hormonal changes and the morning increase in platelet sensitivity to adrenaline. Ambulatory blood pressure recording showed abrupt morning elevations in systolic and diastolic blood pressures over sleeping values. However, morning blood pressure readings were not significantly different from those recorded during the rest of the day and in the evening. The morning rise in mean arterial pressure displayed a significant inverse correlation with the increased platelet sensitivity to adrenaline that was observed during the same hours. CONCLUSIONS: The results indicate that the increased morning responsiveness to adrenaline that was observed in platelets obtained from hypertensive patients does not appear to be mediated by changes in the characteristics of platelet membrane alpha 2-adrenoceptors, but morning blood pressure elevations might play some role in inducing this platelet hyper-reactivity.
Assuntos
Plaquetas/metabolismo , Ritmo Circadiano , Hipertensão/sangue , Agregação Plaquetária , Receptores Adrenérgicos alfa/metabolismo , Difosfato de Adenosina/farmacologia , Adulto , Pressão Sanguínea , Epinefrina/sangue , Epinefrina/farmacologia , Humanos , Hidrocortisona/sangue , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Agregação Plaquetária/efeitos dos fármacosRESUMO
The effects of different doses of the angiotensin-converting enzyme inhibitor benazepril on cardiovascular response to a set of standardized laboratory tasks were analyzed. Eighteen patients (15 men and 3 women) with mild-to-moderate essential hypertension were randomly allocated to receive 10 or 20 mg of benazepril, or placebo, each administered once daily for 2 weeks, according to a double-blind, 3-period design. At the end of each treatment period, patients were examined at resting baseline and while performing mental arithmetic, handgrip and cycle ergometry tests. In comparison with placebo, the average reductions in resting systolic blood pressure (BP) were 8.7 mm Hg (95% confidence intervals [CI] -15.2 to -2.1) with 10 mg of benazepril, and 7.8 mm Hg (95% CI -14.4 to -1.3) with 20 mg; the corresponding reductions in resting diastolic BP were 5.1 mm Hg (95% CI -8.7 to -1.4) and 6.8 mm Hg (95% CI -10.4 to -3.1) (all p < 0.05). During mental arithmetic, the reductions in systolic BP were 10.4 mm Hg (95% CI -17.4 to -3.4) with 10 mg of benazepril, and 13.8 mm Hg (95% CI -20.8 to -6.8) with 20 mg; diastolic BP was reduced by 4.5 mm Hg (95% CI -8.5 to -0.5) and 8.3 mm Hg (95% CI -13.2 to -4.3), respectively (all p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Benzazepinas/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Esforço Físico/efeitos dos fármacos , Estresse Fisiológico/fisiopatologia , Adulto , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Benzazepinas/administração & dosagem , Pressão Sanguínea/fisiologia , Método Duplo-Cego , Teste de Esforço , Feminino , Mãos/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Esforço Físico/fisiologia , Placebos , Pensamento/fisiologiaRESUMO
The effects of the Y2 receptor agonist neuropeptide Y NPY-(13-36) on the depolarization-evoked release of [3H]noradrenaline (NA) from synaptosomal preparations of the medulla oblongata, the hypothalamus, the hippocampal formation and the parieto-occipital cortex of the male rat were studied. NPY-(13-36) (0.1-100 nM) caused a concentration-related inhibition of the depolarization-induced release of [3H]NA in all areas studied, except the parieto-occipital cortex. The results indicate that NPY Y2 receptors are present on NA terminals in all areas studied, except the parieto-occipital cortex and inhibit depolarization-evoked [3H]NA release.
Assuntos
Encéfalo/efeitos dos fármacos , Neuropeptídeo Y/farmacologia , Norepinefrina/metabolismo , Fragmentos de Peptídeos/farmacologia , Potássio/antagonistas & inibidores , Receptores de Neuropeptídeo Y/efeitos dos fármacos , Sinaptossomos/efeitos dos fármacos , Animais , Encéfalo/metabolismo , Masculino , Fentolamina/farmacologia , Ratos , Ratos Wistar , Sinaptossomos/metabolismoRESUMO
Presynaptic receptors may reduce transmitter release with different mechanisms. Both the alpha 2-agonist, clonidine and the Y2-agonist, neuropeptide Y fragment 13-36 (NPY 13-36), induce a concentration-dependent inhibition of the 4-aminopyridine (4-AP)-evoked [3H]noradrenaline ([3H]NA) release from hypothalamic synaptosomes. Changes in alpha 2- and Y2-modulation of noradrenaline (NA) release were observed by lowering the calcium influx with the use of omega-conotoxin (omega-CgTx), a calcium-channel blocking agent. In these experimental conditions, clonidine was less active, whereas NPY 13-36 preserved its efficacy. It therefore seems possible that presynaptic alpha 2-adrenoceptors can primarily inhibit NA release by reducing calcium influx via voltage-sensitive calcium channels (VSCC), while Y2-receptors may inhibit the intracellular release process with a mechanism independent of the calcium entry.
Assuntos
4-Aminopiridina/farmacologia , Hipotálamo/metabolismo , Norepinefrina/metabolismo , Receptores Adrenérgicos alfa 2/fisiologia , Receptores de Neuropeptídeo Y/fisiologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Clonidina/farmacologia , Hipotálamo/efeitos dos fármacos , Masculino , Venenos de Moluscos/farmacologia , Neuropeptídeo Y/farmacologia , Fragmentos de Peptídeos/farmacologia , Peptídeos/farmacologia , Terminações Pré-Sinápticas/metabolismo , Ratos , Ratos Wistar , Receptores Adrenérgicos alfa 2/efeitos dos fármacos , Receptores de Neuropeptídeo Y/efeitos dos fármacos , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo , Fatores de Tempo , ômega-Conotoxina GVIARESUMO
Although ambulatory blood pressure monitoring has been used widely for the evaluation of antihypertensive treatment, little information is available regarding the comparison between this method and casual BP measurement during drug trials. In our study, we tested the efficacy of a new formulation of verapamil, 240 mg sustained-release tablets, and compared the degree of BP reduction as detected by casual (standard mercury manometer) and by 24-hour ambulatory recording (Spacelab ICR 5300). A statistically significant fall in casual BP was observed after verapamil with respect to placebo. Moreover, 24-hour, waking and sleeping ambulatory BPs were significantly reduced by verapamil. The mean BP reduction was similar for office (20.1/16.1 +/- 4.3/3.1 mmHg) and for day-time ambulatory monitoring (13.4/10.7 +/- 4.2/1.9 1.9 mmHg), but no correlation was found between BP fall recorded by the two techniques for individual subjects. This study suggests that sustained-release verapamil is an effective antihypertensive drug. Individual mean BP reduction outside the clinic may not be predicted from office readings and therefore ambulatory BP recording seems to provide a better basis for testing the efficacy of drugs.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Verapamil/administração & dosagem , Adulto , Preparações de Ação Retardada , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Verapamil/uso terapêuticoRESUMO
Seven chicken infectious anemia virus (CIAV) isolates were obtained from seven broiler flocks with poor performance in two states of Brazil. All isolates induced thymus atrophy, bone-marrow aplasia, and low hematocrit values when inoculated into 1-day-old susceptible chicks. The CIAV isolates were resistant to treatment with chloroform and were able to pass through 50-nm-pore-size filters. CIAV-specific antigens could be demonstrated in tissues of experimentally infected chicks using a monoclonal antibody specific for CIAV. These characteristics of the virus and the virus-induced lesions demonstrate that CIAV is present in Brazil and that the virus is associated with production problems.
Assuntos
Anemia/veterinária , Galinhas , Vírus de DNA/isolamento & purificação , Doenças das Aves Domésticas/microbiologia , Viroses/veterinária , Anemia/microbiologia , Anemia/patologia , Animais , Antígenos Virais/análise , Medula Óssea/patologia , Brasil , Linhagem Celular , Vírus de DNA/ultraestrutura , Microscopia Eletrônica , Doenças das Aves Domésticas/patologia , Inoculações Seriadas , Baço/microbiologia , Baço/patologia , Timo/microbiologia , Timo/patologia , Viroses/microbiologia , Viroses/patologiaRESUMO
Histochemical and lectinhistochemical examinations were carried out on nasal mucosa of pigs with or without respiratory diseases. As the results, both acid and neutral mucins coexisted in nasal mucosa of normal pigs while acid sialomucins were mainly observed in nasal mucosa of pigs infected with Bordetella bronchiseptica and/or Pasteurella multocida. Lectinhistochemistry revealed that the nasal epithelial cells of normal pigs were rich in N-acetylgalactosamine, fucose and N-acetyl-glucosamine residues which showed a tendency to disappear in porcine cytomegalovirus infection and to increase in atrophic rhinitis, respectively.
Assuntos
Infecções por Bordetella/veterinária , Bordetella bronchiseptica , Lectinas/metabolismo , Mucosa Nasal/metabolismo , Infecções por Pasteurella/veterinária , Pasteurella multocida , Rinite Atrófica/veterinária , Doenças dos Suínos/metabolismo , Animais , Infecções por Bordetella/metabolismo , Infecções por Bordetella/microbiologia , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/veterinária , Infecções por Citomegalovirus/virologia , Células Epiteliais/metabolismo , Glicoconjugados/metabolismo , Histocitoquímica , Infecções por Pasteurella/metabolismo , Infecções por Pasteurella/microbiologia , Rinite Atrófica/metabolismo , Rinite Atrófica/microbiologia , Suínos , Doenças dos Suínos/microbiologiaRESUMO
In order to investigate whether the severity of ventricular ectopic beats in hypertensive patients is influenced by the autonomic drive to the heart, we evaluated the relationship between the degree of dysrhythmias and 24-h spontaneous heart rate variability, an index of sympatho-vagal balance at cardiac level. Ambulatory 24-h ECG monitoring was used to examine 42 untreated essential hypertensives, previously scored for the presence and the extent of hypertensive target organ damage. No significant difference was found in the prevalence of complex ventricular ectopic beats in patients with a heart rate variability that was lower and higher than the arbitrary cut off points selected to divide subjects into groups. Neither heart rate variability nor the degree of arrhythmias was correlated with blood pressure levels, whereas the degree of ectopy was influenced by the presence of target organ damage and left ventricular hypertrophy (by ECG). Our results seem to exclude an association between dysrhythmias in hypertensives and autonomic outflow to the heart as detected by the analysis of heart rate variability.
Assuntos
Arritmias Cardíacas/fisiopatologia , Frequência Cardíaca/fisiologia , Hipertensão/fisiopatologia , Adulto , Idoso , Arritmias Cardíacas/etiologia , Eletrocardiografia Ambulatorial , Ventrículos do Coração/fisiopatologia , Humanos , Hipertensão/complicações , Pessoa de Meia-IdadeRESUMO
Inhaled bronchodilators, including beta(2)-agonists and antimuscaric receptor antagonists, are the mainstay of pharmacotherapy in chronic obstructive pulmonary disease (COPD). The short-acting beta(2)-agonists, including salbutamol, and fenoterol, have a rapid onset of action, a bronchodilating effect for 3-6 h and are used on demand. The long-acting beta(2)-agonists (LABAs), including salmeterol and formoterol, have 12-hour duration of action and are used with a twice-daily dosing regimen for long-term COPD treatment. Unlike salmeterol, formoterol has a rapid onset of action. Pharmacological characteristics required by novel inhaled LABAs include 24 h bronchodilator effect in vivo which would make them suitable for once daily administration (ultra-LABA), high potency and selectivity for beta(2)-adrenoceptors, rapid onset of action, low oral bioavailability (< 5%) after inhalation, and high systemic clearance. Indacaterol, which has been approved for long-term treatment of COPD in Europe and in the USA, has a 24-h duration of action and a once-daily dosing regimen. Newer ultra-LABAs, including olodaterol, vilanterol, milveterol, carmoterol, and abediterol, are in development. Combination with ICS (fluticasone/salmeterol, budesonide/formoterol, beclomethasone/formoterol) appears to provide an additional benefit over the monocomponent therapy, although the extent of this benefit is variable and often not clinically significant in all the endpoints assessed. In patients with COPD, treatment with ICS is associated with increased risk of pneumonia which should be carefully considered when assessing the risk/benefit ratio of ICS/LABA combinations. Subphenotyping of patients with COPD (e.g., frequent exacerbations, sputum eosinophilia, mixed asthma/COPD phenotype) might help identify those patients who are most likely to benefit from addition of ICS to bronchodilating treatment. Ultra-LABA/ long-acting muscarinic receptor antagonist (LAMA) combination treatment is under development and is likely to become a standard pharmacological strategy for COPD. Dual-pharmacology inhaled muscarinic antagonist-beta(2) agonist (MABA) molecules provide a new approach to the treatment of COPD.
Assuntos
Corticosteroides/uso terapêutico , Agonistas Adrenérgicos beta/uso terapêutico , Broncodilatadores/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Administração por Inalação , Corticosteroides/administração & dosagem , Corticosteroides/química , Corticosteroides/farmacologia , Agonistas Adrenérgicos beta/administração & dosagem , Agonistas Adrenérgicos beta/química , Agonistas Adrenérgicos beta/farmacologia , Animais , Broncodilatadores/administração & dosagem , Broncodilatadores/química , Broncodilatadores/farmacologia , Quimioterapia Combinada , Humanos , Pulmão/efeitos dos fármacos , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Relação Estrutura-AtividadeRESUMO
The effect of organic acids and mannanoligosaccharide addition to the diet was assessed in pigs orally inoculated with Salmonella typhimurium. Forty-six growers were distributed among four treatments: Basal Diet (BD); BD+encapsulated organic acids; BD+free organic acids; BD+mannanoligosaccharide. Seroconversion was monitored, and feces and tissue samples were tested for Salmonella isolation. No treatment prevented the carrier state, but a tendency of lower fecal excretion was observed in the group treated with mannanoligosaccharide.