In teleost fishes the neurochemicals involved in sensing and responding to hypoxia are unresolved. Serotonergic branchial neuroepithelial cells (NECs) are putative O2 chemoreceptors believed to be homologous to the neural crest (NC) derived APUD (amine-precursor uptake and decarboxylation) pulmonary NECs and carotid body type-1 glomus cells. Branchial NECs contain serotonin (5-HT), thought to be central to the induction of the hypoxic cardioventilatory reflexes. However, application of 5-HT in vivo does not elicit cardioventilatory reflexes similar to those elicited by hypoxia. But previous in vitro neural recordings from glossopharyngeal (IX) afferents innervating O2 chemoreceptors in the trout gill show the same discharge response to hypoxic conditions as does that of acetylcholine (ACh) application. This evidence strongly supports the cholinergic hypothesis of chemoreceptor impulse origin rather than a serotonergic-induced impulse origin model. We therefore hypothesized that NECs contain ACh among other neurochemicals in cells belonging to the APUD series. Although serotonergic branchial NECs did not colocalize with ACh using immunohistochemical methods, several populations of ACh and/or tyrosine hydroxylase (TH) (catecholaminergic) positive, dopamine (DA) negative, cells were found throughout the second gill arch of the channel catfish Ictalurus punctatus. In addition, the NC derivation marker zn-12 labelled the HNK-1-like epitope (Human natural killer) expressed by lamellar pillar cells’ collagen column-associated pillar cell adhesion molecules (CC-PCAMs), evidence confirming their hypothesized NC origin.

nÃo hà / At first, a brief discussion on monetary economy and the regimen of target for inflation in Brazil will be performed. This latter has been an important step towards stabilization in our country, as there was an annual average of inflation about 842% within a period immediately before the adoption of the target. Besides influencing in a positive manner the Central Bank of Brazilâs credibility, it is possible to notice an augmented inclusion in this regimen on the part of many countries since 1990, when it had its start in New Zealand. The conferences held by the Monetary Policy Committee (COPOM) will also be taken into consideration, for it has been responsible for the establishment of the target regarding interest rates (SELIC), which is the main tool related to monetary policy assumed by the Central Bank of Brazil in order to maintain inflation inside of the levels proposed by the National Monetary Council (CMN), so as to identify which variables can interfere in and affect the decisions made by such committee. / Inicialmente, fazemos uma breve discussÃo sobre economia monetÃria e o regime de metas de inflaÃÃo no Brasil, que foi um importante passo para a estabilizaÃÃo da inflaÃÃo no paÃs, jà que se teve uma mÃdia anual de inflaÃÃo de 842% num perÃodo imediatamente antes da adoÃÃo das metas. AlÃm de afetar positivamente a credibilidade do Banco Central. Nota-se tambÃm uma adesÃo crescente de diversos paÃses a esse regime desde 1990, quando teve inÃcio na Nova ZelÃndia. TambÃm analisamos as reuniÃes do Comità de PolÃtica MonetÃria (COPOM), responsÃvel pela fixaÃÃo da meta da taxa de juros (Selic), que à o principal instrumento de polÃtica monetÃria utilizada pelo Banco Central do Brasil para manter a inflaÃÃo dentro dos nÃveis estabelecidos pelo Conselho MonetÃrio Nacional (CMN), identificando quais sÃo as variÃveis que podem influenciar e afetar as decisÃes deste comitÃ. Neste artigo, usamos a abordagem estatÃstica para dados de alta freqÃÃncia desenvolvida por Hamilton e Jordà (2002) para a economia brasileira, pretendendo modelar e prever a decisÃo da taxa de juros (Selic) do Banco Central. De acordo com os principais resultados, a taxa de Hazard obtida parece inferir que o Banco Central muda a taxa Selic com uma probabilidade condicional de 36%. VariÃveis como o desvio entre a inflaÃÃo observada e a meta, e a diferenÃa entre o Produto Interno Bruto e o produto potencial parecem ser mais significantemente relevantes em explicar a duraÃÃo e os marks para a mudanÃa do alvo, corroborando com os resultados em Portugal (2008). Somos tambÃm capazes de prever razoavelmente a taxa Selic na amostra."

ATP-sensitive K+ channels (KATP) channels were first described in the cardiac muscles. KATP channels are a complex of regulatory sulphonylurea receptor subunits and pore-forming inward rectifier subunits such as Kir6.1. Nicotine, an exogenous substance, adversely affects cardiovascular function in humans. Acetylcholine (ACh) is well known as a key neurotransmitter of the parasympathetic nervous system. ACh effects are usually related to binding to muscarinic receptors and stimulating second messengers that relay and direct the extracellular signals to different intracellular destinations, resulting in modulated cellular activity. We hypothesize that nicotine and ACh may modulate Kir6.1 channels via different mechanisms. Using the whole cell patch-clamp technique, the interactions of nicotine and ACh with Kir6.1 subunit permanently expressed in Human Embryonic Kidney (HEK-293) cells as well as the underlying mechanisms were studied.<p> Non-transfected HEK-293 cells possess an endogenous K+ current with current density of 3.2 ± 1.4 pA/pF at 150 mV (n = 9). Stable expression of Kir6.1 subunits cloned from rat mesenteric artery in HEK-293 cells yielded a detectable inward rectifier KATP current (-23.9 ± 1.6 pA/pF at 150 mV, n = 6). In the presence of 0.3 mM ATP in the pipette solution, nicotine at 30 and 100 µM increased the expressed Kir6.1 currents by 42 ± 11.8 and 26.2 ± 14.6%, respectively (n = 4-6, p<0.05). In contrast, nicotine at 1-3 mM inhibited Kir6.1 currents (p<0.05). Nicotine at 100 µM increased the production of superoxide anion (O2.-) by 20.3 ± 5.7% whereas at 1 mM it significantly decreased the production of O2.- by 37.7 ± 4.3%. The hypoxanthine/xanthine oxidase (HX/XO) reaction was used as a source of O2.-. Co-application of HX and XO to the transfected HEK-293 cells resulted in a significant and reproducible increase in Kir6.1 currents. Tempol, a scavenger of O2.-, abolished the stimulatory effect of HX/XO on Kir6.1 currents. Tempol also abolished the stimulatory effect of 30 mM nicotine on Kir6.1 currents (-28.3 ± 6.1 pA/pF vs. -31.2 ± 7.3 pA/pF at -150 mV, n = 6-9 for each group, p>0.05). <p> In the presence of 0.3 mM ATP in the pipette solution, ACh concentration-dependently increased the expressed Kir6.1 currents. At 1 µM, ACh increased Kir6.1 currents from -19 ± 2.5 to 31.7 ± 2.1 pA/pF (n = 8, p < 0.05). Pretreatment of the transfected HEK-293 cells with either 2 or 20 µM atropine, 100 nM a-bungarotoxin, 100 µM mecamylamine, 2 µM prazosin, 1 µM propranolol, or 10 µM dihydro-b-erythroidine hydrobromide did not alter the stimulatory effect of ACh on Kir6.1 currents (n = 4 - 5 for each group, p<0.05). When intracellular ATP was increased to 5 mM, ACh at 10 µM still exhibited its stimulatory effect (-16.4 ± 2.3 to 25.5 ± 3.8 pA/pF, n = 8, p<0.05). For the first time, the present study provides an insight for the interactions of nicotine and ACh with Kir6.1 subunits. Our data demonstrate that micromolar concentration of nicotine and ACh stimulated Kir6.1 channels. Nicotine at millimolar concentrations inhibited Kir6.1 channels. The dual effect of nicotine, not mediated by nAChR, are mediated partially by O2.- levels in the cells. The ACh excitatory effect is mediated neither by an AChR-dependent mechanism, nor by alteration in ATP metabolism. This study challenges the traditional explanations for the receptor-mediated effects of nicotine and ACh on ion channels and opens a new door to understand the effects of nicotine and ACh on KATP channels in many cellular systems.

ATP-sensitive K+ channels (KATP) channels were first described in the cardiac muscles. KATP channels are a complex of regulatory sulphonylurea receptor subunits and pore-forming inward rectifier subunits such as Kir6.1. Nicotine, an exogenous substance, adversely affects cardiovascular function in humans. Acetylcholine (ACh) is well known as a key neurotransmitter of the parasympathetic nervous system. ACh effects are usually related to binding to muscarinic receptors and stimulating second messengers that relay and direct the extracellular signals to different intracellular destinations, resulting in modulated cellular activity. We hypothesize that nicotine and ACh may modulate Kir6.1 channels via different mechanisms. Using the whole cell patch-clamp technique, the interactions of nicotine and ACh with Kir6.1 subunit permanently expressed in Human Embryonic Kidney (HEK-293) cells as well as the underlying mechanisms were studied.<p> Non-transfected HEK-293 cells possess an endogenous K+ current with current density of 3.2 ± 1.4 pA/pF at 150 mV (n = 9). Stable expression of Kir6.1 subunits cloned from rat mesenteric artery in HEK-293 cells yielded a detectable inward rectifier KATP current (-23.9 ± 1.6 pA/pF at 150 mV, n = 6). In the presence of 0.3 mM ATP in the pipette solution, nicotine at 30 and 100 µM increased the expressed Kir6.1 currents by 42 ± 11.8 and 26.2 ± 14.6%, respectively (n = 4-6, p<0.05). In contrast, nicotine at 1-3 mM inhibited Kir6.1 currents (p<0.05). Nicotine at 100 µM increased the production of superoxide anion (O2.-) by 20.3 ± 5.7% whereas at 1 mM it significantly decreased the production of O2.- by 37.7 ± 4.3%. The hypoxanthine/xanthine oxidase (HX/XO) reaction was used as a source of O2.-. Co-application of HX and XO to the transfected HEK-293 cells resulted in a significant and reproducible increase in Kir6.1 currents. Tempol, a scavenger of O2.-, abolished the stimulatory effect of HX/XO on Kir6.1 currents. Tempol also abolished the stimulatory effect of 30 mM nicotine on Kir6.1 currents (-28.3 ± 6.1 pA/pF vs. -31.2 ± 7.3 pA/pF at -150 mV, n = 6-9 for each group, p>0.05). <p> In the presence of 0.3 mM ATP in the pipette solution, ACh concentration-dependently increased the expressed Kir6.1 currents. At 1 µM, ACh increased Kir6.1 currents from -19 ± 2.5 to 31.7 ± 2.1 pA/pF (n = 8, p < 0.05). Pretreatment of the transfected HEK-293 cells with either 2 or 20 µM atropine, 100 nM a-bungarotoxin, 100 µM mecamylamine, 2 µM prazosin, 1 µM propranolol, or 10 µM dihydro-b-erythroidine hydrobromide did not alter the stimulatory effect of ACh on Kir6.1 currents (n = 4 - 5 for each group, p<0.05). When intracellular ATP was increased to 5 mM, ACh at 10 µM still exhibited its stimulatory effect (-16.4 ± 2.3 to 25.5 ± 3.8 pA/pF, n = 8, p<0.05). For the first time, the present study provides an insight for the interactions of nicotine and ACh with Kir6.1 subunits. Our data demonstrate that micromolar concentration of nicotine and ACh stimulated Kir6.1 channels. Nicotine at millimolar concentrations inhibited Kir6.1 channels. The dual effect of nicotine, not mediated by nAChR, are mediated partially by O2.- levels in the cells. The ACh excitatory effect is mediated neither by an AChR-dependent mechanism, nor by alteration in ATP metabolism. This study challenges the traditional explanations for the receptor-mediated effects of nicotine and ACh on ion channels and opens a new door to understand the effects of nicotine and ACh on KATP channels in many cellular systems.

No description available.

Posttraumatic Stress Disorder (PTSD) is a psychiatric condition that can develop following exposure to a traumatic event involving actual or threatened death or serious injury. Responses include intense fear, helplessness or horror. Symptoms are characterised into clusters, described as re-experiencing, avoidance, and arousal. These symptoms, which are also evident in other conditions, have been associated with dysfunctions in the central acetylcholinergic system. Benefits from administering acetylcholinesterase inhibitors (AChEI) to people suffering these symptoms have been demonstrated. Donepezil hydrochloride, a reversible inhibitor of the enzyme acetylcholinesterase, is used in the treatment of conditions with difficulties in cognitive function, but has not been used in PTSD. The aim of this thesis was to determine (1) whether there was a difference in the ACh system in people with PTSD and (2) whether administration of an AChEI would change the symtomatology. IDEX (I¹ ² ³ iododexetimide) has been useful in imaging muscarinic-ACh receptors using Single Photon Emission Computerised Tomography (SPECT) and was utilised to investigate whether cholinergic activity in PTSD is altered. One hundred and sixty eight potential subjects were screened and eleven PTSD subjects were enrolled in the IDEX SPECT study. Three healthy non-PTSD control subjects also completed the study. Due to technical complications only the data obtained from eight PTSD and two control subjects was available for analysis. Imaging data for 2 further healthy non-PTSD control subjects were obtained from another study. Sixteen subjects were enrolled in the donepezil open label study (assessed at baseline, Week 2, 6 and 10). Nine PTSD subjects completed the 10-week trial and seven withdrew prematurely (at or after Week 2) due to side effects or a worsening of PTSD symptoms. For the IDEX SPECT study, a voxel-by-voxel statistical analysis of the PTSD subject group versus the control group showed both areas of reduced and increased IDEX uptake. Significant clusters in the PTSD group with a reduced IDEX uptake centred around the bilateral hippocampus, left insula and right precuneus, while increased IDEX uptake appeared in the caudate head. For the donepezil study, in the per-protocol analysis (including only the 9 subjects that completed the protocol), all psychological assessments revealed a difference between the totals obtained at the Week 10 visit compared to those at the Baseline visit and the improvement was in the order of 51%. The intention-to-treat analysis (including all 16 subjects), a repeated measures Analysis of Variance (ANOVA) with a mixed models approach showed that all psychological measures demonstrated statistically significant benefits of the treatment. All subjects who completed the protocol recounted considerable improvement in their overall PTSD symptom profile, which covered symptoms in each of the three clusters. The results of the IDEX SPECT study suggest that alterations in ACh binding in PTSD are evident and may begin to explain a part of the altered cognitive symptomatology apparent in this condition. The pilot open label donepezil trial provided some preliminary evidence that treatment with an AChEI can lessen the intrusions and distress associated with traumatic memories in people with PTSD. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1374974 / Thesis (M.Med.Sc.) -- University of Adelaide, School of Medicine, 2009

Posttraumatic Stress Disorder (PTSD) is a psychiatric condition that can develop following exposure to a traumatic event involving actual or threatened death or serious injury. Responses include intense fear, helplessness or horror. Symptoms are characterised into clusters, described as re-experiencing, avoidance, and arousal. These symptoms, which are also evident in other conditions, have been associated with dysfunctions in the central acetylcholinergic system. Benefits from administering acetylcholinesterase inhibitors (AChEI) to people suffering these symptoms have been demonstrated. Donepezil hydrochloride, a reversible inhibitor of the enzyme acetylcholinesterase, is used in the treatment of conditions with difficulties in cognitive function, but has not been used in PTSD. The aim of this thesis was to determine (1) whether there was a difference in the ACh system in people with PTSD and (2) whether administration of an AChEI would change the symtomatology. IDEX (I¹ ² ³ iododexetimide) has been useful in imaging muscarinic-ACh receptors using Single Photon Emission Computerised Tomography (SPECT) and was utilised to investigate whether cholinergic activity in PTSD is altered. One hundred and sixty eight potential subjects were screened and eleven PTSD subjects were enrolled in the IDEX SPECT study. Three healthy non-PTSD control subjects also completed the study. Due to technical complications only the data obtained from eight PTSD and two control subjects was available for analysis. Imaging data for 2 further healthy non-PTSD control subjects were obtained from another study. Sixteen subjects were enrolled in the donepezil open label study (assessed at baseline, Week 2, 6 and 10). Nine PTSD subjects completed the 10-week trial and seven withdrew prematurely (at or after Week 2) due to side effects or a worsening of PTSD symptoms. For the IDEX SPECT study, a voxel-by-voxel statistical analysis of the PTSD subject group versus the control group showed both areas of reduced and increased IDEX uptake. Significant clusters in the PTSD group with a reduced IDEX uptake centred around the bilateral hippocampus, left insula and right precuneus, while increased IDEX uptake appeared in the caudate head. For the donepezil study, in the per-protocol analysis (including only the 9 subjects that completed the protocol), all psychological assessments revealed a difference between the totals obtained at the Week 10 visit compared to those at the Baseline visit and the improvement was in the order of 51%. The intention-to-treat analysis (including all 16 subjects), a repeated measures Analysis of Variance (ANOVA) with a mixed models approach showed that all psychological measures demonstrated statistically significant benefits of the treatment. All subjects who completed the protocol recounted considerable improvement in their overall PTSD symptom profile, which covered symptoms in each of the three clusters. The results of the IDEX SPECT study suggest that alterations in ACh binding in PTSD are evident and may begin to explain a part of the altered cognitive symptomatology apparent in this condition. The pilot open label donepezil trial provided some preliminary evidence that treatment with an AChEI can lessen the intrusions and distress associated with traumatic memories in people with PTSD. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1374974 / Thesis (M.Med.Sc.) -- University of Adelaide, School of Medicine, 2009

Made available in DSpace on 2017-07-10T17:48:30Z (GMT). No. of bitstreams: 1 Ilton_Isandro_Eckstein.PDF: 1269135 bytes, checksum: 52bc33a50ce148953b29202d47265022 (MD5) Previous issue date: 2012-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Knowing the factors that affect the composition and quality of milk in Dairy Production Systems (SPL) is of utmost importance to the producer. The objective was to evaluate the characteristics of 32 SPL in the city of Toledo, together in partnership with a dairy. We performed the data collection of properties, with the aid of a semi-structured questionnaire, which collected information on the production traits, milk composition and quality, besides the technical and management practices carried out, mainly related to hygiene and management health of milking. Milk samples were analyzed for their composition (fat, protein, lactose and total solids), Somatic Cell Count (SCC), Total Bacterial Count (TBC), and also to the presence of total coliforms and fecal coliforms. Subsequently, data collection, the variables were selected and analyzed using multivariate techniques, using the principal component analysis (PCA) and analysis of Ascendant Hierarchical Classification (AHC). We analyzed variables related to production and milk quality, techniques and practices used at the time of milking, feeding management, milking system and socio-cultural variables related to the producer. The variables that best explained the differences in the PCA were related to the hygienic and sanitary practices (pre and post-dipping, use of detergents in alkaline and acid cleaning, testing for mastitis) held for milking, with the composition of milk and linked to the producer (age, education, length of service). It was found that the use of these practices can help to improve production and milk quality, ensuring a raw material with high commercial value. The grouping of production systems has shown that there is great diversity among the forms of production, allowing identifying the factors that can influence it, in order to form strategies that may result from gains in production and milk quality / Conhecer os fatores que afetam a composição e qualidade do leite em Sistemas de Produção Leiteiros (SPL) é de extrema importância ao produtor. Objetivou-se avaliar as características de 32 SPL, na cidade de Toledo, juntamente em parceria com um laticínio. Foi realizada a coleta de dados das propriedades, com o auxílio de um questionário semi-estruturado, onde se colheu informações acerca das características de produção, composição e qualidade do leite, além das técnicas e práticas de manejo realizadas, principalmente relacionadas ao manejo higiênico-sanitário de ordenha. As amostras de leite foram analisadas em relação a sua composição (gordura, proteína, lactose e sólidos totais), Contagem de Células Somáticas (CCS), Contagem Bacteriana Total (CBT), e também para presença de coliformes totais e coliformes termotolerantes. Posteriormente, a coleta de dados, as variáveis foram selecionadas e analisadas por meio de técnicas multivariadas, sendo utilizada a análise de Componentes Principais (ACP) e a análise de Classificação Hierárquica Ascendente (CHA). Foram analisadas variáveis relacionadas à produção e qualidade do leite, técnicas e práticas utilizadas no momento da ordenha, manejo alimentar, sistema de ordenha e variáveis sócio-culturais relacionadas ao produtor. As variáveis que melhor explicaram as diversidades das ACP foram as relacionadas com as práticas higiênico-sanitária (pré e pós-dipping, utilização dos detergentes alcalino e ácido na higienização, testes para detecção de mastite) realizadas na ordenha, com a composição de leite e vinculadas ao produtor (idade, escolaridade, tempo na atividade). Foi verificado que o uso destas práticas podem auxiliar para melhorar a produção e qualidade do leite, assegurando uma matéria-prima com maior valor comercial. O agrupamento dos sistemas de produção permitiu verificar a existência de grande diversidade entre as formas de produção, possibilitando identificar os fatores que podem influenciá-lo, a fim de formar estratégias que possam resultar ganhos em produção e qualidade do leite

Made available in DSpace on 2014-06-12T17:42:24Z (GMT). No. of bitstreams: 2 arquivo7448_1.pdf: 1841405 bytes, checksum: 67bd6c1d263317c4e54b44bfbc8d21e6 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / A análise de confiabilidade humana (ACH) estuda a execução das ações humanas em um determinado sistema, considerando suas limitações e os fatores que influenciam no seu desempenho. A literatura apresenta os métodos de ACH de primeira e segunda geração, onde a maioria foi desenvolvido para indústria nuclear. Esses métodos apresentam algumas deficiências. Dentre elas, destacam-se suposições irreais de independência e simples representação binária de eventos. Estas são conseqüências da utilização de ferramentas como análise de árvore de eventos e de falhas. Diante disso, apresentam uma grande dificuldade na modelagem das ações humanas, bem como na quantificação dos modelos causais. Portanto, percebe-se que modelar as causalidades existentes nas ações humanas tornou-se um grande desafio para ACH ao longo dos anos. Diante deste contexto, este trabalho mostra que modelar ações humanas por redes Bayesianas proporciona uma maior flexibilidade às variáveis componentes de um determinado sistema, pois além de permitir uma representação mais realista da natureza dinâmica da interface homem-sistema e homem-homem em eventos normais ou anormais de um processo, também representa a relação de dependência entre os eventos e entre os fatores de desempenho. Neste trabalho, utiliza-se redes Bayesianas para avaliação da confiabilidade humana em atividades de substituição de cadeias de isoladores em linhas de transmissão. Ele apresenta claramente a modelagem das ações humanas, bem como a utilização de métodos para construção de rede, com destaque para os mecanismos de quantificação de redes Bayesianas

No description available.