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1.
Brain Sci ; 14(7)2024 Jun 26.
Article in English | MEDLINE | ID: mdl-39061384

ABSTRACT

Motor intention is a high-level brain function related to planning for movement. Although studies have shown that motor intentions can be decoded from brain signals before movement execution, it is unclear whether intentions relating to mental imagery of movement can be decoded. Here, we investigated whether differences in spatial and temporal patterns of brain activation were elicited by intentions to perform different types of motor imagery and whether the patterns could be used by a multivariate pattern classifier to detect such differential intentions. The results showed that it is possible to decode intentions before the onset of different types of motor imagery from functional MR signals obtained from fronto-parietal brain regions, such as the premotor cortex and posterior parietal cortex, while controlling for eye movements and for muscular activity of the hands. These results highlight the critical role played by the aforementioned brain regions in covert motor intentions. Moreover, they have substantial implications for rehabilitating patients with motor disabilities.

2.
Neuroimage ; 264: 119690, 2022 12 01.
Article in English | MEDLINE | ID: mdl-36261058

ABSTRACT

The 'day residue' - the presence of waking memories into dreams - is a century-old concept that remains controversial in neuroscience. Even at the psychological level, it remains unclear how waking imagery cedes into dreams. Are visual and affective residues enhanced, modified, or erased at sleep onset? Are they linked, or dissociated? What are the neural correlates of these transformations? To address these questions we combined quantitative semantics, sleep EEG markers, visual stimulation, and multiple awakenings to investigate visual and affect residues in hypnagogic imagery at sleep onset. Healthy adults were repeatedly stimulated with an affective image, allowed to sleep and awoken seconds to minutes later, during waking (WK), N1 or N2 sleep stages. 'Image Residue' was objectively defined as the formal semantic similarity between oral reports describing the last image visualized before closing the eyes ('ground image'), and oral reports of subsequent visual imagery ('hypnagogic imagery). Similarly, 'Affect Residue' measured the proximity of affective valences between 'ground image' and 'hypnagogic imagery'. We then compared these grounded measures of two distinct aspects of the 'day residue', calculated within participants, to randomly generated values calculated across participants. The results show that Image Residue persisted throughout the transition to sleep, increasing during N1 in proportion to the time spent in this stage. In contrast, the Affect Residue was gradually neutralized as sleep progressed, decreasing in proportion to the time spent in N1 and reaching a minimum during N2. EEG power in the theta band (4.5-6.5 Hz) was inversely correlated with the Image Residue during N1. The results show that the visual and affective aspects of the 'day residue' in hypnagogic imagery diverge at sleep onset, possibly decoupling visual contents from strong negative emotions, in association with increased theta rhythm.


Subject(s)
Sleep Stages , Sleep , Adult , Humans , Sleep Stages/physiology , Wakefulness/physiology , Theta Rhythm , Electroencephalography
3.
Arq Gastroenterol ; 46(1): 69-74, 2009.
Article in Portuguese | MEDLINE | ID: mdl-19466313

ABSTRACT

CONTEXT: There are still many unknown aspects about nonalcoholic steatohepatitis, especially regarding its pathophysiology and pharmacological treatment. Thus, experimental models are important for a better understanding of this disease and the evaluation of the effects of drugs. OBJECTIVE: To develop a model of experimental nonalcoholic steatohepatitis from use of methionine and choline deficient diet. METHODS: Fifty Wistar male rats were studied. A methionine and choline deficient diet has been processed in a craft. A group of 40 animals received the deficient diet for 90 days, and a group of 10 rats (control group) received the standardized ration in the same period. After, the animals were killed by decapitation, and laparotomy was performed. Hepatectomy was performed and the liver was studied by macroscopy and microscopy. The level of significance considered was of 0,05. RESULTS: The rats that received the deficient diet showed significant loss of weight with findings from malnutrition and all of them had at least some degree of macrovesicular steatosis. The diagnosis of nonalcoholic steatohepatitis was performed in 27 (70%) of the 39 rats that received this deficient diet (1 rat died during the study). None of the 10 rats that received the standardized diet had histological abnormalities. CONCLUSION: The diet restricted in methionine and choline induced steatosis and steatohepatitis in an animal model with low cost.


Subject(s)
Animal Feed/adverse effects , Choline Deficiency/complications , Disease Models, Animal , Fatty Liver/etiology , Methionine/deficiency , Animals , Fatty Liver/pathology , Liver/pathology , Male , Rats , Rats, Wistar
4.
Arq. gastroenterol ; Arq. gastroenterol;46(1): 69-74, jan.-mar. 2009. ilus, tab
Article in Portuguese | LILACS | ID: lil-513858

ABSTRACT

CONTEXTO: Ainda existem vários aspectos desconhecidos a respeito da esteatohepatite não-alcoólica, principalmente em relação à fisiopatologia e ao seu tratamento medicamentoso. Dessa forma, os modelos experimentais são importante para o melhor entendimento dessa doença, bem como para a avaliação do efeito das drogas. OBJETIVO: Desenvolver um modelo experimental de esteatohepatite não-alcoólica a partir do uso de dieta deficiente em metionina e colina. MÉTODOS: Foram utilizados 50 ratos machos da linhagem Wistar. A dieta deficiente em metionina e colina foi processada de forma artesanal. Um grupo de 40 animais recebeu a dieta durante 90 dias e utilizou-se um grupo controle com 10 ratos que recebeu ração padronizada pelo mesmo período. Após, os animais foram mortos por decapitação e foi realizada laparotomia com hepatectomia total e preparo do material para análise macroscópica e histológica. O nível de significância foi a = 0,05. RESULTADOS: Os ratos que receberam a dieta apresentaram perda significativa de peso, com achados de desnutrição e todos mostraram, pelo menos, algum grau de esteatose macrovesicular. O diagnóstico de esteatohepatite não-alcoólica foi realizado em 27 (70 por cento) dos 39 ratos que receberam a dieta. Nenhum dos 10 ratos que recebeu ração apresentou alterações histológicas. CONCLUSÃO:A dieta com restrição de metionina e colina desenvolvida apresenta índices elevados de indução de esteatose e esteatohepatite em modelo animal com baixo custo.


CONTEXT: There are still many unknown aspects about nonalcoholic steatohepatitis, especially regarding its pathophysiology and pharmacological treatment. Thus, experimental models are important for a better understanding of this disease and the evaluation of the effects of drugs. OBJECTIVE: To develop a model of experimental nonalcoholic steatohepatitis from use of methionine and choline deficient diet. METHODS: Fifty Wistar male rats were studied. A methionine and choline deficient diet has been processed in a craft. A group of 40 animals received the deficient diet for 90 days, and a group of 10 rats (control group) received the standardized ration in the same period. After, the animals were killed by decapitation, and laparotomy was performed. Hepatectomy was performed and the liver was studied by macroscopy and microscopy. The level of significance considered was of 0,05. RESULTS: The rats that received the deficient diet showed significant loss of weight with findings from malnutrition and all of them had at least some degree of macrovesicular steatosis. The diagnosis of nonalcoholic steatohepatitis was performed in 27 (70 percent) of the 39 rats that received this deficient diet (1 rat died during the study). None of the 10 rats that received the standardized diet had histological abnormalities. CONCLUSION: The diet restricted in methionine and choline induced steatosis and steatohepatitis in an animal model with low cost.


Subject(s)
Animals , Male , Rats , Animal Feed/adverse effects , Choline Deficiency/complications , Disease Models, Animal , Fatty Liver/etiology , Methionine/deficiency , Fatty Liver/pathology , Liver/pathology , Rats, Wistar
5.
J. bras. pneumol ; J. bras. pneumol;32(5): 385-390, set.-out. 2006. tab, graf
Article in Portuguese | LILACS | ID: lil-452393

ABSTRACT

OBJETIVO: Avaliar se as diretrizes do III Consenso Brasileiro no Manejo da Asma estão sendo aplicadas em uma população de asmáticos em um hospital de referência da rede pública de Porto Alegre (RS). MÉTODOS: Todos os pacientes adultos que iniciaram tratamento entre 1999 e 2002 foram avaliados. O tratamento recebido foi classificado em concordante ou discordante do Consenso. As características clínicas da asma e a freqüência do tratamento por especialista foram comparadas entre os grupos. RESULTADOS: Foram avaliados os prontuários de 357 pacientes, com média de idade de 41 anos, sendo 106 homens (29,7 por cento) e 251 mulheres (70,3 por cento), 33 tabagistas (9,2 por cento). O tratamento foi considerado discordante em 246 pacientes (70 por cento), sendo que, neste grupo, houve ausência de tratamento com corticóide inalatório em pacientes com asma persistente em 174 deles (71 por cento). Volume expiratório forçado no primeiro segundo normal, idade entre doze e dezoito anos e asma intermitente foram observados com maior freqüência entre os pacientes com tratamento concordante (p < 0,01). Tratamento discordante não teve correlação com tratamento por pneumologista, gravidade da asma persistente ou número de visitas à emergência. CONCLUSÃO: A maioria dos pacientes com asma tratados em uma unidade de referência da rede pública em Porto Alegre não faz o tratamento preconizado pelos consensos e o subtratamento com corticóide inalatório é a principal causa de discordância.


OBJECTIVE: To determine whether the guidelines put forth in the III Brazilian Consensus on Asthma Management are being applied in a population of asthma patients treated at a public hospital that is a referral center for asthma in the city of Porto Alegre, Brazil. METHODS: All adult asthma patients who began their treatment between 1999 and 2002 were evaluated. The treatment given was classified as consistent or inconsistent with the Consensus guidelines. The clinical features of asthma and the frequency of treatment provided by a specialist were compared between the two groups (those receiving guideline-consistent treatment and those receiving guideline-inconsistent treatment). RESULTS: The charts of 357 patients were evaluated. The study sample consisted of 106 males (29.9 percent) and 251 females (70.3 percent). The mean age was 41 years, and 33 (9.2 percent) of the patients were smokers. The treatment was considered inconsistent with the Consensus guidelines in 246 cases (70 percent). Of those 246, 174 (71 percent) had presented persistent asthma and were not treated with an inhaled corticosteroid. Normal forced expiratory volume in one second, being from 12 to 18 years of age, and having intermittent asthma were more frequently observed among the patients receiving guideline-consistent treatment (p < 0.01). No correlations were found between guideline-inconsistent treatment and being treated by a pulmonologist, severity of persistent asthma or number of emergency room visits. CONCLUSION: Most of the asthma patients treated at the public referral center in Porto Alegre did not receive treatment that was consistent with the Consensus guidelines. Undertreatment with inhaled corticosteroids was the principal source of that inconsistency.


Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Male , Middle Aged , Asthma/drug therapy , Guideline Adherence/statistics & numerical data , Brazil , Consensus , Public Sector , Practice Guidelines as Topic/standards , Retrospective Studies , Severity of Illness Index
6.
J Bras Pneumol ; 32(5): 385-90, 2006.
Article in English, Portuguese | MEDLINE | ID: mdl-17268740

ABSTRACT

OBJECTIVE: To determine whether the guidelines put forth in the III Brazilian Consensus on Asthma Management are being applied in a population of asthma patients treated at a public hospital that is a referral center for asthma in the city of Porto Alegre, Brazil. METHODS: All adult asthma patients who began their treatment between 1999 and 2002 were evaluated. The treatment given was classified as consistent or inconsistent with the Consensus guidelines. The clinical features of asthma and the frequency of treatment provided by a specialist were compared between the two groups (those receiving guideline-consistent treatment and those receiving guideline-inconsistent treatment). RESULTS: The charts of 357 patients were evaluated. The study sample consisted of 106 males (29.9%) and 251 females (70.3%). The mean age was 41 years, and 33 (9.2%) of the patients were smokers. The treatment was considered inconsistent with the Consensus guidelines in 246 cases (70%). Of those 246, 174 (71%) had presented persistent asthma and were not treated with an inhaled corticosteroid. Normal forced expiratory volume in one second, being from 12 to 18 years of age, and having intermittent asthma were more frequently observed among the patients receiving guideline-consistent treatment (p < 0.01). No correlations were found between guideline-inconsistent treatment and being treated by a pulmonologist, severity of persistent asthma or number of emergency room visits. CONCLUSION: Most of the asthma patients treated at the public referral center in Porto Alegre did not receive treatment that was consistent with the Consensus guidelines. Undertreatment with inhaled corticosteroids was the principal source of that inconsistency.


Subject(s)
Asthma/drug therapy , Guideline Adherence/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , Brazil , Child , Consensus , Female , Humans , Male , Middle Aged , Practice Guidelines as Topic/standards , Public Sector , Retrospective Studies , Severity of Illness Index
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