Thyroid dysfunction alters gene expression of proteins related to iron homeostasis and metabolomics in male rats.

Thyroid hormones (THs) are crucial in bodily functions, while iron is essential for processes like oxygen transport. Specialized proteins maintain iron balance, including ferritin, transferrin, ferroportin, and hepcidin. Research suggests that THs can influence iron homeostasis by affecting mRNA and protein expression, such as ferritin and transferrin. Our study focused on male rats to assess mRNA expression of iron homeostasis-related proteins and metabolomics in thyroid dysfunction. We found altered gene expression across various tissues (liver, duodenum, spleen, and kidney) and identified disrupted metabolite patterns in thyroid dysfunction. These findings highlight tissue-specific effects of thyroid dysfunction on essential iron homeostasis proteins and provide insights into associated metabolic changes. Our research contributes to understanding the intricate interplay between thyroid hormones and iron balance. By unveiling tissue-specific gene expression alterations and metabolic disruptions caused by thyroid dysfunction, our work lays a foundation for future investigations to explore underlying mechanisms and develop targeted strategies for managing iron-related complications in thyroid disorders.

COMPARATIVE EVALUATION OF SKIN SUTURE IN RATS WITH POLYGLYCAPRONE 25 AND NYLON.

Currently, the market offers a wide variety of suture threads, made of materials with different structural and chemical properties. Among many other characteristics, they vary in origin, absorption or degradation, and structure. From this variety, the clinical doubt arises as to which material provides the patient with the best healing quality. Objective: This study aims to comparatively evaluate two different types of suture threads-Monocryl® (polyglycaprone 25) and Ethilon® (nylon)-regarding their ability to aid in tissue regeneration by a histological and immunohistochemical analysis of the skin of rats sutured with the aforementioned materials. Methods: This basic experimental study used 12 adult Wistar rats, randomly divided into three groups with four animals each and subjected to four longitudinal incisions under anesthesia. Each group corresponded to a postsurgical evaluation date (one, seven, and 14 days). Results: At 14 postoperative days, the studied groups had no histological difference. However, the use of nylon thread showed greater evidence of earlier fibrotic union. Conclusion: This study found no histological difference in healing 14 days after surgery among the techniques and the types of suture threads. Level of Evidence II, Therapeutic Studies.

Atualmente, encontra-se disponível no mercado uma grande variedade de fios de sutura, compostos de materiais com diferentes propriedades estruturais e químicas, que variam quanto à origem, absorção ou degradação e estrutura, entre outras características. A partir dessa disponibilidade, emerge a dúvida clínica quanto ao material que propicia a melhor qualidade de cicatrização ao paciente. Objetivo: Avaliar comparativamente dois tipos de fios - Monocryl® (poliglicaprone 25) e Ethilon® (nylon) - quanto à sua capacidade de auxílio na regeneração tecidual, por meio da análise histológica e imuno-histoquímica da pele de ratos submetidos a suturas com esses materiais. Métodos: Neste estudo básico experimental, foram utilizados 12 ratos adultos da linhagem Wistar, randomicamente divididos em três grupos com quatros animais cada, que foram submetidos a quatro incisões longitudinais sob anestesia. Cada grupo correspondeu a uma data de avaliação pós-cirúrgica (1, 7 e 14 dias). Resultados: Passados 14 dias após a operação, não houve diferença histológica em relação aos grupos estudados. No entanto, o uso de fio de nylon apresentou evidência de união fibrótica mais precoce. Conclusão: Não há diferença histológica de cicatrização após 14 dias pós-operatórios entre as técnicas e os tipos de fio de sutura. Nível de Evidência II, Estudos Terapêuticos.

Comparative evaluation of skin suture in rats with polyglycaprone 25 and nylon / Avaliação comparativa da sutura de pele com poliglicaprone 25 e nylon em ratos

ABSTRACT Currently, the market offers a wide variety of suture threads, made of materials with different structural and chemical properties. Among many other characteristics, they vary in origin, absorption or degradation, and structure. From this variety, the clinical doubt arises as to which material provides the patient with the best healing quality. Objective: This study aims to comparatively evaluate two different types of suture threads-Monocryl® (polyglycaprone 25) and Ethilon® (nylon)-regarding their ability to aid in tissue regeneration by a histological and immunohistochemical analysis of the skin of rats sutured with the aforementioned materials. Methods: This basic experimental study used 12 adult Wistar rats, randomly divided into three groups with four animals each and subjected to four longitudinal incisions under anesthesia. Each group corresponded to a postsurgical evaluation date (one, seven, and 14 days). Results: At 14 postoperative days, the studied groups had no histological difference. However, the use of nylon thread showed greater evidence of earlier fibrotic union. Conclusion: This study found no histological difference in healing 14 days after surgery among the techniques and the types of suture threads. Level of Evidence II, Therapeutic Studies.

RESUMO Atualmente, encontra-se disponível no mercado uma grande variedade de fios de sutura, compostos de materiais com diferentes propriedades estruturais e químicas, que variam quanto à origem, absorção ou degradação e estrutura, entre outras características. A partir dessa disponibilidade, emerge a dúvida clínica quanto ao material que propicia a melhor qualidade de cicatrização ao paciente. Objetivo: Avaliar comparativamente dois tipos de fios - Monocryl ® (poliglicaprone 25) e Ethilon ® (nylon) - quanto à sua capacidade de auxílio na regeneração tecidual, por meio da análise histológica e imuno-histoquímica da pele de ratos submetidos a suturas com esses materiais. Métodos: Neste estudo básico experimental, foram utilizados 12 ratos adultos da linhagem Wistar, randomicamente divididos em três grupos com quatros animais cada, que foram submetidos a quatro incisões longitudinais sob anestesia. Cada grupo correspondeu a uma data de avaliação pós-cirúrgica (1, 7 e 14 dias). Resultados: Passados 14 dias após a operação, não houve diferença histológica em relação aos grupos estudados. No entanto, o uso de fio de nylon apresentou evidência de união fibrótica mais precoce. Conclusão: Não há diferença histológica de cicatrização após 14 dias pós-operatórios entre as técnicas e os tipos de fio de sutura. Nível de Evidência II, Estudos Terapêuticos.

BENEFITS OF THE WALANT TECHNIQUE AGAINST THE COVID-19 PANDEMIC.

OBJECTIVE: Evaluate the experience of private and public health services with the WALANT procedure in the COVID-19 pandemic. METHODS: This is a retrospective, multicenter longitudinal study gathering cases of hand surgery subjected to the WALANT technique in the Hospitals Dr. Radamés Nardini and IFOR during the COVID-19 pandemic (August 2020). As a parameter, the verbal numerical rating scale for twenty patients referring to the preoperative, intraoperative and postoperative periods was applied. RESULTS: The patients did not feel any pain during surgery, which showed the efficiency of the anesthetic technique in its purpose. CONCLUSION: The results indicate the WALANT technique as beneficial when facing the COVID-19 pandemic, as the main differential of the technique is that it is applied by a well-trained orthopedic hand surgeon. Level of Evidence IV, Case Series.

OBJECTIVE: Avaliar a experiência dos serviços privado e público de saúde com o procedimento WALANT frente à pandemia COVID-19. MÉTODOS: Trata-se de um estudo longitudinal retrospectivo, multicêntrico, de casos de cirurgia de mão submetidos à técnica WALANT nos hospitais Dr. Radamés Nardini e IFOR, durante a pandemia da COVID-19, em agosto de 2020. Como parâmetro, foi aplicada a Escala Verbal de Dor para 20 pacientes referente ao pré-operatório, intra-operatório e no pós-operatório. RESULTADOS: Os pacientes não sentiram nenhuma dor durante a cirurgia, tendo a técnica anestésica de mostrado eficaz. CONCLUSÃO: Pelas análises, foi possível considerar segura e benéfica a técnica WALANT diante da pandemia da COVID-19, que apresenta o diferencial de ser aplicada por um cirurgião ortopédico especialista em mão bem treinado. Nível de Evidência IV, Série de Casos.

Benefits of the walant technique against the covid-19 pandemic / Benefícios da técnica walant em cirurgias da mão frente a pandemia da covid-19

ABSTRACT Objective: Evaluate the experience of private and public health services with the WALANT procedure in the COVID-19 pandemic. Methods: This is a retrospective, multicenter longitudinal study gathering cases of hand surgery subjected to the WALANT technique in the Hospitals Dr. Radamés Nardini and IFOR during the COVID-19 pandemic (August 2020). As a parameter, the verbal numerical rating scale for twenty patients referring to the preoperative, intraoperative and postoperative periods was applied. Results: The patients did not feel any pain during surgery, which showed the efficiency of the anesthetic technique in its purpose. Conclusion: The results indicate the WALANT technique as beneficial when facing the COVID-19 pandemic, as the main differential of the technique is that it is applied by a well-trained orthopedic hand surgeon. Level of Evidence IV, Case Series.

RESUMO Objective: Avaliar a experiência dos serviços privado e público de saúde com o procedimento WALANT frente à pandemia COVID-19. Métodos: Trata-se de um estudo longitudinal retrospectivo, multicêntrico, de casos de cirurgia de mão submetidos à técnica WALANT nos hospitais Dr. Radamés Nardini e IFOR, durante a pandemia da COVID-19, em agosto de 2020. Como parâmetro, foi aplicada a Escala Verbal de Dor para 20 pacientes referente ao pré-operatório, intra-operatório e no pós-operatório. Resultados: Os pacientes não sentiram nenhuma dor durante a cirurgia, tendo a técnica anestésica de mostrado eficaz. Conclusão: Pelas análises, foi possível considerar segura e benéfica a técnica WALANT diante da pandemia da COVID-19, que apresenta o diferencial de ser aplicada por um cirurgião ortopédico especialista em mão bem treinado. Nível de Evidência IV, Série de Casos.

Open and Closed Endotracheal Suction Systems Divergently Affect Pulmonary Function in Mechanically Ventilated Subjects.

BACKGROUND: In mechanically ventilated subjects, intra-tracheal secretions can be aspirated with either open suction systems (OSS) or closed suction systems (CSS). In contrast to CSS, conventional OSS require temporarily disconnecting the patient from the ventilator, which briefly diminishes PEEP and oxygen supply. On the other hand, CSS are more expensive and less effective at aspirating secretions. Thus, it was hypothesized that the 2 procedures differentially affect pulmonary and cardiovascular parameters after suction. METHODS: Subjects in the ICU (N = 66) were quasi-randomized for initial treatment with OSS or CSS in a crossover design. To compare the potential for these suction systems to compromise cardiorespiratory stability, changes in cardiopulmonary physiology were assessed from before to just after use of each suction system (three 10-s aspirations). RESULTS: For most pulmonary and cardiovascular parameters (ie, peak inspiratory pressure, airway resistance, pressure plateau, heart rate, and arterial pressures), the effects of aspiration inversely correlated with baseline values for that parameter, with a similar regression slope between suction systems. However, when controlling for baseline values, OSS caused significantly greater increases in airway resistance and peak inspiratory pressure (P < .001 and < .01 vs CSS, respectively). CONCLUSIONS: Elevated airway resistance prior to endotracheal suction may justify use of a CSS and contraindicate a conventional OSS in mechanically ventilated subjects. Adoption of this approach into clinical guidelines may prevent suction-induced pulmonary injury in subjects, especially for those with underlying diseases involving increased airway resistance or increased alveolar pressure. (ClinicalTrials.gov registration: NCT03256214.).

Thyroxine replacement modifies changes in deiodinase and thyroid hormone transporter expression induced by subclinical hypothyroidism in rats.

PURPOSE: The potential benefits of treating subclinical hypothyroidism (SCH) are unclear and still controversial. Thus, we surgically induced SCH in rats and evaluated the effects of thyroxine (T4) replacement on the gene expression levels of deiodinases and thyroid hormone (TH) transporters in different tissues. METHODS: SCH was induced by hemithyroid electrocauterization. The control animals underwent the same surgical procedure but were not subjected to electrocauterization (sham). After 14 days, half of the SCH animals were treated with T4 (SCH + T4). At the end of the experimental protocol, all of the rats were euthanized, serum hormone concentrations were measured, and RNA analyses were performed on different tissues and organs. RESULTS: Consistent with previous studies, we observed increased TSH levels, normal TH levels, and reduced hypothalamic TRH expression in the SCH group. Additionally, Dio2 mRNA expression was downregulated in the hippocampus and pituitary, and Dio1 was upregulated in the kidney and pituitary of the SCH animals. The changes in Dio3 expression were tissue-specific. Concerning TH transporters, Mct10 expression was upregulated in the pituitary, kidney, hypothalamus, and hippocampus, and Mct8 expression was downregulated in the kidney of the SCH group. Crym expression was upregulated in the kidney and pituitary. Notably, T4 replacement significantly attenuated serum TSH levels and reverted Dio1, Dio2, Mct10, and Crym expression in the pituitary, hippocampus, and kidney to levels that were similar to the sham group. Tissue-specific responses were also observed in the liver and hypothalamus. CONCLUSION: Our results indicate that treatment of SCH should be considered before the appearance of clinical symptoms of hypothyroidism.

Epinephrine in pediatric cardiorespiratory arrest: when and how much?

The objective of the present study was to assess the efficacy of different doses, times for infusion of the first dose, intervals of administration of subsequent doses, and number of epinephrine doses in the survival of children and adolescents who went into cardiorespiratory arrest. It is a review study with data from the PubMedⓇ/MEDLINEⓇdatabase. The search was for articles published from January 1st, 2000 to February 10, 2019, with a sample of patients aged under 18 years, published in English, Portuguese and Spanish. We found 222 articles, of which 16 met the inclusion criteria of the study. The first dose should be given as soon as possible. The standard dose (0.01mg/kg) has a better outcome when compared to the higher dose (0.1mg/kg). There is an iⓇverse relation between the number of epinephrine doses and survival. The interval currently recommended between doses has lower survival when compared to larger intervals. The dosage recommended by the American Heart Association presents a better outcome for survival, but the interval between doses and the maximum number of doses should be better assessed.

Epinephrine in pediatric cardiorespiratory arrest: when and how much? / Epinefrina na parada cardiorrespiratória pediátrica: quando e quanto?

ABSTRACT The objective of the present study was to assess the efficacy of different doses, times for infusion of the first dose, intervals of administration of subsequent doses, and number of epinephrine doses in the survival of children and adolescents who went into cardiorespiratory arrest. It is a review study with data from the PubMedⓇ/MEDLINEⓇdatabase. The search was for articles published from January 1st, 2000 to February 10, 2019, with a sample of patients aged under 18 years, published in English, Portuguese and Spanish. We found 222 articles, of which 16 met the inclusion criteria of the study. The first dose should be given as soon as possible. The standard dose (0.01mg/kg) has a better outcome when compared to the higher dose (0.1mg/kg). There is an iⓇverse relation between the number of epinephrine doses and survival. The interval currently recommended between doses has lower survival when compared to larger intervals. The dosage recommended by the American Heart Association presents a better outcome for survival, but the interval between doses and the maximum number of doses should be better assessed.

RESUMO O objetivo deste estudo foi avaliar a eficácia de diferentes doses, tempos para infusão da primeira dose, intervalos de administração de doses subsequentes e número de doses de epinefrina na sobrevida de crianças e adolescentes que sofreram parada cardiorrespiratória. Trata-se de estudo de revisão, cujas buscas foram feitas na base de dados PubMedⓇ /MEDLINEⓇ. Foram selecionados artigos publicados de 1° de janeiro de 2000 até 10 de fevereiro de 2019, realizados em menores de 18 anos de idade, publicados em inglês, português e espanhol. Foram encontrados 222 artigos, dos quais 16 atenderam os critérios de inclusão no estudo. A primeira dose deve ser aplicada o mais rápido possível. A dose padrão (0,01mg/kg) apresenta melhor desfecho quando comparada à dose alta (0,1mg/kg). Houve relação inversa entre número de doses de epinefrina e sobrevida. O intervalo entre doses recomendado atualmente apresenta menor sobrevida quando comparado a intervalos maiores. A dose recomendada pela American Heart Association apresenta melhor desfecho para sobrevida, porém o intervalo entre doses e o número máximo de doses devem ser melhor avaliados.

Does the combination of resistance training and stretching increase cardiac overload?

OBJECTIVES: To compare the effects of combinations of resistance training (RT) and static stretching (SS) on heart rate (HR), systolic pressure (SBP), diastolic pressure (DBP), rate pressure product (RPP), oxygen saturation (SpO2), rating of perceived effort (RPE), and heart rate variability (HRV) in men. METHODS: Twelve normotensive healthy men participated in four protocols: a) SS+RT, b) RT+SS, c) RT, and d) SS. Variables were measured before, immediately after, and 15, 30, and 45 min after the sessions. RESULTS: The combination of SS and RT increased (p<0.001) HR when compared to the effects of the noncombined protocols (from 2.38 to 11.02%), and this result indicated metabolic compensation. Regarding DBP, there were differences (p<0.001) between the RT and SS groups (53.93±8.59 vs. 67.00±7.01 mmHg). SS has been shown to be able to reduce (p<0.001) SpO2 (4.67%) due to the occlusion caused by a reduction in the caliber of the blood vessels during SS compared to during rest. The increase in RPP (6.88% between RT and SS+RT) along with the HR results indicated higher metabolic stress than that reflected by the RPE (combined protocols increased RPE from 21.63 to 43.25%). The HRV analysis confirmed these results, showing increases (p<0.01) in the LF index between the combined and noncombined protocols. Compared to the effect of RT, the combination of SS and RT promoted a vagal suppression root mean square of the successive differences (RMSSD) index (from 9.51 to 21.52%) between the RT and SS+RT groups (p<0.01) and between the RT and RT+SS groups (p<0.001). CONCLUSION: Static stretching increases cardiac overload and RPE, reducing oxygen supply, especially when performed in combination with RT.

Does the combination of resistance training and stretching increase cardiac overload?

OBJECTIVES: To compare the effects of combinations of resistance training (RT) and static stretching (SS) on heart rate (HR), systolic pressure (SBP), diastolic pressure (DBP), rate pressure product (RPP), oxygen saturation (SpO2), rating of perceived effort (RPE), and heart rate variability (HRV) in men. METHODS: Twelve normotensive healthy men participated in four protocols: a) SS+RT, b) RT+SS, c) RT, and d) SS. Variables were measured before, immediately after, and 15, 30, and 45 min after the sessions. RESULTS: The combination of SS and RT increased (p<0.001) HR when compared to the effects of the noncombined protocols (from 2.38 to 11.02%), and this result indicated metabolic compensation. Regarding DBP, there were differences (p<0.001) between the RT and SS groups (53.93±8.59 vs. 67.00±7.01 mmHg). SS has been shown to be able to reduce (p<0.001) SpO2 (4.67%) due to the occlusion caused by a reduction in the caliber of the blood vessels during SS compared to during rest. The increase in RPP (6.88% between RT and SS+RT) along with the HR results indicated higher metabolic stress than that reflected by the RPE (combined protocols increased RPE from 21.63 to 43.25%). The HRV analysis confirmed these results, showing increases (p<0.01) in the LF index between the combined and noncombined protocols. Compared to the effect of RT, the combination of SS and RT promoted a vagal suppression root mean square of the successive differences (RMSSD) index (from 9.51 to 21.52%) between the RT and SS+RT groups (p<0.01) and between the RT and RT+SS groups (p<0.001). CONCLUSION: Static stretching increases cardiac overload and RPE, reducing oxygen supply, especially when performed in combination with RT.

Evaluation of globins expression in brain, heart, and lung in rats exposed to side stream cigarette smoke.

The side stream cigarette smoke (SSCS) is a contributing factor in the pathogenesis of cigarette smoking-induced toxicity. Hemoglobin (Hb), myoglobin (Mb), neuroglobin (Ngb), and cytoglobin (Cygb) are globins with different distributions and functions in the tissues and have similar actions by providing O2 (oxygen) for respiratory chain, detoxification of ROS and nitric oxide (NO), and protect tissues against irreversible lesions. We aimed to investigate the effects of SSCS exposure on gene and protein expression of Ngb, Cygb, and Mb in different tissue. The Ngb and Cygb gene and protein expression in the cerebral cortex increased after 1 week of rat exposure to SSCS. In hippocampus, the Ngb gene and protein expression increased after 1 week or more of exposure and no change was observed in Cygb gene and protein expression. In myocardium, Mb and Cygb gene expression increased at 1 and 4 weeks of exposure, while protein expression of both increased at 1, 2, 3, and 4 weeks. In lung, observed an increase in Cygb gene and protein expression after 2, 3, and 4 weeks of exposure. The findings suggest that SSCS modulates Ngb, Cygb, and Mb in central and peripheral tissue © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1252-1261, 2017.

Thyroid hormone modulates neuroglobin and cytoglobin in rat brain.

Thyroid hormones (THs) are essential and crucial for brain development, playing a role in growth and differentiation. Two globins named neuroglobin (Ngb) and cytoglobin (Cygb) are located in the brain, and each one has different distribution and function: They seem to have similar action by providing O(2) for respiratory chain, and detoxification of reactive oxygen species (ROS) and nitric oxide (NO) protecting tissues against irreversible lesions. We aimed to investigate the influence of thyroid state in Ngb and Cygb metabolism in different brain regions and evaluate their responses in cerebellum, hippocampus and cerebral cortex (hereafter called as cortex) after supraphysiological doses at different time points of TH administration. Experiments were carried out in rats, divided in eight experimental groups Control (C), thyroidectomy (Tx), and thyroidectomy treated with jugular intravenous injection (i.v). T3 (100 µl/100 g) injection and sacrificed after 30, 60, 120 min and 6, 12 and 24 h. In cortex, we found increase in Ngb gene and protein expression in different time points compared to C group, however Cygb gene and protein expression were decreased. In hippocampus, Ngb and Cygb protein expression increased 24 h after i.v. T3 injection in comparison to Tx. In cerebellum, we found increased Ngb gene expression after 120 min, 6, 12 and 24 h after T3 administration compared to Tx, and in contrast, protein expression was found to be significantly increased only 12 and 24 h compared to Tx. Ngb and Cygb expression in brain is influenced by thyroid hormone state both by its lack or excess.

Efeitos pleiotrópicos das estatinas na sepse / Pleiotropic effects of statins in sepsis

O objetivo do presente estudo foi revisar os efeitos da terapia com estatinas em pacientes com quadro de sepse. Foi realizada uma busca bibliográfica de artigos na base de dados MEDLINE/PubMed, SciELO e LILACS, no período de publicação delimitado entre 2009 e 2013. Foram incluídos artigos referentes a ensaios clínicos randomizados controlados e estudos de coorte observacionais clínicos. Foram encontrados diversos estudos clínicos e observacionais que investigaram o efeito do uso de estatinas em infecções e em sepse, tanto de uso contínuo pré-hospitalar (com ou sem interrupção durante internação) ou com início imediato pós-internação. Alguns estudos descrevem prováveis efeitos positivos e benéficos da terapia com estatinas no quadro de sepse, dentre eles a melhora dos parâmetros inflamatórios e da taxa de mortalidade, porém, esses resultados não se sustentam quando são aplicados métodos estatísticos que levamem conta diferentes variáveis, tais como idade, sexo, comorbidades e gravidade da doença. Até o momento nenhum estudo demonstrou evidências sólidas e significativas quanto à redução de mortalidadee morbidade no quadro séptico associado ao uso de estatinas, indicando que seu efeito benéfico e protetor ainda não foi plenamente delimitado, sendo necessários mais estudos que confirmem os resultados até agora encontrados.

The objective of this study was to review the effects of statin therapy in patients with signs of sepsis. A bibliographic search of articles published between 2009-2013 was performed in the MEDLINE/PubMed, SciELO and LILACS databases. Randomized controlled trials and observational clinical cohort studies were included. The results show that several clinical and observational studies have investigated the effect of statin in infection and sepsis, both pre-hospital continuous use (with or without interruption during hospitalization) or starting immediately post-hospitalization. Some studies describe positive and beneficial effects of statin therapy in the contextof sepsis, including improvement on inflammatory parameters and mortality rates. However, these results do not hold on when statistic methods, which take into account different variables such as age, sex, comorbidities and severity disease, are applied. To date, no study has demonstrated strong and significant evidence regarding the reduction of morbidity and mortality in sepsis associated with the use of statin. This indicates that beneficial and protective effects have not been fully defined yet. More researches are required to confirm the results found so far.

Evaluation of peak cough flow in Brazilian healthy adults.

INTRODUCTION: In this study we aimed to evaluate the peak cough flow (PCF) in healthy Brazilian subjects. METHODS: We evaluated 484 healthy subjects between 18 and 40 years old. Subjects were seated and oriented were asked to perform a maximal inspiration followed by a quick, short and explosive expiration on the peak flow meter. Three measures were carried out and recorded the average of the three results for each individual. RESULTS: The PCF values ranged between 240 and 500 L/min. The PCF values were lower in females than in males. The PCF was inversely proportional to age. CONCLUSION: The values for Brazilian adult healthy subjects regarding PCF were between 240 and 500 L/min.

Importância do sistema nervoso no controle da micção e armazenamento urinário: [revisão] / The importance of the nervous system in the control of voiding and urine storage: [review]

O controle da micção, apesar da aparente simplicidade em seu funcionamento, apresenta vários níveis de regulação com relativa complexidade. Em estados conscientes e inconscientes, envolve a atividade de nervos periféricos, da medula sacral e das áreas centrais que constituem o bulbo, a ponte, o mesencéfalo e o córtex. Neste trabalho de revisão serão abordados quais são as áreas centrais atualmente conhecidas por participarem do controle da micção e armazenamento urinário, assim como a sinalização proveniente do sistema nervoso periférico, que se dirige ao trato urinário inferior. Realizouse uma busca nas bases de dados Pubmed e Scielo utilizando descritores para obter informações sobre o controle central da micção e o armazenamentourinário. A primeira porção do tronco encefálico que demonstrou relação com atividade miccional foi a ponte, principalmente o centro miccional pontino (PMC). É um ponto de convergência de estímulos pró e antimicção e sua principal função é ser o centro de comando para o início e harmonia do esvaziamento vesical. Diferentes regiões distintas disparam após a micção, sugerindo existir neurônios sinalizadores do início do relaxamento detrusor. A substância cinzenta periaquedutal é uma área importante no controle central do trato urinário inferior. Recebe modulação inibitória da região posterior hipotalâmica, envolvida no mecanismo de defesa (luta ou fuga). Outras estruturas como córtex, núcleos da base e cerebelo também vêm sendo evidenciadas por modular a micção. Embora neurônios bulbares sejam conhecidos por integrarem diferentes tipos de informações somatoviscerais e, principalmente, por participarem na regulação cardiovascular, pouco é conhecido sobre a importância desses neurônios sobre o controle vesical.

The micturition control, despite the apparent simplicity in its functioning, shows several levels of relative complexity. In conscious and unconscious states, it involves the activity of peripheral nerves, the sacral spinal cord, and the central areas that constitute the medulla oblongata, pons, midbrain, and cerebral cortex. In this review, the main currently known central areas involved in the urinary storage and voiding are focused, as well as the entrainment of peripheral signals related to the lower urinary tract. Pubmed and Scielo databases were searched using the keywords related to central control of voiding and urine storage. The first portion of the brainstem that demonstrated relationship to voiding activity was the pons, particularly the pontine micturition center (PMC).It is a point of convergence pro-stimuli and anti-urination and its main function is the command center for starting and harmonizing the bladder emptying. Different neurons of distinct regions fire after voiding, suggesting the existence of neurons signaling the initiation of detrusor relaxation. The periaqueductal gray matter is an important central area involved in the control of the lower urinary tract. It receives inhibitory modulation from posterior hypothalamic region, which is responsible for the defense mechanism (flight or fight). Other central structures such as the cerebral cortex, basal ganglia, and cerebellum have also been evidenced for modulating the micturition. Although medullary neurons are known for the integration of different somato-visceral signals and particularly for taking part in cardiovascular regulation, little is still known about the importance of those neurons in micturition control.

Central antioxidant therapy inhibits parasympathetic baroreflex control in conscious rats.

Baroreceptor reflex is an important system for neural control of blood pressure. Recently, reactive oxygen species (ROS) have been shown to play an important role in neuronal activity of central areas related to blood pressure control. The aim of this study was to investigate the effects elicited by ascorbic acid (AAC) and N-acetylcysteine (NAC) injections into the 4thV on the parasympathetic component of the baroreflex. Male Wistar rats were implanted with a stainless steel guide cannula into the 4thV. One day prior to the experiments, the femoral artery and vein were cannulated for pulsatile arterial pressure, mean arterial pressure and heart rate measurements and drug administration, respectively. After baseline recordings, the baroreflex was tested with a pressor dose of phenylephrine (PHE, 3 µg/kg, i.v.) and a depressor dose of sodium nitroprusside (SNP, 30 µg/kg, i.v.) before (control) and 5, 15, 30 and 60 min after AAC or NAC into the 4thV. Control PHE injection induced baroreflex-mediated bradycardia (-93 ± 13 bpm, n=7). Interestingly, after AAC injection into the 4thV, PHE injection produced a transient tachycardia at 5 (40 ± 23 bpm), 15 (26 ± 22 bpm) and 30 min (59 ± 21 bpm). No changes were observed in baroreflex-mediated tachycardia evoked by SNP after AAC injection on 4thV (control: 151 ± 23bpm vs. 135 ± 18 bpm at 5 min after AAC, n=7). In the NAC treated group, PHE induced a reduction in reflex bradycardia at 5 min when compared to control (-11 ± 17 bpm vs. -83 ± 15 bpm, n=7). No changes were observed in baroreflex-mediated tachycardia evoked by SNP after NAC injection on 4thV. The antioxidants AAC and NAC may act in the central nervous system affecting the parasympathetic component of the cardiac baroreflex.

Vehicle influence on potassium replacement effectiveness in hypokalemic rats.

INTRODUCTION: Patients who undergo cardiac surgery are commonly treated with diuretic therapy for the management of volume overload. The concern of hypokalemia important in the adult population submitted to cardiac surgery has been described. Intravenous potassium (K+) replacement dilution is only recommended with sodium chloride 0.9% solution (SF0.9%), likely due to the putative effects of glucose solution 5% (SG5%) on insulin secretion, which influence K+ replacement quality. However, it is not yet experimentally proved the influence of SF0.9% and SG5% on K+ replacement quality. OBJECTIVES: To evaluate the effects of different vehicles of K+ replacement on blood K+ levels in furosemide hypokalemic rats. METHODS: Male Wistar rats divided into four groups: K++SF, K++SG, SF and SG. Jugular vein was cannulation for K+ replacement and femoral vein was cannulated for blood analysis were performed. Furosemide (50mg/kg) was injected S.C. to induce hypokalemia. It was analyzed potassium plasmatic levels 24 hours before furosemide injection, 24 hours after furosemide injection and 30 minutes after post-replacement. RESULTS: There was no significative difference in blood K+ levels when compared to the basal values (pre-furosemide) in all groups. However, the levels [K+] returned to baseline in both groups receiving K++SF or K++SG, which was not observed in groups receiving only SF and SG. Only K+SF presented increased after K+ replacement (P<0.05). CONCLUSION: K+ replacement diluted both in SF and SG did not affect blood K+ levels in rats.

Antihypertensive responses elicited by central moxonidine in rats: possible role of nitric oxide.

In the present study, we investigated the effects of pretreatment with NG-nitro-L-arginine methyl ester (L-NAME) (nitric oxide synthase inhibitor) injected intravenously (IV) on the hypotension, bradycardia, and vasodilation produced by moxonidine (alpha2-adrenergic/imidazoline receptor agonist) injected into the fourth brain ventricle (4th V) in rats submitted to acute hypertension that results from baroreflex blockade by bilateral injections of kynurenic acid (kyn, glutamatergic receptor antagonist) into the nucleus of the solitary tract (NTS) or in normotensive rats. Male Wistar rats (n=5 to 7/group) anesthetized with IV urethane (1.0 g kg(-1) of body weight) and alpha-chloralose (60 mg kg(-1) of body weight) were used. Bilateral injections of kyn (2.7 nmol 100 nL(-1)) into the NTS increased baseline mean arterial pressure (148 +/- 11 mm Hg, vs. control: 102 +/- 4 mm Hg) and baseline heart rate (417 +/- 11 bpm, vs. control: 379 +/- 6 bpm). Moxonidine (20 nmol microL(-1)) into the 4th V reduced mean arterial pressure and heart rate to similar levels in rats treated with kyn into the NTS (68 +/- 9 mm Hg and 359 +/- 7 bpm) or in control normotensive rats (66 +/- 7 mm Hg and 362 +/- 8 bpm, respectively). The pretreatment with L-NAME (25 micromol kg, IV) attenuated the hypotension produced by moxonidine into the 4th V in rats treated with kyn (104 +/- 6 mm Hg) or in normotensive rats (95 +/- 8 mm Hg), without changing bradycardia. Moxonidine into the 4th V also reduced renal, mesenteric, and hindquarter vascular resistances in rats treated or not with kyn into the NTS and the pretreatment with L-NAME IV reduced these effects of moxonidine. Therefore, these data indicate that nitric oxide mechanisms are involved in hypotension and mesenteric, renal, and hindquarter vasodilation induced by central moxonidine in normotensive and in acute hypertensive rats.

Differentiated hemodynamic changes controlled by splanchnic nerve.

The splanchnic (SPL) nerve is a postganglionic sympathetic nerve involved in the tonic regulation of the cardiovascular system. Electrical stimulation of this nerve produces mesenteric vasoconstriction and it has been assumed that vasodilatory responses are dependent on inhibition of the vasoconstrictor tone. Several different central stimuli have been shown to dilate the hindquarter vascular bed and constrict the mesenteric vascular bed. To determine whether vasodilatory and vasoconstrictor effects in different vascular beds are elicited by activation of different sympathetic nerves, we investigated the hemodynamic changes in hindquarter, mesenteric and renal vascular beds evoked by electrical stimulation of the SPL nerve. Stimulation of the intact or sectioned SPL nerve in chloralose-anesthetized, artificially ventilated rats evoked increases in the hindquarter vascular conductance and simultaneously decreased the mesenteric and renal vascular conductance. Intravenous (i.v.) administration of L-NAME prior to stimulation of the proximal end of the sectioned SPL nerve abolished the increase in hindquarter conductance, suggesting the involvement of nitric oxide in this response. In assessing the hemodynamic effects of tonic activity on the SPL nerves, no significant changes were observed after unilateral section of the SPL nerve, but bilateral section of the SPL nerves decreased hindquarter conductance and did not significantly change the mesenteric conductance simultaneously. No consistent response was observed in the renal vascular bed after unilateral and subsequent contralateral section of the SPL nerves. These findings demonstrate that electrical stimulation of the SPL nerve produces mesenteric vasoconstriction and simultaneous hindquarter vasodilatation, which is mediated by nitric oxide. Moreover, the present data suggest that SPL nerves may provide a tonic vasodilatory tone in the hindquarter vascular bed and simultaneously a vasoconstrictor tone in another, undetermined vascular bed.