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1.
Eur Arch Psychiatry Clin Neurosci ; 272(7): 1241-1251, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34997853

RESUMO

Schizophrenia has been associated with structural brain abnormalities and cognitive deficits that partly change during the course of illness. In the present study, cortical thickness in five subregions of the cingulate gyrus was assessed in 44 patients with schizophrenia-spectrum disorder and 47 control persons and related to illness duration and memory capacities. In the patients group, cortical thickness was increased in the posterior part of the cingulate gyrus and related to illness duration whereas cortical thickness was decreased in anterior parts unrelated to illness duration. In contrast, cortical thickness was related to episodic and working memory performance only in the anterior but not posterior parts of the cingulate gyrus. Our finding of a posterior cingulate increase may point to either increased parietal communication that is accompanied by augmented neural plasticity or to effects of altered neurodegenerative processes in schizophrenia.


Assuntos
Giro do Cíngulo , Esquizofrenia , Cognição , Giro do Cíngulo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Memória de Curto Prazo , Esquizofrenia/complicações , Esquizofrenia/diagnóstico por imagem
2.
Climacteric ; 22(4): 377-382, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30652511

RESUMO

Purpose: Midlife women frequently experience stress and menopausal symptoms. Mindfulness is thought to mitigate stress by avoiding emotional reactivity and ruminative thinking. We sought to assess the association of mindfulness and stress on menopausal symptoms among midlife women. Materials and methods: In this cross-sectional study, women aged 40-65 years completed questionnaires, including the Menopause Rating Scale (MRS), the Perceived Stress Scale-4 (PSS-4), and the Mindfulness Attention Awareness Scale (MAAS). Linear regression was used to assess the impact of mindfulness and stress on menopausal symptoms with use of univariate and multivariable analyses, adjusting for patient characteristics. Results: In this cohort of 1744 midlife women, higher mindfulness (MAAS) and lower stress (PSS-4) scores correlated independently with lower menopausal symptom (MRS) scores. On multivariable analysis, a significant interaction effect was observed between the MAAS and PSS-4 on the MRS, such that with higher PSS-4 scores, the magnitude of association between the MAAS and lower MRS scores was larger. Conclusion: Among midlife women, higher mindfulness and lower stress correlated with lower menopausal symptom scores independently. Among women experiencing more stress, the magnitude of association between mindfulness and lower menopausal symptom scores was greater, largely driven by psychological subdomain scores. Mindfulness may mitigate menopausal symptoms among midlife women.


Assuntos
Menopausa , Atenção Plena , Estresse Psicológico , Adulto , Idoso , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Psicometria
3.
Climacteric ; 19(6): 581-587, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27763798

RESUMO

OBJECTIVES: To assess the association between the type of symptom and women's self-reported view of menopause. METHODS: The study was conducted at Mayo Clinic, Rochester MN, between January 2006 and October 2014. Women aged 40-64 were included. Data from 1420 women were analyzed in a cross-sectional design. The Menopause Health Questionnaire was used for symptom assessment. Odds ratios (ORs) and population attributable risk (PAR) (OR × percent frequency) were calculated for each symptom. Logistic regression analyses were performed with the view of menopause as the dependent variable. RESULTS: Anxiety (2.34), depressed mood (2.24), irritability (2.22), vaginal itching (2.27), crying spells (2.1) and breast tenderness (2.08) were associated with highest odds of having a negative view of menopause. Highest PAR (population impact) symptoms were anxiety (22.27), weight gain (20.66), fatigue (20.28) and irritability (19.41). Hot flushes and night sweats, although common, were not associated with a negative view of menopause (OR 1.3 and 1.16; PAR 3.85 and 4.42, respectively). CONCLUSION: Mood symptoms, vaginal itching, weight gain, breast tenderness and fatigue, although less common than hot flushes, were noted to have greater association with a negative view of menopause. Specifically addressing these symptoms during menopausal consultation may improve patient satisfaction and outcomes.


Assuntos
Atitude , Menopausa/fisiologia , Menopausa/psicologia , Adulto , Afeto , Ansiedade , Estudos Transversais , Depressão/psicologia , Fadiga/psicologia , Feminino , Fogachos , Humanos , Humor Irritável , Mastodinia/psicologia , Pessoa de Meia-Idade , Prurido/psicologia , Inquéritos e Questionários , Sudorese , Doenças Vaginais/psicologia , Aumento de Peso
4.
Aesthetic Plast Surg ; 39(3): 425-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25907155

RESUMO

UNLABELLED: HIV-related lipodystrophy and facial lipo-atrophy are well-described problems stigmatizing many HIV patients. As these patients often require large volumes of filler material, a more permanent solution is necessary. Before the popularization of lipofilling, synthetic permanent fillers have mostly been used. We describe a case report of a patient who had undergone removal of a permanent filler, polyacrylamide gel, because of dislocation of the filler, but who presented a massive hemi-facial edema immediately after the removal. Swelling subsided after 5 days. The use of permanent fillers has diminished due to frequent early and late complications, but a high awareness for permanent filler removal complications remains necessary. Possible pathways to explain these late complications are described. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Resinas Acrílicas/efeitos adversos , Técnicas Cosméticas/efeitos adversos , Preenchedores Dérmicos/efeitos adversos , Edema/etiologia , Migração de Corpo Estranho/etiologia , Abscesso/etiologia , Abscesso/terapia , Resinas Acrílicas/uso terapêutico , Adulto , Drenagem/métodos , Edema/fisiopatologia , Face , Seguimentos , Migração de Corpo Estranho/terapia , Infecções por HIV/diagnóstico , Humanos , Injeções Subcutâneas , Masculino , Retratamento , Medição de Risco
5.
Acta Chir Belg ; 112(5): 393-4, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23175932

RESUMO

We report a case of a 54-year-old, morbid obese man who presented with melena, hematemesis and fatigue over the last two days. The cause of this upper gastrointestinal bleeding was found on endoscopy which revealed an ulcerated submucosal mass in the gastric antrum. The haemorrhagia could not be stopped with injection of Aethoxysclerol. The mass was resected by an antrectomy with Roux-en-Y reconstruction. Histologic examination showed a lipoma. No further treatment was necessary. In this case report, we would like to stress the need for histologic diagnosis to differentiate a benign gastric lesion from a malign.


Assuntos
Lipoma/epidemiologia , Obesidade Mórbida/epidemiologia , Antro Pilórico , Neoplasias Gástricas/epidemiologia , Mucosa Gástrica/patologia , Hematemese/etiologia , Humanos , Lipoma/complicações , Lipoma/diagnóstico , Lipoma/patologia , Masculino , Melena/etiologia , Pessoa de Meia-Idade , Neoplasias Gástricas/complicações , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/patologia , Úlcera/patologia
6.
J Neural Eng ; 18(5)2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33690182

RESUMO

Objective.Typically, a brain-computer interface (BCI) is calibrated using user- and session-specific data because of the individual idiosyncrasies and the non-stationary signal properties of the electroencephalogram (EEG). Therefore, it is normal for BCIs to undergo a time-consuming passive training stage that prevents users from directly operating them. In this study, we systematically reduce the training data set in a stepwise fashion, to ultimately arrive at a calibration-free method for a code-modulated visually evoked potential (cVEP)-based BCI to fully eliminate the tedious training stage.Approach.In an extensive offline analysis, we compare our sophisticated encoding model with a traditional event-related potential (ERP) technique. We calibrate the encoding model in a standard way, with data limited to a single class while generalizing to all others and without any data. In addition, we investigate the feasibility of the zero-training cVEP BCI in an online setting.Main results.By adopting the encoding model, the training data can be reduced substantially, while maintaining both the classification performance as well as the explained variance of the ERP method. Moreover, with data from only one class or even no data at all, it still shows excellent performance. In addition, the zero-training cVEP BCI achieved high communication rates in an online spelling task, proving its feasibility for practical use.Significance.To date, this is the fastest zero-training cVEP BCI in the field, allowing high communication speeds without calibration while using only a few non-invasive water-based EEG electrodes. This allows us to skip the training stage altogether and spend all the valuable time on direct operation. This minimizes the session time and opens up new exciting directions for practical plug-and-play BCI. Fundamentally, these results validate that the adopted neural encoding model compresses data into event responses without the loss of explanatory power compared to using full ERPs as a template.


Assuntos
Interfaces Cérebro-Computador , Potenciais Evocados Visuais , Calibragem , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia
7.
Acta Chir Belg ; 110(3): 365-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20690526

RESUMO

Meckel's diverticulum is a common congenital anomaly of the small intestine, affecting 2% of the population. Neoplastic transformation is infrequent and gastrointestinal stromal tumours are exceptional in this location. We report a case of gastrointestinal bleeding caused by a gastrointestinal stromal tumour of Meckel's diverticulum.


Assuntos
Hemorragia Gastrointestinal/etiologia , Tumores do Estroma Gastrointestinal/diagnóstico , Divertículo Ileal/patologia , Idoso , Hemorragia Gastrointestinal/cirurgia , Tumores do Estroma Gastrointestinal/cirurgia , Humanos , Masculino , Divertículo Ileal/cirurgia
8.
J Anim Sci ; 95(2): 616-625, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28380603

RESUMO

Concurrent with a tendency toward higher slaughter weights of fattening pigs, minimum requirements for space allowance are increasing. Allowing pigs more space in existing standard pens, however, leads to a decrease in the number of pigs per pen, which jeopardizes the economic viability of the pig farm. A possible solution includes creating a two-level pen by constructing a second level in an existing pen, to enable an increase in space allowance per pig with the same number of pigs. We investigated the effect of such a pen on the behavior, performance, and postslaughter results of fattening pigs during the entire fattening period (30 to 110 kg). A total of 444 pigs were distributed over standard control pens (0.74 m/pig) and two-level pens (0.99 m/pig). Feed was provided only in a trough at the ground level of the pen. The results show that the increased space allowance and choice of levels in two-level pens influenced the pigs' behavior in a positive way, as they performed less manipulation of pen mates ( < 0.0001). Moreover, pigs lay down more ( = 0.0007) and showed less head knocking ( = 0.005) in two-level pens, suggesting that they were calmer. In line with the behavioral results, pigs in two-level pens had fewer lesions on tails ( = 0.006), ears ( = 0.008), and shoulders ( = 0.01). Growth performance was not affected ( > 0.05), but postslaughter measurements revealed fewer livers with white spots in pigs from two-level pens. This result might be related to lower disease pressure in pens with lower stocking densities. In conclusion, a two-level pen seemed to have positive effects on the behavior of pigs (in terms of pen mate manipulation) and the increase in space allowance seemed to make the pigs calmer. The use of the second level by heavier pigs should, however, be further studied to investigate whether this extra space could be fully counted for the minimal space requirements.


Assuntos
Comportamento Animal , Abrigo para Animais , Suínos/fisiologia , Bem-Estar do Animal , Animais , Feminino , Masculino , Suínos/crescimento & desenvolvimento
9.
J Anim Sci ; 94(10): 4360-4368, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27898873

RESUMO

Today, early weaning is more frequently applied by the modern pig breeder to obtain more litters per year. In addition, more and more European pig breeders apply a batch management system, which allows weaning to occur at fixed time points but entails that the offspring are treated at the litter level and not as individuals. Both evolutions might result in weaning lightweight piglets, which can cause, e.g., growth retardation of the offspring. Hence, the objective of this research was to improve the weaning weight of piglets of the same age by breeding with a highly conformed sire line. Therefore, a total of 23 sows were inseminated, 10 sows with semen of a well-conformed sire line (sire line B) and 13 sows with semen of a less conformed boar (sire line A). In total, 299 offspring were observed to monitor behavior, growth performance, and carcass characteristics. Subsequently, linear mixed models were developed to analyze the growth performance and carcass characteristics wherein only variables classified as significant ( < 0.05) were introduced as fixed factors. Results indicate that no significantly increased weaning weight could be accomplished by breeding with semen of sire line B. This could be due to the significant ( < 0.05) shorter gestation length of sows inseminated with semen of sire line B. However, the offspring of sire line B was defined by better carcass classification characteristics. Furthermore, this study presents that the mean birth weight of each piglet was significantly lower if a bigger litter size was recorded. When considering behavior, it was observed that piglets that did not seclude themselves from the litter had a significantly greater daily weight gain from birth to weaning compared to piglets that showed signs of isolation from the litter. A significantly greater daily gain from birth to slaughter was established for piglets with a greater birth weight. Also, results indicate that barrows had a significantly greater daily growth from weaning to slaughter than gilts. To conclude, this research determines that breeding with highly conformed sire lines does not improve the weaning weight of the offspring and thus cannot serve as a solution for early weaning. However, more research is required by performing more experiments with a greater number of boars and sows to confirm this result. In general, this study allows researchers to continue to improve and standardize the weaning weight of piglets of the same age.


Assuntos
Composição Corporal/genética , Suínos/genética , Aumento de Peso/genética , Animais , Cruzamento , Feminino , Masculino , Suínos/crescimento & desenvolvimento
10.
Am J Clin Nutr ; 67(3): 397-404, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9497182

RESUMO

The aim of this study was to investigate the effect of medium-chain triacylglycerol (MCT) ingestion during exercise on subsequent time-trial cycling performance. Seven well-trained cyclists performed four exercise trials consisting of 2 h at 60% of maximal oxygen uptake followed by a simulated time trial (ie, completion of a preset amount of work as fast as possible) of approximately 15 min duration. During the trials, subjects ingested 1) a 10% carbohydrate solution (CHO; 170 +/- 6 g glucose), 2) a 10% carbohydrate electrolyte with 5% MCT solution (CHO + MCT; 85 +/- 3 g MCT), 3) a 5% MCT solution, or 4) artificially colored and flavored water (placebo). Neither CHO nor CHO + MCT ingestion had any effect on performance compared with placebo ingestion, whereas ingestion of MCT had a negative effect on performance. Average work rates during the time trial were 314 +/- 19, 314 +/- 13, and 312 +/- 18 with CHO, CHO + MCT, and placebo, respectively, and was 17-18% lower in the MCT trial (263 +/- 22 W). In addition, compared with placebo ingestion, MCT ingestion had no effect on total rates of fat or carbohydrate oxidation, nor did it affect exogenous or endogenous carbohydrate utilization. The negative effect of MCT ingestion was associated with increased gastrointestinal complaints (ie, intestinal cramping). These data suggest that large amounts of MCTs (85 g) ingested during prolonged submaximal exercise may provoke gastrointestinal problems leading to decreased exercise performance.


Assuntos
Ciclismo , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Metabolismo Energético , Triglicerídeos/administração & dosagem , Ácido 3-Hidroxibutírico , Glicemia/metabolismo , Calorimetria , Carboidratos da Dieta/efeitos adversos , Gorduras na Dieta/efeitos adversos , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/fisiopatologia , Ácidos Graxos/sangue , Humanos , Hidroxibutiratos/sangue , Lactatos/sangue , Masculino , Triglicerídeos/efeitos adversos
11.
Angiology ; 42(2): 90-8, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2006766

RESUMO

A method for plaque dissolution has been identified that percutaneously delivers a pulsatile high-velocity stream of saline to the site of an atheromatous lesion within a coronary or peripheral artery. In vitro evaluation and in vivo canine and porcine testing were performed using this 'rheolytic' system to determine its feasibility in ablating calcified plaque and soft thrombotic tissue. A prototype rheolytic guidewire capable of providing 30,000 psi of internal pressure was designed to fit within the guidewire lumen of a standard percutaneous transluminal coronary angioplasty catheter. An additional over-the-wire rheolytic catheter was fabricated to follow a standard .014-inch guidewire. The rheolytic devices were tested in vitro with simulated atheromatous and thrombotic lesions to evaluate the size and quantity of the particulate effluent. The particulate was then sterilized, mixed with saline, and introduced percutaneously into the animal kidney and heart for evaluation. The in vitro studies demonstrated that the rheolytic catheter and guidewire were able to follow both a coronary and femoral arterial model and successfully ablate the simulated lesions. The particle size for osseous, muscular, and cartilagenous tissue ranged from 2 to 6 micrometers; for fresh human plaque the particles ranged from 2 to 15 micrometers. Injection of cartilagenous and plaque particles into the animal model caused very slight regions of necrosis but no clinical sequelae. Applications of the rheolytic devices to the animal femoral artery demonstrated that both devices could ablate and cross calified or soft thrombosed lesions without damage to the vessel wall; the rheolytic catheter provided a debulking of the plaque.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Arteriosclerose/terapia , Cateterismo/instrumentação , Doença da Artéria Coronariana/terapia , Animais , Cateterismo/métodos , Cães , Artéria Femoral , Humanos , Técnicas In Vitro , Pressão , Cloreto de Sódio/administração & dosagem , Suínos
12.
J Nurs Educ ; 29(6): 244-8, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2165143

RESUMO

Nurse educators are required to be knowledgeable about a wide variety of complex health care problems in order to provide quality education. At the same time, they are given a multitude of other responsibilities such as participating in scholarly activity, advising students, maintaining an active role in nursing practice, and performing community service. These educators must find innovative ways to present current lectures while at the same time meeting their other obligations. The use of Creighton Online Multiple Modular Expert System (COMMES), a computerized decision support consultant, was evaluated as a technique for faculty use in developing and organizing new lecture content. The study found that COMMES was beneficial as a systematic prompt for lecture content, as a tool for organizing content, and as a means to verify completeness of lecture material.


Assuntos
Tomada de Decisões , Sistemas Inteligentes , Processo de Enfermagem , Ensino/métodos , Currículo , Bacharelado em Enfermagem , Humanos , Pesquisa em Avaliação de Enfermagem , Planejamento de Assistência ao Paciente , Ensino/normas
13.
Dimens Crit Care Nurs ; 13(4): 208-17, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7988334

RESUMO

Due to the short length of stay for directional coronary atherectomy (DCA) patients, critical care nurses play a vital role in providing patients with discharge teaching. Decreased length of stay has left very little time for teaching DCA patients. It is critical for nurses to focus on key points and use concepts and words the patient immediately understands. This article describes key teaching strategies and provides sample written discharge teaching sheets for use in discharge teaching of the DCA patient.


Assuntos
Aterectomia Coronária/enfermagem , Alta do Paciente , Educação de Pacientes como Assunto , Idoso , Cuidados Críticos , Humanos , Masculino
15.
J Bacteriol ; 173(21): 7012-7, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1938903

RESUMO

As reported previously, Saccharomyces cerevisiae cells deficient in all four known genes coding for alcohol dehydrogenases (ADH1 through ADH4) produce considerable amounts of ethanol during aerobic growth on glucose. It has been suggested that ethanol production in such adh0 cells is a corollary of acetaldehyde dismutation in mitochondria. This could be substantiated further by showing that mitochondrial ethanol formation requires functional electron transport, while the proton gradient or oxidative phosphorylation does not interfere with reduction of acetaldehyde in isolated mitochondria. This acetaldehyde-reducing activity is different from classical alcohol dehydrogenases in that it is associated with the inner mitochondrial membrane and also is unable to carry out ethanol oxidation. The putative cofactor is NADH + H+ generated by a soluble, matrix-located aldehyde dehydrogenase upon acetaldehyde oxidation to acetate. This enzyme has been purified from mitochondria of glucose-grown cells. It is clearly different from the known mitochondrial aldehyde dehydrogenase, which is absent in glucose-grown cells. Both acetaldehyde-reducing and acetaldehyde-oxidizing activities are also present in the mitochondrial fraction of fermentation-proficient (ADH+) cells. Mitochondrial acetaldehyde dismutation may have some significance in the removal of surplus acetaldehyde and in the formation of acetate in mitochondria during aerobic glucose fermentation.


Assuntos
Acetaldeído/metabolismo , Mitocôndrias/metabolismo , Saccharomyces cerevisiae/metabolismo , Aldeído Oxirredutases/metabolismo , Transporte de Elétrons , Eletroforese em Gel de Poliacrilamida , Etanol/metabolismo , Cinética , Saccharomyces cerevisiae/ultraestrutura
16.
J Intraven Nurs ; 14(2): 114-8, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2005506

RESUMO

Incorrect technique in subclavian catheter removal may result in fatal air emboli. This article discusses the pathophysiologic development and consequence of air emboli and outlines preventive nursing measures and emergency treatment.


Assuntos
Cateterismo Venoso Central/enfermagem , Embolia Aérea/enfermagem , Veia Subclávia , Cateterismo Venoso Central/efeitos adversos , Embolia Aérea/etiologia , Embolia Aérea/prevenção & controle , Humanos , Avaliação em Enfermagem , Curativos Oclusivos
17.
J Bacteriol ; 172(7): 3909-17, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2193925

RESUMO

A strain of Saccharomyces cerevisiae has been constructed which is deficient in the four alcohol dehydrogenase (ADH) isozymes known at present. This strain (adh0), being irreversibly mutated in the genes ADH1, ADH3, and ADH4 and carrying a point mutation in the gene ADH2 coding for the glucose-repressible isozyme ADHII, still produces up to one third of the theoretical maximum yield of ethanol in a homofermentative conversion of glucose to ethanol. Analysis of the glucose metabolism of adh0 cells shows that the lack of all known ADH isozymes results in the formation of glycerol as a major fermentation product, accompanied by a significant production of acetaldehyde and acetate. Treatment of glucose-growing adh0 cells with the respiratory-chain inhibitor antimycin A leads to an immediate cessation of ethanol production, demonstrating that ethanol production in adh0 cells is dependent on mitochondrial electron transport. Reduction of acetaldehyde to ethanol in isolated mitochondria could also be demonstrated. This reduction is apparently linked to the oxidation of acetaldehyde to acetate. Preliminary data suggest that this novel type of ethanol formation in S. cerevisiae is associated with the inner mitochondrial membrane.


Assuntos
Acetaldeído/metabolismo , Álcool Desidrogenase/genética , Etanol/metabolismo , Genes Fúngicos , Isoenzimas/genética , Mutação , Saccharomyces cerevisiae/genética , Alelos , Antimicina A/análogos & derivados , Antimicina A/farmacologia , Fermentação , Genótipo , Cinética , Mitocôndrias/metabolismo , Oxirredução , Plasmídeos , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia
18.
J Physiol ; 276: 515-24, 1978 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-650479

RESUMO

1. When cardiac preparations are rewarmed following prolonged hypothermia a transient hyperpolarization occurs in K-containing media. This hyperpolarization is correlated with the active Na efflux. It might be due to electrogenic Na pumping or to extracellular K depletion brought about by the activity of an electroneutral Na-K exchange pump. In order to distinguish between these mechanisms the effect of various extracellular K concentrations ([K](o)) on the membrane potential of guineapig atria was studied before and after hypothermia.2. The membrane potential increased with decreasing [K](o) before cooling. It reached values of -64 and -92 mV at 10.8 and 0 mM-K, respectively.3. The membrane hyperpolarized transiently after hypothermia beyong the potential observed before cooling. Maximal values of about -94 mV were obtained during rewarming in solutions containing 0.4-2.7 mM-K. The membrane potential was significantly lower (-88 mV) in K-free media. It was also diminished at [K](o) higher than 2.7 mM and was measured to be -74 mV at 10.8 mM-K.4. The hyperpolarization of the cell membrane during the first 20 min of rewarming was maximal at 2.7 mM-K and yielded 15.5 mV. The hyperpolarization amounted to 7.2 and 10 mV at 0.4 and 10.8 mM-K, respectively. No hyperpolarization occurred in K-free solutions.5. The rate of decline of the transient hyperpolarization increased with [K](o).6. Variations of membrane input resistance after changes in [K](o) were measured in rewarmed atrial trabecula. The measurements revealed an increase in membrane resistance in lower [K](o).7. It is concluded that the transient hyperpolarization of the cardiac cell membrane during rewarming is due to the activation of an electrogenic Na pump.8. The (relative) strength of the pump current at various [K](o) was derived from the observed dependence of the hyperpolarization and of the membrane input resistance on [K](o). The current is estimated to be half-maximal at about 1.5 mM-K.


Assuntos
Miocárdio/metabolismo , Potássio/farmacologia , Sódio/metabolismo , Animais , Função Atrial , Transporte Biológico Ativo , Temperatura Corporal , Condutividade Elétrica , Cobaias , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/metabolismo , Técnicas In Vitro , Potenciais da Membrana
19.
Eur J Appl Physiol Occup Physiol ; 79(2): 202-4, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10029343

RESUMO

The aim of this study was to examine effects of a pulsating pressure anti-gravity suit on the peak values of oxygen uptake (VO2) and power during maximal arm exercise in spinal-cord-injured (SCI) individuals. Five well-trained SCI men (with lesions at levels between T6 and L1) and seven well-trained able-bodied men (ABC) performed two incremental (10 W x min(-1)) arm-cranking tests. During one test the pressure in the anti-G suit pulsated between 4.7 kPa (35 mmHg) and 9.3 kPa (70 mmHg) every 2 s (PPG+), during the other test (PPG-) all the subjects wore the anti-G suit in a deflated state. Tests were performed in a counter-balanced order. Peak VO2 in SCI was 1 ml x kg(-1) x min(-1) lower during PPG+ compared to PPG- (P = 0.05). Peak power and peak heart rate were not significantly different during PPG+ compared to PPG-. These results would suggest that no increase in work capacity can be obtained with a pulsating pressure anti-gravity suit in either SCI or ABC.


Assuntos
Exercício Físico/fisiologia , Trajes Gravitacionais , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Braço/fisiologia , Teste de Esforço , Frequência Cardíaca/fisiologia , Humanos , Masculino , Consumo de Oxigênio/fisiologia
20.
Radiology ; 182(1): 263-7, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1727293

RESUMO

The authors present a percutaneous thrombectomy system (rheolytic thrombectomy catheter [RTC]) in which high-velocity jets of saline solution are used to lyse and remove thrombus. The catheters (4-6 F) direct a 10,000-15,000-psi (0.7-1.05 x 10(5)-kPa) jet of saline solution onto an exhaust port from orifices at the end of the catheter. The jet entrains clot and resulting fragments and brings them into the high-velocity region for lysis and removal. Whole blood clots (10-15 cm) placed in 6-9-mm-diameter tubing were completely dissolved and removed with the RTC in less than 1 minute. In vivo use in a canine model resulted in lysis and removal of clots from a femoral artery, without vessel damage. The small caliber, flexibility, and effective lysis of this system suggest its potential usefulness in large central vessels that are difficult to access surgically and in small-diameter vessels that require more rapid removal of thrombus than can be achieved with thrombolytic therapy.


Assuntos
Cateterismo/instrumentação , Trombose/terapia , Animais , Cães , Desenho de Equipamento , Artéria Femoral , Modelos Cardiovasculares , Poliésteres , Politetrafluoretileno , Radiografia , Cloreto de Sódio , Trombose/diagnóstico por imagem
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