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1.
Stud Health Technol Inform ; 302: 947-951, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37203542

RESUMO

Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. In this work, the non-invasive imaging technique spectral domain optical coherence tomography (SD-OCT) is used to acquire retinal images, which are then analyzed using deep learning techniques. The authors trained a convolutional neural network (CNN) using 1300 SD-OCT scans annotated by trained experts for the presence of different biomarkers associated with AMD. The CNN was able to accurately segment these biomarkers and the performance was further enhanced through transfer learning with weights from a separate classifier, trained on a large external public OCT dataset to distinguish between different types of AMD. Our model is able to accurately detect and segment AMD biomarkers in OCT scans, which suggests that it could be useful for prioritizing patients and reducing ophthalmologists' workloads.


Assuntos
Algoritmos , Degeneração Macular , Humanos , Degeneração Macular/diagnóstico por imagem , Redes Neurais de Computação , Tomografia de Coerência Óptica/métodos , Biomarcadores
2.
Stud Health Technol Inform ; 302: 581-585, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37203752

RESUMO

Glaucoma is one of the leading causes of blindness worldwide. Therefore, early detection and diagnosis are key to preserve full vision in patients. As part of the SALUS study, we create a blood vessel segmentation model based on U-Net. We trained U-Net on three different loss functions and used hyperparameter tuning to find their optimal hyperparameters for each loss function. The best models for each of the loss functions achieved an accuracy of over 93%, Dice scores around 83% and Intersection over Union scores over 70%. They each identify large blood vessels reliably and even recognize smaller blood vessels in the retinal fundus images and thus pave the way for improved glaucoma management.


Assuntos
Cegueira , Glaucoma , Humanos , Fundo de Olho , Glaucoma/diagnóstico por imagem
3.
GMS J Med Educ ; 38(5): Doc88, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34286068

RESUMO

Introduction: In Germany, foreign physicians are a fixed component of the medical profession. According to the German Medical Licensure Act, physicians having completed their qualification in another country are required to pass a knowledge examination which falls within the competence of examination offices or the regional governments. Project outline: The preparatory course consists of 10 modules. On Fridays, individual cases are discussed in small groups and specific examination techniques are trained. On Saturdays, illnesses are simulated by simulated patients. After each encounter, faculty experts, psychologists and peer group members provide the participants with 360° feedback. Due to the COVID-19 pandemic, the course which had been established 2 years beforehand has now been switched to an online class within one week. Friday units were visualized in power-point presentations and tutorial videos were discussed. On Saturdays, the cases were simulated by simulated patients and transmitted via a telemedicine platform. Results: The course could be conducted without interruptions (75 hours of in-class tuition and 75 hours of online tuition). In the oral evaluation the participants criticized telemedicine as a medium for imparting of practical skills. 7/22 (32%) of the participants underwent the knowledge examination and 6/7 (86%) of them passed it (versus 18/19 of the participants of in-class tuition (95%)). Discussion: There was a clear preference for in-class tuition. It was noted that the telemedical setting entailed some restrictions. However, the switch to online classes did not affect the pass rate. Conclusion: The switch from in-class to online units was feasible. The gained insights were taken into account when conceiving the online semester at our faculty and especially the tuition with the support of simulated patients.


Assuntos
COVID-19 , Currículo , Educação Médica , Médicos Graduados Estrangeiros , Internet , Licenciamento em Medicina , Pandemias , Competência Clínica , Avaliação Educacional , Alemanha , Guias como Assunto , Humanos , Distanciamento Físico , Faculdades de Medicina , Estações do Ano
4.
Stud Health Technol Inform ; 281: 1112-1113, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34042862

RESUMO

Data analysis with popular statistical toolchains like R usually needs to be performed on "flat tables" (so-called dataframes). However, data exchange is often done with FHIR, a format that is based on a hierarchical data model. In this paper, we want to present our tool FhirExtinguisher, which tackles the problems of loading FHIR data into statistical tools by extending the FHIRSearch API with an additional projection layer using FHIRPath. This projection layer can be used to select the data elements of interest and create a CSV file, which can be easily read as dataframe by almost any statistical toolchain.


Assuntos
Registros Eletrônicos de Saúde , Comportamento de Utilização de Ferramentas , Análise de Dados
5.
Environ Sci Pollut Res Int ; 26(30): 31215-31224, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31463753

RESUMO

In the present study, in vivo antioxidant properties of the n-butanol extract obtained from aerial parts of Perralderia coronopifolia were investigated in term of its hepatoprotective effect of female Wistar albino rats (n, 36; average age, 48 ± 5 days; weighing 150 ± 18 g) against PCP (pentachlorphenol)-induced toxicity. PCP (20 mg/kg b.w.) and plant extract (50 mg/kg b.w.) were administered daily by gavages for 2 weeks. Vitamin E (100 mg/kg b.w.) was given intraperitoneally as a positive control. Lipid peroxidation (LPO) levels, reduced glutathione (GSH) levels, and glutathione peroxidase (GPx) activities were evaluated in liver homogenates. While, aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, and triglyceride parameters were analyzed in serums. The liver fragments were observed using light microscopy. Experimental results exhibited that PCP-treated group has a significant increase in the liver lipid peroxidation (LPO) levels of animals while decreased in plant extract-treated group. In addition, PCP caused significant decreases in glutathione peroxidase (GPx) activities and reduced glutathione (GSH) levels. Moreover, PCP induced hepatotoxicity by increasing serum transaminase enzymes, cholesterol, and triglyceride levels. While, these levels were restored to control value in animals treated with plant extract. The regularized levels of LPO, GSH, cholesterol, triglyceride, transaminase enzymes, and GPx activities revealed the antioxidant properties of the extract plant as well as of the vitamin E. The histological study showed the hepatoprotective effect of our extracts against PCP-induced acute intoxication, protecting the hepatic architecture and decreasing the functional and structural alterations of the liver. The plant extract had high antioxidant potential and completely prevented the toxic effect of PCP on the above of liver and serum parameters.


Assuntos
Asteraceae/química , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Pentaclorofenol/toxicidade , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , 1-Butanol/química , Alanina Transaminase/sangue , Animais , Antioxidantes/metabolismo , Aspartato Aminotransferases/sangue , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Feminino , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Extratos Vegetais/química , Substâncias Protetoras/química , Ratos Wistar
6.
Braz. J. Pharm. Sci. (Online) ; 53(3): e17095, 2017. tab
Artigo em Inglês | LILACS | ID: biblio-889381

RESUMO

ABSTRACT In this work, the potential chemopreventive activities of Elaeagnus umbellata fruit aqueous (EUFA) and leaf aqueous (EULA) extracts focusing on the modulatory influence of xenobiotic metabolizing enzymes (XMEs), antioxidant enzymes, glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), lactate dehydrogenase (LDH) activity, lipid peroxidation (LP), sulfhydryl groups were investigated in the hepatic and extrahepatic organs of Swiss albino mice (50 and 100 mg/kg body wt given orally for 14 days) and compared with BHA (0.75 % in diet). The modulatory and chemopreventive properties of two different doses EUFA and EULA were observed for cytochrome P450, cytochrome b5, sulfhydryl groups, NADPH-cytochrome P450 reductase, NADH-cytochrome b5 reductase, 7-ethoxyresorufin-deethylase and N,N-dimethylaniline N-oxidase activities in the liver and compared with BHA as a standard. The activities of glutathione S-transferase (GST) and DT-diaphorase (DTD) showed a significant increase in the kidney, forestomach, heart and brain at both doses of EUFA and EULA. The results of EULA-treated groups were found a notable increase in LDH, G6PD, 6PGD, GST and DTD activities. Superoxide dismutase level in liver, kidney and heart exhibited a significant increase at both doses of EULA. Glutathione reductase activity was a remarkable level at high dose of EUFA in liver, kidney and EULA in kidney. Both doses of EUFA were effective in inducing glutathione peroxidase activitiy in heart. The levels of LP at low and high doses of EULA-treated and EUFA-treated were effective in liver and kidney, respectively. The present results demonstrate that significant effects in the level of XMEs and antioxidant enzymes of EUFA and EULA are remarkable for modulating roles and natural chemoprevention properties and therefore is considered for a valuable natural source.


Assuntos
Animais , Camundongos , Extratos Vegetais/análise , Folhas de Planta/metabolismo , Elaeagnaceae/efeitos adversos , Antioxidantes , Prevenção de Doenças , Compostos Fitoquímicos/análise , Frutas/classificação
7.
Stud Health Technol Inform ; 228: 225-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27577376

RESUMO

Smart wearables are capable of supporting physicians during various processes in medical emergencies. Nevertheless, it is almost impossible to operate several computers without neglecting a patient's treatment. Thus, it is necessary to set up a distributed network consisting of two or more computers to exchange data or initiate remote procedure calls (RPC). If it is not possible to create flawless connections between those devices, it is not possible to transfer medically relevant data to the most suitable device, as well as to control a device with another one. This paper shows how wearables can be paired and what problems occur when trying to pair several wearables. Furthermore, it is described as to what interesting scenarios are possible in the context of emergency medicine/paramedicine.


Assuntos
Microcomputadores , Telecomunicações , Telemedicina/instrumentação , Criança , Emergências , Troca de Informação em Saúde , Humanos , Aplicativos Móveis , Pediatria/instrumentação , Pediatria/métodos , Ressuscitação , Telemedicina/métodos
8.
HERD ; 9(3): 212-27, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26293592

RESUMO

OBJECTIVE: The objective of this article was to explore interior spatial qualifications on patient perception of two densities of multioccupancy hospital rooms. BACKGROUND: The research setting of this study was the three- and six-person capacity hospital rooms used for treatment of patients at a large hospital in a major metropolitan city in Turkey. METHOD: The subjects used in the study were randomly selected from among patients treated in the surgical medical sciences' departments of the hospital. Accordingly, a research questionnaire was applied to a total of 101 subjects. RESULTS: Results have shown that the three-person rooms were assessed more positively for privacy, functional, and perceptual qualifications compared to the six-person rooms. An increase in the number of persons and interior units of rooms affects negatively the auditory privacy and privacy areas of other patients. CONCLUSION: Consequently, although these rooms with different spatial sizes were very similar for concentration of persons and commodities, six-person rooms were perceived to be more crowded than three-person rooms.


Assuntos
Aglomeração/psicologia , Decoração de Interiores e Mobiliário/normas , Orientação Espacial , Preferência do Paciente/psicologia , Quartos de Pacientes/normas , Percepção , Privacidade/psicologia , Adolescente , Adulto , Feminino , Ambiente de Instituições de Saúde/normas , Hospitais Urbanos/normas , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Turquia , Adulto Jovem
9.
J Card Surg ; 30(12): 877-80, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26498864

RESUMO

BACKGROUND: Multiple stents make standard coronary artery bypass techniques difficult. We describe our surgical approach, in patients undergoing coronary artery bypass grafting (CABG), in left anterior descending arteries (LAD) with multiple failed overlapping stents. METHODS: We retrospectively reviewed the data of six patients undergoing CABG with multiple failed overlapping stents in the LAD. All patients were operated on electively. After removal of the stents with an open endarterectomy, the long segmental arteriotomy of the LAD was reconstructed with a saphenous vein patch. Afterwards the left internal mammary artery was anastomosed to the vein patch. RESULTS: The mean age was 61.5 ± 7.9 years. Five patients (83.3%) were in Canadian Cardiovascular Society Class III or IV. Four patients (66.6%) had suffered a remote myocardial infarction (>1 month). The average hospital stay was 6.5 ± 1.1 days. Postoperative electrocardiograms showed no specific changes and no myocardial enzyme elevations were noted. Early postoperative angiography showed that all grafts including the endarterectomized LAD were patent. There was no mortality within the 30 days. Patients' mean follow-up time was 35.6 ± 36.7 months. CONCLUSIONS: CABG with open stent endarterectomy is a valuable alternative option for patients with "full-metal jacket" diseased LAD that are not graftable using standard surgical techniques.


Assuntos
Ponte de Artéria Coronária/métodos , Vasos Coronários/cirurgia , Remoção de Dispositivo/métodos , Endarterectomia/métodos , Falha de Prótese , Stents/efeitos adversos , Idoso , Angina Pectoris/cirurgia , Procedimentos Cirúrgicos Eletivos , Feminino , Seguimentos , Humanos , Anastomose de Artéria Torácica Interna-Coronária/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Veia Safena/transplante , Resultado do Tratamento
10.
Gen Physiol Biophys ; 34(4): 433-40, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26374993

RESUMO

The role of the cannabinoid (CB) system in the tolerance to analgesic effect of opioid remains obscure. The aim of the present study was to evaluate the effects of the endocannabinoid nonselective receptor agonist anandamide (AEA) and CB1 receptor antagonist rimonabant (SR141716) on morphine analgesia and tolerance in rats. Male Wistar albino rats weighing 215-230 g were used in these experiments. To constitute morphine analgesic tolerance, a 3-day cumulative dosing regimen was used. The analgesic effects of AEA (10 mg/kg), SR141716 (10 mg/kg), and morphine (5 mg/kg) were considered at 30-min intervals by tail flick (TF) and hot plate (HP) analgesia tests. The analgesic effects of the drugs were measured as TF and HP latencies in all groups for each rat and converted to %MPE. The data were analysed by analysis of variance followed by Tukey test. The findings suggested that AEA in combination with morphine produced a significant increase in expression of analgesic tolerance to morphine. Conversely, cannabinoid receptor antagonist SR141716 attenuated morphine analgesic tolerance. In addition, administration of AEA with morphine increased morphine analgesia. In conclusion, we observed that the cannabinoid receptor agonist anandamide and CB1 receptor antagonist SR141716 plays a significant role in the opioid analgesia and tolerance.


Assuntos
Ácidos Araquidônicos/administração & dosagem , Endocanabinoides/administração & dosagem , Morfina/administração & dosagem , Nociceptividade/efeitos dos fármacos , Nociceptividade/fisiologia , Piperidinas/administração & dosagem , Alcamidas Poli-Insaturadas/administração & dosagem , Pirazóis/administração & dosagem , Analgésicos Opioides/administração & dosagem , Animais , Agonistas de Receptores de Canabinoides/administração & dosagem , Antagonistas de Receptores de Canabinoides/administração & dosagem , Relação Dose-Resposta a Droga , Interações Medicamentosas , Tolerância a Medicamentos/fisiologia , Masculino , Ratos , Ratos Wistar , Rimonabanto , Resultado do Tratamento
11.
J Physiol Sci ; 65(5): 407-15, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25894754

RESUMO

Cannabinoid CB1 and CB2 receptor antagonists may be useful for their potential to increase or prolong opioid analgesia while attenuating the development of opioid tolerance. The aim of this study was to investigate the effects of AM251 (a selective CB1 antagonist) and JTE907 (a selective CB2 antagonist) on morphine analgesia and tolerance in rats. Adult male Wistar albino rats weighing 205-225 g were used in these experiments. To constitute morphine tolerance, we used a 3 day cumulative dosing regimen. After the last dose of morphine was injected on day 4, morphine tolerance was evaluated by analgesia tests. The analgesic effects of morphine (5 mg/kg), ACEA (a CB1 receptor agonist, 5 mg/kg), JWH-015 (a CB2 receptor agonist, 5 mg/kg), AM251 (1 mg/kg) and JTE907 (5 mg/kg) were considered at 30-min intervals (0, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests. Our findings indicate that ACEA and JWH907 significantly increased morphine analgesia and morphine antinociceptive tolerance in the analgesia tests. In contrast, the data suggested that AM251 and JTE907 significantly attenuated the expression of morphine tolerance. In conclusion, we observed that co-injection of AM251 and JTE907 with morphine attenuated expression of tolerance to morphine analgesic effects and decreased the morphine analgesia.


Assuntos
Analgésicos Opioides/farmacologia , Comportamento Animal/efeitos dos fármacos , Antagonistas de Receptores de Canabinoides/farmacologia , Dioxóis/farmacologia , Tolerância a Medicamentos , Morfina/farmacologia , Nociceptividade/efeitos dos fármacos , Piperidinas/farmacologia , Pirazóis/farmacologia , Quinolonas/farmacologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/antagonistas & inibidores , Animais , Agonistas de Receptores de Canabinoides/farmacologia , Relação Dose-Resposta a Droga , Masculino , Limiar da Dor/efeitos dos fármacos , Ratos Wistar , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo
12.
Heart Surg Forum ; 18(6): E263-5, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26726718

RESUMO

We describe a case of a patient with a history of chronic atrial fibrillation who presented with sudden onset of left hemiplegia. Nine months earlier the longstanding warfarin therapy had been suspended due to a hemorrhagic stroke. Transthoracic echocardiography revealed a large free-floating highly mobile mass in the left atrium and severe mitral valve regurgitation. Due to the potential risk of an embolic event or a hemodynamic collapse, a decision to carry out an emergency operation was made irrespective of the neurological condition of the patient. Unfortunately, the patient died on the 18th postoperative day after a freshly occurring hemorrhagic stroke.


Assuntos
Átrios do Coração/cirurgia , Cardiopatias/complicações , Cardiopatias/cirurgia , Hemiplegia/etiologia , Trombose/complicações , Trombose/cirurgia , Idoso de 80 Anos ou mais , Infarto Encefálico/etiologia , Hemorragia Cerebral/etiologia , Evolução Fatal , Feminino , Humanos , Insuficiência da Valva Mitral/etiologia
13.
Percept Mot Skills ; 112(2): 509-24, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21667759

RESUMO

The purpose was to assess whether various colors across room interiors do, in fact, evoke different moods. Digital images of two imaginary living rooms were used as the experimental settings. For each of the experiments, the rooms' spatial characteristics were fixed, with only the colors changed: either warm, cool, or achromatic colors. As predicted, warm colors tended to produce stronger participant responses when rating the scene on "high arousal," "exciting," and "stimulating." Cool colors tended be associated with "not very arousing," but to be rated higher on "spacious" and "restful." It is generally assumed that cool and achromatic colors evoke calmer and more peaceful emotions. The study's results show that the spatial characteristics of the imaginary spaces themselves affected participants' responses only on measures of "happiness" and "vividness." Lastly, sex differences were also found, with women's ratings generally more positive than those of men.


Assuntos
Afeto , Comportamento de Escolha , Percepção de Cores , Decoração de Interiores e Mobiliário , Feminino , Humanos , Masculino , Diferencial Semântico , Fatores Sexuais , Estudantes/psicologia , Turquia
14.
Can J Physiol Pharmacol ; 85(5): 521-6, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17632587

RESUMO

The radial artery (RA) is used as a spastic coronary bypass graft. This study was designed to investigate the mechanism of vasorelaxant effects of YC-1 (3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole), a nitric oxide (NO)-independent soluble guanylate cyclase (sGC) activator, and DEA/NO (diethylamine/nitric oxide), a NO-nucleophile adduct, on the human RA. RA segments (n = 25) were obtained from coronary artery bypass grafting patients and were divided into 3-4 mm vascular rings. Using the isolated tissue bath technique, the endothelium-independent vasodilatation function was tested in vitro by the addition of cumulative concentrations of YC-1 (10-10 to 3 x 10-7 mol/L) and DEA/NO (10-8 to 3 x 10-5 mol/L) following vasocontraction by phenylephrine in the presence or absence of 10-5 mol/L ODQ (1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one), the selective sGC inhibitor, 10-7 mol/L iberiotoxin, a blocker of Ca2+-activated K+ channels, or 10-5 mol/L ODQ plus 10-7 mol/L iberiotoxin. We also evaluated the effect of YC-1 and DEA/NO on the cGMP levels in vascular rings obtained from human radial artery (n = 6 for each drug). YC-1 (10-10 to 3 x 10-7 mol/L) and DEA/NO (10-8 to 3 x 10-5 mol/L) caused the concentration-dependent vasorelaxation in RA rings precontracted with phenylephrine (10-5 mol/L) (n = 20 for each drug). Pre-incubation of RA rings with ODQ, iberiotoxin, or ODQ plus iberiotoxin significantly inhibited the vasorelaxant effect of YC-1, but the inhibitor effect of ODQ plus iberiotoxin was significantly more than that of ODQ and iberiotoxin alone (p < 0.05). The vasorelaxant effect of DEA/NO almost completely abolished in the presence of ODQ and iberiotoxin plus ODQ, but did not significantly change in the presence of iberiotoxin alone (p > 0.05). The pEC50 value of DEA/NO was significantly lower than those for YC-1 (p < 0.01), with no change Emax values in RA rings. In addition, YC-1-stimulated RA rings showed more elevation in cGMP than that of DEA/NO (p < 0.05). These findings indicate that YC-1 is a more potent relaxant than DEA/NO in the human RA. The relaxant effects of YC-1 could be due to the stimulation of the sGC and Ca2+-sensitive K+channels, whereas the relaxant effects of DEA/NO could be completely due to the stimulation of the sGC. YC-1 and DEA/NO may be effective as vasodilator for the short-term treatment of perioperative spasm of coronary bypass grafts.


Assuntos
Hidrazinas/farmacologia , Indazóis/farmacologia , Artéria Radial/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Idoso , Análise de Variância , Ponte de Artéria Coronária/métodos , GMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Ativadores de Enzimas/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Doadores de Óxido Nítrico/farmacologia , Oxidiazóis/farmacologia , Peptídeos/farmacologia , Fenilefrina/farmacologia , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores , Quinoxalinas/farmacologia , Artéria Radial/metabolismo , Artéria Radial/fisiologia , Vasoconstritores/farmacologia
15.
J Cardiothorac Vasc Anesth ; 21(1): 41-4, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17289478

RESUMO

OBJECTIVE: Intravenous anesthetics are often used for anesthesia, sedation, and analgesia in the intraoperative and postoperative periods of coronary artery bypass graft (CABG) surgery. This study was designed to investigate the direct effects of intravenous anesthetics on the human radial artery (RA). DESIGN: In vitro, prospective with repeated measures. SETTING: University research laboratory. PARTICIPANTS: RA segments (n = 20) were obtained from CABG surgery patients and were divided into 3- to 4-mm vascular rings. INTERVENTIONS: Using the organ bath technique, the endothelium-independent vasodilatation function was tested in vitro by the addition of cumulative concentrations of thiopental, ketamine, etomidate, and propofol after vasocontraction by phenylephrine in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME) and indomethacin. MEASUREMENTS AND MAIN RESULTS: Thiopental (10(-8) to 10(-4) mol/L), ketamine(10(-8) to 10(-4) mol/L), propofol (10(-8) to 3 x 10(-4) mol/L), and etomidate (10(-8) to 3 x 10(-4) mol/L) caused concentration-dependent vasorelaxation in human RA rings precontracted with phenylephrine in the presence of L-NAME and indomethacin (n = 20, for each drug). The pEC(50) and maximum relaxant effect values of thiopental and ketamine were significantly higher than for etomidate and propofol (p < 0.05). CONCLUSIONS: These findings indicate that thiopental, ketamine, etomidate, and propofol produce concentration-dependent relaxation on RA rings from humans. Thiopental and ketamine are more potent relaxant agents than etomidate and propofol. Intravenous anesthetics may be effective as alternative vasodilators for treatment of intraoperative and postoperative spasm of coronary artery grafts.


Assuntos
Anestésicos Intravenosos/farmacologia , Ponte de Artéria Coronária , Artéria Radial/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Analgésicos/farmacologia , Anti-Inflamatórios não Esteroides/administração & dosagem , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Etomidato/farmacologia , Feminino , Humanos , Técnicas In Vitro , Indometacina/administração & dosagem , Ketamina/farmacologia , Masculino , Pessoa de Meia-Idade , NG-Nitroarginina Metil Éster/administração & dosagem , Fenilefrina/administração & dosagem , Propofol/farmacologia , Estudos Prospectivos , Tiopental/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/administração & dosagem
16.
Nitric Oxide ; 6(3): 342-6, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12009852

RESUMO

Aging has been reported to cause impotence, the mechanism of which is unknown. Therefore, we investigated the effect of aging on electrical stimulation-induced neurogenic, carbachol-induced, endothelium-dependent, and sodium nitroprusside-induced cGMP-dependent relaxant responses of rabbit corporal smooth muscle. Male New Zealand white rabbits were divided into young (4 months), intermediate (8 months), and old (24 months) groups. Electrical stimulation-, carbachol-, sodium nitroprusside-, and papaverine-induced relaxant response in isolated corporal smooth muscle strips were determined using in vitro muscle technique. Although there was no significant difference in the relaxant response of corporal strips to papaverine among the groups, relaxant responses to carbachol and sodium nitroprusside were significantly lower in corporal strips of old group than both young and intermediate groups. However, in the old and intermediate groups, electrical field stimulation-induced neurogenic relaxation was significantly reduced compared with the young group. KCl-induced (124 mM) contractile responses were the same in all groups. Our data indicate that the presence of age-dependent differences in the NO/cGMP-mediated relaxant responses of corporal tissue in the male rabbits. This may contribute to the development of impotence.


Assuntos
Envelhecimento/fisiologia , Músculo Liso/fisiologia , Óxido Nítrico/fisiologia , Pênis/fisiologia , Animais , Estimulação Elétrica , Técnicas In Vitro , Masculino , Relaxamento Muscular , Coelhos
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