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1.
Eur Rev Med Pharmacol Sci ; 26(23): 8771-8776, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36524495

RESUMO

Pleural effusion affects gas exchange, hemodynamic stability, and respiratory movement, thereby increasing the failure rate of intensive care unit discharge and mortality. Therefore, it is especially important to diagnose pleural effusion quickly to make the appropriate treatment decisions. The present review discusses the role of ultrasound in the diagnosis and puncture/drainage of pleural effusions and highlights the importance of lung ultrasound techniques in this patient population. We searched on PubMed, Embase, and Cochrane Library databases for articles from establishment to October 2022 using the following keywords: "lung ultrasound", "pulmonary ultrasound", "pleural effusion", "ultrasound-guided" and "thoracentesis". Lung ultrasound not only helps clinicians visualize pleural effusion but also to identify its different types and assess pleural effusion volume. It is also very important for thoracentesis, not only to increase safety and reduce life-threatening complications, but also to monitor the amount of fluid after drainage of pleural effusion. Lung ultrasound is a simple, noninvasive bedside technique with good sensitivity and specificity for the diagnosis and treatment of pleural effusions.


Assuntos
Derrame Pleural , Humanos , Derrame Pleural/diagnóstico por imagem , Derrame Pleural/terapia , Toracentese/métodos , Exsudatos e Transudatos , Pulmão/diagnóstico por imagem , Ultrassonografia , Drenagem/métodos
2.
Acta Gastroenterol Belg ; 75(3): 342-8, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23082706

RESUMO

AIM: The study is aim to compare two kinds of cleaning score system for capsule endoscopy, with a view of these two cleaning score system can help to evaluate small bowel cleanliness. METHODS: Three readers evaluated these two cleaning score system by assessing the inter-observer, intra-patient, and intraobserver agreement. RESULTS: The assessment of the reliability and concordance, inter-observer agreement and intra-patient agreement of System1 and System2 was excellent with the intraclass correlation coefficient (ICC) values of 0.873, 0.821, 0.863 and 0.772. The data regarding the assessment on intra-observer agreement and intrapatient agreement of System1 and System2 were available and the results were also excellent with ICC values of 0.887, 0.846, 0.870 and 0.809. The overall adequacy assessment of System1 and System2, there was no significant difference among the three readers of inter-observer agreement (X2 = 0.051, P = 0.822, X2 = 0.085, P = 0.081, X2 = 0.048, P = 0.827) and intra- patient agreement (X2 = 0.196, P = 0.658, X2 = 0.208, P = 0.648, X2 = 0.054, P = 0.817), neither was intra-observer agreement (X2 = 0.208, P = 0.648, X2 = 0.223, P = 0.637, X2 = 0.484, P = 0.487) and intrapatient agreement (X2 = 0.054, P = 0.817, X2 = 0.054, P = 0.817, X2 = 0519, P = 0.471). CONCLUSION: The two system both are simple, operable, and can be used in clinical practice.


Assuntos
Endoscopia por Cápsula , Irrigação Terapêutica/métodos , Humanos , Processamento de Imagem Assistida por Computador , Intestino Delgado , Polietilenoglicóis/administração & dosagem , Reprodutibilidade dos Testes , Estudos Retrospectivos
3.
Exp Oncol ; 29(3): 175-80, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18004240

RESUMO

AIM: To investigate the anti-proliferative effects of Crocus sativus extract and its major constituent, crocin, on three colorectal cancer cell lines (HCT-116, SW-480, and HT-29). The cell growth inhibition effect was compared to that of non-small cell lung cancer (NSCLC) cells. In addition, Crocus sativus' effect on non-cancer cells was evaluated. METHODS: Using high performance liquid chromatography (HPLC), the purity of crocin and the content of crocin extract were determined. Anti-proliferative effects of Crocus sativus extract and crocin on test cells was evaluated by MTS assay. RESULTS: The purity of crocin was found to be 95.9% and the content of crocin in the extract was 22.9%. Significant concentration-related inhibition effects of the extract on all three colorectal cancer cell lines were observed (P<0.01). The proliferation was reduced most significantly in HCT-116 cells, to 45.5% at 1.0 mg/ml and to 6.8% at 3.0 mg/ml. Crocin at 1.0 mM, significantly reduced HCT-116, SW-480, and HT-29 cell proliferation to 2.8%, 52%, and 16.8%, respectively (P<0.01). Since 3.0 mg/ml Crocus sativus extract contained approximately 0.6 mM crocin, the observed effects suggest that crocin is a major responsible constituent in the extract. Significant anti-proliferative effects were also observed in non-small cell lung cancer cells. However, Crocus sativus extract did not significantly affect the growth of non-cancer young adult mouse colon cells. CONCLUSION: Data from this study demonstrated that Crocus sativus extract and its major constituent, crocin, significantly inhibited the growth of colorectal cancer cells while not affecting normal cells. Crocus sativus extract should be investigated further as a viable option in the treatment of colorectal cancer.


Assuntos
Carotenoides/farmacologia , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Crocus/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Neoplasias Pulmonares/metabolismo , Camundongos
4.
J Food Sci ; 72(8): S590-4, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17995625

RESUMO

Diabetes is a serious chronic metabolic disease and has a significant impact on patients' lives and the health care system. We previously observed that the organic solvent extract of American ginseng berry possessed significant antidiabetic effects in obese diabetic ob/ob mice after intraperitoneal injection. If American ginseng berry is useful as a dietary supplement, simple preparation and oral intake would be a convenient, safe, and practical means for consumers. In this study, the simply prepared berry juice was first analyzed using high-performance liquid chromatography, and then administered orally in the ob/ob mice. The animals received daily berry juice 0.6 mL/kg or vehicle for 10 consecutive days. The results indicated that oral juice administration significantly lowered fasting blood glucose levels, and this effect continued for at least 10 d after cessation of the treatment. Data from intraperitoneal glucose tolerance test demonstrated that there was a notable improvement in glucose tolerance in the juice treated group. In addition, the berry juice significantly reduced body weight. Our data suggest that ginseng berry juice, as a dietary supplement, may have functional efficacy in consumers with diabetes.


Assuntos
Bebidas/análise , Glicemia/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Ginsenosídeos/administração & dosagem , Panax/química , Administração Oral , Animais , Fármacos Antiobesidade/administração & dosagem , Fármacos Antiobesidade/uso terapêutico , Glicemia/metabolismo , Cromatografia Líquida de Alta Pressão , Suplementos Nutricionais , Ginsenosídeos/uso terapêutico , Teste de Tolerância a Glucose , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Masculino , Camundongos , Camundongos Obesos , Valor Nutritivo , Distribuição Aleatória , Fatores de Tempo
5.
Exp Oncol ; 28(1): 25-9, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16614703

RESUMO

AIM: Ganoderma lucidum is a commonly used Chinese herb and an important ingredient in traditional Chinese medicine herbal formulations for immune dysfunction related illnesses. The effects of this medicinal mushroom on human colorectal cancer cells have not yet been evaluated. In this study, we investigated the effects of Ganoderma lucidum extract using SW 480 human colorectal cancer cell line. MATERIALS AND METHODS: Two different fractions of Ganoderma lucidum extract, i.e., a fraction containing mainly polysaccharides (GLE-1), and a triterpenoid fraction without polysaccharides (GLE-2) were analyzed. Their antiproliferative activity was evaluated by cell proliferation assay and 3H-thymidine incorporation assay. Scavenging effects of DPPH radical were assessed using ESR-spectroscopy. RESULTS: Our data showed that both GLE-1 and GLE-2 significantly inhibited the proliferation of SW 480 cells. The inhibitory effect of GLE-2 was much stronger than that of GLE-1. GLE-1 inhibited DNA synthesis in the cells and reduced the formation of DPPH radicals. CONCLUSION: Ganoderma lucidum extract inhibits proliferation of human colorectal cancer cells and possesses antioxidant properties.


Assuntos
Divisão Celular/efeitos dos fármacos , Extratos Vegetais/farmacologia , Reishi , Linhagem Celular Tumoral , Neoplasias Colorretais , Replicação do DNA/efeitos dos fármacos , Humanos , Fitoterapia , Polissacarídeos/farmacologia , Timidina/metabolismo
6.
Phytomedicine ; 11(2-3): 182-7, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15070170

RESUMO

In this study, we evaluated the anti-hyperglycemic effect of a polysaccharides fraction from American ginseng berry extract in diabetic ob/ob mice. All animals received daily intraperitoneal injections of polysaccharides at 150 mg/kg body wt. (n = 5), polysaccharides at 50 mg/kg body wt. (n = 5), or vehicle (n = 5) for 10 consecutive days. On Day 5, as compared to the vehicle-treated mice (230.5 +/- 13.5 mg/dl, mean +/- S.E), mice from both treated groups showed significantly lower fasting blood glucose levels (187.4 +/- 20.5 mg/dl and 187.4 +/- 17.1 mg/dl), respectively (both P < 0.05). On Day 10, compared to the vehicle group (240.1 +/- 12.3 mg/dl), the 50 mg/kg dose group were at 188.4 +/- 12.6 mg/dl (P < 0.05), and the 150 mg/kg dose group were normoglycemic (148.8 +/- 17.6 mg/dl, P < 0.01). Those ob/ob mice treated with vehicle did not, however, show significant changes in fasting blood glucose levels. Data from the intraperitoneal glucose tolerance test (IPGTT) showed that, compared to Day 0, there was a significant improvement in glucose tolerance in animals who received the 50 and 150 mg/kg polysaccharide doses, and the area under the curve (AUC) decreased 15.5% (P < 0.05) and 28.2% (P < 0.01), respectively. Interestingly, after cessation of polysaccharide treatment, the fasting blood glucose levels stayed lower, and returned to control concentration on Day 30. We also observed that the polysaccharides fraction did not affect body weight changes in ob/ob mice. Our data suggest that the polysaccharides fraction from American ginseng berry extract has a potential clinical utility in treating diabetic patients.


Assuntos
Hipoglicemiantes/farmacologia , Panax , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Glicemia/efeitos dos fármacos , Diabetes Mellitus/prevenção & controle , Frutas , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Polissacarídeos/administração & dosagem , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico
7.
Phytomedicine ; 10(6-7): 600-5, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-13678250

RESUMO

Previous studies demonstrated that both ginseng root and ginseng berry possess anti-diabetic activity. However, a direct comparison between the root and the berry under the same experimental conditions has not been conducted. In the present study, we compared anti-hyperglycemic effect between Panax ginseng root and Panax ginseng berry in ob/ob mice, which exhibit profound obesity and hyperglycemia that phenotypically resemble human type-2 diabetes. We observed that ob/ob mice had high baseline glucose levels (195 mg/dl). Ginseng root extract (150 mg/kg body wt.) and ginseng berry extract (150 mg/kg body wt.) significantly decreased fasting blood glucose to 143 +/- 9.3 mg/dl and 150 +/- 9.5 mg/dl on day 5, respectively (both P < 0.01 compared with the vehicle). On day 12, although fasting blood glucose level did not continue to decrease in the root group (155 +/- 12.7 mg/dl), the berry group became normoglycemic (129 +/- 7.3 mg/dl; P < 0.01). We further evaluated glucose tolerance using the intraperitoneal glucose tolerance test. On day 0, basal hyperglycemia was exacerbated by intraperitoneal glucose load, and failed to return to baseline after 120 min. After 12 days of treatment with ginseng root extract (150 mg/kg body wt.), the area under the curve (AUC) showed some decrease (9.6%). However, after 12 days of treatment with ginseng berry extract (150 mg/kg body wt.), overall glucose exposure improved significantly, and the AUC decreased 31.0% (P < 0.01). In addition, we observed that body weight did not change significantly after ginseng root extract (150 mg/kg body wt.) treatment, but the same concentration of ginseng berry extract significantly decreased body weight (P < 0.01). These data suggest that, compared to ginseng root, ginseng berry exhibits more potent anti-hyperglycemic activity, and only ginseng berry shows marked anti-obesity effects in ob/ob mice.


Assuntos
Diabetes Mellitus Experimental/prevenção & controle , Hipoglicemiantes/farmacologia , Panax , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Glicemia/efeitos dos fármacos , Diabetes Mellitus/prevenção & controle , Diabetes Mellitus Tipo 2/prevenção & controle , Modelos Animais de Doenças , Frutas , Teste de Tolerância a Glucose , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Raízes de Plantas
8.
Phytomedicine ; 9(3): 254-8, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12046868

RESUMO

In this study, we observed anti-diabetic and anti-obesity effects of Panax ginseng berry in adult C57BL/Ks db/db mice and their lean littermates. Animals received daily intraperitoneal injections of Panax ginseng berry extract at 150 mg/kg body wt. for 12 consecutive days. On Day 5, the extract-treated db/db mice had significantly lower fasting blood glucose levels as compared to vehicle-treated mice (180.5+/-10.2 mg/dl vs. 226.0+/-15.3 mg/dl, P < 0.01). On day 12, the extract-treated db/db mice were normoglycemic (134.3+/-7.3 mg/dl) as compared to vehicle-treated mice (254.8+/-24.1 mg/dl; P < 0.01). Fasting blood glucose levels of lean mice did not decrease significantly after treatment with extract. After 12 days of treatment with the extract, glucose tolerance increased significantly, and overall blood glucose exposure calculated as area under the curve (AUC) decreased 53.4% (P < 0.01) in db/db mice. Furthermore, db/db mice treated with extract (150 mg/kg body wt.) showed weight loss from 51.0+/-1.9 g on Day 0, to 46.6+/-1.7 g on Day 5, and to 45.2+/-1.4 g on Day 12 (P < 0.05 and P < 0.01 compared to Day 0, respectively). The body weight of lean littermates also decreased at the same dose of extract. These data suggest that Panax ginseng berry extract may have therapeutic value in treating diabetic and obese patients.


Assuntos
Fármacos Antiobesidade/farmacologia , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Obesidade/tratamento farmacológico , Panax , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Fármacos Antiobesidade/administração & dosagem , Fármacos Antiobesidade/uso terapêutico , Peso Corporal/efeitos dos fármacos , Frutas , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico
9.
Acta Pharmacol Sin ; 22(4): 289-97, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11742580

RESUMO

Resibufogenin (RBG) is a single compound isolated from Chansu, a traditional Chinese medicine obtained from the skin venom gland of the toad. Formulations of Chansu have been widely applied in China, Japan, and other Asian countries for a long time and are currently used as alternative medicines. However, there have been several reports about the toxicity of Chansu and its medical formulations in the United States recently. As digitalis, RBG possesses both pharmacologic and toxicologic effects. According to our study results, RBG, one of major ingredient of Chansu, induced delayed afterdepolarization and triggered arrhythmias both in cardiac fiber in vitro and in beating heart in vivo at the high concentrations. The electrophysiologic toxic effects of RBG, the possible mechanism of toxicity, and treatment possibilities are discussed in the present review


Assuntos
Arritmias Cardíacas/induzido quimicamente , Bufanolídeos/toxicidade , Cardiotônicos/toxicidade , Ramos Subendocárdicos/efeitos dos fármacos , Animais , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/tratamento farmacológico , Atropina/uso terapêutico , Bufanolídeos/química , Cardiotônicos/química , Eletrofisiologia , Humanos , Ramos Subendocárdicos/fisiologia
10.
Pharmacol Toxicol ; 89(3): 145-8, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11589786

RESUMO

Despite the historical use of cardiac glycosides, the data describing the electrophysiological characteristics of this class of drug are not fully clear. The present study reported the biphasic effect of cardiac glycosides, digoxin (1.25 microM) and acetylstrophanthidin (0.15 microM), on action potential duration in isolated Purkinje fibers by the conventional glass microelectrode technique. At the cycle lengths of 990, 690 and 490 msec., action potential duration lengthened within 10 min. and shortened after 10 min. of digoxin and acetylstrophanthidin administration. The biphasic effect was observed at a concentration of 4.0 mM [K(+)]o. However, at a higher [K(+)]o concentration of 5.4 mM, only the shortening effect on action potential duration was recorded. These results suggest that the biphasic effect of cardiac glycosides on action potential duration is related to the concentration of extracellular potassium and is not related to the stimulating cycle lengths.


Assuntos
Antiarrítmicos/farmacologia , Glicosídeos Cardíacos/farmacologia , Digoxina/farmacologia , Contração Miocárdica/efeitos dos fármacos , Ramos Subendocárdicos/efeitos dos fármacos , Estrofantidina/análogos & derivados , Estrofantidina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Células Cultivadas , Eletrofisiologia , Contração Miocárdica/fisiologia , Miocárdio/citologia , Potássio/metabolismo , Ovinos
11.
Phytomedicine ; 8(3): 178-83, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11417910

RESUMO

Brainstem neurons receiving subdiaphragmatic vagal inputs were recorded in an in vitro neonatal rat brainstem-gastric preparation. Aqueous extracts of American ginseng root (Panax quinquefolius L.) from Wisconsin and Illinois were applied to the gastric compartment or the brainstem compartment of the bath chamber to evaluate the peripheral gut or central brain effects of the extracts on brainstem unitary activity. After P. quinquefolius extract application to the gastric or brainstem compartment, a concentration-related inhibition in neuronal discharge frequency in brainstem unitary activity was observed, suggesting that P. quinquefolius plays an important role in regulating the digestive process and modulating the brain function in the rat. In this study, pharmacological effects of Wisconsin-cultivated P. quinquefolius and Illinois-cultivated P. quinquefolius were compared. Our results showed that Illinois-cultivated P. quinquefolius possesses a significantly stronger peripheral gastric as well as central brain modulating effect on brainstem neuronal activity. Data from our high performance liquid chromatography ginsenoside analysis suggest that this increase in inhibitory effects by Illinois-cultivated P. quinquefolius may be due to its different ginsenoside profile.


Assuntos
Tronco Encefálico/efeitos dos fármacos , Fármacos do Sistema Nervoso Central/farmacologia , Neurônios/efeitos dos fármacos , Panax/química , Extratos Vegetais/farmacologia , Saponinas/farmacologia , Animais , Fármacos do Sistema Nervoso Central/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Sistema Digestório/efeitos dos fármacos , Ginsenosídeos , Illinois , Técnicas In Vitro , Neurônios/metabolismo , Extratos Vegetais/química , Raízes de Plantas/química , Plantas Medicinais , Ratos , Ratos Sprague-Dawley , Saponinas/isolamento & purificação , Wisconsin
12.
J Pharmacol Exp Ther ; 295(1): 177-82, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10991976

RESUMO

Cholecystokinin (CCK) is a major gastrointestinal neuropeptide that is secreted in response to food ingestion. It is involved in the feedback regulation of gastric emptying and also modulates food intake. Leptin, a hormone that regulates food intake and energy balance, is secreted from adipose tissue, gastric mucosa, fundic glands, and other tissues. In a previous report we showed that gastric effects of leptin activated the nucleus tractus solitarius (NTS) neurons responding to gastric vagal stimulation. In this study, using the same in vitro neonatal rat preparation, we investigated the gastric effects of CCK and its interaction with leptin on NTS neurons receiving gastric vagal inputs. We observed that peripheral gastric effects of CCK (300 nM) produced a mean activation response of 271 +/- 3.9% compared with control level (100%) in 33 (60%) neurons tested (P <.01), and this response was abolished by a CCK-A receptor antagonist. A concentration-dependent effect of CCK (10 nM-1.0 microM) on NTS neuronal discharge frequencies was shown. We also observed that leptin (10 nM) applied to the stomach produced a mean activation response of 183 +/- 5.3% in 13 (50%) NTS units that responded to CCK (P <.01). Furthermore, we evaluated the combined effect of CCK and leptin in two groups of NTS neurons. Those NTS units that showed activation responses to both CCK (300 nM) and leptin (10 nM) had a subadditive effect that produced a mean activation response of 338 +/- 12.9% compared with the control level in all 10 (100%) neurons tested (P <.01). Eight (36%) of another 22 units that were not affected by either CCK (300 nM) or leptin (10 nM) alone had an activation response (151 +/- 5.2%; P <.05) when the same concentrations of CCK and leptin were applied together. Subsequently, by comparing the effects of CCK and leptin on a whole-stomach preparation to a partial-stomach preparation, we examined the area of the stomach in which gastric receptors contributed most to NTS unitary activity. We showed that the distal stomach containing the pylorus determined CCK gastric activity, whereas both the proximal and distal stomach are important for leptin's effect. Our data suggest that leptin modulates the potency of CCK signals that modify food intake in the neonatal rat.


Assuntos
Tronco Encefálico/efeitos dos fármacos , Colecistocinina/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Leptina/farmacologia , Núcleo Solitário/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Relação Dose-Resposta a Droga , Mucosa Gástrica/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores da Colecistocinina/efeitos dos fármacos , Receptores da Colecistocinina/fisiologia , Núcleo Solitário/fisiologia
13.
Am J Chin Med ; 28(2): 187-96, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10999437

RESUMO

Chan su (dried toad venom) is a traditional Chinese medicine obtained from the skin venom gland of the toad. Chan su has long been used as a therapeutic agent in China and other Asian countries. Recent reports indicate that Chan su toxicity carries a high mortality rate in the United States. This study focused upon the cardiac electrophysiological and electro-toxicity effects of resibufogenin (RBG), one of the major components in Chan su. Action potentials of isolated sheep and canine heart Purkinje fibers were studied using glass microelectrode recording techniques. The results indicate that RBG significantly affected all parameters of transmembrane action potential, induced delayed after depolarization, and triggered arrhythmias in sheep and canine Purkinje fibers.


Assuntos
Venenos de Anfíbios/farmacologia , Bufanolídeos/farmacologia , Cardiotônicos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Ramos Subendocárdicos/efeitos dos fármacos , Animais , Cães , Eletrofisiologia , Feminino , Masculino , Ramos Subendocárdicos/fisiologia , Ovinos
14.
Pediatr Res ; 48(3): 380-3, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10960507

RESUMO

Leptin (OB protein) elicits a neuroendocrine response to starvation and states of nutritional abundance to stabilize the proportion of body fat. Leptin has dramatic effects on food intake and energy expenditure in adult and juvenile rodents. However, whether the neonatal period is associated with the development of an effective leptin feedback system is still not known. In this study, we evaluated the effects of peripherally administered leptin on body weight changes in neonatal rats during the early suckling period (from birth to 10 d). Our results show that daily i.p. injections of leptin (0.3 microg/g and 1.0 microg/g) to neonatal rats led to a significant reduction in weight gain over 10 d compared with the control group (p < 0.01 and p < 0.01, respectively). Concomitant with a reduction in weight gain, retroperitoneal fat pad weight also significantly decreased in the leptin-treated group. Our data indicate that the potential for energy balance regulation by leptin occurs in the first day after birth. In addition, we also observed that 3 d after discontinuing leptin treatment, the body weight as well as the fat pad weight of leptin-treated pups returned to the control level. Our results demonstrate that leptin reduces body weight gain in neonatal rats.


Assuntos
Peso Corporal/efeitos dos fármacos , Leptina/administração & dosagem , Animais , Animais Recém-Nascidos , Alterações do Peso Corporal , Injeções Intraperitoneais , Ratos , Ratos Sprague-Dawley
15.
Methods Find Exp Clin Pharmacol ; 22(2): 67-76, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10849888

RESUMO

The effects of class III antiarrhythmic agents E-4031 and dofetilide were studied on action potentials and subthreshold delayed afterdepolarizations (DADs) induced by the cardiac glycoside acetylstrophanthidin (AS) in isolated cardiac Purkinje fibers. Action potentials were recorded from cardiac Purkinje fibers using microelectrode techniques. E-4031 and dofetilide consistently increased DAD amplitude, occasionally caused triggered action potentials and shortened action potential duration. The application of E-4031 without prior AS exposure, resulted in the typical class III antiarrhythmic effects of action potential lengthening and the induction of early afterdepolarizations. These findings suggest that under our conditions of AS-induced cell Ca2+ overload, the effects of the "pure" class III antiarrhythmic drugs, E-4031 and dofetilide, are markedly different from those found in non-Ca2+ loaded cells. This may represent an additional electrophysiological mechanism for class III antiarrhythmic drug toxicity.


Assuntos
Antiarrítmicos/farmacologia , Fenetilaminas/farmacologia , Piperidinas/farmacologia , Ramos Subendocárdicos/efeitos dos fármacos , Piridinas/farmacologia , Sulfonamidas/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Ramos Subendocárdicos/fisiologia , Ovinos , Fatores de Tempo
16.
Altern Med Rev ; 5(3): 249-59, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10869104

RESUMO

Insomnia is the most common sleep disorder, and is often associated with significant medical, psychological, and social disturbances. Conventional medical treatment for insomnia includes psychological and pharmacological approaches; however, long-term use of frequently prescribed medications can lead to habituation and problematic withdrawal symptoms. Therefore, herbal and other natural sleep aids are gaining popularity, as herbs commonly used for their sedative-hypnotic effects do not have the drawbacks of conventional drugs. Whether alternative therapies possess activity similar to conventional therapies needs further evaluation.


Assuntos
Terapias Complementares , Fitoterapia , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Humanos
17.
Acta Pharmacol Sin ; 21(11): 977-85, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11501065

RESUMO

AIM: To detect delayed after depolarizations (DAD) in extracellular electrograms using signal averaging technique. METHODS: DAD were induced by acetylstrophanthidin (0.25 mumol.L-1, n = 9) and resibufogenin (0.52 mumol.L-1, n = 5) in sheep cardiac Purkinje fibers. Intracellular voltage was recorded with a conventional microelectrode, and simultaneous extracellular electrograms were recorded differentially from widely spaced electrodes placed in the tissue bath. Noise of electrograms was reduced using signal averaging technique. RESULTS: Acetylstrophanthidin and resibufogenin both induced DAD in the intracellular recording and extracellular DAD (DAD-E) in the extracellular electrogram in sheep heart Purkinje fibers. Acetylstrophanthidin and resibufogenin induced typical changes in the action potential including decrease in action potential amplitude, resting potential, maximum diastolic potential, and action potential duration. Similar shortening occurred in the "Q-T interval" recorded by the extracellular electrogram. With either acetylstrophanthidin or resibufogenin, shortening of stimulation cycle length from 990 ms to 690 ms reduced the coupling interval between action potential upstroke and peak voltage of the DAD (P < 0.01), and the coupling interval between the "QRS" and DAD-E recorded extracellularly (P < 0.01). CONCLUSION: DAD can be detected using the extracellular electrograms combined with the high resolution, signal averaging technique.


Assuntos
Ramos Subendocárdicos/fisiologia , Processamento de Sinais Assistido por Computador , Potenciais de Ação , Animais , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/fisiopatologia , Bufanolídeos , Cardiotônicos , Eletrofisiologia , Técnicas In Vitro , Ovinos , Estrofantidina/análogos & derivados
18.
Zhongguo Yao Li Xue Bao ; 19(4): 309-12, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10375773

RESUMO

AIM: To study the relation between the effect of acetylstrophanthidin on action potential duration (APD) and the extracellular potassium concentration. METHODS: Effect of acetylstrophanthidin (AS 0.15 mmol.L-1) on APD at different extracellular potassium concentrations was studied at the stimulation cycle lengths of 990 and 690 ms in sheep isolated cardiac Purkinje fibers using the standard microelectrode technique. RESULTS: At [K+]o 4.0 mmol.L-1, the biphasic effect of AS on APD appeared obviously. Both APD50 and APD90 were lengthened within the first 10 min of drug exposure. After 10 min, they were shortened at all pacing cycle lengths. On the other hand, at [K+]o 5.4 mmol.L-1, AS only shortened APD markedly without lengthening effect on it. The biphasic and monophasic effects of AS on APD were found at [K+]o 4.0 mmol.L-1 and 5.4 mmol.L-1, respectively. CONCLUSION: The effect of AS on APD was related to the concentration of [K+]o.


Assuntos
Potássio/metabolismo , Ramos Subendocárdicos/fisiologia , Estrofantidina/análogos & derivados , Potenciais de Ação/efeitos dos fármacos , Animais , Técnicas In Vitro , Microeletrodos , Ramos Subendocárdicos/citologia , Estrofantidina/farmacologia
19.
Methods Find Exp Clin Pharmacol ; 17(2): 113-20, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7674698

RESUMO

Few reports exist of digoxin-induced delayed afterdepolarizations (DADs) and triggered activity recorded in cardiac fibers, and the electrophysiological characteristics of digoxin-induced DADs and triggered activity have not been reported in detail. We studied the electrophysiological properties of digoxin-induced DADs and triggered activity is sheep cardiac Purkinje fibers. Transmembrane voltage was recorded using conventional microelectrodes and extracellular electrograms were recorded using a high-gain, signal averaging method. DADs were induced by digoxin (1.25 microM, n = 9 fibers). After exposure to the drug for 20.8 +/- 2.0 min at the pacing cycle lengths of 990, 690, and 490 msec, the DAD amplitudes were 3.7 +/- 0.3, 5.7 +/- 0.6, 6.4 +/- 0.8 mV, respectively. The coupling intervals of DADs to the previous action potential at the same cycle lengths were 845.8 +/- 37.6, 581.3 +/- 23.1, 434.6 +/- 7.0 msec, respectively. Thus, digoxin-induced DADs show typical frequency dependence. Digoxin-induced DADs also occasionally caused triggered action potentials. DADs also were recorded simultaneously using an extracellular signal averaging technique. DADs were easily detected an most of the DAD characteristics measured intracellular could be confirmed in the extracellular electrograms. Digoxin induced a biphasic effect on the action potential duration (measured at 50% of repolarization (APD50) and on the Q-T interval measured from the extracellular electrograms, and in an additional group of fibers (n = 5) this was studied in detail. Digoxin initially lengthened the APD50 and the Q-T interval within the first 10 min of drug exposure, at a time when DADs had not yet developed.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Digoxina/farmacologia , Eletrocardiografia/efeitos dos fármacos , Fármacos Neuromusculares Despolarizantes/farmacologia , Ramos Subendocárdicos/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Estimulação Elétrica , Eletrofisiologia , Coração/inervação , Frequência Cardíaca/efeitos dos fármacos , Técnicas In Vitro , Microeletrodos , Ovinos , Fatores de Tempo
20.
Zhongguo Yao Li Xue Bao ; 15(2): 97-102, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8010120

RESUMO

The purpose of this study was to compare the electrotoxicological effects of resibufogenin (RBG) (n = 14) with acetylstrophanthidin (AS) (n = 14) to induce delayed afterdepolarization (DAD) and triggered activity (TA), and their alteration of the electrophysiological properties in sheep cardiac Purkinje fibers using the extracellular electrograms, signal averaging, and standard microelectrode techniques simultaneously. The results indicated: 1) Lower toxic dose of RBG (0.52 mumol.L-1) and AS (0.25 mumol.L-1) induced intracellular and extracellular DAD (DAD-I and DAD-E) at pacing cycle length of 990 and 690 ms. 2) Higher toxic dose of RBG (2.6 mumol.L-1) and AS (5.0 mumol.L-1) induced DAD and TA, nonsustained or sustained premature action potential and oscillatory potentials; 3) At the beginning period of superfusing the drugs, both RBG and AS caused changes of the electrophysiological characteristics. This study demonstrates that the electro-toxicological characteristics and electrophysiological properties of RBG are similar to that of AS and suggests that RBG belongs to the family of digitalis-like drugs.


Assuntos
Arritmias Cardíacas/fisiopatologia , Bufanolídeos/toxicidade , Cardiotônicos/toxicidade , Ramos Subendocárdicos/fisiologia , Estrofantidina/análogos & derivados , Potenciais de Ação/efeitos dos fármacos , Animais , Arritmias Cardíacas/induzido quimicamente , Eletrofisiologia , Técnicas In Vitro , Potenciais da Membrana/efeitos dos fármacos , Ovinos , Estrofantidina/toxicidade
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