Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Helminthol ; 97: e85, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37945308

RESUMO

Clinostomidae is a diverse family of digenean parasitizing fish-eating birds as adults and fishes as metacercariae. The species composition, within the genus Clinostomum has been steadily increasing in recent years. In Argentina, four named species of Clinostomum have been documented, accompanied by four metacercariae representing distinct genetic lineages whose adults have not been identified. This study focused on examining clinostomids in three fish species - Australoheros scitulus (ASI), Cichlasoma dimerus (CDIM), and Pimelodella laticeps (PLA) - at various localities in Argentina. We conducted both morphological and molecular characterizations of the Clinostomum metacercariae collected from these fish species. Molecular phylogenetic analyses using COI mtDNA were performed to determine the placement of these metacercariae within the clinostomid phylogenetic tree. Clinostomum ASC represents a distinct lineage, morphologically distinguishable from other sequenced metacercariae due to its body shape (widest anteriorly and becoming slender towards the posterior end); this lineage was found to be closely related to C. caffarae. While Clinostomum CDIM and Clinostomum PLA exhibited morphological differences, they clustered together genetically with metacercariae reported in previous studies as Clinostomum L3 and Clinostomum CVI. This outcome, coupled with a low genetic distance (0 to 3%), suggests that they are conspecific with metacercariae found in fish across Mexico, Costa Rica, and Argentina. In light of the extensive diversity of fish species in Argentine freshwater ecosystems (over 500 species), and considering the relatively constrained extent of prior investigations, the anticipation of unearthing additional Clinostomum species or lineages is plausible.


Assuntos
Ciclídeos , Doenças dos Peixes , Trematódeos , Infecções por Trematódeos , Animais , DNA Mitocondrial/genética , Infecções por Trematódeos/veterinária , Metacercárias/anatomia & histologia , Filogenia , Ecossistema , Peixes , Água Doce , América do Sul , Poliésteres
2.
J Helminthol ; 97: e24, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36803884

RESUMO

The Mermithidae is a family of nematodes parasitic in many kinds of insects, spiders, leeches, crustaceans and other invertebrates throughout the world. While conducting an assay with entomopathogenic nematodes, we found Armadillidium vulgare (Crustacea: Isopoda) individuals to be infected with Agamermis sp., marking the fourth known discovery of a mermithid infection in the order Isopoda. In this work, we contribute with an 18S rDNA sequence of the isolated nematode and the morphological and morphometrical characterization of the juveniles.


Assuntos
Isópodes , Mermithoidea , Nematoides , Animais , Mermithoidea/anatomia & histologia , Argentina , Crustáceos , Insetos
3.
Sci Rep ; 12(1): 4338, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35288586

RESUMO

Hadal trenches are depocenters for organic material, and host intensified benthic microbial activity. The enhanced deposition is presumed to be reflected in elevated meiofaunal standing-stock, but available studies are ambiguous. Here, we investigate the distribution of meiofauna along the Atacama Trench axis and adjacent abyssal and bathyal settings in order to relate the meiofauna densities to proxies for food availability. Meiofauna densities peaked at the sediment surface and attenuated steeply with increasing sediment depth. The distribution mirrored the vertical profile of the microbial-driven oxygen consumption rate demonstrating a close linkage between microbial activity and meiofauna density. Meiofaunal standing-stock along the trench axis varied by a factor of two, but were markedly higher than values from the abyssal site at the oceanic plate. Overall, meiofaunal densities poorly correlated with common proxies for food availability such as total organic carbon and phytopigments, but strongly correlated with the microbial benthic O2 consumption rate. We argue that microbial biomass likely represents an important meiofaunal food source for hadal meiofauna. Observations from three trench systems underlying surface water of highly different productivity confirmed elevated meiofaunal densities at the trench axis as compared to abyssal sites on oceanic plates. Food availability appear to drive elevated abundance and variations in meiofauna densities in hadal sediments.


Assuntos
Sedimentos Geológicos , Biomassa , Oceanos e Mares
4.
Mater Sci Eng C Mater Biol Appl ; 33(5): 2937-46, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23623117

RESUMO

Nanostructured films of dioctadecyldimethylammonium bromide (DODAB) and nickel tetrasulfonated phthalocyanine (NiTsPc) were layer-by-layer (LbL) assembled to achieve a synergistic effect considering the distinct properties of both materials. Prior to LbL growth, the effect of NiTsPc on the structure of DODAB vesicles in aqueous medium was investigated by differential scanning calorimetry (DSC). Therefore, DODAB/NiTsPc LbL films were prepared using NiTsPc at concentrations below and above the limit concentration of vesicle formation according to our DSC experiments. As a result, LbL films with distinct nanostructures were obtained, which were studied at micro and nanoscales by micro-Raman and atomic force microscopy, respectively. A linear growth of the LbL films was observed by ultraviolet-visible absorption spectroscopy. However, the bilayer thickness and the surface morphology of the LbL films were radically affected depending on NiTsPc concentration. The electrostatic interaction between DODAB and NiTsPc was identified via Fourier transform infrared (FTIR) absorption spectroscopy as the main driving force responsible for LbL growth. Because LbL films have been widely applied as transducers in sensing devices, DODAB/NiTsPc LbL films having distinct nanostructures were tested as proof-of-principle in preliminary sensing experiments toward dopamine detection using impedance spectroscopy (e-tongue system). The real capacitance vs. dopamine concentration curves were treated using Principal Component Analysis (PCA) and an equivalent electric circuit, revealing the role played by the LbL film nanostructure and the possibility of building calibration curves.


Assuntos
Indóis/química , Nanoestruturas , Níquel/química , Isoindóis , Microscopia de Força Atômica
5.
Diabet Med ; 28(7): 856-64, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21244474

RESUMO

AIMS: Effects of pitavastatin and atorvastatin on the lipid profile and lipoprotein subclasses were compared in patients with Type 2 diabetes with dyslipidaemia. METHODS: Patients with Type 2 diabetes with hypercholesterolaemia and/or hypertriglyceridaemia were randomized to receive pitavastatin 2 mg (n = 16) or atorvastatin 10 mg (n = 15) for 6 months, and blood lipid and lipoprotein profiles and cholesterol and triglyceride contents of 20 lipoprotein subclasses, determined by high-performance liquid chromatography, were compared. RESULTS: At baseline, cholesterol in VLDL and LDL subclasses were increased equally in two groups of patients with diabetes as compared with normolipidaemic control subjects. As compared with baseline, serum levels of total cholesterol, LDL cholesterol, non-HDL cholesterol, LDL cholesterol:HDL cholesterol ratio and apolipoprotein B were decreased after 1, 3 and 6 months of treatment with atorvastatin and pitavastatin. Serum triglyceride levels were decreased after 1, 3 and 6 months of atorvastatin, but only at 3 months of pitavastatin. Serum HDL cholesterol was increased after 1, 3 and 6 months of pitavastatin, whereas HDL cholesterol was even decreased after 6 months of atorvastatin. Cholesterol levels of most VLDL and LDL subclasses were decreased equally in both groups. However, only pitavastatin increased cholesterol of medium HDL subclass. Serum triglyceride and triglyceride contents in VLDL and LDL subclasses were decreased only by atorvastatin. CONCLUSIONS: The impact on lipoprotein subclass profiles was different between pitavastatin and atorvastatin. It may be beneficial to determine lipoprotein subclass profile and select the appropriate statin for each profile in patients with diabetes with an additional cardiovascular risk such as low HDL cholesterol or hypertriglyceridaemia.


Assuntos
Anticolesterolemiantes/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , LDL-Colesterol/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Angiopatias Diabéticas/tratamento farmacológico , Hipercolesterolemia/tratamento farmacológico , Quinolinas/uso terapêutico , Adulto , Idoso , Atorvastatina , Glicemia/efeitos dos fármacos , Doenças Cardiovasculares/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Angiopatias Diabéticas/metabolismo , Feminino , Ácidos Heptanoicos , Humanos , Hipercolesterolemia/sangue , Lipoproteínas/sangue , Masculino , Pessoa de Meia-Idade , Pirróis , Resultado do Tratamento
6.
Diabetes Obes Metab ; 9(3): 323-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17391158

RESUMO

AIM: Left ventricular (LV) diastolic dysfunction has been reported to be prevalent in diabetic subjects, but this recognition could often be missed. We evaluated prevalence of LV diastolic dysfunction and diagnostic utility of brain-natriuretic peptide (BNP) in asymptomatic patients with type 2 diabetes mellitus. RESEARCH DESIGN AND METHODS: Plasma BNP levels and LV geometry and diastolic filling indices, including the ratio of peak early transmitral Doppler flow (E) over flow propagation velocity (Vp) measured by colour M-mode Doppler echocardiography, were analysed in 98 consecutive asymptomatic patients with type 2 diabetes mellitus and 51 age-matched controls. RESULTS: The LV mass index and relative wall thickness were higher in diabetic groups than controls without any differences in LV systolic function. The frequency of diastolic dysfunction defined as E/Vp > or = 1.5 were 31% in diabetic groups and 15% in controls (chi(2) = 4.364, p = 0.037). By receiver-operating characteristic (ROC) curve analysis, a BNP cutoff value of 19.2 pg/ml in controls had a 53.1% positive predictive value (53.1%) and a high negative predictive value (94.4%) for E/Vp >/= 1.5, whereas a BNP cutoff value of 18.1 pg/ml in diabetic groups had a 61.8% positive and 97.3% negative predictive values. CONCLUSIONS: The frequency of E/Vp > or = 1.5 was higher in asymptomatic diabetic patients, suggesting that LV diastolic dysfunction was prevalent. The plasma concentration of BNP could be used to depict LV diastolic dysfunction in such population.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Peptídeo Natriurético Encefálico/sangue , Disfunção Ventricular Esquerda/diagnóstico , Biomarcadores/sangue , Pressão Sanguínea/fisiologia , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Diabetes Mellitus Tipo 2/fisiopatologia , Ecocardiografia Doppler em Cores/métodos , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem
7.
Diabetes Obes Metab ; 8(2): 228-33, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16448528

RESUMO

AIM: This study was conducted to clarify cell death and survival signals in pancreatic beta-cell lipotoxicity. METHODS: Rat insulinoma INS-1 cells, with or without expression of dominant-negative mutant of Akt (K179M), were cultured with palmitate (C16:0) or oleate (C18:1) and cell numbers were determined by 0.2% eosin dye exclusion assay. The Akt activity was determined by anti-3'-phospho-inositide-dependent protein kinase (Akt)/protein kinase B (PKB) or anti-phospho-Akt (Serine 473) immunoblotting, and nuclear protein nuclear factor-kB (NF-kappaB)-binding activity was by supershift analysis. RESULTS: Twenty-four hours treatment with palmitate increased the INS-1 cell number at 0.1-0.2 mM but decreased the cell number at 0.5-1 mM. Oleate did not affect cell number at 0.1-1.0 mM. Palmitate dose-dependently increased phosphorylation of 473th serine in Akt/PKB. The K179M form of Akt/PKB abolished palmitate-induced cell proliferation at the low dose and death at the high dose. Nuclear protein NF-kappaB binding was enhanced at 0.2 and 0.5 mM of palmitate but decreased at 1.0 mM. CONCLUSION: Results suggest that Akt/PKB signalling is involved in palmitate-induced cell death and survival of pancreatic beta cell.


Assuntos
Inibidores Enzimáticos/farmacologia , Células Secretoras de Insulina/metabolismo , Ácido Palmítico/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Morte Celular/efeitos dos fármacos , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Relação Dose-Resposta a Droga , Ensaio de Desvio de Mobilidade Eletroforética , Inibidores Enzimáticos/toxicidade , Células Secretoras de Insulina/citologia , Insulinoma/metabolismo , NF-kappa B/metabolismo , Ácido Oleico/farmacologia , Ácido Oleico/toxicidade , Ácido Palmítico/toxicidade , Ratos , Triglicerídeos/metabolismo
8.
Diabet Med ; 21(9): 983-6, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15317602

RESUMO

AIMS: This randomized crossover placebo-controlled study aimed to assess the efficacy of nateglinide, a phenylalanine-derived insulin secretagogue, on forearm endothelial function in diabetic subjects before and after an oral glucose load. METHODS: Forearm blood flow (FBF) was measured using strain-gauge plethysmography during reactive hyperaemia before and after an oral glucose load (75 g) with a prior use of placebo or nateglinide (90 mg) in 15 diet-treated Type 2 diabetic patients or age-matched controls with normal glucose tolerance. RESULTS: The peak FBF response and total reactive hyperaemic flow (flow debt repayment: FDR), indices of resistance artery endothelial function, were decreased after an oral glucose load in diabetic patients, but unchanged in controls. Nateglinide administered to diabetic patients accelerated insulin secretion and reduced post-challenge plasma glucose, and also abolished the post-challenge impairment of endothelial function. The peak FBF and FDR were well correlated with 120-min glucose levels and 30-min insulinogenic index. CONCLUSIONS: A single challenge of glucose was shown to impair endothelial function in diabetic patients, and the post-challenge endothelial dysfunction was improved by a prior use of nateglinide. Long-term effects of nateglinide on endothelial function in Type 2 diabetic patients need to be clarified in future studies.


Assuntos
Cicloexanos/administração & dosagem , Diabetes Mellitus Tipo 2/fisiopatologia , Glucose/metabolismo , Hipoglicemiantes/administração & dosagem , Fenilalanina/análogos & derivados , Fenilalanina/administração & dosagem , Administração Oral , Glicemia/análise , Estudos Cross-Over , Diabetes Mellitus Tipo 2/metabolismo , Método Duplo-Cego , Endotélio/irrigação sanguínea , Feminino , Antebraço/irrigação sanguínea , Glucose/administração & dosagem , Humanos , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Nateglinida , Fluxo Sanguíneo Regional/fisiologia
10.
Ann Hum Genet ; 68(Pt 3): 196-204, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15180700

RESUMO

The goal of the present study was to investigate inter-individual and age-dependent variation of global DNA methylation in human tissues. In this work, we examined 5-methyldeoxycytidine ((met)C) content by HPLC in human peripheral blood leukocytes obtained from 76 healthy individuals of ages varying from 4 to 94 years (yr), and 39 human placentas from various gestational stages. The HPLC analysis revealed a significant variation of (met)C across individuals and is consistent with the previous findings of age-dependent decrease of global methylation levels in human tissues. The age-dependent decrease of (met)C was relatively small, but statistically highly significant (p= 0.0002) in the aged group (65.9 +/- 8.9 [mean age +/- SD] yr; n = 22) in comparison to the young adult group (19.3 +/- 1.4 yr; n = 21). Males showed a subtle but statistically significant higher mean (met)C content than females. In contrast to the peripheral blood samples, DNA extracted from placentas exhibited gestational stage-dependent increase of methylation levels that appeared to inversely correlate with the expression levels of human endogenous retroviruses. These data may be helpful in further studies of DNA methylation, such as inheritance of epigenetic patterns, environment-induced changes, and involvement of epigenetic changes in disease.


Assuntos
Envelhecimento/fisiologia , Metilação de DNA , Desoxicitidina/análogos & derivados , Desoxicitidina/sangue , Leucócitos/metabolismo , Placenta/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Retrovirus Endógenos/genética , Feminino , Humanos , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Pessoa de Meia-Idade , Gravidez , Trimestres da Gravidez
11.
Diabetologia ; 45(12): 1713-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12488962

RESUMO

AIM/HYPOTHESIS: We analysed Japanese MODY patients for mutations in the HNF-1 alpha gene. METHODS: Fifty unrelated Japanese patients with early-onset diabetes (diagnosed at 25 years of age or younger) or with a strong family history of diabetes were screened for mutations in the HNF-1 alpha gene. Functional studies of the mutant HNF-1alpha were carried out. RESULTS: We identified three new mutations in the HNF-1 alpha gene in the families with a strong family history for diabetes. One mutation (L518P519fsTCC --> A) was identified in three unrelated families, while the other two mutations (T521I and V617I) were identified in one family. We also identified the A site of the promoter (+102G-to-C), which was reported previously. We examined the functional properties of the mutant HNF-1alpha. By increasing the amount of L518P519fsTCC-->A-HNF-1alpha, increasing inhibition of the transcription of human transthyretin (TTR) was observed (up to 61% of the control). Increasing amounts of T521I-HNF-1alpha or V617I-HNF-1alpha mutant proteins increased TTR promoter transcription up to 4.3-fold and 2.4-fold, respectively, whereas both increased transcription up to 12.4-fold of the control. CONCLUSION/INTERPRETATION: The L518P519fsTCC --> A was identified for the first time and this mutation might be a common cause of Japanese MODY3 in Okinawa area. In addition, both the T521I and V617I mutations were present in two patients in the same family. Since the prevalence of these mutations is relatively high (10%, 5/50), the HNF-1 alpha gene needs to be screened for mutations in patients either with early-onset diabetes or with a strong family history for diabetes.


Assuntos
Proteínas de Ligação a DNA , Diabetes Mellitus Tipo 2/genética , Proteínas Nucleares , Fatores de Transcrição/genética , Adulto , Substituição de Aminoácidos , Animais , Células COS , Cisteína , Feminino , Mutação da Fase de Leitura , Deleção de Genes , Glicina , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Mutação de Sentido Incorreto , Linhagem , Ativação Transcricional
12.
Life Sci ; 69(16): 1907-18, 2001 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-11693271

RESUMO

Acute effects of triiodothyronine (T3) on postischemic myocardial stunning and intracellular Ca2+ contents were studied in the isolated working hearts of streptozotocin-induced diabetic rats and age-matched controls. After two weeks of diabetes, serum T3 and T4 levels were decreased to 62.5% and 33.9% of control values. Basal preischemic cardiac performance did not differ between diabetic and control rats. In contrast, during reperfusion after 20-min ischemia, diabetic rats exhibited an impaired recovery of heart rate (at 30-min reperfusion 57.5% of baseline vs. control 88.5%), left ventricular (LV) systolic pressure (44.1% vs. 89.5%), and cardiac work (23.1% vs. 66.0%). When 1 and 100 nM T3 was added before ischemia, heart rate was recovered to 77.2% and 81.8% of baseline, LV systolic pressure to 68.3% and 81.9%, and cardiac work to 50.8% and 59.0%, respectively. Diabetic rat hearts showed a higher Ca2+ content in the basal state and a further increase after reperfusion (4.96+/-1.17 vs. control 3.78+/-0.48 micromol/g, p<0.01). In diabetic hearts, H+ release was decreased after reperfusion (5.24+/-2.21 vs. 8.70+/-1.41 mmol/min/g, p<0.05). T3 administration caused a decrease in the postischemic Ca2+ accumulation (lnM T3 4.66+/-0.41 and 100 nM T3 3.58+/-0.36) and recovered the H+ release (lnM T3 16.2+/-3.9 and 100 nM T3 11.6+/-0.9). T3 did not alter myocardial O2 consumption. Results suggest that diabetic rat hearts are vulnerable to postischemic stunning, and T3 protects the myocardial stunning possibly via inhibiting Ca2+ overload.


Assuntos
Cálcio/antagonistas & inibidores , Coração/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio Atordoado/prevenção & controle , Tri-Iodotironina/farmacologia , Animais , Cálcio/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Relação Dose-Resposta a Droga , Coração/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Técnicas In Vitro , Masculino , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio Atordoado/metabolismo , Miocárdio Atordoado/fisiopatologia , Miocárdio/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Perfusão , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Estreptozocina , Tiroxina/sangue , Tiroxina/fisiologia , Função Ventricular Esquerda/efeitos dos fármacos
13.
Jpn J Ophthalmol ; 45(4): 375-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11485769

RESUMO

BACKGROUND: Ligneous conjunctivitis is a rare condition characterized by chronic, recurrent conjunctivitis associated with pseudomembrane, and it may involve other mucous membranes in the mouth, nasopharynx, trachea, and vagina. We examined and treated a case of presumed ligneous conjunctivitis. CASE: The patient was a 10-year-old boy. His chief complaints were visual impairment, discomfort, and discharge, but no itching in his eyes. His upper eyelids appeared thick without swelling. He had a past history of surgery for lid entropion. His two siblings had similar follicular conjunctivitis. OBSERVATIONS: This case exhibited several characteristics of ligneous conjunctivitis, such as large follicles, recurrent pseudomembrane and normal level IgE in the serum. Indispensable characteristics of vernal keratoconjunctivitis, strong itching, and extensive papillary formation, were not found. In spite of the lack of woody hardness of the conjunctiva, other clinical findings led to the diagnosis of ligneous conjunctivitis. Definite histological diagnosis was not obtained, because of the lack of common histological characteristics among previously reported cases with ligneous conjunctivitis. The boy had developed corticosteroid glaucoma after instillation of dexamethasone 0.1% for 7 months at a previous time. We successfully treated this case with combined instillation of fluorometholon and cyclosporin after trabeculotomy. CONCLUSIONS: Ligneous conjunctivitis must be considered as one type of differential diagnosis of vernal keratoconjunctivitis. Cyclosporin is an effective alternative for the treatment of ligneous conjunctivitis, especially in a case with a possible history of corticosteroid glaucoma.


Assuntos
Conjuntivite/complicações , Criança , Terapia Combinada , Conjuntivite/diagnóstico , Conjuntivite/terapia , Ciclosporina/uso terapêutico , Células Epiteliais/patologia , Fluormetolona/uso terapêutico , Humanos , Masculino , Membranas/patologia , Trabeculectomia
14.
Thyroid ; 11(11): 1009-15, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11762709

RESUMO

We evaluated the effects of hyperthyroidism on cardiac structural changes and postischemic myocardial function, and also studied how an angiotensin-converting enzyme (ACE) inhibitor, cilazapril, can alter these changes. Hyperthyroidism was induced by daily intraperitoneal injection of thyroxine (T4) (600 microg/kg) with or without cilazapril (10 mg/kg per day, orally), and control rats were given by vehicle. After 2 weeks of treatment, T4-treated rats showed increases in blood pressure and heart weight to body weight ratio (HW:BW). Cilazapril decreased blood pressure to control values and reduced HW:BW. In the isolated working heart preparation, T4-treated rats showed a poor postischemic recovery of left ventricular pressure-rate product (14% of baseline at 30 minutes of reperfusion vs. vehicle 85%) and cardiac work (6% vs. 71%). Cilazapril recovered both values to 49% and 43%. Propranolol (500 mg/L in drinking water) decreased blood pressure to the same extent as cilazapril in hyperthyroid rats, but changed neither HW:BW nor the postischemic myocardial dysfunction. Percent recovery of cardiac work was inversely well correlated with HW:BW (R2 = 0.998, p < 0.001). Results indicate that T4-induced cardiac hypertrophy enhances postischemic cardiac dysfunction. Results also indicate renin-angiotensin system (RAS), but not sympathetic nerve activation, is involved in cardiac hypertrophy and postischemic myocardial dysfunction in hyperthyroid rats.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Cardiomegalia/prevenção & controle , Cilazapril/uso terapêutico , Hipertireoidismo/prevenção & controle , Isquemia Miocárdica/prevenção & controle , Antagonistas Adrenérgicos beta/uso terapêutico , Animais , Cardiomegalia/patologia , Cardiomegalia/fisiopatologia , Tamanho Celular , Circulação Coronária/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Hipertireoidismo/patologia , Hipertireoidismo/fisiopatologia , Hipertrofia Ventricular Esquerda/patologia , Masculino , Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Miocárdio/metabolismo , Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Propranolol/uso terapêutico , Ratos , Ratos Sprague-Dawley , Tri-Iodotironina/sangue
15.
Free Radic Biol Med ; 28(6): 999-1004, 2000 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10802232

RESUMO

We previously reported that the mold Monascus anka, traditionally used for fermentation of food, showed antioxidant and hepatoprotective actions against chemically induced liver injuries. In the present study, the antioxidant component of M. anka was isolated and identified. The antioxidant was elucidated to be dimerumic acid. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical was significantly scavenged by the antioxidant whereas hydroxyl radical and superoxide anion were moderately scavenged. When the antioxidant (12 mg/kg) was given to mice prior to carbon tetrachloride (CCl(4), 20 microl/kg, ip) treatment, the CCl(4)-induced liver toxicity in mice seen in an elevation of serum aspartate aminotransferase and alanine aminotransferase activities was depressed, suggesting the hepatoprotective action of the antioxidant. The liver microsomal glutathione S-transferase activity, which is known to be activated by oxidative stress or active metabolites, was increased by CCl(4) treatment and the increase was also depressed by pretreatment with the mold antioxidant. Thus these data confirmed that the dimerumic acid isolated from M. anka is the potential antioxidant and protective against CCl(4)-induced liver injury.


Assuntos
Antioxidantes/química , Sequestradores de Radicais Livres/química , Piperazinas/química , Leveduras/química , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Tetracloreto de Carbono/toxicidade , Espectroscopia de Ressonância de Spin Eletrônica , Glutationa Transferase/metabolismo , Radical Hidroxila/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos , Estrutura Molecular , Estresse Oxidativo , Piperazinas/farmacologia , Superóxidos/metabolismo
16.
Proc Natl Acad Sci U S A ; 97(4): 1784-9, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10677535

RESUMO

To determine the mechanism of the cardiac dilatation and reduced contractility of obese Zucker Diabetic Fatty rats, myocardial triacylglycerol (TG) was assayed chemically and morphologically. TG was high because of underexpression of fatty acid oxidative enzymes and their transcription factor, peroxisome proliferator-activated receptor-alpha. Levels of ceramide, a mediator of apoptosis, were 2-3 times those of controls and inducible nitric oxide synthase levels were 4 times greater than normal. Myocardial DNA laddering, an index of apoptosis, reached 20 times the normal level. Troglitazone therapy lowered myocardial TG and ceramide and completely prevented DNA laddering and loss of cardiac function. In this paper, we conclude that cardiac dysfunction in obesity is caused by lipoapoptosis and is prevented by reducing cardiac lipids.


Assuntos
Cardiopatias/fisiopatologia , Obesidade/fisiopatologia , Tiazolidinedionas , Fatores Etários , Animais , Apoptose , Glicemia/metabolismo , Peso Corporal , Cromanos/farmacologia , Fragmentação do DNA , Ecocardiografia , Humanos , Insulina/sangue , Metabolismo dos Lipídeos , Masculino , Microscopia Eletrônica , Miocárdio/metabolismo , Tamanho do Órgão , RNA Mensageiro/metabolismo , Ratos , Ratos Zucker , Tiazóis/farmacologia , Troglitazona
17.
Hypertension ; 35(3): 699-703, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10720581

RESUMO

We analyzed the association of 2 biallelic polymorphisms of CYP11B2 (P450c11AS) gene (1 in the Lys(173)Arg of exon 3 and the other in the promoter at position -344T/C) with hypertension in 73 hypertensive patients and 134 normotensive subjects. The association between low-renin hypertension and angiotensin I-converting enzyme (ACE) gene was also analyzed. An elevated ratio of plasma aldosterone concentration to plasma renin activity was used to identify low-renin hypertension. Genotypes for CYP11B2 and ACE were determined through polymerase chain reactions. The Arg(173) allele frequency did not differ between hypertensive patients considered as 1 group (34%) and normotensive control subjects (37%). However, only 22% of 58 CYP11B2 alleles studied in 29 patients with low-renin hypertension were Arg(173) alleles, whereas the frequency of this allele was 41% in patients with normal- or high-renin hypertension (P=0.033). An analysis of the distribution of -344C and Arg(173) genotypes indicated that these 2 variants were in complete linkage disequilibrium: -344C was present in a subset of chromosomes carrying the Arg(173) (P<0.001 in low-renin hypertension). Therefore, the frequency of the -344C allele was low in the patients with low-renin hypertension compared with those with normal- or high-renin hypertension. Deletion (D) allele frequencies of the ACE gene were 31% in the patients with low-renin hypertension, 39% in the patients with normal- or high-renin hypertension, and 29% in normotensive control subjects. We detected an association between the CYP11B2 gene polymorphisms and low-renin hypertension with inappropriate elevation of aldosterone. The decreased frequencies of the Arg(173) and -344C variants in the CYP11B2 appear to be genetically linked to low-renin hypertension in the Japanese population studied.


Assuntos
Citocromo P-450 CYP11B2/genética , Hipertensão Renal/sangue , Hipertensão Renal/genética , Renina/sangue , Adulto , Idoso , Aldosterona/sangue , Alelos , Arginina , Análise Mutacional de DNA , Feminino , Regulação Enzimológica da Expressão Gênica , Marcadores Genéticos , Humanos , Japão , Lisina , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Regiões Promotoras Genéticas/fisiologia , Sistema Renina-Angiotensina/genética
18.
Biol Pharm Bull ; 23(3): 309-12, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10726884

RESUMO

The antioxidant action of Artemisia campestris was examined in vitro and in vivo. A water extract of A. campestris showed a strong scavenging action of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals. When the extract was given intraperitoneally to mice prior to carbon tetrachloride (CCl4) treatment, CCl4-induced liver toxicity, as seen by an elevation of serum aspartate aminotransferase and alanine aminotransferase activities, was significantly reduced. Depression of the elevation of serum enzyme levels after CCl4-treatment was also observed by oral administration of the extract. In that case, CCl4-derived lipid peroxidation in the liver was decreased by the extract treatment. These results suggest that the extract of A. campestris scavenges radicals formed by CCl4 treatment resulting in protection against CCl4-induced liver toxicity.


Assuntos
Antioxidantes/farmacologia , Artemisia/química , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Sequestradores de Radicais Livres/farmacologia , Fígado/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais , Animais , Tetracloreto de Carbono/toxicidade , Camundongos
19.
Diabetes ; 48(5): 1020-5, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10331406

RESUMO

The discovery of uncoupling protein (UCP)-2, a ubiquitously expressed protein homologous to UCP-1, has raised the possibility that energy balance of cells might be regulated in tissues other than brown adipocytes. In normal pancreatic islets, UCP-2 is upregulated by leptin and is low in leptin-resistant islets of ZDF rats. To determine whether UCP-2 does, in fact, have uncoupling activity and, if so, whether such activity would favorably influence the abnormalities in leptin-unresponsive UCP-2-underexpressing islets of diabetic ZDF rats, we transferred the UCP-2 gene to the islets of diabetic ZDF rats and lean (+/+) ZDF control rats. Although ATP was reduced by 23% in both groups of islets, the ATP:ADP ratio increased by 42 and 141%, respectively. [3H]palmitate oxidation was increased by 50%, and [3H]glucose oxidation was 42-63% higher. Preproinsulin mRNA was 2.9-fold above control levels, and glucose-stimulated insulin secretion, which was negligible in control ZDF rat islets, was improved in UCP-2-overexpressing islets. The high fat content of the islets was not reduced, however. We conclude that UCP-2 has uncoupling function when overexpressed in leptin-insensitive islets and that its overexpression corrects the underexpression of the insulin gene and ameliorates glucose-stimulated insulin secretion, possibly by increasing the ATP:ADP ratio.


Assuntos
Adenoviridae/genética , Diabetes Mellitus/fisiopatologia , Expressão Gênica , Ilhotas Pancreáticas/fisiologia , Proteínas de Membrana Transportadoras , Proteínas Mitocondriais , Proteínas/genética , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Técnicas de Transferência de Genes , Glucose/metabolismo , Humanos , Insulina , Canais Iônicos , Masculino , Oxirredução , Ácido Palmítico/metabolismo , Proinsulina/genética , Precursores de Proteínas/genética , Ratos , Ratos Zucker , Triglicerídeos/metabolismo , Desacopladores , Proteína Desacopladora 2
20.
Gen Pharmacol ; 32(2): 225-31, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10188624

RESUMO

Antioxidant action of various molds, which are traditionally used for the production of foods or alcoholic beverages in Japan, was studied in vitro and in vivo. Antioxidant action was evaluated by scavenging stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation of rat liver microsomes. Among 40 molds, 16 species showed the DPPH scavenging action, and the molds that can scavenge the DPPH radical inhibited lipid peroxidation. The mold with the strongest action, Monascus anka, was chosen for the investigation of a protective action against liver injury of rats. When galactosamine (GalN, 400 mg/kg) or GalN plus lipopolysaccharide (LPS, 0.5 microg/kg) was given intraperitoneally to rats (Sprague-Dawley), aspartate aminotransferase (AST) and glutathione (GSH) S-transferase (GST) activities in serum were significantly increased. However, such hepatotoxicities seen in the increase in serum enzyme levels were depressed when the extract prepared from M. anka was given 1 and 15 h before the toxic insultant. Liver microsomal GST activity, which is known to be activated by oxidative stress, was increased by GalN or GaIN plus LPS treatment and the increase was also inhibited by pretreatment with the extract. Pathomorphological changes in the liver caused by GalN treatment also were prevented by the mold extract. These results indicate that the extract of M. anka has radical scavenging action and ameliorates chemically induced hepatotoxicity.


Assuntos
Antioxidantes/farmacologia , Ascomicetos/química , Fígado/efeitos dos fármacos , Animais , Aspergillus/química , Extratos Celulares/farmacologia , Ditiotreitol/farmacologia , Galactosamina/farmacologia , Glutationa Transferase/metabolismo , Fígado/patologia , Masculino , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...