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1.
J Vet Cardiol ; 50: 51-62, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37924558

RESUMO

INTRODUCTION/OBJECTIVE: Transient myocardial thickening (TMT) in cats is a poorly characterized clinical entity. Therefore, this study aimed to provide descriptions of additional cats diagnosed with this clinical phenomenon. ANIMALS, MATERIALS, AND METHODS: For this multicenter observational retrospective study, cats diagnosed with TMT were searched in three medical databases. TMT was defined for cats with at least two echocardiograms showing an increased end-diastolic left ventricular wall thickness (LVWTd; i.e. ≥6 mm) at presentation and subsequent echocardiographic normalization (i.e. LVWTd <5.5 mm). Signalment, history, clinical, laboratory, therapeutic, and outcome data were retrieved. RESULTS: Twenty seven cats were included. The median age was 3 years. In 9/27 cats, an antecedent event was documented. At admission, 27/27 cats had evidence of myocardial injury (median value of cardiac troponin I 5.5 ng/mL), 25/27 cats had congestive heart failure, 13/27 cats had hypothermia, 8/27 cats had systemic hypotension, 7/27 cats had bradycardia, and 7/27 cats had electrocardiographic evidence of an arrhythmia. The median LVWTd was 6.4 mm. A potential cause of myocardial injury was identified in 14/27 cats. The median time from diagnosis to a significant reduction in LVWTd was 43 days. DISCUSSION: TMT can be diagnosed in a wide range of cats, including young subjects. An antecedent predisposing event and/or a possible causative trigger can be identified in some. The reduction in LVWTd that defines this phenomenon usually occurs over a variable time frame. CONCLUSIONS: This study represents the largest investigation of TMT in cats and provides additional information on this uncommon clinical entity.


Assuntos
Doenças do Gato , Insuficiência Cardíaca , Gatos , Animais , Estudos Retrospectivos , Miocárdio , Insuficiência Cardíaca/veterinária , Ecocardiografia/veterinária , Eletrocardiografia , Doenças do Gato/diagnóstico por imagem , Doenças do Gato/terapia
2.
Infect Agent Cancer ; 11: 61, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27980608

RESUMO

BACKGROUND: Little is known about the epidemiological characteristics of papillomavirus (HPV) infection among North African countries. Herein, we conducted a molecular epidemiological study to investigate prevalence of HPV type and HPV-16 variants among cervical-screened unvaccinated Tunisian women. METHODS: Cross-sectional study was performed on 494 Tunisian women visiting Women's Healthcare Centers. HPV-DNA detection was carried out on cervical samples using real-time polymerase chain reaction. HPV genotyping and HPV-16 variants were characterized by direct sequencing of L1 viral capsid gene. RESULTS: The overall HPV prevalence was 34% (95% CI: 30-38%) with significantly higher prevalence among women with squamous intraepithelial lesions (SIL) than those with no intraepithelial lesions (NIL) 84% (95% CI: 76-92%) and 24.5% (95% CI: 20-29%) respectively. The distribution of HPV prevalence according to women's age shows a U-shaped curve and the highest HPV prevalence rates were observed among the youngest (≤25 years; 51.2%, 95% CI: 37-67%) and the oldest women (>55 years; 41.7%, 95% The HPV-16 prevalence was 32.8% (95% CI: 22-45%) among women with SIL and 9.2% (95% CI: 6-12%) among women with NIL. Whereas, the HPV-18 prevalence was 1.3% (95% CI: 0-5%) among women with SIL and 0.3% (95% CI: 0-1%) among women with NIL. Among HPV-16 positive women, European lineage (E) was identified as the predominant HPV-16 variant (85.7%, 95% CI: 76-95%). The frequency of E variant was lower among SIL than among NIL women (81%, 95% CI: 64-99%, and 88%, 95% CI: 77-100%, respectively). Conversely, the African-2 variant frequency was higher among SIL than among NIL women (18%, 95% CI: 1-36% and 6%, 95% CI: 2-14%, respectively). In multivariate analysis, young age was the only risk factor that is independently associated with HPV infection. Moreover, HPV infection and menopause were both found to be independently associated with SIL and HSIL. CONCLUSION: HPV DNA testing should be proposed to young and menopausal Tunisian women. Considering HPV prevalence, only 13% of the Tunisian women could be protected by the bivalent HPV vaccine. These results may be helpful for designing an adapted HPV testing and vaccination program in Tunisia.

4.
Clin Radiol ; 68(10): e524-31, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23830776

RESUMO

AIM: To evaluate the role of pretreatment apparent diffusion coefficient (ADC) as a predictor of treatment response and local recurrence in patients with locally advanced rectal cancer who underwent neoadjuvant therapy. MATERIALS AND METHODS: Forty-nine patients who underwent preoperative diffusion-weighted magnetic resonance imaging (MRI) followed by neoadjuvant chemoradiation and surgery were enrolled in the study. The mean tumour ADC was measured independently from multiple, non-overlapping regions of interest (ROIs) to cover the entire tumour area on a single section by two radiologists and patients were followed postoperatively for a median of 16.4 months. Diagnostic accuracy of ADC for predicting treatment response and recurrence was evaluated using the area under the receiver-operating characteristic (ROC) curve, sensitivity, specificity, and predictive values. Univariate and multivariate analyses including clinical tumour (cT) staging, carcinoembryonic antigen (CEA) level, lymph-node involvement, tumour grade, surgical margin, vascular involvement, and ADC were performed with respect to recurrence. Interobserver agreement of ADC values was assessed. RESULTS: Twenty patients showed response to neoadjuvant therapy and recurrence was noted in 17 patients. Low pretreatment ADC, MRI findings of cT4 staging, and node involvement were significantly related to poor treatment response. Sensitivity and specificity of ADC = 0.833 × 10(-3) mm(2)/s for prediction of treatment response was 75 and 48% for reader 1 and 65 and 52% for reader 2, respectively. Univariate and multivariate analyses identified pretreatment tumour ADC as the only predictive factor for recurrence. Sensitivity and specificity of ADC = 0.833 × 10(-3) mm(2)/s for prediction of recurrence was 86 and 77% for reader 1 and 80 and 69% for reader 2, respectively. Interobserver agreement for measuring ADC was good with a kappa value of 0.70. CONCLUSION: Pretreatment rectal tumour ADC values may be an early biomarker for predicting treatment response and local recurrence in patients who underwent neoadjuvant chemoradiation.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Quimiorradioterapia , Meios de Contraste , Feminino , Gadolínio DTPA , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Curva ROC , Resultado do Tratamento
5.
Pak J Biol Sci ; 16(14): 686-91, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24505994

RESUMO

High tibial osteotomy methods include open and closed wedge techniques. The study aims at comparing results of osteotomy methods in patients suffering from genu varum deformity. In a cohort study, 32 patients with genu varum deformity (42 knees) were evaluated. They were divided into two groups and matched according to age and gender. The patients were treated with open and closed wedge osteotomy. After surgery, they were followed up and compared for 6 months. Thirty two patients with genu varum deformity (10 cases of bilateral deformity (31.2%) including 25 women (87.2%) and 7 men (21.8%) were studied. Incidence of complications was the same after open and closed wedge osteotomy operation (12.5%). Patients overall satisfaction from open and closed wedge methods was 87.5 and 75%, respectively. There was statistically significant difference between two groups considering operation duration, weight bearing duration and return to routine activities (p < 0.001). There was no difference in other parameters including varus angle correction, Lysholm score Tegner activity as well as Insall Salvati index. This study demonstrated that there is no difference between two osteotomy methods considering patients' clinical outcomes and both methods are successful in final treatment results.


Assuntos
Genu Varum/cirurgia , Osteotomia/métodos , Tíbia/cirurgia , Atividades Cotidianas , Adulto , Estudos de Coortes , Feminino , Humanos , Articulação do Joelho/cirurgia , Masculino , Resultado do Tratamento , Suporte de Carga/fisiologia
6.
Orthop Traumatol Surg Res ; 98(8): 868-72, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23153666

RESUMO

INTRODUCTION: Combined fractures of the distal third of tibia diaphysis and fibula diaphysis are a common orthopedic injury. There is an ongoing debate about the necessity of fibular fixation when associated to distal third tibial fracture. This study aims at evaluating the role of fibular fixation in the treatment of distal third tibial fractures. HYPOTHESIS: We hypothesized that fixation of the fibula increases the stability of fixation in distal third tibial and fibular fractures. MATERIALS AND METHODS: In a randomized clinical trial, 53 patients with concomitant fractures of tibia and ipsilateral fibula at distal third level were recruited in this study during a 23-month period. Patients were randomized in two groups: patients with fibular fixation (case group) and without fibular fixation (control group). The patients were followed up for at least 6 months postoperatively. RESULTS: There were seven cases exhibiting malalignment on immediate postoperative radiographs. Six of them were in group II (control group) and one was in group I (case group) (P=0.084). We didn't find nonunion in group I and we found three patients in group II (P=0.141). Infection was one in group I and two in group II on gustillo II injuries (P=0.516). CONCLUSION: Despite its low count of patients, our study didn't show any advantage to fix the fibula fracture associated to distal third of tibia diaphysis fracture. It didn't show either an increase of complication after fibula open reduction and internal fixation. LEVEL OF EVIDENCE: Level III. Randomized prospective study.


Assuntos
Fíbula/lesões , Fíbula/cirurgia , Fixação Interna de Fraturas , Fraturas da Tíbia/cirurgia , Adolescente , Adulto , Diáfises/lesões , Feminino , Fraturas Ósseas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
8.
Infect Immun ; 77(5): 1959-67, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19273563

RESUMO

The host cell environment can alter bacterial pathogenicity. We employed a combination of cellular and molecular techniques to study the expression of Campylobacter jejuni polysaccharides cocultured with HCT-8 epithelial cells. After two passages, the amount of membrane-bound high-molecular-weight polysaccharide was considerably reduced. Microarray profiling confirmed significant downregulation of capsular polysaccharide (CPS) locus genes. Experiments using conditioned media showed that sugar depletion occurred only when the bacterial and epithelial cells were cocultured. CPS depletion occurred when C. jejuni organisms were exposed to conditioned media from a different C. jejuni strain but not when exposed to conditioned media from other bacterial species. Proteinase K or heat treatment of conditioned media under coculture conditions abrogated the effect on the sugars, as did formaldehyde fixation and cycloheximide treatment of host cells or chloramphenicol treatment of the bacteria. However, sugar depletion was not affected in flagellar export (fliQ) and quorum-sensing (luxS) gene mutants. Passaged C. jejuni showed reduced invasiveness and increased serum sensitivity in vitro. C. jejuni alters its surface polysaccharides when cocultured with epithelial cells, suggesting the existence of a cross talk mechanism that modulates CPS expression during infection.


Assuntos
Campylobacter jejuni/fisiologia , Células Epiteliais/microbiologia , Polissacarídeos Bacterianos/biossíntese , Linhagem Celular , Técnicas de Cocultura , Meios de Cultivo Condicionados , Perfilação da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos
9.
Hum Exp Toxicol ; 26(10): 789-94, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18025050

RESUMO

Paraquat (PQ) is a highly toxic herbicide that is used in most of the countries without restriction. The cytotoxic effect of PQ is mediated by radicals, which are the products of PQ reduction in cells. The anti-oxidative action of captopril, an angiotensin-converting enzyme inhibitor, appears to be through its ability to scavenge reactive oxygen species. In this study, the heptoprotective effect of captopril against PQ-induced hepatotoxicity was evaluated using primary cultured rat hepatocytes. Hepatocytes were isolated from male Wistar rats using a two-step collagenase perfusion, following incubation in the presence of captopril at 0.1, 0.2, 0.4 and 0.8 mM with or without PQ (5 mM). Hepatoprotective effects of captopril were studied indicating glutathione level intensity, thiobarbituric acid reactive substances (TBARs) formation, lactate dehydrogenase (LDH) leakage and cell viability every 70 min for 210 min. Captopril at 0.2 mM concentration maintained the LDH leakage, glutathione level and cell viability in the presence of 5 mM PQ. In spite of a significant elevation in TBARs formation in the PQ group, captopril did not show any significant protection. In conclusion, our data reveals that incubation of freshly isolated rat hepa-tocytes with captopril (0.2 mM) significantly protected the hepatocytes against the cytotoxicity of PQ (P < 0.05).


Assuntos
Captopril/farmacologia , Citoproteção , Hepatócitos/efeitos dos fármacos , Paraquat/toxicidade , Animais , Glutationa/metabolismo , Hepatócitos/metabolismo , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/análise
10.
Chemosphere ; 65(8): 1381-7, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16777184

RESUMO

Gaseous nitrogen (N) loss from field-applied manure in the form of ammonia (NH(3)) and nitrous oxide (N(2)O) has negative agronomic, environmental and health implications. This study was undertaken to evaluate the combined effect of soil type and dicyandiamide (DCD) on NH(3) and N(2)O emissions following application of liquid hog manure. Soil samples (100g) were placed in 500 mL screw-top Mason-jars and de-ionised water was added to bring the soil samples to 50%, 70% and 90% water-filled pore space (WFPS). Slurry and slurry+DCD treatments were applied at a rate of 116000 l ha(-1). The jars were then sealed and incubated at 21 degrees C for 21 d. Ammonia volatilisation was quantified using boric acid traps while N(2)O gas concentrations were analysed using gas chromatography. Results showed that DCD had no effect (p>0.05) on either NH(3) or N(2)O emissions. However, soil type had a significant effect (p<0.05) on both gases. Overall, the Pugwash soil produced 3 and 2.5 times more NH(3) and N(2)O, respectively, than the Acadia soil. N(2)O emissions from both soils increased with an increase in %WFPS, indicating that during the spring and fall in Atlantic Canada, when soils are generally wet, a significant amount of N(2)O may be emitted from these soils. The relationship between cumulative N(2)O and %WFPS was best described by an exponential function R(2)=0.83 and p<0.05 (both soils). Therefore, soil type should be taken into consideration when formulating N(2)O emission factors. The addition of DCD together with slurry may not be a viable strategy to mitigate N(2)O emissions from acidic soils. To reduce emissions of both gases, livestock slurry should not be applied on wet soils.


Assuntos
Ácidos/química , Amônia/análise , Amônia/química , Guanidinas/química , Óxido Nitroso/análise , Óxido Nitroso/química , Poluentes do Solo/análise , Poluentes do Solo/química , Animais , Fertilizantes , Esterco , Camundongos , Nova Escócia
11.
Acta Diabetol ; 41(3): 104-12, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15666577

RESUMO

Obesity is often accompanied by hyperleptinemia, hyperinsulinemia, and an increased parasympathetic tone. Obese-hyperglycemic mice (Umeå ob/ob) have functional leptin receptors and a raised parasympathetic tone. We studied insulin release in islets isolated from 9-month-old severely obese ob/ob mice. Leptin (0.5-18 nM) did not affect insulin release together with 2.8-20 mM glucose. Leptin (18 microM) had no effect in the presence of low glucose (2.8-5.5 mM), but increased insulin secretion in islets challenged with 11.1 or 16.7 mM glucose. Leptin at 18 microM increased insulin secretion stimulated by the parasympathetic neurotransmitters acetylcholine (ACh; 10 microM) or vasoactive intestinal peptide (VIP; 10 nM), and by 5 mM theophylline or 2.5 microM forskolin. Overnight culture increased the effect of 18 microM leptin, but no effects were observed with 18 nM leptin. Pretreatment of islets with phorbol 12-myristate 13-acetate (PMA) did not suggest any involvement of protein kinase C. In summary, a high concentration of leptin stimulates insulin release in the presence of stimulatory concentrations of glucose alone and with parasympathetic neurotransmitters. Hyperleptinemia and increased parasympathetic stimulation may in part cause the hyperinsulinemia observed in obesity. This may aggravate insulin resistance and the abnormal metabolism in diabetes mellitus.


Assuntos
Acetilcolina/farmacologia , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Leptina/farmacologia , Peptídeo Intestinal Vasoativo/farmacologia , Animais , Cafeína/farmacologia , Células Cultivadas , Colforsina/farmacologia , Feminino , Secreção de Insulina , Ilhotas Pancreáticas/efeitos dos fármacos , Camundongos , Camundongos Obesos , Acetato de Tetradecanoilforbol/farmacologia
12.
Eur J Pharmacol ; 426(1-2): 139-43, 2001 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-11525782

RESUMO

High (30 mM) K(+), known to cause beta-cell membrane depolarisation, significantly decreased the islet total ATP content, supporting the view that beta-cell membrane depolarisation can activate the ATP-consuming Na(+)/K(+) pump. Ouabain (1 mM) did not change the islet ATP content after 5-15 min of incubation in the absence or presence of 3 mM glucose but reduced it after 30 min, and in the presence of 20 mM glucose, the reduction by ouabain occurred already after 15 min. Incubation of islets with ouabain for 60 min decreased the islet ATP content in the presence of 3, 10 or 20 mM glucose or 30 mM K(+). Also, the islet glucose oxidation rate was decreased by ouabain. When K(+) deficiency was used to inhibit the Na(+)/K(+) pump, no change in ATP content was observed irrespective of glucose concentration, although K(+) deficiency caused a slight inhibition of the glucose oxidation rate. Diazoxide reduced the islet glucose oxidation rate and increased the islet ATP content in the presence of 20 mM glucose. There may exist a feedback mechanism decreasing the flow of glucose metabolism in response to reduced ATP consumption by the Na(+)/K(+) pump.


Assuntos
Trifosfato de Adenosina/metabolismo , Ilhotas Pancreáticas/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Diazóxido/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Feminino , Glucose/metabolismo , Glucose/farmacologia , Técnicas In Vitro , Ilhotas Pancreáticas/efeitos dos fármacos , Camundongos , Camundongos Obesos , Ouabaína/farmacologia , Oxirredução/efeitos dos fármacos , Potássio/metabolismo , Potássio/farmacologia , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , Fatores de Tempo
14.
Int J Exp Diabetes Res ; 1(4): 265-74, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11467417

RESUMO

The activity of the beta-cell Na+/K+ pump was studied by using ouabain-sensitive (1mM ouabain) 86Rb+ influx in beta-cell-rich islets of Umeå-ob/ob mice as an indicator of the pump function. The present results show that the stimulatory effect of glucose on ouabain-sensitive 86Rb+ influx reached its approximate maximum at 5mM glucose. Pre-treatment of the islets with 20mM glucose for 60 min strongly reduced the glucose-induced stimulation of the Na+/K+ pump. Pre-treatment (60 or 180 min) of islets at 0 mM glucose, on the other hand, did not affect the magnitude of the glucose-induced stimulation of 86Rb+ influx during the subsequent 5-min incubation. Glibenclamide stimulated the ouabain-sensitive 86Rb+ uptake in the same manner as glucose. The stimulatory effect showed its apparent maximum at 0.5 microM. Pre-treatment (60 min) of islets with 1 microM glibenclamide did not reduce the subsequent stimulation of the ouabain-sensitive 86Rb+ influx. The stimulatory effect of glibenclamide and D-glucose were not additive, suggesting that they may have the same mechanism of action. No direct effect of glibenclamide (0.01-1 microM) was observed on the Na+/K+ ATPase activity in homogenates of islets. Diazoxide (0.4mM) inhibited the Na+/K+ pump. This effect was sustained even after 60 min of pre-treatment of islets with 0.4mM diazoxide. The stimulatory effect of glibenclamide and D-glucose were abolished by diazoxide. It is concluded that nutrient as well as non-nutrient insulin secretagogues activate the Na+/K+ pump, probably as part of the membrane repolarisation process.


Assuntos
Diazóxido/farmacologia , Glucose/farmacologia , Glibureto/farmacologia , Ilhotas Pancreáticas/metabolismo , Ouabaína/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Inibidores Enzimáticos/farmacologia , Feminino , Hipoglicemiantes/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Camundongos , Camundongos Obesos , Radioisótopos de Rubídio/metabolismo , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores
15.
Epidemiol Infect ; 124(1): 137-41, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10722141

RESUMO

Somalia has suffered from a civil war during the last 10 years. In this period the use of whole blood has increased at least twofold in Mogadishu, Somalia compared with pre-war. Screening possibilities are limited. Recent data concerning the prevalence of infections with blood-borne and sexually transmitted agents are not available from this country. To investigate the spread of human immunodeficiency virus (HIV-1/2) and other blood-borne or sexually transmitted agents we tested a total of 256 serum samples collected in the summer of 1995 from blood donors, hospitalized children and adults in Mogadishu. The hepatitis B surface antigen (HbsAg) carrier rate was 191%, 5.6% and 21.3 % among blood donors, hospitalized children and hospitalized adults, respectively. However, no children under 2 years of age were HbsAg positive. The overall presence of antibodies against hepatitis C virus (HCV) was 2.4% (6/256). In blood donors this was 0.6% (1/157). In none of the samples tested, antibodies against HIV 1 and 2 or human T-cell lymphotropic viruses (HTLV I and II) were detected. Our results indicate that, during the civil war in Somalia, no evidence of an increase of HIV infections was found. Our findings indicate that preventive measures in Somalia should focus mainly on prevention of HBV-infections. HBV-vaccine could be administered within the framework of the expanded programme on immunization, as none of the children less than 2 years of age were HbsAg positive.


Assuntos
Antígenos de Bactérias/sangue , Antígenos Virais/sangue , Patógenos Transmitidos pelo Sangue , Infecções por HIV/epidemiologia , Infecções Sexualmente Transmissíveis/epidemiologia , Adolescente , Adulto , Idoso , Doadores de Sangue/estatística & dados numéricos , Criança , Pré-Escolar , Infecções por Chlamydia/epidemiologia , Chlamydia trachomatis , Infecções por Deltaretrovirus/epidemiologia , Infecções por HIV/imunologia , HIV-1 , HIV-2 , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Humanos , Lactente , Pacientes Internados/estatística & dados numéricos , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Infecções Sexualmente Transmissíveis/imunologia , Somália/epidemiologia , Sífilis/epidemiologia
16.
Br J Pharmacol ; 131(8): 1700-6, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11139449

RESUMO

We have previously demonstrated that both D-glucose and glibenclamide stimulate the Na(+)/K(+) pump and suggested that this may be part of the membrane repolarization process, following the primary depolarization by these agents. The aim of this study was to investigate whether the non-sulphonylurea meglitinide (HB 699) exerts similar effects as glibenclamide or glucose on the islet Na(+)/K(+) pump and if effects of meglitinide or glibenclamide on this pump activity is paralleled by changes in islet ATP content and/or ATP/ADP ratio. The acyl-amino-alkyl benzoic acid derivative, meglitinide, stimulated the islet ouabain-sensitive portion of (86)Rb(+) influx (Na(+)/K(+) pump) by 53%, while the ouabain-resistant portion was inhibited by 70%. The stimulatory effect was not additive to that caused by D-glucose, suggesting that both agents may activate the Na(+)/K(+) pump via the same mechanism. Glibenclamide (10 microM) decreased the islet ATP and ADP content as well as the ATP/ADP ratio at 0 mM glucose. These effects were no longer observed at 10 mM glucose. Meglitinide (10 or 50 microM) lowered the islet ATP and ADP content at 0 mM glucose without affecting the ATP/ADP ratio. At 10 mM glucose, however, 10 microM of the drug reduced the islet ATP content but not the ATP/ADP ratio, while 50 microM of the drug, besides lowering the ATP content, also reduced the ATP/ADP ratio. Diazoxide (0.5 mM) increased the islet ATP content in the absence of glucose, an effect not seen in the presence of 10 mM glucose. The rate of glucose oxidation at 1, 10 or 20 mM of the sugar was not affected by glibenclamide (0.1 - 10 microM) and at 10 or 20 mM of the sugar not affected by meglitinide (1 - 100 microM). These results suggest that glibenclamide and meglitinide lower the islet ATP level by indirectly activating the beta-cell Na(+)/K(+) pump, which is a major consumer of ATP in the islets, while diazoxide increases the ATP level due to inhibition of the pump.


Assuntos
Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Benzamidas/farmacologia , Diazóxido/farmacologia , Relação Dose-Resposta a Droga , Feminino , Glucose/metabolismo , Glucose/farmacologia , Glibureto/farmacologia , Hipoglicemiantes/farmacologia , Técnicas In Vitro , Ilhotas Pancreáticas/enzimologia , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Obesos , Oxirredução/efeitos dos fármacos , Radioisótopos de Rubídio/metabolismo
17.
Int J Exp Diabetes Res ; 1(2): 155-64, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11469399

RESUMO

To determine the effect of D-glucose on the beta-cell Na+/K+ pump, 86Rb+ influx was studied in isolated, -cell-rich islets of Umeå-ob/ob mice in the absence or presence of 1mM ouabain. D-glucose (20mM) stimulated the ouabain-sensitive portion of 86Rb+ influx by 65%, whereas the ouabain-resistant portion was inhibited by 48%. The Na+/K+ ATPase activity in homogenates of islets of Umeå-ob/ob mice or normal mice was determined to search for direct effects of D-glucose. Thus, ouabain-sensitive ATP hydrolysis in islet homogenates was measured in the presence of different D-glucose concentrations. No effect of D-glucose (3-20mM) was observed in either ob/ob or normal islets at the optimal Na+/K+ ratio for the enzyme (135mM Na+ and 20mM K+). Neither D-glucose (3-20mM) nor L-glucose or 3-O-methyl-D-glucose (20mM) affected the enzyme activity at a high Na+/K+ ratio (175 mM Na+ and 0.7 mM K+). Diphenylhydantoin (150 microM) decreased the enzyme activity at optimal Na+/K+ ratio, whereas 50 microM of the drug had no effect. The results suggest that D-glucose induces a net stimulation the Na+/K+ pump of beta-cells in intact islets and that D-glucose does not exert any direct effect on the Na+/K+ ATPase activity.


Assuntos
Glucose/farmacologia , Ilhotas Pancreáticas/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , 3-O-Metilglucose/farmacologia , Animais , Feminino , Técnicas In Vitro , Ilhotas Pancreáticas/efeitos dos fármacos , Cinética , Camundongos , Camundongos Obesos , Obesidade/enzimologia , Ouabaína/farmacologia , Valores de Referência , Rubídio/metabolismo , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , Estereoisomerismo
18.
Plant Foods Hum Nutr ; 50(3): 179-87, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9373869

RESUMO

A total of 17 vegetable-type soybean (Glycine max [L.] Merr) genotypes were planted in four-row plots arranged in a randomized complete block design in 1988 and 1989 at Petersburg, Virginia. Each genotype was harvested at four developmental stages and evaluated for phytate content. Highly significant differences for phytate content were observed among the stages of harvest and genotypes, and there was an interaction between genotype x stage of harvest. The significant differences observed for phytate content among genotypes indicated that genetic variation exists among the tested genotypes for selection and improvement through hybridization. Among the genotypes, 'Kingston' and PI 423852 had the highest phytate content in most stages of harvest while PI 416771, 'Emperor', and PI 416982 had the lowest phytate values. A heritability estimate of 81 percent was observed for phytate content. This high heritability value indicates that selecting genotypes for lower phytate content would be effective. Significant correlations were observed for phytate content among genotypes harvested at R6, R7, R8, and overall. The magnitude of association of R6 with the overall phytate mean was especially high. These results illustrate that determining the phytate content of genotypes at the R6 growth stage would be a good predictor of the overall genotypic performance.


Assuntos
Glycine max/química , Glycine max/genética , Ácido Fítico/análise , Análise de Alimentos/métodos , Genótipo , Glycine max/crescimento & desenvolvimento
20.
New Phytol ; 131(1): 61-67, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33863166

RESUMO

Presence of the endophytic; fungus Acremonium coenophialum Morgan-Jones and Gams in tall fescue (Festuca artuidinacea- Sehreb.) enhances host persistence in drought-prone environments. However, the physiological mechanism is not well understood. We investigated the influence of endophyte infection and water deficit on osmotic adjustment, stomatal conductance, tiller survival and leaf elongation rate of genotype GA87-122 and cv. Kentucky-31 (KY31) of tall fescue. Plants were grown in a greenhouse in pots containing fine-silty topsoil (experiment 1) or sand (experiment 2). In expt 1, endophyte-infected (EI) and endophyte-free (EF) isolines of GA87-122 were exposed to two drought preconditioning cycles, after which all pots were re-watered and osmotic adjustment determined. Osmotic adjustment was -0.46 and -0.51 MPa in El leaf blades and tiller bases and -0.29 and -0.13 MPa in EF leaf blades and tiller bases, respectively. In expt 2, EI and EF GA87-122 and KY31 Mere exposed to severe drought after two preconditioning cycles, then re-watered. During the second preconditioning drying cycle of KY31, stomatal conductance tended to be lower in EI than in EF plants, but the difference was significant (P⩽ 0-05) only at two sampling times. Shoot tissues osmotically adjusted 0.17-0.31 MPa more in EI than in EF plants. Tiller survival and leaf elongation rates were higher (P⩽ 0.05) in preconditioned EI than in EF plants. Basal-zone osmotic adjustment was correlated with tiller survival rate in GA87-122 and KY31 (r = 0.87, P⩽ 0.01 for both). Enhanced osmotic adjustment in the meristematic and growing zone might account far improved survival of tillers by facilitating protection of the apical meristem.

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