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1.
Braz. j. biol ; 82: e235612, 2022. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153466

RESUMO

Abstract The experiment was carried out on mango cv. Dusehri to investigate the effect of N, P and K fertilizers on vegetative, reproductive growth, yield and fruit quality. Eight different fertilizer combinations such as T1 (control), T2 (N), T3 (P), T4 (K), T5 (NP), T6 (NK), T7 (PK) and T8 (NPK) were used. Individual or combine fertilizer application of N (1000 g), P (750 g) and K (750 g) were applied during growing season in February and August. All the treatments significantly influenced on vegetative growth, flowering, fruiting, yield and other physiochemical attributes of mango as compared to control. Least effect was observed with individual fertilizer application while combine fertilizer treatments enhanced most of the investigated parameters. Especially, qualitative traits showed non-significant differences between treated and untreated mango trees. However, among the different treatments T8 (NPK) showed significance for fruiting aspects such as maximum size of growth flushes (177.51 mm), total number of panicles/tree (845), total number of flowers/panicle (974), sex ratio (69.18%), fruit retention (13.85%), total number of fruits/tree (379), yield (82 kg/tree), fruit weight (197.5 g), pulp weight (135.5 g) and physiochemical parameters namely TSS (24.53), Vit. C (57.63 mg/100 mL) and total sugar (20.84%). In general, combine application of NPK (T8) were the most effective in enhancing fruiting aspects, yield, physiochemical characteristics as well as improved fruit quality of mango trees.


Resumo O experimento foi realizado em manga cv. Dusehri para investigar o efeito dos fertilizantes N, P e K no crescimento vegetativo, reprodutivo, produtividade e de qualidade do fruto. Foram utilizadas oito combinações diferentes de fertilizantes: T1 (controle), T2 (N), T3 (P), T4 (K), T5 (NP), T6 (NK), T7 (PK) e T8 (NPK). Cada tratamento de N (1.000 g), P (750 g) e K (750 g) foi aplicado duas vezes durante a estação de crescimento em fevereiro e agosto. Todos os tratamentos influenciaram significativamente o crescimento vegetativo, floração, frutificação, produtividade e outros atributos físico-químicos da manga em relação ao controle. Menos efeito foi observado com a aplicação individual de fertilizante, enquanto os tratamentos combinados aumentaram a maioria dos parâmetros investigados. Especialmente as características qualitativas mostraram diferenças não significativas entre mangueiras tratadas e não tratadas. No entanto, entre os diferentes tratamentos, T8 (NPK) apresentou significância para aspectos de frutificação, como tamanho máximo de folgas de crescimento (177,51 mm), número total de panículas/árvore (845), número total de flores/panícula (974), razão sexual (69,18%), retenção de frutos (13,85%), número total de frutos/árvore (379), produção (82 kg/árvore), peso do fruto (197,5 g) e peso da polpa (135,5 g), além de parâmetros físico-químicos, como TSS (24,53), vitamina C (57,63 mg/100 mL) e açúcar total (20,84%). Em geral, a aplicação combinada de NPK (T8) foi a mais eficaz no aprimoramento dos aspectos de frutificação, produtividade, características físico-químicas, além da melhoria da qualidade dos frutos das mangueiras.

2.
Braz J Biol ; 82: e235612, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33681899

RESUMO

The experiment was carried out on mango cv. Dusehri to investigate the effect of N, P and K fertilizers on vegetative, reproductive growth, yield and fruit quality. Eight different fertilizer combinations such as T1 (control), T2 (N), T3 (P), T4 (K), T5 (NP), T6 (NK), T7 (PK) and T8 (NPK) were used. Individual or combine fertilizer application of N (1000 g), P (750 g) and K (750 g) were applied during growing season in February and August. All the treatments significantly influenced on vegetative growth, flowering, fruiting, yield and other physiochemical attributes of mango as compared to control. Least effect was observed with individual fertilizer application while combine fertilizer treatments enhanced most of the investigated parameters. Especially, qualitative traits showed non-significant differences between treated and untreated mango trees. However, among the different treatments T8 (NPK) showed significance for fruiting aspects such as maximum size of growth flushes (177.51 mm), total number of panicles/tree (845), total number of flowers/panicle (974), sex ratio (69.18%), fruit retention (13.85%), total number of fruits/tree (379), yield (82 kg/tree), fruit weight (197.5 g), pulp weight (135.5 g) and physiochemical parameters namely TSS (24.53), Vit. C (57.63 mg/100 mL) and total sugar (20.84%). In general, combine application of NPK (T8) were the most effective in enhancing fruiting aspects, yield, physiochemical characteristics as well as improved fruit quality of mango trees.


Assuntos
Mangifera , Animais , Aves , Fertilizantes , Frutas , Árvores
3.
Reprod Fertil Dev ; 31(2): 272-281, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30071922

RESUMO

In this study we investigated the effect of astaxanthin (Ax), which exhibits strong antioxidant activity, during invitro growth (IVG) on the developmental competence of oocytes and steroidogenesis of granulosa cells derived from early antral follicles. Bovine oocyte-cumulus-granulosa complexes collected from early antral follicles were cultured for 12 days in the presence or absence (control) of 500µM Ax. The viability of oocytes and antrum formation in the granulosa cell layer during IVG culture were greater in the presence than absence of Ax (P<0.05). Regardless of Ax treatment, 17ß-oestradiol production increased during IVG culture; however, progesterone production was significantly lower in the presence than absence of Ax (P<0.05). Reactive oxygen species levels were lower in Ax-treated oocytes than in controls after IVG (P<0.05). Although nuclear maturation and cleavage rates did not differ between the Ax-treated and control groups, Ax treatment led to weaker cathepsin B activity in oocytes and better blastocyst rates than in controls (P<0.05). Accordingly, Ax treatment during IVG increased the total number of cells in blastocysts (P<0.05). These results indicate that Ax supplementation of IVG medium improves the quality of bovine oocytes due to its antioxidative effects on growing oocytes and its suppression of the luteinisation of granulosa cells.


Assuntos
Antioxidantes/farmacologia , Células da Granulosa/efeitos dos fármacos , Oócitos/efeitos dos fármacos , Oogênese/efeitos dos fármacos , Folículo Ovariano/efeitos dos fármacos , Animais , Bovinos , Meios de Cultura , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Células da Granulosa/metabolismo , Oócitos/crescimento & desenvolvimento , Oócitos/metabolismo , Folículo Ovariano/crescimento & desenvolvimento , Folículo Ovariano/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Progesterona/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Xantofilas/farmacologia
4.
Reprod Domest Anim ; 52(5): 781-790, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28512759

RESUMO

The aim of the present research is to study the effect of pH values on the sperm rheotaxis properties. Semen collected from bulls was diluted with SOF medium (1:10). pH of the medium was adjusted using a digital pH meter to the following pH values: 6.0, 6.2, 6.4, 6.4, 6.8, 7.0. All kinetic parameters of sperm (n = 3,385) were determined through a computer-assisted sperm analysis (CASA) system using microfluidic devices with controlled flow velocity. The following parameters were determined: total motility (TM%), positive rheotaxis (PR%), straightline velocity (VSL, µm/s), average path velocity (VAP, µm/s), linearity (LIN, as VSL/VCL, %), beat cross-frequency (BCF, Hz) and curvilinear velocity (VCL, µm/s). Nitric oxide, calcium and potassium were estimated in semen at different pH values. To confirm the effect of nitric oxide and K+ , we used sodium nitroprusside (an NO donor) and KCL as (a K+ donor) to see their effect on sperm PR%. The results showed no difference in TM% at pH (6-7). The PR% was the lowest at pH 6 and 7. The best parameters for the PR% were at pH 6.4-6.6. The concentration of Ca+2 did not change at different pH values. The mean NO values decreased with the increase of pH; however, the mean values of K+ increased with the increase of pH. Addition of high concentration of NO and K+ to the semen media at fixed pH level had a negative effect on TM% and PR%. In conclusion, the bull sperm had the best rheotaxis properties at pH 6.4-6.6 and sensitive to the change of seminal NO and K+ .


Assuntos
Bovinos/fisiologia , Motilidade Espermática/fisiologia , Espermatozoides/fisiologia , Animais , Cálcio/análise , Concentração de Íons de Hidrogênio , Masculino , Microfluídica/métodos , Óxido Nítrico/análise , Potássio/análise , Análise do Sêmen
5.
Reprod Domest Anim ; 51(5): 795-803, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27554536

RESUMO

To improve the reproductive performance of water buffalo to level can satisfy our needs, the mechanisms controlling ovarian follicular growth and development should be thoroughly investigated. Therefore, in this study, the expressions of growth differentiation factor-9 (GDF-9) in buffalo ovaries were examined by immunohistochemistry, and the effects of GDF-9 treatment on follicle progression were investigated using a buffalo ovary organ culture system. Frozen-thawed buffalo ovarian follicles within slices of ovarian cortical tissue were cultured for 14 days in the presence or absence of GDF-9. After culture, ovarian slices were fixed, sectioned and stained. The follicles were morphologically analysed and counted. Expression pattern of GDF-9 was detected in oocytes from primordial follicles onwards, besides, also presented in granulosa cells. Moreover, GDF-9 was detected in mural granulosa cells and theca cells of pre-antral follicles. In antral follicles, cumulus cells and theca cells displayed positive expression of GDF-9. In corpora lutea, GDF-9 was expressed in both granulosa and theca lutein cells. After in vitro culture, there was no difference in the number of primordial follicles between cultured plus GDF-9 and cultured control that indicated the GDF-9 treatment has no effect on the primordial to primary follicle transition. GDF-9 treatment caused a significant decrease in the number of primary and secondary follicles compared with controls accompanied with a significant increase in pre-antral and antral follicles. These results suggest that a larger number of primary and secondary follicles were stimulated to progress to later developmental stages when treated with GDF-9. Vitrification/warming of buffalo ovarian tissue had a little remarkable effect, in contrast to culturing for 14 days, on the expression of GDF-9. In conclusion, treatment with GDF-9 was found to promote progression of primary follicle that could provide an alternative approach to stimulate early follicle development and to improve therapies for the most common infertility problem in buffaloes (ovarian inactivity).


Assuntos
Búfalos/fisiologia , Criopreservação/veterinária , Fator 9 de Diferenciação de Crescimento/farmacologia , Ovário/efeitos dos fármacos , Vitrificação , Animais , Feminino , Ovário/fisiologia
6.
Diabetes Obes Metab ; 17(3): 268-75, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25425451

RESUMO

AIM: To test our hypothesis that initiating therapy with a combination of agents known to improve insulin secretion and insulin sensitivity in subjects with new-onset diabetes would produce greater, more durable reduction in glycated haemoglobin (HbA1c) levels, while avoiding hypoglycaemia and weight gain, compared with sequential addition of agents that lower plasma glucose but do not correct established pathophysiological abnormalities. METHODS: Drug-naïve, recently diagnosed subjects with type 2 diabetes mellitus (T2DM) were randomized in an open-fashion design in a single-centre study to metformin/pioglitazone/exenatide (triple therapy; n = 106) or an escalating dose of metformin followed by sequential addition of sulfonylurea and glargine insulin (conventional therapy; n = 115) to maintain HbA1c levels at <6.5% for 2 years. RESULTS: Participants receiving triple therapy experienced a significantly greater reduction in HbA1c level than those receiving conventional therapy (5.95 vs. 6.50%; p < 0.001). Despite lower HbA1c values, participants receiving triple therapy experienced a 7.5-fold lower rate of hypoglycaemia compared with participants receiving conventional therapy. Participants receiving triple therapy experienced a mean weight loss of 1.2 kg versus a mean weight gain of 4.1 kg (p < 0.01) in those receiving conventional therapy. CONCLUSION: The results of this exploratory study show that combination therapy with metformin/pioglitazone/exenatide in patients with newly diagnosed T2DM is more effective and results in fewer hypoglycaemic events than sequential add-on therapy with metformin, sulfonylurea and then basal insulin.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Peptídeos/uso terapêutico , Tiazolidinedionas/uso terapêutico , Peçonhas/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Quimioterapia Combinada/métodos , Exenatida , Feminino , Hemoglobina A Glicada/efeitos dos fármacos , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemia/etiologia , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Pioglitazona , Ganho de Peso/efeitos dos fármacos , Perda de Peso/efeitos dos fármacos
7.
Reprod Domest Anim ; 49(5): 734-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25041787

RESUMO

In this study, the expressions of VEGF in dog follicles were detected by immunohistochemistry and the effects of VEGF treatment on the primordial to primary follicle transition and on subsequent follicle progression were examined using a dog ovary organ culture system. The frozen-thawed canine ovarian follicles within slices of ovarian cortical tissue were cultured for 7 and 14 days in presence or absence of VEGF. After culture, the ovaries were fixed, sectioned, stained and counted for morphologic analysis. The results showed that VEGF was expressed in the theca cells of antral follicles and in the granulosa cells nearest the oocyte in preantral follicle but not in granulosa cells of primordial and primary follicles; however, the VEGF protein was expressed in CL. After in vitro culture, VEGF caused a decrease in the number of primordial follicles and concomitant increase in the number of primary follicles that showed growth initiation and reached the secondary and preantral stages of development after 7 and 14 days. Follicular viability was also improved in the presence of VEGF after 7 and 14 days in culture. In conclusion, treatment with VEGF was found to promote the activation of primordial follicle development that could provide an alternative approach to stimulate early follicle development in dogs.


Assuntos
Cães/fisiologia , Regulação da Expressão Gênica/fisiologia , Técnicas de Cultura de Órgãos/veterinária , Folículo Ovariano/crescimento & desenvolvimento , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Criopreservação/veterinária , Feminino , Imuno-Histoquímica , Folículo Ovariano/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética
8.
Clin Ter ; 165(2): e145-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24770823

RESUMO

OBJECTIVE: To assess the relation between fetal and maternal blood type (ABO, Rh) incompatibility and development of gestational diabetes mellitus (GDM). MATERIALS AND METHODS: A total of 500 pregnant women underwent diagnostic test for GDM by a 100-g oral glucose tolerance test (OGTT) after an 8 to 12-h overnight fast participated in this study. OGTT was performed between the 24-28 weeks of gestation, but participants who were at high risk for GDM were tested after the first prenatal visit. In the postpartum period, maternal and infant blood types were determined. Presence of GDM was evaluated in terms of matched and unmatched fetal and maternal ABO and Rh blood types separately. RESULTS: GDM was detected in 235 participants. Unmatched ABO blood types between the mother-infant pairs were present in 44.7% (n=105) of GDM (+) and 35.8 % (n=95) of GDM (-) patients. Incompatible feto-maternal ABO blood type was positively correlated with development of GDM which was marginally significant. (p=0.045; R=1.2;95% CL; 1.004-1.48). However, Rh feto-maternal blood type incompatibility was not related with development of GDM. CONCLUSIONS: Feto-maternal ABO blood type incompatibility may be a weak risk factor for the development of GDM.


Assuntos
Sistema ABO de Grupos Sanguíneos , Diabetes Gestacional/etiologia , Isoimunização Rh/complicações , Adulto , Feminino , Humanos , Gravidez , Fatores de Risco
9.
J Intern Med ; 276(4): 352-63, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24690096

RESUMO

Maintaining normoglycaemia not only reduces the risk of diabetic microvascular complications but also corrects the metabolic abnormalities that contribute to the development and progression of hyperglycaemia, that is insulin resistance and beta-cell dysfunction. Progressive beta-cell failure, in addition to side effects associated with many current antidiabetic agents, for example hypoglycaemia and weight gain, presents major obstacles to the achievement of the recommended goal of glycaemic control in patients with type 2 diabetes mellitus (T2DM). Thus, novel effective therapies are needed for optimal glucose control in subjects with T2DM. Most recently, specific inhibitors of the renal sodium-glucose cotransporter 2 (SGLT2) have been developed to produce glucosuria and lower the plasma glucose concentration. Because of the iR unique mechanism of action, which is independent of insulin secretion and insulin action, these agents are effective in lowering the plasma glucose concentration in all stages of the disease and can be combined with all other antidiabetic agents. In this review, we will summarize the available data concerning the mechanism of action, efficacy and safety of this novel class of antidiabetic agents.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose , Animais , Glicemia/metabolismo , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/sangue , Glucose/metabolismo , Hemoglobina A Glicada/metabolismo , Glicosúria , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo
10.
J Endocrinol Invest ; 36(3): 168-73, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22522662

RESUMO

AIM: To compare insulin and GLP-1 analogues therapy on glycemic control in poorly controlled Type 2 diabetes (T2DM) subjects failing on oral therapy. METHODS: The electronic database PubMed was systematically searched for randomized controlled trial (RCT) with duration >16 weeks comparing the addition of insulin therapy vs glucagon-like peptide (GLP-1) analogues in poorly controlled T2DM subjects on oral therapy. RESULTS: We identified 7 RCT with 2199 patients of whom 1119 were assigned to insulin therapy and 1080 received a GLP-1 analogue. Both insulin and GLP-1 analogues were effective in lowering glycated hemoglobin (HbA(1c)) with no statistically significant difference between the mean decreases in HbA(1c). However, insulin was more effective than GLP-1 analogues in lowering the fasting plasma glucose concentration, while GLP-1 agonists were more effective in lowering the postprandial glucose concentration. Insulin therapy was associated with weight gain while GLP-1 analogues consistently caused weight loss and the difference between the mean change in body weight between the two therapies was highly statistically significant. Despite a similar decrease in HbA(1c), the risk of hypoglycemia was 35% lower (p=0.001) with GLP-1 therapy compared to insulin. Compared to insulin, GLP-1 analogues caused a significant decrease in systolic blood pressure and were associated with greater rate of gastrointestinal adverse events. CONCLUSION/INTERPRETATION: In poorly controlled T2DM subjects on oral therapy, GLP-1 analogues and insulin are equally effective in lowering the HbA(1c). However, GLP-1 analogues have additional non-glycemic benefits and lower risk of hypoglycemia. Thus, GLP-1 analogues should be considered as a treatment option in this group of diabetic individuals.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Peptídeo 1 Semelhante ao Glucagon/administração & dosagem , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Administração Oral , Glicemia/análise , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Gastroenteropatias/induzido quimicamente , Gastroenteropatias/epidemiologia , Peptídeo 1 Semelhante ao Glucagon/efeitos adversos , Humanos , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Lipídeos/sangue , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Falha de Tratamento
11.
Diabetologia ; 54(12): 3132-42, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21901280

RESUMO

AIMS/HYPOTHESIS: The mechanisms by which transcription factor 7-like 2 (TCF7L2) regulates the pathways that are important in the pathogenesis of type 2 diabetes are unknown. We therefore examined the role of TCF7L2 in hepatic glucose production (HGP) in vitro and characterised the whole-genome chromatin occupancy of TCF7L2 in hepatocytes. METHODS: We investigated the effect of TCF7L2 silencing and overexpression on HGP from gluconeogenic precursors and used chromatin-immunoprecipitation (ChIP) combined with massively parallel DNA sequencing (ChIP-Seq) to investigate the DNA binding patterns of TCF7L2 across the whole genome. RESULTS: Silencing of TCF7L2 induced a marked increase in basal HGP, which was accompanied by significant increases in the expression of the gluconeogenic genes Fbp1, Pck1 and G6pc. Overexpression of Tcf7l2 reversed this phenotype and significantly reduced HGP. TCF7L2 silencing did not affect the half-maximal inhibitory concentration of insulin or metformin, but HGP remained elevated in TCF7L2-silenced cells due to the increased baseline HGP. Using ChIP-Seq, we detected 2,119 binding events across the genome. Pathway analysis demonstrated that diabetes genes were significantly over-represented in the dataset. Our results indicate that TCF7L2 binds directly to multiple genes that are important in regulation of glucose metabolism in the liver, including Pck1, Fbp1, Irs1, Irs2, Akt2, Adipor1, Pdk4 and Cpt1a. CONCLUSIONS/INTERPRETATION: TCF7L2 is an important regulator of HGP in vitro and binds directly to genes that are important in pathways of glucose metabolism in the liver. These data highlight the possibility that TCF7L2 may affect fasting and postprandial hyperglycaemia in carriers of at-risk TCF7L2 genetic polymorphisms.


Assuntos
Cromatina/metabolismo , Glucose/metabolismo , Hepatócitos/metabolismo , Proteína 2 Semelhante ao Fator 7 de Transcrição/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Imunoprecipitação da Cromatina , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Regulação da Expressão Gênica , Inativação Gênica , Gluconeogênese , Glucose-6-Fosfatase/biossíntese , Glucose-6-Fosfatase/genética , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Metformina/farmacologia , Dados de Sequência Molecular , Ratos , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética
12.
Diabetologia ; 52(4): 574-82, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19183935

RESUMO

AIMS/HYPOTHESIS: The aim of this study was to measure mitochondrial reactive oxygen species (ROS) production directly from skeletal muscle biopsies obtained from obese insulin-resistant non-diabetic and type 2 diabetic participants. METHODS: Ten lean healthy, ten obese non-diabetic and ten type 2 diabetic participants received a euglycaemic-hyperinsulinaemic clamp to measure whole body insulin sensitivity. Mitochondria were isolated from skeletal muscle biopsies, and mitochondrial ATP synthesis and hydrogen peroxide production were measured ex vivo under conditions that maximally stimulate ATP synthesis and ROS production using chemiluminescent and fluorescent techniques, respectively. RESULTS: Compared with lean controls, both obese non-diabetic and type 2 diabetic participants were resistant to insulin, and had a reduced rate of mitochondrial ATP production. Obese insulin-resistant participants had a decreased rate of mitochondrial ROS production, while ROS production rate in participants with type 2 diabetes was similar to that in lean healthy participants. In non-diabetic participants, the rate of ROS production was strongly correlated with the rate of ATP synthesis and the glucose disposal rate measured with the euglycaemic-hyperinsulinaemic clamp. The ROS/ATP ratio in obese insulin-resistant participants was similar to that in lean insulin-sensitive participants, while the ratio was significantly elevated in type 2 diabetes participants. CONCLUSIONS/INTERPRETATION: Since, in absolute terms, the maximal capacity for mitochondrial ROS production was not increased in either obese insulin-resistant participants or in type 2 diabetic participants, these results do not favour a role for increased mitochondrial ROS production in the pathogenesis of insulin resistance in human skeletal muscle. However, care should be taken in extrapolating these ex vivo observations to the in vivo situation.


Assuntos
Trifosfato de Adenosina/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Mitocôndrias Musculares/metabolismo , Obesidade/fisiopatologia , Espécies Reativas de Oxigênio/metabolismo , Adulto , Biópsia , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/patologia , Feminino , Hemoglobina A Glicada/metabolismo , Humanos , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Mitocôndrias Musculares/patologia , Obesidade/patologia , Valores de Referência
13.
Diabet Med ; 25(11): 1289-94, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19046218

RESUMO

OBJECTIVE: To examine the association between insulin resistance in skeletal muscle and liver in non-diabetic subjects. RESEARCH DESIGN AND METHODS: A total of 182 Mexican American subjects without Type 2 diabetes underwent an oral glucose tolerance test and euglycaemic-hyperinsulinaemic clamp performed with (3)[H]glucose. Insulin sensitivity in skeletal muscle was measured as the insulin-stimulated rate of total glucose disposal during the insulin clamp divided by steady-state plasma insulin concentration (TGD/SSPI). Hepatic insulin resistance was measured as the product of basal hepatic glucose production and fasting plasma insulin concentration (HGP x FPI). RESULTS: Hepatic insulin resistance was strongly correlated (r = 0.68, P < 0.0001) with skeletal muscle insulin resistance. Thirty-eight per cent of subjects had increased insulin resistance in both liver and skeletal muscle, while 39% were insulin sensitive in both skeletal muscle and liver. Twenty-three per cent of subjects were discordant for muscle and hepatic insulin resistance (P < 0.0001). Subjects with increased skeletal muscle insulin resistance had a higher 2-h plasma glucose concentration, greater incremental area under the plasma glucose concentration curve, lower fasting plasma insulin concentration and lower rate of basal hepatic glucose production compared with subjects with increased insulin resistance in liver. CONCLUSION: In non-diabetic subjects, insulin resistance in skeletal muscle is an important determinant of the fasting and 2-h plasma glucose concentrations and strongly correlates with hepatic insulin resistance.


Assuntos
Glicemia/metabolismo , Resistência à Insulina/fisiologia , Insulina/metabolismo , Fígado/metabolismo , Músculo Esquelético/metabolismo , Adulto , Índice de Massa Corporal , Jejum/fisiologia , Feminino , Técnica Clamp de Glucose/métodos , Teste de Tolerância a Glucose/métodos , Humanos , Masculino , Valor Preditivo dos Testes , Valores de Referência
15.
Mymensingh Med J ; 11(1): 42-3, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12148397

RESUMO

An eighteen years old boy hailing from Nandail, Mymensingh was complaining of small external genitalia, small testes, and gradual enlargement of breast, weight gain, absence of facial, axillary and public hair, absence of sense of smell. His height was 162 cm, weight 59 kg, BMI-22.52 kg/m2 with eunuchoid body habitus. His stretch penile length was 5 cm, testicular volume < 5 ml, stage B3 development of breast and absence of facial, axillary and public hair. He was found anosmic of standard odors. Patient was clinically and biochemically in euthyroid state with low level of testosterone, LH and FSH and normal serum prolactin level. He was diagnosed as a case of hypogonadotropic hypogonadism due to Kallmann syndrome.


Assuntos
Hipogonadismo/etiologia , Síndrome de Kallmann/complicações , Adolescente , Humanos , Masculino , Fenótipo , Caracteres Sexuais
16.
Dermatology ; 201(2): 101-4, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11053910

RESUMO

For matting of hair, multifactorial mechanisms are responsible. Thereby physical conditions, chemical agents and behavioural factors play the main roles. It seems evident that hair matting is not a hair disease; consequently, cutting off the affected hair and avoiding all possible trigger factors are the therapy of choice.


Assuntos
Cabelo/patologia , Preparações para Cabelo , Humanos , Estresse Mecânico , Estresse Psicológico , Temperatura
17.
Harefuah ; 139(11-12): 414-6, 496, 2000 Dec.
Artigo em Hebraico | MEDLINE | ID: mdl-11341183

RESUMO

Atrophic gastritis is an autoimmune gastropathy in which there is destruction of gastric parietal cells. This results in intrinsic factor deficiency and disturbance in vitamin B12 absorption. Its clinical manifestationa are therefore the consequences of B12 deficiency and include anemia and neurological defect. In addition, lack of B12 results in metabolic changes, including disturbances of methionine metabolism and accumulation of homocysteine. In recent years, there has been increasing evidence suggesting that hyperhomocysteinemia is a risk factor for thrombo-embolic disease. We describe a 51-year-old man with atrophic gastritis, severe B12 deficiency and hyperhomocysteinemia. The initial clinical manifestation was pulmonary embolism, without either anemia or neurological signs. B12 deficiency should therefore be considered in patients being investigated for hypercoagulability.


Assuntos
Gastrite Atrófica/complicações , Embolia Pulmonar/complicações , Gastrite Atrófica/diagnóstico , Humanos , Hiper-Homocisteinemia/complicações , Masculino , Pessoa de Meia-Idade , Embolia Pulmonar/diagnóstico , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico
18.
J Physiol ; 499 ( Pt 1): 121-34, 1997 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9061644

RESUMO

1. We have studied macroscopic current fluctuations associated with the after-hyperpolarization current (IAHP) that follows a 200 ms voltage-clamp step to 0 mV in dentate granule (DG) neurones of the rat hippocampus. This maximally effective stimulus produced a peak IAHP of 205 +/- 20 pA. Background noise was minimized by using the whole-cell single-electrode voltage-clamp configuration. 2. Conventional current-variance analysis was performed on IAHP to obtain estimates of the unitary AHP channel current (i) and the maximal attainable AHP current (Imax). A second approach, utilizing changes in the power spectrum of IAHP 'noise' during the decay of IAHP, was employed to yield an independent estimate of Imax as well as an estimate of the mean open-state duration of AHP channels. 3. Changes in the power spectrum during IAHP decay revealed that the mean channel open time is fixed at 6.9 +/- 0.5 ms and that the decay is due to changes in channel closed-state duration. The same analysis gave a value for Imax of 320 +/- 20 pA (n = 7). 4. Current-variance analysis suggests that channels responsible for generation of IAHP have a unitary current of 0.29 +/- 0.08 pA at -45 mV in 5 mM extracellular potassium and an Imax of 400 +/- 180 (n = 7). Thus, both methods indicate that about 1200 channels are available to generate IAHP in DG neurones and that about 60% are open at the peak of a maximal IAHP. 5. Computer simulations of IAHP currents in a model neurone show that dendritic current sources will result in an underestimation of i while Imax is underestimated to a lesser extent. Estimates of Imax obtained from power-spectrum analysis are more accurate and less affected by neuronal electrotonic structure than estimates of Imax based on current-variance analysis.


Assuntos
Potenciais de Ação/fisiologia , Hipocampo/fisiologia , Neurônios/fisiologia , Animais , Masculino , Técnicas de Patch-Clamp , Ratos , Ratos Wistar
19.
J Neurophysiol ; 76(4): 2691-700, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8899638

RESUMO

1. Whole cell recordings from dentate granule neurons in the hippocampal slice preparation reveal that (1 S, 3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD), a selective agonist at metabotropic glutamate receptors (mGluRs), inhibits a calcium-activated potassium current (IAHP) responsible for the postspike after-hyperpolarization. Inclusion of 1 mM of the Ca2+ chelator ethylene glycol-bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid in the patch pipette reduced the inhibitory action of ACPD on IAHP while having no effect on a similar action of serotonin (5-HT). Thus the known action of ACPD of mobilizing intracellular Ca2+ may be involved in this inhibitor action of ACPD. 2. Inhibition of IAHP is not secondary to effects on Ca2+ currents, because 10 microM ACPD, which inhibits IAHP by 95 +/- 5% (mean +/- SE), reduced the Ca2+ current by only 8 +/- 4%. 3. Activation of mGluRs accelerates the irreversible inhibition of IAHP that develops when 88 microM GTP-gamma-S is included in the pipette filling solution, whereas inclusion of 1 mM GDP-beta-S attenuated the inhibitory action of ACPD. These results indicate that the response to mGluR activation is G protein mediated. 4. Group I mGluRs, which includes mGluR1 and mGluR5, are G-protein-coupled receptors that are known to stimulate phospholipase C (PLC)-mediated hydrolysis of phosphoinositides to produce 1,4,5-triphosphate (IP3), which in turn is known to mobilize the release of intracellular Ca2+. The weak but selective mGluR1 agonist (S)-3-hydroxyphenylglycine (100 microM) completely inhibited IAHP, and the mGluR1 antagonist (S)-4-carboxyphenylglycine (500 microM) reduced IAHP inhibition produced by 5 microM ACPD from 73 +/- 6% to 22 +/- 4%. These results indicate that the mGluR responsible for IAHP inhibition has a similar pharmacological profile to that of those coupled to IP3 production. 5. The effects of agents known to interfere with IP3 production and action also support IP3 involvement in ACPD action. Neomycin (1 mM in pipette solution), which should reduce IP3 production through inhibition of PLC, reduced the ability of 10 microM ACPD to inhibit IAHP from almost 100% to 57 +/- 8% (n = 8). Heparin, an IP3 receptor antagonist that reduces Ca2+ mobilization, attenuated the inhibitory action 10 microM ACPD from almost 100% to 39 +/- 5% (n = 5). Heparin by itself increased the amplitude and duration of IAHP, suggesting that resting levels of IP3 are sufficient to suppress of IAHP partially. 6. In addition to the pool of intracellular Ca2+ that is mobilized by IP3, there is a distinct pool that is responsible for Ca(2+)-triggered Ca2+ release and is blocked by ryanodine or dantrolene. These drugs caused a small reduction of both IAHP and the inhibitory action of ACPD. Possibly the Ca2+ signal mobilized by IP3 is partially amplified by Ca2+ released from the ryanodine-sensitive stores. 7. Activation of PLC can also lead to the production of diacylglycerol and activation of protein kinase C (PKC). However, the inhibitory action of ACPD on IAHP was not affected by staurosporine at a concentration (1 microM) that inhibits both protein kinase A (PKA) and PKC and blocks the action of 5-HT to inhibit IAHP. 8. Activation of PKA by the adenylate cyclase activator forskolin led to inhibition of IAHP. Although activation of mGluR1 agonists can also stimulate adenylate cyclase and activate PKA, inhibition of PKA and the effect of forskolin on IAHP with the Walsh peptide did not affect ACPD inhibition of IAHP. 9. All of our results support the hypothesis that mGluR-mediated inhibition of IAHP is initiated by the production of IP3 and the mobilization of intracellular Ca2+.


Assuntos
Cálcio/fisiologia , Giro Denteado/fisiologia , Inositol 1,4,5-Trifosfato/biossíntese , Neurônios/fisiologia , Canais de Potássio/fisiologia , Receptores de Glutamato Metabotrópico/fisiologia , Animais , Cálcio/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Cicloleucina/análogos & derivados , Cicloleucina/farmacologia , Giro Denteado/citologia , Proteínas de Ligação ao GTP/fisiologia , Heparina/farmacologia , Masculino , Neomicina/farmacologia , Proteína Quinase C/fisiologia , Ratos , Ratos Wistar , Receptores de Glutamato Metabotrópico/agonistas
20.
J Physiol ; 496 ( Pt 1): 139-44, 1996 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-8910202

RESUMO

1. Activation of metabotropic glutamate receptors (mGluRs) inhibits a transient Ca(2+)-activated K+ current (IAHP) responsible for the slow after-hyperpolarization that follows depolarizations of dentate granule neurones in rat hippocampal brain slices. Here we show for the first time that this physiological consequence of mGluR stimulation is selectively attenuated by blockers of protein tyrosine kinases (PTKs). 2. Several distinct types of PTK blockers, including genistein, tyrphostin-B42 and lavendustin-A, reduced the inhibition of IAHP by the selective mGluR agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD). Inhibition of IAHP by 5-HT was unaffected. The PTK blockers by themselves doubled the duration of IAHP suggesting that there exists a tonic inhibitory influence on IAHP that is reduced by PTK antagonists. 3. Inclusion of EGTA (1 mM) in the patch pipette also potentiated the IAHP and reduced the inhibitory action of ACPD on IAHP, consistent with the observation of others that chelation of intracellular Ca2+ prevents protein tyrosine phosphorylation induced by ACPD. 4. we propose that mGluR-initiated inositol 1,4,5-trisphosphate (InsP3) production mobilizes intracellular Ca2+ and leads to increased protein tyrosine phosphorylation which in turn leads to inhibition of IAHP.


Assuntos
Cálcio/fisiologia , Giro Denteado/metabolismo , Neurônios/metabolismo , Canais de Potássio/metabolismo , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptores de Glutamato Metabotrópico/agonistas , Adenilil Ciclases/metabolismo , Animais , Cicloleucina/análogos & derivados , Cicloleucina/farmacologia , Giro Denteado/citologia , Giro Denteado/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Genisteína , Técnicas In Vitro , Isoflavonas/farmacologia , Masculino , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Neurônios/efeitos dos fármacos , Neurotoxinas/farmacologia , Canais de Potássio/fisiologia , Ratos , Ratos Wistar , Estaurosporina/farmacologia
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