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1.
Int J Pediatr Otorhinolaryngol ; 76(6): 879-82, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22445314

RESUMO

OBJECTIVE: The treatment of nasopharyngeal stenosis is challenging because of a high incidence of recurrence after surgical correction. Therefore, many treatment modalities are being tried to cure this problem. The aim of this study is to assess the efficacy of palatal eversion as a new technique for treatment of nasopharyngeal stenosis after adenotonsillectomy. STUDY DESIGN: Case series. METHODS: This study was conducted on 12 patients with nasopharyngeal stenosis after adenotonsillectomy were subjected to treatment by palatal eversion by dividing the soft palate in the midline and removal of the fibrous tissue causing stenosis followed by evertion and fixation of the two palatal division on either side for six weeks to allow complete epithelialization of the stenotic area followed by another operation to reunion the soft palate in the midline. Post-operative follow up was done for one year by flexible nasopharyngoscopy, perceptual speech analysis and polysomnography. RESULTS: Flexible nasopharyngosopic examination of the 12 patients at the end of post-operative period revealed a freely mobile soft palate with no nasopharyngeal stenosis or palatal fistula. Velopharyngeal function and speech assessment by perceptual speech analysis was normal in all 12 cases. No obstructive episodes were recorded in polysomnograms. CONCLUSIONS: Palatal eversion is a promising technique in treatment of post-adenotonsillectomy nasopharyngeal stenosis and it is recommended to be used in a wider scale of patients and other indications as nasopharyngeal stenosis following uvulopalatoplasty and post nasopharyngeal radiotherapy. LEVEL OF EVIDENCE: 4 (case series).


Assuntos
Adenoidectomia/efeitos adversos , Doenças Nasofaríngeas/etiologia , Doenças Nasofaríngeas/cirurgia , Palato Mole/cirurgia , Tonsilectomia/efeitos adversos , Adenoidectomia/métodos , Anestesia Geral/métodos , Criança , Pré-Escolar , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Desbridamento/métodos , Feminino , Seguimentos , Humanos , Intubação Intratraqueal , Laringoscopia/métodos , Masculino , Doenças Nasofaríngeas/fisiopatologia , Polissonografia/métodos , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/cirurgia , Cuidados Pré-Operatórios/métodos , Medição de Risco , Estudos de Amostragem , Tonsilectomia/métodos , Resultado do Tratamento
2.
Microbiol Res ; 166(4): 268-81, 2011 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-20630727

RESUMO

Interaction between arbuscular mycorrhizal fungi as a bio-agent and Rhizoctonia root rot disease of common bean plant was investigated in this study under natural conditions in pot experiment. A mixture of Egyptian formulated AM (Multi-VAM) in suspension form (1 × 10(6) unit L(-1) in concentration) was used at dilution of 5 ml L(-1) water. The results demonstrated that colonization of bean plants with AM fungi significantly increased growth parameters, yield parameters and mineral nutrient concentrations and reduced the negative effects on these parameters as well as both disease severity and disease incidence. Different physical and biochemical mechanisms have been shown to play a role in enhancement of plant resistance against Rhizoctonia solani, namely, improved plant nutrition, improved plant growth, increase in cell wall thickening, cytoplasmic granulation, and accumulation of some antimicrobial substances (phenolic compounds and defense related enzymes).


Assuntos
Fabaceae/imunologia , Fabaceae/microbiologia , Micorrizas/fisiologia , Doenças das Plantas/microbiologia , Rhizoctonia/fisiologia , Fabaceae/crescimento & desenvolvimento , Doenças das Plantas/imunologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/imunologia , Brotos de Planta/microbiologia
3.
Braz. j. microbiol ; Braz. j. microbiol;39(3): 438-444, July-Sept. 2008. graf, tab
Artigo em Inglês | LILACS | ID: lil-494528

RESUMO

Bipolaris oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, three phenolic antioxidants were tested (salicylic acid, benzoic acid and hydroquinone). The antifungal activity of the tested substances were investigated against B. oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, benzoic acid or salicylic acid at 9 mM completely inhibited the growth of B. oryzae. Under field conditions, spraying of benzoic acid at 20 mM led to a significant reduction in disease severity (DS) and disease incidence (DI) on the plant leaves, in addition to a significant increase in the grain yield and its components. Some biochemical responses were also detected, where the application of the previous treatment led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids) in rice leaves and in the total carbohydrate and protein contents of the yielded grains.


Bipolaris oryzae é o agente causador da doença mancha-parda do arroz e é responsável por significativas perdas econômicas. Três antioxidantes fenólicos (ácido salicílico, ácido benzóico e hidroquinona) foram avaliados para o controle dessa doença do arroz. A atividade antifúngica destes compostos foi avaliada in vitro contra B. oryzae em diferentes concentrações e a eficiência de sua aplicação exógena no controle da mancha-parda foi avaliada em condições de campo. Nos ensaios in vitro, os ácidos benzóico e salicílico a 9 mM inibiram completamente a multiplicação de B. oryzae. Em condições de campo, a aspersão de ácido benzóico a 20 mM causou uma redução significativa na gravidade e incidência da doença na folhas da planta, além de aumentar significativamente o rendimento dos grãos e seus componentes. Algumas respostas bioquímicas foram também observadas, verificando-se que a aplicação do tratamento prévio causou um aumento significativo nos pigmentos fotossintéticos totais (clorofila a e b e carotenóides) nas folhas e no conteúdo de carboidratos e proteínas nos grãos.


Assuntos
Ácido Salicílico/análise , Antifúngicos , Antioxidantes/isolamento & purificação , Hidroquinonas/análise , Técnicas In Vitro , Oryza , Pigmentos Biológicos , Folhas de Planta , Métodos , Métodos
4.
Braz J Microbiol ; 39(3): 438-44, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24031243

RESUMO

Bipolaris oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, three phenolic antioxidants were tested (salicylic acid, benzoic acid and hydroquinone). The antifungal activity of the tested substances were investigated against B. oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, benzoic acid or salicylic acid at 9 mM completely inhibited the growth of B. oryzae. Under field conditions, spraying of benzoic acid at 20 mM led to a significant reduction in disease severity (DS) and disease incidence (DI) on the plant leaves, in addition to a significant increase in the grain yield and its components. Some biochemical responses were also detected, where the application of the previous treatment led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids) in rice leaves and in the total carbohydrate and protein contents of the yielded grains.

5.
Transplant Proc ; 35(3 Suppl): 143S-150S, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12742487

RESUMO

BACKGROUND: Sirolimus (Rapammune, rapamycin, RAPA) is a strong immunosuppressive agent that reduces kidney transplant rejection. Hyperlipidemia is a significant side effect of sirolimus treatment and often leads to vascular disease. We have studied the repeatability, reversibility, and dose dependence of the plasma lipid and apoprotein changing effects of sirolimus and attempted to determine the mechanism by which sirolimus induces hypertriglyceridemia in some kidney transplant recipients. METHODS: Six patients with renal allografts maintained on cyclosporine A and prednisone were selected on the basis of their previous hyperlipidemic response to short-term (14 days) sirolimus administration. For longer-term treatment, each patient was started on 10 mg/d sirolimus and continued as tolerated for 42 days to reinduce hyperlipidemia. Timed blood samples were analyzed for lipid, apoprotein, and sirolimus levels. RESULTS: During sirolimus administration, mean total plasma cholesterol increased from 214 to 322 mg/dL (+50%); low density lipoprotein-cholesterol levels changed in a similar pattern. Mean triglyceride level rose from 227 to 432 mg/dL (+95%). ApoB-100 concentration rose from 124 to 160 mg/dL (+28%). ApoC-III level increased from 28.9 to 55.5 mg/dL (+92%). These lipid and apoprotein changes were found to be repeatable, reversible, and dose dependent. [(13)C(4)]-palmitate metabolic studies in four patients with hypertriglyceridemia indicated that the free fatty acid pool was expanded by sirolimus treatment (mean = 42.3%). Incorporation of [(13)C(4)]-palmitate into triglycerides of very low density lipoprotien, intermediate density lipoprotein, low density lipoproteins was decreased 38.3%, 42.1%, and 38.4%, respectively, by sirolimus treatment of these patients. CONCLUSIONS: These results suggest that sirolimus alters the insulin signaling pathway so as to increase adipose tissue lipase activity, decrease lipoprotein lipase activity, or both, resulting in increased hepatic synthesis of triglyceride, increased secretion of VLDL, and increased hypertriglyceridemia.


Assuntos
Hiperlipidemias/epidemiologia , Imunossupressores/uso terapêutico , Transplante de Rim/fisiologia , Lipídeos/sangue , Lipoproteínas/sangue , Sirolimo/uso terapêutico , Adulto , Cadáver , Colesterol/sangue , Ciclosporina/uso terapêutico , Feminino , Humanos , Hiperlipidemias/induzido quimicamente , Imunossupressores/efeitos adversos , Transplante de Rim/imunologia , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Sirolimo/efeitos adversos , Doadores de Tecidos , Transplante Homólogo , Triglicerídeos/sangue
6.
Acta Microbiol Immunol Hung ; 49(4): 445-54, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12512254

RESUMO

The optimum temperature for biomass yield and uricase production by uricolytic fungi, Aspergillus terreus, A. flavus and Trichoderma sp. was at 30 degrees C. The time required for maximum production of uricase and biomass yield was 4 days for two Aspergillus species and 6 days for Trichoderma sp. The optimum pH was at 6.4 for A. terreus and pH 6.6 for A. flavus and Trichoderma sp. The maximum fungal biomass yield was achieved in medium supplemented with 4% poultry waste. The best carbon sources for the production of uricase and mycelia yield were glycerol, sucrose and maltose by A. terreus, A. flavus and Trichoderma sp., respectively. Uric acid was found to be the best nitrogen source for production and activity of uricase by the three tested fungi. The addition of some vitamins to the culture media increased the maximum biomass yield of all the isolates, although no significantly increased uricase production was found.


Assuntos
Aspergillus/enzimologia , Aves Domésticas , Trichoderma/enzimologia , Urato Oxidase/análise , Urato Oxidase/biossíntese , Animais , Aspergillus/metabolismo , Biomassa , Biotransformação , Carbono/química , Carbono/metabolismo , Nitrogênio/metabolismo , Eliminação de Resíduos , Temperatura , Trichoderma/metabolismo , Vitaminas/química , Vitaminas/metabolismo , Resíduos/análise
7.
Microbiol Res ; 156(4): 359-67, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11770854

RESUMO

Histochemical staining of alkaline phosphatase (ALP) and succinate dehydrogenase (SDH) activities in four arbuscular mycorrhizal fungi (Glomus intraradices, G. fasciculatum, G. monosporum and G. mosseae) and their relation to growth and metabolic activities of soybean plants were investigated in a greenhouse experiment. In general, mycorrhizal inoculation significantly increased the growth responses, phosphorus and nitrogen contents, acid and alkaline phosphatases as well as total soluble protein of soybean compared to non-mycorrhizal plants. Stimulation was related to the viability of each mycorrhizal fungus. The localization of succinate dehydrogenase (as a vital stain of metabolically active fungus) and alkaline phosphatase activity (as a potential marker of efficiency of the symbiosis) in the arbuscular mycorrhizal fungi were variable. The activity appeared in young arbuscles and intercellular hyphae, whereas the collapsed arbuscules were inactive. The histochemical staining results demonstrated that the activity of alkaline phosphatase fungi was lower than succinate dehydrogenase. The use of nitroblue tetrazolium chloride as a vital stain for SDH activity showed that all mycorrhizal infection revealed by trypan blue staining was not physiologically active. Thus, the possible utilization of these enzymes to assess the activity of mycorrhizal fungi and its relation with effectively for plant growth and mineral contents is discussed.


Assuntos
Fungos/crescimento & desenvolvimento , Glycine max/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Fosfatase Alcalina/metabolismo , Biomassa , Compostos de Diazônio , Histocitoquímica/métodos , Nitroazul de Tetrazólio , Nitrogênio/análise , Fósforo/análise , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Brotos de Planta/microbiologia , Glycine max/metabolismo , Glycine max/microbiologia , Coloração e Rotulagem/métodos , Succinato Desidrogenase/metabolismo , Simbiose , Azul Tripano
8.
Adv Exp Med Biol ; 501: 79-85, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11787734

RESUMO

Correct temporal and spatial regulation of apoptosis is critical for normal mammary gland development and lactation. Previous work with a strain of transgenic mice that overexpress des(1-3)hIGF-I during pregnancy and lactation suggested that this growth factor inhibits apoptosis. The hypothesis tested within these studies is that overexpression of des(1-3)hIGF-I within the mammary gland inhibits apoptosis and the expression of apoptosis-associated genes that are known to be activated by the transcription factor AP-1. This inhibition of apoptosis was further posited to predispose the tissue to carcinogenesis. TUNEL analysis of mammary tissue from transgenic mice that overexpress des(1-3)hIGF-I under control of the rat whey acidic protein promoter showed only 25% (P < 0.05) of the number of apoptotic cells found in nontransgenic mice at the same stage of lactation. Northern analysis of RNA from these animals showed a 75% (P = 0.08) reduction in c-Jun mRNA abundance. Histological analysis of mammary tissue from nonlactating multiparous WAP-DES mice ranging in age from 13 to 25 months showed a variety of hyperplastic lesions. These lesions aberrantly expressed the transgene. At 23 months of age 50% of the transgenic mice within this study developed adenocarcinomas. These results support the conclusion that inhibition of apoptosis within the mammary gland by IGF-I involves decreased activity of AP-1 and predisposes the tissue to tumors.


Assuntos
Apoptose , Fator de Crescimento Insulin-Like I/fisiologia , Animais , Sobrevivência Celular , Feminino , Expressão Gênica , Humanos , Fator de Crescimento Insulin-Like I/genética , Lactação , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/crescimento & desenvolvimento , Neoplasias Mamárias Animais , Camundongos , Camundongos Transgênicos , Gravidez
9.
Microbiol Res ; 155(3): 243-8, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11061194

RESUMO

The effect of benomyl as a fungicide on the growth rate and ultrastructure of two isolates (P1319 and P623) of Phytophthora infestans is compared. Benomyl caused a concentration-dependent inhibition of the mycelial growth of both isolates. The isolate P1319 was found to be more sensitive to benomyl than the isolate P623. Ultarstructural studies confirmed these observations. The hyphae of isolate P1319 subjected to 100 and 500 ppm benomyl showed more severe changes in the cytoplasm than those of isolate P623. An increase in lipid bodies and vacuoles in the hyphal cytoplasm was the characteristic phenomenon after treatment with benomyl, particularly at a concentration of 500 ppm.


Assuntos
Benomilo/farmacologia , Fungicidas Industriais/farmacologia , Phytophthora/efeitos dos fármacos , Egito , Phytophthora/isolamento & purificação , Phytophthora/ultraestrutura , Doenças das Plantas , Solanum tuberosum/microbiologia
10.
J Gastrointest Surg ; 4(1): 109-14, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10631371

RESUMO

The murine double minutes 2 (MDM2) oncoprotein inhibits p53-mediated tumor suppression. MDM2 has been shown to be overexpressed in sarcomas and more recently was implicated in the pathogenesis of carcinomas. The purpose of this study was to determine the expression pattern of MDM2 in adenomas and colorectal adenocarcinomas and decide whether there is a correlation between MDM2 and p53 protein status. Paraffin-embedded tissues from 52 colorectal cancer (CRC) specimens and their adjacent normal tissue (N-CRC) were studied. In addition, 56 sporadic adenomas were investigated for the immunohistochemical expression of MDM2 and p53 proteins. Immunoreactivity of p53 indicating p53 gene mutation (p53+) was significantly higher in CRC (44%) compared to adenomas (23.2%) (P <0.01). None of the N-CRC specimens expressed the immunoreactive p53 protein. MDM2 overexpression (MDM2+) was similar in adenomas (30.3%) and CRC (25%), but only 2 (3.8%) of 52 N-CRC specimens showed overexpression of MDM2. In most cases MDM2 expression was associated with negative p53 expression (wild-type p53) in both adenomas (r = 0.59, P <0.001) and CRC (r = 0.69, P <0. 0001). No correlation was found between MDM2, p53 expression, and either the histologic grade, nodal stage or morphology of the tumors. There is greater p53 mutation in CRC compared to adenomas and N-CRC. The data indicate that MDM2 is overexpressed in CRC and is significantly associated with wild-type p53 compared to N-CRC specimens from the same patient. The MDM2 expression pattern is similar in adenomas and CRC, which may suggest that MDM2 overexpression is an early event in the progression of CRC.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias Colorretais/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares , Proteínas Proto-Oncogênicas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Adenoma/metabolismo , Animais , Colo/metabolismo , Humanos , Imuno-Histoquímica , Camundongos , Proteínas Proto-Oncogênicas c-mdm2
11.
Lipids ; 33(1): 23-31, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9470170

RESUMO

Studies investigated the effects of dietary fatty acid composition and saturation on the regulation of very low density lipoprotein (VLDL) apo B flux, clearance, and conversion to low density lipoprotein (LDL) in guinea pigs fed semipurified diets containing 15% (w/w) corn oil (CO), lard (LA), or palm kernel oil (PK). Plasma cholesterol levels were highest with dietary PK (3.1 +/- 1.0 mmol/L) followed by LA (2.4 +/- 0.4 mmol/L) and CO (1.6 +/- 0.4 mmol/L) intake. VLDL particles were larger (P < 0.05) in the LA (78 +/- 7 nm) and PK (69 +/- 10 nm) groups compared to animals fed CO (49 +/- 5 nm). VLDL-apo B fractional catabolic rates (FCR) were highest in guinea pigs fed the LA diet (P < 0.05) and VLDL apo B flux, estimated from VLDL 125I-apo B turnover kinetics, were higher in LA compared to PK or CO fed guinea pigs. In the case of PK consumption, the kinetic estimates of VLDL apo B flux significantly underestimated rates compared to direct VLDL apo B secretion measurements and LDL turnover analyses. These data demonstrate that differences in the composition and amount of saturated fatty acids have differential effects on VLDL apo B flux, catabolism, and conversion to LDL which, together with changes in LDL receptor-mediated catabolism, determine plasma LDL cholesterol levels in guinea pigs. The data also indicate that kinetic analysis of VLDL metabolism in PK fed animals is inaccurate possibly due to the presence of a small, nonequilibrating pool of newly synthesized VLDL which is rapidly converted to LDL.


Assuntos
Apolipoproteínas B/sangue , Gorduras na Dieta/administração & dosagem , Lipoproteínas VLDL/sangue , Animais , Apolipoproteínas B/química , Colesterol/sangue , Óleo de Milho/administração & dosagem , Gorduras na Dieta/farmacologia , Cobaias , Cinética , Lipoproteínas LDL/sangue , Lipoproteínas VLDL/química , Masculino , Óleo de Palmeira , Tamanho da Partícula , Óleos de Plantas/administração & dosagem
12.
Am J Clin Nutr ; 65(3): 814-22, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9062534

RESUMO

Dietary soluble-fiber sources such as pectin, guar gum, or psyllium decrease plasma concentrations of low-density-lipoprotein (LDL) cholesterol in guinea pigs by distinct mechanisms, including increases in LDL apolipoprotein (apo) B turnover and/or decreases in LDL apo B flux (J Lipid Res 1995; 36:2394-404). The present studies were undertaken to test whether changes in the rates of very-low-density lipoprotein (VLDL) apo B secretion, VLDL conversion to LDL, and hepatic uptake of VLDL were related to the cholesterol-lowering actions of these soluble fibers. Guinea pigs were fed (by wt) 12.5% pectin, 12.5% guar gum, 7.5% psyllium, or a control diet containing cellulose as the fiber source. Plasma cholesterol concentrations were significantly lower in guinea pigs fed pectin, guar gum, and psyllium by 42%, 46%, and 35%, respectively (P < 0.001), compared with those animals fed the control diet, whereas plasma triacylglycerol concentrations were lower only with guar gum intake. The secretion rate of triacylglycerol, determined after Triton was injected to block VLDL catabolism, was not different among dietary treatment groups whereas the secretion rate of apo B was lower with pectin, guar gum, and psyllium intakes (P < 0.01). In addition, pectin, guar gum, and psyllium significantly altered the composition of newly secreted VLDLs by increasing the number of triacylglycerol and phospholipid molecules in the secreted lipoprotein, indicating the presence of larger nascent VLDLs. In contrast, the average particle diameter of mature VLDLs as determined by electron microscopy was smaller in the dietary soluble-fiber groups in the following order: pectin < psyllium < guar gum. Plasma lecithin-cholesteryl acyltransferase and cholesteryl ester transfer protein activities were lower with intake of pectin, guar gum, and psyllium (P < 0.01). Injection of radiolabeled lipoproteins indicated that pectin, guar gum, and psyllium intakes resulted in more rapid VLDL and LDL apo B turnover and lower LDL apo B flux in guinea pigs fed guar gum and psyllium. These results suggest that the secretion rate of apo B, compositional changes in lipoproteins occurring in the intravascular compartment, and up-regulation of LDL receptors-associated with faster LDL apo B turnover rates-are secondary metabolic responses induced by dietary fiber that contribute to the lowering of plasma cholesterol concentrations.


Assuntos
Apolipoproteínas B/metabolismo , Fibras na Dieta/farmacologia , Lipoproteínas VLDL/metabolismo , Triglicerídeos/metabolismo , Animais , Apolipoproteínas B/sangue , Colesterol/sangue , Fibras na Dieta/administração & dosagem , Cobaias , Cinética , Lipoproteínas VLDL/sangue , Masculino , Fosfatidilcolina-Esterol O-Aciltransferase/sangue , Triglicerídeos/sangue
13.
J Nutr ; 126(10): 2494-504, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8857510

RESUMO

The effects of low/high fat diets and simple/complex carbohydrate intake on specific aspects of plasma VLDL and LDL metabolism were evaluated. Guinea pigs were fed for 4 wk two different fat/carbohydrate concentrations: 2.5/58 (g/100 g) or 25/29 (g/100 g) with either sucrose or cornstarch as the sole carbohydrate source. Intake of high fat diets resulted in higher plasma cholesterol (P < 0.001), whereas sucrose intake resulted in higher plasma triacyglycerol (TAG) concentrations (P < 0.03). Intake of starch increased apolipoprotein (apo) B secretion rates (P < 0.001), and nascent VLDL were smaller and contained less TAG/apo B than particles from the sucrose-fed group (P < 0.01). Guinea pigs fed the starch diets had higher plasma VLDL apo B flux and faster VLDL apo B clearance than those fed sucrose diets (P < 0.01). In addition, more rapid VLDL removal from plasma in guinea pigs fed complex carbohydrate/high fat diets was associated with less conversion of VLDL to LDL and lower plasma cholesterol concentrations compared with the high fat/sucrose group (P < 0.01). Low fat compared with high fat intake resulted in 60% more rapid plasma LDL apo B fractional catabolic rates (FCR). The LDL apo B fractional catabolic rate of all dietary groups was inversely correlated with plasma cholesterol concentrations (r = -0.83, P < 0.001). These results demonstrate that in guinea pigs, low fat diets decrease plasma LDL cholesterol concentrations by increasing LDL turnover rates, and complex carbohydrates reduce plasma TAG by affecting the composition of nascent VLDL particles and by increasing VLDL apo B catabolism.


Assuntos
Carboidratos da Dieta/farmacologia , Gorduras na Dieta/farmacologia , Lipoproteínas LDL/metabolismo , Lipoproteínas VLDL/metabolismo , Animais , Apolipoproteínas B/metabolismo , Apolipoproteínas B/farmacocinética , Gorduras na Dieta/administração & dosagem , Sacarose Alimentar/farmacologia , Cobaias , Lipoproteínas LDL/sangue , Lipoproteínas LDL/farmacocinética , Lipoproteínas VLDL/sangue , Lipoproteínas VLDL/farmacocinética , Masculino , Amido/farmacologia , Triglicerídeos/sangue
14.
J Lipid Res ; 36(6): 1188-98, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7665997

RESUMO

We investigated the effects of dietary fat saturation on very low density lipoprotein (VLDL) production in guinea pigs fed semipurified diets containing 15% (w/w) fat, either corn oil (CO, 58% linoleic acid), lard (LA, 42% oleic and 24% palmitic acids) or palm kernel oil (PK, 52% lauric and 18% myristic acids) for 4 weeks. Animals were given an intravenous injection of Triton WR 1339 to block VLDL catabolism and rates of VLDL triacylglycerol (TAG) and apolipoprotein (apo) B secretion were measured over time. Plasma TAG concentrations increased linearly for 8 h (r = 0.99) and VLDL-TAG secretion rates were significantly higher (P < 0.01) in guinea pigs fed LA (72.7 +/- 14.7 mg/kg-h, n = 12) compared to animals fed PK (55.4 +/- 13.4 mg/kg-h, n = 12) or CO (48.6 +/- 17.5 mg/kg-h, n = 15). VLDL apoB secretion rates were highest in PK-fed animals (3.1 +/- 1.8 mg/kg-h) compared to guinea pigs fed LA (1.5 +/- 0.8 mg/kg-h) or CO (1.1 +/- 0.6 mg/kg-h) diets (P < 0.005). Concurrent with analysis of VLDL secretion, turnover of 125I-labeled LDL was measured. Low density lipoprotein (LDL) fractional catabolic rates were not altered by Triton treatment and LDL apoB specific radioactivity (cpm/microgram) did not change over time indicating that: a) the Triton blockage of VLDL catabolism was complete, and b) there was no direct secretion of LDL by the liver. These data demonstrate that intake of lard increases the rate of VLDL-triacylglycerol secretion and that nascent VLDL particles from the lard and corn oil diet groups have the same relative triacylglycerol content, whereas palm kernel oil intake increases secretion of VLDL particles which have a reduced triacylglycerol content. These results demonstrate that dietary fat chain length and saturation have specific effects on VLDL secretion rates affecting both particle number and composition.


Assuntos
Gorduras na Dieta/administração & dosagem , Lipoproteínas VLDL/metabolismo , Animais , Apolipoproteínas B/metabolismo , Óleo de Milho , Cobaias , Ácidos Láuricos/administração & dosagem , Ácido Linoleico , Ácidos Linoleicos/administração & dosagem , Masculino , Ácido Mirístico , Ácidos Mirísticos/administração & dosagem , Ácido Oleico , Ácidos Oleicos/administração & dosagem , Polietilenoglicóis/farmacologia , Triglicerídeos/metabolismo , Aumento de Peso
15.
Biochim Biophys Acta ; 1256(1): 31-8, 1995 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-7742353

RESUMO

Guinea pigs were fed isocaloric diets containing 52% (w/w) carbohydrate, either sucrose or starch, to investigate effects of simple vs. complex carbohydrates on plasma VLDL and HDL metabolism. Plasma cholesterol concentrations were not different between dietary groups while plasma triacylglycerol (TAG) and VLDL cholesterol levels were significantly increased in animals fed the sucrose diet (P < 0.05). Hepatic VLDL TAG secretion rates measured following intravenous injection of Triton WR-1339 were not affected by carbohydrate type whereas the rate of apo B secretion was 1.9-fold higher in sucrose fed animals (P < 0.02). Nascent VLDL from the sucrose group contained less TAG per apo B suggesting that the higher plasma TAG in animals fed simple carbohydrates results from increased secretion of VLDL particles with lower TAG content. Sucrose fed animals exhibited higher concentrations of hepatic free cholesterol (P < 0.01) while hepatic TAG levels and acyl CoA:cholesterol acyltransferase (ACAT) activity were not different between groups. Plasma HDL cholesterol concentrations and composition, and plasma lecithin cholesterol acyltransferase (LCAT) activity were not affected by diet yet there was a positive correlation between HDL cholesteryl ester content and LCAT activities (r = 0.70, P < 0.05). Hepatic membranes from the sucrose group had a higher hepatic HDL binding protein number (Bmax) with no changes in the dissociation constant (Kd). These results suggest that at the same carbohydrate energy intake, simple sugars induce modest changes in HDL metabolism while VLDL metabolism is affected at multiple sites, as indicated by the higher concentrations of hepatic cholesterol, dissociation in the synthesis rates of VLDL components, and compositional changes in nascent and mature VLDL.


Assuntos
Carboidratos da Dieta/farmacologia , Lipoproteínas HDL/sangue , Lipoproteínas VLDL/sangue , Animais , Colesterol/sangue , Colesterol/metabolismo , Carboidratos da Dieta/administração & dosagem , Cobaias , Fígado/metabolismo , Masculino , Fosfatidilcolina-Esterol O-Aciltransferase/metabolismo , Amido/administração & dosagem , Amido/farmacologia , Esterol O-Aciltransferase/metabolismo , Sacarose/administração & dosagem , Sacarose/farmacologia , Triglicerídeos/sangue , Triglicerídeos/metabolismo
16.
Arterioscler Thromb ; 13(10): 1418-28, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8399078

RESUMO

The effects of dietary fat saturation on the metabolism of low-density lipoprotein (LDL) subfractions were measured in adult male guinea pigs fed semipurified diets containing 15% (wt/wt) corn oil (CO; 58% linoleic acid), lard (24% palmitic/14% stearic acid), or palm kernel oil (PK; 52% lauric/18% myristic acid). Animals fed the CO diet had lower plasma total cholesterol levels than guinea pigs fed the PK or lard diets (P < .01). Plasma LDL-1 (d = 1.019 to 1.05 g/mL) concentrations were 3.5- and 2.4-fold higher in animals fed the PK diet compared with the CO and lard groups, respectively, while LDL-2 (d = 1.05 to 1.09 g/mL) concentrations were not different among groups. For all dietary fat groups LDL-1 had a higher molecular weight and a larger diameter than LDL-2. LDL fractional catabolic rates (FCRs) varied, depending on both the diet and the LDL subfraction. Animals fed the polyunsaturated CO diet had a more rapid LDL FCR than animals from the other two groups (P < .01). Within the same diet group, LDL-2 exhibited a slower turnover rate than LDL-1 in animals fed the PK diet, while no differences in LDL subfraction FCR were found in the CO and lard groups. Animals fed the PK and lard diets did not exhibit significant modifications in the density distribution of LDL subfractions over a period of 33 hours. In contrast, animals fed the CO diet exhibited a shift of more buoyant to denser LDL particles, suggesting that differences in LDL intravascular processing are mediated by dietary fat saturation. In vitro LDL binding to hepatic membranes confirmed the in vivo data with an increased expression of apolipoprotein B/E receptors (Bmax) in animals fed the CO diet (P < .01). Hepatic apolipoprotein B/E receptors exhibited less affinity for LDL-2 in the PK group, a result consistent with the less rapid turnover of LDL-2 in PK-fed animals. The results suggest that dietary fatty acids varying in saturation and composition have distinctive atherogenic potentials. The lowest plasma LDL cholesterol concentrations mediated by CO intake could in part be explained by induced changes in the composition and processing of LDL subfractions, resulting in faster LDL turnover rates in addition to increased expression of hepatic apolipoprotein B/E receptors.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Gorduras na Dieta/farmacologia , Lipoproteínas LDL/sangue , Animais , Apolipoproteínas/metabolismo , Centrifugação com Gradiente de Concentração , Colesterol/sangue , Óleo de Milho/farmacologia , Cobaias , Lipoproteínas/sangue , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Masculino , Óleo de Palmeira , Óleos de Plantas/farmacologia , Receptores de Lipoproteínas/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-3619875

RESUMO

Three groups of cross-bred bucks (Baladi X standard breeds) were exposed to solar radiation for three hours per day during an 8-week experimental period in June and July and were compared with a control subgroup of the same age. Each subgroup (experimental and control) comprised 10 bucks, totalling 60 bucks. The effects were determined and assessed during the 28-week period following the experiment. The exposure to solar radiation at 5 or 12 weeks of age caused a delay in the onset of puberty. In all three groups, the concentration of sperms and the fructose content were decreased. There was a marked increase in the proportion of abnormal or dead sperms and in the methylene blue reduction time. The young animals were most affected by the exposure.


Assuntos
Coelhos/fisiologia , Sêmen/efeitos da radiação , Maturidade Sexual/efeitos da radiação , Espermatozoides/efeitos da radiação , Luz Solar , Fatores Etários , Análise de Variância , Animais , Frutose/efeitos da radiação , Masculino , Temperatura
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