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1.
Int J Surg ; 97: 106168, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34785344

RESUMO

BACKGROUND AND AIMS: Emergency General Surgery (EGS) conditions account for millions of deaths worldwide, yet it is practiced without benchmarking-based quality improvement programs. The aim of this observational, prospective, multicenter, nationwide study was to determine the best benchmark cutoff points in EGS, as a reference to guide improvement measures. METHODS: Over a 6-month period, 38 centers (5% of all public hospitals) attending EGS patients on a 24-h, 7-days a week basis, enrolled consecutive patients requiring an emergent/urgent surgical procedure. Patients were stratified into cohorts of low (i.e., expected morbidity risk <33%), middle and high risk using the novel m-LUCENTUM calculator. RESULTS: A total of 7258 patients were included; age (mean ± SD) was 51.1 ± 21.5 years, 43.2% were female. Benchmark cutoffs in the low-risk cohort (5639 patients, 77.7% of total) were: use of laparoscopy ≥40.9%, length of hospital stays ≤3 days, any complication within 30 days ≤ 17.7%, and 30-day mortality ≤1.1%. The variables with the greatest impact were septicemia on length of hospital stay (21 days; adjusted beta coefficient 16.8; 95% CI: 15.3 to 18.3; P < .001), and respiratory failure on mortality (risk-adjusted population attributable fraction 44.6%, 95% CI 29.6 to 59.6, P < .001). Use of laparoscopy (odds ratio 0.764, 95% CI 0.678 to 0.861; P < .001), and intraoperative blood loss (101-500 mL: odds ratio 2.699, 95% CI 2.152 to 3.380; P < .001; and 500-1000 mL: odds ratio 2.875, 95% CI 1.403 to 5.858; P = .013) were associated with increased morbidity. CONCLUSIONS: This study offers, for the first time, clinically-based benchmark values in EGS and identifies measures for improvement.


Assuntos
Cirurgia Geral , Procedimentos Cirúrgicos Operatórios , Adulto , Idoso , Benchmarking , Estudos de Coortes , Emergências , Feminino , Mortalidade Hospitalar , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Prospectivos , Melhoria de Qualidade , Estudos Retrospectivos
2.
Food Funct ; 9(4): 2426-2432, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29629722

RESUMO

Secoisolariciresinol (SECO) is present in flaxseeds as a glucoside, secoisolariciresinol diglucoside (SDG), which can be metabolized to enterodiol (ED) and enterolactone (EL) by the human intestinal microbiota. The aim of this study was to evaluate the effect of Lactobacillus casei and Lactobacillus acidophilus on the bioaccessibility of flaxseed lignans from a complete in vitro digestion of whole flaxseeds (WFs) and flaxseed flour (FF). Lignans are only detected in the large intestine. The bioaccessibility of SDG for FF digestion can be ordered as follows: control (without probiotics) > L. casei > L. acidophilus; and for WF digestion, only in the presence of L. casei SDG was detected. For SECO and EL, the presence of both probiotics had no effect on FF and WF digestion. However, in the digestion of WF both L. casei and L. acidophilus increased ED bioaccessibility in the first 12 h; but both probiotics had no significant effect on FF digestion.


Assuntos
Linho/microbiologia , Lacticaseibacillus casei/metabolismo , Lactobacillus acidophilus/metabolismo , Lignanas/metabolismo , Extratos Vegetais/metabolismo , Digestão , Linho/química , Linho/metabolismo , Humanos , Intestino Grosso/metabolismo , Intestino Grosso/microbiologia , Lignanas/química , Extratos Vegetais/química , Sementes/química , Sementes/metabolismo , Sementes/microbiologia
3.
Gene ; 240(2): 247-60, 1999 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-10580144

RESUMO

The uridine insertion/deletion RNA editing in trypanosome mitochondria is a unique posttranscriptional RNA maturation process that involves the addition or removal of uridine residues at precise sites usually within the coding regions of mitochondrial transcripts. This process creates initiation and termination codons, corrects frameshifts and even builds entire open-reading frames from nonsense sequences. The development of several in-vitro editing assays has provided much insight into the molecular mechanism of RNA editing, which appears to involve cleavage, U addition, exonuclease trimming and ligation, essentially as proposed in the original 'enzyme cascade' model (Blum, B., Bakalara, N., Simpson, L., 1990. A model for RNA editing in kinetoplastid mitochondria: 'Guide' RNA molecules transcribed from maxicircle DNA provide the edited information. Cell 60, 189-198). However, little is known about the biochemical properties of the proteins involved and the significance and role of this process. This article is a review of recent findings on uridine-insertion/deletion editing in trypanosome mitochondria, with an emphasis on the proteins isolated and characterized that may have a role in this process.


Assuntos
Mitocôndrias/genética , Edição de RNA , Trypanosomatina/genética , Uridina/genética , Animais , Sequência de Bases , Dados de Sequência Molecular , Mutagênese Insercional , Proteínas de Protozoários/metabolismo , RNA Guia de Cinetoplastídeos/genética , RNA Guia de Cinetoplastídeos/metabolismo , RNA de Protozoário/genética , RNA de Protozoário/metabolismo , Deleção de Sequência
4.
FEBS Lett ; 374(1): 100-4, 1995 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-7589492

RESUMO

Phosphofructokinase (PFK) from yeast has been replaced by the non-allosteric isozyme from the slime mold Dictyostelium discoideum. This has been achieved by overexpression of the latter in a PFK-deficient strain of Saccharomyces cerevisiae under the control of the PFK2 promoter. Transformants complemented the glucose-negative growth phenotype exhibiting generation times on glucose-containing media similar to those of an untransformed strain being wild-type for yeast PFK genes. The PFK produced reacted with an antibody against D. discoideum PFK. It exhibited the same subunit size, quaternary structure and kinetic parameters than those of the wild-type enzyme, and was also devoid of specific regulatory properties.


Assuntos
Dictyostelium/enzimologia , Fosfofrutoquinase-1/genética , Saccharomyces cerevisiae/enzimologia , Regulação Alostérica , Animais , Sequência de Bases , Primers do DNA , Dictyostelium/genética , Teste de Complementação Genética , Dados de Sequência Molecular , Mutação , Fosfofrutoquinase-1/análise , Plasmídeos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/genética , Transformação Genética
5.
Mol Biochem Parasitol ; 103(2): 251-9, 1999 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-10551367

RESUMO

The study of RNA editing and other molecular processes in the trypanosome mitochondrion would benefit greatly from the ability to insert and express exogenous DNA in the organelle. However, even with a method to introduce DNA, the current lack of knowledge about mitochondrial transcription would hinder efforts to obtain expression. To circumvent this problem, Leishmania tarentolae promastigotes and Trypanosoma brucei procyclic cells have been transfected with bacteriophage T7 RNA polymerase targeted to the mitochondrion. Mitochondria isolated from the transfectants contained active T7 RNA polymerase, as shown by a comigration in density gradients of mitochondrial marker enzymes and T7 polymerase activity. A DNA cassette under T7 control was introduced into isolated mitochondria from the transfectants by electroporation and the DNA was shown to be transcribed. This system should allow the transcription of foreign genes of choice within the mitochondrial matrix either in a transient assay using electroporation of DNA into isolated mitochondria, or in a stable assay using cells transfected with DNA by the biolistic gun method.


Assuntos
RNA Polimerases Dirigidas por DNA/genética , Marcação de Genes/métodos , Leishmania/genética , Mitocôndrias/genética , Trypanosoma brucei brucei/genética , Animais , Bacteriófago T7/enzimologia , RNA Polimerases Dirigidas por DNA/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/genética , Eletroporação , Mitocôndrias/enzimologia , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes de Fusão/metabolismo , Transcrição Gênica , Transfecção , Proteínas Virais/genética
6.
Mol Biochem Parasitol ; 100(1): 5-17, 1999 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10376989

RESUMO

Glutamate dehydrogenase (GDH) was shown previously to bind the 3' oligo[U] tail of the mitochondrial guide RNAs (gRNAs) of Leishmania tarentolae, apparently in the dinucleotide pocket (Bringaud F, Stripecke R, Frech GC, Freedland S, Turck C, Byrne EM, Simpson L. Mol. Cell. Biol. 1997; 17:3915-3923). Bloodstream Trypanosoma brucei cells in culture represent a good system to investigate the genetic effects of knocking out kinetoplastid nuclear genes to test a role in RNA editing, since editing of several mitochondrial genes occurs but is dispensable for viability (Corell RA, Myler P, Stuart K. Mol. Biochem. Parasitol. 1994; 64:65-74 and Stuart K. In: Benne R, editor. RNA editing--the alteration of protein coding sequences of RNA. New York: Ellis Horwood, 1993:25-52). Both GDH alleles of bloodstream T. brucei in culture were replaced by drug resistant markers without any effect on viability. The ratios of edited to unedited mRNAs for several cryptogenes were assayed by primer extension analysis. The steady state abundances of these edited RNAs were unaffected by the double knockout. This evidence suggests that GDH may not play a role in the editing reaction in bloodstream trypanosomes in culture, but this conclusion is tentative since there could be redundant genes for any biological function. We employed a double allelic replacement technique to generate a tetracycline inducible conditional expression of an ectopic copy of the deleted gene in bloodstream trypanosomes in culture. We used this strategy for genes encoding mitochondrial proteins which are not required during this stage of the life cycle, but as a general strategy it should be appropriate for generation of conditional null mutants for essential genes as well.


Assuntos
Deleção de Genes , Glutamato Desidrogenase/genética , Mitocôndrias/genética , Edição de RNA , RNA/genética , Trypanosoma brucei brucei/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Primers do DNA , DNA de Cinetoplasto/análise , DNA de Cinetoplasto/genética , Marcação de Genes , Genes de Protozoários , Vetores Genéticos , Glutamato Desidrogenase/metabolismo , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mitocondrial , RNA de Protozoário/genética , Transfecção , Trypanosoma brucei brucei/enzimologia , Trypanosoma brucei brucei/crescimento & desenvolvimento
7.
Arch Latinoam Nutr ; 50(2): 148-51, 2000 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-11048586

RESUMO

Cereal bars with peanut and walnut has shown to be snack foods of good organoleptic characteristics and high caloric value, due to their content of protein, lipids and carbohydrates. Cotyledons of mezquite seeds have a high protein content which biological quality improves with thermal processing like toasting, microwave or moist heat under pressure. The purposes of this research were to study the use of mezquite cotyledon (Prosopis chilensis (Mol) Stuntz) in cereal bars with two different levels of peanut or walnut; and to determine the effect of two thermal treatment applied on the cotyledon upon the bar characteristics. Twelve different kind of bars were developed through the combination of two levels of peanut or walnut (15% and 18%); the use of mezquite cotyledon (0% and 6%); and the application of two thermal processing to the cotyledon (microwave and toasting). Cereal bars were analysed for chemical, physical and sensory characteristics: moisture, water activity, proximate chemical composition, sensory quality and acceptability. Moisture content of bars with peanut ranged between 10.4% and 10.9%; and for those with walnut, between 10.5% and 12.3%. Protein content was higher in the bars with mezquite cotiledon, being higher those with peanut. Thermal processing did not have any effect on the chemical composition. Bars with mezquite cotyledon treated by microwave showed a higher acceptability.


Assuntos
Grão Comestível , Fabaceae , Tecnologia de Alimentos/métodos , Plantas Medicinais , Arachis , Grão Comestível/química , Micro-Ondas , Nozes
8.
Arch Latinoam Nutr ; 50(2): 152-6, 2000 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-11048587

RESUMO

The use of walnut or peanut in the elaboration of cereal bars represents a possible risk of undesirable changes during their storage due to their high content of unsaturated fatty acids in the oil; oxidizing of the fatty acids is one of the main causes of deterioration. Development of new snack products implies the use of packages that should protect the food against the damage caused by light and reduce the oxygen concentration of in their interior. The objective of this investigation was to evaluate the physical, chemical and sensory changes in the storage of cereal bars with peanut or walnut and mezquite cotyledon subjected to two thermal treatments, packed in cellophane or milky polypropilene. Four types of bars were elaborated with 6% of mezquite cotyledon, treated by microwaves or toasted, and with 18% of peanut or walnut. The bars were stored for 90 days at room temperature; and each 30 days it was measured moisture content, peroxides index, water activity, sensory quality and acceptability. The peroxides values (4.9-13.8 meq/kg of oil) indicates that the shelf life of the bars in all the studied treatments was 90 days. The packaging materials used allows to maintain in good conditions, for 3 months, the cereals bars of moisture (7.4-11.2%), water activity (0.50-0.65) and sensory acceptability.


Assuntos
Grão Comestível/química , Fabaceae , Manipulação de Alimentos/métodos , Conservação de Alimentos/métodos , Plantas Medicinais , Arachis , Celofane , Micro-Ondas , Nozes , Polipropilenos
9.
Arch Latinoam Nutr ; 37(2): 378-87, 1987 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-3455191

RESUMO

The feasibility of adding chick-pea flour substituting part of wheat flour in yeast-leavened bread-making in order to increase the protein value, was studied. A 70% extraction chick-pea flour of commercial granulometry (150 mu) was prepared. Wheat flours of 74% and 78% extraction were then blended with 5%, 10% and 15% of chick-pea flour. Every flour and blend were subsequently analyzed to determine protein, ash, fiber, fat and maltose content, as well as sedimentation, farinogram and bread-making. Addition of chick-pea flour increased protein, fiber, ash and fat content in the blends, not causing a severe effect on quality, even at the 15% level of substitution. Blends showed an increase in maltose content, W value and bread specific volume. Furthermore, breads prepared were of good quality even without the use of maturing agents.


Assuntos
Pão , Farinha/análise , Tecnologia de Alimentos , Alimentos Fortificados , Fabaceae , Plantas Medicinais , Triticum
10.
Arch Latinoam Nutr ; 51(2): 204-9, 2001 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-11678054

RESUMO

The objective of this study was develop a snack product based on fried beans. For this purpose, three bean varieties were used: Pinto 114, Suave 85 and Tórtola Inia. The beans were treated with two soaking solutions, EDTA disodium salt and a mixture of NaOH/water, to determine if they had some effect on the product's final quality. On the other hand, before the beans were fried, some grains were given thermal treatment (blanched), leaving the other ones without this process (raw); this also had an effect on the final quality of the fried beans. Physical, chemical and sensory characteristics of the final fried products were determined. For three beans varieties, the blanched products had higher water content, higher oil absorption, lower protein content and larger water activity. The soaking solutions had no effect on the quality of manufactured products. The sensory analysis determined that the best treatment for Pinto 114 and Tórtola Inia was NaOH/water-raw grain, and EDTA raw grain for Suave 85.


Assuntos
Fabaceae , Manipulação de Alimentos/métodos , Fabaceae/química , Manipulação de Alimentos/normas , Controle de Qualidade , Paladar
11.
Arch Latinoam Nutr ; 51(3): 303-8, 2001 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-11791484

RESUMO

To increase legume consumption and give a better protein quality in the snack products, mixtures of fried beans-corn were formulate in different proportions: 60:40 (A); 50:50 (B) and 40:60 (C). Fried corn used in mixtures was previously soaked in a predetermined solution (NaOH/EDTA) and then blanched. Three beans varieties (Pinto 114, Suave 85 and Tórtola Inia) were mixed with fried yellow dent corn in the above described proportions, obtaining nine mixtures whose physical, chemical and sensorial characteristics were evaluated. The mixtures were very homogeneous in all the analyzed characteristics. The protein content for the A mix was the greatest, nevertheless the sensorial analysis showed the last acceptance. The moisture content and water activity of these mixtures was low assuring a good microbiological stability under storage conditions. The protein contribution of each species in different prepared mixtures determined the selection of the best cereal/legume mix. From a nutritional stand point the best results were obtained when the 50% of protein was supplied by bans and the 50% by corn. From the mixtures tried in this study, mix C with bean Pinto 114 one closed to the recommended conditions. Nevertheless, for each cereal/legume mix, the best proportion was C, due to its better acceptability, even though it had less nutritional value.


Assuntos
Grão Comestível , Fabaceae , Temperatura Alta , Zea mays/química , Proteínas Alimentares/análise , Grão Comestível/química , Fabaceae/química , Comportamento Alimentar , Manipulação de Alimentos/métodos , Umidade , Lipídeos/análise , Valor Nutritivo , Glycine max , Água/metabolismo
12.
Arch Latinoam Nutr ; 44(1): 36-40, 1994 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-7717805

RESUMO

Three different cereal bars, CM3A-CM3B and CM3C were prepared following the flow sheat of Escobar et al: different amount of oat, wheat germ, and puffed amaranthus were used: to stick them together, natural sweeteners and fats were added. Proximate analysis, were run on raw materials and snack bars. They were evaluated organoleptically to know their quality and acceptability. Bars were kept in accelerated storage at 37 degrees C during 15 days to know their stability. Every 5 days were measured the water activity (Aw), moisture, and peroxides development; also appearance of organoleptic randicity. Acceptability of bar CM3B was 91.67% with 0.0% of rejection; CM3A and CM3C got the same acceptability (66.67%) and 8.33% of rejection. In accelerate storage, Aw and moisture content decreased until reaching a value of 0.48 and 5.9 in the CM3B bar, respectively. Peroxide content of CM3B and CM3C increased gradually up to 12 and 17 meq/kg respectively at 15 days. Rancyd aroma appearance was not the same in the bars, CM3A and CM3B had a decreasing at 15 days, while CM3C showed an increasing at the same time. In brief, CM3B showed the best sensory quality, the higher acceptability and the greater stability in accelerated storage.


Assuntos
Arachis/química , Grão Comestível/química , Análise de Alimentos , Magnoliopsida/química , Conservação de Alimentos
13.
Arch Latinoam Nutr ; 44(1): 57-62, 1994 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-7717808

RESUMO

Two samples of Amaranthus cruentus harvested in 1987 (sample A) and 1990 (sample B) were studied. Whole and refined flours were obtained. The whole flours contained 14.6 and 12.6% protein and 6.6 and 7.3 ether extraction, respectively. Both samples contained significant levels of Ca, P, Mg and K. Amaranth oil contained 19% palmitic acid, 3.4% stearic acid, 3.4% stearic acid, 34% oleic acid and 33% linoleic acid. Docosaenoic acid (C22:1) was present at the level of 9%. The ratio of saturated to unsaturated fatty acids was approximately 1:3. The level of crude fiber was 3.7% in the whole flours and 2.4% in the refined ones. Biological protein quality of flours was measured in the rat by the net protein ratio (NPR) method. The NPR values of the four materials tested ranged from 3.04 to 3.20 (NS), as compared with 4.08 for casein. These values are equivalent to 75-78% of the standard protein. Blends of raw wheat flour and whole amaranth flour fed to rats produced a good complementary effect between proteins, as shown by PER test. Wheat flour gave a poor PER value of 0.54. However, this figure increased with every increment of amaranth flour reaching a value of 2.15 for the blend 25:75. The PER for the amaranth diet (0:100) was 1.94 (casein 2.77). As expected, the extrusion process applied to the wheat/amaranth and corn/amaranth mixtures improved the biological quality of the protein. The wheat flour diet (100:0) gave a PER value of 1.64. Mixture 90:10 produced a low non significant increase in the protein quality.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Farinha/análise , Magnoliopsida/química , Animais , Ácidos Graxos/análise , Minerais/análise , Valor Nutritivo , Óleos de Plantas/análise , Proteínas de Plantas/análise , Ratos
14.
Arch Latinoam Nutr ; 37(3): 515-24, 1987 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-3506405

RESUMO

Experimental bread made of wheat flour complemented with 5, 10 and 15% chick-pea flour was studied, using wheat bread as control. Samples were analyzed for their proximal chemical composition and amino acids content. Crude fiber and protein increased from 0.36% to 0.55%, and from 14% to 17.6%, respectively, when 15% chick-pea flour was added. The lysine content increased as the level of supplementation was raised. Biological quality of proteins was measured in rats as protein efficiency ratio (PER) as well as apparent digestibility resulting in an increase of PER values from 0.90 to 1.34 and small variations in bread protein digestibility. Bread nutritive value was significantly improved by adding chick-pea flour.


Assuntos
Pão , Fabaceae , Farinha , Alimentos Fortificados , Valor Nutritivo , Plantas Medicinais , Aminoácidos/análise , Animais , Peso Corporal , Pão/análise , Distribuição Aleatória , Ratos , Ratos Endogâmicos , Triticum
15.
Arch Latinoam Nutr ; 48(2): 156-9, 1998 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-9830492

RESUMO

Snack with good nutritional value could play an important role in the physical and mental development of children and teenagers since they show a great preference for them. The tendency is increasing their nutritional value by supplying proteins, carbohydrates, fiber, vitamins and minerals in a balanced form. The purpose of this research was to evaluate the chemical, sensorial and nutritional quality of cereal and peanut bars. Three types of bars using different ratios of oat, wheat germ, peanut, toasted and expanded amaranthus and wheat extrudate were prepared. Bars proximate composition was determined according the AOAC methods, and their acceptability according Hedonic Scale. In the biological assays, rats fed with 10% protein diets, were used to obtain the Protein Efficiency Ratio (PER) Net Protein Ratio (NPR) and Apparent Digestibility (AD). Corrected PER, relative PER, relative AD, PER and NPR values did not showed difference between bars CM1 and CM2 (PER: 2.59-2.57; NPR: 3.99-3.95 respectively); CM3 bar showed a lower quality. There were not differences among bars in relation to AD. CM1 and CM2 bars had a better biological quality of the protein being CM3 bar of lower quality. From a chemical and sensorial point of view CM1 bar shows the highest protein content (14.23%) and acceptability (6.8) and CM2 bar shows a high raw fiber content (2.27%).


Assuntos
Arachis , Grão Comestível , Animais , Arachis/química , Grão Comestível/química , Feminino , Masculino , Valor Nutritivo , Proteínas/análise , Ratos , Ratos Wistar
16.
Arch Latinoam Nutr ; 48(2): 160-4, 1998 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-9830493

RESUMO

The use of fatty materials in cereal bars gives to them a good energetic value; however they are exposed to oxidative rancidity which can affect their acceptability and nutritional value. So, the purpose of this research was to determine the stability in storage and the effect of antioxidants on three tipes of cereal bars with peanuts. Cereal bars with 18% of peanuts were prepared, with and without antioxidants (BHA + BHT; 100 ppm). Bars were packed in polyprolpilene-aluminium-polythilene bags, and were stored at room temperature (18-20 degrees C) for 90 days. Each 30 days, analysis of water activity (Aw); moisture content, peroxides index, sensory quality (flavor, aroma and appearance) and acceptability, were carried out. Moisture content was similar in all bars (7.6-9.6%) and Aw was higher in the bar which contained expanded amaranthus and antioxidant. At the 60th day of storage, the peroxide values were lower in the bars with antioxidants; only the bar which included expanded amaranthus showed significant differences (16.4 meq/kg in the bar with antioxidant and 25.7 meq/kg for the control bar). The sensory parameters were kept within normal status without differences between the bars with antioxidants and the control ones, along all the storage period. Shelf life of bars CM1 and CM2 was at least of 60 days when they are kept at 18-20 degrees C.


Assuntos
Antioxidantes , Arachis , Grão Comestível , Conservação de Alimentos , Alumínio/química , Arachis/química , Grão Comestível/química , Umidade , Polietilenos/química , Polipropilenos/química
17.
Biochem Biophys Res Commun ; 271(3): 635-40, 2000 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-10814514

RESUMO

The phosphofructokinase C isozyme (PFK-C) from ascites tumor cells has been cloned and characterized to investigate the particular properties of PFK activity in this type of cells. The isolated cDNA encodes a protein of 784 amino acids and 85.5 kDa, whose expression was constant along tumor growth and markedly decreased when cell proliferation stops. The enzyme was functionally expressed in a PFK-deficient strain of Saccharomyces cerevisiae and purified to homogeneity. Recombinant PFK-C exhibited the same subunit size as the tumor wild-type isozyme and its steady-state kinetic parameters were similar to those of the form present in normal cells. The regulatory properties of the C isozyme accounted for the lack of fructose-1,6-P(2) activation and the P-enolpyruvate inhibition of PFK activity observed in ascites tumor preparations containing the various isozyme types. Nevertheless, PFK-C binds fructose-1,6-P(2) to an allosteric site as suggested by protection against thermal denaturation. Our results indicate that glucose metabolism in tumor cells is not regulated by a mutant form of PFK-C but by a high level expression of the normal C isozyme.


Assuntos
Carcinoma de Ehrlich/enzimologia , Fosfofrutoquinase-1/genética , Regulação Alostérica , Animais , Clonagem Molecular , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Frutosedifosfatos/farmacologia , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glucose/metabolismo , Humanos , Isoenzimas/química , Isoenzimas/genética , Cinética , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Fosfoenolpiruvato/farmacologia , Fosfofrutoquinase-1/química , Ligação Proteica , Desnaturação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Saccharomyces cerevisiae
18.
Plant Foods Hum Nutr ; 52(2): 141-9, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9839813

RESUMO

The use of cactus pear (Opuntia ficus indica L.) to obtain a new natural liquid sweetener was studied. The juice of the fruit (16.5 degrees Brix) was clarified with enzymes, treated with active carbon to take out the color and vacuum concentrated to obtain a 60 degrees Brix syrup or liquid sweetener. Physical and chemical characteristics determined included: a(w); reducing sugars (as inverted sugar); glucose (%); ash content (%); sugar composition by TLC; OD (420 nm) and Y, x, y chromaticity coordinates; viscosity (cps) and density (g/ml). Sensory analyses to determine the relative sweetness were also conducted. Cactus pear syrup contained 52.38% reducing sugar. The syrup had a pH of 4.31, a viscosity of 27.05 cps, an Aw of 0.83, a density of 1.2900 g/ml, an acidity (as citric acid) of 0.74% and an ash content of 1.4%. Compared with traditional sweeteners such as fructose and glucose syrup, the acidity was greater than that of HFCS (high fructose corn syrup) of 0.035%, and the ash values were considered a little high compared to glucose syrup which is 1.0%; these disparities can be attributed to the different processing conditions employed. Sensory evaluation revealed the same relative sweetness for cactus pear syrup and glucose, but lower than fructose; cactus pear syrup had a relative sweetness value of 67 with respect to sucrose (100).


Assuntos
Frutas , Edulcorantes , Carboidratos/análise , Ácido Cítrico/análise , Cristalização , Frutas/química , Glucose/análise , Concentração de Íons de Hidrogênio , Espectrofotometria , Paladar
19.
Plant Foods Hum Nutr ; 41(3): 193-201, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1656424

RESUMO

The effect of processing on chemical composition and protein quality of three legumes was studied. The species analyzed were beans (Phaseolus vulgaris), Tórtola and Coscorrón varieties; lentils (Lens esculenta), Laird variety; and chick peas (Cicer arietinum), California-INIA variety. The legumes were soaked in a solution of Na2 EDTA at 0.03% for 16 h and cooked for a predetermined period for each species. They were dried in a tray drier with cross currents of air flowing at a speed of 10 m/min until the residual moisture content was 8%. The water activity in the resulting products ranged from 0.574 to 0.587, thus completely assuring no microbial activity. No important changes were observed in the legumes protein, fat, or fibre contents after processing. The soaking solution was effective in reducing the phytic acid content from 2.99 to 1.64 mg/100 g in the Tórtola beans, which had the highest acid value prior processing. In all the species the heat treatment reduced the activity of the trypsin inhibitors by at least 50%. Cooking and drying significantly increased protein digestibility in all the legumes studied, with chick peas showing the most dramatic increase: form 54.7% pre-processing to 94.9% post-processing. With regard to Net Protein Ratio (NPR), chick peas had a value of 4.03, followed by Tórtola beans (3.29), Coscorrón (3.09) and lentils (2.61). The NPR value for the casein diet was 4.20.


Assuntos
Fabaceae , Manipulação de Alimentos , Proteínas de Vegetais Comestíveis/normas , Plantas Medicinais , Dessecação , Fibras na Dieta/análise , Digestão , Temperatura Alta , Valor Nutritivo , Ácido Fítico/análise , Óleos de Plantas/análise , Proteínas de Vegetais Comestíveis/análise , Inibidores da Tripsina/análise
20.
EMBO J ; 20(14): 3831-9, 2001 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-11447124

RESUMO

The yeast exosome is a complex of at least 10 essential 3'-5' riboexonucleases which is involved in 3'-processing of many RNA species. An exosome-like complex has been found or predicted to exist in other eukaryotes but not in Escherichia coli. The unicellular parasite Trypanosoma brucei diverged very early in eukaryotic evolution. We show here that T.brucei contains at least eight exosome subunit homologs, but only a subset of these associate in a complex. Accordingly, the T.brucei exosome is smaller than that of yeast. Both free and complex-associated homologs are essential for cell viability and are involved in 5.8S rRNA maturation. We suggest that the exosome was present in primitive eukaryotes, and became increasingly complex during subsequent evolution.


Assuntos
Exorribonucleases/metabolismo , RNA Ribossômico 5,8S/metabolismo , Trypanosoma brucei brucei/enzimologia , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Primers do DNA , Exorribonucleases/química , Teste de Complementação Genética , Espectrometria de Massas , Dados de Sequência Molecular , RNA Ribossômico 5,8S/genética , Saccharomyces cerevisiae/genética
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