Simplified risk-prediction for benchmarking and quality improvement in emergency general surgery. Prospective, multicenter, observational cohort study.

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.

The effect of Lactobacillus acidophilus and Lactobacillus casei on the in vitro bioaccessibility of flaxseed lignans (Linum usitatissimum L.).

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.

Evaluación nutricional y almacenamiento acelerado a 37 degrees C de mezclas de frejol y maíz fritos / Nutritional evaluation and accelerated storage at 37 degrees C of fried bean and corn mixtures

Nutritive value of corn and beans is limited by the deficiency in some aminoacids; so, the combination of both of them might be very advantageous from a nutritional point of view. A research with the following purposes was done: to improve the biological value of corn and bean through the formulation of mixes of fried kernels; and, to know the shelf life of the mixes during an accelerated storage period. Fried kernels mixes, in a ratio of 50:50 per cent, from three varieties of bean (Pinto 114, Suave 85 and Tortola Inia) and dent yellow corn were made; protein value of the mixes was evaluated. Mixes were store at 37 degrees C during 15 days, determining every five days, their peroxides and moisture content and their water activity. All the mixes got values of NPR-Rel higher than 80 per cent; the best one was Suave 85/corn with a value of 88.2 per cent which indicates an improving of the protein quality. The stored products showed along the whole period, low values for peroxides (3.25-6.12 meq/kg oil) which might allow a shelf life of 90 days at room temperature; also, moisture content and water activity were low assuring microbial stability.

[Processing and characterization of fried beans varieties Pinto 114, Suave 85 and Tórtola Inia]. / Elaboración y caracterización de frejoles fritos tipo "snack" cultivar Pinto 114, Suave 85 y Tórtola Inia.

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.

The exosome of Trypanosoma brucei.

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.

Roles of triosephosphate isomerase and aerobic metabolism in Trypanosoma brucei.

Kinetoplastid protozoa compartmentalize the first seven enzymes of glycolysis and two enzymes of glycerol metabolism in a microbody, the glycosome. While in its mammalian host, Trypanosoma brucei depends entirely on glucose for ATP generation. Under aerobic conditions, most of the glucose is metabolized to pyruvate. Aerobic metabolism depends on the activities of glycosomal triosephosphate isomerase and a mitochondrial glycerophosphate oxidase, and on glycerophosphate<-->dihydroxyacetone phosphate exchange across the glycosomal membrane. Using a combination of genetics and computer modelling, we show that triosephosphate isomerase is probably essential for bloodstream trypanosome survival, but not for the insect-dwelling procyclics, which preferentially use amino acids as an energy source. When the enzyme level decreased to about 15% of that of the wild-type, the growth rate was halved. Below this level, a lethal rise in dihydroxyacetone phosphate was predicted. Expression of cytosolic triosephosphate isomerase inhibited cell growth. Attempts to knockout the trypanosome alternative oxidase genes (which are needed for glycerophosphate oxidase activity) were unsuccessful, but when we lowered the level of the corresponding mRNA by expressing a homologous double-stranded RNA, oxygen consumption was reduced fourfold and the rate of trypanosome growth was halved.

[Deep frying snack product of legume/cereal mixture based on corn and three varieties of beans]. / Mezclas legumbre/cereal por fritura profunda de maiz amarillo y de tres cultivares de frejol para consumo "snack".

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.

[Use of mesquite cotyledon (Prosopis chilensis (Mol) Shuntz) in the manufacturing of cereal bars]. / Utilización de cotiledones de algarobo (Prosopis chilensis (Mol) Stuntz) en la elaboración de barras de cereales.

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.

[Storage of cereal bars with mesquite cotyledon (Prosopis chilensis (Mol) Stuntz)]. / Almacenamiento de barras de cereales elaboradas con cotiledones de algarrobo (Prosopis chilensis (Mol) Stuntz.

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.

Phosphofructokinase C isozyme from ascites tumor cells: cloning, expression, and properties.

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.

C to U editing of the anticodon of imported mitochondrial tRNA(Trp) allows decoding of the UGA stop codon in Leishmania tarentolae.

All mitochondrial tRNAs in kinetoplastid protists are encoded in the nucleus and imported into the organelle. The tRNA(Trp)(CCA) can decode the standard UGG tryptophan codon but can not decode the mitochondrial UGA tryptophan codon. We show that the mitochondrial tRNA(Trp) undergoes a specific C to U nucleotide modification in the first position of the anticodon, which allows decoding of mitochondrial UGA codons as tryptophan. Functional evidence for the absence of a UGA suppressor tRNA in the cytosol, using a reporter gene, was also obtained, which is consistent with a mitochondrial localization of this editing event. Leishmania cells have dealt with the problem of a lack of expression within the organelle of this non-universal tRNA by compartmentalizing an editing activity that modifies the anticodon of the imported tRNA.

Uridine insertion/deletion RNA editing in trypanosome mitochondria--a review.

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.

T7 RNA polymerase-driven transcription in mitochondria of Leishmania tarentolae and Trypanosoma brucei.

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.

Knockout of the glutamate dehydrogenase gene in bloodstream Trypanosoma brucei in culture has no effect on editing of mitochondrial mRNAs.

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.

Cactus pear fruit: a new source for a natural sweetner.

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).

[Nutritional characteristics of cereal and peanut bars]. / Características nutricionales de barras de cereales y maní.

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%).

[Storage and use of antioxidants in cereal and peanut bars]. / Almacenamiento y uso de antioxidantes en barras de cereales y maní.

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.

Cloning, sequencing and developmental expression of phosphofructokinase from Dictyostelium discoideum.

Phosphofructokinase (PFK) from Dictyostelium discoideum is a non-allosteric enzyme that lacks any of the characteristic regulatory mechanisms of PFK from other cells. We have determined the DNA sequence and analyzed the amino acid sequence of D. discoideum PFK, as an initial step toward understanding the peculiar properties of this enzyme. Three overlapping fragments, two of cDNA and one of genomic DNA, were isolated, which together could encode the complete sequence of D. discoideum PFK. The constructed full-length cDNA coded for a protein of 834 amino acids, with a calculated molecular mass of 92.4 kDa, which was similar to other eukaryotic and prokaryotic PFK. Alignments of the amino acid sequence with other isozymes revealed that many of the amino acid residues assigned to binding sites of substrates and allosteric effectors are conserved in this enzyme, but changes were also found that may contribute to the absence of allosteric mechanisms. A phylogenetic tree for the eukaryotic PFK family was constructed and showed that the N-terminal domain clustered with those of yeast subunits, whereas the C-terminal domain was more related to PFK from metazoa. Southern blotting indicated that D. discoideum PFK is encoded by a single gene. The enzyme is present throughout the life cycle of D. discoideum, with a gradual decrease of its expression during development.

Functional complementation of yeast phosphofructokinase mutants by the non-allosteric enzyme from Dictyostelium discoideum.

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.

Cereal and nut bars, nutritional quality and storage stability.

Six snack-type bars were manufactured, to contain oat and wheat germ and two different walnut levels, agglutinated with natural sweeteners and fats. Two bars also contained toasted amaranth with brown sugar cover and wheat extrudate, while two others, contained puffed instead of toasted amaranth. Water activity (Aw) and moisture were determined in the manufactured products. Quality and sensory evaluation and proximate analysis were carried out on the bars containing highest levels of walnuts (18%). The caloric contribution of the bars was computed by Atwater methods. The nutritional quality of the bars was determined by means of the Protein Efficiency Ratio (PER) and Net Protein Ratio (NPR), and the results were used to obtain relative PER and relative NPR. Samples of the latter bars were kept under accelerated storage for 15 days at 37 degrees C and analyzed every 5 days to determine their Aw, moisture, peroxide and sensory acceptability. The drying time for the cereal - and walnut - based bars was 45 min at 120 degrees C. All bars presented a good fiber supply and the CN1 bar, containing only oat, wheat germ and walnut, had the greatest protein content. In the sensory evaluation, the walnut level with the greatest preference was 18%. PER and NPR values of the bars did not differ significantly showing values approximately 86% that of the casein value. During storage, the moisture and Aw decreased in all the bars. Peroxides remained within the acceptable ranges; acceptability based on sensory evaluation remained best in the bar with toasted amaranth.(ABSTRACT TRUNCATED AT 250 WORDS)