37 research outputs found
Implementation of nutritional guidelines in a university hospital monitored by repeated point prevalence surveys
Background/Objectives: Malnutrition is present in 20–50% of hospitalized patients, and nutritional care is a challenge. The aim was to evaluate whether the implementation of a nutritional strategy would influence nutritional care performance in a university hospital. Subjects/Methods: This was a prospective quality improvement program implementing guidelines for nutritional care, with the aim of improving nutritional practice. The Nutrition Risk Screening (NRS) 2002 was used. Point prevalence surveys over 2 years to determine whether nutritional practice had improved. Results: In total, 3604 (70%) of 5183 eligible patients were screened and 1230 (34%) were at nutritional risk. Only 53% of the at-risk patients got nutritional treatment and 5% were seen by a dietician. The proportion of patients screened increased from the first to the eighth point prevalence survey (P=0.012), but not the proportion of patients treated (P=0.66). The four initial screening questions in NRS 2002 identified 92% of the patients not at nutritional risk. Conclusions: Implementation of nutritional guidelines improved the screening performance, but did not increase the proportion of patients who received nutritional treatment. Point prevalence surveys were useful to evaluate nutritional practice in this university hospital. In order to improve practice, we suggest using only the four initial screening questions in NRS 2002 to identify patients not at risk, better education in nutritional care for physicians and nurses, and more dieticians employed. Audit of implementation of guidelines, performed by health authorities, and specific reimbursement for managing nutrition may also improve practice.publishedVersio
Skeletal Muscle Myofibrillar and Sarcoplasmic Protein Synthesis Rates Are Affected Differently by Altitude-Induced Hypoxia in Native Lowlanders
As a consequence to hypobaric hypoxic exposure skeletal muscle atrophy is often reported. The underlying mechanism has been suggested to involve a decrease in protein synthesis in order to conserve O2. With the aim to challenge this hypothesis, we applied a primed, constant infusion of 1-13C-leucine in nine healthy male subjects at sea level and subsequently at high-altitude (4559 m) after 7–9 days of acclimatization. Physical activity levels and food and energy intake were controlled prior to the two experimental conditions with the aim to standardize these confounding factors. Blood samples and expired breath samples were collected hourly during the 4 hour trial and vastus lateralis muscle biopsies obtained at 1 and 4 hours after tracer priming in the overnight fasted state. Myofibrillar protein synthesis rate was doubled; 0.041±0.018 at sea-level to 0.080±0.018%⋅hr−1 (p<0.05) when acclimatized to high altitude. The sarcoplasmic protein synthesis rate was in contrast unaffected by altitude exposure; 0.052±0.019 at sea-level to 0.059±0.010%⋅hr−1 (p>0.05). Trends to increments in whole body protein kinetics were seen: Degradation rate elevated from 2.51±0.21 at sea level to 2.73±0.13 µmol⋅kg−1⋅min−1 (p = 0.05) at high altitude and synthesis rate similar; 2.24±0.20 at sea level and 2.43±0.13 µmol⋅kg−1⋅min−1 (p>0.05) at altitude. We conclude that whole body amino acid flux is increased due to an elevated protein turnover rate. Resting skeletal muscle myocontractile protein synthesis rate was concomitantly elevated by high-altitude induced hypoxia, whereas the sarcoplasmic protein synthesis rate was unaffected by hypoxia. These changed responses may lead to divergent adaptation over the course of prolonged exposure
Linking Yeast Gcn5p Catalytic Function and Gene Regulation Using a Quantitative, Graded Dominant Mutant Approach
Establishing causative links between protein functional domains and global gene regulation is critical for advancements in genetics, biotechnology, disease treatment, and systems biology. This task is challenging for multifunctional proteins when relying on traditional approaches such as gene deletions since they remove all domains simultaneously. Here, we describe a novel approach to extract quantitative, causative links by modulating the expression of a dominant mutant allele to create a function-specific competitive inhibition. Using the yeast histone acetyltransferase Gcn5p as a case study, we demonstrate the utility of this approach and (1) find evidence that Gcn5p is more involved in cell-wide gene repression, instead of the accepted gene activation associated with HATs, (2) identify previously unknown gene targets and interactions for Gcn5p-based acetylation, (3) quantify the strength of some Gcn5p-DNA associations, (4) demonstrate that this approach can be used to correctly identify canonical chromatin modifications, (5) establish the role of acetyltransferase activity on synthetic lethal interactions, and (6) identify new functional classes of genes regulated by Gcn5p acetyltransferase activity—all six of these major conclusions were unattainable by using standard gene knockout studies alone. We recommend that a graded dominant mutant approach be utilized in conjunction with a traditional knockout to study multifunctional proteins and generate higher-resolution data that more accurately probes protein domain function and influence
2D-LSPP: An Improved Line Source with Parallel Plane Emission (LSPP) Model for Photon Distribution in Annular Reactors
Does increasing blood pH stimulate protein synthesis in dialysis patients?
BACKGROUND: Although the mechanism of muscle wasting in end-stage renal disease is not fully understood, there is increasing evidence that acidosis induces muscle protein degradation and could therefore contribute to the loss of muscle protein stores of patients on hemodialysis, a prototypical state of chronic metabolic acidosis (CMA). Because body protein mass is controlled by the balance between synthesis and degradation, protein loss can occur as result of either increased breakdown, impaired synthesis, or both. Correction of acidosis may therefore help to maintain muscle mass and improve the health of patients with CMA. We evaluated whether alkalizing patients on hemodialysis might have a positive effect on protein synthesis and on nutritional parameters. METHODS: Eight chronic hemodialysis patients were treated daily with oral sodium bicarbonate (NaHCO(3)) supplementation for 10-14 days, yielding a pre-dialytic plasma bicarbonate concentration of 28.6 +/-1.6 mmol/l. The fractional synthesis rates (FSR) of muscle protein and albumin were obtained by the L-[(2)H(5)ring]phenylalanine flooding technique. RESULTS: Oral NaHCO(3 )supplementation induced a significant increase in serum bicarbonate (21.5 +/- 3.4 vs. 28.6 +/- 1.6 mmol/l; p = 0.018) and blood pH (7.41 vs. 7.46; p = 0.041). The FSR of muscle protein and the FSR of albumin did not change significantly (muscle protein: 2.1 +/- 0.2 vs. 2.0 +/- 0.5% per day, p = 0.39; albumin: 8.3 +/- 2.2 vs. 8.6 +/- 2.5% per day, p = 0.31). Plasma concentrations of insulin-like growth factor 1 decreased significantly (33.4 +/- 21.3 vs. 25.4 +/- 12.3 nmol/l; p = 0.028), whereas thyroid-stimulating hormone, free thyroxin and free triiodothyronine did not change significantly and nutritional parameters showed no improvement. CONCLUSION: In contrast to other findings, raising the blood pH of dialysis patients was not associated with a positive effect on albumin and muscle protein synthesis, or nutritional and endocrinal parameters
Couplage de la filtration granulaire aux résines échangeuses d'ions pour l'enlèvement de la matière organique pour les petites communautés rurales
Radiation Model of a TiO2 Coated, Quartz Wool, Packed Bed Photocatalytic Reactor
The radiation field of a packed-bed photocatalytic reactor filled with quartz wool coated with titanium dioxide was modeled using the Monte Carlo technique and the following information: the radiation flux emitted by the lamps, the diameter size distribution of the quartz fiber cloth, the mass of quartz fibers and of TiO2 that was immobilized on the fiber surface as well as the refractive index and the spectral absorption coefficient of the materials of the system. Modeling predictions were validated with radiometer measurements of the transmitted radiation through the reactor, the root mean square error being < 9.7%. Finally, by means of a parametric study, the validated model was used to analyze the effect of the design variables: the radii of the quartz fibers, thickness of the TiO2 coatings, and amount of TiO2 coated quartz wool, on the distribution and nonuniformity of the radiative energy distribution inside the reactor.Fil: Imoberdorf, Gustavo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química (i); Argentina. Universidad Nacional del Litoral; ArgentinaFil: Vella, G.. Università di Palermo; ItaliaFil: Sclafani, A.. Università di Palermo; ItaliaFil: Rizzuti, L.. Università di Palermo; ItaliaFil: Alfano, Orlando Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química (i); ArgentinaFil: Cassano, Alberto Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química (i); Argentin
Modeling of a TiO2-Coated Quartz Wool-Packed Bed Photocatalytic Reactor
A fixed-bed, photocatalytic laboratory reactor aimed to degrade pollutants from water streams was designed and built. Quartz wool coated with a thin film of TiO2 was employed as the reactor filling. The photocatalyst was placed in the reactor forming a loose packing to guarantee the intimate contact among reactants, photons, and the photocatalytic surface. This reactor was employed to study the photocatalytic decomposition of a model pollutant (formic acid). A reactor–radiation–reaction model was developed, which was comprised of the reactor mass balance, radiation model, and kinetic model for the degradation of formic acid. The local superficial rate of photon absorption, which was necessary to evaluate the kinetic, was obtained from the results of a radiation model. The Monte Carlo approach was employed to solve the radiation model, where the interaction between photons and the TiO2-coated fibers of the packing was considered. The kinetic model was derived from a plausible kinetic scheme. Experimental results obtained in the packed-bed reactor, operating in a differential mode and without mass transfer limitations, were used to estimate the parameters of the kinetic model. A satisfactory agreement was observed between model simulations with the derived parameters and experimental results, with a root mean square error less than 8.3%.Fil: Vella, G.. Università di Palermo; ItaliaFil: Imoberdorf, Gustavo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional del Litoral; ArgentinaFil: Sclafani, A.. Università di Palermo; ItaliaFil: Cassano, Alberto Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional del Litoral; ArgentinaFil: Alfano, Orlando Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional del Litoral; ArgentinaFil: Rizzuti, L.. Università di Palermo; Itali