Low Protein Consumption Research Articles

Insulin-Like Peptides Regulate Feeding Preference and Metabolism in Drosophila.

Fruit flies have eight identified Drosophila insulin-like peptides (DILPs) that are involved in the regulation of carbohydrate concentrations in hemolymph as well as in accumulation of storage metabolites. In the present study, we investigated diet-dependent roles of DILPs encoded by the genes dilp1–5, and dilp7 in the regulation of insect appetite, food choice, accumulation of triglycerides, glycogen, glucose, and trehalose in fruit fly bodies and carbohydrates in hemolymph. We have found that the wild type and the mutant lines demonstrate compensatory feeding for carbohydrates. However, mutants on dilp2,3, dilp3, dilp5, and dilp7 showed higher consumption of proteins on high yeast diets. To evaluate metabolic differences between studied lines on different diets we applied response surface methodology. High nutrient diets led to a moderate increase in concentration of glucose in hemolymph of the wild type flies. Mutations on dilp genes changed this pattern. We have revealed that the dilp2 mutation led to a drop in glycogen levels independently on diet, lack of dilp3 led to dramatic increase in circulating trehalose and glycogen levels, especially at low protein consumption. Lack of dilp5 led to decreased levels of glycogen and triglycerides on all diets, whereas knockout on dilp7 caused increase in glycogen levels and simultaneous decrease in triglyceride levels at low protein consumption. Fruit fly appetite was influenced by dilp3 and dilp7 genes. Our data contribute to the understanding of Drosophila as a model for further studies of metabolic diseases and may serve as a guide for uncovering the evolution of metabolic regulatory pathways.

Long-term metabolic effects of malnutrition: Liver steatosis and insulin resistance following early-life protein restriction.

Early postnatal-life malnutrition remains prevalent globally, and about 45% of all child deaths are linked to malnutrition. It is not clear whether survivors of childhood malnutrition suffer from long-term metabolic effects, especially when they are later in life exposed to a fat and carbohydrate rich obesogenic diet. The lack of knowledge around this dietary “double burden” warrants studies to understand the long-term consequences of children previously exposed to malnutrition. We hypothesized that an early-life nutritional insult of low protein consumption in mice would lead to long-term metabolic disturbances that would exacerbate the development of diet-induced insulin resistance and non-alcoholic fatty liver disease (NAFLD). We investigated the effects of feeding a low protein diet (4% wt/wt) immediately after weaning for four weeks and subsequent feeding of a high carbohydrate high fat feeding for 16 weeks on metabolic function and development of NAFLD. Mice exposed to early-life protein restriction demonstrated a transient glucose intolerance upon recovery by regular chow diet feeding. However, protein restriction after weaning in mice did not exacerbate an obesogenic diet-induced insulin resistance or progression to NAFLD. These data suggest that transient protein restriction in early-life does not exacerbate an obesogenic diet-induced NAFLD and insulin resistance.

Cost Effectiveness Analysis Based Through Nutrition Intake and Nutritional Status in Kidney Failure Patients Who Underwent Hemodialysis and Non Hemodialysis Therapy Productive Age at Makassar City

Background: The high cost of care for patients with kidney failure is a serious problem and requires cost effective planning. Patients undergoing hemodialysis often lack nutritional intake and nutritional status. Factors causing low energy and protein consumption in patients with renal failure are socioeconomic factors such as depression, stress, lack of knowledge and poverty, the patient’s own characteristics in the treatment process. Objective: Analyze and assess the magnitude of the costs incurred for patients with renal failure who undergo advanced age hemodialysis therapy through nutritional intake and nutritional status. Material and Method: In this study data were collected simultaneously at RSUP. Dr.Wahidin Sudirohusodo Makassar through cross sectional study. Qualitative and quantitative approach with descriptive comparative analysis and activity based costing method. Results: The results revealed that the leading cause of renal failure was based on the primary diagnoses of the disease, ranging from hypertensive renal disease, and comorbidities such as non insulin dependent diabetes, acute subendocardial myocardial, aneurysm of artery of upper extremity and other acute renal failure. Through calculation method Activity Based Costing (ABC), financing activity is lower, but can not be denied that there is variable cost per patient perceived kidney failure. Conclusion: Nutritional intake and nutritional status showed comparison with the Cost Effectiveness Analysis method that there was a difference between hemodialysis and non-hemodialysis patients of Rp.1.998.000, - this means that in non-hemodialysis group more effective than hemodialysis group

The Relationship of Infectious Diseases History and Mother Factors to Under Red Line Among Toddler

Abstract: Nutrition under the red line is a state of severe nutritional deficiency caused by low consumption of energy and protein from daily food. Sungai Tiung is the village that has the highest number of children under five with under red line (BGM) from other villages in the working area of Rawat Inap Cempaka Health Center. This study aims to know the relationship of infectious diseases history and mother factors to under red line (BGM) among toddler in Sungai Tiung. This research uses cross-sectional design. The samples are 90 respondents. Sampling used purposive sampling. The independent variables are a history of infectious disease, knowledge, education, and mother care pattern. The dependent variable is under red line (BGM). The instrument in this study used questionaire and Kartu Menuju Sehat (KMS). The result showed that there is a relationship history of infectious diseases with BGM (p-value = 0.03). The results also showed no relationship of knowledge (p-value = 0.12), education (p-value = 0.75) and mother care pattern (p-value = 0.32) with BGM. There is a relationship history of infectious diseases with BGM. So that, there should be efforts to prevent infectious diseases in toddler. Keywords : under red line, toddler, infectious diseases

How Can a Ketogenic Diet Improve Motor Function?

A ketogenic diet (KD) is a normocaloric diet composed by high fat (80–90%), low carbohydrate, and low protein consumption that induces fasting-like effects. KD increases ketone body (KBs) production and its concentration in the blood, providing the brain an alternative energy supply that enhances oxidative mitochondrial metabolism. In addition to its profound impact on neuro-metabolism and bioenergetics, the neuroprotective effect of specific polyunsaturated fatty acids and KBs involves pleiotropic mechanisms, such as the modulation of neuronal membrane excitability, inflammation, or reactive oxygen species production. KD is a therapy that has been used for almost a century to treat medically intractable epilepsy and has been increasingly explored in a number of neurological diseases. Motor function has also been shown to be improved by KD and/or medium-chain triglyceride diets in rodent models of Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and spinal cord injury. These studies have proposed that KD may induce a modification in synaptic morphology and function, involving ionic channels, glutamatergic transmission, or synaptic vesicular cycling machinery. However, little is understood about the molecular mechanisms underlying the impact of KD on motor function and the perspectives of its use to acquire the neuromuscular effects. The aim of this review is to explore the conditions through which KD might improve motor function. First, we will describe the main consequences of KD exposure in tissues involved in motor function. Second, we will report and discuss the relevance of KD in pre-clinical and clinical trials in the major diseases presenting motor dysfunction.

MODERN VISION OF DEVELOPMENT FACTORS OF PROTEIN-ENERGY MALNUTRITION SYNDROME IN PATIENTS, RECEIVING PERITONEAL DIALYSIS

Patients who have end-stage chronic kidney disease (СKD) and who receive substitutive peritoneal dialysis (PD) therapy, often have complication such as protein-energy malnutrition syndrome (PEMS). Important prognostic value is given to nutritional disorders as they increase prior disease development, complicate its correction, influence survival rate of patients of this category.
 Purpose: to explore prevalence of protein-energy malnutrition syndrome in PD patients and define factors of its development.
 Materials and methods: 67 PD patients were examined. Evaluation of nutritional status in patients under investigation was made using development of complex methodology that includes 5 specifications – body mass index (BMI), triceps skinfold, arm circumference – biceps, floating albumin and seraalbumin, absolute number of lymphocyte.
 Results. PEMS was found in 35,8% of patients, 29,8% had mild case and 6% had moderate case with mixed form domination. 26,8% of PD patients had average high or high transport characteristics of abdominal membrane that provided increased protein loss through abdominal membrane on PD. It was determined that with the growth of С-reactive protein (CRP) level nutritional disorders increased. In our research chronic inflammation syndrome was found in 16,3% of cases. Besides, protein loss was growing fast after another dialysis peritonitis. Expressed deficit of daily consumption of protein was registered in 29,2% of patients.
 Conclusion. Our researches analysis allowed us to define that risk factors of formation of protein metabolism disorders in PD patients are low protein consumption, connection with nutritional deficiency syndrome, system inflammatory reaction, protein loss with dialysis fluid having high transport characteristics of abdominal membrane and repeated dialysis peritonitis.

The share of ultra-processed foods determines the overall nutritional quality of diets in Brazil.

To estimate the dietary share of ultra-processed foods and to determine its association with the overall nutritional quality of diets in Brazil. Cross-sectional. Brazil. A representative sample of 32 898 Brazilians aged ≥10 years was studied. Food intake data were collected. We calculated the average dietary content of individual nutrients and compared them across quintiles of energy share of ultra-processed foods. Then we identified nutrient-based dietary patterns, and evaluated the association between quintiles of dietary share of ultra-processed foods and the patterns' scores. The mean per capita daily dietary energy intake was 7933 kJ (1896 kcal), with 58·1 % from unprocessed or minimally processed foods, 10·9 % from processed culinary ingredients, 10·6 % from processed foods and 20·4 % from ultra-processed foods. Consumption of ultra-processed foods was directly associated with high consumption of free sugars and total, saturated and trans fats, and with low consumption of protein, dietary fibre, and most of the assessed vitamins and minerals. Four nutrient-based dietary patterns were identified. 'Healthy pattern 1' carried more protein and micronutrients, and less free sugars. 'Healthy pattern 2' carried more vitamins. 'Healthy pattern 3' carried more dietary fibre and minerals and less free sugars. 'Unhealthy pattern' carried more total, saturated and trans fats, and less dietary fibre. The dietary share of ultra-processed foods was inversely associated with 'healthy pattern 1' (-0·16; 95 % CI -0·17, -0·15) and 'healthy pattern 3' (-0·18; 95 % CI -0·19, -0·17), and directly associated with 'unhealthy pattern' (0·17; 95 % CI 0·15, 0·18). Dietary share of ultra-processed foods determines the overall nutritional quality of diets in Brazil.

Abstract 1257: Paternal sub-optimal nutrition leads to programming of daughters' breast cancer risk in a mouse model

Abstract Background: Dietary patterns are known to induce epigenetic changes in paternal sperm. Acquired epigenetic traits have been shown to be transmitted from parents to offspring via the germ-line (eggs and sperm) and modulate disease risk in offspring. We have shown before that paternal overweight around the time of conception leads to reprogramming of the mammary gland tissue and breast cancer risk in the offspring. Here, we investigated whether paternal sub-optimal nutrition (low protein diet) could epigenetically reprogram the father's germ-line and alter daughters' likelihood of developing breast cancer, using a mouse model. Methods: Male mice were fed control (Con) or low-protein (LP) diets from weaning until sexual maturity; at this point, males were housed together with female mice reared on control diet. Once a vaginal plug was detected, males were euthanized for sperm collection. Pregnant dams were fed the control diet throughout pregnancy and after giving birth. Pups were fed the control diet throughout the experiment. A subset of female offspring was euthanized for mammary tissue harvesting on post-natal day (PND) 50, which was used for morphologic and molecular analyses. Another sub-set of female offspring was treated with 9,12-dimethylbenz[a]anthracene (DMBA) to induce mammary tumors. Results: We found that male LP consumption alters the non-coding RNA content and DNA methylation patterns of the sperm in agreement with previous findings. We also observed that, compared to Con offspring, the female offspring of LP fathers had lower birth weight (p=0.035). This decrease in body weight persisted through sexual maturity when females begun to gain more weight than their control counterparts (p>0.001). In addition, mammary glands of LP offspring were larger(p=0.02) and had increased epithelial density (p=0.001) when compared to Con on PND50. In addition, we found that LP mammary glands had epigenetic alterations, including in DNA methylation and the miRNA expression profiles. These changes in normal mammary tissue were associated with higher rates of DMBA-induced mammary tumor (p=0.04), increased tumor growth (p=0.03) and reduced tumor latency in LP offspring (p=0.03). Mammary tumors of LP offspring had lower rates of apoptosis, which may explain the increased tumor growth in this group. However, the mechanisms mediating this effect still needs to be elucidated. Conclusion: Paternal sub-optimal nutrition programs the female offspring mammary gland development and breast cancer risk. Whether this increase in cancer risk is due to local mammary tissue changes or whether systemic changes play a role remains to be investigated. It also remains to be determined whether epigenetic changes in paternal sperm are functionally linked to changes in mammary gland development and cancer risk. Citation Format: Raquel Santana, Elissa Carney, Hong Cao, Johan Clarke, M. Idalia Cruz, Lu Jin, Yi Fu, Zuolin Cheng, Joseph (Yue) Wang, Sonia de Assis. Paternal sub-optimal nutrition leads to programming of daughters' breast cancer risk in a mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1257. doi:10.1158/1538-7445.AM2017-1257

Maternal high fructose and low protein consumption during pregnancy and lactation share some but not all effects on early-life growth and metabolic programming of rat offspring

Maternal nutritional stress during pregnancy acts to program offspring metabolism. We hypothesized that the nutritional stress caused by maternal fructose or low protein intake during pregnancy would program the offspring to develop metabolic aberrations that would be exacerbated by a diet rich in fructose or fat during adult life. The objective of this study was to characterize and compare the fetal programming effects of maternal fructose with the established programming model of a low-protein diet on offspring. Male offspring from Sprague-Dawley dams fed a 60% starch control diet, a 60% fructose diet, or a low-protein diet throughout pregnancy and lactation were weaned onto either a 60% starch control diet, 60% fructose diet, or a 30% fat diet for 15 weeks. Offspring from low-protein and fructose-fed dam showed retarded growth (P<.05) at weaning (50.3, 29.6 vs 59.1±0.8 g) and at 18 weeks of age (420, 369 vs 464±10.9 g). At 18 weeks of age, offspring from fructose dams expressed greater quantities (P<.05) of intestinal Pgc1a messenger RNA compared with offspring from control or low-protein dams (1.31 vs 0.89, 0.85; confidence interval, 0.78-1.04). Similarly, maternal fructose (P=.09) and low-protein (P<.05) consumption increased expression of Pgc1a in offspring liver (7.24, 2.22 vs 1.22; confidence interval, 2.11-3.45). These data indicate that maternal fructose feeding is a programming model that shares some features of maternal protein restriction such as retarded growth, but is unique in programming of selected hepatic and intestinal transcripts.

THE RELATION BETWEEN PROTEIN AND FERRUM CONSUMPTION WITH HAEMOGLOBIN CONCENTRATION OF YOGYAKARTA STATE UNIVERSITY (UNY) STUDENTS

This study aims to investigate the protein and ferrum consumption with the requirement nutrition and to study their relation with haemoglobin (Hb) concentration of UNY students, through cross sectional model with applying point time approach. The samples are UNY students taken from incidental technic. The food consumption pattern measured by food frequency instrument while the consumption level was measured by recall diet method. Hb concentration was determined using sahli method. The height and body weight were also collected to complete the data. The descriptive analysis and product moment correlation of the data resulted 95% significancy level. The 91,4% respondents showed the low protein consumption and all samples (100%) indicated low ferrum consumption. The correlation between protein and ferrum with Hb concentration provided a 95% significancy level. Keywords: protein, ferrum, haemoglobin

Relationship Between Diet and Body Composition After Biliopancreatic Diversion.

Biliopancreatic diversion (BPD) has been shown to be one of the most effective techniques for losing weight, although the relationship between body composition and diet after the procedure is not well known. Our aim was to assess dietary changes and their effects on body composition. This longitudinal study included all patients eligible for BPD who had undergone body composition analysis. Two assessments were performed: 6 weeks before and 1 year after surgery. Nutritional education was given after surgery by a registered dietitian, and dual energy X-ray absorptiometry was performed and a 3-day food record was collected for further analysis at both of the visits. Forty-six patients were included. The percentage of excess of weight loss was 61.03 % (SD 14.01 %), which was statistically different by gender (p = 0.045). The percentage of subjects reporting a low daily protein consumption of less than 60 g and 1.2 g/kg of ideal body weight (IBW)/day was 15.2 % before surgery and 19.6 % at 12 months (p = 0.006). The weight loss was mainly of fat mass (FM). There were differences of body composition by gender before and after surgery. A simple correlation analysis showed a significant association between daily energy intake and FM (g) only before surgery (p = 0.030), and also between daily protein intake (expressed as total g) and lean body mass (LBM) 12 months after surgery (p = 0.018), but no association was found with achieved protein goal. BPD enhanced by nutritional education seems to improve its results by achieving an adequate weight loss, preserving LBM, decreasing FM, and guaranteeing an appropriate protein intake.

Fragment screening by SPR and advanced application to GPCRs

Surface plasmon resonance (SPR) is one of the primary biophysical methods for the screening of low molecular weight ‘fragment’ libraries, due to its low protein consumption and ‘label-free’ methodology. SPR biosensor interaction analysis is employed to both screen and confirm the binding of compounds in fragment screening experiments, as it provides accurate information on the affinity and kinetics of molecular interactions. The most advanced application of the use of SPR for fragment screening is against membrane protein drug targets, such G-protein coupled receptors (GPCRs). Biophysical GPCR assays using SPR have been validated with pharmacological measurements approximate to cell-based methods, yet provide the advantage of biophysical methods in their ability to measure the weak affinities of low molecular weight fragments. A number of SPR fragment screens against GPCRs have now been disclosed in the literature. SPR fragment screening is proving versatile to screen both thermostabilised GPCRs and solubilised wild type receptors. In this chapter, we discuss the state-of-the-art in GPCR fragment screening by SPR and the technical considerations in performing such experiments.

A simple and widely applicable hit validation strategy for protein–protein interaction inhibitors based on a quantitative ligand displacement assay

Identification of inhibitors for protein–protein interactions (PPIs) from high-throughput screening (HTS) is challenging due to the weak affinity of primary hits. We present a hit validation strategy of PPI inhibitors using quantitative ligand displacement assay. From an HTS for Bcl-xL/Mcl-1 inhibitors, we obtained a hit candidate, I1, which potentially forms a reactive Michael acceptor, I2, inhibiting Bcl-xL/Mcl-1 through covalent modification. We confirmed rapid reversible and competitive binding of I1 with a probe peptide, suggesting non-covalent binding. The advantages of our approach over biophysical assays include; simplicity, higher throughput, low protein consumption and universal application to PPIs including insoluble membrane proteins.

Novel microscale approaches for easy, rapid determination of protein stability in academic and commercial settings

Chemical denaturant titrations can be used to accurately determine protein stability. However, data acquisition is typically labour intensive, has low throughput and is difficult to automate. These factors, combined with high protein consumption, have limited the adoption of chemical denaturant titrations in commercial settings. Thermal denaturation assays can be automated, sometimes with very high throughput. However, thermal denaturation assays are incompatible with proteins that aggregate at high temperatures and large extrapolation of stability parameters to physiological temperatures can introduce significant uncertainties. We used capillary-based instruments to measure chemical denaturant titrations by intrinsic fluorescence and microscale thermophoresis. This allowed higher throughput, consumed several hundred-fold less protein than conventional, cuvette-based methods yet maintained the high quality of the conventional approaches. We also established efficient strategies for automated, direct determination of protein stability at a range of temperatures via chemical denaturation, which has utility for characterising stability for proteins that are difficult to purify in high yield. This approach may also have merit for proteins that irreversibly denature or aggregate in classical thermal denaturation assays. We also developed procedures for affinity ranking of protein–ligand interactions from ligand-induced changes in chemical denaturation data, and proved the principle for this by correctly ranking the affinity of previously unreported peptide–PDZ domain interactions. The increased throughput, automation and low protein consumption of protein stability determinations afforded by using capillary-based methods to measure denaturant titrations, can help to revolutionise protein research. We believe that the strategies reported are likely to find wide applications in academia, biotherapeutic formulation and drug discovery programmes.

Kinetic method for the large-scale analysis of the binding mechanism of histone deacetylase inhibitors

Performing kinetic studies on protein ligand interactions provides important information on complex formation and dissociation. Beside kinetic parameters such as association rates and residence times, kinetic experiments also reveal insights into reaction mechanisms. Exploiting intrinsic tryptophan fluorescence a parallelized high-throughput Förster resonance energy transfer (FRET)-based reporter displacement assay with very low protein consumption was developed to enable the large-scale kinetic characterization of the binding of ligands to recombinant human histone deacetylases (HDACs) and a bacterial histone deacetylase-like amidohydrolase (HDAH) from Bordetella/Alcaligenes. For the binding of trichostatin A (TSA), suberoylanilide hydroxamic acid (SAHA), and two other SAHA derivatives to HDAH, two different modes of action, simple one-step binding and a two-step mechanism comprising initial binding and induced fit, were verified. In contrast to HDAH, all compounds bound to human HDAC1, HDAC6, and HDAC8 through a two-step mechanism. A quantitative view on the inhibitor-HDAC systems revealed two types of interaction, fast binding and slow dissociation. We provide arguments for the thesis that the relationship between quantitative kinetic and mechanistic information and chemical structures of compounds will serve as a valuable tool for drug optimization.

Brain-blood amino acid correlates following protein restriction in murine maple syrup urine disease.

BackgroundConventional therapy for patients with maple syrup urine disease (MSUD) entails restriction of protein intake to maintain acceptable levels of the branched chain amino acid, leucine (LEU), monitored in blood. However, no data exists on the correlation between brain and blood LEU with protein restriction, and whether correction in blood is reflected in brain.MethodsTo address this question, we fed intermediate MSUD mice diets of 19% (standard) and 6% protein, with collection of sera (SE), striata (STR), cerebellum (CE) and cortex (CTX) for quantitative amino acid analyses.ResultsLEU and valine (VAL) levels in all brain regions improved on average 28% when shifting from 19% to 6% protein, whereas the same improvements in SE were on average 60%. Isoleucine (ILE) in brain regions did not improve, while the SE level improved 24% with low-protein consumption. Blood-branched chain amino acids (LEU, ILE, and VAL in sera (SE)) were 362-434 μM, consistent with human values considered within control. Nonetheless, numerous amino acids in brain regions remained abnormal despite protein restriction, including glutamine (GLN), aspartate (ASP), glutamate (GLU), gamma-aminobutyric acid (GABA), asparagine (ASN), citrulline (CIT) and serine (SER). To assess the specificity of these anomalies, we piloted preliminary studies in hyperphenylalaninemic mice, modeling another large neutral aminoacidopathy. Employing an identical dietary regimen, we found remarkably consistent abnormalities in GLN, ASP, and GLU.ConclusionsOur results suggest that blood amino acid analysis may be a poor surrogate for assessing the outcomes of protein restriction in the large neutral amino acidopathies, and further indicate that chronic neurotransmitter disruptions (GLU, GABA, ASP) may contribute to long-term neurocognitive dysfunction in these disorders.

Hitting the target: fragment screening with acoustic in situ co-crystallization of proteins plus fragment libraries on pin-mounted data-collection micromeshes.

Acoustic droplet ejection (ADE) is a powerful technology that supports crystallographic applications such as growing, improving and manipulating protein crystals. A fragment-screening strategy is described that uses ADE to co-crystallize proteins with fragment libraries directly on MiTeGen MicroMeshes. Co-crystallization trials can be prepared rapidly and economically. The high speed of specimen preparation and the low consumption of fragment and protein allow the use of individual rather than pooled fragments. The Echo 550 liquid-handling instrument (Labcyte Inc., Sunnyvale, California, USA) generates droplets with accurate trajectories, which allows multiple co-crystallization experiments to be discretely positioned on a single data-collection micromesh. This accuracy also allows all components to be transferred through small apertures. Consequently, the crystallization tray is in equilibrium with the reservoir before, during and after the transfer of protein, precipitant and fragment to the micromesh on which crystallization will occur. This strict control of the specimen environment means that the crystallography experiments remain identical as the working volumes are decreased from the few microlitres level to the few nanolitres level. Using this system, lysozyme, thermolysin, trypsin and stachydrine demethylase crystals were co-crystallized with a small 33-compound mini-library to search for fragment hits. This technology pushes towards a much faster, more automated and more flexible strategy for structure-based drug discovery using as little as 2.5 nl of each major component.

Food Quality in the Late Postoperative Period of Bariatric Surgery: An Evaluation Using the Bariatric Food Pyramid

Bariatric surgery is an effective intervention in the treatment of obesity, but lifestyle and diet should be monitored after this procedure to ensure success. The Bariatric Food Pyramid was created basing on long-term nutritional care that proposes a standard of healthy living and eating habits considering gastric capacity and specific nutritional needs. The purpose of the current study is to evaluate the life habits and diet quality of patients who have undergone bariatric surgery (who have been recovering for at least 6 months) based on the specific food pyramid. Retrospective data analysis was performed using medical records of patients who had been followed for at least 6 months after bariatric surgery. The following data were collected from patient records: age, gender, education level (years), BMI (preoperative and postoperative), percentage of excess weight loss (EWL) relative to the time of surgery, frequency of physical activity, use of nutritional supplements, usual dietary intake history, and fluid intake. Results were analyzed using descriptive statistics. We evaluated 172 patient records. In this study, there was a low prevalence of physical activity, use of vitamin-mineral supplements, and water intake. There also was low consumption of protein, fruit, vegetables, and vegetable oils. In addition, intake of carbohydrates, sugars, and fats were higher than the recommendations established by the pyramid. The results indicate that patients who have undergone bariatric surgery have an inadequate diet according to food evaluation with the specific pyramid. In the long term, this may lead to weight gain and vitamin and mineral deficiencies.

Influence of Dietary Protein on Glomerular Filtration Before and After Bariatric Surgery: A Cohort Study

Obesity-associated elevations in glomerular filtration rate (GFR) are common and may play a role in the development of kidney disease, so identifying the underlying mechanism is important. We therefore studied whether reductions in dietary protein intake, which is known to modulate GFR, explain why GFR decreases after bariatric surgery-induced weight loss. Cohort study with participants as their own controls. 8 severely obese patients with normal kidney function were recruited from bariatric surgery centers in Indianapolis, IN. All participants were placed on a fixed-protein (50-g/d) diet for 1 week before and after a minimum of a 20-kg weight loss by bariatric surgery and were followed up closely by dieticians for adherence. Ad lib versus low-protein diet before versus after bariatric surgery. Measured GFR, using repeated-measures analysis, was used to estimate the independent effects of diet and surgery. GFR was measured using plasma iohexol clearance. A median of 32.9 (range, 19.5-54.4)kg was lost between the first presurgery visit and first postsurgery visit. Dietetic evaluations and urinary urea excretion confirmed that patients generally adhered to the study diet. GFRs on an ad lib diet were significantly higher before compared to after surgery (GFR medians were 144 (range, 114-178) and 107 (range, 85-147) mL/min, respectively; P=0.01). Although bariatric surgery (-26mL/min; P=0.005) and dietary sodium intake (+7.5mL/min per 100mg of dietary sodium; P=0.001) both influenced GFR, consuming a low-protein diet did not (P=0.7). Small sample size; mostly white women; possible lack of generalizability. The decrease in GFR observed after bariatric surgery is explained at least in part by the effects of surgery and/or dietary sodium intake, but not by low dietary protein consumption.

X-ray scattering experiments with high-flux X-ray source coupled rapid mixing microchannel device and their potential for high-flux neutron scattering investigations

Small-angle X-ray scattering provides global, shape-sensitive structural information about macromolecules in solution. Its extension to time dimension in the form of time-resolved SAXS investigations and combination with other time-resolved biophysical methods contributes immensely to the study of protein dynamics. TR-SAXS can also provide unique information about the global structures of transient intermediates during protein dynamics. An experimental set-up with low protein consumption is essential for an extensive use of TR-SAXS experiments on protein dynamics. In this direction, a newly developed 20-microchannel microfluidic continuous-flow mixer was combined with SAXS. With this set-up, we demonstrate ubiquitin unfolding dynamics after rapid mixing with the chaotropic agent Guanidinium-HCl within milliseconds using only ∼ 40 nanoliters of the protein sample per scattering image. It is suggested that, in the future, this new TR-SAXS platform will help to increase the use of time-resolved small-angle X-ray scattering, wide-angle X-ray scattering and neutron scattering experiments for studying protein dynamics in the early millisecond regime. The potential research field for this set-up includes protein folding, protein misfolding, aggregation in amyloidogenic diseases, function of intrinsically disordered proteins and various protein-ligand interactions.