Malabsorption and nutritional balance in the ICU: fecal weight as a biomarker: a prospective observational pilot study

PubMed Central

2011-01-01

Introduction Malabsorption, which is frequently underdiagnosed in critically ill patients, is clinically relevant with regard to nutritional balance and nutritional management. We aimed to validate the diagnostic accuracy of fecal weight as a biomarker for fecal loss and additionally to assess fecal macronutrient contents and intestinal absorption capacity in ICU patients. Methods This was an observational pilot study in a tertiary mixed medical-surgical ICU in hemodynamically stable adult ICU patients, without clinically evident gastrointestinal malfunction. Fecal weight (grams/day), fecal energy (by bomb calorimetry in kcal/day), and macronutrient content (fat, protein, and carbohydrate in grams/day) were measured. Diagnostic accuracy expressed in terms of test sensitivity, specificity, positive (PPV) and negative predictive value (NPV), and receiver operator curves (ROCs) were calculated for fecal weight as a marker for energy malabsorption. Malabsorption was a priori defined as < 85% intestinal absorption capacity. Results Forty-eight patients (63 ± 15 years; 58% men) receiving full enteral feeding were included. A cut-off fecal production of > 350 g/day (that is, diarrhea) was linked to the optimal ROC (0.879), showing a sensitivity and PPV of 80%, respectively. Specificity and NPV were both 96%. Fecal weight (grams/day) and intestinal energy-absorption capacity were inversely correlated (r = -0.69; P < 0.001). Patients with > 350 g feces/day had a significantly more-negative energy balance compared with patients with < 350 g feces/day (loss of 627 kcal/day versus neutral balance; P = 0.012). Conclusions A fecal weight > 350 g/day in ICU patients is a biomarker applicable in daily practice, which can act as a surrogate for fecal energy loss and intestinal energy absorption. Daily measurement of fecal weight is a feasible means of monitoring the nutritional status of critically ill patients and, in those identified as having malabsorption, can monitor responses to changes in dietary management. PMID:22071233

Hearing Loss, Dizziness, and Carbohydrate Metabolism

PubMed Central

Albernaz, Pedro L. Mangabeira

2015-01-01

Introduction  Metabolic activity of the inner ear is very intense, and makes it sensitive to changes in the body homeostasis. This study involves a group of patients with inner ear disorders related to carbohydrate metabolism disturbances, including hearing loss, tinnitus, dizziness, and episodes of vertigo. Objectives  To describe the symptoms of metabolic inner ear disorders and the examinations required to establish diagnoses. These symptoms are often the first to allow for an early diagnosis of metabolic disorders and diabetes. Methods  Retrospective study of 376 patients with inner ear symptoms suggestive of disturbances of carbohydrate metabolism. The authors present patientś clinical symptoms and clinical evaluations, with emphasis on the glucose and insulin essays. Results  Authors based their conclusions on otolaryngological findings, diagnostic procedures and treatment principles. They found that auditory and vestibular symptoms usually occur prior to other manifestations of metabolic changes, leading to an early diagnosis of hyperinsulinemia, intestinal sugar malabsorption or diabetes. Previously undiagnosed diabetes mellitus type II was found in 39 patients. Conclusions  The identification of carbohydrate metabolism disturbances is important not only to minimize the patients' clinical symptoms, but also to help maintain their general health. PMID:27413410

Boronic acid recognition of non-interacting carbohydrates for biomedical applications: increasing fluorescence signals of minimally interacting aldoses and sucralose.

PubMed

Resendez, Angel; Halim, Md Abdul; Singh, Jasmeet; Webb, Dominic-Luc; Singaram, Bakthan

2017-11-22

To address carbohydrates that are commonly used in biomedical applications with low binding affinities for boronic acid based detection systems, two chemical modification methods were utilized to increase sensitivity. Modified carbohydrates were analyzed using a two component fluorescent probe based on boronic acid-appended viologen-HPTS (4,4'-o-BBV). Carbohydrates normally giving poor signals (fucose, l-rhamnose, xylose) were subjected to sodium borohydride (NaBH 4 ) reduction in ambient conditions for 1 h yielding the corresponding sugar alcohols from fucose, l-rhamnose and xylose in essentially quantitative yields. Compared to original aldoses, apparent binding affinities were increased 4-25-fold. The chlorinated sweetener and colon permeability marker sucralose (Splenda), otherwise undetectable by boronic acids, was dechlorinated to a detectable derivative by reactive oxygen and hydroxide intermediates by the Fenton reaction or by H 2 O 2 and UV light. This method is specific to sucralose as other common sugars, such as sucrose, do not contain any carbon-chlorine bonds. Significant fluorescence response was obtained for chemically modified sucralose with the 4,4'-o-BBV-HPTS probe system. This proof of principle can be applied to biomedical applications, such as gut permeability, malabsorption, etc.

Effect of evening exposure to dim or bright light on the digestion of carbohydrate in the supper meal.

PubMed

Hirota, Naoko; Sone, Yoshiaki; Tokura, Hiromi

2003-09-01

In a previous study we found that daytime exposure to bright as compared to dim light exerted a beneficial effect on the digestion of the evening meal. This finding prompted us to examine whether the digestion of the evening meal is also affected by evening light intensity. Subjects lived in light of 200 lux during the daytime (08:00-17:00 h) and took their evening meal at 17:00 h under 20 lux (evening dim-light condition: 17:00-02:00 h) or 2000 lux (evening bright-light condition: 17:00-02:00 h) until retiring at 02:00 h. Assessment of carbohydrate digestion of the evening meal was accomplished by a breath hydrogen test that is indicative of the malabsorption of dietary carbohydrate. Hydrogen excretion in the breath in the evening under the dim-light condition was significantly less than under the bright-light condition (p < 0.05). This finding is the opposite to that obtained in previous experiments in which subjects were exposed to the different intensities of light during the daytime, and indicates that the exposure to dim light in the evening exerts a better effect on carbohydrate digestion in the evening meal than does the exposure to bright light.

Boronic acid recognition of non-interacting carbohydrates for biomedical applications: increasing fluorescence signals of minimally interacting aldoses and sucralose†

PubMed Central

Resendez, Angel; Halim, Md Abdul; Singh, Jasmeet; Webb, Dominic-Luc

2017-01-01

To address carbohydrates that are commonly used in biomedical applications with low binding affinities for boronic acid based detection systems, two chemical modification methods were utilized to increase sensitivity. Modified carbohydrates were analyzed using a two component fluorescent probe based on boronic acid-appended viologen–HPTS (4,4′-o-BBV). Carbohydrates normally giving poor signals (fucose, l-rhamnose, xylose) were subjected to sodium borohydride (NaBH4) reduction in ambient conditions for 1 h yielding the corresponding sugar alcohols from fucose, l-rhamnose and xylose in essentially quantitative yields. Compared to original aldoses, apparent binding affinities were increased 4–25-fold. The chlorinated sweetener and colon permeability marker sucralose (Splenda), otherwise undetectable by boronic acids, was dechlorinated to a detectable derivative by reactive oxygen and hydroxide intermediates by the Fenton reaction or by H2O2 and UV light. This method is specific to sucralose as other common sugars, such as sucrose, do not contain any carbon-chlorine bonds. Significant fluorescence response was obtained for chemically modified sucralose with the 4,4′-o-BBV–HPTS probe system. This proof of principle can be applied to biomedical applications, such as gut permeability, malabsorption, etc. PMID:29130464

Inherited selective intestinal cobalamin malabsorption and cobalamin deficiency in dogs.

PubMed

Fyfe, J C; Giger, U; Hall, C A; Jezyk, P F; Klumpp, S A; Levine, J S; Patterson, D F

1991-01-01

Inherited selective intestinal malabsorption of cobalamin (Cbl) was observed in a family of giant schnauzer dogs. Family studies and breeding experiments demonstrated simple autosomal recessive inheritance of this disease. Affected puppies exhibited chronic inappetence and failure to thrive beginning between 6 and 12 wk of age. Neutropenia with hypersegmentation, anemia with anisocytosis and poikilocytosis, and megaloblastic changes of the bone marrow were present. Serum Cbl concentrations were low, and methylmalonic aciduria and homocysteinemia were present. Parenteral, but not oral, cyanocobalamin administration rapidly eliminated all signs of Cbl deficiency except for low serum Cbl concentrations. Cbl malabsorption in affected dogs was documented by oral administration of [57Co]cyanocobalamin with or without simultaneous oral administration of intrinsic factor or normal dog gastric juice. Quantitation and function studies of intrinsic factor and transcobalamin-II from affected dogs revealed no abnormality. Other gastrointestinal functions and ileal morphology were normal, indicating a selective defect of Cbl absorption at the level of the ileal enterocyte. Immunoelectron microscopy of ileal biopsies showed that the receptor for intrinsic factor-Cbl complex was absent from the apical brush border microvillus pits of affected dogs. This canine disorder resembles inherited selective intestinal Cbl malabsorption (Imerslund-Gräsbeck syndrome) in humans, and is a spontaneously occurring animal model of early onset Cbl deficiency.

D-Lactic Acidosis in Humans: Review of Update

PubMed Central

Kang, Kyung Pyo; Lee, Sik

2006-01-01

D-Lactic acidosis has been well documented in ruminants. In humans, D-lactic acidosis is very rare, but D-lactic acidosis may be more common than generally believed and should be looked for in a case of metabolic acidosis in which the cause of acidosis is not apparent. The clinical presentation of D-lactic acidosis is characterized by episodes of encephalopathy and metabolic acidosis. The entity should be considered as a diagnosis in a patient who presents with metabolic acidosis accompanied by high anion gap, normal lactate level, negative Acetest, history of short bowel syndrome or malabsorption, and characteristic neurologic manifestations. Low carbohydrate diet, bicarbonate treatment, rehydration, and oral antibiotics would be helpful in controlling symptoms. PMID:24459486

Hypocalcaemia following thyroidectomy unresponsive to oral therapy.

PubMed

Etheridge, Zac C; Schofield, Christopher; Prinsloo, Peter J J; Sturrock, Nigel D C

2014-01-01

Hypocalcaemia due to hypoparathyroidism following thyroidectomy is a relatively common occurrence. Standard treatment is with oral calcium and vitamin D replacement therapy; lack of response to oral therapy is rare. Herein we describe a case of hypoparathyroidism following thyroidectomy unresponsive to oral therapy in a patient with a complex medical history. We consider the potential causes in the context of calcium metabolism including: poor adherence, hungry bone syndrome, malabsorption, vitamin D resistance, bisphosphonate use and functional hypoparathyroidism secondary to magnesium deficiency. Malabsorption due to intestinal hurry was likely to be a contributory factor in this case and very large doses of oral therapy were required to avoid symptomatic hypocalcaemia.

Importance of colonic support for energy absorption as small-bowel failure proceeds.

PubMed

Nordgaard, I; Hansen, B S; Mortensen, P B

1996-08-01

Digestive processes in the human colon are affected by the bacterial fermentation of malabsorbed carbohydrates and protein to short-chain fatty acids, which are absorbed and supply energy. Energy absorption was measured by assessing fecal bomb calorimetry in 148 patients with extremely different small-bowel lengths. Colectomy increased fecal loss of energy by 0.8 MJ/d and carbohydrate excretion fivefold in patients with a small-bowel length between normal and 150-200 cm. Patients with 100-150 cm small bowel, with and without a colon, excreted 1.3 +/- 0.3 and 4.7 +/- 0.5 MJ/d, respectively (P = 0.002), a difference of 3.4 MJ/d. Patients with < 100 cm small bowel excreted 3.1 +/- 0.4 and 8.0 +/- 1.3 MJ/d, respectively (P = 0.03), a difference of 4.9 MJ/d. Similar and highly significant differences were calculated by linear-regression analysis. Considerably less energy was excreted as carbohydrate than as fat in patients with preserved colonic function, probably because fermentation removed carbohydrate as absorbed short-chain fatty acids, whereas a comparable amount of energy was lost as carbohydrate and fat in patients without colonic function. The correlation between malabsorbed energy and small-bowel length was poor (r = -0.41) but increased when data for patients with and without a colon were separated (r = -0.56 and r = -0.58, respectively). Small-bowel length, however, was still an inaccurate measure of intestinal failure to absorb nutrient energy. In conclusion, colonic digestion may support energy supply with up to approximately 4.2 MJ/d as small-bowel failure proceeds, but it is of minor importance in patients with a small-bowel length > 200 cm or malabsorption < 2.1 MJ/d.

Evidence supporting oral sensitivity to complex carbohydrates independent of sweet taste sensitivity in humans.

PubMed

Low, Julia Y Q; Lacy, Kathleen E; McBride, Robert L; Keast, Russell S J

2017-01-01

Compared to simple sugars, complex carbohydrates have been assumed invisible to taste. However, two recent studies proposed that there may be a perceivable taste quality elicited by complex carbohydrates independent of sweet taste. There is precedent with behavioural studies demonstrating that rats are very attracted to complex carbohydrates, and that complex carbohydrates are preferred to simple sugars at low concentrations. This suggests that rats may have independent taste sensors for simple sugars and complex carbohydrates. The aim of this paper is to investigate oral sensitivities of two different classes of complex carbohydrates (a soluble digestible and a soluble non-digestible complex carbohydrate), and to compare these to other caloric and non-nutritive sweeteners in addition to the prototypical tastes using two commonly used psychophysical measures. There were strong correlations between the detection thresholds and mean intensity ratings for complex carbohydrates (maltodextrin, oligofructose) (r = 0.94, P < 0.001). There were no significant correlations between the detection thresholds of the complex carbohydrates (maltodextrin, oligofructose) and the sweeteners (glucose, fructose, sucralose, Rebaudioside A, erythritol) (all P > 0.05). However, moderate correlations were observed between perceived intensities of complex carbohydrates and sweeteners (r = 0.48-0.61, P < 0.05). These data provide evidence that complex carbohydrates can be sensed in the oral cavity over a range of concentrations independent of sweet taste sensitivity at low concentrations, but with partial overlap with sweet taste intensity at higher concentrations.

Evidence supporting oral sensitivity to complex carbohydrates independent of sweet taste sensitivity in humans

PubMed Central

Lacy, Kathleen E.; Keast, Russell S. J.

2017-01-01

Compared to simple sugars, complex carbohydrates have been assumed invisible to taste. However, two recent studies proposed that there may be a perceivable taste quality elicited by complex carbohydrates independent of sweet taste. There is precedent with behavioural studies demonstrating that rats are very attracted to complex carbohydrates, and that complex carbohydrates are preferred to simple sugars at low concentrations. This suggests that rats may have independent taste sensors for simple sugars and complex carbohydrates. The aim of this paper is to investigate oral sensitivities of two different classes of complex carbohydrates (a soluble digestible and a soluble non-digestible complex carbohydrate), and to compare these to other caloric and non-nutritive sweeteners in addition to the prototypical tastes using two commonly used psychophysical measures. There were strong correlations between the detection thresholds and mean intensity ratings for complex carbohydrates (maltodextrin, oligofructose) (r = 0.94, P < 0.001). There were no significant correlations between the detection thresholds of the complex carbohydrates (maltodextrin, oligofructose) and the sweeteners (glucose, fructose, sucralose, Rebaudioside A, erythritol) (all P > 0.05). However, moderate correlations were observed between perceived intensities of complex carbohydrates and sweeteners (r = 0.48–0.61, P < 0.05). These data provide evidence that complex carbohydrates can be sensed in the oral cavity over a range of concentrations independent of sweet taste sensitivity at low concentrations, but with partial overlap with sweet taste intensity at higher concentrations. PMID:29281655

Effect of simethicone on lactulose-induced H2 production and gastrointestinal symptoms.

PubMed

Friis, H; Bodé, S; Rumessen, J J; Gudmand-Høyer, E

1991-01-01

The results of studies of the effect of simethicone on abdominal gas-related symptoms have been contradictory. In a randomized, double-blind cross-over study, 10 healthy volunteers were given 30 g lactulose and 600 mg simethicone or placebo. End-expiratory breath samples were collected and analyzed for H2 and gastrointestinal symptoms registered. There were no differences in biochemical parameters or symptom score between simethicone and placebo. In contrast to previous studies, we used a sufficiently large dose of lactulose to produce gastrointestinal symptoms, a higher dose of simethicone and placebo tablets containing the same additives as the simethicone tablets. There was no demonstrable effect of simethicone on symptoms or intestinal gas production caused by carbohydrate malabsorption.

Malabsorption Syndromes

MedlinePlus

... foods you eat. If you have a malabsorption syndrome, your small intestine cannot absorb nutrients from foods. Causes of malabsorption syndromes include Celiac disease Lactose intolerance Short bowel syndrome. ...

Malabsorption

MedlinePlus

... children who eat a balanced diet suffer from malnutrition. The reason for this may be malabsorption, the ... several months) Treatment When a child suffers from malnutrition, malabsorption is just one of the possible causes. ...

Fructose Malabsorption in Systemic Sclerosis

PubMed Central

Marie, Isabelle; Leroi, Anne-Marie; Gourcerol, Guillaume; Levesque, Hervé; Ménard, Jean-François; Ducrotte, Philippe

2015-01-01

Abstract The deleterious effect of fructose, which is increasingly incorporated in many beverages, dairy products, and processed foods, has been described; fructose malabsorption has thus been reported in up to 2.4% of healthy subjects, leading to digestive clinical symptoms (eg, pain, distension, diarrhea). Because digestive involvement is frequent in patients with systemic sclerosis (SSc), we hypothesized that fructose malabsorption could be responsible for intestinal manifestations in these patients. The aims of this prospective study were to: determine the prevalence of fructose malabsorption, in SSc; predict which SSc patients are at risk of developing fructose malabsorption; and assess the outcome of digestive symptoms in SSc patients after initiation of standardized low-fructose diet. Eighty consecutive patients with SSc underwent fructose breath test. All SSc patients also completed a questionnaire on digestive symptoms, and a global symptom score (GSS) was calculated. The prevalence of fructose malabsorption was as high as 40% in SSc patients. We also observed a marked correlation between the presence of fructose malabsorption and: higher values of GSS score of digestive symptoms (P = 0.000004); and absence of delayed gastric emptying (P = 0.007). Furthermore, in SSc patients with fructose malabsorption, the median value of GSS score of digestive symptoms was lower after initiation of standardized low-fructose diet (4 before vs. 1 after; P = 0.0009). Our study underscores that fructose malabsorption often occurs in SSc patients. Our findings are thus relevant for clinical practice, highlighting that fructose breath test is a helpful, noninvasive method by: demonstrating fructose intolerance in patients with SSc; and identifying the group of SSc patients with fructose intolerance who may benefit from low-fructose diet. Interestingly, because the present series also shows that low-fructose diet resulted in a marked decrease of gastrointestinal clinical manifestations in SSc patients with fructose malabsorption, our findings underscore that fructose malabsorption may play a significant role in the onset of gastrointestinal symptoms in these patients. Finally, we suggest that fructose malabsorption may be due to reduced fructose absorption by enterocytes, impaired enteric microbiome, and decreased intestinal permeability. PMID:26426642

Fructose and lactose intolerance and malabsorption testing: the relationship with symptoms in functional gastrointestinal disorders.

PubMed

Wilder-Smith, C H; Materna, A; Wermelinger, C; Schuler, J

2013-06-01

The association of fructose and lactose intolerance and malabsorption with the symptoms of different functional gastrointestinal disorders (FGID) remains unclear. To investigate the prevalence of fructose and lactose intolerance (symptom induction) and malabsorption and their association with clinical gastrointestinal (GI) as well as non-GI symptoms in FGID and the outcome of dietary intervention. Fructose and lactose intolerance (defined by positive symptom index) and malabsorption (defined by increased hydrogen/methane) were determined in 1372 FGID patients in a single centre using breath testing. Results were correlated with clinical symptoms in different FGID Rome III subgroups. The effectiveness of a targeted saccharide-reduced diet was assessed after 6-8 weeks. Intolerance prevalence across all FGIDs was 60% to fructose, 51% to lactose and 33% to both. Malabsorption occurred in 45%, 32% and 16% respectively. There were no differences in intolerance or malabsorption prevalence between FGID subgroups. FGID symptoms correlated with symptoms evoked during testing (r = 0.35-0.61. P < 0.0001), but not with malabsorption. Non-GI symptoms occurred more commonly in patients with intolerances. Methane breath levels were not associated with constipation using several cut-off thresholds. Adequate symptom relief was achieved in >80% of intolerant patients, irrespective of malabsorption. Fructose and lactose intolerances are common in FGID and associated with increased non-GI symptoms, but not with specific FGID subtypes. Symptoms experienced during breath testing, but not malabsorption, correlate with FGID symptoms. Effective symptom relief with dietary adaptation is not associated with malabsorption. Mechanisms relating to the generation of GI and non-GI symptoms due to lactose and fructose in FGID need to be explored further. © 2013 Blackwell Publishing Ltd.

Fructose and lactose intolerance and malabsorption testing: the relationship with symptoms in functional gastrointestinal disorders

PubMed Central

Wilder-Smith, C H; Materna, A; Wermelinger, C; Schuler, J

2013-01-01

Background The association of fructose and lactose intolerance and malabsorption with the symptoms of different functional gastrointestinal disorders (FGID) remains unclear. Aim To investigate the prevalence of fructose and lactose intolerance (symptom induction) and malabsorption and their association with clinical gastrointestinal (GI) as well as non-GI symptoms in FGID and the outcome of dietary intervention. Methods Fructose and lactose intolerance (defined by positive symptom index) and malabsorption (defined by increased hydrogen/methane) were determined in 1372 FGID patients in a single centre using breath testing. Results were correlated with clinical symptoms in different FGID Rome III subgroups. The effectiveness of a targeted saccharide-reduced diet was assessed after 6–8 weeks. Results Intolerance prevalence across all FGIDs was 60% to fructose, 51% to lactose and 33% to both. Malabsorption occurred in 45%, 32% and 16% respectively. There were no differences in intolerance or malabsorption prevalence between FGID subgroups. FGID symptoms correlated with symptoms evoked during testing (r = 0.35–0.61. P < 0.0001), but not with malabsorption. Non-GI symptoms occurred more commonly in patients with intolerances. Methane breath levels were not associated with constipation using several cut-off thresholds. Adequate symptom relief was achieved in >80% of intolerant patients, irrespective of malabsorption. Conclusions Fructose and lactose intolerances are common in FGID and associated with increased non-GI symptoms, but not with specific FGID subtypes. Symptoms experienced during breath testing, but not malabsorption, correlate with FGID symptoms. Effective symptom relief with dietary adaptation is not associated with malabsorption. Mechanisms relating to the generation of GI and non-GI symptoms due to lactose and fructose in FGID need to be explored further. PMID:23574302

Lactose intolerance: from diagnosis to correct management.

PubMed

Di Rienzo, T; D'Angelo, G; D'Aversa, F; Campanale, M C; Cesario, V; Montalto, M; Gasbarrini, A; Ojetti, V

2013-01-01

This review discusses one of the most relevant problems in gastrointestinal clinical practice: lactose intolerance. The role of lactase-persistence alleles the diagnosis of lactose malabsorption the development of lactose intolerance symptoms and its management. Most people are born with the ability to digest lactose, the major carbohydrate in milk and the main source of nutrition until weaning. Approximately, 75% of the world's population loses this ability at some point, while others can digest lactose into adulthood. Symptoms of lactose intolerance include abdominal pain, bloating, flatulence and diarrhea with a considerable intraindividual and interindividual variability in the severity. Diagnosis is most commonly performed by the non invasive lactose hydrogen breath test. Management of lactose intolerance consists of two possible clinical choice not mutually exclusive: alimentary restriction and drug therapy.

Premenstrual Syndrome (PMS) FAQ

MedlinePlus

... symptoms of PMS: Eat a diet rich in complex carbohydrates. A complex carbohydrate-rich diet may reduce mood symptoms and food cravings. Complex carbohydrates are found in foods made with whole grains, ...

The role of complex carbohydrate catabolism in the pathogenesis of invasive streptococci

PubMed Central

Shelburne, Samuel A.; Davenport, Michael T.; Keith, David B.; Musser, James M.

2009-01-01

Historically, the study of bacterial catabolism of complex carbohydrates has contributed to understanding basic bacterial physiology. Recently, however, genome-wide screens of streptococcal pathogenesis have identified genes encoding proteins involved in complex carbohydrate catabolism as participating in pathogen infectivity. Subsequent studies have focused on specific mechanisms by which carbohydrate utilization proteins might contribute to the ability of streptococci to colonize and infect the host. Moreover, transcriptome and biochemical analyses have uncovered novel regulatory pathways by which streptococci link environmental carbohydrate availability to virulence factor production. Herein we review new insights into the role of complex carbohydrates in streptococcal host-pathogen interaction. PMID:18508271

Use of labelled triolein, vitamin A, and D-xylose in the diagnosis of malabsorption 1

PubMed Central

Wormsley, K. G.

1963-01-01

This paper discusses the type of results given by a group of test procedures used in the study of small intestinal dysfunction. While the chemical estimation of faecal fat remains the most valuable criterion for the laboratory detection of malabsorption, the occurrence of abnormal faecal or blood radioactivity also denotes the presence of malabsorption, although some patients with staetorrhoea appear to `absorb' labelled triolein normally. Analysis of data from the other tests shows that steatorrhoea is not necessarily present in patients who give abnormal results and that the presence of malabsorption does not preclude a normal capacity for handling the test substances. These reservations impair the value of the vitamin A and xylose `tolerance' tests and serum carotene levels as screening procedures for the determination of malabsorption states. On the other hand, these tests show patterns of results which are useful in differentiating idiopathic from secondary steatorrhoea, since patients with secondary malabsorption often handle one or more of these test substances normally. PMID:14058268

Carbohydrates in Supramolecular Chemistry.

PubMed

Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

2016-02-24

Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed.

Glycan complexity dictates microbial resource allocation in the large intestine

USDA-ARS?s Scientific Manuscript database

The structure of the human gut microbiota, which impacts on the health of the host, is controlled by complex dietary carbohydrates and members of the Bacteroidetes phylum are the major contributors to the degradation of complex dietary carbohydrates. The extent to which complex dietary carbohydrates...

Versatile derivatives of carbohydrate-binding modules for imaging of complex carbohydrates approaching the molecular level of resolution.

PubMed

Ding, Shi-You; Xu, Qi; Ali, Mursheda K; Baker, John O; Bayer, Edward A; Barak, Yoav; Lamed, Raphael; Sugiyama, Junji; Rumbles, Garry; Himmel, Michael E

2006-10-01

The innate binding specificity of different carbohydrate-binding modules (CBMs) offers a versatile approach for mapping the chemistry and structure of surfaces that contain complex carbohydrates. We have employed the distinct recognition properties of a double His-tagged recombinant CBM tagged with semiconductor quantum dots for direct imaging of crystalline cellulose at the molecular level of resolution, using transmission and scanning transmission electron microscopy. In addition, three different types of CBMs from families 3, 6, and 20 that exhibit different carbohydrate specificities were each fused with either green fluorescent protein (GFP) or red fluorescent protein (RFP) and employed for double-labeling fluorescence microscopy studies of primary cell walls and various mixtures of complex carbohydrate target molecules. CBM probes can be used for characterizing both native complex carbohydrates and engineered biomaterials.

Recent progress in understanding host immune response to Avian Coccidiosis: Th1 and Th17 responses

USDA-ARS?s Scientific Manuscript database

Coccidiosis is one of the most economically important diseases of chickens caused by Eimeria spp. since it destroys the intestinal epithelium resulting in nutrient malabsorption, body weight loss, and in severe cases, death. Since the life cycle of Eimeria parasites is complex and comprised of intra...

The Pathophysiology of Malabsorption

PubMed Central

Keller, Jutta; Layer, Peter

2014-01-01

Summary Physiological digestion and absorption of nutrients within the gastrointestinal tract requires a complex interaction between motor, secretory, digestive, and absorptive functions that is vulnerable to a multitude of potential disturbances which may lead to global or specific malabsorption syndromes. Potential pathomechanisms that are illustrated in this article include insufficient mechanical breakdown of harder food components due to chewing problems and/or decreased antral contractility, critical reduction of time for absorption in patients with markedly enhanced upper gastrointestinal transit (e.g. dumping syndrome), impaired digestion and absorption of nutrient components caused by reduced gastric acid secretion, pancreatic exocrine insufficiency or reduced biliary secretion, defects of the enteral mucosa with enzyme deficiencies (e.g. disaccharidases) or lack of specific carrier mechanisms (e.g. hexose or aminoacid transporters), and critical quantitative loss of intestinal mucosa in patients with short bowel syndrome. PMID:26288588

Randomized controlled trial of changes in dietary carbohydrate/fat ratio and simple vs complex carbohydrates on body weight and blood lipids: the CARMEN study. The Carbohydrate Ratio Management in European National diets.

PubMed

Saris, W H; Astrup, A; Prentice, A M; Zunft, H J; Formiguera, X; Verboeket-van de Venne, W P; Raben, A; Poppitt, S D; Seppelt, B; Johnston, S; Vasilaras, T H; Keogh, G F

2000-10-01

To investigate the long-term effects of changes in dietary carbohydrate/fat ratio and simple vs complex carbohydrates. Randomized controlled multicentre trial (CARMEN), in which subjects were allocated for 6 months either to a seasonal control group (no intervention) or to one of three experimental groups: a control diet group (dietary intervention typical of the average national intake); a low-fat high simple carbohydrate group; or a low-fat high complex carbohydrate group. Three hundred and ninety eight moderately obese adults. The change in body weight was the primary outcome; changes in body composition and blood lipids were secondary outcomes. Body weight loss in the low-fat high simple carbohydrate and low-fat high complex carbohydrate groups was 0.9 kg (P < 0.05) and 1.8 kg (P < 0.001), while the control diet and seasonal control groups gained weight (0.8 and 0.1 kg, NS). Fat mass changed by -1.3kg (P< 0.01), -1.8kg (P< 0.001) and +0.6kg (NS) in the low-fat high simple carbohydrate, low-fat high complex carbohydrate and control diet groups, respectively. Changes in blood lipids did not differ significantly between the dietary treatment groups. Our findings suggest that reduction of fat intake results in a modest but significant reduction in body weight and body fatness. The concomitant increase in either simple or complex carbohydrates did not indicate significant differences in weight change. No adverse effects on blood lipids were observed. These findings underline the importance of this dietary change and its potential impact on the public health implications of obesity.

Systematic review: the prevalence of idiopathic bile acid malabsorption as diagnosed by SeHCAT scanning in patients with diarrhoea-predominant irritable bowel syndrome.

PubMed

Wedlake, L; A'Hern, R; Russell, D; Thomas, K; Walters, J R F; Andreyev, H J N

2009-10-01

Recurrent, watery diarrhoea affects one-third of patients diagnosed with irritable bowel syndrome ('IBS-D'). Idiopathic bile acid malabsorption ('I-BAM') may be the cause. To determine the prevalence of I-BAM in patients suffering from IBS-D. A systematic search was performed of publications reporting patients presenting with IBS-D type symptoms, who were subsequently confirmed as having I-BAM by SeHCAT scanning. Eighteen relevant studies, 15 prospective, comprising 1223 patients were identified. Five studies (429 patients) indicated that 10% (CI: 7-13) patients had severe bile acid malabsorption (SeHCAT 7 day retention <5% of baseline value). 17 studies (1073 patients) indicated that 32% (CI: 29-35) patients had moderate bile acid malabsorption (SeHCAT <10%). 7 studies (618 patients) indicated that 26% (CI: 23-30) patients had mild (SeHCAT <15%) bile acid malabsorption. Pooled data from 15 studies showed a dose-response relationship according to severity of malabsorption to treatment with a bile acid binder: response to colestyramine occurred in 96% of patients with <5% retention, 80% at <10% retention and 70% at <15% retention. Idiopathic adult-onset bile acid malabsorption is not rare. International guidelines for the management of irritable bowel syndrome need to be revised so that clinicians become more aware of this possibility.

Normal or increased bile acid uptake in isolated mucosa from patients with bile acid malabsorption.

PubMed

Bajor, Antal; Kilander, Anders; Fae, Anita; Gälman, Cecilia; Jonsson, Olof; Ohman, Lena; Rudling, Mats; Sjövall, Henrik; Stotzer, Per-Ove; Ung, Kjell-Arne

2006-04-01

Bile acid malabsorption as reflected by an abnormal Se-labelled homocholic acid-taurine (SeHCAT) test is associated with diarrhoea, but the mechanisms and cause-and-effect relations are unclear. Primarily, to determine whether there is a reduced active bile acid uptake in the terminal ileum in patients with bile acid malabsorption. Secondarily, to study the linkage between bile acid malabsorption and hepatic bile acid synthesis. Ileal biopsies were taken from patients with diarrhoea and from controls with normal bowel habits. Maximal active bile acid uptake was assessed in ileal biopsies using a previously validated technique based on uptake of C-labelled taurocholate. To monitor the hepatic synthesis, 7alpha-hydroxy-4-cholesten-3-one, a bile acid precursor, was assayed in blood. The SeHCAT-retention test was used to diagnose bile acid malabsorption. The taurocholate uptake in specimens from diarrhoea patients was higher compared with the controls [median, 7.7 (n=53) vs 6.1 micromol/g per min (n=17)] (P<0.01) but no difference was seen between those with bile acid malabsorption (n=18) versus diarrhoea with a normal SeHCAT test (n=23). The SeHCAT values and 7alpha-hydroxy-4-cholesten-3-one were inversely correlated. The data do not support bile acid malabsorption being due to a reduced active bile acid uptake capacity in the terminal ileum.

Carbohydrates

MedlinePlus

... include sugars added during food processing and refining. Complex carbohydrates include whole grain breads and cereals, starchy vegetables and legumes. Many of the complex carbohydrates are good sources of fiber. For a healthy ...

Bile acid malabsorption investigated by selenium-75-homocholic acid taurine ((75)SeHCAT) scans: causes and treatment responses to cholestyramine in 298 patients with chronic watery diarrhoea.

PubMed

Borghede, Märta K; Schlütter, Jacob M; Agnholt, Jørgen S; Christensen, Lisbet A; Gormsen, Lars C; Dahlerup, Jens F

2011-12-01

The liver produces and secretes bile acids into the small intestine. In the small intestine, most of the bile acids are absorbed in the distal ileum with portal vein transportation back to the liver and resecretion (enterohepatic recycling). Increased spillover of bile acids from the small intestine into the colon (bile acid malabsorption) may affect the secretion of colonic water and electrolytes and result in watery diarrhoea. The aim of this study was to investigate the frequency of bile acid malabsorption and treatment responses to cholestyramine with (75)SeHCAT scanning among patients suffering from chronic watery diarrhoea. This was a retrospective study that included all patients who received a (75)SeHCAT scan over a five-year period (2004-2009). In total, 298 patients (198 females, 100 men) with a median age of 42 years (range 16-82 years) were investigated. Bile acid malabsorption ((75)SeHCAT retention<15% after seven days) was identified in 201 patients (68%, 95% confidence interval (CI): 62%-73%). Bile acid malabsorption due to ileal dysfunction (Type I) was found in 77 patients, idiopathic bile acid malabsorption (Type II) was found in 68 patients and 56 patients with other conditions had bile acid malabsorption (Type III). Of the 150 patients who were able to take cholestyramine continuously, 108 patients (71%, CI: 63%-78%) reported a positive effect on their bowel habits. Bile acid malabsorption is a frequent problem in patients with chronic watery diarrhoea. Treatment with bile acid binders was effective regardless of type and severity. Copyright © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Nutrition and fluid optimization for patients with short bowel syndrome.

PubMed

Matarese, Laura E

2013-03-01

Short bowel syndrome (SBS) is characterized by nutrient malabsorption and occurs following surgical resection, congenital defect, or disease of the bowel. The severity of SBS depends on the length and anatomy of the bowel resected and the health of the remaining tissue. During the 2 years following resection, the remnant bowel undergoes an adaptation process that increases its absorptive capacity. Oral diet and enteral nutrition (EN) enhance intestinal adaptation; although patients require parenteral nutrition (PN) and/or intravenous (IV) fluids in the immediate postresection period, diet and EN should be reintroduced as soon as possible. The SBS diet should include complex carbohydrates; simple sugars should be avoided. Optimal fat intake varies based on patient anatomy; patients with end-jejunostomies can tolerate a higher proportion of calories from dietary fat than patients with a remnant colon. Patients with SBS are prone to deficiencies in vitamins, minerals, and essential fatty acids; serum levels should be periodically monitored and supplements provided as needed. Prebiotic or probiotic therapy may be beneficial for patients with SBS, although further research is needed to determine optimal protocols. Patients with SBS, particularly those without a colon, are at high risk of dehydration; oral rehydration solutions sipped throughout the day can help maintain hydration. One of the primary goals of SBS therapy is to reduce or eliminate dependence on PN/IV; optimization of EN and hydration substantially increases the probability of successful PN/IV weaning.

The pathogenesis of post-irradiation chronic diarrhoea: measurement of SeHCAT and B12 absorption for differential diagnosis determines treatment.

PubMed

Ludgate, S M; Merrick, M V

1985-05-01

The absorption of vitamin B12 and of a synthetic bile acid analogue 75SeHCAT was measured simultaneously in 26 patients presenting with persistent diarrhoea following pelvic irradiation for treatment of carcinoma of the cervix. Four groups were identified, namely patients with isolated bile acid malabsorption, patients with isolated B12 malabsorption, patients with malabsorption of both and those with malabsorption of neither compound. The therapeutic implications are different for each. Measurement of B12 and bile acid absorption comprises an important new test for the management of patients with this disabling and unpleasant complication of radiotherapy.

[Results of the 75selenium homotaurocholic acid retention test (SeHCAT test) in diagnosis of diarrhea].

PubMed

Balzer, K; Schmitt, G; Reiners, C; Goebell, H

1995-01-15

For that reason absorption of bile acids was investigated using the 75Se-homotaurocholate (SeHCAT) in 239 patients with diarrhoea. SeHCAT retention time was measured as 7 day retention time in a whole body counter. An intact bile acid absorption (negative SeHCAT test) was confirmed in 23 healthy volunteers within the range of 11 to 50% (mean +/- double standard deviation). In 135 patients with a possible type I bile salt malabsorption the SeHCAT test was positive in 78%, thus indicating bile salt malabsorption. The test is very sensitive detecting bile salt malabsorption in Crohn's disease, identifying ileal disease more precisely than radiology. The SeHCAT test ascertained type II primary bile salt malabsorption in 7 patients, as well as type III bile salt malabsorption in patients (9 out of 28) with cholecystectomy, vagotomy, partial gastrectomy and chronic pancreatitis. In addition, a positive SeHCAT test indicating bile acid malabsorption was found in 5 out of 11 patients with irritable syndrome, diarrhoeic form, and in 4 out of 12 patients with lactose intolerance. SeHCAT retention should be measured routinely in patients with chronic diarrhoea for which the cause is not obvious.

The Role of Carbohydrate Response Element Binding Protein in Intestinal and Hepatic Fructose Metabolism.

PubMed

Iizuka, Katsumi

2017-02-22

Many articles have discussed the relationship between fructose consumption and the incidence of obesity and related diseases. Fructose is absorbed in the intestine and metabolized in the liver to glucose, lactate, glycogen, and, to a lesser extent, lipids. Unabsorbed fructose causes bacterial fermentation, resulting in irritable bowl syndrome. Therefore, understanding the mechanisms underlying intestinal and hepatic fructose metabolism is important for the treatment of metabolic syndrome and fructose malabsorption. Carbohydrate response element binding protein (ChREBP) is a glucose-activated transcription factor that controls approximately 50% of de novo lipogenesis in the liver. ChREBP target genes are involved in glycolysis (Glut2, liver pyruvate kinase), fructolysis (Glut5, ketohexokinase), and lipogenesis (acetyl CoA carboxylase, fatty acid synthase). ChREBP gene deletion protects against high sucrose diet-induced and leptin-deficient obesity, because Chrebp -/- mice cannot consume fructose or sucrose. Moreover, ChREBP contributes to some of the physiological effects of fructose on sweet taste preference and glucose production through regulation of ChREBP target genes, such as fibroblast growth factor-21 and glucose-6-phosphatase catalytic subunits. Thus, ChREBP might play roles in fructose metabolism. Restriction of excess fructose intake will be beneficial for preventing not only metabolic syndrome but also irritable bowl syndrome.

The Role of Carbohydrate Response Element Binding Protein in Intestinal and Hepatic Fructose Metabolism

PubMed Central

Iizuka, Katsumi

2017-01-01

Many articles have discussed the relationship between fructose consumption and the incidence of obesity and related diseases. Fructose is absorbed in the intestine and metabolized in the liver to glucose, lactate, glycogen, and, to a lesser extent, lipids. Unabsorbed fructose causes bacterial fermentation, resulting in irritable bowl syndrome. Therefore, understanding the mechanisms underlying intestinal and hepatic fructose metabolism is important for the treatment of metabolic syndrome and fructose malabsorption. Carbohydrate response element binding protein (ChREBP) is a glucose-activated transcription factor that controls approximately 50% of de novo lipogenesis in the liver. ChREBP target genes are involved in glycolysis (Glut2, liver pyruvate kinase), fructolysis (Glut5, ketohexokinase), and lipogenesis (acetyl CoA carboxylase, fatty acid synthase). ChREBP gene deletion protects against high sucrose diet-induced and leptin-deficient obesity, because Chrebp−/− mice cannot consume fructose or sucrose. Moreover, ChREBP contributes to some of the physiological effects of fructose on sweet taste preference and glucose production through regulation of ChREBP target genes, such as fibroblast growth factor-21 and glucose-6-phosphatase catalytic subunits. Thus, ChREBP might play roles in fructose metabolism. Restriction of excess fructose intake will be beneficial for preventing not only metabolic syndrome but also irritable bowl syndrome. PMID:28241431

Evaluation of short stature, carbohydrate metabolism and other endocrinopathies in Bloom's syndrome.

PubMed

Diaz, Alejandro; Vogiatzi, Maria G; Sanz, Maureen M; German, James

2006-01-01

To obtain an understanding of the etiology of proportional dwarfism and endocrinopathies of Bloom's syndrome BS. Admission for 5-day periods to an NIH-supported Clinical Research Center of a randomly selected population of persons with BS (n = 11; mean age 11.5 years, range 9 months to 28.5 years) for clinical and genetic history-taking, physical examination, and endocrinological, gastroenterological and immunological testing. An oral glucose tolerance test was performed in all participants. Impaired glucose tolerance was present in 4 individuals, insulin resistance was observed in 6 individuals, and previously unrecognized diabetes was found in 1. Growth hormone provocation was normal in the 10 individuals tested. Overnight frequent GH sampling was suggestive of neurosecretory dysfunction in 3. Compensated hypothyroidism was found in 2 participants. Lipid profile abnormalities were present in 5 of 10 individuals. Low immunoglobulin concentrations (IgG and/or IgM) were seen in all tested. Intestinal absorption by D-xylose and/or fecal fat measurement was normal in all individuals tested as well. Altered carbohydrate metabolism is very common in BS, and is present from childhood. BS dwarfism is not related to growth hormone deficiency or malabsorption. The basis for the growth restriction in BS remains to be elucidated. Copyright (c) 2006 S. Karger AG, Basel.

Learning about Carbohydrates

MedlinePlus

... added sugar and doesn't contain important nutrients. Complex carbohydrates: These are also called starches. Starches include grain ... pasta, and rice. As with simple sugars, some complex carbohydrate foods are better choices than others. Refined (say: ...

Idiopathic bile acid malabsorption: qualitative and quantitative clinical features and response to cholestyramine.

PubMed

Sinha, L; Liston, R; Testa, H J; Moriarty, K J

1998-09-01

Idiopathic bile acid malabsorption is a poorly recognized cause of chronic diarrhoea. The SeHCAT (75Selenium HomotauroCholic Acid Test) can accurately diagnose this condition. To identify patients with idiopathic bile acid malabsorption, to describe their clinical features, both qualitatively and quantitatively, and to assess the response to cholestyramine. Idiopathic bile acid malabsorption was considered in all patients complaining of chronic diarrhoea. They were included in the study if their SeHCATs were positive (< 15% retention) and secondary causes of bile acid malabsorption were excluded. The response to therapy with cholestyramine was assessed. Nine patients were diagnosed with idiopathic bile acid malabsorption (median SeHCAT retention 8%, range 3-12.6). Their median daily faecal weight was 285 g (range 85-676) and median faecal fat output was 17 mmol/24 h (range 8.3-38.8). Six patients had an immediate response to cholestyramine. There was a marked reduction in stool frequency (median stool frequency pre-treatment 5/day vs. 2/day post-treatment, P = 0.03). Five patients had large volume diarrhoea (faecal weight > 200 g/day) and three had steatorrhoea. Idiopathic bile acid malabsorption, once suspected, especially by documenting true 'large volume' watery diarrhoea or steatorrhoea, is easily diagnosed and response to therapy is often very good. There is often a previous history of gastrointestinal infection and this condition should be considered in patients with chronic diarrhoea of undetermined origin, especially before they are labelled as having irritable bowel syndrome.

Computational modeling of carbohydrate recognition in protein complex

NASA Astrophysics Data System (ADS)

Ishida, Toyokazu

2017-11-01

To understand the mechanistic principle of carbohydrate recognition in proteins, we propose a systematic computational modeling strategy to identify complex carbohydrate chain onto the reduced 2D free energy surface (2D-FES), determined by MD sampling combined with QM/MM energy corrections. In this article, we first report a detailed atomistic simulation study of the norovirus capsid proteins with carbohydrate antigens based on ab initio QM/MM combined with MD-FEP simulations. The present result clearly shows that the binding geometries of complex carbohydrate antigen are determined not by one single, rigid carbohydrate structure, but rather by the sum of averaged conformations mapped onto the minimum free energy region of QM/MM 2D-FES.

Heat capacity changes in carbohydrates and protein-carbohydrate complexes.

PubMed

Chavelas, Eneas A; García-Hernández, Enrique

2009-05-13

Carbohydrates are crucial for living cells, playing myriads of functional roles that range from being structural or energy-storage devices to molecular labels that, through non-covalent interaction with proteins, impart exquisite selectivity in processes such as molecular trafficking and cellular recognition. The molecular bases that govern the recognition between carbohydrates and proteins have not been fully understood yet. In the present study, we have obtained a surface-area-based model for the formation heat capacity of protein-carbohydrate complexes, which includes separate terms for the contributions of the two molecular types. The carbohydrate model, which was calibrated using carbohydrate dissolution data, indicates that the heat capacity contribution of a given group surface depends on its position in the saccharide molecule, a picture that is consistent with previous experimental and theoretical studies showing that the high abundance of hydroxy groups in carbohydrates yields particular solvation properties. This model was used to estimate the carbohydrate's contribution in the formation of a protein-carbohydrate complex, which in turn was used to obtain the heat capacity change associated with the protein's binding site. The model is able to account for protein-carbohydrate complexes that cannot be explained using a previous model that only considered the overall contribution of polar and apolar groups, while allowing a more detailed dissection of the elementary contributions that give rise to the formation heat capacity effects of these adducts.

Immune functional impacts of oyster peptide-based enteral nutrition formula (OPENF) on mice: a pilot study

NASA Astrophysics Data System (ADS)

Cai, Bingna; Pan, Jianyu; Wu, Yuantao; Wan, Peng; Sun, Huili

2013-07-01

Oyster peptides were produced from Crassostrea hongkongensis and used as a new protein source for the preparation of an oyster peptide-based enteral nutrition formula (OPENF). Reserpineinduced malabsorption mice and cyclophosphamide-induced immunosuppression mice were used in this study. OPENF powder is light yellow green and has a protein-fat-carbohydrate ratio of 16:9:75 with good solubility in water. A pilot study investigating immune functional impacts of the OPENF on mice show that the OPENF enhanced spleen lymphocyte proliferation and the activity of natural killer (NK) cells in BALB/c mice. Furthermore, OPENF can improve intestinal absorption, increase food utilization ratio, and maintain the normal physiological function of mice. These results suggest that oyster peptides could serve as a new protein source for use in enteral nutrition formula, but more importantly, also indicate that OPENF has an immunostimulating effect in mice.

Low-Carb Diet: Could It Help You Lose Weight?

MedlinePlus

... body uses carbohydrates as its main fuel source. Complex carbohydrates (starches) are broken down into simple sugars during ... known as blood sugar (glucose). In general, natural complex carbohydrates are digested more slowly and they have less ...

Lactose malabsorption in Polynesian and white children in the south west Pacific studied by breath hydrogen technique.

PubMed Central

Seakins, J M; Elliott, R B; Quested, C M; Matatumua, A

1987-01-01

Lactose malabsorption was studied by a breath hydrogen technique in 139 Samoan and 68 white schoolchildren. The Samoans were studied in four locations, two in Western Samoa and two in New Zealand, and the white children in both the Cook Islands and New Zealand. The prevalence of malabsorption varied with location: for Samoans it ranged from 41% to 60% in Western Samoa and 0% to 35% in New Zealand; white children had rates of 27% in the Cook Islands and 5% in New Zealand. Environmental factors rather than genetic factors are likely to play the main part in initiating if not perpetuating lactose malabsorption. In both races lactose malabsorption had no effect on the acceptance of, consumption of, and number of gastrointestinal symptoms caused by milk and milk biscuits. Children who had symptoms after consuming a particular dairy product were more likely to say they disliked it than those who reported no symptoms. PMID:3119083

Is the subjective perception of lactose intolerance influenced by the psychological profile?

PubMed

Tomba, C; Baldassarri, A; Coletta, M; Cesana, B M; Basilisco, G

2012-10-01

Symptoms of lactose intolerance are often attributed to lactose malabsorption but, as this relationship has not been demonstrated when a small dose of lactose similar to that contained in one cup of milk is ingested by intolerant patients, psychological factors may play a role in altered symptom perception. To assess the hypothesis that the psychological profile influences the symptoms of lactose intolerance. One hundred and two consecutive patients underwent a 15 g lactose hydrogen breath test to assess lactose malabsorption. The patients recorded the presence and severity of symptoms of lactose intolerance during the breath test using visual analogue scales. The psychological profile was assessed using a psychological symptom checklist, and health-related quality of life by means of the short-form health survey. Lactose malabsorption and intolerance were diagnosed in, respectively, 18% and 29% of the patients. The two conditions were not associated, and the severity of intolerance was even less in the patients with malabsorption. Multivariate logistic analysis showed that a high somatisation t-score was significantly associated with lactose intolerance (odds ratio 4.184; 1.704-10.309); the effects of the other psychological variables and of lactose malabsorption were not statistically significant. Health-related quality of life was significantly reduced in the patients with somatisation, but not in those with lactose malabsorption. The symptoms of lactose intolerance during hydrogen breath testing at a low physiological lactose load, are unrelated to lactose malabsorption, but may reveal a tendency towards somatisation that could impair the quality of life. © 2012 Blackwell Publishing Ltd.

A carbohydrate-anion recognition system in aprotic solvents.

PubMed

Ren, Bo; Dong, Hai; Ramström, Olof

2014-05-01

A carbohydrate-anion recognition system in nonpolar solvents is reported, in which complexes form at the B-faces of β-D-pyranosides with H1-, H3-, and H5-cis patterns similar to carbohydrate-π interactions. The complexation effect was evaluated for a range of carbohydrate structures; it resulted in either 1:1 carbohydrate-anion complexes, or 1:2 complex formation depending on the protection pattern of the carbohydrate. The interaction was also evaluated with different anions and solvents. In both cases it resulted in significant binding differences. The results indicate that complexation originates from van der Waals interactions or weak CH⋅⋅⋅A(-) hydrogen bonds between the binding partners and is related to electron-withdrawing groups of the carbohydrates as well as increased hydrogen-bond-accepting capability of the anions. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Applying a Low-FODMAP Dietary Intervention to a Female Ultra-Endurance Runner With Irritable Bowel Syndrome During a Multi-Stage Ultra-Marathon.

PubMed

Gaskell, Stephanie K; Costa, Ricardo J S

2018-05-14

Malabsorption of Fermentable Oligo- Di- and Mono-saccharides and Polyols (FODMAPs) in response to prolonged exercise may increase incidence of upper- and lower-gastrointestinal symptoms (GIS), which are known to impair exercise performance. The case-study aimed to explore the impact of a low-FODMAP diet on exercise-associated GIS in a female ultra-endurance runner diagnosed with irritable bowel syndrome (IBS), competing in a six-day 186.7 km mountainous multi-stage ultra-marathon (MSUM). IBS symptom severity score at diagnosis was 410 and following a low-FODMAP diet (3.9 g FODMAPs·day -1 ) reduced to 70. The diet was applied six-days before (i.e., lead-in diet), and maintained during (5.1 g FODMAPs·day -1 ) the MSUM. Nutrition intake was analysed through dietary analysis software. A validated 100 mm visual analogue scale quantified GIS incidence and severity. GIS were modest during the MSUM (overall mean ± SD: bloating 27 ± 5 mm and flatulence 23 ± 8 mm), except severe nausea (67 ± 14 mm) experienced throughout. Total daily energy (11.7 ± 1.6 MJ·day -1 ) intake did not meet estimated energy requirements (range: 13.9-17.9 MJ·day -1 ). Total daily protein (1.4 ± 0.3 g·kgbody weight (BW) -1 ·day -1 ), carbohydrate (9.1 ± 1.3 g·kgBW -1 ·day -1 ), fat (1.1 ± 0.2 g·kgBW -1 ·day -1 ), and water (78.7 ± 6.4 ml·kgBW -1 ·day -1 ) intakes satisfied current consensus guidelines, except for carbohydrates. Carbohydrate intake during running failed to meet recommendations (43 ± 9 g·h -1 ). The runner successfully implemented a low-FODMAP diet completing the MSUM with minimal GIS. However, suboptimal energy and carbohydrate intake occurred, potentially exacerbated by nausea associated with running at altitude.

The Role of Supplemental Complex Dietary Carbohydrates and Gut Microbiota in Promoting Cardiometabolic and Immunological Health in Obesity: Lessons from Healthy Non-Obese Individuals

PubMed Central

Vinke, Petra C.; El Aidy, Sahar; van Dijk, Gertjan

2017-01-01

Dietary supplementation with complex carbohydrates is known to alter the composition of gut microbiota, and optimal implementation of the use of these so called “prebiotics” could be of great potential in prevention and possibly treatment of obesity and associated cardiometabolic and inflammatory diseases via changes in the gut microbiota. An alternative to this “microbiocentric view” is the idea that health-promoting effects of certain complex carbohydrates reside in the host, and could secondarily affect the diversity and abundance of gut microbiota. To circumvent this potential interpretational problem, we aimed at providing an overview about whether and how dietary supplementation of different complex carbohydrates changes the gut microbiome in healthy non-obese individuals. We then reviewed whether the reported changes in gut bacterial members found to be established by complex carbohydrates would benefit or harm the cardiometabolic and immunological health of the host taking into account the alterations in the microbiome composition and abundance known to be associated with obesity and its associated disorders. By combining these research areas, we aimed to give a better insight into the potential of (foods containing) complex carbohydrates in the treatment and prevention of above-mentioned diseases. We conclude that supplemental complex carbohydrates that increase Bifidobacteria and Lactobacilli, without increasing the deleterious Bacteroides, are most likely promoting cardiometabolic and immunological health in obese subjects. Because certain complex carbohydrates also affect the host’s immunity directly, it is likely that host–microbiome interactions in determination of health and disease characteristics are indeed bidirectional. Overall, this review article shows that whereas it is relatively clear in which direction supplemental fermentable carbohydrates can alter the gut microbiome, the relevance of these changes regarding health remains controversial. Future research should take into account the different causes of obesity and its adverse health conditions, which in turn have drastic effects on the microbiome balance. PMID:28791292

The Role of Supplemental Complex Dietary Carbohydrates and Gut Microbiota in Promoting Cardiometabolic and Immunological Health in Obesity: Lessons from Healthy Non-Obese Individuals.

PubMed

Vinke, Petra C; El Aidy, Sahar; van Dijk, Gertjan

2017-01-01

Dietary supplementation with complex carbohydrates is known to alter the composition of gut microbiota, and optimal implementation of the use of these so called "prebiotics" could be of great potential in prevention and possibly treatment of obesity and associated cardiometabolic and inflammatory diseases via changes in the gut microbiota. An alternative to this "microbiocentric view" is the idea that health-promoting effects of certain complex carbohydrates reside in the host, and could secondarily affect the diversity and abundance of gut microbiota. To circumvent this potential interpretational problem, we aimed at providing an overview about whether and how dietary supplementation of different complex carbohydrates changes the gut microbiome in healthy non-obese individuals. We then reviewed whether the reported changes in gut bacterial members found to be established by complex carbohydrates would benefit or harm the cardiometabolic and immunological health of the host taking into account the alterations in the microbiome composition and abundance known to be associated with obesity and its associated disorders. By combining these research areas, we aimed to give a better insight into the potential of (foods containing) complex carbohydrates in the treatment and prevention of above-mentioned diseases. We conclude that supplemental complex carbohydrates that increase Bifidobacteria and Lactobacilli, without increasing the deleterious Bacteroides , are most likely promoting cardiometabolic and immunological health in obese subjects. Because certain complex carbohydrates also affect the host's immunity directly, it is likely that host-microbiome interactions in determination of health and disease characteristics are indeed bidirectional. Overall, this review article shows that whereas it is relatively clear in which direction supplemental fermentable carbohydrates can alter the gut microbiome, the relevance of these changes regarding health remains controversial. Future research should take into account the different causes of obesity and its adverse health conditions, which in turn have drastic effects on the microbiome balance.

Role of bile acids and bile acid binding agents in patients with collagenous colitis

PubMed Central

Ung, K; Gillberg, R; Kilander, A; Abrahamsson, H

2000-01-01

BACKGROUND—In a retrospective study bile acid malabsorption was observed in patients with collagenous colitis.
AIMS—To study the occurrence of bile acid malabsorption and the effect of bile acid binders prospectively in patients with chronic diarrhoea and collagenous colitis.
METHODS—Over 36 months all patients referred because of chronic diarrhoea completed a diagnostic programme, including gastroscopy with duodenal biopsy, colonoscopy with biopsies, and the 75Se-homocholic acid taurine (75SeHCAT) test for bile acid malabsorption. Treatment with a bile acid binder (cholestyramine in 24, colestipol in three) was given, irrespective of the results of the 75SeHCAT test.
RESULTS—Collagenous colitis was found in 28 patients (six men, 22 women), 27 of whom had persistent symptoms and completed the programme. Four patients had had a previous cholecystectomy or a distal gastric resection. The 75SeHCAT test was abnormal in 12/27 (44%) of the collagenous colitis patients with 75SeHCAT values 0.5-9.7%, and normal in 15 patients (56%). Bile acid binding treatment was followed by a rapid, marked, or complete improvement in 21/27 (78%) of the collagenous colitis patients. Rapid improvement occurred in 11/12 (92%) of the patients with bile acid malabsorption compared with 10/15 (67%) of the patients with normal 75SeHCAT tests.
CONCLUSION—Bile acid malabsorption is common in patients with collagenous colitis and is probably an important pathophysiological factor. Because of a high response rate without serious side effects, bile acid binding treatment should be considered for collagenous colitis, particularly patients with bile acid malabsorption.


Keywords: bile acid malabsorption; collagenous colitis; diarrhoea; cholestyramine; colestipol PMID:10644309

Prevalence of, and predictors of, bile acid malabsorption in outpatients with chronic diarrhea.

PubMed

Gracie, D J; Kane, J S; Mumtaz, S; Scarsbrook, A F; Chowdhury, F U; Ford, A C

2012-11-01

Many physicians do not consider the diagnosis of bile acid malabsorption in patients with chronic diarrhea, or do not have access to testing. We examined yield of 23-seleno-25-homo-tauro-cholic acid (SeHCAT) scanning in chronic diarrhea patients, and attempted to identify predictors of a positive test. Consecutive patients with chronic diarrhea undergoing SeHCAT scan over a 7-year period were identified retrospectively. Bile acid malabsorption was defined as present at a retention of <15%. Medical records were reviewed to obtain information regarding proposed risk factors. Gastrointestinal symptoms were recorded, and patients were classified as having diarrhea-predominant irritable bowel syndrome (IBS-D) if they reported abdominal pain or discomfort. Independent risk factors were assessed using multivariate logistic regression, and odds ratios (ORs) with 99% confidence intervals (CIs) were calculated. Of 373 patients, 190 (50.9%) had bile acid malabsorption. Previous cholecystectomy (OR 2.51; 99% CI 1.10-5.77), terminal ileal resection or right hemicolectomy for Crohn's disease (OR 12.4; 99% CI 2.42-63.8), and terminal ileal resection or right hemicolectomy for other reasons (OR 7.94; 99% CI 1.02-61.6) were associated with its presence. Seventy-seven patients had IBS-D, and 21 (27.3%) tested positive. There were 168 patients with no risk factors for a positive SeHCAT scan, other than chronic diarrhea, and 63 (37.5%) had bile acid malabsorption. Bile acid malabsorption was present in 50% of patients undergoing SeHCAT scanning. Almost 40% of those without risk factors had evidence of bile acid malabsorption, and in those meeting criteria for IBS-D prevalence was almost 30%. © 2012 Blackwell Publishing Ltd.

Chronic diarrhoea after radiotherapy for gynaecological cancer: occurrence and aetiology.

PubMed Central

Danielsson, A; Nyhlin, H; Persson, H; Stendahl, U; Stenling, R; Suhr, O

1991-01-01

The occurrence of chronic diarrhoea was evaluated in 173 consecutive patients previously treated with radiation for gynaecological cancer. A survey of gastrointestinal symptoms showed a high frequency of diarrhoea; 13% of the patients had 21 or more bowel movements a week and 3% had 28 or more. Significantly more patients who had a cholecystectomy were in the group with diarrhoea (chi 2 = 6.26; p less than 0.02). Twenty patients with chronic or intermittent diarrhoea were subject to extended gastrointestinal investigation. Bile acid malabsorption was evaluated by the 75Selenahomocholic acid-taurine test (SeHCAT). Bile acid malabsorption was found in 13 (65%) of the 20 patients further investigated, of whom seven had extremely low whole body retention values, which is consistent with severe malabsorption. The results suggest that bile acid malabsorption is a common cause of diarrhoea after radiation treatment for gynaecological cancer. Bacterial contamination was diagnosed in nine patients (45%) by the [14C]-D-xylose breath test or by the cholyl-[14C]-glycine breath test in combination with a normal test for bile acid malabsorption. All patients with vitamin B-12 deficiency, who were tested for bile acid malabsorption, had low retention times for the SeHCAT (p = 0.05). A significant decline in the frequency of diarrhoea was found after treatment with antibiotics or bile acid sequestrants, or both, in combination with a reduced fat diet. PMID:1955174

Nickel-catalyzed proton-deuterium exchange (HDX) procedures for glycosidic linkage analysis of complex carbohydrates

USDA-ARS?s Scientific Manuscript database

The structural analysis of complex carbohydrates typically requires the assignment of three parameters: monosaccharide composition, the position of glycosidic linkages between monosaccharides, and the position and nature of non-carbohydrate substituents. The glycosidic linkage positions are often de...

Laforin, a dual specificity phosphatase that dephosphorylates complex carbohydrates.

PubMed

Worby, Carolyn A; Gentry, Matthew S; Dixon, Jack E

2006-10-13

Laforin is the only phosphatase in the animal kingdom that contains a carbohydrate-binding module. Mutations in the gene encoding laforin result in Lafora disease, a fatal autosomal recessive neurodegenerative disorder, which is diagnosed by the presence of intracellular deposits of insoluble complex carbohydrates known as Lafora bodies. We demonstrate that laforin interacts with proteins known to be involved in glycogen metabolism and rule out several of these proteins as potential substrates. Surprisingly, we find that laforin displays robust phosphatase activity against a phosphorylated complex carbohydrate. Furthermore, this activity is unique to laforin, since several other phosphatases are unable to dephosphorylate polysaccharides. Finally, fusing the carbohydrate-binding module of laforin to the dual specific phosphatase VHR does not result in the ability of this phosphatase to dephosphorylate polysaccharides. Therefore, we hypothesize that laforin is unique in its ability to utilize a phosphorylated complex carbohydrate as a substrate and that this function may be necessary for the maintenance of normal cellular glycogen.

Clinical implications of lactose malabsorption versus lactose intolerance.

PubMed

Levitt, Michael; Wilt, Timothy; Shaukat, Aasma

2013-07-01

The majority of the world's adult population and an estimated 80 million Americans are hypolactasic and hence malabsorb ingested lactose. Although lactose malabsorption is easily identified, less readily assessed is the clinically important question of how often does this malabsorption induce symptoms. This review summarizes: (1) knowledge concerning the etiology and diagnosis of hypolactasia and the pathophysiology of the symptoms of lactose malabsorption and (2) the results of well-controlled trials of the symptomatic response of lactose malabsorbers to varying dosages of lactose and the efficacy of therapeutic interventions to alleviate these symptoms. We conclude that the clinical significance of lactose malabsorption has been overestimated by both the lay public and physicians in that commonly ingested doses of lactose (ie, the quantity in a cup of milk) usually do not cause perceptible symptoms when ingested with a meal. Symptoms occur when the lactose dosage exceeds that in a cup of milk or when lactose is ingested without other nutrients. Simple dietary instruction, rather than the use of commercial products to reduce lactose intake, is recommended for the vast majority of lactose-malabsorbing subjects.

Clinical use of acid steatocrit.

PubMed

Van den Neucker, A; Pestel, N; Tran, T M; Forget, P P; Veeze, H J; Bouquet, J; Sinaasappel, M

1997-05-01

Malabsorption of fat is an important gastrointestinal cause of malnutrition and growth retardation in childhood. The gold standard for the evaluation of fat malabsorption is the faecal fat balance method. The acid steatocrit method has recently been introduced as a simple method to evaluate faecal fat. The present study was aimed at evaluating the acid steatocrit in clinical practice. Faecal fat excretion and acid steatocrit results were determined in 42 children, half with and half without fat malabsorption. Acid steatocrit results correlated significantly with both faecal fat excretion (p < 0.01) and faecal fat concentration (p < 0.001). Sensitivity and specificity of the acid steatocrit for the diagnosis of malabsorption were 90% and 100%, respectively. We consider the acid steatocrit method useful for the screening and monitoring of patients with steatorrhoea.

Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus

PubMed Central

Rezaie, Ali; Buresi, Michelle; Lembo, Anthony; Lin, Henry; McCallum, Richard; Rao, Satish; Schmulson, Max; Valdovinos, Miguel; Zakko, Salam; Pimentel, Mark

2017-01-01

Objectives: Breath tests (BTs) are important for the diagnosis of carbohydrate maldigestion syndromes and small intestinal bacterial overgrowth (SIBO). However, standardization is lacking regarding indications for testing, test methodology and interpretation of results. A consensus meeting of experts was convened to develop guidelines for clinicians and research. Methods: Pre-meeting survey questions encompassing five domains; indications, preparation, performance, interpretation of results, and knowledge gaps, were sent to 17 clinician-scientists, and 10 attended a live meeting. Using an evidence-based approach, 28 statements were finalized and voted on anonymously by a working group of specialists. Results: Consensus was reached on 26 statements encompassing all five domains. Consensus doses for lactulose, glucose, fructose and lactose BT were 10, 75, 25 and 25 g, respectively. Glucose and lactulose BTs remain the least invasive alternatives to diagnose SIBO. BT is useful in the diagnosis of carbohydrate maldigestion, methane-associated constipation, and evaluation of bloating/gas but not in the assessment of oro-cecal transit. A rise in hydrogen of ≥20 p.p.m. by 90 min during glucose or lactulose BT for SIBO was considered positive. Methane levels ≥10 p.p.m. was considered methane-positive. SIBO should be excluded prior to BT for carbohydrate malabsorption to avoid false positives. A rise in hydrogen of ≥20 p.p.m. from baseline during BT was considered positive for maldigestion. Conclusions: BT is a useful, inexpensive, simple and safe diagnostic test in the evaluation of common gastroenterology problems. These consensus statements should help to standardize the indications, preparation, performance and interpretation of BT in clinical practice and research. PMID:28323273

Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus.

PubMed

Rezaie, Ali; Buresi, Michelle; Lembo, Anthony; Lin, Henry; McCallum, Richard; Rao, Satish; Schmulson, Max; Valdovinos, Miguel; Zakko, Salam; Pimentel, Mark

2017-05-01

Breath tests (BTs) are important for the diagnosis of carbohydrate maldigestion syndromes and small intestinal bacterial overgrowth (SIBO). However, standardization is lacking regarding indications for testing, test methodology and interpretation of results. A consensus meeting of experts was convened to develop guidelines for clinicians and research. Pre-meeting survey questions encompassing five domains; indications, preparation, performance, interpretation of results, and knowledge gaps, were sent to 17 clinician-scientists, and 10 attended a live meeting. Using an evidence-based approach, 28 statements were finalized and voted on anonymously by a working group of specialists. Consensus was reached on 26 statements encompassing all five domains. Consensus doses for lactulose, glucose, fructose and lactose BT were 10, 75, 25 and 25 g, respectively. Glucose and lactulose BTs remain the least invasive alternatives to diagnose SIBO. BT is useful in the diagnosis of carbohydrate maldigestion, methane-associated constipation, and evaluation of bloating/gas but not in the assessment of oro-cecal transit. A rise in hydrogen of ≥20 p.p.m. by 90 min during glucose or lactulose BT for SIBO was considered positive. Methane levels ≥10 p.p.m. was considered methane-positive. SIBO should be excluded prior to BT for carbohydrate malabsorption to avoid false positives. A rise in hydrogen of ≥20 p.p.m. from baseline during BT was considered positive for maldigestion. BT is a useful, inexpensive, simple and safe diagnostic test in the evaluation of common gastroenterology problems. These consensus statements should help to standardize the indications, preparation, performance and interpretation of BT in clinical practice and research.

Phylogenetic diversity of carbohydrate degrading culturable bacteria from Mandovi and Zuari estuaries, Goa, west coast of India

NASA Astrophysics Data System (ADS)

Khandeparker, Rakhee; Verma, Preeti; Meena, Ram M.; Deobagkar, Deepti D.

2011-12-01

Coastal and estuarine waters are highly productive and dynamic ecosystems. The complex carbohydrate composition of the ecosystem would lead to colonisation of microbial communities with abilities to produce an array of complex carbohydrate degrading enzymes. We have examined the abundance and phylogenetic diversity of culturable bacteria with abilities to produce complex carbohydrate degrading enzymes in the Mondovi and Zuari eustauri. It was interesting to note that 65% of isolated bacteria could produce complex carbohydrate degrading enzymes. A majority of these bacteria belonged to Bacillus genera followed by Vibrio, Marinobacter, Exiquinobacterium, Alteromonas, Enterobacter and Aeromonas. Most abundant bacterial genus to degrade hemicellulose and cellulose were Bacillus and Vibrio respectively. Most abundant bacterial genus to degrade hemicellulose and cellulose were Bacillus and Vibrio respectively. It was seen that 46% of Bacillus had ability to degrade both the substrate while only 14% of Vibrio had bifunctionality.

Intestinal Complications of IBD

MedlinePlus

... treated with topical creams or sitz baths. MALABSORPTION & MALNUTRITION Another complication in people with Crohn’s disease is ... the gut that absorbs most nutrients. Malabsorption and malnutrition usually do not develop unless the disease is ...

Carbohydrate Content in the GDM Diet: Two Views: View 1: Nutrition Therapy in Gestational Diabetes: The Case for Complex Carbohydrates.

PubMed

Hernandez, Teri L

2016-05-01

IN BRIEF Restriction of dietary carbohydrate has been the cornerstone for treatment of gestational diabetes mellitus (GDM). However, there is evidence that a balanced liberalization of complex carbohydrate as part of an overall eating plan in GDM meets treatment goals and may mitigate maternal adipose tissue insulin resistance, both of which may promote optimal metabolic outcomes for mother and offspring.

Analysis of ileal sodium/bile acid cotransporter and related nuclear receptor genes in a family with multiple cases of idiopathic bile acid malabsorption

PubMed Central

Montagnani, Marco; Abrahamsson, Anna; Gälman, Cecilia; Eggertsen, Gösta; Marschall, Hanns-Ulrich; Ravaioli, Elisa; Einarsson, Curt; Dawson, Paul A

2006-01-01

The etiology of most cases of idiopathic bile acid malabsorption (IBAM) is unknown. In this study, a Swedish family with bile acid malabsorption in three consecutive generations was screened for mutations in the ileal apical sodium-bile acid cotransporter gene (ASBT; gene symbol, SLC10A2) and in the genes for several of the nuclear receptors known to be important for ASBT expression: the farnesoid X receptor (FXR) and peroxisome proliferator activated receptor alpha (PPARα). The patients presented with a clinical history of idiopathic chronic watery diarrhea, which was responsive to cholestyramine treatment and consistent with IBAM. Bile acid absorption was determined using 75Se-homocholic acid taurine (SeHCAT); bile acid synthesis was estimated by measuring the plasma levels of 7α-hydroxy-4-cholesten-3-one (C4). The ASBT, FXR, and PPARα genes in the affected and unaffected family members were analyzed using single stranded conformation polymorphism (SSCP), denaturing HPLC, and direct sequencing. No ASBT mutations were identified and the ASBT gene did not segregate with the bile acid malabsorption phenotype. Similarly, no mutations or polymorphisms were identified in the FXR or PPARα genes associated with the bile acid malabsorption phenotype. These studies indicate that the intestinal bile acid malabsorption in these patients cannot be attributed to defects in ASBT. In the absence of apparent ileal disease, alternative explanations such as accelerated transit through the small intestine may be responsible for the IBAM. PMID:17171805

[Wernicke-Korsakoff syndrome].

PubMed

Kotov, S V; Lobakov, A I; Isakova, E V; Stashuk, G A; Volchenkova, T V

To study the diagnosis and treatment of non-alcoholic Wernicke-Korsakoff syndrome (WKS). Eight patients (5 men and 3 women), mean age 38,9±1,4 years, with WKS developed due to acute gastrointestinal tract (GIT) disease (3 patients), the exacerbation of chronic GIT disease with malabsorption (2 patients) and after surgery on the upper GIT (3 patients) were included in the study. The disease manifested with consciousness disturbance, symptoms of ataxia, eye movement disorders and bulbar syndrome that developed after 24-48 h. Treatment resistant tonic-clonic seizures were developed in 1 patient. MRI revealed hyper intensive signals on T2-weighted images in the hypothalamus, mamillar bodies, brain stem, hippocampus as well as contrast accumulation in the mamillar bodies. Treatment with vitamin B complex (neurobion) and thiamine exerted a positive effect. Patients with GIT disease with malabsorption are at risk of WKS. Consciousness disturbance, symptoms of ataxia, eye movement disorders indicate the necessity of treatment with thiamine that allows to prevent the development of stable cognitive deficit.

Prevalence of Lactose Malabsorption and Lactose Intolerance in Pediatric Patients with Selected Gastrointestinal Diseases.

PubMed

Pawłowska, Katarzyna; Umławska, Wioleta; Iwańczak, Barbara

2015-01-01

Lactase is an enzyme involved in the hydrolysis of lactose. Deficiency of the enzyme (hypolactasia) may be determined genetically or arise secondarily to disease of small intestine. Under this condition, lactose enters the colon where it is fermented by intestinal microflora and turns to gases and short-chain fatty acids, causing gastrointestinal symptoms known as lactose intolerance (LI). To investigate the incidence of lactose malabsorption (LM), LI and the coexistence of these two conditions in children with upper gastrointestinal tract diseases (UGTD), malabsorption syndrome, inflammatory bowel disease (IBD) and functional gastrointestinal disorders (FGID). Hydrogen breath test (HBT) was conducted in 387 pediatric patients in years 2010-2013. Two hundred thirty two children with gastrointestinal tract diseases were selected and assigned to groups - UGTD, malabsorption syndrome, IBD or FGID. For each group the frequency of LM, frequency and severity of LI and the frequency of their co-occurrence were calculated. Lactose malabsorption was observed in 37.08% of patients with gastrointestinal diseases. Positive HBT result was the most common in children with malabsorption syndrome (52.50%) and less common in UGTD (30.85%), especially in ulcer disease (23.53%). Symptoms after lactose ingestion affected 36.64% of the subjects, and were more specific to lactose malabsorbers than to lactose absorbers (72.10% vs. 15.75%). The higher frequency of LI was noted in children with FGID, especially in irritable bowel syndrome (IBS) (65.22%). The lowest incidence of symptoms was obtained in children with UGTD, especially in those with ulcer disease (27.44%). The incidence of LM with LI was noted in 27.16% of all patients and was the highest in IBS (47.83%) and the lowest in ulcer disease (15.78%). Lactose malabsorption is a common problem in children with gastrointestinal diseases, especially in children with bowel diseases. Lactose intolerance is related to LM, but does not affect all malabsorbers.

Role of bile acids and bile acid binding agents in patients with collagenous colitis.

PubMed

Ung, K A; Gillberg, R; Kilander, A; Abrahamsson, H

2000-02-01

In a retrospective study bile acid malabsorption was observed in patients with collagenous colitis. To study the occurrence of bile acid malabsorption and the effect of bile acid binders prospectively in patients with chronic diarrhoea and collagenous colitis. Over 36 months all patients referred because of chronic diarrhoea completed a diagnostic programme, including gastroscopy with duodenal biopsy, colonoscopy with biopsies, and the (75)Se-homocholic acid taurine ((75)SeHCAT) test for bile acid malabsorption. Treatment with a bile acid binder (cholestyramine in 24, colestipol in three) was given, irrespective of the results of the (75)SeHCAT test. Collagenous colitis was found in 28 patients (six men, 22 women), 27 of whom had persistent symptoms and completed the programme. Four patients had had a previous cholecystectomy or a distal gastric resection. The (75)SeHCAT test was abnormal in 12/27 (44%) of the collagenous colitis patients with (75)SeHCAT values 0.5-9.7%, and normal in 15 patients (56%). Bile acid binding treatment was followed by a rapid, marked, or complete improvement in 21/27 (78%) of the collagenous colitis patients. Rapid improvement occurred in 11/12 (92%) of the patients with bile acid malabsorption compared with 10/15 (67%) of the patients with normal (75)SeHCAT tests. Bile acid malabsorption is common in patients with collagenous colitis and is probably an important pathophysiological factor. Because of a high response rate without serious side effects, bile acid binding treatment should be considered for collagenous colitis, particularly patients with bile acid malabsorption.

Plasma lathosterol as a screening test for bile acid malabsorption due to ileal resection: correlation with 75SeHCAT test and faecal bile acid excretion.

PubMed

Färkkilä, M A; Kairemo, K J; Taavitsainen, M J; Strandberg, T A; Miettinen, T A

1996-04-01

1. Plasma lathosterol concentration, known to reflect cholesterol and bile acid synthesis, was evaluated as a screening test for bile acid malabsorption, comparing it with faecal bile acid measurements, SeHCAT test and Schilling test in 22 subjects of whom six were healthy controls and 16 had Crohn's disease with ileal resections of varying length. 2. Plasma lathosterols and other non-cholesterol sterols were determined by GLC. Faecal bile acids were measured by GLC, and SeHCAT retention times by gamma camera. The study subjects were divided into two groups according to the degree of bile acid malabsorption: controls (faecal bile acids < 10 mg day-1 kg-1, n = 9) and bile acid malabsorption (faecal bile acids > 10 mg day-1 kg-1, n = 13). 3. Faecal bile acid excretion was 5.9 +/- 1.0 mg day-1 kg-1 in control subjects and 45.7 +/- 6.1 mg day-1 kg-1 in the bile acid malabsorption group. The biological half-life of 75SeHCAT (T1/2) was 95.6 +/- 16.3 h and 14.1 +/- 4.1 h, respectively. Plasma lathosterol levels were significantly elevated in patients with bile acid malabsorption (742 +/- 84 micrograms/ml compared with 400 +/- 59 micrograms/ml in control subjects) and correlated closely with faecal bile acid levels (r = 0.779, P < 0.001), with 75SeHCAT T1/2 (r = -0.524, P < 0.05) and with Schilling test (r = -0.591, P < 0.05). Significant correlations were also obtained for delta 8-cholestenol with faecal bile acids (r = 0.784, P < 0.001) and 75SeHCAT (r = -0.505, P < 0.05). The biological half-life of SeHCAT correlated with faecal bile acid excretion (r = -0.702, P < 0.001). Using mean+2 SD of lathosterol (In micrograms/ml cholesterol) as a cut-off value and 10 mg day-1 kg-1 as the upper limit for faecal bile acid excretion, the test gives 100% sensitivity and 82% specificity for plasma lathosterol determination to detect bile acid malabsorption. 4. The results indicate that both the 75SeHCAT test and plasma lathosterol detect bile acid malabsorption in patients with ileal resections for Crohn's disease. However, plasma lathosterol is a simpler and less expensive method.

Bile acid malabsorption in Crohn's disease and indications for its assessment using SeHCAT.

PubMed

Nyhlin, H; Merrick, M V; Eastwood, M A

1994-01-01

Patients with Crohn's disease who suffer from longstanding diarrhoea that does not respond to conventional treatment pose a common clinical problem. Bile acid malabsorption is a possible cause, although its prevalence and clinical importance is unclear. This paper explores the clinical indications for referring patients with Crohn's disease for bile acid assessment and the extent of bile acid malabsorption in this selected group of patients. The selenium labelled bile acid SeHCAT was used to assess the effect of disease on the integrity of the enterohepatic circulation. Altogether 76% of the patients referred for bile acid assessment had longstanding diarrhoea that had not responded to conventional anti-diarrhoeal treatment or an increase in steroid therapy as their sole or predominant symptom. Ninety per cent of patients with bowel resections, almost exclusively ileocaecal, had abnormal SeHCAT retention (< 5% at seven days). Twenty eight per cent of patients with Crohn's disease who had not undergone resection 28% had a SeHCAT retention < 5%, signifying bile acid malabsorption. Nineteen of 22 patients given cholestyramine treatment subsequent to the SeHCAT test had a good symptomatic response. In conclusion, the prevalence of bile acid malabsorption in this selected group with Crohn's disease is sufficiently high to justify performing the SeHCAT test in order to separate the various differential diagnoses.

Reliability of the dual-isotope Schilling test for the diagnosis of pernicious anemia or malabsorption syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domstad, P.A.; Choy, Y.C.; Kim, E.E.

1981-05-01

To evaluate the dual-isotope Schilling test for the diagnosis of pernicious anemia or malabsorption syndrome, 65 studies were selected for clinical correlation. Criteria for pernicious anemia included mean corpuscular volume greater than 100 cu micrometer, serum B12 greater than 100 ng/l, megaloblastic marrow, achlorhydria, reticulocytes greater than 5% on B12 therapy, atrophic gastritis, and elevated serum antibodies to parietal cells or intrinsic factor. Criteria for malabsorption syndrome included: decreased serum B12, folate, and carotene; increased fecal fat; abnormal D-xylose absorption; abnormal radiographic and biopsy findings. /sup 58/Co-cyanocobalamin and /sup 57/Co-cyanocobalamin bound to intrinsic factor were given orally to fasting patients;more » 1 mg of nonradioactive B12 was injected intramuscularly within two hours. Aliquots of 24-hour urine samples were counted. If the excretion of /sup 58/Co was less than 7% and the /sup 57/Co//sup 58/Co ratio was greater than 1.7, the test indicated pernicious anemia; a ratio less than 1.7 indicated malabsorption syndrome. Sensitivity, specificity, and accuracy of the dual-isotope Schilling test were 83%, 98%, and 94% for pernicious anemia, and 67%, 90%, and 86% for malabsorption syndrome, respectively.« less

Exploring the free-energy landscape of carbohydrate-protein complexes: development and validation of scoring functions considering the binding-site topology

NASA Astrophysics Data System (ADS)

Eid, Sameh; Saleh, Noureldin; Zalewski, Adam; Vedani, Angelo

2014-12-01

Carbohydrates play a key role in a variety of physiological and pathological processes and, hence, represent a rich source for the development of novel therapeutic agents. Being able to predict binding mode and binding affinity is an essential, yet lacking, aspect of the structure-based design of carbohydrate-based ligands. We assembled a diverse data set comprising 273 carbohydrate-protein crystal structures with known binding affinity and evaluated the prediction accuracy of a large collection of well-established scoring and free-energy functions, as well as combinations thereof. Unfortunately, the tested functions were not capable of reproducing binding affinities in the studied complexes. To simplify the complex free-energy surface of carbohydrate-protein systems, we classified the studied proteins according to the topology and solvent exposure of the carbohydrate-binding site into five distinct categories. A free-energy model based on the proposed classification scheme reproduced binding affinities in the carbohydrate data set with an r 2 of 0.71 and root-mean-squared-error of 1.25 kcal/mol ( N = 236). The improvement in model performance underlines the significance of the differences in the local micro-environments of carbohydrate-binding sites and demonstrates the usefulness of calibrating free-energy functions individually according to binding-site topology and solvent exposure.

Substance use recovery and diet

MedlinePlus

... nausea). A high-fiber diet with plenty of complex carbohydrates (such as whole grains, vegetables, peas, and beans) ... that are low in fat Get more protein, complex carbohydrates , and dietary fiber Vitamin and mineral supplements may ...

Compatible topologies and parameters for NMR structure determination of carbohydrates by simulated annealing.

PubMed

Feng, Yingang

2017-01-01

The use of NMR methods to determine the three-dimensional structures of carbohydrates and glycoproteins is still challenging, in part because of the lack of standard protocols. In order to increase the convenience of structure determination, the topology and parameter files for carbohydrates in the program Crystallography & NMR System (CNS) were investigated and new files were developed to be compatible with the standard simulated annealing protocols for proteins and nucleic acids. Recalculating the published structures of protein-carbohydrate complexes and glycosylated proteins demonstrates that the results are comparable to the published structures which employed more complex procedures for structure calculation. Integrating the new carbohydrate parameters into the standard structure calculation protocol will facilitate three-dimensional structural study of carbohydrates and glycosylated proteins by NMR spectroscopy.

Compatible topologies and parameters for NMR structure determination of carbohydrates by simulated annealing

PubMed Central

2017-01-01

The use of NMR methods to determine the three-dimensional structures of carbohydrates and glycoproteins is still challenging, in part because of the lack of standard protocols. In order to increase the convenience of structure determination, the topology and parameter files for carbohydrates in the program Crystallography & NMR System (CNS) were investigated and new files were developed to be compatible with the standard simulated annealing protocols for proteins and nucleic acids. Recalculating the published structures of protein-carbohydrate complexes and glycosylated proteins demonstrates that the results are comparable to the published structures which employed more complex procedures for structure calculation. Integrating the new carbohydrate parameters into the standard structure calculation protocol will facilitate three-dimensional structural study of carbohydrates and glycosylated proteins by NMR spectroscopy. PMID:29232406

Three-dimensional representations of complex carbohydrates and polysaccharides--SweetUnityMol: a video game-based computer graphic software.

PubMed

Pérez, Serge; Tubiana, Thibault; Imberty, Anne; Baaden, Marc

2015-05-01

A molecular visualization program tailored to deal with the range of 3D structures of complex carbohydrates and polysaccharides, either alone or in their interactions with other biomacromolecules, has been developed using advanced technologies elaborated by the video games industry. All the specific structural features displayed by the simplest to the most complex carbohydrate molecules have been considered and can be depicted. This concerns the monosaccharide identification and classification, conformations, location in single or multiple branched chains, depiction of secondary structural elements and the essential constituting elements in very complex structures. Particular attention was given to cope with the accepted nomenclature and pictorial representation used in glycoscience. This achievement provides a continuum between the most popular ways to depict the primary structures of complex carbohydrates to visualizing their 3D structures while giving the users many options to select the most appropriate modes of representations including new features such as those provided by the use of textures to depict some molecular properties. These developments are incorporated in a stand-alone viewer capable of displaying molecular structures, biomacromolecule surfaces and complex interactions of biomacromolecules, with powerful, artistic and illustrative rendering methods. They result in an open source software compatible with multiple platforms, i.e., Windows, MacOS and Linux operating systems, web pages, and producing publication-quality figures. The algorithms and visualization enhancements are demonstrated using a variety of carbohydrate molecules, from glycan determinants to glycoproteins and complex protein-carbohydrate interactions, as well as very complex mega-oligosaccharides and bacterial polysaccharides and multi-stranded polysaccharide architectures. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Perception of lactose intolerance impairs health-related quality of life.

PubMed

Casellas, F; Aparici, A; Pérez, M J; Rodríguez, P

2016-09-01

Chronic conditions impair perception of well-being. Malabsorption of lactose is the most frequent form of malabsorption and manifests as lactose intolerance. There is a lack of information regarding their impact on self-perception of health. The objective of this study is to determine the subjective impact of self-reported lactose intolerance or objective lactose malabsorption on patient health by using a patient-reported outcome to measure health-related quality of life (HRQOL) and modification of lactose-containing food diet. A 3-year prospective, cross-sectional study was performed in patients referred for a lactose hydrogen breath test. Patients were asked about their subjective opinion relative to their lactose tolerance and completed a validated, specific questionnaire to determine symptoms of intolerance during habitual consumption of dairy. A 50-g lactose breath test was then performed. Patients were grouped as absorbers vs malabsorbers and tolerant vs intolerants. A total of 580 patients were included (median age 30 years, 419 female). Overall, 324 patients (56%) considered themselves lactose intolerant and that perception was associated with avoidance of dairy consumption (55% vs only 9% of self-defined tolerants). Self-perception of intolerance was associated with lower HRQOL scores (median, 60 vs 70, P<0.01). In contrast, lactose objective malabsorption was not clearly associated with dairy avoidance (41% of malabsorbers avoided dairy vs 31% of absorbers). However, HRQOL scores were also significantly lower in malabsorbers than in absorbers (60 vs 70 respectively, P<0.001). Subjective perception of lactose intolerance affects the decision to avoid dairy even more than objective malabsorption. However, both self-perception of lactose intolerance and objective lactose malabsorption are associated with poorer perceived quality of life.

Lactase Non-Persistence Genotyping: Comparison of Two Real-Time PCR Assays and Assessment of Concomitant Fructose/Sorbitol Malabsorption Rates.

PubMed

Enko, Dietmar; Pollheimer, Verena; Németh, Stefan; Pühringer, Helene; Stolba, Robert; Halwachs-Baumann, Gabriele; Kriegshäuser, Gernot

2016-01-01

Genetic testing is a standard technique for the diagnosis of primary adult-type hypolactasia, also referred to as lactase non-persistence. The aim of this study was to compare the lactase gene (LCT) C/T-13910 polymorphism genotyping results of two commercially available real-time (RT)-PCR assays in patients referred to our outpatient clinic for primary lactose malabsorption testing. Furthermore, concomitant conditions of fructose/sorbitol malabsorption were assessed. Samples obtained from 100 patients were tested in parallel using the LCT T-13910C ToolSet for Light Cycler (Roche, Rotkreuz, Switzerland) and the LCT-13910C>T RealFast Assay (ViennaLab Diagnostics GmbH, Vienna, Austria). Additionally, patients were also screened for the presence of fructose/sorbitol malabsorption by functional hydrogen (H2)/methane (CH4) breath testing (HMBT). Cohen's Kappa (κ) was used to calculate the agreement between the two genotyping methods. The exact Chi-Square test was performed to compare fructose/sorbitol HMBT with LCT genotyping results. Twenty-one (21.0%) patients had a LCT C/C-13910 genotype suggestive of lactase non-persistence, and 79 (79.0%) patients were identified with either a LCT T/C-13910 or T/T-13910 genotype (i.e., lactase persistence). In all genotype groups, concordance between the two RT-PCR assays was 100%. Cohen's κ demonstrated perfect observed agreement (p < 0.001, κ = 1). Fructose and sorbitol malabsorption was observed in 13/100 (13.0%) and 25/100 (25.0%) individuals, respectively. Both RT-PCR assays are robust and reliable LCT genotyping tools in a routine clinical setting. Concomitant fructose and/or sorbitol malabsorption should be considered in individuals with suspected lactase-non-persistence. However, standardization of clinical interpretation of laboratory HMBT results is required.

A single-molecule force spectroscopy study of the interactions between lectins and carbohydrates on cancer and normal cells

NASA Astrophysics Data System (ADS)

Zhao, Weidong; Cai, Mingjun; Xu, Haijiao; Jiang, Junguang; Wang, Hongda

2013-03-01

The interaction forces between carbohydrates and lectins were investigated by single-molecule force spectroscopy on both cancer and normal cells. The binding kinetics was also studied, which shows that the carbohydrate-lectin complex on cancer cells is less stable than that on normal cells.The interaction forces between carbohydrates and lectins were investigated by single-molecule force spectroscopy on both cancer and normal cells. The binding kinetics was also studied, which shows that the carbohydrate-lectin complex on cancer cells is less stable than that on normal cells. Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c3nr00553d

Measurement of serum 7α-hydroxy-4-cholesten-3-one as a marker of bile acid malabsorption in dogs with chronic diarrhoea: a pilot study

PubMed Central

Cross, G.; Taylor, D. R.; Sherwood, R. A.; Watson, P. J.

2016-01-01

Bile acid malabsorption is a common cause of chronic diarrhoea in people, however it has never previously been investigated in dogs, despite clinical suspicion of its existence. The goal of this study was to assess the feasibility of measuring serum 7α-hydroxy-4-cholesten-3-one (C4) in dogs, as a potential marker of bile acid malabsorption, and to see whether this is related to clinical disease severity or the presence of hypocobalaminaemia. Serum C4 concentration was measured in 20 clinically healthy control dogs and 17 dogs with chronic diarrhoea. Three of the 17 affected dogs (17.6 per cent) had a C4 concentration significantly above the range of clinically healthy dogs; these dogs were all poorly responsive to conventional therapy. These results suggest that bile acid malabsorption may be a clinically relevant disorder in dogs with chronic diarrhoea and serum C4 may be a useful tool to investigate this further. PMID:27110372

Measurement of serum 7α-hydroxy-4-cholesten-3-one as a marker of bile acid malabsorption in dogs with chronic diarrhoea: a pilot study.

PubMed

Kent, A C C; Cross, G; Taylor, D R; Sherwood, R A; Watson, P J

2016-01-01

Bile acid malabsorption is a common cause of chronic diarrhoea in people, however it has never previously been investigated in dogs, despite clinical suspicion of its existence. The goal of this study was to assess the feasibility of measuring serum 7α-hydroxy-4-cholesten-3-one (C4) in dogs, as a potential marker of bile acid malabsorption, and to see whether this is related to clinical disease severity or the presence of hypocobalaminaemia. Serum C4 concentration was measured in 20 clinically healthy control dogs and 17 dogs with chronic diarrhoea. Three of the 17 affected dogs (17.6 per cent) had a C4 concentration significantly above the range of clinically healthy dogs; these dogs were all poorly responsive to conventional therapy. These results suggest that bile acid malabsorption may be a clinically relevant disorder in dogs with chronic diarrhoea and serum C4 may be a useful tool to investigate this further.

High Carbohydrate-Fiber Nutrition for Running and Health.

ERIC Educational Resources Information Center

Battinelli, Thomas

1983-01-01

The roles of carbohydrates, fats, proteins, and fiber in producing energy for health and exercise are discussed. Long-distance runners should have a high intake of complex carbohydrates and fiber. (PP)

Malabsorption of Vitamin B12 in Diabetic Patients Treated with Phenformin: A Comparison with Metformin

PubMed Central

Tomkin, Gerald H.

1973-01-01

An investigation into B12 absorption in diabetic patients on long-term phenformin therapy was undertaken and the results were compared to a similar investigation previously reported in diabetics on long-term metformin. Forty-six per cent of patients were found to have B12 malabsorption as shown by abnormal results of Schilling tests. The mechanism of B12 malabsorption is unknown but it is suggested that all patients on long-term phenformin therapy should, like the patients on metformin, have annual serum B12 estimations until the results of a longer follow-up series are known. PMID:4742454

Complex carbohydrates (image)

MedlinePlus

... Glucose is used in the cells of the body and in the brain. Any unused glucose is stored in the liver and muscles as glycogen for use later. Complex carbohydrate foods provide vitamins, minerals, and fiber that are important to the ...

Counting Carbs? Understanding Glycemic Index and Glycemic Load

MedlinePlus

... seems to support the concept that the more complex carbohydrates will lead to better blood sugar control than ... everybody, not only diabetics, to eat the more complex carbohydrates because they will be more gradually absorbed, and ...

Metabolism

MedlinePlus

... anabolism, small molecules are changed into larger, more complex molecules of carbohydrate, protein, and fat. Catabolism (pronounced: kuh-TAB-uh- ... this process, cells break down large molecules (mostly carbohydrates and ... body to move. As complex chemical units are broken down into more simple ...

Microbial degradation of complex carbohydrates in the gut.

PubMed

Flint, Harry J; Scott, Karen P; Duncan, Sylvia H; Louis, Petra; Forano, Evelyne

2012-01-01

Bacteria that colonize the mammalian intestine collectively possess a far larger repertoire of degradative enzymes and metabolic capabilities than their hosts. Microbial fermentation of complex non-digestible dietary carbohydrates and host-derived glycans in the human intestine has important consequences for health. Certain dominant species, notably among the Bacteroidetes, are known to possess very large numbers of genes that encode carbohydrate active enzymes and can switch readily between different energy sources in the gut depending on availability. Nevertheless, more nutritionally specialized bacteria appear to play critical roles in the community by initiating the degradation of complex substrates such as plant cell walls, starch particles and mucin. Examples are emerging from the Firmicutes, Actinobacteria and Verrucomicrobium phyla, but more information is needed on these little studied groups. The impact of dietary carbohydrates, including prebiotics, on human health requires understanding of the complex relationship between diet composition, the gut microbiota and metabolic outputs.

Fungal biodegradation and biotransformation of soluble lignocarbohydrate complexes from straw. [Aspergillus japonicus, Polyporus versicolor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milstein, O.A.; Vared, Y.; Sharma, A.

1983-08-01

Aspergillus japonicus is an efficient degrader of phenolics and carbohydrates present in a mixture of soluble lignocarbohydrate complexes extracted from wheat straw. Trichoderma species attacked part of the carbohydrate but hardly affected the aromatic portion of this solution. Polyporus versicolor had a complex effect; polymerization of low-molecular-size phenolics accompanied the degradation of aromatic and carbohydrate polymers. The addition of xylose to the medium facilitated depolymerization of lignin by the fungi tested and prevented the polymerization of low-molecular-size fractions of lignocarbohydrate complexes by P. versicolor. P. versicolor, in contrast to A. japonicus and Trichoderma species, also excreted into the medium considerablemore » amounts of laccase, but only in the absence of endogenous or exogenous carbohydrates. Apparently, laccase is involved in polymerization rather than degradation of lignin in this organism. A number of extracellular glycanases were also secreted by these fungi. 19 references« less

A thorough experimental study of CH/π interactions in water: quantitative structure-stability relationships for carbohydrate/aromatic complexes.

PubMed

Jiménez-Moreno, Ester; Jiménez-Osés, Gonzalo; Gómez, Ana M; Santana, Andrés G; Corzana, Francisco; Bastida, Agatha; Jiménez-Barbero, Jesus; Asensio, Juan Luis

2015-11-13

CH/π interactions play a key role in a large variety of molecular recognition processes of biological relevance. However, their origins and structural determinants in water remain poorly understood. In order to improve our comprehension of these important interaction modes, we have performed a quantitative experimental analysis of a large data set comprising 117 chemically diverse carbohydrate/aromatic stacking complexes, prepared through a dynamic combinatorial approach recently developed by our group. The obtained free energies provide a detailed picture of the structure-stability relationships that govern the association process, opening the door to the rational design of improved carbohydrate-based ligands or carbohydrate receptors. Moreover, this experimental data set, supported by quantum mechanical calculations, has contributed to the understanding of the main driving forces that promote complex formation, underlining the key role played by coulombic and solvophobic forces on the stabilization of these complexes. This represents the most quantitative and extensive experimental study reported so far for CH/π complexes in water.

Bile acid malabsorption in Crohn's disease and indications for its assessment using SeHCAT.

PubMed Central

Nyhlin, H; Merrick, M V; Eastwood, M A

1994-01-01

Patients with Crohn's disease who suffer from longstanding diarrhoea that does not respond to conventional treatment pose a common clinical problem. Bile acid malabsorption is a possible cause, although its prevalence and clinical importance is unclear. This paper explores the clinical indications for referring patients with Crohn's disease for bile acid assessment and the extent of bile acid malabsorption in this selected group of patients. The selenium labelled bile acid SeHCAT was used to assess the effect of disease on the integrity of the enterohepatic circulation. Altogether 76% of the patients referred for bile acid assessment had longstanding diarrhoea that had not responded to conventional anti-diarrhoeal treatment or an increase in steroid therapy as their sole or predominant symptom. Ninety per cent of patients with bowel resections, almost exclusively ileocaecal, had abnormal SeHCAT retention (< 5% at seven days). Twenty eight per cent of patients with Crohn's disease who had not undergone resection 28% had a SeHCAT retention < 5%, signifying bile acid malabsorption. Nineteen of 22 patients given cholestyramine treatment subsequent to the SeHCAT test had a good symptomatic response. In conclusion, the prevalence of bile acid malabsorption in this selected group with Crohn's disease is sufficiently high to justify performing the SeHCAT test in order to separate the various differential diagnoses. PMID:8307458

Additional Value of CH4 Measurement in a Combined 13C/H2 Lactose Malabsorption Breath Test: A Retrospective Analysis

PubMed Central

Houben, Els; De Preter, Vicky; Billen, Jaak; Van Ranst, Marc; Verbeke, Kristin

2015-01-01

The lactose hydrogen breath test is a commonly used, non-invasive method for the detection of lactose malabsorption and is based on an abnormal increase in breath hydrogen (H2) excretion after an oral dose of lactose. We use a combined 13C/H2 lactose breath test that measures breath 13CO2 as a measure of lactose digestion in addition to H2 and that has a better sensitivity and specificity than the standard test. The present retrospective study evaluated the results of 1051 13C/H2 lactose breath tests to assess the impact on the diagnostic accuracy of measuring breath CH4 in addition to H2 and 13CO2. Based on the 13C/H2 breath test, 314 patients were diagnosed with lactase deficiency, 138 with lactose malabsorption or small bowel bacterial overgrowth (SIBO), and 599 with normal lactose digestion. Additional measurement of CH4 further improved the accuracy of the test as 16% subjects with normal lactose digestion and no H2-excretion were found to excrete CH4. These subjects should have been classified as subjects with lactose malabsorption or SIBO. In conclusion, measuring CH4-concentrations has an added value to the 13C/H2 breath test to identify methanogenic subjects with lactose malabsorption or SIBO. PMID:26371034

Advancements in the treatment of hypothyroidism with L-T4 liquid formulation or soft gel capsule: an update.

PubMed

Fallahi, Poupak; Ferrari, Silvia Martina; Ruffilli, Ilaria; Ragusa, Francesca; Biricotti, Marco; Materazzi, Gabriele; Miccoli, Paolo; Antonelli, Alessandro

2017-05-01

The most recent advance concerning levothyroxine (L-T4) therapy is the development of novel oral formulations: the liquid preparation, and the soft gel capsule. Areas covered: This review evaluates the most recent clinical studies about these new formulations. The liquid formulation has been shown to overcome: the food and beverages intereference with L-T4 tablets absorption, caused by food or coffee at breakfast; malabsorption induced by the increased gastric pH, resulting from atrophic gastritis, or due to proton-pump inhibitors; and malabsorption after bariatric surgery. The use of liquid L-T4 has been studied also in pregnancy, newborns and infants, suggesting a better bioequivalence than tablets. Finally, liquid L-T4 is more active than tablets in the control of thyroid-stimulating hormone (TSH) in hypothyroid patients without malabsorption, drug interference, or gastric disorders, leading to a hypothesized higher absorption of liquid L-T4 also in these patients. Few studies have evaluated soft gel L-T4 with promising results in patients with malabsorption related to coffee or gastritis. Expert opinion: Liquid L-T4 (and soft gel capsules) are more active than the tablet L-T4 in the control of TSH in hypothyroid patients with gastric disorders, malabsorption, or drug interference, but also in patients without absorption disorders.

Extensive Intestinal Resection Triggers Behavioral Adaptation, Intestinal Remodeling and Microbiota Transition in Short Bowel Syndrome

PubMed Central

Mayeur, Camille; Gillard, Laura; Le Beyec, Johanne; Bado, André; Joly, Francisca; Thomas, Muriel

2016-01-01

Extensive resection of small bowel often leads to short bowel syndrome (SBS). SBS patients develop clinical mal-absorption and dehydration relative to the reduction of absorptive area, acceleration of gastrointestinal transit time and modifications of the gastrointestinal intra-luminal environment. As a consequence of severe mal-absorption, patients require parenteral nutrition (PN). In adults, the overall adaptation following intestinal resection includes spontaneous and complex compensatory processes such as hyperphagia, mucosal remodeling of the remaining part of the intestine and major modifications of the microbiota. SBS patients, with colon in continuity, harbor a specific fecal microbiota that we called “lactobiota” because it is enriched in the Lactobacillus/Leuconostoc group and depleted in anaerobic micro-organisms (especially Clostridium and Bacteroides). In some patients, the lactobiota-driven fermentative activities lead to an accumulation of fecal d/l-lactates and an increased risk of d-encephalopathy. Better knowledge of clinical parameters and lactobiota characteristics has made it possible to stratify patients and define group at risk for d-encephalopathy crises. PMID:27681910

Decarbonylation and dehydrogenation of carbohydrates

DOEpatents

Andrews, Mark A.; Klaeren, Stephen A.

1991-01-01

Carbohydrates, especially aldose or ketose sugars, including those whose carbonyl group is masked by hemi-acetal or hemi-ketal formation, are decarbonylated by heating the feed carbohydrate together with a transition metal complex in a suitable solvent. Also, primary alcohols, including sugar alditols are simultaneously dehydrogenated and decarbonylated by heating a mixture of rhodium and ruthenium complexes and the alcohol and optionally a hydrogen acceptor in an acceptable solvent. Such defarbonylation and/or dehydrogenation of sugars provides a convenient procedure for the synthesis of certain carbohydrates and may provide a means for the conversion of biomass into useful products.

Supramolecular Complexation of Carbohydrates for the Bioavailability Enhancement of Poorly Soluble Drugs.

PubMed

Cho, Eunae; Jung, Seunho

2015-10-27

In this review, a comprehensive overview of advances in the supramolecular complexes of carbohydrates and poorly soluble drugs is presented. Through the complexation process, poorly soluble drugs could be efficiently delivered to their desired destinations. Carbohydrates, the most abundant biomolecules, have diverse physicochemical properties owing to their inherent three-dimensional structures, hydrogen bonding, and molecular recognition abilities. In this regard, oligosaccharides and their derivatives have been utilized for the bioavailability enhancement of hydrophobic drugs via increasing the solubility or stability. By extension, polysaccharides and their derivatives can form self-assembled architectures with poorly soluble drugs and have shown increased bioavailability in terms of the sustained or controlled drug release. These supramolecular systems using carbohydrate will be developed consistently in the field of pharmaceutical and medical application.

Histochemistry of lectin-binding sites in Halicryptus spinulosus (Priapulida).

PubMed

Busch, A; Schumacher, U; Storch, V

2001-02-01

Priapulida represent one of the phylogenetically oldest multicellular animal groups. In multicellular animals (Metazoa) cell-to-cell and cell-to-matrix interactions are often mediated by carbohydrate residues of glycoconjugates. To analyze the carbohydrate composition of a phylogenetically old species, lectin histochemistry was employed on 5 specimens of the priapulid Halicryptus spinulosus. Many lectins bound to the chitin-containing cuticle, including those specific for carbohydrates other than N-acetylglucosamine, the principle building block of chitin. The connective tissue of the animals contained both N-acetylglucosamine and N-acetylgalactosamine. Mannose residues were widely distributed with the exception of the cuticle, but complex type carbohydrates were not present in the entire animal. Sialic acid residues were only detected in the cuticle and brush border of the intestinal epithelium, while fucose was limited to the cuticle. Thus, the lectin-binding pattern indicated that sugars typical for the linking region of both N- and O-glycoproteins in mammals are also present in H. spinulosus. Carbohydrate residues that are typical for the complex type of N-linked glycans in vertebrates are not present as are carbohydrate residues typical for the termination of O-linked carbohydrate chains. Hence, a truncated form of both N- and O-linked glycosylation is present in H. spinulosus indicating that more complex patterns of glycosylation developed later during evolution.

A kinetic model to explain the maximum in alpha-amylase activity measurements in the presence of small carbohydrates.

PubMed

Baks, Tim; Janssen, Anja E M; Boom, Remko M

2006-06-20

The effect of the presence of several small carbohydrates on the measurement of the alpha-amylase activity was determined over a broad concentration range. At low carbohydrate concentrations, a distinct maximum in the alpha-amylase activity versus concentration curves was observed in several cases. At higher concentrations, all carbohydrates show a decreasing alpha-amylase activity at increasing carbohydrate concentrations. A general kinetic model has been developed that can be used to describe and explain these phenomena. This model is based on the formation of a carbohydrate-enzyme complex that remains active. It is assumed that this complex is formed when a carbohydrate binds to alpha-amylase without blocking the catalytic site and its surrounding subsites. Furthermore, the kinetic model incorporates substrate inhibition and substrate competition. Depending on the carbohydrate type and concentration, the measured alpha-amylase activity can be 75% lower than the actual alpha-amylase activity. The model that has been developed can be used to correct for these effects in order to obtain the actual amount of active enzyme. 2006 Wiley Periodicals, Inc.

Recent advances in capillary electrophoresis separation of monosaccharides, oligosaccharides, and polysaccharides.

PubMed

Mantovani, Veronica; Galeotti, Fabio; Maccari, Francesca; Volpi, Nicola

2018-01-01

This article illustrates the basis and applications of methodologies for the analysis of simple and complex carbohydrates by means of CE. After a description of the most common and novel approaches useful for the analysis and characterization of carbohydrates, this review covers the recent advances in CE separation of monosaccharides, oligosaccharides, and polysaccharides. Various CE techniques are also illustrated for the study of carbohydrates derived from complex glyco-derivatives such as glycoproteins and glycolipids, essential for biopharmaceutical and glycoproteomics applications as well as for biomarker detection. Most glycans have no significant UV absorption, and derivatization with fluorophore groups prior to separation usually results in higher sensitivity and an improved electrophoretic profile. We also discuss the recent applications and separations by CE of derivatized simple and more complex carbohydrates with different chromophoric active tags. Overall, this review aims to give an overview of the most recent state-of-the-art techniques used in carbohydrate analysis by CE. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbohydrate recognition: A minimalistic approach to binding

NASA Astrophysics Data System (ADS)

Kubik, Stefan

2012-09-01

Synthetic receptors with properties resembling those of carbohydrate-binding proteins are known, but they are structurally rather complex. Elaborate structures are, however, not always required to bind carbohydrates in water -- much simpler compounds can be just as effective.

Oral Lactobacillus Counts Predict Weight Gain Susceptibility: A 6-Year Follow-Up Study

PubMed Central

Rosing, Johanne Aviaja; Walker, Karen Christina; Jensen, Benjamin A.H.; Heitmann, Berit L.

2017-01-01

Background Recent studies have shown an association between weight change and the makeup of the intestinal microbiota in humans. Specifically, Lactobacillus, a part of the entire gastrointestinal tract's microbiota, has been shown to contribute to weight regulation. Aim We examined the association between the level of oral Lactobacillus and the subsequent 6-year weight change in a healthy population of 322 Danish adults aged 35–65 years at baseline. Design Prospective observational study. Results In unadjusted analysis the level of oral Lactobacillus was inversely associated with subsequent 6-year change in BMI. A statistically significant interaction between the baseline level of oral Lactobacillus and the consumption of complex carbohydrates was found, e.g. high oral Lactobacillus count predicted weight loss for those with a low intake of complex carbohydrates, while a medium intake of complex carbohydrates predicted diminished weight gain. A closer examination of these relations showed that BMI change and Lactobacillus level was unrelated for those with high complex carbohydrate consumption. Conclusion A high level of oral Lactobacillus seems related to weight loss among those with medium and low intakes of complex carbohydrates. Absence, or a low level of oral Lactobacillus, may potentially be a novel marker to identify those at increased risk of weight gain. PMID:29020671

Oral Lactobacillus Counts Predict Weight Gain Susceptibility: A 6-Year Follow-Up Study.

PubMed

Rosing, Johanne Aviaja; Walker, Karen Christina; Jensen, Benjamin A H; Heitmann, Berit L

2017-01-01

Recent studies have shown an association between weight change and the makeup of the intestinal microbiota in humans. Specifically, Lactobacillus, a part of the entire gastrointestinal tract's microbiota, has been shown to contribute to weight regulation. We examined the association between the level of oral Lactobacillus and the subsequent 6-year weight change in a healthy population of 322 Danish adults aged 35-65 years at baseline. Prospective observational study. In unadjusted analysis the level of oral Lactobacillus was inversely associated with subsequent 6-year change in BMI. A statistically significant interaction between the baseline level of oral Lactobacillus and the consumption of complex carbohydrates was found, e.g. high oral Lactobacillus count predicted weight loss for those with a low intake of complex carbohydrates, while a medium intake of complex carbohydrates predicted diminished weight gain. A closer examination of these relations showed that BMI change and Lactobacillus level was unrelated for those with high complex carbohydrate consumption. A high level of oral Lactobacillus seems related to weight loss among those with medium and low intakes of complex carbohydrates. Absence, or a low level of oral Lactobacillus, may potentially be a novel marker to identify those at increased risk of weight gain. © 2017 The Author(s) Published by S. Karger GmbH, Freiburg.

Gut-training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance.

PubMed

Costa, Ricardo J S; Miall, Atlanta; Khoo, Anthony; Rauch, Christopher; Snipe, Rhiannon; Camões-Costa, Vera; Gibson, Peter

2017-05-01

Due to gastrointestinal tract adaptability, the study aimed to determine the impact of gut-training protocol over 2 weeks on gastrointestinal status, blood glucose availability, fuel kinetics, and running performance. Endurance runners (n = 25) performed a gut-challenge trial (GC1), consisting of 2 h running exercise at 60% V̇O 2max whilst consuming gel-discs containing 30 g carbohydrates (2:1 glucose/fructose, 10% w/v) every 20 min and a 1 h distance test. Participants were then randomly assigned to a carbohydrate gel-disc (CHO-S), carbohydrate food (CHO-F), or placebo (PLA) gut-training group for 2 weeks of repetitive gut-challenge intervention. Participants then repeated a second gut-challenge trial (GC2). Gastrointestinal symptoms reduced in GC2 on CHO-S (60%; p = 0.008) and CHO-F (63%; p = 0.046); reductions were greater than PLA (p < 0.05). H 2 peak was lower in GC2 on CHO-S (mean (CI): 6 (4-8) ppm) compared with CHO-F (9 (6-12) ppm) and PLA (12 (2-21) ppm) (trial × time: p < 0.001). Blood glucose concentration was higher in GC2 on CHO-S (7.2 (6.3-8.1) mmol·L -1 ) compared with CHO-F (6.1 (5.7-6.5) mmol·L -1 ) and PLA (6.2 (4.9-7.5) mmol·L -1 ) (trial × time: p = 0.015). No difference in oxidation rates, plasma I-FABP, and cortisol concentrations were observed between groups and trials. Distance test improved on CHO-S (5.2%) and CHO-F (4.3%) in GC2, but not on PLA (-2.1%) (trial × time: p = 0.009). Two weeks of gut-training with CHO-S and CHO-F improved gastrointestinal symptoms and running performance compared with PLA. CHO-S also reduced malabsorption and increased blood glucose availability during endurance running compared with PLA.

[Malabsorption is a leading clinical sign of small bowel disease].

PubMed

Parfenov, A I; Krums, L M

The paper presents a variety of clinical manifestations of malabsorption syndrome (MAS) in celiac disease, collagenous sprue, Whipple's disease, Crohn's disease, intestinal lymphangiectasia, amyloidosis, common variable immune deficiency, and treatment of short bowel syndrome. It shows the specific features of the pathophysiology, diagnosis, and treatment of MAS in small bowel diseases.

Exaggerated levothyroxine malabsorption due to calcium carbonate supplementation in gastrointestinal disorders.

PubMed

Csako, G; McGriff, N J; Rotman-Pikielny, P; Sarlis, N J; Pucino, F

2001-12-01

To describe a patient with primary hypothyroidism in whom ingestion of levothyroxine with calcium carbonate led to markedly elevated serum thyrotropin concentrations. A 61-year-old white woman with primary hypothyroidism, systemic lupus erythematosus, celiac disease, and history of Whipple resection for pancreatic cancer was euthyroid with levothyroxine 175-188 micrograms/d. After taking a high dose of calcium carbonate (1250 mg three times daily) with levothyroxine, she developed biochemical evidence of hypothyroidism (thyrotropin up to 41.4 mU/L) while remaining clinically euthyroid. Delaying calcium carbonate administration by four hours returned her serum thyrotropin to a borderline high concentration (5.7 mU/L) within a month. Serum concentrations of unbound and total thyroxine and triiodothyronine tended to decrease, but remained borderline low to normal while the patient concomitantly received levothyroxine and calcium carbonate. Concomitant administration of levothyroxine and calcium carbonate often results in levothyroxine malabsorption. While in most patients the clinical consequences of this interaction, even with prolonged exposure, are relatively small, overt hypothyrodism may develop in patients with preexisting malabsorption disorders. However, as the current case illustrates, the clinical manifestations of the initial levothyroxine deficit may not always be apparent and, of all usual laboratory thyroid function tests, only thyrotropin measurement will reliably uncover the exaggerated levothyroxine malabsorption. Decreased absorption of levothyroxine when given with calcium carbonate may be particularly pronounced in patients with preexisting malabsorption disorders. Once recognized, a change in drug administration schedule usually minimizes or eliminates this interaction.

Manipulation of Muscle Glycogen Concentrations Using High and Low Carbohydrate Diets and Exercise

DTIC Science & Technology

1987-08-01

high in carbohydrates in the form of simple sugars (i.e., sucrose, fructose , lactose) and complex carbohydrates (i.e., starches, dietary fiber...AD-A 187 732 REPORT NO T32-87 MANIPULATION OF MUSCLE GLYCOGEN CONCENTRATIONS USING HIGH AND LOW CARBOHYDRATE DIETS AND EXERCISE U S ARMY RESEARCH...Muscle Glycogen Concentrations Using High and Low Carbohydrate Diets and Exercise 12. PERSONAL AUTHOR(S) Buchbinder, J., Pocost, J., Hodgess, L., Roche

Fructose malabsorption in people with and without gout: A case-control study.

PubMed

Batt, Caitlin; Fanning, Niamh; Drake, Jill; Frampton, Christopher; Gearry, Richard B; Stamp, Lisa K

2017-10-01

Higher fructose intake has been associated with hyperuricaemia and gout. Some individuals malabsorb fructose in the small intestine. The aims of this study were to determine the rate of fructose malabsorption and the effects of gout and fructose malabsorption on serum urate in people with and without gout. A total of 100 people with gout (cases) were age and gender matched with one control without gout. After a low fructose diet, fructose malabsorption was measured using a hydrogen and methane breath test with a 35g fructose load. In a subgroup of 35 cases and 35 controls, serum urate response to the fructose load over 240 minutes was measured. There was no significant difference in the rate of fructose malabsorption between cases and controls (48% vs. 52%; p = 0.67). Cases had a significantly lower mean (SEM) serum urate cumulative incremental concentration from baseline-240 minutes (iAUC 0-240 ) compared to controls 0.97 (0.56) vs. 4.78 (0.55); p < 0.001. C max was significantly lower in cases compared to controls [0.38 (0.003) vs. 0.40 (0.003); p < 0.001]. 95% of cases were receiving allopurinol. There was no significant difference between iAUC 0-240 or C max for malabsorbers compared to normal absorbers irrespective of case-control status. The mean (SEM) increase in serum urate between baseline and 30 minutes was 0.04 (0.004)mmol/l in the controls compared to 0.009 (0.002) in the cases (p < 0.001). The rates of fructose malabsorption are similar in people with and without gout. Allopurinol inhibits the increase in serum urate induced by a fructose load suggesting that people with gout receiving allopurinol may not need to restrict dietary intake of fructose. Copyright © 2017 Elsevier Inc. All rights reserved.

Liquid L-thyroxine versus tablet L-thyroxine in patients on L- thyroxine replacement or suppressive therapy: a meta-analysis.

PubMed

Laurent, Irakoze; Tang, Siying; Astère, Manirakiza; Wang, Kan Ran; Deng, Shuhua; Xiao, Ling; Li, Qi Fu

2018-03-23

To compare the effectiveness of liquid L-T4 (L-thyroxine) and tablet L-T4 in patients on L-T4 replacement or suppressive therapy. The Cochrane Library, PubMed, Embase, and Web of Science databases were searched to identify relevant articles. All prospective or randomized controlled studies (RCTs) comparing liquid L-T4 and tablet L-T4 in patients on L-T4 replacement or suppressive therapy were included in the analysis. Overall, the initial search of the four databases identified 1278 published studies; of these, eight studies were ultimately included in the meta-analysis. TSH (thyroid stimulating hormone) levels were significantly suppressed in patients on liquid L-T4 compared with those on tablet L-T4, in patients on L-T4 suppressive therapy with L-T4 malabsorption (Mean Difference (MD) = -2.26, 95% Confidence Interval (CI): -3.59, -0.93; P = 0.0009)). However, liquid L-T4 and tablet L-T4 did not show a statistically significant difference in patients on L-T4 suppressive therapy without malabsorption (MD = 0.08, 95% CI: -0.31, 0.47; P = 0.69). TSH levels were significantly normalized in patients on liquid L-T4 compared with those on tablet L-T4, in Patients on L-T4 replacement therapy with L-T4 malabsorption (MD = -3.20, 95% CI: -5.08, -1.32; P = 0.0009). However, liquid L-T4 and tablet L-T4 did not show a statistically significant difference in patients on L-T4 replacement therapy without malabsorption (MD = 0.91, 95% CI: -0.03, 1.86; P = 0.06). Liquid L-T4 is more efficient than tablet L-T4 in patients on L-T4 replacement or suppressive therapy with malabsorption. No significant differences were observed in patients without malabsorption. Further studies should be conducted to verify these findings.

CHANGES IN COMPLEX CARBOHYDRATE CONTENT AND STRUCTURE IN RAT LUNGS CAUSED BY PROLONGED OZONE INHALATION

EPA Science Inventory

EPA GRANT NUMBER: R828112C065III
Title: Changes in Complex Carbohydrate Content and Structure in Rat Lungs Caused by Prolonged Ozone Inhalation
Investigator: Bhandaru Radhakrishnamurthy
Institution: Tulane University of Louisiana
EPA...

Biologically-Inspired Peptide Reagents for Enhancing IMS-MS Analysis of Carbohydrates

NASA Astrophysics Data System (ADS)

Bohrer, Brian C.; Clemmer, David E.

2011-09-01

The binding properties of a peptidoglycan recognition protein are translated via combinatorial chemistry into short peptides. Non-adjacent histidine, tyrosine, and arginine residues in the protein's binding cleft that associate specifically with the glycan moiety of a peptidoglycan substrate are incorporated into linear sequences creating a library of 27 candidate tripeptide reagents (three possible residues permutated across three positions). Upon electrospraying the peptide library and carbohydrate mixtures, some noncovalent complexes are observed. The binding efficiencies of the peptides vary according to their amino acid composition as well as the disaccharide linkage and carbohydrate ring-type. In addition to providing a charge-carrier for the carbohydrate, peptide reagents can also be used to differentiate carbohydrate isomers by ion mobility spectrometry. The utility of these peptide reagents as a means of enhancing ion mobility analysis of carbohydrates is illustrated by examining four glucose-containing disaccharide isomers, including a pair that is not resolved by ion mobility alone. The specificity and stoichiometry of the peptide-carbohydrate complexes are also investigated. Trihistidine demonstrates both suitable binding efficiency and successful resolution of disaccharides isomers, suggesting it may be a useful reagent in IMS analyses of carbohydrates.

Reading Food Labels: Tips If You Have Diabetes

MedlinePlus

... the grams of total carbohydrates — which includes sugar, complex carbohydrates and fiber — rather than only the grams of ... 18, 2016. How to use and understand the nutrition facts label. U.S. ... of carbohydrates. American Diabetes Association. http://www.diabetes.org/food- ...

Nickel-catalyzed proton-deuterium exchange (HDX) for linkage analysis of complex carbohydrates

USDA-ARS?s Scientific Manuscript database

The structural assignment of complex carbohydrates typically requires the analysis of at least three parameters: 1. composition; 2. linkage; and 3. substituents. These are often assigned on a small scale by gas chromatography/mass spectrometry (GC/MS). Linkage positions are determined by permethylat...

Simulation of carbohydrates, from molecular docking to dynamics in water.

PubMed

Sapay, Nicolas; Nurisso, Alessandra; Imberty, Anne

2013-01-01

Modeling of carbohydrates is particularly challenging because of the variety of structures resulting for the high number of monosaccharides and possible linkages and also because of their intrinsic flexibility. The development of carbohydrate parameters for molecular modeling is still an active field. Nowadays, main carbohydrates force fields are GLYCAM06, CHARMM36, and GROMOS 45A4. GLYCAM06 includes the largest choice of compounds and is compatible with the AMBER force fields and associated. Furthermore, AMBER includes tools for the implementation of new parameters. When looking at protein-carbohydrate interaction, the choice of the starting structure is of importance. Such complex can be sometimes obtained from the Protein Data Bank-although the stereochemistry of sugars may require some corrections. When no experimental data is available, molecular docking simulation is generally used to the obtain protein-carbohydrate complex coordinates. As molecular docking parameters are not specifically dedicated to carbohydrates, inaccuracies should be expected, especially for the docking of polysaccharides. This issue can be addressed at least partially by combining molecular docking with molecular dynamics simulation in water.

Adding glucose to food and solutions to enhance fructose absorption is not effective in preventing fructose-induced functional gastrointestinal symptoms: randomised controlled trials in patients with fructose malabsorption.

PubMed

Tuck, C J; Ross, L A; Gibson, P R; Barrett, J S; Muir, J G

2017-02-01

In healthy individuals, the absorption of fructose in excess of glucose in solution is enhanced by the addition of glucose. The present study aimed to assess the effects of glucose addition to fructose or fructans on absorption patterns and genesis of gastrointestinal symptoms in patients with functional bowel disorders. Randomised, blinded, cross-over studies were performed in healthy subjects and functional bowel disorder patients with fructose malabsorption. The area-under-the-curve (AUC) was determined for breath hydrogen and symptom responses to: (i) six sugar solutions (fructose in solution) (glucose; sucrose; fructose; fructose + glucose; fructan; fructan + glucose) and (ii) whole foods (fructose in foods) containing fructose in excess of glucose given with and without additional glucose. Intake of fermentable short chain carbohydrates (FODMAPs; fermentable, oligo-, di-, monosaccharides and polyols) was controlled. For the fructose in solution study, in 26 patients with functional bowel disorders, breath hydrogen was reduced after glucose was added to fructose compared to fructose alone [mean (SD) AUC 92 (107) versus 859 (980) ppm 4 h -1 , respectively; P = 0.034). Glucose had no effect on breath hydrogen response to fructans (P = 1.000). The six healthy controls showed breath hydrogen patterns similar to those with functional bowel disorders. No differences in symptoms were experienced with the addition of glucose, except more nausea when glucose was added to fructose (P = 0.049). In the fructose in foods study, glucose addition to whole foods containing fructose in excess of glucose in nine patients with functional bowel disorders and nine healthy controls had no significant effect on breath hydrogen production or symptom response. The absence of a favourable response on symptoms does not support the concomitant intake of glucose with foods high in either fructose or fructans in patients with functional bowel disorders. © 2016 The British Dietetic Association Ltd.

Expression of Na+/glucose co-transporter 1 (SGLT1) is enhanced by supplementation of the diet of weaning piglets with artificial sweeteners.

PubMed

Moran, Andrew W; Al-Rammahi, Miran A; Arora, Daleep K; Batchelor, Daniel J; Coulter, Erin A; Daly, Kristian; Ionescu, Catherine; Bravo, David; Shirazi-Beechey, Soraya P

2010-09-01

In an intensive livestock production, a shorter suckling period allows more piglets to be born. However, this practice leads to a number of disorders including nutrient malabsorption, resulting in diarrhoea, malnutrition and dehydration. A number of strategies have been proposed to overcome weaning problems. Artificial sweeteners, routinely included in piglets' diet, were thought to enhance feed palatability. However, it is shown in rodent models that when included in the diet, they enhance the expression of Na+/glucose co-transporter (SGLT1) and the capacity of the gut to absorb glucose. Here, we show that supplementation of piglets' feed with a combination of artificial sweeteners saccharin and neohesperidin dihydrochalcone enhances the expression of SGLT1 and intestinal glucose transport function. Artificial sweeteners are known to act on the intestinal sweet taste receptor T1R2/T1R3 and its partner G-protein, gustducin, to activate pathways leading to SGLT1 up-regulation. Here, we demonstrate that T1R2, T1R3 and gustducin are expressed together in the enteroendocrine cells of piglet intestine. Furthermore, gut hormones secreted by the endocrine cells in response to dietary carbohydrates, glucagon-like peptides (GLP)-1, GLP-2 and glucose-dependent insulinotrophic peptide (GIP), are co-expressed with type 1 G-protein-coupled receptors (T1R) and gustducin, indicating that L- and K-enteroendocrine cells express these taste elements. In a fewer endocrine cells, T1R are also co-expressed with serotonin. Lactisole, an inhibitor of human T1R3, had no inhibitory effect on sweetener-induced SGLT1 up-regulation in piglet intestine. A better understanding of the mechanism(s) involved in sweetener up-regulation of SGLT1 will allow the identification of nutritional targets with implications for the prevention of weaning-related malabsorption.

Focus on Nutrition: Cats and carbohydrates: implications for health and disease.

PubMed

Laflammme, Dottie

2010-01-01

It has been suggested that high-carbohydrate diets contribute to the development of feline diabetes and obesity. The evidence does not support this. Healthy cats efficiently digest and metabolize properly processed starches and complex carbohydrates. Dietary carbohydrate can efficiently meet cats' cellular requirement for carbohydrate (glucose), sparing protein that would otherwise be needed for gluconeogenesis. Excess calories, regardless of source, contribute to obesity and obesity-related problems, but low-carbohydrate, high-fat diets pose a greater risk for obesity. The increasing prevalence of feline diabetes appears to be due to obesity and aging rather than to dietary carbohydrates. However, once cats become diabetic, consumption of a high-protein, low-carbohydrate diet may be beneficial.

Recent progress in heteronuclear long-range NMR of complex carbohydrates: 3D H2BC and clean HMBC.

PubMed

Meier, Sebastian; Petersen, Bent O; Duus, Jens Ø; Sørensen, Ole W

2009-11-02

The new NMR experiments 3D H2BC and clean HMBC are explored for challenging applications to a complex carbohydrate at natural abundance of (13)C. The 3D H2BC experiment is crucial for sequential assignment as it yields heteronuclear one- and two-bond together with COSY correlations for the (1)H spins, all in a single spectrum with good resolution and non-informative diagonal-type peaks suppressed. Clean HMBC is a remedy for the ubiquitous problem of strong coupling induced one-bond correlation artifacts in HMBC spectra of carbohydrates. Both experiments work well for one of the largest carbohydrates whose structure has been determined by NMR, not least due to the enhanced resolution offered by the third dimension in 3D H2BC and the improved spectral quality due to artifact suppression in clean HMBC. Hence these new experiments set the scene to take advantage of the sensitivity boost achieved by the latest generation of cold probes for NMR structure determination of even larger and more complex carbohydrates in solution.

Exploiting Uniformly 13C-Labeled Carbohydrates for Probing Carbohydrate-Protein Interactions by NMR Spectroscopy.

PubMed

Nestor, Gustav; Anderson, Taigh; Oscarson, Stefan; Gronenborn, Angela M

2017-05-03

NMR of a uniformly 13 C-labeled carbohydrate was used to elucidate the atomic details of a sugar-protein complex. The structure of the 13 C-labeled Manα(1-2)Manα(1-2)ManαOMe trisaccharide ligand, when bound to cyanovirin-N (CV-N), was characterized and revealed that in the complex the glycosidic linkage torsion angles between the two reducing-end mannoses are different from the free trisaccharide. Distances within the carbohydrate were employed for conformational analysis, and NOE-based distance mapping between sugar and protein revealed that Manα(1-2)Manα(1-2)ManαOMe is bound more intimately with its two reducing-end mannoses into the domain A binding site of CV-N than with the nonreducing end unit. Taking advantage of the 13 C spectral dispersion of 13 C-labeled carbohydrates in isotope-filtered experiments is a versatile means for a simultaneous mapping of the binding interactions on both, the carbohydrate and the protein.

(1)H NMR spectroscopy for profiling complex carbohydrate mixtures in non-fractionated beer.

PubMed

Petersen, Bent O; Nilsson, Mathias; Bøjstrup, Marie; Hindsgaul, Ole; Meier, Sebastian

2014-05-01

A plethora of biological and biotechnological processes involve the enzymatic remodelling of carbohydrates in complex mixtures whose compositions affect both the processes and products. In the current study, we employed high-resolution (1)H NMR spectroscopy for the analysis of cereal-derived carbohydrate mixtures as exemplified on six beer samples of different styles. Structural assignments of more than 50 carbohydrate moieties were obtained using (1)H1-(1)H2 groups as structural reporters. Spectroscopically resolved carbohydrates include more than ''20 different'' small carbohydrates with more than 38 isomeric forms in addition to cereal polysaccharide fragments with suspected organoleptic and prebiotic function. Structural motifs at the cleavage sites of starch, β-glucan and arabinoxylan fragments were identified, showing different extent and specificity of enzymatic polysaccharide cleavage during the production of different beer samples. Diffusion ordered spectroscopy supplied independent size information for the characterisation and identification of polysaccharide fragments, indicating the presence especially of high molecular weight arabinoxylan fragments in the final beer. Copyright © 2013 Elsevier Ltd. All rights reserved.

Structural basis of carbohydrate recognition by lectin II from Ulex europaeus, a protein with a promiscuous carbohydrate-binding site.

PubMed

Loris, R; De Greve, H; Dao-Thi, M H; Messens, J; Imberty, A; Wyns, L

2000-08-25

Protein-carbohydrate interactions are the language of choice for inter- cellular communication. The legume lectins form a large family of homologous proteins that exhibit a wide variety of carbohydrate specificities. The legume lectin family is therefore highly suitable as a model system to study the structural principles of protein-carbohydrate recognition. Until now, structural data are only available for two specificity families: Man/Glc and Gal/GalNAc. No structural data are available for any of the fucose or chitobiose specific lectins. The crystal structure of Ulex europaeus (UEA-II) is the first of a legume lectin belonging to the chitobiose specificity group. The complexes with N-acetylglucosamine, galactose and fucosylgalactose show a promiscuous primary binding site capable of accommodating both N-acetylglucos amine or galactose in the primary binding site. The hydrogen bonding network in these complexes can be considered suboptimal, in agreement with the low affinities of these sugars. In the complexes with chitobiose, lactose and fucosyllactose this suboptimal hydrogen bonding network is compensated by extensive hydrophobic interactions in a Glc/GlcNAc binding subsite. UEA-II thus forms the first example of a legume lectin with a promiscuous binding site and illustrates the importance of hydrophobic interactions in protein-carbohydrate complexes. Together with other known legume lectin crystal structures, it shows how different specificities can be grafted upon a conserved structural framework. Copyright 2000 Academic Press.

Simple vs. Complex Carbohydrate Dietary Patterns and the Global Overweight and Obesity Pandemic.

PubMed

Ferretti, Fabrizio; Mariani, Michele

2017-10-04

Nowadays, obesity and being overweight are among the major global health concerns. Many, diet-related diseases impose high tangible and intangible costs, and threaten the sustainability of health-care systems worldwide. In this study, we model, at the macroeconomic level, the impact of energy intake from different types of carbohydrates on the population's BMI (body mass index). We proceed in three steps. First, we develop a framework to analyse both the consumption choices between simple and complex carbohydrates and the effects of these choices on people health conditions. Second, we collect figures for 185 countries (over the period 2012-2014) regarding the shares of simple (sugar and sweetener) and complex (cereal) carbohydrates in each country's total dietary energy supply. Third, we use regression techniques to: (1) estimate the impact of these shares on the country's prevalence of obesity and being overweight; (2) compute for each country an indicator of dietary pattern based on the ratio between simple and complex carbohydrates, weighted by their estimated effects on the prevalence of obesity and being overweight; and (3) measure the elasticity of the prevalence of obesity and being overweight with respect to changes in both carbohydrate dietary pattern and income per capita. We find that unhealthy eating habits and the associated prevalence of excessive body fat accumulation tend to behave as a 'normal good' in low, medium- and high-HDI (Human Development Index) countries, but as an 'inferior good' in very high-HDI countries.

Benefits and hazards of dietary carbohydrate.

PubMed

Connor, William E; Duell, P Barton; Connor, Sonja L

2005-11-01

Since the dawn of civilization, carbohydrate has comprised the largest source of energy in the diet for most populations. The source of the carbohydrate has been from plants in the form of complex carbohydrate high in fiber. Only in affluent cultures has sugar contributed so much of the total energy. When carbohydrate is consumed as a major component of a plant-based diet, a high-carbohydrate, low-fat diet is associated with low plasma levels of total and low-density lipoprotein cholesterol, less coronary heart disease, less diabetes, and less obesity. Very low-carbohydrate (ketogenic) diets may provide short-term solutions but do not lead to a long-term solution for most people.

Lactose intolerance.

PubMed

Vandenplas, Yvan

2015-01-01

Lactose is the main carbohydrate in infant feeding, but its impact decreases as the child gets older and consumes less milk and dairy products. Congenital lactose intolerance is a very rare condition. However, lactase activity may be low and need to mature during the first weeks of life in many infants. However, the evidence that unabsorbed lactose is causing infantile crying and colic is contradictory. Unabsorbed lactose has a bifidogenic effect and improves calcium absorption. Lactose malabsorption may occur secondary and thus temporally to other etiologies such as infectious gastroenteritis, cow's milk allergy and celiac disease. One the cause is treated, lactase activity will gradually return to normal. The vast majority of Asian children will develop late onset congenital lactase deficiency. However, this entity only exceptionally causes symptoms before the age of 4-5 years. Symptoms are abdominal cramps, flatulence and watery, acid stools, and decrease the quality of life but lactose intolerance is not associated with "true disease". The diagnosis is made on clinical grounds and confirmed with a lactose breath test, if needed. These patients need to have a lifetime long reduced lactose intake to improve their quality of life.

Duodenal villous morphology assessed using magnification narrow band imaging correlates well with histology in patients with suspected malabsorption syndrome.

PubMed

Dutta, Amit Kumar; Sajith, Kattiparambil Gangadharan; Shah, Gautam; Pulimood, Anna Benjamin; Simon, Ebby George; Joseph, Anjilivelil Joseph; Chacko, Ashok

2014-11-01

Narrow band imaging with magnification enables detailed assessment of duodenal villi and may be useful in predicting the presence of villous atrophy or normal villi. We aimed to assess the morphology of duodenal villi using magnification narrow band imaging and correlate it with histology findings in patients with clinically suspected malabsorption syndrome. Patients with clinical suspicion of malabsorption presenting at a tertiary care center were prospectively recruited in this diagnostic intervention study. Patients underwent upper gastrointestinal endoscopy using magnification narrow band imaging. The villous morphology in the second part of the duodenum was assessed independently by two endoscopists and the presence of normal or atrophic villi was recorded. Biopsy specimen was obtained from the same area and was examined by two pathologists together. The sensitivity and specificity of magnification narrow band imaging in detecting the presence of duodenal villous atrophy was calculated and compared to the histology. One hundred patients with clinically suspected malabsorption were included in this study. Sixteen patients had histologically confirmed villous atrophy. The sensitivity and specificity of narrow band imaging in predicting villous atrophy was 87.5% and 95.2%, respectively, for one endoscopist. The corresponding figures for the second endoscopist were 81.3% and 92.9%, respectively. The interobserver agreement was very good with a kappa value of 0.87. Magnification narrow band imaging performed very well in predicting duodenal villous morphology. This may help in carrying out targeted biopsies and avoiding unnecessary biopsies in patients with suspected malabsorption. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

Carbohydrate terminology and classification.

PubMed

Cummings, J H; Stephen, A M

2007-12-01

Dietary carbohydrates are a group of chemically defined substances with a range of physical and physiological properties and health benefits. As with other macronutrients, the primary classification of dietary carbohydrate is based on chemistry, that is character of individual monomers, degree of polymerization (DP) and type of linkage (alpha or beta), as agreed at the Food and Agriculture Organization/World Health Organization Expert Consultation in 1997. This divides carbohydrates into three main groups, sugars (DP 1-2), oligosaccharides (short-chain carbohydrates) (DP 3-9) and polysaccharides (DP> or =10). Within this classification, a number of terms are used such as mono- and disaccharides, polyols, oligosaccharides, starch, modified starch, non-starch polysaccharides, total carbohydrate, sugars, etc. While effects of carbohydrates are ultimately related to their primary chemistry, they are modified by their physical properties. These include water solubility, hydration, gel formation, crystalline state, association with other molecules such as protein, lipid and divalent cations and aggregation into complex structures in cell walls and other specialized plant tissues. A classification based on chemistry is essential for a system of measurement, predication of properties and estimation of intakes, but does not allow a simple translation into nutritional effects since each class of carbohydrate has overlapping physiological properties and effects on health. This dichotomy has led to the use of a number of terms to describe carbohydrate in foods, for example intrinsic and extrinsic sugars, prebiotic, resistant starch, dietary fibre, available and unavailable carbohydrate, complex carbohydrate, glycaemic and whole grain. This paper reviews these terms and suggests that some are more useful than others. A clearer understanding of what is meant by any particular word used to describe carbohydrate is essential to progress in translating the growing knowledge of the physiological properties of carbohydrate into public health messages.

Molecular simulations of carbohydrates and protein-carbohydrate interactions: motivation, issues and prospects.

PubMed

Fadda, Elisa; Woods, Robert J

2010-08-01

The characterization of the 3D structure of oligosaccharides, their conjugates and analogs is particularly challenging for traditional experimental methods. Molecular simulation methods provide a basis for interpreting sparse experimental data and for independently predicting conformational and dynamic properties of glycans. Here, we summarize and analyze the issues associated with modeling carbohydrates, with a detailed discussion of four of the most recently developed carbohydrate force fields, reviewed in terms of applicability to natural glycans, carbohydrate-protein complexes and the emerging area of glycomimetic drugs. In addition, we discuss prospectives and new applications of carbohydrate modeling in drug discovery.

The carbohydrate sequence markup language (CabosML): an XML description of carbohydrate structures.

PubMed

Kikuchi, Norihiro; Kameyama, Akihiko; Nakaya, Shuuichi; Ito, Hiromi; Sato, Takashi; Shikanai, Toshihide; Takahashi, Yoriko; Narimatsu, Hisashi

2005-04-15

Bioinformatics resources for glycomics are very poor as compared with those for genomics and proteomics. The complexity of carbohydrate sequences makes it difficult to define a common language to represent them, and the development of bioinformatics tools for glycomics has not progressed. In this study, we developed a carbohydrate sequence markup language (CabosML), an XML description of carbohydrate structures. The language definition (XML Schema) and an experimental database of carbohydrate structures using an XML database management system are available at http://www.phoenix.hydra.mki.co.jp/CabosDemo.html kikuchi@hydra.mki.co.jp.

Use of the SeHCAT test in the investigation of diarrhoea.

PubMed

Ford, G A; Preece, J D; Davies, I H; Wilkinson, S P

1992-04-01

The SeHCAT test was used to investigate possible bile acid malabsorption in 166 patients presenting to a district general hospital with chronic diarrhoea of uncertain cause. Eighty-four (51%) patients had impaired SeHCAT retention. These included 23 of 28 patients with a possible type I abnormality (terminal ileal resection or disease, previous pelvic radiotherapy), 20 of 74 with a possible type II abnormality (idiopathic diarrhoea), 32 of 45 with a possible type III abnormality (post-cholecystectomy, post-vagotomy), and 9 of 19 with diarrhoea associated with diabetes. Patients with severe bile acid malabsorption demonstrated a good response to cholestyramine whereas the response in patients with a mildly abnormal SeHCAT retention was variable. Bile acid malabsorption is an important cause of diarrhoea in patients presenting with unexplained chronic diarrhoea.

Endemic tropical sprue in Rhodesia.

PubMed

Thomas, G; Clain, D J

1976-11-01

The existence of tropical sprue in Africa is controversial. In this paper we present 31 cases seen in Rhodesia over a 15 month period. They have the clinical features, small intestinal morphology, malabsorption pattern, and treatment response of tropical sprue. Other causes of malabsorption, and primary malnutrition, have been excluded. The severity of the clinical state and intestinal malabsorption distinguish these patients from those we have described with tropical enteropathy. The previous work on tropical sprue in Africa is reviewed and it is apparent that, when it has been adequately looked for, it has been found. It is clear that the question of tropical sprue in Africa must be re-examined and that it existence may have hitherto been concealed by the assumption that primary malnutrition is responsible for the high prevalence of deficiency states.

10 Tips for Parents: How to Get Kids to Eat More Complex Carbohydrates.

ERIC Educational Resources Information Center

PTA Today, 1991

1991-01-01

Offers 10 suggestions to help parents encourage their children to eat more complex carbohydrates. Suggestions include microwaving baked potatoes; baking whole-grain breads; snacking on gingersnaps, fig bars, pretzels, or vegetable sticks; mixing cereal into low-fat yogurt; and making soup containing beans, rice, pasta, or potatoes. (SM)

Nanoparticle-enhanced fluorescence emission for non-separation assays of carbohydrates using a boronic acid-alizarin complex.

PubMed

Li, Qianjin; Kamra, Tripta; Ye, Lei

2016-03-04

Addition of crosslinked polymer nanoparticles into a solution of a 3-nitrophenylboronic acid-alizarin complex leads to significant enhancement of fluorescence emission. Using the nanoparticle-enhanced boronic acid-alizarin system has improved greatly the sensitivity and extended the dynamic range of separation-free fluorescence assays for carbohydrates.

Hexameric supramolecular scaffold orients carbohydrates to sense bacteria.

PubMed

Grünstein, Dan; Maglinao, Maha; Kikkeri, Raghavendra; Collot, Mayeul; Barylyuk, Konstantin; Lepenies, Bernd; Kamena, Faustin; Zenobi, Renato; Seeberger, Peter H

2011-09-07

Carbohydrates are integral to biological signaling networks and cell-cell interactions, yet the detection of discrete carbohydrate-lectin interactions remains difficult since binding is generally weak. A strategy to overcome this problem is to create multivalent sensors, where the avidity rather than the affinity of the interaction is important. Here we describe the development of a series of multivalent sensors that self-assemble via hydrophobic supramolecular interactions. The multivalent sensors are comprised of a fluorescent ruthenium(II) core surrounded by a heptamannosylated β-cyclodextrin scaffold. Two additional series of complexes were synthesized as proof-of-principle for supramolecular self-assembly, the fluorescent core alone and the core plus β-cyclodextrin. Spectroscopic analyses confirmed that the three mannosylated sensors displayed 14, 28, and 42 sugar units, respectively. Each complex adopted original and unique spatial arrangements. The sensors were used to investigate the influence of carbohydrate spatial arrangement and clustering on the mechanistic and qualitative properties of lectin binding. Simple visualization of binding between a fluorescent, multivalent mannose complex and the Escherichia coli strain ORN178 that possesses mannose-specific receptor sites illustrates the potential for these complexes as biosensors.

Hyper-Assembly of Self-Assembled Glycoclusters Mediated by Specific Carbohydrate-Carbohydrate Interactions.

PubMed

Yan, Gengwei; Yamaguchi, Takumi; Suzuki, Tatsuya; Yanaka, Saeko; Sato, Sota; Fujita, Makoto; Kato, Koichi

2017-05-04

Hybridization of a self-assembled, spherical complex with oligosaccharides containing Lewis X, a functional trisaccharide displayed on various cell surfaces, yielded well-defined glycoclusters. The self-assembled glycoclusters exhibited homophilic hyper-assembly in aqueous solution in a Ca 2+ -dependent manner through specific carbohydrate-carbohydrate interactions, offering a structural scaffold for functional biomimetic systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Towards complete hydrolysis of soy flour carbohydrates by enzyme mixtures for protein enrichment: A modeling approach.

PubMed

Loman, Abdullah Al; Ju, Lu-Kwang

2016-05-01

Soy protein is a well-known nutritional supplement in proteinaceous food and animal feed. However, soybeans contain complex carbohydrate. Selective carbohydrate removal by enzymes could increase the protein content and remove the indigestibility of soy products for inclusion in animal feed. Complete hydrolysis of soy flour carbohydrates is challenging due to the presence of proteins and different types of non-structural polysaccharides. This study is designed to guide complex enzyme mixture required for hydrolysis of all types of soy flour carbohydrates. Enzyme broths from Aspergillus niger, Aspergillus aculeatus and Trichoderma reesei fermentations were evaluated in this study for soy carbohydrate hydrolysis. The resultant hydrolysate was measured for solubilized carbohydrate by both total carbohydrate and reducing sugar analyses. Conversion data attained after 48h hydrolysis were first fitted with models to determine the maximum fractions of carbohydrate hydrolyzable by each enzyme group, i.e., cellulase, xylanase, pectinase and α-galactosidase. Kinetic models were then developed to describe the increasing conversions over time under different enzyme activities and process conditions. The models showed high fidelity in predicting soy carbohydrate hydrolysis over broad ranges of soy flour loading (5-25%) and enzyme activities: per g soy flour, cellulase, 0.04-30 FPU; xylanase, 3.5-618U; pectinase, 0.03-120U; and α-galactosidase, 0.01-60U. The models are valuable in guiding the development and production of optimal enzyme mixtures toward hydrolysis of all types of carbohydrates present in soy flour and in optimizing the design and operation of hydrolysis reactor and process. Copyright © 2016 Elsevier Inc. All rights reserved.

Carbohydrate-Based Host-Guest Complexation of Hydrophobic Antibiotics for the Enhancement of Antibacterial Activity.

PubMed

Jeong, Daham; Joo, Sang-Woo; Shinde, Vijay Vilas; Cho, Eunae; Jung, Seunho

2017-08-08

Host-guest complexation with various hydrophobic drugs has been used to enhance the solubility, permeability, and stability of guest drugs. Physical changes in hydrophobic drugs by complexation have been related to corresponding increases in the bioavailability of these drugs. Carbohydrates, including various derivatives of cyclodextrins, cyclosophoraoses, and some linear oligosaccharides, are generally used as host complexation agents in drug delivery systems. Many antibiotics with low bioavailability have some limitations to their clinical use due to their intrinsically poor aqueous solubility. Bioavailability enhancement is therefore an important step to achieve the desired concentration of antibiotics in the treatment of bacterial infections. Antibiotics encapsulated in a complexation-based drug delivery system will display improved antibacterial activity making it possible to reduce dosages and overcome the serious global problem of antibiotic resistance. Here, we review the present research trends in carbohydrate-based host-guest complexation of various hydrophobic antibiotics as an efficient delivery system to improve solubility, permeability, stability, and controlled release.

Intestinal lymphangiectasia and reversible high liver stiffness.

PubMed

Milazzo, Laura; Peri, Anna Maria; Lodi, Lucia; Gubertini, Guido; Ridolfo, Anna Lisa; Antinori, Spinello

2014-08-01

Primary intestinal lymphangiectasia (PIL) is a protein-losing enteropathy characterized by tortuous and dilated lymph channels of the small bowel. The main symptoms are bilateral lower limb edema, serosal effusions, and vitamin D malabsorption resulting in osteoporosis. We report here a case of long-lasting misdiagnosed PIL with a peculiar liver picture, characterized by a very high stiffness value at transient elastography, which decreased with clinical improvement. The complex interplay between lymphatic and hepatic circulatory system is discussed. © 2014 by the American Association for the Study of Liver Diseases.

An overview of the management of patients with chronic pancreatitis.

PubMed

Johnstone, Carolyn C

2016-11-23

Chronic pancreatitis is a complex inflammatory condition characterised by irreversible damage to the pancreas. This article explores the pathophysiology of this condition and its effects on pancreatic function. It outlines the causes and presenting features of chronic pancreatitis, as well as its effect on patients' quality of life and the changes to their lifestyle that are likely to be required. Chronic pancreatitis cannot be cured; therefore, treatment aims to control pain, manage problems associated with malabsorption, and assess and manage long-term complications that may develop, such as insulin dependence.

Dynamic aspects of antibody:oligosaccharide complexes characterized by molecular dynamics simulations and saturation transfer difference nuclear magnetic resonance.

PubMed

Theillet, François-Xavier; Frank, Martin; Vulliez-Le Normand, Brigitte; Simenel, Catherine; Hoos, Sylviane; Chaffotte, Alain; Bélot, Frédéric; Guerreiro, Catherine; Nato, Farida; Phalipon, Armelle; Mulard, Laurence A; Delepierre, Muriel

2011-12-01

Carbohydrates are likely to maintain significant conformational flexibility in antibody (Ab):carbohydrate complexes. As demonstrated herein for the protective monoclonal Ab (mAb) F22-4 recognizing the Shigella flexneri 2a O-antigen (O-Ag) and numerous synthetic oligosaccharide fragments thereof, the combination of molecular dynamics simulations and nuclear magnetic resonance saturation transfer difference experiments, supported by physicochemical analysis, allows us to determine the binding epitope and its various contributions to affinity without using any modified oligosaccharides. Moreover, the methods used provide insights into ligand flexibility in the complex, thus enabling a better understanding of the Ab affinities observed for a representative set of synthetic O-Ag fragments. Additionally, these complementary pieces of information give evidence to the ability of the studied mAb to recognize internal as well as terminal epitopes of its cognate polysaccharide antigen. Hence, we show that an appropriate combination of computational and experimental methods provides a basis to explore carbohydrate functional mimicry and receptor binding. The strategy may facilitate the design of either ligands or carbohydrate recognition domains, according to needed improvements of the natural carbohydrate:receptor properties. © The Author 2011. Published by Oxford University Press. All rights reserved.

Structure and Specificity of a Binary Tandem Domain F-Lectin from Striped Bass (Morone saxatilis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bianchet, M.; Odom, E; Vasta, J

2010-01-01

The plasma of the striped bass Morone saxatilis contains a fucose-specific lectin (MsaFBP32) that consists of two F-type carbohydrate recognition domains (CRDs) in tandem. The crystal structure of the complex of MsaFBP32 with l-fucose reported here shows a cylindrical 81-A-long and 60-A-wide trimer divided into two globular halves: one containing N-terminal CRDs (N-CRDs) and the other containing C-terminal CRDs (C-CRDs). The resulting binding surfaces at the opposite ends of the cylindrical trimer have the potential to cross-link cell surface or humoral carbohydrate ligands. The N-CRDs and C-CRDs of MsaFBP32 exhibit significant structural differences, suggesting that they recognize different glycans. Analysismore » of the carbohydrate binding sites provides the structural basis for the observed specificity of MsaFBP32 for simple carbohydrates and suggests that the N-CRD recognizes more complex fucosylated oligosaccharides and with a relatively higher avidity than the C-CRD. Modeling of MsaFBP32 complexed with fucosylated glycans that are widely distributed in prokaryotes and eukaryotes rationalizes the observation that binary tandem CRD F-type lectins function as opsonins by cross-linking 'non-self' carbohydrate ligands and 'self' carbohydrate ligands, such as sugar structures displayed by microbial pathogens and glycans on the surface of phagocytic cells from the host.« less

Carbohydrates as allergens.

PubMed

Commins, Scott P

2015-01-01

Complex carbohydrates are effective inducers of Th2 responses, and carbohydrate antigens can stimulate the production of glycan-specific antibodies. In instances where the antigen exposure occurs through the skin, the resulting antibody production can contain IgE class antibody. The glycan-stimulated IgE may be non-specific but may also be antigen specific. This review focuses on the production of cross-reactive carbohydrate determinants, the recently identified IgE antibody response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal), as well as discusses practical implications of carbohydrates in allergy. In addition, the biological effects of carbohydrate antigens are reviewed in setting of receptors and host recognition.

Label-Free Discovery Array Platform for the Characterization of Glycan Binding Proteins and Glycoproteins.

PubMed

Gray, Christopher J; Sánchez-Ruíz, Antonio; Šardzíková, Ivana; Ahmed, Yassir A; Miller, Rebecca L; Reyes Martinez, Juana E; Pallister, Edward; Huang, Kun; Both, Peter; Hartmann, Mirja; Roberts, Hannah N; Šardzík, Robert; Mandal, Santanu; Turnbull, Jerry E; Eyers, Claire E; Flitsch, Sabine L

2017-04-18

The identification of carbohydrate-protein interactions is central to our understanding of the roles of cell-surface carbohydrates (the glycocalyx), fundamental for cell-recognition events. Therefore, there is a need for fast high-throughput biochemical tools to capture the complexity of these biological interactions. Here, we describe a rapid method for qualitative label-free detection of carbohydrate-protein interactions on arrays of simple synthetic glycans, more complex natural glycosaminoglycans (GAG), and lectins/carbohydrate binding proteins using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The platform can unequivocally identify proteins that are captured from either purified or complex sample mixtures, including biofluids. Identification of proteins bound to the functionalized array is achieved by analyzing either the intact protein mass or, after on-chip proteolytic digestion, the peptide mass fingerprint and/or tandem mass spectrometry of selected peptides, which can yield highly diagnostic sequence information. The platform described here should be a valuable addition to the limited analytical toolbox that is currently available for glycomics.

Use of the SeHCAT test in the investigation of diarrhoea.

PubMed Central

Ford, G. A.; Preece, J. D.; Davies, I. H.; Wilkinson, S. P.

1992-01-01

The SeHCAT test was used to investigate possible bile acid malabsorption in 166 patients presenting to a district general hospital with chronic diarrhoea of uncertain cause. Eighty-four (51%) patients had impaired SeHCAT retention. These included 23 of 28 patients with a possible type I abnormality (terminal ileal resection or disease, previous pelvic radiotherapy), 20 of 74 with a possible type II abnormality (idiopathic diarrhoea), 32 of 45 with a possible type III abnormality (post-cholecystectomy, post-vagotomy), and 9 of 19 with diarrhoea associated with diabetes. Patients with severe bile acid malabsorption demonstrated a good response to cholestyramine whereas the response in patients with a mildly abnormal SeHCAT retention was variable. Bile acid malabsorption is an important cause of diarrhoea in patients presenting with unexplained chronic diarrhoea. PMID:1409191

Levothyroxine Tablet Malabsorption Associated with Gastroparesis Corrected with Gelatin Capsule Formulation.

PubMed

Reardon, David P; Yoo, Peter S

2016-01-01

Treatment of hypothyroidism with levothyroxine sodium often requires multiple dose adjustments and can be complicated by patients with gastric and intestinal dysfunction that limits absorption. In these cases, doses are often titrated higher than commonly used in clinical practice. Multiple formulations of levothyroxine are currently available and some may be preferred in cases of malabsorption. We report a case of a 42-year-old female who presented with a living unrelated kidney transplant evaluation with myxedema while being treated with levothyroxine sodium tablets. She was noted to have gastroparesis secondary to Type I diabetes mellitus which may have contributed to levothyroxine malabsorption. Changing to a gelatin capsule formulation quickly corrected her thyroid function assays. This case suggests that gastroparesis may affect absorption of levothyroxine tablets and the gelatin capsules may be an effective alternative therapy.

Subcutaneous application of levothyroxine as successful treatment option in a patient with malabsorption

PubMed Central

Groener, Jan B.; Lehnhoff, Daniel; Piel, David; Nawroth, Peter P.; Schanz, Jurik; Rudofsky, Gottfried

2013-01-01

Summary Background: Hypothyroidism can usually be treated effectively by oral levothyroxine supplementation. There are, however, some rare circumstances, when oral levothyroxine application is not sufficient, for example malabsorption, interactions with food or other medications, or various gastrointestinal diseases. Case Report: We present a 42 year old woman with refractory and severe symptomatic hypothyroidism after subtotal thyroidectomy in spite of high dose oral levothyroxine supplementation. By stepwise increasing oral levothyroxine dosage up to 2200 micrograms plus 80 micrograms of thyronine, no sufficient substitution could be achieved. After suspicion of enteral malabsorption due to a pathological D-Xylose-test, subcutaneous levothyroxine supplementation was started. Finally, a sustained euthyroid state could be achieved. Conclusions: For selected patients who do not respond to oral treatment subcutaneous application of levothyroxine can be a suitable and effective therapy. PMID:23569562

Absence of histopathological changes of ileum and colon in functional chronic diarrhea associated with bile acid malabsorption, assessed by SeHCAT test: a prospective study.

PubMed

Sciarretta, G; Furno, A; Morrone, B; Malaguti, P

1994-07-01

Chronic diarrhea of unknown origin is often associated with bile acid malabsorption, the pathogenetic role of which is uncertain. The aim of this study was to identify morphological abnormalities in the ileal and colonic mucosa in patients with this disorder. We performed a prospective and blinded histopathological study (between June 1991 and November 1992) of endoscopic biopsies of the distal ileum and colon of 23 patients suffering from chronic diarrhea of unknown origin. In 14, the SeHCAT (75-selena-homo-cholic acid taurine) test was abnormal owing to bile acid malabsorption; in the other nine, the diarrhea control group, the test results were normal. A detailed evaluation of surface epithelium, immune response and inflammatory changes was made. in two patients and two controls, mild villous atrophy was observed; there was also slight inflammation of the ileal and colonic mucosa occurring with the same frequency in both groups. A slight replacement of goblet cells was more evident in the diarrhea control group. Chronic diarrhea of unknown origin associated with bile acid malabsorption does not involve specific morphological changes of ileal or colonic mucosa, and its pathogenesis must be looked for in dysfunction of the ileum and/or colon.

Lactose malabsorption and intolerance: pathogenesis, diagnosis and treatment.

PubMed

Misselwitz, Benjamin; Pohl, Daniel; Frühauf, Heiko; Fried, Michael; Vavricka, Stephan R; Fox, Mark

2013-06-01

Lactose malabsorption is a common condition caused by reduced expression or activity of lactase in the small intestine. In such patients, lactose intolerance is characterized by abdominal symptoms (e.g. nausea, bloating, and pain) after ingestion of dairy products. The genetic basis of lactose malabsorption is established and several tests for this condition are available, including genetic, endoscopic, and H2-breath tests. In contrast, lactose intolerance is less well understood. Recent studies show that the risk of symptoms after lactose ingestion depends on the dose of lactose, lactase expression, intestinal flora, and sensitivity of the gastrointestinal tract. Lactose intolerance has recently been defined as symptoms developing after ingestion of lactose which do not develop after placebo challenge in a person with lactose maldigestion. Such blinded testing might be especially important in those with functional gastrointestinal diseases in whom self-reported lactose intolerance is common. However, placebo-controlled testing is not part of current clinical practice. Updated protocols and high-quality outcome studies are needed. Treatment options of lactose intolerance include lactose-reduced diet and enzyme replacement. Documenting the response to multiple doses can guide rational dietary management; however, the clinical utility of this strategy has not been tested. This review summarizes the genetic basis, diagnosis, and treatment of lactose malabsorption and intolerance.

Lactose malabsorption and intolerance: pathogenesis, diagnosis and treatment

PubMed Central

Pohl, Daniel; Frühauf, Heiko; Fried, Michael; Vavricka, Stephan R; Fox, Mark

2013-01-01

Lactose malabsorption is a common condition caused by reduced expression or activity of lactase in the small intestine. In such patients, lactose intolerance is characterized by abdominal symptoms (e.g. nausea, bloating, and pain) after ingestion of dairy products. The genetic basis of lactose malabsorption is established and several tests for this condition are available, including genetic, endoscopic, and H2-breath tests. In contrast, lactose intolerance is less well understood. Recent studies show that the risk of symptoms after lactose ingestion depends on the dose of lactose, lactase expression, intestinal flora, and sensitivity of the gastrointestinal tract. Lactose intolerance has recently been defined as symptoms developing after ingestion of lactose which do not develop after placebo challenge in a person with lactose maldigestion. Such blinded testing might be especially important in those with functional gastrointestinal diseases in whom self-reported lactose intolerance is common. However, placebo-controlled testing is not part of current clinical practice. Updated protocols and high-quality outcome studies are needed. Treatment options of lactose intolerance include lactose-reduced diet and enzyme replacement. Documenting the response to multiple doses can guide rational dietary management; however, the clinical utility of this strategy has not been tested. This review summarizes the genetic basis, diagnosis, and treatment of lactose malabsorption and intolerance. PMID:24917953

[Oral vitamin B12: Efficacy and safety data in 31 patients with pernicious anemia and food-cobalamin malabsorption].

PubMed

Troilo, Arianna; Mecili, Mustapha; Ciobanu, Ecaterina; Boddi, Vieri; D'Elios, Mario M; Andrès, Emmanuel

2010-12-01

The aim of this study is to validate the efficacy and safety of oral cobalamin therapy in the treatment of cobalamin deficiency related to various causes. It's a retrospective study, including 31 patients with documented cobalamin deficiency related to food-cobalamin malabsorption (n=20) and pernicious anemia (n=11). These patients were treated at least for 3 months with oral cyanocobalamin, between 125 to 1000microg per day. Serum cobalamin levels and hematological parameters were compared before and after the therapy and in relation with the nature of cobalamin deficiency. Safety data were also recorded. After 3 months of therapy, the serum cobalamin levels have significantly increased in all the patients, with a mean of +161.6±79.3pg/mL in the food-cobalamin malabsorption group (P<0,00005) and +136.7±67.4pg/mL in the pernicious anemia group (P<0,0001). Hematological parameters have been normalized in 90 % of the patients, independently of the cause of the cobalamin deficiency. Only 1 patient presented an urticarial reaction. This study confirms the efficacy and safety of oral cobalamin therapy in food-cobalamin malabsorption and also in case of pernicious anemia. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Cellulosic-Derived Biofuels Program in Kentucky - Part 2

DTIC Science & Technology

2014-04-30

and lignin, are complex raw materials. Selection of robust strains of algae that are able to convert C6 (glucose) and C5 carbohydrates from...13 Task B2.03 Development of Metalloporphyrin-Ionic Liquid Complexes for Degradation of Biomass . 14 Task B2.04 –Biomass Conversion Process Scale...Up ............................................................................. 15 Task B3: Carbohydrate to Oil Conversion Process Development

Carbohydrate Counting

MedlinePlus

... help you manage your blood glucose. It sounds complex, but with time you and your diabetes care team can figure out the right balance for you. How Much Carbohydrate? A great place to start may be to ...

[Lactose malabsorption and -intolerance - who will benefit from a lactose-reduced diet?

PubMed

Malham, Mikkel; Olin, Anne Bille; Pærregaard, Anders

2017-02-06

During the last decade, lactose-free diets have become increasingly popular in the general population, either isolated or as a part of a cow's milk-free diet. However, health-related benefits from a lactose-free diet are only documented for individuals with clinical lactose intolerance due to decreased intestinal lactase activity and subsequent lactose malabsorption. In this paper we summarize the current knowledge of lactose intolerance regarding diagnostic procedures and treatment.

Is bile acid malabsorption underdiagnosed? An evaluation of accuracy of diagnosis by measurement of SeHCAT retention.

PubMed Central

Merrick, M V; Eastwood, M A; Ford, M J

1985-01-01

The cause of intractable chronic diarrhoea was found to be malabsorption of bile acid in five out of 42 patients thought to have the irritable bowel syndrome, six out of 29 patients with persistent diarrhoea after surgery for peptic ulcer, 23 who had undergone small bowel resection, and two others. Specific treatment brought symptomatic relief. The diagnosis was established by measuring the proportion of SeHCAT, a synthetic bile salt, retained one week after oral administration of a tracer dose of less than 100 micrograms of the compound labelled with 40 kBq (1 microCi) of selenium-75. These results indicate that malabsorption of bile acid is a more common cause of chronic diarrhoea than is generally appreciated. Measurement of retention of SeHCAT is a simple, accurate, and acceptable means of establishing the diagnosis of this debilitating but treatable condition. PMID:3918708

Is bile acid malabsorption underdiagnosed? An evaluation of accuracy of diagnosis by measurement of SeHCAT retention.

PubMed

Merrick, M V; Eastwood, M A; Ford, M J

1985-03-02

The cause of intractable chronic diarrhoea was found to be malabsorption of bile acid in five out of 42 patients thought to have the irritable bowel syndrome, six out of 29 patients with persistent diarrhoea after surgery for peptic ulcer, 23 who had undergone small bowel resection, and two others. Specific treatment brought symptomatic relief. The diagnosis was established by measuring the proportion of SeHCAT, a synthetic bile salt, retained one week after oral administration of a tracer dose of less than 100 micrograms of the compound labelled with 40 kBq (1 microCi) of selenium-75. These results indicate that malabsorption of bile acid is a more common cause of chronic diarrhoea than is generally appreciated. Measurement of retention of SeHCAT is a simple, accurate, and acceptable means of establishing the diagnosis of this debilitating but treatable condition.

Evaluation of different derivatisation approaches for gas chromatographic-mass spectrometric analysis of carbohydrates in complex matrices of biological and synthetic origin.

PubMed

Becker, M; Zweckmair, T; Forneck, A; Rosenau, T; Potthast, A; Liebner, F

2013-03-15

Gas chromatographic analysis of complex carbohydrate mixtures requires highly effective and reliable derivatisation strategies for successful separation, identification, and quantitation of all constituents. Different single-step (per-trimethylsilylation, isopropylidenation) and two-step approaches (ethoximation-trimethylsilylation, ethoximation-trifluoroacetylation, benzoximation-trimethylsilylation, benzoximation-trifluoroacetylation) have been comprehensively studied with regard to chromatographic characteristics, informational value of mass spectra, ease of peak assignment, robustness toward matrix effects, and quantitation using a set of reference compounds that comprise eight monosaccharides (C(5)-C(6)), glycolaldehyde, and dihydroxyacetone. It has been shown that isopropylidenation and the two oximation-trifluoroacetylation approaches are least suitable for complex carbohydrate matrices. Whereas the former is limited to compounds that contain vicinal dihydroxy moieties in cis configuration, the latter two methods are sensitive to traces of trifluoroacetic acid which strongly supports decomposition of ketohexoses. It has been demonstrated for two "real" carbohydrate-rich matrices of biological and synthetic origin, respectively, that two-step ethoximation-trimethylsilylation is superior to other approaches due to the low number of peaks obtained per carbohydrate, good peak separation performance, structural information of mass spectra, low limits of detection and quantitation, minor relative standard deviations, and low sensitivity toward matrix effects. Copyright © 2013 Elsevier B.V. All rights reserved.

Peptide YY in diabetics treated chronically with an intestinal glucosidase inhibitor.

PubMed

Füessl, H S; Adrian, T E; Uttenthal, L O; Bloom, S R

1988-10-03

Peptide YY (PYY) is a recently discovered peptide found in the distal ileum and colon. It circulates in plasma and concentrations rise in malabsorptive conditions. The potential of PYY as an indicator of impaired carbohydrate digestion was studied in a pharmacological model of intestinal glucosidase inhibition. Thirteen type-2 diabetics on long-term treatment with the alpha-glucosidase inhibitor acarbose (3 x 100 mg per day) had test meals with and without acarbose 100 mg before and after the treatment period (mean 46 weeks), a test meal with acarbose after 20 weeks of continuous treatment and a final test meal without acarbose 6 weeks after cessation of treatment. Without acarbose mean plasma PYY concentrations rose from a mean basal value of 11.5 +/- 2.9 pmol/l to 19.5 +/- 3.9 pmol/l 120 min postprandially (P less than 0.01). Acarbose treatment did not effect basal plasma PYY concentrations but significantly enhanced food stimulated PYY concentrations acutely, at 20 weeks and at the final treatment test meal. Mean incremental integrated plasma responses (area under curve) rose by 183%, 184% and 169%, respectively (P less than 0.05). After cessation of treatment postprandial responses returned to pretreatment values within 6 weeks. Conversely, the integrated incremetal postprandial plasma responses of glucose and insulin were reversibly reduced by acarbose to 58% +/- 9% and 60% +/- 10% of controls, respectively. Self-assesed side effects of flatulence and more frequent bowel action showed no regular relationship to the PYY response. PYY seems to act as an indicator of the increased carbohydrate load to the distal intestine even in the absence of clinical symptoms. It may contribute to the hypoglycaemic effect of alpha-glucosidase inhibitors by slowing down intestinal transit.

Differential impact of amino acids on OXPHOS system activity following carbohydrate starvation in Arabidopsis cell suspensions.

PubMed

Cavalcanti, João Henrique F; Quinhones, Carla G S; Schertl, Peter; Brito, Danielle S; Eubel, Holger; Hildebrandt, Tatjana; Nunes-Nesi, Adriano; Braun, Hans-Peter; Araújo, Wagner L

2017-12-01

Plant respiration mostly depends on the activity of glycolysis and the oxidation of organic acids in the tricarboxylic acid cycle to synthesize ATP. However, during stress situations plant cells also use amino acids as alternative substrates to donate electrons through the electron-transfer flavoprotein (ETF)/ETF:ubiquinone oxidoreductase (ETF/ETFQO) complex to the mitochondrial electron transport chain (mETC). Given this, we investigated changes of the oxidative phosphorylation (OXPHOS) system in Arabidopsis thaliana cell culture under carbohydrate starvation supplied with a range of amino acids. Induction of isovaleryl-CoA dehydrogenase (IVDH) activity was observed under carbohydrate starvation which was associated with increased amounts of IVDH protein detected by immunoblotting. Furthermore, activities of the protein complexes of the mETC were reduced under carbohydrate starvation. We also observed that OXPHOS system activity behavior is differently affected by different amino acids and that proteins associated with amino acids catabolism are upregulated in cells following carbohydrate starvation. Collectively, our results support the contention that ETF/ETFQO is an essential pathway to donate electrons to the mETC and that amino acids are alternative substrates to maintain respiration under carbohydrate starvation. © 2017 Scandinavian Plant Physiology Society.

Calculating binding free energies for protein-carbohydrate complexes.

PubMed

Hadden, Jodi A; Tessier, Matthew B; Fadda, Elisa; Woods, Robert J

2015-01-01

A variety of computational techniques may be applied to compute theoretical binding free energies for protein-carbohydrate complexes. Elucidation of the intermolecular interactions, as well as the thermodynamic effects, that contribute to the relative strength of receptor binding can shed light on biomolecular recognition, and the resulting initiation or inhibition of a biological process. Three types of free energy methods are discussed here, including MM-PB/GBSA, thermodynamic integration, and a non-equilibrium alternative utilizing SMD. Throughout this chapter, the well-known concanavalin A lectin is employed as a model system to demonstrate the application of these methods to the special case of carbohydrate binding.

Conformational analysis of oligosaccharides and polysaccharides using molecular dynamics simulations.

PubMed

Frank, Martin

2015-01-01

Complex carbohydrates usually have a large number of rotatable bonds and consequently a large number of theoretically possible conformations can be generated (combinatorial explosion). The application of systematic search methods for conformational analysis of carbohydrates is therefore limited to disaccharides and trisaccharides in a routine analysis. An alternative approach is to use Monte-Carlo methods or (high-temperature) molecular dynamics (MD) simulations to explore the conformational space of complex carbohydrates. This chapter describes how to use MD simulation data to perform a conformational analysis (conformational maps, hydrogen bonds) of oligosaccharides and how to build realistic 3D structures of large polysaccharides using Conformational Analysis Tools (CAT).

[Specific problems posed by carbohydrate utilization in the rainbow trout].

PubMed

Bergot, F

1979-01-01

Carbohydrate incorporation in trout diets arises problems both at digestive and metabolic levels. Digestive utilization of carbohydrate closely depends on their molecular weight. In addition, in the case of complex carbohydrates (starches), different factors such as the level of incorporation, the amount consumed and the physical state of starch influence the digestibility. The measurement of digestibility in itself is confronted with methodological difficulties. The way the feces are collected can affect the digestion coefficient. Dietary carbohydrates actually serve as a source of energy. Nevertheless, above a certain level in the diet, intolerance phenomena may appear. The question that arises now is to establish the optimal part that carbohydrates can take in the metabolizable energy of a given diet.

Bile acid malabsorption caused by gastrointestinal motility dysfunction? An investigation of gastrointestinal disturbances in familial amyloidosis with polyneuropathy.

PubMed

Suhr, O; Danielsson, A; Steen, L

1992-01-01

Gastrointestinal dysfunction due to autonomous neuropathy is a complication described in various diseases such as diabetes mellitus, multiple sclerosis, and familial amyloidosis with polyneuropathy. We present the results of a prospective investigation of bile acid malabsorption in 17 patients with familial amyloidosis by means of 75Se-labelled homocholic-tauro acid (SeHCAT). The diagnosis was in all cases verified by the DNA test for mutation of transthyretin in position 30. Small-intestinal biopsy specimens were examined for deposits of amyloid, and the presence of gastric retention was evaluated by gastroscopy. In addition, the patients were investigated for bacterial overgrowth by means of the bile acid breath test (BABT). A high frequency of abnormal BABT results (44%) was encountered. However, 65% also had abnormal low SeHCAT values, indicating bile acid malabsorption. Only two patients had abnormal BABT and normal SeHCAT results, indicating bacterial contamination of the small intestine. Bile acid losses increased with the duration of gastrointestinal symptoms. Significantly lower SeHCAT values were encountered in patients with gastric retention, whereas the occurrence of amyloid deposits in small-intestinal biopsy specimens was without effect on SeHCAT retention. Bile acid malabsorption is frequently encountered in familial amyloidosis with polyneuropathy and seems to be more closely associated with gastrointestinal motility dysfunction than with amyloid deposits in the intestinal mucosa.

Oral cholecalciferol versus ultraviolet radiation B: effect on vitamin D metabolites in patients with chronic pancreatitis and fat malabsorption - a randomized clinical trial.

PubMed

Bang, Ulrich C; Matzen, Peter; Benfield, Thomas; Beck Jensen, Jens-Erik

2011-01-01

Patients with chronic pancreatitis (CP) often develop fat malabsorption and are susceptible to hypovitaminosis D. We wanted to evaluate the intestinal uptake of cholecalciferol in patients with CP and fat malabsorption. We did a prospective placebo-controlled study including patients with verified CP and fat malabsorption. They were randomized to 10 weeks of (A) ultraviolet radiation B (UVB) 6 min weekly in a commercial tanning bed, (B) vitamin D supplement 1,520 IU/daily, or (C) placebo. The vitamin D metabolites 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (calcitriol) were quantified at the start and end of the study. In total 30 patients were randomized and 27 completed the study. Compliance to tablets and tanning sessions was >80%. The changes in 25OHD levels in group B (32.3 nmol/l; 95% CI 15-50) were significantly greater than changes in group A (p < 0.001) and group C (p < 0.001). Changes in group A (1.1 nmol/l) did not differ from the placebo group (p = 0.9). Changes in calcitriol levels were identical between groups. Daily vitamin D supplements increased 25OHD in patients with CP compared to placebo whereas weekly tanning bed sessions did not. Copyright © 2011 S. Karger AG, Basel.

Malabsorption Blood Test: Assessing Fat Absorption in Patients with Cystic Fibrosis and Pancreatic Insufficiency

PubMed Central

Mascarenhas, Maria R.; Mondick, John; Barrett, Jeffrey S.; Wilson, Martha; Stallings, Virginia A.; Schall, Joan I.

2015-01-01

The Malabsorption Blood Test (MBT), consisting of pentadecanoic acid (PA), a free fatty acid and triheptadecanoic acid (THA), a triglyceride that requires pancreatic lipase for absorption of the heptadecanoic acid (HA), was developed to assess fat malabsorption in patients with cystic fibrosis (CF) and pancreatic insufficiency (PI). The objective was to construct a population pharmacokinetic (PK) model to describe PA and HA disposition in healthy subjects and CF subjects. A model was simultaneously fit to PA and HA concentrations, consisting of one compartment disposition and a transit model to describe absorption. PA bioavailability estimates for CF subjects without pancreatic enzyme administration [1.07 (0.827,1.42)] and with enzymes [0.88 (0.72,1.09)] indicated PA absorption comparable to healthy subjects. HA bioavailability in CF without enzyme administration was 0.0292 (0.0192,0.0459), and with enzymes increased to 0.606 (0.482,0.823). In CF, compared to taking enzymes with the MBT, HA bioavailability was further decreased by factors of 0.829 (0.664,0.979) and 0.78 (0.491,1.13) with enzymes taken 30 and 60 minutes after MBT, respectively. The MBT detected differences in fat absorption in subjects with CF with and without enzyme administration and with changes in enzyme timing. Future studies will address application of the MBT in CF and other malabsorption diagnoses. PMID:25689042

Molecular simulations of carbohydrates and protein-carbohydrate interactions: motivation, issues and prospects

PubMed Central

Fadda, Elisa; Woods, Robert J.

2014-01-01

The characterization of the 3D structure of oligosaccharides, their conjugates and analogs is particularly challenging for traditional experimental methods. Molecular simulation methods provide a basis for interpreting sparse experimental data and for independently predicting conformational and dynamic properties of glycans. Here, we summarize and analyze the issues associated with modeling carbohydrates, with a detailed discussion of four of the most recently developed carbohydrate force fields, reviewed in terms of applicability to natural glycans, carbohydrate–protein complexes and the emerging area of glycomimetic drugs. In addition, we discuss prospectives and new applications of carbohydrate modeling in drug discovery. PMID:20594934

A novel approach for the quantitation of carbohydrates in mash, wort, and beer with RP-HPLC using 1-naphthylamine for precolumn derivatization.

PubMed

Rakete, Stefan; Glomb, Marcus A

2013-04-24

A novel universal method for the determination of reducing mono-, di-, and oligosaccharides in complex matrices on RP-HPLC using 1-naphthylamine for precolumn derivatization with sodium cyanoborhydride was established to study changes in the carbohydrate profile during beer brewing. Fluorescence and mass spectrometric detection enabled very sensitive analyses of beer-relevant carbohydrates. Mass spectrometry additionally allowed the identification of the molecular weight and thereby the degree of polymerization of unknown carbohydrates. Thus, carbohydrates with up to 16 glucose units were detected. Comparison demonstrated that the novel method was superior to fluorophore-assisted carbohydrate electrophoresis (FACE). The results proved the HPLC method clearly to be more powerful in regard to sensitivity and resolution. Analogous to FACE, this method was designated fluorophore-assisted carbohydrate HPLC (FAC-HPLC).

Prediction of the cause, effects, and prevention of drug-nutrient interactions using attributes and attribute values.

PubMed

Roe, D A

1985-01-01

Drug-nutrient interactions and their adverse outcomes have previously been identified by observation, investigation, and literature reports. Knowing the attributes of the drugs, availability of knowledge base management systems for microcomputer use can facilitate prediction of the mechanism and the effects of drug-nutrient interactions. Examples used to illustrate this approach are prediction of lactose intolerance in drug-induced malabsorption, and prediction of the mechanism responsible for drug-induced flush reactions. In the future we see that there may be many opportunities to use this system further in the investigation of complex drug-nutrient interactions.

Update on diagnostic value of breath test in gastrointestinal and liver diseases

PubMed Central

Siddiqui, Imran; Ahmed, Sibtain; Abid, Shahab

2016-01-01

In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome evaluation of several disorders by simply quantifying the appearance in exhaled breath of a metabolite of a specific substrate administered. The aim of this review is to have an insight into the principles, methods of analysis and performance parameters of various hydrogen, methane and carbon BTs which are available for diagnosing gastrointestinal disorders such as Helicobacter pylori infection, small intestinal bacterial overgrowth, and carbohydrate malabsorption. Evaluation of gastric emptying is routinely performed by scintigraphy which is however, difficult to perform and not suitable for children and pregnant women, this review has abridged the 13C-octanoic acid test in comparison to scintigraphy and has emphasized on its working protocol and challenges. A new development such as electronic nose test is also highlighted. Moreover we have also explored the limitations and constraints restraining the wide use of these BT. We conclude that breath testing has an enormous potential to be used as a diagnostic modality. In addition it offers distinct advantages over the traditional invasive methods commonly employed. PMID:27574563

[Food Allergy and Intolerance : Distinction, Definitions and Delimitation].

PubMed

Kleine-Tebbe, Jörg; Waßmann-Otto, Anja; Mönnikes, Hubert

2016-06-01

Immunologically mediated hypersensitivity to foods is defined as food allergy, mainly due to immunglobulins of class E (IgE) triggering immediate reactions (type I hypersensitivity) with possible involvement of mucosa, skin, airways, intestinal tract, and the vascular system. Primary food allergy is based on (early) IgE sensitization against animal (e. g., cow's milk, hen's eggs) or plant proteins (e. g. peanut, hazelnut or wheat). In the case of secondary food allergies, IgE against pollen proteins (e. g., birch) reacts to structurally related food proteins (with cross-reactions to stone and pit fruits). Non-immunological food intolerance reactions are mostly based on carbohydrate malassimilation (e. g., lactose intolerance, fructose malabsorption) and are rarely due to pseudo-allergies (e. g., flavors, dyes, preservatives) primarily in patients with chronic urticaria. Common intestinal symptoms are mainly due to functional disorders (e. g., irritable bowel disease), rarely because of inflammatory intestinal diseases (e. g., celiac disease). Histamine intolerance, gluten hypersensitivity, and so-called food type III hypersensitivities are controversial diagnoses. The aforementioned disease entities/models are of variable importance for the affected individuals, the public health system, and society in general.

Fabrication of Carbohydrate Microarrays by Boronate Formation.

PubMed

Adak, Avijit K; Lin, Ting-Wei; Li, Ben-Yuan; Lin, Chun-Cheng

2017-01-01

The interactions between soluble carbohydrates and/or surface displayed glycans and protein receptors are essential to many biological processes and cellular recognition events. Carbohydrate microarrays provide opportunities for high-throughput quantitative analysis of carbohydrate-protein interactions. Over the past decade, various techniques have been implemented for immobilizing glycans on solid surfaces in a microarray format. Herein, we describe a detailed protocol for fabricating carbohydrate microarrays that capitalizes on the intrinsic reactivity of boronic acid toward carbohydrates to form stable boronate diesters. A large variety of unprotected carbohydrates ranging in structure from simple disaccharides and trisaccharides to considerably more complex human milk and blood group (oligo)saccharides have been covalently immobilized in a single step on glass slides, which were derivatized with high-affinity boronic acid ligands. The immobilized ligands in these microarrays maintain the receptor-binding activities including those of lectins and antibodies according to the structures of their pendant carbohydrates for rapid analysis of a number of carbohydrate-recognition events within 30 h. This method facilitates the direct construction of otherwise difficult to obtain carbohydrate microarrays from underivatized glycans.

[Clinical-diagnostic estimation of carbohydrates metabolism in obturation jaundice].

PubMed

Nychytaĭlo, M Iu; Malyk, S V

2004-07-01

Complex examination of 175 patients with obturation jaundice was conducted, peculiar attention was spared to the carbohydrates metabolism changes, characterizing hepatic state. It was established, that in obturation jaundice in the liver there are occurring inflammatory changes and disturbances of all kinds of metabolism, including that of carbohydrates, severity of which depends on duration of jaundice, the concurrent diseases presence, they shows lowering of the glucose and glycogen level in the blood, as well as the hepatic glycogen content, that's why they may be applied as a complex of prognostic criterions for the disease course. An early conduction of operative treatment, elimination of the biliary ducts impassability promote the rehabilitation period shortening and the hepatic functional activity normalization.

Present Status of Subclinical Intestinal Malabsorption in the Tropics

PubMed Central

Falaiye, J. M.

1971-01-01

A review of the literature on subclinical intestinal disease shows its probable relevance in certain nutritional deficiencies in the indigenous residents of tropical climates. A significant incidence of intestinal disease has been defined among asymptomatic fit-looking adult Nigerians. The results of subsequent investigation into the pathogenesis of this disorder strongly point to hypoalbuminaemia as the important factor capable of producing a biochemically and histologically defined malabsorptive state leading to subnormal nutritional status among members of this community. ImagesFIG. 3 PMID:5125280

Olmesartan-induced Enteropathy Manifesting as Wernicke-Korsakoff Syndrome.

PubMed

Uehara, Takanori; Ikusaka, Masatomi; Ohira, Yoshiyuki; Noda, Kazutaka; Suzuki, Shingo; Shikino, Kiyoshi; Kondo, Takeshi; Kajiwara, Hideki; Ikegami, Akiko; Hirota, Yusuke

Cases of sprue-like enteropathy associated with olmesartan have sporadically been encountered since it was first reported in 2012, and their most characteristic manifestation is severe diarrhea. We herein report the first case of sprue-like enteropathy manifesting as Wernicke-Korsakoff syndrome due to vitamin B1 malabsorption with only minimally increased bowel movements. When patients are receiving olmesartan and they complain of nonspecific chronic gastrointestinal symptoms, it is important to consider changing the drugs before any serious malabsorption syndrome develops.

Olmesartan-induced Enteropathy Manifesting as Wernicke-Korsakoff Syndrome

PubMed Central

Uehara, Takanori; Ikusaka, Masatomi; Ohira, Yoshiyuki; Noda, Kazutaka; Suzuki, Shingo; Shikino, Kiyoshi; Kondo, Takeshi; Kajiwara, Hideki; Ikegami, Akiko; Hirota, Yusuke

2016-01-01

Cases of sprue-like enteropathy associated with olmesartan have sporadically been encountered since it was first reported in 2012, and their most characteristic manifestation is severe diarrhea. We herein report the first case of sprue-like enteropathy manifesting as Wernicke-Korsakoff syndrome due to vitamin B1 malabsorption with only minimally increased bowel movements. When patients are receiving olmesartan and they complain of nonspecific chronic gastrointestinal symptoms, it is important to consider changing the drugs before any serious malabsorption syndrome develops. PMID:27980272

Enzyme-based processing of soybean carbohydrate: Recent developments and future prospects.

PubMed

Al Loman, Abdullah; Ju, Lu-Kwang

2017-11-01

Soybean is well known for its high-value oil and protein. Carbohydrate is, however, an underutilized major component, representing almost 26-30% (w/w) of the dried bean. The complex soybean carbohydrate is not easily hydrolyzable and can cause indigestibility when included in food and feed. Enzymes can be used to hydrolyze the carbohydrate for improving soybean processing and value of soybean products. Here the enzyme-based processing developed for the following purposes is reviewed: hydrolysis of different carbohydrate-rich by/products from soybean processing, improvement of soybean oil extraction, and increase of nutritional value of soybean-based food and animal feed. Once hydrolyzed into fermentable sugars, soybean carbohydrate can find more value-added applications and further improve the overall economics of soybean processing. Copyright © 2017 Elsevier Inc. All rights reserved.

Glycoconjugate Oxime Formation Catalyzed at Neutral pH: Mechanistic Insights and Applications of 1,4-Diaminobenzene as a Superior Catalyst for Complex Carbohydrates.

PubMed

Østergaard, Mads; Christensen, Niels Johan; Hjuler, Christian T; Jensen, Knud J; Thygesen, Mikkel B

2018-04-18

The reaction of unprotected carbohydrates with aminooxy reagents to provide oximes is a key method for the construction of glycoconjugates. Aniline and derivatives serve as organocatalysts for the formation of oximes from simple aldehydes, and we have previously reported that aniline also catalyzes the formation of oximes from the more complex aldehydes, carbohydrates. Here, we present a comprehensive study of the effect of aniline analogues on the formation of carbohydrate oximes and related glycoconjugates depending on organocatalyst structure, pH, nucleophile, and carbohydrate, covering more than 150 different reaction conditions. The observed superiority of the 1,4-diaminobenzene (PDA) catalyst at neutral pH is rationalized by NMR analyses and DFT studies of reaction intermediates. Carbohydrate oxime formation at pH 7 is demonstrated by the formation of a bioactive glycoconjugate from a labile, decorated octasaccharide originating from exopolysaccharides of the soil bacterium Mesorhizobium loti. This study of glycoconjugate formation includes the first direct comparison of aniline-catalyzed reaction rates and equilibrium constants for different classes of nucleophiles, including primary oxyamines, secondary N-alkyl oxyamines, as well as aryl and arylsulfonyl hydrazides. We identified 1,4-diaminobenzene as a superior catalyst for the construction of oxime-linked glycoconjugates under mild conditions.

Chiral reagents in glycosylation and modification of carbohydrates.

PubMed

Wang, Hao-Yuan; Blaszczyk, Stephanie A; Xiao, Guozhi; Tang, Weiping

2018-02-05

Carbohydrates play a significant role in numerous biological events, and the chemical synthesis of carbohydrates is vital for further studies to understand their various biological functions. Due to the structural complexity of carbohydrates, the stereoselective formation of glycosidic linkages and the site-selective modification of hydroxyl groups are very challenging and at the same time extremely important. In recent years, the rapid development of chiral reagents including both chiral auxiliaries and chiral catalysts has significantly improved the stereoselectivity for glycosylation reactions and the site-selectivity for the modification of carbohydrates. These new tools will greatly facilitate the efficient synthesis of oligosaccharides, polysaccharides, and glycoconjugates. In this tutorial review, we will summarize these advances and highlight the most recent examples.

Carbohydrates as indicators of biogeochemical processes

NASA Astrophysics Data System (ADS)

Lazareva, E. V.; Romankevich, E. A.

2012-05-01

A method is presented to study the carbohydrate composition of marine objects involved into sedimento- and diagenesis (plankton, particulate matter, benthos, and bottom sediments). The analysis of the carbohydrates is based upon the consecutive separation of their fractions with different solvents (water, alkali, and acid). The ratio of the carbohydrate fractions allows one to evaluate the lability of the carbohydrate complex. It is also usable as an indicator of the biogeochemical processes in the ocean, as well of the genesis and the degree of conversion of organic matter in the bottom sediments and nodules. The similarity in the monosaccharide composition is shown for dissolved organic matter and aqueous and alkaline fractions of seston and particulate matter.

Carbohydrate-Aromatic Interactions in Proteins.

PubMed

Hudson, Kieran L; Bartlett, Gail J; Diehl, Roger C; Agirre, Jon; Gallagher, Timothy; Kiessling, Laura L; Woolfson, Derek N

2015-12-09

Protein-carbohydrate interactions play pivotal roles in health and disease. However, defining and manipulating these interactions has been hindered by an incomplete understanding of the underlying fundamental forces. To elucidate common and discriminating features in carbohydrate recognition, we have analyzed quantitatively X-ray crystal structures of proteins with noncovalently bound carbohydrates. Within the carbohydrate-binding pockets, aliphatic hydrophobic residues are disfavored, whereas aromatic side chains are enriched. The greatest preference is for tryptophan with an increased prevalence of 9-fold. Variations in the spatial orientation of amino acids around different monosaccharides indicate specific carbohydrate C-H bonds interact preferentially with aromatic residues. These preferences are consistent with the electronic properties of both the carbohydrate C-H bonds and the aromatic residues. Those carbohydrates that present patches of electropositive saccharide C-H bonds engage more often in CH-π interactions involving electron-rich aromatic partners. These electronic effects are also manifested when carbohydrate-aromatic interactions are monitored in solution: NMR analysis indicates that indole favorably binds to electron-poor C-H bonds of model carbohydrates, and a clear linear free energy relationships with substituted indoles supports the importance of complementary electronic effects in driving protein-carbohydrate interactions. Together, our data indicate that electrostatic and electronic complementarity between carbohydrates and aromatic residues play key roles in driving protein-carbohydrate complexation. Moreover, these weak noncovalent interactions influence which saccharide residues bind to proteins, and how they are positioned within carbohydrate-binding sites.

[The 75-seleno-homocholic acid-taurine test (SeHCAT). A useful method for detecting the idiopathic malabsorption of bile salts in chronic functional diarrhea].

PubMed

D'Arienzo, A; Maurelli, L; Di Siervi, P; Panarese, A; Giannattasio, F; Scuotto, A; Squame, G; Mazzacca, G

1989-07-15

The 75-SeHCAT test has been used for identifying, within a group of patients with chronic functional diarrhea, a subgroup of cases with ileal bile acid malabsorption. Thirty-four subjects were studied: 10 healthy subjects and 24 patients with chronic functional diarrhea. Findings are expressed as percentage of basal abdominal radioactivity after 7 days. Normal values in our control subjects were: over 25% on day 4 and over 10% on day 7. Pathological results were found in 9 of 24 patients (37.5%) on day 4 and of 24 patients (41.7%) on day 7. A significant correlation was found between the percentages of retention on days 4 and 7 (p less than 0.001). In SeHCAT-positive patients cholestyramine administration led to clinical improvement. According to our experience, the SeHCAT test is a useful tool for the evaluation of bile acid malabsorption in the differential diagnosis of chronic functional diarrhea.

Mechanisms of diarrhoea in myotonic dystrophy.

PubMed

Rönnblom, A; Andersson, S; Danielsson, A

1998-07-01

Gastrointestinal (GI) symptoms are common in myotonic dystrophy (MD). Diarrhoea is one of the more disabling of these GI complaints. The mechanisms behind diarrhoea in MD have not previously been investigated systematically. To elucidate the mechanisms behind diarrhoea in MD. Twenty patients with MD and suffering from diarrhoea were investigated in order to detect malabsorption (blood tests and faecal fat excretion) and bile acid malabsorption ([75Se]selenahomocholic acid-taurine (SeHCAT) retention) and to study intestinal morphology (duodenal and rectal biopsies). Two patients had deficiency of folic acid and four showed reduced levels of pancreatic isoamylase, but none of them had steatorrhoea. Two out of eight patients had abnormal bile acid breath tests with normal SeHCAT, indicating small bowel bacterial overgrowth and 12 displayed reduced SeHCAT retention. Duodenal biopsies were normal in eight patients and five out of nine rectal biopsies displayed slight inflammation. A possible mechanism of diarrhoea in MD could be identified in most of the patients. Bile acid malabsorption seems to be a frequent cause and can be treated successfully.

Intestinal lymphangiectasia: an undescribed cause of malabsorption and incomplete immunological recovery in HIV-infected patients.

PubMed

Marco-Lattur, Maria D; Payeras, Antoni; Campins, Antoni A; Pons, Jaume; Cifuentes, Carmen; Riera, Melcior

2011-02-01

Although paradoxical virological and immunological response after HAART has been well studied, intestinal lymphangiectasia (IL) in HIV-1 infected patients has not previously described. To describe HIV patients who developed IL. Clinical Case series. 4 patients with HIV and IL diagnosis based on clinical, endoscopic and pathological findings. All four cases had prior mycobacterial infections with abdominal lymph node involvement and a very low CD4 cell count nadir. They developed intestinal lymphangiectasia despite appropriate virological suppression with HAART and repeatedly negative mycobacterial cultures. Two patients were clinically symptomatic with oedemas, ascites, diarrhoea, asthenia, weight loss; but the other two were diagnosed with malabsorption as a result of laboratory findings, with hypoproteinemia and hypoalbuminemia. Three of them were diagnosed by video capsule endoscopy. IL should be considered in HIV-1 infected patients who present with clinical or biochemical malabsorption parameters when there is no immunological recovery while on HAART. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Laparoscopic surgery for morbid obesity.

PubMed

Hallerbäck, B; Glise, H; Johansson, B; Johnson, E

1998-01-01

Morbid obesity, defined as a body mass index (BMI), i.e. weight (kg)/height (m2) over 36 for males and 38 for females, is a common condition and a threat for health, life and individual well being. Hitherto, surgery is the only effective treatment for weight reduction. Surgical methods can be malabsorptive, reducing the patients ability to absorb nutrients, or restrictive, reducing the capacity of food intake. Exclusively malabsorptive methods have been abandoned due to severe side effects. Restrictive methods, gastroplasties, reduces the compliance capacity of the stomach. Two types are performed laparoscopically, the vertical banded gastroplasty and the adjustable gastric banding. The proximal gastric by pass is also performed laparoscopically and is a combination of a restrictive proximal gastroplasty and a malabsorptive Roux-en-Y gastro-jejunal anastomosis. With laparoscopic adjustable gastric banding mean BMI was reduced from 41 kg/m2 to 33 kg/m2 (n = 43) after one year. Two years after surgery mean BMI was 30 kg/m2 (n = 16). The different operative techniques are further discussed in this paper.

Thinking outside the shunt-sterile CSF malabsorption in pilocytic astrocytomas: case series and review of the literature.

PubMed

Johnson, J A; O'Halloran, P J; Crimmins, D; Caird, J

2016-11-01

Ventriculoperitoneal (VP) shunt insertion is the most common cerebrospinal fluid (CSF) diversionary procedure used for the treatment of chronic hydrocephalus. Sterile CSF ascites is a rare complication of VP shunt insertion. This can arise from either an overproduction of CSF or inadequate filtration of CSF at the level of the peritoneum. By either mechanism, the development of CSF ascites requires an intact VP shunt. The authors discuss two paediatric cases diagnosed with suprasellar pilocytic astrocytomas treated with platinum-based chemotherapy, who subsequently developed sterile CSF ascites. We review the literature with regard to CSF malabsorption and discuss it as a contributing factor to shunt malfunction. CSF malabsorption with resultant ascites is a rare complication of VP shunting with many etiologies. Two common predisposing factors included the use of platinum-based chemotherapeutic agents, as well as the specific neuropathology. Further analysis of these two entities is needed in order to elucidate their role in contributing to the development of CSF ascites in this patient cohort.

Metagenomic evidence for taxonomic dysbiosis and functional imbalance in the gastrointestinal tracts of children with cystic fibrosis

PubMed Central

Manor, Ohad; Levy, Roie; Pope, Christopher E.; Hayden, Hillary S.; Brittnacher, Mitchell J.; Carr, Rogan; Radey, Matthew C.; Hager, Kyle R.; Heltshe, Sonya L.; Ramsey, Bonnie W.; Miller, Samuel I.; Hoffman, Lucas R.; Borenstein, Elhanan

2016-01-01

Cystic fibrosis (CF) results in inflammation, malabsorption of fats and other nutrients, and obstruction in the gastrointestinal (GI) tract, yet the mechanisms linking these disease manifestations to microbiome composition remain largely unexplored. Here we used metagenomic analysis to systematically characterize fecal microbiomes of children with and without CF, demonstrating marked CF-associated taxonomic dysbiosis and functional imbalance. We further showed that these taxonomic and functional shifts were especially pronounced in young children with CF and diminished with age. Importantly, the resulting dysbiotic microbiomes had significantly altered capacities for lipid metabolism, including decreased capacity for overall fatty acid biosynthesis and increased capacity for degrading anti-inflammatory short-chain fatty acids. Notably, these functional differences correlated with fecal measures of fat malabsorption and inflammation. Combined, these results suggest that enteric fat abundance selects for pro-inflammatory GI microbiota in young children with CF, offering novel strategies for improving the health of children with CF-associated fat malabsorption. PMID:26940651

Parasite Carbohydrate Vaccines.

PubMed

Jaurigue, Jonnel A; Seeberger, Peter H

2017-01-01

Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet exist. Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections. We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines. We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases-malaria, toxoplasmosis, and leishmaniasis. The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria. However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored. In particular, the highly abundant glycosylphosphatidylinositol molecules specific for Plasmodium, Toxoplasma , and Leishmania spp. are considered exploitable antigens for this non-traditional vaccine approach. Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development.

Parasite Carbohydrate Vaccines

PubMed Central

Jaurigue, Jonnel A.; Seeberger, Peter H.

2017-01-01

Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet exist. Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections. We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines. We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases—malaria, toxoplasmosis, and leishmaniasis. The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria. However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored. In particular, the highly abundant glycosylphosphatidylinositol molecules specific for Plasmodium, Toxoplasma, and Leishmania spp. are considered exploitable antigens for this non-traditional vaccine approach. Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development. PMID:28660174

Systematic review: effective management strategies for lactose intolerance.

PubMed

Shaukat, Aasma; Levitt, Michael D; Taylor, Brent C; MacDonald, Roderick; Shamliyan, Tatyana A; Kane, Robert L; Wilt, Timothy J

2010-06-15

Lactose intolerance resulting in gastrointestinal symptoms is a common health concern. Diagnosis and management of this condition remain unclear. To assess the maximum tolerable dose of lactose and interventions for reducing symptoms of lactose intolerance among persons with lactose intolerance and malabsorption. Multiple electronic databases, including MEDLINE and the Cochrane Library, for trials published in English from 1967 through November 2009. Randomized, controlled trials of individuals with lactose intolerance or malabsorption. Three investigators independently reviewed articles, extracted data, and assessed study quality. 36 unique randomized studies (26 on lactase- or lactose-hydrolyzed milk supplements, lactose-reduced milk, or tolerable doses of lactose; 7 on probiotics; 2 on incremental lactose administration for colonic adaptation; and 1 on another agent) met inclusion criteria. Moderate-quality evidence indicated that 12 to 15 g of lactose (approximately 1 cup of milk) is well tolerated by most adults. Evidence was insufficient that lactose-reduced solution or milk with a lactose content of 0 to 2 g, compared with greater than 12 g, is effective in reducing symptoms of lactose intolerance. Evidence for probiotics, colonic adaptation, and other agents was also insufficient. Most studies evaluated persons with lactose malabsorption rather than lactose intolerance. Variation in enrollment criteria, outcome reporting, and the composition and dosing of studied agents precluded pooling of results and limited interpretation. Most individuals with presumed lactose intolerance or malabsorption can tolerate 12 to 15 g of lactose. Additional studies are needed to determine the effectiveness of lactose intolerance treatment.

A Simple Technique for Jejunojejunal Revision in Laparoscopic Roux-en-Y Gastric Bypass.

PubMed

Spivak, Hadar

2015-12-01

The lengths of the bypassed segments in the initial laparoscopic roux-en-Y gastric bypass (LRYGB) are usually a matter of the individual surgeon's routine. The literature is inconclusive about the association between the Roux limbs' length and weight-loss or malabsorption (Stefanidis et al. Obes Surg. 21(1):119-24, 2011); (Rawlins et al. Surg Obes Relat Dis. 7(1):45-9, 2011). However, jejunojejunal anastomosis (JJ) "redo" and Roux limb length revision could be considered for patients with a very short Roux limb and weight loss failure or for short common channel and malabsorption. Complications of JJ may also require revision. In over 1000 LRYGBs since 2001, eight patients required JJ revision for failure to lose enough weight (n = 6), malabsorption (n = 1), and stricture (n = 1). Instead of completely taking down the JJ, a simple technique was evolved to keep the enteric limb continuity. In a following step, the biliopancreatic limbs have been transected from the JJ and reconnected proximal (for malabsorption) or distal (for weight loss failure). In this video, a step-by-step the laparoscopic technique for JJ revision and relocating the biliopancreatic limb is presented. Procedure takes 40-60 min to perform using four trocars and the hospital stay was 1-2 nights. No complications occurred during the procedures or postoperative period. Laparoscopic revision of JJ is feasible and safe and should be part of surgeons' options on the long-term management of patients post LRYGB.

Effect of a fish oil-containing beverage on changes in plasma lipid fatty acids in patients with malabsorption

PubMed Central

McCowen, Karen C.; Ling, Pei-Ra; Ollero, Mario; Tawa, Nicholas; Bistrian, Bruce R.

2015-01-01

Background The aim of this pilot study was to assess tolerance of a beverage containing ω-3 fatty acids (fish oil) in patients with malabsorption receiving chronic parenteral nutrition (PN). We wanted to determine whether fish oil could be absorbed and incorporated into plasma fatty acids, and reduce markers of inflammation. Methods This was a small intervention study in home-dwelling PN-dependent patients with chronic malabsorption. Ten patients were provided a drink containing 1.5g of fish oil per day for 12 weeks. Baseline and post-supplement serum fatty acid profiles were compared. Results Five of 10 patients withdrew from the study due to gastrointestinal side effects, principally worsened diarrhea, associated with the supplement. Modest increases were found in 20:5ω-3, 22:5ω-3, and 22:6ω-3 levels in both phospholipids and triglycerides in plasma (all p<0.05). In phospholipids, a reduced arachidonic acid level was seen (p=0.02). These changes were not sufficient to effect improvements in serum tumor necrosis factor-alpha (TNFα), soluble TNF receptor, c-reactive protein or Interleukin-6. Conclusions Some patients with severe malabsorption can absorb oral ω-3 fatty acid supplements and can incorporate these fatty acids into serum phospholipids and triglycerides. However, side effects are very common, and no anti-inflammatory effect was found, presumably related to the modest level of fatty acid change. PMID:20962312

Probing the Complex Architecture of Multimodular Carbohydrate-Active Enzymes Using a Combination of Small Angle X-Ray Scattering and X-Ray Crystallography.

PubMed

Czjzek, Mirjam; Ficko-Blean, Elizabeth

2017-01-01

The various modules in multimodular carbohydrate-active enzymes (CAZymes) may function in catalysis, carbohydrate binding, protein-protein interactions or as linkers. Here, we describe how combining the biophysical techniques of Small Angle X-ray Scattering (SAXS) and macromolecular X-ray crystallography (XRC) provides a powerful tool for examination into questions related to overall structural organization of ultra multimodular CAZymes.

Influence of the π-coordinated arene on the anticancer activity of ruthenium(II) carbohydrate organometallic complexes

NASA Astrophysics Data System (ADS)

Hanif, Muhammad; Meier, Samuel; Nazarov, Alexey; Risse, Julie; Legin, Anton; Casini, Angela; Jakupec, Michael; Keppler, Bernhard; Hartinger, Christian

2013-10-01

The synthesis and in vitro cytotoxicity of a series of RuII(arene) complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well with cellular accumulation. The most lipophilic compound bearing a biphenyl moiety and a cyclohexylidene-protected carbohydrate is the most cytotoxic with unprecedented IC50 values for the compound class in three human cancer cell lines. This compound shows reactivity to the DNA model nucleobase 9-ethylguanine, but does not alter the secondary structure of plasmid DNA indicating that other biological targets are responsible for its cytotoxic effect.

Botulinum neurotoxin A complex recognizes host carbohydrates through its hemagglutinin component.

PubMed

Yao, Guorui; Lee, Kwangkook; Gu, Shenyan; Lam, Kwok-Ho; Jin, Rongsheng

2014-02-12

Botulinum neurotoxins (BoNTs) are potent bacterial toxins. The high oral toxicity of BoNTs is largely attributed to the progenitor toxin complex (PTC), which is assembled from BoNT and nontoxic neurotoxin-associated proteins (NAPs) that are produced together with BoNT in bacteria. Here, we performed ex vivo studies to examine binding of the highly homogeneous recombinant NAPs to mouse small intestine. We also carried out the first comprehensive glycan array screening with the hemagglutinin (HA) component of NAPs. Our data confirmed that intestinal binding of the PTC is partly mediated by the HA moiety through multivalent interactions between HA and host carbohydrates. The specific HA-carbohydrate recognition could be inhibited by receptor-mimicking saccharides.

A higher-complex carbohydrate diet in gestational diabetes mellitus achieves glucose targets and lowers postprandial lipids: a randomized crossover study.

PubMed

Hernandez, Teri L; Van Pelt, Rachael E; Anderson, Molly A; Daniels, Linda J; West, Nancy A; Donahoo, William T; Friedman, Jacob E; Barbour, Linda A

2014-01-01

The conventional diet approach to gestational diabetes mellitus (GDM) advocates carbohydrate restriction, resulting in higher fat (HF), also a substrate for fetal fat accretion and associated with maternal insulin resistance. Consequently, there is no consensus about the ideal GDM diet. We hypothesized that, compared with a conventional, lower-carbohydrate/HF diet (40% carbohydrate/45% fat/15% protein), consumption of a higher-complex carbohydrate (HCC)/lower-fat (LF) Choosing Healthy Options in Carbohydrate Energy (CHOICE) diet (60/25/15%) would result in 24-h glucose area under the curve (AUC) profiles within therapeutic targets and lower postprandial lipids. Using a randomized, crossover design, we provided 16 GDM women (BMI 34 ± 1 kg/m2) with two 3-day isocaloric diets at 31 ± 0.5 weeks (washout between diets) and performed continuous glucose monitoring. On day 4 of each diet, we determined postprandial (5 h) glucose, insulin, triglycerides (TGs), and free fatty acids (FFAs) following a controlled breakfast meal. There were no between-diet differences for fasting or mean nocturnal glucose, but 24-h AUC was slightly higher (∼6%) on the HCC/LF CHOICE diet (P = 0.02). The continuous glucose monitoring system (CGMS) revealed modestly higher 1- and 2-h postprandial glucose on CHOICE (1 h, 115 ± 2 vs. 107 ± 3 mg/dL, P ≤ 0.01; 2 h, 106 ± 3 vs. 97 ± 3 mg/dL, P = 0.001) but well below current targets. After breakfast, 5-h glucose and insulin AUCs were slightly higher (P < 0.05), TG AUC was no different, but the FFA AUC was significantly lower (∼19%; P ≤ 0.01) on the CHOICE diet. This highly controlled study randomizing isocaloric diets and using a CGMS is the first to show that liberalizing complex carbohydrates and reducing fat still achieved glycemia below current treatment targets and lower postprandial FFAs. This diet strategy may have important implications for preventing macrosomia.

Data mining the PDB for glyco-related data.

PubMed

Lütteke, Thomas; von der Lieth, Claus W

2009-01-01

The 3D structural data of glycoprotein or protein-carbohydrate complexes that are found in the Protein Data Bank (PDB) are an interesting data source for glycobiologists. Unfortunately, carbohydrate components are difficult to find with the means provided by the PDB. The GLYCOSCIENCES.de internet portal offers a variety of tools and databases to locate and analyze these structures. This chapter describes how to find PDB entries that feature a specific carbohydrate structure and how to locate carbohydrate residues in a 3D structure file and to check their consistency. In addition to this, methods to statistically analyze torsion angles and the abundance of amino acids both in the neighborhood of glycosylation sites and in the spatial vicinity of non-covalently bound carbohydrate chains are summarized.

Recent progress in chemical and chemoenzymatic synthesis of carbohydrates.

PubMed

Muthana, Saddam; Cao, Hongzhi; Chen, Xi

2009-12-01

The important roles that carbohydrates play in biological processes and their potential application in diagnosis, therapeutics, and vaccine development have made them attractive synthetic targets. Despite ongoing challenges, tremendous progresses have been made in recent years for the synthesis of carbohydrates. The chemical glycosylation methods have become more sophisticated and the synthesis of oligosaccharides has become more predictable. Simplified one-pot glycosylation strategy and automated synthesis are increasingly used to obtain biologically important glycans. On the other hand, chemoenzymatic synthesis continues to be a powerful alternative for obtaining complex carbohydrates. This review highlights recent progress in chemical and chemoenzymatic synthesis of carbohydrates with a particular focus on the methods developed for the synthesis of oligosaccharides, polysaccharides, glycolipids, and glycosylated natural products.

Chemoselective Reactions for the Synthesis of Glycoconjugates from Unprotected Carbohydrates.

PubMed

Villadsen, Klaus; Martos-Maldonado, Manuel C; Jensen, Knud J; Thygesen, Mikkel B

2017-04-04

Glycobiology is the comprehensive biological investigation of carbohydrates. The study of the role and function of complex carbohydrates often requires the attachment of carbohydrates to surfaces, their tagging with fluorophores, or their conversion into natural or non-natural glycoconjugates, such as glycopeptides or glycolipids. Glycobiology and its "omics", glycomics, require easy and robust chemical methods for the construction of these glycoconjugates. This review gives an overview of the rapidly expanding field of chemical reactions that selectively convert unprotected carbohydrates into glycoconjugates through the anomeric position. The discussion is divided in terms of the anomeric bond type of the newly formed glycoconjugates, including O-, N-, S-, and C-glycosides. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent Progress in Chemical and Chemoenzymatic Synthesis of Carbohydrates

PubMed Central

Muthana, Saddam; Cao, Hongzhi; Chen, Xi

2011-01-01

Summary The important roles that carbohydrates play in biological processes and their potential application in diagnosis, therapeutics, and vaccine development have made them attractive synthetic targets. Despite ongoing challenges, tremendous progresses have been made in recent years for the synthesis of carbohydrates. The chemical glycosylation methods have become more sophisticated and the synthesis of oligosaccharides has become more predictable. Simplified one-pot glycosylation strategy and automated synthesis are increasingly used to obtain biologically important glycans. On the other hand, chemoenzymatic synthesis continues to be a powerful alternative for obtaining complex carbohydrates. This review highlights recent progress in chemical and chemoenzymatic synthesis of carbohydrates with a particular focus on the methods developed for the synthesis of oligosaccharides, polysaccharides, glycolipids, and glycosylated natural products. PMID:19833544

Measuring SeHCAT retention: a technical note.

PubMed

Notghi, Alp; O'Brien, Joseph; Low, Chen Sheng; Thomson, William

2011-10-01

TauroH-23-((75)Se)selena-25-homocholic acid (SeHCAT) retention has been used for the diagnosis of bile acid malabsorption since the early 1980s. Bile acid malabsorption has been increasingly recognized as an important cause of severe chronic diarroea with subsequent increase in the number of referrals for the SeHCAT test. In this study, we review and discuss the standard techniques for the measurement of SeHCAT retention and describe a simple and modified technique using a noncollimated whole-body scanner, suitable for most modern dual-headed cameras.

Significance of nutrition in pulmonary tuberculosis.

PubMed

Kant, Surya; Gupta, Harshita; Ahluwalia, Savita

2015-01-01

Malnutrition and tuberculosis are both problems mostly of the developing countries. Tuberculosis can lead to malnutrition and malnutrition may predispose to tuberculosis. Poor nutrition leads to protein-energy malnutrition and micronutrients deficiencies which lead to immunodeficiency. This secondary immunodeficiency increases the host's susceptibility to infection and hence increase the risk for developing tuberculosis. Tuberculosis itself leads to reduction in appetite, nutrient malabsorption, micronutrient malabsorption, and altered metabolism leading to wasting and poor nutritional status. Nutritional status and dietary intake and hence nutritional status of patients get improved during antituberculosis treatment.

Methods of combined bioprocessing and related microorganisms, thermophilic and/or acidophilic enzymes, and nucleic acids encoding said enzymes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, David N.; Apel, William A.; Thompson, Vicki S.

A genetically modified organism comprising: at least one nucleic acid sequence and/or at least one recombinant nucleic acid isolated from Alicyclobacillus acidocaldarius and encoding a polypeptide involved in at least partially degrading, cleaving, transporting, metabolizing, or removing polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, xylan-, glucan-, galactan-, or mannan-decorating groups; and at least one nucleic acid sequence and/or at least one recombinant nucleic acid encoding a polypeptide involved in fermenting sugar molecules to a product. Additionally, enzymatic and/or proteinaceous extracts may be isolated from one or more genetically modified organisms. The extractsmore » are utilized to convert biomass into a product. Further provided are methods of converting biomass into products comprising: placing the genetically modified organism and/or enzymatic extracts thereof in fluid contact with polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, and/or xylan-, glucan-, galactan-, or mannan-decorating groups.« less

Quantitative analysis of total proteins and carbohydrates in the digestive gland-gonad complex (DGG) and hemolymph of the freshwater prosobranch snail Lanistes carinatus.

PubMed

Hassan, Amaal Hassan M; Mahmoud, Salim; El-Hamidy, A

2010-08-01

Laboratory investigations were carried out to quantify the amount of total proteins, carbohydrates and reducing sugar in the hemolymph and Digestive Gland Gonad- complex (DGG) of infected and uinfected lanistes arinatus. Snails were naturally infected with two different types of trematode la:val stages (rediae of gymnocepahalus cercaria and sporocyst of xiphidiocercaria), collected from the River Nile at Sohag governorate, Egypt. Analysis was carried out using an extraction of the DGGs tissue with buffer solution, while snails' hemolymph was applied directly. The results revealed that snail infection by rediae of gymnocephalus cercariae led to non significant increasing in both total carbohydrates and protein in hemolymph. However, infection by sporocysts of xiphidiocercariae caused a significant increasing only in hemolymph total protein. On the other hand, the amount of both reducing sugar and total proteins in DGG did not increase significantly whenever the infection caused by both types of trematode larvae. However, total carbohydrates in DGG increased significantly.

Methods of combined bioprocessing and related microorganisms, thermophilic and/or acidophilic enzymes, and nucleic acids encoding said enzymes

DOEpatents

Thompson, David N.; Apel, William A.; Thompson, Vicki S.; Ward, Thomas E.

2016-03-22

A genetically modified organism comprising: at least one nucleic acid sequence and/or at least one recombinant nucleic acid isolated from Alicyclobacillus acidocaldarius and encoding a polypeptide involved in at least partially degrading, cleaving, transporting, metabolizing, or removing polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, xylan-, glucan-, galactan-, or mannan-decorating groups; and at least one nucleic acid sequence and/or at least one recombinant nucleic acid encoding a polypeptide involved in fermenting sugar molecules to a product. Additionally, enzymatic and/or proteinaceous extracts may be isolated from one or more genetically modified organisms. The extracts are utilized to convert biomass into a product. Further provided are methods of converting biomass into products comprising: placing the genetically modified organism and/or enzymatic extracts thereof in fluid contact with polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, and/or xylan-, glucan-, galactan-, or mannan-decorating groups.

Methods of combined bioprocessing and related microorganisms, thermophilic and/or acidophilic enzymes, and nucleic acids encoding said enzymes

DOEpatents

Thompson, David N; Apel, William A; Thompson, Vicki S; Ward, Thomas E

2013-07-23

A genetically modified organism comprising: at least one nucleic acid sequence and/or at least one recombinant nucleic acid isolated from Alicyclobacillus acidocaldarius and encoding a polypeptide involved in at least partially degrading, cleaving, transporting, metabolizing, or removing polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, xylan-, glucan-, galactan-, or mannan-decorating groups; and at least one nucleic acid sequence and/or at least one recombinant nucleic acid encoding a polypeptide involved in fermenting sugar molecules to a product. Additionally, enzymatic and/or proteinaceous extracts may be isolated from one or more genetically modified organisms. The extracts are utilized to convert biomass into a product. Further provided are methods of converting biomass into products comprising: placing the genetically modified organism and/or enzymatic extracts thereof in fluid contact with polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, and/or xylan-, glucan-, galactan-, or mannan-decorating groups.

Methods of combined bioprocessing and related microorganisms, thermophilic and/or acidophilic enzymes, and nucleic acids encoding said enzymes

DOEpatents

Thompson, David N; Apel, William A; Thompson, Vicki S; Ward, Thomas E

2014-04-08

A genetically modified organism comprising: at least one nucleic acid sequence and/or at least one recombinant nucleic acid isolated from Alicyclobacillus acidocaldarius and encoding a polypeptide involved in at least partially degrading, cleaving, transporting, metabolizing, or removing polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, xylan-, glucan-, galactan-, or mannan-decorating groups; and at least one nucleic acid sequence and/or at least one recombinant nucleic acid encoding a polypeptide involved in fermenting sugar molecules to a product. Additionally, enzymatic and/or proteinaceous extracts may be isolated from one or more genetically modified organisms. The extracts are utilized to convert biomass into a product. Further provided are methods of converting biomass into products comprising: placing the genetically modified organism and/or enzymatic extracts thereof in fluid contact with polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, and/or xylan-, glucan-, galactan-, or mannan-decorating groups.

The hydroxyl-functionalized magnetic particles for purification of glycan-binding proteins.

PubMed

Sun, Xiuxuan; Yang, Ganglong; Sun, Shisheng; Quan, Rui; Dai, Weiwei; Li, Bin; Chen, Chao; Li, Zheng

2009-12-01

Glycan-protein interactions play important biological roles in biological processes. Although there are some methods such as glycan arrays that may elucidate recognition events between carbohydrates and protein as well as screen the important glycan-binding proteins, there is a lack of simple effectively separate method to purify them from complex samples. In proteomics studies, fractionation of samples can help to reduce their complexity and to enrich specific classes of proteins for subsequent downstream analyses. Herein, a rapid simple method for purification of glycan-binding proteins from proteomic samples was developed using hydroxyl-coated magnetic particles coupled with underivatized carbohydrate. Firstly, the epoxy-coated magnetic particles were further hydroxyl functionalized with 4-hydroxybenzhydrazide, then the carbohydrates were efficiently immobilized on hydroxyl functionalized surface of magnetic particles by formation of glycosidic bond with the hemiacetal group at the reducing end of the suitable carbohydrates via condensation. All conditions of this method were optimized. The magnetic particle-carbohydrate conjugates were used to purify the glycan-binding proteins from human serum. The fractionated glycan-binding protein population was displayed by SDS-PAGE. The result showed that the amount of 1 mg magnetic particles coupled with mannose in acetate buffer (pH 5.4) was 10 micromol. The fractionated glycan-binding protein population in human serum could be eluted from the magnetic particle-mannose conjugates by 0.1% SDS. The methodology could work together with the glycan microarrays for screening and purification of the important GBPs from complex protein samples.

Impact of Weight Loss Surgery on Esophageal Physiology

PubMed Central

Naik, Rishi D.; Choksi, Yash A.

2015-01-01

Bariatric surgery has come to the forefront of weight loss treatment due to its complex interactions via anatomic, physiologic, and neurohormonal changes leading to sustained weight loss. Unlike lifestyle and pharmacologic options, which fail to show long-term sustained weight loss, bariatric surgery has been shown to decrease overall mortality and morbidity. Bariatric surgery can be purely restrictive, such as laparoscopic adjustable gastric band (LAGB) or laparoscopic sleeve gastrectomy (LSG), or restrictive-malabsorptive, such as Roux-en-Y gastric bypass (RYGB). These surgeries cause specific anatomic changes that promote weight loss; however, they also have unintended effects on the esophagus, particularly in terms of gastroesophageal reflux disease (GERD) and esophageal motility. Via restrictive surgery, LAGB has been widely reported to cause significant weight loss, although studies have also shown an increase and worsening of GERD as well as elevated rates of esophageal dilation, aperistalsis, and alterations in lower esophageal sphincter pressure. Along with LAGB, LSG has shown not only a worsening of GERD, but also the formation of de novo GERD in patients who were asymptomatic before the operation. In a restrictive-malabsorptive approach, RYGB has been reported to improve GERD and preserve esophageal motility. Bariatric surgery is a burgeoning field with immense implications on overall mortality. Future randomized, controlled trials are needed to better understand which patients should undergo particular surgeries, with greater emphasis on esophageal health and prevention of GERD and esophageal dysmotility. PMID:27134597

[Vitamin B12 deficiency: what's new?].

PubMed

Braillard, O; Casini, A; Samii, K; Rufenacht, P; Junod, Perron N

2012-09-26

Vitamin B12 screening is only recommended among symptomatic patients or in those with risk factors. The main cause of vitamin B12 deficiency is the food cobalamin malabsorption syndrom. Holotranscobalamin is a more reliable marker than cyanocobalamin to confirm vitamin B12 deficiency, but it has not been validated yet in complex situations. An autoimmune gastritis must be excluded in the absence of risk factors but in the presence of a probable deficiency. Oral substitution treatment is effective but requires excellent therapeutic compliance and close follow-up to monitor the response to treatment. It has not yet been studied among patients suffering from severe symptoms, inflammatory bowel disease and ileal resection.

Carbohydrate–Aromatic Interactions in Proteins

PubMed Central

2015-01-01

Protein–carbohydrate interactions play pivotal roles in health and disease. However, defining and manipulating these interactions has been hindered by an incomplete understanding of the underlying fundamental forces. To elucidate common and discriminating features in carbohydrate recognition, we have analyzed quantitatively X-ray crystal structures of proteins with noncovalently bound carbohydrates. Within the carbohydrate-binding pockets, aliphatic hydrophobic residues are disfavored, whereas aromatic side chains are enriched. The greatest preference is for tryptophan with an increased prevalence of 9-fold. Variations in the spatial orientation of amino acids around different monosaccharides indicate specific carbohydrate C–H bonds interact preferentially with aromatic residues. These preferences are consistent with the electronic properties of both the carbohydrate C–H bonds and the aromatic residues. Those carbohydrates that present patches of electropositive saccharide C–H bonds engage more often in CH−π interactions involving electron-rich aromatic partners. These electronic effects are also manifested when carbohydrate–aromatic interactions are monitored in solution: NMR analysis indicates that indole favorably binds to electron-poor C–H bonds of model carbohydrates, and a clear linear free energy relationships with substituted indoles supports the importance of complementary electronic effects in driving protein–carbohydrate interactions. Together, our data indicate that electrostatic and electronic complementarity between carbohydrates and aromatic residues play key roles in driving protein–carbohydrate complexation. Moreover, these weak noncovalent interactions influence which saccharide residues bind to proteins, and how they are positioned within carbohydrate-binding sites. PMID:26561965

Carbohydrates as T-cell antigens with implications in health and disease.

PubMed

Sun, Lina; Middleton, Dustin R; Wantuch, Paeton L; Ozdilek, Ahmet; Avci, Fikri Y

2016-10-01

Glycosylation is arguably the most ubiquitous post-translational modification on proteins in microbial and mammalian cells. During the past few years, there has been intensive research demonstrating that carbohydrates, either in pure forms or in conjunction with proteins or lipids, evoke and modulate adaptive immune responses. We now know that carbohydrates can be directly recognized by T cells or participate in T-cell stimulation as components of T-cell epitopes. T-cell recognition of carbohydrate antigens takes place via their presentation by major histocompatibility complex pathways on antigen-presenting cells. In this review, we summarize studies on carbohydrates as T-cell antigens modulating adaptive immune responses. Through discussion of glycan-containing antigens, such as glycoproteins, glycolipids, zwitterionic polysaccharides and carbohydrate-based glycoconjugate vaccines, we will illustrate the key molecular and cellular interactions between carbohydrate antigens and T cells and the implications of these interactions in health and disease. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Structural Glycomic Analyses at High Sensitivity: A Decade of Progress

NASA Astrophysics Data System (ADS)

Alley, William R.; Novotny, Milos V.

2013-06-01

The field of glycomics has recently advanced in response to the urgent need for structural characterization and quantification of complex carbohydrates in biologically and medically important applications. The recent success of analytical glycobiology at high sensitivity reflects numerous advances in biomolecular mass spectrometry and its instrumentation, capillary and microchip separation techniques, and microchemical manipulations of carbohydrate reactivity. The multimethodological approach appears to be necessary to gain an in-depth understanding of very complex glycomes in different biological systems.

Structural Glycomic Analyses at High Sensitivity: A Decade of Progress

PubMed Central

Alley, William R.; Novotny, Milos V.

2014-01-01

The field of glycomics has recently advanced in response to the urgent need for structural characterization and quantification of complex carbohydrates in biologically and medically important applications. The recent success of analytical glycobiology at high sensitivity reflects numerous advances in biomolecular mass spectrometry and its instrumentation, capillary and microchip separation techniques, and microchemical manipulations of carbohydrate reactivity. The multimethodological approach appears to be necessary to gain an in-depth understanding of very complex glycomes in different biological systems. PMID:23560930

Defined presentation of carbohydrates on a duplex DNA scaffold.

PubMed

Schlegel, Mark K; Hütter, Julia; Eriksson, Magdalena; Lepenies, Bernd; Seeberger, Peter H

2011-12-16

A new method for the spatially defined alignment of carbohydrates on a duplex DNA scaffold is presented. The use of an N-hydroxysuccinimide (NHS)-ester phosphoramidite along with carbohydrates containing an alkylamine linker allows for on-column labeling during solid-phase oligonucleotide synthesis. This modification method during solid-phase synthesis only requires the use of minimal amounts of complex carbohydrates. The covalently attached carbohydrates are presented in the major groove of the B-form duplex DNA as potential substrates for murine type II C-type lectin receptors mMGL1 and mMGL2. CD spectroscopy and thermal melting revealed only minimal disturbance of the overall helical structure. Surface plasmon resonance and cellular uptake studies with bone-marrow-derived dendritic cells were used to assess the capability of these carbohydrate-modified duplexes to bind to mMGL receptors. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Alteration of the carbohydrate-binding specificity of a C-type lectin CEL-I mutant with an EPN carbohydrate-binding motif.

PubMed

Hatakeyama, Tomomitsu; Ishimine, Tomohiro; Baba, Tomohiro; Kimura, Masanari; Unno, Hideaki; Goda, Shuichiro

2013-07-01

CEL-I is a Gal/GalNAc-specific C-type lectin isolated from the sea cucumber Cucumaria echinata. This lectin is composed of two carbohydrate-recognition domains (CRDs) with the carbohydrate-recognition motif QPD (Gln-Pro- Asp), which is generally known to exist in galactose-specific C-type CRDs. In the present study, a mutant CEL-I with EPN (Glu-Pro-Asn) motif, which is thought to be responsible for the carbohydrate-recognition of mannose-specific Ctype CRDs, was produced in Escherichia coli, and its effects on the carbohydrate-binding specificity were examined using polyamidoamine dendrimer (PD) conjugated with carbohydrates. Although wild-type CEL-I effectively formed complexes with N-acetylgalactosamine (GalNAc)-PD but not with mannose-PD, the mutant CEL-I showed relatively weak but definite affinity for mannose-PD. These results indicated that the QPD and EPN motifs play a significant role in the carbohydrate-recognition mechanism of CEL-I, especially in the discrimination of galactose and mannose. Additional mutations in the recombinant CEL-I binding site may further increase its specificity for mannose, and should provide insights into designing novel carbohydrate-recognition proteins.

Systematic review: the management of chronic diarrhoea due to bile acid malabsorption.

PubMed

Wilcox, C; Turner, J; Green, J

2014-05-01

Bile acid malabsorption (BAM) is a common, yet under-recognised, cause of chronic diarrhoea, with limited guidance available on the appropriate management of patients with BAM. To summarise the evidence supporting different treatments available for patients with bile acid malabsorption, noting their impact on clinical outcomes, tolerability and associated side effects. A literature search was conducted through PubMed, the Cochrane Database of Systematic Reviews and Scopus. Relevant articles studied patients who had been diagnosed with BAM and were clinically assessed before and after therapy. A total of 30 relevant publications (1241 adult patients) were identified, which investigated the clinical response to drugs, including colestyramine, colestipol, colesevelam, aluminium hydroxide and obeticholic acid. The most commonly used diagnostic test of bile acid malabsorption was the SeHCAT test (24 studies). Colestyramine treatment was by far the most studied of these agents, and was successful in 70% of 801 patients (range: 63-100%). Colestyramine and colestipol are generally effective treatments of gastrointestinal symptoms from BAM, but may be poorly tolerated and reduce the bioavailability of co-administered agents. Alternative therapies (including colesevelam and aluminium hydroxide) as well as dietary intervention may also have a role, and the promising results of the first proof-of-concept study of obeticholic acid suggest that its novel approach may have an exciting future in the treatment of this condition. Future trials should employ accurate diagnostic testing and be conducted over longer periods so that the long-term benefits and tolerability of these different approaches can be evaluated. © 2014 John Wiley & Sons Ltd.

Mild CFTR mutations and genetic predisposition to lactase persistence in cystic fibrosis

PubMed Central

Mądry, Edyta; Fidler, Ewa; Sobczyńska-Tomaszewska, Agnieszka; Lisowska, Aleksandra; Krzyżanowska, Patrycja; Pogorzelski, Andrzej; Minarowski, Łukasz; Oralewska, Beata; Mojs, Ewa; Sapiejka, Ewa; Marciniak, Ryszard; Sands, Dorota; Korzon-Burakowska, Anna; Kwiecień, Jarosław; Walkowiak, Jarosław

2011-01-01

Taking into account the reported incidence of hypolactasia in cystic fibrosis (CF) and the possible impact of milk products on nutritional status we aimed to assess the genetic predisposition to adult-type hypolactasia (ATH) and its incidence in CF. Single nucleotide polymorphism upstream of the lactase gene (LCT) was assessed in 289 CF patients. In subject with −13910C/C genotype (C/C) predisposing to ATH, hydrogen-methane breath test (BT) with lactose loading was conducted and clinical symptoms typical for lactose malabsorption were assessed. The percentage of CF patients with C/C was similar to that observed in healthy subjects (HS) (31.5 vs 32.5% ). Eleven out of 52 (24.5%) CF C/C patients had abnormal BT results. The recalculated frequency of lactose malabsorption was similar for the entire CF and HS populations (6.9 vs 7.2%). Similarly as in the control group, few CF patients have identified and linked to lactose consumption clinical symptoms. The frequency of LCT polymorphic variants in CF patients having and not having severe mutations of CFTR gene showed significant differences. The C allele was more frequent in homozygotes of the severe mutations than in patients carrying at least one mild/unknown mutation (P<0.0028) and in patients with at least one mild mutation (P<0.0377). In conclusion, CF patients carrying mild CFTR mutations seem to have lower genetic predisposition to ATH. Lactose malabsorption due to ATH in CF is not more frequent than in the general population. Symptomatic assessment of lactose malabsorption in CF is not reliable. PMID:21407263

[Breath tests in children with suspected lactose intolerance].

PubMed

Parra, P Ángela; Furió, C Simone; Arancibia, A Gabriel

2015-01-01

Up to 70% of the world population is lactose intolerance. However, there are no epidemiological studies among Chilean pediatric population affected by this condition. Clinical characterization of a series of children who underwent the lactose intolerance breath test for lactose intolerance study, establishing intolerance and malabsorption frequencies, the most frequent symptoms, and test performance depending on the origin. Patients under 18 years old who took the lactose intolerance breath test in the Gastroenterology Laboratory of the Catholic University of Chile, and who were admitted due to clinically suspected lactose intolerance. Malabsorption was considered when there was as an increase of ≥20ppm above the baseline (H2) or ≥34ppm of H2 and methane (CH4) combined. Intolerance was considered when the above was associated with a symptom intensity score ≥7 during registration. The analysis included194 patients aged 1 to17 years of age. Of these, 102 (53%) presented with malabsorption, and 53 (27%) were intolerant. The frequency of lactose intolerance varied from 7.1 to 45.4%, and it occurred more frequently at older ages. The most common reported symptoms were abdominal pain, bloating and rumbling. Lactose malabsorption and intolerance can be investigated from the first years of life using the lactose breath test plus a symptom questionnaire. An increase in the frequency of intolerance with age, and a greater number of positive tests, if they were requested by a gastroenterologist, were observed. Copyright © 2015 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Subjective perception of lactose intolerance does not always indicate lactose malabsorption.

PubMed

Casellas, Francesc; Aparici, Anna; Casaus, Maite; Rodríguez, Purificación; Malagelada, Juan R

2010-07-01

Symptomatic lactose intolerance is common; however, abdominal symptoms that patients experience after ingestion of lactose-containing foods can have causes beyond lactose malabsorption. We aimed to determine whether symptoms that patients usually attribute to lactose intolerance are comparable to symptoms provoked by a controlled lactose challenge and whether these symptoms are related to lactose absorption capacity. We performed an observational, prospective, transverse study of 353 patients referred for a lactose hydrogen breath test (HBT). Patients completed a validated questionnaire about symptoms associated with consumption of dairy products at home (home symptoms). After a 50-g lactose breath test, they completed the same questionnaire again (lactose challenge symptoms). Patients were assigned to groups of absorbers or malabsorbers according to HBT results and tolerants or intolerants according to the results of the questionnaire. The total symptom score was significantly higher for home symptoms than for the lactose challenge (16 vs 8, P < .01). Symptoms perceived at home were reported to be more intense than those that followed the lactose challenge for lactose absorbers compared with malabsorbers (16 vs 4, P < .01) and lactose tolerants compared with intolerants (12 vs 2, P < .05). Overperception of lactose intolerance at home was similar in men and women. Daily life symptoms that patients associate with lactose intolerance are often unrelated to lactose malabsorption. Even among true lactose malabsorbers, symptom recall tends to be amplified by the patient. Thus, conventional anamnesis is a highly unreliable tool to establish symptomatic lactose malabsorption. Copyright (c) 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

Small intestinal malabsorption in chronic alcoholism: a retrospective study of alcoholic patients by the ¹⁴C-D-xylose breath test.

PubMed

Hope, Håvar; Skar, Viggo; Sandstad, Olav; Husebye, Einar; Medhus, Asle W

2012-04-01

The ¹⁴C-D-xylose breath test was used at Ullevål University Hospital in the period from 1986 TO 1995 for malabsorption testing. The objective of this retrospective study was to reveal whether patients with chronic alcoholism may have intestinal malabsorption. The consecutive ¹⁴C-D-xylose breath test database was reviewed and patients with the diagnosis of chronic alcoholism were identified. ¹⁴C-D-xylose breath test results of the alcoholic patients were compared with the results of untreated celiac patients and patient and healthy controls. In the ¹⁴C-D-xylose breath test, ¹⁴C-D-xylose was dissolved in water and given orally after overnight fast. Breath samples were taken at 30-min intervals for 210 min, and ¹⁴CO₂ : ¹²CO₂ ratios were calculated for each time point, presenting a time curve for ¹⁴C-D-xylose absorption. Urine was collected after 210 min and the fraction of the total d-xylose passed was calculated (U%). ¹⁴CO₂ in breath and ¹⁴C-D-xylose in urine were analyzed using liquid scintillation. Both breath and urine analysis revealed a pattern of malabsorption in alcoholics comparable with untreated celiac patients, with significantly reduced absorption of d-xylose compared with patient and healthy controls. Alcoholic patients have a significantly reduced ¹⁴C-D-xylose absorption, comparable with untreated celiac patients. This indicates a reduced intestinal function in chronic alcoholism.

Congenital Proprotein Convertase 1/3 Deficiency Causes Malabsorptive Diarrhea and other Endocrinopathies in a Pediatric Cohort

PubMed Central

Martín, Martín G.; Lindberg, Iris; Solorzano-Vargas, R. Sergio; Wang, Jiafang; Avitzur, Yaron; Bandsma, Robert; Sokollik, Christiane; Lawrence, Sarah; Pickett, Lindsay A.; Chen, Zijun; Egritas, Odul; Dalgic, Buket; Albornoz, Valeria; de Ridder, Lissy; Hulst, Jessie; Gok, Faysal; Aydoğan, Ayşen; Al-Hussaini, Abdulrahman; Gok, Deniz Engin; Yourshaw, Michael; Wu, S. Vincent; Cortina, Galen; Stanford, Sara; Georgia, Senta

2013-01-01

Background & Aims Proprotein convertase 1/3 (PC1/3) deficiency, an autosomal recessive disorder caused by rare mutations in the PCSK1 gene, has been associated with obesity, severe malabsorptive diarrhea, and certain endocrine abnormalities. Common variants in PCSK1 have also been associated with obesity in heterozygotes in several population studies. PC1/3 is an endoprotease that processes many prohormones expressed in endocrine and neuronal cells. We investigated clinical and molecular features of PC1/3 deficiency. Methods We studied the clinical features of 13 children with PC1/3 deficiency and performed sequence analysis of PCSK1. We measured enzymatic activity of recombinant PC1/3 proteins. Results We identified a pattern of endocrinopathies that develop in an age-dependent manner. Eight of the mutations had severe biochemical consequences in vitro. Neonates had severe malabsorptive diarrhea and failure to thrive, required prolonged parenteral nutrition support, and had high mortality. Additional endocrine abnormalities developed as the disease progressed, including diabetes insipidus, growth hormone deficiency, primary hypogonadism, adrenal insufficiency, and hypothyroidism. We identified growth hormone deficiency, central diabetes insipidus, and male hypogonadism as new features of PCSK1 insufficiency. Interestingly, despite early growth abnormalities, moderate obesity, associated with severe polyphagia, generally appears. Conclusion In a study of 13 children with PC1/3 deficiency caused by disruption of PCSK1, failure of enteroendocrine cells to produce functional hormones resulted in generalized malabsorption. These findings indicate that PC1/3 is involved in processing of one or more enteric hormones that are required for nutrient absorption. PMID:23562752

Complex carbohydrates in the dietary management of patients with glycogenosis caused by glucose-6-phosphatase deficiency.

PubMed

Smit, G P; Ververs, M T; Belderok, B; Van Rijn, M; Berger, R; Fernandes, J

1988-07-01

Carbohydrates with digestion characteristics between those of lente uncooked starches and rapidly digestible oligosaccharides were administered in a dose of 1.5 g/kg body weight to five patients with glycogenosis from glucose-6-phosphatase deficiency. Postprandial duration of normoglycemia and concentrations of blood insulin and lactate were determined. Uncooked barley groats in water, or incorporated in a meal turned out to behave as lente carbohydrates. Uncooked couscous in water, couscous incorporated in a meal, and partially cooked macaroni given as a meal behaved as semilente carbohydrates as compared with uncooked cornstarch and glucose. The in vitro determination of the digestibility index along with the in vivo tolerance test enables us to choose and incorporate semilente carbohydrates in the day-time treatment of patients.

Causes of vitamin B12 and folate deficiency.

PubMed

Allen, Lindsay H

2008-06-01

This review describes current knowledge of the main causes of vitamin B12 and folate deficiency. The most common explanations for poor vitamin B12 status are a low dietary intake of the vitamin (i.e., a low intake of animal-source foods) and malabsorption. Although it has long been known that strict vegetarians (vegans) are at risk for vitamin B12 deficiency, evidence now indicates that low intakes of animal-source foods, such as occur in some lacto-ovo vegetarians and many less-industrialized countries, cause vitamin B12 depletion. Malabsorption of the vitamin is most commonly observed as food-bound cobalamin malabsorption due to gastric atrophy in the elderly, and probably as a result of Helicobacter pylori infection. There is growing evidence that gene polymorphisms in transcobalamins affect plasma vitamin B12 concentrations. The primary cause of folate deficiency is low intake of sources rich in the vitamin, such as legumes and green leafy vegetables, and the consumption of these foods may explain why folate status can be adequate in relatively poor populations. Other situations in which the risk of folate deficiency increases include lactation and alcoholism.

Accounting for genotype–by-environment interactions and non-additive genetic variation in genomic selection for water-soluble carbohydrate concentration in wheat

USDA-ARS?s Scientific Manuscript database

Abiotic stress tolerance traits are often complex and recalcitrant targets for conventional breeding improvement in many crop species. This study evaluated the potential of genomic selection to predict water-soluble carbohydrate concentration (WSCC), an important drought tolerance trait, in wheat un...

Carbohydrates and the human gut microbiota.

PubMed

Chassard, Christophe; Lacroix, Christophe

2013-07-01

Due to its scale and its important role in maintaining health, the gut microbiota can be considered as a 'new organ' inside the human body. Many complex carbohydrates are degraded and fermented by the human gut microbiota in the large intestine to both yield basic energy salvage and impact gut health through produced metabolites. This review will focus on the gut microbes and microbial mechanisms responsible for polysaccharides degradation and fermentation in the large intestine. Gut microbes and bacterial metabolites impact the host at many levels, including modulation of inflammation, and glucose and lipid metabolisms. A complex relationship occurs in the intestine between the human gut microbiota, diet and the host. Research on carbohydrates and gut microbiota composition and functionality is fast developing and will open opportunities for prevention and treatment of obesity, diabetes and other related metabolic disorders through manipulation of the gut ecosystem.

Assessment of Dextran Antigenicity of Intravenous Iron Preparations with Enzyme-Linked Immunosorbent Assay (ELISA).

PubMed

Neiser, Susann; Koskenkorva, Taija S; Schwarz, Katrin; Wilhelm, Maria; Burckhardt, Susanna

2016-07-21

Intravenous iron preparations are typically classified as non-dextran-based or dextran/dextran-based complexes. The carbohydrate shell for each of these preparations is unique and is key in determining the various physicochemical properties, the metabolic pathway, and the immunogenicity of the iron-carbohydrate complex. As intravenous dextran can cause severe, antibody-mediated dextran-induced anaphylactic reactions (DIAR), the purpose of this study was to explore the potential of various intravenous iron preparations, non-dextran-based or dextran/dextran-based, to induce these reactions. An IgG-isotype mouse monoclonal anti-dextran antibody (5E7H3) and an enzyme-linked immunosorbent assay (ELISA) were developed to investigate the dextran antigenicity of low molecular weight iron dextran, ferumoxytol, iron isomaltoside 1000, ferric gluconate, iron sucrose and ferric carboxymaltose, as well as isomaltoside 1000, the isolated carbohydrate component of iron isomaltoside 1000. Low molecular weight iron dextran, as well as dextran-based ferumoxytol and iron isomaltoside 1000, reacted with 5E7H3, whereas ferric carboxymaltose, iron sucrose, sodium ferric gluconate, and isolated isomaltoside 1000 did not. Consistent results were obtained with reverse single radial immunodiffusion assay. The results strongly support the hypothesis that, while the carbohydrate alone (isomaltoside 1000) does not form immune complexes with anti-dextran antibodies, iron isomaltoside 1000 complex reacts with anti-dextran antibodies by forming multivalent immune complexes. Moreover, non-dextran based preparations, such as iron sucrose and ferric carboxymaltose, do not react with anti-dextran antibodies. This assay allows to assess the theoretical possibility of a substance to induce antibody-mediated DIARs. Nevertheless, as this is only one possible mechanism that may cause a hypersensitivity reaction, a broader set of assays will be required to get an understanding of the mechanisms that may lead to intravenous iron-induced hypersensitivity reactions.

Computational carbohydrate chemistry: what theoretical methods can tell us

PubMed Central

Woods, Robert J.

2014-01-01

Computational methods have had a long history of application to carbohydrate systems and their development in this regard is discussed. The conformational analysis of carbohydrates differs in several ways from that of other biomolecules. Many glycans appear to exhibit numerous conformations coexisting in solution at room temperature and a conformational analysis of a carbohydrate must address both spatial and temporal properties. When solution nuclear magnetic resonance data are used for comparison, the simulation must give rise to ensemble-averaged properties. In contrast, when comparing to experimental data obtained from crystal structures a simulation of a crystal lattice, rather than of an isolated molecule, is appropriate. Molecular dynamics simulations are well suited for such condensed phase modeling. Interactions between carbohydrates and other biological macromolecules are also amenable to computational approaches. Having obtained a three-dimensional structure of the receptor protein, it is possible to model with accuracy the conformation of the carbohydrate in the complex. An example of the application of free energy perturbation simulations to the prediction of carbohydrate-protein binding energies is presented. PMID:9579797

The consequences of the intracellular retention of pathogen-derived T-cell-independent antigens on protein presentation to T cells.

PubMed

Leyva-Cobián, F; Outschoorn, I M; Carrasco-Marín, E; Alvarez-Domínguez, C

1997-10-01

Intracellular pathogens can be considered as particulate antigens chemically composed of a complex mixture of T-cell-dependent antigens (TD) (peptides and proteins) and T-cell-independent antigens (TI) (glycolipids and complex polysaccharides). A large range of saccharides (from oligosaccharides to complex polysaccharides) derived from pathogenic microorganisms are being isolated and characterized. They are currently implicated in signaling systems and concomitant host-parasite relationships. However, there are not many structure-function relationships described for these pathogens. This is particularly true of polysaccharides. In this report we have reviewed the role of defined TI antigens in the processing and presentation of defined TD antigens to specific T cells by antigen-presenting cells (APC). We also considered the importance of some of the chemical characteristics shared by different carbohydrates implicated in the inhibition of antigen presentation. These findings are discussed in relation to the clear immunopathological consequences of long retention periods of complex carbohydrate molecules derived from intracellular parasites inside certain APC and the absence of antigen presentation impairment in physiological situations such as the removal of senescent or damaged red blood cells by splenic macrophages or intracellular accumulation of carbohydrates in colostrum and milk macrophages during lactation.

Effect of Raw Milk on Lactose Intolerance: A Randomized Controlled Pilot Study

PubMed Central

Mummah, Sarah; Oelrich, Beibei; Hope, Jessica; Vu, Quyen; Gardner, Christopher D.

2014-01-01

PURPOSE This pilot study aimed to determine whether raw milk reduces lactose malabsorption and/or lactose intolerance symptoms relative to pasteurized milk. METHODS We performed a crossover trial involving 16 adults with self-reported lactose intolerance and lactose malabsorption confirmed by hydrogen (H2) breath testing. Participants underwent 3, 8-day milk phases (raw vs 2 controls: pasteurized, soy) in randomized order separated by 1-week washout periods. On days 1 and 8 of each phase, milk consumption was 473 mL (16 oz); on days 2 to 7, milk dosage increased daily by 118 mL (4 oz), beginning with 118 mL (4 oz) on day 2 and reaching 710 mL (24 oz) on day 7. Outcomes were area under the breath H2 curve (AUC ∆H2) and self-reported symptom severity (visual analog scales: flatulence/gas, audible bowel sounds, abdominal cramping, diarrhea). RESULTS AUC ∆H2 (mean ± standard error of the mean) was higher for raw vs pasteurized on day 1 (113 ± 21 vs 71 ± 12 ppm·min·10−2, respectively, P = .01) but not day 8 (72 ± 14 vs 74 ± 15 ppm·min·10−2, respectively, P = .9). Symptom severities were not different for raw vs pasteurized on day 7 with the highest dosage (P >.7). AUC ∆H2 and symptom severities were higher for both dairy milks compared with soy milk. CONCLUSIONS Raw milk failed to reduce lactose malabsorption or lactose intolerance symptoms compared with pasteurized milk among adults positive for lactose malabsorption. These results do not support widespread anecdotal claims that raw milk reduces the symptoms of lactose intolerance. PMID:24615309

Effect of raw milk on lactose intolerance: a randomized controlled pilot study.

PubMed

Mummah, Sarah; Oelrich, Beibei; Hope, Jessica; Vu, Quyen; Gardner, Christopher D

2014-01-01

This pilot study aimed to determine whether raw milk reduces lactose malabsorption and/or lactose intolerance symptoms relative to pasteurized milk. We performed a crossover trial involving 16 adults with self-reported lactose intolerance and lactose malabsorption confirmed by hydrogen (H2) breath testing. Participants underwent 3, 8-day milk phases (raw vs 2 controls: pasteurized, soy) in randomized order separated by 1-week washout periods. On days 1 and 8 of each phase, milk consumption was 473 mL (16 oz); on days 2 to 7, milk dosage increased daily by 118 mL (4 oz), beginning with 118 mL (4 oz) on day 2 and reaching 710 mL (24 oz) on day 7. Outcomes were area under the breath H2 curve (AUC H2) and self-reported symptom severity (visual analog scales: flatulence/gas, audible bowel sounds, abdominal cramping, diarrhea). AUC H2 (mean ± standard error of the mean) was higher for raw vs pasteurized on day 1 (113 ± 21 vs 71 ± 12 ppm·min·10(-2), respectively, P = .01) but not day 8 (72 ± 14 vs 74 ± 15 ppm·min·10(-2), respectively, P = .9). Symptom severities were not different for raw vs pasteurized on day 7 with the highest dosage (P >.7). AUC H2 and symptom severities were higher for both dairy milks compared with soy milk. Raw milk failed to reduce lactose malabsorption or lactose intolerance symptoms compared with pasteurized milk among adults positive for lactose malabsorption. These results do not support widespread anecdotal claims that raw milk reduces the symptoms of lactose intolerance.

Congenital proprotein convertase 1/3 deficiency causes malabsorptive diarrhea and other endocrinopathies in a pediatric cohort.

PubMed

Martín, Martín G; Lindberg, Iris; Solorzano-Vargas, R Sergio; Wang, Jiafang; Avitzur, Yaron; Bandsma, Robert; Sokollik, Christiane; Lawrence, Sarah; Pickett, Lindsay A; Chen, Zijun; Egritas, Odul; Dalgic, Buket; Albornoz, Valeria; de Ridder, Lissy; Hulst, Jessie; Gok, Faysal; Aydoğan, Ayşen; Al-Hussaini, Abdulrahman; Gok, Deniz Engin; Yourshaw, Michael; Wu, S Vincent; Cortina, Galen; Stanford, Sara; Georgia, Senta

2013-07-01

Proprotein convertase 1/3 (PC1/3) deficiency, an autosomal-recessive disorder caused by rare mutations in the proprotein convertase subtilisin/kexin type 1 (PCSK1) gene, has been associated with obesity, severe malabsorptive diarrhea, and certain endocrine abnormalities. Common variants in PCSK1 also have been associated with obesity in heterozygotes in several population-based studies. PC1/3 is an endoprotease that processes many prohormones expressed in endocrine and neuronal cells. We investigated clinical and molecular features of PC1/3 deficiency. We studied the clinical features of 13 children with PC1/3 deficiency and performed sequence analysis of PCSK1. We measured enzymatic activity of recombinant PC1/3 proteins. We identified a pattern of endocrinopathies that develop in an age-dependent manner. Eight of the mutations had severe biochemical consequences in vitro. Neonates had severe malabsorptive diarrhea and failure to thrive, required prolonged parenteral nutrition support, and had high mortality. Additional endocrine abnormalities developed as the disease progressed, including diabetes insipidus, growth hormone deficiency, primary hypogonadism, adrenal insufficiency, and hypothyroidism. We identified growth hormone deficiency, central diabetes insipidus, and male hypogonadism as new features of PCSK1 insufficiency. Interestingly, despite early growth abnormalities, moderate obesity, associated with severe polyphagia, generally appears. In a study of 13 children with PC1/3 deficiency caused by disruption of PCSK1, failure of enteroendocrine cells to produce functional hormones resulted in generalized malabsorption. These findings indicate that PC1/3 is involved in the processing of one or more enteric hormones that are required for nutrient absorption. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Metabolic syndrome after laparoscopic bariatric surgery.

PubMed

Nugent, Clare; Bai, Chunhong; Elariny, Hazem; Gopalakrishnan, Priya; Quigley, Caitlin; Garone, Michael; Afendy, Mariam; Chan, Oscar; Wheeler, Angela; Afendy, Arian; Younossi, Zobair M

2008-10-01

Metabolic syndrome (MS) is common among morbidly obese patients undergoing bariatric surgery. The aim of this study was to assess the impact and predictors of bariatric surgery on the resolution of MS. Subjects included 286 patients [age 44.0 +/- 11.5, female 78.2%, BMI 48.7 +/- 9.4, waist circumference 139 +/- 20 cm, AST 23.5 +/- 14.9, ALT 30.0 +/- 20.1, type 2 diabetes mellitus (DM) 30.1% and MS 39.2%] who underwent bariatric surgery. Of the entire cohort, 27.3% underwent malabsorptive surgery, 55.9% underwent restrictive surgery, and 16.8% had combination restrictive-malabsorptive surgery. Mean weight loss was 33.7 +/- 20.1 kg after restrictive surgery (follow up period 298 +/- 271 days), 39.4 +/- 22.9 kg after malabsorptive surgery (follow-up period 306 +/- 290 days), and 28.3 +/- 14.1 kg after combination surgery (follow-up period 281 +/- 239 days). Regardless of the type of bariatric surgery, significant improvements were noted in MS (p values from <0.0001-0.01) as well as its components such as DM (p values from <0.0001-0.0005), waist circumference (p values <0.0001), BMI (p values <0.0001), fasting serum triglycerides (p values <0.0001 to 0.001), and fasting serum glucose (p values <0.0001). Additionally, a significant improvement in AST/ALT ratio (p value = 0.0002) was noted in those undergoing restrictive surgery. Multivariate analysis showed that patients who underwent malabsorptive bariatric procedures experienced a significantly greater percent excess weight loss than patients who underwent restrictive procedures (p value = 0.0451). Percent excess weight loss increased with longer postoperative follow-up (p value <0.0001). Weight loss after bariatric surgery is associated with a significant improvement in MS and other metabolic factors.

[Update on chronic pancreatitis: review article].

PubMed

Czul, Frank; Coronel, Emmanuel; Donet, Jean A

2017-01-01

Chronic pancreatitis is a progressive fibro-inflammatory disease of the pancreas characterized by irreversible fibrosis of the gland with eventual failure of exocrine and endocrine functions and hallmark features of abdominal pain, malabsorption, malnutrition, diabetes mellitus and pancreatic calcifications. In many patients this disease results from a complex mix of environmental (eg, alcohol, cigarettes, and occupational chemicals), genetic factors and a few patients with hereditary or autoimmune disease. The management includes medical, endoscopic and surgical approaches with the need for interaction between various specialties, calling for a concerted multidisciplinary approach. This review provides the reader with a comprehensive overview of the studies summarizing the epidemiology, etiology, physiopatology, clinical manifestation, diagnosis and treatments of the disease.

The role of Pyruvate Dehydrogenase Complex in cardiovascular diseases.

PubMed

Sun, Wanqing; Liu, Quan; Leng, Jiyan; Zheng, Yang; Li, Ji

2015-01-15

The regulation of mammalian myocardial carbohydrate metabolism is complex; many factors such as arterial substrate and hormone levels, coronary flow, inotropic state and the nutritional status of the tissue play a role in regulating mammalian myocardial carbohydrate metabolism. The Pyruvate Dehydrogenase Complex (PDHc), a mitochondrial matrix multienzyme complex, plays an important role in energy homeostasis in the heart by providing the link between glycolysis and the tricarboxylic acid (TCA) cycle. In TCA cycle, PDHc catalyzes the conversion of pyruvate into acetyl-CoA. This review determines that there is altered cardiac glucose in various pathophysiological states consequently causing PDC to be altered. This review further summarizes evidence for the metabolism mechanism of the heart under normal and pathological conditions including ischemia, diabetes, hypertrophy and heart failure. Copyright © 2014 Elsevier Inc. All rights reserved.

Nutritional therapy in pediatric Crohn disease: the specific carbohydrate diet.

PubMed

Suskind, David L; Wahbeh, Ghassan; Gregory, Nila; Vendettuoli, Heather; Christie, Dennis

2014-01-01

Crohn disease is characterized by chronic intestinal inflammation in the absence of a recognized etiology. Nutritional therapy in the form of exclusive enteral nutrition (EEN) has an established role within pediatric Crohn disease. Following exclusive enteral nutrition's success, many dietary therapies focusing on the elimination of specific complex carbohydrates have been anecdotally reported to be successful. Many of these therapies have not been evaluated scientifically; therefore, we reviewed the medical records of our patients with Crohn disease on the specific carbohydrate diet (SCD). Seven children with Crohn disease receiving the SCD and no immunosuppressive medications were retrospectively evaluated. Duration of the dietary therapy ranged from 5 to 30 months, with an average of 14.6±10.8 months. Although the exact time of symptom resolution could not be determined through chart review, all symptoms were notably resolved at a routine clinic visit 3 months after initiating the diet. Each patient's laboratory indices, including serum albumin, C-reactive protein, hematocrit, and stool calprotectin, either normalized or significantly, improved during follow-up clinic visits. This chart review suggests that the SCD and other low complex carbohydrate diets may be possible therapeutic options for pediatric Crohn disease. Further prospective studies are required to fully assess the safety and efficacy of the SCD, or any other low complex SCDs in pediatric patients with Crohn disease.

Molecular Simulations of Carbohydrates with a Fucose-Binding Burkholderia ambifaria Lectin Suggest Modulation by Surface Residues Outside the Fucose-Binding Pocket

PubMed Central

Dingjan, Tamir; Imberty, Anne; Pérez, Serge; Yuriev, Elizabeth; Ramsland, Paul A.

2017-01-01

Burkholderia ambifaria is an opportunistic respiratory pathogen belonging to the Burkholderia cepacia complex, a collection of species responsible for the rapidly fatal cepacia syndrome in cystic fibrosis patients. A fucose-binding lectin identified in the B. ambifaria genome, BambL, is able to adhere to lung tissue, and may play a role in respiratory infection. X-ray crystallography has revealed the bound complex structures for four fucosylated human blood group epitopes (blood group B, H type 1, H type 2, and Lex determinants). The present study employed computational approaches, including docking and molecular dynamics (MD), to extend the structural analysis of BambL-oligosaccharide complexes to include four additional blood group saccharides (A, Lea, Leb, and Ley) and a library of blood-group-related carbohydrates. Carbohydrate recognition is dominated by interactions with fucose via a hydrogen-bonding network involving Arg15, Glu26, Ala38, and Trp79 and a stacking interaction with Trp74. Additional hydrogen bonds to non-fucose residues are formed with Asp30, Tyr35, Thr36, and Trp74. BambL recognition is dominated by interactions with fucose, but also features interactions with other parts of the ligands that may modulate specificity or affinity. The detailed computational characterization of the BambL carbohydrate-binding site provides guidelines for the future design of lectin inhibitors. PMID:28680402

75SeHCAT scan in bile acid malabsorption in chronic diarrhoea.

PubMed

Mena Bares, L M; Carmona Asenjo, E; García Sánchez, M V; Moreno Ortega, E; Maza Muret, F R; Guiote Moreno, M V; Santos Bueno, A M; Iglesias Flores, E; Benítez Cantero, J M; Vallejo Casas, J A

Chronic diarrhoea is a common entity in daily clinical practice and it leads to a loss in these patients quality of life. It may be the main symptom of multiple ethiologies including bile acid malabsorption (BAM) which has a comparable prevalence to celiac disease. The BAM results from imbalances in the homeostasis of bile acids in the enterohepatic circulation. It can be a consequence of ileal disease or ileal dysfunction (BAM type i), it can be considered idiopathic or primary (BAM type ii) or associated with other gastrointestinal entities (BAM type iii). Among the different diagnostic methods available, 75 SeHCAT study is the primary current method due to its sensitivity, specificity, safety and low cost. The main disadvantage is that it's not available in all countries, so other diagnostic methods have appeared, such as serum measurement of FGF19 and C4, however they are significantly more complex and costly. The first-line treatment of bile acid diarrhoea is bile acid sequestrant, such as cholestyramine, which can be difficult to administer due to its poor tolerability and gastrointestinal side effects. These are less prominent with newer agents such as colesevelam. In summary, the BAM is a common entity underdiagnosed and undertreated, so it is essential to establish a diagnosis algorithm of chronic diarrhoea in which the 75 SeHCAT study would be first or second line in the differential diagnosis of these patients. Copyright © 2016 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

77 FR 32965 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-04

... importer P-12-0214 03/01/2012 05/01/2012 CBI Laundry and auto Carbohydrate polymers dish wash with acrylic... salt (1:2) initiate. P12-0215 03/01/2012 05/01/2012 CBI Laundry and auto Carbohydrate, polymers dish............ 04/25/2012 04/17/2012 (G) Barium, dialkyl 2-sulfobutanedioate phosphate complexes. P-09-0384...

Crystal structure of reovirus attachment protein σ1 in complex with sialylated oligosaccharides.

PubMed

Reiter, Dirk M; Frierson, Johnna M; Halvorson, Elizabeth E; Kobayashi, Takeshi; Dermody, Terence S; Stehle, Thilo

2011-08-01

Many viruses attach to target cells by binding to cell-surface glycans. To gain a better understanding of strategies used by viruses to engage carbohydrate receptors, we determined the crystal structures of reovirus attachment protein σ1 in complex with α-2,3-sialyllactose, α-2,6-sialyllactose, and α-2,8-di-siallylactose. All three oligosaccharides terminate in sialic acid, which serves as a receptor for the reovirus serotype studied here. The overall structure of σ1 resembles an elongated, filamentous trimer. It contains a globular head featuring a compact β-barrel, and a fibrous extension formed by seven repeating units of a triple β-spiral that is interrupted near its midpoint by a short α-helical coiled coil. The carbohydrate-binding site is located between β-spiral repeats two and three, distal from the head. In all three complexes, the terminal sialic acid forms almost all of the contacts with σ1 in an identical manner, while the remaining components of the oligosaccharides make little or no contacts. We used this structural information to guide mutagenesis studies to identify residues in σ1 that functionally engage sialic acid by assessing hemagglutination capacity and growth in murine erythroleukemia cells, which require sialic acid binding for productive infection. Our studies using σ1 mutant viruses reveal that residues 198, 202, 203, 204, and 205 are required for functional binding to sialic acid by reovirus. These findings provide insight into mechanisms of reovirus attachment to cell-surface glycans and contribute to an understanding of carbohydrate binding by viruses. They also establish a filamentous, trimeric carbohydrate-binding module that could potentially be used to endow other trimeric proteins with carbohydrate-binding properties.

The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center. Five-year report, September 15, 1987--December 31, 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albersheim, Peter; Darvill, Alan

1992-05-01

The Complex Carbohydrate Research Center (CCRC) is the home of ten independent but complementary interdisciplinary research groups led by nine regular faculty and one adjunct faculty. The research of these groups represents a broad spectrum of interests, and they are involved in about 90 collaborations with their CCRC and UGA colleagues and with scientists at other institutions and companies in the US, Canada, Europe, Israel, and Japan. The hallmark of the CCRC is the collaborative, interactive environment encouraged by its directors, faculty and tong-term staff. Newcomers to the CCRC or short-term members soon learn that everyone benefits from this process.more » The team-oriented approach in carbohydrate science translates into the day-today generous giving of one's time and expertise to the work of others, whether it be in sharing specialized instrumentation, participating in the design of experiments and interpretalon of data, providing service to scientists outside the CCRC, or joining collaborative projects. The CCRC is founded on the principle that the cross-fertilization of ideas and know-how leads to the synergistic advancement of science. This report contains a series of appendices that document the extent and breadth of the Plant and Microbial Carbohydrate Center's contributions to collaborative research and education. Several collaborative research projects that have received postdoctoral research associate support from the Grant are highlighted, as these projects are particularly illustrative of the wide-ranging collaborations that have evolved as a result of this Grant and the quality of the science that the Grant enables.« less

Total synthesis of mycobacterial arabinogalactan containing 92 monosaccharide units

NASA Astrophysics Data System (ADS)

Wu, Yong; Xiong, De-Cai; Chen, Si-Cong; Wang, Yong-Shi; Ye, Xin-Shan

2017-03-01

Carbohydrates are diverse bio-macromolecules with highly complex structures that are involved in numerous biological processes. Well-defined carbohydrates obtained by chemical synthesis are essential to the understanding of their functions. However, synthesis of carbohydrates is greatly hampered by its insufficient efficiency. So far, assembly of long carbohydrate chains remains one of the most challenging tasks for synthetic chemists. Here we describe a highly efficient assembly of a 92-mer polysaccharide by the preactivation-based one-pot glycosylation protocol. Several linear and branched oligosaccharide/polysaccharide fragments ranging from 5-mer to 31-mer in length have been rapidly constructed in one-pot manner, which enables the first total synthesis of a biologically important mycobacterial arabinogalactan through a highly convergent [31+31+30] coupling reaction. Our results show that the preactivation-based one-pot glycosylation protocol may provide access to the construction of long and complicated carbohydrate chains.

Polysaccharide Utilization Loci: Fueling Microbial Communities

PubMed Central

Grondin, Julie M.; Tamura, Kazune; Déjean, Guillaume

2017-01-01

ABSTRACT The complex carbohydrates of terrestrial and marine biomass represent a rich nutrient source for free-living and mutualistic microbes alike. The enzymatic saccharification of these diverse substrates is of critical importance for fueling a variety of complex microbial communities, including marine, soil, ruminant, and monogastric microbiota. Consequently, highly specific carbohydrate-active enzymes, recognition proteins, and transporters are enriched in the genomes of certain species and are of critical importance in competitive environments. In Bacteroidetes bacteria, these systems are organized as polysaccharide utilization loci (PULs), which are strictly regulated, colocalized gene clusters that encode enzyme and protein ensembles required for the saccharification of complex carbohydrates. This review provides historical perspectives and summarizes key findings in the study of these systems, highlighting a critical shift from sequence-based PUL discovery to systems-based analyses combining reverse genetics, biochemistry, enzymology, and structural biology to precisely illuminate the molecular mechanisms underpinning PUL function. The ecological implications of dynamic PUL deployment by key species in the human gastrointestinal tract are explored, as well as the wider distribution of these systems in other gut, terrestrial, and marine environments. PMID:28138099

Applying Pose Clustering and MD Simulations To Eliminate False Positives in Molecular Docking.

PubMed

Makeneni, Spandana; Thieker, David F; Woods, Robert J

2018-03-26

In this work, we developed a computational protocol that employs multiple molecular docking experiments, followed by pose clustering, molecular dynamic simulations (10 ns), and energy rescoring to produce reliable 3D models of antibody-carbohydrate complexes. The protocol was applied to 10 antibody-carbohydrate co-complexes and three unliganded (apo) antibodies. Pose clustering significantly reduced the number of potential poses. For each system, 15 or fewer clusters out of 100 initial poses were generated and chosen for further analysis. Molecular dynamics (MD) simulations allowed the docked poses to either converge or disperse, and rescoring increased the likelihood that the best-ranked pose was an acceptable pose. This approach is amenable to automation and can be a valuable aid in determining the structure of antibody-carbohydrate complexes provided there is no major side chain rearrangement or backbone conformational change in the H3 loop of the CDR regions. Further, the basic protocol of docking a small ligand to a known binding site, clustering the results, and performing MD with a suitable force field is applicable to any protein ligand system.

Thermodynamics of alpha-Cyclodextrin-p-Nitrophenyl Glycoside Complexes. A Simple System To Understand the Energetics of Carbohydrate Interactions in Water.

PubMed

Junquera, Elena; Laynez, José; Menéndez, Margarita; Sharma, Sunil; Penadés, Soledad

1996-10-04

Thermodynamic studies of the binding of a series of p-nitrophenyl glycosides (PNPGly) of varying stereochemistry to alpha-cyclodextrin (alpha-CD) were performed at three different temperatures (25, 35, and 42 degrees C) using a microcalorimetric technique. The system p-nitrophenol (PNP) at pH = 3 and alpha-CD was also studied for the sake of comparison. All these complexes were found to be enthalpy driven with a favorable enthalpic term clearly dominant over an unfavorable entropic term. A clear enthalpy-entropy compensation effect was observed at all the temperatures, with a slope close to unity (alpha = 1.02) and an intercept TDeltaS degrees (o) = 2.91 kcal mol(-)(1). This thermodynamic pattern is in agreement with those usually found for lectin-carbohydrate associations and for the binding processes of several host-guest systems. This pattern is explained in terms of the contribution of primarily two driving forces: the van der Waals interactions between the host and the guest, and the solvation/desolvation processes which accompany the association reaction. The presence of the carbohydrate molecule in the PNP ring causes a slight destabilization of the complex at 25 degrees C with respect to the alpha-CD-PNP (pH = 3) complex, although a different behavior has been observed depending on the axial/equatorial configuration of the glycoside and the temperature. This behavior is modulated by the stereochemistry of the glycoside. Differences were observed between the deoxy-derivatives (LAra and LFuc) and those derivatives with a hydroxymethyl group (Glc, Gal, Man). DeltaC(p) degrees values were obtained from the dependency of DeltaH degrees on temperature (=( partial differentialDeltaH degrees / partial differentialT)(p)). These values are small and negative except for alphaMan complex. For the latter complex, discrepancy between the calorimetric and the calculated van't Hoff enthalpies was observed. Parallels are drawn between the thermodynamics of our model and those proposed for carbohydrate-protein associations.

Glycobiology of Reproductive Processes in Marine Animals: The State of the Art

PubMed Central

Gallo, Alessandra; Costantini, Maria

2012-01-01

Glycobiology is the study of complex carbohydrates in biological systems and represents a developing field of science that has made huge advances in the last half century. In fact, it combines all branches of biomedical research, revealing the vast and diverse forms of carbohydrate structures that exist in nature. Advances in structure determination have enabled scientists to study the function of complex carbohydrates in more depth and to determine the role that they play in a wide range of biological processes. Glycobiology research in marine systems has primarily focused on reproduction, in particular for what concern the chemical communication between the gametes. The current status of marine glycobiology is primarily descriptive, devoted to characterizing marine glycoconjugates with potential biomedical and biotechnological applications. In this review, we describe the current status of the glycobiology in the reproductive processes from gametogenesis to fertilization and embryo development of marine animals. PMID:23247316

Molecular basis for disruption of E-cadherin adhesion by botulinum neurotoxin A complex.

PubMed

Lee, Kwangkook; Zhong, Xiaofen; Gu, Shenyan; Kruel, Anna Magdalena; Dorner, Martin B; Perry, Kay; Rummel, Andreas; Dong, Min; Jin, Rongsheng

2014-06-20

How botulinum neurotoxins (BoNTs) cross the host intestinal epithelial barrier in foodborne botulism is poorly understood. Here, we present the crystal structure of a clostridial hemagglutinin (HA) complex of serotype BoNT/A bound to the cell adhesion protein E-cadherin at 2.4 angstroms. The HA complex recognizes E-cadherin with high specificity involving extensive intermolecular interactions and also binds to carbohydrates on the cell surface. Binding of the HA complex sequesters E-cadherin in the monomeric state, compromising the E-cadherin-mediated intercellular barrier and facilitating paracellular absorption of BoNT/A. We reconstituted the complete 14-subunit BoNT/A complex using recombinantly produced components and demonstrated that abolishing either E-cadherin- or carbohydrate-binding of the HA complex drastically reduces oral toxicity of BoNT/A complex in vivo. Together, these studies establish the molecular mechanism of how HAs contribute to the oral toxicity of BoNT/A. Copyright © 2014, American Association for the Advancement of Science.

Nutritional and metabolic responses in common dentex (Dentex dentex) fed on different types and levels of carbohydrates.

PubMed

Pérez-Jiménez, Amalia; Abellán, Emilia; Arizcun, Marta; Cardenete, Gabriel; Morales, Amalia E; Hidalgo, M Carmen

2015-06-01

The present study was aimed to evaluate the capacity of common dentex (Dentex dentex) to efficiently use dietary carbohydrates. So, the effects of different type and levels of carbohydrates on growth performance, feed utilization, fish composition, plasma metabolites and key metabolic pathways in liver and white muscle of common dentex are presented. Nine isonitrogenous (43%) and isoenergetic (22 MJ kg(-1)) diets were formulated combining three types, pregelatinized starch (PS), dextrin (Dx) and maltodextrin (Mx), and three levels (12, 18 and 24%) of carbohydrates. Growth performance was not significantly influenced by treatments. The best feed utilization was observed in 18% Mx group. Higher hepatic lipid content was found in fish fed lower dietary carbohydrate levels. PS induced higher liver and white muscle hexokinase and pyruvate kinase activities compared to the lower values observed for Mx. Malic enzyme and glucose 6-phosphate dehydrogenase in liver and white muscle were lower in Mx group. The influence of dietary carbohydrates source was more noticeable than those induced by the carbohydrate level, when glycolysis and lipogenesis pathways were considered. Common dentex is able to use properly dietary carbohydrates, although optimal dietary inclusion levels are below 24%. The greater protein-sparing effect was promoted by the less complex carbohydrate (maltodextrin) and the best feed utilization indices were obtained at intermediate levels of inclusion (18%). Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of dietary carbohydrates on metabolism of calcium and other minerals in normal subjects and patients with noninsulin-dependent diabetes mellitus.

PubMed

Garg, A; Bonanome, A; Grundy, S M; Unger, R H; Breslau, N A; Pak, C Y

1990-04-01

Transient hypercalciuria has been noted after high carbohydrate meals which is independent of dietary calcium and is probably due to impaired renal calcium reabsorption mediated by an increase in plasma insulin levels. Based on these observations, some investigators believe that long term intake of high carbohydrate diets may increase the risk of nephrolithiasis and possibly osteoporosis. Using a randomized cross-over design, we compared high carbohydrate diets (60% carbohydrate and 25% fat) with high fat diets (50% fat and 35% carbohydrate) for effects on metabolism of calcium and other minerals in eight normal subjects and eight euglycemic patients with noninsulin-dependent diabetes mellitus. All other dietary constituents, such as protein, fiber, fluid, minerals (including Ca, Mg, Na, K, and P), and caffeine intake, were kept constant. Despite higher daylong levels of plasma insulin on the high carbohydrate diets compared to the high fat diet in both normal and noninsulin-dependent diabetic subjects, no changes in daily urinary excretion of calcium or other constituents, associated with renal stone risk, were observed. Furthermore, there was no change in fractional intestinal 47Ca absorption. Although hypercalciuria may ensue transiently after high carbohydrate meals, we conclude that substitution of simple or complex carbohydrates for fats in an isocaloric manner for a longer duration does not result in significant urinary calcium loss, and therefore, high intakes of digestible carbohydrates may not increase the risk of nephrolithiasis or osteoporosis via this mechanism.

Influence of Trp flipping on carbohydrate binding in lectins. An example on Aleuria aurantia lectin AAL.

PubMed

Houser, Josef; Kozmon, Stanislav; Mishra, Deepti; Mishra, Sushil K; Romano, Patrick R; Wimmerová, Michaela; Koča, Jaroslav

2017-01-01

Protein-carbohydrate interactions are very often mediated by the stacking CH-π interactions involving the side chains of aromatic amino acids such as tryptophan (Trp), tyrosine (Tyr) or phenylalanine (Phe). Especially suitable for stacking is the Trp residue. Analysis of the PDB database shows Trp stacking for 265 carbohydrate or carbohydrate like ligands in 5 208 Trp containing motives. An appropriate model system to study such an interaction is the AAL lectin family where the stacking interactions play a crucial role and are thought to be a driving force for carbohydrate binding. In this study we present data showing a novel finding in the stacking interaction of the AAL Trp side chain with the carbohydrate. High resolution X-ray structure of the AAL lectin from Aleuria aurantia with α-methyl-l-fucoside ligand shows two possible Trp side chain conformations with the same occupation in electron density. The in silico data shows that the conformation of the Trp side chain does not influence the interaction energy despite the fact that each conformation creates interactions with different carbohydrate CH groups. Moreover, the PDB data search shows that the conformations are almost equally distributed across all Trp-carbohydrate complexes, which would suggest no substantial preference for one conformation over another.

Effects of carbohydrates on satiety: differences between liquid and solid food.

PubMed

Pan, An; Hu, Frank B

2011-07-01

To examine the satiety effect of carbohydrates with a focus on the comparison of liquid and solid food and their implications for energy balance and weight management. A number of studies have examined the role of dietary fiber, whole grains, and glycemic index or glycemic load on satiety and subsequent energy intake, but results remain inconclusive. Intake of liquid carbohydrates, particularly sugar-sweetened beverages, has increased considerably across the globe in recent decades in both adolescents and adults. In general, liquid carbohydrates produce less satiety compared with solid carbohydrates. Some energy from liquids may be compensated for at subsequent meals but because the compensation is incomplete, it leads to an increase in total long-term energy intake. Recent studies also suggest some potential differential responses of satiety by characteristics of the patients (e.g., race, sex, and body weight status). These differences warrant further research. Satiety is a complex process influenced by a number of properties in food. The physical form (solid vs. liquid) of carbohydrates is an important component that may affect the satiety process and energy intake. Accumulating evidence suggests that liquid carbohydrates generally produce less satiety than solid forms.

Thiamine

MedlinePlus

... B vitamins, and found in many vitamin B complex products. Vitamin B complexes generally include vitamin B1 (thiamine), vitamin B2 (riboflavin), ... is required by our bodies to properly use carbohydrates. It also helps maintain proper nerve function.

Carbohydrate and alditol analysis by high-performance anion-exchange chromatography coupled with electrochemical detection at a cobalt-modified electrode.

PubMed

Casella, Innocenzo G; Contursi, Michela

2003-07-01

A cobalt oxyhydroxide film dispersed on a carbon electrode surface was characterized and proposed as an amperometric sensor for determination of alditols and carbohydrates in flowing streams. Complex mixtures of carbohydrates were separated by anion-exchange chromatography using a moderately alkaline solution as mobile phase. The cobalt modified electrode (GC-Co) was employed under a constant applied potential of 0.5 V (vs Ag/AgCl). Under these experimental conditions the detection limits (S/N=3) for all analyzed electroactive molecules ranged between 0.3 micromol L(-1) and 1.5 micromol L(-1) and the dynamic linear ranges spanned generally three orders of magnitude above the relevant detection limits. Analytical determinations of carbohydrates and alditols in red and white wines, are reported.

Levothyroxine Dosing Following Bariatric Surgery.

PubMed

Gadiraju, Silpa; Lee, Clare J; Cooper, David S

2016-10-01

Based on the mechanisms of drug absorption, increased levothyroxine requirements are expected after bariatric surgery. However, there are conflicting data on this topic. This review evaluates the effects of bariatric surgery on levothyroxine dosing. Data were obtained from PubMed, Scopus, and review of published bibliographies. Six of 10 studies demonstrated decreased postoperative requirements. Most demonstrated correlations between weight loss and dose. Only 3 case reports and 1 case series demonstrated increased levothyroxine requirements, attributed to malabsorption. The loss of both fat and lean body mass may counteract malabsorptive effects from surgery, resulting in decreased postoperative levothyroxine requirements. In addition, the reversal of impaired levothyroxine pharmacokinetics and an altered set point of thyroid hormone homeostasis may also contribute to postoperative levothyroxine reductions.

The effect of exercise on carbohydrate preference in female rats.

PubMed

Keeley, R J; Zelinski, E L; Fehr, L; McDonald, R J

2014-02-01

Exercise has a myriad of health benefits, including positive effects against heart disease, diabetes, and dementia. Cognitive performance improves following chronic exercise, both in animal models and humans. Studies have examined the effect of exercise on feeding, demonstrating a preference towards increased food consumption. Further, sex differences exist such that females tend to prefer carbohydrates over other macronutrients following exercise. However, no clear effect of exercise on macronutrient or carbohydrate selection has been described in animal or human studies. This research project sought to determine the effect of voluntary exercise on carbohydrate selection in female rats. Preference for a complex (starch) versus a simple (dextrose) carbohydrate was assessed using a discriminative preference to context paradigm in non-exercising and voluntarily exercising female rats. In addition, fasting blood glucose and performance in the Morris water task was examined in order to verify the effects of exercise on performance in this task. Female rats given access to running wheels preferred a context previously associated with starch, whereas females with no running wheel access preferred a context previously associated with dextrose. No changes in blood glucose were observed. However, cognitive differences in the Morris water task were observed such that voluntary exercise allowed rats to find a new location of a hidden platform following 4 days of training to an old platform location. These results suggest that voluntary exercise may decrease preservative behaviors in a spatial navigation task through the facilitation of plasticity mechanisms. This study is the first of its kind to demonstrate the influence of exercise on taste preference for complex and simple carbohydrates with this context conditioning paradigm. Copyright © 2014 Elsevier Inc. All rights reserved.

Differential effects of simple vs. complex carbohydrates on VLDL secretion rates and HDL metabolism in the guinea pig.

PubMed

Fernandez, M L; Abdel-Fattah, G; McNamara, D J

1995-04-28

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

Carbohydrate Recognition by an Architecturally Complex α-N-Acetylglucosaminidase from Clostridium perfringens

PubMed Central

Ficko-Blean, Elizabeth; Stuart, Christopher P.; Suits, Michael D.; Cid, Melissa; Tessier, Matthew; Woods, Robert J.; Boraston, Alisdair B.

2012-01-01

CpGH89 is a large multimodular enzyme produced by the human and animal pathogen Clostridium perfringens. The catalytic activity of this exo-α-d-N-acetylglucosaminidase is directed towards a rare carbohydrate motif, N-acetyl-β-d-glucosamine-α-1,4-d-galactose, which is displayed on the class III mucins deep within the gastric mucosa. In addition to the family 89 glycoside hydrolase catalytic module this enzyme has six modules that share sequence similarity to the family 32 carbohydrate-binding modules (CBM32s), suggesting the enzyme has considerable capacity to adhere to carbohydrates. Here we suggest that two of the modules, CBM32-1 and CBM32-6, are not functional as carbohydrate-binding modules (CBMs) and demonstrate that three of the CBMs, CBM32-3, CBM32-4, and CBM32-5, are indeed capable of binding carbohydrates. CBM32-3 and CBM32-4 have a novel binding specificity for N-acetyl-β-d-glucosamine-α-1,4-d-galactose, which thus complements the specificity of the catalytic module. The X-ray crystal structure of CBM32-4 in complex with this disaccharide reveals a mode of recognition that is based primarily on accommodation of the unique bent shape of this sugar. In contrast, as revealed by a series of X-ray crystal structures and quantitative binding studies, CBM32-5 displays the structural and functional features of galactose binding that is commonly associated with CBM family 32. The functional CBM32s that CpGH89 contains suggest the possibility for multivalent binding events and the partitioning of this enzyme to highly specific regions within the gastrointestinal tract. PMID:22479408

Association between Carbohydrate Intake and Serum Lipids

PubMed Central

Ma, Yunsheng; Chiriboga, David E.; Olendzki, Barbara C.; Li, Wenjun; Leung, Katherine; Hafner, Andrea R.; Li, Youfu; Ockene, Ira S.; Hebert, James R.

2006-01-01

Background The effect of dietary carbohydrate on blood lipids has received considerable attention in light of the current trend in lowering carbohydrate intake for weight loss. Objectives To evaluate the association between carbohydrate intake and serum lipids. Methods Blood samples and 24-hour dietary and physical activity recall interviews were obtained from each subject at quarterly intervals for five consecutive quarters between 1994 and 1998 from 574 healthy adults in Central Massachusetts. Relationships between serum lipids and dietary carbohydrate factors were assessed using linear mixed models and adjusting for other risk factors known to be related to blood lipids. Both cross-sectional and longitudinal results were reported. Results Cross-sectional analysis results from this study suggest that higher total carbohydrate intake, percentage of calories from carbohydrate, glycemic index (GI) and/or glycemic load (GL) are related to lower high-density lipoprotein cholesterol (HDL-C) and higher serum triacylglycerol levels, while higher total carbohydrate intake and/or GL are related to lower total and low-density lipoprotein cholesterol (LDL-C) levels. In a one-year longitudinal analysis, GL was positively associated with total and LDL-C levels, and there was an inverse association between percentage of calories from carbohydrate and HDL-C levels. Conclusions Results suggest that there is a complex and predominantly unfavorable effect of increased intake of highly processed carbohydrate on lipid profile, which may have implications for metabolic syndrome, diabetes, and coronary heart disease. Further studies in the form of randomized controlled trials are required to investigate these associations and determine the implications for lipid management. PMID:16582033

[Belated decompensation of an Imerslund-Grasbeck disease].

PubMed

Eitenschenck, L; Armari-Alla, C; Plantaz, D; Pagnier, A; Ducros, V

2005-12-01

Imerslund-Gräsbeck disease is an autosomic recessive disease characterised by a megaloblastic anemia due to a vitamin B12 deficiency and by a moderate proteinuria without kidney failure. It is caused by the malabsorption of Cobalamin-intrinsic factor complex bringing into play cubulin and other proteins (megaline, amnioless), some mutations of which are described at present. We report herein the observation of a child whose diagnosis was made belatedly during an acute decompensation with biological hemophagocytic syndrome. Its evolution was marked by the appearance of neurological disorders at the beginning of the vitamin B12 substitution treatment. These disorder regressed as the dosage was increase. The purpose of this observation is to recapitulate the main characteristics of this disease and to review the current data.

The management of diabetes in terminal illness related to cancer.

PubMed

King, E J; Haboubi, H; Evans, D; Baker, I; Bain, S C; Stephens, J W

2012-01-01

The management of diabetes during terminal illness is complex, with lack of agreement and consensus among physicians and multidisciplinary teams. Despite the plethora of guidelines available for the management of diabetes, there exists no agreed, evidence-based strategy for managing diabetes during terminal illness and at the end of life. A number of physiological factors may influence glycaemic control during terminal illness. These include anorexia, cachexia, malabsorption, renal and hepatic failure. Furthermore, controversy exists on the frequency of blood glucose monitoring, the optimum blood glucose range and how to achieve this. We review the factors influencing blood glucose during terminal illness and provide a suggested approach to managing patients with type 1 and type 2 diabetes during the early and late stages of terminal illness.

Identification of carbohydrate anomers using ion mobility-mass spectrometry.

PubMed

Hofmann, J; Hahm, H S; Seeberger, P H; Pagel, K

2015-10-08

Carbohydrates are ubiquitous biological polymers that are important in a broad range of biological processes. However, owing to their branched structures and the presence of stereogenic centres at each glycosidic linkage between monomers, carbohydrates are harder to characterize than are peptides and oligonucleotides. Methods such as nuclear magnetic resonance spectroscopy can be used to characterize glycosidic linkages, but this technique requires milligram amounts of material and cannot detect small amounts of coexisting isomers. Mass spectrometry, on the other hand, can provide information on carbohydrate composition and connectivity for even small amounts of sample, but it cannot be used to distinguish between stereoisomers. Here, we demonstrate that ion mobility-mass spectrometry--a method that separates molecules according to their mass, charge, size, and shape--can unambiguously identify carbohydrate linkage-isomers and stereoisomers. We analysed six synthetic carbohydrate isomers that differ in composition, connectivity, or configuration. Our data show that coexisting carbohydrate isomers can be identified, and relative concentrations of the minor isomer as low as 0.1 per cent can be detected. In addition, the analysis is rapid, and requires no derivatization and only small amounts of sample. These results indicate that ion mobility-mass spectrometry is an effective tool for the analysis of complex carbohydrates. This method could have an impact on the field of carbohydrate synthesis similar to that of the advent of high-performance liquid chromatography on the field of peptide assembly in the late 1970s.

Identification of carbohydrate anomers using ion mobility-mass spectrometry

NASA Astrophysics Data System (ADS)

Hofmann, J.; Hahm, H. S.; Seeberger, P. H.; Pagel, K.

2015-10-01

Carbohydrates are ubiquitous biological polymers that are important in a broad range of biological processes. However, owing to their branched structures and the presence of stereogenic centres at each glycosidic linkage between monomers, carbohydrates are harder to characterize than are peptides and oligonucleotides. Methods such as nuclear magnetic resonance spectroscopy can be used to characterize glycosidic linkages, but this technique requires milligram amounts of material and cannot detect small amounts of coexisting isomers. Mass spectrometry, on the other hand, can provide information on carbohydrate composition and connectivity for even small amounts of sample, but it cannot be used to distinguish between stereoisomers. Here, we demonstrate that ion mobility-mass spectrometry--a method that separates molecules according to their mass, charge, size, and shape--can unambiguously identify carbohydrate linkage-isomers and stereoisomers. We analysed six synthetic carbohydrate isomers that differ in composition, connectivity, or configuration. Our data show that coexisting carbohydrate isomers can be identified, and relative concentrations of the minor isomer as low as 0.1 per cent can be detected. In addition, the analysis is rapid, and requires no derivatization and only small amounts of sample. These results indicate that ion mobility-mass spectrometry is an effective tool for the analysis of complex carbohydrates. This method could have an impact on the field of carbohydrate synthesis similar to that of the advent of high-performance liquid chromatography on the field of peptide assembly in the late 1970s.

Analysis of Prebiotic Oligosaccharides

NASA Astrophysics Data System (ADS)

Sanz, M. L.; Ruiz-Matute, A. I.; Corzo, N.; Martínez-Castro, I.

Carbohydrates and more specifically prebiotics, are complex mixtures of isomers with different degrees of polymerization (DP), monosaccharide units and/or glycosidic linkages. Many efforts are focused on the search for new products and the determination of their biological activity. However, the study of their chemical structure is fundamental to both acquire a basic knowledge of the carbohydrate and to increase the understanding of the mechanisms for their metabolic effect.

Three-dimensional potential energy surface of selected carbohydrates' CH/π dispersion interactions calculated by high-level quantum mechanical methods.

PubMed

Kozmon, Stanislav; Matuška, Radek; Spiwok, Vojtěch; Koča, Jaroslav

2011-05-09

In this study we present the first systematic computational three-dimensional scan of carbohydrate hydrophobic patches for the ability to interact through CH/π dispersion interactions. The carbohydrates β-d-glucopyranose, β-d-mannopyranose and α-l-fucopyranose were studied in a complex with a benzene molecule, which served as a model of the CH/π interaction in carbohydrate/protein complexes. The 3D relaxed scans were performed at the SCC-DFTB-D level with 3 757 grid points for both carbohydrate hydrophobic sides. The interaction energy of all grid points was recalculated at the DFT-D BP/def2-TZVPP level. The results obtained clearly show highly delimited and separated areas around each CH group, with an interaction energy up to -5.40 kcal mol(-1) . The results also show that with increasing H⋅⋅⋅π distance these delimited areas merge and form one larger region, which covers all hydrogen atoms on that specific carbohydrate side. Simultaneously, the interaction becomes weaker with an energy of -2.5 kcal mol(-1) . All local energy minima were optimized at the DFT-D BP/def2-TZVPP level and the interaction energies of these complexes were refined by use of the high-level ab initio computation at the CCSD(T)/CBS level. Results obtained from the optimization suggest that the CH group hydrogen atoms are not equivalent and the interaction energy at the CCSD(T)/CBS level range from -3.54 to -5.40 kcal mol(-1) . These results also reveal that the optimal H⋅⋅⋅π distance for the CH/π dispersion interaction is approximately (2.310±0.030) Å, and the angle defined as carbon-hydrogen-benzene geometrical centre is (180±30)°. These results reveal that whereas the dispersion interactions with the lowest interaction energies are quite strictly located in space, the slightly higher interaction energy regions adopt a much larger space. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hyperoxaluria

MedlinePlus

... such as gastric bypass, Crohn’s Disease, short bowel syndrome or other malabsorption disorders causing enteric hyperoxaluria . Avoiding, foods high in oxalate in particularly important. Learn more… Types ...

Assessment of Dextran Antigenicity of Intravenous Iron Preparations with Enzyme-Linked Immunosorbent Assay (ELISA)

PubMed Central

Neiser, Susann; Koskenkorva, Taija S.; Schwarz, Katrin; Wilhelm, Maria; Burckhardt, Susanna

2016-01-01

Intravenous iron preparations are typically classified as non-dextran-based or dextran/dextran-based complexes. The carbohydrate shell for each of these preparations is unique and is key in determining the various physicochemical properties, the metabolic pathway, and the immunogenicity of the iron-carbohydrate complex. As intravenous dextran can cause severe, antibody-mediated dextran-induced anaphylactic reactions (DIAR), the purpose of this study was to explore the potential of various intravenous iron preparations, non-dextran-based or dextran/dextran-based, to induce these reactions. An IgG-isotype mouse monoclonal anti-dextran antibody (5E7H3) and an enzyme-linked immunosorbent assay (ELISA) were developed to investigate the dextran antigenicity of low molecular weight iron dextran, ferumoxytol, iron isomaltoside 1000, ferric gluconate, iron sucrose and ferric carboxymaltose, as well as isomaltoside 1000, the isolated carbohydrate component of iron isomaltoside 1000. Low molecular weight iron dextran, as well as dextran-based ferumoxytol and iron isomaltoside 1000, reacted with 5E7H3, whereas ferric carboxymaltose, iron sucrose, sodium ferric gluconate, and isolated isomaltoside 1000 did not. Consistent results were obtained with reverse single radial immunodiffusion assay. The results strongly support the hypothesis that, while the carbohydrate alone (isomaltoside 1000) does not form immune complexes with anti-dextran antibodies, iron isomaltoside 1000 complex reacts with anti-dextran antibodies by forming multivalent immune complexes. Moreover, non-dextran based preparations, such as iron sucrose and ferric carboxymaltose, do not react with anti-dextran antibodies. This assay allows to assess the theoretical possibility of a substance to induce antibody-mediated DIARs. Nevertheless, as this is only one possible mechanism that may cause a hypersensitivity reaction, a broader set of assays will be required to get an understanding of the mechanisms that may lead to intravenous iron-induced hypersensitivity reactions. PMID:27455240

Development and validation of a questionnaire to assess carbohydrate and insulin-dosing knowledge in youth with type 1 diabetes.

PubMed

Koontz, Michaela B; Cuttler, Leona; Palmert, Mark R; O'Riordan, Maryann; Borawski, Elaine A; McConnell, Judy; Kern, Elizabeth O

2010-03-01

OBJECTIVE The American Diabetes Association advocates insulin regimens for youth with type 1 diabetes that involve adjusting insulin dose based on carbohydrate intake and blood glucose level. Implementing these regimens requires knowledge about carbohydrate content of foods and subsequent calculations of insulin dose, skills that may be difficult to gauge in practice. Therefore, we sought to develop and validate a questionnaire, the PedCarbQuiz (PCQ), to assess carbohydrate and insulin-dosing knowledge in youth with type 1 diabetes. RESEARCH DESIGN AND METHODS After development by an expert panel, the PCQ was administered to 75 youth with type 1 diabetes or their parents. Reliability was assessed by Cronbach alpha and split-half testing. To assess validity, scores were correlated with A1C, expert assessments, parent educational level, and complexity of insulin regimen. RESULTS PCQ mean score was 87 +/- 9.7% (range 42-98%). Cronbach alpha was 0.88, and correlation of split halves was 0.59 (P < 0.0001). Higher PCQ scores correlated significantly with lower A1C (r = -0.29, P = 0.01) and expert assessments (r = 0.56, P < 0.001). Scores were significantly higher in parents with college degrees than in those without (P = 0.01) and in participants with more complex insulin regimens (P = 0.003). CONCLUSIONS The PCQ is a novel, easily administered instrument to assess knowledge about carbohydrates and insulin dosing calculations. Initial analyses support the reliability and validity of the PCQ.

Women With Gestational Diabetes Mellitus Randomized to a Higher-Complex Carbohydrate/Low-Fat Diet Manifest Lower Adipose Tissue Insulin Resistance, Inflammation, Glucose, and Free Fatty Acids: A Pilot Study.

PubMed

Hernandez, Teri L; Van Pelt, Rachael E; Anderson, Molly A; Reece, Melanie S; Reynolds, Regina M; de la Houssaye, Becky A; Heerwagen, Margaret; Donahoo, William T; Daniels, Linda J; Chartier-Logan, Catherine; Janssen, Rachel C; Friedman, Jacob E; Barbour, Linda A

2016-01-01

Diet therapy in gestational diabetes mellitus (GDM) has focused on carbohydrate restriction but is poorly substantiated. In this pilot randomized clinical trial, we challenged the conventional low-carbohydrate/higher-fat (LC/CONV) diet, hypothesizing that a higher-complex carbohydrate/lower-fat (CHOICE) diet would improve maternal insulin resistance (IR), adipose tissue (AT) lipolysis, and infant adiposity. At 31 weeks, 12 diet-controlled overweight/obese women with GDM were randomized to an isocaloric LC/CONV (40% carbohydrate/45% fat/15% protein; n = 6) or CHOICE (60%/25%/15%; n = 6) diet. All meals were provided. AT was biopsied at 37 weeks. After ∼7 weeks, fasting glucose (P = 0.03) and free fatty acids (P = 0.06) decreased on CHOICE, whereas fasting glucose increased on LC/CONV (P = 0.03). Insulin suppression of AT lipolysis was improved on CHOICE versus LC/CONV (56 vs. 31%, P = 0.005), consistent with improved IR. AT expression of multiple proinflammatory genes was lower on CHOICE (P < 0.01). Infant adiposity trended lower with CHOICE (10.1 ± 1.4 vs. 12.6 ± 2%, respectively). A CHOICE diet may improve maternal IR and infant adiposity, challenging recommendations for a LC/CONV diet. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Lipidomics of glycosphingolipids.

PubMed

Farwanah, Hany; Kolter, Thomas

2012-02-02

Glycosphingolipids (GSLs) contain one or more sugars that are attached to a sphingolipid moiety, usually to a ceramide, but in rare cases also to a sphingoid base. A large structural heterogeneity results from differences in number, identity, linkage, and anomeric configuration of the carbohydrate residues, and also from structural differences within the hydrophobic part. GSLs form complex cell-type specific patterns, which change with the species, the cellular differentiation state, viral transformation, ontogenesis, and oncogenesis. Although GSL structures can be assigned to only a few series with a common carbohydrate core, their structural variety and the complex pattern are challenges for their elucidation and quantification by mass spectrometric techniques. We present a general overview of the application of lipidomics for GSL determination. This includes analytical procedures and instrumentation together with recent correlations of GSL molecular species with human diseases. Difficulties such as the structural complexity and the lack of standard substances for complex GSLs are discussed.

Lipidomics of Glycosphingolipids

PubMed Central

Farwanah, Hany; Kolter, Thomas

2012-01-01

Glycosphingolipids (GSLs) contain one or more sugars that are attached to a sphingolipid moiety, usually to a ceramide, but in rare cases also to a sphingoid base. A large structural heterogeneity results from differences in number, identity, linkage, and anomeric configuration of the carbohydrate residues, and also from structural differences within the hydrophobic part. GSLs form complex cell-type specific patterns, which change with the species, the cellular differentiation state, viral transformation, ontogenesis, and oncogenesis. Although GSL structures can be assigned to only a few series with a common carbohydrate core, their structural variety and the complex pattern are challenges for their elucidation and quantification by mass spectrometric techniques. We present a general overview of the application of lipidomics for GSL determination. This includes analytical procedures and instrumentation together with recent correlations of GSL molecular species with human diseases. Difficulties such as the structural complexity and the lack of standard substances for complex GSLs are discussed. PMID:24957371

Serum 7 alpha-hydroxy-4-cholesten-3-one concentrations in the evaluation of bile acid malabsorption in patients with diarrhoea: correlation to SeHCAT test.

PubMed Central

Eusufzai, S; Axelson, M; Angelin, B; Einarsson, K

1993-01-01

The synthesis of bile acids is regulated by a homeostatic mechanism in which bile acids returning to the liver from the intestine inhibit their own synthesis. Serum concentrations of the bile acid intermediate 7 alpha-hydroxy-4-cholesten-3-one reflect the rate of bile acid synthesis whereas bile acid malabsorption can be determined by the SeHCAT test. This study was done to evaluate the correlation between the two tests in humans. Twenty eight patients with chronic diarrhoea were included in the study. Fasting serum was collected for the determination of 7 alpha-hydroxy-4-cholesten-3-one, and on the same day the gamma emitting bile acid analogue SeHCAT was given orally and its fractional catabolic rate assessed by repeated external counting over the upper abdomen during the next seven days. There was a highly significant positive correlation between the two tests (Rs = 0.80, p < 0.001). The results show a close relation between intestinal loss and hepatic synthesis of bile acids and imply that analysis of 7 alpha-hydroxy-4-cholesten-3-one in serum should now be evaluated as a possible convenient method for assessing bile acid malabsorption in patients with diarrhoea. PMID:8504974

Defining primary bile acid diarrhea: making the diagnosis and recognizing the disorder.

PubMed

Walters, Julian R F

2010-10-01

Chronic diarrhea due to bile acid malabsorption may be considered as contributing to the diagnosis when it results from secondary causes, such as ileal resection affecting the enterohepatic circulation. However, the primary form (also known as idiopathic bile acid malabsorption) is not well recognized as a common condition and patients are left undiagnosed. Primary bile acid diarrhea can be diagnosed by the nuclear medicine 75Se-homocholyltaurine (SeHCAT) test, although this is unavailable or underutilized in many settings. A systematic review suggests that approximately 30% of patients who would otherwise be diagnosed with diarrhea-predominant irritable bowel syndrome or functional diarrhea have abnormal SeHCAT retention. Serum 7α-hydroxy-4-cholesten-3-one can also be measured to show increased bile acid synthesis. The reasons for the lack of recognition of primary bile acid diarrhea are discussed, and these are compared with the other common cause of malabsorption, celiac disease. The lack of a clear pathophysiological mechanism has been a problem, but recent evidence suggests that impaired feedback control of hepatic bile acid synthesis by the ileal hormone FGF19 results in overproduction of bile acids. The identification of FGF19 as the central mechanism opens up new areas for development in the diagnosis and treatment of primary bile acid diarrhea.

Serum 7 alpha-hydroxy-4-cholesten-3-one concentrations in the evaluation of bile acid malabsorption in patients with diarrhoea: correlation to SeHCAT test.

PubMed

Eusufzai, S; Axelson, M; Angelin, B; Einarsson, K

1993-05-01

The synthesis of bile acids is regulated by a homeostatic mechanism in which bile acids returning to the liver from the intestine inhibit their own synthesis. Serum concentrations of the bile acid intermediate 7 alpha-hydroxy-4-cholesten-3-one reflect the rate of bile acid synthesis whereas bile acid malabsorption can be determined by the SeHCAT test. This study was done to evaluate the correlation between the two tests in humans. Twenty eight patients with chronic diarrhoea were included in the study. Fasting serum was collected for the determination of 7 alpha-hydroxy-4-cholesten-3-one, and on the same day the gamma emitting bile acid analogue SeHCAT was given orally and its fractional catabolic rate assessed by repeated external counting over the upper abdomen during the next seven days. There was a highly significant positive correlation between the two tests (Rs = 0.80, p < 0.001). The results show a close relation between intestinal loss and hepatic synthesis of bile acids and imply that analysis of 7 alpha-hydroxy-4-cholesten-3-one in serum should now be evaluated as a possible convenient method for assessing bile acid malabsorption in patients with diarrhoea.

What tests should you use to assess small intestinal bacterial overgrowth in systemic sclerosis?

PubMed

Braun-Moscovici, Yolanda; Braun, Marius; Khanna, Dinesh; Balbir-Gurman, Alexandra; Furst, Daniel E

2015-01-01

Small intestinal bacterial overgrowth (SIBO) plays a major role in the pathogenesis of malabsorption in SSc patients and is a source of great morbidity and even mortality, in those patients. This manuscript reviews which tests are valid and should be used in SSc when evaluating SIBO. We performed systematic literature searches in PubMed, Embase and the Cochrane library from 1966 up to November 2014 for English language, published articles examining bacterial overgrowth in SSc (e.g. malabsorption tests, breath tests, xylose test, etc). Articles obtained from these searches were reviewed for additional references. The validity of the tests was evaluated according to the OMERACT principles of truth, discrimination and feasibility. From a total of 65 titles, 22 articles were reviewed and 20 were ultimately extracted to examine the validity of tests for GI morphology, bacterial overgrowth and malabsorption in SSc. Only 1 test (hydrogen and methane breath tests) is fully validated. Four tests are partially validated, including jejunal cultures, xylose, lactulose tests, and 72 hours fecal fat test. Only 1 of a total of 5 GI tests of bacterial overgrowth (see above) is fully validated in SSc. For clinical trials, fully validated tests are preferred, although some investigators use partially validated tests (4 tests). Further validation of GI tests in SSc is needed.

Juvenile selective vitamin B₁₂ malabsorption: 50 years after its description-10 years of genetic testing.

PubMed

Gräsbeck, Ralph; Tanner, Stephan M

2011-09-01

Fifty years have passed since the description of juvenile selective malabsorption of cobalamin (Cbl). Quality of life improvements have dramatically reduced the incidence of parasite-induced or nutritional Cbl deficiency. Consequently, inherited defects have become a leading cause of Cbl deficiency in children, which is not always expressed as anemia. Unfortunately, the gold standard for clinical diagnosis, the Schilling test, has increasingly become unavailable, and replacement tests are only in their infancy. Genetic testing is complicated by genetic heterogeneity and differential diagnosis. This review documents the history, research, and advances in genetics that have elucidated the causes of juvenile Cbl malabsorption. Genetic research has unearthed many cases in the past decade, mostly in Europe and North America, often among immigrants from the Middle East or North Africa. Lack of suitable clinical testing potentially leaves many patients inadequately diagnosed. The consequences of suboptimal Cbl levels for neurological development are well documented. By raising awareness, we wish to push for fast track development of better clinical tools and suitable genetic testing. Clinical awareness must include attention to ethnicity, a sensitive topic but effective for fast diagnosis. The treatment with monthly parenteral Cbl for life offers a simple and cost-effective solution once proper diagnosis is made.

Clinical aspects of cobalamin deficiency in elderly patients. Epidemiology, causes, clinical manifestations, and treatment with special focus on oral cobalamin therapy.

PubMed

Andrès, Emmanuel; Vidal-Alaball, Josep; Federici, Laure; Loukili, Noureddine Henoun; Zimmer, Jacques; Kaltenbach, Georges

2007-10-01

The aim of this work was to review the literature concerning cobalamin deficiency in elderly patients. Articles were identified through searches of PubMed-MEDLINE (January 1990 to June 2006), restricted to: English and French language, human subjects, elderly patients (>65 years), clinical trial, review and guidelines. Additional unpublished data from our cohort with cobalamin deficiency at the University Hospital of Strasbourg, France, were also considered. All of the papers and abstracts were reviewed by at least two senior researchers who selected the data used in the study. In elderly people, the main causes of cobalamin deficiency are pernicious anemia and food-cobalamin malabsorption. The recently identified food-cobalamin malabsorption syndrome is a disorder characterized by the inability to release cobalamin from food or from its binding proteins. This syndrome is usually the consequence of atrophic gastritis, related or not to Helicobacter pylori infection, and of the long-term ingestion of antacids and biguanides (in around 60% of the patients). Management of cobalamin deficiency has been well established with the use of cobalamin injections. However, new routes of cobalamin administration (oral and nasal) are currently being developed, especially the use of oral cobalamin therapy to treat food-cobalamin malabsorption.

Osteomalacia in Crohn's disease.

PubMed

Dedeoglu, Meryem; Garip, Yesim; Bodur, Hatice

2014-01-01

Osteomalacia is a metabolic bone disorder characterized by impaired mineralization of the bone matrix. Vitamin D deficiency due to malabsorption syndromes may cause osteomalacia. This is a case of a patient with a 6-year history of seronegative spondyloarthropathy associated with Crohn's disease who was admitted to our outpatient clinic with symptoms of osteomalacia. Osteomalacia is a metabolic bone disease characterized by an impaired mineralization of the bone matrix, frequently caused by disorders in vitamin D or phosphate metabolism. Vitamin D deficiency due to malabsorption syndromes (e.g., Crohn's disease, ulcerative colitis, celiac disease, and jejuno-ileal bypass for obesity) may cause osteomalacia. A 43-year-old male presented with fatigue, low back pain, and morning stiffness. He had a 6-year history of seronegative spondyloarthropathy associated with Crohn's disease. Laboratory findings revealed low serum calcium, low 25-hydroxy vitamin D3, normal phosphorus, elevated parathyroid hormone, and alkaline phosphatase levels. Radiographs revealed grade IV sacroiliitis and Looser zones. He was diagnosed with osteomalacia due to the malabsorption of vitamin D. His symptoms and signs were relieved with supplements of vitamin D and calcium. Osteomalacia should be considered in differential diagnosis when assessing low back pain in the patients with chronic inflammatory bowel disease. Vitamin D deficiency should be treated with vitamin D supplementation in patients with Crohn's disease to prevent osteomalacia.

A short review of malabsorption and anemia

PubMed Central

Fernández-Bañares, Fernando; Monzón, Helena; Forné, Montserrat

2009-01-01

Anemia is a frequent finding in most diseases which cause malabsorption. The most frequent etiology is the combination of iron and vitamin B12 deficiency. Celiac disease is frequently diagnosed in patients referred for evaluation of iron deficiency anemia (IDA), being reported in 1.8%-14.6% of patients. Therefore, duodenal biopsies should be taken during endoscopy if no obvious cause of iron deficiency (ID) can be found. Cobalamin deficiency occurs frequently among elderly patients, but it is often unrecognized because the clinical manifestations are subtle; it is caused primarily by food-cobalamin malabsorption and pernicious anemia. The classic treatment of cobalamin deficiency has been parenteral administration of the vitamin. Recent data suggest that alternative routes of cobalamin administration (oral and nasal) may be useful in some cases. Anemia is a frequent complication of gastrectomy, and has been often described after bariatric surgery. It has been shown that banding procedures which maintain digestive continuity with the antrum and duodenum are associated with low rates of ID. Helicobacter pylori (H pylori) infection may be considered as a risk factor for IDA, mainly in groups with high demands for iron, such as some children and adolescents. Further controlled trials are needed before making solid recommendations about H pylori eradication in these cases. PMID:19787827

Synthesis and emulsifying properties of carbohydrate fatty acid esters produced from Agave tequilana fructans by enzymatic acylation.

PubMed

Casas-Godoy, Leticia; Arrizon, Javier; Arrieta-Baez, Daniel; Plou, Francisco J; Sandoval, Georgina

2016-08-01

Carbohydrate fatty acid esters are non-ionic surfactants with a broad spectrum of applications. These molecules are generally synthesized using short carbohydrates or linear fructans; however in this research carbohydrate fatty acid esters were produced for the first time with branched fructans from Agave tequilana. Using immobilized lipases we successfully acylated A. tequilana fructans with vinyl laurate, obtaining products with different degrees of polymerization (DP). Lipozyme 435 was the most efficient lipase to catalyze the transesterification reaction. HPLC and ESI-MS analysis proved the presence of a mixture of acylated products as a result of the chemical complexity of fructans in the A. tequilana. The ESI-MS spectra showed a molecular mass shift between 183 and 366g/mol for fructooligosaccharides with a DP lower than 6, which indicated the presence of Agave fructans that had been mono- and diacylated with lauric acid. The carbohydrate fatty acid esters (CFAE) obtained showed good emulsifying properties in W/O emulsions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantum dots assisted laser desorption/ionization mass spectrometric detection of carbohydrates: qualitative and quantitative analysis.

PubMed

Bibi, Aisha; Ju, Huangxian

2016-04-01

A quantum dots (QDs) assisted laser desorption/ionization mass spectrometric (QDA-LDI-MS) strategy was proposed for qualitative and quantitative analysis of a series of carbohydrates. The adsorption of carbohydrates on the modified surface of different QDs as the matrices depended mainly on the formation of hydrogen bonding, which led to higher MS intensity than those with conventional organic matrix. The effects of QDs concentration and sample preparation method were explored for improving the selective ionization process and the detection sensitivity. The proposed approach offered a new dimension to the application of QDs as matrices for MALDI-MS research of carbohydrates. It could be used for quantitative measurement of glucose concentration in human serum with good performance. The QDs served as a matrix showed the advantages of low background, higher sensitivity, convenient sample preparation and excellent stability under vacuum. The QDs assisted LDI-MS approach has promising application to the analysis of carbohydrates in complex biological samples. Copyright © 2016 John Wiley & Sons, Ltd.

Deciphering the glycosaminoglycan code with the help of microarrays.

PubMed

de Paz, Jose L; Seeberger, Peter H

2008-07-01

Carbohydrate microarrays have become a powerful tool to elucidate the biological role of complex sugars. Microarrays are particularly useful for the study of glycosaminoglycans (GAGs), a key class of carbohydrates. The high-throughput chip format enables rapid screening of large numbers of potential GAG sequences produced via a complex biosynthesis while consuming very little sample. Here, we briefly highlight the most recent advances involving GAG microarrays built with synthetic or naturally derived oligosaccharides. These chips are powerful tools for characterizing GAG-protein interactions and determining structure-activity relationships for specific sequences. Thereby, they contribute to decoding the information contained in specific GAG sequences.

New modulated design, docking and synthesis of carbohydrate-conjugate heterobimetallic CuII-SnIV complex as potential topoisomerase II inhibitor: in vitro DNA binding, cleavage and cytotoxicity against human cancer cell lines.

PubMed

Tabassum, Sartaj; Afzal, Mohd; Arjmand, Farukh

2014-03-03

New carbohydrate-conjugate heterobimetallic complexes [C₂₂H₅₀N₆O₁₃CuSnCl₂] (3) and [C₂₂H₅₈N₆O₁₇NiSnCl₂] (4) were synthesized from their monometallic analogs [C₂₂H₅₂N₆O₁₃Cu] (1) and [C₂₂H₆₀N₆O₁₇Ni] (2) containing N-glycoside ligand (L). In vitro DNA binding studies of L and complexes (1-4) with CT DNA were carried out by employing various biophysical and molecular docking techniques which revealed that heterobimetallic complex 3 strongly binds to DNA in comparison to 4, monometallic complexes (1 and 2) and the free ligand. Complex 3 cleaves pBR322 DNA via hydrolytic pathway (confirmed by T4 DNA ligase assay) and inhibited Topo-II activity in a dose-dependent manner. Furthermore, complex 3 was docked into the ATPase domain of human-Topo-II in order to probe the possible mechanism of inhibition. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Studies of the prevalence and significance of radiolabeled bile acid malabsorption in a group of patients with idiopathic chronic diarrhea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schiller, L.R.; Hogan, R.B.; Morawski, S.G.

1987-01-01

We studied radiolabeled fecal bile acid excretion in 11 normal subjects and 17 patients with idiopathic chronic diarrhea for three major purposes: to establish normal values for this test in the presence of increased stool volumes (induced in normal subjects by ingestion of poorly absorbable solutions); to test for bile acid malabsorption in the patients and to correlate this with an independent test of ileal function, the Schilling test; and to compare the results of the bile acid excretion test with the subsequent effect of a bile acid binding agent (cholestyramine) on stool weight. In normal subjects fecal excretion ofmore » the radiolabel was increased with increasing stool volumes. As a group, patients with idiopathic chronic diarrhea excreted radiolabeled bile acid more rapidly than normal subjects with induced diarrhea (t1/2 56 +/- 8 vs. 236 +/- 60 h, respectively, p less than 0.005). There was a statistically significant positive correlation between t1/2 of radiolabeled bile acid and Schilling test results in these patients. Although 14 of 17 patients absorbed labeled taurocholic acid less well than any of the normal subjects with comparable volumes of induced diarrhea, cholestyramine had no statistically significant effect on stool weight in the patient group, and in none of the patients was stool weight reduced to within the normal range. In summary, most patients with idiopathic chronic diarrhea have bile acid malabsorption (as measured by fecal excretion of labeled bile acid), but they do not respond to cholestyramine therapy with a significant reduction in stool weight. Although the significance of these findings was not clearly established, the most likely interpretation is that bile acid malabsorption is a manifestation of an underlying intestinal motility or absorptive defect rather than the primary cause of diarrhea.« less

A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation

NASA Astrophysics Data System (ADS)

Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

2013-07-01

A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes. Electronic supplementary information (ESI) available: Experimental details; characterization of probes; the influence of electrolyte pH; probe concentration and glucose concentration on the electrode ECL effect. See DOI: 10.1039/c3nr01598j

D-lactic acidosis in humans: systematic literature review.

PubMed

Bianchetti, Davide G A M; Amelio, Giacomo S; Lava, Sebastiano A G; Bianchetti, Mario G; Simonetti, Giacomo D; Agostoni, Carlo; Fossali, Emilio F; Milani, Gregorio P

2018-04-01

D-lactic acidosis is an uncommon and challenging form of metabolic acidosis that may develop in short bowel syndrome. It has been documented exclusively in case reports and small case series. We performed a review of the literature in the National Library of Medicine and Excerpta Medica databases. We identified 84 original reports published between 1977 and 2017. D-lactic acidosis was observed in 98 individuals ranging in age from 7 months to 86 years with short bowel syndrome. The clinical presentation included Kussmaul breathing, confusion, slurred speech, and gait disturbances. Furthermore, among 99 consecutive patients with short bowel syndrome, 21 reported having episodes with symptoms consistent with D-lactic acidosis. In addition, D-lactic acid might also contribute to acidosis in diabetes mellitus. Finally, abnormally high D-lactic acid was documented after administration or ingestion of large amounts of propylene glycol, as paraneoplastic phenomenon and perhaps also in a so far poorly characterized inherited inborn error of metabolism. In humans with short bowel syndrome (or carbohydrate malabsorption), D-lactic acidosis is likely rather common and under-recognized. This condition should be included in the differential diagnosis of unexplained high-gap metabolic acidosis where the anion causing the acidosis is not known. Furthermore, diabetic acidosis might be caused by accumulation of both ketone bodies and D-lactic acid. Finally, there are endogenous sources of D-lactic acid in subjects with propylene glycol intoxication.

CAZyme discovery and design for sweet dreams.

PubMed

André, Isabelle; Potocki-Véronèse, Gabrielle; Barbe, Sophie; Moulis, Claire; Remaud-Siméon, Magali

2014-04-01

Development of synthetic routes to complex carbohydrates and glyco-conjugates is often hampered by the lack of enzymes with requisite properties or specificities. Indeed, assembly or degradation of carbohydrates requires carbohydrate-active enzymes (CAZymes) able to act on a vast range of glycosidic monomers, oligomers or polymers in a regio-specific or stereo-specific manner in order to produce the desired structure. Sequence-based analyses allow finding the most original enzymes. Novel screening methods have emerged that enable a more efficient exploitation of the CAZyme diversity found in the microbial world or generated by protein engineering. Computational biology methods also play a prominent role in the success of CAZyme design. Such progress allows circumventing current limitations of carbohydrate synthesis and opens new opportunities related to the synthetic biology field. Copyright © 2014 Elsevier Ltd. All rights reserved.

Expanded potential of seleno-carbohydrates as a molecular tool for X-ray structural determination of a carbohydrate-protein complex with single/multi-wavelength anomalous dispersion phasing.

PubMed

Suzuki, Tatsuya; Makyio, Hisayoshi; Ando, Hiromune; Komura, Naoko; Menjo, Masanori; Yamada, Yusuke; Imamura, Akihiro; Ishida, Hideharu; Wakatsuki, Soichi; Kato, Ryuichi; Kiso, Makoto

2014-04-01

Seleno-lactoses have been successfully synthesized as candidates for mimicking carbohydrate ligands for human galectin-9 N-terminal carbohydrate recognition domain (NCRD). Selenium was introduced into the mono- or di-saccharides using p-methylselenobenzoic anhydride (Tol2Se) as a novel selenating reagent. The TolSe-substituted monosaccharides were converted into selenoglycosyl donors or acceptors, which were reacted with coupling partners to afford seleno-lactoses. The seleno-lactoses were converted to the target compounds. The structure of human galectin-9 NCRD co-crystallized with 6-MeSe-lactose was determined with single/multi-wavelength anomalous dispersion (SAD/MAD) phasing and was similar to that of the co-crystal with natural lactose. Copyright © 2014 Elsevier Ltd. All rights reserved.

SusG: A Unique Cell-Membrane-Associated [alpha]-Amylase from a Prominent Human Gut Symbiont Targets Complex Starch Molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koropatkin, Nicole M.; Smith, Thomas J.

SusG is an {alpha}-amylase and part of a large protein complex on the outer surface of the bacterial cell and plays a major role in carbohydrate acquisition by the animal gut microbiota. Presented here, the atomic structure of SusG has an unusual extended, bilobed structure composed of amylase at one end and an unprecedented internal carbohydrate-binding motif at the other. Structural studies further demonstrate that the carbohydrate-binding motif binds maltooligosaccharide distal to, and on the opposite side of, the amylase catalytic site. SusG has an additional starch-binding site on the amylase domain immediately adjacent to the active cleft. Mutagenesis analysismore » demonstrates that these two additional starch-binding sites appear to play a role in catabolism of insoluble starch. However, elimination of these sites has only a limited effect, suggesting that they may have a more important role in product exchange with other Sus components.« less

Portrait of an Enzyme, a Complete Structural Analysis of a Multimodular beta-N-Acetylglucosaminidase from Clostridium perfringens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ficko-Blean, E.; Gregg, K; Adams, J

2009-01-01

Common features of the extracellular carbohydrate-active virulence factors involved in host-pathogen interactions are their large sizes and modular complexities. This has made them recalcitrant to structural analysis, and therefore our understanding of the significance of modularity in these important proteins is lagging. Clostridium perfringens is a prevalent human pathogen that harbors a wide array of large, extracellular carbohydrate-active enzymes and is an excellent and relevant model system to approach this problem. Here we describe the complete structure of C. perfringens GH84C (NagJ), a 1001-amino acid multimodular homolog of the C. perfringens ?-toxin, which was determined using a combination of smallmore » angle x-ray scattering and x-ray crystallography. The resulting structure reveals unprecedented insight into how catalysis, carbohydrate-specific adherence, and the formation of molecular complexes with other enzymes via an ultra-tight protein-protein interaction are spatially coordinated in an enzyme involved in a host-pathogen interaction.« less

Hydroxypropyl cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimers as effective carbohydrate-solubilizers for polycyclic aromatic hydrocarbons.

PubMed

Choi, Jae Min; Jeong, Daham; Piao, Jinglan; Kim, Kyoungtea; Nguyen, Andrew Bao Loc; Kwon, Nak-Jung; Lee, Mi-Kyung; Lee, Im Soon; Yu, Jae-Hyuk; Jung, Seunho

2015-01-12

The removal of polycyclic aromatic hydrocarbons by soil washing using water is extremely difficult due to their intrinsic hydrophobic nature. In this study, the effective aqueous solubility enhancements of seven polycyclic aromatic hydrocarbons by chemically modified hydroxypropyl rhizobial cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimer have been investigated for the first time. In the presence of hydroxypropyl cyclic β-(1 → 2)-D-glucans, the solubility of benzo[a]pyrene is increased up to 38 fold of its native solubility. The solubility of pyrene and phenanthrene dramatically increased up to 160 and 359. Coronene, chrysene, perylene, and fluoranthene also show an increase of 11, 23, 23, and 97 fold, respectively, of enhanced solubility by complexation with synthetic epichlorohydrin β-cyclodextrin dimer. The physicochemical properties of the complex are characterized by Fourier-transform infrared spectra and differential scanning calorimetry. Utilizing a scanning electron microscopy, the morphological structures of native benzo[a]pyrene, pyrene, phenanthrene, coronene, chrysene, perylene, fluoranthene and their complex with novel carbohydrate-solubilizers are studied. These results elucidate that polycyclic aromatic hydrocarbons are able to form an efficient complex with hydroxypropyl cyclic β-(1 → 2)-D-glucans and β-cyclodextrin dimer, suggesting the potential usage of chemically modified novel carbohydrate-solubilizers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Genomic Reconstruction of Carbohydrate Utilization Capacities in Microbial-Mat Derived Consortia

PubMed Central

Leyn, Semen A.; Maezato, Yukari; Romine, Margaret F.; Rodionov, Dmitry A.

2017-01-01

Two nearly identical unicyanobacterial consortia (UCC) were previously isolated from benthic microbial mats that occur in a heliothermal saline lake in northern Washington State. Carbohydrates are a primary source of carbon and energy for most heterotrophic bacteria. Since CO2 is the only carbon source provided, the cyanobacterium must provide a source of carbon to the heterotrophs. Available genomic sequences for all members of the UCC provide opportunity to investigate the metabolic routes of carbon transfer between autotroph and heterotrophs. Here, we applied a subsystem-based comparative genomics approach to reconstruct carbohydrate utilization pathways and identify glycohydrolytic enzymes, carbohydrate transporters and pathway-specific transcriptional regulators in 17 heterotrophic members of the UCC. The reconstructed metabolic pathways include 800 genes, near a one-fourth of which encode enzymes, transporters and regulators with newly assigned metabolic functions resulting in discovery of novel functional variants of carbohydrate utilization pathways. The in silico analysis revealed the utilization capabilities for 40 carbohydrates and their derivatives. Two Halomonas species demonstrated the largest number of sugar catabolic pathways. Trehalose, sucrose, maltose, glucose, and beta-glucosides are the most commonly utilized saccharides in this community. Reconstructed regulons for global regulators HexR and CceR include central carbohydrate metabolism genes in the members of Gammaproteobacteria and Alphaproteobacteria, respectively. Genomics analyses were supplemented by experimental characterization of metabolic phenotypes in four isolates derived from the consortia. Measurements of isolate growth on the defined medium supplied with individual carbohydrates confirmed most of the predicted catabolic phenotypes. Not all consortia members use carbohydrates and only a few use complex polysaccharides suggesting a hierarchical carbon flow from cyanobacteria to each heterotroph. In summary, the genomics-based identification of carbohydrate utilization capabilities provides a basis for future experimental studies of carbon flow in UCC. PMID:28751880

Carbohydrates for improving the cognitive performance of independent-living older adults with normal cognition or mild cognitive impairment.

PubMed

Ooi, Cheow Peng; Loke, Seng Cheong; Yassin, Zaitun; Hamid, Tengku-Aizan

2011-04-13

Mild cognitive impairment (MCI) is an intermediate state between normal cognition and dementia in which daily function is largely intact. This condition may present an opportunity for research into the prevention of dementia. Carbohydrate is an essential and easily accessible macronutrient which influences cognitive performance. A better understanding of carbohydrate-driven cognitive changes in normal cognition and mild cognitive impairment may suggest ways to prevent or reduce cognitive decline. To assess the effectiveness of carbohydrates in improving cognitive function in older adults. We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialized Register on 22 June 2010 using the terms: carbohydrates OR carbohydrate OR monosaccharides OR disaccharides OR oligosaccharides OR polysaccharides OR CARBS. ALOIS contains records from all major healthcare databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many trial databases and grey literature sources. All randomised controlled trials (RCT) that have examined the efficacy of any form of carbohydrates in normal cognition and MCI. One review author selected and retrieved relevant articles for further assessment. The remaining authors independently assessed whether any of the retrieved trials should be included. Disagreements were resolved by discussion.  There is no suitable RCT of any form of carbohydrates involving independent-living older adults with normal cognition or mild cognitive impairment. There are no suitable RCTs on which to base any recommendations about the use of any form of carbohydrate for enhancing cognitive performance in older adults with normal cognition or mild cognitive impairment. More studies of many different carbohydrates are needed to tease out complex nutritional issues and further evaluate memory improvement.

Theoretical analysis of a palladium-based one-dimensional metallo-dielectric photonic band gap structure for applications to H2 sensors

NASA Astrophysics Data System (ADS)

Vincenti, Maria Antonietta; Trevisi, Simona; De Sario, Marco; Petruzzelli, Vincenzo; D'Orazio, Antonella; Prudenzano, Francesco; Cioffi, Nicola; de Ceglia, Domenico; Scalora, Michael

2008-03-01

In this paper we report a numerical study of a palladium-based metallo-dielectric photonic band gap structure for the purpose of detecting H2. In particular, and as an example, we will explore applications to the diagnosis of lactose malabsorption, more commonly known as lactose intolerance condition. This pathology occurs as a result of an incomplete absorption or digestion of different substances, causing an increased spontaneous emission of H2 in human breath. Palladium is considered in order to exploit its well known ability to absorb hydrogen spontaneously. The proposed structure is particularly able to detect the lactose malabsorption level of the patient with relatively high sensitivity and rapidity.

[Chonic diarrhea and malabsorption due to common variable immunodeficiency, gastrectomy and giardiasis infection: a difficult nutritional management].

PubMed

Domínguez-López, M E; González-molero, I; Ramírez-Plaza, C P; Soriguer, F; Olveira, G

2011-01-01

Gastric cancer is a frequent cause of cancer-related mortality in the world. Surgery is the only potentially curative therapy, although the adverse effects of surgery are common and considerable. Common variable immunodeficiency is in many cases cause of gastrointestinal system problems such as chronic diarrhea caused by infestation with giardia lamblia, nodular lymphoid hiperplasia ad loss of villi leading frequently to malapsortion and malnutrition. Nutritional deficiencies due to malapsorption (postgastrectomy and secondary to loss of villi, giardiasis and common variable inmunodeficiency) are common. We present the case of a patient with gastric cancer who underwent a gastrectomy with common variable hipogammaglobulinemia and chronic infestation by giardia lamblia, with serious diarrhea resistant to treatment and malabsorption.

Late vitamin K deficiency bleeding leading to a diagnosis of cystic fibrosis: a case report.

PubMed

Ngo, B; Van Pelt, K; Labarque, V; Van De Casseye, W; Penders, J

2011-01-01

Vitamin K deficiency bleeding (VKDB) in infants still occurs despite worldwide use of prophylaxis. Clinical manifestations can be dramatic with over 50% of patients presenting with intracranial haemorrhage and a mortality rate of 20% in late vitamin K deficiency bleeding. Special attention should be given to infants with a high risk profile (preterm, breast feeding, cholestasis, malabsorption). A tentative diagnosis can be made observing quick normalisation of some easy-to-perform haemostatic parameters (PT, aPTT) after administration of vitamin K. Nowadays, VKDB can still be the first clinical sign of diseases causing malabsorption of fat-soluble vitamins. In this case report, VKDB led to the diagnosis of cystic fibrosis, the most common fatal autosomal recessive disease among Caucasian people.

Crystallization and preliminary X-ray diffraction analysis of mouse galectin-4 N-terminal carbohydrate recognition domain in complex with lactose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krejčiříková, Veronika; Fábry, Milan; Marková, Vladimíra

2008-07-01

Mouse galectin-4 carbohydrate binding domain was overexpressed in E. coli and crystallized in the presence of lactose. The crystals belong to tetragonal space group P42{sub 1}2 and diffraction data were collected to 2.1 Å resolution. Galectin-4 is thought to play a role in the process of tumour conversion of cells of the alimentary tract and the breast tissue; however, its exact function remains unknown. With the aim of elucidating the structural basis of mouse galectin-4 (mGal-4) binding specificity, we have undertaken X-ray analysis of the N-terminal domain, CRD1, of mGal-4 in complex with lactose (the basic building block of knownmore » galectin-4 carbohydrate ligands). Crystals of CRD1 in complex with lactose were obtained using vapour-diffusion techniques. The crystals belong to tetragonal space group P42{sub 1}2 with unit-cell parameters a = 91.1, b = 91.16, c = 57.10 Å and preliminary X-ray diffraction data were collected to 3.2 Å resolution. An optimized crystallization procedure and cryocooling protocol allowed us to extend resolution to 2.1 Å. Structure refinement is currently under way; the initial electron-density maps clearly show non-protein electron density in the vicinity of the carbohydrate binding site, indicating the presence of one lactose molecule. The structure will help to improve understanding of the binding specificity and function of the potential colon cancer marker galectin-4.« less

Drug-nutrient interactions in enteral feeding: a primary care focus.

PubMed

Varella, L; Jones, E; Meguid, M M

1997-06-01

Drug and nutrient interactions are complex and can take many forms, including malabsorption of either the drug or the nutrient component. Some drugs can stimulate or suppress appetite, whereas others can cause nausea and vomiting resulting in inadequate nutritional intake. Absorption of drugs is a complex process that can be affected by the physical characteristics of the gastrointestinal tract (GIT) as well. Depending on the physical properties of a drug, it may be absorbed in a limited area of the GIT or more diffusely along much of the entire length. Many diseases and conditions are also known to affect the GIT either directly or indirectly. Dietary factors also need to be considered when the "food" is an enteral formula. The widespread use of enteral tubes requires that consideration be given to patients receiving both enteral feedings and medication concurrently. The location of a tube in the gastrointestinal tract, as well as the problems involved in crushing and administering solid dosage forms, creates a unique set of problems.

Celiac Disease: Role of the Epithelial Barrier.

PubMed

Schumann, Michael; Siegmund, Britta; Schulzke, Jörg D; Fromm, Michael

2017-03-01

In celiac disease (CD) a T-cell-mediated response to gluten is mounted in genetically predisposed individuals, resulting in a malabsorptive enteropathy histologically highlighted by villous atrophy and crypt hyperplasia. Recent data point to the epithelial layer as an under-rated hot spot in celiac pathophysiology to date. This overview summarizes current functional and genetic evidence on the role of the epithelial barrier in CD, consisting of the cell membranes and the apical junctional complex comprising sealing as well as ion and water channel-forming tight junction proteins and the adherens junction. Moreover, the underlying mechanisms are discussed, including apoptosis of intestinal epithelial cells, biology of intestinal stem cells, alterations in the apical junctional complex, transcytotic uptake of gluten peptides, and possible implications of a defective epithelial polarity. Current research is directed toward new treatment options for CD that are alternatives or complementary therapeutics to a gluten-free diet. Thus, strategies to target an altered epithelial barrier therapeutically also are discussed.

Structural Basis for Carbohydrate Recognition and Anti-inflammatory Modulation by Gastrointestinal Nematode Parasite Toxascaris leonina Galectin*

PubMed Central

Hwang, Eun Young; Jeong, Mi Suk; Park, Sang Kyun; Ha, Sung Chul; Yu, Hak Sun; Jang, Se Bok

2016-01-01

Toxascaris leonina galectin (Tl-gal) is a galectin-9 homologue protein isolated from an adult worm of the canine gastrointestinal nematode parasite, and Tl-gal-vaccinated challenge can inhibit inflammation in inflammatory bowel disease-induced mice. We determined the first X-ray structures of full-length Tl-gal complexes with carbohydrates (lactose, N-acetyllactosamine, lacto-N-tetraose, sialyllactose, and glucose). Bonds were formed on concave surfaces of both carbohydrate recognition domains (CRDs) in Tl-gal. All binding sites were found in the HXXXR and WGXEER motifs. Charged Arg61/Arg196 and Glu80/Glu215 on the conserved motif of Tl-gal N-terminal CRD and C-terminal CRD are critical amino acids for recognizing carbohydrate binding, and the residues can affect protein folding and structure. The polar amino acids His, Asn, and Trp are also important residues for the interaction with carbohydrates through hydrogen bonding. Hemagglutination activities of Tl-gal were inhibited by interactions with carbohydrates and mutations. We found that the mutation of Tl-gal (E80A/E215A) at the carbohydrate binding region induced protein aggregation and could be caused in many diseases. The short linker region between the N-terminal and C-terminal CRDs of Tl-gal was very stable against proteolysis and maintained its biological activity. This structural information is expected to elucidate the carbohydrate recognition mechanism of Tl-gal and improve our understanding of anti-inflammatory mediators and modulators of immune response. PMID:27742836

Development and Validation of a Questionnaire to Assess Carbohydrate and Insulin-Dosing Knowledge in Youth With Type 1 Diabetes

PubMed Central

Koontz, Michaela B.; Cuttler, Leona; Palmert, Mark R.; O'Riordan, MaryAnn; Borawski, Elaine A.; McConnell, Judy; Kern, Elizabeth O.

2010-01-01

OBJECTIVE The American Diabetes Association advocates insulin regimens for youth with type 1 diabetes that involve adjusting insulin dose based on carbohydrate intake and blood glucose level. Implementing these regimens requires knowledge about carbohydrate content of foods and subsequent calculations of insulin dose, skills that may be difficult to gauge in practice. Therefore, we sought to develop and validate a questionnaire, the PedCarbQuiz (PCQ), to assess carbohydrate and insulin-dosing knowledge in youth with type 1 diabetes. RESEARCH DESIGN AND METHODS After development by an expert panel, the PCQ was administered to 75 youth with type 1 diabetes or their parents. Reliability was assessed by Cronbach α and split-half testing. To assess validity, scores were correlated with A1C, expert assessments, parent educational level, and complexity of insulin regimen. RESULTS PCQ mean score was 87 ± 9.7% (range 42–98%). Cronbach α was 0.88, and correlation of split halves was 0.59 (P < 0.0001). Higher PCQ scores correlated significantly with lower A1C (r = −0.29, P = 0.01) and expert assessments (r = 0.56, P < 0.001). Scores were significantly higher in parents with college degrees than in those without (P = 0.01) and in participants with more complex insulin regimens (P = 0.003). CONCLUSIONS The PCQ is a novel, easily administered instrument to assess knowledge about carbohydrates and insulin dosing calculations. Initial analyses support the reliability and validity of the PCQ. PMID:20007940

Lectins from Mycelia of Basidiomycetes

PubMed Central

Nikitina, Valentina E.; Loshchinina, Ekaterina A.; Vetchinkina, Elena P.

2017-01-01

Lectins are proteins of a nonimmunoglobulin nature that are capable of specific recognition of and reversible binding to the carbohydrate moieties of complex carbohydrates, without altering the covalent structure of any of the recognized glycosyl ligands. They have a broad range of biological activities important for the functioning of the cell and the whole organism and, owing to the high specificity of reversible binding to carbohydrates, are valuable tools used widely in biology and medicine. Lectins can be produced by many living organisms, including basidiomycetes. Whereas lectins from the fruit bodies of basidiomycetes have been studied sufficiently well, mycelial lectins remain relatively unexplored. Here, we review and comparatively analyze what is currently known about lectins isolated from the vegetative mycelium of macrobasidiomycetes, including their localization, properties, and carbohydrate specificities. Particular attention is given to the physiological role of mycelial lectins in fungal growth and development. PMID:28640205

The Importance of Ligand Conformational Energies in Carbohydrate Docking: Sorting the Wheat from the Chaff

PubMed Central

Nivedha, Anita K.; Makeneni, Spandana; Foley, B. Lachele; Tessier, Matthew B.; Woods, Robert J.

2014-01-01

Docking algorithms that aim to be applicable to a broad range of ligands suffer reduced accuracy because they are unable to incorporate ligand-specific conformational energies. Here, we develop internal energy functions, Carbohydrate Intrinsic (CHI), to account for the rotational preferences of the glycosidic torsion angles in carbohydrates. The relative energies predicted by the CHI energy functions mirror the conformational distributions of glycosidic linkages determined from a survey of oligosaccharide-protein complexes in the Protein Data Bank. Addition of CHI energies to the standard docking scores in Autodock 3, 4.2, and Vina consistently improves pose ranking of oligosaccharides docked to a set of anti-carbohydrate antibodies. The CHI energy functions are also independent of docking algorithm, and with minor modifications, may be incorporated into both theoretical modeling methods, and experimental NMR or X-ray structure refinement programs. PMID:24375430

Separation of carbohydrates using hydrophilic interaction liquid chromatography.

PubMed

Fu, Qing; Liang, Tu; Li, Zhenyu; Xu, Xiaoyong; Ke, Yanxiong; Jin, Yu; Liang, Xinmiao

2013-09-20

A strategy was developed to rapidly evaluate chromatographic properties of hydrophilic interaction chromatography (HILIC) columns for separating carbohydrates. Seven HILIC columns (Silica, Diol, TSK Amide-80, XAmide, Click Maltose, Click β-CD, and Click TE-Cys columns) were evaluated by using three monosaccharide and seven disaccharides as probes. The influence of column temperature on the peak shape and tautomerization of carbohydrates, as well as column selectivity were investigated. The influence of surface charge property on the retention was also studied by using glucose, glucuronic acid, and glucosamine, which indicated that buffer salt concentration and pH value in mobile phase was necessary to control the ionic interactions between ionic carbohydrates and HILIC columns. According to evaluation results, the XAmide column was selected as an example to establish experimental schemes for separation of complex mixtures of oligosaccharide. Copyright © 2013 Elsevier Ltd. All rights reserved.

Protein-like fully reversible tetramerisation and super-association of an aminocellulose

NASA Astrophysics Data System (ADS)

Nikolajski, Melanie; Adams, Gary G.; Gillis, Richard B.; Besong, David Tabot; Rowe, Arthur J.; Heinze, Thomas; Harding, Stephen E.

2014-01-01

Unusual protein-like, partially reversible associative behaviour has recently been observed in solutions of the water soluble carbohydrates known as 6-deoxy-6-(ω-aminoalkyl)aminocelluloses, which produce controllable self-assembling films for enzyme immobilisation and other biotechnological applications. Now, for the first time, we have found a fully reversible self-association (tetramerisation) within this family of polysaccharides. Remarkably these carbohydrate tetramers are then seen to associate further in a regular way into supra-molecular complexes. Fully reversible oligomerisation has been hitherto completely unknown for carbohydrates and instead resembles in some respects the assembly of polypeptides and proteins like haemoglobin and its sickle cell mutation. Our traditional perceptions as to what might be considered ``protein-like'' and what might be considered as ``carbohydrate-like'' behaviour may need to be rendered more flexible, at least as far as interaction phenomena are concerned.

Diabetes Cannot Be Controlled, But It Can Be Managed

DTIC Science & Technology

2017-05-05

promise that my glucose would be fine. Please keep in mind that this was before we understood insulin to carbohydrate ratios. I refused to eat anything...characterizes diabetes management as a " complex , demanding, and often confusing set of self-care directives" (p. 626). Furthermore, current notions of...lowering your pump basal rate while exercising could prevent hypoglycemia or carbohydrate counting instead of fixed dosing for meals may allow blood sugar to

Carbohydrate-protein interactions investigated on plastic chips statically coated with hydrophobically modified hydroxyethylcellulose.

PubMed

Dang, Fuquan; Maeda, Eiki; Osafune, Tomo; Nakajima, Kazuki; Kakehi, Kazuaki; Ishikawa, Mitsuru; Baba, Yoshinobu

2009-12-15

We developed a novel method for rapid screening of carbohydrate-protein interactions using poly(methyl methacrylate) (PMMA) channels statically coated with hydrophobically modified hydroxyethylcellulose (HM-HEC). We found that a self-assembled monolayer (SAM) of HM-HEC on a PMMA surface intact by water allows rapid and reproducible separations of glycan samples using a 20 mM phosphate without HM-HEC. The underlying mechanism for dynamic and static coatings on the PMMA surface is discussed. Simultaneous analysis of the molecular interaction between a complex mixture of carbohydrates from alpha1-acid glycoprotein and proteins has been successfully achieved in PMMA channels statically coated with a SAM of HM-HEC.

[Definite of nutritional status in patients with metabolic syndrome with the use of modern methods of nutrimetabolomica].

PubMed

Viskunova, A A; Kaganov, B S; Sharafetdinov, Kh Kh; Plotnikova, O A; Pogozheva, A V; Vorozhko, I V

2010-01-01

A comprehensive assessment of nutritional status in 73 patients with metabolic syndrome was assessed. The consumption food pattern of the majority of examined patients have had increased energy intake with excessive fat consumption inadequate intake of complex carbohydrates. In patients with type 2 diabetes inadequate compensation of carbohydrate and lipid metabolism was marked. When assessing body composition method bioelectrical impedance analysis increased content of adipose tissue was revealed are positively correlated with insulin and tumor necrosis factor-alpha. According to indirect calorimetry, increase in the level of resting energy expenditure, reducing the rate of oxidation of fat, increase the rate of oxidation of protein and carbohydrates was noted.

Energetics of lectin-carbohydrate binding. A microcalorimetric investigation of concanavalin A-oligomannoside complexation.

PubMed

Williams, B A; Chervenak, M C; Toone, E J

1992-11-15

Despite years of study, a comprehensive picture of the binding of the lectin from Canavalia ensiformis, concanavalin A, to carbohydrates remains elusive. We report here studies on the interaction of concanavalin A with methyl 3,6-di-O-(alpha-D-mannopyranosyl)-alpha-D-mannopyranoside, the minimum carbohydrate epitope that completely fills the oligosaccharide binding site, and the two conceptual disaccharide "halves" of the trisaccharide, methyl 3-O-(alpha-D-mannopyranosyl)-alpha-D-mannopyranoside and methyl 6-O-(alpha-D-mannopyranosyl)-alpha-D-mannopyranoside, using titration microcalorimetry. In all cases the interaction of protein and carbohydrate is enthalpically driven, with an unfavorable entropic contribution. The choice of concentration scales has an important impact on both the magnitude and, in some cases, the sign of the entropic component of the free energy of binding. The thermodynamic data suggest binding of the two disaccharides may take place in distinct sites, as opposed to binding in a single high affinity site. In contrast to carbohydrate-antibody binding, delta Cp values were small and negative, pointing to possible differences in the motifs used by the two groups of proteins to bind carbohydrates. The thermodynamic data are interpreted in terms of solvent reorganization. Cooperativity during lectin-carbohydrate binding was also investigated. Significant cooperativity was observed only for binding of the trisaccharide, and gave a Hill plot coefficient of 1.3 for dimeric protein.

Carbohydrate phenotyping of human and animal milk glycoproteins.

PubMed

Gustafsson, Anki; Kacskovics, Imre; Breimer, Michael E; Hammarström, Lennart; Holgersson, Jan

2005-03-01

Breast-milk has a well-known anti-microbial effect, which is in part due to the many different carbohydrate structures expressed. This renders it a position as a potential therapeutic for treatment of infection by different pathogens, thus avoiding the drawbacks of many antibiotics. The plethora of carbohydrate epitopes in breast-milk is known to differ between species, with human milk expressing the most complex one. We have investigated the expression of protein-bound carbohydrate epitopes in milk from man, cow, goat, sheep, pig, horse, dromedary and rabbit. Proteins were separated by SDS-PAGE and the presence of carbohydrate epitopes on milk proteins were analysed by Western blotting using different lectins and carbohydrate-specific antibodies. We show that ABH, Lewis (Le)x, sialyl-Lex, Lea, sialyl-Lea and Leb carbohydrate epitopes are expressed mainly on man, pig and horse milk proteins. The blood group precursor structure H type 1 is expressed in all species investigated, while only pig, dromedary and rabbit milk proteins carry H type 2 epitopes. These epitopes are receptors for Helicobacter pylori (Leb and sialyl-Lex), enteropathogenic (H type 1, Lea and Lex) and enterotoxic Escherichia coli (heat-stable toxin; H type 1 and 2), and Campylobacter jejuni (H type 2). Thus, milk from these animals or their genetically modified descendants could have a therapeutic effect by inhibiting pathogen colonization and infection.

pdb-care (PDB carbohydrate residue check): a program to support annotation of complex carbohydrate structures in PDB files.

PubMed

Lütteke, Thomas; von der Lieth, Claus-W

2004-06-04

Carbohydrates are involved in a variety of fundamental biological processes and pathological situations. They therefore have a large pharmaceutical and diagnostic potential. Knowledge of the 3D structure of glycans is a prerequisite for a complete understanding of their biological functions. The largest source of biomolecular 3D structures is the Protein Data Bank. However, about 30% of all 1663 PDB entries (version September 2003) containing carbohydrates comprise errors in glycan description. Unfortunately, no software is currently available which aligns the 3D information with the reported assignments. It is the aim of this work to fill this gap. The pdb-care program http://www.glycosciences.de/tools/pdb-care/ is able to identify and assign carbohydrate structures using only atom types and their 3D atom coordinates given in PDB-files. Looking up a translation table where systematic names and the respective PDB residue codes are listed, both assignments are compared and inconsistencies are reported. Additionally, the reliability of reported and calculated connectivities for molecules listed within the HETATOM records is checked and unusual values are reported. Frequent use of pdb-care will help to improve the quality of carbohydrate data contained in the PDB. Automatic assignment of carbohydrate structures contained in PDB entries will enable the cross-linking of glycobiology resources with genomic and proteomic data collections.

Chemical changes and carbon isotope variations in a cross-section of a large Miocene gymnospermous log

USGS Publications Warehouse

Bates, A.L.; Spiker, E. C.

1992-01-01

The cross-sectional radius of a 3-m (diam.) brown coal gymnospermous log of Miocene age, previously analyzed for carbohydrate and lignin methoxyl content by solid-state 13C nuclear magnetic resonance spectroscopy, was examined using stable carbon isotopic ratios in order to determine if the isotopic composition could be related to chemical changes or to radial position. This study found a possible relationship between ??13C-values and radial position; however, these changes cannot be linked to carbohydrate content and are probably attributable to changing growth conditions during the lifetime of the tree. An apparent linear relationship between the changes in carbohydrate content after sodium para-periodate treatment and corresponding changes in the ??13C-values indicates constant isotopic fractionation between lignin and carbohydrates along the cross-sectional radius. This result indicates that diagenesis has not produced any significant change in the lignin-carbohydrate carbon isotopic fractionation or, alternatively, that diagenesis has erased any fractionation pattern that once existed. A sample of fresh wood from another gymnospermous species was analyzed by the same methods and found to have lignin-carbohydrate carbon isotopic fractionation significantly different from that of the Miocene log section samples, suggesting that differences may be species-related or that the complex mixture of carbohydrates in the fresh wood was isotopically different from that of the degraded wood, and the whole Miocene log was uniformly altered. ?? 1992.

An Approach to Management of Gas in the Elderly

PubMed Central

Hogan, David B.

1989-01-01

In this article I shall review the physiology, clinical manifestations, and management of gaseousness in the elderly. While not an infrequent complaint, little scientific study has been done of the causes or management of this problem. The regualtion of bowel gas is surprisingly complex. When problems occur, it is usually either because of excessive swallowing of air or because of the intraluminal producation of gas by colonic bacteria. Patients present with excessive belching, abdominal pain and bloating, or excessive passage of flatus. Management is determined, in the main, by the results of the history and physical examination. Medications are usually not indicated. Once a malabsorptive state is ruled out, the mainstay of management usually involves either alterations in the patient's diet or avoidance of aerophagia. PMID:21249002

Bile acid malabsorption after intestinal bypass surgery for obesity. A comparison between jejunoileal shunt and biliointestinal bypass.

PubMed

Nyhlin, H; Brydon, G; Danielsson, A; Eriksson, F

1990-01-01

Seventeen patients were operated on with intestinal shunts for morbid obesity, in eight a biliointestinal bypass (BI) was constructed and in the rest a conventional jejunoileal (JI)-shunt. The reduction in weight was similar in both groups, and so was malabsorption of fat, but the BI-group had significantly less bowel motions with less watery diarrhoea. Bile acid malabsorption was measured both chemically by estimating the total amount of faecal bile acids excreted, as well as indirectly by using a 75Se-labelled synthetic bile acid (SeHCAT). Both techniques revealed a substantial loss of bile acid after both types of operation, but patients with BI bypass surgery had significantly lower elimination time of the bile acid than those with JI-shunts. There was a significant negative correlation between SeHCAT retention and total faecal bile acids. However, some patients with low SeHCAT retention had normal or even reduced output of faecal bile acids. Estimation of faecal bile acids may display false negative results when the bile acid pool is decreased. The SeHCAT-test seems to be a better technique for measuring bile acid losses. The study suggests that BI bypass surgery for obesity seems to be advantageous over the JI shunt in reducing the postoperative loss of bile acids and choleretic diarrhoea, without influencing the weight loss.

Abnormal oral glucose tolerance and glucose malabsorption after vagotomy and pyloroplasty. A tracer method for measuring glucose absorption rates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radziuk, J.; Bondy, D.C.

1982-11-01

The mechanisms underlying the abnormal glucose tolerance in patients who had undergone vagotomy and pyloroplasty were investigated by measuring the rates of absorption of ingested glucose and the clearance rate of glucose using tracer methods. These methods are based on labeling a 100-g oral glucose load with (1-/sup 14/C)glucose and measuring glucose clearance using plasma levels of infused (3-/sup 3/H)glucose. The rate of appearance of both ingested and total glucose is then calculated continuously using a two-compartment model of glucose kinetics. It was found that about 30% of the ingested glucose (100 g) failed to appear in the systemic circulation.more » That this was due to malabsorption was confirmed using breath-hydrogen analysis. The absorption period is short (101 +/- 11 min) compared with normal values but the clearance of glucose is identical to that in control subjects, and it peaks 132 +/- 7 min after glucose loading. The peak plasma insulin values were more than four times higher in patients than in normal subjects, and this may afford an explanation of rates of glucose clearance that are inappropriate for the short absorption period. The combination of glucose malabsorption and this clearance pattern could yield the hypoglycemia that may be observed in patients after gastric surgery.« less

Contribution of Colonic Fermentation and Fecal Water Toxicity to the Pathophysiology of Lactose-Intolerance

PubMed Central

Windey, Karen; Houben, Els; Deroover, Lise; Verbeke, Kristin

2015-01-01

Whether or not abdominal symptoms occur in subjects with small intestinal lactose malabsorption might depend on differences in colonic fermentation. To evaluate this hypothesis, we collected fecal samples from subjects with lactose malabsorption with abdominal complaints (LM-IT, n = 11) and without abdominal complaints (LM-T, n = 8) and subjects with normal lactose digestion (NLD, n = 15). Lactose malabsorption was diagnosed using a 13C-lactose breath test. Colonic fermentation was characterized in fecal samples at baseline and after incubation with lactose for 3 h, 6 h and 24 h through a metabolomics approach using gas chromatography-mass spectrometry (GC-MS). Fecal water cytotoxicity was analyzed using a colorimetric assay. Fecal water cytotoxicity was not different between the three groups (Kruskall-Wallis p = 0.164). Cluster analysis of the metabolite patterns revealed separate clusters for NLD, LM-T and LM-IT samples at baseline and after 24 h incubation with lactose. Levels of 5-methyl-2-furancarboxaldehyde were significantly higher in LM-IT and LM-T compared to NLD whereas those of an unidentified aldehyde were significantly higher in LM-IT compared to LM-T and NLD. Incubation with lactose increased short chain fatty acid (SCFA) concentrations more in LM-IT and LM-T compared to NLD. In conclusion, fermentation patterns were clearly different in NLD, LM-IT and LM-T, but not related to differences in fecal water cytotoxicity. PMID:26371036

Contribution of Colonic Fermentation and Fecal Water Toxicity to the Pathophysiology of Lactose-Intolerance.

PubMed

Windey, Karen; Houben, Els; Deroover, Lise; Verbeke, Kristin

2015-09-08

Whether or not abdominal symptoms occur in subjects with small intestinal lactose malabsorption might depend on differences in colonic fermentation. To evaluate this hypothesis, we collected fecal samples from subjects with lactose malabsorption with abdominal complaints (LM-IT, n = 11) and without abdominal complaints (LM-T, n = 8) and subjects with normal lactose digestion (NLD, n = 15). Lactose malabsorption was diagnosed using a (13)C-lactose breath test. Colonic fermentation was characterized in fecal samples at baseline and after incubation with lactose for 3 h, 6 h and 24 h through a metabolomics approach using gas chromatography-mass spectrometry (GC-MS). Fecal water cytotoxicity was analyzed using a colorimetric assay. Fecal water cytotoxicity was not different between the three groups (Kruskall-Wallis p = 0.164). Cluster analysis of the metabolite patterns revealed separate clusters for NLD, LM-T and LM-IT samples at baseline and after 24 h incubation with lactose. Levels of 5-methyl-2-furancarboxaldehyde were significantly higher in LM-IT and LM-T compared to NLD whereas those of an unidentified aldehyde were significantly higher in LM-IT compared to LM-T and NLD. Incubation with lactose increased short chain fatty acid (SCFA) concentrations more in LM-IT and LM-T compared to NLD. In conclusion, fermentation patterns were clearly different in NLD, LM-IT and LM-T, but not related to differences in fecal water cytotoxicity.

An exon 53 frameshift mutation in CUBN abrogates cubam function and causes Imerslund-Gräsbeck syndrome in dogs

PubMed Central

Fyfe, John C.; Hemker, Shelby L.; Venta, Patrick J.; Fitzgerald, Caitlin A.; Outerbridge, Catherine A.; Myers, Sherry L.; Giger, Urs

2013-01-01

Cobalamin malabsorption accompanied by selective proteinuria is an autosomal recessive disorder known as Imerslund-Gräsbeck syndrome in humans and was previously described in dogs due to amnionless (AMN) mutations. The resultant vitamin B12 deficiency causes dyshematopoiesis, lethargy, failure to thrive, and life-threatening metabolic disruption in the juvenile period. We studied 3 kindreds of border collies with cobalamin malabsorption and mapped the disease locus in affected dogs to a 2.9 Mb region of homozygosity on canine chromosome 2. The region included CUBN, the locus encoding cubilin, a peripheral membrane protein that in concert with AMN forms the functional intrinsic factor-cobalamin receptor expressed in ileum and a multi-ligand receptor in renal proximal tubules. Cobalamin malabsorption and proteinuria comprising CUBN ligands were demonstrated by radiolabeled cobalamin uptake studies and SDS-PAGE, respectively. CUBN mRNA and protein expression were reduced ~10 fold and ~20 fold, respectively, in both ileum and kidney of affected dogs. DNA sequencing demonstrated a single base deletion in exon 53 predicting a translational frameshift and early termination codon likely triggering nonsense mediated mRNA decay. The mutant allele segregated with disease in the border collie kindred. The border collie disorder indicates that a CUBN mutation far C-terminal from the intrinsic factor-cobalamin binding site can abrogate receptor expression and cause Imerslund-Gräsbeck syndrome. PMID:23746554

Two Cases of Mistaken Polyuria and Nephrocalcinosis in Infants with Glucose-Galactose Malabsorption: A Possible Role of 1,25(OH)2D3
.

PubMed

Fiscaletti, Melissa; Lebel, Marie-Jeanne; Alos, Nathalie; Benoit, Geneviève; Jantchou, Prévost

2017-01-01

Glucose-galactose malabsorption (GGM) is a rare and potentially fatal disorder. The autosomal recessive mutation of the SGLT1 gene interferes with the active glucose transport in the gut resulting in osmotic diarrhea and failure to thrive (FTT). Two nonrelated infants with GGM are presented as well as a novel mutation in SGLT1. The first case consulted for FTT and presented with hypercalcemia and hypercalciuria. His mother had self-medicated with high doses of vitamin D. The second case consulted for macroscopic hematuria, and presented with dehydration and secondary acute kidney injury. In both cases, the profuse diarrhea, initially mistaken for polyuria, promptly resolved after the introduction of glucose-galactose-free milk. Investigations showed bilateral nephrocalcinosis and high levels of 1,25(OH)2D3 in both patients. We hypothesize that the upregulation of epithelial calcium channels (TRPV6) and 1,25(OH)2D3 are possible factors involved in the pathophysiology of nephrocalcinosis sometimes seen in GGM. Furthermore, a novel intronic SGLT1 mutation (c.207+2dup) is described. These 2 cases demonstrate that a malabsorption disorder such as GGM can present with nephrocalcinosis and/or hypercalcemia, with increased 1,25(OH)2D3 levels in infants. Prompt recognition of GGM is sometimes difficult but crucial.
. © 2017 S. Karger AG, Basel.

Quick fix or long-term cure? Pros and cons of bariatric surgery

PubMed Central

Madura, James A.

2012-01-01

The past decade has seen an enormous increase in the number of bariatric, or weight loss, operations performed. This trend is likely to continue, mirroring the epidemic of obesity around the world and its rising prevalence among children. Bariatric surgery is considered by many to be the most effective treatment for obesity in terms of maintenance of long-term weight loss and improvement in obesity-related comorbid conditions. Although overly simplified, the primary mechanisms of the surgical interventions currently utilized to treat obesity are the creation of a restrictive or malabsorptive bowel anatomy. Operations based on these mechanisms include the laparoscopic adjustable gastric band and laparoscopic vertical sleeve gastrectomy (considered primarily restrictive operations), the laparoscopic biliopancreatic diversion with or without a duodenal switch (primarily malabsorptive operation), and the laparoscopic Roux-en-Y gastric bypass (considered a combination restrictive and selective malabsorptive procedure). Each operation has pros and cons. Important considerations, for the patient and surgeon alike, in the decision to proceed with bariatric surgery include the technical aspects of the operation, postoperative complications including long-term nutritional problems, magnitude of initial and sustained weight loss desired, and correction of obesity-related comorbidities. Herein, the pros and cons of the contemporary laparoscopic bariatric operations are reviewed and ongoing controversies relating to bariatric surgery are discussed: appropriate patient selection, appropriate operation selection for an individual patient, surgeon selection, and how to measure success after surgery. PMID:23091563

Determination of water-extractable nonstructural carbohydrates, including inulin, in grass samples with high-performance anion exchange chromatography and pulsed amperometric detection.

PubMed

Raessler, Michael; Wissuwa, Bianka; Breul, Alexander; Unger, Wolfgang; Grimm, Torsten

2008-09-10

The exact and reliable determination of carbohydrates in plant samples of different origin is of great importance with respect to plant physiology. Additionally, the identification and quantification of carbohydrates are necessary for the evaluation of the impact of these compounds on the biogeochemistry of carbon. To attain this goal, it is necessary to analyze a great number of samples with both high sensitivity and selectivity within a limited time frame. This paper presents a rugged and easy method that allows the isocratic chromatographic determination of 12 carbohydrates and sugar alcohols from one sample within 30 min. The method was successfully applied to a variety of plant materials with particular emphasis on perennial ryegrass samples of the species Lolium perenne. The method was easily extended to the analysis of the polysaccharide inulin after its acidic hydrolysis into the corresponding monomers without the need for substantial change of chromatographic conditions or even the use of enzymes. It therefore offers a fundamental advantage for the analysis of the complex mixture of nonstructural carbohydrates often found in plant samples.

Malabsorption

MedlinePlus

... that of other children of similar age and gender. This is called failure to thrive . The child ... deficiency Secretin stimulation test Small bowel biopsy Stool culture or culture of small intestine aspirate Stool fat ...

The national cholesterol education program diet vs a diet lower in carbohydrates and higher in protein and monounsaturated fat: a randomized trial.

PubMed

Aude, Y Wady; Agatston, Arthur S; Lopez-Jimenez, Francisco; Lieberman, Eric H; Marie Almon; Hansen, Melinda; Rojas, Gerardo; Lamas, Gervasio A; Hennekens, Charles H

2004-10-25

In the United States, obesity is a major clinical and public health problem causing diabetes, dyslipidemia, and hypertension, as well as increasing cardiovascular and total mortality. Dietary restrictions of calories and saturated fat are beneficial. However, it remains unclear whether replacement of saturated fat with carbohydrates (as in the US National Cholesterol Education Program [NCEP] diet) or protein and monounsaturated fat (as in our isocaloric modified low-carbohydrate [MLC] diet, which is lower in total carbohydrates but higher in protein, monounsaturated fat, and complex carbohydrates) is optimal. We randomized 60 participants (29 women and 31 men) to the NCEP or the MLC diet and evaluated them every 2 weeks for 12 weeks. They were aged 28 to 71 years (mean age, 44 years in the NCEP and 46 years in the MLC group). A total of 36% of participants from the NCEP group and 35% from the MLC group had a body mass index (calculated as weight in kilograms divided by the square of height in meters) greater than 27. The primary end point was weight loss, and secondary end points were blood lipid levels and waist-to-hip ratio. Weight loss was significantly greater in the MLC (13.6 lb) than in the NCEP group (7.5 lb), a difference of 6.1 lb (P = .02). There were no significant differences between the groups for total, low density, and high-density lipoprotein cholesterol, triglycerides, or the proportion of small, dense low-density lipoprotein particles. There were significantly favorable changes in all lipid levels within the MLC but not within the NCEP group. Waist-to-hip ratio was not significantly reduced between the groups (P = .27), but it significantly decreased within the MLC group (P = .009). Compared with the NCEP diet, the MLC diet, which is lower in total carbohydrates but higher in complex carbohydrates, protein, and monounsaturated fat, caused significantly greater weight loss over 12 weeks. There were no significant differences between the groups in blood lipid levels, but favorable changes were observed within the MLC diet group.

Dietary fats do not contribute to hyperlipidemia in children and adolescents with type 1 diabetes.

PubMed

Wiltshire, Esko J; Hirte, Craig; Couper, Jennifer J

2003-05-01

To determine the relative influence of diet, metabolic control, and familial factors on lipids in children with type 1 diabetes and control subjects. We assessed fasting serum cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, lipoprotein(a), apolipoprotein (apo)-A1, and apoB in 79 children and adolescents with type 1 diabetes and 61 age- and sex-matched control subjects, together with dietary intakes using a quantitative food frequency questionnaire. Total cholesterol, LDL cholesterol, apoB, HDL cholesterol, and apoA1 were significantly higher in children with diabetes. Children with diabetes had higher percentage energy intake from complex carbohydrates (P = 0.001) and fiber intake (P = 0.02), and they had lower intake of refined sugar (P < 0.001) and percentage energy from saturated fat (P = 0.045) than control subjects. Total cholesterol (beta = 0.43, P < 0.001), LDL cholesterol (beta = 0.4, P < 0.001), and apoB (beta = 0.32, P = 0.006) correlated independently with HbA(1c) but not dietary intake. HDL cholesterol (beta = 0.24, P = 0.05) and apoA1 (beta = 0.32, P = 0.004) correlated independently with HbA(1c), and HDL cholesterol (beta = -0.34, P = 0.009) correlated with percentage energy intake from complex carbohydrates. Triglycerides correlated independently with percentage energy intake from complex carbohydrates (beta = 0.33, P = 0.01) and insulin dose (beta = 0.26, P = 0.04). Subjects with diabetes and elevated LDL (>3.35 mmol/l, >130 mg/dl), for whom dietary therapy would be recommended, had significantly higher HbA(1c) (P = 0.007), but they had higher intake of complex carbohydrates than subjects with LDL cholesterol <3.35 mmol/l. Lipid abnormalities remain common in children and adolescents with type 1 diabetes who adhere to current dietary recommendations, and they relate to metabolic control but not dietary intake.

Effects of free sugars on blood pressure and lipids: a systematic review and meta-analysis of nutritional isoenergetic intervention trials.

PubMed

Fattore, Elena; Botta, Francesca; Agostoni, Carlo; Bosetti, Cristina

2017-01-01

Sugar has been suggested as a central risk factor in the development of noncommunicable diseases. We assessed the evidence of the effects of free sugars compared with complex carbohydrates on selected cardiovascular disease risk factors. We conducted a systematic review and meta-analysis of intervention trials to compare diets that provide a given amount of energy from free sugars with a control diet that provides the same amount of energy from complex carbohydrates. The primary outcomes were: blood pressure, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triacylglycerols, apolipoproteins A-I and B, or very low-density lipoprotein cholesterol. Body weight was also recorded but was not a primary outcome of the studies. In all, 28 studies involving 510 volunteers were included. When free sugars were substituted for complex carbohydrates, no significant increases were detected in systolic or diastolic blood pressure, and no heterogeneity was observed. There were significant increases in HDL cholesterol, LDL cholesterol, and triacylglycerols, although for LDL cholesterol and triacylglycerols there was significant heterogeneity between studies and evidence of publication bias. After adjustment for missing studies, these increases lost significance. Subgroup analyses showed that diets providing the largest total energy intake and energy exchange enhanced the effect of free sugars on total and LDL cholesterol and triacylglycerols. The increase of triacylglycerols was no longer significant when studies with the highest risk of bias were excluded or when only randomized trials were considered. Free sugars had no effect on body weight. In short- or moderate-term isoenergetic intervention trials, the substitution of free sugars for complex carbohydrates had no effect on blood pressure or body weight and an unclear effect on blood lipid profile. Further independent trials are required to assess whether the reduction of free sugars improves cardiovascular disease risk factors. This review was registered at http://www.crd.york.ac.uk/prospero as CRD42016042930. © 2017 American Society for Nutrition.

Histo-blood group carbohydrates as facilitators for infection by Helicobacter pylori.

PubMed

Brandão de Mattos, Cinara Cássia; de Mattos, Luiz Carlos

2017-09-01

Helicobacter pylori infect millions of people around the world. It occupies a niche in the human gastrointestinal tract characterized by high expression of a repertoire of carbohydrates. ABO and Lewis histo-blood group systems are controlled by genes coding for functional glycosyltransferases which synthesize great diversity of related fucosylated carbohydrate in different tissues, including gastrointestinal mucosa, and exocrine secretions. The structural diversity of histo-blood group carbohydrates is highly complex and depends on epistatic interactions among gene-encoding glycosyltransferases. The histo-blood group glycosyltransferases act in the glycosylation of proteins and lipids in the human gastrointestinal tract allowing the expression of a variety of potential receptors in which H. pylori can adhere. These oligosaccharide molecules are part of the gastrointestinal repertoire of carbohydrates which act as potential receptors for microorganisms, including H. pylori. This Gram-negative bacillus is one of the main causes of the gastrointestinal diseases such as chronic active gastritis, peptic ulcer, and cancer of stomach. Previous reports showed that some H. pylori strains use carbohydrates as receptors to adhere to the gastric and duodenal mucosa. Since some histo-blood group carbohydrates are highly expressed in one but not in others histo-blood group phenotypes it has pointed out that quantitative differences among them influence the susceptibility to diseases caused by H. pylori. Additionally, some experiments using animal model are helping us to understand how this bacillus explore histo-blood group carbohydrates as potential receptors, offering possibility to explore new strategies of management of infection, disease treatment, and prevention. This text highlights the importance of structural diversity of ABO and Lewis histo-blood group carbohydrates as facilitators for H. pylori infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Radiolabeled Peptide Scaffolds for PET/SPECT - Optical in Vivo Imaging of Carbohydrate-Lectin Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deutscher, Susan

2014-09-30

The objective of this research is to develop phage display-selected peptides into radio- and fluoresecently- labeled scaffolds for the multimodal imaging of carbohydrate-lectin interactions. While numerous protein and receptor systems are being explored for the development of targeted imaging agents, the targeting and analysis of carbohydrate-lectin complexes in vivo remains relatively unexplored. Antibodies, nanoparticles, and peptides are being developed that target carbohydrate-lectin complexes in living systems. However, antibodies and nanoparticles often suffer from slow clearance and toxicity problems. Peptides are attractive alternative vehicles for the specific delivery of radionuclides or fluorophores to sites of interest in vivo, although, because ofmore » their size, uptake and retention may be less than antibodies. We have selected high affinity peptides that bind a specific carbohydrate-lectin complex involved in cell-cell adhesion and cross-linking using bacteriophage (phage) display technologies (1,2). These peptides have allowed us to probe the role of these antigens in cell adhesion. Fluorescent versions of the peptides have been developed for optical imaging and radiolabeled versions have been used in single photon emission computed tomography (SPECT) and positron emission tomography (PET) in vivo imaging (3-6). A benefit in employing the radiolabeled peptides in SPECT and PET is that these imaging modalities are widely used in living systems and offer deep tissue sensitivity. Radiolabeled peptides, however, often exhibit poor stability and high kidney uptake in vivo. Conversely, optical imaging is sensitive and offers good spatial resolution, but is not useful for deep tissue penetration and is semi-quantitative. Thus, multimodality imaging that relies on the strengths of both radio- and optical- imaging is a current focus for development of new in vivo imaging agents. We propose a novel means to improve the efficacy of radiolabeled and fluorescently labeled peptides, including our lectin/carbohydrate- targeting peptides, by displaying the targeting epitopes on small ~29 amino acid cyclic plant protein scaffolds known as cyclotides. Cyclotides are extremely stable molecules with long serum half-lives and low kidney uptake (7). More than one copy of the peptide can be engineered into the cyclotide loops, thus increasing the avidity of the peptide construct for its target.« less

[Diarrhea with malabsorption and exudative enteropathy caused by intestinal myeloid involvement in a patient with myeloproliferative syndrome].

PubMed

Molas, G; Ponsot, P; Solal-Celigny, P; Amar, M; Paolaggi, J A; Potet, F; Henin, D

1992-01-01

A 41-year-old woman with a myelodysplastic syndrome complained of diarrhea with malabsorption and protein-losing enteropathy after splenectomy. No cause was found and various therapeutic regimens were not effective. Pathological examination of biopsies from stomach, small intestine, and large bowel showed infiltrations interpreted as inflammatory on routine technics. Blast cell infiltration was found on electron microscopy. Treatment by citarabine induced normalization of leukocytosis, and diarrhea disappeared. Six months after the onset of illness, she developed acute myeloblastic leukemia and died of infectious pneumonia. Blastic infiltration of the lamina propria could be responsible for the determinism of symptoms, because of the lack of another etiology, the intensity of the blastic infiltration and the effect of cytotoxic therapy, even in the absence of new biopsies.

[Surgical treatment for morbid obesity].

PubMed

Pablo-Pantoja, Juan

2004-01-01

Obesity has become a serious public health problem in Mexico and at present time and the best treatment for morbid obesity is surgery. Recently, laparoscopic techniques have become available for treatment of this disease. Surgery is indicated in patients with body mass index (BMI) >35 kg/m2, and with comorbidity. Restrictive procedures such as adjustable gastric banding and vertical banded gastroplasty have less incidence of postoperative complications; however efficacy in terms of weight loss is not as good as in malabsorptive or mixed procedures. Patients who undergo these malabsorptive or mixed procedures (gastric bypass, biliopancreatic diversion) are at higher risk for postoperative complication. To date, gastric bypass is considered the care standard for treatment of morbid obesity; it confers an approximately 70% of body-weight-loss excess, with an acceptable rate of complications.

Postdeployment User Guide: Transition Workbook for Combat Veterans

DTIC Science & Technology

2009-12-07

including pork, and especially fatty cuts (eg, prime, chuck). 4. CARBOHYDRATES • Eat whole grains , fresh fruits , and vegetables that are high in fiber...periods of time without eating. Have a healthy snack between meals. 4. Increase complex carbohydrates (eg, whole grains ) and starches in your diet ...back to baseline at some point or having a particularly bad stretch does not mean you have to start again. It just means you may need to add some

Carbohydrate binding sites in a pancreatic alpha-amylase-substrate complex, derived from X-ray structure analysis at 2.1 A resolution.

PubMed Central

Qian, M.; Haser, R.; Payan, F.

1995-01-01

The X-ray structure analysis of a crystal of pig pancreatic alpha-amylase (PPA, EC 3.2.1.1.) that was soaked with the substrate maltopentaose showed electron density corresponding to two independent carbohydrate recognition sites on the surface of the molecule. Both binding sites are distinct from the active site described in detail in our previous high-resolution study of a complex between PPA and a carbohydrate inhibitor (Qian M, Buisson G, Duée E, Haser H, Payan F, 1994, Biochemistry 33:6284-6294). One of the binding sites previously identified in a 5-A-resolution electron density map, lies at a distance of 20 A from the active site cleft and can accommodate two glucose units. The second affinity site for sugar units is located close to the calcium binding site. The crystal structure of the maltopentaose complex was refined at 2.1 A resolution, to an R-factor of 17.5%, with an RMS deviation in bond distances of 0.007 A. The model includes all 496 residues of the enzyme, 1 calcium ion, 1 chloride ion, 425 water molecules, and 3 bound sugar rings. The binding sites are characterized and described in detail. The present complex structure provides the evidence of an increased stability of the structure upon interaction with the substrate and allows identification of an N-terminal pyrrolidonecarboxylic acid in PPA. PMID:7613472

Carbohydrates and activity of natural and recombinant tissue factor.

PubMed

Krudysz-Amblo, Jolanta; Jennings, Mark E; Mann, Kenneth G; Butenas, Saulius

2010-01-29

The effect of glycosylation on tissue factor (TF) activity was evaluated, and site-specific glycosylation of full-length recombinant TF (rTF) and that of natural TF from human placenta (pTF) were studied by liquid chromatography-tandem mass spectrometry. The amidolytic activity of the TF.factor VIIa (FVIIa) complex toward a fluorogenic substrate showed that the catalytic efficiency (V(max)) of the complex increased in the order rTF(1-243) (Escherichia coli) < rTF(1-263) (Sf9 insect cells) < pTF for the glycosylated and deglycosylated forms. Substrate hydrolysis was unaltered by deglycosylation. In FXase, the K(m) of FX for rTF(1-263)-FVIIa remained unchanged after deglycosylation, whereas the k(cat) decreased slightly. A pronounced decrease, 4-fold, in k(cat) was observed for pTF.FVIIa upon deglycosylation, whereas the K(m) was minimally altered. The parameters of FX activation by both rTF(1-263D)-FVIIa and pTF(D)-FVIIa were identical and similar to those for rTF(1-243)-FVIIa. In conclusion, carbohydrates significantly influence the activity of TF proteins. Carbohydrate analysis revealed glycosylation on asparagines 11, 124, and 137 in both rTF(1-263) and pTF. The carbohydrates of rTF(1-263) contain high mannose, hybrid, and fucosylated glycans. Natural pTF contains no high mannose glycans but is modified with hybrid, highly fucosylated, and sialylated sugars.

Compositional evaluation of selected agro-industrial wastes as valuable sources for the recovery of complex carbohydrates.

PubMed

Vojvodić, Aleksandra; Komes, Draženka; Vovk, Irena; Belščak-Cvitanović, Ana; Bušić, Arijana

2016-11-01

Re-utilization of various agro-industrial wastes is of growing importance from many aspects. Considering the variety and complexity of such materials, compositional data and compliant methodology is still undergoing many updates and improvements. Present study evaluated sugar beet pulp (SBP), walnut shell (WS), cocoa bean husk (CBH), onion peel (OP) and pea pods (PP) as potentially valuable materials for carbohydrate recovery. Macrocomponent analyses revealed carbohydrate fraction as the most abundant, dominating in dietary fibres. Upon complete acid hydrolysis of sample alcohol insoluble residues, developed procedures of high performance thin-layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) coupled with 3-methyl-1-phenyl-2-pyrazolin-5-one pre-column derivatization (PMP-derivatization) were used for carbohydrate monomeric composition determination. HPTLC exhibited good qualitative features useful for multi-sample rapid analysis, while HPLC superior separation and quantification characteristics. Distinctive monomeric patterns were obtained among samples. OP, SBP and CBH, due to the high galacturonic acid content (20.81%, 13.96% and 6.90% dry matter basis, respectively), may be regarded as pectin sources, while WS and PP as materials abundant in xylan-rich hemicellulose (total xylan content 15.53%, 9.63% dry matter basis, respectively). Present study provides new and valuable compositional data for different plant residual materials and a reference for the application of established methodology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structural Basis for Carbohydrate Recognition and Anti-inflammatory Modulation by Gastrointestinal Nematode Parasite Toxascaris leonina Galectin.

PubMed

Hwang, Eun Young; Jeong, Mi Suk; Park, Sang Kyun; Ha, Sung Chul; Yu, Hak Sun; Jang, Se Bok

2016-12-02

Toxascaris leonina galectin (Tl-gal) is a galectin-9 homologue protein isolated from an adult worm of the canine gastrointestinal nematode parasite, and Tl-gal-vaccinated challenge can inhibit inflammation in inflammatory bowel disease-induced mice. We determined the first X-ray structures of full-length Tl-gal complexes with carbohydrates (lactose, N-acetyllactosamine, lacto-N-tetraose, sialyllactose, and glucose). Bonds were formed on concave surfaces of both carbohydrate recognition domains (CRDs) in Tl-gal. All binding sites were found in the HXXXR and WGXEER motifs. Charged Arg 61 /Arg 196 and Glu 80 /Glu 215 on the conserved motif of Tl-gal N-terminal CRD and C-terminal CRD are critical amino acids for recognizing carbohydrate binding, and the residues can affect protein folding and structure. The polar amino acids His, Asn, and Trp are also important residues for the interaction with carbohydrates through hydrogen bonding. Hemagglutination activities of Tl-gal were inhibited by interactions with carbohydrates and mutations. We found that the mutation of Tl-gal (E80A/E215A) at the carbohydrate binding region induced protein aggregation and could be caused in many diseases. The short linker region between the N-terminal and C-terminal CRDs of Tl-gal was very stable against proteolysis and maintained its biological activity. This structural information is expected to elucidate the carbohydrate recognition mechanism of Tl-gal and improve our understanding of anti-inflammatory mediators and modulators of immune response. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Facilitating the enzymatic saccharification of pulped bamboo residues by degrading the remained xylan and lignin-carbohydrates complexes.

PubMed

Huang, Caoxing; He, Juan; Li, Xin; Min, Douyong; Yong, Qiang

2015-09-01

Kraft pulping was performed on bamboo residues and its impact on the chemical compositions and the enzymatic digestibility of the samples were investigated. To improve the digestibility of sample by degrading the xylan and lignin-carbohydrates complexes (LCCs), xylanase and α-L-arabinofuranosidase (AF) were supplemented with cellulase. The results showed more carbohydrates were remained in the samples pulped with low effective alkali (EA) charge, compared to conventional kraft pulping. When 120 IU/g xylanase and 15 IU/g AF were supplemented with 20 FPU/g cellulase, the xylan degradation yield of the sample pulped with 12% EA charge increased from 68.20% to 88.35%, resulting in an increased enzymatic saccharification efficiency from 58.98% to 83.23%. The amount of LCCs in this sample decreased from 8.63/100C9 to 2.99/100C9 after saccharification with these enzymes. The results indicated that degrading the remained xylan and LCCs in the pulp could improve its enzymatic digestibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

A photo-cleavable biotin affinity tag for the facile release of a photo-crosslinked carbohydrate-binding protein.

PubMed

Chang, Tsung-Che; Adak, Avijit K; Lin, Ting-Wei; Li, Pei-Jhen; Chen, Yi-Ju; Lai, Chain-Hui; Liang, Chien-Fu; Chen, Yu-Ju; Lin, Chun-Cheng

2016-03-15

The use of photo-crosslinking glycoprobes represents a powerful strategy for the covalent capture of labile protein complexes and allows detailed characterization of carbohydrate-mediated interactions. The selective release of target proteins from solid support is a key step in functional proteomics. We envisaged that light activation can be exploited for releasing labeled protein in a dual photo-affinity probe-based strategy. To investigate this possibility, we designed a trifunctional, galactose-based, multivalent glycoprobe for affinity labeling of carbohydrate-binding proteins. The resulting covalent protein-probe adduct is attached to a photo-cleavable biotin affinity tag; the biotin moiety enables specific presentation of the conjugate on streptavidin-coated beads, and the photolabile linker allows the release of the labeled proteins. This dual probe promotes both the labeling and the facile cleavage of the target protein complexes from the solid surfaces and the remainder of the cell lysate in a completely unaltered form, thus eliminating many of the common pitfalls associated with traditional affinity-based purification methods. Copyright © 2016 Elsevier Ltd. All rights reserved.

NMR and MD Investigations of Human Galectin-1/Oligosaccharide Complexes

PubMed Central

Meynier, Christophe; Feracci, Mikael; Espeli, Marion; Chaspoul, Florence; Gallice, Philippe; Schiff, Claudine; Guerlesquin, Françoise; Roche, Philippe

2009-01-01

Abstract The specific recognition of carbohydrates by lectins plays a major role in many cellular processes. Galectin-1 belongs to a family of 15 structurally related β-galactoside binding proteins that are able to control a variety of cellular events, including cell cycle regulation, adhesion, proliferation, and apoptosis. The three-dimensional structure of galectin-1 has been solved by x-ray crystallography in the free form and in complex with various carbohydrate ligands. In this work, we used a combination of two-dimensional NMR titration experiments and molecular-dynamics simulations with explicit solvent to study the mode of interaction between human galectin-1 and five galactose-containing ligands. Isothermal titration calorimetry measurements were performed to determine their affinities for galectin-1. The contribution of the different hexopyranose units in the protein-carbohydrate interaction was given particular consideration. Although the galactose moiety of each oligosaccharide is necessary for binding, it is not sufficient by itself. The nature of both the reducing sugar in the disaccharide and the interglycosidic linkage play essential roles in the binding to human galectin-1. PMID:20006954

Selective detection of carbohydrates and their peptide conjugates by ESI-MS using synthetic quaternary ammonium salt derivatives of phenylboronic acids.

PubMed

Kijewska, Monika; Kuc, Adam; Kluczyk, Alicja; Waliczek, Mateusz; Man-Kupisinska, Aleksandra; Lukasiewicz, Jolanta; Stefanowicz, Piotr; Szewczuk, Zbigniew

2014-06-01

We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation.

Selective Detection of Carbohydrates and Their Peptide Conjugates by ESI-MS Using Synthetic Quaternary Ammonium Salt Derivatives of Phenylboronic Acids

NASA Astrophysics Data System (ADS)

Kijewska, Monika; Kuc, Adam; Kluczyk, Alicja; Waliczek, Mateusz; Man-Kupisinska, Aleksandra; Lukasiewicz, Jolanta; Stefanowicz, Piotr; Szewczuk, Zbigniew

2014-06-01

We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation.

Bassen-Kornzweig syndrome

MedlinePlus

... Disorders of malabsorption. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of ... Elsevier; 2016:chap 338. Kliegman RM, Stanton BF, St. Geme JW, Schor NF. Defects in the metabolism ...

Effects of Home Gluten Immunogenic Peptide Testing on Children With Celiac Disease

ClinicalTrials.gov

2018-04-18

Celiac Disease; Gluten Sensitivity; Gluten Enteropathy; Gastrointestinal Disease; Digestive System Disease; Diet Modification; Intestinal Disease; Malabsorption Syndromes; Patient Compliance; Diagnostic Self Evaluation; Quality of Life

Familial Mediterranean fever

MedlinePlus

... also help prevent a serious complication called systemic amyloidosis , which is common in people with FMF. NSAIDs ... Amyloidosis may lead to kidney damage or not being able to absorb nutrients from food (malabsorption). Fertility ...

The effects of galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex on Eimeria acervulina infection in broiler chicks

USDA-ARS?s Scientific Manuscript database

Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against pathogenic infection. We hypothesized that a mannose-rich, galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively impact immune status and prevent weight loss resulting from...

Calcium - ionized

MedlinePlus

... diuretics Thrombocytosis (high platelet count) Tumors Vitamin A excess Vitamin D excess Lower-than-normal levels may be due to: Hypoparathyroidism Malabsorption Osteomalacia Pancreatitis Renal failure Rickets Vitamin D deficiency Alternative Names Free calcium; Ionized calcium ...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diehl, J.F.; Adam, S.; Delincee, H.

Toxicological evaluation of irradiated foodstuffs requires knowledge of radiation-induced chemical changes. A review of the literature reveals much information on the radiation chemistry of pure substances, e.g., dilute solutions of individual carbohydrates. Much less is known about the interactions of food constituents during irradiation. In an effort to remedy this situation, radiation effects on various compounds have been studied in systems of increasing complexity. In one approach, gas chromatography was used to investigate the radiolysis of tehalose in pure solution and in the presence of amino acids or proteins. In another approach, radiation-induced aggregation of proteins and of (/sup 14/C)tryptophanmore » with proteins was studied in the absence and presence of carbohydrates (trehalose, starch), emulsified sunfower oil, and a mixture of carbohydrates and emulsified sunflower oil.« less

Carbohydrates in diversity-oriented synthesis: challenges and opportunities.

PubMed

Lenci, E; Menchi, G; Trabocchi, A

2016-01-21

Over the last decade, Diversity-Oriented Synthesis (DOS) has become a new paradigm for developing large collections of structurally diverse small molecules as probes to investigate biological pathways, and to provide a larger array of the chemical space. Drug discovery and chemical biology are taking advantage of DOS approaches to exploit highly-diverse and complex molecular platforms, producing advances in both target and ligand discovery. In this view, carbohydrates are attractive building blocks for DOS libraries, due to their stereochemical diversity and high density of polar functional groups, thus offering many possibilities for chemical manipulation and scaffold decoration. This review will discuss research contributions and perspectives on the application of carbohydrate chemistry to explore the accessible chemical space through appendage, stereochemical and scaffold diversity.

Perception of lactose intolerance in irritable bowel syndrome patients.

PubMed

Dainese, Raffaella; Casellas, Francesc; Mariné-Barjoan, Eugènia; Vivinus-Nébot, Mylène; Schneider, Stéphane M; Hébuterne, Xavier; Piche, Thierry

2014-10-01

The importance of lactose malabsorption in irritable bowel syndrome (IBS) is not well defined and these patients often complain of lactose intolerance. To objectively measure lactose malabsorption, a hydrogen breath test (HBT) can be performed, but a discrepancy emerges between the results of the HBT and the symptomatic response during the HBT. To determine in a group of IBS patients whether self-perceived lactose intolerance and the symptomatic response to lactose HBT were conditioned by other factors besides the presence of lactose malabsorption. Oral challenge to lactose (50 g) was tested in 51 IBS patients to assess HBT malabsorption and the symptomatic response to lactose intolerance was scored on a validated questionnaire. Allergological screening for common inhalants and food allergens (including cow's milk) was performed. The presence of psychological factors (e.g. anxiety, depression, fatigue) was evaluated using validated questionnaires. A total of 21 out of 51 patients (41.1%) were self-perceived to be lactose intolerant, 24/51 (47%) had a positive HBT, and 14/51 (27.4%) presented with symptoms of lactose intolerance during HBT. The serological screening for inhalant and food allergens was positive in 6/21 (28.6%) and 4/21 (19%) of patients who self-perceived lactose intolerance and in 5/14 (37.5%) and 3/14 (21.4%) in intolerant patients symptomatic during HBT. Only 1/51 (1.9%) presented evidence of IgE-mediated hypersensitivity to cow's milk. Patients who experienced symptoms of lactose intolerance during HBT presented more severe IBS symptoms [326 (296-398) vs. 215 (126-295) P=0.05] and a higher score of anxiety, depression, and fatigue. Factors influencing the symptoms of lactose intolerance during HBT resulted in an increase in hydrogen produced and in the severity of IBS. In a cohort of 51 IBS patients, the symptoms of lactose intolerance during HBT were influenced by the capacity to absorb lactose and the severity of IBS. Other factors, such as the psychological status or an adverse reaction to milk, merit consideration as potential cofactors involved in lactose perception and tolerance.

Patterns of organic acids exuded by pioneering fungi from a glacier forefield are affected by carbohydrate sources

NASA Astrophysics Data System (ADS)

Brunner, Ivano; Goren, Asena; Schlumpf, Alessandro

2014-01-01

Bare soils in the area of retreating glaciers are ideal environments to study the role of microorganisms in the early soil formation and in processes of mineral weathering. The aim of our study was to investigate whether the source of carbohydrate would influence the patterns of organic acids exuded by fungal species. Three pioneering fungus species, isolated from fine granitic sediments in front of the Damma glacier from the central Swiss Alps, have previously been found to have the capability to exude organic acids and dissolve granite powder. In batch experiments, various carbohydrates, including glucose, cellulose, pectin, pollen, and cell remnants of cyanobacteria, fungi, and algae, were applied as carbohydrate sources and the patterns of exuded organic acids recorded. The results showed that two fungi, the zygomycete fungus Mucor hiemalis and the ascomycete fungus Penicillium chrysogenum, released a significantly higher amount of organic acids in dependence on specific carbohydrate sources. Pollen and algae as carbohydrate sources triggered significantly the exudation of malate in M. hiemalis, and pollen and cellulose that of oxalate in P. chrysogenum. We conclude that the occurrence of complex carbohydrate sources in nutrient-deficient deglaciated soils may positively influence the exudation of organic acids of fungi. In particular, pollen and remnants of other microorganisms can trigger the exudation of organic acids of fungi in order to promote the weathering of minerals and to make nutrients available that would otherwise be trapped in that cryospheric environment.

Characterization and pharmacodynamic properties of Arnica montana complex.

PubMed

Šutovská, M; Capek, P; Kočmalová, M; Pawlaczyk, I; Zaczyńska, E; Czarny, A; Uhliariková, I; Gancarz, R; Fraňová, S

2014-08-01

A dark brown polymeric complex was isolated from flowering parts of medicinal plant Arnica montana L. by hot alkaline extraction followed by neutralization and multi-step extractions with organic solvents. It was recovered in 5.7% yield, on GPC showed two peaks of molecular mass of 9 and 3.5kDa. The compositional analyses of Arnica complex revealed the presence of carbohydrates (26%), uronic acids (12%), phenolics (1.25mM or 213mg of GAE/1g), and low protein content (∼1%). The carbohydrate moiety was rich mainly in rhamnogalacturonan and arabinogalactan. The antitussive tests showed the reduction of the cough efforts by Arnica complex, however, its total antitussive effect was lower compared with that of codeine, the strongest antitussive agent. The bronchodilatory activity of Arnica complex was similar to salbutamol, a classic antiasthmatic drug, and was confirmed by significantly decreased values of specific airways resistance in vivo and by considerably attenuated the amplitude of acetylcholine and histamine-induced contractions in vitro. Arnica complex did not show any cytotoxic effect on mouse fibroblast cultures and human lung cells, up to the dose of 500μg/mL. Copyright © 2014 Elsevier B.V. All rights reserved.

Changes in Hormonal Concentrations after Different Heavy-Resistance Exercise Protocols in Women

DTIC Science & Technology

1993-01-01

men, we values were 62.1 ± 5.6% (SD) carbohydrate , 13.5 ± 2.3% have previously demonstrated that these two acute pro- protein, and 24.4 ± 6.3% fat...growth hormone. These find- hormone has a complex influence on carbohydrate me- ings may be due to the much higher resting baseline of tabolism, with its...A. WESEMAN. B. P. CONROY, S. E. acteristics of national -caliber United States women weightlifters . GORDON. J. R. HOFFMAN, AND C. M. MARESH. The

Chiral copper(II) complex-catalyzed reactions of partially protected carbohydrates.

PubMed

Allen, C Liana; Miller, Scott J

2013-12-20

Catalyst-controlled regioselective functionalization of partially protected saccharide molecules is a highly important yet under-developed area of carbohydrate chemistry. Such reactions allow for the reduction of protecting group manipulation steps required in syntheses involving sugars. Herein, an approach to these processes using enantiopure copper-bis(oxazoline) catalysts to control couplings of electrophiles to various partially protected sugars is reported. In a number of cases, divergent regioselectivity was observed as a function of the enantiomer of catalyst that is used.

Detection of sialomucin complex (MUC4) in human ocular surface epithelium and tear fluid.

PubMed

Pflugfelder, S C; Liu, Z; Monroy, D; Li, D Q; Carvajal, M E; Price-Schiavi, S A; Idris, N; Solomon, A; Perez, A; Carraway, K L

2000-05-01

To evaluate human ocular surface epithelium and tear fluid for the presence of sialomucin complex (MUC4), a high-molecular-weight heterodimeric glycoprotein composed of mucin (ASGP-1) and transmembrane (ASGP-2) subunits. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis assays were used to identify sialomucin complex RNA in ocular surface epithelia. Immunoprecipitation and immunoblot analysis were used to identify immunoreactive species in human tears and in the corneal and conjunctival epithelia using antibodies specific for carbohydrate and peptide epitopes on the sialomucin complex subunits. Immunofluorescence staining was used to detect sialomucin complex in frozen sections and impression cytology specimens of human cornea and conjunctival epithelia. ASGP-1- and ASGP-2-specific sequences were amplified from RNA extracted from both conjunctival and corneal epithelial biopsies by RT-PCR. Sialomucin complex transcripts were also detected in these tissues by Northern blot analysis, with a greater level of RNA detected in the peripheral than the central corneal epithelium. Sialomucin complex was immunoprecipitated from tear fluid samples and both corneal and conjunctival epithelia and detected by immunoblot analysis with specific anti-ASGP-1 and anti-ASGP-2 antibodies. The ASGP-1 peptide antibody HA-1 stained the full thickness of the corneal and conjunctival epithelia. In contrast, antibody 15H10, which reacts against a carbohydrate epitope on ASGP-1, stained only the superficial epithelial layers of these tissues. No staining was observed in the conjunctival goblet cells. Sialomucin complex was originally identified in rat mammary adenocarcinoma cells and has recently been shown to be produced by the ocular surface epithelia of rats. Furthermore, it has been identified as the rat homologue of human MUC4 mucin. The present studies show that it is expressed in the stratified epithelium covering the surface of the human eye and is present in human tear fluid. Expression of a carbohydrate-dependent epitope on the mucin subunit (ASGP-1) of sialomucin complex occurs in a differentiation-dependent fashion. Sialomucin complex joins MUC1 as another membrane mucin produced by the human ocular surface epithelia but is also found in the tear fluid, presumably in a soluble form, as found on the rat ocular surface.

The biology of Giardia spp.

PubMed Central

Adam, R D

1991-01-01

Gardia spp. are flagellated protozoans that parasitize the small intestines of mammals, birds, reptiles, and amphibians. The infectious cysts begin excysting in the acidic environment of the stomach and become trophozoites (the vegetative form). The trophozoites attach to the intestinal mucosa through the suction generated by a ventral disk and cause diarrhea and malabsorption by mechanisms that are not well understood. Giardia spp. have a number of unique features, including a predominantly anaerobic metabolism, complete dependence on salvage of exogenous nucleotides, a limited ability to synthesize and degrade carbohydrates and lipids, and two nuclei that are equal by all criteria that have been tested. The small size and unique sequence of G. lamblia rRNA molecules have led to the proposal that Giardia is the most primitive eukaryotic organism. Three Giardia spp. have been identified by light lamblia, G. muris, and G. agilis, but electron microscopy has allowed further species to be described within the G. lamblia group, some of which have been substantiated by differences in the rDNA. Animal models and human infections have led to the conclusion that intestinal infection is controlled primarily through the humoral immune system (T-cell dependent in the mouse model). A major immunogenic cysteine-rich surface antigen is able to vary in vitro and in vivo in the course of an infection and may provide a means of evading the host immune response or perhaps a means of adapting to different intestinal environments. Images PMID:1779932

Disaccharidase Deficiencies in Children With Chronic Abdominal Pain.

PubMed

El-Chammas, Khalil; Williams, Sara E; Miranda, Adrian

2017-03-01

Carbohydrate intolerance or malabsorption has been suggested as a cause of chronic abdominal pain (CAP) in a subset of patients. We aimed to evaluate disaccharidase deficiencies in children with functional CAP and to correlate deficiencies with clinical features. Patients presenting to the gastroenterology clinic at Children's Hospital of Wisconsin with abdominal pain prospectively completed a detailed demographic, history, and symptom questionnaire. The CAP cohort included those with at least 1 month of symptoms. Data on disaccharidase activity and histology of endoscopic biopsies were collected retrospectively. Only patients with normal histology were included in the study. The association between groups with low disaccharidases and clinical features was examined. A total of 203 pediatric patients with CAP were included. The mean (SD) age was 11.5 (3.1) years, and 32.5% were male. The percentages of abnormally low disaccharidase levels using the standard laboratory cutoffs were lactase, 37%; sucrase, 21%; glucoamylase, 25%; and palatinase, 8%. Thirty-nine percent of the patients with low lactase also had low sucrase, and 67% of the patients with low sucrase had low lactase. There was no significant difference in the activities of any of the disaccharidases or sucrase/lactase ratio in relation to age. Also, no association was found between stool consistency, stool frequency, or location of pain and low disaccharidase activity. A large proportion of patients with CAP have deficiencies in disaccharidases. Bowel frequency, vomiting, or location of pain was no different between groups, suggesting that these clinical features cannot be used to predict disaccharidase deficiencies.

The Impact of Bariatric Surgery on Type 2 Diabetes Mellitus and the Management of Hypoglycemic Events

PubMed Central

Kassem, Mahmoud Attia Mohamed; Durda, Michael Andrew; Stoicea, Nicoleta; Cavus, Omer; Sahin, Levent; Rogers, Barbara

2017-01-01

Recent studies discussed the benefit of bariatric surgery on obese patients diagnosed with type 2 diabetes mellitus (T2DM). Several factors play an essential role in predicting the impact of bariatric surgery on T2DM, such as ABCD score (age, BMI, C-peptide, and duration of the disease), HbA1c, and fasting blood glucose, incretins [glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP)]. DiaRem score known to include factors such as age, HbA1c, medication, and insulin usage used to predict the remission of T2DM, but it has some limitations. An extensive literature search was conducted on PubMed and Google Scholar using keywords such as gastric bypass, T2DM, bariatric surgery, GLP-1, GIP, and post bariatric hypoglycemia. Restrictive-malabsorptive procedures are most effective in treating T2DM patients based on changes induced in appetite through regulation of gastrointestinal hormones, with decreased hunger and increased satiation. We provide a review of bariatric surgery influence on T2DM and management of post-intervention hypoglycemic events. Post-bariatric surgery hypoglycemia is a serious complication especially when patients develop life-threatening neuroglycopenia with loss of consciousness and seizure. The avoidance of this adverse event may be achieved by strict dietary modification including a restriction on carbohydrates as well as foods with high glycemic index. Further research will provide more information on post-bariatric surgery hyperinsulinemic hypoglycemia pathophysiology and management. PMID:28298900

Genetics Home Reference: glucose-galactose malabsorption

MedlinePlus

... down into glucose and another simple sugar called fructose, and lactose is broken down into glucose and ... infant formulas. However, they are able to digest fructose-based formulas that do not contain glucose or ...

Strategies for carbohydrate model building, refinement and validation

PubMed Central

2017-01-01

Sugars are the most stereochemically intricate family of biomolecules and present substantial challenges to anyone trying to understand their nomenclature, reactions or branched structures. Current crystallographic programs provide an abstraction layer allowing inexpert structural biologists to build complete protein or nucleic acid model components automatically either from scratch or with little manual intervention. This is, however, still not generally true for sugars. The need for carbohydrate-specific building and validation tools has been highlighted a number of times in the past, concomitantly with the introduction of a new generation of experimental methods that have been ramping up the production of protein–sugar complexes and glycoproteins for the past decade. While some incipient advances have been made to address these demands, correctly modelling and refining carbohydrates remains a challenge. This article will address many of the typical difficulties that a structural biologist may face when dealing with carbohydrates, with an emphasis on problem solving in the resolution range where X-ray crystallography and cryo-electron microscopy are expected to overlap in the next decade. PMID:28177313

Strategies for carbohydrate model building, refinement and validation.

PubMed

Agirre, Jon

2017-02-01

Sugars are the most stereochemically intricate family of biomolecules and present substantial challenges to anyone trying to understand their nomenclature, reactions or branched structures. Current crystallographic programs provide an abstraction layer allowing inexpert structural biologists to build complete protein or nucleic acid model components automatically either from scratch or with little manual intervention. This is, however, still not generally true for sugars. The need for carbohydrate-specific building and validation tools has been highlighted a number of times in the past, concomitantly with the introduction of a new generation of experimental methods that have been ramping up the production of protein-sugar complexes and glycoproteins for the past decade. While some incipient advances have been made to address these demands, correctly modelling and refining carbohydrates remains a challenge. This article will address many of the typical difficulties that a structural biologist may face when dealing with carbohydrates, with an emphasis on problem solving in the resolution range where X-ray crystallography and cryo-electron microscopy are expected to overlap in the next decade.

Improved Procedure for Direct Coupling of Carbohydrates to Proteins via Reductive Amination

PubMed Central

Gildersleeve, Jeffrey C.; Oyelaran, Oyindasola; Simpson, John T.; Allred, Benjamin

2009-01-01

Carbohydrate-protein conjugates are utilized extensively in basic research and as immunogens in a variety of bacterial vaccines and cancer vaccines. As a result, there have been significant efforts to develop simple and reliable methods for the construction of these conjugates. While direct coupling via reductive amination is an appealing approach, the reaction is typically very inefficient. In this paper, we report improved reaction conditions providing an approximately 500% increase in yield. In addition to optimizing a series of standard reaction parameters, we found that addition of 500 mM sodium sulfate improves the coupling efficiency. To illustrate the utility of these conditions, a series of high mannose BSA conjugates were produced and incorporated into a carbohydrate microarray. Ligand binding to ConA could be observed and apparent affinity constants (Kds) measured using the array were in good agreement with values reported by surface plasmon resonance. The results show that the conditions are suitable for microgram scale reactions, are compatible with complex carbohydrates, and produce biologically active conjugates. PMID:18597509

Synthesis of carbohydrates in a continuous flow reactor by immobilized phosphatase and aldolase.

PubMed

Babich, Lara; Hartog, Aloysius F; van Hemert, Lieke J C; Rutjes, Floris P J T; Wever, Ron

2012-12-01

Herein, we report a new flow process with immobilized enzymes to synthesize complex chiral carbohydrate analogues from achiral inexpensive building blocks in a three-step cascade reaction. The first reactor contained immobilized acid phosphatase, which phosphorylated dihydroxyacetone to dihydroxyacetone phosphate using pyrophosphate as the phosphate donor. The second flow reactor contained fructose-1,6-diphosphate aldolase (RAMA, rabbit muscle aldolase) or rhamnulose-1-phosphate aldolase (RhuA from Thermotoga maritima) and acid phosphatase. The immobilized aldolases coupled the formed dihydroxyacetone phosphate to aldehydes, resulting in phosphorylated carbohydrates. A final reactor containing acid phosphatase that dephosphorylated the phosphorylated product yielded the final product. Different aldehydes were used to synthesize carbohydrates on a gram scale. To demonstrate the feasibility of the flow systems, we synthesized 0.6 g of the D-fagomine precursor. By using immobilized aldolase RhuA we were also able to obtain other stereoisomers of the D-fagomine precursor. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vitamin B12 in Health and Disease

PubMed Central

O’Leary, Fiona; Samman, Samir

2010-01-01

Vitamin B12 is essential for DNA synthesis and for cellular energy production.This review aims to outline the metabolism of vitamin B12, and to evaluate the causes and consequences of sub-clinical vitamin B12 deficiency. Vitamin B12 deficiency is common, mainly due to limited dietary intake of animal foods or malabsorption of the vitamin. Vegetarians are at risk of vitamin B12 deficiency as are other groups with low intakes of animal foods or those with restrictive dietary patterns. Malabsorption of vitamin B12 is most commonly seen in the elderly, secondary to gastric achlorhydria. The symptoms of sub-clinical deficiency are subtle and often not recognized. The long-term consequences of sub-clinical deficiency are not fully known but may include adverse effects on pregnancy outcomes, vascular, cognitive, bone and eye health. PMID:22254022

The efficacy of a low-fat diet to manage the symptoms of bile acid malabsorption - outcomes in patients previously treated for cancer.

PubMed

Jackson, Amy; Lalji, Amyn; Kabir, Mohammed; Muls, Ann; Gee, Caroline; Vyoral, Susan; Shaw, Clare; Andreyev, H Jervoise N

2017-10-01

Dietary fat ingestion triggers bile secretion into the gastrointestinal tract. Bile acid malabsorption affects >1% of the population, causing loose stool and other gastrointestinal symptoms. The diagnosis is frequently missed. Treatments are often considered ineffective. We evaluated low-fat diets for managing gastrointestinal symptoms in these patients. All patients reporting type 6 or 7 stool were offered a selenium-75 homocholic acid taurine (SeHCAT) scan. Prospective data in patients with 7-day scan retention <20% were analysed. -Patients requiring a bile acid sequestrant were given this before receiving dietary advice. Patients completed a 7-day food diary before dietetic consultations. Personalised dietary interventions, providing 20% of daily energy from fat, were prescribed. Symptoms were assessed using a modified gastrointestinal symptom rating scale questionnaire before and 4-12 weeks after dietary intervention. A total of 114 patients (49 male, median age 64 years, median body mass index 27 kg/m 2 ) were evaluated. 44% of these patients were taking colesevelam. After dietary intervention, there was statistically significant improvement in abdominal pain and nocturnal defecation (0.2% alpha, p=0.001). Improvement in bowel frequency, urgency, flatulence, belching, borborygmi and stool consistency were seen, but did not reach statistical significance (p≤0.004-0.031). Dietary intervention is an effective treatment option for patients with symptomatic bile acid malabsorption and should be routinely considered. © Royal College of Physicians 2017. All rights reserved.

Effects of exogenous lactase administration on hydrogen breath excretion and intestinal symptoms in patients presenting lactose malabsorption and intolerance.

PubMed

Ibba, Ivan; Gilli, Agnese; Boi, Maria Francesca; Usai, Paolo

2014-01-01

To establish whether supplementation with a standard oral dose of Beta-Galactosidase affects hydrogen breath excretion in patients presenting with lactose malabsorption. Ninety-six consecutive patients positive to H2 Lactose Breath Test were enrolled. Mean peak H2 levels, the time to reach the peak H2, the time to reach the cut-off value of 20 ppm, the cumulative breath H2 excretion, the areas under the curve, and a Visual Analogical 10-point Scale for symptoms were calculated. Genotyping of the C/T-13910 variant was carried out. Following the oral administration of Beta-Galactosidase, in 21.88% of the cases, H2 Lactose Breath Test became negative (Group A), while mean peak H2 levels (74.95 ppm versus 7.85), P < 0.0000, in 17.71% (Group B) were still positive, with the H2 level 20 ppm above the baseline, but the peak H2 levels were significantly lower than those observed at the baseline test (186.7 ppm versus 66.64), P < 0.0000, while in 60.41% (Group C) they were still positive with the peak H2 levels similar to those observed at the baseline test (94.43 versus 81.60 ppm). All 96 individuals tested presented the C/C-13910 genotype nonpersistence. The response to oral administration of Beta-Galactosidase in patients with symptoms of lactose malabsorption presents a significant variability.

An exon 53 frameshift mutation in CUBN abrogates cubam function and causes Imerslund-Gräsbeck syndrome in dogs.

PubMed

Fyfe, John C; Hemker, Shelby L; Venta, Patrick J; Fitzgerald, Caitlin A; Outerbridge, Catherine A; Myers, Sherry L; Giger, Urs

2013-08-01

Cobalamin malabsorption accompanied by selective proteinuria is an autosomal recessive disorder known as Imerslund-Gräsbeck syndrome in humans and was previously described in dogs due to amnionless (AMN) mutations. The resultant vitamin B12 deficiency causes dyshematopoiesis, lethargy, failure to thrive, and life-threatening metabolic disruption in the juvenile period. We studied 3 kindreds of border collies with cobalamin malabsorption and mapped the disease locus in affected dogs to a 2.9Mb region of homozygosity on canine chromosome 2. The region included CUBN, the locus encoding cubilin, a peripheral membrane protein that in concert with AMN forms the functional intrinsic factor-cobalamin receptor expressed in ileum and a multi-ligand receptor in renal proximal tubules. Cobalamin malabsorption and proteinuria comprising CUBN ligands were demonstrated by radiolabeled cobalamin uptake studies and SDS-PAGE, respectively. CUBN mRNA and protein expression were reduced ~10 fold and ~20 fold, respectively, in both ileum and kidney of affected dogs. DNA sequencing demonstrated a single base deletion in exon 53 predicting a translational frameshift and early termination codon likely triggering nonsense mediated mRNA decay. The mutant allele segregated with the disease in the border collie kindred. The border collie disorder indicates that a CUBN mutation far C-terminal from the intrinsic factor-cobalamin binding site can abrogate receptor expression and cause Imerslund-Gräsbeck syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

Monoacylglycerol-enriched oil increases EPA/DHA delivery to circulatory system in humans with induced lipid malabsorption conditions.

PubMed

Cruz-Hernandez, Cristina; Destaillats, Frédéric; Thakkar, Sagar K; Goulet, Laurence; Wynn, Emma; Grathwohl, Dominik; Roessle, Claudia; de Giorgi, Sara; Tappy, Luc; Giuffrida, Francesca; Giusti, Vittorio

2016-12-01

It was hypothesized that under induced lipid malabsorption/maldigestion conditions, an enriched sn-1(3)-monoacylglycerol (MAG) oil may be a better carrier for n-3 long-chain PUFAs (LC-PUFAs) compared with triacylglycerol (TAG) from fish oil. This monocentric double blinded clinical trial examined the accretion of EPA (500 mg/day) and DHA (300 mg/day) when consumed as TAG or MAG, into the erythrocytes, plasma, and chylomicrons of 45 obese (BMI ≥30 kg/m 2 and ≤40 kg/m 2 ) volunteers who were and were not administered Orlistat, an inhibitor of pancreatic lipases. Intake of MAG-enriched oil resulted in higher accretion of LC-PUFAs than with TAG, the concentrations of EPA and DHA in erythrocytes being, respectively, 72 and 24% higher at 21 days (P < 0.001). In addition, MAG increased the plasma concentration of EPA by 56% (P < 0.001) as compared with TAG. In chylomicrons, MAG intake yielded higher levels of EPA with the area under the curve (0-10 h) of EPA being 55% greater (P = 0.012). In conclusion, in obese human subjects with Orlistat-induced lipid maldigestion/malabsorption conditions, LC-PUFA MAG oil increased LC-PUFA levels in erythrocytes, plasma, and chylomicrons to a greater extent than TAG. These results indicate that MAG oil might require minimal enzymatic digestion prior to intestinal uptake and transfer across the epithelial barrier. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

Monoacylglycerol-enriched oil increases EPA/DHA delivery to circulatory system in humans with induced lipid malabsorption conditions1

PubMed Central

Cruz-Hernandez, Cristina; Destaillats, Frédéric; Thakkar, Sagar K.; Goulet, Laurence; Wynn, Emma; Grathwohl, Dominik; Roessle, Claudia; de Giorgi, Sara; Tappy, Luc; Giuffrida, Francesca; Giusti, Vittorio

2016-01-01

It was hypothesized that under induced lipid malabsorption/maldigestion conditions, an enriched sn-1(3)-monoacylglycerol (MAG) oil may be a better carrier for n-3 long-chain PUFAs (LC-PUFAs) compared with triacylglycerol (TAG) from fish oil. This monocentric double blinded clinical trial examined the accretion of EPA (500 mg/day) and DHA (300 mg/day) when consumed as TAG or MAG, into the erythrocytes, plasma, and chylomicrons of 45 obese (BMI ≥30 kg/m2 and ≤40 kg/m2) volunteers who were and were not administered Orlistat, an inhibitor of pancreatic lipases. Intake of MAG-enriched oil resulted in higher accretion of LC-PUFAs than with TAG, the concentrations of EPA and DHA in erythrocytes being, respectively, 72 and 24% higher at 21 days (P < 0.001). In addition, MAG increased the plasma concentration of EPA by 56% (P < 0.001) as compared with TAG. In chylomicrons, MAG intake yielded higher levels of EPA with the area under the curve (0–10 h) of EPA being 55% greater (P = 0.012). In conclusion, in obese human subjects with Orlistat-induced lipid maldigestion/malabsorption conditions, LC-PUFA MAG oil increased LC-PUFA levels in erythrocytes, plasma, and chylomicrons to a greater extent than TAG. These results indicate that MAG oil might require minimal enzymatic digestion prior to intestinal uptake and transfer across the epithelial barrier. PMID:27707818

Extension of Drosophila Lifespan by Rhodiola rosea Depends on Dietary Carbohydrate and Caloric Content in a Simplified Diet.

PubMed

Schriner, Samuel E; Coskun, Volkan; Hogan, Sean P; Nguyen, Cindy T; Lopez, Terry E; Jafari, Mahtab

2016-03-01

The root and rhizome extract of Rhodiola rosea has been extensively used in traditional medicine to improve physical and mental performance and to protect against stress. We, and others, have reported that R. rosea can extend lifespan in flies, worms, and yeast. We also previously found that the extract can act independently of dietary restriction (DR), a treatment that can extend lifespan in a range of model organisms. In flies, DR is implemented through a reduction in dietary yeast content. Here, we report that the ability of R. rosea extract to extend lifespan in flies is dependent on the carbohydrate and caloric content when supplemented with a simplified diet composed of yeast and sucrose. R. rosea extract elevated the sugar content in flies and down-regulated hexokinase expression, suggesting that it perturbs carbohydrate metabolism in flies. In our previous studies, bananas, barley malt, and corn syrup provided dietary carbohydrates, and R. rosea extract could extend lifespan with a range of caloric levels. We conclude that the lifespan-extending effect of R. rosea extract in flies is dependent on dietary carbohydrate and caloric contents coupled with an interaction with complex dietary components present in bananas, barley, or corn.

Specific intermolecular interactions of conserved water molecules with amino acids in the Galectin-1 carbohydrate recognition domain

NASA Astrophysics Data System (ADS)

Di Lella, Santiago; Petruk, Ariel A.; Armiño, Diego J. Alonso de; Álvarez, Rosa M. S.

2010-08-01

Water molecules, rigidly associated to protein surfaces, play a key role in stabilizing biomolecules and participating in their biological functions. Recent studies on the solvation properties of the carbohydrate recognition domain of Galectin-1 by means of molecular dynamic simulations have revealed the existence of several water sites which were well correlated to both the bound water molecules observed in the crystal structure of the protein in the free state and to some of the hydroxyl groups of the carbohydrate ligand observed in the crystal structure of the complexed protein. In this work, we present a study using quantum mechanical methods (B3LYP/6-311++G(3df,3dp)//B3LYP/6-31+G(d)) to determine the energy involved in the binding of these water molecules to specific amino acids in the carbohydrate recognition domain of the protein. By modeling the hydroxyl groups of the carbohydrate by methanol, the energies associated to the local interactions between the ligand and the protein have been evaluated by replacing specific water molecules with methanol. The values of the binding energies have been compared to those previously obtained by the molecular dynamic method.

NMR Quantification of Carbohydrates in Complex Mixtures. A Challenge on Honey.

PubMed

Schievano, Elisabetta; Tonoli, Marco; Rastrelli, Federico

2017-12-19

The knowledge of carbohydrate composition is greatly important to determine the properties of natural matrices such as foodstuff and food ingredients. However, because of the structural similarity and the multiple isomeric forms of carbohydrates in solution, their analysis is often a complex task. Here we propose an NMR analytical procedure based on highly selective chemical shift filters followed by TOCSY, which allows us to acquire specific background-free signals for each sugar. The method was tested on raw honey samples dissolved in water with no other pretreatment. In total, 22 sugars typically found in honey were quantified: 4 monosaccharides (glucose, fructose, mannose, rhamnose), 11 disaccharides (sucrose, trehalose, turanose, maltose, maltulose, palatinose, melibiose and melezitose, isomaltose, gentiobiose nigerose, and kojibiose), and 7 trisaccharides (raffinose, isomaltotriose, erlose, melezitose, maltotriose, panose, and 1-kestose). Satisfactory results in terms of limit of quantification (0.03-0.4 g/100g honey), precision (% RSD: 0.99-4.03), trueness (bias % 0.4-4.2), and recovery (97-104%) were obtained. An accurate control of the instrumental temperature and of the sample pH endows an optimal chemical shift reproducibility, making the procedure amenable to automation and suitable to routine analysis. While validated on honey, which is one of the most complex natural matrices in terms of saccharides composition, this innovative approach can be easily transferred to other natural matrices.

The changing roles of dietary carbohydrates: from simple to complex.

PubMed

Griel, Amy E; Ruder, Elizabeth H; Kris-Etherton, Penny M

2006-09-01

The dietary recommendations made for carbohydrate intake by many organizations/agencies have changed over time. Early recommendations were based on the need to ensure dietary sufficiency and focused on meeting micronutrient intake requirements. Because carbohydrate-containing foods are a rich source of micronutrients, starches, grains, fruits, and vegetables became the foundation of dietary guidance, including the base of the US Department of Agriculture's Food Guide Pyramid. Dietary sufficiency recommendations were followed by recommendations to reduce cholesterol levels and the risk for cardiovascular disease; reduction in total fat (and hence saturated fat) predominated. Beginning in the 1970s, carbohydrates were recommended as the preferred substitute for fat by the American Heart Association and others to achieve the recommended successive reductions in total fat and low-density lipoprotein cholesterol (LDL-C). Additional research on fats and fatty acids found that monounsaturated fatty acids could serve as an alternative substitution for saturated fats, providing equivalent lowering of LDL-C without concomitant reductions in high-density lipoprotein cholesterol and increases in triglycerides witnessed when carbohydrates replace saturated fat. This research led to a sharper focus in the guidelines in the 1990s toward restricting saturated fat and liberalizing a range of intake of total fat. Higher-fat diets, still low in saturated fatty acids, became alternative strategies to lower-fat diets. As the population has become increasingly overweight and obese, the emergence of the metabolic syndrome and its associated disruptions in glucose and lipid metabolism has led to reconsiderations of the role of carbohydrate-containing foods in the American diet. Consequently, a review of the evidence for and against high-carbohydrate diets is important to put this controversy into perspective. The current dietary recommendations for carbohydrate intake are supported by the evidence.

Hypoglycemia and endurance exercise: dietary considerations.

PubMed

Rutherford, W J

1990-01-01

Until recently, common dietary prescription for chronic hypoglycemia has been a high-protein, low-carbohydrate regimen (Airola, 1977; Danowski, 1978). Increasing evidence suggests, however, that a diet rich in complex carbohydrates may be more suitable for those involved in endurance exercise (Costill & Miller, 1980; Sherman & Costill, 1984). Although little original research has been undertaken which deals with the effects of performance-enhancing nutritional techniques on the hypoglycemic exerciser, such practices need to be examined in order to understand the mechanisms involved. Specifically, carbohydrate loading would seem to be as important, if not more so, to the hypoglycemic individual as a means of supercompensating glycogen stores prior to endurance performance. The roles of pre-exercise supplements and carbohydrate feedings during exercise in this context are less clear. Although results are mixed, increasing evidence (Snyder et al., 1983; Okano et al., 1988) suggests that carbohydrates may be consumed before exercise with beneficial effects on performance. Because of rapid gastric emptying characteristic of reactive hypoglycemia, it would appear that pre-exercise supplementation may be of particular value to the hypoglycemic exerciser. Further, recent studies (Bergstrom & Hultman, 1967; Coyle et al., 1983; Foster et al., 1986; Leatt & Jacobs, 1986; Horton, 1988) indicate that carbohydrate solutions taken during exercise are effective in maintaining serum glucose levels and improving endurance performance. Careful monitoring of nutritional factors would appear to be critical in creating a suitable dietary environment for the hypoglycemic endurance exerciser.

Absorption patterns of meals containing complex carbohydrates in type 1 diabetes.

PubMed

Elleri, D; Allen, J M; Harris, J; Kumareswaran, K; Nodale, M; Leelarathna, L; Acerini, C L; Haidar, A; Wilinska, M E; Jackson, N; Umpleby, A M; Evans, M L; Dunger, D B; Hovorka, R

2013-05-01

Successful postprandial glycaemia management requires understanding of absorption patterns after meals containing variable complex carbohydrates. We studied eight young participants with type 1 diabetes to investigate a large low-glycaemic-load (LG) meal and another eight participants to investigate a high-glycaemic-load (HG) meal matched for carbohydrates (121 g). On Visit 1, participants consumed an evening meal. On follow-up Visit 2, a variable-target glucose clamp was performed to reproduce glucose and insulin levels from Visit 1. Adopting stable-label tracer dilution methodology, we measured endogenous glucose production on Visit 2 and subtracted it from total glucose appearance measured on Visit 1 to obtain meal-attributable glucose appearance. After the LG meal, 25%, 50% and 75% of cumulative glucose appearance was at 88 ± 21, 175 ± 39 and 270 ± 54 min (mean ± SD), whereas glucose from the HG meal appeared significantly faster at 56 ± 12, 100 ± 25 and 153 ± 39 min (p < 0.001 to 0.003), and resulted in a 50% higher peak appearance (p < 0.001). Higher apparent bioavailability by 15% (p = 0.037) was observed after the LG meal. We documented a 20 min deceleration of dietary mixed carbohydrates compared with dietary glucose for the HG meal and a twofold deceleration for the LG meal. Absorption patterns may be influenced by glycaemic load and/or meal composition, affecting optimum prandial insulin dosing in type 1 diabetes.

[Correctly estimating and appreciating carbohydrates. Nutrition in diabetes mellitus].

PubMed

Krumwiede, Karl-Heinz

2007-09-13

The goal of the treatment of diabetes is a near-normal HbA1c level. In insulin therapy, the dose of insulin must be adjusted to the amount of utilizable carbohydrates consumed to achieve this goal. The bread unit, glycaemic index and glycaemic load are helpful tools for estimating amounts of carbohydrates. The diabetic patient must be informed of the usefulness and limits of these methods. However, it is apparent that not every patient is capable of understanding this complex subject. A possible solution could be to involve relatives or friends in the therapy. On the other hand, a diabetic person is ill-advised if the explanations are made too simple. Incorrect information such as the taste of a particular food is related to the blood sugar trend should be avoided.

Genetics Home Reference: hereditary folate malabsorption

MedlinePlus

... PCFT is important for normal functioning of intestinal epithelial cells, which are cells that line the walls of the intestine. ... intestinal absorption and transport into systemic compartments and tissues. Expert Rev Mol Med. 2009 Jan 28;11: ...

Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium

USDA-ARS?s Scientific Manuscript database

Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively impact immune status and prevent colonization and shedding in Salmonell...

Synthetic assembly of novel avidin-biotin-GlcNAc (ABG) complex as an attractive bio-probe and its interaction with wheat germ agglutinin (WGA).

PubMed

Kumari, Amrita; Koyama, Tetsuo; Hatano, Ken; Matsuoka, Koji

2016-10-01

A tetravalent GlcNAc pendant glycocluster was constructed with terminal biotin through C6 linker. To acquire the multivalent carbohydrate-protein interactions, we synthesized a glycopolymer of tetrameric structure using N-acetyl-d-glucosamine (GlcNAc) as the target carbohydrate by the use of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) as coupling reagent, followed by biotin-avidin complexation leading to the formation of glycocluster of avidin-biotin-GlcNAc conjugate (ABG complex). The dynamic light scattering (DLS) system was implied for size detection and to check the binding affinity of GlcNAc conjugate with a WGA lectin we use fluorometric assay by means of specific excitation of tryptophan at λex 295nm and it was found to be very high Ka∼1.39×10(7) M(-1) in case of ABG complex as compared to GlcNAc only Ka∼1.01×10(4) M(-1) with the phenomenon proven to be due to glycocluster effect. Copyright © 2016 Elsevier Inc. All rights reserved.

Diet composition and the performance of high-intensity exercise.

PubMed

Maughan, R J; Greenhaff, P L; Leiper, J B; Ball, D; Lambert, C P; Gleeson, M

1997-06-01

The crucial role of muscle glycogen as a fuel during prolonged exercise is well established, and the effects of acute changes in dietary carbohydrate intake on muscle glycogen content and on endurance capacity are equally well known. More recently, it has been recognized that diet can also affect the performance of high-intensity exercise of short (2-7 min) duration. If the muscle glycogen content is lowered by prolonged (1-1.5 h) exhausting cycle exercise, and is subsequently kept low for 3-4 days by consumption of a diet deficient in carbohydrate (< 5% of total energy intake), there is a dramatic (approximately 10-30%) reduction in exercise capacity during cycling sustainable for about 5 min. The same effect is observed if exercise is preceded by 3-4 days on a carbohydrate-restricted diet or by a 24 h total fast without prior depletion of the muscle glycogen. Consumption of a diet high in carbohydrate (70% of total energy intake from carbohydrate) for 3-4 days before exercise improves exercise capacity during high-intensity exercise, although this effect is less consistent. The blood lactate concentration is always lower at the point of fatigue after a diet low in carbohydrate and higher after a diet high in carbohydrate than after a normal diet. Even when the duration of the exercise task is kept constant, the blood lactate concentration is higher after exercise on a diet high in carbohydrate than on a diet low in carbohydrate. Consumption of a low-carbohydrate isoenergetic diet is achieved by an increased intake of protein and fat. A high-protein diet, particularly when combined with a low carbohydrate intake, results in metabolic acidosis, which ensues within 24 h and persists for at least 4 days. This appears to be the result of an increase in the circulating concentrations of strong organic acids, particularly free fatty acids and 3-hydroxybutyrate, together with an increase in the total plasma protein concentration. This acidosis, rather than any decrease in the muscle glycogen content, may be responsible for the reduced exercise capacity in high-intensity exercise; this may be due to a reduced rate of efflux of lactate and hydrogen ions from the working muscles. Alternatively, the accumulation of acetyl groups in the carbohydrate-deprived state may reduce substrate flux through the pyruvate dehydrogenase complex, thus reducing aerobic energy supply and accelerating the onset of fatigue.

Energy expenditure and hormone responses in humans after overeating high-fructose corn syrup versus whole-wheat foods

PubMed Central

Ibrahim, Mostafa; Bonfiglio, Susan; Schlögl, Mathias; Vinales, Karyne L.; Piaggi, Paolo; Venti, Colleen; Walter, Mary; Krakoff, Jonathan; Thearle, Marie S.

2017-01-01

Objective We sought to understand how the dietary source of carbohydrates, either high-fructose corn syrup (HFCS) or complex carbohydrates, affects energy expenditure (EE) measures, appetitive sensations, and hormones during 24h of overfeeding. Methods Seventeen healthy participants with normal glucose regulation had 24h-EE measures, fasting blood and 24h urine collection during four different one-day diets including an energy balanced diet, fasting, and two 75% carbohydrate diets (5% fat) given at 200% energy requirements with either HFCS or whole-wheat foods as the carbohydrate source. In eight volunteers, hunger was assessed with visual analog scales the morning after the diets. Results Compared with energy balance, 24h-EE increased 12.8±6.9% with carbohydrate overfeeding (p<0.0001). No differences in 24h-EE or macronutrient utilization were observed between the two high-carbohydrate diets; however, sleeping metabolic rate was higher after the HFCS diet (Δ=35±48 kcal (146±200 kJ); p=0.01). Insulin, ghrelin, and triglycerides increased the morning after both overfeeding diets. Urinary cortisol concentrations (82.8±35.9 v 107.6±46.9 nmol/24h, p=0.01) and morning-after hunger scores (Δ=2.4±2.0 cm, p=0.01) were higher with HFCS overfeeding. Conclusions The dietary carbohydrate source while overeating did not affect 24h-EE, but HFCS overconsumption may predispose to further overeating due to increased glucocorticoid release and increased hunger the following morning. PMID:29193741

Digestible and indigestible carbohydrates: interactions with postprandial lipid metabolism.

PubMed

Lairon, Denis; Play, Barbara; Jourdheuil-Rahmani, Dominique

2007-04-01

The balance between fats and carbohydrates in the human diet is still a matter of very active debate. Indeed, the processing of ordinary mixed meals involves complex processes within the lumen of the upper digestive tract for digestion, in the small intestine mucosa for absorption and resecretion, and in peripheral tissues and in the circulation for final handling. The purpose of this review is to focus on available knowledge on the interactions of digestible or indigestible carbohydrates with lipid and lipoprotein metabolism in the postprandial state. The observations made in humans after test meals are reported and interpreted in the light of recent findings on the cellular and molecular levels regarding possible interplays between carbohydrates and lipid moieties in some metabolic pathways. Digestible carbohydrates, especially readily digestible starches or fructose, have been shown to exacerbate and/or delay postprandial lipemia, whereas some fiber sources can lower it. While interactions between dietary fibers and the process of lipid digestion and absorption have been studied mainly in the last decades, recent studies have shown that dietary carbohydrate moieties (e.g., glucose) can stimulate the intestinal uptake of cholesterol and lipid resecretion. In addition to the well-known glucose/fructose transporters, a number of transport proteins have recently been involved in intestinal lipid processing, whose implications in such interactions are discussed. The potential importance of postprandial insulinemia in these processes is also evaluated in the light of recent findings. The interactions of carbohydrates and lipid moieties in the postprandial state may result from both acute and chronic effects, both at transcriptional and posttranscriptional levels.

Genetics Home Reference: pyruvate dehydrogenase deficiency

MedlinePlus

... form that cells can use. The pyruvate dehydrogenase complex converts a molecule called pyruvate, which is formed from the breakdown of carbohydrates, into another molecule called acetyl-CoA. This conversion ...

Aspergillus oryzae–Saccharomyces cerevisiae Consortium Allows Bio-Hybrid Fuel Cell to Run on Complex Carbohydrates

PubMed Central

Jahnke, Justin P.; Hoyt, Thomas; LeFors, Hannah M.; Sumner, James J.; Mackie, David M.

2016-01-01

Consortia of Aspergillus oryzae and Saccharomyces cerevisiae are examined for their abilities to turn complex carbohydrates into ethanol. To understand the interactions between microorganisms in consortia, Fourier-transform infrared spectroscopy is used to follow the concentrations of various metabolites such as sugars (e.g., glucose, maltose), longer chain carbohydrates, and ethanol to optimize consortia conditions for the production of ethanol. It is shown that with proper design A. oryzae can digest food waste simulants into soluble sugars that S. cerevisiae can ferment into ethanol. Depending on the substrate and conditions used, concentrations of 13% ethanol were achieved in 10 days. It is further shown that a direct alcohol fuel cell (FC) can be coupled with these A. oryzae-enabled S. cerevisiae fermentations using a reverse osmosis membrane. This “bio-hybrid FC” continually extracted ethanol from an ongoing consortium, enhancing ethanol production and allowing the bio-hybrid FC to run for at least one week. Obtained bio-hybrid FC currents were comparable to those from pure ethanol—water mixtures, using the same FC. The A. oryzae–S. cerevisiae consortium, coupled to a bio-hybrid FC, converted food waste simulants into electricity without any pre- or post-processing. PMID:27681904

Aspergillus oryzae-Saccharomyces cerevisiae Consortium Allows Bio-Hybrid Fuel Cell to Run on Complex Carbohydrates.

PubMed

Jahnke, Justin P; Hoyt, Thomas; LeFors, Hannah M; Sumner, James J; Mackie, David M

2016-02-04

Consortia of Aspergillus oryzae and Saccharomyces cerevisiae are examined for their abilities to turn complex carbohydrates into ethanol. To understand the interactions between microorganisms in consortia, Fourier-transform infrared spectroscopy is used to follow the concentrations of various metabolites such as sugars (e.g., glucose, maltose), longer chain carbohydrates, and ethanol to optimize consortia conditions for the production of ethanol. It is shown that with proper design A. oryzae can digest food waste simulants into soluble sugars that S. cerevisiae can ferment into ethanol. Depending on the substrate and conditions used, concentrations of 13% ethanol were achieved in 10 days. It is further shown that a direct alcohol fuel cell (FC) can be coupled with these A. oryzae-enabled S. cerevisiae fermentations using a reverse osmosis membrane. This "bio-hybrid FC" continually extracted ethanol from an ongoing consortium, enhancing ethanol production and allowing the bio-hybrid FC to run for at least one week. Obtained bio-hybrid FC currents were comparable to those from pure ethanol-water mixtures, using the same FC. The A. oryzae-S. cerevisiae consortium, coupled to a bio-hybrid FC, converted food waste simulants into electricity without any pre- or post-processing.

Nickel-Catalyzed Proton-Deuterium Exchange (HDX) Procedures for Glycosidic Linkage Analysis of Complex Carbohydrates.

PubMed

Price, Neil P J; Hartman, Trina M; Vermillion, Karl E

2015-07-21

The structural analysis of complex carbohydrates typically requires the assignment of three parameters: monosaccharide composition, the position of glycosidic linkages between monosaccharides, and the position and nature of noncarbohydrate substituents. The glycosidic linkage positions are often determined by permethylation analysis, but this can be complicated by high viscosity or poor solubility, resulting in under-methylation. This is a drawback because an under-methylated position may be misinterpreted as the erroneous site of a linkage or substituent. Here, we describe an alternative approach to linkage analysis that makes use of a nonreversible deuterium exchange of C-H protons on the carbohydrate backbone. The exchange reaction is conducted in deuterated water catalyzed by Raney nickel, and results in the selective exchange of C-H protons adjacent to free hydroxyl groups. Hence, the position of the residual C-H protons is indicative of the position of glycosidic linkages or other substituents and can be readily assigned by heteronuclear single quantum coherence-nuclear magnetic resonance (HSQC-NMR) or, following suitable derivatization, by gas chromatography-mass spectroscopy (GC/MS) analysis. Moreover, because the only changes to the parent sugar are proton/deuterium exchanges, the composition and linkage analysis can be determined in a single step.

New insights into bile acid malabsorption.

PubMed

Johnston, Ian; Nolan, Jonathan; Pattni, Sanjeev S; Walters, Julian R F

2011-10-01

Bile acid malabsorption occurs when there is impaired absorption of bile acids in the terminal ileum, so interrupting the normal enterohepatic circulation. The excess bile acids in the colon cause diarrhea, and treatment with bile acid sequestrants is beneficial. The condition can be diagnosed with difficulty by measuring fecal bile acids, or more easily by retention of selenohomocholyltaurine (SeHCAT), where this is available. Chronic diarrhea caused by primary bile acid diarrhea appears to be common, but is under-recognized where SeHCAT testing is not performed. Measuring excessive bile acid synthesis with 7α-hydroxy-4-cholesten-3-one may be an alternative means of diagnosis. It appears that there is no absorption defect in primary bile acid diarrhea but, instead, an overproduction of bile acids. Fibroblast growth factor 19 (FGF19) inhibits hepatic bile acid synthesis. Defective production of FGF19 from the ileum may be the cause of primary bile acid diarrhea.

Is Parenteral Levothyroxine Therapy Safe in Intractable Hypothyroidism?

PubMed

Peynirci, Hande; Taskiran, Bengur; Erturk, Erdinc; Sisman, Pınar; Ersoy, Canan

2018-06-01

A 32-year old woman was admitted to the hospital due to intractable hypothyroidism refractory to high dose of oral l-thyroxine therapy. She underwent total thyroidectomy and radioactive iodine therapy due to papillary thyroid cancer. After excluding poor adherence to therapy and malabsorption, levothyroxine absorption test was performed. No response was detected. Transient neurologic symptoms developed during the test. She developed 3 attacks consisting of neurologic symptoms during high dose administration. The patient was considered a case of isolated l-thyroxine malabsorption. She became euthyroid after intramuscular twice weekly l-thyroxine therapy. There are a few case reports regarding isolated l-thyroxine. We report successful long term results of twice weekly administered intramuscular l-thyroxine therapy. We also draw attention to neurologic side effects of high dose l-thyroxine therapy. Copyright © 2017 National Medical Association. Published by Elsevier Inc. All rights reserved.

Raloxifene causing malabsorption of levothyroxine.

PubMed

Siraj, Elias S; Gupta, Manjula K; Reddy, S Sethu K

2003-06-09

To our knowledge, raloxifene hydrochloride, a selective estrogen receptor modulator, has never been reported to interfere with absorption of levothyroxine. We describe a 79-year-old woman with chronic, treated primary hypothyroidism, presenting with increasing levothyroxine requirement while taking raloxifene at the same time as levothyroxine. For two 6- to 8-week periods, we separated the ingestion of raloxifene and levothyroxine by about 12 hours. In addition, we tested the absorption of 1.0 mg of levothyroxine sodium with and without the coadministration of 60 mg of raloxifene hydrochloride on 2 separate occasions by collecting serial blood samples for 6 hours. Hypothyroidism occurred in a reproducible fashion whenever levothyroxine and raloxifene were administered together and improved whenever they were taken separately. Combined administration of levothyroxine and raloxifene resulted in lower levels of serum thyroxine compared with administration of levothyroxine alone. By a yet unknown mechanism, raloxifene caused malabsorption of levothyroxine in our patient when coadministered.

[Congenital intestinal lymphangiectasia].

PubMed

Popović, Dugan D j; Spuran, Milan; Alempijević, Tamara; Krstić, Miodrag; Djuranović, Srdjan; Kovacević, Nada; Damnjanović, Svetozar; Micev, Marjan

2011-03-01

Congenital intestinal lymphangiectasia is a disease which leads to protein losing enteropathy. Tortuous, dilated lymphatic vessels in the intestinal wall and mesenterium are typical features of the disease. Clinical manifestations include malabsorption, diarrhea, steatorrhea, edema and effusions. Specific diet and medication are required for disease control. A 19-year old male patient was hospitalized due to diarrhea, abdominal swelling, weariness and fatigue. Physical examination revealed growth impairment, ascites, and lymphedema of the right hand and forearm. Laboratory assessment indicated iron deficiency anaemia, lymphopenia, malabsorption, inflammatory syndrome, and urinary infection. Enteroscopy and video capsule endoscopy demonstrated dilated lymphatic vessels in the small intestine. The diagnosis was confirmed by intestinal biopsy. The patient was put on high-protein diet containing medium-chain fatty acids, somatotropin and supportive therapy. Congenital intestinal lymphangiectasia is a rare disease, usually diagnosed in childhood. Early recognition of the disease and adequate treatment can prevent development of various complications.

Severe rickets in a young girl caused by celiac disease: the tragedy of delayed diagnosis: a case report.

PubMed

Al-Sharafi, Butheinah A; Al-Imad, Shafiq A; Shamshair, Amani M; Al-Faqeeh, Derhim H

2014-10-08

Celiac disease is a systemic immune mediated disease which usually presents with gastrointestinal symptoms, but it may present with extra gastrointestinal manifestations such as metabolic bone disease and failure to thrive. This may lead to a delay in the diagnosis. We present a 13 year old female from the middle east with an 8 year history of severe rickets causing multiple bone deformities leaving the child crippled with bowing of both of her arms and legs. The patient was also found to have growth failure, anemia and on further workup she was found to have celiac disease. We are presenting this case because it shows a severe case of rickets after malabsorption for many years. Celiac disease should be kept in mind as a cause of rickets in patients not responding to usual forms of treatment or when associated with other manifestations of malabsorption.

Steatorrhea in patients with liver disease

PubMed Central

Williams, C. N.; Sidorov, J. J.

1971-01-01

Intestinal function was studied in 26 patients with seven types of acute and chronic liver disease, documented by liver biopsy. Steatorrhea, defined by a stool fat higher than 6 g. per day, was present in 18 of 23 consecutive patients studied, an incidence of 78.3%. Two patients with infectious hepatitis associated with steatorrhea studied previously were added and the 20 cases were analyzed. The malabsorption found was confined to fat and fat-soluble vitamins; stool excretion varied from 6.1 to 22 g. per day in the seven groups studied. No histological abnormality was seen on jejunal biopsy, serum vitamin B12, D-xylose and Schilling tests were normal, and no radiological findings associated with malabsorption were detected in the small bowel. It is concluded that steatorrhea is a common finding in a wide variety of acute and chronic liver diseases and cannot be attributed to a primary defect of the small bowel. PMID:5150072

Long-term patency, pancreatic function, and pain relief after lateral pancreaticojejunostomy for chronic pancreatitis.

PubMed

Warshaw, A L; Popp, J W; Schapiro, R H

1980-08-01

Ten patients, all with intractable pain due to chronic pancreatitis, were selected for treatment by lateral pancreaticojejunostomy (modified Puestow procedure) after preoperative endoscopic pancreatography in each had revealed dilatation of the main pancreatic duct. Follow-up endoscopic pancreatograms performed 1 yr after surgery show a patent anastomosis in all 10 patients. Eight of these 10 are largely or completely pain-free, but 2 continiue to have pain without improvement after the operation. Surgical success in relieving pain was accompanied neither by improvement in pancreatic function, nor by protection against its further deterioration: Whereas 2 patients had malabsorption and 3 were diabetic preoperatively, 6 had malabsorption and 5 had diabetes postoperatively. This progression of exocrine or endorine pancreatic insufficiency indicates that decompression of the dilated pancreatic duct, although an effective means for relief of pain in chronic pancreatitis, does not prevent continuing destruction of pancreatic glandular tissue.

Right colon carcinoma infiltrating the alimentary limb in a patient with biliopancreatic diversion.

PubMed

López-Tomassetti Fernández, Eudaldo M; Hernández Hernández, Juan Ramón; Jorge, Valentine Nuñez

2014-01-01

Biliopancreatic diversion (BPD) has excellent results, with the average patient losing 60% to 80% of the excess weight in the first 2 years. However, the BPD works by malabsorption and malabsorptive problems may be experienced with the operation. Therefore, monitoring is necessary for life. In the recent literature there is some debate over the possibility that this technique can increase the risk of colon cancer secondary to the action of the unabsorbed food and bile acid on colonic mucosa. We report the case of a 42-year-old patient with a previous bariatric surgery (BPD with 50 cm common channel; 300 cm alimentary limb) who developed a very aggressive right colon cancer 6 years after the operation. We also review our series of 330 patients operated on during a 14-year period to try to answer if there is any relationship between BPD and colon cancer.

Impact of folate therapy on combined immunodeficiency secondary to hereditary folate malabsorption.

PubMed

Kishimoto, Kenji; Kobayashi, Ryoji; Sano, Hirozumi; Suzuki, Daisuke; Maruoka, Hayato; Yasuda, Kazue; Chida, Natsuko; Yamada, Masafumi; Kobayashi, Kunihiko

2014-07-01

Hereditary folate malabsorption (HFM) is a rare autosomal recessive disorder. Severe folate deficiency in HFM can result in immunodeficiency. We describe a female infant with HFM who acquired severe Pneumocystis pneumonia. The objective of the present study was to elucidate her immunological phenotype and to examine the time course of immune recovery following parenteral folate therapy. The patient demonstrated a combined immunodeficiency with an impaired T cell proliferation response, pan-hypogammaglobulinemia, and an imbalanced pro-inflammatory cytokine profile. She had normal white blood cell count, normal lymphocyte subsets, and normal complement levels. Two novel mutations were identified within the SLC46A1 gene to produce a compound heterozygote. We confirmed full recovery of her immunological and neurophysiological status with parenteral folate replacement. The time course of recovery of her immunological profile varied widely, however. HFM should be recognized as a unique form of immunodeficiency. Copyright © 2014 Elsevier Inc. All rights reserved.

Long-term effect of medical treatment of diarrhoea in 377 patients with SeHCAT scan diagnosed bile acid malabsorption from 2003 to 2016; a retrospective study.

PubMed

Damsgaard, B; Dalby, H R; Krogh, K; Jørgensen, S M D; Arveschough, A K; Agnholt, J; Dahlerup, J F; Jørgensen, S P

2018-04-01

Excessive amounts of bile acids entering the colon due to bile acid malabsorption cause chronic bile acid diarrhoea. Diagnosis is possible by measuring the retention fraction of orally ingested 75 Selenium homotaurocholic acid (SeHCAT). The knowledge of long-term effects of medical treatment is sparse. To describe diarrhoea, adherence to treatment, treatment effects and quality of life in a large, well-defined cohort of patients with bile acid diarrhoea. A retrospective survey was performed among 594 patients with bile acid malabsorption verified by SeHCAT scans at our unit between 2003 and 2016. Questionnaires about medical history, diarrhoea, use of medication, and quality of life scores were mailed to all patients. Among 594 patients 377 (69%) responded. Among respondents, 121 (32%) had bile acid diarrhoea due to ileal disease or resection (type 1), 198 (52%) idiopathic bile acid diarrhoea (type 2) and 58 (16%) bile acid diarrhoea due to other non-ileal disease, mainly cholecystectomy (type 3). At follow-up, half of the patients, 184 (50%), reported improvement of diarrhoea. However, 273 patients (74%) still reported diarrhoea and 234 (62%) regularly used anti-diarrhoeal medication. In spite of treatment, 235 (64%) considered reduced quality of life by diarrhoea and 184 (50%) reported that diarrhoea was unaltered or worse than before established diagnosis. Many patients with bile acid diarrhoea continue to have bothersome diarrhoea in spite of correct diagnosis and treatment. © 2018 John Wiley & Sons Ltd.

Nuclear transit study in children with chronic faecal soiling after Hirschsprung disease (HSCR) surgery has revealed a group with rapid proximal colonic treatment and possible adverse reactions to food.

PubMed

Stathopoulos, Lefteris; King, Sebastian K; Southwell, Bridget R; Hutson, John M

2016-08-01

Long-term problems with faecal incontinence occur in up to 50 % of patients after pull-through for Hirschsprung disease (HSCR). The cause often remains unknown, leading to empirical treatments. Using nuclear transit study, we found some patients surprisingly had rapid proximal colonic transit, suspicious of occult diarrhoea. We aimed to assess whether these patients had unrecognized adverse reactions to food. Patients (n = 10, all males, 9.6 year; 4.25-15.5 years) with persistent faecal incontinence following pull-through for HSCR referred to the senior author and after exclusion of anatomical defects, underwent nuclear transit studies. Most (8) subsequently underwent breath hydrogen tests for sugar malabsorption and were tested for adverse reactions to food. Exclusion diets for protein allergens, lactose or fructose were then trialed. Of the 10 patients with rapid intestinal transit proven on nuclear transit study, breath hydrogen tests for fructose and/or lactose malabsorption were done in 8, and were positive in 7/8 patients. Exclusion diets contributed to either resolution or improvement in faecal incontinence in 9/10 patients. Rapid transit in the proximal, ganglionated colon may be present in children with faecal incontinence following pull-through for HSCR, possibly secondary to adverse reactions to food. This study suggests that children with post-operative soiling may benefit from a transit study and hydrogen breath tests to diagnose adverse reactions to food caused by sugar malabsorption.

Bariatric surgery and vitamin D: key messages for surgeons and clinicians before and after bariatric surgery.

PubMed

Peterson, Leigh A

2016-10-01

Obesity is the most widespread nutritional problem globally. Bariatric surgery is the preeminent long-term obesity treatment. Bariatric procedures manipulate the intestines to produces malabsorption and/or restrict the size of the stomach. The most enduring bariatric procedure is the Roux-en-Y gastric bypass, which utilizes both restriction (small stomach pouch) and malabsorption (duodenum bypass). The in-vogue procedure is the vertical sleeve gastrectomy - resection of the greater curvature of the stomach (predominantly restrictive). Malabsorptive procedures function by decreasing nutrient absorption, primarily fat and fat-soluble nutrients (vitamins A, D, E, and K). Most studies of vitamin D status in bariatric surgery candidates reported a prevalence of over 50% vitamin D deficiency (<50 nmol/L), enduring post-operatively with one study reporting 65% deficient at 10 years post-bariatric surgery. Obesity is associated with chronic inflammation, which may contribute to adverse surgical outcomes, e.g. poor healing and infection. Since vitamin D deficiency is also associated with chronic inflammation, obese individuals with vitamin D deficiency have extraordinary risk of adverse surgical outcomes, particularly delayed wound healing and infection due to the role of vitamin D in re-epithelialization and innate immunity. When the risk of adverse surgical outcomes in obesity is combined with that of vitamin D deficiency, there is likely an additive or potentially a synergistic effect. Furthermore, deficiency in fat-soluble vitamins, such as vitamin D, is considered a metabolic complication of bariatric surgery. Thus, determining the vitamin D status of bariatric surgery candidates and amending it preoperatively may prove greatly beneficial acutely and lifelong.

Analysis of the surfaces of wood tissues and pulp fibers using carbohydrate-binding modules specific for crystalline cellulose and mannan.

PubMed

Filonova, Lada; Kallas, Asa M; Greffe, Lionel; Johansson, Gunnar; Teeri, Tuula T; Daniel, Geoffrey

2007-01-01

Carbohydrate binding modules (CBMs) are noncatalytic substrate binding domains of many enzymes involved in carbohydrate metabolism. Here we used fluorescent labeled recombinant CBMs specific for crystalline cellulose (CBM1(HjCel7A)) and mannans (CBM27(TmMan5) and CBM35(CjMan5C)) to analyze the complex surfaces of wood tissues and pulp fibers. The crystalline cellulose CBM1(HjCel7A) was found as a reliable marker of both bacterially produced and plant G-layer cellulose, and labeling of spruce pulp fibers with CBM1(HjCel7A) revealed a signal that increased with degree of fiber damage. The mannan-specific CBM27(TmMan5) and CBM35(CjMan5C) CBMs were found to be more specific reagents than a monoclonal antibody specific for (1-->4)-beta-mannan/galacto-(1-->4)-beta-mannan for mapping carbohydrates on native substrates. We have developed a quantitative fluorometric method for analysis of crystalline cellulose accumulation on fiber surfaces and shown a quantitative difference in crystalline cellulose binding sites in differently processed pulp fibers. Our results indicated that CBMs provide useful, novel tools for monitoring changes in carbohydrate content of nonuniform substrate surfaces, for example, during wood or pulping processes and possibly fiber biosynthesis.

Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium1

USDA-ARS?s Scientific Manuscript database

Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively impact immune status and prevent colonization and shedding in Salmonell...

Ultrasonography to investigate the effect of supplementing whole milk with complex carbohydrates and specific amino acids on curd retention in the abomasum of dairy calves.

PubMed

Singh, K; Leath, S R; Henderson, H V; Molenaar, A J; Watson, T J; Pacheco, D; McMahon, C D

2016-09-01

To determine whether the retention time of curd in the abomasum of calves was influenced by supplementing milk with a plant-derived carbohydrate and amino acid supplement, evaluated non-invasively using ultrasonography. Female dairy calves aged between 2-6 days of age were sourced from a commercial farm in March 2013. All calves were fed whole milk until weaning (4 L per day); 21 calves were supplemented with a probiotic until 18 days of age, and thereafter with a plant-derived complex carbohydrate and amino acid supplement until weaning, and 22 calves were just fed whole milk. Treatment groups were balanced for age, weight and breed. At 9-14, 24-29 and 52-57 days of age, the abomasum of each calf was examined using ultrasonography immediately before and after feeding, 1 and 2 hours after feeding, and then at 30 minute intervals until curd was no longer visible in the abomasum. Abomasal volume and curd size were recorded to assess retention time of curd in the abomasum. At 9-14 days of age, mean retention time of curd in the abomasum was similar (4.6 hours) in both groups. At 24-29 days of age, when the supplemented calves had been receiving the supplement for approximately 10 days, mean curd retention time was longer by 1.4 (SE 0.28) hours in supplemented compared with unsupplemented calves (p<0.001). At 52-57 days of age, mean retention time was longer by 0.7 (SE 0.34) hours compared to unsupplemented calves (p=0.05). Using ultrasonography, changes in abomasal content could be followed non-invasively over time and it was demonstrated that the plant-derived complex carbohydrate supplement increased the curd retention time in the abomasum. We speculate that the increased retention time enables an increased availability of nutrients following a more complete digestion of milk, thereby improving animal performance.

A Central Role of Abscisic Acid in Stress-Regulated Carbohydrate Metabolism

PubMed Central

Kempa, Stefan; Krasensky, Julia; Dal Santo, Silvia; Kopka, Joachim; Jonak, Claudia

2008-01-01

Background Abiotic stresses adversely affect plant growth and development. The hormone abscisic acid (ABA) plays a central role in the response and adaptation to environmental constraints. However, apart from the well established role of ABA in regulating gene expression programmes, little is known about its function in plant stress metabolism. Principal Findings Using an integrative multiparallel approach of metabolome and transcriptome analyses, we studied the dynamic response of the model glyophyte Arabidopsis thaliana to ABA and high salt conditions. Our work shows that salt stress induces complex re-adjustment of carbohydrate metabolism and that ABA triggers the initial steps of carbon mobilisation. Significance These findings open new perspectives on how high salinity and ABA impact on central carbohydrate metabolism and highlight the power of iterative combinatorial approaches of non-targeted and hypothesis-driven experiments in stress biology. PMID:19081841

Anticoagulant activity of marine green and brown algae collected from Jeju Island in Korea.

PubMed

Athukorala, Yasantha; Lee, Ki-Wan; Kim, Se-Kwon; Jeon, You-Jin

2007-07-01

Twenty-two algal species were evaluated for their potential anticoagulant activities. Hot water extracts from selected species, Codium fragile and Sargassum horneri showed high activated partial thromboplastin time (APTT). Ultraflo extract of C. fragile and S. horneri exhibited the most potent anticoagulant activity. Furthermore, in both algal species, active compounds were mainly concentrated in >30kDa faction. The crude polysaccharide fraction (>30kDa; CpoF) of C. fragile composed of approximately 80% carbohydrate and approximately 19% of protein; the crude polysaccharide fraction (>30kDa; CpoF) of S. horneri was composed of 97% of carbohydrate and approximately 2% of protein. Therefore, most probably the active compound, or compounds of the algal species were related to high molecular weight polysaccharide, or a complex form with carbohydrate and protein (proteoglycan).

The Use of NMR to Study Transient Carbohydrate-Protein Interactions.

PubMed

Nieto, Pedro M

2018-01-01

Carbohydrates are biologically ubiquitous and are essential to the existence of all known living organisms. Although they are better known for their role as energy sources (glucose/glycogen or starch) or structural elements (chitin or cellulose), carbohydrates also participate in the recognition events of molecular recognition processes. Such interactions with other biomolecules (nucleic acids, proteins, and lipids) are fundamental to life and disease. This review focuses on the application of NMR methods to understand at the atomic level the mechanisms by which sugar molecules can be recognized by proteins to form complexes, creating new entities with different properties to those of the individual component molecules. These processes have recently gained attention as new techniques have been developed, while at the same time old techniques have been reinvented and adapted to address newer emerging problems.

Vitamins and Minerals

MedlinePlus

... The water-soluble vitamins — C and the B-complex vitamins (such as vitamins B6, B12, niacin, riboflavin, ... day, as well as the right balance of carbohydrates, proteins, fats, and calories. Whole or unprocessed foods — ...

Metabolic alterations in children with environmental enteric dysfunction

USDA-ARS?s Scientific Manuscript database

Environmental enteric dysfunction, an asymptomatic condition characterized by inflammation of the small bowel mucosa, villous atrophy, malabsorption, and increased intestinal permeability, is a major contributor to childhood stunting in low-income countries. Here we report the relationship of increa...

Transcriptomes of Arbuscular Mycorrhizal Fungi and Litchi Host Interaction after Tree Girdling

PubMed Central

Shu, Bo; Li, Weicai; Liu, Liqin; Wei, Yongzan; Shi, Shengyou

2016-01-01

Trunk girdling can increase carbohydrate content above the girdling site and is an important strategy for inhibiting new shoot growth to promote flowering in cultivated litchi (Litchi chinensis Sonn.). However, girdling inhibits carbohydrate transport to the root in nearly all of the fruit development periods and consequently decreases root absorption. The mechanism through which carbohydrates regulate root development in arbuscular mycorrhiza (AM) remains largely unknown. Carbohydrate content, AM colonization, and transcriptome in the roots were analyzed to elucidate the interaction between host litchi and AM fungi when carbohydrate content decreases. Girdling decreased glucose, fructose, sucrose, quebrachitol, and starch contents in the litchi mycorrhizal roots, thereby reducing AM colonization. RNA-seq achieved approximately 60 million reads of each sample, with an average length of reads reaching 100 bp. Assembly of all the reads of the 30 samples produced 671,316 transcripts and 381,429 unigenes, with average lengths of 780 and 643 bp, respectively. Litchi (54,100 unigenes) and AM fungi unigenes (33,120 unigenes) were achieved through sequence annotation during decreased carbohydrate content. Analysis of differentially expressed genes (DEG) showed that flavonoids, alpha-linolenic acid, and linoleic acid are the main factors that regulate AM colonization in litchi. However, flavonoids may play a role in detecting the stage at which carbohydrate content decreases; alpha-linolenic acid or linoleic acid may affect AM formation under the adaptation process. Litchi trees stimulated the expression of defense-related genes and downregulated symbiosis signal-transduction genes to inhibit new AM colonization. Moreover, transcription factors of the AP2, ERF, Myb, WRKY, bHLH families, and lectin genes altered maintenance of litchi mycorrhizal roots in the post-symbiotic stage for carbohydrate starvation. Similar to those of the litchi host, the E3 ubiquitin ligase complex SCF subunit scon-3 and polyubiquitin of AM fungi were upregulated at the perceived stages. This occurrence suggested that ubiquitination plays an important role in perceiving carbohydrate decrease in AM fungi. The transcription of cytochrome b-245 and leucine-rich repeat was detected in the DEG database, implying that the transcripts were involved in AM fungal adaptation under carbohydrate starvation. The transcriptome data might suggest novel functions of unigenes in carbohydrate shortage of mycorrhizal roots. PMID:27065972

Transcriptomes of Arbuscular Mycorrhizal Fungi and Litchi Host Interaction after Tree Girdling.

PubMed

Shu, Bo; Li, Weicai; Liu, Liqin; Wei, Yongzan; Shi, Shengyou

2016-01-01

Trunk girdling can increase carbohydrate content above the girdling site and is an important strategy for inhibiting new shoot growth to promote flowering in cultivated litchi (Litchi chinensis Sonn.). However, girdling inhibits carbohydrate transport to the root in nearly all of the fruit development periods and consequently decreases root absorption. The mechanism through which carbohydrates regulate root development in arbuscular mycorrhiza (AM) remains largely unknown. Carbohydrate content, AM colonization, and transcriptome in the roots were analyzed to elucidate the interaction between host litchi and AM fungi when carbohydrate content decreases. Girdling decreased glucose, fructose, sucrose, quebrachitol, and starch contents in the litchi mycorrhizal roots, thereby reducing AM colonization. RNA-seq achieved approximately 60 million reads of each sample, with an average length of reads reaching 100 bp. Assembly of all the reads of the 30 samples produced 671,316 transcripts and 381,429 unigenes, with average lengths of 780 and 643 bp, respectively. Litchi (54,100 unigenes) and AM fungi unigenes (33,120 unigenes) were achieved through sequence annotation during decreased carbohydrate content. Analysis of differentially expressed genes (DEG) showed that flavonoids, alpha-linolenic acid, and linoleic acid are the main factors that regulate AM colonization in litchi. However, flavonoids may play a role in detecting the stage at which carbohydrate content decreases; alpha-linolenic acid or linoleic acid may affect AM formation under the adaptation process. Litchi trees stimulated the expression of defense-related genes and downregulated symbiosis signal-transduction genes to inhibit new AM colonization. Moreover, transcription factors of the AP2, ERF, Myb, WRKY, bHLH families, and lectin genes altered maintenance of litchi mycorrhizal roots in the post-symbiotic stage for carbohydrate starvation. Similar to those of the litchi host, the E3 ubiquitin ligase complex SCF subunit scon-3 and polyubiquitin of AM fungi were upregulated at the perceived stages. This occurrence suggested that ubiquitination plays an important role in perceiving carbohydrate decrease in AM fungi. The transcription of cytochrome b-245 and leucine-rich repeat was detected in the DEG database, implying that the transcripts were involved in AM fungal adaptation under carbohydrate starvation. The transcriptome data might suggest novel functions of unigenes in carbohydrate shortage of mycorrhizal roots.

Composition of the carbohydrate granules of the cyanobacterium, Cyanothece sp. strain ATCC 51142

NASA Technical Reports Server (NTRS)

Schneegurt, M. A.; Sherman, D. M.; Sherman, L. A.; Mitchell, C. A. (Principal Investigator)

1997-01-01

Cyanothece sp. strain ATCC 51142 is an aerobic, unicellular, diazotrophic cyanobacterium that temporally separates O2-sensitive N2 fixation from oxygenic photosynthesis. The energy and reducing power needed for N2 fixation appears to be generated by an active respiratory apparatus that utilizes the contents of large interthylakoidal carbohydrate granules. We report here on the carbohydrate and protein composition of the granules of Cyanothece sp. strain ATCC 51142. The carbohydrate component is a glucose homopolymer with branches every nine residues and is chemically identical to glycogen. Granule-associated protein fractions showed temporal changes in the number of proteins and their abundance during the metabolic oscillations observed under diazotrophic conditions. There also were temporal changes in the protein pattern of the granule-depleted supernatant fractions from diazotrophic cultures. None of the granule-associated proteins crossreacted with antisera directed against several glycogen-metabolizing enzymes or nitrogenase, although these proteins were tentatively identified in supernatant fractions. It is suggested that the granule-associated proteins are structural proteins required to maintain a complex granule architecture.

Ca2+-Citrate Uptake and Metabolism in Lactobacillus casei ATCC 334

PubMed Central

Mortera, Pablo; Pudlik, Agata; Magni, Christian; Alarcón, Sergio

2013-01-01

The putative citrate metabolic pathway in Lactobacillus casei ATCC 334 consists of the transporter CitH, a proton symporter of the citrate-divalent metal ion family of transporters CitMHS, citrate lyase, and the membrane-bound oxaloacetate decarboxylase complex OAD-ABDH. Resting cells of Lactobacillus casei ATCC 334 metabolized citrate in complex with Ca2+ and not as free citrate or the Mg2+-citrate complex, thereby identifying Ca2+-citrate as the substrate of the transporter CitH. The pathway was induced in the presence of Ca2+ and citrate during growth and repressed by the presence of glucose and of galactose, most likely by a carbon catabolite repression mechanism. The end products of Ca2+-citrate metabolism by resting cells of Lb. casei were pyruvate, acetate, and acetoin, demonstrating the activity of the membrane-bound oxaloacetate decarboxylase complex OAD-ABDH. Following pyruvate, the pathway splits into two branches. One branch is the classical citrate fermentation pathway producing acetoin by α-acetolactate synthase and α-acetolactate decarboxylase. The other branch yields acetate, for which the route is still obscure. Ca2+-citrate metabolism in a modified MRS medium lacking a carbohydrate did not significantly affect the growth characteristics, and generation of metabolic energy in the form of proton motive force (PMF) was not observed in resting cells. In contrast, carbohydrate/Ca2+-citrate cometabolism resulted in a higher biomass yield in batch culture. However, also with these cells, no generation of PMF was associated with Ca2+-citrate metabolism. It is concluded that citrate metabolism in Lb. casei is beneficial when it counteracts acidification by carbohydrate metabolism in later growth stages. PMID:23709502

Carbohydrate catabolic flexibility in the mammalian intestinal commensal Lactobacillus ruminis revealed by fermentation studies aligned to genome annotations

PubMed Central

2011-01-01

Background Lactobacillus ruminis is a poorly characterized member of the Lactobacillus salivarius clade that is part of the intestinal microbiota of pigs, humans and other mammals. Its variable abundance in human and animals may be linked to historical changes over time and geographical differences in dietary intake of complex carbohydrates. Results In this study, we investigated the ability of nine L. ruminis strains of human and bovine origin to utilize fifty carbohydrates including simple sugars, oligosaccharides, and prebiotic polysaccharides. The growth patterns were compared with metabolic pathways predicted by annotation of a high quality draft genome sequence of ATCC 25644 (human isolate) and the complete genome of ATCC 27782 (bovine isolate). All of the strains tested utilized prebiotics including fructooligosaccharides (FOS), soybean-oligosaccharides (SOS) and 1,3:1,4-β-D-gluco-oligosaccharides to varying degrees. Six strains isolated from humans utilized FOS-enriched inulin, as well as FOS. In contrast, three strains isolated from cows grew poorly in FOS-supplemented medium. In general, carbohydrate utilisation patterns were strain-dependent and also varied depending on the degree of polymerisation or complexity of structure. Six putative operons were identified in the genome of the human isolate ATCC 25644 for the transport and utilisation of the prebiotics FOS, galacto-oligosaccharides (GOS), SOS, and 1,3:1,4-β-D-Gluco-oligosaccharides. One of these comprised a novel FOS utilisation operon with predicted capacity to degrade chicory-derived FOS. However, only three of these operons were identified in the ATCC 27782 genome that might account for the utilisation of only SOS and 1,3:1,4-β-D-Gluco-oligosaccharides. Conclusions This study has provided definitive genome-based evidence to support the fermentation patterns of nine strains of Lactobacillus ruminis, and has linked it to gene distribution patterns in strains from different sources. Furthermore, the study has identified prebiotic carbohydrates with the potential to promote L. ruminis growth in vivo. PMID:21995520

Plant Carbohydrate Scavenging through TonB-Dependent Receptors: A Feature Shared by Phytopathogenic and Aquatic Bacteria

PubMed Central

Boulanger, Alice; Lautier, Martine; Guynet, Catherine; Denancé, Nicolas; Vasse, Jacques

2007-01-01

TonB-dependent receptors (TBDRs) are outer membrane proteins mainly known for the active transport of iron siderophore complexes in Gram-negative bacteria. Analysis of the genome of the phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc), predicts 72 TBDRs. Such an overrepresentation is common in Xanthomonas species but is limited to only a small number of bacteria. Here, we show that one Xcc TBDR transports sucrose with a very high affinity, suggesting that it might be a sucrose scavenger. This TBDR acts with an inner membrane transporter, an amylosucrase and a regulator to utilize sucrose, thus defining a new type of carbohydrate utilization locus, named CUT locus, involving a TBDR for the transport of substrate across the outer membrane. This sucrose CUT locus is required for full pathogenicity on Arabidopsis, showing its importance for the adaptation to host plants. A systematic analysis of Xcc TBDR genes and a genome context survey suggested that several Xcc TBDRs belong to other CUT loci involved in the utilization of various plant carbohydrates. Interestingly, several Xcc TBDRs and CUT loci are conserved in aquatic bacteria such as Caulobacter crescentus, Colwellia psychrerythraea, Saccharophagus degradans, Shewanella spp., Sphingomonas spp. or Pseudoalteromonas spp., which share the ability to degrade a wide variety of complex carbohydrates and display TBDR overrepresentation. We therefore propose that TBDR overrepresentation and the presence of CUT loci designate the ability to scavenge carbohydrates. Thus CUT loci, which seem to participate to the adaptation of phytopathogenic bacteria to their host plants, might also play a very important role in the biogeochemical cycling of plant-derived nutrients in marine environments. Moreover, the TBDRs and CUT loci identified in this study are clearly different from those characterized in the human gut symbiont Bacteroides thetaiotaomicron, which allow glycan foraging, suggesting a convergent evolution of TBDRs in Proteobacteria and Bacteroidetes. PMID:17311090

The geometric framework for nutrition reveals interactions between protein and carbohydrate during larval growth in honey bees

PubMed Central

Slater, Garett P.; Rajamohan, Arun; Yocum, George D.; Greenlee, Kendra J.; Bowsher, Julia H.

2017-01-01

ABSTRACT In holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diets are often complex and may interact with one another, necessitating the use of a geometric framework for elucidating nutritional effects. In the honey bee, Apis mellifera, nurse bees provision food to developing larvae, directly moderating growth rates and caste development. However, the eusocial nature of honey bees makes nutritional studies challenging, because diet components cannot be systematically manipulated in the hive. Using in vitro rearing, we investigated the roles and interactions between carbohydrate and protein content on larval survival, growth, and development in A. mellifera. We applied a geometric framework to determine how these two nutritional components interact across nine artificial diets. Honey bees successfully completed larval development under a wide range of protein and carbohydrate contents, with the medium protein (∼5%) diet having the highest survival. Protein and carbohydrate both had significant and non-linear effects on growth rate, with the highest growth rates observed on a medium-protein, low-carbohydrate diet. Diet composition did not have a statistically significant effect on development time. These results confirm previous findings that protein and carbohydrate content affect the growth of A. mellifera larvae. However, this study identified an interaction between carbohydrate and protein content that indicates a low-protein, high-carb diet has a negative effect on larval growth and survival. These results imply that worker recruitment in the hive would decline under low protein conditions, even when nectar abundance or honey stores are sufficient. PMID:28396492

Energy Expenditure and Hormone Responses in Humans After Overeating High-Fructose Corn Syrup Versus Whole-Wheat Foods.

PubMed

Ibrahim, Mostafa; Bonfiglio, Susan; Schlögl, Mathias; Vinales, Karyne L; Piaggi, Paolo; Venti, Colleen; Walter, Mary; Krakoff, Jonathan; Thearle, Marie S

2018-01-01

This study sought to understand how the dietary source of carbohydrates, either high-fructose corn syrup (HFCS) or complex carbohydrates, affects energy expenditure (EE) measures, appetitive sensations, and hormones during 24 hours of overfeeding. Seventeen healthy participants with normal glucose regulation had 24-hour EE measures and fasting blood and 24-hour urine collection during four different 1-day diets, including an energy-balanced diet, fasting, and two 75% carbohydrate diets (5% fat) given at 200% of energy requirements with either HFCS or whole-wheat foods as the carbohydrate source. In eight volunteers, hunger was assessed with visual analog scales the morning after the diets. Compared with energy balance, 24-hour EE increased 12.8% ± 6.9% with carbohydrate overfeeding (P < 0.0001). No differences in 24-hour EE or macronutrient utilization were observed between the two high-carbohydrate diets; however, sleeping metabolic rate was higher after the HFCS diet (Δ = 35 ± 48 kcal [146 ± 200 kJ]; P = 0.01). Insulin, ghrelin, and triglycerides increased the morning after both overfeeding diets. Urinary cortisol concentrations (82.8 ± 35.9 vs. 107.6 ± 46.9 nmol/24 h; P = 0.01) and morning-after hunger scores (Δ = 2.4 ± 2.0 cm; P = 0.01) were higher with HFCS overfeeding. The dietary carbohydrate source while overeating did not affect 24-hour EE, but HFCS overconsumption may predispose individuals to further overeating due to increased glucocorticoid release and increased hunger the following morning. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Protein flexibility and conformational entropy in ligand design targeting the carbohydrate recognition domain of galectin-3.

PubMed

Diehl, Carl; Engström, Olof; Delaine, Tamara; Håkansson, Maria; Genheden, Samuel; Modig, Kristofer; Leffler, Hakon; Ryde, Ulf; Nilsson, Ulf J; Akke, Mikael

2010-10-20

Rational drug design is predicated on knowledge of the three-dimensional structure of the protein-ligand complex and the thermodynamics of ligand binding. Despite the fundamental importance of both enthalpy and entropy in driving ligand binding, the role of conformational entropy is rarely addressed in drug design. In this work, we have probed the conformational entropy and its relative contribution to the free energy of ligand binding to the carbohydrate recognition domain of galectin-3. Using a combination of NMR spectroscopy, isothermal titration calorimetry, and X-ray crystallography, we characterized the binding of three ligands with dissociation constants ranging over 2 orders of magnitude. (15)N and (2)H spin relaxation measurements showed that the protein backbone and side chains respond to ligand binding by increased conformational fluctuations, on average, that differ among the three ligand-bound states. Variability in the response to ligand binding is prominent in the hydrophobic core, where a distal cluster of methyl groups becomes more rigid, whereas methyl groups closer to the binding site become more flexible. The results reveal an intricate interplay between structure and conformational fluctuations in the different complexes that fine-tunes the affinity. The estimated change in conformational entropy is comparable in magnitude to the binding enthalpy, demonstrating that it contributes favorably and significantly to ligand binding. We speculate that the relatively weak inherent protein-carbohydrate interactions and limited hydrophobic effect associated with oligosaccharide binding might have exerted evolutionary pressure on carbohydrate-binding proteins to increase the affinity by means of conformational entropy.

Metaphyseal chondrodysplasia.

PubMed Central

Spranger, J. W.

1977-01-01

Any review of the metaphyseal chondrodysplasias is complicated by their variety and mainly unknown pathogenesis. The more familiar types display considerable clinical and radiological diversity: even more so the rarer disorders which still require complete definition, but differences in their mode of inheritance make diagnostic precision mandatory. These dysplasias present in infancy or in childhood, when the patient, usually dwarfed, may be proportionate, so that some forms may be confused with rickets or other lesions. Mental retardation is unusual, but the skin, hair, nails and facies provide valuable diagnostic features. Radiological abnormalities mainly affect the metaphyses of the shortened limb bones, less often the skull, vertebrae, pelvis, ribs and extremities, and sometimes their distribution may indicate the specific type of dysplasia. In a further complex group multiple systems are involved, notably the pancreas, intestine and lympho-reticular, causing malabsorption and haematological or immunological disorders. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:335375

Bioanalytical Methods for Food Contaminant Analysis

EPA Science Inventory

Foods are complex mixtures of lipids, carbohydrates, proteins, vitamins, organic compounds and other naturally occurring compounds. Sometimes added to this mixture are residues of pesticides, veterinary and human drugs, microbial toxins, preservatives, contaminants from food proc...

Metabolism and Weight Loss: How You Burn Calories

MedlinePlus

... you eat and drink into energy. During this complex biochemical process, calories in food and beverages are ... About 10 percent of the calories from the carbohydrates and protein you eat are used during the ...

Micronutrients in Parenteral Nutrition: Boron, Silicon, and Fluoride

USDA-ARS?s Scientific Manuscript database

Long-term parenteral nutrition (providing nutrients intravenously) is a life-saving treatment for patients with severe malabsorption of nutrients caused by intestinal failure, intestinal trauma (for example, gunshot or stab wounds), and intestinal removal. Metabolic bone disease characterized by min...

Cadherin Domains in the Polysaccharide-Degrading Marine Bacterium Saccharophagus degradans 2-40 Are Carbohydrate-Binding Modules▿

PubMed Central

Fraiberg, Milana; Borovok, Ilya; Bayer, Edward A.; Weiner, Ronald M.; Lamed, Raphael

2011-01-01

The complex polysaccharide-degrading marine bacterium Saccharophagus degradans strain 2-40 produces putative proteins that contain numerous cadherin and cadherin-like domains involved in intercellular contact interactions. The current study reveals that both domain types exhibit reversible calcium-dependent binding to different complex polysaccharides which serve as growth substrates for the bacterium. PMID:21036994

Recognition and Degradation of Plant Cell Wall Polysaccharides by Two Human Gut Symbionts

PubMed Central

Chiang, Herbert; Pudlo, Nicholas A.; Wu, Meng; McNulty, Nathan P.; Abbott, D. Wade; Henrissat, Bernard; Gilbert, Harry J.; Bolam, David N.; Gordon, Jeffrey I.

2011-01-01

Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for catabolism of many complex carbohydrates. However, the role of these systems in degrading the chemically diverse repertoire of plant cell wall glycans remains unknown. Here we show that two closely related human gut Bacteroides, B. thetaiotaomicron and B. ovatus, are capable of utilizing nearly all of the major plant and host glycans, including rhamnogalacturonan II, a highly complex polymer thought to be recalcitrant to microbial degradation. Transcriptional profiling and gene inactivation experiments revealed the identity and specificity of the polysaccharide utilization loci (PULs) that encode individual Sus-like systems that target various plant polysaccharides. Comparative genomic analysis indicated that B. ovatus possesses several unique PULs that enable degradation of hemicellulosic polysaccharides, a phenotype absent from B. thetaiotaomicron. In contrast, the B. thetaiotaomicron genome has been shaped by increased numbers of PULs involved in metabolism of host mucin O-glycans, a phenotype that is undetectable in B. ovatus. Binding studies of the purified sensor domains of PUL-associated hybrid two-component systems in conjunction with transcriptional analyses demonstrate that complex oligosaccharides provide the regulatory cues that induce PUL activation and that each PUL is highly specific for a defined cell wall polymer. These results provide a view of how these species have diverged into different carbohydrate niches by evolving genes that target unique suites of available polysaccharides, a theme that likely applies to disparate bacteria from the gut and other habitats. PMID:22205877

Structural differences between the lignin-carbohydrate complexes present in wood and in chemical pulps.

PubMed

Lawoko, Martin; Henriksson, Gunnar; Gellerstedt, Göran

2005-01-01

Lignin-carbohydrate complexes (LCCs) were prepared in quantitative yield from spruce wood and from the corresponding kraft and oxygen-delignified pulps and were separated into different fractions on the basis of their carbohydrate composition. To obtain an understanding of the differences in lignin structure and reactivity within the various LCC fractions, thioacidolysis in combination with gas chromatography was used to quantify the content of beta-O-4 structures in the lignin. Periodate oxidation followed by determination of methanol was used to quantify the phenolic hydroxyl groups. Furthermore, size exclusion chromatography (SEC) of the thioacidolysis fractions was used to monitor any differences between the original molecular size distribution and that after the delignification processes. Characteristic differences between the various LCC fractions were observed, clearly indicating that two different forms of lignin are present in the wood fiber wall. These forms are linked to glucomannan and xylan, respectively. On pulping, the different LCCs have different reactivities. The xylan-linked lignin is to a large extent degraded, whereas the glucomannan-linked lignin undergoes a partial condensation to form more high molecular mass material. The latter seems to be rather unchanged during a subsequent oxygen-delignification stage. On the basis of these findings, a modified arrangement of the fiber wall polymers is suggested.

Solution conformation of carbohydrates: a view by using NMR assisted by modeling.

PubMed

Díaz, Dolores; Canales-Mayordomo, Angeles; Cañada, F Javier; Jiménez-Barbero, Jesús

2015-01-01

Structural elucidation of complex carbohydrates in solution is not a trivial task. From the NMR view point, the limited chemical shift dispersion of sugar NMR spectra demands the combination of a variety of NMR techniques as well as the employment of molecular modeling methods. Herein, a general protocol for assignment of resonances and determination of inter-proton distances within the saccharides by homonuclear and heteronuclear experiments (i.e., (1)H and (13)C) is described. In addition, several computational tools and procedures for getting a final ensemble of geometries that represent the structure in solution are presented.

The abundance and variety of carbohydrate-active enzymes in the human gut microbiota.

PubMed

El Kaoutari, Abdessamad; Armougom, Fabrice; Gordon, Jeffrey I; Raoult, Didier; Henrissat, Bernard

2013-07-01

Descriptions of the microbial communities that live on and in the human body have progressed at a spectacular rate over the past 5 years, fuelled primarily by highly parallel DNA-sequencing technologies and associated advances in bioinformatics, and by the expectation that understanding how to manipulate the structure and functions of our microbiota will allow us to affect health and prevent or treat diseases. Among the myriad of genes that have been identified in the human gut microbiome, those that encode carbohydrate-active enzymes (CAZymes) are of particular interest, as these enzymes are required to digest most of our complex repertoire of dietary polysaccharides. In this Analysis article, we examine the carbohydrate-digestive capacity of a simplified but representative mini-microbiome in order to highlight the abundance and variety of bacterial CAZymes that are represented in the human gut microbiota.

Cholecystokinin knockout mice are resistant to high-fat diet-induced obesity

PubMed Central

Lo, Chun-Min; King, Alexandra; Samuelson, Linda C; Kindel, Tammy Lyn; Rider, Therese; Jandacek, Ronald J; Raybould, Helen E; Woods, Stephen C; Tso, Patrick

2011-01-01

Background & Aims Cholecystokinin (CCK) is a satiation peptide released during meals in response to lipid intake; it regulates pancreatic digestive enzymes that are required for absorption of nutrients. We proposed that mice with a disruption in the CCK gene (CCK-KO mice) that were fed a diet of 20% butter fat would have altered fat metabolism. Methods We used quantitative magnetic resonance imaging to determine body composition and monitored food intake of CCK-KO mice using an automated measurement system. Intestinal fat absorption and energy expenditure were determined using a noninvasive assessment of intestinal fat absorption and an open circuit calorimeter, respectively. Results After consuming a high-fat diet for 10 weeks, CCK-KO mice had reduced body weight gain and body fat mass and enlarged adipocytes, despite the same level of food intake as wild-type mice. CCK-KO mice also had defects in fat absorption, especially of long-chain saturated fatty acids, but pancreatic triglyceride lipase (PTL) did not appear to have a role in the fat malabsorption. Energy expenditure was higher in CCK-KO than wild-type mice and CCK-KO mice had greater oxidation of carbohydrates while on the high-fat diet. Plasma leptin levels in the CCK-KO mice fed the high-fat diet were markedly lower than in wild-type mice, although levels of insulin, gastric-inhibitory polypeptide, and glucagon-like peptide-1 were normal. Conclusion CCK is involved in regulating the metabolic rate and is important for lipid absorption and control of body weight in mice placed on a high-fat diet. PMID:20117110

Genetics Home Reference: COG5-congenital disorder of glycosylation

MedlinePlus

... in my area? Other Names for This Condition carbohydrate deficient glycoprotein syndrome type IIi CDG IIi CDG2I ... the Golgi by the conserved oligomeric Golgi (COG) complex and the golgin TATA element modulatory factor (TMF). ...

Chemistry Notes.

ERIC Educational Resources Information Center

School Science Review, 1981

1981-01-01

Outlines a variety of laboratory procedures, discussions, and demonstrations including polarizing power and chemical properties of copper and zinc, preparation of boron coordination complex, demonstration of amino-acid synthesis in the primordial environment, classification and reactions of carbohydrates, and four others. (DS)

About the Operation: Liver Transplant

MedlinePlus

... liver is one of the largest and most complex organs in the body. It weighs about three pounds in adults and is made up ... for life. The liver helps process carbohydrates, fats and proteins, and stores vitamins. It processes ...

Evolution and diversity of plant cell walls: from algae to flowering plants.

PubMed

Popper, Zoë A; Michel, Gurvan; Hervé, Cécile; Domozych, David S; Willats, William G T; Tuohy, Maria G; Kloareg, Bernard; Stengel, Dagmar B

2011-01-01

All photosynthetic multicellular Eukaryotes, including land plants and algae, have cells that are surrounded by a dynamic, complex, carbohydrate-rich cell wall. The cell wall exerts considerable biological and biomechanical control over individual cells and organisms, thus playing a key role in their environmental interactions. This has resulted in compositional variation that is dependent on developmental stage, cell type, and season. Further variation is evident that has a phylogenetic basis. Plants and algae have a complex phylogenetic history, including acquisition of genes responsible for carbohydrate synthesis and modification through a series of primary (leading to red algae, green algae, and land plants) and secondary (generating brown algae, diatoms, and dinoflagellates) endosymbiotic events. Therefore, organisms that have the shared features of photosynthesis and possession of a cell wall do not form a monophyletic group. Yet they contain some common wall components that can be explained increasingly by genetic and biochemical evidence.

Dietary fiber and prebiotics and the gastrointestinal microbiota

PubMed Central

Holscher, Hannah D.

2017-01-01

ABSTRACT The gastrointestinal microbiota has an important role in human health, and there is increasing interest in utilizing dietary approaches to modulate the composition and metabolic function of the microbial communities that colonize the gastrointestinal tract to improve health, and prevent or treat disease. One dietary strategy for modulating the microbiota is consumption of dietary fiber and prebiotics that can be metabolized by microbes in the gastrointestinal tract. Human alimentary enzymes are not able to digest most complex carbohydrates and plant polysaccharides. Instead, these polysaccharides are metabolized by microbes which generate short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate. This article reviews the current knowledge of the impact of fiber and prebiotic consumption on the composition and metabolic function of the human gastrointestinal microbiota, including the effects of physiochemical properties of complex carbohydrates, adequate intake and treatment dosages, and the phenotypic responses related to the composition of the human microbiota. PMID:28165863

Microbial mats: an ecological niche for fungi

PubMed Central

Cantrell, Sharon A.; Duval-Pérez, Lisabeth

2013-01-01

Fungi were documented in tropical hypersaline microbial mats and their role in the degradation of complex carbohydrates (exopolymeric substance – EPS) was explored. Fungal diversity is higher during the wet season with Acremonium, Aspergillus, Cladosporium, and Penicillium among the more common genera. Diversity is also higher in the oxic layer and in young and transient mats. Enrichments with xanthan (a model EPS) show that without antibiotics (full community) degradation is faster than enrichments with antibacterial (fungal community) and antifungal (bacterial community) agents, suggesting that degradation is performed by a consortium of organisms (bacteria and fungi). The combined evidence from all experiments indicates that bacteria carried out approximately two-third of the xanthan degradation. The pattern of degradation is similar between seasons and layers but degradation is faster in enrichments from the wet season. The research suggests that fungi thrive in these hypersaline consortia and may participate in the carbon cycle through the degradation of complex carbohydrates. PMID:23577004

H2BC: a new technique for NMR analysis of complex carbohydrates.

PubMed

Petersen, Bent O; Vinogradov, Evguenii; Kay, William; Würtz, Peter; Nyberg, Nils T; Duus, Jens Ø; Sørensen, Ole W

2006-03-20

It is demonstrated that the H2BC NMR pulse sequence (J. Am. Chem. Soc.2005, 127, 6154, Magn. Reson. Chem.2005, 43, 971-974) offers unambiguous assignments and significant simplification of NMR spectra of large and complex carbohydrates compared to other techniques for the establishment of correlations over more than one bond. H2BC almost exclusively correlates protons and proton-bearing carbon spins separated by two covalent bonds and is independent of occasionally vanishing (2)J(CH) coupling constants, which alleviates the problem of missing two-bond correlations in HMBC spectra. H2BC also solves the problem of distinguishing two- and three-bond correlations in HSQC-TOCSY or HMBC. It is a further asset of H2BC that the experiment is significantly shorter than HMBC and HSQC-TOCSY, and hence less sensitive to transverse relaxation. The H2BC experiment is demonstrated on an approximately 30-residue oligosaccharide from Francisella victoria.

The Induction of Protective Immunity against Experimental Eimeria tenella Infection using Serum Exosomes

USDA-ARS?s Scientific Manuscript database

Avian coccidiosis is caused by Eimeria, a unicellular, apicomplexan protist which primarily infects intestinal epithelia resulting in nutrition malabsorption and reduced growth of commercial poultry. Vaccination of chickens with exosomes isolated from antigen presenting cells and containing parasit...

Global Microarray Analysis of Carbohydrate Use in Alkaliphilic Hemicellulolytic Bacterium Bacillus sp. N16-5

PubMed Central

Song, Yajian; Xue, Yanfen; Ma, Yanhe

2013-01-01

The alkaliphilic hemicellulolytic bacterium Bacillus sp. N16-5 has a broad substrate spectrum and exhibits the capacity to utilize complex carbohydrates such as galactomannan, xylan, and pectin. In the monosaccharide mixture, sequential utilization by Bacillus sp. N16-5 was observed. Glucose appeared to be its preferential monosaccharide, followed by fructose, mannose, arabinose, xylose, and galactose. Global transcription profiles of the strain were determined separately for growth on six monosaccharides (glucose, fructose, mannose, galactose, arabinose, and xylose) and four polysaccharides (galactomannan, xylan, pectin, and sodium carboxymethylcellulose) using one-color microarrays. Numerous genes potentially related to polysaccharide degradation, sugar transport, and monosaccharide metabolism were found to respond to a specific substrate. Putative gene clusters for different carbohydrates were identified according to transcriptional patterns and genome annotation. Identification and analysis of these gene clusters contributed to pathway reconstruction for carbohydrate utilization in Bacillus sp. N16-5. Several genes encoding putative sugar transporters were highly expressed during growth on specific sugars, suggesting their functional roles. Two phosphoenolpyruvate-dependent phosphotransferase systems were identified as candidate transporters for mannose and fructose, and a major facilitator superfamily transporter was identified as a candidate transporter for arabinose and xylose. Five carbohydrate uptake transporter 1 family ATP-binding cassette transporters were predicted to participate in the uptake of hemicellulose and pectin degradation products. Collectively, microarray data improved the pathway reconstruction involved in carbohydrate utilization of Bacillus sp. N16-5 and revealed that the organism precisely regulates gene transcription in response to fluctuations in energy resources. PMID:23326578

Novel interactions of complex carbohydrates with peanut (PNA), Ricinus communis (RCA-I), Sambucus nigra (SNA-I) and wheat germ (WGA) agglutinins as revealed by the binding specificities of these lectins towards mucin core-2 O-linked and N-linked glycans and related structures.

PubMed

Chandrasekaran, E V; Xue, Jun; Xia, Jie; Khaja, Siraj D; Piskorz, Conrad F; Locke, Robert D; Neelamegham, Sriram; Matta, Khushi L

2016-10-01

Plant lectins through their multivalent quaternary structures bind intrinsically flexible oligosaccharides. They recognize fine structural differences in carbohydrates and interact with different sequences in mucin core 2 or complex-type N-glycan chain and also in healthy and malignant tissues. They are used in characterizing cellular and extracellular glycoconjugates modified in pathological processes. We study here, the complex carbohydrate-lectin interactions by determining the effects of substituents in mucin core 2 tetrasaccharide Galβ1-4GlcNAcβ1-6(Galβ1-3)GalNAcα-O-R and fetuin glycopeptides on their binding to agarose-immobilized lectins PNA, RCA-I, SNA-I and WGA. Briefly, in mucin core 2 tetrasaccharide (i) structures modified by α2-3/6-Sialyl LacNAc, LewisX and α1-3-Galactosyl LacNAc resulted in regular binding to PNA whereas compounds with 6-sulfo LacNAc displayed no-binding; (ii) strucures bearing α2-6-sialyl 6-sulfo LacNAc, or 6-sialyl LacdiNAc carbohydrates displayed strong binding to SNA-I; (iii) structures with α2-3/6-sialyl, α1-3Gal LacNAc or LewisX were non-binder to RCA-I and compounds with 6-sulfo LacNAc only displayed weak binding; (iv) structures containing LewisX, 6-Sulfo LewisX, α2-3/6-sialyl LacNAc, α2-3/6-sialyl 6-sulfo LacNAc and GalNAc Lewis-a were non-binding to WGA, those with α1-2Fucosyl, α1-3-Galactosyl LacNAc, α2-3-sialyl T-hapten plus 3'/6'sulfo LacNAc displayed weak binding, and compounds with α2-3-sialyl T-hapten, α2.6-Sialyl LacdiNAc, α2-3-sialyl D-Fucβ1-3 GalNAc and Fucα-1-2 D-Fucβ-1-3GalNAc displaying regular binding and GalNAc LewisX and LacdiNAc plus D-Fuc β-1-3 GalNAcα resulting in tight binding. RCA-I binds Fetuin triantennary asialoglycopeptide 100 % after α-2-3 and 25 % after α-2-6 sialylation, 30 % after α-1-2 and 100 % after α-1-3 fucosylation, and 50 % after α-1-3 galactosylation. WGA binds 3-but not 6-Fucosyl chitobiose core. Thus, information on the influence of complex carbohydrate chain constituents on lectin binding is apparently essential for the potential application of lectins in glycoconjugate research.

Bivalent Carbohydrate Binding Is Required for Biological Activity of Clitocybe nebularis Lectin (CNL), the N,N′-Diacetyllactosediamine (GalNAcβ1–4GlcNAc, LacdiNAc)-specific Lectin from Basidiomycete C. nebularis*

PubMed Central

Pohleven, Jure; Renko, Miha; Magister, Špela; Smith, David F.; Künzler, Markus; Štrukelj, Borut; Turk, Dušan; Kos, Janko; Sabotič, Jerica

2012-01-01

Lectins are carbohydrate-binding proteins that exert their biological activity by binding to specific cell glycoreceptors. We have expressed CNL, a ricin B-like lectin from the basidiomycete Clitocybe nebularis in Escherichia coli. The recombinant lectin, rCNL, agglutinates human blood group A erythrocytes and is specific for the unique glycan N,N′-diacetyllactosediamine (GalNAcβ1–4GlcNAc, LacdiNAc) as demonstrated by glycan microarray analysis. We here describe the crystal structures of rCNL in complex with lactose and LacdiNAc, defining its interactions with the sugars. CNL is a homodimeric lectin, each of whose monomers consist of a single ricin B lectin domain with its β-trefoil fold and one carbohydrate-binding site. To study the mode of CNL action, a nonsugar-binding mutant and nondimerizing monovalent CNL mutants that retain carbohydrate-binding activity were prepared. rCNL and the mutants were examined for their biological activities against Jurkat human leukemic T cells and the hypersensitive nematode Caenorhabditis elegans mutant strain pmk-1. rCNL was toxic against both, although the mutants were inactive. Thus, the bivalent carbohydrate-binding property of homodimeric CNL is essential for its activity, providing one of the rare pieces of evidence that certain activities of lectins are associated with their multivalency. PMID:22298779

Effects of infant cereals with different carbohydrate profiles on colonic function--randomised and double-blind clinical trial in infants aged between 6 and 12 months--pilot study.

PubMed

Bernal, María José; Periago, María Jesús; Martínez, Rosario; Ortuño, Inmaculada; Sánchez-Solís, Manuel; Ros, Gaspar; Romero, Fernando; Abellán, Pedro

2013-11-01

Infant cereals are often the elected foodstuff for beginning complementary feeding and provide carbohydrates which are different to those found in maternal milk. The objective of this preliminary study was to ascertain the colonic effects of two infant cereals, with different carbohydrate profiles, in a randomised and double-blind trial in healthy infants. Nineteen term infants between 6.3 and 9.8 months of age were enrolled, after written informed consent was obtained from parents. Ten subjects were allocated to take infant cereal A and nine, infant cereal B. An intervention period was 2 months, with five visits every 15 days, to take anthropometric measurements and faeces samples for the analysis of microbiota, short-chain fatty acids concentration (SCFA), pH value and secretory immunoglobulin A (sIgA). An adequate growth and stool frequency was registered in both intervention groups. Faecal counts of Bifidobacterium, Lactobacillus, Enterobacteriaceae, Enterococcus, Clostridium and Bacteroides did not show any statistical differences. However, a significantly (P < 0.05) higher butyric acid and sIgA, and lower faecal pH were observed in infants who had ingested infant cereal A, with a higher ratio complex/simple carbohydrates. In conclusion, small changes in the carbohydrate profile of infant cereals could lead to significant differences in parameters related to fermentative activity of intestinal microbiota.

Systematic review with meta-analysis: the prevalence of bile acid malabsorption in the irritable bowel syndrome with diarrhoea.

PubMed

Slattery, S A; Niaz, O; Aziz, Q; Ford, A C; Farmer, A D

2015-07-01

Irritable bowel syndrome is a widespread disorder with a marked socioeconomic burden. Previous studies support the proposal that a subset of patients with features compatible with diarrhoea-predominant IBS (IBS-D) have bile acid malabsorption (BAM). To perform a systematic review and meta-analysis to assess the prevalence of BAM in patients meeting the accepted criteria for IBS-D. MEDLINE and EMBASE were searched up to March 2015. Studies recruiting adults with IBS-D, defined by the Manning, Kruis, Rome I, II or III criteria and which used 23-seleno-25-homotaurocholic acid (SeHCAT) testing for the assessment of BAM were included. BAM was defined as 7 day SeHCAT retention of <10%. We calculated the rate of BAM and 95% confidence intervals (CI) using a random effects model. The methodological quality of included studies was evaluated using the Quality Assessment for Diagnostic Accuracy Studies (QUADAS-2). The search strategy identified six relevant studies comprising 908 individuals. The rate of BAM ranged from 16.9% to 35.3%. The pooled rate was 28.1% (95% CI: 22.6-34%). There was significant heterogeneity in effect sizes (Q-test χ(2)  = 17.9, P < 0.004; I(2)  = 72.1%). The type of diagnostic criteria used or study country did not significantly modify the effect. These data provide evidence that in excess of one quarter of patients meeting accepted criteria for IBS-D have bile acid malabsorption. This distinction has implications for the interpretation of previous studies, as well as contemporaneous clinical practice and future guideline development. © 2015 John Wiley & Sons Ltd.

The low FODMAP diet improves gastrointestinal symptoms in patients with irritable bowel syndrome: a prospective study.

PubMed

de Roest, R H; Dobbs, B R; Chapman, B A; Batman, B; O'Brien, L A; Leeper, J A; Hebblethwaite, C R; Gearry, R B

2013-09-01

Current treatment for irritable bowel syndrome (IBS) is suboptimal. Fermentable oligo-, di-, mono-saccharides and polyols (FODMAPs) may trigger gastrointestinal symptoms in IBS patients. Our aim was to determine whether a low FODMAP diet improves symptoms in IBS patients. Irritable bowel syndrome patients, who had performed hydrogen/methane breath testing for fructose and lactose malabsorption and had received dietary advice regarding the low FODMAP diet, were included. The effect of low FODMAP diet was prospectively evaluated using a symptom questionnaire. Furthermore, questions about adherence and satisfaction with symptom improvement, dietary advice and diet were assessed. Ninety patients with a mean follow up of 15.7 months were studied. Most symptoms including abdominal pain, bloating, flatulence and diarrhoea significantly improved (p < 0.001 for all). 75.6%, 37.8% and 13.3% of patients had fructose, lactose malabsorption or small intestinal bacterial overgrowth respectively. Fructose malabsorption was significantly associated with symptom improvement (abdominal pain odds ratio (OR) 7.09 [95% confidence interval (CI) 2.01-25.0], bloating OR 8.71 (95% CI 2.76-27.5), flatulence OR 7.64 (95% CI 2.53-23.0) and diarrhoea OR 3.39 (95% CI 1.17-9.78), p < 0.029 for all). Most patients (75.6%) were adherent to the diet, which was associated with symptom improvement (abdominal pain, bloating, flatulence and diarrhoea all significantly associated with adherence, r > 0.27, p < 0.011). Most patients (72.1%) were satisfied with their symptoms. The low FODMAP diet shows efficacy for IBS patients. The current strategy of breath testing and dietary advice provides a good basis to understand and adhere to the diet. © 2013 John Wiley & Sons Ltd.

Clinical significance of duodenal lymphangiectasia incidentally found during routine upper gastrointestinal endoscopy.

PubMed

Kim, J H; Bak, Y T; Kim, J S; Seol, S Y; Shin, B K; Kim, H K

2009-06-01

Although duodenal lymphangiectasia in individuals without clinical evidence of malabsorption has been reported, the prevalence and clinical significance in this situation are not yet known. The aim of this study was to evaluate the prevalence and clinical significance of incidentally found duodenal lymphangiectasia. A retrospective review of medical records was undertaken for consecutive patients who had undergone diagnostic upper endoscopy between January 2005 and June 2006. A prospective study was then performed in consecutive individuals undergoing routine upper endoscopy for health examination between July 2006 to October 2006. Endoscopic features of duodenal lymphangiectasia were classified into three types: (1) multiple scattered pinpoint white spots; (2) diffuse prominent villi with whitish-discolored tips; and (3) focal small whitish macule or nodule. The histologic grade of duodenal lymphangiectasia was classified according to the depth and severity of lymphatic duct dilatations. Prevalence and clinical data of incidentally found duodenal lymphangiectasia were evaluated in the retrospective and prospective studies. Among 1866 retrospective cases, duodenal lymphangiectasia was endoscopically suspected in 59 cases (3.2%), and histologically confirmed in 35 cases (1.9%). No clinical evidence of malabsorption was noted in the duodenal lymphangiectasia cases. The "scattered pinpoint white spots" type was the most frequently found endoscopic feature (40.0%). Duodenal lymphangiectasia was persistent in seven of 10 individuals who underwent repeat endoscopy after a median of 12 months. Among 134 prospective cases, duodenal lymphangiectasia was histologically confirmed in 12 cases (8.9%). There was no significant clinical difference between groups with and without duodenal lymphangiectasia. Lymphatic duct dilatation was histologically more severe in the "focal small whitish macule or nodule" type than in the other types. Duodenal lymphangiectasia without clinical evidence of malabsorption is not extremely rare among cases undergoing routine upper gastrointestinal endoscopy.

Effects of obesity surgery on non-insulin-dependent diabetes mellitus.

PubMed

Greenway, Scott E; Greenway, Frank L; Klein, Stanley

2002-10-01

Most individuals who have non-insulin-dependent diabetes mellitus are obese. The obese population has proved a frustrating entity regarding weight loss and diabetes control. Results of medical weight loss programs, medications, and behavior therapy have proved disappointing. Bariatric surgery is the most effective method of diabetes management and cure in the morbidly obese population. Surgical procedures to cause malabsorption provide a more dramatic effect on diabetes owing to the imparted bypass of the hormonally active foregut. Pertinent journal articles spanning the last 40 years, as well as textbooks. Bariatric surgical procedures have proven a much more successful method of weight loss and diabetes control in the obese population than conservative methods. These surgical procedures have proven safe with reported mortality rates of 0% to 1.5%. Bariatric operations may be divided based on the method of weight loss and effect on diabetes. The first category is restrictive and includes vertical banded gastroplasty and adjustable silicone gastric banding. These operations improve diabetes by decreasing food intake and body weight with a slowing of gastric emptying. The second category not only contains restrictive components but also elements of malabsorption. This category includes the Roux-en-Y gastric bypass and biliary-pancreatic diversion, which bypass the foregut. Although all of the surgical procedures for obesity offer improved weight loss and diabetes control compared with conservative methods, the Roux-en-Y gastric bypass and biliary-pancreatic diversion offer superior weight loss and resolution of diabetes. The more dramatic effect seen in the surgical procedures to cause malabsorption is likely secondary to the bypass of the foregut resulting in increased weight loss and elevation of the enteroglucagon level.

Hypochlorhydria-induced calcium malabsorption does not affect fracture healing but increases post-traumatic bone loss in the intact skeleton.

PubMed

Haffner-Luntzer, Melanie; Heilmann, Aline; Heidler, Verena; Liedert, Astrid; Schinke, Thorsten; Amling, Michael; Yorgan, Timur Alexander; Vom Scheidt, Annika; Ignatius, Anita

2016-11-01

Efficient calcium absorption is essential for skeletal health. Patients with impaired gastric acidification display low bone mass and increased fracture risk because calcium absorption is dependent on gastric pH. We investigated fracture healing and post-traumatic bone turnover in mice deficient in Cckbr, encoding a gastrin receptor that affects acid secretion by parietal cells. Cckbr-/- mice display hypochlorhydria, calcium malabsorption, and osteopenia. Cckbr-/- and wildtype (WT) mice received a femur osteotomy and were fed either a standard or calcium-enriched diet. Healed and intact bones were assessed by biomechanical testing, histomorphometry, micro-computed tomography, and quantitative backscattering. Parathyroid hormone (PTH) serum levels were determined by enzyme-linked immunosorbent assay. Fracture healing was unaffected in Cckbr-/- mice. However, Cckbr-/- mice displayed increased calcium mobilization from the intact skeleton during bone healing, confirmed by significantly elevated PTH levels and osteoclast numbers compared to WT mice. Calcium supplementation significantly reduced secondary hyperparathyroidism and bone resorption in the intact skeleton in both genotypes, but more efficiently in WT mice. Furthermore, calcium administration improved bone healing in WT mice, indicated by significantly increased mechanical properties and bone mineral density of the fracture callus, whereas it had no significant effect in Cckbr-/- mice. Therefore, under conditions of hypochlorhydria-induced calcium malabsorption, calcium, which is essential for callus mineralization, appears to be increasingly mobilized from the intact skeleton in favor of fracture healing. Calcium supplementation during fracture healing prevented systemic calcium mobilization, thereby maintaining bone mass and improving fracture healing in healthy individuals whereas the effect was limited by gastric hypochlorhydria. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1914-1921, 2016. © 2016 The Authors. Journal of Orthopaedic Research Published by by Wiley Periodicals, Inc.

Superresolution Imaging Captures Carbohydrate Utilization Dynamics in Human Gut Symbionts

PubMed Central

Karunatilaka, Krishanthi S.; Cameron, Elizabeth A.; Martens, Eric C.; Koropatkin, Nicole M.

2014-01-01

ABSTRACT Gut microbes play a key role in human health and nutrition by catabolizing a wide variety of glycans via enzymatic activities that are not encoded in the human genome. The ability to recognize and process carbohydrates strongly influences the structure of the gut microbial community. While the effects of diet on the microbiota are well documented, little is known about the molecular processes driving metabolism. To provide mechanistic insight into carbohydrate catabolism in gut symbionts, we studied starch processing in real time in the model Bacteroides thetaiotaomicron starch utilization system (Sus) by single-molecule fluorescence. Although previous studies have explored Sus protein structure and function, the transient interactions, assembly, and collaboration of these outer membrane proteins have not yet been elucidated in live cells. Our live-cell superresolution imaging reveals that the polymeric starch substrate dynamically recruits Sus proteins, serving as an external scaffold for bacterial membrane assembly of the Sus complex, which may promote efficient capturing and degradation of starch. Furthermore, by simultaneously localizing multiple Sus outer membrane proteins on the B. thetaiotaomicron cell surface, we have characterized the dynamics and stoichiometry of starch-induced Sus complex assembly on the molecular scale. Finally, based on Sus protein knockout strains, we have discerned the mechanism of starch-induced Sus complex assembly in live anaerobic cells with nanometer-scale resolution. Our insights into the starch-induced outer membrane protein assembly central to this conserved nutrient uptake mechanism pave the way for the development of dietary or pharmaceutical therapies to control Bacteroidetes in the intestinal tract to enhance human health and treat disease. PMID:25389179

Human milk glycoconjugates that inhibit pathogens.

PubMed

Newburg, D S

1999-02-01

Breast-fed infants have lower incidence of diarrhea, respiratory disease, and otitis media. The protection by human milk has long been attributed to the presence of secretory IgA. However, human milk contains large numbers and amounts of complex carbohydrates, including glycoproteins, glycolipids, glycosaminoglycans, mucins, and especially oligosaccharides. The oligosaccharides comprise the third most abundant solid constituent of human milk, and contain a myriad of structures. Complex carbohydrate moieties of glycoconjugates and oligosaccharides are synthesized by the many glycosyltransferases in the mammary gland; those with homology to cell surface glycoconjugate pathogen receptors may inhibit pathogen binding, thereby protecting the nursing infant. Several examples are reviewed: A fucosyloligosaccharide inhibits the diarrheagenic effect of stable toxin of Escherichia coli. A different fucosyloligosaccharide inhibits infection by Campylobacter jejuni. Binding of Streptococcus pneumoniae and of enteropathogenic E. coli to their respective receptors is inhibited by human milk oligosaccharides. The 46-kD glycoprotein, lactadherin, inhibits rotavirus binding and infectivity. Low levels of lactadherin in human milk are associated with a higher incidence of symptomatic rotavirus in breast-fed infants. A mannosylated glycopeptide inhibits binding by enterohemorrhagic E. coli. A glycosaminoglycan inhibits binding of gp120 to CD4, the first step in HIV infection. Human milk mucin inhibits binding by S-fimbriated E. coli. The ganglioside, GM1, reduces diarrhea production by cholera toxin and labile toxin of E. coli. The neutral glycosphingolipid, Gb3, binds to Shigatoxin. Thus, many complex carbohydrates of human milk may be novel antipathogenic agents, and the milk glycoconjugates and oligosaccharides may be a major source of protection for breastfeeding infants.

Understanding the bacterial polysaccharide antigenicity of Streptococcus agalactiae versus Streptococcus pneumoniae.

PubMed

Kadirvelraj, Renuka; Gonzalez-Outeiriño, Jorge; Foley, B Lachele; Beckham, Meredith L; Jennings, Harold J; Foote, Simon; Ford, Michael G; Woods, Robert J

2006-05-23

Bacterial surface capsular polysaccharides (CPS) that are similar in carbohydrate sequence may differ markedly in immunogenicity and antigenicity. The structural origin of these phenomena is poorly understood. Such a case is presented by the Gram-positive bacteria Streptococcus agalactiae (Group B Streptococcus; GBS) type III (GBSIII) and Streptococcus pneumoniae (Pn) type 14 (Pn14), which share closely related CPS sequences. Nevertheless, antibodies (Abs) against GBSIII rarely cross-react with the CPS from Pn14. To establish the origin for the variation in CPS antigenicity, models for the immune complexes of CPS fragments from GBSIII and Pn14, with the variable fragment (Fv) of a GBS-specific mAb (mAb 1B1), are presented. The complexes are generated through a combination of comparative Ab modeling and automated ligand docking, followed by explicitly solvated 10-ns molecular dynamics simulations. The relationship between carbohydrate sequence and antigenicity is further quantified through the computation of interaction energies using the Molecular Mechanics-Generalized Born Surface Area (MM-GBSA) method, augmented by conformational entropy estimates. Despite the electrostatic differences between Pn14 and GBSIII CPS, analysis indicates that entropic penalties are primarily responsible for the loss of affinity of the highly flexible Pn14 CPS for mAb 1B1. The similarity of the solution conformation of the relatively rigid GBSIII CPS with that in the immune complex characterizes the previously undescribed 3D structure of the conformational epitope. The analysis provides a comprehensive interpretation for a large body of biochemical and immunological data related to Ab recognition of bacterial polysaccharides and should be applicable to other Ab-carbohydrate interactions.

Carbohydrate Metabolism in Archaea: Current Insights into Unusual Enzymes and Pathways and Their Regulation

PubMed Central

Esser, Dominik; Rauch, Bernadette

2014-01-01

SUMMARY The metabolism of Archaea, the third domain of life, resembles in its complexity those of Bacteria and lower Eukarya. However, this metabolic complexity in Archaea is accompanied by the absence of many “classical” pathways, particularly in central carbohydrate metabolism. Instead, Archaea are characterized by the presence of unique, modified variants of classical pathways such as the Embden-Meyerhof-Parnas (EMP) pathway and the Entner-Doudoroff (ED) pathway. The pentose phosphate pathway is only partly present (if at all), and pentose degradation also significantly differs from that known for bacterial model organisms. These modifications are accompanied by the invention of “new,” unusual enzymes which cause fundamental consequences for the underlying regulatory principles, and classical allosteric regulation sites well established in Bacteria and Eukarya are lost. The aim of this review is to present the current understanding of central carbohydrate metabolic pathways and their regulation in Archaea. In order to give an overview of their complexity, pathway modifications are discussed with respect to unusual archaeal biocatalysts, their structural and mechanistic characteristics, and their regulatory properties in comparison to their classic counterparts from Bacteria and Eukarya. Furthermore, an overview focusing on hexose metabolic, i.e., glycolytic as well as gluconeogenic, pathways identified in archaeal model organisms is given. Their energy gain is discussed, and new insights into different levels of regulation that have been observed so far, including the transcript and protein levels (e.g., gene regulation, known transcription regulators, and posttranslational modification via reversible protein phosphorylation), are presented. PMID:24600042

Unexpected widespread hypophosphatemia and bone disease associated with elemental formula use in infants and children.

PubMed

Gonzalez Ballesteros, Luisa F; Ma, Nina S; Gordon, Rebecca J; Ward, Leanne; Backeljauw, Philippe; Wasserman, Halley; Weber, David R; DiMeglio, Linda A; Gagne, Julie; Stein, Robert; Cody, Declan; Simmons, Kimber; Zimakas, Paul; Topor, Lisa Swartz; Agrawal, Sungeeta; Calabria, Andrew; Tebben, Peter; Faircloth, Ruth; Imel, Erik A; Casey, Linda; Carpenter, Thomas O

2017-04-01

Hypophosphatemia occurs with inadequate dietary intake, malabsorption, increased renal excretion, or shifts between intracellular and extracellular compartments. We noticed the common finding of amino-acid based elemental formula [EF] use in an unexpected number of cases of idiopathic hypophosphatemia occurring in infants and children evaluated for skeletal disease. We aimed to fully characterize the clinical profiles in these cases. A retrospective chart review of children with unexplained hypophosphatemia was performed as cases accumulated from various centres in North America and Ireland. Data were analyzed to explore any relationships between feeding and biochemical or clinical features, effects of treatment, and to identify a potential mechanism. Fifty-one children were identified at 17 institutions with EF-associated hypophosphatemia. Most children had complex illnesses and had been solely fed Neocate® formula products for variable periods of time prior to presentation. Feeding methods varied. Hypophosphatemia was detected during evaluation of fractures or rickets. Increased alkaline phosphatase activity and appropriate renal conservation of phosphate were documented in nearly all cases. Skeletal radiographs demonstrated fractures, undermineralization, or rickets in 94% of the cases. Although the skeletal disease had often been attributed to underlying disease, most all improved with addition of supplemental phosphate or change to a different formula product. The observed biochemical profiles indicated a deficient dietary supply or severe malabsorption of phosphate, despite adequate formula composition. When transition to an alternate formula was possible, biochemical status improved shortly after introduction to the alternate formula, with eventual improvement of skeletal abnormalities. These observations strongly implicate that bioavailability of formula phosphorus may be impaired in certain clinical settings. The widespread nature of the findings lead us to strongly recommend careful monitoring of mineral metabolism in children fed EF. Transition to alternative formula use or implementation of phosphate supplementation should be performed cautiously with as severe hypocalcemia may develop. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular Dissection of Xyloglucan Recognition in a Prominent Human Gut Symbiont

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tauzin, Alexandra S.; Kwiatkowski, Kurt J.; Orlovsky, Nicole I.

Polysaccharide utilization loci (PUL) within the genomes of resident human gutBacteroidetesare central to the metabolism of the otherwise indigestible complex carbohydrates known as “dietary fiber.” However, functional characterization of PUL lags significantly behind sequencing efforts, which limits physiological understanding of the human-bacterial symbiosis. In particular, the molecular basis of complex polysaccharide recognition, an essential prerequisite to hydrolysis by cell surface glycosidases and subsequent metabolism, is generally poorly understood. Here, we present the biochemical, structural, and reverse genetic characterization of two unique cell surface glycan-binding proteins (SGBPs) encoded by a xyloglucan utilization locus (XyGUL) fromBacteroides ovatus, which are integral to growthmore » on this key dietary vegetable polysaccharide. Biochemical analysis reveals that these outer membrane-anchored proteins are in fact exquisitely specific for the highly branched xyloglucan (XyG) polysaccharide. The crystal structure of SGBP-A, a SusD homolog, with a bound XyG tetradecasaccharide reveals an extended carbohydrate-binding platform that primarily relies on recognition of the β-glucan backbone. The unique, tetra-modular structure of SGBP-B is comprised of tandem Ig-like folds, with XyG binding mediated at the distal C-terminal domain. Despite displaying similar affinities for XyG, reverse-genetic analysis reveals that SGBP-B is only required for the efficient capture of smaller oligosaccharides, whereas the presence of SGBP-A is more critical than its carbohydrate-binding ability for growth on XyG. Finally, together, these data demonstrate that SGBP-A and SGBP-B play complementary, specialized roles in carbohydrate capture byB. ovatusand elaborate a model of how vegetable xyloglucans are accessed by theBacteroidetes.« less

Molecular Dissection of Xyloglucan Recognition in a Prominent Human Gut Symbiont

DOE PAGES

Tauzin, Alexandra S.; Kwiatkowski, Kurt J.; Orlovsky, Nicole I.; ...

2016-04-26

Polysaccharide utilization loci (PUL) within the genomes of resident human gutBacteroidetesare central to the metabolism of the otherwise indigestible complex carbohydrates known as “dietary fiber.” However, functional characterization of PUL lags significantly behind sequencing efforts, which limits physiological understanding of the human-bacterial symbiosis. In particular, the molecular basis of complex polysaccharide recognition, an essential prerequisite to hydrolysis by cell surface glycosidases and subsequent metabolism, is generally poorly understood. Here, we present the biochemical, structural, and reverse genetic characterization of two unique cell surface glycan-binding proteins (SGBPs) encoded by a xyloglucan utilization locus (XyGUL) fromBacteroides ovatus, which are integral to growthmore » on this key dietary vegetable polysaccharide. Biochemical analysis reveals that these outer membrane-anchored proteins are in fact exquisitely specific for the highly branched xyloglucan (XyG) polysaccharide. The crystal structure of SGBP-A, a SusD homolog, with a bound XyG tetradecasaccharide reveals an extended carbohydrate-binding platform that primarily relies on recognition of the β-glucan backbone. The unique, tetra-modular structure of SGBP-B is comprised of tandem Ig-like folds, with XyG binding mediated at the distal C-terminal domain. Despite displaying similar affinities for XyG, reverse-genetic analysis reveals that SGBP-B is only required for the efficient capture of smaller oligosaccharides, whereas the presence of SGBP-A is more critical than its carbohydrate-binding ability for growth on XyG. Finally, together, these data demonstrate that SGBP-A and SGBP-B play complementary, specialized roles in carbohydrate capture byB. ovatusand elaborate a model of how vegetable xyloglucans are accessed by theBacteroidetes.« less

Variation of Carbohydrate-Active Enzyme Patterns in the Gut Microbiota of Italian Healthy Subjects and Type 2 Diabetes Patients.

PubMed

Soverini, Matteo; Turroni, Silvia; Biagi, Elena; Quercia, Sara; Brigidi, Patrizia; Candela, Marco; Rampelli, Simone

2017-01-01

The human gut microbiota (GM) has been associated, to date, with various complex functions, essentials for the host health. Among these, it is certainly worth noting the degradation of the so-called microbiota-accessible carbohydrates (MACs), which the GM breaks down through specific enzymes, referred to as carbohydrate-active enzymes (CAZymes). This degradation constitutes the first step in the production of short-chain fatty acids (SCFAs), key microbial small molecules having multiple health-promoting effects for the host organism. The decline in MAC dietary intake in urban Western populations forced the shrinkage of CAZyme repertoire in the GM, as shown by the literature comparing the microbiome layout between Western urban citizens and traditional rural populations. Even if this reduction in GM functional complexity has been associated with the onset of the so-called "diseases of civilization," only few information regarding the CAZyme variation within Western populations has been provided to date, and its connections with diet and health are still unexplored. In this scenario, here we explore the GM-encoded CAZyme repertoire across two Italian adult cohorts, including healthy lean subjects consuming a Mediterranean diet and obese patients affected by type 2 diabetes, consuming a high-fat diet. In order to impute the CAZyme panel, a pipeline consisting of publicly available software - QIIME, FragGeneScan and HMMER - was specifically implemented. Our study highlighted the existence of robust clusters of bacterial species sharing a common MAC degradation profile in the Italian GM, allowing the stratification of the individual GM into different steady states according to the carbohydrate degradation profile, with possible connections with diet and health.

Rapamycin impairs metabolism-secretion coupling in rat pancreatic islets by suppressing carbohydrate metabolism.

PubMed

Shimodahira, Makiko; Fujimoto, Shimpei; Mukai, Eri; Nakamura, Yasuhiko; Nishi, Yuichi; Sasaki, Mayumi; Sato, Yuichi; Sato, Hiroki; Hosokawa, Masaya; Nagashima, Kazuaki; Seino, Yutaka; Inagaki, Nobuya

2010-01-01

Rapamycin, an immunosuppressant used in human transplantation, impairs beta-cell function, but the mechanism is unclear. Chronic (24 h) exposure to rapamycin concentration dependently suppressed 16.7 mM glucose-induced insulin release from islets (1.65+/-0.06, 30 nM rapamycin versus 2.35+/-0.11 ng/islet per 30 min, control, n=30, P<0.01) without affecting insulin and DNA contents. Rapamycin also decreased alpha-ketoisocaproate-induced insulin release, suggesting reduced mitochondrial carbohydrate metabolism. ATP content in the presence of 16.7 mM glucose was significantly reduced in rapamycin-treated islets (13.42+/-0.47, rapamycin versus 16.04+/-0.46 pmol/islet, control, n=30, P<0.01). Glucose oxidation, which indicates the velocity of metabolism in the Krebs cycle, was decreased by rapamycin in the presence of 16.7 mM glucose (30.1+/-2.7, rapamycin versus 42.2+/-3.3 pmol/islet per 90 min, control, n=9, P<0.01). Immunoblotting revealed that the expression of complex I, III, IV, and V was not affected by rapamycin. Mitochondrial ATP production indicated that the respiratory chain downstream of complex II was not affected, but that carbohydrate metabolism in the Krebs cycle was reduced by rapamycin. Analysis of enzymes in the Krebs cycle revealed that activity of alpha-ketoglutarate dehydrogenase (KGDH), which catalyzes one of the slowest reactions in the Krebs cycle, was reduced by rapamycin (10.08+/-0.82, rapamycin versus 13.82+/-0.84 nmol/mg mitochondrial protein per min, control, n=5, P<0.01). Considered together, these findings indicate that rapamycin suppresses high glucose-induced insulin secretion from pancreatic islets by reducing mitochondrial ATP production through suppression of carbohydrate metabolism in the Krebs cycle, together with reduced KGDH activity.

Molecular Dissection of Xyloglucan Recognition in a Prominent Human Gut Symbiont

PubMed Central

Tauzin, Alexandra S.; Kwiatkowski, Kurt J.; Orlovsky, Nicole I.; Smith, Christopher J.; Creagh, A. Louise; Haynes, Charles A.; Wawrzak, Zdzislaw

2016-01-01

ABSTRACT Polysaccharide utilization loci (PUL) within the genomes of resident human gut Bacteroidetes are central to the metabolism of the otherwise indigestible complex carbohydrates known as “dietary fiber.” However, functional characterization of PUL lags significantly behind sequencing efforts, which limits physiological understanding of the human-bacterial symbiosis. In particular, the molecular basis of complex polysaccharide recognition, an essential prerequisite to hydrolysis by cell surface glycosidases and subsequent metabolism, is generally poorly understood. Here, we present the biochemical, structural, and reverse genetic characterization of two unique cell surface glycan-binding proteins (SGBPs) encoded by a xyloglucan utilization locus (XyGUL) from Bacteroides ovatus, which are integral to growth on this key dietary vegetable polysaccharide. Biochemical analysis reveals that these outer membrane-anchored proteins are in fact exquisitely specific for the highly branched xyloglucan (XyG) polysaccharide. The crystal structure of SGBP-A, a SusD homolog, with a bound XyG tetradecasaccharide reveals an extended carbohydrate-binding platform that primarily relies on recognition of the β-glucan backbone. The unique, tetra-modular structure of SGBP-B is comprised of tandem Ig-like folds, with XyG binding mediated at the distal C-terminal domain. Despite displaying similar affinities for XyG, reverse-genetic analysis reveals that SGBP-B is only required for the efficient capture of smaller oligosaccharides, whereas the presence of SGBP-A is more critical than its carbohydrate-binding ability for growth on XyG. Together, these data demonstrate that SGBP-A and SGBP-B play complementary, specialized roles in carbohydrate capture by B. ovatus and elaborate a model of how vegetable xyloglucans are accessed by the Bacteroidetes. PMID:27118585

Gout Diet

MedlinePlus

... provide complex carbohydrates. Avoid foods and beverages with high-fructose corn syrup, and limit consumption of naturally sweet fruit juices. Water. Stay well-hydrated by drinking water. Fats. Cut back on saturated ... fatty poultry and high-fat dairy products. Proteins. Focus on lean meat ...

75 FR 31800 - Substances Generally Recognized as Safe Added to Food for Animals; Notice of Pilot Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-04

... certain food safety issues for complex substances (e.g., macroingredients or biological polymers, such as proteins, carbohydrates, and fats and oils). Finally, FDA tentatively concluded that the reduction in...

Visual Characterization of VX Droplets on Plant Foliage

DTIC Science & Technology

2016-07-01

epicuticular waxes, which are complex lipophilic mixtures of primarily long-chain aliphatics, including primary alcohols (n-alkan-1-ols), aldehydes, fatty...2006). Trichomes act in a complex way relative to spread of herbicide solution and sorption of herbicide. Trichomes may cause reduced wetting and...Bicellular trichomes discharge a mucilage-type secretion that contains callose, a carbohydrate component (1,3-glucan) usually associated with “walling

Bile acid malabsorption demonstrated by SeHCAT in chronic diarrhoea, with special reference to the impact of cholecystectomy.

PubMed

Suhr, O; Danielsson, A; Nyhlin, H; Truedsson, H

1988-12-01

SeHCAT is a gamma-labelled synthetic bile acid, suitable for external measurements and detection of bile acid malabsorption. In this study 138 subjects were investigated with 75SeHCAT. The technique was modified by calculating the biologic half-life of the isotope (WBR-50) within 48 h. All patients with ileocaecal resection had reduced WBR-50 values, as did most (8 of 12) with Crohn's disease affecting the small bowel. Among patients with chronic diarrhoea 24 out of 62 patients had reduced WBR-50 values. Four of the patients with low WBR-50 and one in the group with normal WBR-50 had previously been cholecystectomized. In a consecutive study, 15 patients were investigated before and after cholecystectomy. In 12, WBR-50 decreased after the operation (p less than 0.05). The results demonstrate the impact of cholecystectomy on the interpretation of the SeHCAT retention results. The results may also add to the understanding of diarrhoea secondary to cholecystectomy.

Management of bile acid malabsorption using low-fat dietary interventions: a useful strategy applicable to some patients with diarrhoea-predominant irritable bowel syndrome?

PubMed

Watson, Lorraine; Lalji, Amyn; Bodla, Shankar; Muls, Ann; Andreyev, H Jervoise N; Shaw, Clare

2015-12-01

This study evaluates the efficacy of low-fat dietary interventions in the management of gastrointestinal (GI) symptoms due to bile acid malabsorption. In total, 40 patients with GI symptoms and a 7-day (75)selenium homocholic acid taurine (SeHCAT) scan result of <20%, were prospectively recruited and then advised regarding a low-fat dietary intervention. Before and after dietary intervention, patients rated their GI symptoms using a 10-point numerical scale, and recorded their intake in 7-day dietary diaries. After dietary intervention, the median scores for all GI symptoms decreased, with a significant reduction for urgency, bloating, lack of control, bowel frequency (p ≥: 0.01). Mean dietary fat intake reduced to 42 g fat after intervention (p ≥: 0.01). Low-fat dietary interventions in patients with a SeHCAT scan result of <20% leads to clinically important improvement in GI symptoms and should be widely used. © Royal College of Physicians 2015. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amaral, H.; Palma, R.; Pfau, J.

Bile acid malabsorption has been recognized as an important cause of chronic diarrhea. Se-75HCAT, a bile acid, is absorbed in the terminal ileum. Therefore, measurement of its body retention indicate ileal function not requiring fecal collections. The authors studied 8 normal volunteers presenting with chronic recurrent diarrhea for more than 2 years. Each received orally a 10 ..mu..Ci capsule of SeHCAT (Amersham Intl.) and 3 hours later anterior and posterior whole body activity was measured using a digital camera without collimator. Measurements were repeated daily for 7 days and expressed as % of retention. Three patients had normal retention (1more » celiac disease, 1 inactive Crohn disease and 1 functional diarrhea), another was borderline (an immunodeficiency) and 4 patients presented abnormal bile acid absorption (2 had vagotomy, 1 Crohn disease and 1 idiopathic diarrhea). This last group was treated with cholestyramine showing improvement of the diarrhea, and relapse on drug withdrawal. These findings demonstrate that this technique can identify bile acid malabsorption as the cause of chronic diarrhea by external counting.« less

From past sailors’ eras to the present day: scurvy as a surprising manifestation of an uncommon gastrointestinal disease

PubMed Central

Branquinho, Diogo Ferreira; Pinto-Gouveia, Miguel; Mendes, Sofia; Sofia, Carlos

2015-01-01

A 45-year-old man presented with follicular exanthema in his lower limbs, alternating bowel habits and significant weight loss. His medical history included seronegative arthritis, bipolar disease and an inconclusive diagnostic laparoscopy. Diagnostic work up revealed microcytic anaemia and multivitamin deficiency. Skin biopsy of the exanthema suggested scurvy. Owing to these signs of malabsorption, upper endoscopy with duodenal biopsies was performed, exhibiting villous atrophy and extensive periodic acid-Schiff-positive material in the lamina propria, therefore diagnosing Whipple's disease (WD). After starting treatment with ceftriaxone and co-trimoxazole, an impressive recovery was noted, as the wide spectrum of malabsorption signs quickly disappeared. After a year of antibiotics, articular and cutaneous manifestations improved, allowing the patient to stop taking corticosteroids and antidepressants. This truly unusual presentation reflects the multisystemic nature of WD, often leading to misdiagnosis of other entities. Scurvy is a rare finding in developed countries, but its presence should raise suspicion for small bowel disease. PMID:26376699

Bariatric surgery trends: an 18-year report from the International Bariatric Surgery Registry.

PubMed

Samuel, Isaac; Mason, Edward E; Renquist, Kathleen E; Huang, Yu-Hui; Zimmerman, M Bridget; Jamal, Mohammad

2006-11-01

The epidemic of morbid obesity has increased bariatric procedures performed. Trend analyses provide important information that may impact individual practices. Patient data from 137 surgeons were examined from 1987 to 2004 (41,860 patients) using Cochran-Armitage Trend test and Generalized Linear Model. Over an 18-year period, surgeon preference for combined restrictive-malabsorptive procedures increased from 33% to 94%, while simple gastric restriction decreased correspondingly (P < .0001). Surgeons per worksite doubled and cases per surgeon increased 71%. Laparoscopic procedures increased to 24%. The percentage of males, mean operative age, and initial body mass index (BMI) increased significantly (P < .0001). Postoperative hospital stay decreased from 5.0 to 3.9 days (P < .0001). The most common procedure in 2004 was Roux-en-Y gastric bypass (RYGB) (59%). Bariatric surgery patients are now older and heavier, length of stay is shorter, and the laparoscopic approach is more frequent. From 1987 to 2004, the general trend shows a clear preference for combined restrictive-malabsorptive operations.

Pancreatic enzyme replacement therapy.

PubMed

Layer, P; Keller, J; Lankisch, P G

2001-04-01

Malabsorption due to severe pancreatic exocrine insufficiency is one of the most important late features of chronic pancreatitis. Generally, steatorrhea is more severe and occurs several years prior to malabsorption of other nutrients because synthesis and secretion of lipase are impaired more rapidly, its intraluminal survival is shorter, and the lack of pancreatic lipase activity is not compensated for by nonpancreatic mechanisms. Patients suffer not only from nutritional deficiencies but also from increased nutrient delivery to distal intestinal sites, causing symptoms by profound alteration of upper gastrointestinal secretory and motor functions. Adequate nutrient absorption requires delivery of sufficient enzymatic activity into the duodenal lumen simultaneously with meal nutrients. The following recommendations are based on modern therapeutic concepts: 25,000 to 40,000 units of lipase per meal using pH-sensitive pancreatin microspheres, with dosage increases, compliance checks, and differential diagnosis in case of treatment failure. Still, in most patients, lipid digestion cannot be completely normalized by current standard therapy, and future developments are needed to optimize treatment.

Malabsorption syndrome observed in the common octopus Octopus vulgaris infected with Aggregata octopiana (Protista: Apicomplexa).

PubMed

Gestal, C; Páez de la Cadena, M; Pascual, S

2002-08-15

Octopus vulgaris infected with Aggregata octopiana were collected from an open-water culture system in the Ría of Aldán (NW Spain). Digestive tract infection values were determined with the use of a Neubauer chamber by counting the number of A. octopiana sporocysts. After determining enzyme activity values by the colorimetric Api-Zym system Biomerieux, one representative enzyme of glycosidases, peptid hydrolases and phosphoric hydrolases showing high activity was spectrophotometrically analysed. The enzymes were maltase and leucine-aminopeptidase (LAP) involved in the absorption process, and acid phosphatase, a lysosomic enzyme, respectively. Enzymatic activity of maltase and LAP decreased significantly, with increased sporocyst counts. However, acid phosphatase activity increased with severity of infection, indicating the presence of degradative enzymes from phagocytic cells in the infected area. A detrimental effect on gastrointestinal function may result from a decrease or malfunction of absorption enzymes. The results suggest a malabsorption syndrome resulting from parasitic infection.

[Cancer-vitamins-minerals: Complex relation].

PubMed

Adrianza de Baptista, Gertrudis; Murillo Melo, Carolain

2014-12-01

Since nutrition can influence the process of carcinogenesis, this study's objectives are to review the relationship between nutrition and cancer from the point of view of the role of micronutrients in the treatment of cancer patients, and to get to know the deficit relationship and the excess of micronutrients, with the etiology and cancer treatment. At the same time the patient's weight loss relates, among other things, to the type of cancerous tumor, its location, stage thereof, reason for which it may be associated with the deficiency of macro and micronutrients as from psychogenic, anorectics and mal-absorption effects or with mechanical effects as obstruction, among other toxic effects that are common in the treatment of cancer. Hence, the importance that the nutrition expert must have in making an adequate overall nutritional evaluation that allows the nutritional diagnosis, in studying the dietary patterns, to determine the toxic effects of the antineoplastic treatment in order to handle the treatment's timing excellence, symptoms and signs, and thus act effectively optiimizing the patient's life quality, and therewith his/her survival. There are controversies as to which specific dietary factors are related to cancer etiology and the results of studies on metabolic factors, and therefore, the relationship Cancer-Nutrition is quiet complex.

Magnitude and nature of carbohydrate-aromatic interactions in fucose-phenol and fucose-indole complexes: CCSD(T) level interaction energy calculations.

PubMed

Tsuzuki, Seiji; Uchimaru, Tadafumi; Mikami, Masuhiro

2011-10-20

The CH/π contact structures of the fucose-phenol and fucose-indole complexes and the stabilization energies by formation of the complexes (E(form)) were studied by ab initio molecular orbital calculations. The three types of interactions (CH/π and OH/π interactions and OH/O hydrogen bonds) were compared and evaluated in a single molecular system and at the same level of theory. The E(form) calculated for the most stable CH/π contact structure of the fucose-phenol complex at the CCSD(T) level (-4.9 kcal/mol) is close to that for the most stable CH/π contact structure of the fucose-benzene complex (-4.5 kcal/mol). On the other hand the most stable CH/π contact structure of the fucose-indole complex has substantially larger E(form) (-6.5 kcal/mol). The dispersion interaction is the major source of the attraction in the CH/π contact structures of the fucose-phenol and fucose-indole complexes as in the case of the fucose-benzene complex. The electrostatic interactions in the CH/π contact structures are small (less than 1.5 kcal/mol). The nature of the interactions between the nonpolar surface of the carbohydrate and aromatic rings is completely different from that of the conventional hydrogen bonds where the electrostatic interaction is the major source of the attraction. The distributed multipole analysis and DFT-SATP analysis show that the dispersion interactions in the CH/π contact structure of fucose-indole complex are substantially larger than those in the CH/π contact structures of fucose-benzene and fucose-phenol complexes. The large dispersion interactions are responsible for the large E(form) for the fucose-indole complex.

Lectin-Binding Specificity of the Fertilization-Relevant Protein PDC-109 by Means of Surface Plasmon Resonance and Carbohydrate REcognition Domain EXcision-Mass Spectrometry.

PubMed

Defaus, Sira; Avilés, Manuel; Andreu, David; Gutiérrez-Gallego, Ricardo

2018-04-04

Seminal plasma proteins are relevant for sperm functionality and some appear responsible for establishing sperm interactions with the various environments along the female genital tract towards the oocyte. In recent years, research has focused on characterizing the role of these proteins in the context of reproductive biology, fertility diagnostics and treatment of related problems. Herein, we focus on the main protein of bovine seminal plasma, PDC-109 (BSP-A1/-A2), which by virtue of its lectin properties is involved in fertilization. By means of surface plasmon resonance, the interaction of PDC-109 with a panel of the most relevant glycosidic epitopes of mammals has been qualitatively and quantitatively characterized, and a higher affinity for carbohydrates containing fucose has been observed, in line with previous studies. Additionally, using the orthogonal technique of Carbohydrate REcognition Domain EXcision-Mass Spectrometry (CREDEX-MS), the recognition domain of the interaction complexes between PDC-109 and all fucosylated disaccharides [(Fuc-α1,(3,4,6)-GlcNAc)] has been defined, revealing the specific glycotope and the peptide domain likely to act as the PDC-109 carbohydrate binding site.

Streptococcus pneumoniae Can Utilize Multiple Sources of Hyaluronic Acid for Growth

PubMed Central

Marion, Carolyn; Stewart, Jason M.; Tazi, Mia F.; Burnaugh, Amanda M.; Linke, Caroline M.; Woodiga, Shireen A.

2012-01-01

The mechanisms by which Streptococcus pneumoniae obtains carbohydrates for growth during airway colonization remain to be elucidated. The low concentration of free carbohydrates in the normal human airway suggests that pneumococci must utilize complex glycan structures for growth. The glycosaminoglycan hyaluronic acid is present on the apical surface of airway epithelial cells. As pneumococci express a hyaluronate lyase (Hyl) that cleaves hyaluronic acid into disaccharides, we hypothesized that during colonization pneumococci utilize the released carbohydrates for growth. Hyaluronic acid supported significant pneumococcal growth in an hyl-dependent manner. A phosphoenolpyruvate-dependent phosphotransferase system (PTS) and an unsaturated glucuronyl hydrolase (Ugl) encoded downstream of hyl are also essential for growth on hyaluronic acid. This genomic arrangement is present in several other organisms, suggesting conservation of the utilization mechanism between species. In vivo experiments support the hypothesis that S. pneumoniae utilizes hyaluronic acid as a carbon source during colonization. We also demonstrate that pneumococci can utilize the hyaluronic acid capsule of other bacterial species for growth, suggesting an alternative carbohydrate source for pneumococcal growth. Together, these data support a novel function for pneumococcal degradation of hyaluronic acid in vivo and provide mechanistic details of growth on this glycosaminoglycan. PMID:22311922

Bifidobacteria exhibit social behavior through carbohydrate resource sharing in the gut

PubMed Central

Milani, Christian; Andrea Lugli, Gabriele; Duranti, Sabrina; Turroni, Francesca; Mancabelli, Leonardo; Ferrario, Chiara; Mangifesta, Marta; Hevia, Arancha; Viappiani, Alice; Scholz, Matthias; Arioli, Stefania; Sanchez, Borja; Lane, Jonathan; Ward, Doyle V.; Hickey, Rita; Mora, Diego; Segata, Nicola; Margolles, Abelardo; van Sinderen, Douwe; Ventura, Marco

2015-01-01

Bifidobacteria are common and frequently dominant members of the gut microbiota of many animals, including mammals and insects. Carbohydrates are considered key carbon sources for the gut microbiota, imposing strong selective pressure on the complex microbial consortium of the gut. Despite its importance, the genetic traits that facilitate carbohydrate utilization by gut microbiota members are still poorly characterized. Here, genome analyses of 47 representative Bifidobacterium (sub)species revealed the genes predicted to be required for the degradation and internalization of a wide range of carbohydrates, outnumbering those found in many other gut microbiota members. The glycan-degrading abilities of bifidobacteria are believed to reflect available carbon sources in the mammalian gut. Furthermore, transcriptome profiling of bifidobacterial genomes supported the involvement of various chromosomal loci in glycan metabolism. The widespread occurrence of bifidobacterial saccharolytic features is in line with metagenomic and metatranscriptomic datasets obtained from human adult/infant faecal samples, thereby supporting the notion that bifidobacteria expand the human glycobiome. This study also underscores the hypothesis of saccharidic resource sharing among bifidobacteria through species-specific metabolic specialization and cross feeding, thereby forging trophic relationships between members of the gut microbiota. PMID:26506949

Lanthanide-IMAC enrichment of carbohydrates and polyols.

PubMed

Schemeth, Dieter; Rainer, Matthias; Messner, Christoph B; Rode, Bernd M; Bonn, Günther K

2014-03-01

In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions. Copyright © 2013 John Wiley & Sons, Ltd.

Targeting Common but Complex Proteoglycans on Breast Cancer Cells and Stem Cells Using Evolutionary Refined Malaria Proteins

DTIC Science & Technology

2015-11-01

AWARD NUMBER: W81XWH-13-1-0139 TITLE: Targeting Common but Complex Proteoglycans on Breast Cancer Cells and Stem Cells Using Evolutionary Refined...DATES COVERED 15Aug2013 - 14Aug2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-13-1-0139 Targeting Common but Complex Proteoglycans on...outbreaks in epidemic regions of the world. Prior to this application we discovered that human breast cancer cells express this same carbohydrate

Nutrient Needs of Young Athletes.

ERIC Educational Resources Information Center

Willenberg, Barbara; Hemmelgarn, Melinda

1991-01-01

Explains the nutritional requirements of children and adolescents, and the physiological roles of the major nutrients. Details the nutrient needs of young athletes, including pre- and postgame meals and fluid replacement. Discusses eating disorders and obesity. Advocates a diet rich in complex carbohydrates. (BC)

Morning sickness

MedlinePlus

... of fluids. Eat foods high in protein and complex carbohydrates, such as peanut butter on apple slices or celery; nuts; cheese; crackers; milk; cottage cheese; and yogurt; avoid foods high in fat and salt, but low in nutrition. Ginger products (proven effective against morning sickness) such ...

Zinc supplementation in children with cystic fibrosis

USDA-ARS?s Scientific Manuscript database

Cystic fibrosis (CF) leads to malabsorption of macro- and micronutrients. Symptomatic zinc deficiency has been reported in CF but little is known about zinc homeostasis in children with CF. Zinc supplementation (Zn suppl) is increasingly common in children with CF but it is not without theoretcial r...

Bariatric surgery options.

PubMed

Woodward, Bryan G

2003-01-01

There are multiple surgical procedures used for weight loss. The concept of achieving malabsorption through manipulation of the gastrointestinal contract is briefly discussed. Various surgical options are considered with their advantages and disadvantages, namely vertical banded gastroplasty, gastric banding, Roux-en-y gastric bypass, distal gastric bypass billiopancreatic diversion, and duodental switch.

Synthesis, crystal structure and investigation of mononuclear copper(II) and zinc(II) complexes of a new carboxylate rich tripodal ligand and their interaction with carbohydrates in alkaline aqueous solution

PubMed Central

Stewart, Christopher D.; Pedraza, Mayra; Arman, Hadi; Fan, Hua-Jun; Schilling, Eduardo Luiz; Szpoganicz, Bruno; Musie, Ghezai T.

2016-01-01

A new carboxylate rich asymmetric tripodal ligand, N-[2-carboxybenzomethyl]-N-[carboxymethyl]-β-alanine (H3camb), and its di-copper(II), (NH4)2[1]2, and di-zinc(II), ((CH3)4 N)2[2]2, complexes have been synthesized as carbohydrate binding models in aqueous solutions. The ligand and complexes have been fully characterized using several techniques, including single crystal X-ray diffraction. The interactions of (NH4)2[1]2 and ((CH3)4 N)2[2]2 with D-glucose, D-mannose, D-xylose and xylitol in aqueous alkaline media were investigated using UV–Vis and 13C-NMR spectroscopic techniques, respectively. The molar conductance, NMR and ESI–MS studies indicate that the complexes dissociate in solution to produce the respective complex anions, 1− and 2−. Complexes 1− and 2− showed chelating ability towards the naturally abundant and biologically relevant sugars, D-glucose, D-mannose, D-xylose, and xylitol. The complex ions bind to one molar equivalent of the sugars, even in the presence of stoichiometric excess of the substrates, in solution. Experimentally obtained spectroscopic data and computational results suggest that the substrates bind to the metal center in a bidentate fashion. Apparent binding constant values, pKapp, between the complexes and the substrates were determined and a specific mode of substrate binding is proposed. The pKapp and relativistic density functional theory (DFT) calculated Gibbs free energy values indicate that D-mannose displayed the strongest interaction with the complexes. Syntheses, characterizations, detailed substrate binding studies using spectroscopic techniques, single crystal X-ray diffraction and geometry optimizations of the complex-substrates with DFT calculations are also reported. PMID:25969174

Acarbose: a new option in the treatment of ulcerative colitis by increasing hydrogen production.

PubMed

Zhang, De-Qing; Zhu, Jian-Hong; Chen, Wei-Chang

2012-01-01

Acarbose, which is clinically widely used to treat Type 2 Diabetes, is thought to act at the small intestine by competitively inhibiting enzymes that delay the release of glucose from complex carbohydrates, thereby specifically reducing post prandial glucose excursion. The major side-effect of treatment with acarbose, flatulence, occurs when undigested carbohydrates are fermented by colonic bacteria, resulting in considerable amount of hydrogen. We propose that enteric benefits of acarbose is partly attributable to be their ability to neutralise oxidative stress via increased production of H2 in the gastrointestinal tract. Therefore, symptoms of ulcerative colitis in human beings can be ameliorated by acarbose.

Small intestinal bacterial overgrowth syndrome

PubMed Central

Bures, Jan; Cyrany, Jiri; Kohoutova, Darina; Förstl, Miroslav; Rejchrt, Stanislav; Kvetina, Jaroslav; Vorisek, Viktor; Kopacova, Marcela

2010-01-01

Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO. PMID:20572300

Carbohydrate binding specificity of pea lectin studied by NMR spectroscopy and molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Cheong, Youngjoo; Shim, Gyuchang; Kang, Dongil; Kim, Yangmee

1999-02-01

The conformational details of Man( α1,6)Man( α)OMe are investigated through NMR spectroscopy in conjunction with molecular modeling. The lowest energy structure (M1) in the adiabatic energy map calculated with a dielectric constant of 50 has glycosidic dihedral angles of φ=-60°, ψ=180° and ω=180°. The other low energy structure (M2) has glycosidic dihedral angles of φ=-60°, ψ=180° and ω=-60°. Molecular dynamics simulations and NMR experiments prove that Man( α1,6)Man( α)OMe in the free form exists with conformational averaging of M1 and M2 conformers predominantly. Molecular dynamics simulations of the pea lectin-carbohydrate complex with explicit water molecules starting from the X-ray crystallographic structure of pea lectin show that the protein-carbohydrate interaction centers mainly on the hydrogen bonds and van der Waals interactions between protein and carbohydrate. From the molecular dynamics simulation, it is found that the M1 structure can bind to pea lectin better than the M2 structure. The origin of this selectivity is the water- mediated hydrogen bond interactions between the remote mannose and the binding site of pea lectin as well as the direct hydrogen bond interaction between the terminal mannose and pea lectin. Extensive networks of interactions in the carbohydrate binding site and the metal binding site are important in maintaining the carbohydrate binding properties of pea lectin. Especially, the predominant factors of mannose binding specificity of pea lectin are the hydrogen bond interactions between the 4th hydroxyl groups of the terminal sugar ring and the side chains of Asp-81 and Asn-125 in the carbohydrate binding site, and the additional interactions between these side chains of Asp-81 and Asn-125 and the calcium ion in the metal binding site of pea lectin.

Blocking carbohydrate absorption and weight loss: a clinical trial using a proprietary fractionated white bean extract.

PubMed

Udani, Jay; Singh, Betsy B

2007-01-01

A proprietary fractionated white bean extract of Phaseolus vulgaris has been shown in vitro to inhibit the digestive enzyme alpha-amylase. This may prevent or delay the digestion of complex carbohydrates, potentially resulting in weight loss. A 4-week randomized, double-blind, placebo-controlled study of 25 healthy subjects consuming 1000 mg of a proprietary fractioned white bean extract or an identical placebo twice a day before meals in conjunction with a multi-component weight-loss program, including diet, exercise, and behavioral intervention, was conducted. Both groups reduced their weight and waist size significantly from baseline. The active group lost 6.0 lbs (P=.0002) and 2.2 in (P=.0050), and the placebo group lost 4.7 lbs (P=.0016) and 2.1 in (P=.0001). The differences between groups were not significant (weight P=.4235, waist size P=.8654). Through subsequent exploratory analysis to investigate group findings further, subjects were stratified by total dietary carbohydrate intake. This probative analysis revealed that the tertile of subjects who had consumed the most carbohydrates demonstrated significant reductions in both weight (8.7 lbs vs 1.7 lbs, P=.0412) and waist size (3.3 in vs 1.3 in P=.0100) compared with placebo subjects in the same tertile of carbohydrate intake. Subjects who adhere to a program including dietary modification, exercise, and behavioral intervention can significantly reduce their weight and waist size in a short period of time. In an exploratory analysis of data, the tertile of subjects who ate the most carbohydrates experienced a significant reduction in both weight and waist size with the addition of the white bean extract compared to the placebo group of the same tertile of carbohydrate consumption. Longer studies with a larger pool of subjects are required to validate these findings.

A new derivatization method for δ18O analysis of individual carbohydrates with GC-Pyrolysis-IRMS

NASA Astrophysics Data System (ADS)

Lehmann, M. M.; Siegwolf, R. T.; Saurer, M.; Blees, J.; Fischer, M.; Zech, M.

2015-12-01

Compound specific isotope analysis (CSIA) with gas chromatography coupled to an isotope ratio mass spectrometer (GC-Pyr-IRMS) is nowadays a powerful tool that is widely used by a broad spectrum of research fields to investigate the isotopic signature of diverse metabolites. While many CSIA methods for carbon, hydrogen, and nitrogen isotopes are known, CSIA methods for the analysis of oxygen isotopes (δ18O) are still not widely established. Especially, reliable and precise methods for the δ18O analyses of individual carbohydrates are scarce, which is caused by the highly sensitive nature of the sugars. However, carbohydrates are important components of living organisms, source for many biochemical reactions, and can be found in all organisms, in soils, sediments, and in air. Thus, a method, allowing the investigation of the 18O/16O ratio in carbohydrates will enhance the scope of research using isotopes. We developed a new and easy to handle derivatization method to determine δ18O in carbohydrates with GC-Pyr-IRMS that consists of a catalyzed one-pot reaction in acetonitrile, resulting in complete methylation of all sugar hydroxyl groups within 24 hours, with silver oxide as the proton acceptor and methyl iodide as the methyl group carrier. Results derived from standard material show unrivalled δ18O precision ranging from about 0.2 to 1.1 ‰ for different individual carbohydrates of different classes and a generally very good accuracy, with a narrow range of 0.2 ‰ around the reference value, despite of high area variations. We applied this method on real samples, demonstrating that the method can commonly be used for analyzing honey samples, and for the analyses of more complex carbohydrate mixtures from plant leaves, including glucose, fructose, pinitol, and sucrose. Our new method may be used for food, beverage, and medical applications, as well as for biogeochemical and paleoclimatic sciences.

Food-derived carbohydrates--structural complexity and functional diversity.

PubMed

Tharanathan, Rudrapatnam N

2002-01-01

Carbohydrates are biomolecules abundantly available in nature. They are found in bewildering types ranging from simple sugars through oligo- and polysaccharides to glycoconjugates and saccharide complexes, each exhibiting characteristic bio-physiological and/or nutritional functions both in in vivo and in vitro systems. For example, their presence or inclusion in food dictates the texture (body) and gives desirable customer appeal (satisfaction), or their inclusion in the diet offers beneficial effects of great therapeutic value. Thus, carbohydrates are integrally involved in a multitude of biological functions such as regulation of the immune system, cellular signaling (communication), cell malignancy, antiinfection responses, host-pathogen interactions, etc. If starch is considered the major energy storage carbohydrate, the gums/mucilages and other non-starch carbohydrates are of structural significance. The most investigated properties of starch are its gelatinization and melting behavior, especially during food processing. This has led to the development of the food polymer science approach, which has enabled a new interpretive and experimental frame work for the study of the plasticizing influence of simple molecules such as water, sugars, etc. on food systems that are kinetically constrained. Starch, although considered fully digestible, has been challenged, and starch is found to be partly indigestible in the GI tract of humans. This fraction of starch-resisting digestion in vivo is known as resistant starch (RS). The latter, due to its excellent fermentative capacity in the gut, especially yielding butyric acid is considered a new tool for the creation of fiber-rich foods, which are of nutraceutical importance. By a careful control of the processing conditions the content of RS, a man-made fiber, can be increased to as high as 30%. Arabinoxylans are the major endospermic cell wall polysaccharides of cereals. In wheat they are found complexed with ferulic acid esters, which after oxidative coupling in vivo mediated by H2O2 and peroxidases or even by photochemical means give cross linked diferuloyl derivatives. The latter confer strength and extensibility to the cell wall and offer resistance for digestibility by ruminants. They also help blocking of the ingress of pathogens. The ester bound ferulic acid after oxidation in vivo generates reactive oxygen species that contribute to the fragmentation of non-starch polysaccharides (hemicelluloses), and thereby reduces the product viscosity, a property seen during long-term storage of rice. In plant tissues, the arabinogalactans are implicated in such diverse functions as cell-cell adhesion, nutrition of growing pollen tubes, response to microbial infections, and also as markers of identity expressed in the terminal sequences of saccharide chains.

Chitin-Like Molecules Associate with Cryptococcus neoformans Glucuronoxylomannan To Form a Glycan Complex with Previously Unknown Properties

PubMed Central

Ramos, Caroline L.; Fonseca, Fernanda L.; Rodrigues, Jessica; Guimarães, Allan J.; Cinelli, Leonardo P.; Miranda, Kildare; Nimrichter, Leonardo; Casadevall, Arturo; Travassos, Luiz R.

2012-01-01

In prior studies, we demonstrated that glucuronoxylomannan (GXM), the major capsular polysaccharide of the fungal pathogen Cryptococcus neoformans, interacts with chitin oligomers at the cell wall-capsule interface. The structural determinants regulating these carbohydrate-carbohydrate interactions, as well as the functions of these structures, have remained unknown. In this study, we demonstrate that glycan complexes composed of chitooligomers and GXM are formed during fungal growth and macrophage infection by C. neoformans. To investigate the required determinants for the assembly of chitin-GXM complexes, we developed a quantitative scanning electron microscopy-based method using different polysaccharide samples as inhibitors of the interaction of chitin with GXM. This assay revealed that chitin-GXM association involves noncovalent bonds and large GXM fibers and depends on the N-acetyl amino group of chitin. Carboxyl and O-acetyl groups of GXM are not required for polysaccharide-polysaccharide interactions. Glycan complex structures composed of cryptococcal GXM and chitin-derived oligomers were tested for their ability to induce pulmonary cytokines in mice. They were significantly more efficient than either GXM or chitin oligomers alone in inducing the production of lung interleukin 10 (IL-10), IL-17, and tumor necrosis factor alpha (TNF-α). These results indicate that association of chitin-derived structures with GXM through their N-acetyl amino groups generates glycan complexes with previously unknown properties. PMID:22562469

Effects of short-term low- and high-carbohydrate diets on postprandial metabolism in non-diabetic and diabetic subjects.

PubMed

Culling, K S; Neil, H A W; Gilbert, M; Frayn, K N

2009-06-01

Low-fat high-carbohydrate diets raise plasma triacylglycerol (TG) concentrations. To test whether the nature of the carbohydrate affects metabolic responses, we conducted a randomized cross-over study using a short-term, intensive dietary modification. Eight non-diabetic subjects and four subjects with diet-controlled type 2 diabetes participated. They followed three isoenergetic diets, each for 3 days: high-fat (50% energy from fat), high-starch and high-sugar (each 70% energy from carbohydrate). Normal foods were provided. We measured plasma TG and glucose concentrations, fasting and after a standard test meal, on day 4 following each dietary period. Fasting TG concentrations were greatest following the high-sugar diet (mean+/-SEM for all subjects 1900+/-420micromol/l) and lowest following high-fat (1010+/-130micromol/l) (P=0.001); high-starch (mean 1500+/-310) and high-fat did not differ significantly (P=0.06). There was a greater effect in the diabetic subjects (diet x diabetes status interaction, P=0.008). Postprandial TG concentrations were similarly affected by prior diet (P<0.001) with each diet different from the others (P

Glycemic Index, Glycemic Load, Carbohydrates, and Type 2 Diabetes

PubMed Central

Greenwood, Darren C.; Threapleton, Diane E.; Evans, Charlotte E.L.; Cleghorn, Christine L.; Nykjaer, Camilla; Woodhead, Charlotte; Burley, Victoria J.

2013-01-01

OBJECTIVE Diets with high glycemic index (GI), with high glycemic load (GL), or high in all carbohydrates may predispose to higher blood glucose and insulin concentrations, glucose intolerance, and risk of type 2 diabetes. We aimed to conduct a systematic literature review and dose–response meta-analysis of evidence from prospective cohorts. RESEARCH DESIGN AND METHODS We searched the Cochrane Library, MEDLINE, MEDLINE in-process, Embase, CAB Abstracts, ISI Web of Science, and BIOSIS for prospective studies of GI, GL, and total carbohydrates in relation to risk of type 2 diabetes up to 17 July 2012. Data were extracted from 24 publications on 21 cohort studies. Studies using different exposure categories were combined on the same scale using linear and nonlinear dose–response trends. Summary relative risks (RRs) were estimated using random-effects meta-analysis. RESULTS The summary RR was 1.08 per 5 GI units (95% CI 1.02–1.15; P = 0.01), 1.03 per 20 GL units (95% CI 1.00–1.05; P = 0.02), and 0.97 per 50 g/day of carbohydrate (95% CI 0.90–1.06; P = 0.5). Dose–response trends were linear for GI and GL but more complex for total carbohydrate intake. Heterogeneity was high for all exposures (I2 >50%), partly accounted for by different covariate adjustment and length of follow-up. CONCLUSIONS Included studies were observational and should be interpreted cautiously. However, our findings are consistent with protective effects of low dietary GI and GL, quantifying the range of intakes associated with lower risk. Future research could focus on the type of sugars and other carbohydrates associated with greatest risk. PMID:24265366

Defining the carbohydrate specificities of Abrus precatorius agglutinin as T (Gal beta 1----3GalNAc) greater than I/II (Gal beta 1----3/4GlcNAc).

PubMed

Wu, A M; Lin, S R; Chin, L K; Chow, L P; Lin, J Y

1992-09-25

The combining site of the nontoxic carbohydrate binding protein (Abrus precatorius agglutinin, APA) purified from the needs of Abrus precatorius (Jequirity bean), was studied by quantitative precipitin and precipitin-inhibition assays. Of 26 glycoproteins and polysaccharides tested, all, except sialic acid-containing glycoproteins and desialized ovine salivary glycoproteins, reacted strongly with the lectin, and precipitated over 70% of the lectin added, indicating that APA has a broad range of affinity and recognizes (internal) Gal beta 1----sequences of carbohydrate chains. The strong reaction with desialized porcine and rat salivary glycoproteins as well as pneumococcus type XIV polysaccharide suggests that APA has affinity for one or more of the following carbohydrate sequences: Thomsen-Friedenreich (T, Gal beta 1----3GalNAc), blood group precursor type I and/or type II (Gal beta 1----3/4GlcNAc) disaccharide determinants of complex carbohydrates. Among the oligosaccharides tested, the T structure was the best inhibitor; it was 2.4 and 3.2 times more active than type II and type I sequences, respectively. The blood group I Ma-active trisaccharide, Gal beta 1----4GlcNAc beta 1----6Gal, was about as active as the corresponding disaccharide (II). From the above results, we conclude that the size of the combining site of the A. precatorius agglutinin is probably as large as a disaccharide and most strongly complementary to the Gal beta 1----3GalNAc (T determinant) sequence. The carbohydrate specificities of this lectin will be further investigated once the related oligosaccharide structures become available.

GlycomeDB – integration of open-access carbohydrate structure databases

PubMed Central

Ranzinger, René; Herget, Stephan; Wetter, Thomas; von der Lieth, Claus-Wilhelm

2008-01-01

Background Although carbohydrates are the third major class of biological macromolecules, after proteins and DNA, there is neither a comprehensive database for carbohydrate structures nor an established universal structure encoding scheme for computational purposes. Funding for further development of the Complex Carbohydrate Structure Database (CCSD or CarbBank) ceased in 1997, and since then several initiatives have developed independent databases with partially overlapping foci. For each database, different encoding schemes for residues and sequence topology were designed. Therefore, it is virtually impossible to obtain an overview of all deposited structures or to compare the contents of the various databases. Results We have implemented procedures which download the structures contained in the seven major databases, e.g. GLYCOSCIENCES.de, the Consortium for Functional Glycomics (CFG), the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Bacterial Carbohydrate Structure Database (BCSDB). We have created a new database called GlycomeDB, containing all structures, their taxonomic annotations and references (IDs) for the original databases. More than 100000 datasets were imported, resulting in more than 33000 unique sequences now encoded in GlycomeDB using the universal format GlycoCT. Inconsistencies were found in all public databases, which were discussed and corrected in multiple feedback rounds with the responsible curators. Conclusion GlycomeDB is a new, publicly available database for carbohydrate sequences with a unified, all-encompassing structure encoding format and NCBI taxonomic referencing. The database is updated weekly and can be downloaded free of charge. The JAVA application GlycoUpdateDB is also available for establishing and updating a local installation of GlycomeDB. With the advent of GlycomeDB, the distributed islands of knowledge in glycomics are now bridged to form a single resource. PMID:18803830

Influence of dietary fat and carbohydrates proportions on plasma lipids, glucose control and low-grade inflammation in patients with type 2 diabetes-The TOSCA.IT Study.

PubMed

Vitale, M; Masulli, M; Rivellese, A A; Babini, A C; Boemi, M; Bonora, E; Buzzetti, R; Ciano, O; Cignarelli, M; Cigolini, M; Clemente, G; Citro, G; Corsi, L; Dall'Aglio, E; Del Prato, S; Di Cianni, G; Dolci, M A; Giordano, C; Iannarelli, R; Iovine, C; Lapolla, A; Lauro, D; Leotta, S; Mazzucchelli, C; Montani, V; Perriello, G; Romano, G; Romeo, F; Santarelli, L; di Cola, R Schiano; Squatrito, S; Tonutti, L; Trevisan, R; Turco, A A; Zamboni, C; Riccardi, G; Vaccaro, O

2016-06-01

The optimal macronutrient composition of the diet for the management of type 2 diabetes is debated, particularly with regard to the ideal proportion of fat and carbohydrates. The aim of the study was to explore the association of different proportions of fat and carbohydrates of the diet-within the ranges recommended by different guidelines-with metabolic risk factors. We studied 1785 people with type 2 diabetes, aged 50-75, enrolled in the TOSCA.IT Study. Dietary habits were assessed using a validated food-frequency questionnaire (EPIC). Anthropometry, fasting lipids, HbA1c and C-reactive protein (CRP) were measured. Increasing fat intake from <25 to ≥35 % is associated with a significant increase in LDL-cholesterol, triglycerides, HbA1c and CRP (p < 0.05). Increasing carbohydrates intake from <45 to ≥60 % is associated with significantly lower triglycerides, HbA1c and CRP (p < 0.05). A fiber intake ≥15 g/1000 kcal is associated with a better plasma lipids profile and lower HbA1c and CRP than lower fiber consumption. A consumption of added sugars of ≥10 % of the energy intake is associated with a more adverse plasma lipids profile and higher CRP than lower intake. In people with type 2 diabetes, variations in the proportion of fat and carbohydrates of the diet, within the relatively narrow ranges recommended by different nutritional guidelines, significantly impact on the metabolic profile and markers of low-grade inflammation. The data support the potential for reducing the intake of fat and added sugars, preferring complex, slowly absorbable, carbohydrates.

Collective choice in ants: the role of protein and carbohydrates ratios.

PubMed

Arganda, S; Nicolis, S C; Perochain, A; Péchabadens, C; Latil, G; Dussutour, A

2014-10-01

In a foraging context, social insects make collective decisions from individuals responding to local information. When faced with foods varying in quality, ants are known to be able to select the best food source using pheromone trails. Until now, studies investigating collective decisions have focused on single nutrients, mostly carbohydrates. In the environment, the foods available are a complex mixture and are composed of various nutrients, available in different forms. In this paper, we explore the effect of protein to carbohydrate ratio on ants' ability to detect and choose between foods with different protein characteristics (free amino acids or whole proteins). In a two-choice set up, Argentine ants Linepithema humile were presented with two artificial foods containing either whole protein or amino acids in two different dietary conditions: high protein food or high carbohydrate food. At the collective level, when ants were faced with high carbohydrate foods, they did not show a preference between free amino acids or whole proteins, while a preference for free amino acids emerged when choosing between high protein foods. At the individual level, the probability of feeding was higher for high carbohydrates food and for foods containing free amino acids. Two mathematical models were developed to evaluate the importance of feeding probability in collective food selection. A first model in which a forager deposits pheromone only after feeding, and a second model in which a forager always deposits pheromone, but with greater intensity after feeding. Both models were able to predict free amino acid selection, however the second one was better able to reproduce the experimental results suggesting that modulating trail strength according to feeding probability is likely the mechanism explaining amino acid preference at a collective level in Argentine ants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sugar Lego: gene composition of bacterial carbohydrate metabolism genomic loci.

PubMed

Kaznadzey, Anna; Shelyakin, Pavel; Gelfand, Mikhail S

2017-11-25

Bacterial carbohydrate metabolism is extremely diverse, since carbohydrates serve as a major energy source and are involved in a variety of cellular processes. Bacterial genes belonging to same metabolic pathway are often co-localized in the chromosome, but it is not a strict rule. Gene co-localization in linked to co-evolution and co-regulation. This study focuses on a large-scale analysis of bacterial genomic loci related to the carbohydrate metabolism. We demonstrate that only 53% of 148,000 studied genes from over six hundred bacterial genomes are co-localized in bacterial genomes with other carbohydrate metabolism genes, which points to a significant role of singleton genes. Co-localized genes form cassettes, ranging in size from two to fifteen genes. Two major factors influencing the cassette-forming tendency are gene function and bacterial phylogeny. We have obtained a comprehensive picture of co-localization preferences of genes for nineteen major carbohydrate metabolism functional classes, over two hundred gene orthologous clusters, and thirty bacterial classes, and characterized the cassette variety in size and content among different species, highlighting a significant role of short cassettes. The preference towards co-localization of carbohydrate metabolism genes varies between 40 and 76% for bacterial taxa. Analysis of frequently co-localized genes yielded forty-five significant pairwise links between genes belonging to different functional classes. The number of such links per class range from zero to eight, demonstrating varying preferences of respective genes towards a specific chromosomal neighborhood. Genes from eleven functional classes tend to co-localize with genes from the same class, indicating an important role of clustering of genes with similar functions. At that, in most cases such co-localization does not originate from local duplication events. Overall, we describe a complex web formed by evolutionary relationships of bacterial carbohydrate metabolism genes, manifested as co-localization patterns. This article was reviewed by Daria V. Dibrova (A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia), nominated by Armen Mulkidjanian (University of Osnabrück, Germany), Igor Rogozin (NCBI, NLM, NIH, USA) and Yuri Wolf (NCBI, NLM, NIH, USA).

Structural Basis of Clostridium perfringens Toxin Complex Formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams,J.; Gregg, K.; Bayer, E.

2008-01-01

The virulent properties of the common human and livestock pathogen Clostridium perfringens are attributable to a formidable battery of toxins. Among these are a number of large and highly modular carbohydrate-active enzymes, including the {mu}-toxin and sialidases, whose catalytic properties are consistent with degradation of the mucosal layer of the human gut, glycosaminoglycans, and other cellular glycans found throughout the body. The conservation of noncatalytic ancillary modules among these enzymes suggests they make significant contributions to the overall functionality of the toxins. Here, we describe the structural basis of an ultra-tight interaction (Ka = 1.44 x 1011 M-1) between themore » X82 and dockerin modules, which are found throughout numerous C. perfringens carbohydrate-active enzymes. Extensive hydrogen-bonding and van der Waals contacts between the X82 and dockerin modules give rise to the observed high affinity. The {mu}-toxin dockerin module in this complex is positioned {approx}180 relative to the orientation of the dockerin modules on the cohesin module surface within cellulolytic complexes. These observations represent a unique property of these clostridial toxins whereby they can associate into large, noncovalent multitoxin complexes that allow potentiation of the activities of the individual toxins by combining complementary toxin specificities.« less

Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies.

PubMed Central

Clarke, R.; Frost, C.; Collins, R.; Appleby, P.; Peto, R.

1997-01-01

OBJECTIVE: To determine the quantitative importance of dietary fatty acids and dietary cholesterol to blood concentrations of total, low density lipoprotein, and high density lipoprotein cholesterol. DESIGN: Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers. SUBJECTS: 395 dietary experiments (median duration 1 month) among 129 groups of individuals. RESULTS: Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l. CONCLUSIONS: In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol. PMID:9006469

Starchy food consumption in French adults: a cross-sectional analysis of the profile of consumers and contribution to nutritional intake in a web-based prospective cohort.

PubMed

Szabo de Edelenyi, Fabien; Julia, Chantal; Courtois, Frédéric; Méjean, Caroline; Péneau, Sandrine; Galan, Pilar; Hercberg, Serge; Kesse-Guyot, Emmanuelle

2014-01-01

French Nutritional Guidelines recommend eating starchy foods at each meal, according to appetite, and advise to vary sources. However, the proportion of energy from carbohydrates is currently too low in many Western European countries. Consumption of the different types of starchy foods was assessed among 80,209 adult participants in the French NutriNet-Santé cohort (78% women, mean age 42.9 ± 14.5). Description of starchy food consumption according to sociodemographics was provided as well as the contribution of starchy food to nutritional intake. Determinants of adherence to starchy food nutritional guidelines were estimated using multivariable polytomous logistic regression. Starchy foods contributed approximately 22% of the energy intake, 75% of the complex carbohydrate intake and 36.1% of the fibre intake. About 43% of the subjects had intakes in line with the French Nutritional Guidelines concerning starchy foods. Men met the recommendation more frequently (55 vs. 33% for women), but were also more likely to exceed the recommendation (9.5 vs. 1.3%), even after adjustment for energy intake. According to our multivariable model, starchy food consumption increased also with age. A higher consumption of starchy foods should be promoted in the French population in order to increase the part of the energy intake coming from complex carbohydrates.

Antibody recognition of a unique tumor-specific glycopeptide antigen

PubMed Central

Brooks, Cory L.; Schietinger, Andrea; Borisova, Svetlana N.; Kufer, Peter; Okon, Mark; Hirama, Tomoko; MacKenzie, C. Roger; Wang, Lai-Xi; Schreiber, Hans; Evans, Stephen V.

2010-01-01

Aberrant glycosylation and the overexpression of certain carbohydrate moieties is a consistent feature of cancers, and tumor-associated oligosaccharides are actively investigated as targets for immunotherapy. One of the most common aberrations in glycosylation patterns is the presentation of a single O-linked N-acetylgalactosamine on a threonine or serine residue known as the “Tn antigen.” Whereas the ubiquitous nature of Tn antigens on cancers has made them a natural focus of vaccine research, such carbohydrate moieties are not always tumor-specific and have been observed on embryonic and nonmalignant adult tissue. Here we report the structural basis of binding of a complex of a monoclonal antibody (237mAb) with a truly tumor-specific glycopeptide containing the Tn antigen. In contrast to glycopeptide-specific antibodies in complex with simple peptides, 237mAb does not recognize a conformational epitope induced in the peptide by sugar substitution. Instead, 237mAb uses a pocket coded by germ-line genes to completely envelope the carbohydrate moiety itself while interacting with the peptide moiety in a shallow groove. Thus, 237mAb achieves its striking tumor specificity, with no observed physiological cross-reactivity to the unglycosylated peptide or the free glycan, by a combination of multiple weak but specific interactions to both the peptide and to the glycan portions of the antigen. PMID:20479270