High fat versus high carbohydrate nutritional supplementation: a one year trial in stunted rural Gambian children.

OBJECTIVE: The study tests the hypothesis that a low daily fat intake may induce a negative fat balance and impair catch-up growth in stunted children between 3 and 9y of age. DESIGN: Randomized case-control study. SETTING: Three rural villages of the West Kiang District, The Gambia. SUBJECTS: Three groups of 30 stunted but not wasted children (height for age z-score < or = -2.0, weight for height z-score > or = -2.0) 3-9 y of age were selected by anthropometric survey. Groups were matched for age, sex, village, degree of stunting and season. INTERVENTION: Two groups were randomly assigned to be supplemented five days a week for one year with either a high fat (n = 29) or a high carbohydrate biscuit (n = 30) each containing approximately 1600 kJ. The third group was a non supplemented control group (n = 29). Growth, nutritional status, dietary intake, resting energy expenditure and morbidity were compared. RESULTS: Neither the high fat nor the high carbohydrate supplement had an effect on weight or height gain. The high fat supplement did slightly increase adipose tissue mass. There was no effect of supplementation on resting energy expenditure or morbidity. In addition, the annual growth rate was not associated with a morbidity score. CONCLUSIONS: Results show that neither a high fat nor a high carbohydrate supplement given during 12 months to stunted Gambian children induced catch-up growth. The authors suggest that an adverse effect of the environment on catch-up growth persists despite the nutritional interventions.

Neurolysis using a carbohydrate polymer gel for the treatment of postoperative neuropathic pain.

Perineural and intraneural fibrosis is thought to be the main cause of failure of the many surgical treatments of neuropathic pain. We have used Adcon-T/N carbohydrate polymer gel for prevention of perineural fibrosis in several parts of the body. In this retrospective study, 54 patients who presented with postoperative neuropathic pain had microsurgical epineural neurolysis and relocation of a terminal neuroma. In 19 of them, the carbohydrate gel was applied at the same time. The mean follow-up was four years and the nerve distribution varied. Postoperative improvement in pain scores (visual analogue scale (VAS) and neuropathic pain scale inventory (NPSI)), sensitivity, overall improvement and satisfaction were equivalent in the two groups, with pain relief in about 80% of the patients. There was no significant beneficial effect in the carbohydrate gel group. Patients treated with this device had a higher infection rate (21 compared with 0, p = 0.01) and delayed wound healing (31.6 compared with 11.8, p = 0.2). We conclude that good long-term pain relief is obtained postoperatively independently of the addition of carbohydrate gel. There was a slight but not significant trend towards profound pain relief with the gel.

Effect of carbohydrate overfeeding on whole body macronutrient metabolism and expression of lipogenic enzymes in adipose tissue of lean and overweight humans

OBJECTIVE: Lipids stored in adipose tissue can originate from dietary lipids or from de novo lipogenesis (DNL) from carbohydrates. Whether DNL is abnormal in adipose tissue of overweight individuals remains unknown. The present study was undertaken to assess the effect of carbohydrate overfeeding on glucose-induced whole body DNL and adipose tissue lipogenic gene expression in lean and overweight humans. DESIGN: Prospective, cross-over study. SUBJECTS AND METHODS: A total of 11 lean (five male, six female, mean BMI 21.0+/-0.5 kg/m(2)) and eight overweight (four males, four females, mean BMI 30.1+/-0.6 kg/m(2)) volunteers were studied on two occasions. On one occasion, they received an isoenergetic diet containing 50% carbohydrate for 4 days prior to testing; on the other, they received a hyperenergetic diet (175% energy requirements) containing 71% carbohydrates. After each period of 4 days of controlled diet, they were studied over 6 h after having received 3.25 g glucose/kg fat free mass. Whole body glucose oxidation and net DNL were monitored by means of indirect calorimetry. An adipose tissue biopsy was obtained at the end of this 6-h period and the levels of SREBP-1c, acetyl CoA carboxylase, and fatty acid synthase mRNA were measured by real-time PCR. RESULTS: After isocaloric feeding, whole body net DNL amounted to 35+/-9 mg/kg fat free mass/5 h in lean subjects and to 49+/-3 mg/kg fat free mass/5 h in overweight subjects over the 5 h following glucose ingestion. These figures increased (P<0.001) to 156+/-21 mg/kg fat free mass/5 h in lean and 64+/-11 mg/kg fat free mass/5 h (P<0.05 vs lean) in overweight subjects after carbohydrate overfeeding. Whole body DNL after overfeeding was lower (P<0.001) and glycogen synthesis was higher (P<0.001) in overweight than in normal subjects. Adipose tissue SREBP-1c mRNA increased by 25% in overweight and by 43% in lean subjects (P<0.05) after carbohydrate overfeeding, whereas fatty acid synthase mRNA increased by 66 and 84% (P<0.05). CONCLUSION: Whole body net DNL is not increased during carbohydrate overfeeding in overweight individuals. Stimulation of adipose lipogenic enzymes is also not higher in overweight subjects. Carbohydrate overfeeding does not stimulate whole body net DNL nor expression of lipogenic enzymes in adipose tissue to a larger extent in overweight than lean subjects.

Measurement of 13CO2 in expired air as an index of compliance to a high carbohydrate diet naturally enriched in 13C.

The aim of this study was to determine whether breath 13CO2 measurements could be used to assess the compliance to a diet containing carbohydrates naturally enriched in 13C. The study was divided into two periods: Period 1 (baseline of 4 days) with low 13C/12C ratio carbohydrates. Period 2 (5 days) isocaloric diet with a high 13C/12C ratio (corn, cane sugar, pineapple, millet) carbohydrates. Measurements were made of respiratory gas exchange by indirect calorimetry, urinary nitrogen excretion and breath 13CO2 every morning in post-absorptive conditions, both in resting state and during a 45-min low intensity exercise (walking on a treadmill). The subjects were 10 healthy lean women (BMI 20.4 +/- 1.7 kg/m2, % body fat 24.4 +/- 1.3%), the 13C enrichment of oxidized carbohydrate and breath 13CO2 were compared to the enrichment of exogenous dietary carbohydrates. At rest the enrichment of oxidized carbohydrate increased significantly after one day of 13C carbohydrate enriched diet and reached a steady value (103 +/- 16%) similar to the enrichment of exogenous carbohydrates. During exercise, the 13C enrichment of oxidized carbohydrate remained significantly lower (68 +/- 17%) than that of dietary carbohydrates. The compliance to a diet with a high content of carbohydrates naturally enriched in 13C may be assessed from the measurement of breath 13CO2 enrichment combined with respiratory gas exchange in resting, postabsorptive conditions.

Carbohydrate metabolism and de novo lipogenesis in human obesity.

Respiratory exchange was measured during 14 consecutive hours in six lean and six obese individuals after ingestion of 500 g of dextrin maltose to investigate and compare their capacity for net de novo lipogenesis. After ingestion of the carbohydrate load, metabolic rates rose similarly in both groups but fell earlier and more rapidly in the obese. RQs also rose rapidly and remained in the range of 0.95 to 1.00 for approximately 8 h in both groups. During this time, RQ exceeded 1.00 for only short periods of time with the result that 4 +/- 1 g and 5 +/- 3 g (NS) of fat were synthesized via de novo lipogenesis in excess of concomitant fat oxidation in the lean and obese subjects, respectively. Results demonstrate that net de novo lipid synthesis from an unusually large carbohydrate load is not greater in obese than in lean individuals.

Twenty-four-hour energy expenditure and thermogenesis: response to progressive carbohydrate overfeeding in man.

Short-term overfeeding with carbohydrate induced a marked stimulation of energy expenditure, amounting to 33 per cent of the excess energy intake on the 7th day of overfeeding. This value is larger than that previously reported in man. Stimulation of lipogenesis and increased activity of the sympathetic nervous system seem to be the two major mechanisms which account for the stimulation of energy expenditure during carbohydrate overfeeding.

Cardiac dysfunction and impaired compensatory response to pressure overload in mice deficient in stem cell antigen-1.

Stem cell antigen-1 (Sca-1) has been used to identify cardiac stem cells in the mouse heart. To investigate the function of Sca-1 in aging and during the cardiac adaptation to stress, we used Sca-1-deficient mice. These mice developed dilated cardiomyopathy [end-diastolic left ventricular diameter at 18 wk of age: wild-type (WT) mice, 4.2 mm ± 0.3; Sca-1-knockout (Sca-1-KO) mice, 4.6 mm ± 0.1; ejection fraction: WT mice, 51.1 ± 2.7%; Sca-1-KO mice, 42.9 ± 2.7%]. Furthermore, the hearts of mice lacking Sca-1 demonstrated exacerbated susceptibility to pressure overload [ejection fraction after transaortic constriction (TAC): WT mice, 43.5 ± 3.2%; Sca-1-KO mice, 30.8% ± 4.0] and increased apoptosis, as shown by the 2.5-fold increase in TUNEL(+) cells in Sca-1-deficient hearts under stress. Sca-1 deficiency affected primarily the nonmyocyte cell fraction. Indeed, the number of Nkx2.5(+) nonmyocyte cells, which represent a population of cardiac precursor cells (CPCs), was 2-fold smaller in Sca-1 deficient neonatal hearts. In vitro, the ability of CPCs to differentiate into cardiomyocytes was not affected by Sca-1 deletion. In contrast, these cells demonstrated unrestricted differentiation into cardiomyocytes. Interestingly, proliferation of cardiac nonmyocyte cells in response to stress, as judged by BrdU incorporation, was higher in mice lacking Sca-1 (percentages of BrdU(+) cells in the heart after TAC: WT mice, 4.4 ± 2.1%; Sca-1-KO mice, 19.3 ± 4.2%). These data demonstrate the crucial role of Sca-1 in the maintenance of cardiac integrity and suggest that Sca-1 restrains spontaneous differentiation in the precursor population. The absence of Sca-1 results in uncontrolled precursor recruitment, exhaustion of the precursor pool, and cardiac dysfunction.

Phenotypic features of carbohydrate sulfotransferase 3 (CHST3) deficiency in 24 patients: congenital dislocations and vertebral changes as principal diagnostic features.

We recently reported on the deficiency of carbohydrate sulfotransferase 3 (CHST3; chondroitin-6-sulfotransferase) in six subjects diagnosed with recessive Larsen syndrome or humero-spinal dysostosis [Hermanns et al. (2008); Am J Hum Genet 82:1368-1374]. Since then, we have identified 17 additional families with CHST3 mutations and we report here on a series of 24 patients in 23 families. The diagnostic hypothesis prior to molecular analysis had been: Larsen syndrome (15 families), humero-spinal dysostosis (four cases), chondrodysplasia with multiple dislocations (CDMD "Megarbane type"; two cases), Desbuquois syndrome (one case), and spondylo-epiphyseal dysplasia (one case). In spite of the different diagnostic labels, the clinical features in these patients were similar and included dislocation of the knees and/or hips at birth, clubfoot, elbow joint dysplasia with subluxation and limited extension, short stature, and progressive kyphosis developing in late childhood. The most useful radiographic clues were the changes of the lumbar vertebrae. Twenty-four different CHST3 mutations were identified; 16 patients had homozygous mutations. We conclude that CHST3 deficiency presents at birth with congenital dislocations of knees, hips, and elbows, and is often diagnosed initially as Larsen syndrome, humero-spinal dysostosis, or chondrodysplasia with dislocations. The incidence of CHST3 deficiency seems to be higher than assumed so far. The clinical and radiographic pattern (joint dislocations, vertebral changes, normal carpal age, lack of facial flattening, and recessive inheritance) is characteristic and distinguishes CHST3 deficiency from other disorders with congenital dislocations such as filamin B-associated dominant Larsen syndrome and Desbuquois syndrome.

New insights in carbohydrate-deficient transferrin analysis with capillary electrophoresis-mass spectrometry

Capillary zone electrophoresis (CZE) with UV detection has been widely used for the determination of carbohydrate-deficient transferrin (CDT), an indirect marker of the chronic alcohol consumption (≥60-80g/day). A commercially available method (CEofix? CDT kit), containing a bilayer anionic coating, allows for the analysis of CDT with a high resolution between transferrin (Tf) glycoforms with reduced protein adsorption onto the capillary wall. Although widely used in routine analysis, this procedure presents some limitations in terms of selectivity and sensitivity which may be overcome with mass spectrometry (MS). However, the available method is not MS-compatible due to the non-volatile coating as well as the phosphate and borate buffers present in the background electrolyte (BGE). This study firstly consisted in developing MS-compatible separation conditions, i.e., coating and BGE compositions. Numerous cationic, neutral, and anionic coatings were evaluated in combination with BGEs covering a broad range of pH values. A bilayer coating composed of a cationic layer of 10% polybrene (m/v) and an anionic layer of 10% dextran sulfate (m/v) combined with a BGE composed of 20mM ammonium acetate at pH 8.5 provided the best results in terms of glycoforms' resolution, efficiency, adsorption reduction, migration times' repeatability, and coating stability. The method was then transferred to CZE-MS after investigations of the electrospray ionization (ESI) source, equipped with a sheath-flow interface, and the time-of-flight (TOF/MS) parameters. A successful MS detection of tetrasialo-Tf was obtained during infusion, while the experiments highlighted the challenges and issues encountered with intact glycoprotein analysis by CZE-ESI-MS.

Effect of carbohydrate overfeeding on whole body and adipose tissue metabolism in humans.

OBJECTIVE: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. RESEARCH METHODS AND PROCEDURES: Nine healthy lean volunteers (five men and four women) were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates (indirect calorimetry), and the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue (subcutaneous microdialysis with 1,6(13)C2,6,6(2)H2 glucose) were assessed before and after administration of glucose. Adipose tissue biopsies were obtained at the end of the experiments to monitor mRNAs of key lipogenic enzymes. RESULTS: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Whole body net de novo lipogenesis after glucose loading was markedly increased at the expense of glycogen synthesis. Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase. The fractional activity of adipose tissue pentose-phosphate pathway was 17% to 22% and was not altered by carbohydrate overfeeding. DISCUSSION: Carbohydrate overfeeding markedly increased net de novo lipogenesis at the expense of glycogen synthesis. An increase in mRNAs coding for key lipogenic enzymes suggests that de novo lipogenesis occurred, at least in part, in adipose tissue. The pentose-phosphate pathway is active in adipose tissue of healthy humans, consistent with an active role of this tissue in de novo lipogenesis.

Ad libitum intake of a high-carbohydrate or high-fat diet in young men: effects on nutrient balances.

The effect of diet composition [high-carbohydrate, low-fat (HC) and high-fat, low-carbohydrate (HF) diets] on macronutrient intakes and nutrient balances was investigated in young men of normal body weight. Eleven subjects were studied on two occasions for 48 h in a whole-body indirect calorimeter in a crossover design. Subjects selected their meals from a list containing a large variety of common food, which had a food quotient > 0.85 for the HC diet and < 0.85 for the HF diet. The average ad libitum intake was 14.41 +/- 0.85 MJ/d (67%, 18%, and 15% of energy as carbohydrate, fat, and protein, respectively) with the HC diet and 18.25 +/- 0.90 MJ/d (26%, 61%, and 13% of energy as carbohydrate, fat, and protein, respectively) with the HF diet. Total energy expenditure was not significantly influenced by diet composition: 10.46 +/- 0.27 and 10.97 +/- 0.22 MJ/d for the HC and HF diets, respectively. During the 2 test days, cumulative carbohydrate storage was 418 +/- 72 and 205 +/- 47 g, and fat balance was 29 +/- 17 and 291 +/- 29 g with the HC and HF diets, respectively. Only the HF diet induced a significantly positive fat balance. These results emphasize the important role of the dietary fat content in body fat storage.

Role of CD44H carbohydrate structure in neuroblastoma adhesive properties.

BACKGROUND: CD44 represents a heterogeneous group of surface glycoproteins involved in cell-cell and cell-matrix interactions. CD44H is the major receptor for hyaluronate, and most if not all CD44H known functions are attributed to its ability to recognize hyaluronate. We have previously demonstrated a lack of CD44 expression in high stages and NMYC-amplified tumors and further have shown that NMYC-amplified cell lines either did not express CD44 at all or expressed a nonfunctional receptor. On the other hand, nonamplified cells constitutively expressed an active receptor, suggesting that absence of CD44-mediated hy aluronate binding could be related to increased malignancy in human neuroblastoma. PROCEDURE: In the present study we have compared the glycosylated structure of CD44 expressed by NMYC amplified vs. nonamplified cell lines in relation to their adhesive properties for hyaluronate. These adhesive properties were measured after modifications of the carbohydrate structure with enzymes and inhibitors of N- or O-linked glycosylation. RESULTS AND CONCLUSIONS: Our results indicate that increased sialylation, defective N-linked glycosylation, and substitution of the CD44 glycoprotein with keratan sulfate glycosaminoglycan might include modifications observed on neuroblastoma cells that could account for the inability of the receptor to bind hyaluronate.