In vivo degradation of banana starch: Structural characterization of the degradation process

This work reports the first ultrastructural investigation into the degradation process that starch granules isolated from bananas (cv. Nanicao) undergo during ripening. Starch granules from green bananas had a smooth surface, while granules from ripe bananas were more elongated with parallel striations, as revealed by CSLM and SEM. AFM images revealed that the first layer covering the granule surface is composed of a hard material and, as degradation proceeds, hard and soft regions seem to be repeated at regular intervals. WAXD patterns of banana starches were C-type, and the crystalline index was reduced during ripening. The B-/A-type ratio was increased, indicating the preferential degradation of the A-type allomorph. The branch-chain length distribution showed predominantly short chains of amylopectin (A and B1-chain). The fa/fb ratio was reduced during degradation, while amylose content was increased. The results allowed a detailed understanding of the changes that starch granules undergo during banana ripening. (C) 2010 Elsevier Ltd. All rights reserved.

The Aging Process of the Heart: Obesity Is the Main Risk Factor for Left Atrial Enlargement During Aging The MONICA/KORA (Monitoring of Trends and Determinations in Cardiovascular Disease/Cooperative Research in the Region of Augsburg) Study

Objectives This prospective study evaluated the association of obesity and hypertension with left atrial (LA) volume over 10 years. Background Although left atrial enlargement (LAE) is an independent risk factor for atrial fibrillation, stroke, and death, little information is available about determinants of LA size in the general population. Methods Participants (1,212 men and women, age 25 to 74 years) originated from a sex-and age-stratified random sample of German residents of the Augsburg area (MONICA S3). Left atrial volume was determined by standardized echocardiography at baseline and again after 10 years. Left atrial volume was indexed to body height (iLA). Left atrial enlargement was defined as iLA >= 35.7 and >= 33.7 ml/m in men and women, respectively. Results At baseline, the prevalence of LAE was 9.8%. Both obesity and hypertension were independent predictors of LAE, obesity (odds ratio [OR]: 2.4; p < 0.001) being numerically stronger than hypertension (OR: 2.2; p < 0.001). Adjusted mean values for iLA were significantly lower in normal-weight hypertensive patients (25.4 ml/m) than in obese normotensive individuals (27.3 ml/m; p = 0.016). The highest iLA was found in the obese hypertensive subgroup (30.0 ml/m; p < 0.001 vs. all other groups). This group also presented with the highest increase in iLA (+6.0 ml/m) and the highest incidence (31.6%) of LAE upon follow-up. Conclusions In the general population, obesity appears to be the most important risk factor for LAE. Given the increasing prevalence of obesity, early interventions, especially in young obese individuals, are essential to prevent premature onset of cardiac remodeling at the atrial level. (J Am Coll Cardiol 2009; 54: 1982-9) (C) 2009 by the American College of Cardiology Foundation

Home blood pressure monitoring in paediatric chronic hypertension

Blood pressure (BP) measurement is the basis for the diagnosis and management of arterial hypertension. The aim of this study was to compare BP measurements performed in the office and at home (home blood pressure monitoring, HBPM) in children and adolescents with chronic arterial hypertension. HBPM was performed by the patient or by his/her legal guardian. During a 14-day period, three BP measurements were performed in the morning or in the afternoon (daytime measurement) and in the evening (night-time measurement), with 1-min intervals between measurements, totalling six measurements per day. HBPM was defined for systolic blood pressure (SBP) and diastolic blood pressure (DBP) values. HBPM was evaluated in 40 patients (26 boys), mean age of 12.1 years (4-18 years). SBP and DBP records were analysed. The mean differences between average HBP and doctor`s office BP were 0.6 +/- 14 and 4 +/- 13 mm Hg for SBP and DBP, respectively. Average systolic HBPM (daytime and night-time) did not differ from average office BP, and diastolic HBPM (daytime and night-time) was statistically lower than office BP. The comparison of individual BP measurements along the study period (13 days) by s.d. of differences shows a significant decline only for DBP values from day 5, on which difference tends to disappear towards the end of the study. Mean daytime and night-time SBP and DBP values remained stable throughout the study period, confirming HBPM as an acceptable methodology for BP evaluation in hypertensive children and adolescents. Journal of Human Hypertension (2009) 23, 464-469; doi:10.1038/jhh.2008.167; published online 12 March 2009

Plantain and Banana Starches: Granule Structural Characteristics Explain the Differences in Their Starch Degradation Patterns

Different banana cultivars were used to investigate the influences of starch granule structure and hydrolases on degradation. The highest degrees of starch degradation were observed in dessert bananas during ripening. Scanning electron microscopy images revealed smooth granule surface in the green stage in all cultivars, except for Mysore. The small and round granules were preferentially degraded in all of the cultivars. Terra demonstrated a higher degree of crystallinity and a short amylopectin chain length distribution, resulting in high starch content in the ripe stage. Amylose content and the crystallinity index were more strongly correlated than the distribution of amylopectin branch chain lengths in banana starches. alpha- and beta-amylase activities were found in both forms, soluble in the pulp and associated with the starch granule. Starch-phosphorylase was not found in Mysore. On the basis of the profile of alpha-amylase in vitro digestion and the structural characteristics, it could be concluded that the starch of plantains has an arrangement of granules more resistant to enzymes than the starch of dessert bananas.

Mango starch degradation. I. A microscopic view of the granule during ripening

The starch content of unripe mango Keitt is around 7% (FW), and it is converted to soluble sugars during the ripening of the detached fruit. Despite the importance of starch-to-soluble sugar metabolism for mango quality, little literature is found on this subject and none concerning the physical aspects of starch degradation. This manuscript presents some changes in the physical aspects of the starch granule during ripening, as analyzed by light microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). According to the analysis, unripe Keitt-mango-starch being spherical in shape and measuring around 15,mu m, has A-type X-ray diffraction pattern with a degree of crystallinity around 21% with slight changes after 8 days of ripening. AFM images of the surface of the granules showed ultra microstructures, which are in agreement with a blocklet-based organization of the granules. The AFM-contrast image of growing layers covering the granule showed fibril-like structures, having 20 nm in diameter, transversally connecting the layer to the granule. The appearance of the partially degraded granules and the pattern of degradation were similar to those observed as a result of amylase activity, suggesting a hydrolytic pathway for the degradation of starch from mango cultivar Keitt. These results provide clues to a better understanding of starch degradation in fruits.

Mango starch degradation. II. The binding of alpha-amylase and beta-amylase to the starch granule

During mango ripening, soluble sugars that account for mango sweetening are accumulated through carbon supplied by both photosynthesis and starch degradation. The cultivar Keitt has a characteristic dependence on sugar accumulation during starch degradation, which takes place during ripening, only a few days after detachment from the tree. Most knowledge about starch degradation is based on seeds and leaves currently used as models. However, information about the mango fruit is scarce. This work presents the evaluation of alpha- and beta-amylases in the starch granule surface during fruit development and ripening. Extractable proteins were assayed for amylase activity and detected by immunofluorescence microscopy and correlated to gene expression. The results suggest that both amylases are involved in starch degradation during mango ripening, probably under the dependence of another signal triggered by the detachment from the mother-plant.

ACCM/PALS haemodynamic support guidelines for paediatric septic shock: an outcomes comparison with and without monitoring central venous oxygen saturation

Introduction: The ACCM/PALS guidelines address early correction of paediatric septic shock using conventional measures. In the evolution of these recommendations, indirect measures of the balance between systemic oxygen delivery and demands using central venous or superior vena cava oxygen saturation ( ScvO(2) >= 70%) in a goal-directed approach have been added. However, while these additional goal-directed endpoints are based on evidence-based adult studies, the extrapolation to the paediatric patient remains unvalidated. Objective: The purpose of this study was to compare treatment according to ACCM/PALS guidelines, performed with and without ScvO(2) goal-directed therapy, on the morbidity and mortality rate of children with severe sepsis and septic shock. Design, participants and interventions: Children and adolescents with severe sepsis or fluid-refractory septic shock were randomly assigned to ACCM/PALS with or without ScvO(2) goal-directed resuscitation. Measurements: Twenty-eight-day mortality was the primary endpoint. Results: Of the 102 enrolled patients, 51 received ACCM/PALS with ScvO(2) goal-directed therapy and 51 received ACCM/PALS without ScvO(2) goal-directed therapy. ScvO(2) goal-directed therapy resulted in less mortality ( 28-day mortality 11.8% vs. 39.2%, p = 0.002), and fewer new organ dysfunctions ( p = 0.03). ScvO(2) goal-directed therapy resulted in more crystalloid ( 28 ( 20-40) vs. 5 ( 0-20) ml/kg, p < 0.0001), blood transfusion ( 45.1% vs. 15.7%, p = 0.002) and inotropic ( 29.4% vs. 7.8%, p = 0.01) support in the first 6 h. Conclusions: This study supports the current ACCM/PALS guidelines. Goal-directed therapy using the endpoint of a ScvO(2) = 70% has a significant and additive impact on the outcome of children and adolescents with septic shock.

Chemical sympathectomy further increases muscle protein degradation of acutely diabetic rats

The present work investigated the role of the sympathetic nervous system (SINS) in the control of protein degradation in skeletal muscles from rats with streptozotocin (STZ)-induced diabetes. Diabetes (1, 3, and 5 days after STZ) induced a significant increase in the norepinephrine content of soleus and EDL muscles, but it did not affect plasma catecholamine levels. Chemical sympathectomy induced by guanethidine (100 mg/kg body weight, for 1 or 2 days) reduced muscle norepinephrine content to negligible levels (less than 5%), decreased plasma epinephrine concentration, and further increased the high rate of protein degradation in muscles from acutely diabetic rats. The rise in the rate of proteolysis (nmol.mg wet wt(-1).2h(-1)) in soleus from 1-day diabetic sympathectomized rats was associated with increased activities of lysosomal (0.127 +/- 0.008 vs. 0.086 +/- 0.013 in diabetic control) and ubiquitin (Ub)-proteasome-dependent proteolytic pathways (0.154 +/- 0,007 vs. 0.121 +/- 0.006 in diabetic control). Increases in Ca2+-depenclent (0.180 +/- 0.007 vs. 0.121 +/- 0.011 in diabetic control) and Ub-proteasome-dependent proteolytic systems (0.092 +/- 0.003 vs. 0.060 +/- 0.002 in diabetic control) were observed in EDL from 1-day diabetic sympathectomized rats. The lower phosphorylation levels of AKT and Foxo3a in EDL muscles from 3-day diabetic rats were further decreased by sympathectomy. The data suggest that the SNS exerts acute inhibitory control of skeletal muscle proteolysis during the early stages of diabetes in rats, probably involving the AKT/Foxo signaling pathway.

Quartz Crystal Microbalance monitoring the real-time binding of lectin with carbohydrate with high and low molecular mass

Quartz Crystal Microbalance (QCM) was used to monitor the mass changes on a quartz crystal surface containing immobilized lectins that interacted with carbohydrates. The strategy for lectin immobilization was developed on the basis of a multilayer system composed of Au-cystamine-glutaraldehyde-lectin. Each step of the immobilization procedure was confirmed by FTIR analysis. The system was used to study the interactions of Concanavalin A (ConA) with maltose and Jacalin with Fetuin. The real-time binding of different concentrations of carbohydrate to the immobilized lectin was monitored by means of QCM measurements and the data obtained allowed for the construction of Langmuir isotherm curves. The association constants determined for the specific interactions analyzed here were (6.4 +/- 0.2) X 10(4) M-1 for Jacalin-Fetuin and (4.5 +/- 0.1) x 10(2) M-1 for ConA-maltose. These results indicate that the QCM constitutes a suitable method for the analysis of lectin-carbohydrate interactions, even when assaying low molecular mass ligands such as disaccharides. Published by Elsevier B.V.

Monitoring of protein catabolism in neonates and young infants post-cardiac surgery

Aims: To evaluate cell catabolism by balance of nitrogen and phosphate, and creatinine excretion in children post-cardiac surgery; to establish protein and energy requirements to minimize catabolism; and to assess nutritional therapy by following these parameters and serial anthropometric measurements. Methods: A prospective observational study of children with congenital heart disease undergoing cardiac surgery. Blood samples and 24-h urine collections were obtained postoperatively for creatinine measurement and nitrogen and phosphate balance. Anthropometric measurements (weight, mid-arm muscle circumference and triceps skinfold thickness) were obtained preoperatively and at paediatric intensive care unit and hospital discharge. Results: Eleven children were studied for 3-10 postoperative days. Anabolism was associated with higher protein and energy intakes compared to catabolism (1.1 vs. 0.1 g/kg/day and 54 vs. 17 kcal/kg/day, respectively). On days with anabolism, phosphate balance was greater compared with that on days with catabolism. Daily creatinine excretion did not correlate with protein balance. Anthropometric measurements did not change significantly over time. Conclusions: Children with congenital heart disease undergoing cardiac surgery achieved anabolism with > 55 kcal/kg/day and > 1 g/kg/day of protein. Balance of phosphate was useful to monitor cell breakdown. Anthropometric measurements were not valuable to evaluate nutritional therapy in this population.

The ACB technique: a biomagentic tool for monitoring gastrointestinal contraction directly from smooth muscle in dogs

The aim of this paper was to verify whether AC biosusceptometry (ACB) is suitable for monitoring gastrointestinal (GI) contraction directly from smooth muscle in dogs, comparing with electrical recordings simultaneously. All experiments were performed in dogs with magnetic markers implanted under the serosa of the right colon and distal stomach, and their movements were recorded by ACB. Monopolar electrodes were implanted close to the magnetic markers and their electric potentials were recorded by electromyography (EMG). The effects of neostigmine, hyoscine butylbromide and meal on gastric and colonic parameters were studied. The ACB signal from the distal stomach was very similar to EMG; in the colonic recordings, however, within the same low-frequency band, ACB and EMG signals were characterized by simultaneity or a widely changeable frequency profile with time. ACB recordings were capable of demonstrating the changes in gastric and colonic motility determined by pharmacological interventions as well as by feeding. Our results reinforce the importance of evaluating the mechanical and electrical components of motility and show a temporal association between them. ACB and EMG arecomplementary for studying motility, with special emphasis on the colon. ACB offers an accurate method for monitoring in vivo GI motility.