Lipid and lipoprotein changes after long-term weight reduction: the influence of gender and body fat distribution.

This study was designed: 1) to evaluate the effect of weight loss on body fat distribution, 2) to determine whether indices of body fat distribution can be considered as a prognostic indicator for the ability to lose weight and 3) to evaluate whether a change of body fat distribution is associated with changes in plasma glucose, lipids and lipoproteins in both sexes in order to evaluate a gender difference.

63 obese subjects (41 women and 22 men) were treated on an outpatient basis with an energy-reduced, protein-enriched low calorie diet (3150-4200 kJ/day) for a 6-month period. They were divided in different groups according to gender and body fat distribution using the waist-to-hip circumference ratio.

Body fat topography can be altered by dieting, but not by more than it increases when a person gains weight. Body fat distribution seems to be a significant prognostic indicator for the ability to lose weight in women but not in men. Although body weight and the waist-to-hip circumference decreased significantly, no relationships were found between percent decrease in these parameters and percent changes in plasma glucose, lipids and lipoproteins.

We conclude that an important caloric deficit may lead to a series of metabolic improvements but that gender and the type of fat distribution are important confounding factors in the prediction of metabolic success.     

Endemic Norovirus Infections in Children,Ho Chi Minh City,Vietnam, 2009–2010

We performed a case–control investigation to identify risk factors for norovirus infections among children in Vietnam. Of samples from 1,419 children who had diarrhea and 609 who were asymptomatic, 20.6% and 2.8%, respectively, were norovirus positive. Risk factors included residential crowding and symptomatic contacts, indicating person-to-person transmission of norovirus.     

The effect of midterm peer feedback on student functioning in problem-based tutorials

Within Problem-Based Learning successful learning depends on the quality of cognitive, social and motivational contributions students make to the tutorial group. But at the same time, not all students in PBL automatically contribute in a high quality manner, which might impede successful group functioning. This study investigated whether peer process feedback combined with goal setting can be used to improve the quality of students’ individual contributions. A mixed-methods explanatory design, in which 74 second-year Health Sciences students participated, combined a pre- and posttest with a focus group. The results indicated that the quality of the contributions only increased for students with a below average score on the pre-test. The qualitative data confirmed that the impact of the feedback could be increased by combining individual reflection by means of goal setting with face-to-face discussion. Another suggestion is to investigate whether midterm peer process feedback is more effective for first year students, because they are still developing their tutorial behavior, as opposed to second year students.     

Metabolic inactivation of 2-oxiranylmethyl 2-ethyl2,5-dimethylhexanoate (C10GE) in skin,lung and liver of human,rat and mouse

1. The inactivation of 2-oxiranylmethyl 2-ethyl-2,5-dimethylhexanoate (C₁₀GE), one of the most abundant isomers of the epoxy-resin Cardura®E-10 glycidyl ester, was studied in subcellular fractions of human, C3H mouse and F344 rat liver, lung and skin. 2. C₁₀GE is chemically very stable and resistant to aqueous hydrolysis, but it was rapidly metabolized in both cytosolic and microsomal fractions of all organs by epoxide hydrolase (EH)-catalysed hydrolysis of the epoxide moiety as well as carboxylesterase (CE)-catalysed hydrolysis of the ester bond. In cytosol the epoxide group was also efficiently conjugated with glutathione, catalysed by glutathione S-transferase (GST), but this conjugation was much less important than hydrolysis in human as well as rodent samples. Although CE-catalysed hydrolysis of C₁₀GE would theoretically give rise to the formation of glycidol, a directly acting mutagen, it is highly unlikely that any significant level of glycidol would occur in vivo since reported rates of inactivation of glycidol exceed the total rate of hydrolysis of C₁₀GE. 3. The overall rates of inactivation in vitro decreased in the following order: mouse &;gt; rat &;gt; human. Scaling of the data in vitro to clearances in vivo suggests that the detoxifying capacity in the rodents is similar and about an order of magnitude greater than in human. Nevertheless, the rate of inactivation is 2-3 orders of magnitude greater than for simple epoxides such as butadiene monoxide and about one order of magnitude higher than for the diglycidyl ether of bisphenol A (BADGE). 4. The transdermal penetration and metabolism of [¹⁴C]-C₁₀GE was studied in fresh full-thickness mouse, and dermatomized human and rat skin. Of the total radioactivity applied on the skin, only 0.24±0.06 (SD), 1.8±0.2 and 6.8±0.6% penetrated through human, mouse and rat skin respectively. The corresponding apparent skin permeability constants were 0.81, 6.42 and 26.4X 10^?6 cm/h. 5. During transdermal penetration, [¹⁴C]-C₁₀GE was extensively hydrolysed to the corresponding diol and the free acid. Only 0.01, 0.11 and 0.21% of the applied dose was absorbed unchanged through the human, mouse and rat skin respectively.     

Encapsulation of aluminium hydroxide fillers with polymethyl-methacrylate

A process was developed for the microencapsulation of inorganic filler particles with poly-methyl-methacrylate, to increase the interaction between the hydrophilic filler particles and a polymer matrix. The filler utilised was aluminium hydroxide with an average diameter of 1.9 µm and a specific surface area of 5 m2/g. The process comprised a surface modification, in which a monolayer of isopropoxy titanium isostearate was chemically bound to the surface to render it hydrophobic and to ensure a chemical bond between the filler and the organic phase. Then, an encapsulation reaction was carried out by means of an emulsion-like polymerization process at monomer starved conditions. The modified particles were stabilized in water with sodium-dodecyl-sulphate. A redox system consisting of cumene-hydroperoxide in combination with sodium-formaldehyde-sulphoxylate and iron(II) salt was applied for the initiation of the polymerization. Besides surface polymer, free polymer particles were also formed. The parameters which varied were the filler concentration, the concentration of the initiator components and the surfactant concentration. At optimum conditions, ~50% of the added monomer polymerized at the modified filler surface, thus forming encapsulated filler particles. SEM together with TGA analysis indicated that a smooth polymer layer had been formed on the filler surface. At high filler loading, however, coagulation occurred.