Biomedical subjects

N V Chuyen

Publications and source records attributed to N V Chuyen.

6 recordsLinked to original sources

PubMed2005

Are food advanced glycation end products toxic in biological systems?

Model food advanced glycation end products (AGEs) were prepared as glycated casein (GC) and glycated soy protein (GS) by the reaction of casein or soy protein with glucose at 50 degrees C, relative humidity 75% for seven days in a powder state. These browned proteins were used as materials for animal experiments. A mixture of 20% glycated proteins (GC:GS = 1:1) diet was fed to streptozotocin (STZ)-diabetic rats for 11 weeks. The results showed that: (1) fructoselysine was observed in the hepatic portal veins, arteries, and femoral veins of rats fed with glycated proteins after 2 h of feeding; (2) blood sugar of glycated protein-fed rats was lower than that of diabetic rats fed with intact protein, while HbA1C in blood and glucose in urine of both groups were similar; (3) lipid peroxidation status in serum, liver, and kidney of both groups was similar; (4) superoxide dismutase (SOD) and glutathione-S-transferase (GST) enzymatic activity in serum and liver of both groups were also similar; (5) there were no differences in degree of cataract formation and concentration of glucose, fructose, sorbitol, and lipid peroxide in the lenses of both groups. From the above results, it can be estimated that food AGEs are not toxic in biological systems, and reactive oxygen species increase in diabetic rats is not caused by glycated proteins but by other pathways.

Animal Feed↗

PubMed2004

Prevalence and risk factors for diabetes in Ho Chi Minh City, Vietnam.

AIMS: To determine the prevalence of diabetes and associated risk factors in Ho Chi Minh City, Vietnam. METHODS: A total of 2932 participants aged 15 and above in Ho Chi Minh City were screened for diabetes in a cross-sectional study. The study was conducted from March-May 2001. Demographic, occupation, anthropometry and blood pressure were recorded. Blood glucose was calculated on fasting capillary and venous blood. The classification of diabetes and impaired fasting glucose (IFG) was carried out according to WHO and American Diabetes Association criteria. RESULTS: The crude prevalence of diabetes and IFG were 6.6 and 3.2%, respectively. After age, sex-adjustment to the Vietnam population census, the prevalence was 3.8 and 2.5%, respectively; approximately 40% of cases were found to be newly diagnosed diabetes. The crude prevalence of diabetes in the urban area was approximately 2.8 times higher than that recorded in the 1993 study (6.9 vs. 2.5%, respectively). In this study, there was a positive association between diabetes and sex, age, overweight, waist hip ratio (WHR), and having a history of delivering large for gestational age child; there was a negative association between diabetes and physical activity and occupation. CONCLUSIONS: This study found that the age, sex-adjusted prevalence of diabetes and IFG in Ho Chi Minh City were 3.8 and 2.5%, respectively, a rapid increase in the recent decade. Our study also indicates that ageing, a high WHR level, overweight and a sedentary lifestyle may be important determinants of the increased prevalence of diabetes during this transition period in Vietnam.

Adolescent↗

PubMed2001

Food intake and lipid status of three Vietnamese populations with different incomes.

In order to have basic data for dietary preventive measures against some vascular diseases caused by disorder of lipid metabolism, food intake and lipid status were investigated in three Vietnamese populations with different per capita income levels. Totally, 299 people aged over 18 were involved in this study. Among them, 98 subjects were selected from one commune with low income, 100 and 101 subjects from two urban areas with medium and high income respectively. Food intake was assessed by 24-h recall method and lipid status was evaluated by measuring serum concentration of triglyceride, total cholesterol and its subfractions. The results showed that food consumption, dietary habits and lipid status varied with income levels. In general, diet was still unbalanced in all three groups, and low in fat and protein. In the rural, fat and protein intakes were lower than in the urban. The high prevalence of low serum cholesterol was observed in all three groups, the highest in the rural (45.3%) and the lowest in the urban (11.2%). On the contrary, the prevalence of high serum cholesterol was the lowest in the rural (2%) and the highest in the urban (16%). From these data, it is suggested that the majority of the Vietnamese might be vulnerable to some vascular diseases such as stroke if the situation of low fat intake and low serum cholesterol is not a problem of concern.

Adult↗

PubMed1998

Antioxidative properties of products from amino acids or peptides in the reaction with glucose.

The livers of rats fed with a brownish "soybean paste" (Miso) or peptides-glucose reaction mixture showed lower TBA and chemiluminescence values than those of the control. From these results, it was clear that Miso and peptide-glucose reaction products also exhibited antioxidative effect in vivo. In order to explain this mechanism, the scavenging activity against reactive oxygen species (ROS) of various Maillard reaction products (MRPs) were studied. It was confirmed that peptide-glucose reaction products. Amadori rearrangement products, melanoidins, modified protein and its hydrolysate, brown pigments isolated from Miso and other foodstuffs showed strong scavenging activity against hydroxyl radical and superoxide anion. Consequently, it was estimated that scavenging activity of MRPs against ROS played an important role in the antioxidative effect of MRPs in vivo.

Amino Acids↗

PubMed1998

Maillard reaction and food processing. Application aspects.

The Maillard reaction occurs widely in food and biological systems. This contribution reviews the relation between the Maillard reaction and food processing, particularly its contribution to flavor formation, antioxidative effects, desmutagenic activity and the improvement of protein functional properties. Proteins modified by glucose, and melanoidins are important components of foodstuffs while the reactions of amino acids or peptides with glucose or dicarbonyl compounds produce various kinds of flavor components. Melanoidins and Amadori rearrangement products play an important role in providing antioxidative effects, both in vitro and in vivo. Melanoidins also exhibit desmutagenic activity against carcinogenic compounds. Protein-polysaccharide conjugates, prepared by Maillard reaction at mild conditions, increase the emulsifying activity, as well as antioxidative and antimicrobial effects of the original proteins.

Aldehydes↗

PubMed1990

Nutritional and physiological effects of casein modified by glucose, diacetyl, or hexanal.

Casein was modified by glucose, diacetyl, or hexanal at 50 degrees C, RH 75% for 1, 7, or 11 days. The chemical changes and digestibility in vitro of these nondialyzable caseins were investigated. The effects of these nondialyzable caseins supplemented with lost amino acids, on rats were studied by pair-feeding for 2 months. It was observed that internal organs such as liver, spleen, kidney, stomach, small intestine, cecum, colon and rectum were mostly unchanged. Biochemical values such as hematocrit, cholesterol, triglyceride, GPT, and GOT were also unchanged. However, the quantity of leucocytes was increased and serum glucose was decreased by feeding rats with modified caseins. Significant decrease in weight gain of rats fed with modified casein was observed, and the rate of decrease depended on the degree of modification of casein by carbonyl compounds. From these results, we supported the suggestion that some inhibitory or antinutritional compounds might be formed during the modification of casein by carbonyl compounds.

Aldehydes↗