Biomedical subjects

Myna Panemangalore

Publications and source records attributed to Myna Panemangalore.

6 recordsLinked to original sources

PubMed2006

Micronuclei frequency in lymphocytes and antioxidants in the blood of traditional limited-resource farm workers exposed to pesticides.

Chronic low-level exposure to synthetic pesticides is implicated in many health conditions that result from the induction of oxidative stress, including cytogenetic damage. The objective of this study was to assess the risk of genotoxicity using micronuclei (MN) formation in lymphocytes and to determine changes in blood antioxidants superoxide dismutase (SOD) in erythrocytes (E) and glutathione (GSH) in E and plasma (PL) in farm workers for six months during a growing season. Blood and urine samples were collected once a month for six months (June to November 2003) from farm workers (n = 15) and urban unexposed controls (n = 10). Lymphocytes from blood were separated by density gradient centrifugation using Histopaque and cultured using the standard technique. There was no significant difference in the cytokinesis blocked proliferation index (CBPI) of lymphocytes between the farm workers and the control group, but there was a 76% increase in average MN frequency in lymphocytes of the farm worker group (P <or= 0.05). In addition, MN frequency peaked during August as compared to the other months and the controls (P <or= 0.05). An 18% decline was observed in the activity of E-SOD in the farm worker group (P <or= 0.05). GSH in E and PL were similar in both groups. These data suggest that the farm workers may be at a greater risk of developing genotoxicity due to continued exposure to pesticides, especially during the intensive growing season.

Antioxidants↗

PubMed2005

Competitive foods increase the intake of energy and decrease the intake of certain nutrients by adolescents consuming school lunch.

OBJECTIVE: To determine the influence of competitive foods on energy and nutrient intakes of adolescents participating in a school lunch program. DESIGN: Weighed plate waste data were used to assess the energy and nutrient consumption from school lunch menus items and competitive food items chosen and consumed by adolescents. The two test groups were students choosing competitive foods and those choosing no competitive foods. SUBJECTS/SETTING: Participants were sixth-grade students aged 11 to 13 years purchasing lunch in three public middle school cafeterias in Franklin County, KY (n=493 for no competitive foods and n=250 for competitive foods). The data were collected over 24 days in 2 school years. STATISTICAL ANALYSES PERFORMED: Significant differences between the competitive foods and no competitive foods groups were determined using frequency and analysis of variance procedures. RESULTS: The data indicate that sixth-grade adolescents consumed energy and other nutrients (except iron) at significantly lower than recommended levels; one third of students purchasing school lunch also purchased competitive food items; competitive foods purchasers reduced their school lunch servings, portion weight and/or item selection and increased school lunch item plate waste, resulting in lower intakes of energy (400 kcal vs 530 kcal for no competitive foods), calcium (300 mg vs 362 mg for no competitive foods), and vitamin A (77 retinol equivalents vs 113 retinol equivalents for no competitive foods) from the school lunch; and competitive foods supplied more than one third of total energy for the meal. CONCLUSIONS: These data will enable school cafeteria planners to develop menus that include more nutritious foods, snacks, and drinks instead of the currently available competitive foods.

Adolescent↗

PubMed2005

Food type, food preparation, and competitive food purchases impact school lunch plate waste by sixth-grade students.

Because plate waste reduces nutritional benefits of school lunches, the objective of this study was to determine the factors that influence waste. Lunches of 743 sixth graders in three middle schools were photographed after students made food selections and after eating. Sample items were purchased to determine initial portion weights. The Statistical Package for Social Sciences software (Base 10.0, 1995, SPSS Inc, Chicago, IL) was used for statistical analysis. Preparation method influenced acceptance rates and plate waste: Whole apples had lower acceptance (23%) and greater waste (62%) compared with applesauce (37% acceptance, 23% waste). Mashed potatoes and heated fries had similar acceptance (approximately 69%), but mashed potatoes were wasted less (19% vs 33%, respectively). Students who purchased competitive food items with lunch (n = 250) had significantly greater waste of fruits (52% vs 36%, respectively, P = .0001), grain products (26% vs 14%, respectively, P = .009), meats (25% vs 16%, respectively, P = .015), and mixed dishes (30% vs 18%, respectively, P = .0001). Changing preparation methods and limiting availability of competitive food items may reduce plate waste.

Animals↗

PubMed2005

Pesticides and essential minerals modify endogenous antioxidants and cytochrome P450 in tissues of rats.

Two experiments were conducted in male Sprague Dawley (SD) rats (175-200 g) to determine changes in the activities of endogenous antioxidants superoxide dismutase (SOD), glutathione peroxidase (GPX), cytochrome P450 (ethoxyresorufin deethylase; EROD) and concentrations of glutathione (GSH) in the blood, liver, and small intestinal mucosa (IM). In both experiments, six rats/group were fed diets based on the AIN-93M diet (Control) or the same modified to contain either 500 mg calcium (Low Ca), 7 mg Zn (Low Zn): 2 mg copper (Low Cu), 60 mg zinc (High Zn) or 12 mg copper (High Cu) in the following combination: Control, LCa/LZn, LCa/LZn/LCu, or HZn/HCu, with and without a pesticide mixture containing acephate, endosulfan, and thiram at 25% LD50 for four or two weeks. Pesticides decreased feed intake and weight gain in all groups by 28%. Erythrocyte SOD was higher than control in the HZn/HCu group and in the LCa/LZn/LCu and HZn/HCu groups with pesticide (P#0.05). Plasma GPX declined by more than 55% in all the groups with and without pesticides compared to the control. The LCa/LZn/LCu and HZn/HCu diets with and without pesticides reduced GPX in the IM by up to 88%, 40%, and 74%, respectively, than the control. Plasma GSH was about 20% higher than the control in most groups with and without pesticides in the diet. Liver and IM GSH were higher than the control in the HZn/HCu group, whereas IM GSH concentrations were lower than the control in the LCa/LZn and LCa/LZn/LCu groups (P#0.05). All three experimental diets with and without pesticides had a significant effect on liver EROD activity (P#0.05). The results indicate that endogenous antioxidants and EROD were independently modified by dietary zinc and copper levels and pesticides.

Animals↗

PubMed2005

Interaction between pesticides and essential metal copper increases the accumulation of copper in the kidneys of rats.

Male Sprague-Dawley rats, weighing 175-200 g, six per group were fed AIN 93M diet (CON) or diets containing 500 mg Ca (LCa), 7 mg Zn (LZn), 2 mg Cu (LCu), 60 mg Zn (HZn), or 12 mg Cu (HCu) per kilogram of diet in the following combinations: control (CON), LCa+LZn (LC+Z), LCa+LZn+LCu (LC+Z+C), or HZn+HCu (HZ+C) without or with a pesticides mixture (PM); Endosulfan, Thiram, and Acephate were added to the diets at 25% of LD50/kg. Rats were fed for 2 wk (small intestinal changes) or 4 wk (tissues changes). Plasma Zn was 47% lower than CON in the experimental groups. Plasma Cu and ceruloplasmin concomitantly decreased in the LC+Z+C group and increased with the addition of PM. Kidney Cu was 40% lower in LC+Z+C group, than CON and increased by 31% with PM; in the HZ+C+PM group, kidney Cu was 38% higher than the HZ+C group. Mucosal and small intestines Ca declined by 47% in all experimental groups; PM increased Zn in the LC+Z+C and HZ+C groups; PM further decreased intestinal and mucosal Cu retention in the LC+Z+C and HZ+C groups. Data suggest that low levels of PM in the diet can induce Cu accumulation in the kidney when dietary Zn and Cu are low or high.

Animals↗

PubMed2003

Exposure to low doses of endosulfan and chlorpyrifos modifies endogenous antioxidants in tissues of rats.

Two experiments were conducted in male SD rats (225-250 g) to determine changes in the activities of endogenous antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and concentrations of glutathione (GSH) in tissues after exposure to low doses of endosulfan and chlorpyrifos using a whole body exposure technique. In both experiments, 6 rats/group were exposed 3 hr/day, 5 days/week for 30 days to: 0 (control), 5, 10, 20, 40 and 60% of LD50 of either pesticide in 50% ethanol; actual concentrations were: endosulfan = 0, 0.5, 1.0, 2.0, 4.0, 6.0 mg/250 g body weight; chlorpyrifos = 0, 1.9, 3.8, 7.6, 15.2, and 22.8 mg/250 g body weight. Endosulfan decreased erythrocyte SOD by 21% in all groups and chlorpyrifos increased SOD by 18% in groups 40 and 60. Liver SOD was 12%-20% lower after endosulfan exposure; lung SOD was altered: endosulfan decreased activity by 21% and 51% and chlorpyrifos by 58 and 75% in the 40 and 60 groups, respectively (P < or = 0.05). Both pesticides increased plasma GPX activity at lower levels and reduced it by 26% and 19% in groups 40 and 60, respectively (P < or = 0.05). Liver GPX increased in the 60 group and lung GPX declined between 20% and 38% after endosulfan exposure. GSH in the liver and lung: endosulfan reduced GSH by about 30% at lower levels and increased by 41% or 70% at higher levels; chlorpyrifos decreased GSH by 28-40% in 20 and 60 groups, respectively (P < or = 0.05). Exposure to low, increasing levels of endosulfan and chlorpyrifos can differentially modify endogenous antioxidants SOD, GPX and GSH, which may lead to the development of oxidative stress in some tissues.

Animals↗