Cross-Country Comparison of School Neighborhood Food Environments in Houston, Texas and Guadalajara, Mexico.

Studies in the U.S. and Mexico have observed the clustering of food resources around schools, which may promote the use of these resources. Our study characterized and compared school neighborhood food environments in Guadalajara, Jalisco, and Houston, Texas, and examined socioeconomic disparities in food resource availability across school neighborhoods. We used the Goods and Services Inventory to document the frequency and type of resources within each school neighborhood. School neighborhoods in Guadalajara had significantly more food resources than those in Houston. We found that convenience stores and table service restaurants were the most prevalent food resources in school neighborhoods in both cities. Guadalajara school neighborhoods had a higher prevalence of supermarkets and grocery stores than Houston. Low-income school neighborhoods in Guadalajara with poorly educated residents had significantly more food carts than high-income neighborhoods with more educated residents. In Houston, we found significantly more fast food restaurants and convenience stores in school neighborhoods with more educated residents than school neighborhoods with less educated residents. The influence of food resources within school neighborhoods on the dietary habits of schoolchildren should be further explored in both the U.S. and Mexico. The characterization of school neighborhood food environments can inform policymakers, city planners, and school officials who seek to implement policies to create healthier food environments.

Methods for classifying obesity in spinal cord injury: a review.

STUDY DESIGN: Narrative review. OBJECTIVES: Review methods used to measure and classify obesity in individuals with spinal cord injuries (SCI). Outline the strengths and weaknesses of each method used to measure obesity in individuals with SCI. SETTING: International. METHODS: PubMed was used to identify articles before 2016. Search terms ('obesity' or 'weight status' and 'spinal cord injury'). Filters: adults, English and human. Studies were retained that (1) included participants, 18 years or older, with SCI; (2) took place in inpatient, outpatient or community-based settings and (3) measured obesity status. Unique methods for classifying individuals with SCI as obese were identified and examples are presented. RESULTS: Methods identified for classifying obesity were as follows: World Health Organization body mass index (BMI) cutoff⩾30 kg m-2, BMI cutoff ⩾25-29 kg m-2, and SCI-specific BMI cutoff ⩾22 kg m-2, waist circumference cutoff (women >102 cm, men >88 cm), percent body fat cutoffs ⩾25% using bioelectrical impedance analysis and dual-energy X-ray absorptiometry, computerized tomography scan visceral fat area ⩾100 cm2 and percentage of ideal body weight. CONCLUSIONS: BMI is the most widely used measure of obesity in the SCI literature. Although some studies identified alternative cutoffs or other metrics, there is no standardized obesity classification in SCI. However, research is needed to determine and validate obesity classification specific to SCI due to physiological changes that occur following injury. We recommend that researchers and clinicians proceed with caution and use methodology based on the purpose of measurement.

Relationship of fruit and vegetable intake with adiposity: a systematic review.

UNLABELLED: Fruit and vegetable (FV) intake has been proposed to protect against obesity. The purpose of this paper was to assess the FV consumption to adiposity relationship. Twenty-three publications were included. INCLUSION CRITERIA: longitudinal or experimental designs; FV intake tested in relation to adiposity; child, adolescent or adult participants; published in English-language peer-reviewed journals. EXCLUSION CRITERIA: dietary pattern and cross-sectional designs; participants with health concerns. Experimental studies found increased FV consumption (in conjunction with other behaviours) contributed to reduced adiposity among overweight or obese adults, but no association was shown among children. Longitudinal studies among overweight adults found greater F and/or V consumption was associated with slower weight gain, but only half of child longitudinal studies found a significant inverse association. Limitations in methods prevented a thorough examination of the role of increased FV intake alone or mechanisms of effect. An inverse relationship between FV intake and adiposity among overweight adults appears weak; this relationship among children is unclear. Research needs to clarify the nature of, and mechanisms for, the effects of FV consumption on adiposity. Whether increases in FV intake in isolation from lower caloric intake or increased physical activity will result in declines or slower growth in adiposity remains unclear.

The developmental toxicity of orally administered oxytetracycline in rats and mice.

Timed-pregnant CD rats and CD-1 mice were dosed by gavage with oxytetracycline hydrochloride (OXT) in corn oil on gestational days (gd) 6-15 (0, 1200, 1350, or 1500 mg/kg/day for rats; 0, 1325, 1670, or 2100 mg/kg/day for mice). Deaths among treated females occurred in a dose-related manner in all OXT dose groups (2-7%, mice; 5-24%, rats), but no maternal deaths occurred in the vehicle control groups. Significant dose-related decreases in maternal weight gain during treatment, as well as for corrected gestational weight gain (i.e., maternal gestational weight gain minus gravid uterine weight), were observed at all doses in rats but not in mice. Gravid uterine weight was reduced in a dose-related manner only in mice, with the high-dose group significantly reduced compared to the control group. At termination (gd 20, rats; gd 17, mice), the status of uterine implantation sites was recorded and live fetuses were weighed. Fetuses were examined for external, visceral, and skeletal abnormalities. There were no significant effects of OXT in either species on the incidence of postimplantation loss (resorptions plus dead fetuses) or malformations. In both species, there was a significant trend toward reduced fetal body weight, and each group of rats receiving OXT was significantly reduced compared to the control group. Administration of OXT during organogenesis at doses exceeding the therapeutic range for humans produced maternal and fetal toxicity, but did not produce any treatment-related increase in malformations.

Teratologic evaluation of dinitrotoluene in the Fischer 344 rat.

Technical grade dinitrotoluene (DNT) was administered by gavage (po) to timed-pregnant Fischer 344 rats on Gestational Days (gd) 7 through 20. Mortality rates for the DNT (14, 35, 37.5, 75, 100, or 150 mg/kg/day) groups were 4.5, 7.7, 0.0, 0.0, 4.3, and 46.2% of treated females, respectively. No deaths occurred in the positive control (hydroxyurea, 200 mg/kg/day) or vehicle control (corn oil) groups. At sacrifice on gd 20, the hematological profile for dams in the 100-mg/kg/day group exhibited characteristic signs of DNT toxicity. Treatment-related increases in maternal relative liver and spleen weight (% body weight), and a dose-related decrease in absolute maternal weight gain during gestation (i.e., minus gravid uterine weight) were observed across all DNT groups. A notable increase in prenatal mortality occurred at the high dose (16.8% resorptions or late fetal deaths per litter for controls vs 49.6% for DNT), but but did not reach statistical significance. No statistically significant effects on fetal growth or morphological development as a result of DNT treatment were observed. Hydroxyurea produced mild hematoxicity in dams and fetuses. Effects of hydroxyurea on fetal growth and morphological development included decreased fetal body weight and crown-rump length, and an increased percentage of malformed fetuses (30% per litter). In conclusion, DNT was not found to be teratogenic following oral administration to Fischer 344 rats; embryo/fetal toxicity was observed only at a dose which also produced 46.2% maternal mortality.

Teratologic and postnatal evaluation of aniline hydrochloride in the Fischer 344 rat.

Timed-pregnant Fischer 344 rats were dosed by gavage with aniline hydrochloride (10, 30, or 100 mg/kg/day), a positive control agent (hydroxyurea, 200 mg/kg/day), or vehicle (distilled water) on gestational days (gd) 7 through 20 or gd 7 through parturition. At termination on gd 20 confirmed-pregnant dams exhibited characteristic signs of aniline HCl toxicity, i.e., methemoglobinemia, increased relative spleen weight, decreased red blood cell (RBC) count, and hematological changes indicative of increased hematopoietic activity. High-dose dams exhibited mild methemoglobinemia, increased relative spleen weight, and increased RBC size at termination on postnatal day (pnd) 30. At termination on gd 20, fetuses from aniline-treated dams exhibited increased relative liver weight and enhanced hematopoietic activity, but no evidence of an embryolethal or teratogenic effect was observed. Postnatal signs of toxicity in litters from aniline-treated dams (i.e., decreased body weight, elevated relative liver weight, and elevated relative spleen weight) were transient, and no evidence of toxicity was observed in pups surviving to pnd 60. Hydroxyurea (200 mg/kg/day) administered by gavage proved to be an excellent positive control for embryotoxicity, maternal toxicity, teratogenicity, and postnatal maturational deficits in the Fischer 344 rat. In conclusion, aniline hydrochloride was not teratogenic to Fischer 344 rats, even at maternally toxic doses; transient signs of toxicity were observed postnatally in the offspring in conjunction with mild, but persistent signs of maternal toxicity through pnd 30.

Teratogenicity of a commercial xylene mixture in the mouse.

Pregnant outbred albino (CD-1) mice received (gavage, three times a day in cottonseed oil) a xylene mixture (60.2% m-xylene, 9.1% o-xylene, 13.6% p-xylene, and 17.0% ethyl benzene) on d 6-15 of gestation (d 1 being the day vaginal plugs were observed). The mice were killed on d 18, the general and reproductive health of the dams evaluated, and the fetuses examined and processed to characterize external, visceral, and skeletal malformation. At 3.6 ml/kg.d, xylene killed 12 of 38 dams and caused a significantly (p less than 0.05) smaller average weight gain during pregnancy than did the vehicle (cottonseed oil). Fetuses from dams treated with xylene at 2.4 ml/kg.d and higher doses had average fetal weights significantly lower than that of the control fetuses. However, the percent of resorptions for xylene was significantly greater than for the control only at 3.6 ml/kg-d. At 2.4, 3.0, and 3.6 ml/kg-d xylene produced a significantly (p less than 0.01) greater average percent of malformed fetuses than did the control. Cleft palate was the major malformation at all three doses. When bilateral (multiple) wavy ribs were counted as a malformation, the average percent of malformed fetuses increased from 7.8 to 10.5 at 3.0 ml/kg.d and from 9.1 to 13.4 at 3.6 ml/kg.d. It is concluded that xylene (mixed isomers) is teratogenic to the CD-1 mouse at 2.4 and 3.0 ml/kg.d, doses approaching lethal levels.

Teratogenic evaluation of 2-nitro-p-phenylenediamine, 4-nitro-o-phenylenediamine, and 2,5-toluenediamine sulfate in the mouse.

Pregnant outbred albino (CD-1) mice were given 2-nitro-p-phenylenediamine (2NPPD; 32-256 mg/kg/day), 4-nitro-o-phenylenediamine (4NOPD; 16-1024 mg/kg/day) or 2,5-toluenediamine sulfate (2,5TDS; 16-64 mg/kg/day) by subcutaneous injection on Days 6-15 of gestation. The mice were killed on Day 18, the general health and reproductive health of the dams evaluated, and the fetuses examined and processed in order to characterize external, visceral, and skeletal malformations. The 32 and 128 through 256 mg/kg/day dose levels of 2NPPD produced a significant (p less than 0.05) reduction in average weight gain by the dam during pregnancy. There was also a significance reduction in average fetal weight at 128 mg/kg/day and above. Although 2NPPD administration led to a significant increase in the average percentage of malformed fetuses at 160 mg/kg/day and above, these effects occurred only at dosages which produced significant maternal toxicity. Teratogenic effects were observed with 4NOPD, as administration of this dye led to a significance increase in the average percent of malformed fetuses at 256 mg/kg/day and above. A significant reduction in average weight gain by the dam during pregnancy also was observed at these dose levels, as well as significant reduction in average fetal weight. Although 2,5TDS killed 4 of 31 dams at 48 mg/kg/day, and 9 of 11 dams at 64 mg/kg/day, this compound did not cause a significant increase in the average percent of malformed fetuses. There were indications of embryotoxicity, however, as dosages of 32 mg/kg/day and above led to significant reductions in average fetal weight.