Prevalence of self-reported back pain in school children: A study of sociodemographic differences

The study considers the prevalence of back pain experienced in a nationwide random sample of 2173 Icelandic school children aged 11–12 and 15–16. The study found a 20.6% prevalence of at least weekly back pain. The prevalence of back pain was significantly more frequent among the older children. No gender or class difference was found in the overall sample. Older children from rural areas have significantly more back pain than those living in the city. The need for a thorough epidemiological investigation of the association of back pain in children is emphasized.     

Improvement of Oral Bioavailability and Anti-Tumor Effect of Zingerone Self-Microemulsion Drug Delivery System

This study sought to prepare a self-microemulsion drug delivery system containing zingerone (Z-SMEDDS) to improve the low oral bioavailability of zingerone and anti-tumor effect. Z-SMEDDS was characterized by particle size, zeta potential and encapsulation efficiency, while its pharmacokinetics and anti-tumor effects were also evaluated. Z-SMEDDS had stable physicochemical properties, including average particle size of 17.29 ± 0.07 nm, the zeta potential of -22.81 ± 0.29 mV, and the encapsulation efficiency of 97.96% ± 0.02%. In vitro release studies have shown the release of zingerone released by Z-SMEDDS was significantly higher than free zingerone in different release media. The relative oral bioavailability of Z-SMEDDS was 7.63 times compared with free drug. Meanwhile, the half inhibitory concentration （IC50）of Z-SMEDDS and free zingerone was 8.45 μg/mL and 13.30 μg/mL, respectively on HepG2. This study may provide a preliminary basis for further clinical research and application of Z-SMEDDS.     

Epidemiology of cerebral palsy in El-Kharga District-New Valley (Egypt)

Cerebral palsy (CP) is the most frequent cause of motor handicap among children. The present door to door (every door) study was conducted in El-Kharga District-New Valley to estimate the epidemiology of CP among children. Each child was subjected to complete medical and neurological examination to detect cases with CP. These diseased children were subjected to meticulous neurological and medical assessment, brain MRI, EEG and Stanford Binet (4th edition). It was found that 52 out of 25,540 children had CP yielding prevalence rate of 2.04/1000 (95% CI: 1.48-2.59) of living births. Mean age of children with CP, was 7.17 ± 4.38 years. The order of frequency of different subtypes of CP was as follows, 65.4% had spastic type, 26.9% mixed type and 3.8% for each ataxic and dyskinetic types of CP. The frequency of risk factors of CP in our study is prenatal complications (cyanosis, preterm, jaundice, birth weight and obstructed labor of mothers), first baby, similar condition and recurrent abortions.     

Residence time modeling of hot melt extrusion processes

The hot melt extrusion process is a widespread technique to mix viscous melts. The residence time of material in the process frequently determines the product properties. An experimental setup and a corresponding mathematical model were developed to evaluate residence time and residence time distribution in twin screw extrusion processes.The extrusion process was modeled as the convolution of a mass transport process described by a Gaussian probability function, and a mixing process represented by an exponential function. The residence time of the extrusion process was determined by introducing a tracer at the extruder inlet and measuring the tracer concentration at the die. These concentrations were fitted to the residence time model, and an adequate correlation was found. Different parameters were derived to characterize the extrusion process including the dead time, the apparent mixing volume, and a transport related axial mixing. A 2³ design of experiments was performed to evaluate the effect of powder feed rate, screw speed, and melt viscosity of the material on the residence time. All three parameters affect the residence time of material in the extruder.In conclusion, a residence time model was developed to interpret experimental data and to get insights into the hot melt extrusion process.     

Food environment,walkability, and public open spaces are associated with incident development of cardio-metabolic risk factors in a biomedical cohort

We investigated whether residential environment characteristics related to food (unhealthful/healthful food sources ratio), walkability and public open spaces (POS; number, median size, greenness and type) were associated with incidence of four cardio-metabolic risk factors (pre-diabetes/diabetes, hypertension, dyslipidaemia, abdominal obesity) in a biomedical cohort (n=3205). Results revealed that the risk of developing pre-diabetes/diabetes was lower for participants in areas with larger POS and greater walkability. Incident abdominal obesity was positively associated with the unhealthful food environment index. No associations were found with hypertension or dyslipidaemia. Results provide new evidence for specific, prospective associations between the built environment and cardio-metabolic risk factors.     

Health-Related Quality of Life Among Self-Reported Arthritis Sufferers: Effects of Race/Ethnicity and Residence

Objective: We evaluated differences in health-related quality of life (HRQoL) for African Americans and Caucasians with self-reported arthritis residing in rural and urban areas of a southern state. Methods: 1,191 individuals completed a telephone survey, which included the 12-Item Short Form Health Survey (SF-12). Participants were stratified into groups: African American/rural, Caucasian/rural, African American/urban, and Caucasian/urban. We evaluated differences and associations in HRQoL for the four groups.Results: Multivariable linear regression models revealed that being an African American rural resident was associated with worse self-reported mental health on the SF-12 even after adjusting for multiple confounding variables. In contrast, multivariable linear regression models revealed that being a Caucasian rural resident was associated with worse physical health SF-12 scores.Conclusions: The study revealed differences in HRQoL on the mental and physical health functioning scales of the SF-12 for African American rural and Caucasian rural residents. Researchers assessing HRQoL in arthritis patients should consider using a race/residence product term in their analyses.     

Distribution and time course of corticosterone excretion in faeces and urine of female mice with varying systemic concentrations

Quantification of corticosterone metabolites excreted in faeces and urine is increasingly being used for assessment of preceding corticosterone concentrations in the circulation. This is a promising approach to non-invasive stress assessment in laboratory rodents. It is however unknown whether the proportions of corticosterone metabolites excreted in faeces and urine may differ, depending on the concentration of corticosterone in blood. This uncertainty undermines the applicability of urinary and faecal corticosterone metabolite measurements as biomarkers for stress. Therefore, the terminal distribution and time course of corticosterone excretion, after intravenous injection of varying corticosterone concentrations, was investigated in female mice. Female BALB/c mice excreted 60% of all corticosterone in the urine with an approximate delay of 5 h from tail vein administration. The remaining 40% were excreted in faeces, with an approximate delay of 9 h from administration. The faecal/urinary excretion ratio, as well as time course of excretion, remained unaltered by administration of various doses of corticosterone covering the entire physiological range of serum corticosterone. Although currently untested for other strains of mice and species of animals, these findings add credence to the utility of faecal and urinary corticosterone as non-invasive biomarkers for physiological stress.     

Differences in fracture pattern between an urban and a rural population: A comparative population-based study in Southern Sweden

Differences in the incidence of hip fractures have been reported between urban and rural areas. In this population-based study the characteristics of fracture patterns between the city of Malmö and the nearby rural district of Sjöbo were compared. A total of 782 individuals in Malmö and 486 in Sjöbo were invited to participate. Fracture history for all invited was registered. The odds ratio for fracture was higher in Malmö, particularly for women over 70. More than half of the urban women aged 70 had a history of a fracture. A fourfold increase in fracture prevalence between the ages of 60 and 70 was observed in women in Malmö, whereas the prevalence doubled in Sjöbo. The differences in fracture patterns between these two urban and rural communities may be explained by different lifestyles.     

Air pollution,socioeconomic position,and emergency hospital visits for asthma in Seoul,Korea

Objective Some epidemiological literature has observed that air pollution effects on health differed across regional or individual socioeconomic position. This study evaluated whether regional and individual socioeconomic position, as indicated by health insurance premiums, modified the effect of air pollution on hospital visits for asthma. Methods Effects of ambient air pollutants (particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone) on 92,535 emergency out-patient hospital visits for asthma in Seoul, Korea during 2002 were estimated using case-crossover analysis, adjusting for time trend, weather conditions, and seasonality. Next, interactions between air pollutants and Korean National Health Insurance premium (1) for the individual patient and (2) averaged across the patient’s residence district, were entered, first singly then jointly, in the models. Results Relative risks of emergency outpatient hospital visits were all positively and significantly associated with interquartile increases for selected lags for all air pollutants. In the regression model with interaction terms for both individual premium and regional-average premium, associations with all five-air pollutants ranged from 1.03 to 1.09 times higher among the lowest premium districts compared to the highest premium districts. Of all the pollutants, nitrogen dioxide showed the strongest associations in lower premium districts compared to the higher premium districts. Individual socioeconomic position did not modify the associations in either the single or joint interaction models. Conclusion In Seoul, community but not individual socioeconomic conditions modified risk of asthma hospital visits on high air pollution days.