The effect of food dye and other environmental substances on the host defense reaction in mice in relation to virus infection

Respiratory health effects of residential individual and cumulative risk factors in children living in two cities of the Pearl River Delta Region, China

Background

Indoor environment is complex, with many factors potentially interacting with each other to affect health. However, previous studies have usually focused on effect of a single factor. Assessment of the combined effects of multiple factors can help with understanding the overall health risk.

Methods

A cross-sectional study was conducted among 2,306 school children in Guangzhou and Shenzhen. Questionnaire data on respiratory symptoms and diseases were collected along with sociodemographic and residential environmental information. A subset of children (N=987) were measured for their lung function. A random forest algorithm was applied to screen the top-ranked indoor environmental exposure variables and to form a composite index for cumulative risk of indoor pollution (CRIP). Logistic regressions were conducted to analyze the independent effect of single indoor environmental risk factors and the combined effect of CRIP on children’s respiratory health. Multiple linear regressions were used to examine the independent and combined effects of indoor environmental exposure on lung function.

Results

We found that home dampness and molds as well as environmental tobacco smoke (ETS) were significantly and independently associated with increased prevalence of children’s respiratory symptoms and diseases and with reduced lung function. A higher CRIP level was significantly associated with increased risk of cough with cold (OR =1.37, 95% CI: 1.05–1.79) and wheeze (OR =2.71, 95% CI: 1.16–6.34). A higher CRIP level was also associated with reduced lung function measured as FVC, FEV₁, PEF, FEF_25%, FEF_25–75% and VC.

Conclusions

In children living in the subtropical region of the Pearl River Delta, home dampness and the presence of mold as well as ETS were individual risk factors for children’s respiratory health. The composite CRIP index was associated with respiratory symptoms and lung function, suggesting the utility of this index for predicting the combined effects of multiple risk factors.

Risk factors for chronic and recurrent otitis media-a meta-analysis

Risk factors associated with chronic otitis media (COM) and recurrent otitis media (ROM) have been investigated in previous studies. The objective of this study was to integrate the findings and determine the possible risk factors for COM/ROM based on our meta-analysis. A comprehensive search of electronic bibliographic databases (PubMed, Embase, CNKI and Wanfang database) from 1964 to Dec 2012, as well as a manual search of references of articles, was performed. A total of 2971 articles were searched, and 198 full-text articles were assessed for eligibility; 24 studies were eligible for this meta-analysis. Regarding risk factors for COM/ROM, there were two to nine different studies from which the odds ratios (ORs) could be pooled. The presence of allergy or atopy increased the risk of COM/ROM (OR, 1.36; 95% CI, 1.13–1.64; P = 0.001). An upper respiratory tract infection (URTI) significantly increased the risk of COM/ROM (OR, 6.59; 95% CI, 3.13–13.89; P<0.00001). Snoring appeared to be a significant risk factor for COM/ROM (OR, 1.96; 95% CI, 1.78–2.16; P<0.00001). A patient history of acute otitis media (AOM)/ROM increased the risk of COM/ROM (OR, 11.13; 95% CI, 1.06–116.44; P = 0.04). Passive smoke significantly increased the risk of COM/ROM (OR, 1.39; 95% CI, 1.02–1.89 P = 0.04). Low social status appeared to be a risk factor for COM/ROM (OR, 3.82; 95% CI, 1.11–13.15; P = 0.03). Our meta-analysis identified reliable conclusions that allergy/atopy, URTI, snoring, previous history of AOM/ROM, Second-hand smoke and low social status are important risk factors for COM/ROM. Other unidentified risk factors need to be identified in further studies with critical criteria.

Immunological studies on Amaranth, Sunset Yellow and Curcumin as food colouring agents in albino rats

The use of food dyes is at least controversial because they are only of essential role. Moreover many of them have been related to health problems mainly in children that are considered a very vulnerable group. This study was carried out to investigate the effect of oral administration of Amaranth, Sunset Yellow and Curcumin for 4 weeks at doses of 47, 315 and 157.5 mg/kg b. wt. and after 2 weeks all animals were immunostimulated by intra peritoneal injection of sheep RBCs 10% (1 ml/rat). Body weight, relative body weight, total and differential leukocytes count, mononuclear cell count, delayed hypersensitivity, total protein and serum fractions were determined. Results revealed that oral administration of Amaranth, Sunset Yellow and Curcumin did not affect the body weight gain or the spleen weight. On the other hand Sunset Yellow and Curcumin significantly decreased the weight of thymus gland of the rats. Total leukocyte count were not affected while Amaranth and Curcumin-treated rats revealed a significant decrease in neutrophiles and monocytes and a compensatory increase in lymphocytes. Moreover, oral administration of Sunset Yellow revealed a significant decrease in monocyte percent. Amaranth, Sunset Yellow and Curcumin significantly decreased the delayed hyper sensitivity. Total serum protein, albumin, total globulin and albumin/globulin (A/G) ratio were not affected by administration of the colouring agents. Oral administration of Amaranth increases the density of albumin band. On the other hand oral administration of Curcumin decreases the density of the albumin band. Oral administration of any of the tested colouring agents did not change the density of globulin region as compared to control group. In conclusion we found that both synthetic (Amaranth and Sunset Yellow) and natural (Curcumin) colouring agents used at doses up to 10 times the acceptable daily intake exerted a depressing effect on the cellular but not humoral immune response.

Environmental tobacco smoke exposure: prevalence and mechanisms of causation of infections in children

BACKGROUND AND OBJECTIVES

Environmental tobacco smoke (ETS) exposure is probably one of the most important public health hazards in our community. Our aim with this article is to (1) review the prevalence of ETS exposure in the United States and how this prevalence is often measured in practice and (2) summarize current thinking concerning the mechanism by which this exposure may cause infections in young children.

METHODS

We conducted a Medline search to obtain data published mainly in peer-reviewed journals.

RESULTS

There is still a very high prevalence of ETS exposure among US children ranging from 35% to 80% depending on the method of measurement used and the population studied. The mechanism by which ETS may be related to these infections is not entirely clear but may be through suppression or modulation of the immune system, enhancement of bacterial adherence factors, or impairment of the mucociliary apparatus of the respiratory tract, or possibly through enhancement of toxicity of low levels of certain toxins that are not easily detected by conventional means.

CONCLUSIONS

The prevalence of ETS exposure in the United States is still very high, and its role in causing infections in children is no longer in doubt even if still poorly understood. Research, therefore, should continue to focus on the various mechanisms of causation of these infections and how to best reduce the exposure levels.

Persistent suppression of delayed-type hypersensitivity in adult F344 rats after perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

Recently we observed a suppressed delayed-type hypersensitivity (DTH) response to bovine serum albumin (BSA) in the 4-5-month-old offspring of F344 rat dams receiving as little as 1.0 microg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)/kg on gestational day (GD) 14. This study was designed to characterize better this suppression of the DTH response. First, the persistence of the DTH suppression was determined by measuring the DTH response to BSA in the offspring of dams dosed orally with 3.0 microg TCDD/kg on GD14 as well as in age-matched controls at 4, 8, 12 and 19 months of age. TCDD significantly suppressed the males' DTH response through 19 months of age. While the females' DTH response was reduced at 8, 12 and 19 months, significant suppression was observed only at 4 months of age. Secondly, the lowest maternal dose of TCDD that produced DTH suppression was determined by measuring the DTH response to BSA in the 4- and 14-month-old offspring of dams dosed orally with 0, 0.1, 0.3 or 1.0 microg TCDD/kg on GD14. In the males, suppression was observed at a maternal dose as low as 0.1 microg TCDD/kg at 14 months of age, while a maternal dose of 0.3 microg TCDD/kg was necessary to cause suppression in the 14-month-old females. Both males and females were more sensitive to the suppression at 14 months of age than at 4 months of age. Lastly, the DTH response to a second antigen was examined by measuring the DTH response to either BSA or keyhole limpet hemocyanin (KLH) in the 5- or 4-month-old male offspring, respectively, of dams dosed orally with either 0 or 3.0 microg TCDD/kg on GD14. The DTH response to both antigens was suppressed significantly. Phenotypic analysis was performed on thymus and lymph node suspensions. Significant effects in the thymus included an increased percentage of gammadelta TCR+ cells and a decreased percentage of gammadelta TCR+/CD4- CD8- and MHCI- MHCII- cells. In the popliteal lymph node draining the BSA-injected footpad, there was a decreased percentage of gammadelta TCR+ and MHCI- MHCII- cells and an increased percentage of MHCI+ cells. In conclusion, the suppression of the DTH response associated with perinatal TCDD exposure is persistent through late adulthood, occurs at a low dose (i.e. 0.1 microg TCDD/kg) to the dam, and is more pronounced in males than females. While phenotypic analysis identified differences in subsets of thymocytes and lymph node cells between control and TCDD exposed offspring, no clear correlations were established between altered subpopulations and suppressed DTH responses.