Delay differential model for tumour-immune response with chemoimmunotherapy and optimal control.

We present a delay differential model with optimal control that describes the interactions of the tumour cells and immune response cells with external therapy. The intracellular delay is incorporated into the model to justify the time required to stimulate the effector cells. The optimal control variables are incorporated to identify the best treatment strategy with minimum side effects by blocking the production of new tumour cells and keeping the number of normal cells above 75% of its carrying capacity. Existence of the optimal control pair and optimality system are established. Pontryagin's maximum principle is applicable to characterize the optimal controls. The model displays a tumour-free steady state and up to three coexisting steady states. The numerical results show that the optimal treatment strategies reduce the tumour cells load and increase the effector cells after a few days of therapy. The performance of combination therapy protocol of immunochemotherapy is better than the standard protocol of chemotherapy alone.

Prevalence of depression and suicidal behaviors among male migrant workers in United Arab Emirates.

Migrant workers comprise 80% of the population of the United Arab Emirates, but there is little research on their mental health. To determine the prevalence and correlates of depression among workers living in labor camps, we conducted a cross-sectional survey in labor camps in Al Ain city. The Depression Anxiety and Stress Scale (DASS-42) was used to assess depression and suicidal ideation among the study participants. Off the 319 contacted workers agreed to participate, however 239 fully completed the DASS-42. The prevalence of a score >=10 ("depression") was 25.1% (60/239). Depression was correlated with physical illness (97/301), (adjusted odds ratio-AOR = 2.9; 95% CI 2.26-5.18), working in construction industry (prevalence 124/304), AOR = 2.2; 95%CI 1.56-3.83), earning less than 1,000 UAE Dirham per month (prevalence 203/314), (AOR = 1.8; 95%CI 1.33-3.16), and working more than 8 h a day (prevalence 213/315), (AOR = 2.7; 95%CI 1.19-6.27). 20/261 (6.3%) of the study participants reported thoughts of suicide and 8/265 (2.5%) had attempted suicide. People with suicidal ideation were more likely to have a physical illness (AOR = 8.1, 95%CI 2.49-26.67), earn less than 1,000 UAE Dirham per month (AOR = 5.98, 95%CI 1.26-28.45), and work for more than 8 h a day (AOR = 8.35, 95%CI 1.03-67.23). The study identified self reported indicators of a substantial burden of depression, and thoughts of self-harm among laborers surveyed. Policy level intervention and implementation, is needed to improve working conditions, including minimum wages and regulation of working hours is recommended.

Prevalence of food allergy among children in Al-Ain city, United Arab Emirates.

BACKGROUND: Food allergy (FA) in children is an important health problem. However, the prevalence of FA in the United Arab Emirates (UAE) has not yet been determined. This cross-sectional study was carried out to assess the prevalence of FA among school children aged 6-9 years in Al-Ain city, UAE. METHODS: We used multistage random sampling in order to get a sample of 397 school children whose parents completed a self-administered questionnaire designed to assess the presence or absence of physician diagnosis of FA and other allergic diseases. RESULTS: The study showed that the prevalence of physician-diagnosed FA in children was 8% (95% CI 5.4-10.8%). Eggs, fruits and fish were the main allergies reported. FA was independently related to a family history of FA, to a small sibship size and to a personal history of other atopic diseases. CONCLUSIONS: The prevalence of FA in Al-Ain city was 8%. A history of FA in first-degree family members and a small sibship size were associated with a higher risk of FA in children. FA was related to a personal history of other atopic diseases.

Prevalence and correlates of conduct disorder among inmates of juvenile detention centres, United Arab Emirates.

The prevalence of conduct disorder was assessed in 77 young people in 4 juvenile detention centres in the United Arab Emirates (UAE). The prevalence of conduct disorder was 24.7%, and recidivism, as indicated by repeat admissions to the centres, was found to be associated with conduct disorder. Having a diagnosis of conduct disorder was associated with a lower educational and occupational level of the father, as well as living with a single parent or relatives. Among UAE nationals, conduct disorder was also associated with having a mother who was a non-UAE national.

Prevalence and correlates of conduct disorder among inmates of juvenile detention centres, United Arab Emirates

The prevalence of conduct disorder was assessed in 77 young people in 4 juvenile detention centres in the United Arab Emirates [UAE]. The prevalence of conduct disorder was 24.7%, and recidivism, as indicated by repeat admissions to the centres, was found to be associated with conduct disorder. Having a diagnosis of conduct disorder was associated with a lower educational and occupational level of the father, as well as living with a single parent or relatives. Among UAE nationals, conduct disorder was also associated with having a mother who was a non-UAE national

Asthma and respiratory symptoms among school children in United Arab Emirates.

OBJECTIVES: To determine the prevalence of asthma, wheezing, hay fever, and eczema among primary school children aged 6-13 years in United Arab Emirates (UAE). DESIGN: A cross-sectional study on school children was performed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires. SETTING: Government primary school children in seven Emirates, in UAE. SUBJECTS: Subjects were selected by a multi-stage stratified sampling design. 4200 children targeted for this study, but only 3200 children aged 6-13 years were agreed to participate and responded to the study. The overall response rate was 69.8%. RESULTS: The prevalence of physician diagnosed asthma was 13%, in addition, the wheeze by history was 15.6%. Furthermore, the prevalence of nocturnal cough was 21%. On the other hand, the prevalence of eczema was 11% and hay fever was 14.9%. Parental asthma but not parental atopy was associated with an increased risk of asthma and wheezing in children. CONCLUSIONS: The prevalence of asthma and wheezing in UAE is consistent with that in neighbouring Gulf countries.

Respiratory symptoms and lung function in garage workers and taxi drivers.

The aim of this study was to determine the prevalence of some respiratory symptoms and possible diseases among occupationally-exposed garage workers and taxi drivers. This study involved 158 garage workers and 165 taxi drivers, matched for age, sex, nationality and duration of employment. The mean age of 158 Indian subcontinent garage workers was 34.4 +/- 10.4 years; their mean height and weight were 167.7 +/- 6.6 cm and 72.0 +/- 12.3 kg respectively, and the mean duration of employment garage workers was 8.8 +/- 7.6 years. The mean age of 165 Indian subcontinent male taxi drivers was 34.5 +/- 7.7 years; their mean height and weight were 168.7 +/- 6.1 cm and 71.3 +/- 12.6 kg respectively; and the mean duration of employment was 7.5 +/- 5.4 years. The data on chronic respiratory symptoms showed that garage workers had higher prevalence of symptoms than taxi drivers being significantly greater for chronic phlegm, (p < 0.007); dyspneoa (p < 0.001); and sinusitis (p < 0.03). A higher prevalence of all acute symptoms was recorded in garage workers than in taxi drivers, although the differences were significant only for throat (p < 0.02), hearing problems (p < 0.002); nose (dryness, bleeding and secretion) (p < 0.008); and low back pain (p < 0.05). Almost all forced spirometric tests in the exposed garage workers were lower than in taxi drivers. The results of stepwise multiple regression analysis showed that only phlegm, sinusitis, hearing problems, nasal catarrh, throat, low back pain, smoking and FEF25-75, variables were statistically significant predictors as risk factors. In conclusion, the present study suggests that a high prevalence of respiratory symptoms is associated with exposure to motor vehicle exhaust emission in garage working places. Long-term working as garage workers in the United Arab Emirates (UAE), may be associated with the development of chronic respiratory symptoms and have effects on their daily life and health.