Thesis (M.D.)--University of Hong Kong, 1991. / Also available in print.

Thesis (M.P.H.)--University of Hong Kong, 2007.

No description available.

Cartas al editor. / Revisión por pares

Research report in partial fulfillment for the degree of MMed (Occupational Medicine) / Background Occupational asthma is one of the most commonly reported occupational respiratory diseases in industrialized countries. Literature suggests that about 15% of all adult-onset asthma is caused by workplace exposures. It is potentially preventable and the prognosis is good with early diagnosis and adequate treatment. However, occupational asthma is under-diagnosed and under-reported. Identification of common causative agents and employment of preventative measures are necessary for proper management and control. Objectives 1. To characterize occupational asthma cases assessed at NIOH Occupational Medicine Clinic from 1st January 1997 to 31st December 2007 in terms of: • types of industries, occupations and agents • duration of exposure prior to onset of occupational asthma • time from onset of symptoms to diagnosis • nature of exposure e.g. intermittent, daily, etc. 2. To investigate factors influencing latency period in cases of sensitizer-induced asthma 3. To investigate factors influencing lag time to diagnosis in cases of sensitizer-induced asthma Methods A record review of a series of cases of occupational asthma was done. All cases of occupational asthma diagnosed from 1st January 1997 to 31st December 2007 by NIOH doctors were identified from the Clinic’s electronic database. All the records of patients who had a final diagnosis of occupational asthma were assessed using a standard data capture sheet. Doubtful cases were presented at the NIOH Occupational Medicine clinical discussion meeting for a consensus decision as to whether they qualified to be included in the study or not. Ethical approval was granted by the University of the Witwatersrand Human Research Ethics Committee (Medical). vi Results One hundred and forty two cases of occupational asthma were identified. Of these, 131 were sensitizer-induced and 11 were irritant-induced asthma. Low molecular-weight agents were in the majority with isocyanates, welding fumes, vanadium being the most common. Within the high molecular weight category, wheat was the most common. The majority of cases emanated from the Engineering, Chemical, Smelter and Food industries. Latency period from first exposure to development of symptoms was surprisingly long: a mean of 9.8 years and a median of seven years. The time from onset of symptoms to diagnosis was also long (mean of 4.9 years and median of three years). Younger cases had a shorter latency period and a longer delay in diagnosis. Agents and jobs for irritant-induced asthma cases varied widely and some came from unexpected industries. Discussion This review of asthma referrals to the NIOH Occupational Medicine Clinic has highlighted causative industries and identified exposure agents implicated in cases of occupational asthma. The very wide range of industries, occupations and agents associated with these cases is suggestive of a wide-spread occupational asthma problem in the region referring cases to the Clinic. The long latency period and delay in diagnosis are of concern since prompt diagnosis and removal from exposure is associated with a better prognosis. Irritant-induced asthma is infrequently reported in the local literature, but the range of agents and jobs is possibly indicative of under-diagnosis. Conclusion Occupational asthma is potentially preventable. New cases still arise particularly in poorly controlled workplaces which are capable of employing basic measures to control exposures. Medical surveillance, prompt diagnosis, proper medical management and application of workplace preventative measures are essential in decreasing the burden of disease and impairment

Objective: Reduced maternal levels of vitamin D, E and zinc during pregnancy has been linked to the development of asthma and allergic disease in children. The birth cohort investigated if maternal dietary intake in pregnant Saudi women was associated with childhood asthma and allergic disease up to 24 months of age. Methods: One thousand six hundred and twenty four women were recruited to a prospective birth cohort from an antenatal clinic in Riyadh, Saudi Arabia. A food frequency questionnaire was used to characterize diet during pregnancy and serum micronutrient levels were measured. 1436 singleton children were followed up at 6, 12 and 24 months of age by interview administrated telephone calls. Results: Multivariate analyses revealed no associations between the primary maternal dietary nutrient intakes of vitamin E and zinc and the respiratory outcomes in the cohort children at 24 months of age. There was a borderline significant association between increasing maternal zinc intake and maternal reports of food allergy in the cohort children at 24 months. Positive associations with maternal dietary folate intake with maternally reported ‘itchy rash for at least 6 consecutive months' (OR= 2.36 p-=0.020) and any food allergies (OR= 2.18 p= 0.025). Conclusion: This study suggests no conclusive evidence that maternal intake of vitamin D, E and zinc of Saudi women may lower the risks of developing asthma and allergic disease in early childhood. However, a higher dietary intake of folate during pregnancy increased the risk of reported itchy rash, eczema and food allergy in the cohort children up to 24 months. Further follow up of the cohort will provided evidence that will support or refute whether maternal diet during pregnancy is associated with asthma and allergic disease in childhood.

The SEATON cohort comprising 2000 pregnant women recruited 1997-99 was established to test if maternal nutrition during pregnancy affects the likelihood of children developing asthma. At 32 weeks gestation mothers’ diets were assessed by food frequency questionnaire. 1,924 live singleton births comprised the birth cohort with follow-up at 6 months, 1, 2, 5 and 10 years (the latter the focus of this thesis). Children’s diets were assessed at 5 and 10 years. Their asthmatic status was assessed by International Study of Asthma and Allergies in Childhood questionnaire. Children participating at 5 or 10 years were also invited for measurement of spirometry and allergy. Cross-sectionally at 10 years 934 children (48% boys) participated by return of questionnaire, 449 also took part in the in-depth assessment. Higher maternal vitamin D intakes were associated with decreased odds of ‘doctor diagnosed asthma’, ‘wheeze ever’ and ‘wheeze in the last year’ in the children. Contrary to findings at 5 years no association between maternal vitamin E intake and asthma outcomes was seen. Longitudinally over the 10 years of the study, higher maternal vitamin D and E intakes during pregnancy were both associated with a decreased likelihood of ‘doctor diagnosed asthma’, ‘active asthma’ and ‘wheeze in the last year’ in the children. In conclusion, reduced maternal vitamin D and E intakes during pregnancy are associated with an increased likelihood of childhood asthma during the first ten years of life. Vitamin E appears to be associated with early asthma and wheeze possibly reflecting a role in affecting early airway remodelling processes. Associations with vitamin D were seen consistently over different time-points, possibly having its effect in an immunomodulatory fashion. Intervention trials are required to ascertain if intervention during pregnancy actually reduces childhood asthma rates.

Yang Ping. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 126-145). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Thesis (Ph. D.)--University of Sydney, 1988. / Includes tables and questionnaires. Title from title screen (viewed May 1, 2007). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Department of Pharmacology. Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--University of Sydney, 2008. / Title from title screen (viewed May 8, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Pharmacology, Faculty of Medicine. Degree awarded 2008; thesis submitted 2007. Includes bibliography. Also available in print form.