The objective of this study was to assess and compare the self-perceived work-related stress of emergency department (ED) and general ward (GW) nurses and to assess the relationship between self-perceived stress and salivary cortisol levels in these groups of nurses. Seventy-three female ED (n = 23) and GW (n = 50) nurses from a general hospital completed a self-administered questionnaire. A modified mental health professional stress scale (PSS) was used to measure self-perceived work-related stress. Salivary samples were collected at the start and end of morning shiftwork. An enzyme-linked immunosorbent assay method was used to determine the salivary cortisol concentration (nmol/L). ED nurses perceived that nursing was more stressful (mean, 1.58; 95% confidence interval [CI], 1.35 to 1.81) than did GW nurses (mean, 1.30; 95% CI, 1.18 to 1.40). On the PSS subscales, scores of organizational structure and process, lack of resources, and conflict with other professionals were higher in ED nurses (all P < 0.01). The morning cortisol was significantly lower in ED (geometric mean, 9.10; 95% CI, 6.62 to 12.42 nmol/L) than in GW (geometric mean, 15.45; 95% CI, 11.86 to 20.14 nmol/L) nurses. Log morning salivary cortisol was negatively correlated with PSS (r = -0.255), scores of organizational structure and process, and conflict with other professionals (all P < 0.05). The difference between morning and afternoon cortisol concentration in ED nurses (geometric mean, 6.35; 95% CI 4.14 to 9.93 nmol/L) was lower than in GW nurses (geometric mean, 12.42; 95% CI, 9.38 to 16.28 nmol/L). The log value of the difference correlated marginally with PSS (r = -0.21, P = 0.07) and significantly with scores of organizational structure and process, lack of resources, and conflict with other professionals (all P < 0.05). There was no difference between the two groups in afternoon salivary cortisol level. ED nurses perceived more stress compared with GW nurses. Morning salivary cortisol concentration is better correlated with PSS compared with the morning-afternoon salivary cortisol difference. The result raises the possibility of using a single morning salivary cortisol sample to reflect self-perceived stress.

Nasopharyngeal carcinoma (NPC) is a rare cancer in most parts of world, but rather common in Southern China and Southeast Asia. This study used IARC published datasets to explore the secular trends of incidence rates of NPC among different Chinese populations in Singapore, Hong Kong and Los Angeles, over the time period 1973-1997. We observed great disparity in the risks and time trends of NPC in those selected Chinese populations. The highest risk was in Hong Kong where the incidence rates have declined rapidly throughout the whole study period in both males and females. For Singapore Chinese, the incidence rates also dropped recently in both genders, but the low incidence rates in Los Angeles Chinese have remained essentially unchanged over time. We further assessed the contribution of period and cohort effects to the observed trends in Hong Kong and Singapore populations through age-period-cohort modeling and found that an age-cohort model provided the best fit to the data in both populations, although for Singapore females a simple age-drift model fit the data well. There was a statistically significant decrease in the drop in incidence of NPC for cohorts born around 1940 in Hong Kong and 1958 in Singapore. This indicates that environmental and lifestyle changes play an important role in the declining incidence of NPC over time.

This study aims to assess the difference in self-perceived stress before and after an academic assessment and its association with the marks scored and to study the association of salivary cortisol, Immunoglobulin A (IgA), and chromogranin A (CgA) with stress levels before and after the assessment. Thirty-one third-year dental undergraduates indicated how stressed they felt on a 5-point rating scale just prior to and immediately after a one-hour written test. Five-minute unstimulated whole saliva samples were also collected at those times to measure salivary cortisol, IgA, and CgA. Students rated significantly higher stress scores before (median [inter quartile range]: 3[1]), compared to after the test (2[2]) (p=0.015). Higher cortisol levels (mean: 6.32 nmol/l) were observed before than after the exam (mean: 5.16 nmol/l) (p=0.015). No significant differences were noted between the pre-and post-test saliva samples for salivary IgA and CgA levels. A negative correlation was seen between post-test stress scores and test marks (Spearman's r = -0.325, p=0.07). Dental students perceived a higher level of stress prior to the test, which declined after that. Pre-test stress scores were associated with raised salivary cortisol, but not IgA or CgA. Students who perceived higher levels of stress after the test generally had poorer results.

Evidence for the effect ofoccupational exposure to lead on the male endocrine system is conflicting. This study evaluated the primary (testicular) and secondary (hypothalamo pituitary testicular) effects of exposure to lead in 122 current lead workers and 49 non-exposed workers. The mean current blood lead concentration was 35-2 (range 9-6-77-4) pg/dl in the exposed workers, and 8-3 (range 2-6-14-8) pg/dl in the non-exposed workers. Concentrations of plasma luteinising hormone (LH) and follicle stimulating hormone (FSH) were both significantly higher in the exposed workers, but testosterone (T) was not significantly different between the two groups. In older exposed workers, however (> 40 years), plasma T concentrations were significantly lower, but LH and FSH concentrations were not significantly different. Compared with non-exposed workers, those exposed for less than 10 years had significantly raised LH and FSH and normal T concentrations whereas those exposed for 10 or more years had significaaitly lower T, and normal LH and FSH concentrations. More recently, studies of lead exposed workers have reported positive evidence of a central effectthat is, a disruption of gonadotrophin secretions. Progressive increase in plasma LH and decrease in plasma T concentrations with no change in FSH was noted among workers exposed to a mean blood lead concentration of 70 ,ug/dl for less than one year (five subjects), one to five years (eight subjects), and more than five years (11 subjects) compared with controls (20 subjects).9 On the other hand, Gustafson et al recently reported lower plasma FSH and LH concentrations (especially in workers less than 40 years of age) and no difference in T concentrations in 25 workers compared with age matched controls.'0 The levels of lead absorption were moderate (mean blood lead 40 ,ug/dl, mean duration (SD) 6-4 (4-1) years). The results in some studies were difficult to interpret for reasons such as small sample sizes, possible confounding effects by age and other factors, and on 7 June 2019 by guest. Protected by copyright.

We compared hepatic and serum lipid changes in hepatocellular carcinoma (HCC) patients to have a better understanding of the molecular pathogenesis of this disease and discovery novel lipid biomarkers. Hepatic and serum lipid profiling was conducted in paired liver and serum samples from 50 HCC patients and 24 healthy controls. A total of 20 hepatic and 40 serum lipid signatures were identified, yet there was hardly any significant correlation between them. The results indicated that triglycerides and phosphatidylcholines contributed significantly to altered hepatic lipids, whereas triglycerides and phosphatidylethanolamine-based plasmalogens (PEp) contributed most to altered serum lipids. In serum, PEp (36:4) and (40:6) showed a fair capability to discriminate HCC patients from healthy controls, and were significantly associated with HCC tumor grades (p < 0.05), and thus were identified as potential diagnostic and prognostic biomarkers of HCC. These findings were confirmed by a validation study conducted in an independent cohort consisting of 18 HCC, 20 cirrhosis patients, and 20 healthy controls. This study suggests that hepatic and serum lipid signatures of HCC have to be considered as mostly independent, and the results imply potential roles of PEp species, particularly PEp (36:4) and (40:6), as serum biomarkers for HCC diagnosis and progression.

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We carried out a cross-sectional community study in Singapore to determine the prevalence of specific central nervous system (CNS) symptoms among hand-held cellular telephone (HP) users compared to nonusers and to study the association of risk factors and CNS symptoms among HP users. A total of 808 men and women between 12 and 70 years of age, who lived in one community, were selected using one-stage cluster random sampling and responses to a structured questionnaire. The prevalence of HP users was 44.8%. Headache was the most prevalent symptom among HP users compared to non-HP users, with an adjusted prevalence rate ratio of 1.31 [95% confidence interval, 1.00-1.70]. There is a significant increase in the prevalence of headache with increasing duration of usage (in minutes per day). Prevalence of headache was reduced by more than 20% among those who used hand-free equipment for their cellular telephones as compared to those who never use the equipment. The use of HPs is not associated with a significant increase of CNS symptoms other than headache.

Objective: This study was aimed at exploring and comparing peoples’ concerns over donation of blood specimens for genetic research across three ethnic groups in Singapore: Malay-Muslims, Chinese and Indians. Methods: We conducted 12 focus group sessions among 98 participants with 7–10 in each group. Results: Concerns over donation of blood specimens for genetic research were diverse, with all ethnic groups expressing anxiety about breach of confidentiality, finding out that they have a disease and misuse of research for cloning. Other concerns included fear of pain, blood and needle pricks and misconceptions of adverse health effects such as weight gain from donating blood specimens. Malay-Muslims were generally concerned about the selection process, potential racial discrimination, and religious beliefs regarding blood storage while Chinese and Indians were concerned about giving blood to strangers and being inconvenienced by participating in research. Conclusion: Programmes to promote community participation in genetic research should address the diverse ethnic concerns, design ethnic-sensitive messages and involve the community.