Experimental study of the temporal profile of breath alcohol concentration in a Chinese population after a light meal.

In forensic science, the Widmark equation is widely used to deduce the blood alcohol concentration (BAC) at different time points. But the linear model specified by Widmark might be deficient in predicting the breath alcohol concentration (BrAC) at different time points, and extrapolating the peak and the corresponding time. In order to establish the temporal profile of alcohol concentration which captures the effects of non-linear nature of alcohol absorption, elimination, and peak, in particular of Chinese population after a light meal, a drinking experiment was conducted in this study. To achieve this, a double-blind drinking experiment was conducted to measure the BrAC of 52 Chinese participants after a light meal in this study. Prior to the experiment, all participants were required to abstain from food for 4 hours, more importantly, from alcohol and sedatives for 24 hours. A standard light meal was provided about 30 minutes prior to the alcohol intake in the experiment. The BrAC was measured at a 10-minute interval during the absorption phase and 30-minute interval during the elimination phase respectively. The measurements were stopped when the BrAC fell to 0.010 mg/100 ml or below, or more than 8 hours after the alcohol intake. Then, the temporal profiles of BrAC, assuming linear and non-linear relationships, were established using Full Bayesian approach. The linear component indicated the alcohol impairment in normal social function, with which a light meal is usually accompanied with drinking. On the other hand, the non-linear (gamma distribution) part replicated the absorption phase, elimination phase, and the peak of alcohol concentration. The proposed model well performed than the conventional regression model. Additionally, the confounding factors including gender, body weight, and dosage were controlled for. Results should be useful for the development of cost-effective enforcement measures that could deter against drink driving.

A simulation study of the effects of alcohol on driving performance in a Chinese population.

UNLABELLED: Driving under the influence of alcohol (DUIA) is a significant factor contributing to road traffic crashes, injuries, and fatalities. Although the effects of alcohol on driving performance are widely acknowledged, studies of the effects of alcohol impairment on driving performance and particularly on the control system of Chinese adults are rare. This study attempts to evaluate the effects of alcohol on the driving performance of Chinese adults using a driving simulator. METHOD: A double-blind experimental study was conducted to evaluate the effects of alcohol impairment on the driving performance of 52 Chinese participants using a driving simulator. A series of simulated driving tests covering two driving modules, including emergency braking (EB) and following braking (FB), at 50km/h and 80km/h were performed. Linear mixed models were established to evaluate driving performance in terms of braking reaction time (BRT), the standard deviation of lateral position (SD-LANE), and the standard deviation of speed (SD-SPEED). RESULTS: Driving performance in terms of BRT and SD-LANE was highly correlated with the level of alcohol consumption, with a one-unit increase in breath alcohol concentration (BrAC) degrading BRT and SD-LANE by 0.3% and 0.2%, respectively. Frequent drinkers generally reacted faster in their BRT than less-frequent drinkers and non-drinkers by 10.2% and 30.6%, respectively. Moreover, alcohol impairment had varying effects on certain aspects of the human control system, and automatic action was less likely to be affected than voluntary action from a psychological viewpoint. CONCLUSION: The findings should be useful for planning and developing effective measures to combat drink driving in Chinese communities.

Assessment of quality of life and functional outcome in patients sustaining moderate and major trauma: a multicentre, prospective cohort study.

BACKGROUND: Trauma care systems aim to reduce both death and disability, yet there is little data on post-trauma health status and functional outcome. OBJECTIVES: To evaluate baseline, discharge, six month and 12 month post-trauma quality of life, functional outcome and predictors of quality of life in Hong Kong. METHODS: Multicentre, prospective cohort study using data from the trauma registries of three regional trauma centres in Hong Kong. Trauma patients with an ISS≥9 and aged≥18 years were included. The main outcome measures were the physical component summary (PCS) score and mental component summary (MCS) scores of the Short-Form 36 (SF36) for health status, and the extended Glasgow Outcome Scale (GOSE) for functional outcome. RESULTS: Between 1 January 2010 and 31 September 2010, 400 patients (mean age 53.3 years; range 18-106; 69.5% male) were recruited to the study. There were no statistically significant differences in baseline characteristics between responders (N=177) and surviving non-responders (N=163). However, there were significant differences between these groups and the group of patients who died (N=60). Only 16/400 (4%) cases reported a GOSE≥7. 62/400 (15.5%) responders reached the HK population norm for PCS. 125/400 (31%) responders reached the HK population norm for MCS. If non-responders had similar outcomes to responders, then the percentages for GOSE≥7 would rise from 4% to 8%, for PCS from 15.5% to 30%, and for MCS from 31% to 60%. Univariate analysis showed that 12-month poor quality of life was significantly associated with age>65 years (OR 4.77), male gender (OR 0.44), pre-injury health problems (OR 2.30), admission to ICU (OR 2.15), ISS score 26-40 (OR 3.72), baseline PCS (OR 0.89), one-month PCS (OR 0.89), one-month MCS (OR 0.97), 6-month PCS (OR 0.76) and 6-month MCS (OR 0.97). CONCLUSION: For patients sustaining moderate or major trauma in Hong Kong at 12 months after injury<1 in 10 patients had an excellent recovery, ≤3 in 10 reached a physical health status score≥Hong Kong norm, although as many as 6 in 10 patients had a mental health status score which is≥Hong Kong norm.

Simulation of survivorship bias in observational studies on plasma to red blood cell ratios in massive transfusion for trauma.

BACKGROUND: Observational studies on injured patients requiring massive transfusion have found a survival advantage associated with use of equivalent number of units of fresh frozen plasma (FFP) and packed red blood cells (RBCs) compared with use of FFP based on conventional guidelines. However, a survivorship bias might have favoured the higher use of FFP because patients who died early never had the chance to receive sufficient FFP to match the number of RBC units transfused. METHODS: A Markov model using trauma data from local hospitals was constructed and various FFP transfusion scenarios were applied in Monte Carlo simulations in which the relative risk of death associated with exposure to high FFP transfusion was set at 1.00, so that the FFP : RBC ratio had no influence on mortality outcome. RESULTS: Simulation results showed that the relative risk associated with exposure to high FFP transfusion was less than 1.00 (0.33-0.56 based on programmed delays in achieving an FFP : RBC ratio of 1 : 1-2), thus demonstrating a survivorship bias in favour of FFP : RBC equal to or more than 1 : 1-2 in certain observational trauma studies. This bias was directly proportional to the delay in achieving a FFP : RBC ratio of 1 : 1-2 during resuscitation. CONCLUSION: Some observational studies comparing low and high FFP administration in injured patients requiring massive transfusion probably involve survivorship bias that inflates or creates a survival advantage in favour of a higher FFP : RBC ratio.

Low-voltage, low-power, organic light-emitting transistors for active matrix displays.

Intrinsic nonuniformity in the polycrystalline-silicon backplane transistors of active matrix organic light-emitting diode displays severely limits display size. Organic semiconductors might provide an alternative, but their mobility remains too low to be useful in the conventional thin-film transistor design. Here we demonstrate an organic channel light-emitting transistor operating at low voltage, with low power dissipation, and high aperture ratio, in the three primary colors. The high level of performance is enabled by a single-wall carbon nanotube network source electrode that permits integration of the drive transistor and the light emitter into an efficient single stacked device. The performance demonstrated is comparable to that of polycrystalline-silicon backplane transistor-driven display pixels.

The first 5 years since trauma center designation in the Hong Kong Special Administrative Region, People's Republic of China.

BACKGROUND: In 1994, the Hong Kong Special Administrative Region (HKSAR) introduced plans to implement a trauma system based on the recommendations outlined by Professor Donald Trunkey in his report to the local Hospital Authority. Five government-subsidized public hospitals were subsequently designated as trauma centers in 2003. This article reviews the initial experience in these five centers. METHODS: Prospective trauma registries from January 2004 to December 2008 were reviewed. Primary clinical outcome measures were hospital mortality. The Trauma and Injury Severity Score methodology was used for benchmarking with the Major Trauma Outcome Study (MTOS) database. RESULTS: The majority (83.3%) of the 10,462 patients suffered from blunt trauma. Severe injury, defined as Injury Severity Score>15, occurred in 29.7% of patients. The leading causes of trauma were motor vehicle collisions and falls, with crude hospital mortality rates of 6.9% and 10.7%, respectively. The M-statistic was 0.95, indicating comparable case-mix with the MTOS. The worst outcome occurred in the first year. Significant improvement was seen in patients with penetrating injuries. By 2008, these patients had significantly higher survival rates than expected (Z-statistic=0.85). Although the overall mortality rates for blunt trauma were higher than expected, the difference was no longer statistically significant from the second year onward. CONCLUSIONS: The case-mix of trauma patients in the HKSAR is comparable with that of the MTOS. A young trauma system relatively unburdened by dissimilar reimbursement and patient access issues may achieve significant improvement and satisfactory patient outcomes. Our findings may serve as a useful benchmark for HK and other Southeast Asian cities and trauma systems to establish local coefficients for future evaluations.

Misclassification of injury severity among road casualties in police reports.

This study aims to evaluate the discordance between police reports of injury severity among road casualties and the length of hospital stay and the Injury Severity Scale (ISS) by linking information from the crash records of the Hong Kong Police with the trauma records of a regional hospital. Sensitivity and specificity analyses suggest that police injury grading diverges noticeably from the definition of a 12-h hospital stay. Police reports overestimate injury severity remarkably. The results of logistic regression indicate that age, the ISS, and the position of the victim significantly determine the likelihood of police injury misclassification. Furthermore, an optimal demarcation point of the length of hospital stay for serious injury is estimated.

Risk factors for injury to married women from domestic violence in Hong Kong.

OBJECTIVE: To examine risk factors for injury to married women from domestic violence in Hong Kong. DESIGN: Case control study. SETTING: Regional public hospital, Hong Kong. PATIENTS: All married women aged 18 to 60 years who attended an accident and emergency department for treatment of a domestic violence injury from January 2004 to June 2005. MAIN OUTCOME MEASURES: Social and health characteristics of abused women and their husbands. RESULTS: A total of 293 cases were compared to 313 controls. Eight predictive variables were found to be significant by univariate analysis: woman who is a new immigrant (P = 0.003), woman with no job (P = 0.019), husband with low educational level (P < 0.001), presence of extramarital affairs (P < 0.001), husband's unemployment (P < 0.001), husband's alcohol abuse (P < 0.001), husband's illicit drug abuse (P = 0.032), husband's mental illness (P < 0.001). Five factors were found to be significant in a logistic regression analysis: husband with a low educational level (nil to primary) [adjusted odds ratio = 2.78; 95% confidence interval, 1.149-6.727], husband unemployed (adjusted odds ratio = 9.031; 95% confidence interval, 5.163-15.796), presence of extramarital affairs (adjusted odds ratio = 5.218; 95% confidence interval, 2.899-9.395), husband's alcohol abuse (adjusted odds ratio = 6.089; 95% confidence interval, 3.460-10.716), husband's mental illness (adjusted odds ratio = 9.443; 95% confidence interval, 2.351-37.926). CONCLUSIONS: Several significant risk factors have been identified for injury incurred during domestic violence to married women in Hong Kong. It provides information useful for developing local preventive strategies.

Patients with systemic lupus erythematosus show increased platelet activation and endothelial dysfunction induced by acute hyperhomocysteinemia.

OBJECTIVE: Hyperhomocysteinemia adversely affects the endothelium, although the exact mechanism is unclear. Systemic lupus erythematosus (SLE) is an inflammatory disease with a high atherothrombotic tendency. We examined whether acute hyperhomocysteinemia exacerbates endothelial and platelet dysfunction in patients with SLE. METHODS: Twelve SLE patients and 15 controls were recruited. Oral methionine was used to achieve acute hyperhomocysteinemia. Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery; also assessed were the levels of von Willebrand factor (vWF) and plasminogen activator inhibitor type 1 (PAI-1). Platelet activation was assessed by the levels of beta-thromboglobulin (beta-TG), fibrinogen binding, and P-selectin expression using flow cytometry. RESULTS: After oral methionine loading, vWF levels increased significantly, whereas FMD remained unchanged in both groups. PAI-1 increased significantly only in controls. Fibrinogen binding to platelets increased significantly only in SLE patients. Beta-TG remained unchanged in SLE patients but increased significantly in controls. Platelet P-selectin expression did not change in either group. CONCLUSION: These results suggest that the prothrombotic tendency after acute hyperhomocysteinemia is mediated by endothelial dysfunction and platelet activation in patients with SLE and healthy controls.

Immunohistochemical localization of fibroblast growth factors FGF-1 and FGF-2, and receptors FGFR2 and FGFR3 in the epithelium of human odontogenic cysts and tumors.

Acidic (FGF-1) and basic (FGF-2) fibroblast growth factors are members of a family of growth factors that function in growth, differentiation and regeneration of a variety of tissues. Their presence in human odontogenic cysts and tumors has not been previously investigated. This study was designed to detect immunohistochemically the presence of these factors and two fibroblast growth factor receptors (FGFR2 and FGFR3) in a cross section of odontogenic cysts and tumors, to determine if they may be involved in the differentiation of odontogenic epithelium or, more specifically, in the development of particular cysts or tumors. Archival formalin-fixed paraffin-embedded tissues were used. With some exceptions, FGF-2 and the receptor FGFR2, were found in the cytoplasm and occasionally in the nuclei of cells of odontogenic epithelium, while FGF-1 and the receptor FGFR3, were absent or only focally or weakly detected, using standard immunohistochemical techniques. The data are similar to those published for normal murine odontogenesis, suggesting that these factors are associated with odontogenic differentiation rather than pathogenesis. The presence of significant nuclear staining in odontogenic epithelium associated with embryonic mesenchyme in ameloblastic fibromas and ameloblastic fibro-odontomas suggests that FGF-2 may be involved in directing nuclear activity at the histodifferentiation stage of odontogenesis.

Late forming supernumerary tooth in the premaxilla: a case report.

A case of late forming supernumerary tooth in the premaxilla is presented in this report. The patient has been followed-up radiographically from the age of 9 years but the supernumerary tooth could only be detected radiographically when the patient was 11 years old. This emphasises the importance of thorough clinical and radiographic examination of the developing dentition in children.

Inhibition of proliferation of estrogen receptor-positive MCF-7 human breast cancer cells by flavonoids in the presence and absence of excess estrogen.

The flavonoids are a group of naturally-occurring, low molecular weight compounds that are widespread in plants. Representatives of several different classes of flavonoids were tested for their effects on the proliferation of an estrogen receptor-positive human breast cancer cell line, MCF-7. The IC50S (concentration at which cell proliferation was inhibited by 50%), based on [3H]thymidine incorporation, ranged from 4.2 to 18.0 micrograms/mL. The cells were viable at these concentrations. The possibility that flavonoids may block cell proliferation by binding to the estrogen receptor was explored. The cells were depleted of endogenous steroids and incubated with individual flavonoids at their IC50 concentration. Half of the cells were exposed to an excess concentration of 17 beta-estradiol to see if this affected antiproliferation by the flavonoids. Of the flavonoids tested, only the inhibition of cell proliferation by genistein was reversed with the addition of excess, competing estrogen. Baicalein, galangin, hesperetin, naringenin and quercetin apparently exert their antiproliferative activity via some other mechanism.

Demand for and utilization of dental services among Hong Kong employees with and without dental benefit coverage.

The objectives of the present study were to investigate the effects of employer-provided dental benefits on the pattern of demand for and utilization of dental services among Hong Kong employees and to analyse whether employees' awareness about an existing dental benefit programme influenced their dental service demand and utilization. Staff from 11 selected companies with and without dental benefits responded to questionnaires concerning their personal factors, demand for dental services, and utilization of dental services and about their awareness of their dental benefit coverage. Overall response rate was 67%. The socio-demographic characteristics of those respondents who were covered and those who were not were similar. Forty per cent of the covered respondents were not aware of their dental benefit coverage, so analysis was performed with three groups of respondents, covered and aware, covered and unaware, and uncovered. A larger proportion of employees in the "aware" group had visited a dentist in the previous 12 months and had visited a dentist for asymptomatic reasons. The "aware" group reported more "low expenditure" items and less "high expenditure" items. Those who were aware of their dental benefit coverage irrespective of the type of scheme reported a significantly higher demand than those who were not aware of their coverage. Demand and utilization of the covered, but unaware, group was more similar to the uncovered group than to the "aware" group. Coverage per se had no apparent effect on the demand for dental services. Further studies will be necessary to establish that higher dental care demand and utilization induced by third party schemes also leads to improved oral health.

Inhibition of human breast cancer cell proliferation and delay of mammary tumorigenesis by flavonoids and citrus juices.

Two citrus flavonoids, hesperetin and naringenin, found in oranges and grapefruit, respectively, and four noncitrus flavonoids, baicalein, galangin, genistein, and quercetin, were tested singly and in one-to-one combinations for their effects on proliferation and growth of a human breast carcinoma cell line, MDA-MB-435. The concentration at which cell proliferation was inhibited by 50% (IC50), based on incorporation of [3H]thymidine, varied from 5.9 to 140 micrograms/ml for the single flavonoids, with the most potent being baicalein. IC50 values for the one-to-one combinations ranged from 4.7 micrograms/ml (quercetin + hesperetin, quercetin + naringenin) to 22.5 micrograms/ml (naringenin + hesperetin). All the flavonoids showed low cytotoxicity (> 500 micrograms/ml for 50% cell death). Naringenin is present in grapefruit mainly as its glycosylated form, naringin. These compounds, as well as grapefruit and orange juice concentrates, were tested for their ability to inhibit development of mammary tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) in female Sprague-Dawley rats. Two experiments were conducted in which groups of 21 rats were fed a semipurified diet containing 5% corn oil and were given a 5-mg dose of DMBA intragastrically at approximately 50 days of age while in diestrus. One week later, individual groups were given double-strength grapefruit juice or orange juice or fed naringin or naringenin at levels comparable to that provided by the grapefruit juice; in the second experiment, the rats were fed a semipurified diet containing 20% corn oil at that time. As expected, rats fed the high-fat diet developed more tumors than rats fed the low-fat diet, but in both experiments tumor development was delayed in the groups given orange juice or fed the naringin-supplemented diet compared with the other three groups. Although tumor incidence and tumor burden (grams of tumor/rat) were somewhat variable in the different groups, rats given orange juice had a smaller tumor burden than controls, although they grew better than any of the other groups. These experiments provide evidence of anticancer properties of orange juice and indicate that citrus flavonoids are effective inhibitors of human breast cancer cell proliferation in vitro, especially when paired with quercetin, which is widely distributed in other foods.

Prevalence and structure of dental benefit schemes in Hong Kong.

Before the impact of employer-provided dental benefit schemes on the dental care delivery system can be evaluated in Hong Kong, the prevalence of these schemes and their structures must be established. A mailed questionnaire survey was conducted of a representative group of companies with more than 100 employees (n = 495). Response rate to the mail survey was 38 per cent (n = 186). Non-respondents were stratified according to their nature of business and one third was randomly selected for a follow-up by telephone to which 84 per cent responded (n = 81). After adjustment, 16 per cent of companies of that size were found to be providing dental benefit schemes to their staff. The prevalence was related to the nature of business of the companies. Among companies providing dental benefits, administrators from selected companies were interviewed. It was found that dental benefit schemes could be broadly divided into two types: One characterised by cash-benefit and the other by service-benefit. Treatment items covered by the schemes were mostly simple services such as diagnostic items, simple restorations and simple extractions. The influence of these dental benefit schemes on the dental care-seeking behaviour of the beneficiaries is under investigation.

Energy cost of ambulation in healthy and disabled Filipino children.

The energy expenditures (Ee) for locomotion by nondisabled and disabled Filipino children aged 7 to 13 were determined and compared using indirect calorimetry. Forty-one controls (20 boys and 21 girls) ambulated at a comfortable pace; 16 children (eight boys and eight girls) with lower extremity poliomyelitis of varying severity ambulated by (1) wheelchair propulsion, (2) bilateral axillary crutches, (3) unilateral lower extremity ankle-foot orthoses or knee-ankle-foot orthoses, and (4) unassisted. Disabled children, regardless of their mode of ambulation, had to expend significantly more energy to ambulate than normal children (p less than 0.05). Wheelchair propulsion cost 16% more energy than the normal gait; crutch ambulation cost 41% more than the control. Children using unilateral braces sacrificed speed to attain near-normal Ee. When they ambulated without orthoses, their Ee increased by 109% over the control. In ascending order, the least energy was expanded by normal ambulation followed by disabled ambulation with unilateral brace, disabled propelling a wheelchair, disabled ambulation with bilateral axillary crutches, and disabled ambulation without brace. Efficiency of locomotion was reflected in the values obtained for Ee in terms of kcal x 10(-3)/kg/m, as demonstrated by the lower Ee but slower ambulation of children with braces, as compared to the nondisabled children.