Research Advances in Sympathetic Remodeling after Myocardial Infarction and Its Significance in Forensic Science.

Sympathetic remodeling after myocardial infarction is presented as denervation, sympathetic nerve sprouting and sympathetic hyperinnervation, and is closely related to ventricular tachyarrhythmias and even sudden cardiac death at convalescence in patients with myocardial infarction. This article reviews the anatomic structure, morphology and functional remodeling of cardiac sympathetic nerve, as well as its role in healed myocardial infarction identification, which may provide references for forensic research.

Expressions of TGF-ß1 and Eâ ¢A-FN after Rat Skeletal Muscle Contusion and Wound Age Estimation.

ABSTRACT: Objective To study the expressions of transforming growth factor-ß1 （TGF-ß1） and EⅢA-fibronectin （EⅢA-FN） at different time points of antemortem injury, antemortem injury postmortem expression and postmortem injury and to explore their application value in wound age estimation. Methods A model of rat skeletal muscle contusion was established. The rats were randomly divided into normal control group （n=5）, antemortem contusion group （n=40）, antemortem contusion postmortem expression group （n=110） and postmortem injury group （n=25）. The expressions of TGF-ß1 and EⅢA-FN after rat skeletal muscles antemortem contusion were detected with immunohistochemical staining. Expression changes of TGF-ß1 and EⅢA-FN mRNA in each group were analyzed with real-time fluorescence quantitative PCR. Results Immunohistochemical staining results showed that a large number of polymorphonuclear leukocyte, mononuclear cells and fibroblastic cells showed a strong expression of TGF-ß1 in wounded zones 12 h-14 d after antemortem contusion. EⅢA-FN was mainly distributed in the extracellular matrix, 3 to 7 d post-traumatic. Real-time fluorescence quantitative PCR results showed that TGF-ß1 and EⅢA-FN mRNA in antemortem injury group reached the peak at 3 and 5 d post-traumatic respectively. The expressions of TGF-ß1 and EⅢA-FN mRNA in antemortem contusion postmortem expression group peaked at 6 h and 12 h postmortem. The expression of TGF-ß1 and EⅢA-FN mRNA in postmortem injury group 0.5-12 h postmortem was significantly lower than those of the normal control group and the antemortem contusion group. Conclusion TGF-ß1 and EⅢA-FN might become a reference index for skeletal muscle wound age estimation.

[Comparison of the Skin and Skeletal Muscle Contusion in Rats Induced by Blunt Force with Different Heights].

OBJECTIVES: To explore the differences in the repair process of skin and skeletal muscle after contusion caused by blunt force attack with different heights. METHODS: Three degrees of contusion were performed on SD rats' right hind limbs by a designed free-dropping device falling from 15, 30 and 50 cm heights, which as a main consideration factor for degree of injury. The repair process of skin and skeletal muscle at 6 h, 24 h, 3 d, 7 d and 13 d after contusion were observed using routine histological methods. RESULTS: Hematoma within skin and/or muscle was found in the rats' hind limbs after contusion with three different heights. The repair processes were similar at 24 h after contusion. However, with the increase of height, the display degree was more obvious. At 3 d after contusion, the RBC of the hemorrhagic region would be decomposed and elapsed in 15 cm contusion group, but for 30 cm contusion group, it delayed to 7 d. At 13 d after contusion, the similar result was found in 15 cm and 30 cm contusion groups, in contrast, the 50 cm contusion group was still in the proliferative phase. CONCLUSIONS: With the increase of height, the occurring rate of hematoma within skin and muscle at the same time increases, and the more serious histological appearance after contusion, including inflammation and proliferation, the longer healing process are observed. According to the results of present study and considering forensic application, the contusion model with 50 cm height （2.58 J/cm²ï¼‰ is recommended as the experimental animal model for the future study of wound age estimation on contusion.

Ischaemic heart disease: trends in mortality in Hong Kong, 1970-89.

STUDY OBJECTIVE: To describe the time trends for ischaemic heart disease (IHD) mortality in Hong Kong between 1970 and 1989, and to examine these trends in relation to the risk factors for IHD. DESIGN: A descriptive epidemiological study of time trends using mortality and population data from the Hong Kong Census and Statistics Department. Direct standardisation using the world population was made to adjust for the changing age structure. Log-linear analyses for trends were performed for the whole period and separately for 1970-79 and 1980-89. The cohort effect was studied by regrouping the data into five year groups according to the year of birth. The influences of risk factors, including hypertension, diet, and smoking, on the time trends of IHD were explored. The role of improved hospital treatment of myocardial infarction on the trends of mortality from categories of IHD was also examined. SETTING: The total Hong Kong population, 1970-89. MAIN RESULTS: The substantial and steady decline of IHD mortality seen in most western countries in the past two decades was not observed in Hong Kong, which showed a plateau or slowly decreasing trend only in the past decade for both women and men. The decreasing trends were more apparent in the younger age groups, especially for women. Cohort analysis showed no significant cohort effect in men, but women born more recently had a lower mortality. Trends of risk factors did not show any close relationship with the mortality trends of IHD, except that a decrease in cigarette smoking might have contributed to the slight decrease in IHD mortality in recent years. Better detection and wider availability of treatment for hypertension might also have contributed to the decrease in IHD mortality. CONCLUSIONS: Hong Kong started to show a slow decline in IHD mortality during the 1980s, about one to two decades later than in other western countries and with the decreasing trend less pronounced. The reasons for this decline are not clear. More detailed information from systematic, population based surveys on life style and risk factors for IHD among the general population are needed.

Predicted maximal oxygen uptake in normal Hong Kong Chinese schoolchildren and those with respiratory diseases.

To assess the maximum oxygen uptake (V'O2 max) of Hong Kong Chinese children and to explore its association with respiratory illnesses, we conducted the Multistage Fitness Test (MFT), a 20-m shuttle run test, in 1,427 schoolchildren aged between 8-12 years. Information on respiratory symptoms in the previous year, cumulative respiratory illnesses, and habitual physical activities were collected. Spirometry was carried out to derive forced expiratory volume in 1 sec (FEV1). The V'O2max was 30.3 mL x kg( - 1) x min( - 1) for boys, and 28.6-mL x kg( - 1) x min( - 1) for girls; these values were low by Western standards. V'O2max was significantly reduced in children with asthma ( - 1.3 mL x kg( - 1) x min( - 1)) and bronchitis ( - 0.7.mL x kg( - 1) x min( - 1)) when adjusted for other covariates. A significant decrease in FEV1 was also observed in these children. The correlation between V'O2max and FEV1 was significant but weak. Habitual physical activity was an independent predictor of V'O2max, but not of FEV1. The low V'O2 max in Hong Kong children may be explained in part by ethnic differences and possibly a low level of physical activity.

Lung cancer mortality among a cohort of men in a silicotic register.

To examine any association between silicosis and lung cancer, the clinic records of a cohort of 1502 silicotic workers diagnosed after 1981 were reviewed. All of the essential data, including occupational exposure, smoking habits, radiographic extent of silicosis, and vital status of each subject, were noted. The standardized mortality ratio for various causes of death was calculated. Thirty-three patients died from lung cancer, giving a standardized mortality ratio of 1.94 (95% confidence interval, 1.35 to 2.70). However, smoking accounted for most of the excess of lung cancer deaths among the silicotic workers in the cohort, and no consistent relationship between lung cancer mortality risk and either duration of exposure to silica dust or severity of silicosis was observed. There is no conclusive evidence in our data to support the hypothesis that lung cancer may be associated with silicosis.

Adverse effects of low-level air pollution on the respiratory health of schoolchildren in Hong Kong.

To evaluate the respiratory effects of long-term exposure to air pollution, schoolchildren (ages 8 to 12 years) from two districts in Hong Kong with contrasting air quality were studied. Parents of 1660 children completed questionnaires on respiratory symptoms, and 1294 children had their ventilatory function tested with a spirometer. After adjustment for relevant covariates, children living in the more polluted district had increased odds ratios for frequent cough (1.74), frequent sputum (1.87), chronic sputum (1.84), and doctor-diagnosed asthma (1.98). Children of both sexes in the more polluted district had significantly poorer lung function, and the differences among girls were more marked. The study provides additional evidence for the adverse effects of long-term exposure to relatively low-level air pollution.

Occupational injuries in Shunde City--a county undergoing rapid economic change in southern China.

A survey was carried out in Shunde City of Southern China to look into the occurrence of occupational injuries in the 'township industries' during the years 1989-1993. A total of 981 major injuries and 159 fatal injuries were recorded for 602,533 person years over the 5 years, giving a major injury rate of 1.63/1000 per year and a fatal injury rate of 0.26/1000 per year. Both the major injury rate and the fatal injury rate increased from 1989 to 1993. Males had a higher fatal injury rate while females had a higher major injury rate. The majority of the injuries occurred in the younger age group with the 20-29 age group taking up more than half of the total casualties. Industries having high injury rates included building and construction, furniture, paper mill and printing. Electrical appliances manufacturing, sewing and shoe making were the industries having low injury rates. Enterprises with foreign capitals and those managed by individuals also had lower injury rates. Machinery injuries were the most common type of major injuries while electrocution, being hit by heavy objects and falling from height accounted for over 60% of fatal injuries. The implications of the differential distributions of the occurrence of the injures were discussed.

A fatal laboratory accident with toxic gases inhalation.

Three university students were exposed to toxic vapours (acryloyl chloride 96% and methacrylic anhydride 94%) in a laboratory accident. They all gave a history of minimal exposure and presented with mild symptoms. One patient died on the same day. The other two cases were uneventful. This paper reports on these three cases, followed by a discussion on irritant gas intoxication.

Health care needs in the Tai Po district of Hong Kong initial indications from a population-based study.

The objective of this study was to obtain a representative profile of residents in Tai Po district, Hong Kong, with regard to their health status, health service use and socio- demographic characteristics. From October 1992 to February 1993, a cross-sectional telephone survey of 7573 Tai Po residents was undertaken. Acute illness episodes in the past month, chronic illness history, and treatment choices for acute and chronic illnesses were used as outcomes. Socio-demographic data were also obtained. Seventeen per cent of respondents reported having acute illness in the previous month, 66% of whom attended private clinics; 5.2% reported having chronic illness, 58.5% of whom attended public clinics. Most (88.5%) acute illness sufferers who used Western medical services for acute illness did so within Tai Po, while 52.7% of chronic illness sufferers used services outside of the district. Older, female, and lower income respondents were more likely to use public clinics. These preliminary findings help to reflect the health needs of residents in Tai Po.

Characteristics of workers attending the pneumoconiosis clinic for silicosis assessment in Hong Kong: retrospective study.

OBJECTIVE: To describe and analyse the baseline characteristics of workers attending the pneumoconiosis clinic for assessment of silicosis. DESIGN: Retrospective cross-sectional study. SETTING: Outpatient clinic. PATIENTS: One thousand and fifty-six patients with silica dust exposure attending the pneumoconiosis clinic for compensation assessment. MAIN OUTCOME MEASURES: Baseline demographic characteristics, lung function parameters, and radiographic findings. RESULTS: Six hundred and forty-eight patients were diagnosed with silicosis, of which 10 were female. Excluding the data on female patients, the mean duration of dust exposure was 24.2 years. The majority of patients were involved in caisson work and stone splitting. Most newly diagnosed patients had simple silicosis. Less than a quarter (24.8%) had progressive massive fibrosis. Lung function parameters at diagnosis were within the normal range. Pulmonary tuberculosis remained an important co-existing disease. CONCLUSION: The major cause of silicosis in Hong Kong is chronic silica dust exposure in the construction industry. Simple silicosis predominated at diagnosis, with normal lung function parameters seen in the majority of patients.

Factors associated with the utilization of traditional Chinese medicine in a small town in Hong Kong.

The practice of Traditional Chinese Medicine (TCM) is largely unregulated in Hong Kong. Yet, as previous studies have shown, a sizable segment of the population consults TCM practitioners for health problems. This paper uses health care utilization data from a telephone health survey of 847 adult subjects in Tai Po District who had suffered from acute illness in the past month, to examine the profile of TCM users in the District. Women, older residents, unemployed workers, low skill laborers, current smokers and subjects dissatisfied with the quality of private sector clinics were significantly more likely to consult TCM practitioners.

Aircraft noise, hearing ability, and annoyance.

The relationship between aircraft noise, loss of hearing, and annoyance was explored in a study in two schools located near an international airport in Taiwan. Sixth-grade students (N = 242) were recruited from two schools and were classified into high- and low-noise-exposure groups, based on environmental noise measurements. Personal-equivalent 24-h noise exposure was measured to determine noise exposure at the individual level, and it was compared with hearing threshold level and with aircraft noise measured at the environmental level. Individual hearing threshold levels did not differ between environmental high- and low-noise-exposure groups, as evidenced by the lack of difference between the two groups for noise exposure measured at the individual level. However, the proportion of students who were annoyed by aircraft noise was higher in the environmental high-noise-exposure group, although personal 24-h noise exposure was not a factor for annoyance. The results indicated that environmental noise measurement was not an appropriate criterion for assessment of auditory damage (or noise-induced hearing loss) in Taiwan. As well, aircraft-noise exposure in Taiwan did not appear to affect the hearing threshold but nonetheless annoyed schoolchildren near the airport.

Research on air pollution and health in Hong Kong.

The relation between air pollution and health was reviewed with reference to major air pollution incidents that occurred in the early to mid-twentieth century, and the more recent findings of health effects at relatively low concentrations of air pollutants. Findings of epidemiological studies in Hong Kong on air pollution and health were then described. These range from cross-sectional studies, before-and-after study, and the popular time series studies. In general, results concurred with findings reported in many overseas studies. Future research needs include the study of health effects in the primary care setting, exposure assessment studies, panel studies, health economic studies, and experimental studies for the detection of threshold levels of exposure.

Overview of occupational health research in Hong Kong.

A review was undertaken to collect and collate information on studies that have been done in Hong Kong in the field of occupational health. Both published and unpublished reports related to occupational health research in Hong Kong during the period 1966-1997 were sought. The data collection was performed through various means, including electronic Medline searches and manual searches of local academic and professional journals. Relevant information for each report was abstracted and collated. A total of 357 studies/reports related to occupational health in Hong Kong were identified during the period 1964 to 1997. Few reports were available before 1980. Roughly similar numbers of reports were found for chemical hazards, dust and ergonomics (including psychosocial factors). In addition, there were substantial numbers of reports on physical hazards. Organic solvents, silica dust, compressed air and noise were the specific hazards more frequently reported. The manufacturing and construction industries were the more frequently studied groups. Recent studies have focused more attention on the non-industrial sectors, including the service sector, offices, schools, hospitals and transport. The vast majority of the reports were based on cross-sectional surveys. A significant number of published reports were discussion or review papers. Most studies were less than adequate in terms of documenting causal relationships. Despite the limited resources, occupational health researchers in Hong Kong have made great achievements in the past decades. The study subjects and the numbers of studies reflected major health problems accompanying the development and changes of local industries and trades from time to time.

Mortality mapping in Hong Kong, 1979-83 and 1984-88: feasibility study and the patterns of cancers.

To examine the practicability and value of mapping cancers in Hong Kong, selected data from consecutive censuses were used to assess the demographic stability and socioeconomic characteristics of the 27 districts. Mortality data in two quinquennia (1979-1988) were used to calculate the districts' standardized mortality ratios (SMRs) for various cancers and their ranks were presented in maps. Correlations were calculated between the SMRs for the cancers, and between the SMRs and the socioeconomic characteristics. Population sizes and socioeconomic characteristics of the districts were fairly stable in most districts. The SMRs of many cancers differed widely between districts. Affluent districts tended to have high SMRs for colorectal and breast cancers, but low SMRs for nasopharyngeal cancer (NPC) as well as liver and lung cancers. The directions of the SMR ranking correlations between the two quinquennia were generally consistent. Statistically significant correlations between some cancers were replicated, particularly for males, and between some cancers and socioeconomic characteristics.

Mortality mapping in Hong Kong, 1979-83 and 1984-88: the patterns of major non-malignant diseases.

We examined the spatial patterns of mortality from various non-malignant diseases in Hong Kong during the two quinquennia, 1979-83 and 1984-88. Population data and parameters reflecting socioeconomic factors, including ethnic backgrounds, were selected from census data. Mortality data were obtained from death registration files. The standardized mortality ratios (SMRs) for major diseases were calculated for 27 census districts. The rankings of the districts' SMRs were shown in map form. Correlations were calculated between the districts' SMRs for the diseases, between them and the SMRs for cancers, and between them and socioeconomic and ethnic parameters. Many spatial patterns and correlations showed consistency and were biologically plausible. These results showed that mapping for a rapidly growing city such as Hong Kong could be a valuable exercise for detecting "at risk" populations where causal factors for non-malignant diseases can be investigated and identified for possible elimination.