Out-of-hospital cardiac arrest in Hong Kong

OBJECTIVES

To evaluate the effectiveness of the local emergency medical services system in resuscitation of out-of-hospital cardiac arrest and identify areas for improvement.

METHODS

This was a prospective descriptive study of adults with nontraumatic out-of-hospital cardiac arrest treated in the three accident & emergency departments that serve the whole of Hong Kong Island from March 15, 1999, to October 15, 1999. Patient characteristics, circumstances of cardiac arrest, final outcomes, and response times of the ambulance service were recorded according to the Utstein style.

RESULTS

Three hundred twenty patients were included. There was male predominance, and the mean age was 71.5 years. The majority of cardiac arrests occurred at patients' homes. In 57.5% of cases the arrest was not witnessed. The bystander cardiopulmonary resuscitation (CPR) rate was 15.6%. The most common electrocardiographic (ECG) rhythm at scene was asystole. Ventricular fibrillation or pulseless ventricular tachycardia constituted 14.1%. The average call to dispatch interval was 1.04 minutes. The average call to CPR interval was 9.82 minutes. The average total prehospital interval was 27.55 minutes. The overall immediate survival rate was 14.1% and the rate of survival to hospital discharge was 1.25%.

CONCLUSION

The prognosis of out-of-hospital cardiac arrest in Hong Kong was dismal. Every link in the chain of survival has to be improved.

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.

Morbidity patterns of non-urgent patients attending accident and emergency departments in Hong Kong: cross-sectional study

OBJECTIVES

To study the morbidity patterns of non-urgent patients utilising accident and emergency services and compare these patients with 'true' accident and emergency cases. To analyse the morbidity pattern of non-urgent cases over different time periods, and across different age groups.

DESIGN

A cross-sectional study completed over a 1-year period.

SETTING

Four accident and emergency departments in Hong Kong.

PATIENTS

Two thousand, four hundred and ten patients randomly selected from four accident and emergency departments.

MAIN OUTCOME MEASURES

The morbidity patterns by body system, according to the International Classification of Primary Care, were tabulated and analysed for 'true' accident and emergency cases versus non-urgent cases. The ten most frequent diagnoses for the 'true' accident and emergency and non-urgent cases were also compared. Further analysis of accident and emergency service utilisation was conducted comparing different age groups, and also different time periods.

RESULTS

Significantly more cases presenting to the accident and emergency service with respiratory and digestive problems were found to be non-urgent, rather than appropriate accident and emergency cases. In contrast, significantly more cases presenting with circulatory and neurological problems were appropriate cases for accident and emergency department management. The morbidity pattern for the ten most frequent diagnoses seen in non-urgent cases was noted to be similar to the Hong Kong general practice morbidity pattern for self-limiting conditions. Utilisation of accident and emergency services for acute self-limiting conditions was more marked in the late evening, and also among children and the younger population in general.

CONCLUSION

The utilisation of accident and emergency services by patients requiring a general practice service only, reflects problems in the primary health care delivery system. These may be solved by appropriate interfacing between general practitioners and other service providers, with the aim of providing seamless health care. Without revision of primary health care services, accident and emergency departments will continue to be used inappropriately by patients as an alternative to general practice care.

Marathon finishers and non-finishers characteristics. A preamble to success

BACKGROUND

To investigate if the characteristics and training profiles of runners are significant indicators to predict a successful completion of a marathon.

METHODS

EXPERIMENTAL DESIGN

comparative investigation between two groups of runners at a marathon race.

SETTING

participants of the study came from the 1998 Standard Chartered New Airport International Marathon in Hong Kong.

PARTICIPANTS

113 runners were investigated, of which 58 runners dropped out at the first 10 km of the race, while the other 55 were those that consulted for physiotherapy service after the marathon.

MEASURES

using questionnaire, the characteristics and the training profiles of these runners were obtained. These included weekly training distance, longest and shortest training distance per session in one week; warm-up and stretching exercise with the training sessions, number of marathons previously finished and the runners' opinion of optimal training mileage to complete a marathon.

RESULTS

Independent t-tests with Bonferroni adjustment were used to investigate the difference between the two groups, the results showed significant difference in the weekly training distance (p=0.00), longest and shortest training distance per week (p=0.00), and personal opinion on optimal weekly training distance for a marathon (p=0.00). Logistic regression modeling was then employed to determine variables that best predict the likelihood of completing a marathon.

CONCLUSIONS

The findings indicate that the non-finishers are poorly prepared and the results also identify that the longest mileage covered per training session is the best predictor for a successful completion of a marathon with an odds of 1.21.

Photodynamic Therapy for Bowen's Disease (Squamous Cell Carcinoma in situ) of the Digit

BACKGROUND

Surgical excision is the preferred method of eradicating Bowen's disease (BD). However, when BD occurs on the digit, surgical intervention can sometimes lead to scar contracture and loss of function of the digit.

OBJECTIVE

To evaluate the effectiveness of photodynamic therapy (PDT) in eradicating BD of the digit while preserving the full function of the digit.

METHODS

Four patients of chronic arsenism with biopsy-proven BD on the digit were treated with PDT by using a newly designed light-emitting diode (LED) array with a peak wavelength of 630 nm (630 +/- 40 nm; 40 mW/cm2 at skin surface). After partial removal of the thickened horny layer and 16 hours of occlusion with a 2% aminolevulinic acid (ALA) solution, each lesion was irradiated with 240 J/cm2 in two fractions with a 90-minute interval.

RESULTS

All patients experienced a significant burning, tingling sensation that was tolerable during the procedure except one who needed local anesthesia. All treated digits healed without scarring in 2 weeks. Posttreatment biopsy in one patient showed normal epidermis and a slight fibrosis in the papillary dermis. Three patients remained free of recurrence (75%) at 15-17 months (average 16 months) after one treatment. One patient's BD recurred at 8 months, but was successfully treated without recurrence after 20 months.

CONCLUSION

Our preliminary study suggests that PDT using 2% 5-ALA solution and an LED array is an effective, noninvasive method to treat digital BD with the benefit of scar-free contracture and loss of digital function. Among the various factors that would affect the results of PDT, we feel that partial removal of the thickened horny layer is the most important step to achieve sufficient therapeutic effect in digital BDs.

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.

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.

Depigmented genital extramammary Paget's disease: a possible histogenetic link to Toker's clear cells and clear cell papulosis

BACKGROUND

The histogenesis of extramammary Paget's disease (EMPD) is still controversial. Benign pagetoid cells of the nipple first described by Toker and the similar clear cells found in white maculopapules of clear cell papulosis (CCP) have been proposed to be potential precursor cells giving rise to EMPD and primary intraepidermal Paget's disease in the nipple. The observation of a rare case of depigmented EMPD provided us with a chance to examine further the interesting Toker's clear cell/CCP hypothesis.

METHODS

We performed pathologic studies, including Fontana-Masson stain and immunostaining for AE1/AE3 and S100P, on a new case of depigmented EMPD manifesting a 4 x 3 cm hypopigmented-depigmented patch on the root of the penis.

RESULTS

The lesion showed extensive intraepithelial proliferation of atypical pagetoid cells with markedly reduced epidermal melaninization but nearly normal numbers of melanocytes. The tumor cells were strongly positive for AE1/AE3 by immunostaining. Some tumor cells displayed tadpole-like morphology resembling the pagetoid cells of CCP. Such morphology was not observed in two random examples of non-depigmented genital EMPD.

CONCLUSIONS

The findings of tadpole-shaped pagetoid cells and depigmentation in the present case suggest that depigmented EMPD may be histogenetically related to CCP. Depigmented EMPD should be considered in the differential diagnosis of vitiligo, depigmented mycosis fungoides and lichen sclerosus located along the milk line.

Study of the melt pelletization process focusing on the micromeritic property of pellets

Melt pelletization of lactose 450 M was carried out in an 8-l high shear mixer using PEG 3000 as the meltable binder. The pore size and size distribution of the melt pellets were determined using mercury intrusion porosimetry. The pore size distribution of melt pellets was found to be bimodal. With a higher binder concentration, post-melt impeller speed or longer post-melt processing time, the fraction of large pores in the agglomerates was reduced but the tendency of the agglomerates to develop sub-micron pores increased. The extent of formation of large pores was dependent on the interplay between the inter-particle distance of lactose particles and the contraction property of molten binder. High process temperature was associated with a greater amount of water loss from the melt agglomerates. The water vapor liberated from the lactose particles, was trapped in the molten PEG during the pelletization process. The formation of sub-micron pores was a result of escape of this water vapor on solidification of the molten PEG as well as agglomerate densification. The quantity of sub-micron pores produced was found to be related to the level of water loss. The melt agglomeration gave rise to large agglomerates when long post-melt processing time, high post-melt impeller speed or binder concentration was used.

Cell volume-dependent phosphorylation of proteins of the cortical cytoskeleton and cell-cell contact sites. The role of Fyn and FER kinases

Cell volume affects diverse functions including cytoskeletal organization, but the underlying signaling pathways remained undefined. We have shown previously that shrinkage induces Fyn-dependent tyrosine phosphorylation of the cortical actin-binding protein, cortactin. Because FER kinase was implicated in the direct phosphorylation of cortactin, we investigated the osmotic responsiveness of FER and its relationship to Fyn and cortactin. Shrinkage increased FER activity and tyrosine phosphorylation. These effects were abolished by the Src family inhibitor PP2 and strongly mitigated in Fyn-deficient but not in Src-deficient cells. FER overexpression caused cortactin phosphorylation that was further enhanced by hypertonicity. Exchange of tyrosine residues 421, 466, and 482 for phenylalanine prevented cortactin phosphorylation by hypertonicity and strongly decreased it upon FER overexpression, suggesting that FER targets primarily the same osmo-sensitive tyrosines. Because constituents of the cell-cell contacts are substrates of Fyn and FER, we investigated the effect of shrinkage on the adherens junctions. Hypertonicity provoked Fyn-dependent tyrosine phosphorylation in beta-catenin, alpha-catenin, and p120(Cas) and caused the dissociation of beta-catenin from the contacts. This process was delayed in Fyn-deficient or PP2-treated cells. Thus, FER is a volume-sensitive kinase downstream from Fyn, and the Fyn/FER pathway may contribute to the cell size-dependent reorganization of the cytoskeleton and the cell-cell contacts.

Regulated interactions between dynamin and the actin-binding protein cortactin modulate cell shape

The dynamin family of large GTPases has been implicated in the formation of nascent vesicles in both the endocytic and secretory pathways. It is believed that dynamin interacts with a variety of cellular proteins to constrict membranes. The actin cytoskeleton has also been implicated in altering membrane shape and form during cell migration, endocytosis, and secretion and has been postulated to work synergistically with dynamin and coat proteins in several of these important processes. We have observed that the cytoplasmic distribution of dynamin changes dramatically in fibroblasts that have been stimulated to undergo migration with a motagen/hormone. In quiescent cells, dynamin 2 (Dyn 2) associates predominantly with clathrin-coated vesicles at the plasma membrane and the Golgi apparatus. Upon treatment with PDGF to induce cell migration, dynamin becomes markedly associated with membrane ruffles and lamellipodia. Biochemical and morphological studies using antibodies and GFP-tagged dynamin demonstrate an interaction with cortactin. Cortactin is an actin-binding protein that contains a well defined SH3 domain. Using a variety of biochemical methods we demonstrate that the cortactin-SH3 domain associates with the proline-rich domain (PRD) of dynamin. Functional studies that express wild-type and mutant forms of dynamin and/or cortactin in living cells support these in vitro observations and demonstrate that an increased expression of cortactin leads to a significant recruitment of endogenous or expressed dynamin into the cell ruffle. Further, expression of a cortactin protein lacking the interactive SH3 domain (CortDeltaSH3) significantly reduces dynamin localization to the ruffle. Accordingly, transfected cells expressing Dyn 2 lacking the PRD (Dyn 2(aa)DeltaPRD) sequester little of this protein to the cortactin-rich ruffle. Interestingly, these mutant cells are viable, but display dramatic alterations in morphology. This change in shape appears to be due, in part, to a striking increase in the number of actin stress fibers. These findings provide the first demonstration that dynamin can interact with the actin cytoskeleton to regulate actin reorganization and subsequently cell shape.

Factors associated with non-urgent utilization of Accident and Emergency services: a case-control study in Hong Kong

Accident and Emergency Departments (A&E) have been a popular source of primary care, and studies have shown that up to two thirds of patients attending A&E have problems that could be managed by general practitioners (GPs). Although many studies have found that patients of lower socio-economic class with less social support have a higher utilization rate of A&E, some recent studies have revealed contrary evidence. In this study 2410 patients were randomly selected from four A&E at different times. The gold standard in differentiating true emergency cases and GP cases was based on a retrospective record review conducted independently by a panel of emergency physicians. Two emergency physicians reviewed each case independently, and if their independent ratings were in agreement, this became the gold standard. Patients classified as GP cases were given a telephone interview, and a sample was selected and matched with cases from general out patient clinics (GOPC) in the public sector by morbidity. Reasons for not attending a private GP included closure of clinic, deterioration of symptoms, GPs' inability to diagnose properly, and patients' wish to continue medical treatment in the same hospital. Reasons why non-urgent patients did not choose to attend the nearby public GOPC included affordability, closure of the GOPC, patients' wish to continue treatment at the same hospital, GOPC too far away, no improvement shown after visits to GOPC doctors, and GOPC doctors' inability to make proper diagnoses. The reasons for high level of utilization of A&E services are complex and reflect problems of delivery of GP services. There is an urgent need for GPs to set up a network system to provide out of hours services, and also for a better interfacing between primary and secondary care, and between public and private sectors, so that patients can be referred back to GPs. Interim clinical services provided to those non-urgent cases by nursing practitioners or by GPs working in A&E could also facilitate discharge of patients to primary care facilities.

The decrease of mitochondrial NADH dehydrogenease and drug induced apoptosis in doxorubicin resistant A431 cells

Doxorubicin (DOX) resistant A10A cells derived from human squamous carcinoma A431 cells were found to exhibit a smaller degree of apoptosis after DOX treatment as compared to their parent cells. Induction of reactive oxygen species (ROS) formation and mitochondrial depolarization by DOX were more pronounced in the parent cells than in the A10A cells. The fact that catalase suppressed the DOX effect on ROS induction, mitochondrial depolarization and apoptosis in both cell lines suggests an involvement of ROS in the DOX-induced apoptosis. To investigate the underlying mechanisms for DOX resistance in A10A cells, RT-PCR based differential display was used. One of the clones, which was down-regulated in the A10A cells, had sequence homology with part of the mitochondrial NADH dehydrogenase III (ND3) gene. NADH dehydrogenase plays an important role in generating ROS during DOX treatment. The results indicate that down-regulation of ND3 may at least in part contribute to the mechanism for A10A cells resistant to DOX-induced apoptosis.

Recent trends of stroke mortality in Hong Kong: age, period, cohort analyses and the implications

This study describes the time trend of cerebrovascular disease (CVD) mortality during the period 1976-1995 in Hong Kong and explores the period and birth cohort effects using Poisson regression models with correction for overdispersion of data. A clear downward trend was observed for age-adjusted CVD mortality rate in both sexes. It decreased from 84 per 100,000 to 41 per 100,000 among men (a 51% drop), and from 56 per 100,000 to 35 per 100,000 among women (a 38% drop). The rate of decline was in general greater in the second decade and among males, resulting in a significant downward trend for the male-to-female rate ratio. Both the period of death and the birth cohort showed a significant effect on the reduction in mortality rates, but the latter seemed to have a more substantial influence. However, an increasing trend was observed among younger males in the second decade, and the protective cohort effect seemed to be waning for the more recent cohorts in both sexes. Closer monitoring of the situation in the next years is warranted.

Profile and outcomes of patients transported to an accident and emergency department by helicopter: prospective case series

OBJECTIVES

To study the profile of airlifted patients and their outcomes after arrival at the hospital, and to evaluate the appropriateness of their prehospital care and the decision to use aeromedical evacuation.

DESIGN

Prospective case series.

SETTING

Accident and emergency department of a public hospital, Hong Kong.

PATIENTS

All patients transported to the department by a helicopter of the Government Flying Service from June 1998 through November 1998.

MAIN OUTCOME MEASURES

Demographic data, sources and locations of referral, clinical features, triage category, interventions used, and outcome.

RESULTS

A total of 186 patients were transferred by helicopter during the 6-month study period. The 101 patients who had been transferred from a rural hospital or clinic were older (mean age, 50 years versus 35 years), comprised more females (55% versus 26%), had a higher overall mortality rate (19.8% versus 3.6%), and had a higher hospital admission rate (91.1% versus 37.6%) than the 85 patients who had been airlifted from the scene of an emergency. Neurological disorders were the most common presentation among interfacility transfers (21.8%). Among the 85 scene transfers, limb injuries (32.1%) and heat illnesses (24.4%) were the most common reasons for helicopter transport. Most interfacility transfers were appropriate, but 34.1% of patients who had been transferred from the scene of the emergency were later discharged and 21.1% refused consultation.

CONCLUSIONS

Scene and interfacility transfers by helicopter have different patient profiles, and a substantial proportion of scene transfers may be inappropriate. Guidelines such as field triage and helicopter dispatch criteria need to be established.

Bizarre paediatric facial burns

Child abuse and neglect account for a significant number of paediatric burn injuries. It is of great importance because of the high mortality, high frequency of repeated abuse, as well as the physical, psychological and social sequelae that it causes. Burn abuse is often under-recognized and under-reported because it is difficult to define non-accidental injury. On the other hand, false accusation of burn abuse is extremely damaging to the family. Bizarre and unusual burn injuries can be caused by accident and should not automatically be assumed to be deliberate injury. Three boys of age 1-7 years with bizarre facial burns were admitted to the Burns Unit at the Prince of Wales Hospital between February 1995 and July 1999. One was burned by his baby-sitter with hot water steam and the other two were burned by their mothers with hot boiled eggs. The unusual causes of their burns raised the suspicion of child abuse and formal investigations were carried out by the Social Services Department. Detail assessment including a developmental history of the child and the psychosocial assessment of the family revealed that these three boys were burned because of poor medical advice and innocent cultural belief.

Intermittent pulse therapy with itraconazole for onychomycosis. Experience in Hong Kong Chinese

Forty-four Hong Kong Chinese adults comprising 10 cases of fingernail and 42 cases of toenail onychomycosis were recruited for a 3-weekly itraconazole pulse therapy. Each pulse consisted of seven consecutive daily 400 mg doses with a 3-week interval between treatments. All patients in the fingernail group and 37 in the toenail group completed the study. The clinical cure, clinical response and mycological cure rates at week 36 were 70, 90 and 90% for fingernail and 35, 81 and 68% for toenail groups, respectively. Side-effects including biochemical abnormalities were minimal, and returned to normal upon cessation of treatment. We conclude that itraconazole pulse therapy is very effective, safe and well-tolerated for fingernail and toenail onychomycosis.

A new recommendation for maternal weight gain in Chinese women

OBJECTIVE

To characterize the distribution of maternal weight gain in Chinese women living in a well-nourished community, to recommend target weight gains from quartile values derived from women with good pregnancy outcomes, and to quantify the risk for adverse pregnancy outcomes encountered among subjects with weight gain outside these recommendations.

DESIGN

A retrospective study on maternal anthropometry and pregnancy outcomes was conducted among Chinese women who delivered a singleton pregnancy in a university hospital in Hong Kong.

SUBJECTS

Nine hundred eight women who delivered during the study period were identified. Among them, 754 (83%) had complete anthropometry data. The normative distribution of maternal weight gain was derived from 504 women who had a good pregnancy outcome.

STATISTICS

Analysis of variance was used to compare total weight gain among women of different prepregnancy weight. Fisher exact test was used in the univariate analysis of the association between risk factors and corresponding adverse pregnancy outcomes. Adjusted odds ratios for adverse outcomes were determined by multiple logistic regression models controlling for the following factors: maternal age, duration of gestation, prepregnancy body mass index (BMI), height, parity, and smoking.

RESULTS

A maternal weight-gain chart and recommendations for total weight gains in Chinese women were derived from the distribution of weight gain in subjects with good pregnancy outcomes. The recommended total weight gain was 13 to 16.7 kg, 11 to 16.4 kg, and 7.1 to 14.4 kg respectively for women of low (BMI < 19), moderate (BMI: 19 to 23.5), and high (BMI > 23.5) prepregnancy BMI. Women who did not achieve the lower quartile value had more than twice the risk of having low-birth-weight infants. Those with excessive weight gain were at risk for needing assisted delivery.

APPLICATIONS

As maternal anthropometry differs across ethnic groups, different recommendations should be made for specific populations.

Measuring the inappropriate utilization of accident and emergency services?

Accident and Emergency (A&E) departments are increasingly popular venues for primary care, causing a serious threat to healthcare quality. This paper reports the development of a comprehensive research method for identifying primary care patients attending A&E. Patients were randomly selected from the four A&E departments across different time periods and different regions in Hong Kong. The definition of GP cases was based on a retrospective record review conducted by a panel of emergency physicians using the standard laid down by the Hong Kong College of Family Physicians. The patients sampled were similar in sex and age distribution to A&E attendees for the whole territory. The level of GP cases was found to be 57 per cent, with a significantly higher proportion of patients in the younger age group. The high level of use reflects the lack of a well co-ordinated development of primary care services and interfacing with secondary care.

Influence of production variables on the sphericity of melt pellets

This paper reports the influence of post-melt impeller speed, post-melt processing time, binder concentration and particle size of bulk material on the sphericity of pellets produced by melt pelletization in a high shear mixer. Lactose was used as the bulk material with polyethylene glycol 3000 as a meltable binder. The sphericity of pellets was found to be affected by post-melt impeller speed and post-melt processing time. Binder concentration and particle size of bulk material had a lesser effect on pellet sphericity. The melt pelletization process can be divided into two spheronization phases (a fast initial rate, followed by a slower rate). The change in the spheronization rate was associated with the pellet size, porosity and flow pattern of the processing material. The present study established a bi-exponential mathematical model to relate the pellet sphericity with post-melt specific energy consumption. The relationship of pellet sphericity with post-melt specific energy consumption was independent of the effects of the production variables.

An international comparison of childhood injuries in Hong Kong

OBJECTIVES

This study describes 7813 childhood injuries in Shatin, Hong Kong. Supplementary analyses include developmental specificity of external causes and comparison with international childhood injury data.

METHODS

Children aged 0-15 attending the accident and emergency (A&E) department of the Prince of Wales Hospital in Hong Kong were recruited for the study. Attendance records of participants from the A&E department were analyzed. Details concerning the injury, including the International Classification of Diseases, ninth revision, external cause of injury (E code), nature of injury (N code), abbreviated injury scale, and injury severity scale constitute core measurements, along with participants' age, gender, and respective A&E procedural data.

RESULTS

Males (65.7%) and fall related injuries (44.2%) predominate, while contusion (34.6%) is the prevailing nature of injury. Two age external cause dimensions are derived from a correspondence analysis. Children 0-1 years old are associated with falls, poisoning, scalds, and machinery related injury. Adolescents aged 12-15 are associated with motor related injury, animal related injury, and cuts/piercings. In comparison with international data, unintentional child injuries in Hong Kong comprised more falls but fewer poisonings and burns.

CONCLUSION

A large proportion of falls, along with low proportion of poisonings and burns, are characteristics of childhood injury profile in Hong Kong. From the results of age external cause correspondence analysis, prevention strategies for different external cause should be developmentally specific.

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.

Evaluation on the antipruritic role of transcutaneous electrical nerve stimulation in the treatment of pruritic dermatoses

BACKGROUND

Pruritus is a common and sometimes distressing symptom in many dermatological conditions. Response to conventional pharmaceutical agents may not be satisfactory, and adverse effects are real problems.

OBJECTIVE

To evaluate the short-term efficacy and adverse effects of transcutaneous electrical nerve stimulation (TENS) for ameliorating pruritus in patients with dermatoses.

METHODS

A prospective 1-week study using TENS given once daily for treating pruritic dermatoses in 5 patients.

RESULTS

Significant amelioration of pruritus was obtained without adverse effect referable to TENS treatment, and a subjective reduced use of conventional topical drugs was also reported by all patients.

CONCLUSIONS

TENS is a useful aramentarium for short-term amelioration of pruritus in pruritic dermatoses. Long-term efficacy and safety await further studies.