Epidemiology and seasonality of respiratory tract virus infections in the tropics

Acute viral respiratory tract infections are a significant cause of morbidity worldwide. Information on the epidemiology and seasonality of these infections is important in planning vaccination and treatment strategies. In temperate climes, there are distinct seasonal peaks in the winter months. This paper reviews the seasonal trends of respiratory viral infections in the tropics. Despite the absence of a winter season, consistent seasons of infection, albeit less distinct, have been observed. With few exceptions, respiratory syncytial virus and influenza infections have been observed mainly during the rainy seasons in Asian, African and South American countries.     

Thermocoagulation of fetal sacrococcygeal teratoma

Fetal sacrococcygeal teratoma can lead to a high output cardiac failure resulting in hydrops fetalis. One of the prenatal therapeutic options is to occlude the feeding vessels by radiofrequency ablation. We present a case of fetal sacrococcygeal teratoma diagnosed at 13 weeks of gestation. The tumour increased in size more than 100 fold over 5 weeks causing polyhydramnios and cardiac and placental enlargement. Thermocoagulation was performed at 18 weeks' gestation by passing an insulated electric wire through an 18 gauge needle placed close to the feeding vessels of the tumour at its neck. Blood supply to the tumour was successfully reduced. However, fetal death was diagnosed 2 days after the procedure. We speculate that it may be safer to limit the extent of coagulation in one attempt but to repeat the procedure at a later stage when necessary.     

Clinicopathologic and prognostic significance of the histologic activity of noncancerous liver tissue in hepatitis B virus-associated hepatocellular carcinoma

We prospectively studied 66 patients infected with the hepatitis B virus who underwent liver resection for hepatocellular carcinoma (HCC) to evaluate the influence of the histologic activity of noncancerous liver tissue on clinicopathologic features and prognosis. Based on the histologic activity index (HAI) score of nontumorous liver tissue, patients were classified into 3 groups: mild, moderate, or severe hepatitis. Overall, higher HAI scores were more frequent in patients with poorer liver function: lower serum albumin levels and higher indocyanine green retention at 15 minutes. Moreover, patients with moderate hepatitis had more frequent venous invasion, and the tumor size decreased with increasing HAI scores. Similar results were observed when the fibrosis category was excluded in the calculation of HAI scores. The overall or disease-free survival rates did not differ significantly among the 3 groups of patients. However, higher fibrosis scores were associated significantly with shorter disease-free survival rates. HAI scores correlated significantly with certain clinicopathologic features. In patients with hepatitis B-related HCC, a higher fibrosis score in the nontumorous liver tissue, but not histologic hepatitic activity, seems to be a significant factor predisposing to shorter survival.     

Adolescent suicide in Hong Kong during 1980-2000

Analyses of adolescent suicide statistics in Hong Kong for the period 1980 to 2000 revealed several phenomena. First, while adolescent suicide rates (10-24 age group) in Hong Kong were relatively stable for the period under study, there was a gradual rising trend where adolescent suicide rates in the 1990s were higher than those in the 1980s. Second, suicide rates for adolescents aged 10-24 were lower than those of other adult age groups. Third, while adolescent suicide rates in Hong Kong were lower than those reported in some English-speaking countries and Mainland China, the figures were higher than those reported in Taiwan. Fourth, suicide rates among teenagers in early adolescence were lower than those among adolescents in late adolescence. Fifth, although male adolescent suicide rates were in general higher than female adolescent suicide rates (10-24 age group), gender differences in suicide rates appeared to be moderated by age. Sixth, there was a gradual rising trend in adolescent proportional mortality rates for suicide in the 1990s. Seventh, proportional mortality rates for suicide among teenagers in early adolescence were lower than those among adolescents in late adolescence. Finally, while jumping from a height was a common method of adolescent suicide, there was a rising trend of using other methods such as taking drugs, hanging and charcoal burning. The observed adolescent suicide phenomena are discussed with reference to the socio-cultural context of Hong Kong.     

Use of bisphosphonate to manage avulsion fracture of tibial tuberosity with underlying angiomatosis: a case report

An unusual case of avulsion fracture of the tibial tuberosity with underlying angiomatosis in a middle-aged man is described, with particular emphasis on the successful use of bisphosphonate in its treatment and the value of serial dual energy X-ray absorptiometry in its subsequent disease monitoring. This case illustrates the importance of careful correlation of the clinical, radiological, and histological findings in the management of skeletal tumour and tumour-like lesions. The differential diagnosis of osteolysis with vascular ectasia is discussed.     

Hospital and community-based care for patients with chronic schizophrenia in Hong Kong

Background: There have been few studies on the impact of de-institutionalization on psychiatric patients' lives in Chinese culture. The objectives of the present study were: (1) to compare quality of life (QOL) of Chinese patients with schizophrenia living in three different treatment settings (hospital, long-stay care home and half-way house) in Hong Kong, and (2) to identify factors associated with patients' subjective well-being. Method: A matched-group design was used. Subjects (n = 204) living in the three treatment settings were matched according to age, sex, educational level, marital status, length of psychiatric illness and number of previous psychiatric admissions. Multiple measures for the evaluation of QOL included the Satisfaction With Life Scale (SWLS), WHO Quality of Life Measure-Abbreviated version-Hong Kong (WHOQOL-BREF-HK), Life Event List (LEL) and the Global Assessment Scale (GAS). Psychiatric symptoms were evaluated with the Brief Psychiatric Rating Scale (BPRS). Results: Significant differences in objective QOL indices (global level of functioning, number of life events and income) between subjects staying in hospital and community-based residential services were found in favour of the less restrictive community settings. However, with respect to global life satisfaction, subjects preferred the more secure settings despite their restrictiveness. Predictors of subjective well-being were educational level, negative life events and the BPRS items of somatic concern, anxiety and guilt feelings. The impact of negative life events on subjective well-being decreased over time. Conclusion: In a cohort of Chinese patients with chronic schizophrenia, community-based treatment settings had a positive impact on objective QOL indices but not on subjective well-being. Negative life events, education level, and the BPRS items of somatic concern, anxiety and guilt feelings were predictors of subjective well-being which seemed to adapt to external circumstances over time. Accepted: 1 October 2002 Correspondence to Dr. G. S. Ungvari     

Primary CD56 positive lymphomas of the gastrointestinal tract

BACKGROUND: Primary CD56 positive lymphoma of the gastrointestinal (GI) tract is rare. Genotypically, these tumors can be classified into natural killer (NK)-like T-cell lymphoma or NK cell lymphoma by the presence or absence of T-cell receptor (TCR) gene rearrangement. However, they have a considerable degree of morphologic and immunophenotypic overlap, making a definitive diagnosis difficult. METHODS: The clinicopathologic features of three patients with primary CD56 positive lymphoma of the small and large bowel are presented. This is followed by a review of the English literature from 1966 to the present. RESULTS: All patients had CD56 positive/CD3epsilon positive disease on paraffin section. Two patients were positive for Epstein-Barr virus-encoded early nuclear RNAs (EBER) according to in situ histochemistry results and were negative for TCR gene rearrangement, consistent with primary NK lymphoma of the GI tract. The other patient was EBER negative with rearranged TCR, consistent with NK-like T-cell lymphoma. There was no clinical or histologic evidence of enteropathy in any of the patients. The major presenting symptoms included fever, weight loss, and intestinal perforation. All patients died between 1 week and 6 months after diagnosis despite undergoing surgery and intensive chemotherapy. CONCLUSIONS: These results, together with a literature review, suggest that primary NK cell lymphoma of the GI tract may be considered a distinct clinicopathologic entity. Both primary NK and NK-like T-cell lymphoma pursue an aggressive clinical course. EBER and TCR gene rearrangement are useful in distinguishing NK cell lymphoma from NK-like T-cell lymphoma, particularly when frozen tissue is not available for immunophenotyping.     

Lace-like enhancement pattern of osteosarcoma of rib and liver metastasis in CT scans

The rib is an uncommon site of osteosarcoma. With the use of adjuvant chemotherapy and aggressive surgical resection of the metastatic pulmonary lesions, extrapulmonary metastases are becoming more clinically evident. Primary rib osteosarcoma with extrapulmonary metastasis is exceedingly rare. A case is reported, showing that the pattern of metastasis of rib osteosarcoma is similar to that of primary bone osteosarcoma. The liver metastasis occurred after resection of the metastatic pulmonary lesions. A CT scan of the primary rib lesion and liver metastasis both showed a lace-like enhancement pattern, its histological appearance corresponding with neoplastic osteoid. With the increasing use of CT abdomen for localization of extrapulmonary metastases, lace-like enhancement may be seen more readily in the future.     

The cytokine response to physical activity and training

Cytokines are soluble glycoproteins that are produced by and mediate communication between and within immune and nonimmune cells, organs and organ systems throughout the body. Pro- and anti-inflammatory mediators constitute the inflammatory cytokines, which are modulated by various stimuli, including physical activity, trauma and infection. Physical activity affects local and systemic cytokine production at different levels, often exhibiting striking similarity to the cytokine response to trauma and infection. The present review examines the cytokine response to short term exercise stress, with an emphasis on the balance between pro- and anti-inflammatory mechanisms and modulation of both innate and specific immune parameters through cytokine regulation. The effects of long term exercise on cytokine responses and the possible impact on various facets of the immune system are also discussed, with reference to both cross-sectional and longitudinal studies of exercise training. Finally, the validity of using exercise as a model for trauma and sepsis is scruti- nised in the light of physiological changes, symptomatology and outcome, and limitations of the model are addressed. Further studies, examining the effect of exercise, trauma and infection on novel cytokines and cytokine systems are needed to elucidate the significance of cytokine regulation by physical activity and, more importantly, to clarify the health implications of short and long term physical activity with respect to overall immune function and resistance to infection.