FEV3, FEV6 and their derivatives for detecting airflow obstruction in adult Chinese.

BACKGROUND: Forced expiratory volume in 3 seconds (FEV(3)) and 6 seconds (FEV(6)) could complement FEV(1) and forced vital capacity (FVC) for detecting airflow obstruction. OBJECTIVE: To compare FEV(1)/ FEV(6) and FEV(3)/FVC with FEV(1)/FVC in the detection of airflow obstruction. METHOD: Previous lung function data were re-analysed to establish reference values for FEV(3) and FEV(6). Data from a separate cohort of male smokers were used as test set. FEV(1), FEV(3), FEV(6), FVC, FEV(1)/FVC, FEV(1)/ FEV(6) and FEV(3)/FVC were regressed against age, standing height, weight and body mass index, and the mean and 95% confidence intervals for the lower limit of normal (LLN) values for these parameters were determined. RESULTS: The percentage of smokers with airflow obstruction in the test population using FEV(1)/FVC < LLN was 15.0%, while using FEV(1)/ FEV(6) < LLN and FEV(3)/FVC < LLN they were respectively 18.5% and 18.1%. Using FEV(1)/FVC < LLN as reference, the sensitivity and specificity of FEV(1)/ FEV(6) < LLN in identifying airflow obstruction were 82.3% and 92.8%, while those for FEV(3)/FVC < LLN were 78.5% and 92.6%; the positive and negative predictive values were 67% and 96.7% for FEV(1)/ FEV(6) < LLN and 65.3% and 96% for FEV(3)/FVC < LLN. CONCLUSION: FEV(3)/FVC < LLN and FEV(1)/ FEV(6) < LLN are comparable to FEV(1)/FVC < LLN for detecting airflow obstruction. FEV(3)/FVC < LLN could be useful in screening for airflow obstruction, while FEV(1)/ FEV(6) < LLN is useful in detecting airflow limitation in the elderly or in subjects with severe airflow obstruction.

Comparison of circumferential resection margin clearance criteria with survival after surgery for cancer of esophagus.

BACKGROUND: Circumferential resection margin (CRM) is widely recognized as an important prognostic factor in esophageal cancer. The aim of this study was to evaluate the clinical significance of CRM according to the current criteria of the Royal College of Pathologists (RCP) and the College of American Pathologists (CAP). METHODS: Patients (115) who underwent esophagectomy between 2000 and 2006 were included in this retrospective study. Factors such as neo-adjuvant therapy, site, histological type, size, and lymph node involvement were tested to determine predictability of CRM involvement. Along with these, age, sex, CRM, and adjuvant therapy were analyzed to determine influence on survival. RESULTS: On the basis of CRM, patients were divided into three groups (involved, 0.1-1 mm and >1mm). Size (T) was the only factor strongly predictive of CRM involvement (P < 0.001). Size (T; P = 0.04) and lymph node involvement (N; P = 0.0003) were found to significantly influence overall survival (OS). When patients with CRM (involved and 0.1-1mm) were compared with those with CRM > 1 mm, OS was significantly prolonged in the latter (P = 0.02). CONCLUSION: This study appears to lend credence to the RCP criteria for definition of CRM over the CAP criteria.

Elevated plasma adiponectin levels in patients with chronic obstructive pulmonary disease.

BACKGROUND: Adiponectin is an anti-inflammatory adipokine that may play a role in chronic obstructive pulmonary disease (COPD) pathogenesis. OBJECTIVE: To investigate the relationship between adiponectin, interleukin (IL) 6, IL-8 and C-reactive protein (CRP) and COPD by evaluating these biomarkers in ever-smokers with or without the disease. METHOD: Plasma levels of adiponectin, IL-6, IL-8 and CRP were measured using commercially available kits in COPD patients (n = 71), healthy ever-smokers (n = 62) and non-smokers (n = 51). RESULTS: There were significant increases in plasma adiponectin, IL-6 and CRP in COPD patients (median [IQR] 4.39 microg/ml [2.68-6.98], 4.19 pg/ml [<2.40-6.40], 8.75 mg/l [4.26-40.63], respectively) compared to healthy ever-smokers (1.90 microg/ml [0.86-2.86], <2.40 pg/ml [<2.40-2.77], 3.71 mg/l [1.97-10.37 mg/l], respectively, P < 0.001) and non-smokers (1.76 microg/ml [1.34-2.52], <2.40 pg/ml [<2.40-2.78], 3.12 mg/l [2.11-5.71], respectively, P < 0.001). COPD patients had lower plasma IL-8 levels than healthy ever-smokers. Among ever-smokers with or without COPD, plasma adiponectin, IL-6 and CRP levels were inversely correlated with forced expiratory volume in 1 second (% predicted) after adjustment for age, body mass index, smoking status and pack-years. CONCLUSION: Our findings suggest that in COPD patients, adiponectin might be associated with COPD pathogenesis.

Emerging occupational lung infections.

Recent experiences of emerging infections, such as severe acute respiratory syndrome (SARS) and avian influenza (H5N1), have highlighted the risks of serious pulmonary infections from occupational exposures. Occupationally acquired human immunodeficiency virus (HIV) infection could also result in life-threatening, opportunistic lung infections as a result of host immunosuppression. These three occupationally acquired infections are major public health problems that carry with them enormous economic and societal implications. The present review discusses their microbiology, epidemiology and mode of transmission, clinical features, treatment and, more importantly, prevention. Health care workers (HCWs), who are a valuable health care resource especially in the developing nations, are at high risk for acquiring these diseases. Drugs for the treatment of HIV infection are expensive and not widely available in the developing world where they are most needed. As there is no well-recognised effective treatment for SARS and avian influenza, prevention of infection is most important. HCWs should be aware of occupationally acquired infections and know how to protect themselves. Regular training should be provided by all health care institutions on infection control measures and the use of personal protective equipment.

Polymorphisms in manganese superoxide dismutase and catalase genes: functional study in Hong Kong Chinese asthma patients.

BACKGROUND: Reactive oxygen species may contribute to the pathogenesis of asthma. Functional genetic polymorphisms of antioxidant enzymes, superoxide dismutase (SOD) and catalase are good candidates for asthma susceptibility. OBJECTIVE: To investigate the association of the manganese-containing form of SOD (MnSOD) gene at amino acid position 16 (Val16Ala) and catalase gene in the promoter at A-21T and C-262T polymorphisms and asthma in a Hong Kong Chinese population. METHODS: The association study was conducted in a case-control design in asthma patients (n=251) and healthy controls (n=316) by genotyping. The functional significance was assessed by determining erythrocyte SOD and catalase activity. RESULTS: The Val allele of MnSOD at Val16Ala and the A allele of catalase gene at A-21T were not different between patients and controls, while the C allele of catalase gene at C-262T was found to be significantly different between patients and controls (P=0.033). The less frequent variant of catalase gene (-262T) was found to be protective from the development of asthma in a Hong Kong Chinese non-smoking population (adjusted odds ratio=0.35, 0.15-0.85; P=0.017). Asthma patients had elevated erythrocyte SOD and catalase activities in comparison with healthy controls (P<0.01). However, their activities were not associated with different genotypes within healthy controls or asthma patients. CONCLUSION: This is the first report showing that SOD and catalase functional activities are not associated with their respective genetic polymorphisms but related to the presence of asthma in a Hong Kong Chinese population.

Lung cancer epidemiology and risk factors in Asia and Africa.

In industrialised countries, lung cancer is the most common form of cancer among males and it is growing among females. For both sexes, rates reflect smoking behaviours. The pattern appears to be different in Asia, particularly in China, where lung cancer rates in men reflect high smoking rates but high rates among non-smoking women appear to be related to other factors. The incidence of lung cancer is low in most African countries, but it is increasing. In addition to tobacco smoking, a number of etiological factors have been identified for lung cancer: indoor exposure to environmental tobacco smoke, cooking oil vapour, coal burning, or radon, outdoor air pollution and occupational exposure to asbestos and other carcinogens. Recent studies have shown that dietary factors may be important, with high consumption of vegetables and fruits being protective while preserved food and fatty food are harmful, and certain infections such as Mycobacterium tuberculosis, human papilloma virus and Microsporum canis are associated with a high risk of lung cancer. Among non-smokers, the probable role of genetic predisposition in lung cancer by increasing the individual's susceptibility to environmental carcinogens is currently being studied actively. As the single most important cause for lung cancer is tobacco smoke and, with increased sales, a major epidemic is predicted for both Asia and Africa, all health care professionals, government health authorities and national and international health organisations must join in a concerted effort against tobacco.

Over-expression of interleukin 10 in mucosal T cells of patients with active ulcerative colitis.

Ulcerative colitis (UC), a chronic inflammatory bowel disease, exhibits pronounced increase of T lymphocytes in the inflamed mucosa. To understand the role of intestinal T lymphocytes in the pathogenesis of UC their cytokine production in the mucosa was analysed. Intestinal T lymphocytes of UC, Crohn's disease and control patients were analysed for cytokine mRNA levels by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) directly after isolation without in vitro stimulation. Frequencies of cytokine positive cells were determined in UC and control colon by immunomorphometry. T lymphocytes in normal colon expressed interleukin (IL)-2, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta1, but not IL-4, IL-5 or IL-10. In UC, a highly significant increase in IL-10 mRNA levels in T lymphocytes and an increased frequency of IL-10 positive cells was seen in colon. IL-10 mRNA levels were also elevated in T lymphocytes of the non-inflamed ileum and correlated with disease activity at both locations. CD4+ T lymphocytes were the major source of IL-10 mRNA. IL-2, IFN-gamma and TNF-alpha mRNA levels were decreased in colonic T lymphocytes, and virtually no IL-2, IFN-gamma, TNF-alpha or TGF-beta positive cells were detected in basal lymphoid aggregates. However, scattered IL-10 positive cells were found here. Lamina propria outside the aggregates contained IL-10-, IFN-gamma, TNF-alpha and TGF-beta but not IL-2 positive cells. T cells of UC patients did not express IL-4 or IL-5. Taken, together the data suggest a generalized activation of IL-10 producing CD4+ T cells along the intestine of UC patients. The local environment seems to determine the biological consequences of elevated IL-10.

Extra-pulmonary and pulmonary tuberculosis in Hong Kong.

OBJECTIVE: To compare the characteristics of patients with pulmonary and extra-pulmonary tuberculosis and to describe the organ involvement, diagnosis and treatment of extra-pulmonary tuberculosis. MATERIALS AND METHODS: All patients with a diagnosis of tuberculosis treated by the Hong Kong Government Tuberculosis and Chest Service (Chest Service) in 1996 were studied. RESULTS: Of the 5757 patients treated, 13.7% had extra-pulmonary tuberculosis alone and 8.6% had both extra-pulmonary tuberculosis and pulmonary tuberculosis. Extra-pulmonary tuberculosis was more common in women under 30 and over 75 years of age. Only six patients had human immunodeficiency virus (HIV) infection, of whom two had extra-pulmonary tuberculosis. The most common site of extra-pulmonary involvement was the pleura, followed by the lymph nodes. Miliary tuberculosis occurred in only 2.9%. Lymph node involvement occurred significantly higher in women, while pleural disease was significantly higher in men. The duration of treatment varied according to the site of disease, being shorter (6 months) for those with pleural disease only and >9 months for those with miliary, meningeal, gastrointestinal and genitourinary disease; 80.3% completed treatment at 12 months and 85.5% at 24 months. Of those who completed treatment, 1.4% had a relapse of disease at 24 months follow-up; there was no significant difference between those with pulmonary or extra-pulmonary disease. CONCLUSION: In Hong Kong, extra-pulmonary tuberculosis is common, affecting 22.3% of TB patients, and is unrelated to HIV infection. There are sex differences in the organs most commonly affected. The rate of relapse of disease is low for those who completed treatment, irrespective of the site of involvement.

Characterisation of mucosal lymphoid aggregates in ulcerative colitis: immune cell phenotype and TcR-gammadelta expression.

BACKGROUND AND AIMS: A histopathological feature considered indicative of ulcerative colitis (UC) is the so-called basal lymphoid aggregates. Their relevance in the pathogenesis of UC is, however, unknown. We have performed a comprehensive analysis of the immune cells in these aggregates most likely corresponding to the lymphoid follicular hyperplasia also described in other colitides. METHODS: Resection specimens of UC and normal colon were analysed by immunomorphometry, immunoflow cytometry, and immunoelectron microscopy, using a large panel of monoclonal antibodies. RESULTS: (1) In all cases of UC, colonic lamina propria contained numerous basal aggregates composed of lymphocytes, follicular dendritic cells, and CD80/B7.1 positive dendritic cells. (2) CD4(+)CD28(-) alphabeta T cells and B cells were the dominant cell types in the aggregates. (3) The aggregates contained a large fraction of cells that are normally associated with the epithelium: that is, gammadelta T cells (11 (7)%) and alpha(E)beta(7)(+) cells (26 (13)%). The gammadelta T cells used Vdelta1 and were CD4(-)CD8(-). Immunoelectron microscopy analysis demonstrated TcR-gammadelta internalisation and surface downregulation, indicating that the gammadelta T cells were activated and engaged in the disease process. (4) One third of cells in the aggregates expressed the antiapoptotic protein bcl-2. CONCLUSIONS: Basal lymphoid aggregates in UC colon are a consequence of anomalous lymphoid follicular hyperplasia, characterised by abnormal follicular architecture and unusual cell immunophenotypes. The aggregates increase in size with severity of disease, and contain large numbers of apoptosis resistant cells and activated mucosal gammadelta T cells. The latter probably colonise the aggregates as an immunoregulatory response to stressed lymphocytes or as a substitute for defective T helper cells in B cell activation. gammadelta T cells in the aggregates may be characteristic of UC.

Intraepithelial lymphocytes in human gut have lytic potential and a cytokine profile that suggest T helper 1 and cytotoxic functions.

The functional properties of intraepithelial lymphocytes (IEL) in normal human jejunum, ileum, and colon were investigated. Cytokine mRNA expression in IEL and enterocytes was determined by reverse transcriptase-PCR and IFN-gamma+ IEL by immunohistochemistry. Polyclonal activators were used to study proliferation and IFN-gamma secretion of IEL, and an anti-CD3-mediated redirected cytotoxicity assay was used to determine the lytic potential of IEL. Freshly isolated IEL at all three gut levels expressed mRNA for IL-1 beta, IL-2, IL-8, IFN-gamma, and TNF-alpha. Approximately 10% of IEL produced IFN-gamma, suggesting that IEL are immunologically active in vivo, performing similar functions along the intestine. IEL could be stimulated further in vitro to express IL-10, TNF-beta, and TGF-beta 1, while no Th2-type cytokines were induced, suggesting suppressive and cytolytic functions for IEL. All three jejunal IEL subpopulations (CD4-CD8-TCR-gamma delta+, CD4+TCR-alpha beta+, CD8+TCR-alpha beta+) expressed the same four cytokines, IL-2, IL-8, IFN-gamma, and TNF-alpha, indicating that CD4+TCR-alpha beta+ IEL are Th1 cells and that TCR-gamma delta+ IEL and CD8+TCR-alpha beta+ IEL include cytotoxic effector cells. Indeed, freshly isolated jejunal IEL displayed cytolytic activity. IEL were induced to proliferation by anti-CD3/TCR complex mAbs and leukoagglutinin, but not by Con A. There was no correlation between the magnitude of the proliferative response and the amounts of secreted IFN-gamma. Enterocytes expressed IL-1 beta and IL-8, and sometimes TNF-alpha. Although jejunal enterocytes express HLA-DR and hsp60, Ag presentation by these cells may induce anergy since their cytokine profile is different from that of classical APCs.

Cell- and region-specific expression of biliary glycoprotein and its messenger RNA in normal human colonic mucosa.

The localization of biliary glycoprotein (BGP) and its mRNA in normal colonic mucosa was studied by immunohistochemistry and in situ hybridization. BGP mRNA was confined to columnar epithelial cells and expressed abundantly in the superficial mature cells and at low levels in differentiating cells in the upper crypts. Epithelial expression of BGP coincided with that of BGP mRNA. Ultrastructurally, BGP was localized to microfilaments of the fuzzy coat of the columnar cells at the luminal surface and the upper crypts. Additionally, BGP was found in cryptal caveolated cells. The results are consistent with primary transcriptional regulation of BGP production and suggest that BGP synthesis is controlled by the degree of cytodifferentiation. The fuzzy-coat localization of BGP implies a role in nonspecific defense mechanisms against pathogens.

Expression of carcinoembryonic antigen and nonspecific cross-reacting 50-kDa antigen in human normal and cancerous colon mucosa: comparative ultrastructural study with monoclonal antibodies.

The precise localization of carcinoembryonic antigen (CEA) and non-specific cross-reacting 50-kDa antigen (NCA 50) in normal colon mucosa and colon adenocarcinoma was investigated by using an indirect immunoperoxidase electron microscopic technique with specific monoclonal antibodies. In normal adult colon both antigens were localized to microvesicles and filaments of the "fuzzy coat" on the apical surface of the epithelial cells. In addition, NCA 50 was found in the narrow spaces between adjoining microvilli. Mature columnar cells at the free luminal surface contained most of the antigen positive material. CEA and NCA 50 were also detected as intracellular components of goblet cells. In multilayered tumor glands, the cell surface expression of the antigens was dependent on the position of the tumor cell in the gland. The neoplastic cells showed either a predominant apical labeling or a positive staining of almost the entire cell surface. Some of the neoplastic cells contained CEA in so-called "intracellular lumina." In contrast to normal colon epithelial cells most tumor cells synthesized NCA 50 actively. In normal colonic mucosa, unlike in cancerous tissue, CEA and NCA 50 appear to be released via vesicles formed from the microvillous membrane of mature columnar cells. These results are consistent with the hypothesis that CEA and NCA play a role in the nonspecific defense against microorganisms in the large intestine.

Immunomorphologic studies of human decidua-associated lymphoid cells in normal early pregnancy.

Human decidual lymphocytes from early, normal pregnancy were characterized in situ with respect to ultrastructure and distribution of subsets. The ultrastructure of isolated decidual gamma delta T cells was also studied. CD45+ cells comprised 11 +/- 2% of all decidual cells. The majority were localized in large lymphoid cell clusters (LCC), near endometrial glands, or as intraepithelial lymphocytes (IEL) in glandular epithelium. The major cell populations in LCC were CD56+TCR-gamma delta+ cells, CD56+ cells, TCR-alpha beta+CD4+ cells, and TCR-alpha beta+CD8+ cells. All expressed activation markers (CD45RO, Kp43, and/or HML-1) and MHC class II Ag (HLA-DR, HLA-DP, and/or HLA-DQ). No B cells were found. Almost all IEL were activated TCR-gamma delta+ cells (CD56+ and CD56-). The glandular epithelial cells expressed heat shock protein 60 at the basolateral side facing the TCR-gamma delta+ IEL. Decidual lymphocytes displayed cytoplasmic processes, microvilli, characteristic cytoplasmic granules, and had intimate contact with neighboring cells. Lymphocytes in the outer rim of LCC and the stroma showed signs of cellular movement. Two main morphotypes of gamma delta T cells could be distinguished. One had single microvilli, membrane-bound granules, and nuclear inclusions. The other had many microvilli, nonmembrane-bound granules and cytoplasmic multivesicular bodies. Our data suggest that LCC are centers of immune reactivity where T and NK cells become activated. The activated cells may guard against infections and undue trophoblast invasion and/or be involved in modulating the local maternal immune system toward unresponsiveness against the semiallogeneic fetus.

Fibrosing alveolitis: chest radiography and CT as predictors of clinical and functional impairment at follow-up in 26 patients.

Findings on the original and follow-up chest radiographs and computed tomographic (CT) scans were correlated with clinical and functional parameters in 26 patients with fibrosing alveolitis. Assessment of chest radiographs included determination of a standard profusion score and an average profusion score. The CT assessment included pattern, extent, and distribution of disease. The standard profusion score showed no significant correlation with clinical or functional parameters (P greater than .05). However, the average profusion score of the six lung zones correlated with severity of dyspnea and with static lung volumes (P less than .01). Extent of irregular linear opacities on CT scans correlated with severity of dyspnea and impairment in gas transfer (carbon monoxide-diffusing capacity) (P less than .01). The profusion of ground-glass opacities on the radiograph showed no significant correlations (P greater than .05). The profusion and extent of ground-glass opacities on CT scans correlated with severity of dyspnea, impairment in gas transfer, and reduction in static lung volumes (P less than .01). Ground-glass opacities on CT scans preceded and predicted the development of irregular linear opacities on follow-up CT scans and correlated with an increase in the average profusion score of the chest radiograph (P less than .01).