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An estimation of the effective plume-chimney height above a forced draft, air-cooled heat exchanger operating under natural convection has been carried out by employing Chilton-Colburn and Reynolds analogies of natural convection heat transfer on a flat plate to calculate the differential pressure in driving entrained air from the surrounding air. The results show that the Chilton-Colburn analogy performs closely with the Nusselt number–Equivalence method previously used by Chu [1] and renders support for its applicability. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the relation between hepatitis C virus (HCV) antibody profiles and response to therapy of chronic HCV infection of genotype 1b. Materials and Methods: Quantitative assays of antibody response to HCV antigens were performed sequentially using immunoblot confirmatory assays in 25 patients with genotype 1b chronic hepatitis C who received a 24-week course of interferon and ribavirin therapy. Results: 12 patients had a sustained response (group A), and 13 did not (group B). Serum titers of HCV RNA were significantly higher in group B than in group A (p = 0.02). Pretreatment antibody reactivity to core, N53, N54, and N55 antigens did not differ significantly between the two groups, but group A had significantly higher titers of anti-E2/NS1 than group B (p = 0.04). Sustained response was noted in none of seven patients with HCV RNA > 106 copies/ml, but did occur in 12 of 18 patients with HCV RNA < 106 copies/ml (p < 0.01). Among the latter, all seven patients with anti- E2/NS1 had sustained responses, as did five (45%) of 11 without (p = 0.04). Antibody profiles changed little or not at all at the end of treatment or at 6 months after treatment in both groups. Conclusion: In chronic hepatitis C of genotype 1b, patients with HCV RNA > 106 copies/mI respond poorly to therapy compared to those with HCV RNA < 106 copies/mL Among the latter, the presence of pretreatment anti-E2/NS1 correlated with sustained response. Quantitative assay of antibody response to HCV antigens at the end of treatment had no additional value to predict a sustained response. [ABSTRACT FROM AUTHOR]

Chan MHM, Wong VWS, Wong CK, Chan PKS, Chu CM, Hui DSC, Suen MWM, Sung JJY, Chung SSC, Lam CWK (The Chinese University of Hong Kong, NT; United Christian Hospital, Kowloon; and Alice Ho Miu Ling Nethersole Hospital, NT, Hong Kong). Serum LD1 isoenzyme and blood lymphocyte subsets as prognostic indicators for severe acute respiratory syndrome. J Intern Med 2004; 255: 512–518. The pathophysiology of severe acute respiratory syndrome (SARS) is at present poorly understood, but advanced age and serum total lactate dehydrogenase (LD) activity >300 U L−1 have been associated with adverse clinical outcomes. Blood leucocytes and lymphocyte subsets were reported to decrease, respectively, in 47% and up to 100% of 38 patients in Beijing. However, their prognostic implications have not been thoroughly investigated. To investigate serum total LD, LD isoenzymes, and other parameters including blood lymphocyte subsets as prognostic indicators in SARS patients for adverse clinical outcomes in terms of admission to intensive care unit (ICU) and death. Retrospective analysis. A total of 109 patients with a clinical diagnosis of SARS according to the modified World Health Organization case definition of SARS were recruited from two major acute hospitals in Hong Kong. They were either involved in the initial outbreak of SARS, or cases from the community outbreak of Amoy Gardens between 10 March and 5 May 2003. The clinical diagnosis was subsequently confirmed by serological test and/or molecular analysis. Serum total LD and LD isoenzyme activities, complete blood picture with total leucocyte count and differential counts, absolute counts of CD3+, CD4+, CD8+, natural killer cells and B lymphocytes were measured daily upon admission. Receiver operating characteristic curve analysis was used to determine and compare different cut-offs for various biochemical and immunological parameters at peak serum total LD concentration in predicting adverse clinical outcomes. Of a total of 109 patients, 41 were admitted to ICU and 42 died. Of 42 fatal patients, 24 died in ICU and 18 died in general medical wards. Age was found to be an independent prognostic indictor for death with an area under curve ( AUC) of 0.96 [95% confidence interval (CI) = 0.90–0.99] but not for admission to ICU [ AUC = 0.61 (CI = 0.51–0.70)]. Whilst serum total LD could only achieve AUC of 0.68 (CI = 0.59–0.77) for predicting death, LD1 isoenzyme was found to be the best biochemical prognostic indicator with AUC of 0.84 (CI = 0.75–0.90), sensitivity of 62% (CI = 46–76%), specificity of 93% (CI = 83–98%) at cut-off activity of ≥80 U L−1. CD3+, CD4+, CD8+ and natural killer cell counts were promising immunological prognostic indicators for predicting admission to ICU with AUC of 0.94 (CI = 0.86–0.98), 0.91 (CI = 0.81–0.96), 0.93 (CI = 0.85–0.98), and 0.87 (CI = 0.76–0.94), respectively. Apart from age, serum LD1 activity was the best prognostic indicator for predicting death in patients with SARS compared with serum total LD activity, haemoglobin concentration, leucocyte and lymphocyte counts. Its release could possibly be from blood erythrocytes and body tissues other than the myocardium. Blood CD3+, CD4+, CD8+ and natural killer cell counts were found to be good prognostic indicators for predicting admission to ICU in patients with SARS compared with age, leucocyte count and LD isoenzymes. The suppressed CD3+, CD4+, CD8+, and natural killer cell counts were also implicated in the pathophysiology of SARS. Patients with increased serum LD1 should be closely monitored to ensure prompt management, and preparation for admission to ICU could be planned ahead for patients with suppressed lymphocyte subsets. [ABSTRACT FROM AUTHOR]

Discusses the prognosis, outcome and sequelae of SARS. Considerable morbidity and mortality in the acute phase of SARS; Worldwide fatality rate; Limited published data on the sequelae of SARS; Clinical follow-up of patients who recovered from SARS; Lung function testing; Detection of mild decrease in carbon monoxide diffusing capacity.

Reports seven cases of Pneumocystis jiroveci pneumonia (PcP) manifesting as immunorestitution disease (IRD) in HIV-negative immunosuppressed hosts in Hong Kong. Clinical manifestations of PcP; Patient characteristics; Definition of IRD; Clinical manifestation of PcP as a form of IRD; Detection of an upsurge of lymphocyte counts.