Waist-to-height ratio, body mass index and waist circumference for screening paediatric cardio-metabolic risk factors: a meta-analysis

Waist-to-height ratio (WHtR) is superior to body mass index and waist circumference for measuring adult cardio-metabolic risk factors. However, there is no meta-analysis to evaluate its discriminatory power in children and adolescents. A meta-analysis was conducted using multiple databases, including Embase and Medline. Studies were included that utilized receiver-operating characteristics curve analysis and published area under the receiver-operating characteristics curves (AUC) for adiposity indicators with hyperglycaemia, elevated blood pressure, dyslipidemia, metabolic syndrome and other cardio-metabolic outcomes. Thirty-four studies met the inclusion criteria. AUC values were extracted and pooled using a random-effects model and were weighted using the inverse variance method. The mean AUC values for each index were greater than 0.6 for most outcomes including hypertension. The values were the highest when screening for metabolic syndrome (AUC > 0.8). WHtR did not have significantly better screening power than other two indexes in most outcomes, except for elevated triglycerides when compared with body mass index and high metabolic risk score when compared with waist circumference. Although not being superior in discriminatory power, WHtR is convenient in terms of measurement and interpretation, which is advantageous in practice and allows for the quick identification of children with cardio-metabolic risk factors at an early age.

IL10 receptor is a novel therapeutic target in DLBCLs

Diffuse large B-cell lymphoma (DLBCL) is a biologically and clinically heterogeneous disease with marked genomic instability and variable response to conventional R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy. More clinically aggressive cases of DLBCLs have high level of circulating interleukin 10 (IL10) cytokine and evidence of activated intracellular STAT3 (signal transducer and activator of transcription 3) signaling. We investigated the role of IL10 and its surface receptor in supporting the neoplastic phenotype of DLBCLs. We determined that IL10RA gene is amplified in 21% and IL10RB gene in 10% of primary DLBCLs. Gene expression of IL10, IL10RA and IL10RB was markedly elevated in DLBCLs. We hypothesized that DLBCLs depend for their proliferation and survival on IL10-STAT3 signaling and that blocking the IL10 receptor (IL10R) would induce cell death. We used anti-IL10R blocking antibody, which resulted in a dose-dependent cell death in all tested activated B-cell-like subtype of DLBCL cell lines and primary DLBCLs. Response of germinal center B-cell-like subtype of DLBCL cell lines to anti-IL10R antibody varied from sensitive to resistant. Cells underwent cell cycle arrest, followed by induction of apoptosis. Cell death depended on inhibition of STAT3 and, to a lesser extent, STAT1 signaling. Anti-IL10R treatment resulted in interruption of IL10-IL10R autostimulatory loop. We thus propose that IL10R is a novel therapeutic target in DLBCLs.

Developments in early intervention for psychosis in Hong Kong

The year 2011 marked the 10-year milestone of early intervention for psychosis in Hong Kong. Since 2001, the landscape of early psychosis services has changed markedly in Hong Kong. Substantial progress has been made in the areas of early intervention service implementation, knowledge generation, and public awareness promotion. Favourable outcomes attributable to the early intervention service are supported by solid evidence from local clinical research studies; early intervention service users showed improved functioning, ameliorated symptoms, and decreased hospitalisation and suicide rates. Continued development of early intervention in Hong Kong over the decade includes the introduction and maturation of several key platforms, such as the Hospital Authority Early Assessment Service for Young People with Psychosis programme, the Psychosis Studies and Intervention Unit by the University of Hong Kong, the Hong Kong Early Psychosis Intervention Society, the Jockey Club Early Psychosis Project, and the postgraduate Psychological Medicine (Psychosis Studies) programme. In this paper, we reviewed some of the major milestones in local service development with reference to features of the Hong Kong mental health system. We describe chronologically the implementation and consolidation of public early intervention services as well as recent progresses in public awareness work that are tied in with knowledge generation and transfer, and outline the prospects for early intervention in the next decade and those that follow.

Comprehensive gene expression profiling and immunohistochemical studies support application of immunophenotypic algorithm for molecular subtype classification in diffuse large B-cell lymphoma: a report from the International DLBCL Rituximab-CHOP Consortium Program Study

Gene expression profiling (GEP) has stratified diffuse large B-cell lymphoma (DLBCL) into molecular subgroups that correspond to different stages of lymphocyte development-namely germinal center B-cell like and activated B-cell like. This classification has prognostic significance, but GEP is expensive and not readily applicable into daily practice, which has lead to immunohistochemical algorithms proposed as a surrogate for GEP analysis. We assembled tissue microarrays from 475 de novo DLBCL patients who were treated with rituximab-CHOP chemotherapy. All cases were successfully profiled by GEP on formalin-fixed, paraffin-embedded tissue samples. Sections were stained with antibodies reactive with CD10, GCET1, FOXP1, MUM1 and BCL6 and cases were classified following a rationale of sequential steps of differentiation of B cells. Cutoffs for each marker were obtained using receiver-operating characteristic curves, obviating the need for any arbitrary method. An algorithm based on the expression of CD10, FOXP1 and BCL6 was developed that had a simpler structure than other recently proposed algorithms and 92.6% concordance with GEP. In multivariate analysis, both the International Prognostic Index and our proposed algorithm were significant independent predictors of progression-free and overall survival. In conclusion, this algorithm effectively predicts prognosis of DLBCL patients matching GEP subgroups in the era of rituximab therapy.

Quadratic Nonlinear Optical Properties of Polymeric Organic Materials

We discuss our rational approach to incorporate optically nonlinear molecules into polymeric and cross-linked materials through the use of isocyanate-hydroxy coupling chemistry. Thin film fabrication, optical loss, poling, second harmonic generation, and electro-optic properties are discussed.

Narrow-band imaging in the evaluation of villous morphology: a feasibility study assessing a simplified classification and observer agreement

BACKGROUND AND STUDY AIMS

To determine the utility of narrow-band imaging with optical magnification (NBI-Z) in the evaluation of villous morphology.

PATIENTS AND METHODS

Patients considered at risk of having celiac disease were invited. After standard endoscopy, they underwent further evaluation with NBI-Z which was digitally recorded. Targeted biopsies of each area videoed with NBI-Z were performed and tissue sent for histopathological analysis. Two expert endoscopists then selected the best representative videos (developmental phase). Next, 41 representative images of these videos were classified as follows: villous patterns present (N) or absent (A). Images showing absence of villi were then classified as cerebriform (C) or flat (F), corresponding to partial or total villous atrophy respectively. Three NBI-Z-naïve endoscopists then graded the videos. They underwent an interactive training session (learning phase) with video and images from a digital library before embarking on the actual assessment. To test for reproducibility, all videos were randomly reordered and graded again after a week.

RESULTS

Forty-one videos (10 celiac disease, 31 normal) from 21 patients (3 celiac disease, 18 normal) were analyzed. The overall sensitivity and specificity in correctly distinguishing the presence or absence of villi were 93.3% and 97.8% respectively, with interobserver and intraobserver agreement (kappa, κ) at 0.82 and 0.86. The sensitivity and specificity in differentiating partial from total villous atrophy were 83.3% and 100%, κ at 0.73 and 0.68 respectively.

CONCLUSIONS

Using a simplified classification, we demonstrated the feasibility of using NBI-Z to detect villous atrophy in patients presenting with suspected celiac disease.

The effects of high-dose esomeprazole on gastric and oesophageal acid exposure and molecular markers in Barrett's oesophagus

BACKGROUND

Acid reflux is often difficult to control medically.

AIM

To assess the effect of 40 mg twice daily esomeprazole (high-dose) on gastric and oesophageal pH and symptoms, and biomarkers relevant to adenocarcinoma, in patients with Barrett's oesophagus (BO).

METHODS

Eighteen patients, treated with proton pump inhibitors as prescribed by their treating doctor, had their therapy increased to high-dose esomeprazole for 6 months.

RESULTS

At entry into the study, 9/18 patients had excessive 24-h oesophageal acid exposure, and gastric pH remained <4 for >16 h in 8/18. With high-dose esomeprazole, excessive acid exposure occurred in 2/18 patients, and gastric pH <4 was decreased from 38% of overall recording time and 53% of the nocturnal period to 15% and 17%, respectively (P < 0.001). There was a reduction in self-assessed symptoms of heartburn (P = 0.0005) and regurgitation (P < 0.0001), and inflammation and proliferation in the Barrett's mucosa. There was no significant change in p53, MGMT or COX-2 expression, or in aberrant DNA methylation.

CONCLUSIONS

High-dose esomeprazole achieved higher levels of gastric acid suppression and control of oesophageal acid reflux and symptoms, with significant decreases in inflammation and epithelial proliferation. There was no reversal of aberrant DNA methylation.

Immunophenotypic analysis of the Kaposi sarcoma herpesvirus (KSHV; HHV-8)-infected B cells in HIV+ multicentric Castleman disease (MCD)

AIMS

Kaposi sarcoma herpesvirus (KSHV) is aetiologically related to Kaposi sarcoma, classical and extracavitary primary effusion lymphoma (PEL; EC-PEL) and multicentric Castleman disease (MCD), entities preferentially occurring in HIV-infected individuals. Characterization of HIV-associated PELs/EC-PELs suggests that the KSHV-infected malignant cells originate from a pre-terminal stage of B-cell differentiation. However, only limited phenotypic studies have been performed on HIV+ MCD, including for PR domain containing 1 with zinc finger domain/B lymphocyte-induced maturation protein 1 (PRDM1/BLIMP1), a key regulator of terminal B-cell differentiation. The aim was to characterize KSHV-infected cells in 17 cases of HIV+ MCD.

METHODS AND RESULTS

Double immunohistochemistry and immunohistochemistry-in situ hybridization were used to characterize the KSHV-infected cells in MCD; the results were compared with the phenotypic profiles of 39 PELs/EC-PELs and seven PEL cell lines. Whereas the immunophenotype of KSHV-infected cells in MCD and malignant KSHV+ PEL cells was similar (PAX5, Bcl-6-; PRDM1/BLIMP1, IRF4/MUM1+; Ki67+), the MCD KSHV-infected cells differed, as they expressed OCT2, cytoplasmic lambda immunoglobulin; variably expressed CD27; lacked CD138; and were Epstein-Barr virus negative.

CONCLUSIONS

Although both PEL and MCD originate from KSHV-infected pre-terminally differentiated B cells, these findings, with previously reported genetic studies, indicate HIV+ MCD may arise from extrafollicular B cells, whereas PELs may originate from cells that have traversed the germinal centre.

Effects of Multisensory Therapy on Behaviour of Adult Clients with Developmental Disabilities

OBJECTIVES

The objective of this review was to present the best available evidence on the effect of multisensory therapy in adult clients with developmental disabilities on the frequency of challenging behaviour, the frequency of stereotypic self-stimulating behaviour, and the frequency of relaxing behaviour INCLUSION CRITERIA: The review summarised all the relevant studies relating to the multisensory therapy intervention.

TYPES OF PARTICIPANTS

Trials which included adult clients (aged 18-60) diagnosed with mental retardation according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders: IV Classification or those with an Intelligence Quotient < 70 and who stayed in institutions.Types of interventions: Multisensory therapy/ multisensory environment/ SnoezelenTypes of outcomes measures: Outcome measures of interest were challenging behaviour, stereotypic self-stimulating behaviour and relaxing behaviour.Types of studies: This study considered any randomized or quasi-randomized controlled trials that investigated the effectiveness of multisensory therapy on adult clients with developmental disabilities. Due to a limited number of high quality RCT's on this subject, papers using other experimental or observational designs were also included.

SEARCH STRATEGY

Electronic databases were used to search for primary publications. The reference lists and bibliographies of retrieved articles were reviewed to identify research not located through other search strategies.

CRITICAL APPRAISAL

Two reviewers assessed all identified abstracts and full reports were retrieved for all studies that met the inclusion criteria of the review. Studies identified from bibliography searches were assessed on the study title. Methodological quality was assessed by two reviewers using a checklist. Disagreements between reviewers were resolved by discussion with a third reviewer.

DATA EXTRACTION

Data were extracted independently by two reviewers using a data extraction tool. A third reviewer dealt with disagreements.

DATA SYNTHESIS

In all studies percentages of clients in each category and/or change in group mean score for outcomes were reported. If appropriate, results from comparable groups of studies were pooled in statistical meta-analysis using Review Manager Software from the Cochrane Collaboration. Odds ratio (for categorical outcome data) or weighted mean differences (for continuous data) and their 95% confidence intervals were calculated for each analysis. Heterogeneity between combined studies was tested using standard chi-square test. For the purpose of this review, where possible, intention to treat and/or completer analysis were performed. Where statistical pooling was not appropriate or possible, the findings were summarised in narrative form.

RESULTS

130 publications were identified through the various database searches and review of reference list and bibliographies. However, only 15 English publications were included in the review. The present evidence showed that multisensory therapy promoted participants' positive emotions and they reported being happier and more relaxed. Evidence also indicated that participants' had displayed more positive emotions and less negative emotions after therapy sessions.

CONCLUSIONS

This systematic review demonstrated a beneficial effect of multisensory therapy in promoting participants' positive emotions. Out of the 15 reviewed studies, 12 studies had a single treatment group only. While the reviewers acknowledge the difficulty in carrying out randomised controlled trial in people with developmental disabilities and challenging behaviour, the lack of trial-derived evidence makes it difficult to produce a strong conclusion to show the effectiveness of the multisensory therapy.

Prevalence and risk factors of airflow obstruction in an elderly Chinese population

It is common practice to use a forced expiratory volume in one second (FEV(1))/ forced vital capacity (FVC) ratio of <70% as evidence of airflow obstruction. As the FEV(1)/FVC ratio falls with age, the lower limit of normal range (LLN), defined as the bottom 5% in a health reference population, of FEV(1)/FVC ratio has been suggested as a better index to reduce over-diagnosis of chronic obstructive pulmonary disease (COPD), particularly in the elderly. However, there are no large scale studies that focus on the diagnosis of COPD in the elderly based on these definitions. The present prospective epidemiological study involved 1,149 elderly subjects aged > or =60 yrs in the community. Detailed questionnaires, pre- and post-bronchodilator spirometry were performed. In total, 1,008 subjects (mean age 74.2+/-6.4 yrs; 271 males) completed satisfactory spirometry testing. Airflow obstruction was present in 25.9% as defined by the post-bronchodilator FEV(1)/FVC ratio of <70% and in 12.4% defined by the LLN of FEV(1)/FVC ratio. Moderate COPD, at least, was found in 14.0% of patients according to the post-bronchodilator FEV(1)/FVC ratio of <70% and in 8.5% of patients according to LLN of FEV(1)/FVC ratio. In the present elderly Chinese population (mostly females, with low education level and previous exposure to biomass during formative years), the prevalence of chronic obstructive pulmonary disease varied markedly depending on definitions adopted. Further longitudinal studies are needed to determine the precise definition of chronic obstructive pulmonary disease.

Gastric emptying and the organization of antro-duodenal pressures in the critically ill

The motor dysfunctions underlying delayed gastric emptying (GE) in critical illness are poorly defined. Our aim was to characterize the relationship between antro-duodenal (AD) motility and GE in critically ill patients. AD pressures were recorded in 15 mechanically ventilated patients and 10 healthy volunteers for 2 h (i) during fasting, (ii) following an intragastric nutrient bolus with concurrent assessment of GE using the (13)C-octanoate breath test and (iii) during duodenal nutrient infusion. Propagated waves were characterized by length and direction of migration. Critical illness was associated with: (i) slower GE (GEC: 3.47 +/- 0.1 vs 2.99 +/- 0.2; P = 0.046), (ii) fewer antegrade (duodenal: 44%vs 83%, AD: 16%vs 83%; P < 0.001) and more retrograde (duodenal: 46%vs 12%, AD: 38%vs 4%; P < 0.001) waves, (iii) shorter wave propagation (duodenal: 4.7 +/- 0.3 vs 6.0 +/- 0.4 cm; AD: 7.7 +/- 0.6 vs 10.9 +/- 0.9 cm; P = 0.004) and (iv) a close correlation between GE with the percentage of propagated phase 3 waves that were antegrade (r = 0.914, P = 0.03) and retrograde (r = -0.95, P = 0.014). In critical illness, the organization of AD pressure waves is abnormal and associated with slow GE.

Effects of air pollution on asthma hospitalization rates in different age groups in Hong Kong

AIMS

To assess the relationship between levels of ambient air pollutants and hospitalization rates for asthma in Hong Kong (HK).

METHODS

This is a retrospective ecological study. Data of daily emergency hospital admissions to 15 major hospitals in HK for asthma and indices of air pollutants [sulphur dioxide (SO(2)), nitrogen dioxide (NO(2)), ozone (O(3)), particulates with an aerodynamic diameter of <10 microm particulate matter (PM(10)) and 2.5 microm (PM(2.5))] and meteorological variables from January 2000 to December 2005 were obtained from several government departments. Analysis was performed by the generalized additive models with Poisson distribution. The effects of time trend, season, other cyclical factors, temperature and humidity were adjusted. Autocorrelation and overdispersion were corrected.

RESULTS

Altogether, 69 716 admissions were assessed. Significant associations were found between hospital admissions for asthma and levels of NO(2), O(3), PM(10) and PM(2.5). The relative risks (RR) for hospitalization for every 10 microg/m(3) increase in NO(2), O(3), PM(10) and PM(2.5) were 1.028, 1.034, 1.019 and 1.021, respectively, at a lag day that ranged from cumulative lag 0-4 to 0-5. In a multi-pollutant model, O(3) was significantly associated with increased admissions for asthma. The younger age group (0-14 years) tended to have a higher RR for each 10 microg/m(3) increase in pollutants than those aged 15-65 years. The elderly (aged >/=65 years) had a shorter 'best' lag time to develop asthma exacerbation following exposure to pollutants than those aged <65 years.

CONCLUSION

Adverse effects of ambient concentrations of air pollutants on hospitalization rates for asthma are evident. Measures to improve air quality in HK are urgently needed.

EUS-guided tissue sampling: comparison of "dual sampling" (Trucut biopsy plus FNA) with "sequential sampling" (Trucut biopsy and then FNA as required)

BACKGROUND AND STUDY AIMS

Both endoscopic ultrasound- (EUS-) guided tissue sampling techniques, fine-needle aspiration (FNA) and Trucut biopsy, have advantages and limitations. The aim of this study was to develop a strategy of combining these two EUS-guided sampling techniques in order to maximize the diagnostic accuracy and minimize duplication.

PATIENTS AND METHODS

In this multicenter study we performed "dual sampling" (i. e. with both FNA and Trucut biopsy) in 95 patients during phase 1 of the study and "sequential sampling" (i. e. performing FNA only when Trucut biopsy tissue cores were macroscopically inadequate) in 72 patients during phase 2.

RESULTS

During the study period, 167/401 patients referred for EUS-guided sampling were eligible for the study; only solid lesions were included. In 143/167 patients (86 %), sampling was performed via the transesophageal or transgastric routes. When the dual sampling strategy was used, an accurate diagnosis was achieved in 78/95 patients by FNA, compared with 85/95 by Trucut biopsy ( P = 0.21). The combined accuracy of the dual sampling strategy was higher than FNA alone (88/95 vs. 78/95, P = 0.048), but was not significantly higher than Trucut biopsy alone (88/95 vs. 85/95, P = 0.61). Using the sequential sampling strategy, an accurate diagnosis was achieved in 66/72 patients (92 %) compared with 88/95 (93 %) for dual sampling ( P = 1.0), and 8/72 patients (11 %) had to undergo FNA after Trucut biopsy failed to obtain an adequate sample. One patient with mediastinal tuberculosis developed a cold abscess following Trucut biopsy.

CONCLUSION

A sequential sampling strategy, in which EUS-guided Trucut biopsy is attempted first, and FNA performed only when Trucut biopsy fails to obtain a macroscopically adequate sample, achieves a diagnostic accuracy of 92 %, with 11 % of patients requiring both sampling procedures.

Low energy electron storage ring with tunable compaction factor

A low energy electron storage ring is designed to have many desirable properties, such as varying momentum compaction factor, damping partition numbers, favorable betatron tunes for multiturn accumulations, and excellent dynamic aperture. This storage ring can be used for debunching rf linac beams in one turn, for compression of linac pulses, and more importantly for a compact photon source based on inverse Compton scattering of laser beams.

Circumferential and axial distribution of esophageal mucosal damage in reflux disease

The aim of this study was to evaluate the axial and radial distribution of histological markers including hyperplasia of the basal cell layer, elongation of the papillae and dilatation of the intercellular spaces of the squamous epithelium in patients with nonerosive reflux disease compared to controls and to relate this to the macroscopic topography in erosive reflux disease. Two different study populations were included in this report. Endoscopic esophageal biopsies were taken from 21 healthy control subjects and 21 nonerosive reflux disease patients before and after 4 weeks of esomeprazole therapy. Endoscopic still images from 50 erosive reflux disease patients were reviewed for the radial orientation of LA grade A and/or B esophagitis (Los Angeles criteria for grading of reflux esophagitis). The 3 o'clock position of the squamocolumnar junction showed significantly thicker basal cell layer (P=0.011) and more intercellular space dilatation (P=0.01) in nonerosive reflux disease patients compared to the 9 o'clock position. Only a significant difference in dilatation of the intercellular spaces (P=0.018) between nonerosive reflux disease patients and controls were observed in the 3 o'clock region at the squamocolumnar junction, whereas 1-2 cm orally, all three histological criteria differed significantly (P<or=0.01). After treatment, on the contrary, papillary length was significantly less pronounced at the squamocolumnar junction (P<0.01). Endoscopically, erosions were predominantly visualized in the 3 o'clock region (P<0.05). Histological mucosal changes in nonerosive reflux disease patients and visible mucosal erosions in erosive reflux disease patients occur most frequently at the same position, namely in the 3 o'clock quadrant in the distal esophagus. The histological difference between nonerosive reflux disease patients and controls are more distinct 1-2 cm oral to rather than at the squamocolumnar junction. However the effect of therapy is most pronounced at the squamocolumnar junction.

Magnification endoscopy for diagnosis of nonerosive reflux disease: a proposal of diagnostic criteria and critical analysis of observer variability

BACKGROUND AND STUDY AIMS

This study tested the diagnostic value of high-resolution endoscopy for the recognition of subtle diagnostic esophageal mucosal changes in nonerosive reflux disease.

PATIENTS AND METHODS

Ten control subjects and eleven patients with nonerosive reflux disease confirmed by a validated questionnaire, standard endoscopy, and 24-hour pH-metry participated in the study. Still images were collected by high-resolution endoscopes from the distal esophagus in a standardized manner, incorporating iodine staining. Assessments were repeated in the patients with reflux disease after 4 weeks of esomeprazole therapy. Interobserver variability in the recognition of the proposed criteria was initially evaluated by 27 endoscopists using an Internet-based process. After optimisation of image quality the evaluation was repeated face-to-face with six expert endoscopists.

RESULTS

No criterion was identified in either assessment that was sufficiently sensitive and specific to patients with reflux disease to be clinically useful. The kappa value, used to assess interobserver variation, was acceptably high only for invisibility of palisade vessels (0.59). Triangular indentations, apical mucosal breaks, and pinpoint blood vessels at the squamocolumnar junction were identified more frequently in the patients with reflux disease ( P < 0.05). These changes and the invisibility of the palisade vessels were significantly less prevalent in reflux patients after therapy ( P < 0.01).

CONCLUSIONS

Though some distal esophageal mucosal appearances observed with the high-resolution endoscope appeared to be related to nonerosive esophageal mucosal injury, none of these changes proved to be sufficiently sensitive and specific to justify their use as a diagnostic criterion for nonerosive reflux disease.

Mortality from non-malignant respiratory diseases among people with silicosis in Hong Kong: exposure-response analyses for exposure to silica dust

OBJECTIVES

To examine the exposure-response relationships between various indices of exposure to silica dust and the mortality from non-malignant respiratory diseases (NMRDs) or chronic obstructive pulmonary diseases (COPDs) among a cohort of workers with silicosis in Hong Kong.

METHODS

The concentrations of respirable silica dust were assigned to each industry and job task according to historical industrial hygiene measurements documented previously in Hong Kong. Exposure indices included cumulative dust exposure (CDE) and mean dust concentration (MDC). Penalised smoothing spline models were used as a preliminary step to detect outliers and guide further analyses. Multiple Cox's proportional hazard models were used to estimate the dust effects on the risk of mortality from NMRDs or COPDs after truncating the highest exposures.

RESULTS

371 of the 853 (43.49%) deaths occurring among 2789 workers with silicosis during 1981-99 were from NMRDs, and 101 (27.22%) NMRDs were COPDs. Multiple Cox's proportional hazard models showed that CDE (p = 0.009) and MDC (p<0.001) were significantly associated only with NMRD mortality. Subgroup analysis showed that deaths from NMRDs (p<0.01) and COPDs (p<0.05) were significantly associated with both CDE and MDC among underground caisson workers and among those ever employed in other occupations with high exposure to silica dust. No exposure-response relationship was observed for surface construction workers with low exposures. A clear upward trend for both NMRDs and COPDs mortality was found with increasing severity of radiological silicosis.

CONCLUSION

This study documented an exposure-response relationship between exposure to silica dust and the risk of death from NMRDs or COPDs among workers with silicosis, except for surface construction workers with low exposures. The risk of mortality from NMRDs increased significantly with the progression of International Labor Organization categories, independent of dust effects.

Association between air pollution and general practitioner visits for respiratory diseases in Hong Kong

BACKGROUND

Few studies have explored the relation between air pollution and general practitioner (GP) consultations in Asia. Clinic attendance data from a network of GPs were studied, and the relationship between daily GP consultations for upper respiratory tract infections (URTI) and non-URTI respiratory diseases and daily air pollutant concentrations measured in their respective districts was examined.

METHODS

A time series study was performed in 2000-2002 using data on daily patient consultations in 13 GP clinics distributed over eight districts. A Poisson regression model was constructed using the generalised additive model approach for each GP clinic, and associations with daily numbers of first visits for URTI were sought for daily concentrations of the following air pollutants: SO(2), NO(2), O(3), PM(10,) and PM(2.5). A summary relative risk of first visits to the GP for URTI per unit increase in concentration for each air pollutant was derived using a random effect model. First visits for non-URTI respiratory diseases were analysed in three GP clinics.

RESULTS

Significant associations were observed between first visits for URTI and an increase in the concentrations of NO(2), O(3), PM(10), and PM(2.5). The excess risk was highest for NO(2) (3.0%), followed by O(3) (2.5%), PM(2.5) (2.1%), and PM(10) (2.0%). Similar associations with these air pollutants were found for non-URTI respiratory diseases.

CONCLUSIONS

These results provide further evidence that air pollution contributes to GP visits for URTI and non-URTI respiratory diseases in the community.

Antro-pyloro-duodenal motor responses to gastric and duodenal nutrient in critically ill patients

BACKGROUND

Gastric emptying is frequently delayed in critical illness which compromises the success of nasogastric nutrition. The underlying motor dysfunctions are poorly defined.

AIMS

To characterise antro-pyloro-duodenal motility during fasting, and in response to gastric and duodenal nutrient, as well as to evaluate the relationship between gastric emptying and motility, in the critically ill.

SUBJECTS

Fifteen mechanically ventilated patients from a mixed intensive care unit; 10 healthy volunteers.

METHODS

Antro-pyloro-duodenal pressures were recorded during fasting, after intragastric administration (100 ml; 100 kcal), and during small intestinal infusion of liquid nutrient (6 hours; 1 kcal/min). Gastric emptying was measured using a (13)C octanoate breath test.

RESULTS

In healthy subjects, neither gastric nor small intestinal nutrient affected antro-pyloro-duodenal pressures. In patients, duodenal nutrient infusion reduced antral activity compared with both fasting and healthy subjects (0.03 (0-2.47) waves/min v 0.14 (0-2.2) fasting (p = 0.016); and v 0.33 (0-2.57)/min in healthy subjects (p = 0.005)). Basal pyloric pressure and the frequency of phasic pyloric pressure waves were increased in patients during duodenal nutrient infusion (3.12 (1.06) mm Hg; 0.98 (0.13)/min) compared with healthy subjects (-0.44 (1.25) mm Hg; p<0.02 after 120 minutes; 0.29 (0.15)/min; p = 0.0002) and with fasting (-0.06 (1.05) mm Hg; p<0.03 after 160 minutes; 0.49 (0.13)/min; (p = 0.0001). Gastric emptying was delayed in patients (gastric emptying coefficient 2.99 (0.2) v 3.47 (0.1); p = 0.015) and inversely related to the number of pyloric pressure waves (r = -0.563, p = 0.029).

CONCLUSIONS

Stimulation of pyloric and suppression of antral pressures by duodenal nutrient are enhanced in the critically ill and related to decreased gastric emptying.

Radial distribution of dilated intercellular spaces of the esophageal squamous epithelium in patients with reflux disease exhibiting discrete endoscopic lesions

INTRODUCTION

Dilatation of intercellular spaces of the esophageal squamous epithelium has been suggested as a marker of early acid reflux-induced damage. This change is a potentially useful addition to histomorphological changes that represent so called minimal endoscopic lesions. We have assessed dilatation of intercellular spaces with regard to: (1) interobserver variability, and (2) whether the incidence of this varies between 'red streaks' and the adjacent normal looking squamous epithelium.

METHODS

Esophageal biopsies from 44 patients with chronic gastro-esophageal reflux (GERD) were evaluated. At endoscopy, these patients had one or more red streaks on the tops of the mucosal folds in the distal esophagus. Biopsies were taken from the red streaks and from the normal-appearing mucosa 1 cm lateral to the red streaks. Biopsies were assessed in a blinded fashion by two independent pathologists (MV & RF). Criteria for assessing intercellular space dilatation were evaluated and agreed on prior to the study.

RESULTS

Good interobserver agreement was recorded (kappa = 0.82 at the streaks and 0.77 for the control tissues) for absence/presence of intercellular space dilatation. Red streak and control biopsies differed significantly (p = 0.0001), with respect to presence of dilated intercellular spaces, with 90.5 % of the former demonstrating this as present compared to 56.1% in the controls.

CONCLUSION

This study supports the concept that esophageal mucosal minimal changes due to reflux is localised and that dilatation of intercellular spaces is an early sign of reflux-induced epithelial damage. The low interobserver variability in the assessment of intercellular space dilatation suggests that this may be a useful variable for assessment of early signs of acid-reflux induced damage to the squamous epithelium of the esophagus by use of light microscopy.

The efficacy of thymosin in the treatment of chronic hepatitis B virus infection: a meta-analysis

BACKGROUND

Trials of thymosin treatment in chronic hepatitis B virus infection have been small and the results have been inconsistent.

AIM

To conduct a meta-analysis to evaluate the efficacy of thymosin treatment in chronic hepatitis B virus infection.

METHODS

Randomized controlled trials comparing thymosin for over 24 weeks vs. placebo (or usual care) in the treatment of chronic hepatitis B virus infection were identified through MEDLINE, EMBASE and the Cochrane Register of Clinical Trials. Biochemical (normalization of transaminases) and virological (loss of hepatitis B virus DNA and hepatitis B e antigen) responses were analysed using the intention-to-treat method. The odds ratio was used to measure the magnitude of the efficacy.

RESULTS

Five trials (353 patients) were identified. The odds ratio (95% confidence interval) of the virological response of thymosin over placebo at the end of treatment, 6 months post-treatment and 12 months post-treatment were 0.56 (0.2-1.52), 1.67 (0.83-3.37) and 2.67 (1.25-5.68), respectively. There was an increasing trend of the virological response with time since the cessation of thymosin treatment (P=0.02). There was no difference in the biochemical response between the thymosin and placebo groups at the end of treatment, 6 months post-treatment and 12 months post-treatment.

CONCLUSIONS

Thymosin is effective in suppressing viral replication in chronic hepatitis B virus infection, but the effect is delayed until 12 months after the cessation of treatment.

Red streaks in the oesophagus in patients with reflux disease: is there a histomorphological correlate?

BACKGROUND

The Los Angeles classification of reflux oesophagitis includes sharply demarcated areas of erythema without any associated slough within the definition of reflux-induced mucosal breaks, though there is uncertainty as to whether these "red streaks" actually represent such a mucosal lesion. This study evaluates the histopathology of these red streaks.

METHODS

Forty patients with one or more red streaks on the tops of the mucosal folds in the distal oesophagus were included in a multinational, multicentre prospective study. All patients were referred for upper gastrointestinal endoscopy to investigate chronic heartburn and acid regurgitation. Biopsies were taken from the red streaks and from control biopsies from more normal appearing mucosa 1 cm lateral to the red streaks. A two-sided probability test using normal approximation assessed differences in the histological findings at the two biopsy locations.

RESULTS

Compared to control biopsies, biopsies of red streaks had a significantly thicker basal cell layer (mean +/- s 41% +/- 32% versus 18% +/- 23% of mucosal thickness, P=0.001) and longer papillae (mean +/- s 71% +/- 19% versus 49% +/- 24% of mucosal thickness, P= 0.001). Of the red streak biopsies, 25% had either newly re-epithelized lesions or granulation tissue beneath squamous epithelium. Only 10% of the control biopsies had moderate or more marked regenerative changes (based on elongation of papillae and basal cell hyperplasia), compared to 65.1% of red streak biopsies. Of the biopsies from the red streak itself, 7% showed no abnormality and 27.9% only slight changes. In comparison, 25% of the biopsies from control biopsies showed no regenerative changes and 62.5% only slight change due to gastro-oesophageal reflux disease.

CONCLUSION

The histomorphological counterpart to the endoscopically visible red streaks of the distal oesophagus is marked regenerative changes of the squamous epithelium and/or capillary rich granulation tissue beneath the squamous epithelium. Red streaks are validated as being indicative of acid/peptic mucosal injury, but they do not satisfy a strict definition of a mucosal break.

Identification and characterization of human BIC, a gene on chromosome 21 that encodes a noncoding RNA

BIC was originally identified as a gene transcriptionally activated by promoter insertion at a common retroviral integration site in B cell lymphomas induced by avian leukosis virus (Tam et al., Mol. Cell. Biol. 17 (1997) 1490). The human homolog of this gene was cloned and characterized. It consists of three exons within a 13 kb region located in chromosome 21q21. Similar to the avian homolog, the human BIC lacks a long open reading frame (ORF). Highest levels of BIC expression are detected in the spleen and thymus by Northern analysis. In addition, the mouse homolog of BIC was identified. Comparison of BIC cDNAs from human, mouse and chicken reveals 78% identity over 138 nucleotides. However, there is no homology among the multiple short ORFs present in these cDNAs. The region of sequence homology is predicted by computer analysis to form an imperfect RNA duplex, which is structurally similar among the three species. Based on the lack of a conserved ORF and the evolutionary conservation of RNA secondary structure, we presume that BIC functions as a noncoding RNA.

Remote substituent effects on the oxymercuration of 2-substituted norbornenes: an experimental and theoretical study

The effect of a remote substituent on regioselectivity in the oxymercuration of 2-substituted norbornenes has been investigated experimentally and theoretically using density functional theory (DFT). Regioselectivities of 1:1 to 14:1 were observed with various 2-substituted norbornenes. Exo-2-substituted norbornenes always gave greater regioselectivities compared to the corresponding endo-2-substituted norbornenes. The effects of solvents on the regioselectivity have also been examined, and ethereal solvents were found to be the best choice giving the optimal yield and regioselectivity. The relative rate of oxymercuration was estimated by competition experiments. The least reactive substrate (X = OAc) gave the highest regioselectivity. According to DFT predictions, the increased difference between the reaction barriers that results in the greater regioselectivity is correlated directly with the larger polarity of the C=C double bond, which is attacked by the mercury and oxygen. A number of stable exo and endo conformers were predicted. All exo conformers show the same polarity of the double bond, while some endo conformers have a reversal of this polarity. All the conformers except those with the OAc substituent are very close in energy and thus should react. The existence of a mixture of endo conformers with the C=C double bond of opposite polarity clearly explains a decrease in regioselectivity for the endo species. The origin of the greatest regioselectivity for the OAc-2-norbornenes lies in the fact that the conformer with the largest polarity is notably lower in energy than others due to an internal C-H-O hydrogen bond.

Intramolecular 1,3-dipolar cycloadditions of norbornadiene-tethered nitrones

Efficient routes to the synthesis of norbornadiene-tethered nitrones have been developed, and their intramolecular 1,3-dipolar cycloadditions were studied. The cycloadditions occurred in moderate to good yields for a variety of substrates and were found to be highly regio- and stereoselective, giving single regio- and stereoisomers in most cases.

Study on the reactivity of the alkene component in ruthenium-catalyzed [2 + 2] cycloadditions between an alkene and an alkyne. Part 1

[reaction: see text] The ruthenium-catalyzed [2 + 2] cycloadditions of 7-substituted norbornadienes with an alkyne have been investigated. The cycloadditions were found to be highly regio- and stereoselective, giving only the anti-exo cycloadducts as the single regio- and stereoisomers in good yields. The results on the relative rate of different 7-substituted norbornadienes in the Ru-catalyzed [2 + 2] cycloadditions with an alkyne indicated that the reactivity of the alkene component decreases dramatically as the alkene becomes more electron deficient.

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.

Intramolecular 1,3-dipolar cycloadditions of norbornadiene-tethered nitrile oxides

Efficient routes to the synthesis of norbornadiene-tethered nitrile oxides have been developed, and their intramolecular 1,3-dipolar cycloadditions were studied. The cycloadditions occurred in good yields for a variety of substrates and were found to be highly regio- and stereoselective, giving single regio- and stereoisomers in most cases.

Impacts and patterns of disturbed gastrointestinal function in critically ill patients

Disordered upper gastrointestinal tract motility occurs frequently in intensive care unit patients and often represents a substantial treatment challenge. In addition to specific complications such as pulmonary aspiration and diarrhea, abnormal gastrointestinal motility is a limiting factor for delivery and success of enteral nutrition. The pathophysiologies involved are incompletely understood because of the difficulties of making measurements of gastrointestinal function in critically ill patients. With the recent development of techniques that overcome some of these difficulties, the prospects are brighter for significant advances in this field.

Ruthenium-catalyzed [2 + 2] cycloadditions of 2-substituted norbornenes

The studies of remote substituent effects in controlling regio- and stereoselectivities in chemical reactions provide important information in understanding long-range stereoelectronic effects. The effect of remote substituents on ruthenium-catalyzed [2 + 2] cycloadditions of 2-substituted norbornenes has been investigated. The cycloadditions occurred at room temperature in excellent yields, and regioselectivities of 1.2:1 to 7.5:1 were observed with various 2-substituted norbornenes.

Treatment of radiation proctitis with argon plasma coagulation

BACKGROUND AND STUDY AIMS

Radiation proctitis is a troublesome complication of pelvic irradiation for malignancy. One common and occasionally serious complication is rectal bleeding. Therapeutic options for this condition are limited. This study was undertaken to evaluate the usefulness of argon plasma coagulation (APC) in the treatment of rectal bleeding due to radiation proctitis.

PATIENTS AND METHODS

Fifteen patients referred for treatment of rectal bleeding due to radiation proctitis were offered APC during flexible sigmoidoscopy. Data were collected retrospectively to assess patients' response to treatment. Patients were asked to score overall well-being, bleeding, fecal urgency, incontinence, and stool frequency. Transfusion requirements and nadir hemoglobin before and after treatment were also recorded. Matched data were assessed using the Wilcoxon signed-rank test.

RESULTS

Rectal bleeding improved significantly after treatment with APC (median pre-treatment score = 3, median post-treatment score = 1; P<0.001). Transfusion requirements ceased in three patients who had previously been anemic. Hemoglobin levels increased from a mean of 108 g/l to 133 g/l in 13 patients. In addition, other parameters of bowel function, including urgency, incontinence, and stool frequency, improved significantly after treatment. Two patients developed rectal strictures after therapy, but these were asymptomatic and treated with rectal dilation. No other complications were observed.

CONCLUSION

APC improved patient well-being and significantly reduced rectal bleeding in patients with radiation proctitis. Transfusion requirements were also reduced. APC is useful and safe in patients in whom radiation proctitis is refractory to other treatments.