Assessing oral health and the minimally important differences in oral health-related quality of life of non-diabetic and diabetic patients: a cross-sectional study

BACKGROUND

Non-diabetics and diabetics might have different oral health problems and impacts on their oral health-related quality of life (OHRQoL). Comparison of oral health status and coping strategies between these patients, and evaluation of factors associated with OHRQoL might facilitate better treatment planning for improved patient-centred outcome.

METHODS

One hundred and eleven non-diabetics and 107 diabetics attending a public hospital were clinically examined and evaluated for coping strategies (abbreviated coping orientation to problems experienced) and OHRQoL [short-form oral health impact profile (OHIP-14S)]. Factors associated with OHRQoL were analysed through correlation/partial correlation. Minimally important differences (MID) of OHIP-14S were calculated to confirm associations between attachment loss, caries, and tooth loss with OHRQoL.

RESULTS

Non-diabetics had worse periodontal status. Diabetics had more missing teeth. Non-diabetics and diabetics employed maladaptive coping to manage oral health problems. Overall, non-diabetics reported worse OHRQoL. Determination of MID showed that non-diabetics with high-severe attachment loss and <20 teeth experienced poorer OHRQoL. Diabetics with caries, high-severe attachment loss, and <25 teeth experienced poorer OHRQoL.

CONCLUSION

Different factors were associated with OHRQoL of non-diabetics and diabetics. Delivery of treatment aimed at maintaining teeth in a periodontally healthy and caries free state, and provision of more chewing units might help improve OHRQoL of diabetics. © 2024 Australian Dental Association.

Consensus recommendations for the screening, diagnosis, and management of Helicobacter pylori infection in Hong Kong

Helicobacter pylori infection causes chronic gastric inflammation that contributes to various gastroduodenal diseases, including peptic ulcer and gastric cancer. Despite broad regional variations, the prevalence of resistance to antibiotics used to manage H pylori infection is increasing worldwide; this trend could hinder the success of eradication therapy. To increase awareness of H pylori and improve the diagnosis and treatment of its infection in Hong Kong, our consensus panel proposed a set of guidance statements for disease management. We conducted a comprehensive review of literature published during 2011 and 2021, with a focus on articles from Hong Kong or other regions of China. We evaluated the evidence using the Oxford Centre for Evidence-Based Medicine's 2011 Levels of Evidence and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system and sought consensus through online voting and a subsequent face-to-face meeting, which enabled us to develop and refine the guidance statements. This report consists of 24 statements regarding the epidemiology and burden, screening and diagnosis, and treatment of H pylori. Key guidance statements include a recommendation to use the test-and-treat approach for high-risk individuals, as well as the confirmation that triple therapy with a proton pump inhibitor, amoxicillin, and clarithromycin remains a valid first-line option for adults and children in Hong Kong.

Serum microRNA Levels as a Biomarker for Diagnosing Non-Alcoholic Fatty Liver Disease in Chinese Colorectal Polyp Patients

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases and its prevalence is increasing worldwide. It is reported that NAFLD is associated with colorectal polyps. Since identifying NAFLD in its early stages could prevent possible disease progression to cirrhosis and decrease the risk of HCC by early intervention, patients with colorectal polyp may thus be considered a target group for screening NAFLD. This study aimed to investigate the potential of serum microRNAs (miRNAs) in identifying NAFLD for colorectal polyp patients. Serum samples were collected from 141 colorectal polyp patients, of which 38 had NAFLD. The serum level of eight miRNAs was determined by quantitative PCR and delta Ct values of different miRNA pairs which were compared between NAFLD and control groups. A miRNA panel was formulated from candidate miRNA pairs by multiple linear regression model and ROC analysis was performed to evaluate its diagnostic potential for NAFLD. Compared to the control group, the NAFLD group showed significantly lower delta Ct values of miR-18a/miR-16 (6.141 vs. 7.374, p = 0.009), miR-25-3p/miR-16 (2.311 vs. 2.978, p = 0.003), miR-18a/miR-21-5p (4.367 vs. 5.081, p = 0.021) and miR-18a/miR-92a-3p (8.807 vs. 9.582, p = 0.020). A serum miRNA panel composed of these four miRNA pairs significantly identified NAFLD in colorectal polyp patients with an AUC value of 0.6584 (p = 0.004). The performance of the miRNA panel was further improved to an AUC value of 0.8337 (p < 0.0001) when polyp patients with other concurrent metabolic disorders were removed from the analysis. The serum miRNA panel is a potential diagnostic biomarker for screening NAFLD in colorectal polyp patients. This serum miRNA test could be performed for colorectal polyp patients for early diagnosis and for prevention of the disease from progressing into more advanced stages.

High-dose proton pump inhibitors are associated with hospitalisation in bronchiectasis exacerbation

BACKGROUND Bronchiectasis is a common respiratory disease complicated by periodic exacerbations. The association with different degrees of gastric acid suppression has not been well studied.METHODS A retrospective cohort study of 350 patients was conducted to investigate the association of different gastric acid suppressants with bronchiectasis exacerbation that required hospitalisation. Components of FACED (FEV₁% predicted, age, chronic colonisation by Pseudomonas aeruginosa, radiological extent of the disease, and dyspnoea) were adjusted in multivariate analysis.RESULTS Among patients with exacerbation of bronchiectasis, 52 (14.9%) required hospitalisation. Prescription of a high-dose of proton pump inhibitors (PPI) was associated with increased risk of bronchiectasis exacerbation requiring hospitalisation (adjusted OR 2.77, 95% CI 1.01-7.59; P = 0.05). There was no significant association with use of a histamine-2 receptor antagonist (H2RA) (OR 1.28, 95% CI 0.32-5.06) or low-dose PPI (OR 1.47, 95% CI 0.42-5.13). Nonetheless, patients prescribed a high dose of PPI required a significantly longer hospital stay for exacerbation (13.1 ± 1.4 days) than patients not prescribed a gastric acid suppressant (8.2 ± 2.6 days) or those on a low dose PPI (8.3 ± 1.3 days) and H2RA (6.50 ± 1.50 days).CONCLUSIONS Risk of bronchiectasis exacerbation requiring hospitalisation was increased among high-dose PPI users, but not those prescribed an H2RA or low-dose PPI.

Safety and effectiveness of low-dose aspirin for the prevention of gastrointestinal cancer in adults without atherosclerotic cardiovascular disease: a population-based cohort study

OBJECTIVE

To assess the association between low-dose aspirin and the incidence of colorectal cancer (CRC), gastric cancer (GC), oesophageal cancer (EC) and gastrointestinal bleeding (GIB) in adults without established atherosclerotic cardiovascular disease.

DESIGN

Cohort study with propensity score matching of new-users of aspirin to non-users.

SETTING

Clinical Data Analysis and Reporting System database, Hong Kong.

PARTICIPANTS

Adults ≥40 years with a prescription start date of either low-dose aspirin (75-300 mg/daily) or paracetamol (non-aspirin users) between 1 January 2004 to 31 December 2008 without a history of atherosclerotic cardiovascular disease.

MAIN OUTCOME MEASURES

The primary outcome was the first diagnosis of gastrointestinal cancer (either CRC, GC or EC) and the secondary outcome was GIB. Individuals were followed from index date of prescription until the earliest occurrence of an outcome of interest, an incident diagnosis of any type of cancer besides the outcome, death or until 31 December 2017. A competing risk survival analysis was used to estimate HRs and 95% CIs with death as the competing risk.

RESULTS

After matching, 49 679 aspirin and non-aspirin users were included. The median (IQR) follow-up was 10.0 (6.4) years. HRs for low-dose aspirin compared with non-aspirin users were 0.83 for CRC (95% CI, 0.76 to 0.91), 0.77 for GC (95% CI, 0.65 to 0.92) and 0.88 for EC (95% CI, 0.67 to 1.16). Patients prescribed low-dose aspirin had an increased risk of GIB (HR 1.15, 95% CI, 1.11 to 1.20), except for patients prescribed proton pump inhibitors or histamine H2-receptor antagonists (HR 1.03, 95% CI, 0.96 to 1.10).

CONCLUSION

In this cohort study of Chinese adults, patients prescribed low-dose aspirin had reduced risks of CRC and GC and an increased risk of GIB. Among the subgroup of patients prescribed gastroprotective agents at baseline, however, the association with GIB was attenuated.

IL-1 beta and TNF-alpha play an essential role in modulating the risk of both periodontitis and Alzheimer's disease

BACKGROUND

Periodontitis, a chronic systemic inflammatory disease, is a common health problem in the elderly. With increasing recognition that inflammation plays a key role in the pathophysiology of Alzheimer's disease (AD), our research team has been studying how systemic inflammation affects the brain immune responses. Aging is a major risk factor for both periodontitis and AD. As aging causes dysregulation of immune responses, we aimed to define the roles of cytokines in the pathogenesis of periodontitis and AD.

METHODS

To induce experimental periodontitis, female WT mice were injected with heat-killed P. gingivalis into their buccal mucosa three times per week every other week for a total of 5 weeks. Another group of mice were injected with IL-1b and TNF-a following the same timeline as above. Sickness Behavior and cognitive functions were assessed through open field and puzzle box test. Mandibular jaws were harvested for Micro-CT scan. Different brain regions were harvested for biochemical analysis.

RESULTS

Mice injected with heat-killed bacteria had worsened long-term memory functions. It also significantly increased periodontal bone loss, which was accompanied by increased gene expression levels of IL-1b and TNF-a in the gums. Significant elevated levels of pro-inflammatory cytokines in the liver as well as different brain regions were also observed. Immunostaining revealed increased levels of phospho-tau in WT mice injected with heat-killed bacteria, suggesting that elevated systemic cytokine levels caused by the injection of heat-killed bacteria can lead to the appearance of AD pathology. Another group of mice injected with IL-1b and TNF-a displayed hyperactivity and worsened short-term memory functions. Injections of cytokines also induced periodontal bone loss, which was accompanied by elevated levels of inflammatory cytokines in the liver as well as different brain regions.

CONCLUSION

Taken together, our study revealed that increased cytokine immune response in the gums led to periodontal bone loss, brain inflammation and modulated the cognitive functions of WT mice. This research demonstrated that cytokines play a crucial role in the pathogenesis of both periodontitis and AD. Acknowledgement: The study is supported by Health and Medical Research Fund (HMRF 04151216) to RCCC. RPHW is awarded by Hong Kong PhD Fellowship.

Feasibility study of a single-use balloon-assisted robotic colonoscope in healthy volunteers

Background and study aims  Despite its widespread adoption, colonoscope still has its limitations. Advancement is often limited by the looping of colon. The isolation of SARS-CoV-2 in stool raises concern for the risk of disease transmission. A single-use robotic colonoscope, the NISInspire-C System, that features a balloon-suction anchorage mechanism was developed to address these. Methods  The NISInspire-C balloons are designed to provide anchorage for straightening of the colon during advancement. Angulation at the bending section is tendon-wire driven by servo mechanisms integrated into a robotic control console. This was a pilot, prospective trial to evaluate the safety and feasibility of this system. Healthy volunteers underwent examination with the NISInspire-C, followed by the conventional colonoscope. The procedure time, cecal intubation rates (CIR), complications, and level of pain were measured. Results  A total of 19 subjects underwent the examination. The cecal intubation rate was 89.5 % (17/19) and the overall time-to-cecum was 26.3 minutes (SD: 17.9 mins). There were no procedure-related complications. Polyps were detected in seven of 19 (36.8 %) subjects during the NISInspire-C procedure. Three more subjects were found to have adenomatous polyps with the conventional colonoscope. There was minimal variation in level of pain during the procedures with the two colonoscopes. Conclusion  The single-use robotic colonoscope NISInspire-C is a safe and feasible alternative to the conventional colonoscope. Further technical refinement is needed to improve the CIR. This study was limited by its small sample size.

Short- and potential long-term adverse health outcomes of COVID-19: a rapid review

The coronavirus disease 2019 (COVID-19) pandemic has resulted in millions of patients infected worldwide and indirectly affecting even more individuals through disruption of daily living. Long-term adverse outcomes have been reported with similar diseases from other coronaviruses, namely Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). Emerging evidence suggests that COVID-19 adversely affects different systems in the human body. This review summarizes the current evidence on the short-term adverse health outcomes and assesses the risk of potential long-term adverse outcomes of COVID-19. Major adverse outcomes were found to affect different body systems: immune system (including but not limited to Guillain-Barré syndrome and paediatric inflammatory multisystem syndrome), respiratory system (lung fibrosis and pulmonary thromboembolism), cardiovascular system (cardiomyopathy and coagulopathy), neurological system (sensory dysfunction and stroke), as well as cutaneous and gastrointestinal manifestations, impaired hepatic and renal function. Mental health in patients with COVID-19 was also found to be adversely affected. The burden of caring for COVID-19 survivors is likely to be huge. Therefore, it is important for policy makers to develop comprehensive strategies in providing resources and capacity in the healthcare system. Future epidemiological studies are needed to further investigate the long-term impact on COVID-19 survivors.

SARS-CoV-2 Induces a More Robust Innate Immune Response and Replicates Less Efficiently Than SARS-CoV in the Human Intestines: An Ex Vivo Study With Implications on Pathogenesis of COVID-19

BACKGROUND AND AIMS

Besides prominent respiratory involvement, gastrointestinal manifestations are commonly reported in Coronavirus Disease 2019 (COVID-19) patients. We compared infection of ex vivo human intestinal tissues by SARS-CoV-2 and SARS-CoV with respect to their replication kinetics and immune activation profile.

METHODS

Human intestinal tissues were obtained from patients while undergoing surgical operations at Queen Mary Hospital, Hong Kong. Upon surgical removal, the tissues were immediately processed and infected with SARS-CoV-2 or SARS-CoV. Replication kinetics were determined with immunohistochemistry, qRT-PCR, and plaque assays. Immune activation in the infected intestinal tissues was assessed by detecting the gene expression of interferons and representative pro-inflammatory cytokines and chemokines.

RESULTS

SARS-CoV-2 could infect and productively replicate in the ex vivo human intestinal tissues with release of infectious virus particles, but not in ex vivo human liver and kidney tissues. Importantly, SARS-CoV-2 replicated less efficiently than SARS-CoV, induced less cytopathology in the human intestinal epithelium, and induced a more robust innate immune response including the activation of both type I and type III interferons, than SARS-CoV in human intestinal tissues.

CONCLUSION

Using the ex vivo human intestinal tissues as a physiologically relevant model, our data indicated that SARS-CoV-2 could productively replicate in the human gut and suggested that the gastrointestinal tract might serve as an alternative route of virus dissemination. SARS-CoV-2 replicated less efficiently and induced less cytopathology than SARS-CoV in keeping with the clinical observations reported for COVID-19 and SARS, which might be the result of a more robust immune activation by SARS-CoV-2 than SARS-CoV in the human intestine.

Joint recommendations on management of anaemia in patients with gastrointestinal bleeding in Hong Kong

The demand for blood products continues to grow in an unsustainable manner in Hong Kong. While anaemia associated with gastrointestinal bleeding (GIB) is the leading indication for transfusion, there is no local recommendation regarding best practices for transfusion. We aimed to provide evidence-based recommendations regarding management of anaemia in patients with acute and chronic GIB. We reviewed all original papers, meta-analyses, systematic reviews, or guidelines that were available in PubMed. For acute GIB, a restrictive transfusion strategy, targeting a haemoglobin threshold of 7 to 8 g/dL, should be adopted because overtransfusion is associated with significantly higher all-cause mortality and re-bleeding. A liberal transfusion strategy should only be considered in patients with co-existing symptomatic coronary artery disease, targeting a haemoglobin threshold of 9 to 10 g/dL. When acute GIB settles, patients should be prescribed iron supplements if iron deficiency is present. For chronic GIB, iron stores should be replenished aggressively via iron supplementation before consideration of blood transfusion, except in patients with symptoms of severe anaemia. Oral iron replacement is the preferred first-line therapy, while intravenous iron is indicated for patients with inflammatory bowel disease, poor response or poor tolerability to oral iron, and in whom a rapid correction of iron deficit is preferred. Intravenous iron is underutilised and the risk of anaphylactic reaction to current preparations is extremely low. These recommendations are provided to local clinicians to facilitate judicious and appropriate use of red cell products and iron replacement therapy in patients with GIB.

Three-dimensional pharyngeal airway changes in dento-skeletal class II patients after two-jaw orthognathic surgery with segmentation - a pilot study

PURPOSE

To investigate short- and long-term post-surgical three-dimensional changes of pharyngeal airway morphology and hyoid bone position in dento-skeletal class II deformity patients after two-jaw surgery with segmentation.

METHODS

Relations between skeletal movement, hyoid bone position and three-dimensional pharyngeal airway changes were retrospectively analyzed on pre- and post-surgical CBCTs in dento-skeletal class II patients who underwent orthognathic two-jaw surgery with segmentation.

RESULTS

While long-term significant reductions in length (P= 0.003), surface area (P= 0.042) and volume (P= 0.004) were found in the nasopharynx, the highly significant increases in oropharyngeal airway length, surface area, volume and the minimal cross-sectional area (P < 0.05) prevailed only in the short-term. Although a significant antero-superior movement of the hyoid bone was detected both in short- and long-term follow-up CBCTs (P < 0.05), only its superior, but not the anterior movement was found to be associated with an increased lateral width of the oropharyngeal minimal cross-sectional area.

CONCLUSION

Two-jaw orthognathic surgery with segmentations in dento-skeletal class II patients improved oropharyngeal airway parameters significantly in the short-, but not long-term.

Brain responses to stimuli mimicking dental treatment among non-phobic individuals: A meta-analysis

Numerous neuroimaging studies have attempted to identify how the brain responds to stimuli mimicking dental treatment in normal non-phobic individuals. However, results were sometimes inconsistent due to small sample sizes and methodological variations. This meta-analysis employs standardized procedures to summarize data from previous studies to identify brain regions that were consistently activated across studies, elicited by stimuli such as pictures, sounds, or audiovisual footage mimicking those encountered during dental treatments. A systematic literature search was carried out using PubMed and Scopus. The meta-analysis analyzed data from 120 healthy subjects from seven neuroimaging studies. We assessed the risk of bias among the included studies with the Risk of Bias Assessment Tool for Nonrandomized Studies. One study appeared to have a high risk of selection bias, whereas the others were considered to have a low risk of bias. Results revealed three clusters of activation with cluster sizes ranging from 768 mm³ to 1,424 mm³ . Stimuli mimicking dental treatment consistently activated the bilateral anterior insula; right dorsal anterior cingulate, putamen, and medial prefrontal cortex; and left claustrum. This study confirmed that audio and/or visual stimuli mimicking dental treatment consistently activated the fear-related brain regions among healthy subjects, mostly consistent with activations from general anxiety but without the involvement of the amygdala.

Identification of serum miR-139-3p as a non-invasive biomarker for colorectal cancer

Aberrant levels of circulating microRNAs are potential biomarkers for the early detection of colorectal cancer. The aim of this study was to study miR-139-3p and miR-622 in serum as a non-invasive biomarker for colorectal cancer diagnosis. We applied quantitative polymerase chain reaction to determine the levels of miR-139-3p and miR-622 in 42 pairs of tumor and adjacent non-tumor tissues, and in serum samples of 117 patients and 90 control subjects. Our results showed that miR-139-3p was silenced whereas miR-622 was overexpressed in colorectal cancer. Similarly, serum miR-139-3p level was significantly lower in colorectal cancer patients than in control subjects whereas miR-622 was more frequently detectable in patients. ROC analysis showed that AUC of miR-139-3p was 0.9935, with a sensitivity of 96.6% and specificity of 97.8%. Serum miR-139-3p level showed high sensitivity and specificity for both early and late stage CRCs and proximal and distal CRCs. Detectable serum miR-622 showed a sensitivity of 87.5% and specificity of 63.5% for discriminating CRC patients, but the sensitivity dropped for late stage patients (72.7%). We also included analyses of the blood CEA level for comparing the diagnostic performance of these blood-based biomarkers. The median level in CRC patients (3.6 ng/ml) was significantly higher than that in control (1.8 ng/ml). The AUC value of CEA in diagnosing CRC patients was 0.7515. CEA showed a positive correlation with tumor stage and age of patients and its level was higher in male. Collectively, serum miR-139-3p has strong potential as a promising non-invasive biomarker in colorectal cancer detection.

Bleeding-related hospital admissions and 30-day readmissions in patients with non-valvular atrial fibrillation treated with dabigatran versus warfarin

Essentials Bleeding is a common cause of hospital admission and readmission in oral anticoagulant users. Patients with dabigatran and warfarin were included to assess hospital admission risk. Dabigatran users had a higher risk of 30-day readmission with bleeding than warfarin users. Close monitoring following hospital discharge for dabigatran-related bleeding is warranted.

SUMMARY

Background Reducing 30-day hospital readmission is a policy priority worldwide. Warfarin-related bleeding is among the most common cause of hospital admissions as a result of adverse drug events. Compared with warfarin, dabigatran achieves a full anticoagulation effect more quickly following its initiation; hence it may lead to early-onset bleeds. Objectives To compare the incidence of bleeding-related hospital admissions and 30-day readmissions with dabigatran vs. warfarin in patients with non-valvular atrial fibrillation (NVAF). Methods This was a retrospective cohort study using a population-wide database managed by the Hong Kong Hospital Authority. Patients newly diagnosed with NVAF from 2010 through to 2014 and prescribed dabigatran or warfarin were 1:1 matched by propensity score. The incidence rate of hospital admission with bleeding (a composite of gastrointestinal bleeding, intracranial hemorrhage and bleeding at other sites) was assessed. Results Among the 51 946 patients with NVAF, 8309 users of dabigatran or warfarin were identified, with 5160 patients matched by propensity score. The incidence of first hospitalized bleeding did not differ significantly between groups (incidence rate ratio, 0.92; 95% confidence interval [CI], 0.66-1.28). Among patients who were continuously prescribed their initial anticoagulants upon discharge, dabigatran use was associated with a higher risk of 30-day readmission with bleeding over warfarin (adjusted hazard ratio, 2.87; 95%CI, 1.10-7.43). Conclusion When compared with warfarin, dabigatran was associated with a comparable incidence of first hospital admission but a higher risk of 30-day redmission with respect to bleeding. Close early monitoring of patients initiated on dabigatran following hospital discharge for bleeding is warranted.

Immunoglobulin G4-related disease in Hong Kong: clinical features, treatment practices, and its association with multisystem disease

INTRODUCTION

Immunoglobulin G4-related disease remains an under-recognised and evolving disease. Local data are sparse and previous publications have been limited to individual case reports or case series only. We conducted this study to review the clinical features, treatment practices, and factors associated with multisystem involvement in Hong Kong. We described the clinical features and treatment modalities of the largest cohort of immunoglobulin G4-related disease in our locality thus far.

METHODS

We retrospectively evaluated all patients with immunoglobulin G4-related disease between January 2003 and December 2015 in Queen Mary Hospital and combined this with patient data extracted from previous local publications. We analysed the clinical features, treatment practices, and factors associated with the number of organ systems involved.

RESULTS

A total of 104 patients (55 from Queen Mary Hospital and 49 from literature review) were identified. Patients were predominantly older men (mean [standard deviation] age, 61.9 [12.7] years; male-to-female ratio=3:1) and 94.4% had elevated pre-treatment serum immunoglobulin G4 levels. Hepatobiliary and pancreatic system (40.4%), salivary gland (33.7%), lymph node (29.8%), and eye (19.2%) were the most common organ systems involved. Lymphadenopathy was associated with glucocorticoid use (odds ratio=2.65; 95% confidence interval, 1.08-6.54; P=0.034). Pre-treatment serum immunoglobulin G4 levels correlated with the number of organ systems involved (β=0.347; P=0.004) and, specifically, more associated with patients having salivary gland involvement than those without (mean, 1109 mg/dL vs 599 mg/dL; P=0.012).

CONCLUSION

We identified pre-treatment serum immunoglobulin G4 to be associated with multisystem disease, especially with salivary gland involvement, highlighting its potential for disease prognostication and monitoring. Increased physician awareness and multidisciplinary efforts are required for early diagnosis and optimal management of this masquerading disease.

Oral treponeme major surface protein: Sequence diversity and distributions within periodontal niches

Treponema denticola and other species (phylotypes) of oral spirochetes are widely considered to play important etiological roles in periodontitis and other oral infections. The major surface protein (Msp) of T. denticola is directly implicated in several pathological mechanisms. Here, we have analyzed msp sequence diversity across 68 strains of oral phylogroup 1 and 2 treponemes; including reference strains of T. denticola, Treponema putidum, Treponema medium, 'Treponema vincentii', and 'Treponema sinensis'. All encoded Msp proteins contained highly conserved, taxon-specific signal peptides, and shared a predicted 'three-domain' structure. A clone-based strategy employing 'msp-specific' polymerase chain reaction primers was used to analyze msp gene sequence diversity present in subgingival plaque samples collected from a group of individuals with chronic periodontitis (n=10), vs periodontitis-free controls (n=10). We obtained 626 clinical msp gene sequences, which were assigned to 21 distinct 'clinical msp genotypes' (95% sequence identity cut-off). The most frequently detected clinical msp genotype corresponded to T. denticola ATCC 35405^T , but this was not correlated to disease status. UniFrac and libshuff analysis revealed that individuals with periodontitis and periodontitis-free controls harbored significantly different communities of treponeme clinical msp genotypes (P<.001). Patients with periodontitis had higher levels of clinical msp genotype diversity than periodontitis-free controls (Mann-Whitney U-test, P<.05). The relative proportions of 'T. vincentii' clinical msp genotypes were significantly higher in the control group than in the periodontitis group (P=.018). In conclusion, our data clearly show that both healthy and diseased individuals commonly harbor a wide diversity of Treponema clinical msp genotypes within their subgingival niches.

Randomised clinical trial: rifaximin versus placebo for the treatment of functional dyspepsia

BACKGROUND

Gut dysbiosis may contribute to pain and bloating in patients with functional gastrointestinal disease.

AIMS

To determine if treatment with rifaximin would improve the symptoms of functional dyspepsia in Chinese patients in a double-blinded, randomised, placebo-controlled trial.

METHODS

Consecutive subjects with a diagnosis of functional dyspepsia as per the Rome III criteria were randomised to receive rifaximin 400 mg or placebo, all taken three times daily for 2 weeks. The investigators and study subjects were blinded to the treatment allocation. Subjects were followed up for 8 weeks. The primary end point was adequate relief of global dyspeptic symptoms (GDS). Secondary endpoints were relief of individual dyspeptic symptoms.

RESULTS

Eighty-six subjects were recruited. At week 8, there were significantly more subjects in the rifaximin than in the placebo group who experienced adequate relief of GDS (78% vs. 52%, P = 0.02). A trend favouring rifaximin group was also noted in the preceding 4 weeks. Rifaximin was also superior to placebo in providing adequate relief of belching and post-prandial fullness/bloating (PPF) in subjects at week 4. Subgroup analysis revealed that female subjects had more significant response to rifaximin treatment (adequate relief of GDS at week 4: 76% vs. 42%, P = 0.006; week 8: 79% vs. 47%, P = 0.008), as well as improvements in their belching and PPF at week 4. The incidences of adverse effects were similar in both groups.

CONCLUSIONS

Treatment with 2 weeks of rifaximin led to adequate relief of global dyspeptic symptoms, belching and post-prandial fullness/bloating in subjects with functional dyspepsia. The difference was more marked in females. (clinicaltrials.org NCT01643083).

Effects of nucleoside analogue prescription for hepatitis B on the incidence of liver cancer in Hong Kong: a territory-wide ecological study

BACKGROUND

The temporal relationship between nucleoside analogue therapy for chronic hepatitis B (CHB) and liver cancer development has not been evaluated at a population level.

AIM

To investigate the impact of nucleoside analogue prescription on liver cancer incidence in a CHB-prevalent region.

METHODS

We obtained territory-wide nucleoside analogue prescription data from 1999, when nucleoside analogue was first available in Hong Kong, to 2012 and the population-based liver cancer incidence data from 1990 to 2012. We compared the liver cancer incidences from 1990 to 1998 and 1999 to 2012 with adjustment for local hepatitis B surface antigen seroprevalence.

RESULTS

Nucleoside analogue prescription patient headcount increased from 2006 per year in 1999 to 26 411 in 2012. Prescription volume in 2012 was highest among 55-64 years (30.3%), higher than 65-74 years (13.0%) and ≥75 years (5.8%). Age-standardised liver cancer incidence 1999-2012 decreased by 1.88%/year (95% CI 3.34% to 0.42%/year). NA therapy was associated with decline in age-adjusted liver cancer incidence (2.7 per 100 000 persons, P < 0.001, 95% CI 1.4-4.0 per 100 000 persons). Fifty-five to sixty-four years age group had the most significant decline (men: 24.0 per 100 000 persons, P = 0.001, 95% CI 11.4-36.6 per 100 000 persons; women: 8.5 per 100 000 persons, P = 0.009, 95% CI 2.3-14.6 per 100 000 persons). No significant association was noted in age groups 65-74 years and ≥75 years (both P > 0.05).

CONCLUSIONS

Nucleoside analogue prescription was associated with a reduction of overall liver cancer incidence in a CHB-prevalent region. The lack of association among individuals of ≥65 years was consistent with the low nucleoside analogue prescription volume in elderly patients, mitigating the impact of CHB treatment on liver cancer.

Systematic review with meta-analysis: the association between the use of calcium channel blockers and gastrointestinal bleeding

BACKGROUND

Due to their potential anti-platelet effect, it is suggested that calcium channel blockers (CCBs) are associated with gastrointestinal bleeding (GIB). However, results from previous studies are conflicting.

AIM

To conduct a systematic review and meta-analysis of randomised controlled trials (RCTs) and observational studies to clarify the association between CCBs and GIB.

METHODS

We conducted a systematic search of PubMed, EMBASE, Cochrane library and Trial Register databases up to January 2015. Studies that evaluated exposure to CCBs reporting GIB outcomes were included in the meta-analysis. The inverse variance method with random effects model was used to calculate the pooled estimates.

RESULTS

Seventeen studies (four RCTs, eleven case-control and two cohort studies) were included in the meta-analysis. The summary risk ratio (RR) for GIB was 1.17 (95% CI 1.01-1.36) for CCB users vs. non-users. Subgroup analysis showed that CCB use was associated with a moderately higher risk of lower GIB (RR = 1.83, 95% CI 1.17-2.84) but not upper GIB. However, data from four RCTs did not support association between CCBs and GIB (RR = 0.93, 95% CI 0.82-1.05). Subgroup analyses further showed that the increased risk of GIB among CCB users was only observed in studies that failed to adjust for prior history of GIB (RR = 1.67, 95% CI 1.34-2.08) or use of anti-ulcer drugs (RR = 1.40, 95% CI 1.19-1.65).

CONCLUSION

Our meta-analysis showed a marginal association between calcium channel blocker use and the risk of gastrointestinal bleeding. This association is of dubious clinical significance, as the effects of different comparators or adjustment for confounding factors render this association nonsignificant.

Hospital Authority audit of the outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong

OBJECTIVES

To review the short-term outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong.

DESIGN

Historical cohort study.

SETTING

All Hospital Authority hospitals in Hong Kong.

PATIENTS

This was a multicentre retrospective study of all patients who underwent endoscopic resection of superficial upper gastro-intestinal lesions between January 2010 and June 2013 in all government-funded hospitals in Hong Kong.

MAIN OUTCOME MEASURES

Indication of the procedures, peri-procedural and procedural parameters, oncological outcomes, morbidity, and mortality.

RESULTS

During the study period, 187 lesions in 168 patients were resected. Endoscopic mucosal resection was performed in 34 (18.2%) lesions and endoscopic submucosal dissection in 153 (81.8%) lesions. The mean size of the lesions was 2.6 (standard deviation, 1.8) cm. The 30-day morbidity rate was 14.4%, and perforations and severe bleeding occurred in 4.3% and 3.2% of the patients, respectively. Among patients who had dysplasia or carcinoma, R0 resection was achieved in 78% and the piecemeal resection rate was 11.8%. Lateral margin involvement was 14% and vertical margin involvement was 8%. Local recurrence occurred in 9% of patients and 15% had residual disease. The 2-year overall survival rate and disease-specific survival rate was 90.6% and 100%, respectively.

CONCLUSION

Endoscopic mucosal resection and endoscopic submucosal dissection were introduced in low-to-moderate-volume hospitals with acceptable morbidity rates. The short-term survival was excellent. However, other oncological outcomes were higher than those observed in high-volume centres and more secondary procedures were required.

Accuracy of capsule colonoscopy in detecting colorectal polyps in a screening population

BACKGROUND & AIMS

Capsule colonoscopy is a minimally invasive imaging method. We measured the accuracy of this technology in detecting polyps 6 mm or larger in an average-risk screening population.

METHODS

In a prospective study, asymptomatic subjects (n = 884) underwent capsule colonoscopy followed by conventional colonoscopy (the reference) several weeks later, with an endoscopist blinded to capsule results, at 10 centers in the United States and 6 centers in Israel from June 2011 through April 2012. An unblinded colonoscopy was performed on subjects found to have lesions 6 mm or larger by capsule but not conventional colonoscopy.

RESULTS

Among the 884 subjects enrolled, 695 (79%) were included in the analysis of capsule performance for all polyps. There were 77 exclusions (9%) for inadequate cleansing and whole-colon capsule transit time fewer than 40 minutes, 45 exclusions (5%) before capsule ingestion, 15 exclusions (2%) after ingestion and before colonoscopy, and 15 exclusions (2%) for site termination. Capsule colonoscopy identified subjects with 1 or more polyps 6 mm or larger with 81% sensitivity (95% confidence interval [CI], 77%-84%) and 93% specificity (95% CI, 91%-95%), and polyps 10 mm or larger with 80% sensitivity (95% CI, 74%-86%) and 97% specificity (95% CI, 96%-98%). Capsule colonoscopy identified subjects with 1 or more conventional adenomas 6 mm or larger with 88% sensitivity (95% CI, 82%-93) and 82% specificity (95% CI, 80%-83%), and 10 mm or larger with 92% sensitivity (95% CI, 82%-97%) and 95% specificity (95% CI, 94%-95%). Sessile serrated polyps and hyperplastic polyps accounted for 26% and 37%, respectively, of false-negative findings from capsule analyses.

CONCLUSIONS

In an average-risk screening population, technically adequate capsule colonoscopy identified individuals with 1 or more conventional adenomas 6 mm or larger with 88% sensitivity and 82% specificity. Capsule performance seems adequate for patients who cannot undergo colonoscopy or who had incomplete colonoscopies. Additional studies are needed to improve capsule detection of serrated lesions. Clinicaltrials.gov number: NCT01372878.

Primary sensory neurons regulate Toll-like receptor-4-dependent activity of glial cells in dorsal root ganglia

Toll-like receptor-4 (TLR4) has been identified in primary sensory neurons, both in vivo and in vitro, but is reportedly absent from satellite glial cells (SGCs). Herein we reveal that, in rat dorsal root ganglia (DRG), SGCs do express TLR4 but this expression is inhibited by direct contact with neurons. Thus, TLR4 mRNA and protein is strongly up-regulated in isolated DRG glial cells in the absence of neurons. Lipopolysaccharide (LPS) increased cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNFα) mRNA expression with greater efficacy in DRG glial cell cultures than in mixed DRG cell cultures containing TLR4-positive neurons. Using an insert co-culture system, we have shown that neuronal inhibition of glial cell TLR4 is likely to be dependent on cell-cell contact rather than diffusible factors from neurons. LPS stimulated prostaglandin E2 (PGE2) production from DRG glial cells in a TLR4- and COX-2-dependent manner. In addition, exogenous PGE2 potentiated LPS-stimulated COX-2 mRNA while inhibiting TNFα mRNA expression by DRG cells, suggestive of a complex regulatory system to control inflammation within the DRG. In addition to LPS, conditioned medium from heat-shocked DRG neurons also increased COX-2 mRNA expression in DRG glial cells in a partially TLR4-dependent manner. We therefore hypothesize that neuronal suppression of glial TLR4 activity is a protective mechanism to prevent uncontrolled inflammation within the DRG. Under conditions where DRG neuronal viability is compromised, DRG glial cells become responsive to PAMPs (pathogen-associated molecular patterns) and DAMPs (danger-associated molecular patterns) and generate a range of classical inflammatory responses.

Differential expression of Toll-like receptor 4 in healthy and diseased human gingiva

BACKGROUND AND OBJECTIVE

Lipopolysaccharide (LPS)-mediated signaling in host cells involves Toll-like receptor 4 (TLR4) accessory molecules, including LPS-binding protein (LBP), cluster of differentiation 14 (CD14) and lymphocyte antigen 96 (MD-2). However, expression of these innate defense molecules in various compartments of the human periodontium is unclear. The aim of this study was to investigate the expression profile of TLR4 in human gingiva.

MATERIAL AND METHODS

Human gingival biopsies were collected from healthy gingival or chronic periodontitis tissue. Primary gingival keratinocytes and fibroblasts were cultured. Immunohistochemical analysis for TLR4 was performed. Transcripts of TLR4, MD-2, CD14 and LBP, and their protein products, were examined using RT-PCR, immunoprecipitation and immunoblotting. The interactions between these molecules in keratinocytes and fibroblasts were investigated by co-immunoprecipitation.

RESULTS

TLR4 immunoreactivity was found in healthy gingival epithelium and periodontitis tissue, and appeared to be lower in junctional epithelium ( p ≤ 0.01). Fibroblasts and inflammatory cells stained more strongly for TLR4 in diseased periodontal tissues (p < 0.001). Three TLR4 splicing variants, two MD-2 splicing variants and one CD14 mRNA were expressed by gingival keratinocytes and fibroblasts. Expression of TLR4, CD14 and MD-2 proteins was detected in keratinocytes and fibroblasts in vitro. TLR4 protein from gingival keratinocytes and fibroblasts could be co-immunoprecipitated with CD14 or MD-2, suggesting an association between the related molecules in vivo. LBP transcript was detected in gingival biopsies, but not in primary cultures of gingival keratinocytes or fibroblasts.

CONCLUSION

TLR4, CD14 and MD-2, but not LBP, are expressed in human gingival keratinocytes and fibroblasts. The TLR4 expression level in the junctional epithelium appeared to be lowest within the periodontal epithelial barrier.

Increased risk of advanced neoplasms among asymptomatic siblings of patients with colorectal cancer

BACKGROUND & AIMS

Colorectal cancer (CRC) is the second-most common cancer in Hong Kong. Relatives of patients with CRC have an increased risk of colorectal neoplasm. We assessed the prevalence of advanced neoplasms among asymptomatic siblings of patients with CRC.

METHODS

Patients with CRC were identified from the Prince of Wales Hospital CRC Surgery Registry from 2001 to 2011. Colonoscopies were performed for 374 siblings of patients (age, 52.6 ± 7.4 y) and 374 age- and sex-matched siblings of healthy subjects who had normal colonoscopies and did not have a family history of CRC (controls, 52.7 ± 7.4 y). We identified individuals with advanced neoplasms (defined as cancers or adenomas of at least 10 mm in diameter, high-grade dysplasia, with villous or tubulovillous characteristics).

RESULTS

The prevalence of advanced neoplasms was 7.5% among siblings of patients and 2.9% among controls (matched odds ratio [mOR], 3.07; 95% confidence interval [CI], 1.5-6.3; P = .002). The prevalence of adenomas larger than 10 mm was higher among siblings of patients than in controls (5.9% vs 2.1%; mOR, 3.34; 95% CI, 1.45-7.66; P = .004), as was the presence of colorectal adenomas (31.0% vs 18.2%; mOR, 2.19; 95% CI, 1.52-3.17; P < .001). Six cancers were detected among siblings of patients; no cancers were detected in controls. The prevalence of advanced neoplasms among siblings of patients was higher when their index case was female (mOR, 4.95; 95% CI, 1.81-13.55) and had distally located CRC (mOR, 3.10; 95% CI, 1.34-7.14).

CONCLUSIONS

In Hong Kong, siblings of patients with CRC have a higher prevalence of advanced neoplasms, including CRC, than siblings of healthy individuals. Screening is indicated in this high-risk population. ClinicalTrials.gov number: NCT00164944.

Use of biologics for inflammatory bowel disease in Hong Kong: consensus statement

OBJECTIVE; With the increasing use of biologics in patients with inflammatory bowel disease, the Hong Kong IBD Society developed a set of consensus statements intended to serve as local recommendations for clinicians about the appropriate use of biologics for treating inflammatory bowel disease.

PARTICIPANTS

The consensus meeting was held on 9 July 2011 in Hong Kong. Draft consensus statements were developed by core members of the Hong Kong IBD Society, including local gastroenterologists and colorectal surgeons experienced in managing patients with inflammatory bowel disease.

EVIDENCE

Published literature and conference proceedings on the use of biologics in management of inflammatory bowel disease, and guidelines and consensus issued by different international and regional societies on recommendations for biologics in inflammatory bowel disease patients were reviewed.

CONSENSUS PROCESS

Four core members of the consensus group drafted 19 consensus statements through the modified Delphi process. The statements were first circulated among a clinical expert panel of 15 members for review and comments, and were finalised at the consensus meeting through a voting session. A consensus statement was accepted if at least 80% of the participants voted "accepted completely or "accepted with some reservation".

CONCLUSIONS

Nineteen consensus statements about inflammatory bowel disease were generated by the clinical expert panel meeting. The statements were divided into four parts which covered: (1) epidemiology of the disease in Hong Kong; (2) treatment of the disease with biologics; (3) screening and contra-indications pertaining to biologics; and (4) patient monitoring after use of biologics. The current statements are the first to describe the appropriate use of biologics in the management of inflammatory bowel disease in Hong Kong, with an aim to provide guidance for local clinical practice.

Prevalence and diversity of Synergistetes taxa in periodontal health and disease

BACKGROUND AND OBJECTIVE

Members of the phylum Synergistetes have previously been identified within periodontitis subgingival plaque and are considered putative periodontopathogens. This study compared the diversity of subginigval Synergistetes in a cohort of subjects with periodontitis (n = 10) vs. periodontitis-free controls (n = 10).

MATERIAL AND METHODS

Pooled subgingival plaque samples from all deep periodontal pockets or all sulci were collected from the periodontitis and periodontitis-free subjects, respectively. Bacterial 16S rRNA genes were PCR-amplified from purified subgingival plaque DNA using a Synergistetes 'selective' primer set. PCR products were cloned and sequenced to analyze the prevalence and diversity of Synergistetes operational taxonomic units (OTUs) present in plaque samples of both subject groups.

RESULTS

A total of 1030 non-chimeric 16S rRNA clones were obtained, of which 162 corresponded to members of the phylum Synergistetes. A significantly larger number of Synergistetes clones were obtained from periodontitis subgingival plaque than from periodontitis-free controls (25.4% vs. 5.9%, p < 0.001). All Synergistetes clones corresponded to cluster A oral Synergistetes, and fell into 31 OTUs (99% sequence identity cut-off). Twenty-nine Synergistetes OTUs were detected in the periodontitis group while eight were detected in the periodontitis-free group (p < 0.001). Five Synergistetes OTUs; including one OTU corresponding to the recently-characterized species Fretibacterium fastidiosum, were more prevalent in the periodontitis subjects (p < 0.05).

CONCLUSION

OTUs belonging to oral Synergistetes cluster A were more readily detectable and were more diverse in subgingival plaque from periodontitis subjects compared with periodontitis-free controls. Specific Synergistetes OTUs appear to be associated with periodontitis.

A pale Chinese boy with recurrent painful digital swelling

Thalassaemia is the most common haemoglobinopathy in the Chinese population. However, recurrent painful digital swelling is not a typical manifestation of this well-known hereditary condition. We describe a case of co-inheritance of beta-thalassaemia and sickle cell trait in a Chinese family and a child who suffered from sickle cell/beta-thalassaemia with recurrent dactylitis. This report highlights awareness of this rare condition in the Chinese population, since acute manifestations can be life-threatening and mimic other emergency conditions. Prompt management can prevent further complications and avoid unnecessary interventions due to delay in diagnosis. A detailed family history and examination of the patient's peripheral blood smear is crucial to reach a correct diagnosis.

Genetic polymorphism studies in periodontitis and Fcγ receptors

Periodontitis is a complex chronic subgingival plaque-induced inflammatory disease influenced by multiple factors, including genetics, behavior and the environment. Many genetic association studies have been conducted in periodontology. One of the most extensively investigated gene families is the Fcγ receptor gene family, which plays a key role in regulating host immune responses to bacteria. Unlike other genetic polymorphisms reported in periodontology, most Fcγ receptor polymorphisms reported not only have established biological functions but are reported to associate with other autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. There are, however, few recent reviews summarizing the association of this gene family with periodontitis. This article critically reviews the current understanding of genetic polymorphism studies in periodontitis, then summarizes the research status of Fcγ receptor polymorphisms and periodontitis and also of other genes involved in the regulatory network of Fcγ receptors, with special reference to their anticipated biological roles. Moreover, some possible future research directions in the related area are discussed.

SNPs of Fc-gamma receptor genes and chronic periodontitis

Genetic polymorphisms of host defense genes might increase risk for periodontitis. This case-control study investigated whether 102 single-nucleotide polymorphisms (SNPs) in Fc gamma receptor (FCGR) genes are associated with chronic periodontitis. Cases were 190 Hong Kong Chinese patients with severe chronic periodontitis, and there were 169 periodontitis-free individuals as controls. Genotype CC and allele C of rs445509 (p < 0.0001, OR = 0.30) of FCGR3A were significantly more prevalent among control individuals than among cases, after adjustment for age, sex, and smoking. Smoking was significantly associated with chronic periodontitis (p = 0.003, OR = 3.35). Within the limitations of this study, SNP rs445509 of FCGR3A seem to be negatively associated, while smoking was positively associated, with severe chronic periodontitis among Hong Kong Chinese.

Initial presentation and management of osteosarcoma, and its impact on disease outcome

OBJECTIVE

To evaluate the initial presenting symptoms and management of osteosarcoma in Hong Kong Chinese children, in relation to any possible impact on disease outcomes.

DESIGN

Retrospective study.

SETTING

A tertiary referral centre of bone cancer in a university teaching hospital in Hong Kong.

PATIENTS

All children aged younger than 18 years with a diagnosis of osteosarcoma who received treatment from March 1994 to October 2005.

RESULTS

A total of 51 children were studied. The median age of onset was 13 (range, 3-20) years; 61% were males. The tumours were located in the distal femur and proximal tibia, which accounted for 45% and 22% of the cases, respectively; 24% of patients had metastatic disease at presentation. Swelling (76%) and pain (90%) were the most common presenting complaints. Approximately one third of the patients had a preceding history of trauma. The median duration of initial symptoms to first medical consultation of any sort was 30 (range, 0-360) days. The median time from the first consultation to a definitive diagnosis was 21 (range, 0-350) days; 25% were diagnosed more than 52 days after presentation. Bonesetters were initially consulted by 37% of these patients. From presentation to diagnosis, the median duration was 61 (range, 4-361) days. Analysis of the duration of pre-diagnosis symptoms did not correlate significantly with the development of metastatic disease, response to chemotherapy, feasibility of limb salvage surgery, relapse rates, or survival rates.

CONCLUSIONS

In Hong Kong, initial consultation to bonesetters was common. A relatively long delay in between symptom onset and diagnosis of osteosarcoma was encountered. The public and medical practitioners should be made aware of this disease, especially in adolescents.

Single nucleotide polymorphisms of complement component 5 and periodontitis

BACKGROUND AND OBJECTIVE

Polymorphisms of host defence genes might increase one's risks for periodontitis. This study investigated whether tagging single nucleotide polymorphisms (SNPs) of the gene encoding complement component 5 (C5) are associated with periodontitis in a Hong Kong Chinese population.

MATERIAL AND METHODS

Eleven tagging SNPs of 229 patients with at least moderate periodontitis and 207 control subjects without periodontitis were genotyped using an i-plexGOLD MassARRAY mass-spectrometry system.

RESULTS

Genotype AG of SNP rs17611 was more prevalent in the group of periodontitis patients than in the controls (54.6% vs. 41.7%, p = 0.007). The haplotype CGCA of the haplotype block consisting of rs1035029, rs17611, rs25681 and rs992670 was significantly associated with periodontitis in a dominant model (p = 0.001). The SNP rs17611 showed high linkage disequilibrium with rs1035029, rs25681 and rs992670. Smoking was also significantly associated with periodontitis (p = 0.006).

CONCLUSION

The tagging SNP rs17611 of the C5 gene and smoking may be associated with periodontitis among the Hong Kong Chinese population.

Identification of retinoic acid-regulated nuclear matrix-associated protein as a novel regulator of gastric cancer

BACKGROUND

Retinoic acid-regulated nuclear matrix-associated protein (RAMP) is a WD40 repeat-containing protein that is involved in various biological functions, but little is known about its role in human cancer. This study aims to delineate the oncogenic role of RAMP in gastric carcinogenesis.

METHODS

RAMP expression was examined by real-time quantitative RT-PCR, immunohistochemistry and western blotting. Inhibition of RAMP expression was performed by siRNA-mediated knockdown. The functional effects of RAMP on cell kinetics were measured by cell viability assay, colony formation assay and flow cytometry. Cell lines stably expressing RAMP were established to investigate the oncogenic effects of RAMP in vitro.

RESULTS

Ramp was readily expressed in all seven gastric cancer cell lines and was significantly increased in human gastric cancer tissues when compared with their adjacent non-cancerous tissues (P<0.001). In keeping with this, expression of RAMP protein was higher in gastric cancer tissues compared with their adjacent non-cancerous tissues, whereas moderate protein expression were noted in intestinal metaplasia. Knockdown of RAMP in gastric cancer cells significantly reduced cell proliferation (P<0.01) and soft agar colony formation (P<0.001), but induced apoptosis and G(2)/M arrest. In additional, knockdown RAMP induced cell apoptosis is dependent on functional accumulation of p53 and p21 and induction of cleaved caspases-9, caspases-3 and PARP. Strikingly, overexpression of RAMP promoted anchorage-independent cell growth in soft agar.

CONCLUSION

Our findings demonstrate that RAMP plays an oncogenic role in gastric carcinogenesis. Inhibition of RAMP may be a promising approach for gastric cancer therapy.

Exploring the oral bacterial flora: current status and future directions

OBJECTIVE

The oral cavity forms an indispensable part of the human microbiome, for its unique and diverse microflora distributed within various niches. While majority of these organisms exhibit commensalism, shifts in bacterial community dynamics cause pathological changes within oral cavity and distant sites. The aim of this review was to appraise the current and emerging methods of detecting bacteria of the oral cavity paying particular attention to the cultivation independent methods.

DESIGN

Literature pertaining to cultivation based and cultivation independent methods of oral bacterial identification was reviewed.

METHODS

The specific advantages and disadvantages of cultivation based, microscopic, immunological and metagenomic identification methods were appraised.

RESULTS

Because of their fastidious and exacting growth requirements, cultivation based studies grossly underestimate the extent of bacterial diversity in these polymicrobial infections. Culture independent methods deemed more sensitive in identifying difficult to culture and novel bacterial species.

CONCLUSION

Apart from characterizing potentially novel bacterial species, the nucleic acid sequence data analyzed using various bioinformatics protocols have revealed that there are in excess of 700 bacterial species inhabiting the mouth. Moreover, the latest pyrosequencing based methods have further broadened the extent of bacterial diversity in oral niches.

Predicting mortality in patients with bleeding peptic ulcers after therapeutic endoscopy

BACKGROUND & AIMS

Despite advances in management of patients with bleeding peptic ulcers, mortality is still 10%. This study aimed to identify predictive factors and to develop a prediction model for mortality among patients with bleeding peptic ulcers.

METHODS

Consecutive patients with endoscopic stigmata of active bleeding, visible vessels, or adherent clots were recruited, and risk factors for mortality were identified in this deprivation cohort by using multiple stepwise logistic regression. A prediction model was then built on the basis of these factors and validated in the evaluation cohort.

RESULTS

From 1993 to 2003, 3220 patients with bleeding peptic ulcers were treated. Two hundred eighty-four of the patients developed rebleeding (8.8%); emergency surgery was performed on 47 of these patients, whereas others were managed with endoscopic retreatment. Two hundred twenty-nine of these sustained in-hospital death (7.1%). In patients older than 70 years, presence of comorbidity, more than 1 listed comorbidity, hematemesis on presentation, systolic blood pressure below 100 mm Hg, in-hospital bleeding, rebleeding, and need for surgery were significant predictors for mortality. Helicobacter pylori-related ulcers had lower risk of mortality. The receiver operating characteristic curve comparing the prediction of mortality with actual mortality showed an area under the curve of 0.842. From 2004 to 2006, data were collected prospectively from a second cohort of patients with bleeding peptic ulcers, and mortality was predicted by using the model developed. The receiver operating characteristic curve showed an area under the curve of 0.729.

CONCLUSIONS

Among patients with bleeding peptic ulcers after endoscopic hemostasis, advanced age, presence of listed comorbidity, multiple comorbidities, hypovolemic shock, in-hospital bleeding, rebleeding, and need for surgery successfully predicted in-hospital mortality.

Bactericidal and sporicidal performance of a polymer-encapsulated chlorine dioxide-coated surface

Aims:  To investigate the physical characteristics and the bactericidal and sporicidal potential of a polymer‐encapsulated ClO₂ coating.

Methods and Results:  An antimicrobial coating based on polymer‐encapsulated ClO₂ was developed. A low viscosity, water/oil/water double emulsion coating was formulated for easy on‐site application. Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus were applied onto the coating to study the bactericidal capabilities of the coating. The bactericidal performance of the coating increased when the contact time with the tested bacteria increased. Over 99% of the E. coli, Ps. aeruginosa, B. subtilis were killed with a contact time of 30 min. Although endospores of B. subtilis are more resistant, about 75% of the spores were killed after 72 h on the coating. Moreover, a sustained release of gaseous ClO₂ was achieved to maintain about 90% removal of B. subtilis with a 10‐min contact time during a 28‐day study period. The coating also exhibits antiadhesive properties against bacteria.

Conclusions:  A polymer‐encapsulated ClO₂ coating with sustained release of ClO₂ and promising bactericidal and sporicidal features was tested for 28 days.

Significance and Impact of the Study:  This study provides a new direction for developing polymer‐encapsulated ClO₂ coatings that possess persistent bactericidal and sporicidal properties.

One man, one disease?

We report the case of a 12-year-old girl with a strong family history of malignancy who presented with immature teratoma and gliomatosis peritonei. Despite first and second line chemotherapy, the disease ran an unusually refractory course. Although the presentation was not the typical tumour presentation of Li-Fraumeni syndrome (LFS), we proceeded to undertake tumour genetic testing of the patient and her parents. LFS was diagnosed in this patient and her father with a sequence variation of CGG>TGG, R248W, which is one of the most common transcriptionally inactive mutations detected in LFS. Genetic counselling was offered to the father. A tumour screening programme and genetic screening for the p53 gene mutation for the surviving family members can be offered once consent is obtained from the father. This case illustrates the importance of cancer genetic study, even if the tumour presentation is not typical for any familial cancer syndrome.

Functional role of the KLF6 tumour suppressor gene in gastric cancer

Gastric cancer is the second most common cancer and a leading cause of cancer-related death worldwide. The Kruppel-like factor 6 (KLF6) tumour suppressor gene had been previously shown to be inactivated in a number of human cancers through loss of heterozygosity (LOH), somatic mutation, decreased expression and increased alternative splicing into a dominant negative oncogenic splice variant, KLF6-SV1. In the present study, 37 gastric cancer samples were analysed for the presence of loss of heterozygosity (LOH) of the KLF6 locus and somatic mutation. In total, 18 of 34 (53%) of the gastric cancer samples analysed demonstrated KLF6 locus specific loss. Four missense mutations, such as T179I, R198G, R71Q and S180L, were detected. Interestingly, two of these mutations R71Q and S180L have been identified independently by several groups in various malignancies including prostate, colorectal and gastric cancers. In addition, decreased wild-type KLF6 (wtKLF6) expression was associated with loss of the KLF6 locus and was present in 48% of primary gastric tumour samples analysed. Functional studies confirmed that wtKLF6 suppressed proliferation of gastric cancer cells via transcriptional regulation of the cyclin-dependent kinase inhibitor p21 and the oncogene c-myc. Functional characterisation of the common tumour-derived mutants demonstrated that the mutant proteins fail to suppress proliferation and function as dominant negative regulators of wtKLF6 function. Furthermore, stable overexpression of the R71Q and S180L tumour-derived mutants in the gastric cancer cell line, Hs746T, resulted in an increased tumourigenicity in vivo. Combined, these findings suggest an important role for the KLF6 tumour suppressor gene in gastric cancer development and progression and identify several highly cancer-relevant signalling pathways regulated by the KLF6 tumour suppressor gene.

Sjögren's syndrome sufferers have increased oral yeast levels despite regular dental care

AIM

To investigate the prevalence and quantity of oral yeasts and their association with oral candidiasis in Sjögren's syndrome (SS) patients receiving regular dental care.

MATERIALS AND METHODS

Yeasts in oral rinse and full-mouth supra-gingival plaque samples from 25 primary SS, 27 secondary SS and 29 control subjects were selectively cultured. All yeasts except single-species isolates were genotyped using pulsed field gel electrophoresis (PFGE).

RESULTS

Ten (19%) SS sufferers had symptomless candidiasis. SS subjects had a higher prevalence (73%vs 7%) and quantity of yeasts than controls in both oral rinse and plaque samples (P < 0.05). The prevalence of yeasts in plaque was associated with candidiasis regardless of denture wearing (P < or = 0.04). Candida albicans was the predominant yeast isolated. PFGE showed 20 (66% of total) C. albicans isolate pairs, i.e. C. albicans species isolated from plaque and oral rinse samples of the same individual, were of closely related genetic clonal types (P < 0.01).

CONCLUSIONS

Despite effective oral hygiene, more SS subjects than controls had detectable levels of oral yeasts and their presence in supra-gingival plaque was associated with candidiasis. Candida albicans colonized supra-gingival biofilm even in well-maintained SS individuals, posing a challenge to the control of oral candidiasis.