Molecular identification of coxsackievirus A24 variant,isolated from an outbreak of acute hemorrhagic conjunctivitis in Singapore in 2005

Summary An outbreak of acute hemorrhagic conjunctivitis (AHC) was reported in Singapore military camps in the year 2005. A total of 103 conjunctival swab specimens were collected from military personnel diagnosed clinically with AHC. PCR testing on these conjunctival specimens revealed the presence of an enterovirus, and this was confirmed by virus isolation. Molecular typing using a partial VP1 gene confirmed a variant of coxsackievirus A24 (CA24v) as the most likely etiological agent for the outbreak. Full-length genome sequencing was carried out on 2 selected virus strains, DSO-26SIN05 and DSO-52SIN05. Sequence comparison and phylogenetic analyses of the VP4, VP1 and 3Cpro gene regions were performed, clustering the Singapore CA24v strains with viruses originating from Asia in the post-2000 era. In addition, we report evolution rates of 4.2 × 10⁻³ and 1.0 × 10⁻³ nucleotide/year, respectively, for the VP4 capsid and 3Cpro gene regions. Our result shows a focal evolutionary point around 1965–1966, suggesting that the CA24v virus has been evolving constantly since its emergence in Singapore, nearly 40 years ago.     

A review on healthy ageing interventions addressing physical,mental and social health of independent community-dwelling older adults

Healthy ageing is a multi-dimensional concept which appertains to all older adults. This study reviewed the intervention characteristics, intervention content and effectiveness of multi-dimensional healthy ageing interventions (MHAIs) addressing physical, mental and social health among independent community-dwelling older adults. A search was conducted in PubMed, CINAHL, Embase, Scopus, and PsycINFO for studies published from Jan 2007 to October 2016. 18 publications were included, accounting for 15 studies. The review reflected the complexity, variations and methodological considerations of developing a comprehensive MHAI. It demonstrated the possibility of integrating person-focused to environment-focused content topics in future MHAIs, beyond the physical, mental and social health dimensions. Among the reviewed studies, health education programs reported improvements in quality of life and life satisfaction while health assessment and education programs promoted positive health behaviors. Future MHAIs studies need to employ more robust research methods and greater contextual information reports to build stronger evidence base.     

Oxidative metabolism of the human eosinophil

We have compared the oxidative metabolism of human eosinophils (80%-90% purity) to that of neutrophils. Hexose monophosphate (HMP) shunt activity of eosinophils was higher than that of neutrophils under either resting or phagocytizing conditions. Eosinophil HMP shunt activity also was stimulated by phorbol myristate acetate, a membrane- active agent. Eosinophils showed a marked incorporation of 125I into trichloroacetic acid-insoluble material under resting conditions, which increased markedly during phagocytosis. Eosinophils likewise showed a greater reduction of nitroblue tetrazolium dye during phagocytosis than did neutrophils. Measurement of other parameters of oxidative metabolism indicated that eosinophils generated superoxide anion following phagocytosis and also elicited a burst of chemiluminescence similar to that observed during phagocytosis by neutrophils. Measurement of NADPH oxidase activity demonstrated that this enzyme was 3-6 times more active in fractions isolated from eosinophils than in corresponding fractions isolated from neutrophils; this was observed over a range of substrate concentrations. The eosinophil enzyme sedimented differently than the neutrophil enzyme with differential centrifugation; neither showed sedimentation characteristics of peroxidase. These data indicate that eosinophils possess a similar, although in some ways more potent, oxidative burst than neutrophils and are consistent with a role for NADPH oxidase in the initiation of that burst.     

Risk factors for avascular bone necrosis in systemic lupus erythematosus

OBJECTIVE: To study the predictive factors for avascular necrosis (AVN) of bone in patients with systemic lupus erythematosus (SLE). METHOD: The records of 38 SLE patients who developed clinically apparent AVN during the course of their disease were reviewed. Information on clinical presentation, corticosteroid usage and autoantibody profiles was obtained, and comparison was made between these patients and 143 consecutive control SLE patients who did not have AVN. RESULTS: The point prevalence of AVN in our SLE population was 12%. Patients with AVN, when compared with controls, had a significantly higher incidence of neurological disease (39% vs 14%; P < 0.001) and Cushingoid body habitus after steroid treatment (79% vs 53%; P = 0.004). The highest cumulative prednisolone dose in 1 and 4 months was significantly higher in the AVN group than the controls (1.8 vs 1.1 and 4.5 vs 2.8 g, respectively; P < 0.01 in both) and showed a linear trend with the incidence of AVN (chi2 test for trend, P < 0.01 in both). Lupus anticoagulant was associated with AVN (P = 0.02, odds ratio 2.88 [1.14- 7.28]). Logistic regression analysis revealed that the highest cumulative prednisolone dose administered in 4 months, the maximum and mean daily prednisolone dosage, and the lupus anticoagulant were independent risk factors for AVN. CONCLUSIONS: Corticosteroid remains the major predisposing factor for AVN in SLE. Patients who require an initial high-dose steroid for disease control are at risk of AVN, especially if they are positive for the lupus anticoagulant or develop Cushingoid habitus after steroid treatment. High-risk patients should be closely monitored so that early AVN can be diagnosed by sensitive techniques such as magnetic resonance imaging and radioisotope bone scanning.      

Modulation of spontaneous outgrowth of Epstein-Barr virus immortalized B-cell clones by granulocyte-macrophage colony-stimulating factor and interleukin-3

Spontaneous outgrowth of immortalized Epstein-Barr virus (EBV) infected B-cell clones will occur from cultures of peripheral blood mononuclear cells (PBMNCs) of some persons with a history of EBV infection. We determined that outgrowth of such clones may be reproducibly modulated by supplementation of cultures with the hematopoietic growth factors GM- CSF and interleukin-3 (IL-3). Continuous supplementation of cultures with GM-CSF facilitates emergence of immortalized B-cell clones, whereas supplementation with IL-3 completely prevents their emergence. The effect of GM-CSF may be direct, at least in part, as the proliferation of pure clones of EBV-transformed B lymphocytes was augmented in response to GM-CSF. An indirect mechanism appears to be responsible for the inhibition of transformed B-cell outgrowth in response to IL-3, as IL-3 had no inhibitory effect on proliferation of pure transformed B-cell clones and IL-3-mediated inhibition could be eliminated by antibody neutralization of gamma-interferon (gamma-IFN) or tumor necrosis factor-alpha (TNF-alpha) early in culture. The mechanisms of these effects deserve further study and may have clinical relevance to use of hematopoietic growth factors for support of bone marrow (BM) function in immunocompromised patients.     

Pulp revascularization for immature replanted teeth: a case report

Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8‐year‐old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow‐up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra‐alveolar period and maintained in a viable storage medium may be treated with revascularization.