Three-year epidemiology of hospitalised paediatric burn patients in a Malaysian Tertiary Hospital 2016 - 2018.

INTRODUCTION: Burn injuries incur not just significant morbidity but also long-term psychosocial impact. This study aims to identify the clinico-demographics of children hospitalised for burns and factors associated with prolonged hospitalisation. MATERIALS AND METHODS: Written medical records of burn patients admitted to the Sultanah Aminah Hospital paediatric surgical ward, from January 2016 to December 2018, were retrospectively reviewed. Details on the patients' socio-demographic background, burn injuries, management and outcomes were recorded and analysed with logistic regression. RESULTS AND CONCLUSION: Of the 255 children included in the study, the majority were males (62.7%), children aged between 1 to 3 years (43.1%), and of the Malay ethnic group (83.1%). The commonest injury mechanism was scalds burns (81.2%). Staphylococcus aureus remained the commonest organism cultured from paediatric burn wounds. Most patients (66.4%) were hospitalised for less than 1 week. A significant number of patients experienced complications from their injuries. Multivariate analysis showed burns affecting total body surface area > 10% (adjusted OR, 13.45 [95% CI 6.25 - 28.96]; p = < 0.001) and non-scald burns (adjusted OR, 2.70 [95% CI 1.12 - 6.50]; p = 0.027) were the two main factors associated with prolonged hospitalisation of more than 1 week. These findings describing the epidemiology and outcomes of paediatric burn cases in a tertiary centre in Malaysia may inform future practice. More importantly, the information may contribute to the identification of at-risk populations and advise the development of effective prevention strategies to reduce the incidence and morbidity associated with paediatric burns in this region.

Role of oral flora in chemotherapy-induced oral mucositis in vivo.

OBJECTIVE: To determine if commensal oral microflora impacts the severity of chemotherapy-induced oral mucositis (OM). DESIGN: Specific-pathogen-free (SPF) and germ-free Swiss Webster mice in the experimental groups were dosed with 5-fluorouracil (5-FU) to induce OM. Mice in the control group received phosphate buffered saline. Comparative analyses of the epithelial thickness and cell proliferation/turnover rates, as well as the expression levels of metalloproteinases and pro-inflammatory mediators in the oral mucosa between the control and experimental groups were determined by histopathological and immunohistochemical analyses. RESULTS: 5-FU-treated SPF and germ-free mice showed characteristic features of OM with reduced oral epithelial thickness, presence of inflammatory cells in the connective tissues, and increased levels of expression of metalloproteinases and pro-inflammatory cytokines compared to the respective control groups. When 5-FU-treated SPF and germ-free mice were compared, 5-FU-treated germ-free mice exhibited less severe epithelial destruction with higher expression of the cell proliferation marker Ki67, coupled with lower expression levels of metalloproteinases and pro-inflammatory cytokine in the oral mucosa. CONCLUSION: This study provides the first histopathological evidence that oral flora has a detrimental effect on chemotherapy-induced OM in vivo.

Bacterial species associated with persistent apical periodontitis exert differential effects on osteogenic differentiation.

AIM: To determine if bacteria associated with persistent apical periodontitis induce species-specific pro-inflammatory cytokine responses in macrophages, and the effects of this species-specific microenvironment on osteogenic differentiation. METHODOLOGY: Macrophages were exposed to Enterococcus faecalis, Streptococcus oralis, Streptococcus mitis, Fusobacterium nucleatum, Treponema denticola or Tannerella forsythia, and levels of TNF-α and IL-1ß elicited were determined by immunoassay. Following treatment of MG-63 pre-osteoblasts with conditioned media from bacteria-exposed macrophages, osteogenic differentiation and viability of osteoblasts were analyzed by Alizarin Red Staining and MTS assay, respectively. Statistical analysis was carried out by one-way anova with the Tukey post-hoc test. Differences were considered to be significant if P < 0.05. RESULTS: Macrophages exposed to Gram-positive bacteria did not produce significant amounts of cytokines. F. nucleatum-challenged macrophages produced up to four-fold more TNF-α and IL-1ß compared to T. denticola or T. forsythia. Only conditioned media from macrophages treated with Gram-negative bacteria decreased mineralization and viability of osteoblasts. CONCLUSIONS: Gram-positive bacteria did not impact osteogenic differentiation and appeared innocuous. Gram-negative bacteria, in particular F. nucleatum elicited an enhanced pro-inflammatory response in macrophages, inhibited osteogenic differentiation and reduced cell viability. The findings suggest that the presence of this organism could potentially increase the severity of persistent apical periodontitis.

Secreted adenosine triphosphate from Aggregatibacter actinomycetemcomitans triggers chemokine response.

Extracellular ATP (eATP) is an important intercellular signaling molecule secreted by activated immune cells or released by damaged cells. In mammalian cells, a rapid increase of ATP concentration in the extracellular space sends a danger signal, which alerts the immune system of an impending danger, resulting in recruitment and priming of phagocytes. Recent studies show that bacteria also release ATP into the extracellular milieu, suggesting a potential role for eATP in host-microbe interactions. It is currently unknown if any oral bacteria release eATP. As eATP triggers and amplifies innate immunity and inflammation, we hypothesized that eATP secreted from periodontal bacteria may contribute to inflammation in periodontitis. The aims of this study were to determine if periodontal bacteria secrete ATP, and to determine the function of bacterially derived eATP as an inducer of inflammation. Our results showed that Aggregatibacter actinomycetemcomitans, but not Porphyromonas gingivalis, Prevotella intermedia, or Fusobacterium nucleatum, secreted ATP into the culture supernatant. Exposure of periodontal fibroblasts to filter sterilized culture supernatant of A. actinomycetemcomitans induced chemokine expression in an eATP-dependent manner. This occurred independently of cyclic adenosine monophosphate and phospholipase C, suggesting that ionotrophic P2X receptor is involved in sensing of bacterial eATP. Silencing of P2X7 receptor in periodontal fibroblasts led to a significant reduction in bacterial eATP-induced chemokine response. Furthermore, bacterial eATP served as a potent chemoattractant for neutrophils and monocytes. Collectively, our findings provide evidence for secreted ATP of A. actinomycetemcomitans as a novel virulence factor contributing to inflammation during periodontal disease.

Fusobacterium nucleatum induces cytokine production through Toll-like-receptor-independent mechanism.

AIM: To determine whether Fusobacterium nucleatum's ability to invade cells allows the bacteria to activate pro-inflammatory response through cytosolic pattern recognition receptors, independent of surface Toll-like receptors (TLRs). METHODOLOGY: HEK293T cells, which lack endogenous TLRs, and overexpressing dominant negative myeloid differentiation primary response gene 88 (MyD88DN) protein, were infected with F. nucleatum and the production of interleukin-8 (IL-8) was determined. The necessity for intracellular invasion of the bacteria for cytokine production was also investigated by blocking bacterial invasion with cytochalasin D. The roles of NFĸB and p38 mitogen-activated protein kinase (MAPK) and nucleotide-binding oligomerization domain-1 (NOD-1) signalling pathways in F. nucleatum-induced IL-8 secretion were determined. RESULTS: Fusobacterium nucleatum-infected HEK293T cells produced IL-8 independent of the MYD88 signalling. This response was inhibited by preventing F. nucleatum invasion into HEK293T cells. p38 MAPK but not the NFĸB signalling pathway was required for F. nucleatum-mediated IL-8 production. HEK293T cells expressed NOD-1 but not NOD-2. Yet, inhibition of NOD-1 signalling did not affect F. nucleatum-induced IL-8 secretion. CONCLUSIONS: Fusobacterium nucleatum invasion led to cytokine production, which is mediated by the p38 MAPK signalling but independent of TLRs, NOD-1, NOD-2 and NFĸB signalling.

Over-investigated and under-treated: children with febrile convulsion in a Malaysian district hospital.

INTRODUCTION: We conducted a retrospective audit on the inpatient assessment and care of children admitted with febrile convulsion to Hospital Batu Pahat, a district hospital in Malaysia, using the Malaysian national clinical practice guidelines and the American Academy of Paediatrics practice parameters on febrile convulsion as the reference standards. METHODS: The case notes of 100 consecutive children admitted in 2004 were analysed. The documentation of major clinical features, selection of investigations, the timeliness of antipyresis and frequency of parental education were evaluated. RESULTS: In general, the major clinical features that were relevant to the presenting problem were adequately documented, although fever was not mentioned as a presenting complaint in one quarter of the cases. On an average, about five investigations were ordered for every patient on admission. There was no major difference in the number of investigations conducted between children who were more severely ill and the rest of the patients. The majority of the investigations did not yield any useful diagnostic information. Only 38 percent of the children received antipyretics and 53 percent were tepid-sponged during fever, with 23 percent having received tepid-sponging without concurrently receiving antipyretics. No parental education on febrile convulsion was recorded in half of the cases. CONCLUSION: Excessive unjustified investigations, deficient antipyresis when required and inadequate communication with the family of children with febrile convulsion were observed. Awareness of such deficiencies from this audit should lead to regular staff education, monitoring and future audits in order to improve the quality of our clinical care.