Breaking the Barrier: A Study on Multi-drug Resistance in Breast Abscess at an Academic Malaysian Hospital.

BACKGROUND: In recent years, the increase in antibiotics usage locally has led to a worrying emergence of multi-drug resistant organisms (MDRO), with the Malaysian prevalence rate of methicillin-resistant Staphylococcus aureus (MRSA) ranging from 17.2 to 28.1% between 1999 and 2017. A study has shown that 7% of all non-lactational breast abscesses are caused by MRSA. Although aspiration offers less morbidities compared to surgical drainage, about 20% of women infected by MRSA who initially underwent aspiration subsequently require surgical drainage. This study is conducted to determine the link between aetiology, antimicrobial resistance pattern and treatment modalities of breast abscesses. METHODS: Retrospective study of reviewing microbiology specimens of breast abscess patients treated at Universiti Malaya Medical Centre from 2015 to 2020. Data collected from microbiology database and electronic medical records were analysed using SPSS V21. RESULT: A total of 210 specimens from 153 patients were analysed. One-fifth (19.5%) of the specimens isolated were MDRO. Lactational associated infections had the largest proportion of MDR in comparison to non-lactational and secondary infections (38.5%, 21.7%, 25.7%, respectively; p = 0.23). Staphylococcus epidermidis recorded the highest number of MDR (n = 12) followed by S. aureus (n = 8). Adjusted by aetiological groups, the presence of MDRO is linked to failure of single aspirations (p = 0.554) and significantly doubled the risk of undergoing surgical drainage for resolution (p = 0.041). CONCLUSION: MDR in breast abscess should be recognised as an increasing healthcare burden due to a paradigm shift of MDRO and a rise of resistance cases among lactational associated infection that were vulnerable to undergo surgical incision and drainage for resolution.

Cytoprotective Effects of the Tiger's Milk Mushroom Lignosus rhinocerotis (Agaricomycetes) Sclerotia against Oxidative Stress in PC12 Cells.

Lignosus rhinocerotis (Cooke) Ryvarden has been reported to possess numerous pharmacological effects. However, little is known about its potential role in mitigating the detrimental effects of oxidative stress. The present study investigated the cytoprotective effects of L. rhinocerotis extracts against hydrogen peroxide (H2O2)-induced oxidative stress of rat pheochromocytoma (PC12) cells. In the pre-treatment model, PC12 cells were pre-treated with aqueous (LRAQ) or ethanolic (LRET) extracts of L. rhinocerotis for 24 h, followed by 30 µM of H2O2 for 24 h. In the co-treatment model, the cells were incubated with LRAQ or LRET and H2O2 for 2 or 24 h to induce oxidative stress. Cell viability, intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential (MMP), and apoptotic cells with activated caspase-3/7 were quantified. Additionally, LRET was separated into fractions by chromatographic methods prior to analysis by gas chromatography-mass spectrometry (GCMS). 320 µg/ml aqueous extract showed a significant cytoprotective effect of 70.0 ± 22.4% and 133.92 ± 8.8% in the pre-treatment and co-treatment models, respectively, compared to untreated H2O2-challenged cells. LRAQ also showed a reduction (p < 0.05) in the percentage of depolarized cells of 37.6 ± 0.6% at 640 ug/ml and 53.4 ± 4.5% at 320 ug/ml in the pre-treatment and co-treatment models, respectively, compared to untreated H2O2-challenged cells. LRAQ or LRET showed a reduction (p < 0.01) in caspase 3/7 activity compared to untreated H2O2-challenged cells in the co-treatment model. However, LRAQ or LRET did not reduce excessive ROS formation (p > 0.05). The cytoprotective effects could be attributed to the presence of fatty acids, phenols, phytosterols, and dicarboxylic acids. In conclusion, L. rhinocerotis extracts demonstrated cytoprotective effects against H2O2-induced oxidative stress in an in vitro model, contributing to the maintenance of cellular integrity through the regulation of mitochondrial function and apoptosis.

Anti- and Pro-Oxidant Properties of Essential Oils against Antimicrobial Resistance.

The rapid evolution of antimicrobial resistance (AMR) has remained a major public health issue, reducing the efficacy of antibiotics and increasing the difficulty of treating infections. The discovery of novel antimicrobial agents is urgently needed to overcome the challenges created by AMR. Natural products such as plant extracts and essential oils (EOs) have been viewed as potential candidates to combat AMR due to their complex chemistry that carries inherent pro-oxidant and antioxidant properties. EOs and their constituents that hold pro-oxidant properties can induce oxidative stress by producing reactive oxygen species (ROS), leading to biological damage in target cells. In contrast, the antioxidant properties scavenge free radicals through offsetting ROS. Both pro-oxidant and antioxidant activities in EOs represent a promising strategy to tackle AMR. Thus, this review aimed to discuss how pro-oxidants and antioxidants in EOs may contribute to the mitigation of AMR and provided a detailed description of the challenges and limitations of utilizing them as a means to combat AMR.

Defining the optimal time to appendectomy: A step toward precision surgery.

BACKGROUND: We aimed to investigate the association between time from admission to appendectomy on perioperative outcomes in order to determine optimal time-to-surgery windows. METHODS: We performed a retrospective review of all the appendectomies performed between July 2018 to May 2020. We first compared the perioperative outcomes using preselected time-to-surgery cut-offs, then determined optimal safe windows for surgery, and finally identified subgroups of patients who may require early intervention. RESULTS: Six hundred twenty-one appendectomies were performed in the time period. The patients with a time-to-surgery of ≥12 hours had a significantly longer length of stay (median 2 days [interquartile range 1-3] vs 3 days [interquartile range 2-4], mean difference = 0.74 [95% confidence interval 0.32-1.17, P = .0006]) and higher 30-day readmission risk (odds ratio 2.58, 95% confidence interval 1.12-5.96, P = .0266) versus those with a time-to-surgery of <12 hours. These differences persisted when the time-to-surgery was dichotomized by <24 or ≥24 hours. A time-to-surgery beyond 25 hours was associated with a 3.34-fold increased odds of open conversion (P = .040), longer operation time (mean difference 15.8 mins, 95% confidence interval 3.4-28.3, P = .013) and longer postoperative length of stay (mean difference 10.3 hours, 95% confidence interval 3.4-20.2, P = .042) versus a time-to-surgery of <25 hours. The patients with time-to-surgery beyond 11 hours had a 1.35-fold increased odds of 30-day readmission (95% confidence interval 1.02-5.43, P = .046) compared with those who underwent appendectomy before 11 hours. Older patients, patients with American Society of Anesthesiologist score II to III, and individuals with long duration of preadmission symptoms had higher risk of prolonged operation time, open conversion, increased length of stay, and postoperative morbidity with increasing time-to-surgery. CONCLUSION: This study identified the safe windows for appendectomy to be 11 to 25 hours from admission for most perioperative outcomes. However, certain patient subgroups may be less tolerant of surgical delays.

CXCR3 signalling partially contributes to the pathogenesis of neuropathic pain in male rodents.

BACKGROUND: Currently, there is a lack of effective therapy for chronic pain. Increasing evidence has shown that chemokines and their correlative receptors involved in the neuron-glial cell cross-talk could contribute to the pathogenesis of neuropathic pain. Our previous studies suggested that CXCR3 expression was elevated in the spinal dorsal horn after nerve injury. OBJECTIVES: In this study, we aimed to explore the role of CXCR3 signalling in chronic pain modulation. METHODS: Reverse transcription quantitative PCR and Western blotting were used to measure the expression of CXCR3 and its ligands in the spinal cord following chronic constriction injury (CCI) of the sciatic nerve. Cxcr3 -knockout mice were used to observe the effect of the receptor on pain-related behaviour and microglial activation. Immunohistochemistry was used to investigate the expression of two activation markers for spinal microglia, Iba-1 and phosphorylated-p38 (p-p38) in these mice. RESULTS: The expression of CXCR3 and its ligand CXCL11 was upregulated in the lumbar dorsal horn of the spinal cord in CCI models. In Cxcr3 -knockout mice, CCI-induced tactile allodynia and thermal hyperalgesia were observed to be alleviated during the early stage of pain processing. Meanwhile, the expression of the glial activation markers, namely, Iba-1 and p-p38, was decreased. CONCLUSION: Our results demonstrate that CXCR3 could be a key modulator involved in pain modulation of the spinal cord; therefore, CXCR3-related signalling pathways could be potential targets for the treatment of intractable pathological pain.

Neuritin Protein Expression Is Positively Correlated with Neurite Outgrowth Induced by the Tiger Milk Mushroom, Lignosus rhinocerotis (Agaricomycetes), in PC12 Cells.

Neuritin is important in neuritogenesis, neurite arborization, and neurite extension. Lignosus rhinocerotis sclerotia extracts and nerve growth factor (NGF) have been well documented to possess positive neurite stimulatory effects. However, the correlation of neuritin expression with neurite outgrowth of L. rhinocerotis and NGF cotreatment of PC12 cells remains unknown. Thus, the present study investigated neuritin expression in PC12 cells treated with 5 ng/mL of NGF and L. rhinocerotis extracts (20-1280 µg/mL) concurrently for 48 h. The neurite outgrowth score was quantitated, and total protein was harvested for enzyme-linked immunosorbent assay. There was a significant difference (P = 0.051) in neuritin protein abundance in 640 µg/mL of L. rhinocerotis aqueous cotreatment with 5 ng/mL of NGF-treated cells (5 ± 0.39 ng/mL) and 50 ng/mL of NGF-treated PC12 cells (5 ± 0.48 ng/mL) compared to untreated cells (1.9 ± 0.65 ng/ mL), with an average neurite length of 98 ± 3.66, 106 ± 3.00, and 73 ± 4.79 µm, respectively. Expression of microtubule element ß3 tubulin was increased in PC12 cells treated with 50 ng/mL of NGF (3.5 ± 0.21-fold) and also cells cotreated with 640 µg/mL of extract and 5 ng/mL of NGF (4.9 ± 0.29-fold) compared to untreated cells. Upregulation of ß3 tubulin expression in this study confirmed the elongation of PC12 cell processes. Correlation analysis showed that neuritin protein abundance is positively proportional to the average neurite length in PC12 cells cotreated with L. rhinocerotis extract and 5 ng/mL of NGF. This study highlights that neuritin modulation is involved in neurite outgrowth induced by L. rhinocerotis treatment. To our knowledge, this is the first report to show that tiger milk mushroom extracts induce neuritin expression.

Draft Genome Sequence of Lactarius deliciosus Strain CBS 582.63 from the CBS-KNAW Culture Collection.

A type strain of Lactarius deliciosus was obtained from the CBS-KNAW culture collection. The mycelium was cultured using potato dextrose agar, and the extracted genomic DNA was subjected to PacBio genome sequencing. Upon assembly and annotation, the genome size was estimated to be 54 Mbp, with 12,753 genes.

Clinacanthus Nutans Hexane Extracts Induce Apoptosis Through a Caspase-Dependent Pathway in Human Cancer Cell Lines

Background: Clinacanthus nutans (C.nutans) is a plant consumed as a cancer treatment in tropical Asia. Despite the availability of numerous anecdotal reports, evaluation of active anticancer effects has remained elusive. Therefore we here examined antiproliferative, reactive oxygen species (ROS)-inducing and apoptosis mechanisms of whole plant extracts in different cancer cell lines. Methods: Antiproliferative actions of five solvent extracts (hexane, chloroform, ethyl acetate, methanol and water) of C.nutans were tested on non-small cell lung cancer (A549), nasopharygeal cancer (CNE1) and liver cancer (HepG2) cells using MTT assay. The most potent anticancer extract was then assessed by flow cytometry to study cell cycle changes . Intracellular levels of ROS were quantified by DCFH-DA assay. Involvement of the caspase pathway in induction of apoptosis was assessed using caspase assay kits. GC-MS analysis was performed to identify phytoconstituents in the extracts. Results: Hexane and chloroform extracts were antiproliferative against all three cell lines, while the ethyl acetate extract, at 300 µg/mL, was antiproliferative in the CNE1 but not A549 and HepG2 cases. Methanol and water extracts did not inhibit cancer cell proliferation. The most potent anticancer hexane extract was selected for further testing. It induced apoptosis in all three cell lines as shown by an increase in the percentage of cell in sub-G1 phase. Dose-dependent increase in ROS levels in all three cell lines indicated apoptosis to be possibly modulated by oxidative stress. At high concentrations (>100 µg/mL), hexane extracts upregulated caspases 8, 9 and 3/7 across all three cell lines. GC-MS analysis of the hexane extract revealed abundance of 31 compounds. Conclusion : Among the five extracts of C.nutans, that with hexane extract demonstrated the highest antiproliferative activity against all three cancer cell lines tested. Action appeared to be via ion of intracellular ROS, and induction of apoptosis via intrinsic and extrinsic caspase pathways.

Validation of the modified Ranson versus Glasgow score for pancreatitis in a Singaporean population.

BACKGROUND: The characteristics of patients with acute pancreatitis in multi-ethnic Singapore differ from that of the populations used in formulating the modified Ranson and Glasgow scores. The use of these scoring systems has not previously been validated in the Singaporean setting. This study aims to validate and compare the prognostic use of the modified Ranson and Glasgow scores, and to determine the superiority of one score over the other in predicting the outcome for acute pancreatitis in the Singaporean population. METHODS: This is a 3-year retrospective study of patients diagnosed with acute pancreatitis at our centre. Patients with chronic pancreatitis, acute on chronic pancreatitis, iatrogenic pancreatitis, pancreatic cancer as well as those with incomplete Ranson or Glasgow scores were excluded from the study. Case notes and computer records were reviewed for local complications of pancreatitis and organ failure. Receiver operator characteristic (ROC) curves of the Ranson and Glasgow scores were plotted for the prediction of severity and mortality. RESULTS: Between January 2010 and December 2012, 230 cases were diagnosed with acute pancreatitis. A majority of the patients had mild pancreatitis (n = 194, 84.3%), and the overall 30-day mortality rate was 3.5% (n = 8). ROC of the Ranson and Glasgow scoring systems for mortality showed an area under curve (AUC) of 0.854 (P = 0.001) and 0.776 (P = 0.008), respectively. For severity, the AUC for the modified Ranson and Glasgow score was calculated to be 0.694 and 0.668, respectively. CONCLUSIONS: The ROC curves of Ranson and Glasgow scores for mortality are comparable with that published in earlier studies. In a Singaporean population, the Ranson score is more accurate in the prediction of mortality. However, both scoring systems are poor predictors for severity of acute pancreatitis.

Alendronate Attenuates Spinal Microglial Activation and Neuropathic Pain.

UNLABELLED: Many derivatives of bisphosphonates, which are inhibitors of bone resorption, have been developed as promising agents for painful pathologies in patients with bone resorption-related diseases. The mechanism for pain relief by bisphosphonates remains uncertain. Studies have reported that bisphosphonates could reduce central neurochemical changes involved in the generation and maintenance of bone cancer pain. In this study, we hypothesized that bisphosphonates would inhibit spinal microglial activation and prevent the development of hyperalgesia caused by peripheral tissue injury. We investigated the effects of alendronate (a nitrogen-containing bisphosphonate) on the development of neuropathic pain and its role in modulating microglial activation in vivo and in vitro. Intrathecal and intraperitoneal administration of alendronate relieved neuropathic pain behaviors induced by chronic constriction sciatic nerve injury. Alendronate also significantly attenuated spinal microglial activation and p38 mitogen-activated protein kinase (MAPK) phosphorylation without affecting astrocytes. In vitro, alendronate downregulated phosphorylated p38 and phosphorylated extracellular signal regulated kinase expression in lipopolysaccharide-stimulated primary microglia within 1 hour, and pretreatment with alendronate for 12 and 24 hours decreased the expression of inflammatory cytokines (tumor necrosis factor α, and interleukins 1ß and 6). These findings indicate that alendronate could effectively relieve chronic constriction sciatic nerve injury-induced neuropathic pain by at least partially inhibiting the activation of spinal microglia and the p38 MAPK signaling pathway. PERSPECTIVE: Alendronate could relieve neuropathic pain behaviors in animals by inhibiting the activation of spinal cord microglia and the p38 MAPK cell signaling pathway. Therapeutic applications of alendronate may be extended beyond bone metabolism-related disease.

Ministry of Health Clinical Practice Guidelines: Anxiety Disorders.

The Ministry of Health (MOH) has developed the clinical practice guidelines on Anxiety Disorders to provide doctors and patients in Singapore with evidence-based treatment for anxiety disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on anxiety disorders, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Different peripheral tissue injury induces differential phenotypic changes of spinal activated microglia.

The purpose of this study is to investigate the possible different cellular marker expression associated with spinal cord microglial activation in different pain models. Immunohistochemistry and western blotting analysis of CD45, CD68, and MHC class I antigen as well as CD11b and Iba-1 in the spinal cord were quantitatively compared among widely used three pain animal models, complete Freund's adjuvant (CFA) injection, formalin injection, and chronic constriction injury (CCI) models. The results showed that significant upregulated expressions of CD45 and MHC class I antigen in spinal microglia as well as morphological changes with increased staining with CD11b and Iba-1 were seen in CCI and formalin models and not found in CFA-induced inflammatory pain model. CD68 expression was only detected in CCI model. Our findings suggested that different peripheral tissue injuries produced differential phenotypic changes associated with spinal microglial activation; peripheral nerve injury might induce spinal microglia to acquire these immunomolecular phenotypic changes.

Activation of Src family kinases in spinal microglia contributes to formalin-induced persistent pain state through p38 pathway.

UNLABELLED: Protein tyrosine phosphorylation has been implicated in normal and pathological functions such as cell proliferation, migration and differentiation. Recently, some studies have shown that Src family kinases (SFKs) were involved in neurological disorders and neuropathic pain states in which microglial activation plays a role. In the formalin test, we have reported that microglia undergo at least 2 distinct stages of activation on the basis of signaling events regarding p38 mitogen-activated protein kinases (MAPK). Here, we investigated the involvement of SFKs signaling in a formalin pain animal model and the association with p38 MAPK. Our results showed that SFKs were activated in the spinal microglia beginning 1 day after peripheral formalin injection lasting for 7 days. Pretreatment with SFK specific inhibitor PP2 could not inhibit formalin-induced spontaneous pain behaviors. However, PP2 inhibited formalin injury, induced persistent mechanical hyperalgesia, and reversed microglial phospho-p38 expression as well using immunohistostaining and Western blot at day 3 and 7 after injection. Our results suggested that the activation of the Src/p38MAPK signaling cascade in spinal microglia contributed to late stage persistent mechanical hyperalgesia evoked by formalin injection into the paw. PERSPECTIVE: This study presents unique properties of spinal microglial activation in a pain animal model. This finding could potentially help clinicians to further understand the contributions of spinal microglia to acute and persistent pain state.

Peripheral formalin injection induces unique spinal cord microglial phenotypic changes.

Microglia are resident immune cells of brain and activated by peripheral tissue injury. In the present study, we investigated the possible induction of several microglial surface immunomolecules in the spinal cord, including leukocyte common antigen (LCA/CD45), MHC class I antigen, MHC class II antigen, Fc receptor, and CD11c following formalin injection into the rat's hind paw. CD45 and MHC class I were upregulated in the activated microglia, which was evident on day 3 with the peak expression on day 7 following peripheral formalin injection. There was a very low basal expression of MHC class II, CD11c, and the Fc receptor, which did not change after the formalin injection. These results, for the first time, indicate that peripheral formalin injection can induce phenotypic changes of microglia with distinct upregulation of CD45 and MHC class I antigen. The data suggest that phenotypic changes of the activated microglia may be a unique pattern of central changes following peripheral tissue injury.