MyMedR

Antibacterial alkaloids from Artabotrys crassifolius Hook.f. & Thomson

Tan KK, Khoo TJ, Rajagopal M, Wiart C

Nat Prod Res, 2015;29(24):2346-9.

PMID: 25738993 DOI: 10.1080/14786419.2015.1013954

Chloroform extract of bark of Artabotrys crassifolius Hook.f. & Thomson exhibited antibacterial activities against both American Type Culture Collection and clinical bacterial strains in vitro with zones of inhibition ranging from 7 to 14 mm. Further analysis of this extract yielded artabotrine, liridine, lysicamine and atherospermidine. Artabotrine displayed a broad array of antibacterial activity mostly against Gram-positive bacteria with minimum inhibitory concentration (MIC) values ranging from 1.25 μg/mL to 5 μg/mL. Of note, artabotrine, liridine and lysicamine are bactericidal against Gram-negative extended-spectrum beta-lactamase-producing Klebsiella with MIC values equal 2.5, 2.5 and 10 μg/mL, respectively, and minimum bactericidal concentrations values equal to 2.5, 5 and 20 μg/mL.

Fulltext Management of isolated splenic injuries after blunt trauma: an institution's experience over 6 years

Tan KK, Chiu MT, Vijayan A

Med J Malaysia, 2010 Dec;65(4):304-6.

PMID: 21901951

Forty-two patients with traumatic blunt splenic injuries were admitted over a six year period. Vehicular-related collisions and fall from height accounted for the injuries in 38 (90.5%) of them. Eleven (26.2%) underwent immediate surgery (7 splenectomy and 4 splenorrhaphy), while the remaining 31 patients were treated nonoperatively of which 3 underwent angio-embolisation. Twenty seven patients had either grade III or IV splenic injuries. Operative management was more likely in patients with lower haemoglobin or with more severe splenic injury. Nonoperative management can be adopted in patients with blunt isolated splenic injuries but operative management is still indispensable in certain instances.

Fulltext Syringocystadenoma papilliferum arising in a naevus sebaceous

Faheem NAA, Kwan Z, Yong ASW, Ch'ng CC, Tan KK, Naicker M, et al.

Malays J Pathol, 2019 Apr;41(1):47-49.

PMID: 31025637

Naevus sebaceus is a cutaneous hamartoma with the potential of developing into benign or malignant neoplasms. Syringocystadenoma papilliferum (SCAP) have been reported to originate from naevus sebaceus. SCAP is a rare, benign adnexal skin tumour of apocrine or eccrine type of differentiation which typically presents as a nodule or a plaque on the scalp or face. We report a case of syringocystadenoma papilliferum arising in an undiagnosed pre-existing naevus sebaceus in a 56-year-old female.

Fulltext Neonatal rash - a case study

Kwa SK, Sinniah D, Tan KK

Aust Fam Physician, 2012 Sep;41(9):707-9.

PMID: 22962649

An infant, aged 48 days, is brought in by her mother to her doctor because of a rash that started during the neonatal period.

Fulltext Pneumonia presenting as acute abdomen in children: a report of three cases

Vendargon S, Wong PS, Tan KK

Med J Malaysia, 2000 Dec;55(4):520-3.

PMID: 11221169

From 10th September 1998 till 5th June 1999, the Paediatric and Cardiothoracic Surgery Units of Sultanah Aminah Hospital Johor Bahru managed three children with lung collapse secondary to pneumonia. The dominant initial clinical presentation in all three cases was acute abdominal pain. Basal pneumonia was diagnosed in two cases post-operatively after surgical contributory causes were excluded intra-operatively. Thoracotomy, evacuation of infected debris and decortication of the collapsed lung was done in all three cases. In children presenting with acute abdominal pain, basal pneumonia should be considered as a possible contributory cause.

Fulltext Successful closure of a recto-prostatic fistula

Koh KB, Wightman JA, Tan KK

Med J Malaysia, 1997 Mar;52(1):94-6.

PMID: 10968063

Recto-prostatic fistula is a rare complication of prostatic surgery, occurring usually because surgical planes are not appreciated. We describe a combined abdomino-perineal approach for the repair of a large recto-prostatic fistula with the interposition of omentum and gracilis without formally closing the fistula in layers.

Hemothorax due to hemorrhagic disease of the newborn

Kaur P, Tan KK

Acta Paediatr Jpn, 1994 Feb;36(1):95-6.

PMID: 8165919

A three day old male, term infant with hemothorax due to hemorrhagic disease of the newborn was treated successfully with vitamin K and thoracocentesis. Exclusive breast feeding and absence of vitamin K prophylaxis were important diagnostic clues, although hemothorax as a sole manifestation of hemorrhagic disease of the newborn is rare. This case highlighted the good prognosis of an uncommon complication when prompt diagnosis and appropriate treatment are instituted. The importance of vitamin K prophylaxis to all newborns is emphasized.

Unusual ritual burns of the hand

Tay YG, Tan KK

Burns, 1996 Aug;22(5):409-12.

PMID: 8962663

Six hands from five patients were seen with full-thickness burns following a ritual practice between June 1993 and June 1994. Three hands were treated with excision and medium-thickness split-skin grafts, one patient was treated with a medium-thickness split skin graft taken from the instep of the foot. The first patient with bilateral burns of the palms refused surgery and returned 3 months later with contractures of the palms. The results of the treated hands are presented.

Importance of a thorough examination

Pau WS, Tan KK

Pediatr Infect Dis J, 2008 Jun;27(6):569-70.

PMID: 18449061 DOI: 10.1097/INF.0b013e318168db08

Scrub typhus is a common cause of febrile illness among children from rural regions in tropical countries. We described 2 cases of scrub typhus with an eschar localized in the genitalia that was missed during the routine medical examination of a febrile child.

Fulltext Estimating the population health and economic impacts of introducing a pneumococcal conjugate vaccine in Malaysia- an economic evaluation

Shafie AA, Ahmad N, Naidoo J, Foo CY, Wong C, Pugh S, et al.

Hum Vaccin Immunother, 2020 07 02;16(7):1719-1727.

PMID: 31951782 DOI: 10.1080/21645515.2019.1701911

Pneumococcal disease is a potentially fatal bacterial infection that is vaccine-preventable. Malaysia has yet to adopt a pneumococcal conjugate vaccine (PCV) into its national immunization program (NIP). In 2016, pneumonia was the 3rd leading cause of death in children under five in Malaysia, accounting for 3.8% of under-five deaths. Introducing a pneumococcal conjugate vaccine (PCV) is an effective strategy to reduce the disease burden. This study used a decision-analytic model to assess the potential impacts of introducing the available PCVs (13-valent and 10-valent) in Malaysia. Epidemiological and costs inputs were sourced from published literature. For each vaccination program, health outcomes and associated healthcare costs were estimated. The scenarios of initiating PCV13 vs. PCV10 and the status quo (no pneumococcal vaccine) were compared. Serotype trends of Finland and the U.K. were used to model the clinical impacts of PCV10 and PCV13 respectively. The base-case analysis used a societal perspective over a 5-year time horizon. Compared with PCV10, PCV13 was projected to avert an additional 190,628 cases of pneumococcal disease and 1126 cases of death. The acquisition of PCV13 was estimated to cost an incremental US$89,904,777, offset by a cost reduction of -US$250,219,914 on pneumococcal disease-related medical care and lost productivity. PCV13 demonstrated a higher cost-saving potential over PCV10. Compared with no vaccination, PCV13 was estimated as cost-saving. Results were robust across a series of sensitivity analyses. The introduction of PCV13 in a NIP was estimated to reduce a significant burden of disease and to be a cost-saving for the Malaysian health system.

Fulltext Emotional exhaustion is associated with work related stressors: a cross-sectional multicenter study in Malaysian public hospitals

Khoo EJ, Aldubai S, Ganasegeran K, Lee BX, Zakaria NA, Tan KK

Arch Argent Pediatr, 2017 06 01;115(3):212-219.

PMID: 28504485 DOI: 10.5546/aap.2017.eng.212

INTRODUCTION: Emotional exhaustion is an important component of burnout. Burnout is common among doctors. It affects the physical and mental health of doctors, their performance and the quality of care they provide. This study aimed to investigate the level and factors associated with emotional exhaustion among doctors in pediatric practice in Malaysia.

POPULATION AND METHODS: A self-administered questionnaire was used in this multicenter cross-sectional study. It included questions on the socio-demographics, work characteristics, Emotional Exhaustion, Perceived Stress Scale and sources of job stress. Descriptive, univariate and multivariate analysis were conducted using the SPSS software.

RESULTS: A total of 197 doctors working in the Pediatric department in eight hospitals returned complete questionnaire. High and moderate emotional exhaustion was reported by 25.4% and 24.4% doctors, respectively. In bivariate analysis, 29 out of the 38 items of sources of stress showed significant association with emotional exhaustion (p <0.05).The significant predictors of emotional exhaustion in the multivariate analysis were: scoring higher on the Perceived Stress Score, dealing with patient's psychosocial problems, disrespectful interactions with colleagues/ subordinates, lack of appreciation from supervisors, lack of incentives and promotions, time pressures and deadlines to meet, and setting unrealistic goals of having them imposed on oneself (p <0.05). The most common source of stress was dealing with difficult parents (80.2%).

CONCLUSIONS: Emotional exhaustion is associated with sources of stress in the workplace but not with socio-demographic factors.

Fulltext Parental preferences with regards to disclosure following adverse events occurring in relation to medication use or diagnosis in the care of their children - perspectives from Malaysia

Wong CH, Tan TR, Heng HY, Ramesh T, Ting PW, Lee WS, et al.

Med J Malaysia, 2016 Aug;71(4):186-192.

PMID: 27770117

Open disclosure is poorly understood in Malaysia but is an ethical and professional responsibility. The objectives of this study were to determine: (1) the perception of parents regarding the severity of medical error in relation to medication use or diagnosis; (2) the preference of parents for information following the medical error and its relation to severity; and (3) the preference of parents with regards to disciplinary action, reporting, and legal action.

Fulltext Prolonged treatment with omeprazole does not improve the eradication rate of Helicobacter pylori infection--a short report [corrected]

Goh KL, Parasakthi N, Peh SC, Anderson PE, Tan KK

Singapore Med J, 1995 Dec;36(6):619-20.

PMID: 8781634

Omeprazole has been shown to have a suppressive effect on Helicobacter pylori. The aim of this study was to determine if prolonged treatment with omeprazole would result in a higher eradication rate than short course treatment. Twenty patients with endoscopy proven duodenal ulcers and unequivocal evidence of Helicobacter pylori (HP) infection based on culture, histology, urease test and Gram's stain of a fresh tissue smear were treated with omeprazole 40 mg om for 2-4 weeks. Following ulcer healing, patients received either maintenance omeprazole 20 mg om or placebo for up to one year. All 20 patients had healed ulcers following a 2-4 week course of omeprazole 40 mg om.. All were negative for HP at the end of treatment. Thirteen patients received short course therapy with omeprazole only, followed by placebo. On follow-up endoscopy at 3 months, only one of 13 (7.7%) had eradicated the bacteria. Seven patients received maintenance treatment with omeprazole 20mg om for one year. Following completion of treatment, patients were followed up at 1, 3 and 6 months. Only one of 7 (14.3%) patients had eradicated the infection on long term follow-up. The eradication rates of HP with both short and long course omeprazole monotherapy were low.

Fulltext Rarity of sarcoidosis in Malaysia. Report of a case.

Tang KY, Khoo OT, Tan KK

Singapore Med J, 1964 Sep;4(3):115-21.

PMID: 14232046

A case of sarcoidosis is reported in the hope that this seemingly rare disease in Malaysia will be better recognised. A brief review of the literature is made and various points regarding the aetiology, pathology, clinical features and diagnosis are discussed.

Virus Propagation and Cell-Based Colorimetric Quantification

Tan JY, Wong JE, Zainal N, AbuBakar S, Tan KK

J Vis Exp, 2023 Apr 07.

PMID: 37092849 DOI: 10.3791/64578

Zika virus (ZIKV) is a mosquito-borne virus belonging to the genus Flavivirus. ZIKV infection has been associated with congenital brain abnormalities and potentially Guillain-Barré syndrome in adults. Research on ZIKV to understand the disease mechanisms is important to facilitate vaccine and treatment development. The method of quantifying viruses is crucial and fundamental in the field of virology. The focus forming assay (FFA) is a virus quantification assay that detects the viral antigen with antibodies and identifies the infection foci of cells using the peroxidase immunostaining technique. The current study describes the virus propagation and quantification protocol using both 24-well and 96-well (high throughput) formats. Compared with other similar studies, this protocol has further described foci size optimization, which can serve as a guide to expand the use of this assay for other viruses. Firstly, ZIKV propagation is performed in Vero cells for 3 days. The culture supernatant containing ZIKV is harvested and quantitated using the FFA. Briefly, the virus culture is inoculated onto Vero cells and incubated for 2-3 days. Foci formation is then determined after optimized staining processes, including cell fixation, permeabilization, blocking, antibody binding, and incubation with peroxidase substrate. The stained virus foci are visualized using a stereo microscope (manual counting in 24-well format) or software analyzer (automated counting in 96-well format). The FFA provides reproducible, relatively fast results (3-4 days) and is suitable to be used for different viruses, including non-plaque-forming viruses. Subsequently, this protocol is useful for the study of ZIKV infection and could be used to detect other clinically important viruses.

Monitoring Changes in Human Umbilical Vein Endothelial Cells upon Viral Infection Using Impedance-Based Real-Time Cell Analysis

Wong JE, Zainal N, AbuBakar S, Tan KK

J Vis Exp, 2023 May 05.

PMID: 37212555 DOI: 10.3791/64887

Endothelial cells line the inner surface of all blood and lymphatic vessels, creating a semi-permeable barrier regulating fluid and solute exchange between blood or lymph and their surrounding tissues. The ability of a virus to cross the endothelial barrier is an important mechanism that facilitates virus dissemination in the human body. Many viruses are reported to alter endothelial permeability and/or cause endothelial cell barrier disruption during infection, which is able to cause vascular leakage. The current study describes a real-time cell analysis (RTCA) protocol, using a commercial real-time cell analyzer to monitor endothelial integrity and permeability changes during Zika virus (ZIKV) infection of the human umbilical vein endothelial cells (HUVECs). The impedance signals recorded before and after ZIKV infection were translated to cell index (CI) values and analyzed. The RTCA protocol allows the detection of transient effects in the form of cell morphological changes during a viral infection. This assay could also be useful for studying changes in the vascular integrity of HUVECs in other experimental setups.

Epidemiology, clinical characteristics and outcomes of multisystem inflammatory syndrome in children

Chun-Ern Ng D, Liew CH, Tan KK, Lim HY, Zailanalhuddin NEB, Tan SF, et al.

Pediatr Int, 2023;65(1):e15690.

PMID: 38037505 DOI: 10.1111/ped.15690

BACKGROUND: We describe the epidemiology, clinical characteristics, and outcomes of multisystem inflammatory syndrome in children (MIS-C) among children from Negeri Sembilan, Malaysia.

METHODS: A retrospective, multicentre, observational study was performed among children ≤15 years old who were hospitalized for MIS-C between January 18, 2021 and June 30, 2023. The incidence of MIS-C was estimated using reported SARS-CoV-2 cases and census population data. Descriptive analyses were used to summarize the clinical presentation and outcomes.

RESULTS: The study included 53 patients with a median age of 5.7 years (IQR 1.8-8.7 years); 75.5% were males. The overall incidence of MIS-C was approximately 5.9 cases per 1,000,000 person-months. Pediatric intensive care unit (PICU) admission was required for 22 (41.5%) patients. No mortalities were recorded. Children aged 6-12 years were more likely to present with cardiac dysfunction/shock (odds ratio [OR] 5.43, 95% confidence interval [CI] 1.67-17.66), whereas children below 6 years were more likely to present with a Kawasaki disease phenotype (OR 5.50, 95% CI 1.33-22.75). Twenty patients (37.7%) presented with involvement of at least four organ systems, but four patients (7.5%) demonstrated single-organ system involvement.

CONCLUSION: An age-based variation in the clinical presentation of MIS-C was demonstrated. Our findings suggest MIS-C could manifest in a spectrum, including single-organ involvement. Despite the high requirement for PICU admission, the prognosis of MIS-C was favorable, with no recorded mortalities.

Acquired tracheo-oesophageal fistula following tracheal intubation in a burned patient

Tan KK, Lee JK, Tan I, Sarvesvaran R

Burns, 1993 Aug;19(4):360-1.

PMID: 8357487

A 27-year old male sustained a 60 per cent TBSA burn with inhalation injury following a road traffic accident. He developed respiratory distress on day 3 postburn, and was intubated and ventilated. He was noted to have greenish aspirate from his trachea on day 17 of ventilation. He succumbed from sepsis and died on day 21 post injury. At post-mortem, a large tracheo-oesophageal fistula (TOF) was found at the level of the cuff of the nasotracheal tube.

Posterolateral spinal fusion with ostegenesis induced BMSC seeded TCP/HA in a sheep model

Shamsul BS, Tan KK, Chen HC, Aminuddin BS, Ruszymah BH

Tissue Cell, 2014 Apr;46(2):152-8.

PMID: 24630213 DOI: 10.1016/j.tice.2014.02.001

Autogenous bone graft is the gold standard for fusion procedure. However, pain at donor site and inconsistent outcome have left a surgeon to venture into some other technique for spinal fusion. The objective of this study was to determine whether osteogenesis induced bone marrow stem cells with the combination of ceramics granules (HA or TCP/HA), and fibrin could serve as an alternative to generate spinal fusion. The sheep's bone marrow mesenchymal stem cells (BMSCs) were aspirated form iliac crest and cultured for several passages until confluence. BMSCs were trypsinized and seeded on hydroxyapatite scaffold (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) for further osteogenic differentiation in the osteogenic medium one week before implantation. Six adult sheep underwent three-level, bilateral, posterolateral intertransverse process fusions at L1-L6. Three fusion sites in each animal were assigned to three treatments: (a) HA constructs group/L1-L2, (b) TCP/HA constructs group/L2-L3, and (c) autogenous bone graft group/L5-L6. The spinal fusion segments were evaluated using radiography, manual palpation, histological analysis and scanning electron microscopy (SEM) 12 weeks post implantation. The TCP/HA constructs achieved superior lumbar intertransverse fusion compared to HA construct but autogenous bone graft still produced the best fusion among all.

Differential osteogenic activity of osteoprogenitor cells on HA and TCP/HA scaffold of tissue engineered bone

Ng AM, Tan KK, Phang MY, Aziyati O, Tan GH, Isa MR, et al.

J Biomed Mater Res A, 2008 May;85(2):301-12.

PMID: 17688285

Biomaterial, an essential component of tissue engineering, serves as a scaffold for cell attachment, proliferation, and differentiation; provides the three dimensional (3D) structure and, in some applications, the mechanical strength required for the engineered tissue. Both synthetic and naturally occurring calcium phosphate based biomaterial have been used as bone fillers or bone extenders in orthopedic and reconstructive surgeries. This study aims to evaluate two popular calcium phosphate based biomaterial i.e., hydroxyapatite (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) granules as scaffold materials in bone tissue engineering. In our strategy for constructing tissue engineered bone, human osteoprogenitor cells derived from periosteum were incorporated with human plasma-derived fibrin and seeded onto HA or TCP/HA forming 3D tissue constructs and further maintained in osteogenic medium for 4 weeks to induce osteogenic differentiation. Constructs were subsequently implanted intramuscularly in nude mice for 8 weeks after which mice were euthanized and constructs harvested for evaluation. The differential cell response to the biomaterial (HA or TCP/HA) adopted as scaffold was illustrated by the histology of undecalcified constructs and evaluation using SEM and TEM. Both HA and TCP/HA constructs showed evidence of cell proliferation, calcium deposition, and collagen bundle formation albeit lesser in the former. Our findings demonstrated that TCP/HA is superior between the two in early bone formation and hence is the scaffold material of choice in bone tissue engineering.

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