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Fulltext Therapeutic plasma exchange (TPE) for semi-critical neurology presentations in a non-acute neurology set-up: clinical practice and challenges

Fu KS, Wong PY, Hiew FL

BMJ Neurol Open, 2020;2(1):e000020.
PMID: 33681775 DOI: 10.1136/bmjno-2019-000020

Introduction: Therapeutic plasma exchange (TPE) for semi-critical neurological manifestations can be managed in non-acute setting instead of critical care unit. In 2014, we established a non-acute neurology TPE unit for semi-critical haemodynamically stable patients. In this study, we aimed to evaluate the technical and safety parameters from the first 3 years of service.
Materials and methods: We analysed prospectively collected TPE data for patients treated with centrifugation TPE at our non-acute neurology TPE unit in Kuala Lumpur Hospital between May 2015 and June 2018.
Results: A total of 245 TPE procedures were performed in 55 patients for nine neurological indications, predominantly the central nervous system (79%). Twenty four per cent (n=13) had category I and 73% (n=40) had category II indication (American Society for Apheresis (ASFA) 2019). Others (4%) were not in ASFA indications. Neuromyelitis optica spectrum disorders accounted for half (51%) of the total patients. Twenty-three (41.8%) patients experienced adverse events, with hypotensive episodes being the the most common (n=12/55, 21.8%). Five (9.1%) patients had catheter-related blood stream infection, correlating with higher exchange plasma volume (p=0.023). Symptomatic hypocalcaemia was less common (n=5/55, 9.1%) and allergic reaction to human albumin was rare (n=1/55, 1.8%). Four technical errors detected. Three involved centrifugation sets manufacturing defects and one involved error in centrifugation set installation. Seven (2.9%) procedures were terminated: 5 for adverse effects and 2 for technical errors.
Conclusion: Performing TPE among semi-critical patients with neurology manifestations in basic non-acute set-up proved safe, with predictable complications. This set-up reduced the reliance on critical care services for TPE procedures.
In-vitro and in-vivo studies of a cytotoxin from Campylobacter jejuni

Pang T, Wong PY, Puthucheary SD, Sihotang K, Chang WK

J Med Microbiol, 1987 May;23(3):193-8.
PMID: 3585956

Studies were performed on a cytotoxin (CT) from human strains of Campylobacter jejuni isolated in Malaysia. CT was detected by cytopathic effect (CPE) on HeLa cells at titres from 8 to 32, in culture filtrates from 14 (48%) of 29 human isolates. The CPE correlated well with a quantitative 51Cr-release assay where a specific release of 54-68% was noted. CT production was lost after 5-7 subcultures. CT activity was also detected in 5 (26%) of 19 faecal filtrates from which CT-producing isolates were subsequently obtained. The mol. wt of CT was estimated by Sephadex G-50 chromatography to be greater than 30,000. In a suckling-mouse assay, CT consistently failed to demonstrate fluid accumulation after intragastric inoculation of culture filtrate. The Removable Intestinal Tie Adult Rabbit Diarrhoea (RITARD) assay was also used. Rabbits given CT-producing strains of C. jejuni developed bacteraemia and severe watery mucus-containing diarrhoea for the duration of the experiment with death of some animals. Rabbits given CT non-producing strains had less severe disease and none died. Rabbits given partially-purified CT had diarrhoea for 3 days but none died.
Crazing Effect on the Bio-Based Conducting Polymer Film

Wong PY, Takeno A, Takahashi S, Phang SW, Baharum A

Polymers (Basel), 2021 Oct 06;13(19).
PMID: 34641240 DOI: 10.3390/polym13193425

The biodegradability problem of polymer waste is one of the fatal pollutFions to the environment. Enzymes play an essential role in increasing the biodegradability of polymers. In a previous study, antistatic polymer film based on poly(lactic acid) (PLA) as a matrix and polyaniline (PAni) as a conductive filler, was prepared. To solve the problem of polymer wastes pollution, a crazing technique was applied to the prepared polymer film (PLA/PAni) to enhance the action of enzymes in the biodegradation of polymer. This research studied the biodegradation test based on crazed and non-crazed PLA/PAni films by enzymes. The presence of crazes in PLA/PAni film was evaluated using an optical microscope and scanning electron microscopy (SEM). The optical microscope displayed the crazed in the lamellae form, while the SEM image revealed microcracks in the fibrils form. Meanwhile, the tensile strength of the crazed PLA/PAni film was recorded as 19.25 MPa, which is almost comparable to the original PLA/PAni film with a tensile strength of 20.02 MPa. However, the Young modulus decreased progressively from 1113 MPa for PLA/PAni to 651 MPa for crazed PLA/PAni film, while the tensile strain increased 150% after crazing. The significant decrement in the Young modulus and increment in the tensile strain was due to the craze propagation. The entanglement was reduced and the chain mobility along the polymer chain increased, thus leading to lower resistance to deformation of the polymer chain and becoming more flexible. The presence of crazes in PLA/PAni film showed a substantial change in weight loss with increasing the time of degradation. The weight loss of crazed PLA/PAni film increased to 42%, higher than that of non-crazed PLA/PAni film with only 31%. The nucleation of crazes increases the fragmentation and depolymerization of PLA/PAni film that induced microbial attack and led to higher weight loss. In conclusion, the presence of crazes in PLA/PAni film significantly improved enzymes' action, speeding up the polymer film's biodegradability.
Single dose of atezolizumab plus chemotherapy in active psoriasis with advanced non-small cell lung cancer

Wong PY, How SH, Ismail I, Hassan R

J Oncol Pharm Pract, 2022 Mar;28(2):471-474.
PMID: 34565238 DOI: 10.1177/10781552211038899

INTRODUCTION: Immunotherapy has been recognized as the standard of care in addition to chemotherapy in the treatment of advanced non-small cell lung cancer. Most immunotherapy trials, however, exclude patients with autoimmune disease owing to concerns of disease exacerbation.
CASE REPORT: We report a case of a patient with advanced non-small cell lung cancer and underlying active psoriasis who experienced a remarkable response, without developing psoriasis flares, following treatment with a single dose of atezolizumab and first-line chemotherapy.
MANAGEMENT AND OUTCOME: The patient remained asymptomatic 10 months since treatment discontinuation, without disease progression, despite having received only a single dose of atezolizumab and six cycles of chemotherapy.
DISCUSSION: Little is known about the optimum duration required to achieve a durable response with immunotherapy. Patients with autoimmune disease are commonly excluded from immunotherapy trials owing to a higher risk of autoimmune disease flares or immune-related adverse events. The remarkable outcome observed in this case offers some insights into the possible durable response with limited doses of immunotherapy and a safer approach for administering immunotherapy in patients with autoimmune disease. Initiating chemotherapy to induce remission in active autoimmune disease prior to administering immunotherapy could potentially be an ideal approach that facilitates the use of immunotherapy in this patient population.
Fulltext Limited doses of immunotherapy use in advanced non-small cell lung cancer elderly patients with ECOG of 2 and high PDL-1 expression

Wong PY, How SH, Hassan R, Abdul Azih MN

Aging Med (Milton), 2021 Dec;4(4):345-349.
PMID: 34964016 DOI: 10.1002/agm2.12179

Immunotherapy is an effective treatment in advanced non-small cell lung cancer (NSCLC) patients with high PDL-1 expression. Here, we report three such patients with durable response despite limited doses immunotherapy.
The mediating effect of Internet gaming disorder's symptoms on loneliness and aggression among undergraduate students and working adults in Malaysia

T'ng ST, Ho KH, Sim DE, Yu CH, Wong PY

Psych J, 2020 Feb;9(1):96-107.
PMID: 31797557 DOI: 10.1002/pchj.320

Insufficient attention has been given to the integration of the mediating effect of Internet gaming disorder (IGD) symptoms on loneliness and four components of aggression-physical aggression, verbal aggression, anger, and hostility-in the Malaysian context. In the present study, 410 participants with (a) at least 1 year of Internet gaming experience and (b) between ages 20- to 39 years were recruited using the probability proportional to size sampling method. Participants were undergraduate students and working adults. Self-reported questionnaires (the Internet Gaming Disorder Scale, University of California, Los Angeles Loneliness Scale, and the Buss-Perry Aggression Questionnaire) were used. The present study found that loneliness positively predicted four components of aggression (i.e., anger, hostility, physical aggression, and verbal aggression) and symptoms of IGD. Relationships between loneliness and the four components of aggression were partially mediated by IGD symptoms. The present study enriches and consolidates existing empirical evidence, particularly in the Malaysian context. If the mediating effect is not emphasized, it may lead to spurious conclusions that can significantly diminish the effectiveness of interventions that are meant to manage aggression.
Determination of biogenic amines in chicken, beef, and mutton by dansyl chloride microwave derivatization in Malaysia

Yue CS, Lim AK, Chia ML, Wong PY, Chin JSR, Wong WH

J Food Sci, 2023 Feb;88(2):650-665.
PMID: 36624628 DOI: 10.1111/1750-3841.16404

In this study, an improved dansyl-chloride derivatization technique using a microwave synthesizer was used for the qualitative and quantitative analyses of biogenic amine in the fresh meat samples. The derivatization technique was optimized in terms of temperature, reaction time, and spinning speed. The derivatization method together with a validated reversed-phase HPLC-DAD method was used for the determination of biogenic amines in chicken, beef, and mutton sold in the wet market. The results of the analyses showed that tryptamine, putrescine, and histamine were generally detected in all the three types of meat. Higher levels of histamine were found in chicken and beef. However, low levels of histamine were observed in mutton. Tyramine was either detected low or moderate in all the three types of meat. The biogenic amines of the fresh meat sold in the wet market is generally higher than the reported values. The mechanisms of biogenic amines-dansyl-chloride formation were investigated and proposed. PRACTICAL APPLICATION: The biogenic amine derivatization method was improved. The improved derivatization method can be potentially used for various food products beside meats for routine biogenic amine analyses due to its fast analysis time and simplicity. High levels of biogenic amines were generally found in the meat sold in the wet markets. However, proper handling of the raw meat can reduce the risk of infection.
Clopidogrel Vs Aspirin Monotherapy Following Dual Antiplatelet Therapy After Percutaneous Coronary Intervention: A Systematic Review and Meta-analysis

Tan BE, Wong PY, Baibhav B, Thakkar S, Azhar AZ, Rao M, et al.

Curr Probl Cardiol, 2023 Aug;48(8):101174.
PMID: 35341798 DOI: 10.1016/j.cpcardiol.2022.101174

Current guidelines recommend 6-12 months of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) followed by aspirin monotherapy indefinitely. We aimed to assess the efficacy and safety of clopidogrel vs aspirin in the post-PCI population after completing DAPT. We systematically searched 5 electronic databases to identify studies comparing clopidogrel with aspirin following completion of DAPT after PCI. We pooled outcomes for major adverse cardiac events (MACE), cardiac death, all-cause death, major bleeding, myocardial infarction (MI), and stroke. We included 5 studies with 13,850 patients, of whom 5601 (40.4%) received clopidogrel. Mean follow-up was 12-36 months. All patients received drug-eluting stents. Duration of DAPT before antiplatelet monotherapy was 1-18 months. Clopidogrel was associated with reductions in MACE (Risk ratio [RR] 0.77, 95% confidence interval [CI] 0.65-0.91), any stroke (RR 0.51; 95% confidence interval [CI] 0.35-0.76), ischemic stroke (RR 0.55; 95% CI 0.32-0.94), and hemorrhagic stroke (RR 0.24; 95% CI 0.09-0.68) when compared with aspirin. Cardiac death (RR 0.87; 95% CI 0.53-1.41), all-cause death (RR 1.06; 95% CI 0.81-1.39), major bleeding (RR 0.74; 95% CI 0.43-1.29), MI (RR 1.01; 95% CI 0.64-1.60), repeat revascularization (RR 0.88; 95% CI 0.71-1.09), target vessel revascularization (RR 0.76; 95% CI 0.52-1.13), and stent thrombosis (RR 0.96; 95% CI 0.35-2.59) were not significantly different among groups. Compared with aspirin, clopidogrel was associated with reductions in MACE and stroke (ischemic and hemorrhagic) following DAPT completion after PCI. There were no significant differences in mortality, major bleeding, MI, and repeat revascularization between groups.
Fulltext Poor Sleep Quality, Depression and Social Support Are Determinants of Serum Phosphate Level among Hemodialysis Patients in Malaysia

Ng ESY, Wong PY, Kamaruddin ATH, Lim CTS, Chan YM

Int J Environ Res Public Health, 2020 Jul 16;17(14).
PMID: 32708766 DOI: 10.3390/ijerph17145144

Despite optimal control of serum phosphate level being imperative to avoid undesirable health outcomes, hyperphosphataemia is a highly prevalent mineral abnormality among the dialysis population. This study aimed to determine factors associated with hyperphosphatemia among hemodialysis patients in Malaysia. Multiple linear regression analysis was used to ascertain the possible factors that influence serum phosphate levels. A total of 217 hemodialysis patients were recruited. Hyperphosphatemia was prevalent. Only approximately 25% of the patients were aware that optimal control of hyperphosphatemia requires the combined effort of phosphate binder medication therapy, dietary restriction, and dialysis prescription. The presence of diabetes mellitus may affect serum phosphate levels, complicating dietary phosphorus management. Patients who were less depressive portrayed higher serum phosphate levels, implying intentional non-compliance. Better compliance on phosphate binder, longer sleep duration, and higher social support was associated with a lower level of serum phosphate. Despite sleep disturbance being one of the most prevalent and intense symptom burdens identified by hemodialysis patients, relatively few studies have addressed this issue. It is time to formulate sleep therapeutic interventions besides the encouragement of strong social support, hoping which many clinical outcomes including hyperphosphatemia can be better controlled among hemodialysis patients.