Displaying publications 121 - 140 of 147 in total

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  1. Penjor D, Khizuan AK, Chong AW, Wong KT
    J Laryngol Otol, 2014 Dec;128(12):1117-9.
    PMID: 25382114 DOI: 10.1017/S0022215114002655
    Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissue that most commonly affects the feet and lower limbs. It is rare for this infection to occur on the face, and it is exceptionally rare for it to involve the nose and sinuses. This paper reports a rare case of nasal chromoblastomycosis in a 50-year-old Malaysian male.
  2. Wong KT, Pathmanathan R
    J Parasitol, 1994 Apr;80(2):327-30.
    PMID: 8158479
    The ultrastructure of the human skeletal muscle sarcocyst found in Malaysia is reported. Sarcocyst-positive, formalin-fixed tongue tissues were postfixed in osmium tetroxide. The primary cyst wall consisted of a thin membrane supported by osmiophilic material that was interrupted regularly by vesicle-like invaginations. Although there were no cytophaneres, stubby protrusions of the primary wall were observed. These protrusions were accentuated by dense, curvilinear material externally. The primary wall was wavy over about half the cross section of the cyst. The granular ground substance underlying the primary wall occasionally contained hitherto undescribed coiled microtubular structures. Branching septa extended from the ground substance into the cyst, separating mature merozoites into compartments. A few peripheral metrocytes and many laminated myelin figure-like structures, probably degenerating merozoites, were found. Although the human muscular sarcocyst has the same basic ultrastructure as those found in other animals, the stubby protrusions and coiled microtubular structures in the ground substance have not been described previously in nonhuman animals.
  3. Lum LC, Wong KT, Lam SK, Chua KB, Goh AY, Lim WL, et al.
    J Pediatr, 1998 Dec;133(6):795-8.
    PMID: 9842048
    During an outbreak of hand-foot-mouth disease caused by enterovirus 71 (EV-71) in 1997, 4 children presented with sudden cardiopulmonary collapse and minimal neurologic features. All children received cardiopulmonary resuscitation but died within a few hours of admission. Postmortem studies showed infection by EV-71 with extensive damage to the medulla and pons. We postulate an etiologic link between EV-71 and brainstem encephalomyelitis as the cause of pulmonary edema and death.
  4. Zhang J, Mohamad FH, Wong JH, Mohamad H, Ismail AH, Mohamed Yusoff AA, et al.
    Malays J Med Sci, 2018 Feb;25(1):101-113.
    PMID: 29599640 DOI: 10.21315/mjms2018.25.1.12
    Background: Bamboo shoot has been used as a treatment for epilepsy in traditional Chinese medicine for generations to treat neuronal disorders such as convulsive, dizziness and headaches. 4-hydroxybenzoic acid (4-hba) is a non-flavonoid phenol found abundantly inDendrocalamus aspershoots (bamboo), fruits (strawberries and apples) and flowers. Kv1.4 is a rapidly inactivatingShaker-related member of the voltage-gated potassium channels with two inactivation mechanisms; the fast N-type and slow C-type. It plays vital roles in repolarisation, hyperpolarisation and signaling the restoration of resting membrane potential through the regulation of the movement of K+across the cellular membrane.

    Methods: Chemical compounds fromDendrocalamus asperbamboo shoots were purified and identified as major palmitic acids mixed with other minor fatty acids, palmitic acid, 4-hydroxybenzaldehyde, lauric acid, 4-hydroxybenzoic acid and cholest-4-ene-3-one. The response of synthetic 4-hydroxybenzoic acid was tested on Kv1.4 potassium channel which was injected into viable oocytes that was extracted fromXenopus laevis. The current were detected by the two-microelectrode voltage clamp, holding potential starting from -80 mV with 20 mV step-up until +80 mV. Readings of treatments with 0.1% DMSO, 4-hba concentrations and K channel blockers were taken at +60 mV. The ratio of tail/peak amplitude is the index of the activity of the Kv1.4 channels withn≥ 6 (number of oocytes tested). The decreases of the ratios of five different concentrations (1 μM, 10 μM, 100 μM, 1 mM and 2.5 mM) were compared with 0.1% DMSO as the control.

    Results: All concentration showed statistically significant results withP< 0.05 except for 100 μM. The normalised current of the 4-hba concentrations were compared with potassium channel blockers (TEA and 4-AP) and all groups showed statistically significant results. This study also showed that time taken for each concentration to affect Kv1.4 does not play any significant roles.

    Conclusion: 4-hydroxybenzoic acid was found to be able to enhance the inactivation of Kv1.4 by lowering the membrane potential so that the abnormal neuronal firing can be inhibited. With IC50 slightly higher than 10 μM, increasing concentrations (100 μM, 1 mM and 2.5 mM) had shown to exhibit toxicity effects. The best concentration from this study is 10 μM with Hill slope of 0.1799.

  5. Zhang J, Mohamad H, Wong JH, Bilal M, Ismail AHB, Lloyd AJ, et al.
    Malays J Med Sci, 2017 Mar;24(2):94-99.
    PMID: 28894409 DOI: 10.21315/mjms2017.24.2.12
    The α1β2γ2 subtype of GABAA receptors is the most commonly found GABAA receptor subtype in the mammalian cortex and hippocampus. It is expressed heterologously in the Xenopus laevis oocyte as a α1β2γ2S/L subtype for application as an in vitro model for the screening of compounds that modulate receptor activities. In fact, 4-hydroxybenzaldehyde (4-HB) has been identified as one of the major components in Dendrocalamus asper bamboo shoots in our previous study, and the current study showed that at 101.7 μM, 4-HB significantly reduced the GABA-induced chloride current of GABAA receptors expressed on Xenopus oocytes, indicating a possible GABAergic antagonistic effect at high concentrations.
  6. Jayaram G, Wong KT, Jalaludin MA
    Malays J Pathol, 1998 Jun;20(1):45-8.
    PMID: 10879264
    Primary mucoepidermoid carcinoma (MEC) of thyroid is an uncommon tumour and reports on its' cytology are consequently scanty. A 46-year-old male presented with a thyroid nodule of nine months duration. Fine needle aspiration (FNA) cytology of the nodule showed features of a malignant tumor that was different from the usual types of thyroid carcinoma. Monolayers and syncytial clusters of round and spindle tumour cells with large vesicular nuclei and single macronucleoli were present. A diagnosis of carcinoma was given with the comment that this was unlike any of the usual types of thyroid cancer and that a metastatic malignancy should be ruled out. The cytological picture of MEC may not always be distinctive enough for accurate tumour typing. Nevertheless the cytological features are usually sufficiently different to rule out all of the usual types of thyroid carcinoma. This distinction may be important from the point of view of differing prognosis in MEC of thyroid (as compared to differentiated thyroid cancers) and the need to exclude a metastatic carcinoma, especially from a primary in one of the salivary glands.
  7. Ong BB, Wong KT
    Malays J Pathol, 1996 Dec;18(2):121-3.
    PMID: 10879233
    A rare case of a 22-week-old foetus with unilateral adrenal cytomegaly and left diaphragmatic hernia is reported. Typical cytomegalic cells were found focally in the left adrenal but the right adrenal was normal. There was no stigmata of the Beckwith-Wiedermann syndrome. The association of adrenal cytomegaly with various congenital malformations, the significance and possible pathogenesis of this condition is discussed.
  8. Wong KT, Chan KS
    Malays J Pathol, 1990 Dec;12(2):101-6.
    PMID: 2102964
    We describe the design and management of a 35 mm slide database using a menu-driven dBASE III PLUS programme and a microcomputer in a large department of pathology that also caters for the individual pathologist. Existing systems described in the literature are geared towards slides of general medicine and do not address the needs of the individual pathologist. A total of 11,481 slides in the Department of Pathology, Faculty of Medicine, University of Malaya, were filed into a single database with each record representing one slide. Nine fields which comprised the slide accession number, reference number, slide category, SNOMED codes, and a description of the slide in natural language, seemed adequate for slide definition. The menu-driven programme had functions which included the abilities to add, delete, edit and back-up records, and to search for desired slides. Although slides may be searched for in various fields, we found that searches using natural language alone were both comprehensive and efficient, provided a standard format of description was adhered to and data entries scrutinized carefully for errors. We believe therefore, that for the pathologist working alone, coded language fields are not absolutely necessary, as manual coding and additional data entry can be time consuming. As expected, for databases larger than 10,000 slides, a 80286 microprocessor-based microcomputer was more efficient. We are of the opinion that a system such as ours is very useful for a large department of pathology or the individual pathologist to file and retrieve 35 mm slides.
  9. Tan LJ, Othman MS, Hiu J, Wong KT, Lai SK
    Malays J Pathol, 2021 Apr;43(1):81-85.
    PMID: 33903310
    BACKGROUND: Small bowel volvulus is defined as the torsion of the small intestine, potentially leading to bowel obstruction, gangrene and perforation. It is a rare condition, especially in adults.

    CASE PRESENTATION: A 30-year-old man was retrieved from the jungle with severe weight loss and abdominal symptoms. He succumbed to death despite 22 days of intensive medical treatment. An autopsy revealed a ruptured gangrenous ileal volvulus with peritonitis and subdiaphragmatic abscess. Further laboratory analysis detected systemic Candida tropicalis and intestinal gramnegative bacterial sepsis, systemic Zika virus viremia, leptospirosis complicating rhabdomyolysis and disseminated intravascular coagulopathy, Type I Herpes Simplex virus infection of the tongue and upper gastrointestinal tract. The cause of death was the ruptured ileal volvulus, complicated with upper gastrointestinal bleeding due to Herpes simplex virus esophagitis in a malnourished patient with resolving leptospirosis and underlying Zika virus co-infection.

    CONCLUSION: Rare clinical scenarios of adult-onset intestinal volvulus with concomitant multiple infections precludes clinical diagnosis and early treatment, leading to devastating consequences of clinical outcome. The positive clinical and postmortem correlation is a good learning lesson in many disciplines of medicine and science.

  10. Pathmanathan R, Wong KT
    Med J Malaysia, 1995 Mar;50(1):117.
    PMID: 7752967
    Comment on: Teoh MK, Chong JM, Mohamed J, Phang KS. Protection by tocotrienols against hypercholesterolaemia and atheroma. Med J Malaysia. 1994 Sep;49(3):255-62
  11. Liam CK, Wong KT, Lim YC
    Med J Malaysia, 1997 Mar;52(1):84-6.
    PMID: 10968059
    A 24-year-old man who was initially thought to have nocardiosis of his mediastinal lymph node which progressed to involve his right lung, had to undergo a right pneumonectomy when he failed to respond to treatment with sulphadiazine. Histology of the right lung specimen and a subsequent axillary lymph node biopsy revealed that he actually had lymphocyte-depleted Hodgkin's disease.
  12. Wong KT, Ng TS
    Med J Malaysia, 1984 Mar;39(1):52-5.
    PMID: 6334801
    This communication describes a survey on 94 cases of alleged paraquat poisoning for a period of one-and a-half years in Perak state. The highest prevalence of such cases was noted in the district of Batang Padang. The incidences between males and females as well as between married and single persons were found to be equal, 81.9% were Indians and 73.4% were suicidal cases. More than 80% of the cases were in the 10-to-40-years age group.
  13. Wong KT, Ng SC, Kuperan P, Yap SF, Menaka N, Bosco J
    Med J Malaysia, 1990 Jun;45(2):136-43.
    PMID: 2152018
    A retrospective study of 37 cases of multiple myeloma admitted from 1980 to 1987 to the University Hospital Kuala Lumpur, Malaysia, was carried out to analyse the biodata, clinical presentation, laboratory and radiological profiles. The cases were selected after they had satisfied preset diagnostic criteria. The mean age was 60 years. There was no sex or ethnic preponderance. The most common symptom was bone pain. Pallor was detected in 73% of the patients. Haemoglobin was less than 120 g/L in 95%, and ESR was greater than 100 mm/hr in 70% of cases. Bone marrow and trephine biopsies were diagnostically important. Hypercalcaemia occurred in seven cases out of which three were IgA myelomas. Either serum creatinine or blood urea was raised in nearly 50% of cases. The most common heavy chain paraprotein was IgG while Kappa light chain was the commoner light chain type. 86% of cases had osteolytic lesions. These findings are, in general, similar to those of larger studies on multiple myeloma.

    Study site: University Malaya Medical Centre (UMMC)
  14. Goh KJ, Tan CT, Chew NK, Tan PS, Kamarulzaman A, Sarji SA, et al.
    N Engl J Med, 2000 Apr 27;342(17):1229-35.
    PMID: 10781618 DOI: 10.1056/NEJM200004273421701
    BACKGROUND: Between September 1998 and June 1999, there was an outbreak of severe viral encephalitis due to Nipah virus, a newly discovered paramyxovirus, in Malaysia.
    METHODS: We studied the clinical features of the patients with Nipah virus encephalitis who were admitted to a medical center in Kuala Lumpur. The case definition was based on epidemiologic, clinical, cerebrospinal fluid, and neuroimaging findings.
    RESULTS: Ninety-four patients with Nipah virus infection were seen from February to June 1999 (mean age, 37 years; ratio of male patients to female patients, 4.5 to 1). Ninety-three percent had had direct contact with pigs, usually in the two weeks before the onset of illness, suggesting that there was direct viral transmission from pigs to humans and a short incubation period. The main presenting features were fever, headache, dizziness, and vomiting. Fifty-two patients (55 percent) had a reduced level of consciousness and prominent brain-stem dysfunction. Distinctive clinical signs included segmental myoclonus, areflexia and hypotonia, hypertension, and tachycardia and thus suggest the involvement of the brain stem and the upper cervical spinal cord. The initial cerebrospinal fluid findings were abnormal in 75 percent of patients. Antibodies against Hendra virus were detected in serum or cerebrospinal fluid in 76 percent of 83 patients tested. Thirty patients (32 percent) died after rapid deterioration in their condition. An abnormal doll's-eye reflex and tachycardia were factors associated with a poor prognosis. Death was probably due to severe brain-stem involvement. Neurologic relapse occurred after initially mild disease in three patients. Fifty patients (53 percent) recovered fully, and 14 (15 percent) had persistent neurologic deficits.
    CONCLUSIONS: Nipah virus causes a severe, rapidly progressive encephalitis with a high mortality rate and features that suggest involvement of the brain stem. The infection is associated with recent contact with pigs.
  15. Choo SW, Chong JL, Gaubert P, Hughes AC, O'Brien S, Chaber AL, et al.
    Sci Total Environ, 2022 Feb 14.
    PMID: 35176378 DOI: 10.1016/j.scitotenv.2022.153666
  16. Woon KL, Yi CL, Pan KC, Etherington MK, Wu CC, Wong KT, et al.
    J Phys Chem C Nanomater Interfaces, 2019 May 16;123(19):12400-12410.
    PMID: 32952765 DOI: 10.1021/acs.jpcc.9b01900
    Understanding the excited-state dynamics and conformational relaxation in thermally activated delayed fluorescence (TADF) molecules, including conformations that potentially support intramolecular through-space charge transfer, can open new avenues for TADF molecular design as well as elucidate complex photophysical pathways in structurally complex molecules. Emissive molecules comprising a donor (triphenylamine, TPA) and an acceptor (triphenyltriazine, TRZ) bridged by a second donor (9,9-dimethyl-9-10-dihydroacridin, DMAC, or phenoxazine, PXZ) are synthesized and characterized. In solution, the flexibility of the sp3-hybridized carbon atom in DMAC of DMAC-TPA-TRZ, compared to the rigid PXZ, allows significant conformational reorganization, giving rise to multiple charge-transfer excited states. As a result of such a reorganization, the TRZ and TPA moieties become cofacially aligned, driven by a strong dipole-dipole attraction between the TPA and TRZ units, forming a weakly charge-transfer dimer state, in stark contrast to the case of PXZ-TPA-TRZ where the rigid PXZ bridge only supports a single PXZ-TRZ charge transfer (CT) state. The low-energy TPA-TRZ dimer is found to have a high-energy dimer local triplet state, which quenches delayed emission because the resultant singlet CT local triplet energy gap is too large to mediate efficient reverse intersystem crossing. However, organic light-emitting diodes using PXZ-TPA-TRZ as an emitting dopant resulted in external quantum efficiency as high as 22%, more than two times higher than that of DMAC-TPA-TRZ-based device, showing the impact that such intramolecular reorganization and donor-acceptor dimerization have on TADF performance.
  17. Wong KT, Pathmanathan R
    Trans R Soc Trop Med Hyg, 1992 11 1;86(6):631-2.
    PMID: 1287922
    The prevalence of human skeletal muscle sarcocystosis in Malaysia was determined by serial examination of formalin-fixed, paraffin-embedded sections of tongue tissues obtained from consecutive, routine autopsies of subjects aged 12 years or more. Of 100 tongues examined, 21% were found to contain Sarcocystis; 66 cysts were found. The number of cysts per case varied from 1 to 13. In one case, 5 cysts were found in a single tissue section. The age range of positive cases was from 16 to 57 years (mean 37.7 years). Prevalence did not differ with regard to race, sex or occupation. The prevalence of human muscular sarcocystosis in our study was higher than that reported elsewhere. Preferential localization of Sarcocystis in tongue or head and neck and/or genuinely high prevalence in south-east Asia are possible explanations for this observation.
  18. Wong KT, Pathmanathan R
    Trop Geogr Med, 1993;45(4):191.
    PMID: 8236476
  19. Fong MY, Wong KT, Rohela M, Tan LH, Adeeba K, Lee YY, et al.
    Trop Biomed, 2010 Dec;27(3):447-50.
    PMID: 21399585 MyJurnal
    We report a case of unusual cutaneous toxoplasmosis manifestation in a HIV-positive patient. He presented with hard and painful nodular lesions on the arms, hands and chest. Serology tests for anti-Toxoplasma antibody were negative. However, histopathologic examination of the lesion revealed foci of macrophages containing crescent-shaped organisms resembling the zoites of the protozoan parasite Toxoplasma gondii. Ultrastructure examination under electron microscopy and PCR confirmed the organism as T. gondii.
  20. Junaid OQ, Wong KT, Khaw LT, Mahmud R, Vythilingam I
    Trop Biomed, 2018 Dec 01;35(4):981-998.
    PMID: 33601846
    Co-infection with multiple different parasites is a common phenomenon in both human and animals. Among parasites that frequently co-infect the same hosts, are the filarial worms and malaria parasites. Despite this, the mechanisms underlying the interactions between these parasites is still relatively unexplored with very few studies available on the resulting pathologies due to co-infection by filarial nematodes and malaria parasites. Hence, this study investigated the histopathological effect of Brugia pahangi and Plasmodium berghei ANKA (PbA) infections in gerbil host. Gerbils grouped into B. pahangi-infected, PbA-infected, B. pahangi and PbA-coinfected, and uninfected control, were necropsied at different time points of post PbA infections. Brugia pahangi infections in the gerbils were first initiated by subcutaneous inoculation of 50 infective larvae, while PbA infections were done by intraperitoneal injection of 106 parasitized red blood cells after 70 days patent period of B. pahangi. Organs such as the lungs, kidneys, spleen, heart and liver were harvested aseptically at the point of necropsy. There was significant hepatosplenomegaly observed in both PbA-infected only and coinfected gerbils. The spleen, liver and lungs were heavily pigmented. Both B. pahangi and PbA infections (mono and coinfections) resulted in pulmonary edema, while glomerulonephritis was associated with PbA infections. The presence of both parasites induced extramedullary hematopoiesis in the spleen and liver. These findings suggest that the pathologies associated with coinfected gerbils were synergistically induced by both B. pahangi and PbA infections.
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