MyMedR

Salmonella typhi meningitis. A case report and family investigations

Chye GH, Hong ST

Med J Malaysia, 1975 Mar;30(3):219-22.

Radial probe endobronchial ultrasound (R-EBUS) guided transbronchial cryobiopsy in the diagnosis of peripheral solitary pulmonary nodule

Kho SS, Tie ST

Med J Malaysia, 2019 08;74(4):349-351.

PMID: 31424050

Solitary pulmonary nodule (SPN) always raises suspicion for early lung cancer, in which accurate and less invasive biopsy is needed. We report a case of transbronchial cryobiopsy of right upper lobe SPN under radial endobronchial ultrasound (R-EBUS) guidance after an inconclusive computed tomography guided transthoracic needle aspiration. A diagnosis of Stage 1B adenocarcinoma of the lung was made. Patient subsequently underwent curative right upper lobectomy after ruling out mediastinal lymph node involvement. To the best of our knowledge, this is the first report of R-EBUS guided transbronchial cryobiopsy case reported from Malaysia.

Effect of diarrhoea on Tacrolimus trough level in a post liver transplant patient

Tan ST, Yoong BK

Med J Malaysia, 2020 11;75(6):734-735.

PMID: 33219186

Tacrolimus, which bonds to an immunophilin, FK506 binding protein (FKBP) has emerged as one of the most widely used immunosuppressant post solid organ transplantation. It offers excellent patient survival rates post-transplantation and a lesser number of acute rejections as compared to cyclosporine. Tacrolimus has a narrow therapeutic window with overexposure leading to acute and chronic forms of nephrotoxicity. Remarkably few data have been published on the overexposure to tacrolimus following mild diarrhoea in post-transplant patients who received treatment with tacrolimus. We observed a post-liver transplant patient with increased trough level of tacrolimus during severe diarrhoea with no complications following a timely adjustment on the dose of tacrolimus.

Fulltext Use of new radiochromic devices for peripheral dose measurement: potential in-vivo dosimetry application

Chiu-Tsao ST, Chan M

Biomed Imaging Interv J, 2009 Oct;5(4):e16.

PMID: 21610987 DOI: 10.2349/biij.5.4.e16

The authors have studied the feasibility of using three new high-sensitivity radiochromic devices in measuring the doses to peripheral points outside the primary megavoltage photon beams. The three devices were GAFCHROMIC® EBT film, prototype Low Dose (LD) Film, and prototype LD Card. The authors performed point dosimetry using these three devices in water-equivalent solid phantoms at x = 3,5,8,10, and 15 cm from the edge of 6 MV and 15 MV photon beams of 10x10 cm(2), and at depths of 0, 0.5 cm, and depth of maximum dose. A full sheet of EBT film was exposed with 5000 MU. The prototype LD film pieces were 1.5x2 cm(2) in size. Some LD films were provided in the form of a card in 1.8x5 cm(2) holding an active film in 1.8x2 cm(2). These are referred to as "LD dosimeter cards". The small LD films and cards were exposed with 500 MU. For each scanned film, a 6 mm circular area centered at the measurement point was sampled and the mean pixel value was obtained. The calibration curves were established from the calibration data for each combination of film/cards and densitometer/scanner. The doses at the peripheral points determined from the films were compared with those obtained using ion chamber at respective locations in a water phantom and general agreements were found. It is feasible to accurately measure peripheral doses of megavoltage photon beams using the new high-sensitivity radiochromic devices. This near real-time and inexpensive method can be applied in a clinical setting for dose measurements to critical organs and sensitive patient implant devices.

Fulltext Investigation on the conA binding properties of Klebsiella pneumoniae

Anuar AS, Tay ST

Trop Biomed, 2014 Dec;31(4):802-12.

PMID: 25776607 MyJurnal

Klebsiella pneumoniae is a healthcare-associated bacterial pathogen which causes severe diseases in immunocompromised individuals. Concanavalin A (conA), a lectin which recognizes proteins with mannose or glucose residues, has been reported to agglutinate K. pneumoniae and hence, is postulated to have therapeutical potential for K. pneumoniae-induced liver infection. This study investigated the conA binding properties of a large collection of clinical isolates of K. pneumoniae. ConA agglutination reaction was demonstrated by 94 (51.4%) of 183 K. pneumoniae isolates using a microtiter plate assay. The conA agglutination reactions were inhibited in the presence of 2.5 mg/ml D-mannose and 2.5 mg/ml glucose, and following pretreatment of the bacterial suspension with protease and heating at 80ºC. Majority of the positive isolates originated from respiratory specimens. Isolation of conA-binding proteins from K. pneumoniae ATCC 700603 strain was performed using conA affinity column and the conA binding property of the eluted proteins was confirmed by western blotting analysis using conA-HRP conjugates. Proteins with molecular weights ranging from 35 to 60 kDa were eluted from the conA affinity column, of which four were identified as outer membrane protein precursor A (37 kDa), outer membrane protein precursor C (40 kDa), enolase (45 kDa) and chaperonin (60 kDa) using mass spectrometry analysis. Several conA binding proteins (including 45 and 60 kDa) were found to be immunogenic when reacted with rabbit anti-Klebsiella antibody. The function and interplay of the conA binding proteins in bacterium-host cell relationship merits further investigation.

Fulltext Diversity and killer activity of yeasts in Malaysian fermented food samples

Lim SL, Tay ST

Trop Biomed, 2011 Aug;28(2):438-43.

PMID: 22041766

The biodiversity and the killer activity of yeasts isolated from various types of fermented food in Malaysia were investigated in this study. Of 252 yeasts isolated from 48 fermented food samples in this study, 19 yeast species were identified based on sequence analysis of the ITS1-5.8S-ITS2 partial fragments of the yeasts. A total of 29 (11.5%) of the yeast isolates demonstrated killer activity to at least one Candida species tested in this study; including 22 isolates of Trichosporon asahii, 4 isolates of Pichia anomala, and one isolate each of Pichia norvegensis, Pichia fermentans and Issatchenkia orientalis, respectively. The presence of killer yeasts reflects antagonism that occurs during microbial interaction in the fermented food, whereby certain yeasts produce killer toxins and possibly other toxic substances in competition for limited nutrients and space. The anti-Candida activity demonstrated by killer yeasts in this study should be further explored for development of alternative therapy against candidiasis.

Fulltext Anti-Candida activity and biofilm inhibitory effects of secreted products of tropical environmental yeasts

Tan HW, Tay ST

Trop Biomed, 2011 Apr;28(1):175-80.

PMID: 21602784

This study describes the killer phenotypes of tropical environmental yeasts and the inhibition effects of the culture filtrates on the biofilm of Candida albicans. A total of 26 (10.5%) of 258 yeast isolates obtained from an environmental sampling study demonstrated killer activity to Candida species. The killer yeasts were identified as species belonging to the genus Aureobasidium, Pseudozyma, Ustilago and Candida based on sequence analysis of the ITS1-5.8S-ITS2 region of the yeasts. Pseudozyma showed the broadest killing effects against sensitive strains of Candida. New species of Ustilago and Pseudozyma demonstrating killer phenotypes were identified in this study. Interestingly, more than 50% reduction in the metabolic activity of Candida albicans biofilm was noted after exposure to the culture filtrates of the nine killer yeasts. Purification and characterization of toxin and metabolites are essential for understanding the yeast killing effects.

The early immunisation of infants in Malaysia

Chen ST, Choong MM

Med J Malaya, 1971 Sep;26(1):15-9.

PMID: 4258569

Some epidemiological aspects of diphtheria in Malaysia

Chen ST, Puthucheary SD

Trop Geogr Med, 1976 Sep;28(3):211-5.

PMID: 1006789

In Malysia, the proportion of children fully immunized againest diphtheria is generally low (20%). On the other hand, the Schick conversion rate rises with age and reaches 90% by 11 years of age. It is noted that asymptomatic carriers are an important epidemiological factor in diphtheria and that carrier rates for school children are high (prevalence of 7.5% while the rate of coloization with C. diphtheriae over a period of one year was 30%). Although immunization protects against clinical diphtheria, it does not prevent the carrier state. Thus, for the control of diphtheria, one should aim for 100% compliance. Some suggestions as to how higher levels of immunity may be achieved are described.

Morbidity pattern amongst some primary school entrants in Malaysia

Chen ST, Dugdale AE

Trop Geogr Med, 1972 Sep;24(3):269-74.

PMID: 4636102

Weight and height curves for Malaysian schoolchildren

Chen ST, Dugdale AE

Med J Malaya, 1970 Dec;25(2):99-101.

PMID: 4251142

Fulltext Craniofacial anthropometric norms of Malays

Ngeow WC, Aljunid ST

Singapore Med J, 2009 May;50(5):525-8.

PMID: 19495526

INTRODUCTION: This study was undertaken to establish the craniofacial anthropometric norms of young adult Malaysian Malays.
METHODS: The study group consisted of convenient samples of 100 healthy volunteers (aged 18-25 years), with an equal number of female and male subjects who had no history of mixed racial parentage. 22 linear measurements were taken twice from 22 landmarks over six craniofacial regions.
RESULTS: The Malays shared many similar sizes of measurements with the Singaporean Chinese. Their left eye fissure length and mouth width (ch-ch) were almost identical for both genders. However, Malay females had an upper lip height (sn-sto) (left) and ear width (pra-pa) similar to Singaporean Chinese females. Six other measurements, viz. the head width (eu-eu), head circumference (on-op), face height (n-gn), lower face height (sn-gn), (left) eye fissure height (ps-pi), cutaneous upper lip height (sn-ls) and cutaneous upper lip height (ls-sto), were 0.4-4.3 mm less in the Malays. Measurements for another four parameters, viz. the length of the head (g-op), biocular width (ex-ex), lower vermillion height (sto-li) and (left) ear length (sa-sba), were 0.5-3.6 mm higher in the Malays. Only three measurements were obviously different; the height of the head (v-n) and intercanthal width (en-en), were lower, and the protrusion of the nasal tip (sn-prn) was higher in the Malays.
CONCLUSION: These findings suggest that three features, i.e. the height of the head (v-n), intercanthal width (en-en) and protrusion of the nasal tip (sn-prn) may be useful in differentiating a Malay face from a Singaporean Chinese one.

Fulltext Efficacy and safety of loratadine compared with astemizole in Malaysian patients with allergic rhinitis

Lee ST, Amin MJ

Singapore Med J, 1994 Dec;35(6):591-4.

PMID: 7761882

Nonsedating selective peripheral H1 receptor antagonists are an important advance in antihistaminic therapy in allergic patients. This is a randomised, double-blind parallel group study comparing the use of two such agents viz loratadine 10mg daily and astemizole 10mg daily for two weeks in 39 Malaysian allergic rhinitis patients. At these dosages, both drugs were demonstrated to be efficacious (p < 0.05) for controlling nasal symptoms and safe in terms of short term biochemical and haematological changes and adverse effects noted. Evaluating efficacy criteria utilised in this study loratadine and astemizole were comparable but loratadine was significantly more effective in three areas viz: (i) in diminishing nasal symptoms after 2 weeks of treatment (p = 0.03); (ii) physician's efficacy evaluation after 2 weeks' treatment (p = 0.009); (iii) patient's efficacy evaluation after 2 weeks' treatment (p = 0.019).
Study site: Allergy clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia

Fulltext Branchial fistula--a review

Lee ST, Krishnan MM

Singapore Med J, 1991 Feb;32(1):50-2.

PMID: 2017707

Congenital branchial fistula and their embryology is well described in the literature. The accepted standard treatment method includes stepladder excision for extensive fistulas. This paper presents two cases (Case 1 and 2) which are embryologically typical of second and third arch origin respectively; and a third case (Case 3) which has not been previously described. Case 3 appears to be a hitherto unreported combination of first and second arch origin. Case 1 and 2 were treated via a standard stepladder excision approach. A different newer approach was utilised in Case 3, that is, stripping of the fistulous tract with Myer's vein stripper. Unlike the stepladder approach, this is simple and avoids extensive time consuming dissection. However, being a blind procedure, it is not generally advocated if vital structures exist in the proximity.

Emerging viral diseases

Nichol ST, Arikawa J, Kawaoka Y

Proc Natl Acad Sci U S A, 2000 Nov 07;97(23):12411-2.

PMID: 11035785

Chronic disseminated histiocytosis X: a case report

Ong ST, Lian CB

J Clin Pediatr Dent, 1992;17(1):33-5.

PMID: 1290758

A case of chronic disseminated histiocytosis X (Hand-Schuller-Christian Disease) of the mandible is presented. Multi-modal approach to management is discussed.

Fulltext Moderate-to-severe food insecurity is positively correlated with the risk of eating disorders in the aftermath of the COVID-19 pandemic

Tan ST, Shahril PIA

Ethics Med Public Health, 2023 Apr;27:100874.

PMID: 36776244 DOI: 10.1016/j.jemep.2023.100874

BACKGROUND: The COVID-19 pandemic may have worsened food insecurity and altered the eating behaviour of young adults. Therefore, this cross-sectional study aims to investigate the correlation between moderate-to-severe food insecurity and the risk of eating disorders among young urbanists in Malaysia after the pandemic-led lockdown.

METHODS: The food security status and the risk of eating disorders were assessed using the validated Food Insecurity Experience Scale (FIES) and Eating Attitude Test (EAT-26), respectively.

RESULTS: Among the 208 young urbanists, approximately one-third (30.8%) were moderate-to-severe food insecure and about one-fifth (18.8%) were at risk of eating disorders after the nationwide lockdown. With the adjustment of gender, the binary logistic regression analysis revealed that moderate-to-severe food insecure individuals were 2.279 times (P = 0.030, 95% CI = 1.084-4.791) more likely to engage in disordered eating in the aftermath of the COVID-19 pandemic. The findings of partial correlation further indicated that moderate-to-severe food insecurity was positively correlated (rpartial = 0.156, P = 0.024) with bulimia and food preoccupation after the outbreak.

CONCLUSIONS: Governments and non-governmental organizations must work closely to develop effective policies to address food insecurity and disordered eating behaviour among young urbanists - after the pandemic.

The use of the indirect immunoperoxidase test for the serodiagnosis of rickettsial diseases in Malaysia

Tay ST, Rohani MY

Southeast Asian J Trop Med Public Health, 2002 Jun;33(2):314-20.

PMID: 12236431

The indirect immunoperoxidase (HP) test has been used extensively in most government hospitals in Malaysia for the serodiagnosis of scrub typhus, murine typhus and tick typhus during the 1990s. The test was used to determine the IgG and IgM antibody titers in patients' sera for three rickettsial species, ie Orientia tsutsugamushi OT; the causative agent of scrub typhus), Rickettsia typhi (RT; the causative agent of murine typhus), and TT118 spotted fever group rickettsiae (TT; the causative agent of tick typhus). The serological findings obtained from Malaysian hospitals using the IIP test (1994-1999) were analyzed. During the six-year period, a total of 61,501 patients' sera were tested, of which 9.6%, 10.5%, and 12.9% had antibody (IgG and/or IgM of > or = 1:50) for OT, RT and TT respectively. A total of 8.6%, 9.8%, and 9.7% of sera had IgG antibody of > or = 1:50 for OT, RT, and TT respectively, indicating past infection. A total of 3.4%, 3.8%, and 6.4 % of sera had IgM antibody of > or = 1:50 for OT, RT, and TT respectively, indicating recent infection. A total of 2,986 (4.9%), 1,882 (3.1%), and 1,574 (2.6%) of sera had IgG and/or IgM antibody titers of > or = 1:400 for OT, RT, and TT respectively, suggesting active rickettsial infection. The seropositivity rates of OT, RT and TT varied according to geographical locations. While the seropositivity of OT remained constant during the six-year period, a reduction in the seropositivity of both RT and TT was noted during recent years. The serological findings reflect the endemicity of rickettsial diseases, including tick typhus, and endemic typhus in various parts of Malaysia. Awareness of these diseases by health and medical staff and by the general public is important if the mortality and morbidity associated with scrub typhus, tick typhus, and murine typhus in Malaysia, are to be reduced.

Enzymatic characterisation of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii and other environmental Cryptococcus spp

Chan MY, Tay ST

Mycoses, 2010 Jan;53(1):26-31.

PMID: 19389064 DOI: 10.1111/j.1439-0507.2008.01654.x

This study compared the enzymatic activity of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii, environmental isolates of C. neoformans and non-neoformans Cryptococcus. Most of the cryptococcal isolates investigated in this study exhibited proteinase and phospholipase activities. Laccase activity was detected from all the C. neoformans and C. gattii isolates, but not from the non-neoformans Cryptococcus isolates. There was no significant difference in the proteinase, phospholipase and laccase activities of C. neoformans and C. gattii. However, significant difference in the enzymatic activities of beta-glucuronidase, alpha-glucosidase, beta-glucosidase and N-acetyl-beta-glucosaminidase between C. neoformans and C. gattii isolates was observed in this study. Environmental isolates of C. neoformans exhibited similar enzymatic profiles as the clinical isolates of C. neoformans, except for lower proteinase and laccase activities.

Detection of IgM and IgG antibodies to Cryptococcus neoformans proteins in blood donors and HIV patients with active cryptococcosis

Chai HC, Tay ST

Mycoses, 2009 Mar;52(2):166-70.

PMID: 18643920 DOI: 10.1111/j.1439-0507.2008.01549.x

The serological responses to Cryptococcus neoformans proteins of blood donors and HIV patients with active cryptococcosis from a tropical region were investigated in this study. Exposure to C. neoformans, an organism ubiquitous in the environment, contributes to the antibody responses observed in the blood donors. IgG responses to cryptococcal proteins were stronger than IgM responses in most sera tested in this study. A 53-kDa cryptococcal protein fragment was identified as the most immunoreactive protein on the IgM immunoblots of both blood donors and patients. Overall, there was no obvious difference in IgG responses of patients when compared with blood donors. Some immunogenic protein fragments (27.5, 76, 78 and 91.5 kDa) were detected at least two times more frequently on IgM immunoblots of patients compared with those of blood donors. It is yet to be investigated whether the proteins identified in this study may have any potential to be used as biomarker for cryptococcosis.

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