MyMedR

Preliminary evaluation of the INDX DIP-S-TICKS with positive rickettsial samples in Malaysia

Koay AS, Cheong YM

Malays J Pathol, 1993 Jun;15(1):69-73.

Forty-four serum samples of various reactivities to rickettsial antigens demonstrated by the indirect immunoperoxidase technique were tested with INDX Dip-S-Ticks (INDX Integrated Diagnostics Inc., USA) Kit for the detection of tick borne diseases. The kit utilised Rickettsia rickettsii the causative agent of Rocky Mountain spotted fever (RMSF) as antigens. The samples positive for endemic typhus were also tested against R. typhi, the agent for endemic typhus by the same method. The aim of this study was to determine the extent of cross-reactivity of R. rickettsii with rickettsial infections in Malaysia. Nine out of 12 tick typhus, 4 out of 10 scrub typhus and 4 out of 12 endemic typhus samples cross reacted with R. rickettsii. Ten out of 12 endemic samples were positive with R. typhi by the same method. From the study, we concluded that the INDX Dip-S-Ticks Kit can be used as a rapid screening test to detect endemic and tick-borne rickettsial infections in Malaysia but a second serological test is strongly recommended on all weakly reactive cases.

Fulltext In-vitro susceptibility of Burkholderia pseudomallei to cefoperazone-sulbactam combination

Koay AS, Rohani MY, Cheong YM

Med J Malaysia, 1997 Jun;52(2):158-60.

PMID: 10968074

Melioidosis is endemic in Malaysia. Emerging resistance with new and current antimicrobial agents has underscored the need to look further for new antimicrobial agents for the treatment of melioidosis. Hence, we evaluated the in-vitro susceptibility of fifty locally isolated strains of Burkholderia pseudomallei, the causative agent of melioidosis to cefoperazone-sulbactam combination using the method of NCCLS. All the fifty strains tested were susceptible in-vitro to cefoperazone-sulbactam. The MIC90 of the organism for cefoperazone-sulbactam was 4 mg/L. The results of our findings suggested that cefoperazone-sulbactam may be useful in the treatment of melioidosis.

Enterotoxin production by Staphylococcus aureus strains isolated from humans, foods and animals in Malaysia

Lim YS, Jegathesan M, Koay AS

Southeast Asian J. Trop. Med. Public Health, 1982 Mar;13(1):133-7.

PMID: 7112212

Enterotoxin production by strains of Staphylococcus aureus isolated from human, food and animal sources was investigated. Of the 130 isolates studied, 27 (20.8%) were found to be enterotoxigenic. The most common enterotoxin detected from human sources was enterotoxin C whereas enterotoxin B occurred more frequently in staphylococcal strains of food origin. The 2 enterotoxigenic strains, from animals isolated from a dog and a goat, produced enterotoxins A and C, respectively. Enterotoxin E was not detected alone from any of the enterotoxigenic strains studied, but occurred together with other enterotoxins. The need to detect enterotoxin in staphylococcal strains and in suspected foods for the confirmation of staphylococcal food poisoning is discussed.

In-vitro susceptibility of Pseudomonas pseudomallei isolated in Malaysia to some new cephalosporins and a quinolone

Cheong YM, Joseph PG, Koay AS

Southeast Asian J. Trop. Med. Public Health, 1987 Mar;18(1):94-6.

PMID: 3477872

The current drugs recommended for treatment of melioidosis are tetracycline, chloramphenicol and cotrimoxazole. Unfortunately these drugs are not the drug of choice in an acutely ill patient with septicaemia prior to the availability of laboratory results. With the discovery of the new cephalosporins which have a broad spectrum of activity clinicians are using them either alone or in combination with other antibiotics in such critical situations. Hence, an in-vitro study was carried out on the susceptibility of 41 strains of P. pseudomallei isolated in Malaysia, to these new cephalosporins and a new quinolone. The results showed that all the cephalosporins tested had some activity on the strains tested, with ceftazidime being the most active drug. Pefloxacin had very poor activity. However, further clinical studies are required to determine the duration, dosage and in-vivo activity of the antibiotics.

Fulltext Serological detection of enterotoxin from food poisoning strains of Staphylococcus aureus isolated in Malaysia

Lim YS, Jegathesan M, Koay AS

Singapore Med J, 1985 Jun;26(3):304-6.

PMID: 4048994

Cultures of Staphylococcus aureus from eight food poisoning incidents in Malaysia were examined for their ability to produce enterotoxins. Five of the eight strains were found to be enterotoxigenic, the enterotoxins detected being A and E (three strains), A and C (one strain), and C (one strain). Penicillinase production was observed in four of the five enterotoxigenic strains; the penicillin·sensitive strain was also found to be coagulase-negative. The bacteriological and epidemiological investigations for confirming staphylococcal food poisoning are presented. The preventive measures to be taken in reducing such outbreaks are emphasized.

Auxotypes and serogroups of tetracycline-resistant Neisseria gonorrhoeae isolated in Malaysia

Koay AS, My R, Cheong YM

J Clin Microbiol, 1996 Jul;34(7):1863-5.

PMID: 8784614

Between 1992 and 1994, 253 tetracycline-resistant Neisseria gonorrhoeae (TRNG) strains were isolated and characterized by auxotype and serogroup (A/S) classes to study TRNG prevalence in different years. TRNG accounted for 28.1, 42.5, and 51.9% of the strains isolated in 1992, 1993, and 1994, respectively, showing a significant increase in each successive year (chi square = 26.7, P < 0.001). There was no significant increase in penicillinase-producing TRNG, which accounted for 53.1, 53.8, and 63.2% of the TRNG isolates. The 253 TRNG isolates belonged to 53 A/S classes. Eighteen A/S classes not observed in 1992 were detected in 1993, and 11 A/S classes not observed in 1992 and 1993 were isolated in 1994, indicating dissemination of the tetracycline resistance gene among the N. gonorrhoeae strains in Malaysia. Its emergence and subsequent rapid spread are alarming. The plasmid is capable of self-transfer (S.A. Morse, S.R. Johnson, J.W. Biddle, and M.C. Roberts, J. Infect. Dis. 155:819-822, 1987), allowing further dissemination of tetracycline resistance.

Fulltext Challenges in diagnosis and management of pseudoptosis secondary to asymmetrical skin creases

Ting SL, Koay AC, Yew YH, Chua CN

Med J Malaysia, 2011 Jun;66(2):121-3.

PMID: 22106691 MyJurnal

Asymmetrical eyelid skin crease may be mistaken for ptosis due to apparent narrowing of the palpebral fissure in the eye without the skin crease. This study describes a series of patients who were mistakenly referred for ptosis operation as a result of absent skin crease.

Development and evaluation of dot-immunobinding assay for detection of scrub typhus infection in Leptotrombidium fletcheri (Acari: Trombiculidae)

Ho TM, Shara S, Koay AS, Cheong YM

J Med Entomol, 1992 Jul;29(4):611-3.

PMID: 1495069

A dot-immunobinding assay (DIBA) was compared with a direct fluorescent antibody technique (DFAT) for the detection of Rickettsia tsutsugamushi infection in Leptotrombidium fletcheri (Womersley & Heaslip). Laboratory colonies of infected and noninfected chiggers were examined. The relative proportions of positive, negative, and indeterminate results were significantly different between DIBA and DFAT for infected but not for noninfected chiggers. DIBA was more sensitive and had a better negative predictive value and a lower false negative percentage than DFAT. It was concluded that DIBA is a suitable alternative to DFAT for detecting scrub typhus infection in chiggers.

Fulltext Pulsed-field gel electrophoresis as an epidemiologic tool in the investigation of laboratory acquired Salmonella typhi infection

Koay AS, Jegathesan M, Rohani MY, Cheong YM

Southeast Asian J. Trop. Med. Public Health, 1997 Mar;28(1):82-4.

PMID: 9322288

Strains of Salmonella typhi implicated in two separate cases of laboratory acquired infection from patients and the medical laboratory technologists who processed the patients' samples were analysed by pulsed-field gel electrophoresis. Although all four isolates were of bacteriophage type E1, PFGE was able to demonstrate that the strains responsible for the two laboratory acquired cases were not genetically related. The PFGE patterns of the isolates from the MLTs were found to be identical to those of the corresponding patients after digestion with restriction enzyme AvrII. This provided genetic as well as epidemiological evidence for the source of the laboratory acquired infections.

Fulltext Development and preliminary evaluation of an IgM dot-immunobinding assay (IgM-DIA) for rapid serodiagnosis of scrub typhus infection

Koay AS, Tay ST, Cheong YM, Yasin RM

Southeast Asian J. Trop. Med. Public Health, 1995 Jun;26(2):350-3.

PMID: 8629074

An IgM dot-immunobinding assay (IgM-DIA) was developed for the diagnosis of scrub typhus infection. The whole cell antigens of Karp, Kato and Gilliam strains of Rickettsia tsutsugamushi were immobilized onto nitrocellulose paper and reacted with patients sera. The presence of IgM R. tsutsugamushi specific antibody in the patient sera could be detected by the observation of a visible brown dot on the nitrocellulose paper. The IgM-DIA has a sensitivity of 90.4% and specificity of 81.4% as compared to the indirect immunoperoxidase test. The IgM-DIA is rapid, simple, cost-effective, does not require microscope or incubator. It is recommended as a rapid screening test for the diagnosis of scrub typhus infection in the field or rural area within the hyperendemic region.

Fulltext The occurrence of enterotoxigenic strains of Staphylococcus aureus in foods

Lim YS, Jegathesan M, Koay AS, Kang SH

Med J Malaysia, 1983 Mar;38(1):27-30.

PMID: 6633330

Enterotoxin production by strains of Staphylococcus aureus isolated from foods unconnected with outbreaks offood poisoning was investigated. Twenty-three percent of 217 strains examined produced enterotoxins A, B, C, D or E. Enterotoxin C was found to occur most frequently. Enterotoxin A was not detected alone from any of the strains examined, but occurred together with other enterotoxins. The overall number of strains isolated from raw foods which produced one or more enterotoxins was higher than that for cooked foods. Antibiotic sensitivities were unrelated to enterotoxin production and no correlation could be found between methicillin resistance and enterotoxigenicity.

Fulltext Lack of association between Gly82Ser, 1704G/T and 2184A/G of RAGE gene polymorphisms and retinopathy susceptibility in Malaysian diabetic patients

Ng ZX, Kuppusamy UR, Poh R, Tajunisah I, Koay AC, Fong KC, et al.

Genet. Mol. Res., 2012 Mar 01;11(1):455-61.

PMID: 22427038 DOI: 10.4238/2012.March.1.2

Diabetic retinopathy is the most common diabetic eye disease, occurring in about 60% of type 2 diabetic patients. Other than known clinical risk factors, the influence of genes has been suggested as part of the development of diabetic retinopathy. We investigated the association of Gly82Ser, 1704G/T and 2184A/G polymorphisms in the RAGE gene with retinopathy in type 2 diabetic patients in Malaysia. Ninety-eight unrelated retinopathy patients and 185 unrelated healthy controls from all over Malaysia were recruited in this study. The allele and genotype frequencies of the three gene polymorphisms were investigated using PCR-RFLP. The allele frequency of the three polymorphisms did not differ significantly between the control and the retinopathy group (P > 0.05). Analysis of the frequency of GA+AA, GT+TT and AG+GG in the retinopathy group did not reveal significant differences (P > 0.05) compared to the control group. We conclude that RAGE gene Gly82Ser, 1704G/T and 2184A/G polymorphisms are not associated with retinopathy development in the Malaysian population.

Fulltext The use of preserved bovine pericardium for emergency temporizing graft in corneal perforation

Koay AC, Yew YH, Ngo CT, Loo VP, Intan G, Chua CN

Med J Malaysia, 2008 Dec;63(5):421-2.

PMID: 19803308 MyJurnal

Corneal perforation is an ocular emergency that requires early intervention to avoid permanent visual loss from endophthalmitis or irreversible structural changes. Although tectonic keratoplasty is the best choice for patching a large perforation, a donor cornea is not always immediately available. Consequently, an alternative material is required while awaiting a donor cornea. We report the use of preserved bovine pericardium as a temporizing graft to maintain the ocular integrity in two patients with corneal perforation.

Fulltext Prevalence and antibiotic susceptibility of Ureaplasma urealyticum in Malaysian neonates with respiratory distress

Tay ST, Boo NY, Khoo TB, Koay AS, Rohani MY

Med J Malaysia, 1997 Dec;52(4):409-11.

PMID: 10968119

Ureaplasma urealyticum was isolated from the endotracheal aspirates of 39 (21.4%) of 182 neonates with respiratory distress requiring ventilatory support. Mycoplasma hominis was isolated from one (0.5%) neonate. Bacterial cultures were negative in 123 (67.6%) neonates. Antibiotic susceptibility test carried out on ten isolates of U. urealyticum showed that all the organisms were sensitive to erythromycin but resistant to lincomycin and sulfamethoxazole trimethoprim. All, except one, U. urealyticum were sensitive to tetracycline and minocycline. Two isolates were resistant to ciprofloxacin. This study showed that U.urealyticum was a common organism isolated from the endotracheal aspirates of neonates with respiratory distress.

Fulltext Treating an infected transcatheter pacemaker system via percutaneous extraction

Koay A, Khelae S, Wei KK, Muhammad Z, Mohd Ali R, Omar R

HeartRhythm Case Rep, 2016 Jul;2(4):360-362.

PMID: 28491710 DOI: 10.1016/j.hrcr.2016.04.006

Fulltext Resveratrol-Based Nanoformulations as an Emerging Therapeutic Strategy for Cancer

Sharifi-Rad J, Quispe C, Mukazhanova Z, Knut E, Turgumbayeva A, Kipchakbayeva A, et al.

Front Mol Biosci, 2021;8:649395.

PMID: 34540888 DOI: 10.3389/fmolb.2021.649395

Resveratrol is a polyphenolic stilbene derivative widely present in grapes and red wine. Broadly known for its antioxidant effects, numerous studies have also indicated that it exerts anti-inflammatory and antiaging abilities and a great potential in cancer therapy. Regrettably, the oral administration of resveratrol has pharmacokinetic and physicochemical limitations such as hampering its effects so that effective administration methods are demanding to ensure its efficiency. Thus, the present review explores the published data on the application of resveratrol nanoformulations in cancer therapy, with the use of different types of nanodelivery systems. Mechanisms of action with a potential use in cancer therapy, negative effects, and the influence of resveratrol nanoformulations in different types of cancer are also highlighted. Finally, the toxicological features of nanoresveratrol are also discussed.

Techniques for successful early retrieval of the Micra transcatheter pacing system: A worldwide experience

Afzal MR, Daoud EG, Cunnane R, Mulpuru SK, Koay A, Hussain A, et al.

Heart Rhythm, 2018 06;15(6):841-846.

PMID: 29427820 DOI: 10.1016/j.hrthm.2018.02.008

BACKGROUND: Experience with retrieval of the Micra transcatheter pacing system (TPS) is limited because of its relatively newer technology. Although abandonment of the TPS at end of life is recommended, certain situations such as endovascular infection or device embolization warrant retrieval.

OBJECTIVE: The purpose of this study was to report the worldwide experience with successful retrieval of the Micra TPS.

METHODS: A list of all successful retrievals of the currently available leadless pacemakers (LPs) was obtained from the manufacturer of Micra TPS. Pertinent details of retrieval, such as indication, days postimplantation, equipment used, complications, and postretrieval management, were obtained from the database collected by the manufacturer. Other procedural details were obtained directly from the operators at each participating site.

RESULTS: Data from the manufacturer consisted of 40 successful retrievals of the Micra TPS. Operators for 29 retrievals (73%) provided the consent and procedural details. Of the 29 retrievals, 11 patients underwent retrieval during the initial procedure (immediate retrieval); the other 18 patients underwent retrieval during a separate procedure (delayed retrieval). Median duration before delayed retrieval was 46 days (range 1-95 days). The most common reason for immediate retrieval was elevated pacing threshold after tether removal. The most common reasons for delayed retrieval included elevated pacing threshold at follow-up, endovascular infection, and need for transvenous device. Mean procedure duration was 63.11 ± 56 minutes. All retrievals involved snaring via a Micra TPS delivery catheter or steerable sheath. No serious complications occurred during the reported retrievals.

CONCLUSION: Early retrieval of the Micra TPS is feasible and safe.

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