Acanthamoeba sp. is a free-living amoeba known to cause chronic central nervous system infection or eye infection in humans. Many cases remain undetected for want of a good detection system. We report for the first time a rapid staining method to facilitate the identification of Acanthamoeba sp. using the modified Field's staining technique. A. castellanii, which was used in the present experiment, is maintained in our laboratory in mycological peptone medium (Gibco). The cultures were pooled together and smears were made on glass slides for staining purposes. Different types of stains such as Field's stain, modified Field's stain, Wright's stain, Giemsa stain, Ziehl-Neelsen stain, and trichrome stain were used to determine the best stain for the identification of this amoeba. The concentration of various stains and the duration of staining were varied to provide the best color and contrast for each stain. Acanthamoeba was also obtained from the brain of experimentally infected mice and was stained with various stains as mentioned above to determine the best stain for use in identifying the presence of this parasite in experimentally infected animals. The modified Field's stain gives a very good color contrast as compared with other stains. Furthermore, it takes only 20 s to be carried out using the least number of reagents, making it suitable for both laboratory and field use.
This case study of medical schools in Malaysia addresses their role in meeting the demands of a young nation. Throughout the growth and development of these medical schools, there have been efforts to coordinate and cooperate with providers of health care. The treatment of illness must mesh with the changing paradigm of health and wellness as an achievable and indeed desirable goal, not only for the individual but also for society. The scientific basis of medicine is being emphasized with the advent of evidence-based medicine and outcome measures. Innovations have been made to bring the schools in closer contact with the service providers. Malaysia has prepared farsighted plans to become a developed nation by the year 2020. Accordingly, its health services will use advances in information technology and will introduce telemedicine in various strategic applications to extend the reach of the health care team. It is incumbent on the medical schools to move in concert with the Ministry of Health to realize goals of the nation and the society.
MeSH terms: Delivery of Health Care; Education, Medical/organization & administration*; Humans; Malaysia; Organizational Objectives; Patient Care Team; Schools, Medical/organization & administration*; Social Responsibility*; Telemedicine
This study aims to determine the prevalence of and risk factors associated with retinopathy of prematurity (ROP) in very low birth weight (VLBW) infants. All premature VLBW infants, admitted into the neonatal intensive care unit of the University Hospital Kuala Lumpur, were screened from 4 weeks of life. Perinatal and neonatal data were retrieved from the infants' medical notes. Between August 1994 and July 1996, 100 infants had their eyes examined serially. Of the 15 (15%) infants with ROP, all were less than 31 weeks gestation, and only 1 infant had birth weight above 1250 g. Five (5%) infants had severe ROP; 4 infants underwent cryotherapy for stage 3 threshold disease. Infants with ROP, as compared to infants without ROP, had lower birth weight [mean (SEM) 993 (50) g versus 1205 (22) g, P < 0.001], lower gestational age [mean (SEM) 28.0 (0.4) weeks versus 30.1 (0.2) weeks, P < 0.001], higher rates of patent ductus arteriosus and chronic lung disease, greater number of radiographic examinations and episodes of late-onset suspected/confirmed sepsis, and required longer duration of supplemental oxygen, ventilation, xanthine, antibiotics and intralipid use, but were slower to establish full enteral feeds. On multivariate logistic regression analysis, birth weight < or = 1000 g [OR 2.38, 95% CI 1.25, 4.55, P = 0.009] and gestational age < or = 28 weeks [OR 2.86, 95% CI 1.47, 5.56, P = 0.002] were significant predictors of increased risk of this disease. In conclusion, ROP is strongly associated with smaller, more immature and sicker neonates. Prevention of prematurity would help reduce the incidence of this disease.
We studied the relationship between different ethnic groups, obstructive sleep apnoea (OSA) and ischaemic heart disease. Four hundred and thirty-two inpatients from the medical wards were interviewed. Limited overnight sleep studies were done in 129 of those who had habitual snoring, daytime sleepiness based on an Epworth sleepiness scale of 8 or more, or a large neck size of 40 cm or more. There were 315 Chinese (72.9%), 67 Malays (15.5%), 43 Indians (10%) and 3 from other races (1.4%). The prevalence of OSA was 19.7%, 30% and 12% among the Chinese, Malays and Indians, respectively. The prevalence ratio for OSA was 1.52 in Malays using Chinese patients as the baseline (P = 0.07). The median neck circumference was 37 cm in both racial groups. The median body mass index was 22.7 kg/m2 in Chinese compared to 23.6 kg/m2 in Malays. The median apnoea-hypopnoea index was 22.7, 19.0 and 26.9 events/hour among the Chinese, Malays and Indians, respectively. OSA was independently associated with the prevalence of IHD (adjusted prevalence ratio 1.68; 95% CI: 1.15, 2.46; P = 0.009). The prevalence of ischaemic heart disease (IHD) was 31%, 24% and 28% in Chinese, Malays and Indians, respectively. The prevalence ratio for IHD in Malays compared to Chinese was 0.77. After adjusting for OSA, there was an even greater reduction in the risk of IHD (adjusted prevalence ratio 0.70). This suggests that OSA is a confounder in the relationship between race and ischaemic heart disease.
Joint hypermobility is a clinical entity that has been little studied in Southeast Asia in contrast to the many studies that have been conducted in the West. A pioneer study was conducted in Singapore involving 306 subjects from the three major races i.e. Chinese, Malays and Indians. Their ages ranged from 15 to 39 years. The objective was to ascertain the joint mobility profile in a study sample representative of the Singapore population and the prevalence of joint hypermobility amongst normal individuals. Joint mobility was assessed using criteria according to Carter and Wilkinson modified by Beighton et al. The distribution of the three major races in the study sample was based on the 1990 census of the Singapore population. The prevalence of joint hypermobility was found to be 17%. The results showed that joint mobility decreases with age and that females had consistently higher degree of joint mobility compared to males throughout the age group. Among the racial groups, Malays had the highest degree of joint mobility followed by Indians and Chinese.
MeSH terms: Adolescent; Adult; Age Factors; China/ethnology; Cross-Sectional Studies; Elbow Joint/physiology; Female; Finger Joint/physiology; Humans; India/ethnology; Joint Instability/classification*; Joint Instability/ethnology; Joint Instability/physiopathology; Joints/physiology*; Knee Joint/physiology; Malaysia/ethnology; Male; Sex Factors; Singapore; Spine/physiology; Prevalence; Range of Motion, Articular/physiology*; European Continental Ancestry Group; Asian Continental Ancestry Group
Resistance to activated protein C (APC-R) is the commonest inherited cause of thrombosis among Caucasians. Few studies have been carried out on its prevalence in Asians. We conducted a prospective study on 60 patients with thromboembolism to determine its prevalence in our local population. The Factor V Leiden (VaQ506) mutation associated with this condition was detected by amplification of the Factor V gene by polymerase chain reaction (PCR) and digestion of the fragment with Mnl I. Three patients were found to be heterozygous for this mutation. None of the 3 patients had other concomitant hypercoagulable states. In addition, we studied the prevalence of this condition in Malays which was found to be 0.5%. Our study suggests that the incidence of APC-R is much lower here compared to the West.
MeSH terms: Adult; Aged; Aged, 80 and over; China/ethnology; Factor V/genetics; Female; Heterozygote; Humans; India/ethnology; Malaysia/ethnology; Male; Middle Aged; Prospective Studies; Singapore; Thromboembolism/genetics*; Deoxyribonucleases, Type II Site-Specific; Cohort Studies; Incidence; Prevalence; Polymerase Chain Reaction; Point Mutation/genetics; Activated Protein C Resistance/genetics*; European Continental Ancestry Group/genetics; Asian Continental Ancestry Group/genetics
Nineteen strains of vancomycin-resistant Enterococcus faecium isolated from 10 of 75 (13.3%) tenderloin beef samples were examined for resistance to selected antibiotics, presence of plasmids, and genetic diversity by random amplification of polymorphic DNA analysis. All strains showed multiple resistant to the antibiotics tested. Multiple antibiotic indexing of the vancomycin-resistant E. faecium strains showed that all (100%) originated from high risk contamination environments where antibiotics were often used. Plasmids ranging in size from 1.5 to 36 megadalton were detected in 15 of 19 (79%) strains. Thus, three plasmid profiles and eight antibiotypes were observed among the E. faecium strains. A high degree of polymorphism was obtained by combining the results of the two primers used; with the 19 E. faecium strains being differentiated into 19 RAPD-types. These preliminary results suggest that RAPD-PCR has application for epidemiologic studies and that resistance patterns and plasmid profiling could be used as an adjunct to RAPD for the typing of E. faecium in the study area.
MeSH terms: Animals; Anti-Bacterial Agents/pharmacology*; Cattle; DNA, Bacterial/genetics; Drug Resistance, Microbial; Malaysia; Meat/microbiology*; Microbial Sensitivity Tests; Plasmids/analysis; Risk Factors; Vancomycin/pharmacology*; Genetic Variation; Enterococcus faecium/drug effects*; Enterococcus faecium/genetics; Enterococcus faecium/isolation & purification; Drug Resistance, Multiple; Random Amplified Polymorphic DNA Technique
In mid-1997, several children died in Sarawak, Malaysia, during an epidemic of enterovirus-71 (EV71) hand, foot, and mouth disease. The children who died had a febrile illness that rapidly progressed to cardiopulmonary failure and the cause was not satisfactorily resolved. We describe the isolation and identification of a subgenus B adenovirus from the children who died.
Twenty-four 8 to 9 week-old Pasteurella multocida -free rabbits were divided into three equal groups, the first group was pretreated with hydrocortisone and inoculated intranasally with pasteurella multocida serotype A:3. The second group was inoculated intranasally with P. multocida without hydrocortisone treatment. The third group was inoculated with phosphate buffered saline only and used as a control group. Pasteurella multocida was isolated from the nasal cavity of all infected rabbits in group 1 and 2 and from the trachea of seven rabbits in group 1 and five rabbits in group 2. This study was conducted to observe the ultrastructural changes of the upper respiratory tract of hydrocortisone treated and non-treated rabbits infected with P. multocida serotype A:3. The ultrastructural changes detected in infected rabbits were ciliary destruction and deciliation of the ciliated epithelial cells, cellular swelling, goblet cell hyperplasia and endothelial cell damage. Pasteurella multocida was observed attached to the degenerated cilia, microvilli and mucus. Pasteurella multocida infection was associated with inflammatory responses, which may have caused tissue damage. It is possible that hydrocortisone modulates the severity of infection as an immune suppressor and an inhibitor of goblet cell secretion.
We screened 38 G6PD-deficient male Chinese neonates for known G6PD mutations using established PCR-based techniques. We found 50.0% (19 of 38) were mutation 1376G>T, 34.2% (13 of 38) were mutation 1388G>A, 5.2% (2 of 38 ) were mutation 95A>G and 2.2% (1 of 38) was mutation 1024C>T. In 7% (3 of 38) of the cases the mutations remained uncharacterised. Sixty three percent (24 of 38) of the G6PD deficient neonates had neonatal jaundice with 28.9 % (11 of 38) developing moderate to severe hyperbilirubinemia. The group of neonates with 1388 mutation showed the highest incidence of moderate to severe hyperbilirubinemia requiring phototherapy and/or exchange transfusion respectively. Majority (70%) of the G6PD deficient neonates showed severe enzyme deficiency. However, there was no meaningful association between the level of enzyme activity and the severity of neonatal jaundice. In summary, four mutations account for more than 90% of the G6PD deficiency cases among the Chinese in Malaysia and the pattern of distribution of the molecular variants is similar to those found among the Chinese in Taiwan and southern mainland China. Our findings also suggest the possible association of nt 1388 mutation with severe neonatal jaundice.
The microsporidian genus Nosema is characterized by development in direct control with host cell cytoplasm, diplokaryotic nuclei throughout development and disporous sporogony. The genus Vairimorpha exhibits the same features plus an octoporous sporogony producing uninucleate spores in a sporophorous vesicle. A microsporidium from diamondback moth, Plutella xylostella, falls between Nosema and Vairimorpha in that it initiates but fails to complete the octosporous sequence in this host. The name Vairimorpha imperfecta n.sp. is proposed. Merogony is mainly by formation of buds from multinucleate meronts, the buds remaining attached in chains. Diplokaryotic spores measure 4.3 x 2.0 microns (fresh) and have 15.5 coils of the polar tube in 1 rank. The octosporous sporogony is aborted owing to irregular formation of nuclear spindles, incomplete cytoplasmic fission and bizarre deposition of electron-dense episporontal secretions. Phylogenetic analyses of the sequences of the small subunit rRNA genes of V. imperfecta and of several Nosema and Vairimorpha spp. place V. imperfecta in a clade with Nosema spp. from Lepidoptera rather than in the clade containing the more typical species of Vairimorpha. It is suggested that the ancestors of the Vairimorpha/Nosema complex of species exhibited both disporous and octosporous sporogonies, as does the type species of Vairimorpha, Vairimorpha necatrix. It would follow that true Nosema spp. have lost the ability to express an octosporous sequence and that V. imperfecta is in the process of losing it. It is proposed that the genera Nosema and Vairimorpha be placed in the same family Nosematidae Labbé 1899, rather than in separate families and orders as at present.
Lipoprotein(a) [Lp(a)] is formed when apolipoprotein(a) is linked to low density lipoprotein (LDL)-cholesterol via a single disulfide bond. It is an independent risk factor for myocardial infarction and raised concentrations are associated with an increased risk of developing coronary artery disease. Singapore has a multi-racial population of 77% Chinese, 14% Malays and 7% Indians. Studies have shown that the Indians have significantly higher standardised mortality ratios (SMR) compared to the Chinese and the Malays. We measured serum Lp(a) concentrations in 803 healthy individuals recruited from the Multiphasic Health Screening Programme, using the Macra Lp(a) sandwich enzyme immunoassay kit (Strategics Diagnostics, Delaware, USA). Lp(a) concentrations were skewed in all three groups. Our population mean was 9.0 mg/dl, with 50th, 75th and 95th percentile values of 10.2, 19.8 and 43.1 mg/dl, respectively, which are lower than values reported from Caucasian populations (15.0, 29.0 and 60.0 mg/dl, respectively). Males had lower Lp(a) concentrations than females (P < 0.05). The Indian group had significantly higher concentrations (median 12.3 mg/dl) compared to their Chinese (median 9.6 mg/dl) and Malay (median 8.4 mg/dl) counterparts (P < 0.05). This could partly account for the higher SMR seen in the Indian population in Singapore. As serum Lp(a) concentrations are method- and population-dependent, we recommend that laboratories determine their own reference ranges by their method to avoid misclassification of the coronary heart disease (CHD) risk of patients.
MeSH terms: Adolescent; Adult; Age Factors; Aged; China/ethnology; Female; Humans; India/ethnology; Malaysia/ethnology; Male; Middle Aged; Sex Factors; Singapore/epidemiology; Lipoprotein(a)/blood*
A simple technique for removal of the distal fragment of the broken intramedullary interlocking nail is described. It was successfully used in three patients with a broken nail due to nonunion. The technique requires only cerclage wire, which is available in any operating room, avoiding the difficulties obtaining the custom made hook and of excessive exposure to radiation.
MeSH terms: Bone Nails*; Bone Wires; Femoral Fractures/surgery*; Fracture Fixation, Intramedullary/instrumentation*; Fractures, Ununited/complications; Humans; Prosthesis Failure*; Tibial Fractures/surgery*
We report a case of a 14-month-old-infant with severe congenital mitral stenosis who presented with pulmonary oedema, acute renal failure and haemodynamic instability. Balloon dilatation was successfully performed under fluoroscopic and transesophageal echocardiographic guidance. Cathet. Cardiovasc. Intervent. 48:191-193, 1999.
A simple high-performance liquid chromatographic method using UV detection was developed for the determination of alpha-tocopherol in human plasma. The method entailed direct injection of the plasma sample after deproteinization using acetonitrile-tetrahydrofuran (3:2). The mobile phase comprised methanol-tetrahydrofuran (94:6) and analysis was run at a flow-rate of 1.5 ml/min with the detector operating at 292 nm. A Crestpak C18S (5 microm, 250 mm x 4.6 mm ID) was used for the chromatographic separation. The method had a mean recovery of 93%, while the within-day and between-day coefficients of variation and percentage errors were all less than 7%. The speed, specificity, sensitivity and reproducibility of this method make it particularly suitable for routine determination of alpha-tocopherol in human plasma. Moreover, only a small sample plasma volume (100 microl) is required for the analysis.
We describe a convenient, versatile and safe method for preparing bacterial DNA for ribotyping analysis. In this method, extraction of bacterial DNA from Salmnonella typhi and Burkholderia pseudomallei. and subsequent restriction endonuclease digestion, was performed in agarose blocks/plugs thus minimizing shearing and loss of DNA, problems commonly associated with liquid phase phenol extraction. Digested DNA in the plugs was then electrophoresed directly, transferred to nylon membranes and hybridized with labeled rDNA probes in the usual manner to provide reproducible restriction patterns. This method is particularly useful for bacterial species where standard DNA extraction in the liquid phase using phenol has been problematic (e.g. B. pseudomallei) but can be used for any bacterial species. The DNA extracted within the agarose plugs can be stored for long periods and can be used in other, widely-used typing methods such as pulsed-field gel electrophoresis (PFGE) and PCR-based techniques. Embedding live cells directly in agarose plugs also minimizes the risk of exposure to these virulent human pathogens among laboratory workers.
Between February and April, 1999, an outbreak of viral encephalitis occurred among pig-farmers in Malaysia. We report findings for the first three patients who died.