Browse publications by year: 2002

  1. Chan PW, Samsinah H, Azlin NM
    J Paediatr Child Health, 2002 Dec;38(6):622.
    PMID: 12410882
    MeSH terms: Adolescent; Asthma/ethnology*; Asthma/etiology*; Child; Child, Preschool; Folklore*; Fruit/adverse effects*; Humans; Malaysia/epidemiology
  2. Jayaram G, Yahya H
    Diagn Cytopathol, 2002 Nov;27(5):322-4.
    PMID: 12412003
    MeSH terms: Biopsy, Needle; Humans; Malaysia; Mass Screening; Neoplasms/epidemiology; Quality Assurance, Health Care*; Incidence
  3. Lan GQ, Abdullah N, Jalaludin S, Ho YW
    Poult Sci, 2002 Oct;81(10):1522-32.
    PMID: 12412919
    We evaluated the efficacy of supplementation of active Mitsuokella jalaludinii culture (AMJC) on the growth performance, nutrient use, and mineral concentrations in tibia bone and plasma of broiler chickens fed corn-soybean meal diets. Dietary treatments included low-nonphytate P (NPP) feed (containing 0.24% and 0.232% NPP for chicks from 1 to 21 and 22 to 42 d of age, respectively), low-NPP feed added with different levels of AMJC (equivalent to 250, 500, 750, and 1,000 U phytase/kg of feed), and normal-NPP feed (containing 0.46 and 0.354% NPP for chicks from 1 to 21 and 22 to 42 d of age, respectively). Supplementation of AMJC to low-NPP feed increased (P < 0.05) weight gain and feed intake and decreased (P < 0.05) feed:gain ratio of chickens during the whole experiment (Days 1 to 42). Supplementation of AMJC increased (P < 0.05) the AME value, digestibility of DM and CP, and retention of P, Ca, and Cu. Mn retention in broilers was only increased (P < 0.05) by AMJC supplementation from 18 to 20 d of age, and Zn retention was improved (P < 0.05) only at a high level of AMJC (equivalent to 1,000 U phytase/kg of feed) supplementation. Chicks fed low-NPP feed added with AMJC had similar tibia ash percentages as those fed the normal-NPP diet. Generally, supplementing AMJC to low-NPP feed increased (P < 0.05) Ca, decreased significantly (P < 0.05) Mn and Cu, but did not affect Zn and P concentrations in tibia ash. Supplementing AMJC also increased (P < 0.05) plasma P but had no effect on plasma Ca or Mn. Plasma Zn concentration was increased only when a high level of AMJC (equivalent to 1,000 U phytase/kg of feed) was used. In conclusion, AMJC supplementation to low-NPP feed improved growth performance; AME value; digestibility of CP and DM; use of Ca, P, and Cu; and bone mineralization.
    MeSH terms: Animals; Animal Nutritional Physiological Phenomena*; Biological Availability; Chickens/physiology*; Zea mays*; Digestion; Eating; Male; Minerals/analysis; Minerals/blood; Minerals/pharmacokinetics; Peptococcaceae/enzymology*; 6-Phytase/administration & dosage; 6-Phytase/biosynthesis*; Soybeans*; Tibia/chemistry; Weight Gain; Dietary Supplements; Probiotics
  4. Hughes AJ, Biggs BA
    Intern Med J, 2002 Nov;32(11):541-53.
    PMID: 12412938
    The diagnosis and management of parasitic diseases of the central nervous system (CNS) is difficult, even for infectious diseases physicians and neurologists. Furthermore, few overviews of the spectrum of causative helminths and clinical syndromes have been published. In the present study, we review the seven most common parasitic diseases of the CNS: (i) cysticercosis, (ii) neuroschistosomiasis, (iii) paragonimiasis, (iv) angiostrongyliasis, (v) hydatid disease, (vi) sparganosis and (vii) gnathostomiasis. Major syndromes of parasitic disease of the CNS and their differential causes are discussed, including: (i) cystic lesions, (ii) enhancing granulomas (with and without creeping subcutaneous eruptions), (iii) eosinophilic meningoencephalitis and (iv) spinal cord disease. Specific risk factors that predispose to these infections are also discussed and particular attention is drawn to the situation in Australia.
    MeSH terms: Angiostrongylus; Animals; Australia; Echinococcosis/diagnosis; Echinococcosis/therapy; Gnathostoma; Humans; Magnetic Resonance Imaging; Paragonimiasis/diagnosis; Paragonimiasis/therapy; Sparganosis/diagnosis; Sparganosis/therapy; Tomography, X-Ray Computed; Spirurida Infections/diagnosis; Spirurida Infections/therapy; Strongylida Infections/diagnosis; Strongylida Infections/therapy; Neurocysticercosis/diagnosis; Neurocysticercosis/therapy; Central Nervous System Parasitic Infections/diagnosis*; Central Nervous System Parasitic Infections/therapy*; Neuroschistosomiasis/diagnosis; Neuroschistosomiasis/therapy
  5. Chia CS, Ban K, Ithnin H, Singh H, Krishnan R, Mokhtar S, et al.
    Immunol Lett, 2002 Dec 03;84(3):163-72.
    PMID: 12413732
    This is the first report on the detection of IL-18, IFN-gamma and IL-10 proteins in hepatocelllular carcinoma. In the apparently normal surrounding tissue, 13 out of 17 paired specimens showed positive immunoreactivity to IL-18 (76.5%) compared with six out of 17 in the tumour portion (35.3% of specimens). Thus, a significantly higher number of IL-18 positive specimens was found in the hepatocytes of apparently normal surrounding tissue compared with the tumour (P=0.018). In contrast, the number of specimens with positive immunoreactivity to the antibody against the Th1 cytokine, IFN-gamma expression in the hepatocytes was lower. Only one specimen from the apparently normal surrounding tissue (one out of 17; 5.9%) and three other specimens from the tumour portion (three out of 17; 17.6%) had positive immunoreactivity. Similarly, the expression of the Th2 cytokine, IL-10 in normal (four out of 17; 23.5%) and tumour portions (five out of 17; 29.4%) was also low. Thus, there did not appear to be predominant Th2 immune response as denoted by IL-10 expression. Using the Spearman correlation rank test, a significant correlation between IL-18 expression in the apparently normal surrounding tissue and high alpha-foetoprotein (AFP) levels of >350 IU/l. No correlation between IL-18 expression in the tumour portion and clinicopathological factors was found. There was also no correlation found between IL-18 and the other cytokines, namely, IFN-gamma and IL-10 expression These new findings provide additional information on the type of cytokines expressed in the tumour microenvironment and give a further insight into the role of cytokines in the pathogenesis of cancer which is critical for the development of effective immunotherapeutic approaches for cancer therapy in the future.
    MeSH terms: Female; Carcinoma, Hepatocellular/diagnosis; Carcinoma, Hepatocellular/immunology*; Carcinoma, Hepatocellular/metabolism; Humans; Immunohistochemistry; Liver Neoplasms/diagnosis; Liver Neoplasms/immunology*; Liver Neoplasms/metabolism; Male; Middle Aged; Prognosis; Cytokines/biosynthesis; Cytokines/immunology*; Interleukin-10/biosynthesis; Interleukin-10/immunology; Interferon-alpha/biosynthesis; Interferon-alpha/immunology; Interleukin-18/biosynthesis; Interleukin-18/immunology
  6. Usman A, Razak IA, Chantrapromma S, Fun HK, Philip V, Sreekanth A, et al.
    Acta Crystallogr C, 2002 Nov;58(Pt 11):o652-4.
    PMID: 12415171
    The title compound, C(16)H(17)N(5)S, is in the thione form and crystallizes with two independent molecules in the asymmetric unit. In both molecules, the pentamethyleneimine five-membered ring adopts an envelope conformation, and in one of the molecules this ring shows positional disorder. The thione S and hydrazine N atoms are in the Z configuration with respect to the C-N bond.
    MeSH terms: Crystallization; Hydrazines; Molecular Conformation; Thiones
  7. Chantrapromma S, Usman A, Fun HK, Poh BL, Karalai C
    Acta Crystallogr C, 2002 Nov;58(Pt 11):o675-7.
    PMID: 12415179
    In the title adduct, 1,3,5,7-tetraazatricyclo[3.3.1.1(3,7)]decane-4-nitrobenzene-1,2-diol-water (1/2/1), C(6)H(12)N(4).2C(6)H(5)NO(4).H(2)O, the hexamethylenetetramine molecule acts as an acceptor of intermolecular O-H.N hydrogen-bonding interactions from the water molecule and the hydroxy groups of one of the two symmetry-independent 4-nitrocatechol molecules. The structure is built from molecular layers which are stabilized by three intermolecular O-H.O, two intermolecular O-H.N and four intermolecular C-H.O hydrogen bonds. The layers are further interconnected by one additional intermolecular O-H.N and two intermolecular C-H.O hydrogen bonds.
    MeSH terms: Alkanes; Catechols; Hydrogen; Hydrogen Bonding; Methenamine; Nitrobenzenes; Water
  8. Banjade DP, Shrestha SL, Shukri A, Tajuddin AA, Bhat M
    Australas Phys Eng Sci Med, 2002 Sep;25(3):110-8.
    PMID: 12416587
    This is a study using LiF:Mg;Ti thermoluminescent dosimeter (TLD) rods in phantoms to investigate the effect of lack of backscatter on exit dose. Comparing the measured dose with anticipated dose calculated using tissue maximum ratio (TMR) or percentage depth dose (PDD) gives rise to a correction factor. This correction factor may be applied to in-vivo dosimetry results to derive true dose to a point within the patient. Measurements in a specially designed humanoid breast phantom as well as patients undergoing radiotherapy treatment were also been done. TLDs with reproducibility of within +/- 3% (1 SD) are irradiated in a series of measurements for 6 and 10 MV photon beams from a medical linear accelerator. The measured exit doses for the different phantom thickness for 6 MV beams are found to be lowered by 10.9 to 14.0% compared to the dose derived from theoretical estimation (normalized dose at dmax). The same measurements for 10 MV beams are lowered by 9.0 to 13.5%. The variations of measured exit dose for different field sizes are found to be within 2.5%. The exit doses with added backscatter material from 2 mm up to 15 cm, shows gradual increase and the saturated values agreed within 1.5% with the expected results for both beams. The measured exit doses in humanoid breast phantom as well as in the clinical trial on patients undergoing radiotherapy also agreed with the predicted results based on phantom measurements. The authors' viewpoint is that this technique provides sufficient information to design exit surface bolus to restore build down effect in cases where part of the exit surface is being considered as a target volume. It indicates that the technique could be translated for in vivo dose measurements, which may be a conspicuous step of quality assurance in clinical practice.
    MeSH terms: Breast/radiation effects*; Equipment Design; Fluorides; Humans; Models, Biological; Neoplasms/radiotherapy*; Radiotherapy Dosage*; Scattering, Radiation; Sensitivity and Specificity; Thermoluminescent Dosimetry/instrumentation*; Thermoluminescent Dosimetry/methods*; Reproducibility of Results; Lithium Compounds; Phantoms, Imaging*
  9. Lim CK, Yew KM, Ng KH, Abdullah BJ
    Australas Phys Eng Sci Med, 2002 Sep;25(3):144-50.
    PMID: 12416592 DOI: 10.1007/BF03178776
    Development of computer-based medical inference systems is always confronted with some difficulties. In this paper, difficulties of designing an inference system for the diagnosis of arthritic diseases are described, including variations of disease manifestations under various situations and conditions. Furthermore, the need for a huge knowledge base would result in low efficiency of the inference system. We proposed a hierarchical model of the fuzzy inference system as a possible solution. With such a model, the diagnostic process is divided into two levels. The first level of the diagnosis reduces the scope of diagnosis to be processed by the second level. This will reduce the amount of input and mapping for the whole diagnostic process. Fuzzy relational theory is the core of this system and it is used in both levels to improve the accuracy.
    MeSH terms: Algorithms*; Arthritis/classification*; Arthritis/diagnosis*; Diagnosis, Computer-Assisted/methods*; Diagnosis, Differential; Expert Systems*; Humans; Models, Statistical; Fuzzy Logic*
  10. Sosroseno W, Bird PS, Gemmell E, Seymour GJ
    J. Periodontol., 2002 Oct;73(10):1133-40.
    PMID: 12416770
    It has previously been suggested that CD4+ T cells play a pivotal role in regulating the immune response to periodontal pathogens. The aim of the present study therefore was to determine delayed type hypersensitivity (DTH), spleen cell proliferation, serum and splenic anti-Porphyromonas gingivalis antibody levels, and lesion sizes following challenge with viable P. gingivalis in CD4-depleted BALB/c mice immunized with P. gingivalis outer membrane proteins (OMP).
    MeSH terms: Abscess/immunology; Abscess/microbiology; Animals; Antibodies, Bacterial/biosynthesis; Bacterial Outer Membrane Proteins/immunology; Enzyme-Linked Immunosorbent Assay; Female; Foot; Hypersensitivity, Delayed; Immunization; Mice, Inbred BALB C; Spleen/cytology; Spleen/immunology; Wound Healing/immunology; CD4-Positive T-Lymphocytes/physiology*; Porphyromonas gingivalis/immunology*; Porphyromonas gingivalis/pathogenicity; Mice
  11. Meekes ET, Fransen JJ, van Lenteren JC
    J Invertebr Pathol, 2002 Sep;81(1):1-11.
    PMID: 12417207
    Entomopathogenic fungi of the genus Aschersonia are specific for whitefly and scale insects. They can be used as biological control agents against silverleaf whitefly, Bemisia argentifolii and greenhouse whitefly, Trialeurodes vaporariorum. Forty-four isolates of Aschersonia spp. were tested for their ability to sporulate and germinate on semi-artificial media and to infect insect hosts. Seven isolates sporulated poorly (less than 1x10(7) conidia/dry weight) and 10 were not able to infect either of the whitefly species. Several isolates were able to produce capilliconidia. Infection level was not correlated with germination on water agar. After a selection based on spore production and infection, virulence of 31 isolates was evaluated on third instar nymphs of both whitefly species on poinsettia (Euphorbia pulcherrima). Whitefly infection levels varied between 2 and 70%, and infection percentages of B. argentifolii correlated with that of T. vaporariorum. However, mortality was higher for T. vaporariorum than for B. argentifolii, as a result of a higher 'mortality due to unknown causes.' Several isolates, among which unidentified species of Aschersonia originating from Thailand and Malaysia, A. aleyrodis from Colombia, and A. placenta from India showed high spore production on semi-artificial medium and high infection levels of both whitefly species.
    MeSH terms: Animals; Mitosporic Fungi/pathogenicity*; Hemiptera/microbiology*; Pest Control, Biological/methods*
  12. Sudthongkong C, Miyata M, Miyazaki T
    Arch Virol, 2002 Nov;147(11):2089-109.
    PMID: 12417946
    Tropical iridovirus infection causes severe epizootic resulting in mass mortalities and large economic losses in freshwater ornamental fishes cultured in Southeast Asian countries, in wild fish seedlings captured in South China Sea, and in marine fishes farmed in Japan, Singapore, and Thailand. All of tropical iridovirus-infected fishes histopathologically showed the systemic formation of inclusion body-bearing cells and necrosis of virus-infected splenocytes and hematopoietic cells. We designed primer sets for the ATPase gene and the major capsid protein (MCP) gene and sequenced the PCR products derived from 5 iridovirus isolates from sea bass in South China Sea, red sea bream in Japan, brown-spotted grouper with a grouper sleepy disease in Thailand, dwarf gourami from Malaysia and African lampeye from Sumatra Island, Indonesia. The ATPase gene and the MCP gene of these 5 viral isolates were highly homologous (> 95.8%, > 94.9% identity, respectively) and the deduced amino acid sequences of the ATPase and the MCP were also highly identical (> 98.1%, > 97.2% identity, respectively). Based on the high homology, these 5 isolates of tropical iridovirus from various fishes in geographically different regions were determined to have a single origin and to be native to Southeast Asian regions. However, these sequences were far different from those of members of the genera Ranavirus, Lymphocystivirus and Iridovirus in the Family Iridoviridae. We propose a new genus "Tropivirus" for tropical iridovirus in the Family Iridoviridae.
    MeSH terms: Adenosine Triphosphatases/genetics*; Amino Acid Sequence; Animals; Base Sequence; China; DNA, Viral/chemistry*; Fish Diseases/pathology; Fish Diseases/virology*; Fishes; Inclusion Bodies, Viral/ultrastructure; Japan; Molecular Sequence Data; Phylogeny; Iridovirus/classification; Iridovirus/genetics*; Capsid Proteins/genetics*
  13. Wang CY, Chiu CL, Har KO, Chan C, Rahman ZA
    Int J Oral Maxillofac Surg, 2002 Oct;31(5):506-10.
    PMID: 12418566
    This study compares the use of inhalation sedation using sevoflurane (group S) with inhalation sedation using nitrous oxide (group N) in patients undergoing bilateral extraction of third molar teeth under local anaesthesia. The study was designed as a cross-over study. Seventeen ASA I, day surgery patients were studied. Patients were randomly allocated to receive either 8 l/min 50% nitrous oxide in oxygen (group N) or same flow of 1% sevoflurane (group S) for the first procedure. Each patient then had the alternate method of sedation for the second procedure. There were no significant differences between the methods in patient co-operation and surgeon's satisfaction with sedation. Psychomotor tests were comparable in both groups. The patients were significantly more sedated in the group S compared to group N (P=0.004). Significantly more patients complained of an unpleasant odour group S (P<0.01) but none withdrew from the study for this reason. No adverse cardiorespiratory effects resulted from sevoflurane or nitrous oxide sedation. Both methods gave good amnesia during the procedure. There was high acceptance of both methods and the patients rated the technique as equally satisfactory. We conclude that inhalation sedation with sevoflurane is a suitable alternative method to nitrous oxide sedation.
    MeSH terms: Adult; Ambulatory Surgical Procedures; Anesthesia, Dental*; Anesthesia, Local; Attitude of Health Personnel; Cooperative Behavior; Dentist-Patient Relations; Female; Humans; Male; Memory/drug effects; Methyl Ethers/administration & dosage*; Molar, Third/surgery; Nitrous Oxide/administration & dosage*; Psychomotor Performance/drug effects; Statistics as Topic; Tooth Extraction; Conscious Sedation*; Patient Satisfaction; Cross-Over Studies; Anesthetics, Inhalation/administration & dosage*; Statistics, Nonparametric
  14. Liam CK, Loo KL, Wong CM, Lim KH, Lee TC
    Respirology, 2002 Dec;7(4):345-50.
    PMID: 12421243 DOI: 10.1046/j.1440-1843.2002.00409.x
    OBJECTIVE: The aim of this study was to investigate the prevalence of skin prick test (SPT) reactivity to common aeroallergens among Malaysian asthmatic patients with and without rhinitis.
    METHODOLOGY: An SPT using eight aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat fur, cockroach, Acacia sp., Bermuda grass, Aspergillus fumigatus and Aspergillus niger) was performed on 206 asthmatic patients.
    RESULTS: One hundred and forty patients (68%) were reactive to at least one of the aeroallergens. Among the SPT-positive patients, a positive prick test reaction to the house dust mites, D. pteronyssinus (93.6%), and D. farinae (81.4%) was most common, followed by cat fur (20.0%), cockroach (7.9%), Bermuda grass (7.9%), Acacia sp. (7.9%), A. fumigatus (0.7%) and A. niger (0.7%). A history of rhinitis was elicited in 111 (53.9%) patients and 95 (85.3%) of these patients were SPT-positive compared with only 45 (47.4%) of 95 patients with asthma symptoms alone (P < 0.001). The presence of rhinitis and a young age of onset of asthma were independent factors for positive SPT reaction to at least one of the aeroallergens.
    CONCLUSIONS: The prevalence of SPT reactivity to common aeroallergens is high among Malaysian asthmatics, particularly in those with an early age of onset and in those with coexisting rhinitis.
    Study site: Asthma Clinic, University of Malaya Medical Centre, Kuala Lumpur, Malaysia
    MeSH terms: Adolescent; Adult; Aged; Allergens/immunology*; Asthma/immunology*; Asthma/epidemiology; Child; Female; Hospitals, University; Humans; Malaysia; Male; Middle Aged; Outpatient Clinics, Hospital; Rhinitis/immunology*; Rhinitis/epidemiology; Skin Tests; Comorbidity; Age of Onset
  15. Boey CC, Goh KL
    J Gastroenterol Hepatol, 2002 Dec;17(12):1250-3.
    PMID: 12423267
    Recurrent abdominal pain in children is not a single condition but a description of a wide spectrum of clinical manifestations, some of which fit into a definite pattern, such as the irritable bowel syndrome, while others do not. Organic disorders may be present, but in the majority of children they cannot be detected. Although children with recurrent abdominal pain do not generally have psychological or psychiatric illness, there is a growing body of evidence to suggest that psychosocial stress plays an important role in this condition. This review will look into some of this evidence. The precise pathophysiology that results in abdominal pain is still not clearly understood, but the current belief is that visceral hypersensitivity or hyperalgesia and changes in the brain-gut axis linking the central and enteric nervous systems are important mechanisms.
    MeSH terms: Child; Colonic Diseases, Functional/complications; Humans; Recurrence; Stress, Psychological; Abdominal Pain/etiology; Abdominal Pain/psychology*
  16. Ng ST, Sanusi Jangi M, Shirley MW, Tomley FM, Wan KL
    Exp Parasitol, 2002 11 13;101(2-3):168-73.
    PMID: 12427472
    The protozoan parasite Eimeria tenella has a complex life cycle that includes two major asexual developmental stages, the merozoite and the sporozoite. The expressed sequence tag (EST) approach has been previously used to study gene expression of merozoites. We report here the generation and analysis of 556 ESTs from sporozoites. Comparative analyses of the two datasets reveal a number of transcripts that are preferentially expressed in a specific stage, including previously uncharacterised sequences. The data presented indicate the invaluable potential of the comparative EST analysis for providing information on gene expression patterns in the different developmental stages of E. tenella.
    MeSH terms: Animals; Base Sequence; Molecular Sequence Data; RNA, Messenger/genetics; Gene Library; Eimeria tenella/genetics*; Eimeria tenella/growth & development; DNA, Complementary/chemistry; Gene Expression Regulation, Developmental/genetics*; Expressed Sequence Tags*
  17. Yap CK, Ismail A, Tan SG, Omar H
    Bull Environ Contam Toxicol, 2002 Dec;69(6):877-84.
    PMID: 12428166
    MeSH terms: Congenital Abnormalities/etiology*; Congenital Abnormalities/veterinary*; Animals; Environmental Monitoring; Malaysia; Water Pollutants/adverse effects*; Metals, Heavy/adverse effects*; Bivalvia*
  18. Chan BC, To KF, Pang JC, Chung YF, Lo KW, Tong JH, et al.
    Int J Cancer, 2002 Dec 10;102(5):492-8.
    PMID: 12432552
    A panel of monoclonal antibodies specific to Hong Kong Chinese nasopharyngeal carcinoma (NPC)-associated Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) variants has been generated. These monoclonal antibodies not only differentiate the Hong Kong Chinese NPC-associated LMP1 variants from the prototype B95-8 LMP1, derived from Caucasian infectious mononucleosis, but also differentiate the 2 highly homologous LMP1 deletion variants commonly found in Hong Kong primary NPC. The predominant deletion type variant, DV-Asp335, is characterized by an aspartic acid at residue 335 located in the cytoplasmic C-terminal region, whereas the other minor deletion variant, DV-Gly335, has a glycine in the same residue position. 335D is hitherto found predominantly in LMP1 of the China 1 strain in association with NPC in the Chinese populations located in southern China and Malaysia. These antibodies, which are applicable in ELISA, immunofluorescence, immunoprecipitation, immunoblotting and immunohistochemistry on paraffin sections, are the first variant-specific anti-LMP1 monoclonal antibodies produced, and will be useful in investigating the functional significance of 335D in NPC.
    MeSH terms: Antibodies, Monoclonal/biosynthesis*; Antibodies, Viral/biosynthesis; Antibody Specificity; Herpesvirus 4, Human/immunology*; Humans; Immunohistochemistry; Nasopharyngeal Neoplasms/virology*; Genetic Variation; Viral Matrix Proteins/genetics; Viral Matrix Proteins/immunology*; Gene Deletion
  19. Isobe KO, Tarao M, Zakaria MP, Chiem NH, Minh le Y, Takada H
    Environ Sci Technol, 2002 Nov 1;36(21):4497-507.
    PMID: 12433157
    This is the first report on fecal pollution using molecular markers in Southeast Asia where serious sewage pollution has occurred. A simple and sensitive analytical method using gas chromatography-mass spectrometry for 10 sterols in various environmental samples was developed to monitor extensive areas of tropical Asia. First, the method was applied to wastewater to confirm that >95% of sterols existed in the particulate phase. Then the approach was applied to a tropical Asian region, Malaysia and Vietnam, with a selection of 59 sampling stations in total. River water and sediment samples were collected and analyzed for chemical markers (coprostanol and other sterols) and microbiological markers (fecal coliforms and fecal streptococci). Particulate coprostanol concentrations ranged from <0.0001 to 13.47 microg/L in tropical river and estuarine waters, indicating severe fecal pollution in populous areas. Coprostanol concentrations in the sediments ranged from 0.005 to 15.5 microg/g-dry. The sedimentary coprostanol concentrations were lower than those reported in some urban areas of industrialized countries. This is probably because frequent heavy rain induces intensive input of eroded soil, which dilutes fecal material in river sediments. The relationship between the concentrations of fecal sterols and bacterial indicators was examined in an attempt to develop public health criteria for coprostanol levels applicable to the tropical region. Coprostanol concentrations of 30-100 ng/L or percent coprostanol levels of 2% corresponded to approximately 1000 fecal coliforms per 100 mL, which is set for secondary contact limit in many countries. These coprostanol concentrations were lower than those proposed as criteria in temperate countries, probably owing to greater survival of bacteria in warmer tropical waters. On the basis of these criteria, extensive monitoring of sediments suggests that poor sanitary conditions exist in most of the urbanized area of Malaysia and in several urban and rural sites in Vietnam.
    MeSH terms: Cholestanol/analysis*; Environmental Monitoring; Feces/chemistry*; Malaysia; Gas Chromatography-Mass Spectrometry; Sensitivity and Specificity; Sewage*; Tropical Climate; Vietnam; Water Pollutants/analysis*
  20. Koh WP, Taylor MB, Hughes K, Chew SK, Fong CW, Phoon MC, et al.
    Int J Epidemiol, 2002 Oct;31(5):1001-7.
    PMID: 12435775 DOI: 10.1093/ije/31.5.1001
    BACKGROUND: Chlamydia pneumoniae, a bacterium that causes respiratory infections, is probably under-diagnosed. There is also interest in its possible role in the aetiology of coronary heart disease. This is the first population-based seroprevalence survey of C. pneumoniae infection in Singapore.

    METHODS: A random sample of 1,068 people aged 18-69 years was selected from the participants of the Singapore National Health Survey conducted in 1998. Sera and data on certain clinical measurements and conditions had been collected. IgG antibodies for C. pneumoniae were detected using an indirect microimmunofluorescence test and positivity graded. Seropositivity was defined as IgG titre >/=1:16.

    RESULTS: There were no statistically significant differences in the prevalence rates of seropositivity to C. pneumoniae for age group 18-69 years among the three ethnic groups, i.e. Chinese (males 76.7%, females 68.3%), Malays (males 75.4%, females 59.1%), and Asian Indians (males 74.6%, females 59.4%). The seropositivity rate for people aged 18-69 years in Singapore was 75.0% for males and 65.5% for females (difference of 9.5%, P < 0.001). In both genders combined, seropositivity increased from 46.5% in the age group 18-29 to reach a plateau of 78.9% in the age group 40-49, which remained stable to 60-69 years. There was no association of seropositivity with smoking, diabetes mellitus, hypertension or body mass index after adjustment for age and gender.

    CONCLUSION: The high prevalence rates in our study population and the higher rate in males compared to females are consistent with studies from other parts of the world. No significant difference in prevalence rates was observed among Chinese, Malays and Indians. The pattern of rising and levelling off of seropositivity with age suggests that C. pneumoniae infection occurs early in life, and in older ages the high level of seropositivity is probably maintained by re-infections or chronic infections. Chlamydia pneumoniae infection was not found to be associated with the cardiovascular risk factors examined.
    MeSH terms: Adolescent; Adult; Aged; Antibodies, Bacterial/blood*; China/ethnology; Female; Humans; Immunoglobulin G/blood*; India/ethnology; Malaysia/ethnology; Male; Middle Aged; Singapore/epidemiology; Seroepidemiologic Studies; Chlamydophila pneumoniae/immunology*; Age Distribution; Sex Distribution; Pneumonia, Bacterial/immunology; Pneumonia, Bacterial/epidemiology*; Fluorescent Antibody Technique, Indirect; Chlamydophila Infections/immunology; Chlamydophila Infections/epidemiology*
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