Browse publications by year: 1999

  1. Raman R
    PMID: 23119520 DOI: 10.1007/BF02997994
    A mechanical explanation for the hyperacousis that sometimes occurs after stapedectomy or stapedotomy is offered.
  2. Easton A
    BMJ, 1999 Apr 03;318(7188):893.
    PMID: 10102839 DOI: 10.1136/bmj.318.7188.893a
    MeSH terms: Animals; Disease Outbreaks; Disease Reservoirs; Encephalitis, Japanese/epidemiology*; Encephalitis, Japanese/prevention & control; Humans; Malaysia/epidemiology; Swine
  3. Pueppke SG, Broughton WJ
    Mol. Plant Microbe Interact., 1999 Apr;12(4):293-318.
    PMID: 10188270
    Genetically, Rhizobium sp. strain NGR234 and R. fredii USDA257 are closely related. Small differences in their nodulation genes result in NGR234 secreting larger amounts of more diverse lipo-oligosaccharidic Nod factors than USDA257. What effects these differences have on nodulation were analyzed by inoculating 452 species of legumes, representing all three subfamilies of the Leguminosae, as well as the nonlegume Parasponia andersonii, with both strains. The two bacteria nodulated P. andersonii, induced ineffective outgrowths on Delonix regia, and nodulated Chamaecrista fasciculata, a member of the only nodulating genus of the Caesalpinieae tested. Both strains nodulated a range of mimosoid legumes, especially the Australian species of Acacia, and the tribe Ingeae. Highest compatibilities were found with the papilionoid tribes Phaseoleae and Desmodieae. On Vigna spp. (Phaseoleae), both bacteria formed more effective symbioses than rhizobia of the "cowpea" (V. unguiculata) miscellany. USDA257 nodulated an exact subset (79 genera) of the NGR234 hosts (112 genera). If only one of the bacteria formed effective, nitrogen-fixing nodules it was usually NGR234. The only exceptions were with Apios americana, Glycine max, and G. soja. Few correlations can be drawn between Nod-factor substituents and the ability to nodulate specific legumes. Relationships between the ability to nodulate and the origin of the host were not apparent. As both P. andersonii and NGR234 originate from Indonesia/Malaysia/Papua New Guinea, and NGR234's preferred hosts (Desmodiinae/Phaseoleae) are largely Asian, we suggest that broad host range originated in Southeast Asia and spread outward.
    MeSH terms: Carbohydrate Sequence; Lipopolysaccharides/chemistry*; Molecular Sequence Data; Nitrogen Fixation/genetics; Rhizobium/genetics; Rhizobium/physiology; Rhizobium/chemistry*; Species Specificity; Reproducibility of Results
  4. Zamri-Saad M, Effendy AW, Israf DA, Azmi ML
    Vet. Microbiol., 1999 Mar 12;65(3):233-40.
    PMID: 10189198
    A study to determine the immunoglobulin and cellular responses in the respiratory tract of goats following intranasal exposures to formalin-killed Pasteurella haemolytica A2 was carried out. Forty-two goats were divided into two groups. Goats in Group 1 were subjected to double intranasal exposures to formalin-killed P. haemolytica A2 while goats in Group 2 were the unexposed control. Prior to and at weekly intervals post-exposure, three goats from each group were killed, serum samples were collected while the lungs were flushed with 50 ml normal saline before the right apical lobes were fixed in 10% buffered formalin. Both serum and lung lavage fluid were subjected to enzyme-linked immunosorbent assay (ELISA) to determine the levels of IgA, IgM and IgG while the formalin-fixed tissues were examined histologically. IgA levels in the lung lavage fluid increased rapidly to reach a significantly (p < 0.05) high level as early as Week 2 post-exposure and remained significantly (p < 0.05) high throughout the study period. The IgM levels increased at an intermediate rate to reach a significantly (p < 0.05) high level at Week 3 post-exposure before they decreased to an insignificant (p > 0.05) level the following week and the weeks thereafter. IgG levels increased gradually and only reached a significantly (p < 0.01) high level at Weeks 5 and 6 of the study. The size of the bronchus-associated lymphoid tissue (BALT) and the number of lymphocytes in BALT increased significantly from Week 2 and remained high thereafter. However, differences in the numbers of BALT were insignificant (p > 0.05) initially before becoming significantly (p < 0.05) high at Weeks 5 and 6. The BALT responses were parallel to those of imunoglobulins in the lung lavage fluid.
    MeSH terms: Administration, Intranasal; Animals; Antibodies, Bacterial/biosynthesis; Enzyme-Linked Immunosorbent Assay/veterinary; Formaldehyde/chemistry; Goats; Immunity, Cellular/immunology; Immunoglobulins/analysis; Immunoglobulins/blood; Lymphoid Tissue/immunology; Lymphoid Tissue/microbiology; Pasteurella Infections/immunology; Pasteurella Infections/veterinary*; Respiratory System/immunology*; Respiratory System/microbiology; Respiratory Tract Diseases/immunology; Respiratory Tract Diseases/veterinary*; Goat Diseases/immunology*; Goat Diseases/microbiology; Mannheimia haemolytica/immunology*; Bronchoalveolar Lavage/veterinary
  5. Wong KT, Shamsol S
    J. Cutan. Pathol., 1999 Jan;26(1):13-6.
    PMID: 10189239
    The association of mast cells with typical lesions of Kimura's disease was investigated by quantitative methods after immunohistochemical staining for Factor VIII-related antigen and counterstaining with toluidine blue. Formalin-fixed, paraffin-embedded, tissue sections from 9 confirmed cases of Kimura's disease were examined after staining to estimate mast cell and blood vessel densities by counting 100 random fields under oil immersion. There was a statistically significant increase of both mast cells and blood vessels in Kimura's disease (p<0.01) compared with normal skin and reactive lymph node controls. However, as far as the individual Kimura's disease lesion is concerned, there was generally no correlation between areas with mast cell increase and the degree of vascularity. Moreover, when lesions of less than 1 year's duration were compared with older lesions, there appeared to be a relative decrease in mast cells and a concomitant increase in vascularity in the latter. These results confirmed that mast cells are associated with Kimura's disease, and suggest that they may be involved in its early pathogenesis, although its possible role in angiogenesis may not be direct.
    MeSH terms: Adolescent; Adult; Angiolymphoid Hyperplasia with Eosinophilia/metabolism; Angiolymphoid Hyperplasia with Eosinophilia/pathology*; Cell Count; Child; Female; Humans; Immunohistochemistry; Male; Mast Cells/cytology; Mast Cells/pathology*; Mast Cells/chemistry; Middle Aged; Neovascularization, Pathologic; Skin/blood supply; Skin/pathology; Skin/chemistry; von Willebrand Factor/analysis
  6. Zhang CY, Tan BK
    Phytother Res, 1999 Mar;13(2):157-9.
    PMID: 10190192
    14-deoxyandrographolide (DA) and 14-deoxy-11,12-didehydroandrographolide (DDA) are two diterpenoids isolated from A. paniculata, a popular folk medicine used as an antihypertensive drug in Malaysia. We have previously reported that DDA exhibited a greater hypotensive effect in anaesthetized rats and a vasorelaxant activity in isolated rat aorta, compared with DA. Their vasorelaxant activities were mediated through the activation of the enzymes, nitric oxide synthase (NOS) and guanylyl cyclase. The present study demonstrated that both DA and DDA stimulated nitric oxide (NO) release from human endothelial cells. DDA compared with DA caused a greater production of NO; this is in line with the finding of the earlier study that the vasorelaxant effect of DDA was more dependent on endothelium than DA.
    MeSH terms: Antihypertensive Agents/pharmacology*; Cell Line; Diterpenes/pharmacology*; Dose-Response Relationship, Drug; Endothelium, Vascular/drug effects*; Endothelium, Vascular/metabolism; Humans; Malaysia; Phytotherapy; Nitric Oxide/metabolism*; Vasodilator Agents/pharmacology*
  7. Hashim HD
    Rev. - Off. Int. Epizoot., 1999 Apr;18(1):47-51.
    PMID: 10190203
    Besides response and recovery, prevention and preparedness are the two critical components of any contingency plan. The author discusses the various elements which must be present in the prevention and preparedness plan of countries in Asia. As the continent has such diverse peoples and veterinary infrastructures, the actual plan may vary from one country to another, but must incorporate those elements which are crucial to ensure the success of the preparedness plan.
    MeSH terms: Animals; Animal Diseases/epidemiology; Animal Diseases/prevention & control*; Asia/epidemiology; Disease Outbreaks/prevention & control; Disease Outbreaks/veterinary*; Emergency Medical Services/organization & administration; Humans; Quarantine/organization & administration; Quarantine/veterinary; Veterinary Medicine/organization & administration*
  8. Sharma HS, Sharma S
    J Accid Emerg Med, 1999 Mar;16(2):150-3.
    PMID: 10191459
    Foreign body aspiration is one of the leading causes of accidental death in children. Food items are the most common items aspirated in infants and toddlers, whereas older children are more likely to aspirate non-food items. Laryngeal impaction of a foreign body is very rare as most aspirated foreign bodies pass through the laryngeal inlet and get lodged lower down in the airway. Two rare cases of foreign body aspiration with subglottic impaction in very young children (under 2 years of age) are described. In both the cases subglottic impaction occurred consequent to attempted removal of foreign body by blind finger sweeping. The clinical presentation, investigations, and management of these rare cases are discussed.
    MeSH terms: Emergency Treatment; Endoscopy/methods*; Female; Follow-Up Studies; Foreign Bodies/diagnosis; Foreign Bodies/surgery*; Humans; Infant; Laryngoscopy; Larynx*; Male; Treatment Outcome
  9. Wan Nazaimoon WM, Faridah I, Singaraveloo M, Ismail IS, Wan Mohamad WB, Letchuman R, et al.
    Diabetes Res. Clin. Pract., 1999 Jan;43(1):59-66.
    PMID: 10199589
    This study determined the prevalence of glutamic acid decarboxylase antibodies (GAD Ab) in a group of 926 young Malaysian diabetics of three ethnic groups, Malay, Chinese, and Indian. Patients were clinically diagnosed to be Type 1 or Type 2 before the age of 40 years. The overall GAD Ab positivity was 17.4% (161/926), significantly higher in the Type 1 than the Type 2 diabetics (35.5%, 116/329 vs. 7.5%, 45/597, P=0.0001). Compared to GAD Ab negative patients, seropositive diabetics were diagnosed at younger age (21.2+/-0.9 vs. 27.4+/-0.3 y, P=0.0001), had lower fasting (289+/-27.4 vs. 640+/-17.6 pmol/l, P=0.0001) and post-glucagon C-peptide levels (527+/-51.8 vs. 1030+/-28.9 pmol/l, P=0.0001). There were no racial differences in the prevalence of GAD Ab; of the total Type 1, 30.8, 36.4, and 39.4% were Malay, Chinese, and Indian diabetics, respectively and of the total Type 2, 8.8, 8.2, and 4.4% were Malay, Chinese, and Indian diabetics respectively. There was a curvilinear relationship between GAD Ab and the post-glucagon C-peptide levels, suggesting that GAD Ab do play a role in the beta-cells destruction and could be an important immune marker for the LADA group. This study reconfirmed previous reports that the autoimmune mechanisms in the Type 1 Asian diabetics are indeed different from the Caucasians, and further investigations should be carried out to explain the differences.
    MeSH terms: Adolescent; Adult; Aged; Antibodies/analysis*; Child; Child, Preschool; China/ethnology; Diabetes Mellitus/ethnology; Diabetes Mellitus/immunology*; Diabetes Mellitus/epidemiology; Female; Glutamate Decarboxylase/immunology*; Humans; India/ethnology; Infant; Malaysia/epidemiology; Male; Middle Aged; Seroepidemiologic Studies; Age of Onset
  10. Zhang ZW, Shimbo S, Miyake K, Watanabe T, Nakatsuka H, Matsuda-Inoguchi N, et al.
    Eur J Clin Nutr, 1999 Mar;53(3):226-32.
    PMID: 10201805
    To examine the accuracy of food composition table (FCT)-based estimation of dietary nutrient element intake in reference to the instrumental measurement by inductively-coupled plasma mass spectrometry (ICP-MS).
    MeSH terms: Adult; Calcium, Dietary/administration & dosage*; China; Female; Food Analysis*; Humans; Japan; Korea; Malaysia; Philippines; Mass Spectrometry*; Taiwan; Phosphorus, Dietary/administration & dosage*; Iron, Dietary/administration & dosage*
  11. Shimbo S, Zhang ZW, Miyake K, Watanabe T, Nakatsuka H, Matsuda-Inoguchi N, et al.
    Eur J Clin Nutr, 1999 Mar;53(3):233-8.
    PMID: 10201806
    To examine the accuracy of food composition table (FCT)-based estimation of dietary nutrient element intake in reference to the instrumental measurement by inductively-coupled plasma mass spectrometry (ICP-MS), as an extension of the first part of this study.
    MeSH terms: Adult; China; Copper/administration & dosage*; Cross-Sectional Studies; Female; Food Analysis*; Humans; Korea; Magnesium/administration & dosage*; Malaysia; Potassium/administration & dosage*; Sodium/administration & dosage*; Mass Spectrometry*; Zinc/administration & dosage*
  12. Dale JW, Nor RM, Ramayah S, Tang TH, Zainuddin ZF
    J. Clin. Microbiol., 1999 May;37(5):1265-8.
    PMID: 10203468
    Molecular typing with IS6110 was applied to Mycobacterium tuberculosis isolates from all parts of Malaysia. The degree of clustering increased with patient age, suggesting that reactivation may contribute to clustering. Identical banding patterns were also obtained for isolates from widely separate regions. Therefore, the use of clustering as a measure of recent transmission must be treated with caution. Strains related to the Beijing family were common in Peninsular Malaysia but were less common in Sabah and Sarawak, while a distinct group of strains comprised nearly 40% of isolates from East Malaysia but such strains were rare in Peninsular Malaysia. Single-copy strains, common in South and Southeastern Asia, constituted nearly 20% of isolates from the peninsula but were virtually absent in East Malaysia. The marked geographical difference in the prevailing strains indicates not only a restricted dissemination of M. tuberculosis but also a considerable degree of stability in the banding patterns.
    MeSH terms: Adult; Age Factors; DNA Transposable Elements*; Humans; Malaysia; Middle Aged; Mycobacterium tuberculosis/genetics*; Tuberculosis/transmission*; Gene Dosage
  13. Sekiguchi H, Machida Y
    J Clin Pediatr Dent, 1999;23(2):107-11.
    PMID: 10204450
    The number of dentists in Japan may be too high. The ratio of dentists/population, in China, Indonesia, Thailand, and Malaysia, is less than 1 dentist for every 10,000 people. From this data, it can be seen that there is a shortage of dentists in China, Indonesia, Thailand, and Malaysia. The shortage of pediatric dentists in these Asian countries is serious, particularly in the Philippines where the number of children with dental caries is increasing. There is an urgent need to increase the number of pediatric dentists in these countries. However, one problem is that dental schools in the Philippines and Singapore, do not have a department of pediatric dentistry.
    MeSH terms: Asia/epidemiology; Dental Caries/epidemiology; Dentists/supply & distribution*; Health Services Needs and Demand; Humans; Schools, Dental/statistics & numerical data; Prevalence
  14. Wong CF, Yuen KH, Peh KK
    Int J Pharm, 1999 Feb 01;178(1):11-22.
    PMID: 10205621
    Controlled release buccal patches were fabricated using Eudragit NE40D and studied. Various bioadhesive polymers, namely hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose and Carbopol of different grades, were incorporated into the patches, to modify their bioadhesive properties as well as the rate of drug release, using metoprolol tartrate as the model drug. The in-vitro drug release was determined using the USP 23 dissolution test apparatus 5 with slight modification, while the bioadhesive properties were evaluated using texture analyzer equipment with chicken pouch as the model tissue. The incorporation of hydrophilic polymers was found to affect the drug release as well as enhance the bioadhesiveness. Although high viscosity polymers can enhance the bioadhesiveness of the patches, they also tend to cause non-homogeneous distribution of the polymers and drug, resulting in non-predictable drug-release rates. Of the various bioadhesive polymers studied, Cekol 700 appeared to be most satisfactory in terms of modifying the drug release and enhancement of the bioadhesive properties.
    MeSH terms: Acrylic Resins; Adhesiveness; Administration, Topical; Animals; Carboxymethylcellulose Sodium/chemistry; Chickens; Delayed-Action Preparations/pharmacokinetics*; Delayed-Action Preparations/chemistry; Lactose/analogs & derivatives; Lactose/chemistry; Methylcellulose/analogs & derivatives; Methylcellulose/chemistry; Models, Biological; Mouth Mucosa/metabolism*; Oxazines; Polymers/chemistry*; Polyvinyls/chemistry; Solubility; Viscosity; Drug Design*; Drug Delivery Systems*; In Vitro Techniques
  15. Choo KE, Davis TM, Ismail A, Tuan Ibrahim TA, Ghazali WN
    Acta Trop., 1999 Mar 15;72(2):175-83.
    PMID: 10206117
    The Typhidot test, which detects IgM and IgG antibodies to a Salmonella typhi-specific outer membrane protein, is as sensitive as, and more specific than, the Widal test in the diagnosis of enteric fever in Malaysian children. It is easier and quicker to perform. In order to increase diagnostic accuracy in an area of high endemicity, the Typhidot-M test has been developed in which IgG is first removed. This theoretically allows improved detection of IgM, and thus would differentiate new from recent infections. We evaluated both tests in 134 unselected febrile children admitted to the General Hospital Kota Bharu, Malaysia. The children were divided into two groups: (i) those who were blood and/or stool culture positive for S. typhi and/or who had clinical features strongly suggestive of enteric fever (n = 62); and (ii) those who were both culture-negative and had clinical evidence of another diagnosis (n = 72). The sensitivity and specificity of the Typhidot and Typhidot-M tests were identical at 90.3 and 93.1%, respectively. Both tests had comparable sensitivity but greater specificity than those of the Widal test (91.9 and 80.6%, respectively). When used together, a positive result for Typhidot and/or Typhidot-M was more specific than either test alone (95.2%) but specificity was lower (87.5%). We conclude that the Typhidot and Typhidot-M tests have comparatively high diagnostic accuracy, suggesting that IgM can be detected in children who may have a predominant IgG response to S. typhi. Using these tests in combination increases the negative predictive value but at the cost of a lower positive predictive value.
    MeSH terms: Antibodies, Bacterial/blood*; Child; Child, Preschool; Female; Humans; Immunoglobulin G/blood; Immunoglobulin M/blood; Immunosorbent Techniques*; Infant; Malaysia; Male; Predictive Value of Tests; Reagent Kits, Diagnostic; Salmonella typhi/growth & development; Salmonella typhi/immunology*; Sensitivity and Specificity; Typhoid Fever/diagnosis*
  16. Liam CK, Lim KH, Wong CM, Tang BG
    Int. J. Tuberc. Lung Dis., 1999 Apr;3(4):300-9.
    PMID: 10206500
    SETTING: An urban university teaching hospital.
    OBJECTIVES: To determine patients' attitudes to tuberculosis and their knowledge of the disease, and factors associated with treatment compliance.
    DESIGN: All adult patients commenced on treatment for tuberculosis from September 1994 to February 1996 were interviewed on initiation of treatment. To assess patient compliance with treatment, hospital clinical records were reviewed retrospectively.
    RESULTS: A total of 135 patients with a mean age (±SD) of 41.9 (±17.4) years (range 15–84 years) were interviewed. The patients had limited understanding and knowledge about tuberculosis. There was a negative correlation between patient age and tuberculosis knowledge score (r = −0.18, P = 0.038). Patients with tertiary education had better knowledge than the others. Of 118 patients who were followed-up in our chest clinic, 80 (67.8%) completed the prescribed treatment. Compliance with treatment and follow-up was not affected by age, sex, ethnic group, educational level, occupation, extent of knowledge, tuberculosis symptoms, hospitalisation for tuberculosis or duration of the prescribed treatment regimen. There was a trend toward poorer compliance among patients who equated disappearance of tuberculosis symptoms with cure of the disease.
    CONCLUSIONS: Malaysian patients with newly diagnosed tuberculosis attending a university teaching hospital had misconceptions and limited knowledge about the disease and its treatment. Educational background was an important determinant of a patient's level of knowledge about tuberculosis. Compliance was not affected by patient characteristics. Adequate counselling and education of patients and close relatives on tuberculosis and the necessity for prolonged treatment may help to improve treatment compliance.
    Study site: Chest clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
    MeSH terms: Adolescent; Adult; Aged; Aged, 80 and over; Analysis of Variance; Drug Therapy, Combination; Female; Hospitals, Teaching; Hospitals, University; Hospitals, Urban; Humans; Health Knowledge, Attitudes, Practice*; Malaysia/epidemiology; Male; Middle Aged; Outpatient Clinics, Hospital; Patient Compliance*; Surveys and Questionnaires; Retrospective Studies; Tuberculosis/drug therapy*; Tuberculosis/epidemiology; Tuberculosis/psychology*; Chi-Square Distribution; Statistics, Nonparametric
  17. Goh AY, Lum LC, Chan PW, Bakar F, Chong BO
    Arch. Dis. Child., 1999 May;80(5):424-8.
    PMID: 10208946
    OBJECTIVES: To compare the modes of death and factors leading to withdrawal or limitation of life support in a paediatric intensive care unit (PICU) in a developing country.

    METHODS: Retrospective analysis of all children (< 12 years) dying in the PICU from January 1995 to December 1995 and January 1997 to June 1998 (n = 148).

    RESULTS: The main mode of death was by limitation of treatment in 68 of 148 patients, failure of active treatment including cardiopulmonary resuscitation in 61, brain death in 12, and withdrawal of life support with removal of endotracheal tube in seven. There was no significant variation in the proportion of limitation of treatment, failure of active treatment, and brain death between the two periods; however, there was an increase in withdrawal of life support from 0% in 1995 to 8% in 1997-98. Justification for limitation was based predominantly on expectation of imminent death (71 of 75). Ethnic variability was noted among the 14 of 21 patients who refused withdrawal. Discussions for care restrictions were initiated almost exclusively by paediatricians (70 of 75). Diagnostic uncertainty (36% v 4.6%) and presentation as an acute illness were associated with the use of active treatment.

    CONCLUSIONS: Limitation of treatment is the most common mode of death in a developing country's PICU and active withdrawal is still not widely practised. Paediatricians in developing countries are becoming more proactive in managing death and dying but have to consider sociocultural and religious factors when making such decisions.

    MeSH terms: Cause of Death; Child; Child, Preschool; Critical Care/methods*; Developing Countries*; Ethnic Groups; Euthanasia, Passive*; Female; Humans; Infant; Infant, Newborn; Life Support Care/methods*; Malaysia; Male; Retrospective Studies
  18. Foong ALS, Rossiter JC, Chan PT
    J Adv Nurs, 1999 Mar;29(3):542-548.
    PMID: 28796333 DOI: 10.1046/j.1365-2648.1999.00921.x
    Socio-cultural perspectives on the image of nursing: The Hong Kong dimension¶Using structured interviews a study was undertaken with 19 high school students in Hong Kong to elicit their perceptions of nursing as a profession. The study also sought to gauge the extent of the students' intentions on pursuing a career in nursing. Responses were content analysed to determine the extent of knowledge and understanding held, intentions on choosing nursing as a career and their reasons. Findings suggest the image of nursing to be poor and that nursing as a career is far from desirable amongst the teenagers of Hong Kong. The reasons appear to be related to the notion of monetary rewards and status within the Hong Kong community. There is also a lack of knowledge as to what nurses do. The implications of such findings include the lost potential for recruitment of candidates of high calibre with a lot to offer the profession and their society. It suggests the need for the profession to find ways of publicizing and marketing the positive aspects with elements of realism which the general population in that part of the world could relate to more readily.
  19. Quah BS, Hashim I, Simpson H
    J. Pediatr. Surg., 1999 Mar;34(3):512-4.
    PMID: 10211672
    Congenital diaphragmatic hernia through the foramen of Bochdalek may present after infancy. A 21/2-year-old Malay girl presented with acute respiratory distress. Chest examination showed reduced chest expansion and decreased breath sounds on the left side. Chest radiograph showed a large "cyst" in the left chest, which was thought to be a lung cyst under tension. Tube thoracostomy resulted in clinical improvement. Results of a barium study showed that the cyst perforated by the thoracostomy tube was the stomach, which had herniated through a Bochdalek diaphragmatic defect. Surgical repair of the diaphragmatic defect and closure of the perforated stomach was performed successfully. Congenital diaphragmatic hernia should be included in the differential diagnosis of respiratory distress in young children. Nasogastric tube placement must be considered as an early diagnostic or therapeutic intervention when the diagnosis is suspected.
    MeSH terms: Child, Preschool; Diagnosis, Differential; Dilatation, Pathologic/etiology; Female; Hernia, Diaphragmatic/complications*; Hernia, Diaphragmatic/surgery; Humans; Respiratory Insufficiency/etiology; Stomach Diseases/etiology*; Hernias, Diaphragmatic, Congenital*
  20. Underwood AP, Bianco AE
    Mol. Biochem. Parasitol., 1999 Mar 15;99(1):1-10.
    PMID: 10215019
    Random amplification of polymorphic DNA (RAPD) was used to analyse genomic DNA from virgin females and males of Brugia malayi, with a view to identifying sex-specific differences predicted by an XX/XY system of chromosomal sex determination. A product of 2338 bp, amplified with the arbitrary primer 5' GTTGCGATCC 3', was obtained exclusively from males. Primers based on the sequence of this product amplified a DNA fragment of the expected size from each of two independent isolates of B. malayi (from Malaysia and Indonesia) by PCR. No reaction product was obtained from the closely related species Brugia pahangi. In a genetic cross between B. malayi males and B. pahangi females, F1 hybrid microfilariae were PCR-positive, indicating that the locus is paternally-inherited. Southern blotting demonstrated that the target sequence resides in the high molecular weight fraction of genomic DNA, confirming that it is of chromosomal, rather than mitochondrial, origin. Sequencing of the locus revealed significant similarity with members of a family of reverse transcriptase-like genes in Caenorhabditis elegans. In-frame stops indicate that the gene is non-functional, but multiple bands of hybridisation in Southern blots suggest that the RT sequence may be the relic of a transposable element. Multiple repeats of the dinucleotide AT occurred in another region of the sequence. These varied in number between the two isolates of B. malayi in the manner of a microsatellite, surprisingly the first to be described from the B. malayi genome. Because of its association with the Y chromosome, we have given the locus the acronym TOY (Tag On Y). Identification of this chromosome-specific marker confirms the XX/XY heterogametic karyotype in B. malayi and opens the way to elucidation of the role of Y in sex determination.
    MeSH terms: Amino Acid Sequence; Animals; Crosses, Genetic; Female; Genetic Markers/genetics*; Male; Molecular Sequence Data; RNA-Directed DNA Polymerase/genetics; Species Specificity; Y Chromosome/genetics*; Blotting, Southern; Brugia malayi/genetics*; Brugia malayi/physiology; DNA, Helminth/analysis; DNA, Helminth/isolation & purification; Microsatellite Repeats/genetics; Random Amplified Polymorphic DNA Technique; Sex Determination Processes
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