Displaying publications 201 - 220 of 587 in total

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  1. Welch QB, Shu LC, Thangavelu S, Lie-Injo EL
    Hum Hered, 1978;28(1):62-5.
    PMID: 618819
    812 West Malaysian Orang Asli belonging to four ethnic groups were surveyed for adenosine deaminase (ADA; EC 3.5.4.4) using starch gel electrophoresis. Only the common ADA1 and ADA2 alleles were found, with the frequencies of the latter being 0.025, 0.103, 0.115 and 0.028 in the Semai, Semelai, Temuan, and Jakun groups, respectively. A new 'breeding genetic distance' was applied to these gene frequencies and the Semelai and Temuan were found to be more closely related to each other, and to have considerably more evolutionary flexibility on this scale of 'micro-evolution' than the other two groups. The Semai and Jakun were more similar to each other on the basis of these ADA gene frequencies.
    Matched MeSH terms: Phenotype
  2. Lie-Injo LE, Ganesan J, Herrera A, Lopez CG
    Hum Hered, 1978;28(1):37-40.
    PMID: 304028
    In a study of Malaysians of different racial groups, 1,510 sera (908 from Malays, 371 from Chinese and 231 from Indians) were identified for their protease inhibitor (Pi) types. The gene frequencies for the alleles PiM, PiS and PiX in Malays were, respectively, 0.979, 0.015, and 0.007. In Chinese, the frequencies were 0.981, 0.019 and 0.000, and in Indians they were 0.976, 0.24, and 0.000. It is interesting that the usually rare PiX type is found in appreciable frequency in the Malays. Two different types with unusual behavior and obscure origin were also found.
    Matched MeSH terms: Phenotype
  3. Welch QB, Lie-Injo LE, Ganesan J
    Hum Hered, 1975;25(1):69-72.
    PMID: 1150296
    944 adenosine deaminase phenotypings of Malay, Chinese, and Indian blood donors and newborns at Kuala Lumpur, Malaysia, yielded ADA1 gene frequency estimates of 0.885 for the Malays, 0.939 for the Chinese, and 0.853 for the Indians.
    Matched MeSH terms: Phenotype
  4. Blake NM, Kirk RL, Mehra B
    Hum Hered, 1969;19(1):20-4.
    PMID: 5798080
    Matched MeSH terms: Phenotype
  5. Welch QB, Lie-Injo LE
    Hum Hered, 1972;22(5):503-7.
    PMID: 4670071
    Matched MeSH terms: Phenotype
  6. Wong WM, Tham YC, Ayton LN, Britten-Jones AC, Edwards TL, Grigg J, et al.
    Asia Pac J Ophthalmol (Phila), 2024;13(5):100098.
    PMID: 39366638 DOI: 10.1016/j.apjo.2024.100098
    PURPOSE: The objective of this paper is to shed light on the current landscape of genotyping practices, phenotyping practices and availability of essential vision rehabilitation management for inherited retinal diseases (IRD) in the Asia-Pacific (APAC) Region.

    METHODS: The 62-item questionnaire was distributed electronically via email. The questions covered five domains: (1) structure of the IRD service and registry/database; (2) genotyping practices; (3) genetic counselling; (4) deep phenotyping practices; (5) low-vision rehabilitation services.

    RESULTS: The survey was completed by 36 of 45 centres in twelve countries and regions in APAC. Among these centres, 42 % reported managing more than 1000 patients. Notably, 39 % of centres lack an IRD database or registry, and 44 % of centres have tested less than one-quarter of their IRD patients. The majority of centres (67 %) do not have genetic counsellors. While there was consistency in the imaging-based investigations, there was marked heterogeneity for functional testing using electrophysiology and formal perimetry. Only 34 % of centres confirmed the availability of access to low-vision assistive devices.

    CONCLUSIONS: This study reveals several critical gaps in managing IRDs in the APAC region. These include the lack of IRD database/registry in one-third of centres, a substantial proportion of patients remaining genetically undiagnosed, and limited availability of genetic counsellors. The findings also underscore a need to harmonise investigations for evaluating retinal function and identify areas for improvement in the provision of low-vision rehabilitation services.

    Matched MeSH terms: Phenotype
  7. Yong KW, Pingguan-Murphy B, Xu F, Abas WA, Choi JR, Omar SZ, et al.
    Sci Rep, 2015;5:9596.
    PMID: 25872464 DOI: 10.1038/srep09596
    Cryopreservation represents an effective technique to maintain the functional properties of human adipose-derived stem cells (ASCs) and allows pooling of cells via long-term storage for clinical applications, e.g., cell-based therapies. It is crucial to reduce freezing injury during the cryopreservation process by loading the ASCs with the optimum concentration of suitable cryoprotective agents (CPAs). In this study, human ASCs were preserved for 3 months in different combinations of CPAs, including 1) 0.25 M trehalose; 2) 5% dimethylsulfoxide (DMSO); 3) 10% DMSO; 4) 5% DMSO + 20% fetal bovine serum (FBS); 5) 10% DMSO + 20% FBS; 6) 10% DMSO + 90% FBS. Interestingly, even with a reduction of DMSO to 5% and without FBS, cryopreserved ASCs maintained high cell viability comparable with standard cryomedium (10% DMSO + 90% FBS), with normal cell phenotype and proliferation rate. Cryopreserved ASCs also maintained their differentiation capability (e.g., to adipocytes, osteocytes and chondrocytes) and showed an enhanced expression level of stemness markers (e.g., NANOG, OCT-4, SOX-2 and REX-1). Our findings suggest that 5% DMSO without FBS may be an ideal CPA for an efficient long-term cryopreservation of human ASCs. These results aid in establishing standardized xeno-free long-term cryopreservation of human ASCs for clinical applications.
    Matched MeSH terms: Phenotype*; Immunophenotyping
  8. Sanders KL, Malhotra A, Thorpe RS
    J Evol Biol, 2004 Jul;17(4):721-31.
    PMID: 15271071
    We analyse molecular and phenotypic evolution in a group of taxonomically problematic Indomalayan pitvipers, the Trimeresurus sumatranus group. Mitochondrial DNA sequencing provides a well-resolved phylogeny, with each species representing a distinct lineage. Multivariate morphological analysis reveals a high level of phenotypic differentiation, which is congruent between the sexes but does not reflect phylogenetic history. An adaptive explanation for the observed pattern of differentiation is supported by independent contrasts analysis, which shows significant correlations between current ecology and the characters that most account for the variation between taxa, including those that are presently used to identify the species. Reduced precipitation and altitude, and increased temperature, are correlated with higher numbers of scales on the head, body and tail. It is hypothesized that scale number plays an important role in heat and water exchange by influencing the area of exposed of interstitial skin, and that colour pattern variation reflects selection pressures involving camouflage and thermoregulation. Ecological convergence in traits used for classification is found to have important implications for species identification where taxa are distributed over varying environments.
    Matched MeSH terms: Phenotype*
  9. Mostafa H, Amin AM, Teh CH, Murugaiyah V, Arif NH, Ibrahim B
    Drug Alcohol Depend, 2016 12 01;169:80-84.
    PMID: 27788404 DOI: 10.1016/j.drugalcdep.2016.10.016
    BACKGROUND: Alcohol-dependence (AD) is a ravaging public health and social problem. AD diagnosis depends on questionnaires and some biomarkers, which lack specificity and sensitivity, however, often leading to less precise diagnosis, as well as delaying treatment. This represents a great burden, not only on AD individuals but also on their families. Metabolomics using nuclear magnetic resonance spectroscopy (NMR) can provide novel techniques for the identification of novel biomarkers of AD. These putative biomarkers can facilitate early diagnosis of AD.

    OBJECTIVES: To identify novel biomarkers able to discriminate between alcohol-dependent, non-AD alcohol drinkers and controls using metabolomics.

    METHOD: Urine samples were collected from 30 alcohol-dependent persons who did not yet start AD treatment, 54 social drinkers and 60 controls, who were then analysed using NMR. Data analysis was done using multivariate analysis including principal component analysis (PCA) and orthogonal partial least square-discriminate analysis (OPLS-DA), followed by univariate and multivariate logistic regression to develop the discriminatory model. The reproducibility was done using intraclass correlation coefficient (ICC).

    RESULTS: The OPLS-DA revealed significant discrimination between AD and other groups with sensitivity 86.21%, specificity 97.25% and accuracy 94.93%. Six biomarkers were significantly associated with AD in the multivariate logistic regression model. These biomarkers were cis-aconitic acid, citric acid, alanine, lactic acid, 1,2-propanediol and 2-hydroxyisovaleric acid. The reproducibility of all biomarkers was excellent (0.81-1.0).

    CONCLUSION: This study revealed that metabolomics analysis of urine using NMR identified AD novel biomarkers which can discriminate AD from social drinkers and controls with high accuracy.

    Matched MeSH terms: Phenotype*
  10. Jiamsakul A, Chaiwarith R, Durier N, Sirivichayakul S, Kiertiburanakul S, Van Den Eede P, et al.
    J Med Virol, 2016 Feb;88(2):234-43.
    PMID: 26147742 DOI: 10.1002/jmv.24320
    HIV drug resistance assessments and interpretations can be obtained from genotyping (GT), virtual phenotyping (VP) and laboratory-based phenotyping (PT). We compared resistance calls obtained from GT and VP with those from PT (GT-PT and VP-PT) among CRF01_AE and subtype B HIV-1 infected patients. GT predictions were obtained from the Stanford HIV database. VP and PT were obtained from Janssen Diagnostics BVBA's vircoType(TM) HIV-1 and Antivirogram®, respectively. With PT assumed as the "gold standard," the area under the curve (AUC) and the Bland-Altman plot were used to assess the level of agreement in resistance interpretations. A total of 80 CRF01_AE samples from Asia and 100 subtype B from Janssen Diagnostics BVBA's database were analysed. CRF01_AE showed discordances ranging from 3 to 27 samples for GT-PT and 1 to 20 samples for VP-PT. The GT-PT and VP-PT AUCs were 0.76-0.97 and 0.81-0.99, respectively. Subtype B showed 3-61 discordances for GT-PT and 2-75 discordances for VP-PT. The AUCs ranged from 0.55 to 0.95 for GT-PT and 0.55 to 0.97 for VP-PT. Didanosine had the highest proportion of discordances and/or AUC in all comparisons. The patient with the largest didanosine FC difference in each subtype harboured Q151M mutation. Overall, GT and VP predictions for CRF01_AE performed significantly better than subtype B for three NRTIs. Although discrepancies exist, GT and VP resistance interpretations in HIV-1 CRF01_AE strains were highly robust in comparison with the gold-standard PT.
    Matched MeSH terms: Phenotype*
  11. Farah Wahida I, Aminuddin BS, Munirah S, Chua KH, Fuzina NH, Isa MR, et al.
    Med J Malaysia, 2004 May;59 Suppl B:190-1.
    PMID: 15468882
    This study was to assess collagen type II and collagen type I gene expression in tissue-engineered human auricular: cartilage formed via tissue engineering technique. Large-scale culture expansions were transformed into 3D in vitro construct and were implanted subcutaneously on the dorsal of athymic mice. After 8 weeks, explanted construct was processed in the same manner of native cartilage to facilitate cells for gene expression analysis. Isolated cells from in vivo construct demonstrated expression of type II collagen gene comparable to native cartilage. This study verified that tissue-engineered auricular cartilage expressed cartilage specific gene, collagen type II after in vivo maturation.
    Matched MeSH terms: Phenotype*
  12. Ong-Abdullah M, Ordway JM, Jiang N, Ooi SE, Kok SY, Sarpan N, et al.
    Nature, 2015 Sep 24;525(7570):533-7.
    PMID: 26352475 DOI: 10.1038/nature15365
    Somaclonal variation arises in plants and animals when differentiated somatic cells are induced into a pluripotent state, but the resulting clones differ from each other and from their parents. In agriculture, somaclonal variation has hindered the micropropagation of elite hybrids and genetically modified crops, but the mechanism responsible remains unknown. The oil palm fruit 'mantled' abnormality is a somaclonal variant arising from tissue culture that drastically reduces yield, and has largely halted efforts to clone elite hybrids for oil production. Widely regarded as an epigenetic phenomenon, 'mantling' has defied explanation, but here we identify the MANTLED locus using epigenome-wide association studies of the African oil palm Elaeis guineensis. DNA hypomethylation of a LINE retrotransposon related to rice Karma, in the intron of the homeotic gene DEFICIENS, is common to all mantled clones and is associated with alternative splicing and premature termination. Dense methylation near the Karma splice site (termed the Good Karma epiallele) predicts normal fruit set, whereas hypomethylation (the Bad Karma epiallele) predicts homeotic transformation, parthenocarpy and marked loss of yield. Loss of Karma methylation and of small RNA in tissue culture contributes to the origin of mantled, while restoration in spontaneous revertants accounts for non-Mendelian inheritance. The ability to predict and cull mantling at the plantlet stage will facilitate the introduction of higher performing clones and optimize environmentally sensitive land resources.
    Matched MeSH terms: Phenotype*
  13. Tan JA, Tan KL, Omar KZ, Chan LL, Wee YC, George E
    Eur J Pediatr, 2009 Sep;168(9):1049-54.
    PMID: 19034506 DOI: 10.1007/s00431-008-0877-9
    INTRODUCTION: Interactions of different hemoglobin variants with thalassemia alleles can result in various clinical phenotypes. HbE-beta-thalassemia generally manifests with severe anemia where individuals exhibit beta-thalassemia major with regular blood transfusions or beta-thalassemia intermedia with periodic blood transfusions. This study presents a unique Malay family with three beta-globin gene defects-HbE, Hb South Florida, and IVS1-1 (G-->A).

    MATERIALS AND METHODS: HbE activates a cryptic splice site that produces non-functional mRNAs. Hb South Florida is a rare beta-hemoglobin variant, and its interactions with other beta-thalassemia alleles have not been reported. IVS1-1 is a Mediterranean mutation that affects mRNA processing giving rise to beta(o)-thalassemia.

    RESULTS AND DISCUSSION: Fifteen mutations along the beta-globin gene complex were analyzed using the amplification refractory mutation system. Hb South Florida was identified by direct sequencing using genomic DNA.

    CONCLUSION: The affected child with HbE/IVS1-1 produced a beta-thalassemia major phenotype. Compound heterozygosity for Hb South Florida/IVS1-1 produced a beta-thalassemia carrier phenotype in the mother.

    Matched MeSH terms: Phenotype*
  14. Bere A, Tayib S, Kriek JM, Masson L, Jaumdally SZ, Barnabas SL, et al.
    Clin Immunol, 2014 Feb;150(2):210-9.
    PMID: 24440646 DOI: 10.1016/j.clim.2013.12.005
    HIV-infected individuals experience more persistent HPV infections and are less likely to resolve genital warts. This study compared phenotype and functions of NK and T cells from genital warts and blood from 67 women. We compared in vitro functional responses of NK and T cells by multiparametric flow cytometry. HIV+ women had significantly lower frequencies of CD4 T cells in warts (p = 0.001) and blood (p = 0.001). While the distribution of NK cell subsets was similar, HIV+ women tended to have lower frequencies of CD56(Dim) NK cells in both blood (p = 0.0001) and warts (p = 0.006) than HIV- women. Wart NK cells from HIV+ women expressed significantly lower CD107a and produced IFN-γ. HAART status was not associated with differences in NK cell functionality. We conclude that wart NK cells from HIV+ women have defects in their ability to degranulate and/or secrete IFN-γ, which may provide insights into why HIV+ women fail to spontaneously resolve genital warts.
    Matched MeSH terms: Phenotype*; Immunophenotyping
  15. Ariffin H, Azanan MS, Abd Ghafar SS, Oh L, Lau KH, Thirunavakarasu T, et al.
    Cancer, 2017 Nov 01;123(21):4207-4214.
    PMID: 28654149 DOI: 10.1002/cncr.30857
    BACKGROUND: Large epidemiologic studies have reported the premature onset of age-related conditions, such as ischemic heart disease and diabetes mellitus, in childhood cancer survivors, decades earlier than in their peers. The authors investigated whether young adult survivors of childhood acute lymphoblastic leukemia (ALL) have a biologic phenotype of cellular ageing and chronic inflammation.

    METHODS: Plasma inflammatory cytokines were measured using a cytometric bead array in 87 asymptomatic young adult survivors of childhood ALL (median age, 25 years; age range, 18-35 years) who attended annual follow-up clinic and compared with healthy, age-matched and sex-matched controls. Leukocyte telomere length (LTL) was measured using Southern blot analysis.

    RESULTS: Survivors had significant elevation of plasma interleukin-2 (IL-2), IL-10, IL-17a, and high-sensitivity C-reactive protein levels (all P 0.8 mg/dL) was related to increased odds of having metabolic syndrome (odds ratio, 7.256; 95% confidence interval, 1.501-35.074). Survivors also had significantly shorter LTL compared with controls (median, 9866 vs 10,392 base pairs; P = .021). Compared with published data, LTL in survivors was similar to that in healthy individuals aged 20 years older. Survivors who received cranial irradiation had shorter LTL compared with those who had not (P = .013).

    CONCLUSIONS: Asymptomatic young adult survivors of childhood ALL demonstrate a biologic profile of chronic inflammation and telomere attrition, consistent with an early onset of cellular processes that drive accelerated aging. These processes may explain the premature development of age-related chronic conditions in childhood cancer survivors. Understanding their molecular basis may facilitate targeted interventions to disrupt the accelerated aging process and its long-term impact on overall health. Cancer 2017;123:4207-4214. © 2017 American Cancer Society.

    Matched MeSH terms: Phenotype*
  16. Loh LC, Ong CK, Koo HJ, Lee SM, Lee JS, Oh YM, et al.
    PMID: 30174423 DOI: 10.2147/COPD.S165898
    Background: COPD-associated mortality was examined using a novel approach of phenotyping COPD based on computed tomography (CT)-emphysema index from quantitative CT (QCT) and post-bronchodilator (BD) forced expiratory volume in 1 second (FEV1) in a local Malaysian cohort.

    Patients and methods: Prospectively collected data of 112 eligible COPD subjects (mean age, 67 years; male, 93%; mean post-BD FEV1, 45.7%) was available for mortality analysis. Median follow-up time was 1,000 days (range, 60-1,400). QCT and clinicodemographic data were collected at study entry. Based on CT-emphysema index and post-BD FEV1% predicted, subjects were categorized into "emphysema-dominant," "airway-dominant," "mild mixed airway-emphysema," and "severe mixed airway-emphysema" diseases.

    Results: Sixteen patients (14.2%) died of COPD-associated causes. There were 29 (25.9%) "mild mixed," 23 (20.5%) "airway-dominant," 15 (13.4%) "emphysema-dominant," and 45 (40.2%) "severe mixed" cases. "Mild mixed" disease was proportionately more in Global Initiative for Chronic Obstructive Lung Disease (GOLD) Group A, while "severe mixed" disease was proportionately more in GOLD Groups B and D. Kaplan-Meier survival estimates showed increased mortality risk with "severe mixed" disease (log rank test, p=0.03) but not with GOLD groups (p=0.08). Univariate Cox proportionate hazard analysis showed that age, body mass index, long-term oxygen therapy, FEV1, forced volume capacity, COPD Assessment Test score, modified Medical Research Council score, St Georges' Respiratory Questionnaire score, CT-emphysema index, and "severe mixed" disease (vs "mild mixed" disease) were associated with mortality. Multivariate Cox analysis showed that age, body mass index, and COPD Assessment Test score remain independently associated with mortality.

    Conclusion: "Severe mixed airway-emphysema" disease may predict COPD-associated mortality. Age, body mass index, and COPD Assessment Test score remain as key mortality risk factors in our cohort.
    Matched MeSH terms: Phenotype*
  17. Kruszka P, Porras AR, Sobering AK, Ikolo FA, La Qua S, Shotelersuk V, et al.
    Am J Med Genet A, 2017 Jan;173(1):42-53.
    PMID: 27991738 DOI: 10.1002/ajmg.a.38043
    Down syndrome is the most common cause of cognitive impairment and presents clinically with universally recognizable signs and symptoms. In this study, we focus on exam findings and digital facial analysis technology in individuals with Down syndrome in diverse populations. Photos and clinical information were collected on 65 individuals from 13 countries, 56.9% were male and the average age was 6.6 years (range 1 month to 26 years; SD = 6.6 years). Subjective findings showed that clinical features were different across ethnicities (Africans, Asians, and Latin Americans), including brachycephaly, ear anomalies, clinodactyly, sandal gap, and abundant neck skin, which were all significantly less frequent in Africans (P 
    Matched MeSH terms: Phenotype*
  18. Nadarajan VS, Ang CH, Bee PC
    Eur J Haematol, 2012 Feb;88(2):175-8.
    PMID: 21950422 DOI: 10.1111/j.1600-0609.2011.01712.x
    We investigated the role of lipocalin-2 (LCN-2) and its receptor (SLC22A17) in mediating clonal dominance in a patient with both BCR-ABL and JAK2-V617F mutations. LCN-2 mRNA showed a near 50-fold increase in expression, accompanied by down-regulation of SLC22A17, coinciding with increase in BCR-ABL transcripts, loss of JAK2-V617F and change of clinical phenotype from polycythaemia vera to chronic myeloid leukaemia. These changes were reversed after commencing imatinib mesylate. Consistent with experimental studies, BCR-ABL+ cells express LCN-2 leading to suppression of BCR-ABL- cells and explain their eventual dominance when occurring together with JAK2-V617F.
    Matched MeSH terms: Phenotype*
  19. Abdullah UYH, Ibrahim HM, Mahmud NB, Salleh MZ, Teh LK, Noorizhab MNFB, et al.
    Hemoglobin, 2020 May;44(3):184-189.
    PMID: 32586164 DOI: 10.1080/03630269.2020.1781652
    Effective prevention of β-thalassemia (β-thal) requires strategies to detect at-risk couples. This is the first study attempting to assess the prevalence of silent β-thal carriers in the Malaysian population. Hematological and clinical parameters were evaluated in healthy blood donors and patients with β-thal trait, Hb E (HBB: c.79G>A)/β-thal and β-thal major (β-TM). β-Globin gene sequencing was carried out for 52 healthy blood donors, 48 patients with Hb E/β-thal, 34 patients with β-TM and 38 patients with β-thal trait. The prevalence of silent β-thal carrier phenotypes found in 25.0% of healthy Malaysian blood donors indicates the need for clinician's awareness of this type in evaluating β-thal in Malaysia. Patients with β-TM present at a significantly younger age at initial diagnosis and require more blood transfusions compared to those with Hb E/β-thal. The time at which genomic DNA was extracted after blood collection, particularly from patients with β-TM and Hb E/β-thal, was found to be an important determinant of the quality of the results of the β-globin sequencing. Public education and communication campaigns are recommended as apparently healthy individuals have few or no symptoms and normal or borderline hematological parameters. β-Globin gene mutation characterization and screening for silent β-thal carriers in regions prevalent with β-thal are recommended to develop more effective genetic counseling and management of β-thal.
    Matched MeSH terms: Phenotype*
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