MyMedR

Displaying publications 41 - 60 of 81 in total

Abstract:

Sort:

Toward understanding the distribution of Laurasian frogs: a test of Savage's biogeographical hypothesis using the genus Bombina

Zheng Y, Fu J, Li S

Mol Phylogenet Evol, 2009 Jul;52(1):70-83.
PMID: 19348953 DOI: 10.1016/j.ympev.2009.03.026

Several anuran groups of Laurasian origin are each co-distributed in four isolated regions of the Northern Hemisphere: central/southern Europe and adjacent areas, Korean Peninsula and adjacent areas, Indo-Malaya, and southern North America. Similar distribution patterns have been observed in diverse animal and plant groups. Savage [Savage, J.M., 1973. The geographic distribution of frogs: patterns and predictions. In: Vial, J.L. (Ed.), Evolutionary Biology of the Anurans. University of Missouri Press, Columbia, pp. 351-445] hypothesized that the Miocene global cooling and increasing aridities in interiors of Eurasia and North America caused a southward displacement and range contraction of Laurasian frogs (and other groups). We use the frog genus Bombina to test Savage's biogeographical hypothesis. A phylogeny of Bombina is reconstructed based on three mitochondrial and two nuclear gene fragments. The genus is divided into three major clades: an Indo-Malaya clade includes B. fortinuptialis, B. lichuanensis, B. maxima, and B. microdeladigitora; a European clade includes B. bombina, B. pachypus, and B. variegata; and a Korean clade contains B. orientalis. The European and Korean clades form sister-group relationship. Molecular dating of the phylogenetic tree using the penalized likelihood and Bayesian analyses suggests that the divergence between the Indo-Malaya clade and other Bombina species occurred 5.9-28.6 million years ago. The split time between the European clade and the Korean clade is estimated at 5.1-20.9 million years ago. The divergence times of these clades are not significantly later than the timing of Miocene cooling and drying, and therefore can not reject Savage's hypothesis. Some other aspects of biogeography of Bombina also are discussed. The Korean Peninsula and the Shandong Peninsula might have supplied distinct southern refugia for B. orientalis during the Pleistocene glacial maxima. In the Indo-Malaya clade, the uplift of the Tibetan Plateau might have promoted the split between B. maxima and the other species.
Cytotoxic, Antitumor and Immunomodulatory Effects of the Water-Soluble Polysaccharides from Lotus (Nelumbo nucifera Gaertn.) Seeds

Zheng Y, Wang Q, Zhuang W, Lu X, Miron A, Chai TT, et al.

Molecules, 2016 Nov 02;21(11).
PMID: 27827862

Lotus is an edible and medicinal plant, and the extracts from its different parts exhibit various bioactivities. In the present study, the hot water-soluble polysaccharides from lotus seeds (LSPS) were evaluated for their cancer cell cytotoxicity, immunomodulatory and antitumor activities. LSPS showed significant inhibitory effects on the mouse gastric cancer MFC cells, human liver cancer HuH-7 cells and mouse hepatocarcinoma H22 cells. The animal studies showed that LSPS inhibited tumor growth in H22 tumor-bearing mice with the highest inhibition rate of 45.36%, which is comparable to that induced by cyclophosphamide (30 mg/kg) treatment (50.79%). The concentrations of white blood cells were significantly reduced in cyclophosphamide-treated groups (p < 0.01), while LSPS showed much fewer side effects according to the hematology analysis. LSPS improved the immune response in H22 tumor-bearing mice by enhancing the spleen and thymus indexes, and increasing the levels of serum cytokines including tumor necrosis factor-α and interleukin-2. Moreover, LSPS also showed in vivo antioxidant activity by increasing superoxide dismutase activity, thus reducing the malondialdehyde level in the liver tissue. These results suggested that LSPS can be used as an antitumor and immunomodulatory agent.
Immune-stealth VP28-conjugated heparin nanoparticles for enhanced and reversible anticoagulation

Hussein HR, Chang CY, Zheng Y, Yang CY, Li LH, Lee YT, et al.

Nanotechnology, 2024 Feb 09;35(17).
PMID: 38262054 DOI: 10.1088/1361-6528/ad21a2

Heparins are a family of sulfated linear negatively charged polysaccharides that have been widely used for their anticoagulant, antithrombotic, antitumor, anti-inflammatory, and antiviral properties. Additionally, it has been used for acute cerebral infarction relief as well as other pharmacological actions. However, heparin's self-aggregated macrocomplex may reduce blood circulation time and induce life-threatening thrombocytopenia (HIT) complicating the use of heparins. Nonetheless, the conjugation of heparin to immuno-stealth biomolecules may overcome these obstacles. An immunostealth recombinant viral capsid protein (VP28) was expressed and conjugated with heparin to form a novel nanoparticle (VP28-heparin). VP28-heparin was characterized and tested to determine its immunogenicity, anticoagulation properties, effects on total platelet count, and risk of inducing HIT in animal models. The synthesized VP28-heparin trimeric nanoparticle was non-immunogenic, possessed an average hydrodynamic size (8.81 ± 0.58 nm) optimal for the evasion renal filtration and reticuloendothelial system uptake (hence prolonging circulating half-life). Additionally, VP28-heparin did not induce mouse death or reduce blood platelet count when administered at a high dosein vivo(hence reducing HIT risks). The VP28-heparin nanoparticle also exhibited superior anticoagulation properties (2.2× higher prothrombin time) and comparable activated partial thromboplastin time, but longer anticoagulation period when compared to unfractionated heparin. The anticoagulative effects of the VP28-heparin can also be reversed using protamine sulfate. Thus, VP28-heparin may be an effective and safe heparin derivative for therapeutic use.
Fulltext Association analysis identifies 65 new breast cancer risk loci

Michailidou K, Lindström S, Dennis J, Beesley J, Hui S, Kar S, et al.

Nature, 2017 Nov 02;551(7678):92-94.
PMID: 29059683 DOI: 10.1038/nature24284

Breast cancer risk is influenced by rare coding variants in susceptibility genes, such as BRCA1, and many common, mostly non-coding variants. However, much of the genetic contribution to breast cancer risk remains unknown. Here we report the results of a genome-wide association study of breast cancer in 122,977 cases and 105,974 controls of European ancestry and 14,068 cases and 13,104 controls of East Asian ancestry. We identified 65 new loci that are associated with overall breast cancer risk at P
Grand challenges in bioinformatics education and training

Işık EB, Brazas MD, Schwartz R, Gaeta B, Palagi PM, van Gelder CWG, et al.

Nat Biotechnol, 2023 Aug;41(8):1171-1174.
PMID: 37568018 DOI: 10.1038/s41587-023-01891-9
Fulltext Identification of novel breast cancer susceptibility loci in meta-analyses conducted among Asian and European descendants

Shu X, Long J, Cai Q, Kweon SS, Choi JY, Kubo M, et al.

Nat Commun, 2020 Mar 05;11(1):1217.
PMID: 32139696 DOI: 10.1038/s41467-020-15046-w

Known risk variants explain only a small proportion of breast cancer heritability, particularly in Asian women. To search for additional genetic susceptibility loci for breast cancer, here we perform a meta-analysis of data from genome-wide association studies (GWAS) conducted in Asians (24,206 cases and 24,775 controls) and European descendants (122,977 cases and 105,974 controls). We identified 31 potential novel loci with the lead variant showing an association with breast cancer risk at P
Fulltext Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus

Lawrenson K, Kar S, McCue K, Kuchenbaeker K, Michailidou K, Tyrer J, et al.

Nat Commun, 2016 Sep 07;7:12675.
PMID: 27601076 DOI: 10.1038/ncomms12675

A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10(-20)), ER-negative BC (P=1.1 × 10(-13)), BRCA1-associated BC (P=7.7 × 10(-16)) and triple negative BC (P-diff=2 × 10(-5)). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10(-3)) and ABHD8 (P<2 × 10(-3)). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3'-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk.
Fulltext Genome-wide association analysis in East Asians identifies breast cancer susceptibility loci at 1q32.1, 5q14.3 and 15q26.1

Cai Q, Zhang B, Sung H, Low SK, Kweon SS, Lu W, et al.

Nat Genet, 2014 Aug;46(8):886-90.
PMID: 25038754 DOI: 10.1038/ng.3041

In a three-stage genome-wide association study among East Asian women including 22,780 cases and 24,181 controls, we identified 3 genetic loci newly associated with breast cancer risk, including rs4951011 at 1q32.1 (in intron 2 of the ZC3H11A gene; P=8.82×10(-9)), rs10474352 at 5q14.3 (near the ARRDC3 gene; P=1.67×10(-9)) and rs2290203 at 15q26.1 (in intron 14 of the PRC1 gene; P=4.25×10(-8)). We replicated these associations in 16,003 cases and 41,335 controls of European ancestry (P=0.030, 0.004 and 0.010, respectively). Data from the ENCODE Project suggest that variants rs4951011 and rs10474352 might be located in an enhancer region and transcription factor binding sites, respectively. This study provides additional insights into the genetics and biology of breast cancer.
Ethnic differences of intraocular pressure and central corneal thickness: the Singapore Epidemiology of Eye Diseases study

Chua J, Tham YC, Liao J, Zheng Y, Aung T, Wong TY, et al.

Ophthalmology, 2014 Oct;121(10):2013-22.
PMID: 24950592 DOI: 10.1016/j.ophtha.2014.04.041

PURPOSE:
To determine the ethnic differences in the distribution of intraocular pressure (IOP) and central corneal thickness (CCT) in a multi-ethnic Asian population by self-reported ethnicity and genetic ancestry.
DESIGN:
Population-based, cross-sectional study.
PARTICIPANTS:
A total of 10 033 adults (3353 Chinese, 3280 Malays, and 3400 Indians) aged >40 years.
METHODS:
Participants underwent standardized systemic and ocular examinations and interviewer-administered questionnaires for risk factor assessment. The IOP readings were obtained by Goldmann applanation tonometry (Haag-Streit, Konig, Switzerland) before pupil dilation. The CCT was measured with ultrasound pachymetry. Genetic ancestry was derived using principal component (PC) analysis. Regression models were used to investigate the association of IOP and CCT with potential risk factors and genetic ancestry.
MAIN OUTCOME MEASURES:
Intraocular pressure and CCT.
RESULTS:
After excluding participants with a history of glaucoma surgery or medication, refractive surgery, corneal edema, or corneal dystrophy, IOP and CCT readings were available for 3251 Chinese, 3232 Malays, and 3317 Indians. The mean IOP readings in the Chinese, Malay, and Indian participants were 14.3±3.1, 15.3±3.7, and 15.8±2.9 mmHg, respectively (P
Prevalence, racial variations, and risk factors of age-related macular degeneration in Singaporean Chinese, Indians, and Malays

Cheung CM, Li X, Cheng CY, Zheng Y, Mitchell P, Wang JJ, et al.

Ophthalmology, 2014 Aug;121(8):1598-603.
PMID: 24661862 DOI: 10.1016/j.ophtha.2014.02.004

To describe the prevalence and risk factors for age-related macular degeneration (AMD) in a multiethnic Asian cohort of Chinese, Malay, and Indian persons.
Health burden associated with visual impairment in Singapore: the Singapore epidemiology of eye disease study

Wang X, Lamoureux E, Zheng Y, Ang M, Wong TY, Luo N

Ophthalmology, 2014 Sep;121(9):1837-42.
PMID: 24768238 DOI: 10.1016/j.ophtha.2014.03.017

To assess the impact of visual impairment (VI) on health-related quality of life and to compare the health burden of VI and other health conditions in Singapore.
Search for displaced supersymmetry in events with an electron and a muon with large impact parameters

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2015 Feb 13;114(6):061801.
PMID: 25723204

A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at √[s]=8 TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7 fb(-1). Events are selected with an electron and muon with opposite charges that both have transverse impact parameter values between 0.02 and 2 cm. The search has been designed to be sensitive to a wide range of models with nonprompt e-μ final states. Limits are set on the "displaced supersymmetry" model, with pair production of top squarks decaying into an e-μ final state via R-parity-violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to cτ=2 cm, excluding masses below 790 GeV at 95% confidence level.
Study of vector boson scattering and search for new physics in events with two same-sign leptons and two jets

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2015 Feb 6;114(5):051801.
PMID: 25699433

A study of vector boson scattering in pp collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.4 fb(-1) collected with the CMS detector. Candidate events are selected with exactly two leptons of the same charge, two jets with large rapidity separation and high dijet mass, and moderate missing transverse energy. The signal region is expected to be dominated by electroweak same-sign W-boson pair production. The observation agrees with the standard model prediction. The observed significance is 2.0 standard deviations, where a significance of 3.1 standard deviations is expected based on the standard model. Cross section measurements for W(±)W(±) and WZ processes in the fiducial region are reported. Bounds on the structure of quartic vector-boson interactions are given in the framework of dimension-eight effective field theory operators, as well as limits on the production of doubly charged Higgs bosons.
Search for top squark and Higgsino production using diphoton Higgs boson decays

Chatrchyan S, Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, et al.

Phys Rev Lett, 2014 Apr 25;112(16):161802.
PMID: 24815637

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top quark (the top squark) and the Higgs boson (Higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 fb-1 of proton-proton collision data at s=8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the top squark mass below 360 to 410 GeV, depending on the Higgsino mass.
Search for monotop signatures in proton-proton collisions at √s=8 TeV

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2015 Mar 13;114(10):101801.
PMID: 25815923

Results are presented from a search for new decaying massive particles whose presence is inferred from an imbalance in transverse momentum and which are produced in association with a single top quark that decays into a bottom quark and two light quarks. The measurement is performed using 19.7 fb^{-1} of data from proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS detector at the CERN LHC. No deviations from the standard model predictions are observed and lower limits are set on the masses of new invisible bosons. In particular, scalar and vector particles, with masses below 330 and 650 GeV, respectively, are excluded at 95% confidence level, thereby substantially extending a previous limit published by the CDF Collaboration.
CmCML11 interacts with CmCAMTA5 to enhance γ-aminobutyric acid (GABA) accumulation by regulating GABA shunt in fresh-cut cantaloupe

You W, Zhang J, Ru X, Xu F, Wu Z, Jin P, et al.

Plant Physiol Biochem, 2024 Jan;206:108217.
PMID: 38039581 DOI: 10.1016/j.plaphy.2023.108217

The effect of calcium chloride (CaCl2) treatment on γ-aminobutyric acid (GABA) accumulation in fresh-cut cantaloupe and the involved mechanisms were investigated. The result showed that 1% (w/v) CaCl2 treatment increased GABA content and activities of glutamate decarboxylase (GAD) and succinate semialdehyde dehydrogenase (SSADH), while decreased glutamate (Glu) content and GABA transaminase (GABA-T) activities in fresh-cut cantaloupe. CmCML11 and CmCAMTA5 expressions of CaCl2-treated fruit increased by 187.4% and 165.6% than control fruit in the initial 6 h. Besides, expressions of GABA shunt genes, including CmGAD1, CmGAD2, CmGABA-T and CmSSADH were also up-regulated by CaCl2 treatment during early storage. Moreover, acting as a transcriptional activator, CmCAMTA5 could bind to the CG-box in promoters of CmGAD1, CmGABA-T and CmSSADH and activate their transcription. Furthermore, the interaction between CmCML11 and CmCAMTA5 could enhance the transcriptional activation on GABA shunt genes which were regulated by CmCAMTA5. Collectively, our findings revealed that CaCl2 treatment promoted GABA accumulation in fresh-cut cantaloupe via the combined effect of CmCML11 and CmCAMTA5 in the regulation of expressions of CmGAD1, CmGABA-T, and CmSSADH in GABA shunt.
Tinnitus and tinnitus disorder: Theoretical and operational definitions (an international multidisciplinary proposal)

De Ridder D, Schlee W, Vanneste S, Londero A, Weisz N, Kleinjung T, et al.

Prog Brain Res, 2021;260:1-25.
PMID: 33637213 DOI: 10.1016/bs.pbr.2020.12.002

As for hypertension, chronic pain, epilepsy and other disorders with particular symptoms, a commonly accepted and unambiguous definition provides a common ground for researchers and clinicians to study and treat the problem. The WHO's ICD11 definition only mentions tinnitus as a nonspecific symptom of a hearing disorder, but not as a clinical entity in its own right, and the American Psychiatric Association's DSM-V doesn't mention tinnitus at all. Here we propose that the tinnitus without and with associated suffering should be differentiated by distinct terms: "Tinnitus" for the former and "Tinnitus Disorder" for the latter. The proposed definition then becomes "Tinnitus is the conscious awareness of a tonal or composite noise for which there is no identifiable corresponding external acoustic source, which becomes Tinnitus Disorder "when associated with emotional distress, cognitive dysfunction, and/or autonomic arousal, leading to behavioural changes and functional disability.". In other words "Tinnitus" describes the auditory or sensory component, whereas "Tinnitus Disorder" reflects the auditory component and the associated suffering. Whereas acute tinnitus may be a symptom secondary to a trauma or disease, chronic tinnitus may be considered a primary disorder in its own right. If adopted, this will advance the recognition of tinnitus disorder as a primary health condition in its own right. The capacity to measure the incidence, prevalence, and impact will help in identification of human, financial, and educational needs required to address acute tinnitus as a symptom but chronic tinnitus as a disorder.
Child and adolescent psychiatry in the Far East: A 5-year follow up on the Consortium on Academic Child and Adolescent Psychiatry in the Far East (CACAP-FE) study

Hirota T, Guerrero A, Sartorius N, Fung D, Leventhal B, Ong SH, et al.

Psychiatry Clin Neurosci, 2019 Feb;73(2):84-89.
PMID: 30471156 DOI: 10.1111/pcn.12800

AIM: Data pertaining to child and adolescent psychiatry (CAP) training systems are limited as extant research has mostly been derived from one-time data collection. This 5-year follow-up survey collects updated information on CAP training systems in the Far East, allowing for the tracking of system changes over the past 5 years.
METHODS: Data were obtained from 18 countries, or functionally self-governing areas, in the Far East, 17 of which were also included in the original study. An online questionnaire was completed by leading CAP professionals in each country. Questions were expanded in the present study to capture the contents of CAP training.
RESULTS: When compared to data from the original study, there has been progress in CAP training systems in the last 5 years. Specifically, there has been an increase in the number of countries with CAP training programs and national guidelines for the training. In addition, the number of CAP departments/divisions affiliated with academic institutions/universities has increased. Findings from 12 of 18 countries in the present study provide data on clinical contents. All informants of the present study reported the need for more child and adolescent psychiatrists and allied professionals.
CONCLUSION: Despite progress in CAP training systems over the last 5 years, the need for more professionals in child and adolescent mental health care in all the relevant areas in this region have yet to be adequately addressed. Continued national efforts and international collaborations are imperative to developing and sustaining new CAP training systems while facilitating improvements in existing programs.
Fulltext Elasticity and damping ratio measurement of droplets on super-hydrophobic surfaces

Sun Y, Zheng Y, Song L, Sun P, Zhao M, Zhou Y, et al.

R Soc Open Sci, 2022 Jan;9(1):211632.
PMID: 35242354 DOI: 10.1098/rsos.211632

The measurement of the droplets' elasticity is vitally important in microfluidic and ink-jet printing. It refers to the ability of the droplet to restore its original shape and strong robustness. This study investigated a novel method to measure elasticity. The plate coated with super-hydrophobic layers pressed on a droplet and the elastic force was recorded by an electronic balance. Meanwhile, a mathematical model was constructed to calculate the changes of the droplet area under the force. The measurement showed that external work mainly converts into surface energy and the damping ratio increases from 0.068 to 0.261 with the increase of mass fraction from 0 to 80 wt%. It also indicates that the novel method can accurately and efficiently measure the elasticity of droplets.
Fulltext PDLLA-Zn-nitrided Fe bioresorbable scaffold with 53-μm-thick metallic struts and tunable multistage biodegradation function

Shen D, Qi H, Lin W, Zhang W, Bian D, Shi X, et al.

Sci Adv, 2021 Jun;7(23).
PMID: 34088662 DOI: 10.1126/sciadv.abf0614

Balancing the biodegradability and mechanical integrity of a bioresorbable scaffold (BRS) with time after implantation to match the remodeling of the scaffolded blood vessel is important, but a key challenge in doing so remains. This study presents a novel intercalated structure of a metallic BRS by introducing a nanoscale Zn sacrificial layer between the nitrided Fe platform and the sirolimus-carrying poly(d,l-lactide) drug coating. The PDLLA-Zn-FeN BRS shows a multistage biodegradation behavior, maintaining mechanical integrity at the initial stage and exhibiting accelerated biodegradation at the subsequent stage in both rabbit abdominal aortas and human coronary arteries, where complete biodegradation was observed about 2 years after implantation. The presence of the nanoscale Zn sacrificial layer with an adjustable thickness also contributes to the tunable biodegradation of BRS and allows the reduction of the metallic strut thickness to 53 μm, with radial strength as strong as that of the current permanent drug-eluting stents.

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links