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1.
RSC Adv ; 13(28): 19317-19324, 2023 Jun 22.
Article in English | MEDLINE | ID: mdl-37377878

ABSTRACT

Hexagonal NaYF4:Tm, Yb upconversion (UC) phosphors with excellent UC luminescence quantum efficiency and chemical stability meet demands for applications in bioimaging and anti-counterfeiting printing. In this work, a series of NaYF4:Tm, Yb upconversion microparticles (UCMPs) with different concentrations of Yb were synthesized by a hydrothermal method. Then, the UCMPs become hydrophilic through surface oxidation of the oleic acid (C-18) ligand to azelaic acid (C-9) using the Lemieux-von Rodloff reagent. The structure and morphology of UCMPs were investigated by X-ray diffraction and scanning electron microscopy. The optical properties were studied using diffusion reflectance spectroscopy and photoluminescent spectroscopy under 980 nm laser irradiation. The emission peaks of the Tm3+ ions are 450, 474, 650, 690, and 800 nm, attributed to the transitions from the excited state to ground state 3H6. These emissions are the results of two or three photon absorption through multi-step resonance energy transfer from excited Yb3+, confirmed via a power-dependent luminescence study. The results show that the crystal phases and luminescence properties of the NaYF4:Tm, Yb UCMPs are controlled by changing the Yb doping concentration. The printed patterns are readable under the excitation of a 980 nm LED. Moreover, the zeta potential analysis shows that the UCMPs after surface oxidation are water dispersible. In particular, the naked eye can observe the enormous upconversion emissions in UCMPs. These findings indicated that this fluorescent material is an ideal candidate for anti-counterfeiting and biological applications.

2.
J Intellect Disabil Res ; 66(8-9): 717-725, 2022 08.
Article in English | MEDLINE | ID: mdl-35713265

ABSTRACT

BACKGROUND: Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are neurodevelopmental disorders in need of innovative 'real-world' outcome measures to evaluate treatment effects. Instrumented gait analysis (IGA) using wearable technology offers a potentially feasible solution to measure "real-world' neurological and motor dysfunction in these groups. METHODS: Children (50% female; 6-16 years) diagnosed with PWS (n = 9) and AS (n = 5) completed 'real-world' IGA assessments using the Physilog®5 wearable. PWS participants completed a laboratory assessment and a 'real-world' long walk. The AS group completed 'real-world' caregiver-assisted assessments. Mean and variability results for stride time, cadence, stance percentage (%) and stride length were extracted and compared across three different data reduction protocols. RESULTS: The wearables approach was found to be feasible, with all participants able to complete at least one assessment. This study also demonstrated significant agreement, using Lin's concordance correlation coefficient (CCC), between laboratory and 'real-world' assessments in the PWS group for mean stride length, mean stance % and stance % CV (n = 7, CCC: 0.782-0.847, P = 0.011-0.009). CONCLUSION: 'Real-world' gait analysis using the Physilog®5 wearable was feasible to efficiently assess neurological and motor dysfunction in children affected with PWS and AS.


Subject(s)
Angelman Syndrome , Prader-Willi Syndrome , Wearable Electronic Devices , Angelman Syndrome/complications , Angelman Syndrome/diagnosis , Angelman Syndrome/therapy , Child , Feasibility Studies , Female , Gait Analysis , Humans , Immunoglobulin A , Male
3.
Soc Sci Med ; 301: 114902, 2022 05.
Article in English | MEDLINE | ID: mdl-35306269

ABSTRACT

AIMS: This study explores the effects of two evidence-based alcohol reduction counseling interventions on readiness to change, alcohol abstinence self-efficacy, social support, and alcohol abstinence stigma among people with HIV (PWH) who have hazardous alcohol use in Vietnam. METHODS: PWH receiving antiretroviral therapy (ART) were screened for hazardous drinking and randomized to one of three study arms: combined intervention (CoI), brief intervention (BI), and standard of care (SOC). A quantitative survey was conducted at baseline (N = 440) and 3-month post-intervention (N = 405), while in-depth interviews were conducted with a subset of BI and CoI participants at baseline (N = 14) and 3 months (N = 14). Data was collected from March 2016 to August 2017. A concurrent mixed-methods model was used to triangulate quantitative and qualitative data to cross-validate findings. RESULTS: At 3 months, receiving the BI and CoI arms was associated with 2.64 and 3.50 points higher in mean readiness to change scores, respectively, compared to the SOC group (BI: ß = 2.64, 95% CI: 1.17-4.12; CoI: ß = 3.50, 95% CI 2.02-4.98). Mean alcohol abstinence self-efficacy scores were 4.03 and 3.93 points higher among the BI and CoI arm at 3 months, compared to SOC (BI: ß = 4.03, 95% CI: 0.17-7.89; CoI: ß = 3.93, 95% CI: 0.05-7.81). The impacts of the interventions on social support and alcohol abstinence stigma were not significant. Perceived challenges to refusing drinks at social events remained due to strong alcohol abstinence stigma and perceived negative support from family and friends who encouraged participants to drink posed additional barriers to reducing alcohol use. CONCLUSIONS: Both the CoI and BI were effective in improving readiness to change and alcohol abstinence self-efficacy among PWH. Yet, participants still faced significant barriers to reducing their drinking due to social influences and pressure to drink. Interventions at different levels addressing social support and alcohol abstinence stigma are warranted.


Subject(s)
Alcohol Abstinence , HIV Infections , Alcohol Drinking/psychology , Asian People , HIV Infections/complications , HIV Infections/psychology , Humans , Social Stigma , Vietnam
4.
Cancer Causes Control ; 32(4): 391-399, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33559769

ABSTRACT

INTRODUCTION: In Vietnam, 60% of men living with HIV smoke tobacco, and 92% of HIV-infected people who inject drugs (PWID) smoke tobacco. Tobacco use increases mortality through increased health risks including tuberculosis and malignancy in HIV-infected smokers. However, tobacco use treatment is not widely available in Vietnam. The objective was to examine current barriers and facilitators of smoking cessation and tobacco use treatment for HIV-infected PWID in Hanoi, Vietnam. METHODS: Native speaking ethnographers conducted semi-structured qualitative interviews about tobacco use and tobacco use treatment with sixteen HIV-infected PWID and eight healthcare providers, recruited from four HIV-Methadone Maintenance Treatment (MMT) clinics in Hanoi, Vietnam. Interviews were recorded, transcribed, and translated for thematic analysis in Dedoose. RESULTS: Clients and providers had learned the general health risks of smoking from public awareness campaigns. Half had tried to quit previously, often motivated by advice from family members but not by HIV providers' advice. Almost all clients did not want to quit, citing the low price of tobacco, prevalence of smoking in Vietnam, and physical cravings. HIV provider's counseling was brief, inconsistent, and limited by low provider knowledge and competing burdens of HIV and injection drug use. Providers recently trained by NGO-led seminars on tobacco prioritized tobacco use treatment. CONCLUSIONS: Smoking cessation efforts for people living with HIV/AIDS (PLHA) and PWID smokers in Hanoi, Vietnam could benefit from further community public awareness campaigns, and exploring increased tobacco taxation. Tobacco use treatment at HIV clinics could benefit from involving family and friends in cessation, and training providers in treatment methods.


Subject(s)
HIV Infections/psychology , Smoking Cessation/psychology , Substance Abuse, Intravenous/psychology , Tobacco Use Disorder/psychology , Adult , Family , Health Personnel , Health Promotion , Humans , Male , Motivation , Vietnam
5.
Drug Alcohol Depend ; 215: 108249, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32871505

ABSTRACT

INTRODUCTION: Hazardous drinking is widespread among people with HIV (PWH). PWH are also vulnerable to depression due to HIV-related social stigma, and social support can play an important role in improving mental health for this population. No studies have explored whether social support modifies the association of hazardous drinking and depressive symptoms among PWH. METHODS: We used baseline data from a randomized controlled trial of two evidence-based alcohol reduction interventions among antiretroviral therapy clients in Vietnam. Hazardous alcohol use was defined as having a score ≥8 for men and ≥ 7 for women on the Alcohol Use Disorders Identification Test. The presence of depression symptoms was defined as a score ≥ 5 on the Patient Health Questionnaire-9. Social support was measured with a 5-question modified version of the Medical Outcomes Study Social Support Instrument. Crude (CPRs) and adjusted prevalence ratios (aPRs) of the association were presented. RESULTS: Hazardous drinking was significantly associated with increased likelihood of having depressive symptoms (aPR = 1.26;95%CI 1.04-1.52). Hazardous drinking and depression symptoms were not associated among those with high social support (aPR = 1.01;95%CI 0.76-1.35), but were associated among those with medium (aPR = 1.24;95%CI 0.92-1.69) and low social support (aPR = 1.71;95%CI 1.25-2.34). CONCLUSIONS: Social support significantly modified the association between hazardous drinking and depression symptoms among ART clients in Vietnam. Interventions to decrease hazardous alcohol use are broadly indicated for PWH in Vietnam and other low-resource settings, but special attention or modifications may be needed to support mental health among those with lower levels of social support.


Subject(s)
Alcoholism/therapy , Anti-Retroviral Agents/therapeutic use , HIV Infections/drug therapy , Social Support , Adult , Alcoholism/epidemiology , Alcoholism/psychology , Depression/psychology , Ethanol , Female , HIV Infections/epidemiology , Humans , Male , Middle Aged , Prevalence , Social Stigma , Vietnam/epidemiology
6.
J Pharm Biomed Anal ; 172: 243-252, 2019 Aug 05.
Article in English | MEDLINE | ID: mdl-31071649

ABSTRACT

Herein, we successfully fabricated a novel nanostructure based on hierarchical urchin-like FeCo oxide supported carbon spheres (FeCo Oxide/CSs) via a two-step hydrothermal method followed by a simple annealing step at 300 °C under air. It was found that such urchin-like FeCo Oxide/CSs structure exhibited superior catalytic activity towards hydrazine oxidation to CSs, Fe Oxide/CSs, Co Oxide/CSs, and FeCo Hydroxide/CSs material. In this regard, the FeCo Oxide/CSs displayed a wide linear detection range of 0.1-516.6 µM, low detection limit of 0.1 µM, and long-term stability. The material also showed good selectivity towards hydrazine detection in the presence of various interferences, such as uric acid, ascorbic acid, urea, dopamine, Na+, SO42-, K+, and Cl-. The excellent sensing performance of the FeCo Oxide/CSs was assumed to the unique hierarchical urchin structure with the high density and uniformity of nano-sized FeCo Oxide nanoneedles, which produced massive electroactive sites and enhanced charge transfer ability. The achieved results implied that the FeCo Oxide/CSs may be a great candidate for sensitive hydrazine detection.


Subject(s)
Carbon/chemistry , Carbonates/chemistry , Cobalt/chemistry , Ferric Compounds/chemistry , Hydrazines/chemistry , Nanostructures/chemistry , Oxides/chemistry , Electrochemical Techniques/methods , Electrodes , Hydroxides/chemistry , Limit of Detection , Metal Nanoparticles/chemistry , Oxidation-Reduction
8.
Acta Chromatogr ; 28(3): 373-385, 2016.
Article in English | MEDLINE | ID: mdl-27974871

ABSTRACT

Prions of the baker's yeast Saccharomyces cerevisiae allow for the inheritance of complex traits based solely on the acquisition of cytoplasmic protein aggregates and confer distinctive phenotypes to the cells which harbor them, creating heterogeneity within an otherwise clonal cell population. These phenotypes typically arise from a loss-of-function of the prion-forming protein that is unable to perform its normal cellular function(s) while sequestered in prion amyloid aggregates, but the specific biochemical consequences of prion infection are poorly understood. To begin to address this issue, we initiated a direct investigation into the potential control that yeast prions exert over fungal lipid content by utilizing the prions [URE3] and [PSI+], the first two prions discovered in yeast. We utilized silica gel high-performance thin-layer chromatography (HPTLC)-densitometry to conduct pair-wise quantifications of the relative levels of free sterols, free fatty acids, and triacylglycerols [petroleum ether-diethyl ether-acetic acid (80:20:1) mobile phase, phosphomolybdic acid (PMA) detection reagent]; steryl esters and squalene (hexane-petroleum ether-diethyl ether-acetic acid (50:20;5:1), PMA]; and phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol (chloroform-diethyl ether-acetic acid (65:25:4.5), cupric sulfate-phosphoric acid) in otherwise clonal prion-infected ([PSI+] or [URE3]) and prion-free ([psi-] or [ure-o]) cells in two growth phases: log-phase and stationary phase. Our analysis revealed multiple statistically significant differences (p < 0.00625) between prion-infected and prion-free cells. Interestingly, prion-induced changes varied dramatically by growth phase, indicating that prions exert differential influences on cell physiology between log and stationary growth. Further experimental replication and extension of the analysis to other prions is expected to resolve additional physiological effects of prion infection. This investigation demonstrates that HPTLC-densitometry is an effective method for studying prion-induced alterations in lipid content in yeast.

9.
Transl Psychiatry ; 6(12): e984, 2016 12 13.
Article in English | MEDLINE | ID: mdl-27959330

ABSTRACT

DNA methylation of the Fragile X mental retardation 1 (FMR1) exon 1/intron 1 boundary has been associated with executive dysfunction in female carriers of a FMR1 premutation (PM: 55-199 CGG repeats), whereas neuroanatomical changes have been associated with executive dysfunction in PM males. To our knowledge, this study for the first time examined the inter-relationships between executive function, neuroanatomical structure and molecular measures (DNA methylation and FMR1 mRNA levels in blood) in PM and control (<44 CGG repeats) females. In the PM group, FMR1 intron 1 methylation was positively associated with executive function and cortical thickness in middle and superior frontal gyri, and left inferior parietal gyrus. By contrast, in the control group, FMR1 intron 1 methylation was negatively associated with cortical thickness of the left middle frontal gyrus and superior frontal gyri. No significant associations were revealed for either group between FMR1 mRNA and neuroanatomical structure or executive function. In the PM group, the lack of any significant association between FMR1 mRNA levels and phenotypic measures found in this study suggests that either FMR1 expression is not well conserved between tissues, or that FMR1 intron 1 methylation is linked to neuroanatomical and cognitive phenotype in PM females via a different mechanism.


Subject(s)
Brain/pathology , DNA Methylation/genetics , Executive Function/physiology , Fragile X Syndrome/genetics , Fragile X Syndrome/pathology , Adult , DNA Mutational Analysis , Exons/genetics , Female , Fragile X Syndrome/complications , Fragile X Syndrome/diagnosis , Humans , Introns/genetics , Magnetic Resonance Imaging , Middle Aged , Neuropsychological Tests , Phenotype , Statistics as Topic , Trinucleotide Repeats/genetics , Young Adult
10.
Sci Rep ; 6: 29366, 2016 07 08.
Article in English | MEDLINE | ID: mdl-27387142

ABSTRACT

Fragile X tremor ataxia syndrome (FXTAS) is a late-onset disorder manifesting in a proportion of FMR1 premutation individuals (PM: 55-199 CGG triplet expansions). FXTAS is associated with elevated levels of FMR1 mRNA which are toxic. In this study, relationships between neurocognitive and intra-step gait variability measures with mRNA levels, measured in blood samples, were examined in 35 PM and 35 matched control females. The real-time PCR assays measured FMR1 mRNA, and previously used internal control genes: ß-Glucuronidase (GUS), Succinate Dehydrogenase 1 (SDHA) and Eukaryotic Translation Initiation Factor 4A (EI4A2). Although there was significant correlation of gait variability with FMR1 mRNA levels (p = 0.004) when normalized to GUS (FMR1/GUS), this was lost when FMR1 was normalized to SDHA and EI4A2 (2IC). In contrast, GUS mRNA level normalized to 2IC showed a strong correlation with gait variability measures (p < 0.007), working memory (p = 0.001) and verbal intelligence scores (p = 0.008). PM specific changes in GUS mRNA were not mediated by FMR1 mRNA. These results raise interest in the role of GUS in PM related disorders and emphasise the importance of using appropriate internal control genes, which have no significant association with PM phenotype, to normalize FMR1 mRNA levels.


Subject(s)
Ataxia/complications , Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/complications , Gait/genetics , Glucuronidase/genetics , Memory, Short-Term , Tremor/complications , Adult , Ataxia/blood , Ataxia/genetics , Case-Control Studies , Female , Fragile X Mental Retardation Protein/blood , Fragile X Syndrome/blood , Fragile X Syndrome/genetics , Glucuronidase/blood , Humans , Male , Middle Aged , Mutation , RNA, Messenger/blood , Real-Time Polymerase Chain Reaction/standards , Tremor/blood , Tremor/genetics , Trinucleotide Repeat Expansion
11.
J Nanosci Nanotechnol ; 12(4): 3506-10, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22849156

ABSTRACT

In this study, the electrochemical performance of an electroless nickel/immersion gold (ENIG) surface finish was evaluated as a function of the Au immersion time by the water immersion migration test. As the Au plating time increased, the electroless nickel phosphorous (EN-P) changed from amorphous to crystalline and then increased in crystallinity. X-ray diffraction (XRD) was used to evaluate the crystallinity of the plating layer. The electrical resistance of the electrodes was tracked as the sample was immersed in water with a 5 V bias. The microstructures of the electrodes after the electrochemical migration test were observed by using secondary electron microscopy (SEM) and energy dispersive spectroscopy (EDS). As the Au immersion time increased, the EN-P's crystallinity and Au thickness increased. This enhanced the electrochemical migration protection of the surface finish layer.

12.
Food Chem Toxicol ; 50(8): 2845-53, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22609490

ABSTRACT

The safety of the apple polyphenol extract EvesseEPC, which is rich in flavan-3-ols, particularly epicatechin, was evaluated. Both in a bacterial reverse mutation test and a mouse lymphoma assay, EvesseEPC showed a positive response in vitro. In vivo studies (UDS test in hepatocytes, bone marrow micronucleus test and comet assay in intestinal cells) were all negative and hence Evesse EPC is considered not to have genotoxic properties in vivo. In a 90-day study in rats, EvesseEPC was administered at dietary levels of 0%, 1.25%, 2% and 3.25%. Body weights were decreased in the high-dose group in both sexes without effects on feed or water intake. In the high-dose group, thrombocytes (males) and creatinine (both sexes) were decreased, prothrombin time (males) was increased, and liver, kidneys and spleen weights were increased (males), without histological correlates. Diffuse acinar cell hypertrophy, observed in the parotid salivary glands in all treatment groups, was not considered as adverse and presumably reflected a local, reversible and adaptive response to direct contact with EvesseEPC. The NOAEL for EvesseEPC in rats was 2% in the diet, equivalent to an overall average intake of 1.3 and 1.5 g/kg body weight/day for males and females, respectively.


Subject(s)
Flavonoids/pharmacology , Malus/chemistry , Plant Extracts/pharmacology , Polyphenols/pharmacology , Animals , Female , Flavonoids/adverse effects , Male , Mice , Micronucleus Tests , Plant Extracts/adverse effects , Polyphenols/adverse effects , Rats , Rats, Wistar
13.
Malar J ; 9: 181, 2010 Jun 24.
Article in English | MEDLINE | ID: mdl-20573274

ABSTRACT

BACKGROUND: Artemisinin derivatives have been used for malaria treatment in Vietnam since 1989. Reported malaria cases have decreased from 1,672,000 with 4,650 deaths in 1991, to 91,635 with 43 deaths in 2006. Current national guidelines recommend artemisinin-based combination therapy (ACT), although artesunate is still available as monotherapy through the private sector. Recent reports suggest that effectiveness of ACT and artesunate monotherapy has declined in western Cambodia. This study examined Plasmodium falciparum resistance patterns over 10 years in southwest Vietnam in infected patients treated with artemisinin compounds. METHODS: The study was conducted in two communes in Phuoc Long district, Binh Phuoc province, 100 km west of the Cambodian border. This was chosen as a likely site for emerging artemisinin resistance because of the high prevalence of P. falciparum malaria, and the length of time that artemisinin had been in use. In vivo and in vitro monitoring of P. falciparum susceptibility to anti-malarial drugs was conducted in 1998, 2001, 2004/5, and 2008/9. Patients with confirmed P. falciparum malaria received therapy with 5 or 7 days of artemisinin (1998 and 2001 respectively) or 7 days of artesunate RESULTS: In the four surveys, 270 patients were recruited and treated. The mean parasite clearance times differed between 1998, 2001 and 2004/5 (1.8, 2.3 and 2.1 days, P < 0.01) but not between 1998 and 2008/2009. The mean parasite clearance times were correlated with parasite density at day 0 (r = 0.4; P < 0.001). Treatment failure rates after PCR adjustment were 13.8%, 2.9%, 1.2%, and 0% respectively. Susceptibility of P. falciparum to artemisinin in in vitro tests was stable during the period, except for a rise in EC90 and EC99 in 2001. CONCLUSIONS: This study showed stable levels of P. falciparum sensitivity to artemisinin compounds in the two sites over a ten-year period. The introduction of ACT in this area in 2003 may have protected against the development of artemisinin resistance. Adherence to the latest WHO and Vietnamese guidelines, which recommend ACT as first-line therapy in all malarious areas, and continued monitoring along the Vietnam-Cambodia border will be essential to prevent the spread of artemisinin resistance in Vietnam.


Subject(s)
Anti-Infective Agents/therapeutic use , Antimalarials/pharmacology , Artemisinins/pharmacology , Malaria, Falciparum/drug therapy , Plasmodium falciparum/drug effects , Adolescent , Adult , Artesunate , Child , Drug Resistance/genetics , Female , Follow-Up Studies , Genotype , Humans , Inhibitory Concentration 50 , Malaria, Falciparum/parasitology , Male , Parasitemia/drug therapy , Parasitic Sensitivity Tests , Plasmodium falciparum/genetics , Plasmodium falciparum/isolation & purification , Polymerase Chain Reaction , Recurrence , Sensitivity and Specificity , Time Factors , Vietnam , Young Adult
14.
Diagn Microbiol Infect Dis ; 67(2): 172-9, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20466196

ABSTRACT

Hepatitis D virus (HDV) infection is an important etiologic agent of fulminant hepatitis and may aggravate the clinical course of chronic hepatitis B infection resulting in cirrhosis and liver failure. This report describes the establishment of a real-time reverse transcriptase polymerase chain reaction method that allows the quantitative detection of HDV-1 and HDV-3 with a sensitivity in a linear range of 2 x 10(3) to 10(8) copies/mL. Additionally, the new assay provides the opportunity to distinguish HDV-1 from HDV-3 by a subsequent melting curve analysis, an important option because these HDV types are highly associated with severe clinical outcome. The results of the melting curve analysis of 42 HDV sequences obtained in this study and the phylogenetic analysis based on 139 full-length sequences from GenBank were consistent and showed that all sequences described here cluster within the HDV-1 clade. Therefore, this assay is useful for monitoring of antiviral treatment and molecular epidemiologic studies of HDV distribution.


Subject(s)
Hepatitis D/diagnosis , Hepatitis Delta Virus/classification , Hepatitis Delta Virus/isolation & purification , Polymerase Chain Reaction/methods , Serum/virology , Transition Temperature , Virology/methods , Cluster Analysis , Hepatitis D/virology , Hepatitis Delta Virus/genetics , Humans , Molecular Sequence Data , Phylogeny , RNA, Viral/genetics , Sensitivity and Specificity , Sequence Analysis, DNA , Sequence Homology
15.
New Phytol ; 186(1): 135-47, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20074093

ABSTRACT

Allopolyploidy is a major driving force in plant evolution and can induce rapid structural changes in the hybrid genome. As major components of plant genomes, transposable elements are involved in these changes. In a previous work, we observed turnover of retrotransposon insertions in natural allotretraploid tobacco (Nicotiana tabacum). Here, we studied the early stages of allopolyploid formation by monitoring changes at retrotransposon insertion sites in the Th37 synthetic tobacco. We used sequence-specific amplification polymorphism (SSAP) to study insertion patterns of two populations of the Tnt1 retrotransposon in Th37 S4 generation plants, and characterized the nature of polymorphic insertion sites. We observed significant amplification of young Tnt1 populations. Newly transposed copies were amplified from maternal elements and were highly similar to Tnt1A tobacco copies amplified in response to microbial factors. A high proportion of paternal SSAP bands were not transmitted to the hybrid, corresponding to various rearrangements at paternal insertion sites, including indels or the complete loss of the Tnt1/flanking junction. These data indicate that major changes, such as retrotransposon amplification and molecular restructuring in or around insertion sites, occur rapidly in response to allopolyploidy.


Subject(s)
Nicotiana/genetics , Polyploidy , Retroelements/genetics , Base Sequence , Chromosome Segregation/genetics , Crosses, Genetic , Molecular Sequence Data , Mutagenesis, Insertional/genetics , Phylogeny , Polymorphism, Genetic , Sequence Alignment
16.
Clin Genet ; 76(5): 471-6, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19796183

ABSTRACT

Fragile X-associated tremor/ataxia syndrome (FXTAS) affects older males carrying premutation, that is, expansions of the CGG repeat (in the 55-200 range), in the FMR1 gene. The neurological changes are linked to the excessive FMR1 messenger RNA (mRNA), becoming toxic through a 'gain-of-function'. Because elevated levels of this mRNA are also found in carriers of the smaller expansion (grey zone) alleles, ranging from 40 to 54 CGGs, we tested for a possible role of these alleles in the origin of movement disorders associated with tremor. We screened 228 Australian males affected with idiopathic Parkinson's disease and other causes of parkinsonism recruited from Victoria and Tasmania for premutation and grey zone alleles. The frequencies of either of these alleles were compared with the frequencies in a population-based sample of 578 Guthrie spots from consecutive Tasmanian male newborns (controls). There was a significant excess of premutation carriers (Fisher's exact test p = 0.006). There was also a more than twofold increase in grey zone carriers in the combined sample of the Victorian and Tasmanian cases, with odds ratio (OR ) = 2.36, and 95% confidence intervals (CI): 1.20-4.63, as well as in Tasmanian cases only (OR = 2.33, 95% CI: 1.06-5.13), compared with controls. The results suggest that the FMR1 grey zone alleles, as well as premutation alleles, might contribute to the aetiology of disorders associated with parkinsonism.


Subject(s)
Alleles , Fragile X Mental Retardation Protein/genetics , Parkinsonian Disorders/genetics , Trinucleotide Repeat Expansion/genetics , Aged , Australia , Humans , Male , Middle Aged , RNA, Messenger/metabolism
17.
Article in English | MEDLINE | ID: mdl-19062682

ABSTRACT

In 2002 an antimalarial drug resistance survey was carried out in a seasonally endemic area of Vietnam. Sulfadoxine/pyrimethamine (S/P) was the standard treatment recommended for uncomplicated Plasmodium falciparum malaria in that area at the time. Early or late treatment failure as defined by WHO was observed in 14.9% (7/47) of patients. Molecular analysis of treatment failure isolates identified that 5/6 carried two or more dhfr and dhps polymorphisms associated with S/P resistance. Chloroquine resistance-associated polymorphisms occurred in 38.5% (15/39) of the isolates. These results support the move to artemisinin-based combination therapy for malaria in Vietnam.


Subject(s)
Antimalarials/pharmacology , Plasmodium falciparum/genetics , Polymorphism, Genetic , Protozoan Proteins/genetics , Adolescent , Adult , Animals , Child , Child, Preschool , Chloroquine/pharmacology , DNA, Protozoan/genetics , Drug Combinations , Drug Resistance , Female , Humans , Male , Middle Aged , Plasmodium falciparum/isolation & purification , Pyrimethamine/pharmacology , Sulfadoxine/pharmacology , Vietnam , Young Adult
18.
Mol Phylogenet Evol ; 47(3): 1181-9, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18455443

ABSTRACT

Mariner-like elements (MLEs) are ubiquitous DNA mobile elements found in almost all eukaryote genomes. Nevertheless most of the known copies are inactive and the question of the genome invasion by MLEs remains largely hypothetical. We have previously reported the presence of highly homologous copies of MLEs in the genome of phylogenetically distant crustacea living in the same hydrothermal environment suggesting the possibility of horizontal transfer. In order to further support the hypothesis that horizontal transmission of MLEs might occur between crustacean sympatric species, we described here 85 MLE sequences found in the genome of a large spectrum of coastal crab species. The number of the MLEs copies in genomes was variable. Half of these MLEs fit with the irritans subfamily of MLEs whereas the second half grouped in a new subfamily called marmoratus. In addition, a molecular phylogeny of crabs was established by using the 16S information. The comparison between 16S and MLEs based trees reveals their incongruence, and suggests either the existence of horizontal transfer events between phylogenetically distant species, or an ancestral MLE polymorphism followed by different evolution and stochastic loss.


Subject(s)
Brachyura/genetics , DNA Transposable Elements/genetics , Amino Acid Sequence , Animals , Consensus Sequence , Genome/genetics , Phylogeny
19.
Mol Phylogenet Evol ; 40(2): 609-19, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16690328

ABSTRACT

Mariner-like elements (MLEs) have been widely detected in terrestrial species. The first complete MLE isolated from a marine invertebrate was detected in the genome of the hydrothermal crab Bythograea thermydron by Halaimia-Toumi et al. [Halaimia-Toumi, N., Casse, N., Demattei, M.V., Renault, S., Pradier, E., Bigot, Y., Laulier, M., 2004. The GC-rich transposon Bytmar1 from the deep-sea hydrothermal crab, Bythograea thermydron, may encode three transposase isoforms from a single ORF. J. Mol. Evol. 59, 747-760] and called Bytmar1. Here, we report the isolation of three new Bytmar1 relatives from the genomes of one hydrothermal amphipod Ventiella sulfuris (Vensmar1) and two coastal crustacea, Maia brachydactila (Maibmar1) and Cancer pagurus (Canpmar1). Like Bytmar1, these MLEs have an unusually high GC content, a high CpG ratio, and a low TpA ratio. Their consensus sequence encodes a transposase that is preceded by an N-flag, as in Bytmar1, which could be a marine feature. Only one of the 19 clones obtained, Vensmar1.3, encoded for a full-length transposase. The phylogenetic analyses revealed that all these Bytmar1-related elements can be differentiated into two clusters, corresponding to the coastal or hydrothermal origin of their hosts. They also confirmed that the irritans sub-family comprises at least four lineages that seem to depend on the taxonomical position and habitat of their hosts. Finally, we observed that elements coding for two potentially complete transposases exhibiting 99.5% similarity, Bytmar1.11 and Vensmar1.3, were present in the genome of two distantly related hydrothermal crustacea, one Amphipod and one Decapod. The hypothesis of horizontal transfers is discussed in the light of the sequence similarities observed.


Subject(s)
Crustacea/genetics , DNA Transposable Elements/genetics , DNA-Binding Proteins/genetics , Gene Transfer, Horizontal/genetics , Genome/genetics , Amino Acid Sequence , Animals , Molecular Sequence Data , Oceans and Seas , Open Reading Frames/genetics , Phylogeny , Sequence Alignment , Transposases
20.
Genet Epidemiol ; 26(4): 294-304, 2004 May.
Article in English | MEDLINE | ID: mdl-15095389

ABSTRACT

A model for the transmission of the CGG repeat sequence associated with the fragile-X dynamic mutation in the FMR1 gene is developed. The model incorporates both haplotype and family effects on the expansion rate of the sequence. The resulting random effects model is fitted to new data, using computer-intensive Markov chain Monte Carlo methods. The results demonstrate both the FRAXAC1-DXS458 haplotype and family effects on the transmission of CGG repeats from mother to offspring.


Subject(s)
Bayes Theorem , Fragile X Syndrome/genetics , Australia , Chi-Square Distribution , Female , Genetic Variation , Genetics, Population , Genotype , Haplotypes , Humans , Male , Mothers , Mutation , Phenotype , United States
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