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1.
Circ Res ; 134(2): 189-202, 2024 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-38152893

RESUMEN

BACKGROUND: Diabetes is a major risk factor for atherosclerotic cardiovascular diseases with a 2-fold higher risk of cardiovascular events in people with diabetes compared with those without. Circulating monocytes are inflammatory effector cells involved in both type 2 diabetes (T2D) and atherogenesis. METHODS: We investigated the relationship between circulating monocytes and cardiovascular risk progression in people with T2D, using phenotypic, transcriptomic, and metabolomic analyses. cardiovascular risk progression was estimated with coronary artery calcium score in a cohort of 672 people with T2D. RESULTS: Coronary artery calcium score was positively correlated with blood monocyte count and frequency of the classical monocyte subtype. Unsupervised k-means clustering based on monocyte subtype profiles revealed 3 main endotypes of people with T2D at varying risk of cardiovascular events. These observations were confirmed in a validation cohort of 279 T2D participants. The predictive association between monocyte count and major adverse cardiovascular events was validated through an independent prospective cohort of 757 patients with T2D. Integration of monocyte transcriptome analyses and plasma metabolomes showed a disruption of mitochondrial pathways (tricarboxylic acid cycle, oxidative phosphorylation pathway) that underlined a proatherogenic phenotype. CONCLUSIONS: In this study, we provide evidence that frequency and monocyte phenotypic profile are closely linked to cardiovascular risk in patients with T2D. The assessment of monocyte frequency and count is a valuable predictive marker for risk of cardiovascular events in patients with T2D. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04353869.


Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Humanos , Monocitos/metabolismo , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Factores de Riesgo , Estudios Prospectivos , Calcio/metabolismo , Fenotipo , Factores de Riesgo de Enfermedad Cardiaca
2.
Cells ; 11(24)2022 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-36552823

RESUMEN

Identified across multiple psychiatric disorders, the dopamine (DA) transporter (DAT) Ala559Val substitution triggers non-vesicular, anomalous DA efflux (ADE), perturbing DA neurotransmission and behavior. We have shown that DAT Val559 mice display a waiting impulsivity and changes in cognitive performance associated with enhanced reward motivation. Here, utilizing a within-subject, lever-pressing paradigm designed to bias the formation of goal-directed or habitual behavior, we demonstrate that DAT Val559 mice modulate their nose poke behavior appropriately to match context, but demonstrate a perseverative checking behavior. Although DAT Val559 mice display no issues with the cognitive flexibility required to acquire and re-learn a visual pairwise discrimination task, devaluation of reward evoked habitual reward seeking in DAT Val559 mutants in operant tasks regardless of reinforcement schedule. The direct DA agonist apomorphine also elicits locomotor stereotypies in DAT Val559, but not WT mice. Our observation that dendritic spine density is increased in the dorsal medial striatum (DMS) of DAT Val559 mice speaks to an imbalance in striatal circuitry that might underlie the propensity of DAT Val559 mutants to exhibit compulsive behaviors when reward is devalued. Thus, DAT Val559 mice represent a model for dissection of how altered DA signaling perturbs circuits that normally balance habitual and goal-directed behaviors.


Asunto(s)
Trastornos Mentales , Ratones , Masculino , Animales , Conducta Compulsiva , Recompensa , Cuerpo Estriado , Motivación
3.
Cancers (Basel) ; 14(19)2022 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-36230761

RESUMEN

Purpose: Prediction of treatment response to androgen deprivation therapy (ADT) prior to treatment initiation remains difficult. This study was undertaken to investigate whether 68Ga-PSMA-11 PET/CT features extracted from different radiomic zones within the prostate gland might predict response to ADT in patients with advanced prostate cancer (PCa). Methods: A total of 35 patients with prostate adenocarcinoma underwent two 68Ga-PSMA-11 PET/CT scans­termed PET-1 and PET-2­before and after 3 months of ADT, respectively. The prostate was divided into three radiomic zones, with zone-1 being the metabolic tumor zone, zone-2 the proximal peripheral tumor zone, and zone-3 the extended peripheral tumor zone. Patients in the response group were those who showed a reduction ratio > 30% for PET-derived parameters measured at PET-1 and PET-2. The remaining patients were classified as non-responders. Results: Seven features (glcm_idmn, glcm_idn, glcm_imc1, ngtdm_Contrast, glrlm_rln, gldm_dn, and shape_MeshVolume) from zone-1, two features (gldm_sdlgle and shape_MinorAxisLength) from zone-2, and two features (diagnostics_Mask-interpolated_Minimum and shape_Sphericity) from zone-3 successfully distinguished responders from non-responders to ADT. One predictive feature (shape_SurfaceVolumeRatio) was consistently identified in all of the three zones. Conclusions: this study demonstrates the potential usefulness of radiomic features extracted from different prostatic zones in distinguishing responders from non-responders prior to ADT initiation.

4.
Med Phys ; 48(9): 5192-5201, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34214211

RESUMEN

PURPOSE: In most radiomic studies related to cancer research, the traditional tumor-centric view has predominated. In this retrospective study, we go beyond the single-tumor region and investigate the utility of proposed radiomic zones for risk classification and clinical outcome predictions using radiomic features extracted from 11 C-choline positron emission tomography (PET) imaging and supervised machine learning in prostate tumors. MATERIALS AND METHODS: Seventy-seven prostate tumors were selected and delineated. The prostate organ was divided into three radiomic zones, with zone-1 being the metabolic tumor zone, zone-2 the proximal peripheral tumor zone, and zone-3 the extended peripheral tumor zone. LIFEx was used for PET-radiomic feature extraction. Risk groups were created using Gleason scores (GS), prostate-specific antigen (PSA) levels, clinical TNM staging, and progression-free survival (PFS). Random forest (RF) and AdaBoost advanced machine learning algorithms were used for supervised machine learning. Accuracy, positive predictive value, area under the receiver operating characteristic curve (AreaROC), and other metrics were calculated for comparisons of predictive performance between zones. RESULTS: For the GS risk classification group, the accuracies of risk classification predictions were 71%, 71%, and 67% using RF and 65%, 64%, and 63% using AdaBoost for zones -1, -2, and -3, respectively. For the PSA group, the accuracies of risk classification predictions were 74%, 65%, and 64% using RF and 76%, 66%, and 67% using AdaBoost for zones -1, -2, and -3, respectively. For the TNM group, the accuracies of risk classification predictions were 68%, 76%, and 78% using RF and 66%, 75%, and 80% using AdaBoost for zones -1, -2, and -3, respectively. For the PFS group, the accuracies of clinical outcome predictions were 77%, 75%, and 83% using RF and 77%, 74%, and 83% using AdaBoost in zones -1, -2, and -3, respectively. CONCLUSIONS: We proposed three radiomic zones with different standard uptake value characteristics and created four risk groups of prostate cancer patients for testing this idea. We showed that these radiomic zones have different predicting strengths in classifying risk groups and might allow us to identify a radiomic zone with higher accuracy for patient outcome prediction.


Asunto(s)
Colina , Neoplasias de la Próstata , Humanos , Imagen por Resonancia Magnética , Masculino , Tomografía de Emisión de Positrones , Neoplasias de la Próstata/diagnóstico por imagen , Estudios Retrospectivos , Aprendizaje Automático Supervisado
5.
Ground Water ; 58(6): 1012-1022, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32500931

RESUMEN

The coastal aquifers and inland waters of the Long Xuyen Quadrangle and Ca Mau Peninsula of southern Vietnam have been significantly impacted by sea water intrusion (SI) as a result of recent anthropogenic activities. This study identified the evolution and spatial distribution of hydrochemical conditions in coastal aquifers at this region using Hydrochemical Facies Evolution Diagram (HFE-D) and Geographical Information System mapping. Hydraulic heads and water chemistry were measured at 31 observation wells in four layered aquifers during dry and rainy seasons in early (2005), and more recent (2016), stages of agricultural development. Hydrochemical facies associated with intrusion or freshening stages were mapped in each aquifer after assigning mixing index values to each facies. The position of groundwater freshening and SI phases differed in Holocene, Upper Pleistocene, Middle Pleistocene, and Lower Pleistocene aquifers. The geographic position of freshening and intrusion fronts differ in dry and rainy seasons, and shifted after 11 years of groundwater abstraction in all four aquifers. The spatial and temporal differences in hydrochemical facies distributions according to HFE-D reflect the relative impact of SI in the four aquifers. The study results provide a better understanding of the evolution of groundwater quality associated with SI in a peninsular coastal aquifer system, and highlight the need for improving groundwater quality and management in similar coastal regions.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Facies , Proteína de la Hemocromatosis , Humanos , Agua de Mar , Vietnam , Contaminantes Químicos del Agua/análisis
6.
Development ; 147(8)2020 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-32122991

RESUMEN

The Drosophila male germline stem cell (GSC) lineage provides a great model to understand stem cell maintenance, proliferation, differentiation and dedifferentiation. Here, we use the Drosophila GSC lineage to systematically analyze the transcriptome of discrete but continuously differentiating germline cysts. We first isolated single cysts at each recognizable stage from wild-type testes, which were subsequently applied for RNA-seq analyses. Our data delineate a high-resolution transcriptome atlas in the entire male GSC lineage: the most dramatic switch occurs from early to late spermatocyte, followed by the change from the mitotic spermatogonia to early meiotic spermatocyte. By contrast, the transit-amplifying spermatogonia cysts display similar transcriptomes, suggesting common molecular features among these stages, which may underlie their similar behavior during both differentiation and dedifferentiation processes. Finally, distinct differentiating germ cell cyst samples do not exhibit obvious dosage compensation of X-chromosomal genes, even considering the paucity of X-chromosomal gene expression during meiosis, which is different from somatic cells. Together, our single cyst-resolution, genome-wide transcriptional profile analyses provide an unprecedented resource to understand many questions in both germ cell biology and stem cell biology fields.


Asunto(s)
Linaje de la Célula/genética , Drosophila melanogaster/citología , Drosophila melanogaster/genética , Perfilación de la Expresión Génica , Células Germinativas/citología , Células Madre/citología , Animales , Diferenciación Celular/genética , Bases de Datos Genéticas , Compensación de Dosificación (Genética) , Regulación del Desarrollo de la Expresión Génica , Masculino , Meiosis/genética , Mitosis/genética , Familia de Multigenes , Reproducibilidad de los Resultados , Espermatocitos/citología , Espermatocitos/metabolismo , Espermatogénesis/genética , Transcripción Genética , Transcriptoma/genética
7.
PLoS One ; 12(6): e0179616, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28662105

RESUMEN

We previously reported a significant reduction in the prevalence of human immunodeficiency virus type 1 (HIV) from 2007 to 2012 in people who inject drugs (PWID; 35.9% to 18.5%, p < 0.001) and female sex workers (FSW; 23.1% to 9.8%, p < 0.05), but not in blood donors (BD) or pregnant women, in Haiphong, Vietnam. Our aim in the present study was to assess trends in the prevalence of infection with hepatitis B and C viruses (HBV and HCV, respectively). We also investigated the coinfection rates of HBV and HCV with HIV in the same groups. Between 2007 and 2012, HBV prevalence was significantly decreased in BD (18.1% vs. 9.0%, p = 0.007) and slightly decreased in FSW (11.0% vs. 3.9%, p = 0.21), but not in PWID (10.7% vs. 11.1%, p = 0.84). HCV prevalence was significantly decreased in PWID (62.1% in 2007 vs. 42.7% in 2008, p < 0.0001), but it had rebounded to 58.4% in 2012 (2008 vs. 2012, p < 0.0001). HCV prevalence also increased in FSW: 28.6% in 2007 and 2009 vs. 35.3% in 2012; however, this difference was not significant (2007 vs. 2012, p = 0.41). Rates of coinfection with HBV and HCV among HIV-infected PWID and FSW did not change significantly during the study period. Our findings suggest that the current harm reduction programs designed to prevent HIV transmission in PWID and FSW may be insufficient to prevent the transmission of hepatitis viruses, particularly HCV, in Haiphong, Vietnam. New approaches, such as the introduction of catch-up HBV vaccination to vulnerable adult populations and the introduction of HCV treatment as prevention, should be considered to reduce morbidity and mortality due to HIV and hepatitis virus coinfection in Vietnam.


Asunto(s)
Infecciones por VIH/epidemiología , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Adulto , Femenino , Humanos , Masculino , Prevalencia , Trabajo Sexual , Abuso de Sustancias por Vía Intravenosa , Vietnam/epidemiología , Adulto Joven
8.
Trends Cell Biol ; 27(7): 527-540, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28268050

RESUMEN

Asymmetric cell division (ACD) gives rise to two daughter cells with distinct fates. ACD is widely used during development and by many types of adult stem cells during tissue homeostasis and regeneration. ACD can be regulated by extrinsic cues, such as signaling molecules, as well as by intrinsic factors, such as organelles and cortex proteins. The recent discovery of asymmetric histone inheritance during stem cell ACD has revealed another intrinsic mechanism by which ACD produces two distinct daughters. In this review we discuss these findings in the context of cell-cycle regulation, as well as other studies of ACD, to begin understanding the underlying mechanisms and biological relevance of this phenomenon.


Asunto(s)
Histonas/metabolismo , Células Madre/metabolismo , División Celular Asimétrica , Humanos
9.
Phys Rev Lett ; 116(19): 191602, 2016 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-27232016

RESUMEN

We use the soft-collinear bootstrap to construct the 8-loop integrand for the 4-point amplitude and 4-stress-tensor correlation function in planar maximally supersymmetric Yang-Mills theory. Both have a unique representation in terms of planar, conformal integrands grouped according to a hidden symmetry discovered for correlation functions. The answer we find exposes a fundamental tension between manifest locality and planarity with manifest conformality not seen at lower loops. For the first time, the integrand must include terms that are finite even on-shell and terms that are divergent even off-shell (so-called pseudoconformal integrals). We describe these novelties and their consequences in this Letter, and we make the full correlator and amplitude available as part of the Supplemental Material.

10.
Cell ; 163(4): 920-33, 2015 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-26522592

RESUMEN

A long-standing question concerns how stem cells maintain their identity through multiple divisions. Previously, we reported that pre-existing and newly synthesized histone H3 are asymmetrically distributed during Drosophila male germline stem cell (GSC) asymmetric division. Here, we show that phosphorylation at threonine 3 of H3 (H3T3P) distinguishes pre-existing versus newly synthesized H3. Converting T3 to the unphosphorylatable residue alanine (H3T3A) or to the phosphomimetic aspartate (H3T3D) disrupts asymmetric H3 inheritance. Expression of H3T3A or H3T3D specifically in early-stage germline also leads to cellular defects, including GSC loss and germline tumors. Finally, compromising the activity of the H3T3 kinase Haspin enhances the H3T3A but suppresses the H3T3D phenotypes. These studies demonstrate that H3T3P distinguishes sister chromatids enriched with distinct pools of H3 in order to coordinate asymmetric segregation of "old" H3 into GSCs and that tight regulation of H3T3 phosphorylation is required for male germline activity.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Histonas/metabolismo , Espermatogénesis , Animales , Proteínas de Drosophila/química , Drosophila melanogaster/citología , Células Germinativas/citología , Células Germinativas/metabolismo , Histonas/química , Masculino , Mitosis , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Células Madre/citología , Células Madre/metabolismo , Testículo/metabolismo , Treonina/metabolismo
11.
AIDS Res Hum Retroviruses ; 31(7): 757-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25970090

RESUMEN

We previously reported a significant decrease in HIV-1 prevalence, with no increase in drug-resistant HIV-1 among injecting drug users (IDU), female sex workers (FSW), and blood donors (BD), in Haiphong, Vietnam, from 2007 to 2009. In 2012, 388 IDU, 51 FSW, and 200 BD were recruited for further analysis. None had a history of antiretroviral treatment. From 2007 to 2012, HIV-1 prevalence was reduced from 35.9% to 18.6% (p<0.001), 23.1% to 9.8% (p<0.05), and 2.9% to 1% (p=0.29) in IDU, FSW, and BD, respectively. Of 79 anti-HIV-1 antibody-positive samples, 61 were successfully analyzed for the pol-reverse transcriptase (RT) region. All HIV-1 strains were CRF01_AE. Nonnucleoside RT inhibitor-resistant mutations, Y181C/I, were detected in three subjects; one had the nucleoside RT inhibitor-resistant mutations L74V and M184V and one had E138K. The prevalence of transmitted drug-resistant HIV-1 in Haiphong increased slightly from 1.8% in 2007 to 6.6% in 2012 (p=0.06).


Asunto(s)
Farmacorresistencia Viral , Genotipo , Infecciones por VIH/epidemiología , Infecciones por VIH/virología , VIH-1/clasificación , VIH-1/genética , Epidemiología Molecular , Adulto , Donantes de Sangre , Transmisión de Enfermedad Infecciosa , Femenino , Variación Genética , Infecciones por VIH/transmisión , Transcriptasa Inversa del VIH/genética , VIH-1/aislamiento & purificación , Humanos , Masculino , Datos de Secuencia Molecular , Mutación Missense , Prevalencia , Análisis de Secuencia de ADN , Trabajo Sexual , Abuso de Sustancias por Vía Intravenosa , Vietnam/epidemiología
12.
Chromosome Res ; 21(3): 255-69, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23681658

RESUMEN

It has long been known that epigenetic changes are inheritable. However, except for DNA methylation, little is known about the molecular mechanisms of epigenetic inheritance. Many types of stem cells undergo asymmetric cell divisions to generate self-renewed stem cells and daughter cells committed for differentiation. Still, whether and how stem cells retain their epigenetic memory remain questions to be elucidated. During the asymmetric division of Drosophila male germline stem cell (GSC), our recent studies revealed that the preexisting histone 3 (H3) are selectively segregated to the GSC, whereas newly synthesized H3 deposited during DNA replication are enriched in the differentiating daughter cell. We propose a two-step model to explain this asymmetric histone distribution. First, prior to mitosis, preexisting histones and newly synthesized histones are differentially distributed at two sets of sister chromatids. Next, during mitosis, the set of sister chromatids that mainly consist of preexisting histones are segregated to GSCs, while the other set of sister chromatids enriched with newly synthesized histones are partitioned to the daughter cell committed for differentiation. In this review, we apply current knowledge about epigenetic inheritance and asymmetric cell division to inform our discussion of potential molecular mechanisms and the cellular basis underlying this asymmetric histone distribution pattern. We will also discuss whether this phenomenon contributes to the maintenance of stem cell identity and resetting chromatin structure in the other daughter cell for differentiation.


Asunto(s)
División Celular Asimétrica , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Células Germinativas/citología , Histonas/metabolismo , Células Madre/citología , Animales , División Celular Asimétrica/genética , Drosophila melanogaster/genética , Epigénesis Genética , Masculino , Células Madre/metabolismo
13.
J Med Virol ; 85(6): 1069-76, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23588734

RESUMEN

Human papillomavirus (HPV) has several intragenotypic variants with different geographical and ethnic distributions. This study aimed to elucidate the distribution patterns of E6 and E7 (E6/E7) intragenotypic variants of HPV type 16 (HPV-16), which is most common worldwide, and HPV-52, which is common in Asian countries such as Japan, the Philippines, and Vietnam. In previous studies, genomic DNA samples extracted from cervical swabs were collected from female sex workers in these three countries and found to be positive for HPV-16 or HPV-52. Samples were amplified further for their E6/E7 genes using type-specific primers and analyzed genetically. Seventy-nine HPV-16 E6/E7 genes were analyzed successfully and grouped into three lineages: European (Prototype), European (Asian), and African-2. The prevalences of HPV-16 European (Prototype)/European (Asian) lineages were 19.4%/80.6% (n = 31) in Japan, 75.0%/20.8% (n = 24) in the Philippines, and 0%/95.8% (n = 24) in Vietnam. The 109 HPV-52 E6/E7 genes analyzed successfully were grouped into four lineages, A-D; the prevalences of lineages A/B/C/D were, respectively, 5.1%/92.3%/0%/2.6% in Japan (n = 39), 34.4%/62.5%/0%/3.1% in the Philippines (n = 32), and 15.8%/73.7%/7.9%/2.6% in Vietnam (n = 38). The distribution patterns of HPV-16 and HPV-52 lineages in these countries differed significantly (P < 0.000001 and P = 0.0048, respectively). There was no significant relationship between abnormal cervical cytology and either HPV-16 E6/E7 lineages or specific amino acid mutations, such as E6 D25E, E6 L83V, and E7 N29S. Analysis of HPV-16 and HPV-52 E6/E7 genes can be a useful molecular-epidemiological tool to distinguish geographical diffusion routes of these HPV types in Asia.


Asunto(s)
Proteínas Oncogénicas Virales/genética , Papillomaviridae/genética , Proteínas E7 de Papillomavirus/genética , Infecciones por Papillomavirus/epidemiología , Proteínas Represoras/genética , Adolescente , Adulto , Anciano , Pueblo Asiatico , Población Negra , Femenino , Humanos , Japón/epidemiología , Persona de Mediana Edad , Proteínas Oncogénicas Virales/clasificación , Papillomaviridae/clasificación , Papillomaviridae/aislamiento & purificación , Proteínas E7 de Papillomavirus/clasificación , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/etnología , Infecciones por Papillomavirus/virología , Filipinas/epidemiología , Filogenia , Embarazo , Prevalencia , Proteínas Represoras/clasificación , Vietnam/epidemiología , Población Blanca
14.
J Med Virol ; 85(2): 288-94, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23161344

RESUMEN

Vaccines against two high-risk human papillomavirus (HPV) types, HPV-16, and HPV-18, are in use currently, with high efficacy for preventing infections with these HPV types and consequent cervical cancers. However, circulating HPV types can vary with geography and ethnicity. The aim of this study was to investigate the prevalence of HPV types and the association between HPV types and abnormal cervical cytology among female sex workers in Northern Vietnam. Cervical swabs and plasma samples were collected from 281 female sex workers at two health centers in Hanoi and Hai Phong in 2009. The HPV L1 gene was amplified by PCR using original and modified GP5(+)/6(+) primers. Amplified PCR products were genotyped by the microarray system GeneSquare (KURABO) and/or clonal sequencing. Of the 281 women, 139 (49.5%) were positive for HPV DNA. Among the HPV-positive samples, 339 strains and 29 different types were identified. Multiple-type and high risk-type HPV infections were found in 85 (61.2%) and 124 (89.2%) women, respectively. The most common genotype was HPV-52, followed by HPV-16, HPV-18, and HPV-58. Abnormal cervical cytology was detected in 3.2% (9/281) of the women, and all of these samples were positive for HPV-DNA. Age ≤25 years and infection with human immunodeficiency virus were associated positively with HPV infection among the women while ever smoking was associated negatively. These results show that HPV-52 is most prevalent among female sex workers in Northern Vietnam, most of whom had normal cervical cytology. This information may be important for designing vaccination strategies in Vietnam.


Asunto(s)
Papillomaviridae/clasificación , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Trabajadores Sexuales , Adolescente , Adulto , Cuello del Útero/patología , Estudios Transversales , Técnicas Citológicas , ADN Viral/química , ADN Viral/genética , Femenino , Genotipo , Humanos , Análisis por Micromatrices , Datos de Secuencia Molecular , Papillomaviridae/genética , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN , Vietnam/epidemiología , Adulto Joven
15.
Science ; 338(6107): 679-82, 2012 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-23118191

RESUMEN

Stem cells can self-renew and generate differentiating daughter cells. It is not known whether these cells maintain their epigenetic information during asymmetric division. Using a dual-color method to differentially label "old" versus "new" histones in Drosophila male germline stem cells (GSCs), we show that preexisting canonical H3, but not variant H3.3, histones are selectively segregated to the GSC, whereas newly synthesized histones incorporated during DNA replication are enriched in the differentiating daughter cell. The asymmetric histone distribution occurs in GSCs but not in symmetrically dividing progenitor cells. Furthermore, if GSCs are genetically manipulated to divide symmetrically, this asymmetric mode is lost. This work suggests that stem cells retain preexisting canonical histones during asymmetric cell divisions, probably as a mechanism to maintain their unique molecular properties.


Asunto(s)
División Celular Asimétrica , Proteínas de Drosophila/metabolismo , Células Germinativas/citología , Células Germinativas/metabolismo , Histonas/metabolismo , Células Madre/citología , Células Madre/metabolismo , Animales , Animales Modificados Genéticamente , Diferenciación Celular , Drosophila , Epigénesis Genética , Masculino
16.
J Vis Exp ; (61)2012 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-22473446

RESUMEN

Epigenetics remains a rapidly developing field that studies how the chromatin state contributes to differential gene expression in distinct cell types at different developmental stages. Epigenetic regulation contributes to a broad spectrum of biological processes, including cellular differentiation during embryonic development and homeostasis in adulthood. A critical strategy in epigenetic studies is to examine how various histone modifications and chromatin factors regulate gene expression. To address this, Chromatin Immunoprecipitation (ChIP) is used widely to obtain a snapshot of the association of particular factors with DNA in the cells of interest. ChIP technique commonly uses cultured cells as starting material, which can be obtained in abundance and homogeneity to generate reproducible data. However, there are several caveats: First, the environment to grow cells in Petri dish is different from that in vivo, thus may not reflect the endogenous chromatin state of cells in a living organism. Second, not all types of cells can be cultured ex vivo. There are only a limited number of cell lines, from which people can obtain enough material for ChIP assay. Here we describe a method to do ChIP experiment using Drosophila tissues. The starting material is dissected tissue from a living animal, thus can accurately reflect the endogenous chromatin state. The adaptability of this method with many different types of tissue will allow researchers to address a lot more biologically relevant questions regarding epigenetic regulation in vivo(1, 2). Combining this method with high-throughput sequencing (ChIP-seq) will further allow researchers to obtain an epigenomic landscape.


Asunto(s)
Inmunoprecipitación de Cromatina/métodos , Drosophila/química , Animales , ADN/análisis , ADN/genética , Drosophila/genética , Ensayos Analíticos de Alto Rendimiento/métodos
17.
AIDS Res Hum Retroviruses ; 28(10): 1349-51, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22264087

RESUMEN

We reported previously that the prevalence of drug-resistant HIV-1 among antiretroviral therapy (ART)-naive individuals in Northern Vietnam was 2.9% in 2007 and 6.2% in 2008. To investigate the continuing trend of prevalence, we collected plasma samples from 958 individuals in Hai Phong and Hanoi in 2009, extracted viral RNA from HIV-1 antibody-positive samples, and analyzed them genetically. HIV-1 antibody prevalence was 26.8% in injecting drug users (n=302), 13.4% in female sex workers (n=284), 0.5% in blood donors (n=206), and 0.6% in pregnant women (n=166). All HIV-1 strains were CRF01_AE. Nonnucleoside reverse-transcriptase inhibitor resistance mutations were found in two (2.0%) of the 102 successfully analyzed cases (one case with the Y181C and one with the K101E). No nucleoside reverse-transcriptase inhibitor resistance or protease inhibitor resistance mutations were detected. The prevalence of circulating ART-resistant HIV-1 in Northern Vietnam did not increase from 2007 to 2009, although the rate of ART coverage did increase.


Asunto(s)
Farmacorresistencia Viral/genética , Inhibidores de la Proteasa del VIH/uso terapéutico , Seropositividad para VIH/tratamiento farmacológico , VIH-1/efectos de los fármacos , VIH-1/genética , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Productos del Gen pol del Virus de la Inmunodeficiencia Humana/genética , Adulto , Donantes de Sangre/estadística & datos numéricos , Consumidores de Drogas/estadística & datos numéricos , Femenino , Genotipo , Seropositividad para VIH/epidemiología , VIH-1/patogenicidad , Humanos , Masculino , Datos de Secuencia Molecular , Mutación Missense/genética , Filogenia , Embarazo , Prevalencia , ARN Viral , Vigilancia de Guardia , Trabajadores Sexuales/estadística & datos numéricos , Vietnam/epidemiología
18.
Nature ; 480(7375): 123-7, 2011 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-22037307

RESUMEN

Endocycles are variant cell cycles comprised of DNA synthesis (S)- and gap (G)-phases but lacking mitosis. Such cycles facilitate post-mitotic growth in many invertebrate and plant cells, and are so ubiquitous that they may account for up to half the world's biomass. DNA replication in endocycling Drosophila cells is triggered by cyclin E/cyclin dependent kinase 2 (CYCE/CDK2), but this kinase must be inactivated during each G-phase to allow the assembly of pre-Replication Complexes (preRCs) for the next S-phase. How CYCE/CDK2 is periodically silenced to allow re-replication has not been established. Here, using genetic tests in parallel with computational modelling, we show that the endocycles of Drosophila are driven by a molecular oscillator in which the E2F1 transcription factor promotes CycE expression and S-phase initiation, S-phase then activates the CRL4(CDT2) ubiquitin ligase, and this in turn mediates the destruction of E2F1 (ref. 7). We propose that it is the transient loss of E2F1 during S phases that creates the window of low Cdk activity required for preRC formation. In support of this model overexpressed E2F1 accelerated endocycling, whereas a stabilized variant of E2F1 blocked endocycling by deregulating target genes, including CycE, as well as Cdk1 and mitotic cyclins. Moreover, we find that altering cell growth by changing nutrition or target of rapamycin (TOR) signalling impacts E2F1 translation, thereby making endocycle progression growth-dependent. Many of the regulatory interactions essential to this novel cell cycle oscillator are conserved in animals and plants, indicating that elements of this mechanism act in most growth-dependent cell cycles.


Asunto(s)
Ciclo Celular/fisiología , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/enzimología , Factores de Transcripción E2F/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Animales , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/metabolismo , Femenino , Masculino , Fase S/fisiología , Glándulas Salivales/citología , Factores de Transcripción , Complejos de Ubiquitina-Proteína Ligasa
19.
Dis Esophagus ; 23(4): 324-8, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-19863643

RESUMEN

To assess feasibility and tolerance of a modification in the usual radiochemotherapy regimen for esophageal cancer by using a leucovorin, 5-fluorouracil bolus, and infusion-cisplatin regimen (six cycles), beginning with two cycles of chemotherapy before conventional radiotherapy (50 Gy), 33 patients, 30 were men, 62.8 +/- 9.5 years, were treated for an esophageal carcinoma (29 squamous cell), 27 of these were in stage III (based on computed tomography scan). Neoadjuvant chemotherapy was well tolerated; concomitant radiochemotherapy was associated with severe adverse events mostly hematological in 23 patients. Complete response was achieved in 70%; median overall survival was 14 months, and 2-year survival was 40 +/- 11%. More than one-third of cycles could be performed as outpatients. This regimen seems safe and efficient, and could be conducted in an outpatient basis.


Asunto(s)
Antineoplásicos/administración & dosificación , Cisplatino/administración & dosificación , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/radioterapia , Fluorouracilo/administración & dosificación , Leucovorina/administración & dosificación , Complejo Vitamínico B/administración & dosificación , Anciano , Quimioterapia Adyuvante , Terapia Combinada , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Proyectos Piloto
20.
Dev Cell ; 15(6): 890-900, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19081076

RESUMEN

E2F transcription factors are key regulators of cell proliferation that are inhibited by pRb family tumor suppressors. pRb-independent modes of E2F inhibition have also been described, but their contribution to animal development and tumor suppression is unclear. Here, we show that S phase-specific destruction of Drosophila E2f1 provides a novel mechanism for cell cycle regulation. E2f1 destruction is mediated by a PCNA-interacting-protein (PIP) motif in E2f1 and the Cul4(Cdt2) E3 ubiquitin ligase and requires the Dp dimerization partner but not direct Cdk phosphorylation or Rbf1 binding. E2f1 lacking a functional PIP motif accumulates inappropriately during S phase and is more potent than wild-type E2f1 at accelerating cell cycle progression and inducing apoptosis. Thus, S phase-coupled destruction is a key negative regulator of E2f1 activity. We propose that pRb-independent inhibition of E2F during S phase is an evolutionarily conserved feature of the metazoan cell cycle that is necessary for development.


Asunto(s)
Proteínas Cullin/metabolismo , Proteínas de Drosophila/metabolismo , Factor de Transcripción E2F1/metabolismo , Regulación de la Expresión Génica , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Ciclo Celular , Drosophila melanogaster , Factor de Transcripción E2F1/química , Modelos Biológicos , Fosforilación , Unión Proteica , Proteína de Retinoblastoma/metabolismo , Fase S , Homología de Secuencia de Aminoácido , Temperatura
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