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1.
Animal ; 16(10): 100628, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36108456

RESUMO

Increasing the productive lifespan of dairy cows is important to achieve a sustainable dairy industry, but making strategic culling decisions based on cow profitability is challenging for farmers. The objective of this study was to carry out a lifetime cost-benefit analysis based on production and health records and to explore different culling decisions among farmers. The cost-benefit analysis was conducted for 22 747 dairy cows across 114 herds in Quebec, Canada for which feed costs and the occurrence of diseases were reported. Costs and revenues related to productive lifespan were compared among cohorts of cows that left their respective herd at the end of their last completed lactation or stayed for a complete additional lactation. Hierarchical clustering analysis was carried out based on costs and revenues to explore different culling decisions among farmers. Our results showed that the knowledge of lifetime cumulative costs and revenues was of great importance to identify low-profitable cows at an earlier lactation, while only focusing on current lactation costs and revenues can lead to an erroneous assessment of profitability. While culling decisions were mostly based on current lactation costs and revenues and disregarded the occurrence of costly events on previous lactations, there was variation among farmers as we identified three different culling decision clusters. Monitoring cumulative costs and revenues would help farmers to identify low-profitable cows at an earlier lactation and make the decision to increase herd productive lifespan and farm profitability by keeping the most profitable cows.


Assuntos
Indústria de Laticínios , Lactação , Animais , Bovinos , Análise Custo-Benefício , Indústria de Laticínios/métodos , Fazendeiros , Feminino , Humanos , Longevidade , Leite
2.
Sci Rep ; 10(1): 4147, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139753

RESUMO

Developing targeted nanoparticles is a rising strategy to improve drug delivery in oncology. Antibodies are the most commonly used targeting agents. However, determination of their optimal number at the surface remains a challenging issue, mainly due to the difficulties in measuring precisely surface coating levels when prototyping nanoparticles. We developed an original quantitative assay to measure the exact number of coated antibodies per nanoparticle. Using flow cytometry optimized for submicron particle analysis and beads covered with known amounts of human IgG-kappa mimicking various amounts of antibodies, this new method was tested as part of the prototyping of docetaxel liposomes coated with trastuzumab against Her2+ breast cancer. This quantification method allowed to discriminate various batches of immunoliposomes depending on their trastuzumab density on nanoparticle surface (i.e., 330 (Immunoliposome-1), 480 (Immunoliposome-2) and 690 (Immunoliposome-3), p = 0.004, One-way ANOVA). Here we showed that optimal number of grafted antibodies on nanoparticles should be finely tuned and highest density of targeting agent is not necessarily associated with highest efficacy. Overall, this new method should help to better prototype third generation nanoparticles.


Assuntos
Docetaxel/química , Lipossomos/química , Trastuzumab/química , Análise de Variância , Citometria de Fluxo , Nanopartículas/química
3.
J Dairy Sci ; 101(9): 8572-8585, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29935823

RESUMO

The objective of this study was to examine the effect of feeding systems [component and total mixed rations (TMR)] and dietary grain sources (barley, commercial concentrate, corn grain, and high-moisture corn) on lactation characteristics and milk composition. A total of 852,242 test-day records, information on animal characteristics, feed composition, and feeding systems from 104,129 Holstein cows in 4,319 herds covering a period of 5 yr were obtained from Quebec's Dairy Herd Improvement Association (Valacta). We performed descriptive statistics and graphical representations of the data for each type of feeding system and grain source by parity (1 to 3). The milk records were binned in 15-d in milk blocks. Mixed models using a combination of forward and backward stepwise selections were developed to predict milk and milk component yields. The TMR-fed cows had greater yield of milk, fat, protein, and lactose and lower milk urea N (MUN) concentration than component-fed cows at all parities. Cows fed a TMR had higher peak milk yields and greater persistency after peak lactation compared with component-fed cows. In addition, greater yields of milk fat and protein from peak to mid-lactation were found in TMR- versus component-fed cows. In general, greater milk fat and protein yields as well as lower MUN concentration were observed in cows fed corn grain or high-moisture corn compared with barley or commercial concentrate, but parity influenced these relationships. The feeding system by day in milk blocks interaction was significant in models of milk and components yields for all parities, but only for second-lactation cows for MUN concentration. This means that effect of TMR and component feeding differs with stage of lactation. In conclusion, feeding TMR and corn-based diets are associated with greater yield of milk and milk components under commercial conditions.


Assuntos
Ração Animal , Indústria de Laticínios/métodos , Lactação/fisiologia , Leite/química , Animais , Bovinos , Indústria de Laticínios/instrumentação , Dieta , Grão Comestível , Feminino , Gravidez , Quebeque , Zea mays
4.
J Neurol Sci ; 373: 335-338, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28131216

RESUMO

BACKGROUND: Rituximab (RTX) is increasingly used in the treatment of neuromyelitis optica spectrum disorder (NMO-SD). Administration regimen is not consensual as there is no reliable biomarker of RTX efficacy. In most cases, after induction, RTX is administered systematically every 6months. OBJECTIVE: To assess efficacy and safety of a maintenance regimen based on CD19+ CD27+ memory B-cell (mBc) detection. METHODS: We conducted a study in two French centers, including patients with NMO-SD who received an induction therapy with RTX. We compared the number of administered infusions, relapses and EDSS depending on two maintenance schemes (S1: administration of 1g RTX infusion every 6months or S2: a scheme based on regular mBc detection. 1g RTX was administered if mBc was >0.05%) RESULTS: 40 patients were included (mean age: 40.2years, F/M sex ratio: 5/1). Aquaporin-4 antibodies were positive in 75% patients. Under S1 regimen, all patients received 2 infusions per year, whereas under S2, they received 1.62 infusion per year. The mean interval between infusions under S2 was 7.4months, without decrease of clinical efficacy. CONCLUSION: In our study, mBc-based administration of RTX allowed personalizing treatment administration and in several cases to lower the cumulative dose without loss of efficacy.


Assuntos
Subpopulações de Linfócitos B/efeitos dos fármacos , Fatores Imunológicos/administração & dosagem , Neuromielite Óptica/tratamento farmacológico , Neuromielite Óptica/imunologia , Medicina de Precisão/métodos , Rituximab/administração & dosagem , Adulto , Antígenos CD19/análise , Aquaporina 4/imunologia , Autoanticorpos/sangue , Subpopulações de Linfócitos B/imunologia , Biomarcadores/sangue , Relação Dose-Resposta a Droga , Esquema de Medicação , Estudos de Viabilidade , Feminino , Humanos , Fatores Imunológicos/efeitos adversos , Memória Imunológica , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva , Rituximab/efeitos adversos , Resultado do Tratamento , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/análise , Adulto Jovem
5.
Int J Lab Hematol ; 39(1): 32-41, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27566136

RESUMO

INTRODUCTION: In daily practice in haematology laboratories, spurious increased MCHC induces an analytical alarm and needs prompt corrective action to ensure delivery of the right results to the clinicians. The aim of this study was to establish a 'decision tree' using the new parameters red blood cells (RBC-O) and haemoglobin (HGB-O) from the Sysmex XN-10 RET obtained by flow cytometry to deliver appropriate results. METHODS: From 128 unknown patients with MCHC > 365 g/L, all erythrocyte parameters including reticulocyte parameters were measured and analysed in parallel with blood smears, chemistry index and osmolarity. Differences between optical parameters (RBC-O, HGB-O) and usual parameters (RBC, HGB) obtained by impedance and photometry were reported also. RESULTS: Four groups were defined from observations: -RBC agglutination (n = 22); -optical interference (n = 17); -RBC disease (n = 18); and -others (n = 71). The use of RBC-O and HGB-O permitted efficient correction of the abnormalities when RBC agglutination and/or optical interference were present in 36 of 39 patients. Reticulocyte parameters permitted to elaborate an RBC score that allowed a highly sensitive detection of RBC disease patients (17/18). CONCLUSION: Based on new parameters, we propose a 'decision tree' that delivers time savings and supports biological interpretation in case of elevated MCHC.


Assuntos
Citometria de Fluxo/métodos , Hemoglobinas/metabolismo , Reticulócitos/metabolismo , Adulto , Feminino , Humanos , Masculino
6.
J Thromb Haemost ; 15(1): 187-193, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27662257

RESUMO

Essentials The clinical enumeration of microparticles (MPs) is hampered by a lack of standardization. A new strategy to standardize MP counts by flow cytometry was evaluated in a multicenter study. No difference was found between instruments using forward or side scatter as the trigger parameter. This study demonstrated that beads can be used as a standardization tool for MPs. Click to hear the ISTH Academy's webinar on microvesicles SUMMARY: Background Microparticles (MPs) are extracellular vesicles resulting from the budding of cellular membranes that have a high potential as emergent biomarkers; however, their clinical relevance is hampered by methodological enumeration concerns and a lack of standardization. Flow cytometry (FCM) remains the most commonly used technique with the best capability to determine the cellular origin of single MPs. However, instruments behave variably depending on which scatter parameter (forward (FSC) or side scatter (SSC)) provides the best resolution to discriminate submicron particles. To overcome this problem, a new approach, based on two sets of selected beads adapted to FSC or SSC-optimized instruments, was recently proposed to reproducibly enumerate platelet-derived MP counts among instruments with different optical systems. Objective The objective was to evaluate this strategy in an international workshop that included 44 laboratories accounting for 52 cytometers of 14 types. Methods/Results Using resolution capability and background noise level as criteria to qualify the instruments, the standardization strategy proved to be compatible with 85% (44/52) of instruments. All instruments correctly ranked the platelet MP (PMP) levels of two platelet-free plasma samples. The inter-laboratory variability of PMP counts was 37% and 28% for each sample. No difference was found between instruments using forward or side-scattered light as the relative sizing parameter. Conclusions Despite remaining limitations, this study is the first to demonstrate a real potential of bead-based strategies for standardization of MP enumeration across different FCM platforms. Additional standardization efforts are still mandatory to evaluate MPs' clinical relevance at a multicenter level.


Assuntos
Micropartículas Derivadas de Células , Citometria de Fluxo/normas , Calibragem , Humanos , Neutrófilos/metabolismo , Tamanho da Partícula , Plasma , Contagem de Plaquetas , Sensibilidade e Especificidade
7.
J Dairy Sci ; 99(11): 9263-9270, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27544853

RESUMO

The purpose was to describe the prevalence and effect of elevated milk ß-hydroxybutyrate (BHB) as detected by routine Fourier-transform infrared analysis in Dairy Herd Improvement milk samples. Data collected over 4 yr included cow information as well as milk yield and composition from 498,310 samples from postparturient Holstein cows (5-35d in milk) from 4,242 herds. The following thresholds were used to classify cows based on their early lactation milk BHB concentration: <0.15mmol/L=negative; 0.15 to 0.19mmol/L=suspect; and ≥0.20mmol/L=positive. Overall prevalence (suspect + positive) was 22.6% and was higher for older cows (18.7, 19.5, and 27.6%, for cows in their first, second, and third or greater lactation, respectively). Distribution with regards to days in milk was different among parity groups, with first-lactation cows having highest prevalence (30%) in the first week after calving; cows in their second and third and greater parity had the highest prevalence in the second week after calving, at 25.8 and 34.6%, respectively. Season of calving affected the prevalence of elevated milk BHB, with cows calving in the fall and spring seasons showing higher prevalence. Distribution among herds was highly variable, as 45% of herds had a prevalence of 20% or less, 47% of herds had a prevalence between 21 and 40%, 6% of herds had a prevalence between 40 and 50%, and 2% of herds had a prevalence of 50% or above. Positive cows had lower milk yield, protein concentration and yield, and lower Transition Cow Index than negative cows, but also higher fat concentration and yield, as well as higher somatic cell count than negative cows. Suspect cows were generally intermediate. The present analysis highlights the opportunity for elevated milk BHB monitoring at the herd level through routine BHB testing in Dairy Herd Improvement milk samples.


Assuntos
Ácido 3-Hidroxibutírico , Leite , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Feminino , Lactação , Prevalência
8.
Trop Biomed ; 33(1): 120-134, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33579149

RESUMO

The increase of the burden of dengue and chikungunya and the relative failure of traditional vector control strategies have highlighted the need to develop new control methods. RIDL-SIT, a vector control method based on the release of engineered male mosquitoes, has shown promising results from field trials conducted in the Cayman Islands and Brazil. In large scale use, a small proportion of females might be released along with the males. Such females are potential virus vectors; here we investigate the vertical transmission of dengue and chikungunya of homozygous OX513A females.We provided females of OX513A-My1 and a wild type comparator strain with blood meals artificially infected with dengue serotype 1, 2, 3, 4 or chikungunya viruses. For 14 days post-feeding, eggs laid by females were collected. Larvae and their mothers were first tested by qRT-PCR, then by inoculation on cell cultures to search for infectious viral particles. We found no significant difference between the minimum infection rate of OX513A-My1 and wild type females. We also discussed the potential number of females being released, a fraction of the female wild population. Consequently, we conclude that there are no evidence that OX513A-My females, if released into the environment, would cause more harm than their wild counterparts.

9.
Cytometry A ; 89(2): 148-58, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25963580

RESUMO

Clinical determination of MP counts using flow cytometry has not been fully accepted yet due to the lack of standardization protocols. In the past 5 years, we have proposed two versions of a method with reproducible PMP counts in plasma samples. Both methods use forward scatter (FSC)-based threshold set with reference beads of appropriate sizes; first using 0.5 µm beads and later with 0.3 µm beads. Both systems provide reproducible PMP counts. However, this technique works only with some of currently used commercial flow cytometers. Instruments with limited resolution or generating heterogeneous FSC signals are excluded. Such performances are incompatible with the required interinstrument standardization. Here we show that (i) flow cytometers with sub-optimal FSC capabilities generally have higher SSC resolution and background rejection capacity, and (ii) that the same biological entities, "dim and bright PMP," both can be counted using alternative strategies, either as previously described, based on FSC measurements, or as presented here, based on SSC detection. The critical element in the standardization protocol is the use of different sizes of reference beads. This study was designed to permit simultaneous access to both FSC- and SSC-optimized platforms. A new range of about 0.17-0.6 µm eq. (µm-equivalents) is proposed for an alternative SSC-based MP gate generating the same PMP counts as those obtained in the previously proposed 0.3-1 µm eq. FSC-based MP gate. The two equivalent standardization options reconcile intrinsically different scattering behaviors between SSC- and FCS--triggered instruments and open the opportunity for multicenter studies in the future.


Assuntos
Micropartículas Derivadas de Células/fisiologia , Citometria de Fluxo/métodos , Plaquetas/fisiologia , Citometria de Fluxo/normas , Humanos , Luz , Contagem de Plaquetas , Padrões de Referência , Espalhamento de Radiação
10.
J Dairy Sci ; 98(3): 2063-73, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25597973

RESUMO

In Québec first calving occurs on average at 27 mo, whereas the target is 23 to 24.5 mo to maximize herd profitability. The aim of this study was to quantify current and future heifer growth using individual heifer random regressions and to generate indicators (such as heifer weight and height at 15 and 24 mo, average daily gain before and after 15 mo, age at which optimal weight for breeding is attained, i.e., 55% of mature weight, and reliability of the 15- and 24-mo weight predictions) that could be used as a practical on-farm tool. Dairy heifer weight estimated by heart girth circumference and height measured at the withers (from 0 to 27 mo) were obtained from the Valacta database (DHI agency, Ste-Anne-de-Bellevue, QC, Canada) from 1995 to 2012. Indicators were calculated based on the current situation of Holstein (HO), Ayrshire (AY), Jersey (JE), and Brown Swiss (BS) heifer growth in Québec. Heifers with less than 2 records were excluded from the analysis. Mature weights were determined by weight at calving of cows from third or greater lactation for a given breed and were 710 kg for HO, 625 kg for AY, 470 kg for JE, and 670 kg for BS. Estimated weights at 15 and 24 mo were 425 and 627, 334 and 482, 297 and 429, and 379 and 560 kg for HO, AY, JE, and BS, respectively, which are heavy enough for breeding and calving, except for AY. Relative reliabilities of the 15- and 24-mo weight predictions were on average 89 and 60%, respectively, based on measurements up to 15 mo. For HO, AY, JE, and BS, wither heights at 15 and 24 mo were 134 and 143, 125 and 134, 122 and 131, and 130 and 140 cm, respectively. Age at optimal breeding weight was 13.6, 15.5, 12.6, and 14.5 mo for HO, AY, JE, and BS, respectively. These data suggest that it is realistic to expect a first calving at 24 mo for HO, JE, and BS. A growth delay was observed for AY; average daily gain was 655 and 538 g/d before and after 15 mo, respectively. The average daily gain before and after 15 mo was 848 and 747 g/d for HO, 603 and 486 g/d for JE, and 775 and 662 g/d for BS, respectively. These indicators could be calculated for an individual heifer and on a herd-level basis and used on farm as a management tool for reducing age at first breeding and at first calving.


Assuntos
Tamanho Corporal , Bovinos/fisiologia , Indústria de Laticínios/métodos , Reprodução , Fatores Etários , Animais , Bovinos/crescimento & desenvolvimento , Indústria de Laticínios/economia , Feminino , Modelos Econômicos , Quebeque , Análise de Regressão , Reprodutibilidade dos Testes
11.
J Thromb Haemost ; 12(10): 1601-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25088020

RESUMO

BACKGROUND: Autoimmune thrombotic thrombocytopenic purpura (AI-TTP) is characterized by an excess of circulating ultralarge von Willebrand factor (VWF) caused by anti-ADAMTS-13 autoantibodies. Animal studies, however, have shown that endothelial cell activation may also be an important trigger of AI-TTP. OBJECTIVES: To prospectively study circulating biomarkers of endothelial lesion and activation, such as circulating endothelial cells (CECs), soluble P-selectin (sP-selectin), or VWF, and of endothelial repair, such as circulating progenitor cells (CPCs) and endothelial progenitor cells (EPCs), in AI-TTP, in relation to disease severity and prognosis. RESULTS: Twenty-two patients were included in this study. CEC (P < 0.01), VWF (P < 0.05) and sP-selectin (P < 0.01) levels were significantly increased during crisis, and returned to baseline levels during remission. Both CEC (P < 0.05) and sP-selectin (P < 0.05) levels were significantly higher in patients who died or developed neurologic sequelae. CPC levels were substantially increased during the acute phase of the disease (P < 0.001), and returned to baseline levels during remission. Among CPCs, EPC levels were also increased during crisis (P < 0.05) and significantly decreased during remission. Patients who received < 16 plasma exchanges (PEs) had significantly higher EPC counts (P < 0.05) than those who needed more numerous PEs to obtain remission, suggesting that initial EPC counts may be associated with faster endothelial repair. CONCLUSION: The profile of circulating endothelial markers shows massive endothelial activation and repair/remodeling during AI-TTP, and suggests that CECs and EPCs may be promising prognostic biomarkers of the disease.


Assuntos
Doenças Autoimunes/sangue , Células Endoteliais/citologia , Púrpura Trombocitopênica Trombótica/sangue , Células-Tronco/citologia , Adulto , Idoso , Doenças Autoimunes/terapia , Biomarcadores/metabolismo , Feminino , França , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Selectina-P/sangue , Prognóstico , Estudos Prospectivos , Púrpura Trombocitopênica Trombótica/terapia , Indução de Remissão , Adulto Jovem , Fator de von Willebrand/metabolismo
12.
J Thromb Haemost ; 11 Suppl 1: 24-35, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23809108

RESUMO

Microparticles (MPs) represent a heterogeneous population of submicronic vesicles that are released in response to cell activation or apoptosis. MPs harbor a large repertoire of cell surface receptors and mRNA and biological activities representative of their parent cells and related to their involvement in many biological functions. Although MP generation is a physiological response, a dramatic increase in circulating MPs is detectable in a variety of thrombosis-associated disorders compared with healthy individuals. In this review, we will discuss a new vision of MPs as complex and ambivalent structures that express both activators and inhibitors of coagulation but also convey fibrinolytic properties. After summarizing our current knowledge about the role of MPs in venous and arterial thrombosis, this review will explore how this new vision of MPs influences their definition as emergent biomarkers in thrombotic diseases. Among the studies that have aimed to establish a link between thrombosis and MPs, a few studies have demonstrated a predictive value of MPs. So far, it is unclear whether this limited causative association is the result of current technical concerns and limited standardization or has to be integrated into a more complex vision of the role of MPs as key systems for regulating the balance between coagulation and fibrinolysis.


Assuntos
Artérias/patologia , Microesferas , Trombose/etiologia , Veias/patologia , Animais , Fibrinólise , Humanos
13.
Bioresour Technol ; 142: 510-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23759434

RESUMO

Here is presented a new design of a floating marine MFC in which the inter-electrode space is constant. This design allows the generation of stable current for applications in environments where the water column is large or subject to fluctuations such as tidal effects. The operation of the first prototype was validated by running a continuous test campaign for 6months. Performance in terms of electricity generation was already equivalent to what is conventionally reported in the literature with basic benthic MFCs despite the identification of a large internal resistance in the proposed design of the floating system. This high internal resistance is mainly explained by poor positioning of the membrane separating the anode compartment from the open seawater. The future objectives are to achieve more consistent performance and a second-generation prototype is now being developed, mainly incorporating a modification of the separator position and a stainless steel biocathode with a large bioavailable surface.


Assuntos
Fontes de Energia Bioelétrica , Biofilmes , Eletrodos , Aço Inoxidável , Aerobiose , Reatores Biológicos
14.
J Thromb Haemost ; 2013 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-23551930

RESUMO

Microparticles (MP) are sub-micron sized vesicles released by activated or apoptotic cells. They are generally defined as 0.1 to 1 µm membrane particles that expose the anionic phospholipid phosphatidylserine (PS) and membrane antigens representative of their cellular origin [1]. It is now well recognized that MP behave as vectors of bioactive molecules, playing a role in blood coagulation, inflammation, cell activation and cancer metastasis. In clinical practice, circulating MP originating from blood and vascular cells are elevated in a variety of prothrombotic and inflammatory disorders, cardiovascular diseases, autoimmune conditions, infectious diseases and cancer [1-3]. © 2013 International Society on Thrombosis and Haemostasis.

15.
Andrology ; 1(3): 421-30, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23536489

RESUMO

During the last phase of spermatogenesis, called spermiogenesis, the nucleosome-based chromatin structure is replaced by a protamine-based DNA packaging. Not much is known about the chromatin remodelling involved in humans and animals. Here, we have investigated initiation of chromatin remodelling over seven probands of which five were diagnosed with non-obstructive azoospermia (NOA) and two with obstructive azoospermia (OA) (failed vaso-vasostomy patients with proven fertility prior to vasectomy, Johnsen scores ≥9). Chromatin remodelling was studied evaluating the presence of nucleosomes, histone H3, pre-protamine 2 and protamine 1. This approach was feasible since the local initiation of nucleosome eviction in the sub acrosomal domain, which was visible in alkaline nuclear spread preparations. The patterns of nucleosome and H3 loss were largely congruent. Nucleus wide incorporation of protamine 1 could already be observed at the late round spermatid stage. Both for nucleosome loss and for protamine 1 incorporation, there was distinct variation within and between probands. This did not relate to the efficiency of sperm production per meiocyte. Pre-protamine 2 was always confined to the subacrosomal domain, confirming the role of this area in chromatin remodelling.


Assuntos
Montagem e Desmontagem da Cromatina , Espermátides/metabolismo , Humanos , Masculino
16.
J Thromb Haemost ; 10(3): 437-46, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22212198

RESUMO

BACKGROUND: Microparticles (MP) are small vesicles of 0.1-1 µm, released in response to activation or apoptosis. Over the past decade, they received an increasing interest both as biomarkers and biovectors in coagulation, inflammation and cancer. Clinical studies were conducted to assess their contribution to the identification of patients at cardiovascular risk. However, among the limitation of such studies, pre-analytical steps remains an important source of variability and artifacts in MP analysis. OBJECTIVES: Because data from the literature are insufficient to establish recommendations, the objective of the present study was to assess the impact of various pre-analytical parameters on MP measurement. These parameters included the type of collection tube, phlebotomy conditions, transportation practices, centrifugation steps and freezing. METHODS: MP were assessed by three methods: flow cytometry using a standardized approach, a thrombin generation test (Calibrated Automated Thrombogram(®)) and a procoagulant phospholipid-dependent clotting time assay (STA(®) -Procoag-PPL). RESULTS: The main results show that the three major pre-analytical parameters which impact on MP-related data are the delay before the first centrifugation, agitation of the tubes during transportation and the centrifugation protocol. CONCLUSIONS: Based on both this work and literature data, we propose a new protocol that needs to be validated on a larger scale before being applied for multicenter studies.


Assuntos
Coagulação Sanguínea , Micropartículas Derivadas de Células/metabolismo , Manejo de Espécimes/normas , Adulto , Anticoagulantes/farmacologia , Biomarcadores/sangue , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea/normas , Centrifugação/normas , Criopreservação/normas , Feminino , Citometria de Fluxo/normas , Congelamento , Humanos , Masculino , Pessoa de Meia-Idade , Flebotomia/normas , Guias de Prática Clínica como Assunto , Trombina/metabolismo , Fatores de Tempo , Adulto Jovem
18.
Trop Biomed ; 28(1): 48-54, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21602768

RESUMO

Ovitrap surveillance was conducted in methodically selected areas in Bentong, Pahang, Malaysia from June 2008 till December 2009 in order to identify insular sites with stable Aedes aegypti population. Eleven sites were surveyed in Bentong district, Pahang, and one of these locations (N3º33' E101º54') was found to have an ovitrap index of Ae. aegypti and Aedes albopictus ranging from 8%-47% and 37%-78% respectively, indicating that this site could be a high-risk area for dengue outbreak. Ae. aegypti larvae were found in both indoor and outdoor ovitraps (p>0.05) while significant difference between the populations of Ae. albopictus larvae from indoors and outdoors was observed (p<0.01). Data collected in this study could provide important entomological information for designing an effective integrated vector control programme to combat Aedes mosquitoes in this area.


Assuntos
Aedes/crescimento & desenvolvimento , Vetores de Doenças , Animais , Dengue/epidemiologia , Dengue/transmissão , Ecossistema , Humanos , Malásia , Densidade Demográfica
19.
Transfus Clin Biol ; 18(2): 62-9, 2011 Apr.
Artigo em Francês | MEDLINE | ID: mdl-21444231

RESUMO

Cell-derived microparticles are complex vesicular structures that can be shedded by activated or apoptotic endothelial cells. Cell-derived microparticles are composed of a phospholipid bilayer that exposes transmembrane proteins and receptors and encloses cytosolic components such as enzymes, transcription factors and mRNA derived from their parent cells. Thus, they behave as biological conveyors playing a key role in the tuning of vascular homeostasis. This review will address the potential of microparticles as efficient vectors of biological activities in pathologies. Based on the model of endothelial vesiculation, the first part of this review will develop the contribution of endothelial microparticles to coagulation inflammation and angiogenesis and their role in vascular disorders. The second part will be focused on the multifaceted impact of cell-derived microparticles present in blood products and its relevance to transfusion medicine.


Assuntos
Micropartículas Derivadas de Células/fisiologia , Inflamação/sangue , Trombose/sangue , Coagulação Sanguínea/fisiologia , Fatores de Coagulação Sanguínea/fisiologia , Transfusão de Componentes Sanguíneos , Preservação de Sangue , Proteínas Sanguíneas/fisiologia , Micropartículas Derivadas de Células/química , Micropartículas Derivadas de Células/transplante , Células Endoteliais/fisiologia , Células Endoteliais/ultraestrutura , Homeostase , Humanos , Terapia de Imunossupressão , Inflamação/etiologia , Neovascularização Fisiológica/fisiologia , Fosfatidilserinas/sangue , Doenças Vasculares/sangue , Doenças Vasculares/patologia
20.
Rev Med Interne ; 32(1): 54-63, 2011 Jan.
Artigo em Francês | MEDLINE | ID: mdl-20541851

RESUMO

Exposure to deleterious processes of metabolic, infectious, autoimmune or mechanical origin, alters the endothelium which progresses towards a proinflammatory and procoagulant activation, senescence and apoptosis. This "response to injury" of the endothelium plays a key role in the initiation and progression of cardiovascular disorders. In the last 10 years, identification in peripheral blood of circulating endothelial cells (CEC) and endothelial-derived microparticles (EMP) reflecting endothelium damage has led to the development of new noninvasive methods for endothelium exploration. Indeed, these biomarkers were associated with most of the cardiovascular risk factors, were correlated with established parameters of endothelial dysfunction, and were indicative of a poor clinical outcome. Moreover, they behave as biological vectors able to disseminate deleterious signals in the vascular compartment. More recently, this concept has been enlarged by the discovery of a potent repair mechanism based on the recruitment of the circulating endothelial progenitors cells (EPC) from the bone marrow, able to regenerate injured endothelial cells. Cardiovascular risk factors alter EPC number and function. Because the damage/repair balance plays a critical role in the endothelium homeostasis, CEC, EMP and EPC could be combined in an endothelium phenotype that defines the "vascular competence" of each individual. In the future, progress in standardization of available methodologies to measure these emerging biomarkers is a crucial step to establish their clinical interest for assessment of vascular risk and monitoring of vascular-directed therapeutics.


Assuntos
Doenças Cardiovasculares/patologia , Doenças Cardiovasculares/fisiopatologia , Micropartículas Derivadas de Células/patologia , Células Endoteliais/patologia , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Células-Tronco/patologia , Apoptose , Vasos Sanguíneos/patologia , Vasos Sanguíneos/fisiopatologia , Doenças Cardiovasculares/sangue , Endotélio Vascular/citologia , Humanos , Regeneração , Cicatrização
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