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1.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35110411

RESUMO

In persons living with HIV-1 (PLWH) who start antiretroviral therapy (ART), plasma virus decays in a biphasic fashion to below the detection limit. The first phase reflects the short half-life (<1 d) of cells that produce most of the plasma virus. The second phase represents the slower turnover (t1/2 = 14 d) of another infected cell population, whose identity is unclear. Using the intact proviral DNA assay (IPDA) to distinguish intact and defective proviruses, we analyzed viral decay in 17 PLWH initiating ART. Circulating CD4+ T cells with intact proviruses include few of the rapidly decaying first-phase cells. Instead, this population initially decays more slowly (t1/2 = 12.9 d) in a process that largely represents death or exit from the circulation rather than transition to latency. This more protracted decay potentially allows for immune selection. After ∼3 mo, the decay slope changes, and CD4+ T cells with intact proviruses decay with a half-life of 19 mo, which is still shorter than that of the latently infected cells that persist on long-term ART. Two-long-terminal repeat (2LTR) circles decay with fast and slow phases paralleling intact proviruses, a finding that precludes their use as a simple marker of ongoing viral replication. Proviruses with defects at the 5' or 3' end of the genome show equivalent monophasic decay at rates that vary among individuals. Understanding these complex early decay processes is important for correct use of reservoir assays and may provide insights into properties of surviving cells that can constitute the stable latent reservoir.


Assuntos
Antirretrovirais/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Provírus/efeitos dos fármacos , Vírion/efeitos dos fármacos , Linfócitos T CD4-Positivos/efeitos dos fármacos , Células Cultivadas , DNA Viral/efeitos dos fármacos , Humanos , Estudos Longitudinais , Carga Viral/efeitos dos fármacos , Latência Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
2.
PLoS Pathog ; 18(9): e1010845, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36074794

RESUMO

Antiretroviral therapy (ART) effectively inhibits HIV-1 replication but is not curative due to the persistence of a latent viral reservoir in resting CD4+ T cells. This reservoir is a major barrier to cure. Sequencing studies have revealed that the population of proviruses persisting in ART-treated individuals is dominated by defective proviruses that cannot give rise to viral rebound due to fatal defects including large deletions and APOBEC3-mediated hypermutation. Near full genome sequencing (nFGS) of individual proviruses is used in reservoir assays to provide an estimate of the fraction of proviruses that are intact. nFGS methods rely on a long-distance outer PCR capturing most (~9 kb) of the genome, followed by nested inner PCRs. The outer PCR is carried out at limit dilution, and interpretation of the results is based on the assumption that all proviruses are quantitatively captured. Here, we evaluate nFGS methods using the intact proviral DNA assay (IPDA), a multiplex digital droplet PCR assay that quantitates intact and defective proviruses with single molecule sensitivity using only short, highly efficient amplicons. We analyzed proviral templates of known sequence to avoid the additional complication of sequence polymorphism. With the IPDA, we quantitated molecular yields at each step of nFGS methods. We demonstrate that nFGS methods are inefficient and miss ~70% of full-length proviruses due to amplification failure at the initial outer PCR step. In contrast, proviruses with large internal deletions encompassing 70% of the genome can be quantitatively amplified under the same conditions. Accurate measurement of the latent reservoir of HIV-1 is essential for evaluating the efficacy of cure strategies, and the bias against full length proviruses in nFGS methods must be considered.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Linfócitos T CD4-Positivos , DNA Viral/genética , HIV-1/genética , Humanos , Provírus/genética , Carga Viral
3.
Am J Kidney Dis ; 83(3): 370-385, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37879527

RESUMO

All vitamins play essential roles in various aspects of body function and systems. Patients with chronic kidney disease (CKD), including those receiving dialysis, may be at increased risk of developing vitamin deficiencies due to anorexia, poor dietary intake, protein energy wasting, restricted diet, dialysis loss, or inadequate sun exposure for vitamin D. However, clinical manifestations of most vitamin deficiencies are usually subtle or undetected in this population. Testing for circulating levels is not undertaken for most vitamins except folate, B12, and 25-hydroxyvitamin D because assays may not be available or may be costly to perform and do not always correlate with body stores. The last systematic review through 2016 was performed for the Kidney Disease Outcome Quality Initiative (KDOQI) 2020 Nutrition Guideline update, so this article summarizes the more recent evidence. We review the use of vitamins supplementation in the CKD population. To date there have been no randomized trials to support the benefits of any vitamin supplementation for kidney, cardiovascular, or patient-centered outcomes. The decision to supplement water-soluble vitamins should be individualized, taking account the patient's dietary intake, nutritional status, risk of vitamins deficiency/insufficiency, CKD stage, comorbid status, and dialysis loss. Nutritional vitamin D deficiency should be corrected, but the supplementation dose and formulation need to be personalized, taking into consideration the degree of 25-hydroxyvitamin D deficiency, parathyroid hormone levels, CKD stage, and local formulation. Routine supplementation of vitamins A and E is not supported due to potential toxicity. Although more trial data are required to elucidate the roles of vitamin supplementation, all patients with CKD should undergo periodic assessment of dietary intake and aim to receive various vitamins through natural food sources and a healthy eating pattern that includes vitamin-dense foods.


Assuntos
Deficiência de Vitaminas , Insuficiência Renal Crônica , Deficiência de Vitamina D , Humanos , Vitaminas/uso terapêutico , Vitamina D , Suplementos Nutricionais , Insuficiência Renal Crônica/complicações , Deficiência de Vitamina D/epidemiologia , Deficiência de Vitamina D/etiologia , Vitamina A , Deficiência de Vitaminas/epidemiologia , Deficiência de Vitaminas/complicações , Vitamina K
4.
PLoS Pathog ; 17(6): e1009445, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34181697

RESUMO

We conducted a longitudinal study of cryptosporidiosis from birth to three years of age in an urban slum of Dhaka Bangladesh. Fecal DNA was extracted from monthly surveillance samples and diarrheal stool samples collected from 392 infants from birth to three years. A pan-Cryptosporidium qPCR assay was used to identify sub-clinical and symptomatic cryptosporidiosis. Anthropometric measurements were collected quarterly to assess child nutritional status. 31% (121/392) of children experienced a single and 57% (222/392) multiple infections with Cryptosporidium. Repeat infections had a lower burden of parasites in the stool (Cq slope = -1.85; p<0.0001) and were more likely to be sub-clinical (Chi square test for trend; p = 0.01). Repeat infections were associated with the development of growth faltering (Pearson correlation = -0.18; p = 0.0004). High levels of fecal IgA antibodies against the Cryptosporidium Cp23 sporozoite protein at one year of life were associated with a delay in reinfection and amelioration of growth faltering through three years of life (HAZ IgA high responders -1.323 ± 0.932 versus HAZ -1.731 ± 0.984 p = 0.0001). We concluded that nonsterile immunity to cryptosporidiosis in young children was associated with high levels of mucosal IgA anti-Cp23 and protection from diarrhea and growth faltering. Trial Registration: NCT02764918.


Assuntos
Transtornos da Nutrição Infantil/imunologia , Transtornos da Nutrição Infantil/parasitologia , Criptosporidiose/imunologia , Imunidade nas Mucosas/imunologia , Imunoglobulina A/imunologia , Bangladesh , Pré-Escolar , Criptosporidiose/complicações , Diarreia/parasitologia , Feminino , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Proteínas de Protozoários/imunologia , Esporozoítos/imunologia
5.
Proc Natl Acad Sci U S A ; 117(31): 18692-18700, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690683

RESUMO

A scalable approach for quantifying intact HIV-1 proviruses is critical for basic research and clinical trials directed at HIV-1 cure. The intact proviral DNA assay (IPDA) is a novel approach to characterizing the HIV-1 reservoir, focusing on the genetic integrity of individual proviruses independent of transcriptional status. It uses multiplex digital droplet PCR to distinguish and separately quantify intact proviruses, defined by a lack of overt fatal defects such as large deletions and APOBEC3G-mediated hypermutation, from the majority of proviruses that have such defects. This distinction is important because only intact proviruses cause viral rebound on ART interruption. To evaluate IPDA performance and provide benchmark data to support its implementation, we analyzed peripheral blood samples from 400 HIV-1+ adults on ART from several diverse cohorts, representing a robust sample of treated HIV-1 infection in the United States. We provide direct quantitative evidence that defective proviruses greatly outnumber intact proviruses (by >12.5 fold). However, intact proviruses are present at substantially higher frequencies (median, 54/106 CD4+ T cells) than proviruses detected by the quantitative viral outgrowth assay, which requires induction and in vitro growth (∼1/106 CD4+ T cells). IPDA amplicon signal issues resulting from sequence polymorphisms were observed in only 6.3% of individuals and were readily apparent and easily distinguished from low proviral frequency, an advantage of the IPDA over standard PCR assays which generate false-negative results in such situations. The large IPDA dataset provided here gives the clearest quantitative picture to date of HIV-1 proviral persistence on ART.


Assuntos
DNA Viral/sangue , Infecções por HIV , Provírus/genética , Latência Viral/genética , Adulto , Feminino , Infecções por HIV/sangue , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos
6.
Semin Dial ; 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34378234

RESUMO

Emerging research suggests that a more liberalized diet, specifically a more plant-based diet resulting in liberalization of potassium intake, for people receiving hemodialysis is necessary and the benefits outweigh previously thought risks. If the prescribed hemodialysis diet is to be liberalized, the need to illuminate and prevent potential pitfalls of a liberalized potassium diet is warranted. This paper explores such topics as partial to full adherence to a liberalized diet and its consequences if any, the advantages of a high-fiber intake, the theoretical risk of anemia when consuming a more plant-dominant diet, the potential benefits against renal acid load and effect on metabolic acidosis with increased fruit and vegetable intake, the putative change in serum potassium levels, carbohydrate quality, and the healthfulness of meat substitutes. The benefits of a more plant-based diet for the hemodialysis population are multifold; however, the possible pitfalls of this type of diet must be reviewed and addressed upon meal planning in order to be avoided.

7.
Am Heart J ; 223: 87-97, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32203684

RESUMO

BACKGROUND: The evolution and clinical impact of cardiac remodeling after large ST-elevation myocardial infarction (STEMI) is not well delineated in the current therapeutic era. METHODS: The PRESERVATION I trial longitudinally assessed cardiac structure and function in STEMI patients receiving primary percutaneous coronary intervention (PCI). Echocardiograms were performed immediately post-PCI and at 1, 3, 6 and 12 months after STEMI. The extent of cardiac remodeling was assessed in patients with ejection fraction (EF) ≤ 40% after PCI. Patients were stratified by the presence or absence of reverse remodeling, defined as an increase in end-diastolic volume (EDV) of ≤10 mL or decrease in EDV at 1 month, and evaluated for an association with adverse events at 1 year. RESULTS: Of the 303 patients with large STEMI enrolled in PRESERVATION I, 225 (74%) had at least moderately reduced systolic function (mean EF 32 ±â€¯5%) immediately after primary PCI. In the following year, there were significant increases in EF and LV volumes, with the greatest magnitude of change occurring in the first month. At 1 month, 104 patients (46%) demonstrated reverse remodeling, which was associated with a significantly lower rate of death, recurrent myocardial infarction and repeat cardiovascular hospitalization at 1 year (HR 0.44; 95% CI: 0.19-0.99). CONCLUSION: Reduced EF after large STEMI and primary PCI is common in the current therapeutic era. The first month following primary reperfusion is a critical period during which the greatest degree of cardiac remodeling occurs. Patients demonstrating early reverse remodeling have a significantly lower rate of adverse events in the year after STEMI.


Assuntos
Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST/patologia , Infarto do Miocárdio com Supradesnível do Segmento ST/cirurgia , Remodelação Ventricular , Idoso , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
8.
Proc Biol Sci ; 287(1930): 20201107, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32635864

RESUMO

Many arthropod hosts are infected with bacterial endosymbionts that manipulate host reproduction, but few bacterial taxa have been shown to cause such manipulations. Here, we show that a bacterial strain in the genus Rickettsiella causes cytoplasmic incompatibility (CI) between infected and uninfected hosts. We first surveyed the bacterial community of the agricultural spider Mermessus fradeorum (Linyphiidae) using high throughput sequencing and found that individual spiders can be infected with up to five different strains of maternally inherited symbiont from the genera Wolbachia, Rickettsia, and Rickettsiella. The Rickettsiella strain was pervasive, found in all 23 tested spider matrilines. We used antibiotic curing to generate uninfected matrilines that we reciprocally crossed with individuals infected only with Rickettsiella. We found that only 13% of eggs hatched when uninfected females were mated with Rickettsiella-infected males; in contrast, at least 83% of eggs hatched in the other cross types. This is the first documentation of Rickettsiella, or any Gammaproteobacteria, causing CI. We speculate that induction of CI may be much more widespread among maternally inherited bacteria than previously appreciated. Further, our results reinforce the importance of thoroughly characterizing and assessing the inherited microbiome before attributing observed host phenotypes to well-characterized symbionts such as Wolbachia.


Assuntos
Coxiellaceae/fisiologia , Citoplasma/microbiologia , Aranhas/microbiologia , Animais , Feminino , Interações Hospedeiro-Patógeno , Masculino , Simbiose
9.
J Evol Biol ; 33(10): 1507-1511, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32894786

RESUMO

Maternally transmitted bacterial symbionts can be important mediators of the interactions between insect herbivores and their foodplants. These symbionts are often facultative (present in some host individuals but not others) and can have large effects on their host's phenotype, thus giving rise to heritable variation upon which selection can act. In the cowpea aphid (Aphis craccivora), it has been established that the facultative endosymbiont Arsenophonus improves aphid performance on black locust trees (Robinia pseudoacacia) but not on fava (Vicia faba). Here, we tested whether this fitness differential translated into contemporaneous evolution of aphid populations associated with the different plants. In a laboratory study lasting 16 weeks, we found that the frequency of Arsenophonus-infected individuals significantly increased over time for aphid populations on black locust but declined for aphid populations on fava. By the end of the experiment, Arsenophonus infection was >3× more common on black locust than fava, which is comparable to previously described infection frequencies in natural field populations. Our results clearly demonstrate that aphid populations with mixed facultative symbiont infection status can rapidly evolve in response to the selective environments imposed by different host plants. This selection differential may be a sufficient explanation for the global association between Arsenophonus-infected cowpea aphids and black locust trees, without invoking additional assortative mechanisms. Because the aphid and plant originate from different parts of the world, we further hypothesize that Arsenophonus infection may have acted as a preadaptation that has promoted functional specialization of infected aphids on a novel host plant.


Assuntos
Afídeos/genética , Evolução Biológica , Gammaproteobacteria/fisiologia , Herbivoria , Seleção Genética , Animais , Afídeos/microbiologia , Robinia , Simbiose , Vicia faba
10.
Microb Ecol ; 79(2): 472-481, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31300838

RESUMO

Maternally inherited bacterial endosymbionts are common in arthropods, but their distribution and prevalence are poorly characterized in many host taxa. Initial surveys have suggested that vertically transmitted symbionts may be particularly common in spiders (Araneae). Here, we used diagnostic PCR and high-throughput sequencing to evaluate symbiont infection in 267 individual spiders representing 14 species (3 families) of agricultural spiders. We found 27 operational taxonomic units (OTUs) that are likely endosymbiotic, including multiple strains of Wolbachia, Rickettsia, and Cardinium, which are all vertically transmitted and frequently associated with reproductive manipulation of arthropod hosts. Additional strains included Rickettsiella, Spiroplasma, Rhabdochlamydia, and a novel Rickettsiales, all of which could range from pathogenic to mutualistic in their effects upon their hosts. Seventy percent of spider species had individuals that tested positive for one or more endosymbiotic OTUs, and specimens frequently contained multiple symbiotic strain types. The most symbiont-rich species, Idionella rugosa, had eight endosymbiotic OTUs, with as many as five present in the same specimen. Individual specimens within infected spider species had a variety of symbiotypes, differing from one another in the presence or absence of symbiotic strains. Our sample included both starved and unstarved specimens, and dominant bacterial OTUs were consistent per host species, regardless of feeding status. We conclude that spiders contain a remarkably diverse symbiotic microbiota. Spiders would be an informative group for investigating endosymbiont population dynamics in time and space, and unstarved specimens collected for other purposes (e.g., food web studies) could be used, with caution, for such investigations.


Assuntos
Bactérias/isolamento & purificação , Técnicas Bacteriológicas/métodos , Entomologia/métodos , Microbiota , Aranhas/microbiologia , Simbiose/fisiologia , Animais , Bactérias/classificação , Fenômenos Fisiológicos Bacterianos , Privação de Alimentos , Sequenciamento de Nucleotídeos em Larga Escala , Kentucky , Microbiota/genética , Reação em Cadeia da Polimerase
11.
Circulation ; 137(15): 1571-1582, 2018 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-29263150

RESUMO

BACKGROUND: Ezetimibe, when added to simvastatin, reduces cardiovascular events after acute coronary syndrome. We explored outcomes stratified by diabetes mellitus (DM). METHODS: In IMPROVE-IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial), 18 144 patients after acute coronary syndrome with low-density lipoprotein cholesterol 50 to 125 mg/dL were randomized to 40 mg ezetimibe/simvastatin (E/S) or 40 mg placebo/simvastatin. The primary composite end point was cardiovascular death, major coronary events, and stroke. DM was a prespecified subgroup. RESULTS: The 4933 (27%) patients with DM were more often older and female, had had a prior myocardial infarction and revascularization, and presented more frequently with non-ST segment elevation acute coronary syndrome compared with patients without DM (each P<0.001). The median admission low-density lipoprotein cholesterol was lower among patients with DM (89 versus 97 mg/dL, P<0.001). E/S achieved a significantly lower median time-weighted average low-density lipoprotein cholesterol compared with placebo/simvastatin, irrespective of DM (DM: 49 versus 67 mg/dL; no DM: 55 versus 71 mg/dL; both P<0.001). In patients with DM, E/S reduced the 7-year Kaplan-Meier primary end point event rate by 5.5% absolute (hazard ratio, 0.85; 95% confidence interval, 0.78-0.94); in patients without DM, the absolute difference was 0.7% (hazard ratio, 0.98; 95% confidence interval, 0.91-1.04; Pint=0.02). The largest relative reductions in patients with DM were in myocardial infarction (24%) and ischemic stroke (39%). No differences in safety outcomes by treatment were present regardless of DM. When stratified further by age, patients ≥75 years of age had a 20% relative reduction in the primary end point regardless of DM (Pint=0.91), whereas patients <75 years of age with DM had greater benefit than those without (Pint=0.011). When stratified by the TIMI (Thrombolysis in Myocardial Infarction) Risk Score for Secondary Prevention, all patients with DM demonstrated benefit with E/S regardless of risk. In contrast, among patients without DM, those with a high risk score experienced a significant (18%) relative reduction in the composite of cardiovascular death, myocardial infarction, and ischemic stroke with E/S compared with placebo/simvastatin, whereas patients without DM at low or moderate risk demonstrated no benefit with the addition of ezetimibe to simvastatin (Pint =0.034). CONCLUSIONS: In IMPROVE-IT, the benefit of adding ezetimibe to statin was enhanced in patients with DM and in high-risk patients without DM. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00202878.


Assuntos
Síndrome Coronariana Aguda/terapia , Diabetes Mellitus/terapia , Dislipidemias/tratamento farmacológico , Dislipidemias/mortalidade , Combinação Ezetimiba e Simvastatina/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/mortalidade , Idoso , Biomarcadores/sangue , LDL-Colesterol/sangue , Comorbidade , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/mortalidade , Dislipidemias/diagnóstico , Combinação Ezetimiba e Simvastatina/efeitos adversos , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
13.
Circulation ; 136(25): 2440-2450, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-28972004

RESUMO

BACKGROUND: Patients who experience an acute coronary syndrome are at heightened risk of recurrent ischemic events, including stroke. Ezetimibe improved cardiovascular outcomes when added to statin therapy in patients stabilized after acute coronary syndrome. We investigated the efficacy of the addition of ezetimibe to simvastatin for the prevention of stroke and other adverse cardiovascular events in IMPROVE-IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial), with a focus on patients with a stroke before randomization. METHODS: Patients who experienced acute coronary syndrome were randomized to a placebo/simvastatin or ezetimibe/simvastatin regimen and followed for a median of 6 years. Treatment efficacy was assessed for the entire population and by subgroups for the first and total (first and subsequent) events for the end points of stroke of any etiology, stroke subtypes, and the primary trial end point at 7 years. RESULTS: Of 18 144 patients, 641 (3.5%) experienced at least 1 stroke; most were ischemic (527, 82%). Independent predictors of stroke included prior stroke, older age, atrial fibrillation, congestive heart failure, diabetes mellitus, myocardial infarction, and renal dysfunction. There was a nonsignificant reduction in the first event of stroke of any etiology (4.2% versus 4.8%; hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.73-1.00; P=0.052) with ezetimibe/simvastatin versus placebo/simvastatin, driven by a significant 21% reduction in ischemic stroke (3.4% versus 4.1%; HR, 0.79; 95% CI, 0.67-0.94; P=0.008) and a nonsignificant increase in hemorrhagic stroke (0.8% versus 0.6%; HR, 1.38; 95% CI, 0.93-2.04; P=0.11). Evaluating total events, including the first and all recurrent strokes, ezetimibe/simvastatin reduced stroke of any etiology (HR, 0.83; 95% CI, 0.70-0.98; P=0.029) and ischemic stroke (HR, 0.76; 95% CI, 0.63-0.91; P=0.003). Patients who had experienced a stroke prior to randomization were at a higher risk of recurrence and demonstrated an absolute risk reduction of 8.6% for stroke of any etiology (10.2% versus 18.8%; number needed to treat=12; HR, 0.60; 95% CI, 0.38-0.95; P=0.030) and 7.6% for ischemic stroke (8.7% versus 16.3%; number needed to treat=13; HR, 0.52; 95% CI, 0.31-0.86; P=0.011) with ezetimibe added to simvastatin therapy. CONCLUSIONS: The addition of ezetimibe to simvastatin in patients stabilized after acute coronary syndrome reduces the frequency of ischemic stroke, with a particularly large effect seen in patients with a prior stroke. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00202878.


Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Anticolesterolemiantes/uso terapêutico , Ezetimiba/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Sinvastatina/uso terapêutico , Acidente Vascular Cerebral/prevenção & controle , Síndrome Coronariana Aguda/mortalidade , Síndrome Coronariana Aguda/patologia , Idoso , Fibrilação Atrial/complicações , LDL-Colesterol/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Efeito Placebo , Modelos de Riscos Proporcionais , Recidiva , Fatores de Risco , Resultado do Tratamento
14.
N Engl J Med ; 372(25): 2387-97, 2015 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-26039521

RESUMO

BACKGROUND: Statin therapy reduces low-density lipoprotein (LDL) cholesterol levels and the risk of cardiovascular events, but whether the addition of ezetimibe, a nonstatin drug that reduces intestinal cholesterol absorption, can reduce the rate of cardiovascular events further is not known. METHODS: We conducted a double-blind, randomized trial involving 18,144 patients who had been hospitalized for an acute coronary syndrome within the preceding 10 days and had LDL cholesterol levels of 50 to 100 mg per deciliter (1.3 to 2.6 mmol per liter) if they were receiving lipid-lowering therapy or 50 to 125 mg per deciliter (1.3 to 3.2 mmol per liter) if they were not receiving lipid-lowering therapy. The combination of simvastatin (40 mg) and ezetimibe (10 mg) (simvastatin-ezetimibe) was compared with simvastatin (40 mg) and placebo (simvastatin monotherapy). The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, unstable angina requiring rehospitalization, coronary revascularization (≥30 days after randomization), or nonfatal stroke. The median follow-up was 6 years. RESULTS: The median time-weighted average LDL cholesterol level during the study was 53.7 mg per deciliter (1.4 mmol per liter) in the simvastatin-ezetimibe group, as compared with 69.5 mg per deciliter (1.8 mmol per liter) in the simvastatin-monotherapy group (P<0.001). The Kaplan-Meier event rate for the primary end point at 7 years was 32.7% in the simvastatin-ezetimibe group, as compared with 34.7% in the simvastatin-monotherapy group (absolute risk difference, 2.0 percentage points; hazard ratio, 0.936; 95% confidence interval, 0.89 to 0.99; P=0.016). Rates of prespecified muscle, gallbladder, and hepatic adverse effects and cancer were similar in the two groups. CONCLUSIONS: When added to statin therapy, ezetimibe resulted in incremental lowering of LDL cholesterol levels and improved cardiovascular outcomes. Moreover, lowering LDL cholesterol to levels below previous targets provided additional benefit. (Funded by Merck; IMPROVE-IT ClinicalTrials.gov number, NCT00202878.).


Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Anticolesterolemiantes/uso terapêutico , Azetidinas/uso terapêutico , LDL-Colesterol/sangue , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Sinvastatina/uso terapêutico , Idoso , Anticolesterolemiantes/efeitos adversos , Azetidinas/efeitos adversos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/prevenção & controle , Método Duplo-Cego , Quimioterapia Combinada , Ezetimiba , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue
15.
Proc Biol Sci ; 285(1879)2018 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-29848647

RESUMO

Generalist predators with broadly overlapping niches commonly coexist on seemingly identical sets of prey. Here, we provide empirical demonstration that predators can differentially exploit fine-grained niches generated by variable, heritable and selective defences within a single prey species. Some, but not all, clones of the aphid Aphis craccivora are toxic towards the dominant invasive predatory ladybeetle, Harmonia axyridis However, other less competitive ladybeetle species are not affected by the aphid's toxic trait. In laboratory and open field experiments, we show: (i) that subdominant ladybeetle species were able to exploit the toxic aphids, benefitting from the suppression of the dominant predator; and (ii) that this narrow-spectrum toxicity can function as an anti-predator defence for the aphid, but depends on enemy community context. Our results demonstrate that niche differentiation among generalist predators may hinge upon previously underappreciated heritable variation in prey defence, which, in turn, may promote diversity and stability of enemy communities invaded by a dominant predator.


Assuntos
Afídeos/química , Besouros/fisiologia , Cadeia Alimentar , Comportamento Predatório , Vespas/fisiologia , Animais , Afídeos/genética , Afídeos/parasitologia , Besouros/crescimento & desenvolvimento , Feminino , Hereditariedade , Larva/crescimento & desenvolvimento , Larva/fisiologia , Especificidade da Espécie , Vespas/crescimento & desenvolvimento
16.
Eur Heart J ; 37(48): 3576-3584, 2016 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-27569841

RESUMO

AIMS: To examine the efficacy and safety of ezetimibe added to statin in patients with prior coronary artery bypass graft surgery (CABG) following hospitalization for an acute coronary syndrome (ACS). METHODS AND RESULTS: In the IMPROVE-IT trial, post-ACS patients with mean low density lipoprotein cholesterol (LDL-C) of 93.8 mg/dL at presentation were randomized to simvastatin/ezetimibe or simvastatin/placebo. The primary endpoint was cardiovascular death, major coronary event or stroke, and the median follow-up was 6 years. Efficacy and safety endpoints were examined by prior CABG status. Among 18 134 patients, 1684 (9.3%) had a prior CABG (median age 69 years, 82% male). During the trial, the median time-weighted LDL-C level was 55.0 mg/dL with simvastatin/ezetimibe vs. 69.9 mg/dL with simvastatin/placebo in patients with prior CABG (P < 0.001), and it was 53.6 mg/dL vs. 69.5 mg/dL, respectively, in patients without prior CABG (P < 0.001). The rate of the primary endpoint was higher in patients with vs. without prior CABG [56% vs. 32%, adj. hazard ratio 1.45, 95% confidence interval (CI) 1.33-1.58]. Patients with prior CABG receiving simvastatin/ezetimibe had an 8.8% (95% CI 3.1-14.6%) lower absolute risk over simvastatin/placebo in the primary endpoint, whereas patients without prior CABG had a 1.3% (95% CI 0-2.6%) lower absolute risk (P-interaction = 0.02). There were no between-group significant differences in safety endpoints. CONCLUSION: The clinical benefit of adding ezetimibe to statin appears to be enhanced in patients with prior CABG, supporting the use of intensive lipid lowering therapy in these high-risk patients following ACS.


Assuntos
Síndrome Coronariana Aguda , Idoso , Anticolesterolemiantes , LDL-Colesterol , Ponte de Artéria Coronária , Método Duplo-Cego , Quimioterapia Combinada , Ezetimiba , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases , Masculino , Sinvastatina , Resultado do Tratamento
17.
Circulation ; 132(13): 1224-33, 2015 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-26330412

RESUMO

BACKGROUND: Statins lower low-density lipoprotein cholesterol (LDL-C) and high-sensitivity C-reactive protein (hs-CRP); addition of ezetimibe to statins further reduces LDL-C and hs-CRP. An analysis of the relationship between achieved LDL-C and hs-CRP targets and outcomes for simvastatin and ezetimibe/simvastatin was prespecified in Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT). METHODS AND RESULTS: The IMPROVE-IT trial randomly assigned 18 144 patients stabilized after acute coronary syndrome to simvastatin or ezetimibe/simvastatin. LDL-C and hs-CRP were measured at baseline and 1 month after randomization. Outcomes were assessed in those achieving one or both of the prespecified targets of LDL-C<70 mg/dL and hs-CRP<2 mg/L versus achieving neither target, adjusting for differences in baseline characteristics. An exploratory analysis examined targets of LDL-C<50 mg/dL and hs-CRP<1 mg/L. Patients meeting both targets at baseline, with no 1-month values, or with end points before 1 month were excluded. Of 15 179 patients, 39% achieved the dual LDL-C (<70 mg/dL) and hs-CRP (<2 mg/L) targets at 1 month, 14% met neither target, 14% met only the hs-CRP target, and 33% met only the LDL-C target. Those achieving dual targets had lower primary end point rates than those meeting neither target (cardiovascular death, major coronary event, or stroke; 38.9% versus 28.0%; adjusted hazard ratio, 0.73; 0.66-0.81; P<0.001). More patients treated with ezetimibe/simvastatin met dual targets than those treated with simvastatin alone (50% versus 29%, P<0.001). The association of dual-target attainment with improved outcomes was similar irrespective of treatment assignment (P-interaction=0.65). Similar findings were observed using the exploratory targets. CONCLUSIONS: Significantly more patients treated with ezetimibe/simvastatin met prespecified and exploratory dual LDL-C and hs-CRP targets than patients treated with simvastatin alone. Reaching both LDL-C and hs-CRP targets was associated with improved outcomes after multivariable adjustment. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov; Unique identifier: NCT00202878.


Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Anticolesterolemiantes/uso terapêutico , Proteína C-Reativa/análise , LDL-Colesterol/sangue , Ezetimiba/uso terapêutico , Sinvastatina/uso terapêutico , Síndrome Coronariana Aguda/sangue , Idoso , Anticolesterolemiantes/administração & dosagem , Biomarcadores , Doenças Cardiovasculares/mortalidade , Revascularização Cerebral , Comorbidade , Creatinina/sangue , Método Duplo-Cego , Monitoramento de Medicamentos , Quimioterapia Combinada , Eletrocardiografia , Ezetimiba/administração & dosagem , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/tratamento farmacológico , Revascularização Miocárdica , Sinvastatina/administração & dosagem , Resultado do Tratamento
18.
Am Heart J ; 182: 89-96, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27914504

RESUMO

BACKGROUND: We aimed to determine the efficacy and safety of adding ezetimibe (Ez) to simvastatin (S) in a post-acute coronary syndrome (ACS) population in a prespecified on-treatment analysis. METHODS: We evaluated 17,706 post-ACS patients from the IMPROVE-IT trial who had low-density lipoprotein cholesterol values between 50 and 125 mg/dL and who received Ez 10 mg/d with S 40 mg/d (Ez/S) or placebo with simvastatin 40 mg/d (P/S). The primary composite end point was cardiovascular death, myocardial infarction, unstable angina, coronary revascularization ≥30 days postrandomization, or stroke. The on-treatment analysis included patients who received study drug for the duration of the trial or experienced a primary end point or noncardiovascular death within 30 days of drug discontinuation. RESULTS: Mean low-density lipoprotein cholesterol values at 1 year were 71 mg/dL for P/S and 54 mg/dL for Ez/S (absolute difference -17 mg/dL = -24%; P < .001). The 7-year Kaplan-Meier estimate of the primary end point occurred in 32.4% in the P/S arm and 29.8% in the Ez/S arm (absolute difference 2.6%; HRadj 0.92 [95% CI 0.87-0.98]; P = .01). The absolute treatment effect favoring Ez/S was 30% greater than in the intention-to-treat analysis of IMPROVE-IT. CONCLUSIONS: This analysis provides additional support for the efficacy and safety of adding Ez to S in this high-risk, post-ACS population.


Assuntos
Síndrome Coronariana Aguda , LDL-Colesterol/sangue , Ezetimiba , Sinvastatina , Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/tratamento farmacológico , Idoso , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/efeitos adversos , Relação Dose-Resposta a Droga , Monitoramento de Medicamentos/métodos , Sinergismo Farmacológico , Quimioterapia Combinada/métodos , Quimioterapia Combinada/estatística & dados numéricos , Ezetimiba/administração & dosagem , Ezetimiba/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sinvastatina/administração & dosagem , Sinvastatina/efeitos adversos , Resultado do Tratamento
19.
Microb Ecol ; 70(1): 274-86, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25613091

RESUMO

Some insects are infected with maternally inherited bacterial endosymbionts that protect them against pathogens or parasitoids. The weevil Sitona obsoletus (=Sitona lepidus) is invasive in New Zealand, and suspected to contain such defensive symbionts, because it is particularly resistant to a Moroccan strain of the parasitoid Microctonus aethiopoides (which successfully attacks many other weevil species), and shows geographic variation in susceptibility to an Irish strain of the same parasitoid. Using 454 pyrosequencing, we investigated the bacterial community associated with S. obsoletus, two other exotic weevils (Sitona discoideus and Listronotus bonariensis) and two endemic New Zealand weevils (Irenimus aequalis and Steriphus variabilis). We found that S. obsoletus was infected by one strain of Wolbachia and two strains of Rickettsia, none of which were found in any other weevil species examined. Using diagnostic PCR, we found that S. obsoletus in the Northland region, where parasitism is highly variable, were primarily infected with Wolbachia and Rickettsia strain 2, indicating that these two symbionts should be investigated for potential defensive properties. In comparison, S. discoideus lacked any apparent maternally inherited bacterial endosymbionts. In the other weevil species, we found a different strain of Wolbachia and two different strains of Spiroplasma. Two weevil species (St. variabilis and L. bonariensis) were infected with distinct strains of Nardonella, the ancestral endosymbiont of weevils, whereas three weevil species (S. obsoletus, S. discoideus, and I. aequalis) lacked evidence for Nardonella infection. However, I. aequalis was consistently infected with a novel Enterobacteriaceae strain, suggesting that a symbiont replacement may have taken place, similar to that described for other weevil clades.


Assuntos
Rickettsia/genética , Simbiose , Gorgulhos/microbiologia , Wolbachia/genética , Animais , Sequência de Bases , Primers do DNA/genética , Geografia , Funções Verossimilhança , Metagenômica , Modelos Genéticos , Dados de Sequência Molecular , Nova Zelândia , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Especificidade da Espécie
20.
J Invertebr Pathol ; 132: 111-114, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26410254

RESUMO

Maternally-inherited bacteria can affect the fitness and population dynamics of their host insects; for solitary bees, such effects have the potential to influence bee efficacy as pollinators. We screened bee species for bacterial associates using 454-pyrosequencing (4 species) and diagnostic PCR (183 specimens across 29 species). The endosymbiont Wolbachia was abundant, infecting 18 species, including all specimens from the family Halictidae. Among commercially-supplied orchard bees (family Megachilidae), only 2/7 species were Wolbachia-infected, but one species showed variable infection among specimens. Two other maternally-inherited bacteria, Arsenophonus and Sodalis, were also detected, neither of which was fixed in infection frequency. Differential endosymbiont infection could potentially compromise fitness and reproductive compatibility among commercially redistributed pollinator populations.


Assuntos
Abelhas/microbiologia , Enterobacteriaceae/fisiologia , Gammaproteobacteria/fisiologia , Interações Hospedeiro-Patógeno , Wolbachia/fisiologia , Animais , Enterobacteriaceae/isolamento & purificação , Gammaproteobacteria/isolamento & purificação , Dinâmica Populacional , Simbiose , Wolbachia/isolamento & purificação
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