Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 143
Filtrar
1.
Breast Cancer Res ; 22(1): 137, 2020 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-33276807

RESUMEN

BACKGROUND: Survival rates for breast cancer (BC) have improved, but quality of life post-diagnosis/treatment can be adversely affected, with survivors reporting a constellation of psychoneurological symptoms (PNS) including stress, anxiety, depression, pain, fatigue, sleep disturbance, and cognitive dysfunction. METHODS: To assess a potential relationship between telomere length (TL) and the development/persistence of PNS, we longitudinally studied 70 women (ages 23-71) with early stage BC (I-IIIA) at 5 time-points: prior to treatment (baseline), the mid-point of their chemotherapy cycle, 6 months, 1 year, and 2 years following the initiation of chemotherapy. Measures quantified included assessments of each of the PNS noted above and TL [using both a multiplex qPCR assay and a chromosome-specific fluorescence in situ hybridization (FISH) assay]. RESULTS: Variables associated with qPCR mean TLs were age (p = 0.004) and race (T/S ratios higher in Blacks than Whites; p = 0.019). Significant differences (mostly decreases) in chromosome-specific TLs were identified for 32 of the 46 chromosomal arms at the mid-chemo time-point (p = 0.004 to 0.049). Unexpectedly, the sequential administration of doxorubicin [Adriamycin], cyclophosphamide [Cytoxan], and docetaxel [Taxotere] (TAC regimen) was consistently associated with higher TLs, when compared to TLs in women receiving a docetaxel [Taxotere], Carboplatin [Paraplatin], and trastuzumab [Herceptin] [TCH] chemotherapy regimen [association was shown with both the qPCR and FISH assays (p = 0.036)]. Of the PNS, pain was significantly negatively associated with TL (higher pain; shorter telomeres) for a subset of chromosomal arms (5q, 8p, 13p, 20p, 22p, Xp, Xq) (p = 0.014-0.047). Chromosomal TLs were also associated with 7 of the 8 cognitive domains evaluated, with the strongest relationship being noted for chromosome 17 and the visual memory domain (shorter telomeres; lower scores). CONCLUSIONS: We showed that race and age were significantly associated with telomere length in women treated for early stage BC and that acquired telomere alterations differed based on the woman's treatment regimen. Our study also demonstrated that pain and cognitive domain measures were significantly related to telomere values in this study cohort. Expanding upon the knowledge gained from this longitudinal study could provide insight about the biological cascade of events that contribute to PNS related to BC and/or its treatment.

2.
Front Cell Dev Biol ; 8: 590008, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33224952

RESUMEN

Stroke may cause severe death and disability but many clinical trials have failed in the past, partially because the lack of an effective method to regenerate new neurons after stroke. In this study, we report an in vivo neural regeneration approach through AAV NeuroD1-based gene therapy to repair damaged brains after ischemic stroke in adult non-human primates (NHPs). We demonstrate that ectopic expression of a neural transcription factor NeuroD1 in the reactive astrocytes after monkey cortical stroke can convert 90% of the infected astrocytes into neurons. Interestingly, astrocytes are not depleted in the NeuroD1-converted areas, consistent with the proliferative capability of astrocytes. Following ischemic stroke in monkey cortex, the NeuroD1-mediated astrocyte-to-neuron (AtN) conversion significantly increased local neuronal density, reduced microglia and macrophage, and surprisingly protected parvalbumin interneurons in the converted areas. Furthermore, the NeuroD1 gene therapy showed a broad time window in AtN conversion, from 10 to 30 days following ischemic stroke. The cortical astrocyte-converted neurons showed Tbr1+ cortical neuron identity, similar to our earlier findings in rodent animal models. Unexpectedly, NeuroD1 expression in converted neurons showed a significant decrease after 6 months of viral infection, indicating a downregulation of NeuroD1 after neuronal maturation in adult NHPs. These results suggest that in vivo cell conversion through NeuroD1-based gene therapy may be an effective approach to regenerate new neurons for tissue repair in adult primate brains.

3.
J Mater Chem B ; 2020 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-33185219

RESUMEN

In this paper, a new magnetic molecular imprinted polymer-cyclodextrin (MMIP-CD) material was prepared by connecting ß-cyclodextrin (CD) on the surface of a magnetic molecular imprinted polymer (MMIP) and used for the rapid and specific adsorption of zearalenone (ZEN). By using warfarin as the virtual template molecule, tetraethyl orthosilicate (TEOS) as the crosslinking agent, and (3-aminopropyl) triethoxysilane (APTES) as the functional monomer, a MMIP was produced by surface imprinting technology. Sulfobutyl ether-ß-cyclodextrin attached to the surface of the MMIP under heating conditions produced a new specific adsorption material with exceptional adsorption capacity and excellent selectivity for ZEN. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and TEM-mapping results showed that the prepared MMIP-CD had a uniform particle size of about 480 nm, and the molecularly imprinted layer was successfully wrapped on the surface of the nanoparticles with a thickness of about 50 nm, whereby the cyclodextrin was effectively attached to the surface of the MMIP. The adsorption mechanism of MMIP-CD was confirmed by kinetic adsorption and thermodynamic adsorption experiments, the maximum adsorption capacity was found to be about 30 mg g-1, and the adsorption equilibrium could be reached within 20 min. The value of IF (QMMIP-CD/QMNIP) is 4.642. This showed that compared with MNIP, MMIP-CD showed a greatly improved specific adsorption capacity of ZEN. Selective experiments proved that MMIP-CD effectively combined the advantages of MMIP and CD, enhancing the adsorption capacity together with reducing the disadvantages that MMIP cannot distinguish structural analogs and CD cannot identify hydrophobic compounds effectively. In actual sample testing, the limit of quantification (LOQ) and limit of detection (LOD) were 0.1 ng kg-1 and 0.3 ng kg-1, respectively. The stability and detection precision of this method were 0.98-2.76% and 1.67-3.88%, respectively. The results proved that MMIP-CD had good development potential in the field of selective adsorption of ZEN, and laid the foundation for follow-up research.

4.
Phys Rev Lett ; 125(18): 183003, 2020 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-33196257

RESUMEN

We show that jet emission from a Bose condensate with periodically driven interactions, also known as "Bose fireworks", contains essential information on the condensate wave function, which is difficult to obtain using standard detection methods. We illustrate the underlying physics with two examples. When condensates acquire phase patterns from external potentials or from vortices, the jets display novel substructure, such as oscillations or spirals, in their correlations. Through a comparison of theory, numerical simulations, and experiments, we show how one can quantitatively extract the phase and the helicity of a condensate from the emission pattern. Our work, demonstrating the strong link between jet emission and the underlying quantum system, bears on the recent emphasis on jet substructure in particle physics.

5.
PLoS One ; 15(11): e0242490, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33201884

RESUMEN

BACKGROUND: The quantitative measurement of current perception threshold (CPT) has been used as a method to assess the function of nerve fibers in neuropathy diseases. The aim of this study was to assess the test-retest reliability measuring CPT using the circular pin electrodes for assessing the function of cutaneous thin nerve fibers. METHODS: CPT measurement was repeated on two separate days with at least one-week interval in 55 volunteers. Superficial blood flow (SBF) and skin temperature (ST) were measured on the skin in an around area concentric to the circular pin electrodes after the process of finding CPTs. The coefficient of variation (CV) and intra-class correlation coefficient (ICC) were calculated. The correlation between each two of CPT, SBF increment and ST increment was analyzed. RESULTS: No significant differences were found for CPT, SBF and ST between two sessions. SBF was found to be significantly increased after the process of finding CPT. CPT values of males were found to be higher than females. SBF increment was found to be positively correlated with ST increment. The ICC values for CPT, SBF and ST were 0.595, 0.852 and 0.728, respectively. The CV values for CPT, SBF and ST were 25.53%, 12.59% and 1.94%, respectively. CONCLUSIONS: The reliability of CPT measurement using circular pin electrodes is fair, and need consistence of measurements in longitudinal studies.

6.
Free Radic Biol Med ; 2020 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-33131696

RESUMEN

Alzheimer (AD) is a degenerative disease that can lead memory loss and behavioral dysfunction. Aß protein and phosphorylation of Tau protein are related to the onset of AD. However, at present, its treatment and drugs are limited. The purpose of our study is to evaluate whether phosphocreatine (PCr) could protect neuronal injury induced by Aß protein in vivo and in vitro through AKT/GSK-3ß/Tau/APP/CDK5 pathways. Differentiated PC-12 cells were cultured with Aß25-35 for 24 h, while the mice were injected with D-Galactose for eight weeks, both of them were pretreated with PCr for 2 h. The results showed PCr could obviously induce cells and hippocampus apoptosis using DAPI and TUNEL. PCr decreased the levels of intercellular reactive oxygen species (ROS) and malondialdehyde (MDA), and increased the activities of superoxide dismutase (SOD). Besides, the apoptosis pathway was detected using Western blot, showing that PCr could significantly reduce caspase-3, caspase-9, Bcl-2/Bax expression in vivo and in vitro. At the same time, PCr could decreased Ca2+ and apoptosis by Flow Cytometry in PC-12 cells. We observed that the morphological alteration of hippocampus injury was mitigated with the pretreatment of PCr. Furthermore, PCr pretreatment could decrease Aß25-35-induced PC-12 cells apoptosis with APP cDNA transfection, which up-regulated AKT/GSK-3ß/CDK5 pathways and induced Tau phosphorylation. In summary, PCr could reduce Aß25-35 toxicity to protect neuronal cells via AKT/GSK-3ß/CDK5 pathways.

7.
EClinicalMedicine ; 28: 100603, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33134905

RESUMEN

Background: Routine services for tuberculosis (TB) are being disrupted by stringent lockdowns against the novel SARS-CoV-2 virus. We sought to estimate the potential long-term epidemiological impact of such disruptions on TB burden in high-burden countries, and how this negative impact could be mitigated. Methods: We adapted mathematical models of TB transmission in three high-burden countries (India, Kenya and Ukraine) to incorporate lockdown-associated disruptions in the TB care cascade. The anticipated level of disruption reflected consensus from a rapid expert consultation. We modelled the impact of these disruptions on TB incidence and mortality over the next five years, and also considered potential interventions to curtail this impact. Findings: Even temporary disruptions can cause long-term increases in TB incidence and mortality. If lockdown-related disruptions cause a temporary 50% reduction in TB transmission, we estimated that a 3-month suspension of TB services, followed by 10 months to restore to normal, would cause, over the next 5 years, an additional 1⋅19 million TB cases (Crl 1⋅06-1⋅33) and 361,000 TB deaths (CrI 333-394 thousand) in India, 24,700 (16,100-44,700) TB cases and 12,500 deaths (8.8-17.8 thousand) in Kenya, and 4,350 (826-6,540) cases and 1,340 deaths (815-1,980) in Ukraine. The principal driver of these adverse impacts is the accumulation of undetected TB during a lockdown. We demonstrate how long term increases in TB burden could be averted in the short term through supplementary "catch-up" TB case detection and treatment, once restrictions are eased. Interpretation: Lockdown-related disruptions can cause long-lasting increases in TB burden, but these negative effects can be mitigated with rapid restoration of TB services, and targeted interventions that are implemented as soon as restrictions are lifted. Funding: USAID and Stop TB Partnership.

8.
Int J Infect Dis ; 102: 463-471, 2020 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-33130212

RESUMEN

OBJECTIVES: In this data collation study, we aimed to provide a comprehensive database describing the epidemic trends and responses during the first wave of coronavirus disease 2019 (COVID-19) throughout the main provinces in China. METHODS: From mid-January to March 2020, we extracted publicly available data regarding the spread and control of COVID-19 from 31 provincial health authorities and major media outlets in mainland China. Based on these data, we conducted descriptive analyses of the epidemic in the six most-affected provinces. RESULTS: School closures, travel restrictions, community-level lockdown, and contact tracing were introduced concurrently around late January but subsequent epidemic trends differed among provinces. Compared with Hubei, the other five most-affected provinces reported a lower crude case fatality ratio and proportion of critical and severe hospitalised cases. From March 2020, as the local transmission of COVID-19 declined, switching the focus of measures to the testing and quarantine of inbound travellers may have helped to sustain the control of the epidemic. CONCLUSIONS: Aggregated indicators of case notifications and severity distributions are essential for monitoring an epidemic. A publicly available database containing these indicators and information regarding control measures is a useful resource for further research and policy planning in response to the COVID-19 epidemic.

9.
Wellcome Open Res ; 5: 81, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32500100

RESUMEN

Background: The COVID-19 epidemic was declared a Global Pandemic by WHO on 11 March 2020. By 24 March 2020, over 440,000 cases and almost 20,000 deaths had been reported worldwide. In response to the fast-growing epidemic, which began in the Chinese city of Wuhan, Hubei, China imposed strict social distancing in Wuhan on 23 January 2020 followed closely by similar measures in other provinces. These interventions have impacted economic productivity in China, and the ability of the Chinese economy to resume without restarting the epidemic was not clear. Methods: Using daily reported cases from mainland China and Hong Kong SAR, we estimated transmissibility over time and compared it to daily within-city movement, as a proxy for economic activity. Results: Initially, within-city movement and transmission were very strongly correlated in the five mainland provinces most affected by the epidemic and Beijing. However, that correlation decreased rapidly after the initial sharp fall in transmissibility. In general, towards the end of the study period, the correlation was no longer apparent, despite substantial increases in within-city movement. A similar analysis for Hong Kong shows that intermediate levels of local activity were maintained while avoiding a large outbreak. At the very end of the study period, when China began to experience the re-introduction of a small number of cases from Europe and the United States, there is an apparent up-tick in transmission. Conclusions: Although these results do not preclude future substantial increases in incidence, they suggest that after very intense social distancing (which resulted in containment), China successfully exited its lockdown to some degree. Elsewhere, movement data are being used as proxies for economic activity to assess the impact of interventions. The results presented here illustrate how the eventual decorrelation between transmission and movement is likely a key feature of successful COVID-19 exit strategies.

10.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(5): 509-512, 2020 Oct 01.
Artículo en Chino | MEDLINE | ID: mdl-33085233

RESUMEN

OBJECTIVE: This study aimed to investigate the expression of HOX transcript antisense intergenic RNA (HOTAIR) in salivary adenoid cystic carcinoma (SACC) and explore its influence on prognosis. METHODS: A total of 86 cases of patients with SACC who underwent surgical resection treatment from March 2007 to March 2014 were selected. In the same period, 45 cases of normal salivary gland tissues were obtained. The expression of HOTAIR was detected via real-time fluorescent quantitative polymerase chain reaction. The patients were followed up after the surgery, and the follow-up deadline was March 31, 2019. The deaths and survival times of patients were recorded. Based on the quartile value of the relative expression level of HOTAIR in SACC patients, the patients were divided into low expression group and high expression group. Kaplan-Meier method and Log-Rank test were used to compare the survival time of the two groups. Taking the age, sex, tumor location, pathological type, tumor diameter, TNM stage, nerve invasion and lymph node metastasis as independent variables, Cox proportional hazards regression model was used to analyze the multiple factors affecting survival time. RESULTS: The relative expression of HOTAIR in SACC tissue was 2.48±0.22, which was higher than that in normal salivary gland tissue at 1.03±0.13, and the difference was statistically significant (t=39.812, P<0.001). No nerve invasion and lymph node metastasis were observed in these patients compared with those patients with TNM stages Ⅰ or Ⅱ, while the relative expression of HOTAIR in the tissues of patients with TNM stages Ⅲ or Ⅳ, nerve invasion, and lymph node metastasis increased (P<0.05). Kaplan-Meier survival analysis showed that the average survival time and cumulative survival rate in the low expression group were higher than those in the high expression group [(113.32±10.77) months vs. (59.75±6.50) months and 72.73% vs. 39.06%, respectively, P=0.004]. Cox proportional hazard regression analysis showed that nerve invasion, lymph node metastasis, and the high expression of HOTAIR were the inde-pendent risk factors for the prognosis of patients with SACC (HR=3.274, 2.971, and 2.911, respectively, P<0.05). CONCLUSIONS: HOTAIR was highly expressed in patients with SACC tissues and associated with poor prognosis. It is a risk factor for prog-nosis, and it is expected to be a potential marker for the prognostic assessment of patients with SACC.


Asunto(s)
Carcinoma Adenoide Quístico , Neoplasias de las Glándulas Salivales , Humanos , Metástasis Linfática , Pronóstico , Tasa de Supervivencia
11.
Am J Hypertens ; 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32870256

RESUMEN

BACKGROUND: microRNAs serve as important regulators of the pathogenesis of cardiac hypertrophy. Among them, miR-183 is well documented as a novel tumor suppressor in previous studies, whereas it exhibits a downregulated expression in cardiac hypertrophy recently. The present study was aimed to examine the effect of miR-183 on cardiomyocytes hypertrophy. METHODS: Angiotensin II (Ang II) was used for establishment of cardiac hypertrophy model in vitro. Neonatal rat ventricular cardiomyocytes (NRVMs) transfected with miR-183 mimic or negative control were further utilized for the phenotype analysis. Moreover, the bioinformatics analysis and luciferase reporter assays were used for exploring the potential target of miR-183 in cardiomyocytes. RESULTS: We observed a significant decreased expression of miR-183 in hypertrophic cardiomyocytes. Overexpression of miR-183 significantly attenuated the cardiomyocytes size morphologically and pro-hypertrophic genes expression. Moreover, we demonstrated that TIAM1 was a direct target gene of miR-183 verified by bioinformatics analysis and luciferase reporter assays, which showed a decreased mRNA and protein expression in the cardiomyocytes transfected with miR-183 upon Ang II stimulation. Additionally, the downregulated TIAM1 expression was required for the attenuated effect of miR-183 on cardiomyocytes hypertrophy. CONCLUSION: Taken together, these evidences indicated that miR-183 acted as a cardio-protective regulator for the development of cardiomyocytes hypertrophy via directly regulation of TIAM1.

12.
Perfusion ; : 267659120957856, 2020 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-32909511

RESUMEN

BACKGROUND: Contrast-induced nephropathy (CIN) has become a common cause of hospital-acquired acute kidney injury in elderly patients. Trimetazidine (TMZ) is a type of anti-ischemic drug developed in recent years, which can reduce the incidence of CIN. This study aimed to evaluate the efficacy of TMZ in the prevention of contrast-induced nephropathy in elderly patients with renal insufficiency undergoing percutaneous coronary intervention (PCI) and to explore the mechanism of action. METHODS: A total of 310 elderly patients with renal insufficiency undergoing elective PCI were enrolled and randomly assigned to a control group (n = 155, hydration only) and a TMZ group (n = 155, 20 mg thrice daily orally 24 hours before and 72 hours after PCI). The primary endpoint of the study was the incidence of CIN, which was defined as an increase of 25% or more, or an absolute increase of 0.5 mg/dL or more in serum creatinine from baseline value, at 48 to 72 hours following the exposure to contrast media (CM). RESULTS: The incidence of CIN was significantly lower in the TMZ group than that in the control group (3.2% vs. 9.7%, p = 0.021). There was no difference regarding the incidence of major adverse events during hospitalization between the TMZ group and control group (1.9% vs. 2.6%, p = 1.000). Binary logistic regression results showed that TMZ was protective factors of CIN (OR = 0.274; 95% CI: 0.089-0.847; p = 0.025). CONCLUSION: Therefore, we came to the conclusion that prophylactic administration of TMZ can prevent the occurrence of CIN in elderly patients with renal insufficiency undergoing PCI and has a certain protective effect on the renal function of patients. According to the experimental results and the mechanism of TMZ on cardiomyocytes, we speculate that TMZ increases kidney glucose metabolism, reduces fatty acid oxidation, and also has a protective effect on kidney free radical damage and ischemia-reperfusion injury.

14.
Environ Sci Pollut Res Int ; 27(34): 42449-42459, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32710354

RESUMEN

Overweight/obesity modified the effects of ambient particulate matter (PM) exposure on blood pressure (BP). This study aims to assess whether interaction of underweight and short-term PM exposure on BP exists in Chinese children. A cross-sectional analysis including 144,513 children aged 6 to 17 years in 2016 Health Promotion Program for Children and Adolescents of Suzhou, China, was performed. Daily concentrations of inhalable PM (PM10) and fine PM (PM2.5) were extracted from air monitoring stations close to students' schools. We applied generalized linear mixed-effects models to estimate the interactions. Estimated changes (95% confidence intervals (CIs)) of systolic BP (SBP), diastolic BP (DBP), and odds ratios (ORs) (95% CIs) for prevalence of HBP were calculated. Significant interactions between PM and underweight on BP and prevalence of high BP (HBP) were observed. For example, at lag 6, the ORs (95% CIs) for HBP by each 10 µg/m3 changes of PM2.5 were 1.066 (1.039, 1.093) and 1.036 (1.028, 1.043) among underweight and normal weight subjects, respectively; these values for PM10 were 1.048 (1.031, 1.065) and 1.025 (1.021, 1.030). At lag 5, the increases of SBP for PM2.5 were 0.32 (95% CI 0.22, 0.43) mmHg and 0.23 (95% CI 0.29, 0.26) mmHg, while changes of DBP were 0.27 (95% CI 0.18, 0.35) mmHg and 0.19 (95% CI 0.16, 0.21) mmHg among underweight and normal weight subjects, respectively. Stratified analyses demonstrated that these interactions were only obtained in males. Effects of short-term PM exposure on BP and prevalence of HBP are enhanced in underweight children and adolescents.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Adolescente , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Presión Sanguínea , Niño , China/epidemiología , Estudios Transversales , Exposición a Riesgos Ambientales/análisis , Humanos , Masculino , Material Particulado/análisis , Delgadez
15.
Lancet Glob Health ; 8(9): e1132-e1141, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32673577

RESUMEN

BACKGROUND: COVID-19 has the potential to cause substantial disruptions to health services, due to cases overburdening the health system or response measures limiting usual programmatic activities. We aimed to quantify the extent to which disruptions to services for HIV, tuberculosis, and malaria in low-income and middle-income countries with high burdens of these diseases could lead to additional loss of life over the next 5 years. METHODS: Assuming a basic reproduction number of 3·0, we constructed four scenarios for possible responses to the COVID-19 pandemic: no action, mitigation for 6 months, suppression for 2 months, or suppression for 1 year. We used established transmission models of HIV, tuberculosis, and malaria to estimate the additional impact on health that could be caused in selected settings, either due to COVID-19 interventions limiting activities, or due to the high demand on the health system due to the COVID-19 pandemic. FINDINGS: In high-burden settings, deaths due to HIV, tuberculosis, and malaria over 5 years could increase by up to 10%, 20%, and 36%, respectively, compared with if there was no COVID-19 pandemic. The greatest impact on HIV was estimated to be from interruption to antiretroviral therapy, which could occur during a period of high health system demand. For tuberculosis, the greatest impact would be from reductions in timely diagnosis and treatment of new cases, which could result from any prolonged period of COVID-19 suppression interventions. The greatest impact on malaria burden could be as a result of interruption of planned net campaigns. These disruptions could lead to a loss of life-years over 5 years that is of the same order of magnitude as the direct impact from COVID-19 in places with a high burden of malaria and large HIV and tuberculosis epidemics. INTERPRETATION: Maintaining the most critical prevention activities and health-care services for HIV, tuberculosis, and malaria could substantially reduce the overall impact of the COVID-19 pandemic. FUNDING: Bill & Melinda Gates Foundation, Wellcome Trust, UK Department for International Development, and Medical Research Council.


Asunto(s)
Infecciones por Coronavirus/epidemiología , Países en Desarrollo , Infecciones por VIH/prevención & control , Accesibilidad a los Servicios de Salud , Malaria/prevención & control , Pandemias , Neumonía Viral/epidemiología , Tuberculosis/prevención & control , Infecciones por VIH/epidemiología , Infecciones por VIH/mortalidad , Humanos , Malaria/epidemiología , Malaria/mortalidad , Modelos Teóricos , Tuberculosis/epidemiología , Tuberculosis/mortalidad
16.
Anal Bioanal Chem ; 412(19): 4725-4737, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32476035

RESUMEN

This study was based on the specific binding ability of magnetic molecularly imprinted polymers (MMIPs) combined with a high-performance liquid chromatography-fluorescence detector (HPLC-FLD) for the rapid determination of zearalenone (ZEN) in cereals. A novel magnetic molecularly imprinted polymer was prepared by surface imprinting technology. Warfarin was used as a virtual template, 3-aminopropyl triethoxysilane (APTES) was used as the functional monomer, and tetraethyl orthosilicate (TEOS) was used as the cross-linking agent. Analysis by a vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that MMIPs were prepared with a particle size about 450 nm, the imprinted molecular layer accounting for 10.7% of the total mass, and saturation magnetization of about 34.54 emu/g. The maximum adsorption capacity (Qmax) of the thermodynamic and kinetic adsorption experiments were 13.90 mg/g and 8.71 mg/g, respectively. The Langmuir model showed that the binding sites were uniformly distributed on the surface of the MMIPs. The Scatchard analysis showed that MMIPs had two types of binding sites with Qmax of 8.22 mg/g and 15.37 mg/g, respectively. In actual sample detection, the limit of detection (LOD) and limit of quantification (LOQ) were 0.4 ng/kg and 0.9 ng/kg, respectively. The sample recovery rate was 90.56-99.96%, the daytime stability was 1.35-2.87%. These results showed that MMIPs had good performance in selectively identifying ZEN and were suitable for determining ZEN in cereals.

17.
Science ; 369(6502): 413-422, 2020 07 24.
Artículo en Inglés | MEDLINE | ID: mdl-32532802

RESUMEN

The ongoing coronavirus disease 2019 (COVID-19) pandemic poses a severe threat to public health worldwide. We combine data on demography, contact patterns, disease severity, and health care capacity and quality to understand its impact and inform strategies for its control. Younger populations in lower-income countries may reduce overall risk, but limited health system capacity coupled with closer intergenerational contact largely negates this benefit. Mitigation strategies that slow but do not interrupt transmission will still lead to COVID-19 epidemics rapidly overwhelming health systems, with substantial excess deaths in lower-income countries resulting from the poorer health care available. Of countries that have undertaken suppression to date, lower-income countries have acted earlier. However, this will need to be maintained or triggered more frequently in these settings to keep below available health capacity, with associated detrimental consequences for the wider health, well-being, and economies of these countries.


Asunto(s)
Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Países en Desarrollo , Salud Global , Pandemias/prevención & control , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Pobreza , Infecciones por Coronavirus/transmisión , Humanos , Aceptación de la Atención de Salud , Neumonía Viral/transmisión , Salud Pública
18.
J Mater Chem B ; 8(28): 6115-6127, 2020 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-32558871

RESUMEN

Articular cartilage injuries are a major orthopedic problem. Cartilage repair is a long-standing challenge due to the limited self-regenerative capability of cartilage. Tissue engineering offers a new and effective approach to cartilage repair. We report herein the fabrication of 3D scaffolds that mimic the native structure of cartilage, by first preparing poly(lactic-co-glycolic acid) (PLGA) electrospun nanofiber incorporated hydroxybutyl chitosan (HBC) hydrogels (HBC-NF hydrogels) and then injecting the hydrogels into a 3D printed poly(ε-caprolactone) (PCL) framework with internal microchannels for improved mechanical support and substance exchange. The thus-obtained HBC-NF hydrogels exhibited outstanding gelation properties with a gelling time of no more than 15 s at 37 °C. With the incorporation of the nanofibers, human mesenchymal stem cells (hMSCs) showed good proliferation in the HBC-NF hydrogels. The relative gene expression levels for mesenchymal condensation and matrix deposition significantly increased in the HBC-NF hydrogels due to the addition of the nanofibers, suggesting substantially enhanced cartilage differentiation. Furthermore, the injection of the HBC-NF hydrogels into the 3D printing PCL framework led to the formation of 3D scaffolds with significantly improved mechanical performance. More importantly, the construction of regulable internal microchannels for cell growth and the exchange of nutrients and waste products were achieved via co-printing of PCL and a sacrificial material, Pluronic F-127. The PCL reinforced HBC-NF hydrogel scaffolds with internal microchannels showed enhanced chondrogenesis and mechanical properties in vivo. In summary, the current work has demonstrated that PCL framework reinforced HBC-NF hydrogels with tunable internal microchannels provide an ideal biomimetic microenvironment for the growth and cartilage differentiation of hMSCs, therefore holding promise for potential applications in cartilage tissue engineering.

19.
J Cardiovasc Pharmacol ; 76(2): 237-245, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32467530

RESUMEN

As a receptor for transforming growth factor-ß, nodal and activin, activin receptor-like kinase 7 (ALK7) previously acts as a suppressor of tumorigenesis and metastasis, which has emerged to play a key role in cardiovascular diseases. However, the potential effect and molecular mechanism of ALK7 on vascular smooth muscle cells' (VSMCs) phenotypic modulation have not been investigated. Using cultured mouse VSMCs with platelet-derived growth factor-BB administration, we observed that ALK7 showed a significantly increased expression in VSMCs accompanied by decreased VSMCs differentiation marker genes. Loss-of-function study demonstrated that ALK7 knockdown inhibited platelet-derived growth factor-BB-induced VSMCs phenotypic modulation characterized by increased VSMCs differentiation markers, reduced proliferation, and migration of VSMCs. Such above effects were reversed by ALK7 overexpression. Notably, we noticed that ALK7 silencing dramatically enhanced PPARγ expression, which was required for the attenuated effect of ALK7 knockdown on VSMCs phenotypic modulation. Collected, we identified that ALK7 acted as a novel and positive regulator for VSMCs phenotypic modulation partially through inactivation of PPARγ, which suggested that neutralization of ALK7 might act as a promising therapeutic strategy of intimal hyperplasia.

20.
Artículo en Inglés | MEDLINE | ID: mdl-32305710

RESUMEN

A highly efficient and selective method was successfully developed by using magnetic molecularly imprinted polymers (MMIPs) combined with high performance liquid chromatography (HPLC) to quickly determine patulin (PAT) in juice. MMIPs was prepared by surface imprinting method using Fe3O4 nanoparticles as supporter, 2-oxindole as virtual template, (3-Aminopropyl) triethoxysilane (APTES) as functional monomer and tetraethyl orthosilicate (TEOS) as crosslinking agent. The structure of the product was characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that MMIP with a particle size of about 450 nm was successfully prepared, the imprinted molecular layer accounted for about 11.6% of the total mass, and the saturation magnetization was about 6.82 emu/g. The maximum adsorption capacities (Qmax) of kinetic and thermodynamic adsorption experiments were 1.97 mg/g and 4.241 mg/g, respectively. The adsorption process was highly selective and fitted well with the pseudo-second-order model. Langmuir model demonstrated that the binding sites were evenly distributed on the surface of the MMIPs. Scatchard analysis showed that MMIPs had two types of binding sites with Qmax of 4.53 mg/g and 5.73 mg/g, respectively. In the actual sample application, the limit of detection (LOD) and the limit of quantification (LOQ) were 3 µg/kg and 10 µg/kg. And the recovery rate of the sample was 86.44-95.50%. MMIPs possessed excellent applicability with stability of 1.11-3.16% and accuracy of 0.63-1.94%. These results indicated that MMIPs had good performance in separating PAT and was suitable for determining PAT in actual samples.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA