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1.
Br J Cancer ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32037402

RESUMO

BACKGROUND: Cancer poses a huge disease burden, which could be reduced by adopting healthy lifestyles mainly composed of healthy diet, body weight, physical activity, limited alcohol consumption, and avoidance of smoking. However, no systematic review has summarised the relations of combined lifestyle factors with cancer morbidity and mortality. METHODS: EMBASE and PubMed were searched up to April 2019. Cohort studies investigating the association of combined lifestyle factors with risks of incident cancer and cancer mortality were selected. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using random-effects models. Heterogeneity and publication bias tests were conducted. RESULTS: The HRs (95% CIs) comparing individuals with the healthiest versus the least healthy lifestyles were 0.71 (0.66-0.76; 16 studies with 1.9 million participants) for incident cancer and 0.48 (0.42-0.54; 30 studies with 1.8 million participants) for cancer mortality. Adopting the healthiest lifestyles was also associated with 17 to 58% lower risks of bladder, breast, colon, endometrial, oesophageal, kidney, liver, lung, rectal, and gastric cancer. The relations were largely consistent and significant among participants with different characteristics in the subgroup analyses. CONCLUSIONS: Adopting healthy lifestyles is associated with substantial risk reduction in cancer morbidity and mortality, and thus should be given priority for cancer prevention.

2.
J Clin Neurophysiol ; 37(1): 28-34, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31895187

RESUMO

Posttraumatic Stress Disorder (PTSD) is a leading psychiatric disorder that mainly affects military and veteran populations but can occur in anyone affected by trauma. PTSD treatment remains difficult for physicians because most patients with PTSD do not respond to current pharmacological treatment. Psychotherapy is effective, but time consuming and expensive. Substance use disorder is often concurrent with PTSD, which leads to a significant challenge for PTSD treatment. Cannabis has recently received widespread attention for the potential to help many patient populations. Cannabis has been reported as a coping tool for patients with PTSD and preliminary legalization data indicate Cannabis use may reduce the use of more harmful drugs, such as opioids. Rigorous clinical studies of Cannabis could establish whether Cannabis-based medicines can be integrated into treatment regimens for both PTSD and substance use disorder patients.

3.
BMC Cancer ; 20(1): 41, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31948422

RESUMO

BACKGROUND: There is increasing recognition that PROs are important in the estimation of the burden of long-term survival among patients with gastric cancer. The study aimed to develop a disease-specific instrument to assess patient-reported outcomes for Chinese patients with gastric cancer. METHOD: Following the FDA's draft guidance for patient-reported outcome, conceptual framework and item pool were defined based on relevant existing work. A draft scale was formed after revising some items based on feedback from experts and Chinese patients with gastric cancer. The pre-survey and formal survey were conducted in eight different hospitals in Shanxi Province, and two item-selection process based on classical test theory and item response theory. Finally, the patient-reported outcomes measure for Chinese patients with gastric cancer (GC-PROM) was validated in terms of reliability, validity, and feasibility. The minimal clinically important difference was determined by distribution-based method. RESULTS: The final GC-PROM consisted of 38 items, 13 subdomains, and 4 domains. Reliability was verified by Cronbach's alpha coefficient for four domains and 13 subdomains respectively. The validity results showed that the multidimensional scale fulfilled expectations. In the formal survey, the completion rate was 96.16%, and the average filling time was less than half an hour. The values of the minimal clinically important difference were 4.14, 3.41, 3.37, and 3.28 in the four domains. CONCLUSIONS: The GC-PROM had good reliability, validity, and feasibility and thus can be considered an effective clinical evaluation instrument for Chinese patients with gastric cancer.

4.
Arch Physiol Biochem ; : 1-9, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31994910

RESUMO

This research was designed to detect the function of low-density lipoprotein receptor (LDLR)-related protein 8 (LRP8) in breast cancer (BC). Our results revealed that LRP8 was highly expressed in BC tissues and cell lines compared with human normal breast tissues. The poor prognosis of patients with BC was associated with the up-regulation of LRP8 while inversely connected with overexpression of miR-1262. Functionally, LRP8 depletion in BC cells impaired the proliferative, clonogenic, invasive, and migratory capabilities, which was consistent with the effects of upregulated miR-1262. Bioinformatics prediction and luciferase reporter assay confirmed that miR-1262 was an upstream factor for LRP8 and negatively regulated the expression of LRP8. Further experiments illustrated that the co-transfection of miR-1262 antamir and si-LRP8 could significantly suppress the promoting impacts caused by the transfection of miR-1262 antamir alone. These findings highlighted that LRP8 accelerated the BC development by contributing cellular aggressiveness, which was modulated by miR-1262.

5.
Diabetologia ; 63(1): 21-33, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31482198

RESUMO

AIMS/HYPOTHESIS: A healthy lifestyle has been widely recommended for the prevention and management of type 2 diabetes. However, no systematic review has summarised the relationship between combined lifestyle factors (including, but not limited to, smoking, alcohol drinking, physical activity, diet and being overweight or obese) and incident type 2 diabetes and risk of health outcomes among diabetic individuals. METHODS: EMBASE and PubMed were searched up to April 2019 without language restrictions. References included in articles in relevant publications were also screened. Cohort studies investigating the combined associations of at least three lifestyle factors with incident type 2 diabetes and health outcomes among diabetic individuals were included. Reviewers were paired and independently screened studies, extracted data and evaluated study quality. Random-effects models were used to calculate summary HRs. Heterogeneity and publication bias tests were also conducted. RESULTS: Compared with participants considered to have the least-healthy lifestyle, those with the healthiest lifestyle had a 75% lower risk of incident diabetes (HR 0.25 [95% CI 0.18, 0.35]; 14 studies with approximately 1 million participants). The associations were largely consistent and significant among individuals from different socioeconomic backgrounds and baseline characteristics. Among individuals with type 2 diabetes (10 studies with 34,385 participants), the HRs (95% CIs) were 0.44 (0.33, 0.60) for all-cause death, 0.51 (0.30, 0.86) for cardiovascular death, 0.69 (0.47, 1.00) for cancer death and 0.48 (0.37, 0.63) for incident cardiovascular disease when comparing the healthiest lifestyle with the least-healthy lifestyle. CONCLUSIONS/INTERPRETATION: Adoption of a healthy lifestyle is associated with substantial risk reduction in type 2 diabetes and long-term adverse outcomes among diabetic individuals. Tackling multiple risk factors, instead of concentrating on one certain lifestyle factor, should be the cornerstone for reducing the global burden of type 2 diabetes.

6.
Immunity ; 52(1): 109-122.e6, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31882361

RESUMO

Recent work suggests that cholesterol metabolism impacts innate immune responses against infection. However, the key enzymes or the natural products and mechanisms involved are not well elucidated. Here, we have shown that upon DNA and RNA viral infection, macrophages reduced 7-dehydrocholesterol reductase (DHCR7) expression. DHCR7 deficiency or treatment with the natural product 7-dehydrocholesterol (7-DHC) could specifically promote phosphorylation of IRF3 (not TBK1) and enhance type I interferon (IFN-I) production in macrophages. We further elucidated that viral infection or 7-DHC treatment enhanced AKT3 expression and activation. AKT3 directly bound and phosphorylated IRF3 at Ser385, together with TBK1-induced phosphorylation of IRF3 Ser386, to achieve IRF3 dimerization. Deletion of DHCR7 and the DHCR7 inhibitors including AY9944 and the chemotherapy drug tamoxifen promoted clearance of Zika virus and multiple viruses in vitro or in vivo. Taken together, we propose that the DHCR7 inhibitors and 7-DHC are potential therapeutics against emerging or highly pathogenic viruses.


Assuntos
Desidrocolesteróis/metabolismo , Fator Regulador 3 de Interferon/metabolismo , Interferon Tipo I/biossíntese , Macrófagos/imunologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Estomatite Vesicular/imunologia , Células A549 , Animais , Linhagem Celular , Colesterol/metabolismo , Ativação Enzimática/imunologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células RAW 264.7 , Interferência de RNA , RNA Interferente Pequeno/genética , Vírus da Estomatite Vesicular Indiana/imunologia
7.
Nature ; 577(7790): 410-415, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31875848

RESUMO

The metabolic pathways encoded by the human gut microbiome constantly interact with host gene products through numerous bioactive molecules1. Primary bile acids (BAs) are synthesized within hepatocytes and released into the duodenum to facilitate absorption of lipids or fat-soluble vitamins2. Some BAs (approximately 5%) escape into the colon, where gut commensal bacteria convert them into various intestinal BAs2 that are important hormones that regulate host cholesterol metabolism and energy balance via several nuclear receptors and/or G-protein-coupled receptors3,4. These receptors have pivotal roles in shaping host innate immune responses1,5. However, the effect of this host-microorganism biliary network on the adaptive immune system remains poorly characterized. Here we report that both dietary and microbial factors influence the composition of the gut BA pool and modulate an important population of colonic FOXP3+ regulatory T (Treg) cells expressing the transcription factor RORγ. Genetic abolition of BA metabolic pathways in individual gut symbionts significantly decreases this Treg cell population. Restoration of the intestinal BA pool increases colonic RORγ+ Treg cell counts and ameliorates host susceptibility to inflammatory colitis via BA nuclear receptors. Thus, a pan-genomic biliary network interaction between hosts and their bacterial symbionts can control host immunological homeostasis via the resulting metabolites.

8.
Front Genet ; 10: 1195, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31824577

RESUMO

Mediation analysis has been a powerful tool to identify factors mediating the association between exposure variables and outcomes. It has been applied to various genomic applications with the hope to gain novel insights into the underlying mechanism of various diseases. Given the high-dimensional nature of epigenetic data, recent effort on epigenetic mediation analysis is to first reduce the data dimension by applying high-dimensional variable selection techniques, then conducting testing in a low dimensional setup. In this paper, we propose to assess the mediation effect by adopting a high-dimensional testing procedure which can produce unbiased estimates of the regression coefficients and can properly handle correlations between variables. When the data dimension is ultra-high, we first reduce the data dimension from ultra-high to high by adopting a sure independence screening (SIS) method. We apply the method to two high-dimensional epigenetic studies: one is to assess how DNA methylations mediate the association between alcohol consumption and epithelial ovarian cancer (EOC) status; the other one is to assess how methylation signatures mediate the association between childhood maltreatment and post-traumatic stress disorder (PTSD) in adulthood. We compare the performance of the method with its counterpart via simulation studies. Our method can be applied to other high-dimensional mediation studies where high-dimensional mediation variables are collected.

9.
Ther Clin Risk Manag ; 15: 1333-1341, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31814728

RESUMO

Background: The re-hospitalization rate of patients with heart failure remains at a high level, and studies of the subject have focused mainly on event-time outcomes. In addition to using re-hospitalization data with the outcomes of the event-time-count, this study introduces the conditional frailty model, which could help obtain more reasonable results. Materials and methods: This prospective observational cohort study enrolled 1484 patients with heart failure caused by coronary heart disease. The outcomes of heart failure readmissions and the case report form data were collected. Based on the traditional Cox model with event-time outcomes, the mixed effects of a conditional frailty model were added to analyze the event-time-count longitudinal data. Results: The Cox regression model showed that non-manual work, diastolic dysfunction, and better medical compensation increased the risk of heart failure readmission, whereas treatment with beta-blockers decreased the risk. The conditional frailty model further revealed that age, female sex, non-manual work, better medical compensation, longer QRS duration, and treatment with percutaneous coronary intervention increased the risk of heart failure readmission. Conclusion: This study obtained more reliable, reasonable results based on longitudinal data and a mixed model. The results could provide more clinical epidemiological evidence for the management of heart failure.

10.
Neurol Sci ; 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31758346

RESUMO

BACKGROUND AND OBJECTIVES: Parkinson's disease (PD) is one of the most common forms of neurodegenerative disorders, and its etiology remains unclear. Single nucleotide polymorphisms (SNPs) of alpha-synuclein (SNCA) have been found to be significantly associated with PD risk. In particular, the variant rs11931074 was found in one meta-analysis to appear to play a role in the occurrence of PD. This finding has been questioned in subsequent studies, however. The aim of this study was to determine the relationship between PD risk and rs11931074 polymorphism. METHODS: We performed a systematic online search, including PubMed, Web of Science, EMBASE, Cochrane Library, and CNKI (China National Knowledge Infrastructure), aiming to identify case-control studies looking at the role of rs11931074 in PD. We performed calculations of pooled odds ratio (OR) and 95% confidence interval (95% CI) to assess the associations, and subgroup meta-analyses to verify differences between various ethnicities of different study populations. RESULTS: A total of 13 studies involving 13,403 cases and 28,408 controls met the inclusion criteria after assessment by two reviewers. Overall, there exists significant associations between SNCA rs11931074 polymorphism and the risk of PD under five genetic models (allele contrast model: T vs. G, OR = 1.28, 95% CI = 1.12-1.45, P = 0.0001; homozygote model: TG vs. GG, OR = 1.55, 95% CI = 1.17-2.05, P = 0.002; heterozygote model (TT vs. GG, OR = 1.23, 95% CI = 1.05-1.42, P = 0.009; dominant model: TG+TT vs. GG: OR = 1.25, 95% CI = 1.05-1.50, P = 0.01 and recessive model: TT vs. TG+GG: OR = 1.40, 95% CI = 1.18-1.68, P = 0.0002). When ethnicities were stratified, significant associations were found in the allelic, homozygote, and recessive models for Asians, and in the allelic model for Caucasians. CONCLUSION: SNCA rs11931074 polymorphism is found to be associated with PD risk and this risk appears to be influenced by genetic status and ethnicity.

11.
Microsc Microanal ; : 1-10, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31753061

RESUMO

Atom probe tomography (APT) has emerged as an important tool in characterizing three-dimensional semiconductor devices. However, the complex structure and hybrid nature of a semiconductor device can pose serious challenges to the accurate measurement of dopants. In particular, local magnification and trajectory aberration observed when analyzing hybrid materials with different evaporation fields can cause severe distortions in reconstructed geometry and uncertainty in local chemistry measurement. To address these challenges, this study systematically investigates the effect of APT sampling directions on the measurement of n-type dopants P and As in an Si fin field-effect transistor (FinFET). We demonstrate that the APT samples made with their Z-axis perpendicular to the center axis of the fin are effective to minimize the negative effects that result from evaporation field differences between the Si fin and SiO2 on reconstruction and achieve improved measurement of dopant distributions. In addition, new insights have been gained regarding the distribution of ion-implanted P and As in the Si FinFET.

12.
Front Pharmacol ; 10: 1247, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695615

RESUMO

Global cerebral ischemia (GCI) commonly occurs in the elderly. Subcortical white matter lesions and oligodendrocyte (OLG) loss caused by cerebral ischemia have been implicated in the development of post-ischemic depression and cognitive impairment. OLGs are necessary for axonal myelination; the disrupted differentiation of OLG progenitor cells (OPCs) is associated with impaired remyelination. Evidence has indicated that increased levels of inflammatory cytokines released from activated microglia induce depression-like behaviors by affecting neurotransmitter pathways, but the mechanisms remain elusive. We explored the potential mechanisms that link microglia activation with GCI-induced depression and cognitive dysfunction by studying effects of minocycline on white matter damage, cytokine levels, and the monoaminergic neurotransmitters. An acute GCI animal model was generated through bilateral common carotid artery occlusion to induce ischemic inflammation and subcortical white matter damage. Minocycline, an inhibitor of microglia activation, was intraperitoneally administrated immediately after surgery and continued daily for additional six days. Minocycline shortened the immobile duration in tail suspension test and forced swimming test, while no improvement was found in Morris water maze test. The plasma levels of IL-1ß, IL-6, TNF-α, HMGB1, and netrin-1 were significantly reduced with the treatment of minocycline. Minocycline treatment substantially reversed demyelination in corpus callosum and hippocampus, alleviated hippocampal microglia activation, and promoted OPCs maturation, while no effect was found on hippocampal neurodegeneration. Besides, the content of dopamine (DA) in the hippocampus was upregulated by minocycline treatment after GCI. Collectively, our data demonstrated that minocycline exerts an anti-depressant effect by inhibiting microglia activation, promoting OPCs maturation and remyelination. Increased DA in hippocampus may also play a role in ameliorating depressive behavior with minocycline treatment.

13.
BMJ ; 367: l5584, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619383

RESUMO

OBJECTIVE: To investigate the association between weight changes across adulthood and mortality. DESIGN: Prospective cohort study. SETTING: US National Health and Nutrition Examination Survey (NHANES) 1988-94 and 1999-2014. PARTICIPANTS: 36 051 people aged 40 years or over with measured body weight and height at baseline and recalled weight at young adulthood (25 years old) and middle adulthood (10 years before baseline). MAIN OUTCOME MEASURES: All cause and cause specific mortality from baseline until 31 December 2015. RESULTS: During a mean follow-up of 12.3 years, 10 500 deaths occurred. Compared with participants who remained at normal weight, those moving from the non-obese to obese category between young and middle adulthood had a 22% (hazard ratio 1.22, 95% confidence interval 1.11 to 1.33) and 49% (1.49, 1.21 to 1.83) higher risk of all cause mortality and heart disease mortality, respectively. Changing from obese to non-obese body mass index over this period was not significantly associated with mortality risk. An obese to non-obese weight change pattern from middle to late adulthood was associated with increased risk of all cause mortality (1.30, 1.16 to 1.45) and heart disease mortality (1.48, 1.14 to 1.92), whereas moving from the non-obese to obese category over this period was not significantly associated with mortality risk. Maintaining obesity across adulthood was consistently associated with increased risk of all cause mortality; the hazard ratio was 1.72 (1.52 to 1.95) from young to middle adulthood, 1.61 (1.41 to 1.84) from young to late adulthood, and 1.20 (1.09 to 1.32) from middle to late adulthood. Maximum overweight had a very modest or null association with mortality across adulthood. No significant associations were found between various weight change patterns and cancer mortality. CONCLUSIONS: Stable obesity across adulthood, weight gain from young to middle adulthood, and weight loss from middle to late adulthood were associated with increased risks of mortality. The findings imply that maintaining normal weight across adulthood, especially preventing weight gain in early adulthood, is important for preventing premature deaths in later life.


Assuntos
Doenças Cardiovasculares , Causas de Morte , Mortalidade Prematura/tendências , Mortalidade/tendências , Neoplasias , Ganho de Peso , Perda de Peso , Adulto , Índice de Massa Corporal , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Neoplasias/mortalidade , Inquéritos Nutricionais , Obesidade/diagnóstico , Obesidade/mortalidade , Estudos Prospectivos , Fatores de Risco , Estados Unidos/epidemiologia , Razão Cintura-Estatura
14.
BMC Infect Dis ; 19(1): 765, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477045

RESUMO

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) is an emerging zoonotic infectious disease caused by hantaviruses which circulate worldwide. So far, it was still considered as one of serious public health problems in China. The present study aimed to reveal the stabilities and variations of hantavirus infection in Hebei province located in North China through a long-term retrospective observation. METHODS: The epidemiological data of HFRS cases from all 11 cities of Hebei province since 1981 through 2016 were collected and descriptively analyzed. The rodent densities, species compositions and virus-carrying rates of different regions were collected from six separated rodent surveillance points which set up since 2007. The molecular diversity and phylogenetic relationship of hantaviruses circulating among rodents were analyzed based on partial viral glycoprotein gene. RESULTS: HFRS cases have been reported every year in Hebei province, since the first local case was identified in 1981. The epidemic history can be artificially divided into three phases and a total of 55,507 HFRS cases with 374 deaths were reported during 1981-2016. The gender and occupational factors of susceptible population were invarible throughout, however age of that was gradually aging. The annual outbreak peak always present in spring, while the main epidemic region had gradully altered from south to northeast. Surveillance of rodents revealed that residential rodents significantly possessed higher density and virus-carring rate than field rodents. The house rat, Rattus norvegicus, was the dominant rodent species and Seoul virus S3 sub-genotype which is continued but slightly evolving perhaps to be the sole pathogen for local HFRS cases of Hebei province. CONCLUSIONS: This long-term province-wide surveillance and epidemiological analysis has revealed the stabilities and variations of hantavirus infection in North China. In order to improve current prevention and control strategies of HFRS in China, all surveillance should be continuously enhanced and variations should be paid more attentions.


Assuntos
Infecções por Hantavirus/epidemiologia , Febre Hemorrágica com Síndrome Renal/epidemiologia , Animais , China/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Epidemias/estatística & dados numéricos , Genótipo , Hantavirus/classificação , Hantavirus/genética , Hantavirus/isolamento & purificação , Infecções por Hantavirus/virologia , Febre Hemorrágica com Síndrome Renal/virologia , Humanos , Filogenia , Dinâmica Populacional , Vigilância da População , Ratos , Estudos Retrospectivos , Roedores/virologia , Fatores de Tempo , Zoonoses/epidemiologia , Zoonoses/virologia
15.
Nat Microbiol ; 4(12): 2331-2346, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31477895

RESUMO

The special organelle-located MAVS, STING and TLR3 are important for clearing viral infections. Although TLR4 triggers NF-κB activation to produce pro-inflammatory cytokines for bacterial clearance, effectors with special organelle localization have not been identified. Here, we screened more than 280 E3 ubiquitin ligases and discovered that the endoplasmic reticulum-located Hrd1 regulates TLR4-induced inflammation during bacterial infection. Hrd1 interacts directly with the deubiquitinating enzyme Usp15. Unlike the classical function of Hrd1 in endoplasmic reticulum-associated degradation, Usp15 is not degraded but loses its deubiquitinating activity for IκBα deubiquitination, resulting in excessive NF-κB activation. Importantly, Hrd1 deficiency in macrophages protects mice against lipopolysaccharide-induced septic shock, and knockdown of Usp15 in Hrd1-knockout macrophages restores the reduced IL-6 production. This study proposes that there is crosstalk between Hrd1 and TLR4, thereby linking the endoplasmic reticulum-plasma membrane function during bacterial infection.

16.
Cells ; 8(8)2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31412678

RESUMO

In recent decades, the biomedical applications of mesenchymal stem cells (MSCs) have attracted increasing attention. MSCs are easily extracted from the bone marrow, fat, and synovium, and differentiate into various cell lineages according to the requirements of specific biomedical applications. As MSCs do not express significant histocompatibility complexes and immune stimulating molecules, they are not detected by immune surveillance and do not lead to graft rejection after transplantation. These properties make them competent biomedical candidates, especially in tissue engineering. We present a brief overview of MSC extraction methods and subsequent potential for differentiation, and a comprehensive overview of their preclinical and clinical applications in regenerative medicine, and discuss future challenges.

17.
Med Phys ; 46(11): 4803-4815, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31408539

RESUMO

PURPOSE: In computed tomography (CT), miscalibrated or imperfect detector elements produce stripe artifacts in the sinogram. The stripe artifacts in Radon space are responsible for concentric ring artifacts in the reconstructed images. In this work, a novel optimization model is proposed to remove the ring artifacts in an iterative reconstruction procedure. METHOD: In the proposed optimization model, a novel ring total variation (RTV) regularization is developed to penalize the ring artifacts in the image domain. Moreover, to correct the sinogram, a new correcting vector is proposed to compensate for malfunctioning of detectors in the projection domain. The optimization problem is solved by using the alternating minimization scheme (AMS). In each iteration, the fidelity term along with the RTV regularization is solved using the alternating direction method of multipliers (ADMM) to find the image, and then the correcting coefficient vector is updated for certain detectors according to the obtained image. Because the sinogram and the image are simultaneously updated, the proposed method basically performs in both image and sinogram domains. RESULTS: The proposed method is evaluated using both simulated and physical phantom datasets containing different ring artifact patterns. In the simulated datasets, the Shepp-Logan phantom, a real chest scan image and a noisy low-contrast phantom are considered for the performance evaluation of our method. We compare the quantitative root mean square error (RMSE) and structural similarity (SSIM) results of our algorithm with wavelet-Fourier sinogram filtering method by Munch et al., the ring artifact reduction method by Brun et al., and the TV-based ring correction method by Paleo and Mirone. Our proposed method is also evaluated using a physical phantom dataset where strong ring artifacts are manifest due to the miscalibration of a large number of detectors. Our proposed method outperforms the competing methods in terms of both qualitative and quantitative evaluation results. CONCLUSION: The experimental results in both simulated and physical phantom datasets show that the proposed method achieves the state-of-the-art ring artifact reduction performance in terms of RMSE, SSIM, and subjective visual quality.

18.
J Nanosci Nanotechnol ; 19(12): 7953-7959, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196315

RESUMO

The aim of this study was to investigate the manifestation and significance of changes in both telomere length and the expression of human telomere protective protein (hPOT1) in the peripheral blood leukocytes of patients with atherosclerosis (AS). One hundred subjects-excluding those with acute or chronic inflammation, cancer, and autoimmune diseases-were enrolled in this study and divided into two groups: the atherosclerosis group (AS group) and control group. We extracted peripheral blood leukocyte DNA along with its peripheral proteins. After purity testing, a digoxigeninlabeled telomere probe was used for Southern blotting; the length of the telomeres was obtained by image scanning and software analysis. After extracting the peripheral proteins, hPOT1 expression was detected by western blotting and scanned with an image analysis software system. We found that the telomere lengths in the peripheral blood leukocytes of AS and control groups were 7.45 ± 1.15 kb versus 8.11 ± 0.69 kb, respectively, and that the difference between them was statistically significant (p < 0.005). The expression level of hPOT1 protein in the peripheral blood leukocytes of the AS group was significantly higher than that of the control group (t = 3.77, p < 0.01). As can be determined from these results, telomere length in the peripheral blood leukocytes of AS patients was significantly shorter compared with that of the control group. The regulation of telomere length by hPOT1 by negative regulation may be one of the influencing factors in AS. Therefore, it is suggested that change in telomere length may play a role in the occurrence and development of AS.

19.
Bioorg Med Chem ; 27(12): 2657-2665, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047774

RESUMO

Two series of moscatilin derivatives were designed, synthesized and evaluated as anti-tumor and anti-angiogenesis agents. Most of these compounds showed moderate-to-obvious cytotoxicity against five cancer cell lines (A549, HepG2, MDA-MB-231, MKN-45, HCT116). Among these cell lines, compounds had obvious effects on HCT116. Especially for 8Ae, the IC50 was low to 0.25 µM. 8Ae can inhibit the viability and induce the apoptosis of HCT116 cells but exhibit no cytotoxic activity in noncancerous NCM460 colon cells. 8Ae can also arrest the G2/M cell cycle in HCT116 cells by inhibiting the α-tubulin expression. Zebrafish bioassay-guided screen showed the 22 moscatilin derivatives had potent anti-angiogenic activities and compound 8Ae had better activities than positive compound. Molecular docking indicated 8Ae interacted with tubulin at the affinity of -7.2 Kcal/mol. In conclusion, compound 8Ae was a potential antitumor and anti-angiogenesis candidate for further development.

20.
J Xray Sci Technol ; 27(3): 397-416, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31081796

RESUMO

BACKGROUNDAs one type of the state-of-the-art detectors, photon counting detectors are used in spectral computed tomography (CT) to classify the received photons into several energy channels and generate multichannel projections simultaneously. However, FBP reconstructed images contain severe noise due to the low photon counts in each energy channel.OBJECTIVEA spectral CT image denoising method based on tensor-decomposition and non-local means (TDNLM) is proposed.METHODSIn a CT image, it is widely accepted that there exists self-similarity over the spatial domain. In addition, because a multichannel CT image is obtained from the same object at different energies, images among different channels are highly correlated. Motivated by these two characteristics of the spectral CT images, tensor decomposition and non-local means are employed to recover fine structures in spectral CT images. Moreover, images in all energy channels are added together to form a high signal-to-noise ratio image, which is applied to encourage the signal preservation of the TDNLM. The combination of TD, NLM and the guidance of a high-quality image enhances the low-dose spectral CT, and a parameter selection strategy is designed to achieve the optimal image quality.RESULTSThe effectiveness of the developed algorithm is validated on both numerical simulations and realistic preclinical applications. The root mean square error (RMSE) and the structural similarity (SSIM) are used to quantitatively assess the image quality. The proposed method successfully restored high-quality images (average RMSE=0.0217 cm-1 and SSIM=0.987) from noisy spectral CT images (average RMSE=0.225 cm-1 and SSIM=0.633). In addition, RMSE of each decomposed material component is also remarkably reduced. Compared to the state-of-the-art iterative spectral CT reconstruction algorithms, the proposed method achieves comparable performance with dramatically reduced computational cost, resulting in a speedup of >50.CONCLUSIONSThe outstanding denoising performance, the high computational efficiency and the adaptive parameter selection strategy make the proposed method practical for spectral CT applications.

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