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1.
PLoS Comput Biol ; 19(6): e1011193, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37384793

RESUMO

Gestational Diabetes Mellitus (GDM), a serious complication during pregnancy which is defined by abnormal glucose regulation, is commonly treated by diabetic diet and lifestyle changes. While recent findings place the microbiome as a natural mediator between diet interventions and diverse disease states, its role in GDM is still unknown. Here, based on observation data from healthy pregnant control group and GDM patients, we developed a new network approach using patterns of co-abundance of microorganism to construct microbial networks that represent human-specific information about gut microbiota in different groups. By calculating network similarity in different groups, we analyze the gut microbiome from 27 GDM subjects collected before and after two weeks of diet therapy compared with 30 control subjects to identify the health condition of microbial community balance in GDM subjects. Although the microbial communities remain similar after the diet phase, we find that the structure of their inter-species co-abundance network is significantly altered, which is reflected in that the ecological balance of GDM patients was not "healthier" after the diet intervention. In addition, we devised a method for individualized network analysis of the microbiome, thereby a pattern is found that GDM individuals whose microbial networks are with large deviations from the GDM group are usually accompanied by their abnormal glucose regulation. This approach may help the development of individualized diagnosis strategies and microbiome-based therapies in the future.


Assuntos
Diabetes Gestacional , Microbioma Gastrointestinal , Microbiota , Gravidez , Feminino , Humanos , Microbioma Gastrointestinal/fisiologia , Dieta , Glucose
2.
Phys Chem Chem Phys ; 26(32): 21789-21800, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39101563

RESUMO

Two-dimensional silicon-carbide (SixCy) materials stand out for their compatibility with current silicon-based technologies, offering unique advantages in nanoelectronics and photocatalysis. In this study, we employ density functional theory and nonequilibrium Green's function methods to investigate the electronic properties, electron transport characteristics, and optoelectronic qualities of experimentally synthesized monolayer Si9C15. Utilizing the modified deformation potential theory formula, we unveil Si9C15's significant directional anisotropy in electron mobility (706.42 cm2 V-1 s-1) compared to holes (432.84 cm2 V-1 s-1) in the a direction. The electrical transport calculations reveal that configurations with a 3 nm channel length demonstrate an ON state when biased, reaching a peak current of 150 nA. Moreover, this maximum current value escalates to 200 nA under tensile strain, marking an increase of approximately 100 times compared to the 5 nm channel, which remains in an OFF state. Si9C15 exhibits high light absorption coefficients (∼105 cm-1) and suitable band edge positions for water splitting at pH 0-7. Applying 1-5% tensile strain can tune the conduction band minimum and valence band maximum closer to the standard redox potentials, enhancing photocatalytic water splitting efficiency. Remarkably, under illumination at pH 0 and 7, Si9C15 can spontaneously catalyze water splitting, demonstrating its potential as a highly efficient photocatalyst. Our findings emphasize the importance of strain control and device length optimization for performance enhancement in nanoelectronics and renewable energy applications, positioning Si9C15 as a promising material for high-performance field-effect transistors and photocatalytic water splitting.

3.
Phys Chem Chem Phys ; 26(5): 4284-4297, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38231547

RESUMO

In this study, we have investigated the electron mobility of monolayered (ML) tetrahex-GeC2 by solving the linearized Boltzmann transport equation (BTE) with the normalized full-band relaxation time approximation (RTA) using density functional theory (DFT). Contrary to what the deformation potential theory (DPT) suggested, the ZA acoustic mode was determined to be the most restrictive for electron mobility, not the LA mode. The electron mobility at 300 K is 803 cm2 (V s)-1, exceeding the 400 cm2 (V s)-1 of MoS2 which was calculated using the same method and measured experimentally. The ab initio quantum transport simulations were performed to assess the performance limits of sub-10 nm DG ML tetrahex-GeC2 n-type MOSFETs, including gate lengths (Lg) of 3 nm, 5 nm, 7 nm, and 9 nm, with the underlap (UL) effect considered for the first two. For both high-performance (HP) and low-power (LP) applications, their on-state currents (Ion) can meet the requirements of similar nodes in the ITRS 2013. In particular, the Ion is more remarkable for HP applications than that of the extensively studied MoS2. For LP applications, the Ion values at Lg of 7 and 9 nm surpass those of arsenene, known for having the largest Ion among 2D semiconductors. Subthreshold swings (SSs) as low as 69/53 mV dec-1 at an Lg of 9 nm were observed for HP/LP applications, and 73 mV dec-1 at an Lg of 5 nm for LP applications, indicating the excellent gate control capability. Moreover, the delay time τ and power dissipation (PDP) at Lg values of 3 nm, 5 nm, 7 nm, and 9 nm are all below the upper limits of the ITRS 2013 HP/LP proximity nodes and are comparable to or lower than those of typical 2D semiconductors. The sub-10 nm DG ML tetrahex-GeC2 n-type MOSFETs can be down-scaled to 9 nm and 5 nm for HP and LP applications, respectively, displaying desirable Ion, delay time τ, and PDP in the ballistic limit, making them a potential choice for sub-10 nm transistors.

4.
BMC Pulm Med ; 23(1): 248, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37415133

RESUMO

BACKGROUND: Interstitial lung disease (ILD) is a frequently observed comorbidity in autoimmune diseases such as dermatomyositis/polymyositis (DM/PM), and it is significantly associated with specific autoantibody types. One unique antibody type is the anti-transcription intermediate factor-1γ antibody (anti-TIF-1γ Ab), which has a positive rate of only 7%. It is often found in combination with malignancy and rarely with ILD, particularly rapidly progressive ILD (RPILD). In some cases, the presence of ILD in individuals with DM may indicate a paraneoplastic syndrome. Pneumocystis jiroveci pneumonia (PJP) typically occurs due to intensive immunosuppressive therapy, human immunodeficiency virus (HIV) infection, or malignancy, and rarely as an isolated condition. CASE PRESENTATION: A 52-year-old man with a history of rapid weight loss but non-HIV infected and not immunosuppressed who presented with fever, cough, dyspnea, weakness of the extremities, characteristic rash and mechanic's hand. Pathogenic tests suggested PJP, laboratory tests suggested a single anti-TIF-1γ Ab positive DM, imaging suggested ILD, and pathology revealed no malignancy. RPILD and acute respiratory distress syndrome (ARDS) developed after anti-infection and steroid hormone therapy. After mechanical support therapy such as Extracorporeal Membrane Oxygenation (ECMO), the patient developed late-onset cytomegalovirus pneumonia (CMVP), complicated bacterial infection, and ultimately death. Additionally, we discuss the potential causes of rapid weight loss, the mechanisms by which anti-TIF-1γ Ab may lead to ILD, and the possible connection between anti-TIF-1γ Ab positivity, rapid weight loss, immune abnormalities, and opportunistic infections. CONCLUSIONS: This case emphasizes the importance of early recognition of malignant tumors and pulmonary lesions, assessment of the body's immune status, prompt initiation of immunosuppressive treatment, and prevention of opportunistic infections in individuals with single anti-TIF-1γ Ab positive DM presenting with rapid weight loss.


Assuntos
Dermatomiosite , Doenças Pulmonares Intersticiais , Neoplasias , Infecções Oportunistas , Pneumocystis carinii , Pneumonia por Pneumocystis , Masculino , Humanos , Pessoa de Meia-Idade , Dermatomiosite/complicações , Neoplasias/complicações , Autoanticorpos , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/diagnóstico , Fatores de Transcrição , Pneumonia por Pneumocystis/complicações , Pneumonia por Pneumocystis/diagnóstico , Infecções Oportunistas/complicações , Redução de Peso , Estudos Retrospectivos
5.
Proc Natl Acad Sci U S A ; 117(30): 17528-17534, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32661171

RESUMO

While abrupt regime shifts between different metastable states have occurred in natural systems from many areas including ecology, biology, and climate, evidence for this phenomenon in transportation systems has been rarely observed so far. This limitation might be rooted in the fact that we lack methods to identify and analyze possible multiple states that could emerge at scales of the entire traffic network. Here, using percolation approaches, we observe such a metastable regime in traffic systems. In particular, we find multiple metastable network states, corresponding to varying levels of traffic performance, which recur over different days. Based on high-resolution global positioning system (GPS) datasets of urban traffic in the megacities of Beijing and Shanghai (each with over 50,000 road segments), we find evidence supporting the existence of tipping points separating three regimes: a global functional regime and a metastable hysteresis-like regime, followed by a global collapsed regime. We can determine the intrinsic critical points where the metastable hysteresis-like regime begins and ends and show that these critical points are very similar across different days. Our findings provide a better understanding of traffic resilience patterns and could be useful for designing early warning signals for traffic resilience management and, potentially, other complex systems.

6.
Proc Natl Acad Sci U S A ; 116(1): 23-28, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30591562

RESUMO

Percolation transition is widely observed in networks ranging from biology to engineering. While much attention has been paid to network topologies, studies rarely focus on critical percolation phenomena driven by network dynamics. Using extensive real data, we study the critical percolation properties in city traffic dynamics. Our results suggest that two modes of different critical percolation behaviors are switching in the same network topology under different traffic dynamics. One mode of city traffic (during nonrush hours or days off) has similar critical percolation characteristics as small world networks, while the other mode (during rush hours on working days) tends to behave as a 2D lattice. This switching behavior can be understood by the fact that the high-speed urban roads during nonrush hours or days off (that are congested during rush hours) represent effective long-range connections, like in small world networks. Our results might be useful for understanding and improving traffic resilience.

7.
Proc Natl Acad Sci U S A ; 116(18): 8673-8678, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-30979803

RESUMO

The concept of resilience can be realized in natural and engineering systems, representing the ability of a system to adapt and recover from various disturbances. Although resilience is a critical property needed for understanding and managing the risks and collapses of transportation systems, an accepted and useful definition of resilience for urban traffic as well as its statistical property under perturbations are still missing. Here, we define city traffic resilience based on the spatiotemporal clusters of congestion in real traffic and find that the resilience follows a scale-free distribution in 2D city road networks and 1D highways with different exponents but similar exponents on different days and in different cities. The traffic resilience is also revealed to have a scaling relation between the cluster size of the spatiotemporal jam and its recovery duration independent of microscopic details. Our findings of universal traffic resilience can provide an indication toward better understanding and designing of these complex engineering systems under internal and external disturbances.

8.
Proc Natl Acad Sci U S A ; 116(45): 22452-22457, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31624122

RESUMO

Catastrophic and major disasters in real-world systems, such as blackouts in power grids or global failures in critical infrastructures, are often triggered by minor events which originate a cascading failure in interdependent graphs. We present here a self-consistent theory enabling the systematic analysis of cascading failures in such networks and encompassing a broad range of dynamical systems, from epidemic spreading, to birth-death processes, to biochemical and regulatory dynamics. We offer testable predictions on breakdown scenarios, and, in particular, we unveil the conditions under which the percolation transition is of the first-order or the second-order type, as well as prove that accounting for dynamics in the nodes always accelerates the cascading process. Besides applying directly to relevant real-world situations, our results give practical hints on how to engineer more robust networked systems.

9.
Nanotechnology ; 32(2): 025201, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-32957095

RESUMO

Some advances have been achieved in developing heterojunctions consisting of indium-gallium-zinc oxide (a-IGZO) films and two dimensional (2D) van der Waals materials for optoelectronic applications in recent years, however, the improvement of IGZO channel itself via constructing such heterojunctions is rarely reported. Here, we report the huge improvement in photoresponse performances for the IGZO phototransistor devices by introducing boron nitride (BN)/black phosphorus (BP) interface engineering. By creating an appropriate band bending and an efficient photo-generated carrier transfer path between IGZO and BP, the recombination of the photo-generated carriers in the IGZO channel is significantly suppressed. As a result, the corresponding photoresponsivity at a wavelength of 447 nm can be promoted from 0.05 A W-1 to 0.3 A W-1. A corresponding maximum external quantum efficiency of 83.4% was obtained for the BN/BP decorated IGZO phototransistor. The results imply that such interface engineering via 2D materials can be used as a general route to high performance oxide-semiconductor based optoelectronic devices.

10.
Transp Res Part C Emerg Technol ; 122: 102893, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33519128

RESUMO

Passenger contact in public transit (PT) networks can be a key mediate in the spreading of infectious diseases. This paper proposes a time-varying weighted PT encounter network to model the spreading of infectious diseases through the PT systems. Social activity contacts at both local and global levels are also considered. We select the epidemiological characteristics of coronavirus disease 2019 (COVID-19) as a case study along with smart card data from Singapore to illustrate the model at the metropolitan level. A scalable and lightweight theoretical framework is derived to capture the time-varying and heterogeneous network structures, which enables to solve the problem at the whole population level with low computational costs. Different control policies from both the public health side and the transportation side are evaluated. We find that people's preventative behavior is one of the most effective measures to control the spreading of epidemics. From the transportation side, partial closure of bus routes helps to slow down but cannot fully contain the spreading of epidemics. Identifying "influential passengers" using the smart card data and isolating them at an early stage can also effectively reduce the epidemic spreading.

11.
Br J Cancer ; 122(5): 640-647, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31853007

RESUMO

BACKGROUND: We have been investigating the molecular mechanisms of cisplatin-induced chemoresistance in head and neck squamous cell carcinoma (HNSCC). Based on our previous findings, the present study investigates how the Mre11, Rad50, and NBS1 (MRN) DNA repair complex interacts at the molecular level with the programmed cell death ligand 1 (PD-L1) in cisplatin-induced chemoresistance. METHODS: Human HNSCC cell lines were used to determine the role played by PD-L1 in cisplatin resistance. Initial experiments investigated PD-L1 expression levels in cells exposed to cisplatin and whether PD-L1 interacts directly with the MRN complex. Finally, in vitro studies and in vivo experiments on BALB/c nu/nu mice were performed to determine whether interference of PD-L1 or NBS1 synthesis modulated cisplatin resistance. RESULTS: Exposure to cisplatin resulted in PD-L1 being upregulated in the chemoresistant but not the chemosensitive cell line. Subsequent co-immunoprecipitation studies demonstrated that PD-L1 associates with NBS1. In addition, we found that the knockdown of either PD-L1 or NBS1 re-sensitised the chemoresistant cell line to cisplatin. Finally, but perhaps most importantly, synergy was observed when both PD-L1 and NBS1 were knocked down making the formerly chemoresistant strain highly cisplatin sensitive. CONCLUSIONS: PD-L1 plays a pivotal role in cisplatin resistance in chemoresistant human HNSCC cell lines.


Assuntos
Hidrolases Anidrido Ácido/metabolismo , Antígeno B7-H1/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cisplatino/farmacologia , Proteínas de Ligação a DNA/metabolismo , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Proteína Homóloga a MRE11/metabolismo , Proteínas Nucleares/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Antígeno B7-H1/biossíntese , Antígeno B7-H1/genética , Linhagem Celular Tumoral , Reparo do DNA , Resistencia a Medicamentos Antineoplásicos , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Distribuição Aleatória , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Nanomedicine ; 14(2): 397-404, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29074310

RESUMO

The development of inner ear gene carriers and delivery systems has enabled genetic defects to be repaired and hearing to be restored in mouse models. Today, promising advances in translational therapies provide confidence that targeted molecular therapy for inner ear diseases will be developed. Unfortunately, the currently available non-invasive modalities, such as Computerized Tomography scan or Magnetic Resonance Imaging provide insufficient resolution to identify most pathologies of the human inner ear, even when the current generation of contrast agents is utilized. The development of targeted contrast agents may play a critical role in determining the cause of, and treatment for, sensorineural hearing loss. Such agents should be able to pass through the cochlea barriers, possess minimal cytotoxicity, and easily conjugate to a targeting agent, without distorting the anatomic details. This review focuses on a series of contrast agents which may fit these criteria for potential clinical application.


Assuntos
Orelha Interna/patologia , Perda Auditiva Neurossensorial/fisiopatologia , Imagem Molecular/métodos , Animais , Meios de Contraste/metabolismo , Orelha Interna/diagnóstico por imagem , Orelha Interna/metabolismo , Humanos
13.
Proc Natl Acad Sci U S A ; 112(3): 669-72, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25552558

RESUMO

A critical phenomenon is an intrinsic feature of traffic dynamics, during which transition between isolated local flows and global flows occurs. However, very little attention has been given to the question of how the local flows in the roads are organized collectively into a global city flow. Here we characterize this organization process of traffic as "traffic percolation," where the giant cluster of local flows disintegrates when the second largest cluster reaches its maximum. We find in real-time data of city road traffic that global traffic is dynamically composed of clusters of local flows, which are connected by bottleneck links. This organization evolves during a day with different bottleneck links appearing in different hours, but similar in the same hours in different days. A small improvement of critical bottleneck roads is found to benefit significantly the global traffic, providing a method to improve city traffic with low cost. Our results may provide insights on the relation between traffic dynamics and percolation, which can be useful for efficient transportation, epidemic control, and emergency evacuation.

14.
Chaos ; 27(8): 083105, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28863477

RESUMO

Epidemic propagation on complex networks has been widely investigated, mostly with invariant parameters. However, the process of epidemic propagation is not always constant. Epidemics can be affected by various perturbations and may bounce back to its original state, which is considered resilient. Here, we study the resilience of epidemics on networks, by introducing a different infection rate λ2 during SIS (susceptible-infected-susceptible) epidemic propagation to model perturbations (control state), whereas the infection rate is λ1 in the rest of time. Noticing that when λ1 is below λc, there is no resilience in the SIS model. Through simulations and theoretical analysis, we find that even for λ2 < λc, epidemics eventually could bounce back if the control duration is below a threshold. This critical control time for epidemic resilience, i.e., cdmax, seems to be predicted by the diameter (d) of the underlying network, with the quantitative relation cdmax ∼ dα. Our findings can help to design a better mitigation strategy for epidemics.


Assuntos
Doenças Transmissíveis/epidemiologia , Suscetibilidade a Doenças/epidemiologia , Epidemias , Modelos Teóricos , Humanos , Probabilidade , Mídias Sociais , Fatores de Tempo
15.
BMC Cancer ; 16: 190, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26951044

RESUMO

BACKGROUND: The Mre11-Rad50-Nbs1 (MRN) complex is well known for its crucial role in initiating DNA double strand breaks (DSBs) repair pathways to resistant irradiation (IR) injury and thus facilitating radioresistance which severely reduces radiocurability of nasopharyngeal cancer (NPC). Targeting native cellular MRN function would sensitize NPC cells to IR. METHODS: A recombinant adenovirus containing a mutant Rad50 gene (Ad-RAD50) expressing Rad50 zinc hook domain but lacking the ATPase domain and the Mre11 interaction domain was constructed to disrupt native cellular MRN functions. The effects of Ad-RAD50 on the MRN functions were assessed in NPC cells lines using western blot, co-immunoprecipitation and confocal microscopy analyses. The increased radiosensitivity of transient Ad-RAD50 to IR was examined in NPC cells, including MTT assay, colony formation. The molecular mechanisms of radiosensitization were confirmed by neutral comet assay and western bolts. Nude mice subcutaneous injection, tumor growth curve and TUNEL assay were used to evaluate tumor regression and apoptosis in vivo. RESULTS: Rad50 is remarkably upregulated in NPC cells after IR, implying the critical role of Rad50 in MRN functions. The transient expression of this mutant Rad50 decreased the levels of native cellular Rad50, Mre11 and Nbs1, weakened the interactions among these proteins, abrogated the G2/M arrest induced by DSBs and reduced the DNA repair ability in NPC cells. A combination of IR and mutant RAD50 therapy produced significant tumor cytotoxicity in vitro, with a corresponding increase in DNA damage, prevented proliferation and cell viability. Furthermore, Ad-RAD50 sensitized NPC cells to IR by causing dramatic tumor regression and inducing apoptosis in vivo. CONCLUSION: Our findings define a novel therapeutic approach to NPC radiosensitization via targeted native cellular Rad50 disruption.


Assuntos
Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Neoplasias Nasofaríngeas/genética , Tolerância a Radiação/genética , Hidrolases Anidrido Ácido , Animais , Apoptose , Carcinoma , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Proteína Homóloga a MRE11 , Camundongos , Complexos Multiproteicos , Mutação , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/radioterapia , Proteínas Nucleares/metabolismo , Ligação Proteica , Radiação Ionizante , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Lipids Health Dis ; 15(1): 190, 2016 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-27825356

RESUMO

BACKGROUND: The aim of the study is to compare the profiles of antibodies (IgM and IgG) against oxidized low-density lipoprotein (oxLDL) of hematological diseases. METHODS: The serum antibodies of oxLDL-IgM and oxLDL-IgG for 446 cases with hematological diseases and 90 patients with primary hypertension and 90 healthy controls were measured by enzyme-linked immunosorbent assay (ELISA) in a cross-section survey. The association of serum oxLDL-LgM and oxLDL-IgG with hematological diseases was analyzed by multiple linear regression model. RESULTS: Comparing with the hypertension or normal groups, the levels of TCH, TG, LDL-c, HDL-c, oxLDL, and oxLDL-IgG were lower and the levels of ADP and oxLDL-IgM were higher in the hematological diseases group. The levels of oxLDL-IgG antibodies titer were different among hematological diseases group. The results of correlation and multiple regression analysis showed that the seven hematological disease subgroups were positively related to the oxLDL-IgM antibody titer but negatively related to the oxLDL-IgG antibody titer, having been adjusted for potential confounding factors such as age, SBP, DBP, BMI, TCH, TG, ADP, oxLDL, HDL-c, LDL-C. CONCLUSIONS: Here we show that oxLDL-IgG antibodies titer were lower and of oxLDL-IgM titer were higher than hypertension and healthy individuals. Also oxLDL-IgG titer were different among hematological diseases group.


Assuntos
Anticorpos/sangue , Doenças Hematológicas/sangue , Lipoproteínas LDL/sangue , Adulto , Idoso , Anticorpos/imunologia , Ensaio de Imunoadsorção Enzimática , Hipertensão Essencial , Feminino , Voluntários Saudáveis , Doenças Hematológicas/imunologia , Humanos , Hipertensão/sangue , Hipertensão/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/isolamento & purificação , Imunoglobulina M/sangue , Imunoglobulina M/isolamento & purificação , Lipoproteínas LDL/imunologia , Masculino , Pessoa de Meia-Idade
18.
Hepatobiliary Pancreat Dis Int ; 15(6): 612-618, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27919850

RESUMO

BACKGROUND: Functional imaging such as CT perfusion can detect morphological and hemodynamic changes in hepatocellular carcinoma (HCC). Pre-carcinoma and early HCC nodules are difficult to differentiate by observing only their hemodynamics changes. The present study aimed to investigate hemodynamic parameters and evaluate their differential diagnostic cut-off between pre-carcinoma and early HCC nodules using CT perfusion and receiver operating characteristic (ROC) curves. METHODS: Male Wistar rats were randomly divided into control (n=20) and experimental (n=70) groups. Diethylnitrosamine (DEN) was used to induce pre-carcinoma and early HCC nodules in the experimental group. Perfusion scanning was carried out on all survival rats discontinuously from 8 to 16 weeks. Hepatic portal perfusion (HPP), hepatic arterial fraction (HAF), hepatic arterial perfusion (HAP), hepatic blood volume (HBV), hepatic blood flow (HBF), mean transit time (MTT) and permeability of capillary vessel surface (PS) data were provided by mathematical deconvolution model. The perfusion parameters were compared among the three groups of rats (control, pre-carcinoma and early HCC groups) using the Kruskal-Wallis test and analyzed with ROC curves. Histological examination of the liver tissues with hematoxylin and eosin staining was performed after CT scan. RESULTS: For HPP, HAF, HBV, HBF and MTT, there were significant differences among the three groups (P<0.05). HAF had the highest areas under the ROC curves: 0.80 (control vs pre-carcinoma groups) and 0.95 (control vs early HCC groups) with corresponding optimal cut-offs of 0.37 and 0.42, respectively. The areas under the ROC curves for HPP was 0.79 (control vs pre-carcinoma groups) and 0.92 (control vs early HCC groups) with corresponding optimal cut-offs of 136.60 mL/min/100 mg and 108.47 mL/min/100 mg, respectively. CONCLUSIONS: CT perfusion combined with ROC curve analysis is a new diagnosis model for distinguishing between pre-carcinoma and early HCC nodules. HAF and HPP are the ideal reference indices.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico por imagem , Detecção Precoce de Câncer/métodos , Cirrose Hepática Experimental/diagnóstico por imagem , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Imagem de Perfusão/métodos , Animais , Área Sob a Curva , Velocidade do Fluxo Sanguíneo , Permeabilidade Capilar , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/fisiopatologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/fisiopatologia , Diagnóstico Diferencial , Dietilnitrosamina , Artéria Hepática/diagnóstico por imagem , Artéria Hepática/fisiopatologia , Veias Hepáticas/diagnóstico por imagem , Veias Hepáticas/fisiopatologia , Circulação Hepática , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/patologia , Cirrose Hepática Experimental/fisiopatologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas Experimentais/fisiopatologia , Masculino , Veia Porta/diagnóstico por imagem , Veia Porta/fisiopatologia , Valor Preditivo dos Testes , Curva ROC , Ratos Wistar , Fatores de Tempo
19.
Glia ; 63(9): 1537-52, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25808326

RESUMO

A radial array of fortified astrocytes (FASTs) is the load bearing structure of the rat optic nerve head (ONH). At the retinal end the ONH is suspended on a fluid filled extracellular space occupied by modified pigment cells which generate a glomerular-like formation of villi. We propose that regulation of fluid in and out of this space may contribute to buffering the normal fluctuations of intraocular pressure. The energy requirement for the fluid transfer process is provided by the dense vascularity of the ONH and is reflected in the giant mitochondria of the FASTs. We propose that glaucoma occurs when a maintained rise in pressure overwhelms the capacity of this regulatory system. Under these circumstances the FAST array becomes detached from its anchorage in the surrounding ONH sheath. Progressively driven backwards by the pressure, the FASTs degenerate. We propose that the degeneration of the FASTs is associated with ischemic damage caused by the backward stretching of their blood supply. Retraction of the FAST processes deprives the retinal ganglion cell axons of their energy support, resulting in axotomy. We consider that our previously observed rescue of axons and FASTs by transplantation of olfactory ensheathing cells is due to replacement of this lost energy source.


Assuntos
Glaucoma/metabolismo , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Astrócitos/patologia , Axônios/metabolismo , Axônios/patologia , Modelos Animais de Doenças , Feminino , Glaucoma/patologia , Glaucoma/cirurgia , Pressão Intraocular/fisiologia , Modelos Biológicos , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Nervo Óptico/anatomia & histologia , Nervo Óptico/irrigação sanguínea , Nervo Óptico/metabolismo , Nervo Óptico/patologia , Ratos , Retina/anatomia & histologia , Retina/metabolismo , Retina/patologia , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Transplante
20.
Anal Biochem ; 447: 49-54, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24184356

RESUMO

Our interests are in the development of immunoassay-based fast scanning methods for persistent organic pollutants. To develop the immunoassay method of polybrominated diphenyl ether (PBDE), a model compound of PBDE, 2,3',4,5',6-pentabromodiphenylether (BDE-121), has been chosen to develop its antibody and the competitive indirect enzyme-linked immunosorbent assay (ELISA) is developed. The hapten of BDE-121 containing reactive carboxylic acid was synthesized and conjugated to carrier proteins (bovine serum albumin [BSA] and ovalbumin [OVA]). Anti-BDE-121 polyclonal antibody was then developed in rabbits as a result of immunization with the BDE-121-BSA conjugate. The optimal amount of coating antigen BDE-121-OVA conjugate and the dilution of antiserum needed in the ELISA were determined with the checkerboard method, and the effects of the properties of PBST (phosphate-buffered saline and Tween 20) buffer (pH and salt concentration) and chemical solvent (types and concentrations) on the ELISA were investigated to achieve a rapid robust assay with high sensitivity. Under the optimized conditions, the developed indirect ELISA shows a linear detection range from 1.74 to 84.1 ng/ml, with an IC50 value of 8.07 ng/ml and a detection limit of 0.644 ng/ml. In total, 11 kinds of compounds were tested for calculating the cross-reactivity, which was less than 8% for nearly all of them. Real samples were analyzed by the proposed immunoassay and gas chromatography/mass spectrometry (GC/MS).


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Éteres Difenil Halogenados/análise , Animais , Éteres Difenil Halogenados/sangue , Éteres Difenil Halogenados/imunologia , Haptenos/química , Haptenos/imunologia , Humanos , Decoração de Interiores e Mobiliário , Masculino , Pintura/análise , Coelhos
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