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3.
Nanoscale Adv ; 4(22): 4756-4765, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36381512

RESUMO

Biomimetic properties allow soft robots to complexly interact with the environment. As the bridge between the robot and the operating object, the gripping hand is an important organ for its connection with the outside world, which requires the ability to provide feedback from the grasped object, similar to the human sensory and nervous system. In this work, to cope with the difficulty of integrating complex sensing and communication systems into flexible soft grippers, we propose a GO/PI composite bilayer film-based gripper with two types of tactile sensors and a LC passive wireless transmission module to obtain the grip information and transmit it to the processor. The bilayer film structure demonstrates good photothermal driving performance. Pressure and material sensors are located at the tips of the gripper's fingers to acquire tactile information which is wirelessly transmitted to the processor for analysis via the LC circuit. The grasping and feedback of the gripper are presented through an intelligent display system, realizing the wireless interconnection between the robot terminal and processing system, exhibiting broad application potential.

4.
Int J Mol Sci ; 23(3)2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35163709

RESUMO

Chorioamnionitis (CAM) is an increasingly common disease affecting pregnant women which derives from bacterial vaginosis. In different clinical cases, it has been shown that CAM can cause multiple risk factors for fetal brain damage, such as infection, and intra-uterine asphyxia. However, the molecular mechanism remains unknown. In this study, we established a novel CAM mouse model by exposing pregnant mice to a combination of three risk factors: vaginal lipopolysaccharides (LPS), amniotic LPS, and ischemic reperfusion. We found amniotic LPS caused Parkinson's disease-like fetal brain damage, in a dose and time-dependent manner. Moreover, the mechanism of this fetal brain damage is apoptosis induced by amniotic LPS but it was inhibited by being pretreated with a vaginal LPS challenge before amniotic LPS injection. In contrast, amniotic LPS with continuous ischemic reperfusion caused a higher level of apoptotic cell death than amniotic LPS alone. In particular, a potential neuroprotective biomarker phosphorylation (p)-CREB (ser133) appeared in only vaginal LPS preconditioned before amniotic LPS, whereas ischemic reperfusion triggered IKK phosphorylation after amniotic LPS. Despite the need for many future investigations, this study also discussed a developed understanding of the molecular mechanism of how these phenotypes occurred.


Assuntos
Corioamnionite , Lipopolissacarídeos , Animais , Apoptose , Encéfalo/metabolismo , Corioamnionite/metabolismo , Feminino , Humanos , Lipopolissacarídeos/metabolismo , Camundongos , Gravidez , Reperfusão
5.
ACS Appl Mater Interfaces ; 14(4): 6138-6147, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35050581

RESUMO

Soft robots based on bionics have attracted extensive attention in recent years. However, most of previous works focused on the motion of robots that were incapable of communication and perception. In this work, an untethered crawling robot is proposed with integration of motion, communication, and location based entirely on a flexible material, which is capable of being utilized as a sensing platform. The hydrophilic graphene oxide film, capable of photothermal conversion, allows the robot to undergo a large deformation stimulated by near-infrared light. Conductive fabric with low resistivity and high mechanical strength, replacing the traditional rigid circuit, is utilized to complete the communication of the robot. The designed communication module allows an electrical signal to be inductively coupled to the soft robot instead of being generated by batteries or through transmission lines. The perception of the robot is demonstrated by covering sensitive materials. Furthermore, the positioning and identification of the robot are verified by an external coil array. The proposed soft crawling robot provides an innovative strategy for the integration of multifunctional robots and shows great potential in bionic devices, intelligent robots, and advanced sensors.

6.
Sci Rep ; 11(1): 20019, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34625602

RESUMO

Dysfunction of immunoinhibitory signals and persistent T cell activation reportedly play important roles in the development of vasculitis. The skin is one of the most accessible organs, and it is suitable for the characterization of immune cell signatures. However, the inhibitory checkpoint molecules in the skin and their relevance to vasculitis have not been studied. Here, we investigated the profile of immune checkpoint molecules in the skin and peripheral blood of patients with vasculitis and healthy donors. We found that some of the inhibitory checkpoint molecules, including programmed cell death 1 receptor (PD-1), were elevated in T-cells in the blood of patients with systemic and cutaneous vasculitis. In addition, programmed death-ligand 1 (PD-L1) expression was elevated in the skin of patients with cutaneous vasculitis. Histologically, PD-L1 was highly expressed in the vessels in the skin along with CD4+ and CD8+ T-cell infiltration in patients with cutaneous vasculitis. Notably, plasma soluble PD-L1 levels were increased, and these correlated with C-reactive protein in patients with systemic vasculitis. Our findings suggest that inhibitory checkpoint molecules might be differentially modulated in the skin and peripheral blood of patients with vasculitis, and that the alteration of the PD-L1/PD-1 axis may be associated with the regulation of T-cell activation in vasculitis.


Assuntos
Antígeno B7-H1 , Biomarcadores , Ativação Linfocitária/imunologia , Receptor de Morte Celular Programada 1 , Vasculite/imunologia , Adulto , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Pele/metabolismo
7.
Risk Manag Healthc Policy ; 14: 2011-2019, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34040464

RESUMO

After the first wave of the COVID-19 pandemic that began in early 2020 was brought under control, there have been some regional and small-scale cases of new infections in China. In order to prevent the resurgence of the epidemic, the Chinese government has continued the use of effective prevention and control measures in key epidemic areas. New prevention and control measures have also been developed based on the characteristics of the epidemic and the social habits of the Chinese people. The strategies applied in China include large-scale nucleic acid testing, travel health code management, and patient treatment based on a combination of Chinese and Western medicine. These measures can provide a reference point for the global public health system that is facing the pandemic. The article suggests that to prevent a pandemic, we must not only rely on vaccines and drugs, but also need to take actions and apply social measures to manage the risk of infectious diseases.

8.
J Dermatol ; 48(5): 703-706, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33600009

RESUMO

We assessed the IgG and IgM prevalence of anti-phosphatidylserine/prothrombin complex (aPS/PT) antibodies (Abs) in patients with vasculitis using a novel commercial ELISA kit. To examine whether aPS/PT Abs were involved in the pathogenesis of cutaneous vasculitis, inbred wild-type rats were intravenously administered with a rat IgM class aPS/PT monoclonal Ab established previously or with rat immunoglobulins as controls. To express PS on the surface of vascular endothelium, these rats were given a subcutaneous injection of cell-free histones in advance. Serum IgM aPS/PT Ab levels were elevated in patients with systemic vasculitis with skin involvement and cutaneous arteritis compared to those in patients with systemic vasculitis without skin involvement and healthy controls. There was no significant difference in the serum levels of IgG aPS/PT Abs between the patients and healthy controls. Correspondingly, inbred wild-type rats intravenously administered with the aPS/PT monoclonal IgM Ab after appropriate priming-subcutaneous histone injection developed cutaneous vasculitis. Some rats given rat IgM instead of the aPS/PT monoclonal Ab also developed cutaneous vasculitis, whereas vasculitis did not occur in rats given IgG or only priming by histones. We suggested that IgM aPS/PT Abs could be involved in the pathogenesis of cutaneous vasculitis based on these findings.


Assuntos
Dermatopatias Vasculares , Vasculite , Animais , Anticorpos Antifosfolipídeos , Humanos , Fosfatidilserinas , Protrombina , Ratos
10.
Zhongguo Gu Shang ; 33(11): 1037-41, 2020 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-33269854

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of local application of tranexamic acid (TXA) in reducing perioperative blood loss in total hip arthroplasty via direct anterior approach (DAA). METHODS: From July 2013 to September 2018, 46 patients with avascular necrosis of the femoral head were divided into tranexamic acid group (n=23) and saline group (n=23). In the tranexamic acid group, there were 14 males and 9 females, aged 52 to 72(63.70±5.34) years old. They were diluted with 3 g tranexamic acid in 50 ml normal saline and immersed in the joint cavity for 3 min after prosthesis replacement;in the normal saline group, there were 13 males and 10 females, aged 55 to 73 (61.26±5.78) years, who were treated with the sameamount of normal saline. The blood loss, hemoglobin value, number of blood transfusion cases, the time of first landing after operation, the incidence of thrombosis and incision adverse events were compared between the two groups. Harris score was used to evaluate hip joint function at 1 and 3 months after operation. RESULTS: The incision healed well and no obvious complications occurred in the two groups. All patients were followed up for 12 to 59 months(averaged 31.11 months). No hip pain was found in the follow-up patients. Hip joint function was improved effectively and no prosthesis loosening occurred. The total perioperative blood loss in tranexamic acid group and normal saline group was(740.09±77.14) ml and (1 069.07±113.53) ml respectively, 24 hours after operation, the drainage volume was (87.61±9.28) ml, (233.83±25.62) ml, the hidden blood loss was (409.65±38.01) ml and (588.33±57.16) ml. the difference of hemoglobin before and after operation was (24.78±2.19) g / L and (33.57±2.95) g / L, the difference was statistically significant (P<0.05). There was no significant difference in blood loss, incidence of deep vein thrombosis and pulmonary embolism, and Harris score of hip joint between the two groups (P>0.05). CONCLUSION: local application of tranexamic acid in total hip arthroplasty through direct anterior approach can safely and effectively reduce perioperative blood loss, and does not increase the risk of thrombosis, and does not affect the normal recovery of joint function.


Assuntos
Antifibrinolíticos , Antivirais , Artroplastia de Quadril , Hepatite C Crônica , Ácido Tranexâmico , Idoso , Antifibrinolíticos/uso terapêutico , Artroplastia de Quadril/efeitos adversos , Perda Sanguínea Cirúrgica/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Segurança , Ácido Tranexâmico/uso terapêutico , Resultado do Tratamento
11.
Front Microbiol ; 11: 1279, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32695073

RESUMO

To investigate the mechanisms of phospholipase C (PLC)-mediated calcium (Ca2+) signaling in Alternaria alternata, the regulatory roles of PLC were elucidated using neomycin, a specific inhibitor of PLC activity. Three isotypes of PLC designated AaPLC1, AaPLC2, and AaPLC3 were identified in A. alternata through genome sequencing. qRT-PCR analysis showed that fruit wax extracts significantly upregulated the expression of all three PLC genes in vitro. Pharmacological experiments showed that neomycin treatment led to a dose-dependent reduction in spore germination and appressorium formation in A. alternata. Appressorium formation was stimulated on hydrophobic and pear wax-coated surfaces but was significantly inhibited by neomycin treatment. The appressorium formation rates of neomycin treated A. alternata on hydrophobic and wax-coated surfaces decreased by 86.6 and 47.4%, respectively. After 4 h of treatment, exogenous CaCl2 could partially reverse the effects of neomycin treatment. Neomycin also affected mycotoxin production in alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), and tentoxin (TEN), with exogenous Ca2+ partially reversing these effects. These results suggest that PLC is required for the growth, infection structure differentiation, and secondary metabolism of A. alternata in response to physiochemical signals on the pear fruit surface.

12.
Toxins (Basel) ; 12(2)2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-32075318

RESUMO

Black spot caused by Alternaria alternata is one of the important diseases of pear fruit during storage. Isothiocyanates are known as being strong antifungal compounds in vitro against different fungi. The aim of this study was to assess the antifungal effects of the volatile compound 2-phenylethyl isothiocyanate (2-PEITC) against A. alternata in vitro and in pear fruit, and to explore the underlying inhibitory mechanisms. The in vitro results showed that 2-PEITC significantly inhibited spore germination and mycelial growth of A. alternata-the inhibitory effects showed a dose-dependent pattern and the minimum inhibitory concentration (MIC) was 1.22 mM. The development of black spot rot on the pear fruit inoculated with A. alternata was also significantly decreased by 2-PEITC fumigation. At 1.22 mM concentration, the lesion diameter was only 39% of that in the control fruit at 7 days after inoculation. Further results of the leakage of electrolyte, increase of intracellular OD260, and propidium iodide (PI) staining proved that 2-PEITC broke cell membrane permeability of A. alternata. Moreover, 2-PEITC treatment significantly decreased alternariol (AOH), alternariolmonomethyl ether (AME), altenuene (ALT), and tentoxin (TEN) contents of A. alternata. Taken together, these data suggest that the mechanisms underlying the antifungal effect of 2-PEITC against A. alternata might be via reduction in toxin content and breakdown of cell membrane integrity.


Assuntos
Alternaria/efeitos dos fármacos , Antifúngicos/farmacologia , Contaminação de Alimentos/prevenção & controle , Isotiocianatos/farmacologia , Micotoxinas/biossíntese , Pyrus/microbiologia , Alternaria/metabolismo , Alternaria/fisiologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Frutas/microbiologia , Germinação/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Esporos/efeitos dos fármacos , Esporos/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/farmacologia
14.
RSC Adv ; 10(3): 1829-1837, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35494694

RESUMO

The antifungal activity of benzyl isothiocyanate (BITC) against pear pathotype-Alternaria alternata, the causal agent of pear black spot, and its possible mechanisms were studied. The results indicated that both the spore germination and mycelial growth of A. alternata were significantly inhibited by BITC in a dose-dependent manner. BITC concentrations at 1.25 mM completely suppressed mycelial growth of A. alternata and prevented ≥50% of black spot development in wounded pears inoculated with A. alternata. Microscopic analyses and propidium iodide (PI) staining showed that spore morphology in A. alternata treated with BITC at 0.625 mM was severely damaged. Relative electrical conductivity and lysis ability assays further showed that BITC treatment destroyed the integrity of the plasma membrane. Additionally, mycotoxin production was inhibited by 0.312 mM BITC, and the inhibitory rates of alternariol monomethyl ether (AME), alternariol (AOH), altenuene (ALT) and tentoxin (TEN) were 89.36%, 84.57%, 91.41% and 67.78%, respectively. The above results suggest that BITC exerts antifungal activity through membrane-targeted mechanisms.

15.
Iran J Allergy Asthma Immunol ; 14(3): 261-72, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26546894

RESUMO

Activated macrophages have been classified into classical (M1) and alternative (M2) macrophages. We aimed to establish a method to yield enough number of macrophages to analyze their molecular, biological and immunological functions. We used drugs; adjuvant albumin from chicken egg whites--Imject Alum (OVA-Alum) and OVA Complete Freund Adjuvant (OVA-CFA), to induce macrophages to M2 and M1 respectively. We analyzed the phenotype of purified macrophages induced under these immune conditions, using flow cytometry (FACS) to detect cell-surface molecules and the enzyme-linked immunosorbent assay (ELISA) was used to detect cytokines. The cDNA microarray was employed to measure changes in expression level of cell surface protein between M1 and M2 macrophages. Phenotype analysis of purified macrophages, induced under these immune conditions, showed macrophages induced by OVA-Alum was almost M2 while the proportion of M1 macrophages induced by OVA-CFA was significantly higher. The results also showed higher expression level of macrophage galactose N- acetyl-galactosamine specific lectin-2 protein (MGL1/2-PE), a known M2 macrophage marker, on the surface of Alum-induced macrophages. On the basis of these preliminary data, ELISA results revealed that after macrophage stimulation with lipopolysaccharides (LPS), the level of interleukin (IL)-10 produced by Alum- induced macrophages was higher than the level of IL-10 produced by CFA-induced macrophages. In contrast, the level of tumor necrosis factor-alpha (TNF-α) produced by CFA-induced macrophages was higher than Alum-induced macrophages. The cDNA microarray confirmed previous results and suggest immunoglobulin-like type 2 receptor alpha (Pilra) as a new marker for M1, macrophage galactose N-acetylgalactosamine-specific lectin 2 (Mgl2) as M2 macrophages marker.


Assuntos
Hipersensibilidade/imunologia , Macrófagos/imunologia , Células Th1/imunologia , Células Th2/imunologia , Compostos de Alúmen/farmacologia , Animais , Polaridade Celular , Adjuvante de Freund/farmacologia , Masculino , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Ovalbumina/imunologia
16.
Biochem Biophys Res Commun ; 468(1-2): 228-33, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26523514

RESUMO

During pregnancy, both ischemic reperfusion and bacterial agent LPS are known risk factors for fetal brain damage. However, there is a lack of evidence to explain whether vaginal LPS affects the fetus response to ischemic reperfusion. Here we reported that there was more than 2 folds higher vulnerability of fetal brain hemorrhage response to ischemic reperfusion when mother mouse was treated with vaginal LPS. As our previously reported, ischemic reperfusion induces P53-dependent fetal brain damage was based on a molecular mechanism: the transcriptional pattern was changed from HIF-1alpha-dependent to P53-dependent immediately. In the present work, only with vaginal LPS precondition, phosphorylation of activated transcriptional factor (ATF) 2 at Thr71 appeared in response to ischemic reperfusion. Moreover, this phosphorylation was completely blocked by pre-treatment with a P53 inhibitor, pifithrin-α. We concluded that vaginal LPS precondition trigged the p53-dependent phosphorylation of ATF2 in response to ischemic reperfusion, which played an important role of increasing vulnerability to hemorrhage in fetus.


Assuntos
Encéfalo/patologia , Doenças Fetais/etiologia , Feto/patologia , Hemorragias Intracranianas/etiologia , Lipopolissacarídeos/imunologia , Traumatismo por Reperfusão/complicações , Vagina/imunologia , Fator 2 Ativador da Transcrição/análise , Fator 2 Ativador da Transcrição/imunologia , Animais , Encéfalo/imunologia , Encéfalo/metabolismo , Feminino , Doenças Fetais/genética , Doenças Fetais/imunologia , Doenças Fetais/patologia , Feto/imunologia , Feto/metabolismo , Inflamação/complicações , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Hemorragias Intracranianas/genética , Hemorragias Intracranianas/imunologia , Hemorragias Intracranianas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/patologia , Ativação Transcricional , Fator de Necrose Tumoral alfa/imunologia , Proteína Supressora de Tumor p53/imunologia
17.
Autoimmunity ; 48(4): 259-66, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25352178

RESUMO

Ankylosis is a major pathological manifestation of spondyloarthropathy. The aim of this study was to evaluate the effects of anti-IL-17 therapy on spontaneous ankylosing enthesitis in mice. In this study, we used male DBA/1 mice as a spontaneous ankylosis model. Serum IL-17 concentrations were determined using enzyme-linked immunosorbent assay. Male DBA/1 mice from different litters were mixed and caged together preceding the treatment at 10 weeks (wk) of age (prophylaxis) or 21 wk of age (intervention). Treatment with anti-IL-17 antibodies or saline was initiated after caging in groups of mice and administered weekly. The onset of tarsal ankylosis was assessed by ankle swelling and histopathological examination. Pathological changes and mRNA expression levels were assessed in joints and ears obtained at the experimental end-point. We found that circulating IL-17 increased with the onset of ankylosis in male DBA/1 mice, coinciding with the onset of dermatitis. The symptoms of dermatitis corresponded to the pathological characteristics of psoriasis: acanthosis with mild hyperkeratosis, scaling, epidermal microabscess formation and augmented expression of K16, S100A8 and S100A9. Prophylactic administration of anti-IL-17 antibodies significantly prevented the development of both ankylosis and dermatitis in male DBA/1 mice caged together. On the other hand, administration of anti-IL-17 antibodies after disease onset had a lesser but significant effect on ankylosis progression but did not affect dermatitis progression. In conclusion, IL-17 is a key mediator in the pathogenic process of tarsal ankylosis and psoriasis-like dermatitis in male DBA/1 mice caged together. Thus, IL-17 is a potential therapeutic target in ankylosing enthesitis and psoriasis in humans.


Assuntos
Anquilose/metabolismo , Anquilose/patologia , Anticorpos Monoclonais/farmacologia , Dermatite/metabolismo , Dermatite/patologia , Interleucina-17/metabolismo , Psoríase/metabolismo , Psoríase/patologia , Animais , Anquilose/tratamento farmacológico , Anquilose/prevenção & controle , Anticorpos Monoclonais/administração & dosagem , Dermatite/sangue , Dermatite/tratamento farmacológico , Dermatite/prevenção & controle , Modelos Animais de Doenças , Progressão da Doença , Interleucina-17/antagonistas & inibidores , Interleucina-17/sangue , Interleucina-6/sangue , Interleucina-6/metabolismo , Masculino , Camundongos , Pré-Medicação , Psoríase/tratamento farmacológico , Psoríase/prevenção & controle
18.
PLoS One ; 9(10): e110577, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25329663

RESUMO

Ischemic reperfusion (IR) during the perinatal period is a known causative factor of fetal brain damage. So far, both morphologic and histologic evidence has shown that fetal brain damage can be observed only several hours to days after an IR insult has occurred. Therefore, to prevent fetal brain damage under these circumstances, a more detailed understanding of the underlying molecular mechanisms involved during an acute response to IR is necessary. In the present work, pregnant mice were exposed to IR on day 18 of gestation by clipping one side of the maternal uterine horn. Simultaneous fetal electrocardiography was performed during the procedure to verify that conditions resulting in fetal brain damage were met. Fetal brain sampling within 30 minutes after IR insult revealed molecular evidence that a fetal response was indeed triggered in the form of inhibition of the Akt-mTOR-S6 synthesis pathway. Interestingly, significant changes in mRNA levels for both HIF-1α and p53 were apparent and gene regulation patterns were observed to switch from a HIF-1α-dependent to a p53-dependent process. Moreover, pre-treatment with pifithrin-α, a p53 inhibitor, inhibited protein synthesis almost completely, revealing the possibility of preventing fetal brain damage by prophylactic pifithrin-α treatment.


Assuntos
Lesões Encefálicas/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Útero/metabolismo , Animais , Benzotiazóis/administração & dosagem , Lesões Encefálicas/patologia , Feminino , Feto/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Gravidez , Reperfusão , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Tolueno/administração & dosagem , Tolueno/análogos & derivados , Útero/patologia
19.
ISRN Obstet Gynecol ; 2014: 193816, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25006477

RESUMO

Introduction. Prenatal programming secondary to maternal protein restriction renders an inherent susceptibility to neural compromise in neonates and any addition of glucocorticosteroids results in further damage. This is an investigation of consequent global gene activity due to effects of antenatal steroid therapy on a protein restriction mouse model. Methods. C57BL/6N pregnant mice were administered control or protein restricted diets and subjected to either 100 µ g/Kg of dexamethasone sodium phosphate with normosaline or normosaline alone during late gestation (E10-E17). Nontreatment groups were also included. Brain samples were collected on embryonic day 17 and analyzed by mRNA microarray analysis. Results. Microarray analyses presented 332 significantly regulated genes. Overall, neurodevelopmental genes were overrepresented and a subset of 8 genes allowed treatment segregation through the hierarchical clustering method. The addition of stress or steroids greatly affected gene regulation through glucocorticoid receptor and stress signaling pathways. Furthermore, differences between dexamethasone-administered treatments implied a harmful effect during conditions of high stress. Microarray analysis was validated using qPCR. Conclusion. The effects of antenatal steroid therapy vary in fetuses according to maternal-fetal factors and environmental stimuli. Defining the key regulatory networks that signal either beneficial or damaging corticosteroid action would result in valuable adjustments to current treatment protocols.

20.
Biochim Biophys Acta ; 1773(4): 556-64, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17320201

RESUMO

Mutations in RecQL4 are a causative factor in Rothmund-Thomson syndrome, a human autosomal recessive disorder characterized by premature aging. To study the role of RecQL4, we employed a cell-free experimental system consisting of Xenopus egg extracts. RecQL4 loading onto chromatin was observed regardless of the presence or absence of EcoRI. However, in the absence of EcoRI, RecQL4 loading was suppressed by geminin, an inhibitor of pre-replicative complex formation, while in the presence of EcoRI, it was not affected. These results suggest that under the former condition, RecQL4-loading depended on DNA replication, while under the latter, the interaction occurred in response to double-stranded DNA breaks (DSBs) induced by EcoRI. DSB-induced RecQL4 loading depended on the function of the ataxia-telangiectasia mutated protein, DNA-dependent protein kinase (DNA-PK), and replication protein A, while there were only minor changes in DNA replication-associated RecQL4 loading upon suppression of these proteins. Furthermore, analyses using a chromatin-immunoprecipitation assay and quantification of gammaH2AX after induction of DSBs suggested that RecQL4 is loaded adjacent to Ku heterodimer-binding sites on damaged chromatin, and functions in the repair of DSBs.


Assuntos
Extratos Celulares , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Óvulo/enzimologia , RecQ Helicases/metabolismo , Xenopus/metabolismo , Androstadienos/farmacologia , Animais , Cafeína/farmacologia , Cromatina/metabolismo , Imunoprecipitação da Cromatina , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Desoxirribonuclease EcoRI/metabolismo , Histonas/metabolismo , Humanos , Óvulo/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Rad51 Recombinase/metabolismo , Proteína de Replicação A/deficiência , Fatores de Tempo , Wortmanina , Proteínas de Xenopus/metabolismo
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