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1.
Cancers (Basel) ; 15(23)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38067368

RESUMO

We developed machine and deep learning models to predict chemoradiotherapy in rectal cancer using 18F-FDG PET images and harmonized image features extracted from 18F-FDG PET/CT images. Patients diagnosed with pathologic T-stage III rectal cancer with a tumor size > 2 cm were treated with neoadjuvant chemoradiotherapy. Patients with rectal cancer were divided into an internal dataset (n = 116) and an external dataset obtained from a separate institution (n = 40), which were used in the model. AUC was calculated to select image features associated with radiochemotherapy response. In the external test, the machine-learning signature extracted from 18F-FDG PET image features achieved the highest accuracy and AUC value of 0.875 and 0.896. The harmonized first-order radiomics model had a higher efficiency with accuracy and an AUC of 0.771 than the second-order model in the external test. The deep learning model using the balanced dataset showed an accuracy of 0.867 in the internal test but an accuracy of 0.557 in the external test. Deep-learning models using 18F-FDG PET images must be harmonized to demonstrate reproducibility with external data. Harmonized 18F-FDG PET image features as an element of machine learning could help predict chemoradiotherapy responses in external tests with reproducibility.

2.
Materials (Basel) ; 16(12)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37374410

RESUMO

This study examines the impacts of copper and boron in parts per million (ppm) on the microstructure and mechanical properties of spheroidal graphite cast iron (SCI). Boron's inclusion increases the ferrite content whereas copper augments the stability of pearlite. The interaction between the two significantly influences the ferrite content. Differential scanning calorimetry (DSC) analysis indicates that boron alters the enthalpy change of the α + Fe3C → γ conversion and the α → γ conversion. Scanning electron microscope (SEM) analysis confirms the locations of copper and boron. Mechanical property assessments using a universal testing machine show that the inclusion of boron and copper decreases the tensile strength and yield strength of SCI, but simultaneously enhances elongation. Additionally, in SCI production, the utilization of copper-bearing scrap and trace amounts of boron-containing scrap metal, especially in the casting of ferritic nodular cast iron, offers potential for resource recycling. This highlights the importance of resource conservation and recycling in advancing sustainable manufacturing practices. These findings provide critical insights into the effects of boron and copper on SCI's behavior, contributing to the design and development of high-performance SCI materials.

3.
Materials (Basel) ; 16(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36837296

RESUMO

Additively manufactured austenitic stainless steel 316L is composed of a cellular structure, which has a directionality, and is observed with a different morphology depending on the observation direction. The cellular structure morphology that appears with a high probability in grains with a specific grain orientation is determined. Taylor factor, which is calculated by considering grain orientation, is related to cellular structure morphology due to the directional cellular structure in additively manufactured austenitic stainless steel 316L. The Taylor factor affects the mechanical properties. The yield strength of additively manufactured SUS316L can be explained by the correlation between cellular structure morphology, grain orientation, and Taylor factor.

4.
Life (Basel) ; 12(10)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36294963

RESUMO

GPR119 is a novel cannabinoid receptor that is primarily expressed in the pancreas and gastrointestinal tract and has beneficial effects on glucose homeostasis exerted through the stimulation of GLP-1 secretion, as demonstrated in the rodent brain. GLP-1 also has important anti-inflammatory effects in chronic inflammatory diseases, including type 1 and 2 diabetes, asthma, psoriasis, and neurodegenerative disorders. Recently, there has been increasing interest in the effect of the gut microbiota on both the gut and the brain. However, few studies have examined how gut microbes affect brain health through the endocannabinoid system. NEUROMIDE is a compound that shares a bioidentical structure with certain commensal bacterial metabolites, acting as a CB1 and GPR119 agonist. In an in vitro system exposed to reactive oxygen species (ROS), pretreatment with NEUROMIDE resulted in a significant increase in cell viability. The ROS-exposed system also showed decreased acetylcholine and an increase in inflammatory cytokines such as IL-1ß, changes that were counteracted in a dose-dependent manner in the NEUROMIDE treatment groups. To measure the effectiveness of NEUROMIDE in an in vivo system, we used scopolamine-treated mice as a neurodegenerative disease model and performed a series of passive avoidance tests to observe and quantify the cognitive impairment of the mice. Mice in the NEUROMIDE treatment group had increased latency time, thus indicating an improvement in their cognitive function. Furthermore, the NEUROMIDE treatment groups showed dose-dependent increases in acetylcholine along with decreases in TNF-α and IL-1ß. These experiments demonstrate that NEUROMIDE can potentially be used for neuroprotection and the improvement of cognitive ability.

5.
Genes Genomics ; 44(5): 571-582, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35254656

RESUMO

BACKGROUND: Calcium ions play a pivotal role in cell proliferation, differentiation, and migration. Under basal conditions, the calcium level is tightly regulated; however, cellular activation by growth factors increase the ion level through calcium pumps in the plasma membrane and endoplasmic reticulum for calcium signaling. Orai1 is a major calcium channel in the cell membrane of non-excitable cells, and its activity depends on the stromal interaction molecule 1 (Stim1). Several groups reported that the store-operated calcium entry (SOCE) can be modulated through phosphorylation of Stim1 by protein kinases such as extracellular signal-regulated kinase (ERK), protein kinase A (PKA), and p21-activated kinase (PAK). PKC is a protein kinase that is activated by calcium and diacylglycerol (DAG), but it remains unclear what role activated PKC plays in controlling the intracellular calcium pool. OBJECTIVES: Here, we investigated whether PKC-ß controls intracellular calcium dynamics through Stim1. METHODS: Several biochemical methods such as immune-precipitation, site directed mutagenesis, in vitro kinase assay were employed to investigate PKC interaction with and phosphorylation of Stim1. Intracellular calcium mobilization, via Stim1 mediated SOCE channel, were studied using in the presence of PKC activator or inhibitor under a confocal microscope. RESULTS: Our data demonstrate that PKC interacts with and phosphorylates Stim1 in vitro. phosphorylation of Stim1 at its C-terminal end appears to be important in the regulation of SOCE activity in HEK293 and HeLa cells. Additionally, transient intracellular calcium mobilization assays demonstrate that the SOCE activity was inhibited by PKC activators or activated by PKC inhibitors. CONCLUSION: In sum, our data suggest a repressive role of PKC in regulating calcium entry through SOCE.


Assuntos
Cálcio , Proteínas de Neoplasias , Cálcio/metabolismo , Células HEK293 , Células HeLa , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fosforilação , Molécula 1 de Interação Estromal/genética , Molécula 1 de Interação Estromal/metabolismo
6.
J Neurogenet ; 35(4): 387-398, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34670462

RESUMO

The digestion of food and absorption of nutrients occurs in the gut. The nutritional value of food and its nutrients is detected by enteroendocrine cells, and peptide hormones produced by the enteroendocrine cells are thought to be involved in metabolic homeostasis, but the specific mechanisms are still elusive. The enteroendocrine cells are scattered over the entire gastrointestinal tract and can be classified according to the hormones they produce. We followed the changes in combinatorial expression of regulatory peptides in the enteroendocrine cells during metamorphosis from the larva to the adult fruit fly, and re-confirmed the diverse composition of enteroendocrine cell populations. Drosophila enteroendocrine cells appear to differentially regulate peptide expression spatially and temporally depending on midgut region and developmental stage. In the late pupa, Notch activity is known to determine which peptides are expressed in mature enteroendocrine cells of the posterior midgut, and we found that the loss of Notch activity in the anterior midgut results in classes of enteroendocrine cells distinct from the posterior midgut. These results suggest that enteroendocrine cells that populate the fly midgut can differentiate into distinct subtypes that express different combinations of peptides, which likely leads to functional variety depending on specific needs.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster , Células Enteroendócrinas , Peptídeos
7.
Sci Rep ; 9(1): 6163, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992512

RESUMO

Quasi-static and dynamic compressive properties of an FCC-based metastable HEA (composition; V10Cr10Fe45Co35 (at.%)) showing both Transformation Induced Plasticity (TRIP) and TWinning Induced Plasticity (TWIP) were investigated at room and cryogenic temperatures. During the quasi-static and dynamic compression at room temperature, the FCC to BCC TRIP occurred inside FCC grains, and resulted in very high strain-hardening rate and consequently maximum compressive strength over 1.6 GPa. The dynamic compressive strength was higher by 240 MPa than the quasi-static strength because of strain-rate-hardening effect, and kept increasing with a high strain-hardening rate as the twinning became activated. The cryogenic-temperature strength was higher than the room-temperature strength as the FCC to BCC TRIP amount increased by the decrease in stability of FCC phase with decreasing temperature. Under dynamic loading at cryogenic temperature, twins were not formed because the increase in SFE due to adiabatic heating might not be enough to reach the TWIP regime. However, the dynamically compressed specimen showed the higher strength than the quasi-statically compressed specimen as the strain-rate-hardening effect was added with the TRIP.

8.
Am J Chin Med ; 46(3): 689-705, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29595070

RESUMO

Although garlic induces apoptosis in cancer cells, it is unclear whether the effects are similar to those of cisplatin against bladder cancer (BC). Therefore, this study investigated whether garlic extracts and cisplatin show similar activity when used to treat BC. The effect of garlic on T24 BC cell line was examined in a BALB/C-nude mouse xenograft model and compared with that of cisplatin. Tissue microarray analysis and gene network analysis were performed to identify differences in gene expression by control tumors and tumors exposed to garlic extract or cisplatin. Investigation of gene expression based on tissues from 165 BC patients and normal controls was then performed to identify common targets of garlic and cisplatin. Tumor volume and tumor weight in cisplatin (0.05[Formula: see text]mg/kg)- and garlic-treated mice were significantly smaller than those in negative control mice. However, cisplatin-treated mice also showed a significant reduction in body weight. Microarray analysis of tumor tissue identified 515 common anticancer genes in the garlic and cisplatin groups ([Formula: see text]). Gene network analysis of 252 of these genes using the Cytoscape and ClueGo software packages mapped 17 genes and 9 gene ontologies to gene networks. BC (NMIBC and MIBC) patients with low expression of centromere protein M (CENPM) showed significantly better progression-free survival than those with high expression. Garlic extract shows anticancer activity in vivo similar to that of cisplatin, with no evident of side effects. Both appear to act by targeting protein-DNA complex assembly; in particular, expression of CENPM.


Assuntos
Antineoplásicos/administração & dosagem , Centrômero/metabolismo , Cisplatino/administração & dosagem , Alho/química , Proteínas Nucleares/metabolismo , Fitoterapia , Extratos Vegetais/administração & dosagem , Neoplasias da Bexiga Urinária/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Proteínas de Ciclo Celular , DNA/metabolismo , Modelos Animais de Doenças , Intervalo Livre de Doença , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Terapia de Alvo Molecular , Proteínas de Neoplasias/metabolismo , Ligação Proteica/efeitos dos fármacos , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
9.
Sci Rep ; 7(1): 1927, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28512311

RESUMO

Ferrite + austenite duplex lightweight steels have been actively developed by adding low-density Al for overcoming a limitation of stiffness deterioration by a traditional approach to obtain a weight reduction. Multiple-stage deformation mechanism in lightweight steels, i.e., simultaneous formation of deformation-induced martensite and deformation twin and additional plasticity by twinning, has been nominated as an attractive strategy, but shows a steady flow behavior with early plastic instability. Here, we present a newly designed Fe-0.3C-9Mn-5Al steel in order to obtain an optimal level of stability of austenite and a resultant outstanding combination of tensile strength and ductility, e.g., 874 MPa and 72%, together with sufficiently high strain hardening. These enhanced properties are attributed to the decreased austenite stability by controlling the austenite size and alloying partitioning due to variation in austenite fraction inside duplex microstructures. The present work gives a promise for structural applications requiring both reduced specific weight and remarkable deformability.

10.
Sci Rep ; 7(1): 1255, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28455494

RESUMO

Needs for steel designs of ultra-high strength and excellent ductility have been an important issue in worldwide automotive industries to achieve energy conservation, improvement of safety, and crashworthiness qualities. Because of various drawbacks in existing 1.5-GPa-grade steels, new development of formable cold-rolled ultra-high-strength steels is essentially needed. Here we show a plausible method to achieve ultra-high strengths of 1.0~1.5 GPa together with excellent ductility above 50% by actively utilizing non-recrystallization region and TRansformation-Induced Plasticity (TRIP) mechanism in a cold-rolled and annealed Fe-Mn-Al-C-based steel. We adopt a duplex microstructure composed of austenite and ultra-fine ferrite in order to overcome low-yield-strength characteristics of austenite. Persistent elongation up to 50% as well as ultra-high yield strength over 1.4 GPa are attributed to well-balanced mechanical stability of non-crystallized austenite with critical strain for TRIP. Our results demonstrate how the non-recrystallized austenite can be a metamorphosis in 1.5-GPa-grade steel sheet design.

11.
J Med Food ; 20(4): 420-424, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28406731

RESUMO

The aim of this study was to evaluate the wrinkle improving effect of hyaluronic acid intakes. Wrinkles were induced by exposing the skin of hairless mice to ultraviolet B (UVB) irradiation for 14 weeks. Hyaluronic acid was administered to the mice for 14 weeks including 4 weeks before experiments. Skin tissue was assayed by enzyme-linked immunosorbent assay to determine protein expression of wrinkle-related markers. The group supplemented with high concentrations of hyaluronic acid appeared significantly better than control group for collagen, matrix metalloproteinase 1, interleukin (IL)-1ß, and IL-6 assay. Transforming growth factor-ß1 (TGF-ß1) and hyaluronic acid synthase 2 (HAS-2) were not shown to be significantly different. In conclusion, hyaluronic acid administration regulated expression levels of proteins associated with skin integrity, and improved the wrinkle level in skin subjected to UVB irradiation.


Assuntos
Ácido Hialurônico/uso terapêutico , Envelhecimento da Pele/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Administração Oral , Animais , Colágeno/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Interleucina-6/metabolismo , Metaloproteinase 13 da Matriz/metabolismo , Camundongos , Camundongos Pelados , Proteoma , Fator de Crescimento Transformador beta1/metabolismo , Raios Ultravioleta
12.
Food Chem ; 194: 920-7, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26471635

RESUMO

The production of excessive reactive oxygen species by exposure to oxidative stress and solar radiation are primary factors in skin damage. We examined the effects of a citrus-based juice mixture and its bioactive compounds on antioxidant and anti-ageing activities in human dermal fibroblasts and hairless mice via the regulation of antioxidant enzymes and the mitogen-activated protein kinase pathway. The citrus-based juice mixture reduced H2O2-induced cell damage and intracellular reactive oxygen species production in human dermal fibroblasts. Citrus-based juice mixture pretreatment suppressed the activation of the H2O2-mediated mitogen-activated protein kinase pathway by activating the expression of activator protein 1 and matrix metalloproteinases. Moreover, it increased the expression levels of antioxidant enzymes such as glutathione reductase, catalase and manganese superoxide dismutase. In addition, oral administration of the citrus-based juice mixture decreased skin thickness and wrinkle formation and increased collagen content on an ultraviolet light B-exposed hairless mouse. These results indicate that the citrus-based juice mixture is a potentially healthy beverage for the prevention of oxidative stress-induced premature skin ageing.


Assuntos
Citrus/química , Animais , Antioxidantes , Humanos , Peróxido de Hidrogênio/metabolismo , Masculino , Camundongos , Camundongos Pelados , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Envelhecimento da Pele
13.
J Nanosci Nanotechnol ; 15(11): 9228-33, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26726673

RESUMO

We prepared nanopastes containing various additives such as acetylene black (AB paste), 3,5-dinitrosalicylic acid (NSA paste) and SiC2 particles (SO paste), and these nanopastes were employed in preparation of photoelectrodes for dye sensitized solar cells (DSSCs). Photoelectrodes of AB, NSA and SO paste have characteristics of large pore size, superior interconnection among particles, and scattering due to spherical particle shape, respectively. Photovoltaic parameters of cells formed from the pastes were compared with cell formed from the paste without additive. Among the pastes, AB paste exhibited the best cell efficiency improvement of 9.647%. NSA paste also exhibited considerable cell efficiency improvement without much deleterious impact on transparency. The advantages and disadvantages of each nanopastes were analysed for the commercialization of DSSCs.

14.
Mol Cells ; 35(1): 41-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23307288

RESUMO

Store-operated calcium entry (SOCE) channels composed of Stim and Orai proteins play a critical role in diverse biological processes. Upon endoplasmic reticulum (ER)-mediated calcium (Ca(2+)) depletion, Stim proteins oligomerize with Orai to initiate Ca(2+) influx across the plasma membrane. The ubiquitin-like (UBL) and ubiquitin-associated (UBA) domains of ubiquilin 1 are involved in the degradation of presenilin and polyglutamine proteins. Through screening of Orai1 interaction partner(s) that might have an effect on SOCE, ubiquilin 1 was identified as a target of Orai1. However, the UBL and UBA domains of ubiquilin 1 were dispensable for this interaction. Additionally, ubiquilin 1 and Orai1 colocalized in the cytosolic compartment. Ubiquilin 1 increased the ubiquitination of Orai1, resulting in the formation of a high-molecular-weight form. MG132, a proteasome inhibitor, failed to block the degradation of Orai1, whereas bafilomycin A, a lysosome inhibitor, prevented Orai1 degradation. Confocal microscopy studies demonstrated that a fraction of Orai1 colocalized with ubiquilin 1 and the autophagosomal marker LC3. Because Orai1 is a constituent of SOCE, we determined the effect of ubiquilin 1 on Orai1-mediated Ca(2+) influx. As we expected, intracellular Ca(2+) mobilization, a process normally potentiated by Orai1, was downregulated by ubiquilin 1. Taken together, these findings suggest that ubiquilin 1 downregulates intracellular Ca(2+) mobilization and its downstream signaling by promoting the ubiquitination and lysosomal degradation of Orai1.


Assuntos
Canais de Cálcio/metabolismo , Sinalização do Cálcio , Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Proteínas Relacionadas à Autofagia , Western Blotting , Canais de Cálcio/genética , Proteínas de Transporte/genética , Proteínas de Ciclo Celular/genética , Inibidores de Cisteína Proteinase/farmacologia , Citosol/efeitos dos fármacos , Citosol/metabolismo , Inibidores Enzimáticos/farmacologia , Células HEK293 , Células HeLa , Humanos , Imunoprecipitação , Leupeptinas/farmacologia , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Macrolídeos/farmacologia , Proteínas de Membrana/genética , Proteínas de Neoplasias/genética , Proteína ORAI1 , Fagossomos/efeitos dos fármacos , Fagossomos/metabolismo , Plasmídeos/genética , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/metabolismo , ATPases Translocadoras de Prótons/antagonistas & inibidores , Transdução de Sinais , Molécula 1 de Interação Estromal , Técnicas do Sistema de Duplo-Híbrido , Ubiquitinação
15.
Radiat Oncol J ; 30(2): 78-87, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22984686

RESUMO

PURPOSE: Troglitazone (TRO) is a peroxisome proliferator-activated receptor γ (PPARγ) agonist. TRO has antiproliferative activity on many kinds of cancer cells via G1 arrest. TRO also increases Cu(2+)/Zn(2+)-superoxide dismutase (CuZnSOD) and catalase. Cell cycle, and SOD and catalase may affect on radiation sensitivity. We investigated the effect of TRO on radiation sensitivity in cancer cells in vitro. MATERIALS AND METHODS: Three human cervix cancer cell lines (HeLa, Me180, and SiHa) were used. The protein expressions of SOD and catalase, and catalase activities were measured at 2-10 µM of TRO for 24 hours. Cell cycle was evaluated with flow cytometry. Reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate. Cell survival by radiation was measured with clonogenic assay. RESULTS: By 5 µM TRO for 24 hours, the mRNA, protein expression and activity of catalase were increased in all three cell lines. G0-G1 phase cells were increased in HeLa and Me180 by 5 µM TRO for 24 hours, but those were not increased in SiHa. By pretreatment with 5 µM TRO radiation sensitivity was increased in HeLa and Me180, but it was decreased in SiHa. In Me180, with 2 µM TRO which increased catalase but not increased G0-G1 cells, radiosensitization was not observed. ROS produced by radiation was decreased with TRO. CONCLUSION: TRO increases radiation sensitivity through G0-G1 arrest or decreases radiation sensitivity through catalase-mediated ROS scavenging according to TRO dose or cell types. The change of radiation sensitivity by combined with TRO is not dependent on the PPARγ expression level.

16.
Radiat Oncol J ; 30(2): 88-95, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22984687

RESUMO

PURPOSE: The fibrates are ligands for peroxisome proliferator-activated receptor (PPAR) α and used clinically as hypolipidemic drugs. The fibrates are known to cause peroxisome proliferation, enhance superoxide dismutase (SOD) expression and catalase activity. The antioxidant actions of the fibrates may modify radiation sensitivity. Here, we investigated the change of the radiation sensitivity in two cervix cancer cell lines in combination with fenofibrate (FF). MATERIALS AND METHODS: Activity and protein expression of SOD were measured according to the concentration of FF. The mRNA expressions were measured by using real time reverse-transcription polymerase chain reaction. Combined cytotoxic effect of FF and radiation was measured by using clonogenic assay. RESULTS: In HeLa cells total SOD activity was increased with increasing FF doses up to 30 µM. In the other hand, the catalase activity was increased a little. As with activity the protein expression of SOD1 and SOD2 was increased with increasing doses of FF. The mRNAs of SOD1, SOD2, PPARα and PPARγ were increased with increasing doses of FF. The reactive oxygen species (ROS) produced by radiation was decreased by preincubation with FF. The surviving fractions (SF) by combining FF and radiation was higher than those of radiation alone. In Me180 cells SOD and catalase activity were not increased with FF. Also, the mRNAs of SOD1, SOD2, and PPARα were not increased with FF. However, the mRNA of PPARγ was increased with FF. CONCLUSION: FF can reduce radiation sensitivity by ROS scavenging via SOD induction in HeLa. SOD induction by FF is related with PPARα.

17.
J Vet Med Sci ; 72(7): 887-92, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20215718

RESUMO

This study was designed to evaluate the nuclear maturation and maturation promoting factor (MPF) level at different maturation times, and the effect of parthenogenetic activation on nuclear maturation in canine oocytes. Cumulus-oocyte complexes (COCs) were matured in TCM-199 supplemented with 10% fetal bovine serum, hormones, 0.57 mM cysteine, and 10 ng/ml epidermal growth factor for 72 hr at 38.5 degrees C. In Experiment 1, COCs at 0, 24, 48 and 72 hr of culture were assessed for nuclear maturation and MPF levels using histone H1 kinase activity assay. A significantly higher rate of oocytes at 72 hr than 0, 24 and 48 hr of culture developed to metaphase I-anaphase I and metaphase II. Relative abundance of histone H1 kinase activity of oocytes matured for 48 hr increased to ~1.5 x, with a marked increase to approximately 2.5 x for 72 hr, significantly higher than others. In Experiment 2, oocytes matured for 48 hr were parthenogenetically activated with 5 microm ionomycin for 5 min (Group 1) and followed by 10 microg/ml cycloheximide for 3 hr (Group 2), or no treatment (Control). Oocytes were then cultured for 24 hr and assessed for nuclear maturation. A significantly higher rate of oocytes in Group 1 developed to metaphase II than in Group 2 and the control. These results indicated that ionomycin treatment at 48 hr of in vitro maturation had a positive influence on oocyte progression to the metaphase II stage.


Assuntos
Oócitos/fisiologia , Animais , Bovinos , Técnicas de Cultura de Células/métodos , Núcleo Celular/fisiologia , Cicloeximida/farmacologia , Cães , Feminino , Humanos , Ionomicina/farmacologia , Metáfase , Oócitos/citologia , Oócitos/efeitos dos fármacos , Oócitos/enzimologia , Partenogênese/efeitos dos fármacos , Partenogênese/fisiologia , Protamina Quinase/metabolismo , Maturidade Sexual/fisiologia
18.
Cryobiology ; 58(2): 181-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19141297

RESUMO

Boar semen is extremely vulnerable to cold shock and sensitive to peroxidative damage due to high content of unsaturated fatty acids in the phospholipids of the plasma membrane and the relatively low antioxidant capacity of seminal plasma. The present study evaluated the influence of alpha-tocopherol supplementation at various concentrations in the boar semen extender during cryopreservation on post-thawed sperm motility characteristics (total sperm motility, MOT; local motility, LCM; curvilinear velocity, VCL; straight linear velocity, VSL; and average path velocity, VAP), sperm qualities (viability, acrosomal integrity and apoptosis), expression of stress protein (HSP70), and the expression of pro-apoptotic (Bax and Bak) and anti-apoptotic (Bcl-2l and Bcl-xl) genes. Semen collected from 10 Duroc boars was cryopreserved in lactose-egg yolk buffer supplemented with various concentrations of alpha-tocopherol (0, 100, 200, 400, 600 and 800 microM) using the straw-freezing procedure and stored at -196 degrees C for a minimum period of one month. In frozen-thawed groups, sperm motility was significantly (P<0.05) lower than that of fresh sperm. In fresh sperm, HSP70 immunoreactivity expression was observed in the equatorial region, but in frozen-thawed groups, expressions were mostly observed in the sperm head. Higher apoptosis rates were observed in 600 and 800 microM alpha-tocopherol supplemented frozen-thawed groups. In alpha-tocopherol supplemented frozen-thawed groups immediately after thawing, the expression was similar to that of fresh group. But after incubation at 37 degrees C for 3h, the expression in 200 and 800 microM alpha-tocopherol supplemented groups was higher than that of others. Expression of pro-apoptotic genes was significantly higher and anti-apoptotic genes was significantly (P<0.01) lower in alpha-tocopherol supplemented frozen-thawed groups compared to fresh sperm group. In conclusion, alpha-tocopherol, supplemented at 200 microM concentration in boar semen extender during cryopreservation had a positive effect on post-thawed sperm survivability.


Assuntos
Criopreservação/veterinária , Preservação do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Suínos , alfa-Tocoferol/farmacologia , Acrossomo/efeitos dos fármacos , Acrossomo/ultraestrutura , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Sobrevivência Celular/efeitos dos fármacos , Criopreservação/métodos , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Imuno-Histoquímica , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Preservação do Sêmen/métodos , Motilidade dos Espermatozoides/efeitos dos fármacos
19.
J Nanosci Nanotechnol ; 8(10): 5586-9, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19198504

RESUMO

We develop a simple method to synthesize nano tube or wire structure of tin-oxide for gas sensor application. It is realized by the rheotaxial growth and thermal oxidation (RGTO) of tin on porous single-wall carbon nanotubes (SWNTs) as a template. The morphology and chemical property of thus formed nanostructures are examined. The electrical and NO(x) gas sensing properties are also investigated. The sensor exhibits a fast response time of less than 100 seconds and a good recovery. A sensing response of 23,400% to 10 ppm concentration at 200 degrees C is observed.

20.
Proteomics ; 7(15): 2591-602, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17610306

RESUMO

The activity and localization of large-conductance Ca2+ -activated K+ (BKCa) channels are known to be modulated by several different proteins. Although many binding partners have been identified via yeast two-hybrid screening, this method may not detect certain classes of interacting proteins such as low affinity binding proteins or multi-component protein complexes. In this study, we employed mass spectrometry to identify proteins that interact with BKCa channels. We expressed and purified the 'tail domain' of the rat BKCa channel alpha-subunit, a 54-kDa region that is crucial for expression and functional activity of the channel. Using rat brain lysate and purified 'tail domain', we identified several novel proteins that interact with the BKCa channel. These included the myelin basic protein (MBP), upon which we performed subsequent biochemical and electrophysiological studies. Interaction between the BKCa channel and MBP was confirmed in vivo and in vitro. MBP co-expression affected the Ca2+ -dependent activation of the BKCa channel by increasing its Ca2+ sensitivity. Moreover, we showed that calmodulin (CaM) interacts with the BKCa channel via MBP. Since CaM is a key regulator of many Ca2+ -dependent processes, it may be recruited by MBP to the vicinity of the BKCa channel, modulating its functional activity.


Assuntos
Calmodulina/metabolismo , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Canais de Potássio Cálcio-Ativados/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Córtex Cerebral/química , Glutationa Transferase/metabolismo , Imuno-Histoquímica , Espectrometria de Massas , Modelos Químicos , Dados de Sequência Molecular , Proteína Básica da Mielina , Proteínas do Tecido Nervoso/genética , Técnicas de Patch-Clamp , Fragmentos de Peptídeos/química , Testes de Precipitina , Ligação Proteica , Estrutura Terciária de Proteína , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Coloração pela Prata , Fatores de Transcrição/genética
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