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1.
Opt Express ; 27(8): A397-A403, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31052891

RESUMO

The fabrication and feasibility assessment of n-side up, thin-epilayer, AlGaInP-based vertical light-emitting-diodes (LEDs; emitting area: 1 mm × 1 mm) with a copper-invar-copper-composite metal (CIC) substrate was obtained by wafer bonding and epilayer transferring technologies. The structure of CIC substrate is a top Cu layer of 20 µm, a middle Invar layer of 64 µm, and a bottom Cu layer of 20 µm. The invar layer consists of Fe and Ni at a ratio of 70% to 30%. The coefficient of thermal expansion for CIC is about 6.1 × 10-6 /K, which is similar to that of the GaAs substrate (5.7 × 10-6 /K) and AlGaInP epilayers. Due to the high thermal conductivity (160 W/m-K) of 104-µm-thick CIC, the high performances of the packaged LEDs are obtained. They present a low red shift phenomenon (from 623 to 642 nm for 100 mA to 1 A) and a high output power 212 mW at 800 mA. The CIC substrate can be extended to fabricate high-efficiency thin film LEDs with conventional vertical electrodes.

2.
Insect Mol Biol ; 27(6): 752-765, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29892979

RESUMO

In animals, differentiation of germline from soma usually takes place during embryogenesis. Genes and their products that are preferentially expressed in the embryonic germ cells are regarded as candidates for maintaining germline fate or promoting germline identity. In Drosophila, for example, the protein encoded by the germline gene vasa is specifically restricted to the germ cells, while products of the gap gene hunchback (hb), a somatic gene, are preferentially expressed in the neuroblasts. In this study, we report the expression of both messenger RNA and protein encoded by Aphb, an hb orthologue in the asexual viviparous pea aphid Acyrthosiphon pisum, in germ cells as well as in neuroblasts. We infer that expression of Aphb messenger RNA in the germ cells during the formation of germaria is required for the anterior localization of Aphb in the protruding oocytes. Germarial expression and anterior localization of ApKrüppel was also identified but, unlike Aphb, its expression was not detected in the migrating germ cells. Very similar patterns of hb expression were also identified in the green peach aphid Myzus persicae, suggesting that germline expression of hb is conserved within the Aphididae. To date, this pattern of hb germline expression has not been reported in other insects.


Assuntos
Afídeos/metabolismo , Células Germinativas/metabolismo , Proteínas de Insetos/metabolismo , Animais , Afídeos/embriologia , Sequência de Bases , Proteínas de Ligação a DNA , Proteínas de Drosophila , Desenvolvimento Embrionário , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição
4.
Biochem Biophys Res Commun ; 465(3): 613-9, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26315268

RESUMO

The localization of adenylyl cyclase A (ACA) to uropod of cells is required for the stream formation during Dictyostelium development. RacC is a Dictyostelium orthologue of Cdc42. We identified a streaming defect of racC(-) cells as they are clearly less polarized and form smaller and fragmented streams. ACA-YFP is mainly associated with intracellular vesicular structures, but not with the plasma membrane in racC(-) cells. racC(-) cells have a slightly higher number of vesicles than Ax3 cells, suggesting that the defect of ACA trafficking is not simply due to the lack of vesicle formation. While the ACA-YFP vesicles traveled with an average velocity of 9.1 µm/min in Ax3 cells, a slow and diffusional movement without direction with an average velocity of 4 µm/min was maintained in racC(-) cells. Images acquired by using total internal reflection fluorescence (TIRF) microscopy and fluorescence recovery after photobleaching (FRAP) analysis revealed that a significantly decreased number of ACA-YFP vesicles appeared near the cell membrane, indicating a defect in ACA-YFP vesicle trafficking. These results suggest an important role of RacC in the rapid and directional movements of ACA vesicles on microtubules to the plasma membrane, especially to the back of polarized cell.


Assuntos
Adenilil Ciclases/metabolismo , Extensões da Superfície Celular/metabolismo , Dictyostelium/fisiologia , Frações Subcelulares/enzimologia , Proteína cdc42 de Ligação ao GTP/metabolismo , Agregação Celular/fisiologia , Transporte Proteico/fisiologia
5.
Osteoarthritis Cartilage ; 23(2): 232-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25450843

RESUMO

OBJECTIVE: We sought to determine (1) whether change in the tibial plateau inclination (TPI) after high tibial osteotomy (HTO) is different from change in the knee joint line orientation (KJLO) relative to the ground; (2) whether, in varus knee OA patients before and after HTO, these radiographic measures are different from those in normal control; and (3) whether the postoperative values of the TPI and KJLO relative to the ground are associated with short term clinical outcome scores after HTO. DESIGN: Fifty patients who underwent HTO and 75 normal controls were assessed with four radiographic measures. We compared the measures before HTO with those after HTO and with those of the normal controls, then examined associations between the postoperative radiographic measures and clinical outcome scores 1-year after HTO. RESULTS: After HTO, TPI increased 9.0°, whereas KJLO relative to the ground only increased 4.1°, with a compensatory change of the ankle joint line orientation. However, the postoperative KJLO relative to the ground in the HTO group was significantly different from that of the normal controls (mean difference, 4.9°; P < 0.001). In the multiple regression analyses, the postoperative radiographic measures were not associated with outcome clinical scores 1 year after HTO. CONCLUSION: After HTO the relative KJLO changed significantly less than did the anatomical geometry of the proximal tibia. Although the KJLO after the HTO was still significantly different from that of normal knees, its value did not adversely affect clinical outcome scores 1 year after HTO.


Assuntos
Articulação do Tornozelo/anatomia & histologia , Articulação do Joelho/anatomia & histologia , Osteoartrite do Joelho/cirurgia , Osteotomia , Tíbia/cirurgia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteotomia/métodos , Período Pós-Operatório
6.
Clin Exp Immunol ; 178(3): 537-47, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25098704

RESUMO

We investigated the impact of rice prolamin extract (RPE) on lipopolysaccharide (LPS)-induced nuclear factor (NF)-κB signalling in intestinal epithelial cells and macrophages, and determined the therapeutic efficacy of RPE in acute murine colitis. The effect of RPE on LPS-induced NF-κB signalling and proinflammatory gene expression was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in-vivo efficacy of RPE was assessed in mice with 3% dextran sulphate sodium (DSS)-induced colitis. Apoptotic and cellular proliferative activities were evaluated by immunostaining with cleaved caspase-3 and proliferating cell nuclear antigen (PCNA) antibodies. RPE inhibited LPS-induced expression of monocyte chemotactic protein (MCP)-1, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha and LPS-induced NF-κB signalling in intestinal epithelial cells and macrophages. RPE-fed, DSS-exposed mice showed less weight loss, longer colon length and lower histological score compared to control diet-fed, DSS-exposed mice. Immunostaining analysis revealed a significant decrease of cleaved caspase-3 positive cells in RPE-fed, DSS-exposed mice compared to DSS-exposed mice. Also, the number of PCNA-positive cells within intact colonic crypts decreased significantly in RPE-fed, DSS-exposed mice compared to control diet-fed, DSS-exposed mice. DSS-induced NF-κB signalling was inhibited by RPE. RPE ameliorates intestinal inflammation by inhibiting NF-κB activation and modulating intestinal apoptosis and cell proliferation in an acute murine colitis.


Assuntos
Apoptose/efeitos dos fármacos , Colite/tratamento farmacológico , Intestinos/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Oryza/química , Extratos Vegetais/farmacologia , Prolaminas/farmacologia , Doença Aguda , Animais , Proliferação de Células/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/uso terapêutico
7.
Osteoporos Int ; 24(11): 2819-25, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23681087

RESUMO

UNLABELLED: We report the bone attenuation of ankle joint measured on computed tomography (CT) and the cause of injury in patients with ankle fractures. The results showed age- and gender-dependent low bone attenuation and low-energy trauma in elderly females, which suggest the osteoporotic features of ankle fractures. INTRODUCTION: This study was performed to investigate the osteoporotic features of ankle fracture in terms of bone attenuation and cause of injury. METHODS: One hundred ninety-four patients (mean age 51.0 years, standard deviation 15.8 years; 98 males and 96 females) with ankle fracture were included. All patients underwent CT examination, and causes of injury (high/low-energy trauma) were recorded. Mean bone attenuations of the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis were measured on CT images. Patients were divided into younger age (<50 years) and older age (≥50 years) groups, and mean bone attenuation and causes of injury were compared between the two groups in each gender. RESULTS: Proportion of low-energy trauma was higher in the older age group than in the younger age group, but the difference was only significant in female gender (p = 0.011). The older age group showed significantly lower bone attenuation in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis than the younger age group in both genders. The older age group showed more complex pattern of fractures than the younger age group. With increasing age, bone attenuations tended to decrease and the difference of bone attenuation between the genders tended to increase in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis. CONCLUSIONS: Ankle fracture had features of osteoporotic fracture that is characterized by age- and gender-dependent low bone attenuation. Ankle fracture should not be excluded from the clinical and research interest as well as from the benefit of osteoporosis management.


Assuntos
Fraturas do Tornozelo , Articulação do Tornozelo/diagnóstico por imagem , Fraturas por Osteoporose/diagnóstico por imagem , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Fraturas por Osteoporose/etiologia , Reprodutibilidade dos Testes , Fatores Sexuais , Tálus/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
8.
Osteoporos Int ; 24(4): 1399-406, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23052930

RESUMO

UNLABELLED: The 12-week home-based virtual cycling training (hVCT) improved lower limb muscle strength and areal bone mineral density (aBMD) than the control program in children with cerebral palsy (CP). A muscle strengthening program, rather than general physical activity, is more specific in enhancing aBMD for these children. A novel hVCT is an effective and efficient strategy that enhances lower limb bone density in these children. INTRODUCTION: This is the first study to assess the efficacy of a novel hVCT program on bone density for children with spastic CP using a well-designed randomized controlled trial. METHODS: Twenty-seven ambulatory children with spastic CP, aged 6-12 years, were randomly assigned to the hVCT group (n=13) or control group (n=14). Outcome measures-motor function [Gross Motor Function Measure-66 (GMFM-66)], muscle strength (curl up scores and isokinetic torque of knee extensor and flexor muscle) and aBMD of the lumbar and distal femur-were administered before and immediately after the 12-week intervention. RESULTS: Analysis of covariance results show that the hVCT group had greater distal femur aBMD and isokinetic torques of knee extensor and flexor muscles than the control group at posttreatment (p<0.05). However, curl up scores, GMFM-66, and lumbar aBMD at posttreatment did not differ between the two groups. CONCLUSIONS: Analytical findings suggest that the muscle strengthening program is more specific in enhancing bone density for children with CP than general physical activity. Thus, the proposed 12-week hVCT protocol is an effective and efficient strategy for improving lower limb aBMD in these children.


Assuntos
Ciclismo/fisiologia , Densidade Óssea/fisiologia , Paralisia Cerebral/reabilitação , Terapia por Exercício/métodos , Serviços de Assistência Domiciliar , Terapia de Exposição à Realidade Virtual/métodos , Paralisia Cerebral/fisiopatologia , Criança , Feminino , Fêmur/fisiopatologia , Humanos , Articulação do Joelho/fisiopatologia , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Resultado do Tratamento , Caminhada/fisiologia
9.
Phys Chem Chem Phys ; 15(39): 16579-85, 2013 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-23959211

RESUMO

Layered Li2MnO3·3LiNi0.5-xMn0.5-xCo2xO2 (x = 0, 0.05, 0.1, 0.165) microspheres with Mn-rich core were successfully synthesized by a simple two-step precipitation calcination method and intensively evaluated as cathode materials for lithium ion batteries. The X-ray powder diffractometry (XRD) results indicate that the growth of Li2MnO3-like regions is impeded due to the presence of cobalt (Co) in the material. The field-emission scanning electron microscopy (FESEM) data reveal the core-shell-like structure with a Mn-rich core in the as-prepared particles. The charge-discharge testing reveals that the capacity is markedly improved by adding Co. The activation of the cathode after Co doping becomes easier and can be accomplished completely when charged to 4.6 V at the C/40 rate in the initial cycle. Superior electrochemical performances are obtained for samples with x = 0.05 and 0.1. The corresponding initial discharge capacities are separately 281 and 285 mA h g(-1) at C/40 between 2 and 4.6 V at room temperature. After 250 cycles at C/2, the respective capacity retentions are 71.2% and 70.4%, which are better compared to the normal Li-excess Li2MnO3·3LiNi0.4Mn0.4Co0.2O2 sample with a uniform distribution of Mn element in the particles. The initial discharge capacities of both samples are approximately 250 mA h g(-1) at a rate of C/2 between 2 and 4.6 V at 55 °C after activation. Furthermore, the samples are investigated by electrochemical impedance spectroscopy (EIS) at room and elevated temperature, revealing that the key factor affecting electrochemical performance is the charge transfer resistance in the particles.

10.
Lupus ; 21(14): 1582-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23161579

RESUMO

Neonatal lupus is a passively acquired autoimmune syndrome resulting from the transplacental passage of maternal anti-Ro/SSA and/or anti-La/SSB antibodies to the fetus. Few past studies have reported central nervous system involvement in neonatal lupus, and most cases had a good neurological outcome. We report here a preterm case of neonatal lupus with thrombocytopenia and comorbid hemorrhagic stroke. In the follow-up, the infant developed spastic quadriplegia and showed delayed milestones. We believe that this is the first reported case of neonatal lupus accompanied by perinatal hemorrhagic stroke. We present this case to remind clinicians to conduct regular central nervous system surveys in cases of neonatal lupus.


Assuntos
Hemorragia Cerebral/etiologia , Lúpus Eritematoso Sistêmico/congênito , Acidente Vascular Cerebral/etiologia , Trombocitopenia/etiologia , Hemorragia Cerebral/patologia , Humanos , Recém-Nascido , Lúpus Eritematoso Sistêmico/complicações , Masculino , Nascimento Prematuro , Quadriplegia/etiologia , Acidente Vascular Cerebral/patologia
11.
Osteoarthritis Cartilage ; 19(7): 853-7, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21352935

RESUMO

OBJECTIVE: Translation and transcultural adaptation of the Hip Disability and Osteoarthritis Outcome Score (HOOS LK 2.0) into Korean language was performed, followed by test of psychometric properties. DESIGN: A Korean version of the HOOS was produced according to internationally recommended guidelines, which included forward translation, reconciliation, back translation, harmonization, cognitive debriefing and proof reading. The psychometric properties including reliability and validity were evaluated. The reliability, including the internal consistency and test-retest reliability, was then evaluated in a hip osteoarthritis population (OA group, n=75). The validity, including the convergent validity was assessed comparing HOOS with the Short Form-36 (SF-36) and pain on a visual analogue scale (VAS) scale. Responsiveness was evaluated in a population scheduled for total hip arthroplasty (THA group, n=35). RESULTS: All subscales of the HOOS showed satisfactory internal consistency (Cronbach's alpha>0.7) without floor and ceiling effects. Intraclass correlation coefficient (ICC) spanned from 0.78 to 0.93. In terms of convergent validity, Activity of Daily Living (ADL) subscale showed the strongest correlations with Physical Function (PF) (r=0.801) and Bodily Pain (BP) (r=0.810) in the subscales of SF-36. For responsiveness, all HOOS subscale scores improved significantly (P<0.05) postoperatively. CONCLUSIONS: The Korean version of HOOS showed satisfactory internal consistency, test-retest reliability, convergent validity, and responsiveness. This study shows that the HOOS questionnaire developed in West is, with transcultural adaptation, relevant for use among patients in East Asia.


Assuntos
Avaliação da Deficiência , Osteoartrite do Quadril/fisiopatologia , Avaliação de Resultados em Cuidados de Saúde/métodos , Psicometria/métodos , Atividades Cotidianas , Adulto , Idoso , Comparação Transcultural , Feminino , Humanos , Coreia (Geográfico) , Masculino , Pessoa de Meia-Idade , Medição da Dor , Reprodutibilidade dos Testes
12.
Clin Nephrol ; 75 Suppl 1: 27-31, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21269590

RESUMO

Acute promyelocytic leukemia (APL) with transcripting three isoforms of mRNA from PML-RAR alpha fusion genes following renal transplantation has never been reported in the literature. A 39-year-old man received a cadaveric renal allograft for IgA chronic kidney disease in 2006 and was consecutively immunosuppressed by tacrolimus, mycophenolate mofetil, and prednisolone. In 2008, he presented with gum bleeding and weight loss. Following bone marrow biopsy, we diagnosed acute promyelocytic leukemia. Molecular analysis demonstrated atypical presence consisting of three isoforms of mRNA from PML-RAR alpha fusion genes. The patient was administered with three courses of consolidation chemotherapy plus atretinoin, resulting in complete remission and did not jeopardize his allograft function. This novel finding suggests that the leukemogenesis of APL may be polyclonal, sharing similar progenitor targeting on complicated karyotypes, responding well to current chemotherapy.


Assuntos
Transplante de Rim/efeitos adversos , Leucemia Promielocítica Aguda/etiologia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Exame de Medula Óssea , Quimioterapia Combinada , Humanos , Imunossupressores/uso terapêutico , Cariotipagem , Leucemia Promielocítica Aguda/diagnóstico , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/genética , Masculino , Proteínas de Fusão Oncogênica/genética , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Homólogo , Resultado do Tratamento
13.
Biochim Biophys Acta ; 1793(7): 1199-209, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19409937

RESUMO

Previous study demonstrated that WASP localizes on vesicles during Dictyostelium chemotaxis and these vesicles appear to be preferentially distributed at the leading and trailing edge of migrating cells. In this study, we have examined the role of PCH family proteins, Nwk/Bzz1p-like protein (NLP) and Syndapin-like protein (SLP), in the regulation of the formation and trafficking of WASP-vesicles during chemotaxis. NLP and SLP appear to be functionally redundant and deletion of both nlp and slp genes causes the loss of polarized F-actin organization and significant defects in chemotaxis. WASP and NLP are colocalized on vesicles and interactions between two molecules via the SH3 domain of NLP/SLP and the proline-rich repeats of WASP are required for vesicle formation from Golgi. Microtubules are required for polarized trafficking of these vesicles as vesicles showing high directed mobility are absent in cells treated with nocodazole. Our results suggest that interaction of WASP with NLP/SLP is required for the formation and trafficking of vesicles from Golgi to the membrane, which might play a central role in the establishment of cell polarity during chemotaxis.


Assuntos
Quimiotaxia/fisiologia , Dictyostelium/metabolismo , Proteínas de Drosophila/metabolismo , Complexo de Golgi/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , Vesículas Secretórias/metabolismo , Fatores de Transcrição/metabolismo , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Actinas/metabolismo , Animais , Dictyostelium/genética , Microtúbulos , Nucleoplasminas , Prolina/química , Prolina/metabolismo , Transporte Proteico , Domínios de Homologia de src
14.
Osteoarthritis Cartilage ; 18(3): 312-6, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19914196

RESUMO

OBJECTIVE: To investigate the prevalence of hip osteoarthritis (OA) in a community-based elderly Korean population and to identify its risk factors. DESIGN: Radiographs of hip and knee were evaluated in 288 men and 386 women (age>or=65 years) that participated in the Korean Longitudinal Study on Health and Aging (KLoSHA). Minimum joint space widths (JSW), center-edge angles (CEA), and neck-shaft angles were measured on hip radiographs, and tibio-femoral angles on knee radiographs. Hip OA was defined as minimum JSW of or=40 degrees) and deformities of femoral neck and knee joint. Multivariate analysis with generalized estimating equation (GEE) model was performed to exclude confounding factors. RESULTS: When hip OA was defined as JSWor=70 years) was identified as a significant risk factors with an odds ratio (OR) of 10.0. However, when hip OA was defined as a JSW of or=70 years), female, large CEA (>or=40 degrees), and acetabular dysplasia (CEA<20 degrees) were identified as significant risk factors with ORs of 2.1, 2.1, 2.3, and 10.2, respectively. CONCLUSIONS: The prevalence of hip OA in elderly Korean was 2.1% (JSWor=70 years), female, large CEA (>or=40 degrees), and acetabular dysplasia (CEA<20 degrees) appeared to be significant risk factors of hip OA.


Assuntos
Luxação do Quadril/epidemiologia , Articulação do Quadril/anormalidades , Osteoartrite do Quadril/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Progressão da Doença , Feminino , Luxação do Quadril/diagnóstico por imagem , Luxação do Quadril/etiologia , Articulação do Quadril/diagnóstico por imagem , Humanos , Estudos Longitudinais , Masculino , Osteoartrite do Quadril/complicações , Osteoartrite do Quadril/diagnóstico por imagem , Valor Preditivo dos Testes , Prevalência , Radiografia , República da Coreia/epidemiologia , Fatores de Risco , Estatística como Assunto
15.
Mol Cell Neurosci ; 42(4): 382-90, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19733667

RESUMO

Microglia activation and migration are known to play crucial roles for the response to brain injuries. Extracellular ADP was reported to induce microglia chemotaxis and membrane ruffles through P2Y12 receptor. In this study, we examined the role of VASP phosphorylation in ADP-induced microglia chemotaxis and membrane ruffle formation. ADP stimulation transiently increased intracellular cAMP level, VASP phosphorylation at Ser153, membrane ruffle formation, and chemotaxis. PKA inhibitor effectively inhibited VASP phosphorylation and chemotaxis, indicating that P2Y12-mediated activation of PKA and subsequent VASP phosphorylation are involved in the regulation of microglia chemotaxis. Forskolin and okadaic acid induced sustained VASP phosphorylation at a high level, causing a significant reduction of the retraction of membrane ruffles and chemotaxis. In forskolin- or okadaic acid-treated cells, phosphorylated VASP remained at the membrane cortex, and size and number of mature focal adhesions were not increased, indicating that prolonged phosphorylation of VASP could inhibit transformation of focal complexes into focal adhesions. VASP knockdown cells showed markedly reduced frequency and distance of membrane ruffling upon ADP stimulation, reinforcing the idea that VASP is required for the ruffle formation. Cells expressing GFP-VASP(S153A) also showed a significant reduction of protrusion distance during ruffle formation, but the frequency and the distance of retraction were not affected by FSK at all. This result suggests that dephosphorylation of VASP might be required for the growth of adhesion strength during membrane retraction. Our results suggest that VASP phosphorylation by PKA plays an important role in membrane ruffle formation and chemotaxis via the regulation of focal adhesion formation/maturation.


Assuntos
Moléculas de Adesão Celular/metabolismo , Quimiotaxia/fisiologia , Adesões Focais/metabolismo , Proteínas dos Microfilamentos/metabolismo , Microglia/fisiologia , Fosfoproteínas/metabolismo , Actinas/metabolismo , Difosfato de Adenosina/farmacologia , Adenilil Ciclases/metabolismo , Animais , Moléculas de Adesão Celular/genética , Linhagem Celular , Extensões da Superfície Celular/metabolismo , Extensões da Superfície Celular/ultraestrutura , Quimiotaxia/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ativação Enzimática , Camundongos , Proteínas dos Microfilamentos/genética , Microglia/citologia , Paxilina/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosfoproteínas/genética , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Purinérgicos P2/metabolismo , Receptores Purinérgicos P2Y12
16.
Water Sci Technol ; 61(10): 2477-89, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20453320

RESUMO

Canonical discriminant analysis (CDA) was applied in order to distinguish the water-quality and the sediment-quality parameters from neighboring rivers, and to recognize similarities of water and sediment properties between a lagoon and neighboring rivers. Two set of constructed discriminant functions showed a marked contribution to most of the discriminant variables. In water, the significant parameters - the total nitrogen, algae, dissolved oxygen and total phosphate - were combined as the nutrient effect factor. The recognition capacities of the two discriminant functions were 95.6 and 4.4%, respectively; the Kaoping River showed the most similarities with the water quality in Dapeng Bay; in sediment, the significant parameters porosity, Cd, Cr, Al, and Pb were combined as the heavy metal effect factor. The recognition capacities were 82.6 and 17.4%, respectively, but the sediment properties in these three rivers had no significant similarity with the Dapeng Bay.


Assuntos
Água Doce , Sedimentos Geológicos/análise , Poluentes da Água/análise , China , Análise Discriminante , Eucariotos/isolamento & purificação , Alimentos , Geografia , Metais/análise , Nitrogênio/análise , Oxigênio/análise , Fosfatos/análise , Rios
17.
J Cell Biol ; 126(2): 539-48, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7518469

RESUMO

We have investigated the binding of soluble tenascin-C (TN-C) to several cell lines using a radioligand binding assay. Specific binding was demonstrated to U-251MG human glioma cells and to a line of bovine aortic endothelial cells, but hamster fibroblasts showed no specific binding. Recombinant proteins corresponding to specific domains of TN-C were used to map the binding site(s) in TN-C. The alternatively spliced segment (TNfnA-D) inhibited the binding of native TN-C most strongly, and itself bound to glioma and endothelial cells. Scatchard analysis of TNfnA-D binding indicated 2-5 x 10(5) binding sites per cell, with an apparent 2 nM dissociation constant. The cell surface receptor for TNfnA-D was identified as a 35-kD protein on the basis of blot binding assays and affinity chromatography of membrane extracts on native TN-C and TNfnA-D columns. Protein sequencing indicated that this 35-kD receptor was annexin II. Annexin II is well characterized as a cytoplasmic protein, so it was surprising to find it as a presumably extracellular receptor for TN-C. To confirm that it was the 35-kD receptor, we obtained purified annexin II and demonstrated its binding to TNfnA-D and TN-C at nM concentrations. Antibodies to annexin II prominently stained the external surface of live endothelial cells and blocked the binding of TNfnA-D to the cells. Thus annexin II appears to be a receptor for the alternatively spliced segment of TN-C, and may mediate cellular responses to soluble TN-C in the extracellular matrix.


Assuntos
Processamento Alternativo , Anexina A2/metabolismo , Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo , Sequência de Aminoácidos , Animais , Anexina A2/química , Anexina A2/isolamento & purificação , Sítios de Ligação , Bovinos , Moléculas de Adesão Celular Neuronais/genética , Células Cultivadas , Endotélio/citologia , Proteínas da Matriz Extracelular/genética , Glioma , Humanos , Cinética , Pulmão/química , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/genética , Ensaio Radioligante , Receptores de Superfície Celular/química , Receptores de Superfície Celular/isolamento & purificação , Proteínas Recombinantes/metabolismo , Análise de Sequência , Tenascina , Células Tumorais Cultivadas
18.
J Cell Biol ; 147(3): 559-76, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-10545500

RESUMO

We have identified a Dictyostelium discoideum gene encoding a serine/threonine kinase, PAKa, a putative member of the Ste20/PAK family of p21-activated kinases, with a kinase domain and a long NH(2)-terminal regulatory domain containing an acidic segment, a polyproline domain, and a CRIB domain. PAKa colocalizes with myosin II to the cleavage furrow of dividing cells and the posterior of polarized, chemotaxing cells via its NH(2)-terminal domain. paka null cells are defective in completing cytokinesis in suspension. PAKa is also required for maintaining the direction of cell movement, suppressing lateral pseudopod extension, and proper retraction of the posterior of chemotaxing cells. paka null cells are defective in myosin II assembly, as the myosin II cap in the posterior of chemotaxing cells and myosin II assembly into cytoskeleton upon cAMP stimulation are absent in these cells, while constitutively active PAKa leads to an upregulation of myosin II assembly. PAKa kinase activity against histone 2B is transiently stimulated and PAKa incorporates into the cytoskeleton with kinetics similar to those of myosin II assembly in response to chemoattractant signaling. However, PAKa does not phosphorylate myosin II. We suggest that PAKa is a major regulator of myosin II assembly, but does so by negatively regulating myosin II heavy chain kinase.


Assuntos
Quimiotaxia , Citoesqueleto/metabolismo , Dictyostelium/citologia , Miosinas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae , Actinas/metabolismo , Sequência de Aminoácidos , Animais , Divisão Celular/efeitos dos fármacos , Polaridade Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Clonagem Molecular , AMP Cíclico/farmacologia , Citoesqueleto/efeitos dos fármacos , Dictyostelium/efeitos dos fármacos , Dictyostelium/genética , Dictyostelium/fisiologia , Ativação Enzimática/efeitos dos fármacos , Deleção de Genes , Células Gigantes/citologia , Células Gigantes/efeitos dos fármacos , Células Gigantes/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , MAP Quinase Quinase Quinases , Dados de Sequência Molecular , Miosinas/genética , Testes de Precipitina , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Pseudópodes/efeitos dos fármacos , Pseudópodes/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/genética , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Domínios de Homologia de src
19.
J Nanosci Nanotechnol ; 9(6): 3449-54, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19504867

RESUMO

Plasma immersion ion implantation (PIII) is an effective method to increase the corrosion resistance and inhibit nickel release from orthopedic NiTi shape memory alloy. Nitrogen was plasma-implanted into NiTi using different pulsing frequencies to investigate the effects on the nano-scale surface morphology, structure, wettability, as well as biocompatibility. X-ray photoelectron spectroscopy (XPS) results show that the implantation depth of nitrogen increases with higher pulsing frequencies. Atomic force microscopy (AFM) discloses that the nano-scale surface roughness increases and surface features are changed from islands to spiky cones with higher pulsing frequencies. This variation in the nano surface structures leads to different surface free energy (SFE) monitored by contact angle measurements. The adhesion, spreading, and proliferation of osteoblasts on the implanted NiTi surface are assessed by cell culture tests. Our results indicate that the nano-scale surface morphology that is altered by the implantation frequencies impacts the surface free energy and wettability of the NiTi surfaces, and in turn affects the osteoblast adhesion behavior.

20.
Trends Biochem Sci ; 26(9): 557-66, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11551793

RESUMO

Many important biological processes, including chemotaxis (directional cell movement up a chemoattractant gradient), require a clearly established cell polarity and the ability of the cell to respond to a directional signal. Recent advances using Dictyostelium cells and mammalian leukocytes have provided insights into the biochemical and molecular pathways that control chemotaxis. Phosphoinositide 3-kinase plays a central and possibly pivotal role in establishing and maintaining cell polarity by regulating the subcellular localization and activation of downstream effectors that are essential for regulating cell polarity and proper chemotaxis. This review outlines our present understanding of these pathways.


Assuntos
Polaridade Celular/fisiologia , Quimiotaxia/fisiologia , Transdução de Sinais , Actinas/metabolismo , Animais , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Dictyostelium/citologia , Dictyostelium/metabolismo , Metabolismo dos Lipídeos , Miosinas/metabolismo , Miosinas/ultraestrutura , Fosfatidilinositol 3-Quinases/metabolismo
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