Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Int J Obes (Lond) ; 42(4): 755-764, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29762555

RESUMO

OBJECTIVE: Studies have indicated that weight regain following weight loss predisposes obese individuals to metabolic disorders; however, the molecular mechanism of this potential adverse effect of weight regain is not fully understood. Here we investigated global transcriptome changes and the immune response in mouse white adipose tissue caused by weight regain. DESIGN: We established a diet switch protocol to compare the effects of weight regain with those of weight gain without precedent weight loss, weight loss maintenance and chow diet. We conducted a time course analysis of global transcriptome changes in gonadal white adipose tissue (gWAT) during the weight fluctuation. Co-expression network analysis was used to identify functional modules associated with the weigh regain phenotype. Immune cell populations in gWAT were characterized by flow-cytometric immunophenotyping. Metabolic phenotypes were monitored by histological analysis of adipose tissue and liver, and blood-chemistry and body weight/composition analyses. RESULTS: In total, 952 genes were differentially expressed in the gWAT in the weight regain vs the weight gain group. Upregulated genes were associated with immune response and leukocyte activation. Co-expression network analysis showed that genes involved in major histocompatibility complex I and II-mediated antigen presentation and T-cell activation function were upregulated. Consistent with the transcriptome analysis results, flow cytometry demonstrated significant increases in subsets of T cells and proinflammatory M1 macrophages in the gWAT in the weight regain as compared to the weight gain group. In addition, upregulation of adaptive immune responses was associated with high incidence of adipocyte death and upregulation of high mobility group box 1, a well-known component of damage-associated molecular patterns. CONCLUSIONS: Our global transcriptome analysis identified weight regain-induced activation of adaptive immune responses in mouse white adipose tissue. Results suggest that activation of adipocyte death-associated adaptive immunity in adipose tissue may contribute to unfavorable metabolic effects of weight regain following weight loss.


Assuntos
Tecido Adiposo Branco/imunologia , Tecido Adiposo Branco/metabolismo , Transcriptoma/fisiologia , Aumento de Peso/imunologia , Aumento de Peso/fisiologia , Tecido Adiposo Branco/química , Animais , Perfilação da Expressão Gênica , Gônadas/química , Gônadas/metabolismo , Fígado/química , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL
2.
J Synchrotron Radiat ; 23(2): 448-54, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26917132

RESUMO

At third-generation light sources, the photon beam position stability is a critical issue for user experiments. In general, photon beam position monitors are developed to detect the real photon beam position, and the position is controlled by a feedback system in order to maintain the reference photon beam position. At Pohang Light Source II, a photon beam position stability of less than 1 µm r.m.s. was achieved for a user service period in the beamline, where the photon beam position monitor is installed. Nevertheless, a detailed analysis of the photon beam position data was necessary in order to ensure the performance of the photon beam position monitor, since it can suffer from various unknown types of noise, such as background contamination due to upstream or downstream dipole radiation, and undulator gap dependence. This paper reports the results of a start-to-end study of the photon beam position stability and a singular value decomposition analysis to confirm the reliability of the photon beam position data.

3.
Minerva Urol Nefrol ; 67(1): 1-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25664959

RESUMO

AIM: Active surveillance is the recommended treatment of option for men with very low-risk prostate cancer. In this study, the clinicopathological results of patients who were initially treated with active surveillance and subsequently underwent robot-assisted radical prostatectomy during follow-up are described. METHODS: A prospective cohort of 106 men enrolled in active surveillance was reviewed. Pathologic specimens for patients who ultimately underwent robot-assisted radical prostatectomy for progression or personal preference were analyzed. RESULTS: After exclusion of 14 patients who were lost to follow-up or with incomplete data collection, 92 men were included in the present analyses. Median follow-up was 27.6 months (range 3.3 to 193.1). Twenty-nine patients underwent robot-assisted radical prostatectomy. Progression occurred in 32 patients (34.8%), of which 23 men elected to undergo surgery. Robot-assisted radical prostatectomy was performed in 6 additional patients who chose definitive intervention due to anxiety. Pathologic analyses revealed organ-confined disease in 24 patients (82.8%), and Gleason score was ≥ 7 in nine (31%). Fourteen (48.3%) specimens were identified as having an advanced disease (Gleason score ≥ 7 and/or T3). In comparison to the patients with low-risk disease post-operatively (Gleason score <7 and T2), patients with advanced disease had significantly higher PSA density level and lower prostate volume. CONCLUSION: In this prospective active surveillance cohort, the progression rate was 34.8% over the follow-up period of 27.6 months. In specimens of patients who underwent robot-assisted radical prostatectomy, 48.3% displayed advanced pathologic features. Therefore we recommend that patients considering active surveillance should be counseled on risk of advanced disease as a possible hazard.


Assuntos
Biomarcadores Tumorais/sangue , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Procedimentos Cirúrgicos Robóticos , Idoso , Progressão da Doença , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , New Jersey , Estudos Prospectivos , Prostatectomia/métodos , Neoplasias da Próstata/sangue , Neoplasias da Próstata/radioterapia , Radioterapia Adjuvante/métodos , Fatores de Risco , Procedimentos Cirúrgicos Robóticos/instrumentação , Procedimentos Cirúrgicos Robóticos/métodos , Resultado do Tratamento
4.
Br J Cancer ; 110(6): 1634-44, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24518599

RESUMO

BACKGROUND: Androgen ablation is the first-line therapy for patients with metastatic prostate cancer (CaP). However, castration resistance will eventually emerge. In the present study, we have investigated the role of bone morphogenetic protein-6 (BMP-6) in the development of castration-resistant prostate cancer (CRPC) in the context of bone metastases. METHODS: We initially investigated the clinical course of 158 men with advanced CaP who were treated with primary androgen deprivation therapy. To elucidate the underlying mechanism of CRPC in the context of bone metastases, we examined the impact of bone stromal cells on CaP in the absence of androgens using a co-culture model. RESULTS: In the 158 patients, we found that the median time to prostate-specific antigen progression was significantly shorter when bone metastases were present (14 months (95% CI, 10.2-17.8 months) vs 57 months (95% CI, 19.4-94.6 months)). These results suggest that bone-tumour interactions may accelerate castration resistance. Consistent with this hypothesis, in vitro co-cultures demonstrated that CaP cells proliferated under an androgen-depleted condition when incubated with bone stromal cells. Mechanistically, gene expression analysis using quantitative polymerase chain reaction arrays showed a dramatic induction of BMP-6 by CaP cell lines in the presence of bone stromal cells. Further studies revealed that WNT5A derived from bone stromal cells induced the expression of BMP-6 by CaP cells; BMP-6 in turn stimulated cellular proliferation of CaP cells in an androgen-deprived media via a physical interaction between Smad5 and ß-catenin. Intracellularly, WNT5A increased BMP-6 expression via protein kinase C/NF-κB pathway in CaP cell lines. CONCLUSIONS: These observations suggest that bone-CaP interaction leads to castration resistance via WNT5A/BMP-6 loop.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Proteína Morfogenética Óssea 6/biossíntese , Neoplasias Ósseas/secundário , Neoplasias Ósseas/terapia , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/terapia , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Wnt/biossíntese , Adulto , Anilidas/uso terapêutico , Proteína Morfogenética Óssea 6/metabolismo , Neoplasias Ósseas/metabolismo , Comunicação Celular/fisiologia , Processos de Crescimento Celular , Linhagem Celular Tumoral , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Nitrilas/uso terapêutico , Orquiectomia , Neoplasias de Próstata Resistentes à Castração/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Androgênicos/metabolismo , Estudos Retrospectivos , Células Estromais/patologia , Compostos de Tosil/uso terapêutico , Proteínas Wnt/metabolismo , Proteína Wnt-5a
5.
Ann Oncol ; 23(2): 401-5, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21515665

RESUMO

BACKGROUND: The gene encoding human 8-oxoguanine glycosylase 1 (hOGG1) is involved in DNA base excision repair from oxidatively damaged DNA. A case-control study was conducted to evaluate the correlation between the susceptibility and clinicopathological outcomes of prostate cancer (CaP) and hOGG1 genotype. PATIENTS AND METHODS: Subjects were recruited from 266 CaP patients and 266 age-matched benign prostatic hyperplasia patients. The hOGG1 codon 326 genotype was determined by peptide nucleic acid-mediated PCR clamping and compared with Gleason score and tumor stage. RESULTS: The Cys allele at codon 326 of hOGG1 was associated with an increased risk of CaP in comparison with the Ser allele (P = 0.005). Gleason scores of 8 or higher were observed more often in patients with the mutant genotypes Ser/Cys and Cys/Cys than in those with a wild-type genotype (P = 0.045), and the Cys/Cys homozygous genotype was associated with a significantly higher risk of metastatic disease in comparison with the Ser/Ser genotype (P = 0.017). CONCLUSIONS: These results suggest that hOGG1 is associated with the susceptibility to CaP and its aggressive clinicopathological characteristics.


Assuntos
DNA Glicosilases/genética , Neoplasias da Próstata/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/patologia , República da Coreia , Fatores de Risco
6.
Clin Transl Oncol ; 23(3): 459-467, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32617871

RESUMO

PURPOSE: This study investigated the degree of tumor cell infiltration in the tumor cavity and ventricle wall based on fluorescent signals of 5-aminolevulinic acid (5-ALA) after removal of the magnetic resonance (MR)-enhancing area and analyzed its prognostic significance in glioblastoma. METHODS: Twenty-five newly developed isocitrate dehydrogenase (IDH)-wildtype glioblastomas with complete resection both of MR-enhancing lesions and strong purple fluorescence on resection cavity were retrospectively analyzed. The fluorescent signals of 5-ALA were divided into strong purple, vague pink, and blue colors. The pathologic findings were classified into massively infiltrating tumor cells, infiltrating tumor cells, suspicious single-cell infiltration, and normal-appearing cells. The pathological findings were analyzed according to the fluorescent signals in the resection cavity and ventricle wall. RESULTS: There was no correlation between fluorescent signals and infiltrating tumor cells in the resection cavity (p = 0.199) and ventricle wall (p = 0.704) after resection of the MR-enhancing lesion. The median progression-free survival (PFS) and median overall survival (OS) were 12.5 (± 2.1) and 21.1 (± 3.5) months, respectively. In univariate analysis, the presence of definitive infiltrating tumor cells in the resection cavity and ventricle wall was significantly related to the PFS (p = 0.002) and OS (p = 0.027). In multivariate analysis, the absence of definitive infiltrating tumor cells improved PFS (hazard ratio: 0.184; 95% CI: 0.049-0.690, p = 0.012) and OS (hazard ratio: 0.124; 95% CI: 0.015-0.998, p = 0.050). CONCLUSIONS: After resection both of the MR-enhancing lesions and strong purple fluorescence on resection cavity, there was no correlation between remnant fluorescent signals and infiltrating tumor cells. The remnant definitive infiltrating tumor cells in the resection cavity and ventricle wall significantly influenced the prognosis of patients with glioblastoma. Aggressive surgical removal of infiltrating tumor cells may improve their prognosis.


Assuntos
Ácido Aminolevulínico/metabolismo , Neoplasias Encefálicas/patologia , Movimento Celular , Glioblastoma/patologia , Isocitrato Desidrogenase , Fármacos Fotossensibilizantes/metabolismo , Idoso , Ácido Aminolevulínico/administração & dosagem , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/cirurgia , Ventrículos Cerebrais/metabolismo , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Feminino , Fluorescência , Glioblastoma/metabolismo , Glioblastoma/mortalidade , Glioblastoma/cirurgia , Humanos , Estimativa de Kaplan-Meier , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fármacos Fotossensibilizantes/administração & dosagem , Prognóstico , Intervalo Livre de Progressão , Protoporfirinas/metabolismo , Estudos Retrospectivos , Proteínas Supressoras de Tumor/genética
7.
Acta Neurol Scand ; 121(3): 171-7, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19839943

RESUMO

OBJECTIVE: To investigate the potential of our newly developed three-dimensional immersive virtual reality (VR) program modeled on a real street crossing as an assessment tool for extrapersonal neglect in stroke patients. METHODS: Thirty-two patients with right-hemispheric stroke (neglect group, 16; non-neglect group, 16) were enrolled. The deviation angle, reaction time, left-to-right reaction time ratio, visual and auditory cue rates, and failure rate were evaluated during missions to keep a virtual avatar safe from a traffic accident in the VR program. The line bisection test and letter cancellation test were also evaluated. RESULTS: The deviation angle, left-to-right reaction time ratio, left visual and auditory cue rates and left failure rate in the VR program showed significant differences between the two groups (P < 0.05). Depending on the direction of approach of the virtual car, the left parameters were significantly higher than the right parameters in the neglect group (P < 0.05). In the neglect group, the line bisection test correlated significantly with the deviation angle (P < 0.05). None of the other virtual reality parameters significantly correlated with the paper and pencil tests. CONCLUSION: Post-stroke neglect in the extrapersonal space can be easily and safely detected and measured using our three-dimensional immersive virtual street crossing program.


Assuntos
Gráficos por Computador , Transtornos da Percepção/diagnóstico , Espaço Pessoal , Percepção Espacial/fisiologia , Interface Usuário-Computador , Estimulação Acústica/métodos , Idoso , Sinais (Psicologia) , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Transtornos da Percepção/etiologia , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Acidente Vascular Cerebral/complicações
8.
Surg Endosc ; 23(2): 409-15, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18813991

RESUMO

INTRODUCTION: Plasma vascular endothelial growth factor (VEGF) levels are increased after surgery and may stimulate tumor growth after cancer resection. Angiopoietin 1 (Ang 1) and Ang 2 are proteins that impact VEGF-related angiogenesis (VRA). Ang 1 stabilizes mature vessels and inhibits VRA, whereas Ang 2 destabilizes vessels and promotes VRA. The ratio of Ang 1 to Ang 2 reflects the net effect; a low ratio promotes VRA. This study's purpose was to determine the impact of open and minimally invasive (MIS) colorectal resection (CR) for benign indications on plasma Ang 1 and 2 levels. METHODS: A total of 30 patients operated by MIS and 26 operated by open procedure were studied. Plasma was obtained preoperatively (PO) and on postoperative days (POD) 1 and 3. Plasma Ang 1 and Ang 2 levels were assessed via enzyme-linked immunosorbent assay (ELISA) in duplicate. Data were compared using Wilcoxon's matched-pair test and the Mann-Whitney U-test (significance p < 0.05). RESULTS: Indications, types of resection, and morbidity for the groups were similar. The mean MIS incision length was 4.7 +/- 1.6 cm while it was 16.8 +/- 7.1 cm for the open group (p = 0.0001). For both groups Ang 2 levels were significantly higher and the Ang 1 to Ang 2 ratio was significantly lower on POD 1 and 3 compared with preoperative results. Ang 1 levels were significantly decreased on POD 1 and 3 in the MIS group but only on POD 1 in the open group. For unclear reasons, preoperative Ang 1 levels and Ang 1 to Ang 2 ratios were significantly different between the groups, which precludes comparison of the postoperative results between groups. CONCLUSION: CR for benign pathology results in higher Ang 2 levels, lower Ang 1 levels, and lower Ang 1 to Ang 2 ratios early after surgery. These alterations are proangiogenic. These results, plus the already noted VEGF increases, suggest that surgery results in proangiogenic plasma protein changes that may stimulate tumor growth early after surgery. The duration of the Ang 1 and 2 changes needs to be determined.


Assuntos
Angiopoietina-1/sangue , Angiopoietina-2/sangue , Colectomia , Doenças do Colo/cirurgia , Laparoscopia , Doenças Retais/cirurgia , Adulto , Idoso , Doenças do Colo/sangue , Doenças do Colo/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doenças Retais/sangue , Doenças Retais/patologia , Fatores de Risco , Fatores de Tempo
9.
Biochemistry (Mosc) ; 74(8): 910-6, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19817692

RESUMO

Mechanistically similar selenophosphate synthetases (SPS) have been isolated from different organisms. SPS from Escherichia coli is an ATP-dependent enzyme with a C-terminal glycine-rich Walker sequence that has been assumed to take part in the first step of ATP binding. Three C-terminally truncated mutants of SPS, containing the N-terminal 238 (SPS(238)), 262 (SPS(262)), and 332 (SPS(332)) amino acids of the 348-amino-acid protein, have been extracted from cell pellets, and two of these (SPS(262) and SPS(332)) have been purified to homogeneity. SPS(238) has been obtained in a highly purified form. Binding of the fluorescent ATP-derivative TNP-ATP and Mn-ATP to the proteins was examined for all truncated mutants of SPS and a catalytically inactive C17S mutant. It has been shown that TNP-ATP can be used as a structural probe for ATP-binding sites of SPS. We observed two TNP-ATP binding sites per molecule of enzyme for wild-type SPS and SPS(332) mutant and one TNP-ATP binding site for SPS(238) mutant. The stoichiometry of Mn-ATP-binding was 2 mol of ATP per mol of protein determined with [(14)C]ATP by HPLC gel-filtration column chromatography under saturating conditions. The binding stoichiometries for SPS(332), SPS(262), and SPS(238) were 2, 1.6, and 1, respectively. The C17S mutant exhibits about one third of wild type SPS TNP-ATP-binding ability and converts 12% of ATP in the ATPase reaction to ADP in the absence of selenide. The C-terminus contributes two thirds to the TNP-ATP binding; SPS(238) likely has one ATP-binding site removed by truncation.


Assuntos
Trifosfato de Adenosina/química , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Fosfotransferases/química , Trifosfato de Adenosina/metabolismo , Sítios de Ligação , Escherichia coli/química , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Cinética , Fosfotransferases/genética , Fosfotransferases/metabolismo , Ligação Proteica
10.
J Mater Sci Mater Med ; 20(10): 1991-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19459033

RESUMO

Glass ionomer cements (GICs) have potential orthopaedic applications. Solgel processing is reported as having advantages over the traditional melt-quench route for synthesizing the glass phase of GICs, including far lower processing temperatures and higher levels of glass purity and homogeneity. This work investigates a novel glass formulation, BT 101 (0.48 SiO(2)-0.36 ZnO-0.12 CaO-0.04 SrO) produced by both the melt-quench and the solgel route. The glass phase was characterised by X-ray diffraction (XRD) to determine whether the material was amorphous and differential thermal analysis (DTA) to measure the glass transition temperature (T (g)). Particle size analysis (PSA) was used to determine the mean particle size and X-ray photoelectron spectroscopy (XPS) was used to investigate the structure and composition of the glass. Both glasses, the melt-quench BT 101 and the solgel BT 101, were mixed with 50 wt% polyacrylic acid (M (w), 80,800) and water to form a GIC and the working time (T (w)) and the setting time (T (s)) of the resultant cements were then determined. The cement based on the solgel glass had a longer T (w) (78 s) as compared to the cement based on the melt derived glass (19 s). T (s) was also much longer for the cement based on the solgel (1,644 s) glass than for the cement based on the melt-derived glass (25 s). The cements based on the melt derived glass produced higher strengths in both compression (sigma(c)) and biaxial flexure (sigma(f)), where the highest strength was found to be 63 MPa in compression, at both 1 and 7 days. The differences in setting and mechanical properties can be associated to structural differences within the glass as determined by XPS which revealed the absence of Ca in the solgel system and a much greater concentration of bridging oxygens (BO) as compared to the melt-derived system.


Assuntos
Química Inorgânica/métodos , Cimentos de Ionômeros de Vidro/síntese química , Cimentos de Ionômeros de Vidro/farmacologia , Vidro/química , Fenômenos Biomecânicos , Análise Diferencial Térmica , Cimentos de Ionômeros de Vidro/química , Teste de Materiais , Tamanho da Partícula , Transição de Fase , Fenômenos Físicos , Difração de Raios X
11.
J Nutr Biochem ; 18(5): 322-31, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-16963253

RESUMO

Obesity is major risk factor for many disorders, including diabetes, hypertension and heart disease. Unfortunately, there is a dearth of therapeutic agents available to clinicians for the treatment of obesity. The principal aim of this study was to investigate whether PEGylated all-trans retinoic acid (PRA) can have favorable stability and biological activity in 3T3-L1 preadipocytes as an antiobesity drug. Here, we found that PRA inhibits the process of adipogenesis, including survival of adipocytes and differentiation to mature adipocytes. The results showed that RA nanoparticles (NPs) were prepared by PEGylation; below 200 nm, PRA-NPs were obtained. Moreover, PRA decreased glycerol-3-phosphate dehydrogenase activity in 3T3-L1 preadipocytes by acting with major adipocyte marker proteins such as PPARgamma2, C/EBPalpha and aP2 modulators. Apoptosis, in addition, increased as the level of RA increased from 10 to 20 microM, whereas PRA reduced apoptosis with increasing concentrations. Our data suggest that PRA-NP has potential as an antiobesity drug carrier due to its small particle size and PEGylated core-shell structure. In addition, our results suggest that PRA inhibits the process of adipogenesis and may be developed to treat obesity. Based on these results, PRA is suitable for adipocyte studies, and an enhanced effect of PRA with adipocyte differentiation offers a challenging approach for pharmaceutical applications.


Assuntos
Adipócitos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Tretinoína/química , Tretinoína/farmacologia , Células 3T3 , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteína alfa Estimuladora de Ligação a CCAAT/efeitos dos fármacos , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Ciclo Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Camundongos , Nanopartículas , PPAR gama/metabolismo , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia
12.
Int J Pharm ; 341(1-2): 35-43, 2007 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-17482781

RESUMO

We have elsewhere reported the work on the preparation of semi-interpenetrating polymer networks (SIPNs) composed of chitosan (CS) and poloxamer to improve the mechanical strength of CS sponge. This study focuses on evaluation of the CS/poloxamer SIPNs to intend for wound dressing application and the efficacy of dehydroepiandrosterone (DHEA)-loaded CS/poloxamer SIPNs in the wound model studies. The properties required for ideal wound dressing, such as equilibrium water content (EWC), water absorption (A(w)), water vapor transmission rate (WVTR), and evaporative water loss, were examined. The CS/poloxamer SIPNs were found to have a water content of 90% of their weight which could prevent the wound bed from accumulation of exudates and also have excellent water adsorption. The WVTR of CS/poloxamer SIPNs was found to be 2,508.2+/-65.7gm(-2)day(-1), indicating that the SIPNs can maintain a moist environment over wound bed in moderate to heavily exuding wound which enhances epithelial cell migration during the healing process. Also, the CS/poloxamer SIPNs in vitro assessment showed proper biodegradation and low cytotoxicity for wound dressing application. The wound healing efficacy of CS/poloxamer SIPNs as a wound dressing was evaluated on experimental full thickness wounds in a mouse model. It was found that the wounds covered with CS/poloxamer SIPNs or DHEA-loaded CS/poloxamer SIPNs were completely filled with new epithelium without any significant adverse reactions after 3 weeks. The results thus indicate that CS/poloxamer SIPNs could be employed in the future as potential wound dressing materials.


Assuntos
Bandagens , Materiais Biocompatíveis , Queimaduras/tratamento farmacológico , Quitosana/química , Desidroepiandrosterona/farmacologia , Portadores de Fármacos , Poloxâmero/química , Cicatrização/efeitos dos fármacos , Adsorção , Animais , Queimaduras/patologia , Queimaduras/fisiopatologia , Sobrevivência Celular/efeitos dos fármacos , Química Farmacêutica , Quitosana/toxicidade , Desidroepiandrosterona/química , Desidroepiandrosterona/uso terapêutico , Modelos Animais de Doenças , Composição de Medicamentos , Feminino , Fibroblastos/efeitos dos fármacos , Humanos , Hidrólise , Queratinócitos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Células NIH 3T3 , Poloxâmero/toxicidade , Pele/efeitos dos fármacos , Pele/patologia , Volatilização , Água/química
13.
Proc Inst Mech Eng H ; 221(8): 821-32, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18161242

RESUMO

The aim of this study was to examine how the interaction between ligament tensions and contact forces guides the knee joint through its specific pattern of passive motion. A computer model was built based on cadaver data. The passive motion and the ligament lengthening and force patterns predicted by the model were verified with data from the literature. The contribution of each ligament and contact force was measured in terms of the rotational moment that it produced about the tibial medial plateau and the anterior-posterior (AP) force that it exerted on the tibia. The high tension of the anterior cruciate ligament (ACL) and the geometric constraints of the anterior horns of the menisci were found to be key features that stabilized the knee at full extension. The mutual effect of the cruciates was found as the reason for the screw-home mechanism at early flexion. Past 300, the AP component of contact force on the convex geometry of the lateral tibial plateau and tension of the lateral collateral ligament (LCL) were identified as elements that control the joint motion. From 60 degrees to 90 degrees, reduction in the tension of the ACL was determined as a reason for continuation of the tibial anterior translation. From 90 degrees to 120 degrees, increase in the tension of the posterior cruciate ligament and the AP component of the contact force on the convex geometry of the lateral tibial plateau pushed the tibia more anteriorly. This anterior translation was limited by the constraining effects of the ACL tension and the AP component of the contact force on the medial meniscus. The important guiding role observed for the LCL suggests that it should not be overlooked in knee models.


Assuntos
Cartilagem Articular/fisiologia , Articulação do Joelho/fisiologia , Ligamentos Articulares/fisiologia , Modelos Biológicos , Movimento/fisiologia , Amplitude de Movimento Articular/fisiologia , Tíbia/fisiologia , Fenômenos Biomecânicos/métodos , Cartilagem Articular/anatomia & histologia , Simulação por Computador , Fricção , Humanos , Articulação do Joelho/anatomia & histologia , Propriedades de Superfície , Tíbia/anatomia & histologia
14.
Proc Inst Mech Eng H ; 220(8): 813-22, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17236515

RESUMO

The motion of the unloaded knee is associated with tibial internal rotation and femoral posterior translation. Although it is known that the passive motion is the result of the interaction between the articular surfaces and the ligaments, the mechanism through which the particular pattern of motion is guided is not completely understood. The goal of this study was to focus on the tibial geometry and to identify the roles that its geometric features have in guiding the passive knee motion. The method used in this study simplified the geometry of the tibial plateaux and the menisci into basic features that could be eliminated individually. The generated tibial geometry was implemented in a computer model to simulate the passive motion. Different parts of the geometry were eliminated individually and the comparison between the simulation results was used to identify the role that each part of the geometry had in guiding the passive motion. The medial meniscus was found as the feature that promoted the tibial internal rotation and restrained the femoral posterior translation. The lateral meniscus and the medial aspect of the tibial eminence, on the other hand, were found as the elements that confined the tibial internal rotation.


Assuntos
Fenômenos Biomecânicos/métodos , Cartilagem Articular/fisiologia , Articulação do Joelho/fisiologia , Modelos Biológicos , Movimento/fisiologia , Amplitude de Movimento Articular/fisiologia , Tíbia/fisiologia , Cartilagem Articular/anatomia & histologia , Simulação por Computador , Humanos , Articulação do Joelho/anatomia & histologia , Propriedades de Superfície , Tíbia/anatomia & histologia
15.
Cancer Res ; 60(11): 2840-4, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10850425

RESUMO

Bone morphogenetic proteins (BMPs) are potential regulators of prostate cancer cell growth and metastasis that signal through an interaction with BMP membrane receptors (BMPRs) type I and type II. In the present study, Western blot and immunohistochemical analysis of BMPRs were carried out in benign and malignant human prostate tissues to explain the loss of BMP response in human prostate cancer cells. The results demonstrated that the benign prostate specimens expressed high levels of all three BMPRs. In normal prostate, BMPRs were localized predominantly to epithelial cells. Among prostate cancer specimens, well-differentiated cancers were positive for the expression of BMPR-II, BMPR-IA, and BMPR-IB, for the most part. In contrast, only 1 of 10 poorly differentiated prostate cancer cases was positive for each of the three BMPRs (P < 0.005 for all three receptors). Taken together, these results indicate that human prostate cancer cells frequently exhibit loss of expression of BMPRs and suggest that loss of BMPRs may play an important role during the progression of prostate cancer.


Assuntos
Neoplasias da Próstata/metabolismo , Proteínas Serina-Treonina Quinases/biossíntese , Receptores de Fatores de Crescimento/biossíntese , Western Blotting , Receptores de Proteínas Morfogenéticas Ósseas Tipo I , Receptores de Proteínas Morfogenéticas Ósseas Tipo II , Progressão da Doença , Células Epiteliais/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Próstata/metabolismo , Neoplasias da Próstata/patologia , Fatores de Crescimento Transformadores/metabolismo
16.
Cancer Res ; 56(1): 44-8, 1996 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-8548772

RESUMO

Transforming growth factor beta 1 (TGF-beta 1), a potential regulator of growth of prostate cancer cells, exerts its effects through interaction with membrane receptors. In the present study, an attempt was made to establish a correlation between TGF-beta 1 sensitivity and TGF-beta receptor expression in three prostate cancer cell lines (PC3, DU145, and LNCaP). In a dose-dependent manner, TGF-beta 1 inhibited the proliferation of PC3 and DU145 cells but not LNCaP cells. Since TGF-beta signals through a heteromeric complex composed of TGF-beta receptors type II and type I, the expression of these receptors was investigated by Western blot analysis and reverse transcriptase-PCR. These studies demonstrated that all three prostate cancer cell lines express type II receptor. In contrast, type I receptor was detected only in the TGF-beta 1-sensitive PC3 and DU145 cells but not in the TGF-beta 1-insensitive LNCaP cells. To investigate the possibility that the undetectable expression of type I receptor in LNCaP cells is due to a change in the respective gene, Southern blot analysis was performed. The result demonstrated that there was a genetic change in type I receptor gene in these cells. Subsequently, when LNCaP cells were transiently transfected with T beta R-I cDNA, sensitivity to TGF-beta 1 was restored. These observations indicate that LNCaP cells contain a defective T beta R-I gene which rendered these cells insensitive to the action of TGF-beta 1.


Assuntos
Neoplasias da Próstata/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/genética , Fator de Crescimento Transformador beta/farmacologia , Sequência de Bases , Divisão Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Dados de Sequência Molecular , Neoplasias da Próstata/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais/genética , Células Tumorais Cultivadas
17.
Cancer Res ; 61(18): 6665-8, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11559531

RESUMO

The transforming growth factor-beta (TGF-beta) receptor complex and its downstream signaling intermediates constitute a tumor suppressor pathway. In many cancers, expression of TGF-beta type II receptor (TbetaR-II) is markedly decreased. In the present study, we show that the hepatocytes isolated from 15-day-old, but not 9-month-old, mice heterozygous for the deletion of the TbetaR-II gene are slightly less sensitive to the growth-inhibitory effect of TGF-beta when compared with wild-type littermates of same age. In addition, the proliferation index of hepatocytes as indicated by bromodeoxyuridine incorporation is mildly increased in the heterozygous mice. These subtle changes in cellular phenotype did not result in either gross or microscopic abnormality of the liver. The treatment of these mice with the chemical carcinogen, diethylnitrosamine, results in a significantly enhanced tumorigenesis in the liver when compared with the wild-type littermates. Our results demonstrate the gene-dosage effect of TbetaR-II and indicate that the reduced expression of TbetaR-II in mice increases susceptibility to tumorigenesis in the liver.


Assuntos
Transformação Celular Neoplásica/genética , Neoplasias Hepáticas Experimentais/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Animais , Carcinógenos , Dietilnitrosamina , Feminino , Dosagem de Genes , Genes cdc/fisiologia , Predisposição Genética para Doença , Heterozigoto , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/fisiologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenobarbital/farmacologia , Gravidez , Proteínas Serina-Treonina Quinases , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/biossíntese , Fator de Crescimento Transformador beta/biossíntese , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta1
18.
Biochim Biophys Acta ; 829(2): 150-5, 1985 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-3995047

RESUMO

The irreversible inactivation of S-adenosylhomocysteine hydrolase purified from hamster and bovine liver by adenosine analogs substituted in the 5' and 2 positions has been investigated in detail. 5'-Cyano-5'-deoxyadenosine inactivates as potently as 9-beta-D-arabinofuranosyladenine (Ara-A). Substitution of the Ara-A at the 2 position by halogens or deleting N at the 3 position decreases its potency. Although weak, 2',3'-dideoxyadenosine can also inactivate the enzyme. The irreversible inactivation of the hydrolase in rat hepatocytes incubated with 2-chloroadenosine or 3-deaza-Ara-A could be demonstrated, concomitant with increases in 35S-labeled S-adenosylhomocysteine and S-adenosylmethionine in the hepatocytes.


Assuntos
Hidrolases/antagonistas & inibidores , Nucleosídeos/farmacologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Adenosil-Homocisteinase , Animais , Bovinos , Cricetinae , Técnicas In Vitro , Cinética , Fígado/enzimologia , Masculino , Ratos , Ratos Endogâmicos , Vidarabina/análogos & derivados , Vidarabina/farmacologia
19.
Biochim Biophys Acta ; 1489(2-3): 389-92, 1999 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-10673040

RESUMO

The suppression subtractive hybridization (SSH) method was used to isolate developmentally regulated genes during carnation flower maturation. Carnation flower maturation-related clones obtained by the SSH were serially assigned as CFMI (carnation flower maturation-induced) clones. Northern blot analysis showed that several CFMI clones were differentially expressed during flower development. One of the clones, CFMI-3, showed similarity to various animal secretory phospholipases A2 (PLA2). Since little is known about PLA2 gene sequence in plant species, the CFMI-3 clone was selected for further characterization by sequence analysis. Full sequence analysis reveals that the CFMI-3 contains a Ca2+ binding domain, a PLA2 active site, and 12 conserved Cys residues, which is a distinct characteristic of PLA2. Amino acid sequence alignment of CFMI-3 to various putative plant PLA2 confirmed that the CFMI-3 cDNA is the full-length putative PLA2 cDNA identified in plant species.


Assuntos
Fosfolipases A/genética , Plantas/enzimologia , Sequência de Aminoácidos , Sequência de Bases , DNA Complementar , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Fosfolipases A2 , Homologia de Sequência de Aminoácidos
20.
J Clin Oncol ; 19(11): 2856-64, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11387358

RESUMO

PURPOSE: Elevated local and circulating levels of transforming growth factor beta(1) (TGF-beta(1)) have been associated with prostate cancer invasion and metastasis. We tested the hypothesis that preoperative plasma TGF-beta(1) levels would independently predict cancer stage and prognosis in patients who undergo radical prostatectomy. PATIENTS AND METHODS: The study group consisted of 120 consecutive patients who underwent radical prostatectomy for clinically localized prostate cancer (median follow-up, 53.8 months). Preoperative plasma levels of TGF-beta(1) were measured and correlated with pathologic parameters and clinical outcomes. TGF-beta(1) levels also were measured in 44 healthy men without cancer, in 19 men with prostate cancer metastatic to regional lymph nodes, and in 10 men with prostate cancer metastatic to bone. RESULTS: Plasma TGF-beta(1) levels in patients with lymph node metastases (14.2 +/- 2.6 ng/mL) and bone metastases (15.5 +/- 2.4 ng/mL) were higher than those in radical prostatectomy patients (5.2 +/- 1.3 ng/mL) and healthy subjects (4.5 +/- 1.2 ng/mL) (P <.001). In a preoperative analysis, preoperative plasma TGF-beta(1) level and biopsy Gleason sum both were predictors of organ-confined disease (P =.006 and P =.006, respectively) and PSA progression (P <.001 and P =.021, respectively). In a postoperative multivariate analysis, preoperative plasma TGF-beta(1) level, pathologic Gleason sum, and surgical margin status were predictors of PSA progression (P =.020,P =.020, and P =.022, respectively). In patients who progressed, preoperative plasma TGF-beta(1) levels were higher in those with presumed distant compared with local-only failure (P =.019). CONCLUSION: Plasma TGF-beta(1) levels are markedly elevated in men with prostate cancer metastatic to regional lymph nodes and bone. In men without clinical or pathologic evidence of metastases, the preoperative plasma TGF-beta(1) level is a strong predictor of biochemical progression after surgery, presumably because of an association with occult metastatic disease present at the time of radical prostatectomy.


Assuntos
Biomarcadores Tumorais/análise , Prostatectomia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Fator de Crescimento Transformador beta/sangue , Adulto , Idoso , Estudos de Casos e Controles , Progressão da Doença , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Prognóstico , Antígeno Prostático Específico/análise , Fator de Crescimento Transformador beta1
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA