Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Inf Syst Front ; : 1-17, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-36000075

RESUMO

The acquisition of personal information has been generally accepted in the pandemic situation as an effective measure to prevent infection, while at the same time raising concerns regarding the infringement of personal privacy. The current study aimed to propose and empirically test a research model for restaurant customers on the disclosure of personal information in a pandemic situation. Privacy calculus theory and institutional theory were applied to theoretically explain the drivers/inhibitors and behavioral responses that affect disclosure of personal information. We verified that the most influential factor on intention to disclose was "perceived benefit", followed by "government pressure" as another strong predictor. We present theoretical and practical implications for restaurant managers and policy agencies.

2.
Elife ; 112022 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-35420543

RESUMO

Preys use their memory - where they sensed a predatory threat and whether a safe shelter is nearby - to dynamically control their survival instinct to avoid harm and reach safety. However, it remains unknown which brain regions are involved, and how such top-down control of innate behavior is implemented at the circuit level. Here, using adult male mice, we show that the anterior hypothalamic nucleus (AHN) is best positioned to control this task as an exclusive target of the hippocampus (HPC) within the medial hypothalamic defense system. Selective optogenetic stimulation and inhibition of hippocampal inputs to the AHN revealed that the HPC→AHN pathway not only mediates the contextual memory of predator threats but also controls the goal-directed escape by transmitting information about the surrounding environment. These results reveal a new mechanism for experience-dependent, top-down control of innate defensive behaviors.


Assuntos
Comportamento Animal , Medo , Animais , Comportamento Animal/fisiologia , Medo/fisiologia , Hipocampo , Hipotálamo/fisiologia , Instinto , Masculino , Camundongos , Vias Neurais/fisiologia
3.
Polymers (Basel) ; 13(8)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918722

RESUMO

Embryonic salivary gland mesenchyme (eSGM) secretes various growth factors (bioactives) that support the proper growth and differentiation of salivary gland epithelium. Therefore, eSGM cells can be used as feeder cells for in vitro-cultured artificial salivary gland if their survival and bioactivity are properly maintained. As eSGM is encapsulated in a hyaluronan (HA)-rich developmental milieu, we hypothesized that mimicking this environment in vitro via surface immobilization of HA might enhance survival and bioactivity of eSGM. In this study, various HA derivatives, conjugated with catechol (HA-CA), thiol (HA-SH), or amine (HA-EDA) moieties, respectively, were screened for their efficacy of culturing eSGM-derived feeder cells in vitro. Among these HA derivatives, HA-CA showed the highest surface coating efficiency and growth enhancement effect on the embryonic submandibular gland. In addition, the HA-CA coating enhanced the production of growth factors EGF and FGF7, but not FGF10. These effects were maintained when eSGM cells isolated from the embryonic salivary gland were re-seeded to develop the feeder layer cells. CD44s (a major HA receptor) in eSGM cells were clustered at the cell membrane, and enhanced EGF expression was detected only in CD44 cluster-positive cells, suggesting that membrane clustering of CD44 is the key mechanism for the increased expression of EGF.

4.
Int J Mol Sci ; 22(2)2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33435128

RESUMO

CXC-chemokine receptor type 4 (CXCR4), a 7-transmembrane receptor family member, displays multifaceted roles, participating in immune cell migration, angiogenesis, and even adipocyte metabolism. However, the activity of such a ubiquitously expressed receptor in epithelial gland organogenesis has not yet been fully explored. To investigate the relationship between CXCL12/CXCR4 signaling and embryonic glandular organogenesis, we used an ex vivo culture system with live imaging and RNA sequencing to elucidate the transcriptome and protein-level signatures of AMD3100, a potent abrogating reagent of the CXCR4-CXCL12 axis, imprinted on the developing organs. Immunostaining results showed that CXCR4 was highly expressed in embryonic submandibular gland, lung, and pancreas, especially at the periphery of end buds containing numerous embryonic stem/progenitor cells. Despite no significant increase in apoptosis, AMD3100-treated epithelial organs showed a retarded growth with significantly slower branching and expansion. Further analyses with submandibular glands revealed that such responses resulted from the AMD3100-induced precocious differentiation of embryonic epithelial cells, losing mitotic activity. RNA sequencing analysis revealed that inhibition of CXCR4 significantly down-regulated polycomb repressive complex (PRC) components, known as regulators of DNA methylation. Treatment with PRC inhibitor recapitulated the AMD3100-induced precocious differentiation. Our results indicate that the epigenetic modulation by the PRC-CXCR12/CXCR4 signaling axis is crucial for the spatiotemporal regulation of proliferation and differentiation of embryonic epithelial cells during embryonic glandular organogenesis.


Assuntos
Benzilaminas/farmacologia , Diferenciação Celular , Ciclamos/farmacologia , Receptores CXCR4/metabolismo , Transdução de Sinais , Glândula Submandibular/metabolismo , Animais , Quimiocina CXCL12/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética , Camundongos , Organogênese , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Proteínas Repressoras/metabolismo , Glândula Submandibular/efeitos dos fármacos , Glândula Submandibular/embriologia , Glândula Submandibular/fisiologia
5.
Am J Physiol Cell Physiol ; 320(3): C448-C461, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33471620

RESUMO

Gram-negative bacterial lipopolysaccharide (LPS) increases the susceptibility of cells to pathogenic diseases, including inflammatory diseases and septic syndrome. In our experiments, we examined whether LPS induces epithelial barrier disruption in secretory epithelia and further investigated its underlying mechanism. The activities of Ca2+-activated Cl- channels (CACC) and epithelial Na+ channels (ENaC) were monitored with a short-circuit current using an Ussing chamber. Epithelial membrane integrity was estimated via transepithelial electrical resistance and paracellular permeability assays. We found that the apical application of LPS evoked short-circuit current (Isc) through the activation of CACC and ENaC. Although LPS disrupted epithelial barrier integrity, this was restored with the inhibition of CACC and ENaC, indicating the role of CACC and ENaC in the regulation of paracellular pathways. We confirmed that LPS, CACC, or ENaC activation evoked apical membrane depolarization. The exposure to a high-K+ buffer increased paracellular permeability. LPS induced the rapid redistribution of zonula occludens-1 (ZO-1) and reduced the expression levels of ZO-1 in tight junctions through apical membrane depolarization and tyrosine phosphorylation. However, the LPS-induced epithelial barrier disruption and degradation of ZO-1 were largely recovered by blocking CACC and ENaC. Furthermore, although LPS-impaired epithelial barrier became vulnerable to secondary bacterial infections, this vulnerability was prevented by inhibiting CACC and ENaC. We concluded that LPS induces the disruption of epithelial barrier integrity through the activation of CACC and ENaC, resulting in apical membrane depolarization and the subsequent tyrosine phosphorylation of ZO-1.


Assuntos
Canais de Cloreto/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Lipopolissacarídeos/farmacologia , Canais de Sódio/metabolismo , Animais , Células Cultivadas , Masculino , Potenciais da Membrana/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Proteína da Zônula de Oclusão-1/metabolismo
6.
Acta Biomater ; 115: 275-287, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32853803

RESUMO

Dry mouth, or xerostomia, caused by salivary gland dysfunction significantly impacts oral/systemic health and quality of life. Although in vitro-generated artificial salivary glands have been considered as the fundamental solution, its structural complexity is difficult to reproduce using current biomaterials. Therefore, understanding and recapitulating the roles of biomacromolecules in salivary gland organogenesis is needed to solve these problems. Hyaluronic acid (HA) is a macromolecule abundant during salivary gland organogenesis, but its role remains unknown. Here, we verify the effects of HA on salivary gland organogenesis and artificial organ germ formation in solubilized and substrate-immobilized forms. In embryonic submandibular glands (eSMG), we found dense HA layers encapsulating proliferative c-Kit+ progenitor cells that were expressing CD44, an HA receptor. The blockage of HA synthesis, or degradation of HA, impaired eSMG growth by ablating the c-Kit+ progenitor cell population. We also found that high-molecular-weight (HMW) HA has a significant role in eSMG growth. Based on these findings, we discovered that HA is also crucial for in vitro formation of salivary gland organ germs, one of the most promising candidates for salivary gland tissue regeneration. We significantly enhanced salivary gland organ germ formation by supplementing HMW HA in solution; this effect was further increased when the HMW HA was immobilized on the substrate by polydopamine/HA co-immobilization. Our study suggests that the current use of HA in salivary gland tissue engineering can be further optimized.


Assuntos
Ácido Hialurônico , Xerostomia , Humanos , Qualidade de Vida , Glândulas Salivares , Engenharia Tecidual
7.
Adv Mater ; 32(31): e2001566, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32520432

RESUMO

Nanomaterials with antioxidant properties are promising for treating reactive oxygen species (ROS)-related diseases. However, maintaining efficacy at low doses to minimize toxicity is a critical for clinical applications. Tuning the surface strain of metallic nanoparticles can enhance catalytic reactivity, which has rarely been demonstrated in metal oxide nanomaterials. Here, it is shown that inducing surface strains of CeO2 /Mn3 O4 nanocrystals produces highly catalytic antioxidants that can protect tissue-resident stem cells from irradiation-induced ROS damage. Manganese ions deposited on the surface of cerium oxide (CeO2 ) nanocrystals form strained layers of manganese oxide (Mn3 O4 ) islands, increasing the number of oxygen vacancies. CeO2 /Mn3 O4 nanocrystals show better catalytic activity than CeO2 or Mn3 O4 alone and can protect the regenerative capabilities of intestinal stem cells in an organoid model after a lethal dose of irradiation. A small amount of the nanocrystals prevents acute radiation syndrome and increases the survival rate of mice treated with a lethal dose of total body irradiation.


Assuntos
Antioxidantes/química , Cério/química , Compostos de Manganês/química , Nanopartículas Metálicas/química , Óxidos/química , Protetores contra Radiação/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Duodeno/metabolismo , Duodeno/efeitos da radiação , Raios gama , Humanos , Antígeno Ki-67/metabolismo , Camundongos , Modelos Biológicos , Protetores contra Radiação/farmacologia , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Irradiação Corporal Total
8.
J Clin Med ; 9(3)2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-32182826

RESUMO

Cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic AMP (cAMP)-regulated chloride channel, is critical for secretion and absorption across diverse epithelia. Mutations or absence of CFTR result in pathogeneses, including cancer. While CFTR has been proposed as a tumor suppressing gene in tumors of the intestine, lung, and breast cancers, its effects in head and neck cancer (HNC) have yet to be investigated. This study aimed to define expression patterns and epigenetic modifications of CFTR in HNC. CFTR was expressed in normal but not in HNC cells and tissues. Treatment with 5-aza-2'-deoxycytidine (5-Aza-CdR) was associated with rescued expression of CFTR, whose function was confirmed by patch clamp technique. Further experiments demonstrated that CFTR CpG islands were hypermethylated in cancer cells and tissues and hypomethylated in normal cells and tissue. Our results suggest that CFTR epigenetic modifications are critical in both down-regulation and up-regulation of CFTR expression in HNC and normal cells respectively. We then investigated the impact of CFTR on expressions and functions of cancer-related genes. CFTR silencing was closely associated with changes to other cancer-related genes, suppressing apoptosis while enhancing proliferation, cell motility, and invasion in HNC. Our findings demonstrate that hypermethylation of CFTR CpG islands and CFTR deficiency is closely related to HNC.

9.
Korean J Thorac Cardiovasc Surg ; 44(1): 25-31, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22263120

RESUMO

BACKGROUND: Mature autogenous arteriovenous fistulas have better long term patency and require fewer secondary interventions compared to arteriovenous prosthetic graft. Our Study evaluated vascular patency rates and incidence of interventions in autogenous arteriovenous fistulas and grafts. MATERIAL AND METHODS: A total of 166 vascular access operations were performed in 153 patients between December 2002 and November 2009. Thirty seven caeses were excluded due to primary access failure and loss of follow-up. One group of 92 autogenous arterioveous fistulas and the other group of 37 arteriovenous prosthetic grafts were evaluated retrospectively. Primary and secondary patency rates were estimated using the Kaplan-Meier method. RESULTS: The primary patency rate (84%, 67%, 51% vs. 51%, 22%, 9% at 1, 3, 5 year; p=0.0000) and secondary patency rate (96%, 88%, 68% vs. 88%, 65%, 16% at 1. 3, 5 year; p=0.0009) were better in autogenous fistula group than prosthetic graft group. Interventions to maintain secondary patency were required in 23% of the autogenous fistula group (average 0.06 procedures/patient/year) and 65% of prosthetic graft group (average 0.21 procedures/patient/year). So the autogenous fistula group had fewer intervention rate than prosthetic graft group (p=0.01) The risk factor of primary patency was diabetus combined with ischemic heart disease and the secondary patency's risk factor was age. CONCLUSION: Autogenous arteriovenous fistulas showed better performance compared to prosthetic grafts in terms of primary & secondary patency and incidence of interventions.

10.
Clin Transplant ; 21(1): 126-35, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17302601

RESUMO

BACKGROUND: While hand-assisted laparoscopic donor nephrectomy (HLDN) is less invasive, which can encourage kidney donation, it requires more exact information about the renal vascular anatomy because of its limited visual field during nephrectomy. MRA is also an attractive choice because of its minimal invasiveness; further, it is an outpatient-based procedure, it uses non-nephrotoxic contrast material and it has no radiation. The aim of our study was to evaluate the effectiveness of gadolinium enhanced three-dimensional MRA (GdE-3D MRA) in a group of potential live donors who were candidates for HLDN. METHODS: From September 2002 to December 2004, 40 potential live renal donors were evaluated prospectively with GdE-3D MRA, and this imaging modality was performed before the gold standard, the intra-arterial digital subtraction angiogram (IA-DSA), was carried out. All the images were reviewed in a blinded manner by the attending vascular radiologist. The MRA findings were compared with the DSA findings and the surgical findings as the reference methods. We evaluated the accuracy of MRA for imaging the renal architectures, and especially for imaging the renal accessory arteries and the early branching arteries that are important determinants for selection of the donor kidney. RESULTS: Both the MRA and DSA images showed consistent findings with the surgical findings in 92.5% of the 40 donors. There were no discrepant cases in depicting the main renal artery. MRA showed 100% specificity for imaging both the renal accessory arteries and the early branching arteries, when compared with the surgical findings. The kappa values for the MRA and DSA for the accessory arteries were all 0.66 compared with the intraoperative findings. MRA also depicted one huge renal cyst in one donor and many small renal cysts in the other donors that could not be imaged by DSA. There were no adverse events during the MRA procedure. None of the findings missed by MRA resulted in deleterious consequences at laparoscopic nephrectomy for the donor and graft. CONCLUSIONS: Our limited experience with GdE-3D MRA for imaging the renal structures in kidney donor evaluation for HLDN has been quite satisfactory.


Assuntos
Artéria Hepática/anatomia & histologia , Rim/anatomia & histologia , Doadores Vivos , Angiografia por Ressonância Magnética , Nefrectomia/métodos , Coleta de Tecidos e Órgãos/métodos , Angiografia , Artéria Hepática/diagnóstico por imagem , Humanos , Rim/diagnóstico por imagem , Laparoscopia , Reprodutibilidade dos Testes , Estudos Retrospectivos
11.
J Korean Med Sci ; 20(6): 994-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16361811

RESUMO

We evaluated the risk of coronary-artery disease in patients with chronic renal failure (CRF) by measuring the coronary-artery calcium scores with electron beam CT (EBCT). A total of 81 CRF patients were divided into three groups; pre-dialysis (group I, n = 35), hemodialysis (group II, n = 31) and peritoneal dialysis (group III, n = 15). The several serum biochemical markers and calcium score levels by EBCT were determined. The Ca x P products were significantly higher in groups II (p < 0.05) and III (p < 0.01) than in group I. The serum calcium levels were significantly higher in group III than in both group I (p < 0.01) and II (p < 0.05). The serum calcium level in 15 patients with a calcium score > 400 was significantly higher than the 66 patients with a score < or =400 (p < 0.01). The calcium score was significantly higher in the 15 patients with cardiovascular complications than in the 66 patients without cardiovascular complications (628.9+/-904.8 vs. 150.4+/-350.9, p < 0.01). EBCT seemed to be a good diagnostic tool for evaluating the risk of coronary-artery disease ''noninvasively'' in CRF patients who are at increased risk of cardiovascular morbidity and mortality.


Assuntos
Calcinose/diagnóstico por imagem , Cálcio/metabolismo , Vasos Coronários/metabolismo , Falência Renal Crônica/diagnóstico por imagem , Adolescente , Adulto , Idoso , Calcinose/etiologia , Calcinose/metabolismo , Cálcio/sangue , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/metabolismo , Feminino , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/metabolismo , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal , Diálise Renal , Fatores de Risco , Tomografia Computadorizada por Raios X
12.
Adv Perit Dial ; 21: 25-30, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16686280

RESUMO

Instead of the peritoneal equilibration test (PET), the dialysis adequacy and transport test (DATT) is an easy and convenient method to classify peritoneal transport type. However, the peritoneal transport characteristics obtained from the DATT and the PET are not same in some cases. In the present study, we investigated the ability of the DATT to identify peritoneal transport characteristics in a clinical setting, and we analyzed the characteristics of patients with a discrepancy between the DATT and the PET. We studied 106 patients on continuous ambulatory peritoneal dialysis (CAPD) who underwent 198 simultaneous DATTs and PETs. The 24-hour dialysate-to-plasma ratio of creatinine (D / P(Cr)) from each DATT was compared with the adjusted 4-hour D/P(Cr) from the corresponding PET. Based on the degree of the mean discrepancy between the 24-hour D / P(Cr) and the adjusted 4-hour D / P(Cr) the patients were divided into three groups: Group A patents had 24-hour D / P(Cr) values that were lower than the adjusted 4-hour D / P(Cr) values (n=13). Group B patients had 24-hour D / P(Cr) values that were equivalent to the adjusted 4-hour D / P(Cr) values (n=156). Group C patients had 24-hour D / P(Cr) values that were higher than the adjusted 4-hour D / P(Cr) values (n=29). The comparative analysis among the three groups was adjustedforperitoneal transport characteristics, dialysis adequacy indices, nutrition status, and daily dialysis prescription. The 24-hour D / P(Cr) from the DATT correlated significantly with the 4-hour D / P(Cr) (gamma = 0.759, p < 0.0001). In 156 cases (78.8%), the D / P(Cr) values from the DATT and the PET showed reasonable agreement; but, in 42 cases (21.2%), the values were discordant. In 94 cases (47.5%), the peritoneal transport groups as classified by the DATT and the PET were discordant. The mean difference in D / P(Cr) between the DATT and the PET was 0.07 +/- 0.08, and the DATT differed significantly from the PET in categorizing the low and low-average transport groups (p < 0.05). A significant difference was seen between the three groups in daily exchange volume (group A: 7384.6 +/- 1502.2 mL; group B: 7537.3 +/- 1087.7 mL; group C: 6675.9 +/- 1414.6 mL; p < 0.05) and in the frequency of daily exchanges (group A: 3.7 +/- 0.8 exchanges; group B: 3.8 +/- 0.4 exchanges; group C: 3.4 +/- 0.7 exchanges; p < 0.05). We confirmed that the DATT is an easy and convenient method of identifying peritoneal membrane transport instead of the PET, and that the DATT can be generalized to patients receiving various dialysis prescriptions and to patients receiving four daily exchanges. However, the DATT may be less accurate for CAPD patients with low or low-average transport, and the higher value of D / P(Cr) derived from the DATT, as compared with the PET, is attributable to longer dwell times and a lower dwell volume.


Assuntos
Diálise Peritoneal Ambulatorial Contínua , Peritônio/metabolismo , Transporte Biológico , Creatinina/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...