Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
1.
Acta Radiol ; 64(10): 2687-2696, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37691270

RESUMO

BACKGROUND: Biannual Ultrasound showed insufficient sensitivity in detecting small or early-stage hepatocellular carcinoma (HCC). Abbreviated magnetic resonance imaging (A-MRI) protocols with fewer sequences demonstrated higher HCC detection sensitivity than ultrasound with acceptable cost and examination time. PURPOSE: To compare the diagnostic performance of gadoxetic acid-enhanced A-MRI with a full sequence MRI (F-MRI) protocol for small HCC (≤2 cm) in cirrhotic or hepatitis B virus-infected high-risk patients. MATERIAL AND METHODS: Two hundred and four consecutive patients with 166 pathologically confirmed small HCC who underwent preoperative gadoxetic acid-enhanced MRI were retrospectively included. A-MRI set comprised T1-weighted hepatobiliary phase imaging, T2-weighted imaging, diffusion-weighted imaging and apparent diffusion coefficient mapping. Two independent radiologists blinded to clinical data assessed the A-MRI set and F-MRI set. Per-patient HCC and per-lesion HCC diagnostic performance were compared. RESULTS: Per-patient HCC detection sensitivity of A-MRI set was 93.8% and 91.2% for observer 1 and observer 2, and, for the F-MRI set, the per-patient HCC detection sensitivity was 96.6% and 95.2%, respectively. There was no significant difference in per-patient sensitivity, specificity and per-lesion HCC detection sensitivity between the two imaging sets for both readers. (P = 0.06-0.25) The A-MRI set showed higher sensitivity on HCC without arterial phase hyperenhancement, and the F-MRI set demonstrated with higher sensitivity on HCC with arterial phase hyperenhancement (P < 0.05). CONCLUSION: A-MRI using diagnostic criteria including hypointensity on hepatobiliary phase plus mild to moderate hyperintensity on T2-weighted imaging or restricted diffusion demonstrated comparable sensitivity and specificity for small HCC compared to the F-MRI protocol in high-risk patients.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Estudos Retrospectivos , Meios de Contraste , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Sensibilidade e Especificidade
2.
Eur Radiol ; 32(6): 4198-4209, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35079885

RESUMO

OBJECTIVES: To explore the importance of three-dimensional (3D) quantitative analysis during gadoxetic acid-enhanced magnetic resonance imaging (MRI) of microvascular invasion (MVI) and early recurrence (< 2 years) after surgery of single hepatocellular carcinoma (HCC) ≤ 3 cm. METHODS: Two hundred fourteen patients with pathologically confirmed HCC (training cohort: n = 169; validation cohort: n = 45) were included retrospectively. The 3D quantitative parameters (volume, sphericity, and compacity) and conventional MRI features were analyzed. The significant predictors for MVI were identified using univariate and multivariate logistic regression analyses. Nomograms were constructed from the prediction model, and the relationship between the significant predictors and early recurrence rates was evaluated using the Kaplan-Meier method. RESULTS: Tumor sphericity (odds ratio [OR] = 0.000; p < 0.001), non-smooth tumor margin (OR = 3.353; p = 0.015), and peritumoral hypointensity on hepatobiliary phase (HBP) (OR = 14.067; p = 0.003) were independent significant factors for MVI. When these three factors were combined, the diagnostic specificity of the training and validation cohorts was 97.0 (128/132) and 87.9 (29/33), respectively. The nomogram based on the predictive model performed satisfactorily in the training (C-index: 0.885) and validation (C-index: 0.869) cohorts. Early recurrence rates of patients with two or three significant factors were significantly higher than those with none in the training (29.1% vs. 10.2%, p = 0.007) and validation (36.4% vs. 6.7%, p = 0.037) cohorts. CONCLUSIONS: Lower sphericity combined with non-smooth tumor margin and peritumoral hypointensity on HBP are potential predictive factors for MVI and associated with early recurrence after surgery of HCC ≤ 3 cm. KEY POINTS: • Lower sphericity, non-smooth tumor margin, and peritumoral hypointensity on HBP were important indicators of the occurrence of MVI in HCC. • The combinational model prepared from these findings satisfactorily predicted MVI, and the presence of these predictors was associated with an early recurrence rate after surgical resection in HCC patients. • This model could help clinicians in the preoperative management of small HCC ≤ 3 cm.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Imageamento por Ressonância Magnética/métodos , Invasividade Neoplásica/patologia , Estudos Retrospectivos
3.
Acta Radiol ; 63(6): 734-742, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33969700

RESUMO

BACKGROUND: Gadoxetic acid-enhanced magnetic resonance imaging (MRI) has been widely used in clinical practice. However, scientific evidence is lacking for recommending a particular sequence for measuring tumor size. PURPOSE: To retrospectively compare the size of hepatocellular carcinoma (HCC) measured on different gadoxetic acid-enhanced MRI sequences using pathology as a reference. MATERIAL AND METHODS: A total of 217 patients with single HCC who underwent gadoxetic acid-enhanced MRI before surgery were included. The size of the HCC was measured by two abdominal radiologists independently on the following sequences: T1-weighted; T2-weighted; b-500 diffusion-weighted imaging (DWI); and arterial, portal venous, transitional, and hepatobiliary phases. Tumor size measured on MRI was compared with pathological size by using Pearson correlation coefficient, independent-sample t test, and Bland-Altman plot. Agreement between two readers was evaluated with intraclass correlation coefficient (ICC). RESULTS: Correlation between the MR images and pathology was high for both readers (0.899-0.955). Absolute error between MRI and pathologic assessment was lowest on hepatobiliary phase images for both readers (reader 1, 2.8±4.2 mm; reader 2, 3.2±3.4 mm) and highest on arterial phase images for reader 1 (4.9±4.4 mm) and DWI phase images for reader 2 (5.1±4.9 mm). Absolute errors were significantly different for hepatobiliary phase compared with other sequences for both readers (reader 1, P≤0.012; reader 2, P≤0.037). Inter-reader agreements for all sequence measurements were strong (0.971-0.997). CONCLUSION: The performance of gadoxetic acid-enhanced MRI sequences varied with HCC size, and the hepatobiliary phase may be optimal among these sequences.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Meios de Contraste , Gadolínio DTPA , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Sensibilidade e Especificidade
4.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 53(1): 63-70, 2022 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-35048602

RESUMO

OBJECTIVE: To study the role of M2 macrophage-derived exosomes (M2-exo) in osteogenic differentiation and Hedgehog signaling pathway of mouse bone marrow mesenchymal stem cells (BMSCs) under in vitro high-glucose and high-insulin conditions. METHODS: RAW 264.7 cells were induced toward M2 macrophage polarization and then M2-exo were extracted and identified. Immunofluorescence assay was performed to detect the internalization of M2-exo by BMSCs. BMSCs were divided into the normal control group (Control group), the high-glucose and high-insulin group (HGI group), and the HGI with M2-exo intervention group (HGI+M2e group). BMSCs in the Control group were cultured in osteogenic inductive medium with 5.5 mmol/L glucose, but no insulin or M2-exo. BMSCs in the HGI group were cultured in osteogenic inductive medium with 25 mmol/L glucose and 174 nmol/L insulin. BMSCs in the HGI+M2e group were cultured in the same medium as that of the HGI group, with the additional treatment of 6, 30, 60 µg/mL M2-exo, respectively. After osteogenic induction for 7 days and 14 days, alkaline phosphatase (ALP) staining and alizarin red staining were performed respectively to assess the osteogenic differentiation potential of BMSCs from different groups. In addition, BMSCs in the Control group, HGI group, and HGI+M2e group treated with 30 µg/mL M2-exo were examined with qPCR after osteogenic induction for 14 days and Western blot after osteogenic induction for 21 days to assess the osteogenesis and the expression of Hedgehog pathway-related genes and proteins. RESULTS: M2 macrophage polarization was induced successfully, with highly positive expression of CD206, the M2 polarization surface marker. The M2-exo had the typical structure of round or oval-shaped bilayered-membrane vesicles. The diameter distribution of M2-exo ranged from 50 to 125 nm (accounting for 99.14% of all M2-exo). M2-exo samples showed positive expression of exosomal markers CD9, CD63 and CD81 proteins. Immunofluorescence staining showed that M2-exo were taken up and internalized by BMSCs. After osteogenic induction for 7 days, the ALP activity of BMSCs in the HGI group was lower than that of the Control group. After interventions of 6 µg/mL, 30 µg/mL, and 60 µg/mL M2-exo, the ALP activity of the HGI+M2-exo group was significantly increased compared with that of the HGI group ( P<0.05). After osteogenic induction for 14 days, the number of mineralized nodules in the HGI group was lower than that in the Control group, and after intervention, only the HGI+M2e group treated with 30 µg/mL M2-exo showed higher level of mineralization than that in the HGI group ( P<0.05). qPCR analysis revealed that the expression levels of the osteogenesis-related genes, including Runx2, Alp and Ocn, and Hedgehog pathway-related genes, including Gli1, Smo and Ptch1, were downregulated in the HGI group, all being lower than those of the Control group to varying degrees, while 30 µg/mL M2-exo treatment could promote the up-regulation of these genes, showing significant difference in comparison with their expression levels in the HGI group ( P<0.05). In addition, Western blot analysis showed that the expression of the osteogenesis-related proteins, including RUNX2 and COL1A1, and GLI1, the Hedgehog signaling pathway protein, was down-regulated in the HGI group, while the expression of COL1A1 and GLI1 was up-regulated after 30 µg/mL M2-exo treatment, showing significant difference when compared with that of the HGI group ( P<0.05). CONCLUSION: High glucose and high insulin had inhibitory effect on the osteogenic differentiation potential of BMSCs. After intervention with M2-exo, the Hedgehog signaling pathway in BMSCs was activated and the osteogenic differentiation potential was enhanced, suggesting that M2-exo might have therapeutic potentials for the treatment of diabetic bone disease.


Assuntos
Exossomos , Insulinas , Células-Tronco Mesenquimais , Animais , Células da Medula Óssea , Diferenciação Celular , Células Cultivadas , Glucose , Proteínas Hedgehog , Macrófagos , Camundongos , Osteogênese
5.
Biochem Biophys Res Commun ; 503(1): 79-85, 2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-29852172

RESUMO

The noradrenergic neurons of the locus coeruleus (LC) are associated with various brain functions and psychiatric disorders, such as addiction and depression. It has been shown that neuropeptide galanin (GAL) inhibits neuronal excitability in LC, but the mechanisms remain unclear. In the present study, we investigated the ionic and signal transduction mechanisms underlying inhibitory effect of GAL on LC neurons using whole-cell patch clamp recording in rat brain slices. Bath application of GAL decreased the spontaneous firings and induced a dose-dependent hyperpolarization of LC neurons and this effect was attenuated by knockdown of Galr1, but not Galr2, confirming that mainly GALR1 mediates the inhibition effect of GAL. The inhibitory effect of GAL was also blocked by treatments of pertussis toxin (PTX), GTP-γ-s or GDP-ß-s, respectively, indicating that the functions of PTX sensitive Gi/o protein are required for GAL-induced hyperpolarization. Moreover, the blockers of GIRK (tertiapin-Q or SCH2 3390 hydrochloride) attenuated the GAL response while blocker of BK/SK/KATP channels or TASK-1/3 channels did not affect it significantly, suggesting that GIRK channels play an important role in GAL-induced hyperpolarization in LC neurons. Taken together, the inhibitory effect of GAL on LC neurons is mediated by GALR1 via PTX-sensitive Gi/o proteins, which activate GIRK channels.


Assuntos
Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Locus Cerúleo/metabolismo , Receptor Tipo 1 de Galanina/metabolismo , Neurônios Adrenérgicos/efeitos dos fármacos , Neurônios Adrenérgicos/metabolismo , Animais , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/antagonistas & inibidores , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Galanina/metabolismo , Técnicas de Silenciamento de Genes , Locus Cerúleo/citologia , Locus Cerúleo/efeitos dos fármacos , Masculino , Técnicas de Patch-Clamp , Toxina Pertussis/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Precursores de Proteínas/metabolismo , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Ratos , Ratos Sprague-Dawley , Receptor Tipo 1 de Galanina/antagonistas & inibidores , Receptor Tipo 1 de Galanina/genética , Receptor Tipo 2 de Galanina/antagonistas & inibidores , Receptor Tipo 2 de Galanina/genética , Receptor Tipo 2 de Galanina/metabolismo , Transdução de Sinais
6.
J Cell Mol Med ; 21(12): 3515-3528, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28656644

RESUMO

The cholinergic impairment is an early marker in Alzheimer's disease (AD), while the mechanisms are not fully understood. We investigated here the effects of glycogen synthase kinse-3 (GSK-3) activation on the cholinergic homoeostasis in nucleus basalis of Meynert (NBM) and frontal cortex, the cholinergic enriched regions. We activated GSK-3 by lateral ventricular infusion of wortmannin (WT) and GF-109203X (GFX), the inhibitors of phosphoinositol-3 kinase (PI3-K) and protein kinase C (PKC), respectively, and significantly decreased the acetylcholine (ACh) level via inhibiting choline acetyl transferase (ChAT) rather than regulating acetylcholinesterase (AChE). Neuronal axonal transport was disrupted and ChAT accumulation occurred in NBM and frontal cortex accompanied with hyperphosphorylation of tau and neurofilaments. Moreover, ChAT expression decreased in NBM attributing to cleavage of nuclear factor-κB/p100 into p52 for translocation into nucleus to lower ChAT mRNA level. The cholinergic dysfunction could be mimicked by overexpression of GSK-3 and rescued by simultaneous administration of LiCl or SB216763, inhibitors of GSK-3. Our data reveal the molecular mechanism that may underlie the cholinergic impairments in AD patients.


Assuntos
Acetilcolina/metabolismo , Núcleo Basal de Meynert/metabolismo , Lobo Frontal/metabolismo , Quinase 3 da Glicogênio Sintase/genética , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Androstadienos/farmacologia , Animais , Transporte Axonal/efeitos dos fármacos , Núcleo Basal de Meynert/efeitos dos fármacos , Núcleo Basal de Meynert/patologia , Colina O-Acetiltransferase/genética , Colina O-Acetiltransferase/metabolismo , Lobo Frontal/efeitos dos fármacos , Lobo Frontal/patologia , Regulação da Expressão Gênica , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/metabolismo , Homeostase/efeitos dos fármacos , Homeostase/genética , Indóis/farmacologia , Cloreto de Lítio/farmacologia , Masculino , Maleimidas/farmacologia , NF-kappa B/genética , NF-kappa B/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , Técnicas Estereotáxicas , Wortmanina , Proteínas tau/genética , Proteínas tau/metabolismo
7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 46(3): 359-62, 2015 May.
Artigo em Chinês | MEDLINE | ID: mdl-26121852

RESUMO

OBJECTIVE: To construct recombinant plasmid pET28a-Rv0757 with Mycobacterium tuberculosis (Mtb) Rv0757 gene, and to determine the effect of the protein of Rv0757 gene on ANA-1 cells. METHODS: We recombined the amplified Rv0757 gene into theprokaryotic plasmid pET28a (+). The expressed product was identified by SDS-PAGE and Western blot. Murine macrophages were treated with purified protein PhoP. Survived cells, lactic dehydrogenase (LDH), nitric oxide (NO), and cell apoptosis were detected after the treatment. RESULTS: We successfully constructed the recombinant plasmid pET28a-Rv0757. The target protein was confirmed by SDS-PAGE and Western blot. The protein had no significant effect on cell numbers and LDH activities in the culture supernatant, but it inhibited the release of NO and apoptosis of ANA-1 cells. CONCLUSION: pET28a-Rv0757 plasmid with prokaryotic expression was successfully constructed. The targetprotein has no toxicity on macrophages, but it can inhibit NO release and cell apoptosis of ANA-1.


Assuntos
Proteínas de Bactérias/genética , Macrófagos/microbiologia , Mycobacterium tuberculosis , Animais , Apoptose , Western Blotting , Linhagem Celular , Eletroforese em Gel de Poliacrilamida , L-Lactato Desidrogenase/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Plasmídeos
8.
Stem Cell Rev Rep ; 20(2): 538-553, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38049593

RESUMO

BACKGROUND: Premature ovarian insufficiency (POI) is a relatively common gynecologic endocrine disorder, which is hypogonadism associated with amenorrhea, increased levels of gonadotropins, and hypoestrogenism. POI resulting from ovarian autoimmunity is a poorly understood clinical condition lacking effective treatments. This study is aimed to investigate the therapeutic effect of mesenchymal stem cells (MSCs) on autoimmune premature ovarian insufficiency. METHODS: In this study, in vivo and in vitro experiments were conducted to clarify the therapeutic effects and possible mechanisms of human bone marrow-derived MSCs (hBMSCs) on autoimmune POI, and to provide an experimental evidence for the treatment of autoimmune POI by hBMSCs. Noteworthy, in this study, we used interferon-gamma (IFN-γ) to induce autoimmune inflammation in human granulosa cell line KGN, simulating the pathophysiological changes of granulosa cells in autoimmune POI, and therefore sought to establish an in vitro cell model of autoimmune POI, which is still lacking in experimental methodology. RESULTS: And we found that, in vitro, co-culture of hBMSCs could promote granulosa cell proliferation, inhibit apoptosis, improve hormone synthesis capacity, and reduce the occurrence of pyroptosis; and in vivo, hBMSCs resulted in improved estrous cycle disorders in autoimmune POI mice, increased serum estradiol, decreased follicle-stimulating hormone, improved ovarian morphology, increased number of primordial and primary follicles, decreased number of atretic follicles, and decreased ovarian granulosa cell apoptosis. CONCLUSIONS: hBMSCs have therapeutic effects on autoimmune POI both in vitro and in vivo.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Insuficiência Ovariana Primária , Humanos , Camundongos , Feminino , Animais , Medula Óssea/metabolismo , Transplante de Células-Tronco Mesenquimais/métodos , Insuficiência Ovariana Primária/terapia , Insuficiência Ovariana Primária/metabolismo
9.
Abdom Radiol (NY) ; 48(2): 494-501, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36369529

RESUMO

PURPOSE: Tumor size is an important prognostic factor without consideration of the necrotic and cystic components within tumor for patients with gastrointestinal stromal tumors (GISTs). We aimed to extract the enhancing viable component from the tumor using computed tomography (CT) post-processing software and evaluate the value of preoperative CT features for predicting the disease-free survival (DFS) after curative resection for patients with primary gastric GISTs. METHODS: 132 Patients with primary gastric GISTs who underwent preoperative contrast-enhanced CT and curative resection were retrospectively analyzed. We used a certain CT attenuation of 30 HU to extract the enhancing tissue component from the tumor. Enhancing tissue volume and other CT features were assessed on venous-phase images. We evaluated the value of preoperative CT features for predicting the DFS after surgery. Univariate and multivariate Cox regression analyses were performed to find the independent risk factor for predicting the DFS. RESULTS: Of the 132 patients, 68 were males and 64 were females, with a mean age of 61 years. The median follow-up duration was 60 months, and 28 patients experienced disease recurrence and distant metastasis during the follow-up period. Serosal invasion (p < 0.001; HR = 5.277) and enhancing tissue volume (p = 0.005; HR = 1.447) were the independent risk factors for predicting the DFS after curative resection for patients with primary gastric GISTs. CONCLUSION: Preoperative contrast-enhanced CT could be useful for predicting the DFS after the surgery of gastric GISTs, and serosal invasion and enhancing tissue volume were the independent risk factors.


Assuntos
Tumores do Estroma Gastrointestinal , Neoplasias Gástricas , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Tumores do Estroma Gastrointestinal/diagnóstico por imagem , Tumores do Estroma Gastrointestinal/cirurgia , Intervalo Livre de Doença , Estudos Retrospectivos , Recidiva Local de Neoplasia , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios X/métodos
10.
Anal Chem ; 84(5): 2219-23, 2012 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-22279970

RESUMO

An ultraviolet-visible light (UV-Vis)-reversible but fluorescence-irreversible chemosensor was developed for the detection of copper. Coordination between the probe, 2-pyridylaldehyde fluorescein hydrazone (FHP), and Cu(2+) gave a reversible UV-Vis response, Storage of the probe-Cu complex resulted in hydrolytic cleavage of the N═C bond, which released the fluorophore (ring-opened fluorescein hydrazine) and gave irreversible fluorescence. Thus, FHP becomes a multifunctional chemosensor, and its reversibility can be controlled by the reaction time. Cu(2+) in living cells could be detected using FHP and general fluorescence methods.


Assuntos
Cobre/análise , Corantes Fluorescentes/química , Luz , Espectrofotometria Ultravioleta , Raios Ultravioleta , Água/química , Complexos de Coordenação/química , Células Hep G2 , Humanos , Hidrazinas/química , Microscopia Confocal
11.
Analyst ; 136(9): 1892-7, 2011 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-21373697

RESUMO

A strategy for the determination of the presence of thiol-containing amino acids was successfully established by simply assembling copper chloride and xylenol orange (3,3'-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonephthalein trisodium salt; XO) in a 1 : 1 molar ratio in quasi-physiological water solution (pH 6.0). The copper(II)-XO ensemble was highly selective for thiol species such as cysteine, homocysteine, and glutathione without interference from other amino acids and could quantitatively detect thiol in the range from 10 to 200 µM with a linear relationship having an average molar absorbance constant of 6530 L mol(-1) cm(-1) in pure water. The whole recognition process for thiol gave rise to a rapid visual color change from purple-red to yellow which can be observed simultaneously with the naked-eye.


Assuntos
Colorimetria/métodos , Indicadores e Reagentes/química , Plasma/química , Compostos de Sulfidrila/sangue , Água/química , Ânions/química , Técnicas Biossensoriais/métodos , Cor , Cobre/metabolismo , Cisteína/sangue , Glutationa/sangue , Homocisteína/sangue , Humanos , Concentração de Íons de Hidrogênio , Modelos Lineares , Estrutura Molecular , Espectrofotometria Ultravioleta/métodos , Xilenos/metabolismo
12.
Nucleic Acids Res ; 37(8): 2630-44, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19270069

RESUMO

Recent studies demonstrated that PNZIP and its homologs encode a special cyclase and play an important role in chlorophyll biosynthesis in higher plants. To investigate the molecular mechanism governing the PNZIP gene, the PNZIP promoter was isolated and analyzed. Deletion analysis indicated that G-box is an important element in the regulation of the reporter gene expression. Further mutation assay demonstrated that G-box and GATACT elements are necessary and sufficient for the high and tissue-specific expression of the GUS gene. Using yeast one-hybrid screening, we have isolated a novel tobacco bZIP protein, NtbZIP, which can specifically recognize the G-box of the PNZIP promoter. The NtbZIP protein shares a limited amino acid homology to Arabidopsis ABI5 and AtAREB1 and very low homology to other bZIP proteins. Northern blot analysis showed that the NtbZIP gene is not induced by exogenous ABA and is expressed in different tobacco organs. Cotransformation assays showed that the NtbZIP protein could activate the transcription of the GUS gene driven by the PNZIP promoter. Transgenic tobaccos analysis demonstrated that constitutively expressing antisense NtbZIP gene resulted in a lower NTZIP synthesis and reduced chlorophyll levels. We suggest that NTZIP is a target gene of NtbZIP, which is involved in the regulation of chlorophyll biosynthesis.


Assuntos
Nicotiana/genética , Oxigenases/genética , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Transativadores/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , DNA Complementar/isolamento & purificação , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Genes Reporter , Dados de Sequência Molecular , Proteínas Nucleares/análise , Oxigenases/biossíntese , Fotossíntese/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/metabolismo , Elementos de Resposta , Análise de Sequência , Distribuição Tecidual , Nicotiana/enzimologia , Nicotiana/metabolismo , Transativadores/análise
13.
Eur J Radiol ; 142: 109840, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34237492

RESUMO

PURPOSE: To evaluate the value of preoperative computed tomography (CT) features including morphologic and quantitative features for predicting the Ki-67 labeling index (Ki-67LI) of gastric gastrointestinal stromal tumors (GISTs). METHODS: We retrospectively included 167 patients with gastric GISTs who underwent preoperative contrast-enhanced CT. We assessed the morphologic features of preoperative CT images and the quantitative features including the maximum diameter of tumor, total tumor volume, mean total tumor CT value, necrosis volume, necrosis volume ratio, enhanced tissue volume, and mean CT value of enhanced tissue. Potential predictive parameters to distinguish the high-level Ki-67LI group (>4%, n = 125) from the low-level Ki-67LI group (≤4%, n = 42) were compared and subsequently determined in multivariable logistic regression analysis. RESULTS: Growth pattern (p = 0.036), shape (p = 0.000), maximum diameter (p = 0.018), total tumor volume (p = 0.021), mean total tumor CT value (p = 0.009), necrosis volume (p = 0.006), necrosis volume ratio (p = 0.000), enhanced tissue volume (p = 0.027), and mean CT value of enhanced tissue (p = 0.004) were significantly different between the two groups. Multivariate logistic regression analysis indicated that lobulated/irregular shape (odds ratio [OR] = 3.817; p = 0.000) and high necrosis volume ratio (OR = 1.935; p = 0.024) were independent factors of high-level Ki-67LI. CONCLUSIONS: Higher necrosis volume ratio in combination with lobulated/irregular shape could potentially predict high expression of Ki-67LI for gastric GISTs.


Assuntos
Tumores do Estroma Gastrointestinal , Neoplasias Gástricas , Tumores do Estroma Gastrointestinal/diagnóstico por imagem , Tumores do Estroma Gastrointestinal/cirurgia , Humanos , Antígeno Ki-67 , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios X
14.
Analyst ; 135(11): 2918-23, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20877823

RESUMO

A novel strategy for the determination of oxalate anions was successfully established using a copper ion and pyrocatechol violet (PV) ensemble. The sensor ensemble can discriminate oxalate over other common anions including F(-), Cl(-), I(-), Br(-), HPO(4)(2-), PO(4)(3-), AcO(-), CO(3)(2-), SO(4)(2-), ClO(4)(-), P(2)O(7)(4-), S(2-) (deposited by Ag(+)), CN(-) (shielded by Fe(3+)) and can detect oxalate at low microgram levels in quasi-physiological aqueous solutions. The detection of the oxalate anion gives rise to a rapid observable visual color change from blue to yellow.


Assuntos
Benzenossulfonatos/química , Cobre/química , Compostos Organometálicos/química , Oxalatos/análise , Água/química , Cor , Íons/química , Estrutura Molecular , Observação , Compostos Organometálicos/síntese química , Soluções , Spinacia oleracea/química , Visão Ocular
15.
Br J Radiol ; 93(1116): 20200673, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33002375

RESUMO

OBJECTIVE: This study aimed to investigate if CT-detected extramural venous invasion (ctEMVI) was associated with the presence of lymph node metastasis (LNM) and survival outcomes in patients with gastric cancer. METHODS: We retrospectively reviewed 105 patients with pathologically proved gastric cancer who underwent pre-operative CT examinations and received radical gastrectomy with extended lymphadenectomy. Differences in CT characteristics between the LNM-positive and -negative groups were assessed by two observers. Binary logistic regression analysis was performed to determine the risk factors of lymph node metastasis in gastric cancer. Progression-free survival analysis was performed by Kaplan-Meier method. RESULTS: Two observers reached good inter-reader agreements in ctEMVI and ctN status with κ values of 0.711 and 0.751, respectively. The frequency of ctEMVI-positive status was 58.1% (61/105) in patients with gastric cancer. The LNM-positive group showed higher possibility of ctEMVI-positive status (81.7% vs 26.7%, p<0.001), larger tumor volume (mean volume, 40.77 vs 22.09 mL, p<0.001), poor tumor margin (45.0% vs 26.7% , p = 0.054) and high enhancement on arterial phase (43.3% vs 26.7%, p = 0.023) and venous phase (60.0% vs 44.4%, p = 0.048), than LNM-negative group. In multivariate analysis, ctEMVI status and tumor volume were identified as independent risk factors for lymph node metastasis with odds ratio (OR) of 9.804 (95% CI, 3.076-31.246; p<0.001) and 1.030 (95% CI, 1.001-1.060; p = 0.044). CT-detected EMVI presented better diagnostic efficiency for lymph node metastasis than CT-defined N status, with sensitivity (81.7% vs 70.0%), specificity (73.3% vs 71.1%), accuracy (78.1% vs 70.5), PPV (80.3% vs 76.4%), and NPV (75.0% vs 64.0%), respectively. Kaplan-Meier curves showed that patients with positive ctEMVI findings has lower PFS rate than patients with negative ctEMVI findings (Log-rank test, p = 0.007). CONCLUSION: CT-detected EMVI was significantly associated with lymph node metastasis and progression free survival in patients with gastric cancer. Compared to CT-defined N status, ctEMVI provided superior diagnostic performance to predict pathologic Nstatus. ADVANCES IN KNOWLEDGE: Our study proved that CT-detected EMVI is a promising imaging marker to predict lymph node metastasis and poor prognosis, which may contribute to the precise evaluation of gastric cancer before surgery.


Assuntos
Gastrectomia , Excisão de Linfonodo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios X , Neoplasias Vasculares/diagnóstico por imagem , Neoplasias Vasculares/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Correlação de Dados , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Intervalo Livre de Progressão , Estudos Retrospectivos , Veias
16.
Artigo em Inglês | MEDLINE | ID: mdl-30884754

RESUMO

As a new type of public health service product, online medical websites (OMWs) are becoming quite popular. OMWs can address patients' basic medical problems remotely and give health guidance online. Compared to traditional hospitals, OMWs are more convenient and inexpensive, they can usually provide a better service for patients with poor medical conditions (especially in rural areas), and they also contribute to the rational distribution of medical resources. Therefore, key factors that affect patients' acceptance of OMWs must be identified to contribute to public health. By integrating perceived risk (PR) and the technology acceptance model (TAM), we proposed a modified TAM and clarified how PR and other factors affect patients' behavioral intention (BI) towards OMWs. A sample of 245 research participants in China took part in this study and the structural equation model (SEM) was used to test our hypotheses. The results revealed that perceived usefulness (PU) is a positive predictor of BI but has no significant effect on attitude (ATT), while perceived ease of use (PEOU) can affect BI through PU and attitude (ATT). Moreover, trust (TRU) was identified as a mediator of PR and PU/PEOU. Also, the doctor⁻patient relationship (DPR) was shown to moderate PR and TRU. In order to increase patients' BI, OMW providers need further innovations to improve patients' TRU and reduce their PR.


Assuntos
Atitude Frente aos Computadores , Internet , Informática Médica/estatística & dados numéricos , Sistemas On-Line/estatística & dados numéricos , China , Confidencialidade , Humanos , Modelos Teóricos , Relações Médico-Paciente , Confiança
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 193: 324-329, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29268232

RESUMO

We constructed a novel probe for hydrazine detection based on ICT and PET mechanism. Phthalimide and acetyl ester groups were used as the recognition units. Addition of hydrazine produced a turn-on fluorescence at 525nm along with the fluorescent color change from dark to yellow. The probe could selectively detect hydrazine over other related interfering species. The detection limit of the probe for hydrazine was calculated to be 0.057µM which was lower than the EPA standard (0.320µM). Furthermore, the probe could also be applied for the imaging of hydrazine in living cells.


Assuntos
Neoplasias da Mama/metabolismo , Fluoresceína/química , Corantes Fluorescentes/química , Hidrazinas/análise , Imagem Molecular/métodos , Feminino , Humanos , Limite de Detecção , Espectrometria de Fluorescência , Células Tumorais Cultivadas
18.
J Child Neurol ; 31(5): 613-20, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26442942

RESUMO

Focal cortical dysplasia type IIB is a commonly encountered subtype of developmental malformation of the cerebral cortex and is often associated with pharmacoresistant epilepsy. In this study, to investigate the molecular etiology of focal cortical dysplasia type IIB, the authors performed micro ribonucleic acid (RNA) microarray on surgical specimens from 5 children (2 female and 3 male, mean age was 73.4 months, range 50-112 months) diagnosed of focal cortical dysplasia type IIB and matched normal tissue adjacent to the lesion. In all, 24 micro RNAs were differentially expressed in focal cortical dysplasia type IIB, and the microarray results were validated using quantitative real-time polymerase chain reaction (PCR). Then the putative target genes of the differentially expressed micro RNAs were identified by bioinformatics analysis. Moreover, biological significance of the target genes was evaluated by investigating the pathways in which the genes were enriched, and the Hippo signaling pathway was proposed to be highly related with the pathogenesis of focal cortical dysplasia type IIB.


Assuntos
Epilepsia/genética , Epilepsia/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Malformações do Desenvolvimento Cortical do Grupo I/genética , Malformações do Desenvolvimento Cortical do Grupo I/metabolismo , MicroRNAs/metabolismo , Ontologias Biológicas , Encéfalo/diagnóstico por imagem , Criança , Pré-Escolar , Biologia Computacional , Epilepsia/tratamento farmacológico , Feminino , Perfilação da Expressão Gênica , Hipocampo/metabolismo , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Malformações do Desenvolvimento Cortical do Grupo I/tratamento farmacológico , MicroRNAs/genética , Análise de Sequência com Séries de Oligonucleotídeos
19.
Plant Physiol Biochem ; 42(4): 321-7, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15120117

RESUMO

We have isolated and characterized a new photosynthetic tissue-specific gene NTZIP (Nicotiana tabacum leucine zipper) from tobacco (N. tabacum). Its deduced amino acid sequence has two highly conserved regions, leucine zipper and [EX(n)DEXRH](2) motifs, which are related to the gene's biochemical functions. NTZIP was expressed in leaves and stems, but was not detected in roots or flowers, suggesting that its physiological functions might be associated with photosynthesis. Northern blot analysis showed that NTZIP mRNA accumulation was induced by light signals, increased greatly under low temperatures and was repressed by strong light illumination. Furthermore, a number of homologs of NTZIP were isolated from cucumber (Cucumis sativus), rape (Brassica napus), clover (Trifolium repens), willow (Salix babylonica), rosebush (Rusa dovurica), wheat (Triticum aestivum) and spinach (Spinacia oleracea), proving the ubiquitous existence of the NTZIP-like genes in higher plants. Transgenic tobaccos constitutively expressing antisense RNA to NTZIP displayed chlorosis and a lack of ability to turn green even under normal growth conditions. The chlorophyll deficiency was further confirmed by chlorophyll content determination and gas exchange analysis. Based on these observations, we propose that NTZIP may be involved in chlorophyll biosynthesis, and might define a novel family of evolutionarily conserved proteins with its homologs in other plant species.


Assuntos
Clorofila/biossíntese , Zíper de Leucina/genética , Nicotiana/metabolismo , RNA Antissenso/genética , Sequência de Aminoácidos , Northern Blotting , Southern Blotting , Dióxido de Carbono/metabolismo , DNA de Plantas/análise , Genes de Plantas , Dados de Sequência Molecular , Fotossíntese/fisiologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estrutura Secundária de Proteína , RNA Mensageiro/biossíntese , RNA de Plantas/genética , Nicotiana/genética
20.
Int J Psychiatry Med ; 48(2): 109-19, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25377152

RESUMO

OBJECTIVE: This study investigated the association between plasma galanin level and depression severity. METHODS: The severity of depression symptoms of 79 patients with major depressive disorder (MDD; 52 women and 27 men, 71 patients in onset, 8 in remission) was assessed using the 17-item Hamilton Depression Rating Scale. Venous fasting blood samples (5 mL) were taken from the 79 MDD patients, 35 healthy siblings, and 19 healthy controls, and plasma samples were prepared. Galanin levels in the plasma were measured by radioimmunoassay. RESULTS: Plasma galanin in MDD patients was significantly higher than that of remission patients, healthy siblings, or healthy controls (P < 0.05) There was no significant difference between the healthy sibling and healthy control groups (P = 0.924). Plasma galanin of remission patients was also significantly higher than that of healthy controls (P < 0.05). There was no significant correlation between age and galanin levels in the 79 patients (r = 0.053, P = 0.646), nor was there a correlation between age and galanin levels when patients were stratified by gender (P > 0.05). There was a significant positive correlation between plasma galanin levels and depression severity in women MDD patients (r = 0.329, df = 42, P = 0.020), but not in men patients. CONCLUSIONS: Plasma galanin levels may be an important biomarker for depression severity, especially in female patients.


Assuntos
Transtorno Depressivo Maior , Galanina/sangue , Sistemas Neurossecretores/metabolismo , Adulto , Biomarcadores/sangue , Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Escalas de Graduação Psiquiátrica , Radioimunoensaio , Fatores Sexuais , Estatística como Assunto
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa