Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Entropy (Basel) ; 25(6)2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37372260

RESUMO

The ability to predict the size of information cascades in online social networks is crucial for various applications, including decision-making and viral marketing. However, traditional methods either rely on complicated time-varying features that are challenging to extract from multilingual and cross-platform content, or on network structures and properties that are often difficult to obtain. To address these issues, we conducted empirical research using data from two well-known social networking platforms, WeChat and Weibo. Our findings suggest that the information-cascading process is best described as an activate-decay dynamic process. Building on these insights, we developed an activate-decay (AD)-based algorithm that can accurately predict the long-term popularity of online content based solely on its early repost amount. We tested our algorithm using data from WeChat and Weibo, demonstrating that we could fit the evolution trend of content propagation and predict the longer-term dynamics of message forwarding from earlier data. We also discovered a close correlation between the peak forwarding amount of information and the total amount of dissemination. Finding the peak of the amount of information dissemination can significantly improve the prediction accuracy of our model. Our method also outperformed existing baseline methods for predicting the popularity of information.

2.
BMC Plant Biol ; 22(1): 512, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36324083

RESUMO

BACKGROUND: Calcineurin B-like proteins (CBLs) are ubiquitous Ca2+ sensors that mediate plant responses to various stress and developmental processes by interacting with CBL-interacting protein kinases (CIPKs). CBLs and CIPKs play essential roles in acclimatization of crop plants. However, evolution of these two gene families in the genus Medicago is poorly understood. RESULTS: A total of 68 CBL and 135 CIPK genes have been identified in five genomes from Medicago. Among these genomes, the gene number of CBLs and CIPKs shows no significant difference at the haploid genome level. Phylogenetic and comprehensive characteristic analyses reveal that CBLs and CIPKs are classified into four clades respectively, which is validated by distribution of conserved motifs. The synteny analysis indicates that the whole genome duplication events (WGDs) have contributed to the expansion of both families. Expression analysis demonstrates that two MsCBLs and three MsCIPKs are specifically expressed in roots, mature leaves, developing flowers and nitrogen fixing nodules of Medicago sativa spp. sativa, the widely grown tetraploid species. In particular, the expression of these five genes was highly up-regulated in roots when exposed to salt and drought stress, indicating crucial roles in stress responses. CONCLUSIONS: Our study leads to a comprehensive understanding of evolution of CBL and CIPK gene families in Medicago, but also provides a rich resource to further address the functions of CBL-CIPK complexes in cultivated species and their closely related wild relatives.


Assuntos
Secas , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Medicago/metabolismo , Filogenia , Proteínas Serina-Treonina Quinases/genética , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Ligação ao Cálcio/genética
3.
Proc Natl Acad Sci U S A ; 116(14): 6554-6559, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30877241

RESUMO

Finding an optimal subset of nodes in a network that is able to efficiently disrupt the functioning of a corrupt or criminal organization or contain an epidemic or the spread of misinformation is a highly relevant problem of network science. In this paper, we address the generalized network-dismantling problem, which aims at finding a set of nodes whose removal from the network results in the fragmentation of the network into subcritical network components at minimal overall cost. Compared with previous formulations, we allow the costs of node removals to take arbitrary nonnegative real values, which may depend on topological properties such as node centrality or on nontopological features such as the price or protection level of a node. Interestingly, we show that nonunit costs imply a significantly different dismantling strategy. To solve this optimization problem, we propose a method which is based on the spectral properties of a node-weighted Laplacian operator and combine it with a fine-tuning mechanism related to the weighted vertex cover problem. The proposed method is applicable to large-scale networks with millions of nodes. It outperforms current state-of-the-art methods and opens more directions for understanding the vulnerability and robustness of complex systems.

4.
BMC Plant Biol ; 19(1): 554, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842763

RESUMO

BACKGROUND: Gametogenesis is a key step in the production of ovules or pollen in higher plants. The sex-determination aspects of gametogenesis have been well characterized in the model plant Arabidopsis. However, little is known about this process in androdioecious plants. Tapiscia sinensis Oliv. is a functionally androdioecious tree, with both male and hermaphroditic individuals. Hermaphroditic flowers (HFs) are female-fertile flowers that can produce functional pollen and set fruits. However, compared with male flowers (MFs), the pollen viability and number of pollen grains per flower are markedly reduced in HFs. MFs are female-sterile flowers that fail to set fruit and that eventually drop. RESULTS: Compared with HF, a notable cause of MF female sterility in T. sinensis is when the early gynoecium meristem is disrupted. During the early stage of HF development (stage 6), the ring meristem begins to form as a ridge around the center of the flower. At this stage, the internal fourth-whorl organ is stem-like rather than carpelloid in MF. A total of 52,945 unigenes were identified as transcribed in MF and HF. A number of differentially expressed genes (DEGs) and metabolic pathways were detected as involved in the development of the gynoecium, especially the ovule, carpel and style. At the early gynoecium development stage, DEGs were shown to function in the metabolic pathways regulating ethylene biosynthesis and signal transduction (upstream regulator), auxin, cytokinin transport and signalling, and sex determination (or flower meristem identity). CONCLUSIONS: Pathways for the female sterility model were initially proposed to shed light on the molecular mechanisms of gynoecium development at early stages in T. sinensis.


Assuntos
Flores/crescimento & desenvolvimento , Genes de Plantas , Magnoliopsida/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Flores/genética , Magnoliopsida/anatomia & histologia , Magnoliopsida/genética , RNA-Seq , Análise de Sequência de RNA , Diferenciação Sexual/genética , Árvores/anatomia & histologia , Árvores/genética
5.
J Sci Food Agric ; 96(11): 3882-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26696532

RESUMO

BACKGROUND: Plastic-covered ridge-furrow farming systems for rainfall concentration (RC) improve the water availability for crops and increase the water use efficiency (WUE), thereby stabilizing high yields. In this study, we optimized the mulching patterns for RC planting to mitigate the risks of drought during crop production in semiarid agricultural areas. We conducted a 4-year field study to determine the RC effects on corn production of mulching in furrows with 8% biodegradable films (RCSB ), liquid film (RCSL ), bare furrow (RCSN ) and conventional flat (CF) farming. RESULTS: We found that RC significantly (P > 0.05) increased the soil moisture in the top 0-100 cm layer and the topsoil temperature (0-20 cm) during the corn-growing period. Mulching with different materials in planting furrows further improved the rain-harvesting, moisture-retaining and yield-increasing effects of RC planting. Compared with CF, the 4-year average total dry matter amount per plant for RCSB , RCSL and RCSN treatments increased by 42.1%, 30.8% and 17.2%, respectively. The grain yield increased by 59.7%, 53.4% and 32.6%, respectively. CONCLUSION: Plastic-covered ridge and furrow mulched with biodegradable film and liquid film is recommended for use in the semiarid Loess Plateau of China to alleviate the effects of drought on crop production. © 2015 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Plásticos Biodegradáveis , Conservação dos Recursos Naturais/métodos , Produção Agrícola/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimento , Plásticos Biodegradáveis/efeitos adversos , China , Clima Desértico/efeitos adversos , Poluição Ambiental/prevenção & controle , Folhas de Planta/crescimento & desenvolvimento , Chuva , Estações do Ano , Solo/química , Temperatura , Água/análise
6.
Ying Yong Sheng Tai Xue Bao ; 34(4): 1009-1014, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37078320

RESUMO

To evaluate the effects of nitrogen (N) application rates on the growth, photosynthetic traits and yield of winter wheat under elevated atmospheric ammonia (NH3) concentrations could provide guidance for N management under high NH3 environment. We conducted a split-plot experiment for two consecutive years (2020-2021 and 2021-2022) with top-open chambers. The treatments included two NH3 concentrations [elevated ambient NH3 concentration at 0.30-0.60 mg·m-3 (EAM) and air NH3 concentration at 0.01-0.03 mg·m-3 (AM)] and two N application rates [recommended N dose (+N) and no N application (-N)]. We analyzed the effects of aforementioned treatments on net photosynthetic rate (Pn), stomatal conductance (gs), chlorophyll content (SPAD value), plant height, and grain yield. The results showed that averaged across the two years, EAM significantly increased Pn, gs, and SPAD values at the jointing and booting stages at the -N level by 24.6%, 16.3%, 21.9% and 20.9%, 37.1%, 5.7%, respectively, compared with AM. However, EAM significantly decreased Pn, gs, and SPAD values at jointing and booting stages at +N level by 10.8%, 5.9%, 3.6% and 6.8%, 18.9%, 9.3%, respectively, over AM treatment. There was a significant effect of NH3 treatment, N application rates and their interaction on plant height and grain yield. Compared with AM, EAM increased the average plant height and grain yield by 4.5% and 32.1% at -N level and decreased by 1.1% and 8.5% at +N level, respectively. In a nutshell, the eleva-ted ambient NH3 concentration had positive effect on photosynthetic characteristics, plant height, and grain yield under ambient N condition, but a inhibitory effect under N application.


Assuntos
Amônia , Triticum , Nitrogênio/farmacologia , Folhas de Planta , Fertilizantes , Fotossíntese , Grão Comestível
7.
Open Life Sci ; 18(1): 20220592, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37333485

RESUMO

Retiform hemangioendothelioma (RH) is a type of low-grade malignant angiosarcoma. It commonly involves the skin and subcutaneous tissue of the lower extremities, but a few cases have been reported in the gut. However, hepatic RH has not been previously reported. This report presents the case of RH of the liver in a 61-year-old woman who was admitted to the hospital having presented with liver space-occupying lesions of 2 months evolution. The patient underwent an abdominal ultrasound examination, which indicated a hemangioma, but abdominal computed tomography diagnosed a liver abscess. In order to determine the nature of the lesion, an ultrasound-guided liver biopsy was performed, after which a pathological diagnosis confirmed the presence of RH in the liver. The patient underwent ultrasound-guided microwave ablation three times and has been followed up for 8 years with no tumor recurrence or metastasis. Surgical excision is still the first choice for the treatment of hepatic RH. As shown in this case, however, for patients who refuse to undergo surgery or have surgical contraindications, ultrasound-guided microwave ablation is an alternative treatment option. The report of this case expands the scope of liver tumors to a certain extent and provides a reference for clinical diagnosis and treatment.

8.
Mitochondrial DNA B Resour ; 3(2): 734-735, 2018 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-33474303

RESUMO

Zelkova schneideriana Hand.-Mazz. (Ulmaceae) is an endangered species endemic to China. In this study, we reported its complete chloroplast (cp) genome based on Illumina pair-end sequencing. The whole genome was 158,999 bp long, consisting of a pair of inverted repeat (IR) regions of 26,427 bp, a large single copy (LSC) region of 87,397 bp and a small single copy (SSC) region of 18,748 bp. The cp genome contained 133 genes, including 88 protein-coding genes (80 PCG species), 37 tRNA genes (30 tRNA species), and eight rRNA genes (4 rRNA species). The overall G+C content of the whole genome was 35.6%, and the corresponding values of the LSC, SSC, and IR regions were 33.0, 28.3, and 42.4%, respectively. The maximum likelihood phylogenetic analysis of 25 selected chloroplast genomes demonstrated that Z. schneideriana was closely related to Ulmus macrocarpa and Ulmus pumila.

9.
Gene ; 662: 66-75, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29625266

RESUMO

Lysigenous aerenchyma is formed through programmed cell death (PCD) in Typha angustifolia leaves. However, the genome and transcriptome data for this species are unknown. To further elucidate the molecular basis of PCD during aerenchyma formation in T. angustifolia leaves, transcriptomic analysis of T. angustifolia leaves was performed using Illumina sequencing technology, revealing 73,821 unigenes that were produced by assembly of the reads in T1, T2 and T3 samples. The important pathways, such as programmed cell death (PCD), aerenchyma formation, and ethylene responsiveness were regulated by these unigenes. 1-aminocyclopropane-1-carboxylate synthase (ACS) and 1-aminocyclopropane-1-carboxylate oxidase (ACO) were highly up-regulated as key enzymes for ethylene synthesis, along with respiratory burst oxidase homolog (RBOH), metallothionein, calmodulin-like protein (CML), and polygalacturonase (PG), may collectively explain the PCD involved in T. angustifolia aerenchyma formation. We hypothesize that fermentation, metabolism and glycolysis generate ATP for PCD. We searched the 73,821 unigenes against protein databases, and 24,712 were annotated. Based on sequence homology, 16,012 of the 73,821 annotated unigenes were assigned to one or more Gene Ontology (GO) terms. Meanwhile, a total of 9537 unigenes were assigned to 126 pathways in the KEGG database. In summary, this investigation provides important guidelines for exploring the molecular mechanisms of aerenchyma formation in aquatic plants.


Assuntos
Regulação da Expressão Gênica de Plantas/genética , Folhas de Planta/anatomia & histologia , Typhaceae/genética , Apoptose , Bases de Dados Genéticas , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Genes de Plantas/genética , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , NADPH Oxidases , Folhas de Planta/genética , Folhas de Planta/metabolismo , Espécies Reativas de Oxigênio , Análise de Sequência de RNA , Transcriptoma/genética , Typhaceae/metabolismo
10.
Eur J Radiol ; 62(2): 289-94, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17258417

RESUMO

PURPOSE: To assess the utility of contrast-enhanced ultrasonography (ceUS) in the assessment of the therapeutic response to high intensity focused ultrasound (HIFU) ablation in patients with uterine fibroid. MATERIALS AND METHODS: Sixty-four patients with a total of 64 uterine fibroids (mean: 5.3+/-1.2 cm; range: 3.2-8.9 cm) treated with HIFU ablation under the ultrasound guidance were evaluated with ceUS after receiving an intravenous bolus injection of a microbubble contrast agent (SonoVue) within 1 week after intervention. We obtained serial ceUS images during the time period from beginning to 5 min after the initiation of the bolus contrast injection. All of the patients underwent a contrast enhanced MRI (ceMRI) and ultrasound guided needle puncture biopsy within 1 week after HIFU ablation. And as a follow-up, all of the patients underwent US at 1, 3, 6 and 12 months after HIFU treatment. The volume change was observed and compared to pre- and post-HIFU ablation. The results of the ceUS were compared with those of the ceMRI in terms of the presence or absence of residual unablated tumor and pathologic change in the treated lesions. RESULTS: On ceUS, diagnostic accuracy was 100%, while residual unablated tumors were found in three uterine fibroids (4.7%) and failed treatment was found in eight uterine fibroids (12.5%). All the 11 fibroids were subjected to additional HIFU ablation. Of the 58 ablated fibroids without residual tumors on both the ceUS and ceMRI after the HIFU ablation, the volumes of all the fibroids decreased in different degrees during the 1 year follow-up USs. And histologic examinations confirmed findings of necrotic and viable tumor tissue, respectively. CONCLUSION: CEUS is potentially useful for evaluating the early therapeutic effect of percutaneous HIFU ablation for uterine fibroids.


Assuntos
Meios de Contraste , Aumento da Imagem , Leiomioma/terapia , Terapia por Ultrassom , Neoplasias Uterinas/terapia , Adulto , Biópsia por Agulha , Ablação por Cateter , Feminino , Seguimentos , Gadolínio DTPA , Humanos , Histerectomia , Leiomioma/diagnóstico por imagem , Leiomioma/patologia , Leiomioma/cirurgia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Neoplasia Residual , Período Pós-Operatório , Resultado do Tratamento , Ultrassonografia Doppler em Cores , Neoplasias Uterinas/diagnóstico por imagem , Neoplasias Uterinas/patologia , Neoplasias Uterinas/cirurgia
11.
Zhongguo Gu Shang ; 30(1): 29-32, 2017 Jan 25.
Artigo em Zh | MEDLINE | ID: mdl-29327545

RESUMO

OBJECTIVE: To accurately define the injury position of medial patellar retinaculum with acute injury under the guiding of high frequency ultrasonography, and to study therapeutic effects of suture operation on medial patellar retinaculum in the injuried position. METHODS: From June 2009 to March 2014, there were 17 patients with acute patellar dislocation, 6 males and 11 females with average age of (16.2±6.2) years old. The duration time of patellar dislocation was 2 weeks. Before operation, the medial patellar retinaculum of all patients were examined with the high frequency ultrasonography, and the skin with the non-continuous fiber was iudicated as the surface mark under the high frequency ultrasonography. The injury position of medial retinaculum was in the middle of 5 patients who were treated with suture operation of arthroscopic medial retinaculum. The injury position was in the patellar edge in 12 patients who were treated with fixing bone anchor on patella and arthroscopic suture operation of medial retinaculum. The CT examination and Kujala scores, patellar tilt angle on CT film, measured maximal angles of passive or active knee flexion and apprehension test were observed before treatment and postoperative 18 months. RESULTS: Eighteen months after treatment, Kujala scores were 92.2±11.1 and patellar tilt angle were(11.5±4.2) °, and there was no statistical difference between post-operation and pre-operation. The difference between maximal angles of passive knee flexion(133.5±4.2) ° and normal had no statistically significance. Maximal angles of active knee flexion were(153.5±4.6) °. Ultrasonography showed the continuous fiber of medial retinaculum. A patient showed positive apprehension test and no patient had the recurrence patella instability after operation. CONCLUSIONS: The injury position of medial patellar retinaculum was accurately shown by high frequency ultrasonography and treated with arthroscopic suture operation. Knee immobilization time after operation was shorten. Eighteen months after operation, knee joint function was good, and no patient had the recurrence patella instability.


Assuntos
Artroscopia , Patela/lesões , Luxação Patelar/cirurgia , Ligamento Patelar/lesões , Adolescente , Feminino , Humanos , Articulação do Joelho , Masculino , Patela/diagnóstico por imagem , Luxação Patelar/diagnóstico por imagem , Ligamento Patelar/diagnóstico por imagem , Ultrassonografia
12.
Ying Yong Sheng Tai Xue Bao ; 26(5): 1382-90, 2015 May.
Artigo em Zh | MEDLINE | ID: mdl-26571655

RESUMO

A field experiment was conducted to determine the regulation of crop photosynthesis and output and water saving effect under ridge and furrow rain harvesting with supplemental irrigation in Guanzhong irrigation district. The experiment was set with 5 treatments with irrigation at returning green stage, and the widths of both ridge and furrow being 60 cm. T1, T2 and T3 were in the ridge and furrow rain harvesting planting pattern, with the irrigation volumes being 0, 375 and 750 m3 · hm(-2) respectively, T4 was flat planting with irrigation (border irrigation) of 750 m3 · hm(-2) and CK was flat planting without irrigation. Effects on winter wheat photosynthetic organs, photosynthetic rate, yield and water use efficiency, etc. were tested. The results showed that compared with T4, T1, T2 and T3 treatments increased the grain yield by 2.8%, 9.6% and 18.9%, improved the harvest index by 2.0% to 8.5%, advanced the flag leaf chlorophyll content by 41.9% to 64.4% significantly, and improved the 0-40 cm layer soil moisture content by 0.1%-4.6% during the whole growth period. Photosynthetic rates at the flowering and filling stages also increased by 22.3% to 54.2% and -4.3% to 67.2%, respectively. Total water use efficiencies (WUEy) were 17.9%, 10.4% and 15.4% higher than that of T4, and 69.3%, 58.6% and 65.7% higher than that of CK (P < 0.05), respectively, and enhanced precipitation utilization efficiency ( PUE ) by 94.3%-124.5% than CK. Leaf areas of T2 and T3 treatments at each growth stage were significantly higher than that of T4 and CK, irrigation water use efficiencies (IUE) were 119.1% and 18.8% higher than that of T4, respectively. Therefore, it was concluded that ridge and furrow rain harvesting cultivation could maintain higher grain yield than border irrigation without irrigation or with irrigation reduction by 50%. The utilization efficiency of irrigation water under the condition of irrigation reduction by 50% was improved significantly, and the ridge and furrow rain harvesting could significantly improve whole cropland water use efficiency in the year of less rainfall.


Assuntos
Irrigação Agrícola , Agricultura/métodos , Fotossíntese , Chuva , Triticum/fisiologia , Biomassa , Clorofila , Folhas de Planta , Solo , Água
14.
Zhonghua Zhong Liu Za Zhi ; 25(4): 368-71, 2003 Jul.
Artigo em Zh | MEDLINE | ID: mdl-12921569

RESUMO

OBJECTIVE: To investigate the relation of heparanase gene and angiogenesis with the progress of gastric carcinoma (GC). METHODS: Expression of heparanase mRNA in 52 GC tissue was detected by in situ hybridization assay. Microvessel density (MVD) was examined by immunohistochemical method. MVD and heparanase mRNA expression were analysed with their relation to histological grade, invasion depth,lymph node metastasis and organ metastasis. RESULTS: MVD was 73.2 +/- 22.8 in 25 (48.1%) tissue with positive heparanase mRNA. It was 44.8 +/- 11.9 in 27 (51.9%) tissues with negative heparanase mRNA, between which the difference was significant (P < 0.001). MVD and heparanase mRNA expression were related with lymph node metastasis and depth of serosal invasion in GC (P < 0.005). CONCLUSION: Heparanase, being related to angiogenesis in gastric cancer, promotes growth, invasion and metastasis. Heparanase mRNA expression is an important predictor of the biological behavior of human gastric carcinoma.


Assuntos
Adenocarcinoma/enzimologia , Glucuronidase/biossíntese , Neovascularização Patológica/enzimologia , Neoplasias Gástricas/enzimologia , Adenocarcinoma/irrigação sanguínea , Adenocarcinoma/patologia , Adulto , Idoso , Feminino , Mucosa Gástrica/enzimologia , Regulação Neoplásica da Expressão Gênica , Glucuronidase/genética , Humanos , Metástase Linfática , Masculino , Microcirculação/patologia , Pessoa de Meia-Idade , Invasividade Neoplásica , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Neoplasias Gástricas/irrigação sanguínea , Neoplasias Gástricas/patologia
15.
World J Gastroenterol ; 16(1): 131-5, 2010 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-20039461

RESUMO

Biliary cystadenocarcinoma is a very rare malignant cystic tumor of the liver, which is often misdiagnosed due to a poor recognition of it. We report a case of a 60-year-old man with biliary cystadenocarcinoma with his real time contrast enhanced ultrasound (CEUS) characteristics compared to those of computed tomography (CT) and magnetic resonance imaging (MRI), which were correlated with the surgical and pathologic findings. Cystic wall enhancement, internal septations and intra-cystic solid portions in the arterial phase were observed on CEUS after contrast agent injection. The enhancement was washed out progressively and depicted as hypo-enhancement in the portal and late phases. CT revealed a large irregular cystic lesion in the left liver lobe with no clear septations and solid components. MRI showed an irregular cystic occupying lesion with septations.


Assuntos
Neoplasias do Sistema Biliar/diagnóstico por imagem , Meios de Contraste , Cistadenocarcinoma/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Fosfolipídeos , Hexafluoreto de Enxofre , Ultrassonografia Doppler em Cores , Neoplasias do Sistema Biliar/patologia , Neoplasias do Sistema Biliar/cirurgia , Cistadenocarcinoma/patologia , Cistadenocarcinoma/cirurgia , Hepatectomia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Tomografia Computadorizada por Raios X
16.
J Ultrasound Med ; 27(6): 867-74, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18499846

RESUMO

OBJECTIVE: The purpose of this study was to investigate the feasibility of percutaneous microwave coagulation therapy (PMCT) guided by contrast-enhanced ultrasonography (CEUS) for controlling active bleeding in rabbit livers. METHODS: Twenty actively bleeding rabbit liver models, produced with an 18-gauge semiautomatic biopsy needle and confirmed with CEUS, were randomly divided into 2 groups: a PMCT group (n=10, with a microwave antenna placed into the bleeding site under ultra-sonographic guidance and worked at 60 W for 30 seconds on average) and a control group (n=10, with the active bleeding site not treated). After therapy procedures were performed, lactated Ringer's solution resuscitation was then performed in both groups to maintain the mean arterial pressure at 70 mm Hg for 1 hour. The intraperitoneal blood loss, total resuscitation volume, mean arterial pressure, and hematocrit value were recorded. Macroscopic and microscopic examinations were performed at the end of the study. RESULTS: After PMCT, the former bleeding site appeared on CEUS as a round or an oval area devoid of contrast. The PMCT group had lower blood loss (30.4+/-7.2 versus 101.6 +/- 18.2 mL; P< .05) and a lower total resuscitation volume (56.5+/-10 versus 186+/-36.6 mL; P< .05) than the control group. The mean hematocrit value in the PMCT group was significantly higher than that in the control group (26%+/-4% versus 19%+/-4%; P< .05) at the end of the experiment. CONCLUSIONS: Contrast-enhanced ultrasonographically guided PMCT significantly decreased blood loss in a rabbit model of active liver bleeding. It provides a simple and quick method to control blood loss in liver injuries with active bleeding.


Assuntos
Hemorragia/terapia , Fígado/irrigação sanguínea , Micro-Ondas/uso terapêutico , Ultrassonografia de Intervenção , Animais , Meios de Contraste , Estudos de Viabilidade , Hemorragia/diagnóstico por imagem , Hemostasia , Fígado/diagnóstico por imagem , Fosfolipídeos , Coelhos , Hexafluoreto de Enxofre
17.
J Ultrasound Med ; 26(2): 201-12, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17255182

RESUMO

OBJECTIVE: The purpose of this study was to evaluate the therapeutic efficacy of high-intensity focused ultrasound (HIFU) in the treatment of uterine fibroids by using imaging and histopathologic examination. METHODS: From May 2004 to June 2005, 119 consecutive patients with 187 uterine fibroids were treated with HIFU. Sixty-two fibroids received ultrasonographically guided needle puncture biopsy 1 week before and after HIFU treatment, respectively, to confirm the diagnosis and to assess the early therapeutic efficacy. Hematoxylin-eosin staining and electron microscopy were performed to characterize more subtle phenotypic changes to determine treatment success. Immediate therapeutic effects were assessed at follow-up with Doppler ultrasonography and computed tomography or magnetic resonance imaging. All patients were followed for 6 to 12 months to observe long-term therapeutic effects. Fibroid mean diameters, volumes, and reduction rates 1, 3, 6, and 12 months after HIFU treatment were calculated and compared with 1-way analysis of variance and Student-Newman-Keuls tests. RESULTS: No severe complications were observed after HIFU ablation. Fifty-one (82.3%) of 62 biopsy specimens revealed obvious signs of necrosis under light microscopy, and more subtle changes in cellular structure that indicated nonviability could be found in 60 specimens (96.8%) under electron microscopy. However, viable cells still could be found in 16 specimens (25.8%). Follow-up images showed absence or reduction of blood supply in the lesions after HIFU ablation. Median reductions in tumor size as a percentage of initial tumor volume at 1, 3, 6, and 12 months after HIFU treatment were 21.2%, 29.6%, 44.8%, and 48.7%, respectively. CONCLUSIONS: Imaging and histopathologic evidence directly validate HIFU ablation as an effective treatment of uterine fibroids.


Assuntos
Leiomioma/diagnóstico , Leiomioma/terapia , Terapia por Ultrassom/métodos , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/terapia , Adulto , Biópsia por Agulha , Feminino , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento , Ultrassonografia de Intervenção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA