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1.
Environ Sci Pollut Res Int ; 31(16): 23822-23838, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38430440

RESUMEN

The rapid development of industrial society is also accompanied by the generation of a large amount of heavy metal wastewater, which has caused serious harm to the ecological environment and human society. Natural sphalerite has an important value in the environmental field due to its own semiconducting properties. In order to effectively remove Ag+ from wastewater containing silver, this study develops a natural mineral-based Ag+ adsorbent material (sphalerite) based on elemental affinity qualities and mineralization principles. The results of batch experiments showed that the initial Ag+ concentration of 50 mg/L reduced to 0.094 mg/L with a reaction duration of 15 min, a sphalerite dose of 5 g/L, an initial particle size of -400 mesh (38 µm), a reaction temperature of 25 °C, and a pH of 5. The highest adsorption capacity is 19.77 mg/g, and the adsorption behavior is consistent with the Freundlich isotherm model and pseudo-second-order adsorption kinetics. The results of solution chemical analysis indicate that the presence of Ag+ is primarily influenced by the presence of S2-. Further analysis using SEM-EDS, FTIR, and XPS techniques reveals that Ag+ is chemically adsorb onto the mineral surface, resulting in the formation of Ag2S. DFT calculations further confirm the overlap between the Ag 4d orbitals and the S 3p orbitals on the surface of sphalerite, further confirming its chemical adsorption. Mulliken populations suggest that charge transfer occurs between Ag+ and S atoms in the sphalerite surface. This research systematically reveals the Ag+ adsorption mechanism on sphalerite surface and expands research ideas for treating heavy metal wastewater.


Asunto(s)
Metales Pesados , Sulfuros , Contaminantes Químicos del Agua , Compuestos de Zinc , Humanos , Aguas Residuales , Adsorción , Metales Pesados/análisis , Minerales , Cinética , Contaminantes Químicos del Agua/análisis , Concentración de Iones de Hidrógeno
2.
Nanomaterials (Basel) ; 13(13)2023 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-37446452

RESUMEN

Recent advancements have led to the synthesis of novel monolayer 2D carbon structures, namely quasi-hexagonal-phase fullerene (qHPC60) and quasi-tetragonal-phase fullerene (qTPC60). Particularly, qHPC60 exhibits a promising medium band gap of approximately 1.6 eV, making it an attractive candidate for semiconductor devices. In this study, we conducted comprehensive molecular dynamics simulations to investigate the mechanical stability of 2D fullerene when placed on a graphene substrate and encapsulated within it. Graphene, renowned for its exceptional tensile strength, was chosen as the substrate and encapsulation material. We compared the mechanical behaviors of qHPC60 and qTPC60, examined the influence of cracks on their mechanical properties, and analyzed the internal stress experienced during and after fracture. Our findings reveal that the mechanical reliability of 2D fullerene can be significantly improved by encapsulating it with graphene, particularly strengthening the cracked regions. The estimated elastic modulus increased from 191.6 (qHPC60) and 134.7 GPa (qTPC60) to 531.4 and 504.1 GPa, respectively. Moreover, we observed that defects on the C60 layer had a negligible impact on the deterioration of the mechanical properties. This research provides valuable insights into enhancing the mechanical properties of 2D fullerene through graphene substrates or encapsulation, thereby holding promising implications for future applications.

3.
Clin Exp Hypertens ; 45(1): 2131806, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-36266998

RESUMEN

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death. Oxidative stress is an important pathological process of a variety of CVDs. Xinshuaining preparation has a therapeutic effect on the heart failure. However, the anti-oxidative stress role of Xinshuaining preparation in H9c2 cells is still unclear. METHODS: The medicated serum of Xinshuaining preparation was acquired and utilized to hatch with H2O2-induced H9c2 cells. Main components in the Xinshuaining preparation were analyzed by liquid chromatography-mass spectrometry (LC/MS). The effect of medicated serum on the cell viability, apoptosis rate, the oxidative stress indicators (SOD, GSH-Px, and MDA), mitochondrial membrane potential (MMP), and ROS level was evaluated by CCK-8, flow cytometry, commercial biochemical detection kits, and JC-1 staining. Additionally, the associated mechanism was determined by the detection of the protein levels (PI3K, phosphorylated PI3K, Akt, phosphorylated Akt, and Nrf-2) through western blot assays, which was also further assessed with the application of LY294002. RESULTS: The medicated serum of Xinshuaining preparation notably increased the H2O2-reduced, the cell viability, the concentration of SOD and GSH-Px, MMP level and the relative protein expression level of phosphorylated PI3K and Akt and Nrf-2, while dampened the H2O2-elevated the level of the cell apoptosis rate, MDA, and ROS. However, Xinshuaining preparation on the cell viability, apoptosis, and oxidative stress was notably antagonized by LY294002 pre-treatment. CONCLUSIONS: The medicated serum of Xinshuaining preparation increased the cell viability and suppressed apoptosis and oxidative stress via the PI3K/Akt/Nrf-2 signaling pathway.


Asunto(s)
Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatidilinositol 3-Quinasas/farmacología , Peróxido de Hidrógeno/toxicidad , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Estrés Oxidativo , Apoptosis , Superóxido Dismutasa/metabolismo
4.
Chemosphere ; 300: 134546, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35405198

RESUMEN

Cu(II)-EDTA is a highly stable typical metal-organic complex in a wide pH range (3.0-12.0) and it is difficult to deeply purify Cu(II) by conventional precipitation methods. In this study, Fe(III) replacement/diethyldithiocarbamate (DDTC) precipitation combined process is proposed as a promising strategy to achieve the deep purification of Cu(II) from Cu(II)-EDTA acidic wastewater. The underlying mechanism has also been systematically elucidated by chemical equilibriums, experiments, and density functional theory (DFT) calculations, laying a foundation for the development and application. Chemical equilibriums show that Fe(III) replacement favors the stoichiometric release of Cu(II) from Cu(II)-EDTA and the formation of Fe(III)-EDTA complex under acidic conditions. Experimentally, Cu(II) is removed (over 99.99%) and deeply purified (under 0.008 mg/L) under the optimal conditions, which is lower than the most stringent discharge standards of copper ions in electroplating effluent (<0.5 mg/L, China). DFT calculations reveal that DDTC could further precipitate the released free copper ions via the carbon disulfide (-C(=S)-S) chelating group while exhibiting a slight effect on the Fe(III) in Fe(III)-EDTA. Considering these results, the electronic structures of Cu(II) and Fe(III), as well as their interaction with EDTA and DDTC ligands, are discussed to understand the mechanism of Fe(III)/DDTC process. By introducing a low dosage of Fe(III), the DDTC could efficiently purify Cu(II) from the Cu(II)-EDTA acid wastewater and realize the near-zero discharge of metal pollutants in metal-organic complex wastewater. It is believed that the main findings may benefit the water pollution reduction and comprehensive recycling of metal resources.


Asunto(s)
Complejos de Coordinación , Contaminantes Químicos del Agua , Cobre/química , Ditiocarba , Ácido Edético/química , Compuestos Férricos/química , Iones , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis
5.
PLoS One ; 13(11): e0206883, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30481179

RESUMEN

The alpha regulator subunit B'' of protein phosphatase 2 (PPP2R3A), a regulatory subunit of protein phosphatase 2A (PP2A), was reported to present a special subcellular localization in cardiomyocytes and elevate in non-ischemia failing hearts. PPP2R3A has two transcriptions PR72 and PR130. PR72 acts as a negative regulator of the Wnt signaling cascade, while the Wnt signaling cascade plays a pivotal role in cardiac development. And PR130 was found to be involved in cardiac development of zebrafish in our previous study. Thus, to investigate the function of PR72 in heart, two stable pr72 knockout (KO) zebrafish lines were generated using Transcription Activator-Like Effector Nuclease (TALEN) technology. Homozygous pr72 KO fish struggled to survive to adulthood and exhibited cardiac developmental defects, including enlarged ventricular chambers, reduced cardiomyocytes and decreased cardiac function. And the defective sarcomere ultrastructure that affected mitochondria, I bands, Z lines, and intercalated disks was also observed. Furthermore, the abnormal heart looping was detected in mutants which could be rescued by injection with wild type pr72 mRNA. Additionally, it was found that Wnt effectors were elevated in mutants. Those indicated that deletion of pr72 in zebrafish interrupted cardiac development, probably through activation of the Wnt pathway.


Asunto(s)
Cardiopatías Congénitas/genética , Corazón/crecimiento & desarrollo , Proteína Fosfatasa 2/genética , Vía de Señalización Wnt/genética , Proteínas de Pez Cebra/genética , Animales , Animales Modificados Genéticamente , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Humanos , Miocardio/citología , Miocardio/metabolismo , Miocardio/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Pez Cebra
6.
Asian Pac J Cancer Prev ; 14(12): 7215-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24460278

RESUMEN

BACKGROUND: Variation in metabolic genes is regarded as an important factor in processes leading to cancer. However, the effect of GSTT1 null genotype is divergent in the form of lung cancer. METHODS: Studies were conducted at different research databases from 1990 to 2013 and the total odds ratio (OR) and 95% confidence interval (CI) were calculated for lung cancer. Review Manager 5.2 and STATE 12 are employed. RESULTS: Total OR value is calculated from 17 articles with 2,118 cases and 2,915 controls. We discovered no significant increase in lung cancer risk among subjects carrying GSTT1 null genotype [OR = 1.15; 95% CI 0.97-1.36] in this meta- analysis. CONCLUSION: The GSTT1 deletion polymorphism does not have a significant effect on the susceptibility to lung cancer overall in China.


Asunto(s)
Predisposición Genética a la Enfermedad , Glutatión Transferasa/genética , Neoplasias Pulmonares/genética , Polimorfismo Genético/genética , Estudios de Casos y Controles , China , Humanos , Pronóstico , Factores de Riesgo
7.
Zhonghua Yi Xue Za Zhi ; 90(43): 3087-90, 2010 Nov 23.
Artículo en Chino | MEDLINE | ID: mdl-21211333

RESUMEN

OBJECTIVE: to study the biochemistry of blood and feature of pathology of an animal model in rabbits with the early primary hyperparathyroidism(PHPT). METHODS: 60 rabbits were divided into six groups of 10 each and fed a control diet (Ca:P, 1:0.7) or a high-phosphate diet (Ca:P, 1:7) for 1-, 2- or 3-month intervals. Compared with the control animals, serum PTH levels, serum calcium levels and serum phosphorus levels were determined. The parathyroid and kidneys of all animals were performed by the histologic examination. RESULTS: compared with the control animals, serum parathyroid hormone (PTH) levels were elevated at 1-, 2-, 3-month intervals in experimental group (t = -7.665, t = -16.033, t = 12.877 respective, P < 0.05), whereas serum calcium levels were decreased at all three time intervals (t = 6.184, t = 9.329, t = 13.842, respective, P < 0.05), but serum phosphorus levels did not change (t = 0.611, t = 1.041, t = 1.941, respective, P > 0.05). Parathyroid histopathologic studies demonstrated no change at 1 month whereas six of ten experimental animals showed mild hyperplasia at 2 months and nine of ten showed mild to moderate hyperplasia with gland enlargement at 3 months compared with control animals. Histopathologic examination of the kidneys showed no change at 1 month but focal parenchymal inflammation with calcium deposition at 2- and 3-month in the experimental groups. CONCLUSION: the high-phosphate diet successfully induced an animal model in rabbits with the early primary hyperparathyroidism, which has a better stability and reproducibility.


Asunto(s)
Modelos Animales de Enfermedad , Hiperparatiroidismo Primario/sangre , Hiperparatiroidismo Primario/patología , Animales , Calcio/sangre , Dieta , Riñón/patología , Glándulas Paratiroides/patología , Hormona Paratiroidea/sangre , Fosfatos/administración & dosificación , Fósforo/sangre , Conejos
8.
Chin Med J (Engl) ; 122(5): 541-7, 2009 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-19323905

RESUMEN

BACKGROUND: The solitary pulmonary nodule (SPN) is one of the most common findings on chest radiographs. The objectives of clinical practice are to differentiate malignant nodules from benign nodules in the least invasive way and to make a specific diagnosis. This study was aimed to evaluate the correlation between perfusion imaging features and microvessel density (MVD) and vascular endothelial growth factors (VEGF) in SPNs using multi-slice computed tomography (MSCT); and to provide the theoretical basis for SPN blood flow pattern and blood flow quantitative features. Also, the study called for the discussion of the method's clinical application value in the differential diagnosis of benign and malignant SPNs. METHODS: Sixty-eight patients with SPN underwent multi-location dynamic contrast enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4 ml/s) MSCT. Precontrast and postcontrast attenuations on every scan was studied. Perfusion, peak height, and the ratio of the peak height of the SPN to that of the aorta were analyzed. Perfusion was calculated using the maximum gradient of the time-density curves (TDC) and the peak height of the aorta. The quantitative parameters (perfusion, peak height, ratio of peak height of the SPN to that of the aorta) of the blood flow pattern were compared with MVD and the VEGF expression of immunohistochemistry. RESULTS: The perfusion peak heights of malignant ((96.15 +/- 11.55) HU) and inflammatory ((101.15 +/- 8.41) HU) SPNs were significantly higher than those of benign ((47.24 +/- 9.15) HU) SPNs (P < 0.05, P < 0.05). Ratios of SPN-to-aorta of malignant and inflammatory SPNs were significantly higher than those of benign SPNs (P < 0.05, P < 0.05). No significant differences were found between the peak height and SPN-to-aorta ratio of malignant SPNs and inflammatory SPNs (P > 0.05, P > 0.05). The precontrast densities of inflammatory SPNs were lower than those of malignant SPNs (P < 0.05). Perfusion values of malignant and inflammatory SPNs were significantly higher than those of the benign SPNs (P < 0.05, P < 0.05). The VEGF positive expressions appeared in 32 patients with malignant SPNs and 2 patients with benign SPNs, and the average value of the MVD was higher in patients with malignant SPNs (36.88 +/- 6.76) than in patients with either benign (4.51 +/- 0.60) or inflammatory (26.11 +/- 5.43) SPNs (P < 0.05, P < 0.05). There were statistically significant correlations between the CT perfusion feature and the MVD. The highest correlation was between the peak height of SPN and the MVD (r = 0.657, P < 0.05). CONCLUSIONS: Tumor microvessel density and VEGF expression facilitate the exploration of the pathophysiological basis of CT perfusion in SPNs. Multi-slice CT perfusion has shown strong positive correlations with angiogenesis in SPNs.


Asunto(s)
Microvasos/patología , Nódulo Pulmonar Solitario/diagnóstico por imagen , Nódulo Pulmonar Solitario/patología , Tomografía Computarizada por Rayos X/métodos , Factor A de Crecimiento Endotelial Vascular/análisis , Adulto , Anciano , Femenino , Humanos , Inmunohistoquímica , Técnicas In Vitro , Pulmón/diagnóstico por imagen , Pulmón/metabolismo , Pulmón/patología , Masculino , Persona de Mediana Edad , Neovascularización Patológica , Imagen de Perfusión , Nódulo Pulmonar Solitario/metabolismo
9.
Clin Imaging ; 31(3): 165-77, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17449377

RESUMEN

The aim of this study was to investigate the relationship between 16-slice spiral CT perfusion imaging and tumor angiogenesis and cyclin D1 expression in patients with peripheral lung cancer. Fifty-eight patients with peripheral lung cancer underwent 16-slice spiral CT perfusion imaging. The CT perfusion imaging was analyzed for time density curve (TDC), perfusion parametric maps, and the respective perfusion parameters. Correlation between the respective perfusion parameters and immunohistochemical findings of microvessel density measurement and cyclin D1 expression was evaluated.


Asunto(s)
Ciclina D1/biosíntesis , Neoplasias Pulmonares , Neovascularización Patológica/diagnóstico por imagen , Tomografía Computarizada Espiral/métodos , Adenocarcinoma/irrigación sanguínea , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/metabolismo , Adulto , Anciano , Carcinoma de Células Grandes/irrigación sanguínea , Carcinoma de Células Grandes/diagnóstico por imagen , Carcinoma de Células Grandes/metabolismo , Carcinoma de Células Pequeñas/irrigación sanguínea , Carcinoma de Células Pequeñas/diagnóstico por imagen , Carcinoma de Células Pequeñas/metabolismo , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/irrigación sanguínea , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/metabolismo , Masculino , Persona de Mediana Edad
10.
Ai Zheng ; 26(1): 73-7, 2007 Jan.
Artículo en Chino | MEDLINE | ID: mdl-17222372

RESUMEN

BACKGROUND & OBJECTIVE: Angiography, a common method in evaluating blood supply of lung carcinoma, is invasive and complicated, with low success rate for bronchial artery, and could not assure to show all supply blood vessels at a time. This study was to explore clinical value of 16 slices spiral CT angiography with 3-dimensional CT (3DCT) and CT virtual endoscopy (CTVE) in diagnosing and evaluating supply blood vessels and blood supply of lung carcinoma, so as to find a non-invasive, safe, simple and effective method in diagnosing blood supply of lung carcinoma. METHODS: A total of 72 patients with pathologically proved lung carcinoma underwent 16 slices spiral CT angiography with 3DCT. Volume rendering (VR), maximum intensity projection (MIP), and surface shaded display (SSD) of supply blood vessels of lung carcinoma were used as 3DCT models. CTVE of bronchial artery was performed in 25 patients. Color VR of tumor lesion was performed in all patients. RESULTS: Supply blood vessels were showed in 68 patients, 59 of them showed only bronchial artery, 5 showed intercostals arteries, and 4 showed mixed types, including bronchial artery, intercostals arteries, or branch arteries of subclavian artery. The bronchial artery entered into enlarged mediastinal lymph nodes in 4 patients. CTVE well displayed the orifice and lumen of bronchial arteries in the 25 patients. The extent of red color of tumor lesion on VR color image were divided into 4 types: no color (n=11), light red (n=17), moderate red (n=32), and heavy red (n=12); the added CT values of tumor lesion after enhanced CT were (6.16+/-2.23) Hu, (15.71+/-3.13) Hu, (25.47+/-2.71) Hu, and (44.31+/-19.68) Hu, respectively. The corresponding rate between enhanced type and distributive type of red color on color VR was 86.1%. CONCLUSIONS: The 16 slices spiral CT angiography with 3DCT and CTVE could show clearly supply blood vessels and blood supply of lung carcinoma. It is a non-invasive, simple and effective method in evaluating and diagnosing blood supply of lung carcinoma.


Asunto(s)
Arterias Bronquiales/diagnóstico por imagen , Neoplasias Pulmonares/irrigación sanguínea , Tomografía Computarizada Espiral/métodos , Adulto , Anciano , Anciano de 80 o más Años , Angiografía/métodos , Angioscopía/métodos , Femenino , Humanos , Imagenología Tridimensional , Neoplasias Pulmonares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
11.
Chin Med J (Engl) ; 119(15): 1248-55, 2006 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-16919183

RESUMEN

BACKGROUND: Hyperparathyroidism (HPT) occurs at an early age and has a high disability rate. Unfortunately, confirmed diagnosis in most patients is done at a very late stage, when the patients have shown typical symptoms and signs, and when treatment does not produce any desirable effect. It has become urgent to find a method that would detect early bone diseases in HPT to obtain time for the ideal treatment. This study evaluated the accuracy of high field magnetic resonance imaging (MRI) combined with spiral computed tomography (SCT) scan in detecting early bone diseases in HPT, through imaging techniques and histopathological examinations on an animal model of HPT. METHODS: Eighty adult rabbits were randomly divided into two groups with forty in each. The control group was fed normal diet (Ca:P = 1:0.7); the experimental group was fed high phosphate diet (Ca:P = 1:7) for 3, 4, 5, or 6-month intervals to establish the animal model of HPT. The staging and imaging findings of the early bone diseases in HPT were determined by high field MRI and SCT scan at the 3rd, 4th, 5th and 6th month. Each rabbit was sacrificed after high field MRI and SCT scan, and the parathyroid and bones were removed for pathological examination to evaluate the accuracy of imaging diagnosis. RESULTS: Parathyroid histopathological studies revealed hyperplasia, osteoporosis and early cortical bone resorption. The bone diseases in HPT displayed different levels of low signal intensity on T(1)WI and low to intermediate signal intensity on T(2)WI in bone of stage 0, I, II or III, but showed correspondingly absent, probable, osteoporotic and subperiosteal cortical resorption on SCT scan. CONCLUSION: High field MRI combined with SCT scan not only detects early bone diseases in HPT, but also indicates staging, and might be a reliable method of studying early bone diseases in HPT.


Asunto(s)
Enfermedades Óseas/diagnóstico , Hiperparatiroidismo/complicaciones , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada Espiral/métodos , Animales , Enfermedades Óseas/patología , Calcio/sangre , Femenino , Masculino , Osteoporosis/diagnóstico , Fósforo/sangre , Conejos
12.
Hepatobiliary Pancreat Dis Int ; 3(2): 204-8, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15138110

RESUMEN

BACKGROUND: Multirow-detector helical CT (MDCT) allows faster Z-axis coverage and improves longitudinal resolution to scan the entire liver. This study was to evaluate the value of multiphase hepatic CT scans using MDCT in diagnosing hypervascular hepatocellular carcinoma (HCC). METHODS: Multiphase hepatic CT scans in 40 patients were carried out with a Marconi Mx8000 MDCT scanner. The scans of early arterial phase (EAP), late arterial phase (LAP) and portal venous phase (PVP) were started at 21, 34 and 85 seconds after injection of contrast medium, respectively. The number of detected lesions was calculated in each phase. The density of the liver and tumor was greater than 1 cm for HCC, and the density of the liver and tumor in each phase was statistically calculated. RESULTS: A total of 61 lesions were found in the 40 patients, and lesions greater than 1 cm were seen in 47 cases. The density differences between the liver and tumor were statistically significant (P<0.05) at the LAP and EAP and between the LAP, EAP and PVP. In the 61 lesions, the detectability in the EAP, LAP and the double arterial phases (DAP) was 32%, 87%, and 94%, respectively. Significant difference was found between the LAP plus PVP and the EAP plus PVP; but no significant difference was observed between the DAP plus PVP and the LAP plus PVP. CONCLUSIONS: The utility of MDCT scan in the liver has optimized the protocol of arterial phase scan. MDCT is possible to scan the entire liver in a real arterial phase and it is very valuable in the detection of small HCC.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Hígado/irrigación sanguínea , Neovascularización Patológica/diagnóstico por imagen , Tomografía Computarizada Espiral/instrumentación , Femenino , Humanos , Hígado/diagnóstico por imagen , Masculino , Persona de Mediana Edad
13.
Zhongguo Fei Ai Za Zhi ; 6(3): 176-80, 2003 Jun 20.
Artículo en Chino | MEDLINE | ID: mdl-21266113

RESUMEN

BACKGROUND: To investigate the origin of tumor blood vessel and blood supply during pulmonary carcinogenesis, and the relationship between vascular endothelial growth factor (VEGF), its receptor Flk-1 and angiogenesis. METHODS: One hundred Wistar rats were instilled with 3-methylcholanthrene (MCA) and diethylinitrosamine (DEN) to induce pulmonary squamous cell carcinoma through left lower lobe bronchus. To acquire different pathological phase during the carcinogenesis, rats were killed in 15, 35, 55, 65, 75 days after instillation. Yellow and green silastics were respectively injected into the bronchial and pulmonary arteries of 30 rats in 55, 65, 75 days after instillation. Intertumor microvessel density (MVD) was marked by anti-von Willebrand factor monoantibody. VEGF and Flk-1 expression were examined by immunohistochemistry. RESULTS: In the tumor area the tumor blood vessels were yellow and connected with distorted bronchial artery and very few green incomplete branches of pulmonary artery were seen. Silastic particles could be seen in the disordered tumor blood vessels by microscope after bronchial artery perfusion. There was no silastic particles in the carcinoma interstitial blood vessels after pulmonary artery perfusion. MVD count significantly increased in carcinoma in situ (39.50±12.60) and infiltrative carcinoma (61.05±19.92) as compared to atypical hyperplasia (8.92±3.80)(both P < 0.01), and the increased vessels originated from bronchial artery, but not pulmonary artery. The expression of VEGF and Flk-1 increased during pulmonary carcinogenesis. The positive coefficients of VEGF and FLK-1 expressions became higher and higher from epithelial proliferation to squamous metaplasia, to atypical hyperplasia, to carcinoma in situ and finally to infiltrative carcinoma. There was significant correlation between MVD and VEGF expression (r=0.979 8, P < 0.005), as well as between MVD and Flk-1 expression (r=0.907 8, P < 0.05). CONCLUSIONS: Angiogenesis is the important phenomenon of the rat pulmonary carcinogenesis and the newly formed blood vessels in tumor connect with the branches of bronchial artery, but not pulmonary artery. This confirms that the blood supply of pulmonary carcinoma is from bronchial artery, not from pulmonary artery. VEGF and Flk-1 are closely related to angiogenesis of tumor.

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