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1.
Artigo em Inglês | MEDLINE | ID: mdl-39031346

RESUMO

Copper is an essential element in the human body, involved in many physiological and metabolic functions, including coagulation, oxidative metabolism, and hormone production. The maintenance of copper homeostasis within cells is a complex procedure that is intrinsically controlled by a multitude of intricate mechanisms. Disorders of copper homeostasis encompass a wide range of pathological conditions, including degenerative neurological diseases, metabolic disorders, cardio-cerebrovascular diseases, and tumors. Cuproptosis, a recently identified non-apoptotic mode of cell death mode, is characterized by copper dependence and the regulation of mitochondrial respiration. Cuproptosis represents a novel form of cell death distinct from the previously described modes, including apoptosis, necrosis, pyroptosis, and ferroptosis. Excess copper has been shown to induce cuproptosis by stimulating protein toxic stress responses via copper-dependent abnormal oligomerization of lipoylation proteins within the tricarboxylic acid cycle and the subsequent reduction of iron-sulfur cluster protein levels. Ferredoxin1 facilitates the lipoacylation of dihydrolipoyl transacetylase, which in turn degrades iron-sulfur cluster proteins by reducing Cu2+ to Cu+, thereby inducing cell death. Furthermore, copper homeostasis is regulated by the copper transporter, and disturbances in this homeostasis result in cuproptosis. Current evidence suggests that cuproptosis plays an important role in the onset and development of several cardiovascular diseases. Copper-chelating agents, including ammonium tetrathiomolybdate (VI) and DL-penicillamine, have been shown to facilitate the alleviation of cardiovascular disease by inhibiting cuproptosis. It is hypothesized that oxidative phosphorylation inhibitors such as physical training may inhibit cuproptosis by inhibiting the protein stress response. In conclusion, the implementation of physical training may be a viable strategy to reducte the incidence of cuproptosis.

2.
Rofo ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38885652

RESUMO

Over the last few years, there has been an increasing focus on integrating artificial intelligence (AI) into existing imaging systems. This also applies to ultrasound. There are already applications for thyroid and breast lesions that enable AI-assisted sonography directly on the device. However, this is not yet the case for lymph nodes.The aim was to test whether already established programs for AI-assisted sonography of breast lesions and thyroid nodules are also suitable for identifying and measuring superficial lymph nodes. For this purpose, the two programs were used as a supplement to routine ultrasound examinations of superficial lymph nodes. The accuracy of detection by AI was then evaluated using a previously defined score. If available, a comparison was made with cross-sectional imaging.The programs that were used are able to adequately detect lymph nodes in the majority of cases (78.6%). Problems were caused in particular by a high proportion of echo-rich fat, blurred differentiation from the surrounding tissues and the occurrence of lymph node conglomerates. The available cross-sectional images did not contradict the classification of the lesion as a lymph node in any case.In the majority of cases, the tested programs are already able to detect and measure superficial lymph nodes. Further improvement can be expected through specific training of the software. Further developments and studies are required to assess risk of malignancy. · The inclusion of AI in imaging is increasingly becoming a scientific focus.. · The detection of lymph nodes is already possible using device-integrated AI software.. · Malignancy assessment of the detected lymph nodes is not yet possible.. · Rink M, Künzel J, Stroszczynski C et al. Smart scanning: automatic detection of superficially located lymph nodes using ultrasound - initial results. Fortschr Röntgenstr 2024; DOI 10.1055/a-2331-0951.

3.
Clin Hemorheol Microcirc ; 86(3): 263-273, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38489171

RESUMO

BACKGROUND: The continuous development of ultrasound techniques increasingly enables better description and visualization of unclear lesions. New ultrasound systems must be evaluated with regard to all these diagnostic possibilities. METHODS: A multifrequency C1-7 convex probe (SC7-1M) with the new high-end system Resona A20 Series was used. Modern technologies, including HiFR CEUS, SR CEUS and multimodal tissue imaging with shear wave elastography (SWE), fat evaluation and viscosity measurements (M-Ref) were applied. RESULTS: Of n = 70 (mean value 48,3 years±20,3 years, range 18-84 years) cases examined, a definitive diagnosis could be made in n = 67 cases, confirmed by reference imaging and/or follow-up. Of these, n = 22 cases were malignant changes (HCC (hepatocellular carcinoma) n = 9, CCC (cholangiocellular carcinoma) n = 3, metastases of colorectal carcinomas or recurrences of HCC n = 10). In all 12 cases of HCC or CCC, the elastography measurements using the shear wave technique (with values >2 m/s to 3.7 m/s) showed mean values of 2.3±0.31 m/s and a degree of fibrosis of F2 to F4. In n = 14 cases, changes in the fat measurement (range 0.51 to 0.72 dB/cm/MHz, mean values 0.58±0.12 dB/cm/MHz) in the sense of proportional fatty changes in the liver were detected. In the 4 cases of localized fat distribution disorders, the values were >0.7 dB/cm/MHz in the sense of significant fatty deposits in the remaining liver tissue. Relevant changes in the viscosity measurements with values >1.8 kPa were found in n = 31 cases, in n = 5 cases of cystic lesions with partially sclerosing cholangitis, in n = 13 cases of malignant lesions and in n = 9 cases post-interventionally, but also in n = 4 cases of benign foci with additional systemic inflammation. CONCLUSIONS: The results are promising and show a new quality of ultrasound-based liver diagnostics. However, there is a need for further investigations with regard to the individual aspects, preferably on a multi-center basis.


Assuntos
Carcinoma Hepatocelular , Técnicas de Imagem por Elasticidade , Neoplasias Hepáticas , Humanos , Técnicas de Imagem por Elasticidade/métodos , Meios de Contraste , Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Viscosidade , Fígado/diagnóstico por imagem , Fígado/patologia , Ultrassonografia/métodos
4.
Clin Hemorheol Microcirc ; 86(1-2): 159-168, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37638428

RESUMO

BACKGROUND: Liver biotransformation is the major route for drug metabolism in humans, often catalysed by cytochrome P450 (CYP) enzymes. This first-pass effect can lead to hepatotoxicity and influences the bioavailability of drugs. OBJECTIVE: We aimed to establish in vitro culture systems simulating the liver first-pass to study effects of the proteasome inhibitor MG-132 simultaneously on hepatocytes and cancer cells. METHODS: The first-pass effect was simulated by conditioned medium transfer (CMT) from pre-treated HepG2 CYP3A4-overexpressing cells to either pancreatic cancer cell line PANC-1 or primary colon cancer cells, and by indirect co-culture (CC) of liver and cancer cells in a shared medium compartment. Experimental proteasome inhibitor MG-132 was used as test substance as it is detoxified by CYP3A4. RESULTS: Cancer cells showed higher viabilities in the first-pass simulation by CMT and CC formats when compared to monocultures indicating effective detoxification of MG-132 by HepG2 CYP3A4-overexpressing cells. HepG2-CYP3A4 cells showed reduced viabilites after treatment with MG-132. CONCLUSIONS: We successfully established two different culture systems to simulate the liver first-pass effect in vitro. Such systems easily allow to study drug effects simultaneously on liver and on target cancer cells. They are of great value in pre-clinical cancer research, pharmaceutical research and drug development.


Assuntos
Citocromo P-450 CYP3A , Leupeptinas , Neoplasias , Humanos , Células Hep G2 , Inibidores de Proteassoma/farmacologia , Fígado , Sistema Enzimático do Citocromo P-450/metabolismo , Biotransformação
5.
J Gastrointestin Liver Dis ; 32(4): 479-487, 2023 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-38147619

RESUMO

AIMS: To assess the value of using integrated parametric ultrasound software for contrast-enhanced ultrasonography (CEUS) of liver tumors. METHODS: 107 patients with liver tumors were studied. CEUS were performed to detect focal lesions. Parametric images were based on continuous CINE LOOPs, from the early-arterial phase (15 s) to the portal-venous phase (1 min) generated by perfusion software. The evaluations of the parametric images and their dignity for liver lesions were performed independently by an experienced and a less-experienced investigator. Computed tomography, magnetic resonance imaging scans or histological analysis were used as references. RESULTS: High parametric image quality were obtained in all patients. Among the patients, 44% lesions were benign, 56% were malignant. The experienced investigator correctly classified 46 of 47 (98%) as benign, and 60 of 60 (100%) as malignant tumors based on the parametric images. The less-experienced investigator correctly classified 39 of 47 (83%) as benign, and 49 of 60 (82%) malignant tumors, acheaving a high statistical accuracy of 98% with this type of diagnostic. CONCLUSION: Parametric imaging for grading the malignant degree of tumor may be a good complement to existing ultrasound techniques and was particularly helpful for improving the assessments of the less-experienced examiner.


Assuntos
Interpretação de Imagem Assistida por Computador , Neoplasias Hepáticas , Ultrassonografia , Humanos , Meios de Contraste , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Perfusão/métodos , Sensibilidade e Especificidade , Ultrassonografia/métodos , Software
6.
Cells ; 12(15)2023 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-37566045

RESUMO

Cancer patients are at a very high risk of serious thrombotic events, often fatal. The causes discussed include the detachment of thrombogenic particles from tumor cells or the adverse effects of chemotherapeutic agents. Cytostatic agents can either act directly on their targets or, in the case of a prodrug approach, require metabolization for their action. Cyclophosphamide (CPA) is a widely used cytostatic drug that requires prodrug activation by cytochrome P450 enzymes (CYP) in the liver. We hypothesize that CPA could induce thrombosis in one of the following ways: (1) damage to endothelial cells (EC) after intra-endothelial metabolization; or (2) direct damage to EC without prior metabolization. In order to investigate this hypothesis, endothelial cells (HUVEC) were treated with CPA in clinically relevant concentrations for up to 8 days. HUVECs were chosen as a model representing the first place of action after intravenous CPA administration. No expression of CYP2B6, CYP3A4, CYP2C9 and CYP2C19 was found in HUVEC, but a weak expression of CYP2C18 was observed. CPA treatment of HUVEC induced DNA damage and a reduced formation of an EC monolayer and caused an increased release of prostacyclin (PGI2) and thromboxane (TXA) associated with a shift of the PGI2/TXA balance to a prothrombotic state. In an in vivo scenario, such processes would promote the risk of thrombus formation.


Assuntos
Neoplasias , Pró-Fármacos , Trombose , Humanos , Pró-Fármacos/farmacologia , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Células Endoteliais/metabolismo , Ciclofosfamida/uso terapêutico , Sistema Enzimático do Citocromo P-450/metabolismo , Neoplasias/tratamento farmacológico , Trombose/tratamento farmacológico
7.
Clin Hemorheol Microcirc ; 83(3): 305-314, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36683497

RESUMO

BACKGROUND: Physical training in patients with heart failure can affect hemodynamic, cardiac and angiogenesis parameters. OBJECTIVE: The aim of the present study was to investigate the effects of traditional moderate-intensity rehabilitation training and interval training on some angiogenesis factors in coronary artery bypass graft (CABG) patients. METHODS: Thirty CABG patients (mean age±SD, 55±3 years) were randomly assigned to one of three groups: high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) or the control group. After the initial assessments, eligible patients in the experimental groups (HIIT and MICT) performed exercise training for 8 weeks, while the control group did not. Angiogenesis and angiostatic indices, including pro-adrenomedullin (pro-ADM), basic fibroblast growth factor (bFGF), and endostatin, were then measured. RESULTS: The results showed no significant difference between pro-ADM in the HIIT and MICT groups (P = 0.99), but a significant difference was found between MICT and the control group and between HIIT and the control group (P = 0.001). There is also no significant difference between the bFGF levels in the HIIT and MICT training groups (P = 1.00), but the changes in this factor between the training groups and the control group were significant (P = 0.001). There was a significant difference between the levels of endostatin in all three groups. CONCLUSIONS: Two methods of cardiac rehabilitation (HIIT and MICT) may be useful for the recovery of patients with coronary artery bypass grafting. This improvement manifested itself in changes in angiogenesis and angiostatic indices in this study. However, more extensive studies are needed to investigate the effects of these two types of rehabilitation programs on other indicators of angiogenesis and angiostatic.


Assuntos
Reabilitação Cardíaca , Ponte de Artéria Coronária , Exercício Físico , Treinamento Intervalado de Alta Intensidade , Humanos , Pessoa de Meia-Idade , Reabilitação Cardíaca/métodos , Endostatinas , Treinamento Intervalado de Alta Intensidade/métodos
8.
Clin Hemorheol Microcirc ; 83(1): 31-46, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35466932

RESUMO

AIM: To examine to what extent the high frame rate contrast-enhanced ultrasound (HiFR) diagnostic enables the conclusive diagnosis of liver changes with suspected malignancy. MATERIAL/METHODS: Ultrasound examinations were performed by an experienced examiner using a multifrequency probe (SC6-1) on a high-end ultrasound system (Resona 7, Mindray) to clarify liver changes that were unclear on the B-scan. A bolus of 1-2.4 ml of the Sulphur hexafluoride ultrasound microbubbles contrast agent SonoVue™ (Bracco SpA, Italy) was administered with DICOM storage of CEUS examinations from the early arterial phase (5-15 s) to the late phase (5-6 min). Based on the image files stored in the PACS, an independent reading was performed regarding image quality and finding-related diagnostic significance (0 not informative/non-diagnostic to 5 excellent image quality/confident diagnosis possible). References were clinical follow-up, if possible, comparison to promptly performed computed tomography or magnetic resonance imaging, in some cases also to histopathology. RESULTS: We examined 100 patients (42 women, 58 men, from 18 years to 90 years, mean 63±13 years) with different entities of focal and diffuse liver parenchymal changes, which could be detected in all cases with sufficient image quality with CEUS and with high image quality with HiFR-CEUS. Proportionally septate cysts were found in n = 19 cases, scars after hemihepatectomy with local reduced fat in n = 5 cases, scars after microwave ablation in n = 19 cases, hemangiomas in n = 9 cases, focal nodular hyperplasia in n = 8 cases, colorectal metastases in n = 15 cases, hepatocellular carcinoma (HCC) in n = 11 cases, Osler disease in n = 8 cases. The size of lesions ranged from 5 mm to 200 mm with a mean value of 33.1±27.8 mm. Conclusive diagnoses could be made by the experienced investigator in 97/100 cases with CEUS, confirmed by reference imaging, in parts by histopathology or follow-up. The image quality for HiFR CEUS was rated with a score of 3 to 5; 62 cases were assessed with an average of good (4 points), 27 cases with very good (5 points), and in 11 cases (3 points) still satisfactory despite aggravated acoustic conditions. The specificity of HIFR-CEUS was 97%, the sensitivity 97%, the positive predictive value 94%, the negative predictive value 99% and the accuracy 97%. CONCLUSION: HIFR-CEUS has demonstrated has demonstrated an improved image quality resulting in a high diagnostic accuracy. In the hands of an experienced investigator, HiFR-CEUS allows the assessment of focal and diffuse unclear liver parenchymal changes on B-scan and dynamic assessment of microcirculation in solid and vascular changes.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Masculino , Humanos , Feminino , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Cicatriz/patologia , Meios de Contraste , Ultrassonografia/métodos , Imageamento por Ressonância Magnética
9.
Cells ; 11(15)2022 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-35954291

RESUMO

The characterization of novel radiotracers toward their metabolic stability is an essential part of their development. While in vitro methods such as liver microsome assays or ex vivo blood or tissue samples provide information on overall stability, little or no information is obtained on cytochrome P450 (CYP) enzyme and isoform-specific contribution to the metabolic fate of individual radiotracers. Herein, we investigated recently established CYP-overexpressing hepatoblastoma cell lines (HepG2) for their suitability to study the metabolic stability of radiotracers in general and to gain insight into CYP isoform specificity. Wildtype HepG2 and CYP1A2-, CYP2C19-, and CYP3A4-overexpressing HepG2 cells were incubated with radiotracers, and metabolic turnover was analyzed. The optimized protocol, covering cell seeding in 96-well plates and analysis of supernatant by radio thin-layer-chromatography for higher throughput, was transferred to the evaluation of three 18F-labeled celecoxib-derived cyclooxygenase-2 inhibitors (coxibs). These investigations revealed time-dependent degradation of the intact radiotracers, as well as CYP isoform- and substrate-specific differences in their metabolic profiles. HepG2 CYP2C19 proved to be the cell line showing the highest metabolic turnover for each radiotracer studied here. Comparison with human and murine liver microsome assays showed good agreement with the human metabolite profile obtained by the HepG2 cell lines. Therefore, CYP-overexpressing HepG2 cells provide a good complement for assessing the metabolic stability of radiotracers and allow the analysis of the CYP isoform-specific contribution to the overall radiotracer metabolism.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Linhagem Celular , Citocromo P-450 CYP2C19 , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos , Camundongos , Isoformas de Proteínas
10.
Clin Hemorheol Microcirc ; 79(1): 231-243, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34487034

RESUMO

Cell-based in vitro liver models are an important tool in the development and evaluation of new drugs in pharmacological and toxicological drug assessment. Hepatic microsomal enzyme complexes, consisting of cytochrome P450 oxidoreductase (CPR) and cytochrome P450 monooxygenases (CYPs), play a decisive role in catalysing phase-1 biotransformation of pharmaceuticals and xenobiotics. For a comprehensive understanding of the phase-1 biotransformation of drugs, the availability of well-characterized substances for the targeted modulation of in vitro liver models is essential. In this study, we investigated diphenyleneiodonium (DPI) for its ability to inhibit phase-1 enzyme activity and further its toxicological profile in an in vitro HepG2 cell model with and without recombinant expression of the most important drug metabolization enzyme CYP3A4.Aim of the study was to identify effective DPI concentrations for CPR/CYP activity modulation and potentially associated dose and time dependent hepatotoxic effects. The cells were treated with DPI doses up to 5,000nM (versus vehicle control) for a maximum of 48 h and subsequently examined for CYP3A4 activity as well as various toxicological relevant parameters such as cell morphology, integrity and viability, intracellular ATP level, and proliferation. Concluding, the experiments revealed a time- and concentration-dependent DPI mediated partial and complete inhibition of CYP3A4 activity in CYP3A4 overexpressing HepG2-cells (HepG2-CYP3A4). Other cell functions, including ATP synthesis and consequently the proliferation were negatively affected in both in vitro cell models. Since neither cell integrity nor cell viability were reduced, the effect of DPI in HepG2 can be assessed as cytostatic rather than cytotoxic.


Assuntos
Citostáticos , Hepatoblastoma , Neoplasias Hepáticas , Biotransformação , Linhagem Celular , Células Clonais , Citocromo P-450 CYP3A/genética , Células Hep G2 , Hepatoblastoma/tratamento farmacológico , Humanos , Oniocompostos
11.
Sci Rep ; 11(1): 17677, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34480040

RESUMO

The aim of this present clinical pilot study is the display of typical perfusion results in patients with solid, non-cystic breast lesions. The lesions were characterized using contrast enhanced ultrasound (CEUS) with (i) time intensity curve analyses (TIC) and (ii) parametric color maps. The 24 asymptomatic patients included were genetically tested for having an elevated risk for breast cancer. At a center of early detection of familial ovary and breast cancer, those patients received annual MRI and grey-scale ultrasound. If lesions remained unclear or appeared even suspicious, those patients also received CEUS. CEUS was performed after intravenous application of sulfur hexafluoride microbubbles. Digital DICOM cine loops were continuously stored for one minute in PACS (picture archiving and communication system). Perfusion images and TIC analyses were calculated off-line with external perfusion software (VueBox). The lesion diameter ranged between 7 and 15 mm (mean 11 ± 3 mm). Five hypoechoic irregular lesions were scars, 6 lesions were benign and 12 lesions were highly suspicious for breast cancer with irregular enhancement at the margins and a partial wash out. In those 12 cases, histopathology confirmed breast cancer. All the suspicious lesions were correctly identified visually. For the perfusion analysis only Peak Enhancement (PE) and Area Under the Curve (AUC) added more information for correctly identifying the lesions. Typical for benign lesions is a prolonged contrast agent enhancement with lower PE and prolonged wash out, while scars are characterized typically by a reduced enhancement in the center. No differences (p = 0.428) were found in PE in the center of benign lesions (64.2 ± 28.9 dB), malignant lesions (88.1 ± 93.6 dB) and a scar (40.0 ± 17.0 dB). No significant differences (p = 0.174) were found for PE values at the margin of benign lesions (96.4 ± 144.9 dB), malignant lesions (54.3 ± 86.2 dB) or scar tissue (203.8 ± 218.9 dB). Significant differences (p < 0.001) were found in PE of the surrounding tissue when comparing benign lesions (33.6 ± 25.2 dB) to malignant lesions (15.7 ± 36.3 dB) and scars (277.2 ± 199.9 dB). No differences (p = 0.821) were found in AUC in the center of benign lesions (391.3 ± 213.7), malignant lesions (314.7 ± 643.9) and a scar (213.1 ± 124.5). No differences (p = 0.601) were found in AUC values of the margin of benign lesions (313.3 ± 372.8), malignant lesions (272.6 ± 566.4) or scar tissue (695.0 ± 360.6). Significant differences (p < 0.01) were found in AUC of the surrounding tissue for benign lesions (151.7 ± 127.8), malignant lesions (177.9 ± 1345.6) and scars (1091 ± 693.3). There were no differences in perfusion evaluation for mean transit time (mTT), rise time (RT) and time to peak (TTP) when comparing the center to the margins and the surrounding tissue. The CEUS perfusion parameters PE and AUC allow a very good assessment of the risk of malignant breast lesions and thus a downgrading of BI-RADS 4 lesions. The use of the external perfusion software (VueBox, Bracco, Milan, Italy) did not lead to any further improvement in the diagnosis of suspicious breast lesions and does appears not to have any additional diagnostic value in breast lesions.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Mama/diagnóstico por imagem , Ultrassonografia Mamária , Feminino , Humanos , Imageamento por Ressonância Magnética , Projetos Piloto , Software
12.
Int J Mol Sci ; 22(3)2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540846

RESUMO

The adherence and shear-resistance of human umbilical venous endothelial cells (HUVEC) on polymers is determined in vitro in order to qualify cardiovascular implant materials. In these tests, variable fractions of HUVEC do not adhere to the material but remain suspended in the culture medium. Nonadherent HUVEC usually stop growing, rapidly lose their viability and can release mediators able to influence the growth and function of the adherent HUVEC. The aim of this study was the investigation of the time dependent behaviour of HUVEC under controlled nonadherent conditions, in order to gain insights into potential influences of these cells on their surrounding environment in particular adherent HUVEC in the context of in vitro biofunctionality assessment of cardiovascular implant materials. Data from adherent or nonadherent HUVEC growing on polystyrene-based cell adhesive tissue culture plates (TCP) or nonadhesive low attachment plates (LAP) allow to calculate the number of mediators released into the culture medium either from adherent or nonadherent cells. Thus, the source of the inflammatory mediators can be identified. For nonadherent HUVEC, a time-dependent aggregation without further proliferation was observed. The rate of apoptotic/dead HUVEC progressively increased over 90% within two days. Concomitant with distinct blebbing and loss of membrane integrity over time, augmented releases of prostacyclin (PGI2, up to 2.91 ± 0.62 fg/cell) and platelet-derived growth factor BB (PDGF-BB, up to 1.46 ± 0.42 fg/cell) were detected. The study revealed that nonadherent, dying HUVEC released mediators, which can influence the surrounding microenvironment and thereby the results of in vitro biofunctionality assessment of cardiovascular implant materials. Neglecting nonadherent HUVEC bears the risk for under- or overestimation of the materials endothelialization potential, which could lead to the loss of relevant candidates or to uncertainty with regard to their suitability for cardiac applications. One approach to minimize the influence from nonadherent endothelial cells could be their removal shortly after observing initial cell adhesion. However, this would require an individual adaptation of the study design, depending on the properties of the biomaterial used.


Assuntos
Adesão Celular/fisiologia , Técnicas de Cultura de Células , Células Endoteliais da Veia Umbilical Humana/citologia , Apoptose , Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Morte Celular , Divisão Celular , Meios de Cultivo Condicionados/química , Citocinas/análise , Epoprostenol/análise , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Mediadores da Inflamação/análise , Peptídeos e Proteínas de Sinalização Intercelular/análise , L-Lactato Desidrogenase/análise , Poliestirenos , Proteínas Recombinantes/farmacologia , Propriedades de Superfície , Tromboxano A2/análise , Fator de Necrose Tumoral alfa/farmacologia
13.
Clin Hemorheol Microcirc ; 78(1): 29-40, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33523044

RESUMO

The external perfusion software (VueBox™) for contrast-enhanced ultrasound (CEUS), enables the quantitative analysis of micro-vascularization within non-cystic lesions in terms of characterization and detection. This review summarizes our work about parathyroid gland, thyroid gland, liver, prostate and other tissues as well as original studies in the use of parametric perfusion imaging. Useful perfusion parameters are introduced.


Assuntos
Meios de Contraste/uso terapêutico , Imagem de Perfusão/métodos , Ultrassonografia/métodos , Feminino , Humanos , Masculino
14.
Clin Hemorheol Microcirc ; 78(1): 103-116, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33554890

RESUMO

OBJECTIVE: To assess the impact and procedural input of intraoperative ultrasound (IOUS) with contrast-enhanced ultrasound (CEUS) and ultrasound elastography on surgical decision making during the procedure and consequently the outcome after hepato-pancreatico-biliary (HPB) surgery. MATERIALS AND METHODS: Data of 50 consecutive patients, who underwent HPB surgery from 04/2018 to 07/2018 were prospectively collected for this study. During surgery, IOUS with a high-resolution ultrasound device using CEUS after bolus injection of 2.4-5 ml dulphur hexafluoride microbubbles using a 6-9 MHz probe and a share wave and strain elastography was performed by an experienced examiner. Process and time analysis were carried out using mobile phone timer. RESULTS: The IOUS with CEUS and elastography correctly identified 42 malignant tumors and 4 benign lesions. In 3 cases, the examination provided false positive result (identifying 3 benign lesions as malignant) and in 1 case a malignant lesion was incorrectly assessed as benign (sensitivity 97,7%, specificity 57,1%, PPV 93,3% and NPV 80%).The specific question by the surgeon could be answered successfully in 98% of the cases. In 76% of the cases, there was a modification (42%) or a fundamental change (34%) of the planned surgical approach due to the information provided by the IOUS. Within the last group, the IOUS had a major impact on therapy outcome. In 7 patients an additional tumor resection was required, in 5 patients the tumor was assessed as inoperable, and in total in 5 patients an intraoperative RFA (4/5) or postoperative RITA (1/5) was required.Regarding procedural input, there was only a slight, but significant difference between the transport and set-up times before the intraoperative use (mean: 14 min 22 s) and the return transport (mean 13 min 6 s), (p = 0,038). The average examination time was 14 minutes, which makes only one third of the overall time demand. CONCLUSION: Combination of IOUS with CEUS and elastography in oncological HPB surgery provides valuable information that affects surgical decision-making. The procedural input of about 45 minutes seems to be a good investment considering the improvement of the surgical procedure and a significant modification of the therapy approach in the majority of the cases.


Assuntos
Neoplasias do Sistema Biliar/diagnóstico por imagem , Meios de Contraste/uso terapêutico , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Ultrassonografia/métodos , Neoplasias do Sistema Biliar/cirurgia , Tomada de Decisões , Feminino , Humanos , Neoplasias Hepáticas/cirurgia , Masculino , Neoplasias Pancreáticas/cirurgia
15.
Life (Basel) ; 11(2)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513794

RESUMO

The application of cytostatic drugs or natural substances to inhibit cancer growth and progression is an important and evolving subject of cancer research. There has been a surge of interest in marine bioresources, particularly algae, as well as cyanobacteria and their bioactive ingredients. Dried biomass products of Arthrospira and Chlorella have been categorized as "generally recognized as safe" (GRAS) by the US Food and Drug Administration (FDA). Of particular importance is an ingredient of Arthrospira: phycocyanin, a blue-red fluorescent, water-soluble and non-toxic biliprotein pigment. It is reported to be the main active ingredient of Arthrospira and was shown to have therapeutic properties, including anti-oxidant, anti-inflammatory, immune-modulatory and anti-cancer activities. In the present review, in vitro and in vivo data on the effects of phycocyanin on various tumor cells and on cells from healthy tissues are summarized. The existing knowledge of underlying molecular mechanisms, and strategies to improve the efficiency of potential phycocyanin-based anti-cancer therapies are discussed.

16.
Clin Hemorheol Microcirc ; 77(3): 247-257, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32924990

RESUMO

BACKGROUND: Capsular contractures around breast implants usually develop leading to pain and aesthetically inadequate results and ultimately often requires the replacement of the implants. Textured silicone implants are the most commonly placed implant, but polyurethane-coated implants are increasingly being used in an attempt to ameliorate the long-term complications associated with implant insertion. AIM: Capsular contracture is traditionally classified using the Baker scale, a subjective classification system based upon clinical findings. Aim of this study was to evaluate the association between pain due capsular contraction, Baker score and different techniques of US elastography. MATERIAL AND METHODS: Patients were contacted who had undergone an implant replacement due to capsular contracture. Inclusion criterion was the re-implantation of a PU-coated implant. In the third year after changing the implant a follow-up examination was performed in 16 patients with 23 implants. A conventional examination with anamnesis, tactile and visual findings to obtain a Baker score, and ultrasound examinations including shear wave elastography, ARFI and compound elastography were performed. In addition, pain was evaluated using a visual analogue scale (VAS). RESULTS: The pain data showed a significant improvement (before implant exchange: 4.1±2.8 score points) with significance in favor of the current state (1.7±1.0 pain score points; p = 0.002). All patients suffered from less or no pain three years after exchange of the implant. Pain values and elastography (ARFI values) correlated well (r = 0,873), with increasing Baker score the ARFI values increased. US elastography evaluations can locally determine tissue density but correlate only to a limited extent with the test findings according to Baker. US elastography values of mammary gland tissue without implant did not differ from mammary gland tissue around implants. CONCLUSION: Preoperative Baker scores prior to exchange and the current Baker scores at the follow-up showed significantly lower score points three years after exchange of the implants. Ultrasound elastography seems to be an objective classification of capsular fibrosis. These first results motivate to initiate a prospective multicenter investigation.


Assuntos
Implantes de Mama/efeitos adversos , Técnicas de Imagem por Elasticidade/métodos , Fibrose/diagnóstico por imagem , Ultrassonografia/métodos , Implante Mamário/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos
17.
Clin Hemorheol Microcirc ; 75(2): 201-217, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31985458

RESUMO

Implantation of synthetic small-diameter vascular bypass grafts is often associated with an increased risk of failure, due to thrombotic events or late intimal hyperplasia. As one of the causes an insufficient hemocompatibility of the artificial surface is discussed. Endothelialization of synthetic grafts is reported to be a promising strategy for creating a self-renewing and regulative anti-thrombotic graft surface. However, the establishment of a shear resistant cell monolayer is still challenging. In our study, cyto- and immuno-compatible poly(ether imide) (PEI) films were explored as potential biomaterial for cardiovascular applications. Recently, we reported that the initial adherence of primary human umbilical vein endothelial cells (HUVEC) was delayed on PEI-films and about 9 days were needed to establish a confluent and almost shear resistant HUVEC monolayer. To accelerate the initial adherence of HUVEC, the PEI-film surface was functionalized with an aptamer-cRGD peptide based endothelialization supporting system. With this functionalization the initial adherence as well as the shear resistance of HUVEC on PEI-films was considerable improved compared to the unmodified polymer surface. The in vitro results confirm the general applicability of aptamers for an efficient functionalization of substrate surfaces.


Assuntos
Aptâmeros de Peptídeos/metabolismo , Éter/metabolismo , Imidas/metabolismo , Polímeros/metabolismo , Técnicas de Cultura de Células , Humanos
18.
Clin Hemorheol Microcirc ; 74(1): 45-52, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31796667

RESUMO

INTRODUCTION: Stromal-epithelial interactions are fundamental for normal organ development and there is a multitude of evidence that the different components of the microenvironment are also necessary for the maintenance and promotion of the "tumor organ". Deregulated tumor associated extracellular matrix (tECM) is a hallmark of cancer, causing an alteration in the amount and composition of the different components (i.e. proteins, proteoglycans, glycoproteins and polysaccharids) of the ECM. As epithelial-stromal interactions are reciprocal, it is possible that tECM itself is able to initiate tumor development. We therefore established a mouse model to examine the influence of tECM of murine breast cancer on developing breast tissue in mice. MATERIALS AND METHODS: Breast cancer was established in 5 BALB/c mice by subcutaneous injection of 1×106 4T1 cells in 100µl PBS into the left mammary fat pad. The mammary fat pad including the primary tumor was excised after two weeks, decellularised and labelled as tumor extracellular matrix (tECM). Tumor ECM of 4T1 tumors was implanted into the 4th inguinal mammary fat pad of BALB/c mice (n = 5) aged 5 days. After 12 weeks the fourth mammary fat pad including the primary tumor was excised. Tissue was used for paraffin embedding and mouse breast cancer PCR array. Murine breast cancer tissue (BCT) and normal murine breast tissue (BT) served as control. RESULTS: Gene array analysis of 84 breast cancer-specific transcripts revealed that the mammary gland cells which were exposed to tumor ECM (tECM-BT) showed a similarly high overexpression for 22 genes as apparent for breast cancer tissue (BCT). The corresponding scatter plot showed a high agreement in the expression of the examined genes between the mammary gland cells which were exposed to tumor ECM and the breast cancer tissue. DISCUSSION: Our results clearly demonstrate that the tECM is able to shift the gene expression pattern of murine mammary epithelial cells towards that of carcinoma, indicating a role in breast cancer initiation. These data underlines that the acellular component of the tumor (ECM) can lead to a transformation of mammary gland tissue cells. These data show for the first time that the interaction of normal breast tissue cells with tumor ECM leads to an exchange of information and a consecutive overexpression of tumor-specific genes.


Assuntos
Neoplasias da Mama/patologia , Matriz Extracelular/metabolismo , Glândulas Mamárias Animais/patologia , Animais , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Microambiente Tumoral
19.
Toxicology ; 412: 37-47, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30500380

RESUMO

Preclinical drug safety assessment includes in vitro studies with physiologically relevant cell cultures. As an in vitro system for hepatic toxicology testing, we have been generating cell clones of human hepatoblastoma cell line HepG2 by lentiviral transduction of phase I cytochrome P450 (CYP) enzymes. Here, we present a stable CYP2C19-overexpressing HepG2 cell clone (HepG2-2C19 C1) showing an enzyme activity of approximately 82 pmol x min-1 x mg-1 total cellular protein. The phenotypic stability over several passages of HepG2-2C19 C1 renders them to be a suitable reference cell clone for benchmarking CYP2C19 enzyme activity. In addition, we were interested to analyze acute cytotoxicity of the model drug cyclophosphamide (CPA) metabolized by HepG2-2C19 C1 and by a previously generated CYP3A4-overexpressing HepG2 cell clone. Upon 10 mM CPA exposure, we were able to detect its metabolites 4-hydroxy-cyclophosphamide and acrolein in CYP3A4- and CYP2C19-expressing cell clones, but not in parental HepG2 cell line. XTT and ATP assays showed a modest reduction of cell viability of not more than 50% with high dose (10 mM) CPA treatment. By contrast, dramatic acute cytotoxic effects of CPA were evident by the formation of nuclear γH2AX foci and by increased cell death events. These effects were paralleled by substantial decreases of cell membrane integrity as measured by the trypan blue exclusion test. Our data on CYP enzyme overexpressing HepG2 cell clones clearly show that cytotoxicity of CPA is dramatically underestimated by standard metabolic activity tests. Thus, additional tests to quantitate DNA damage formation and cell death induction might be required to realistically assess cytotoxicity of such compounds.


Assuntos
Ciclofosfamida/toxicidade , Citocromo P-450 CYP2C19/fisiologia , Citocromo P-450 CYP3A/fisiologia , Acroleína/metabolismo , Células Hep G2 , Humanos
20.
Clin Hemorheol Microcirc ; 70(4): 423-431, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30347604

RESUMO

AIM: Aim of this study was to firstly describe reproducible, objective perfusion parameters of contrast-enhanced ultrasound (CEUS) kinetics of parathyroid gland adenoma (PA) using perfusion analysis software (VueBox®, Bracco, Italy). Thereby the efficiency of quantitative CEUS for characterization of PA should be evaluated comparing US to postoperative histopathological findings after PA resection. MATERIAL AND METHODS: 42 patients with symptoms/lab work suggestive of pHPT presented a parathyroid gland lesion in B-mode US, which was consequently analyzed by dynamic CEUS. CEUS was performed by one experienced examiner after i.v.-injection of max. 2.4 ml sulphurhexaflouride microbubbles saving digital DICOM cine loops (up to 25 s) and images. PA were evaluated during arterial, venous and late phase (up to 3 min.) for perfusion characterization. A retrospective, blinded VueBox® perfusion analysis of arterial phase of 28/42 PA was performed by a second, independent examiner placing 3 ROIs manually in the PA (center, rim of PA, surrounding thyroid gland tissue) to objectify findings. US findings were correlated to postoperative histology after PA resection. RESULTS: Out of 42 patients with PA findings in CEUS, perfusion analysis could be performed in 28/42 cases only as some CEUS cine loops had too much moving. In three cases the second examiner could not detect PA retrospectively, in 25 cases PA were characterized correctly resulting in a sensitivity rate of 89.3 %. VueBox® perfusion analysis confirmed that PA present a persisting hypervascularization of the rim with higher TTP (mean 7.93 s centrally, 8.36 s rim-sided), mTT (mean 56.6 s centrally, 64.5 s rim-sided) and lower PE (mean 10542.93 rm2 centrally, 8909.21 rm2 rim-sided) peripherally followed by a central wash-out during later phases. RT was comparable in all defined regions. CONCLUSION: VueBox® analysis of parathyroid gland CEUS examinations seemed to be a valuable tool for quantification of a PA's perfusion and can help to detect and localize hyperfunctional parathyroid glands prior to surgery.


Assuntos
Adenoma/diagnóstico por imagem , Meios de Contraste/uso terapêutico , Hiperparatireoidismo Primário/diagnóstico por imagem , Glândulas Paratireoides/diagnóstico por imagem , Neoplasias das Paratireoides/diagnóstico por imagem , Ultrassonografia/métodos , Adenoma/diagnóstico , Adenoma/patologia , Adulto , Idoso , Meios de Contraste/farmacologia , Feminino , Humanos , Hiperparatireoidismo Primário/patologia , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/patologia , Neoplasias das Paratireoides/diagnóstico , Neoplasias das Paratireoides/patologia , Estudos Retrospectivos
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