Search results for "VITRO"

The short-circuited everted sac of rat colon mucosa.

1981

A short-circuited preparation of everted rat colon sacs is described. The serosal current electrode is a AgAgCl wire. A cylindrical agar bridge or AgAgCl electrode may be employed on the mucosal side. Effects of Ag+ ions liberated from the electrodes on ion transport could not be demonstrated. Fluid and sodium are absorbed and bicarbonate secreted. Potassium and chloride movements are not significantly different from zero. The preparation remains stable for at least 2 h. Sodium absorption is diminished by 50% and bicarbonate secretion abolished in the absence of glucose. In principle, similar ion transport properties were found as in Ussing-chamber preparations. The advantage of the everted…

Unraveling the extracellular matrix-tumor cell interactions to aid better targeted therapies for neuroblastoma

2021

Treatment in children with high-risk neuroblastoma remains largely unsuccessful due to the development of metastases and drug resistance. The biological complexity of these tumors and their microenvironment represent one of the many challenges to face. Matrix glycoproteins such as vitronectin act as bridge elements between extracellular matrix and tumor cells and can promote tumor cell spreading. In this study, we established through a clinical cohort and preclinical models that the interaction of vitronectin and its ligands, such as αv integrins, are related to the stiffness of the extracellular matrix in high-risk neuroblastoma. These marked alterations found in the matrix led us to speci…

Synergistic effect of recombinant CD4-immunoglobulin in combination with azidothymidine, dideoxyinosine and 0.5 beta-monoclonal antibody on human imm…

1994

Data are presented which indicate that combinations of rCD4 immunoglobulin with azidothymidine, dideoxyinosine or 0.5 beta mouse monoclonal antibodies directed against the V3 region of HIV-1, were more effective in treatment of acute HIV infection in vitro than each compound alone. It is suggested that combination therapy with these compounds is more beneficial in treatment of HIV-infected patients than monotherapy, especially with respect to a reduction of the known side effects and the formation of resistant HIV strains after treatment with nucleoside analogues.

Accuracy and the role of experience in dynamic computer guided dental implant surgery: an in-vitro study

2019

Background To compare the accuracy of implant placement using the conventional freehand method and a dynamic navigation system; to assess the role of the surgeon’s experience in implant placement using these two methods. Material and Methods A randomized in-vitrostudy was conducted. Six resin mandible models and 36 implants were used. Two researchers with differing clinical experience (novice and experienced) placed implants using either the Navident dynamic navigation system (navigation group) or the conventional freehand method (freehand group). Accuracy was measured by overlaying the real position in the postoperative CBCT on the virtual presurgical placement of the implant in a CBCT ima…

Comparative Analysis of the Vascular Actions of Diterpenes Isolated from Euphorbia canariensis

1998

Abstract We have analysed the effects of 2,3-diepiingol 7,12-diacetate-8-isobutyrate (compound 1), ingenol-3-angelate-17-benzoate (compound 2), ingenol-3-angelate-17-benzoate-20-acetate (compound 3) and 3,5,7,8,9,15-hexahydroxyjatropha-6(17),11-dien-14-one-5,8-bis(2-methylbutyrate)-7-(2-methylpropionate) (compound 4), four diterpenes isolated from E. canariensis, on the isometric tension developed by isolated rabbit basilar and carotid arteries. Concentration-response curves to these compounds were obtained cumulatively in both arteries at resting tension and active tone (KCl, 50 mM). At resting tension a concentration-dependent contraction was induced by the four compounds. In the basilar …

Intraluminal Doppler-Sonography: Analysis and “in Vitro Test” of a New Device

1992

In treating patients with coronary heart disease it’ s necessary first to determine what influence the stenose has on the coronary blood flow. This is a prerequisite for any invasive treatment method. Coronary angiography explosures are only partially useful in attaining a functional evaluation of the haemodynamic stenoses.

Validación de Procedimientos Poblacionales mediante Convolución para el Establecimiento de Correlaciones In Vitro-In Vivo

2018

Para desarrollar medicamentos que sean efectivos y seguros es necesario conocer su comportamiento tanto in vitro como in vivo. Uno de los desafíos en la investigación biofarmacéutica es correlacionar la información de liberación in vitro de un fármaco con los perfiles plasmáticos in vivo. Por lo tanto, durante los últimos años se ha incrementado el uso de modelos matemáticos que sean capaces de predecir el comportamiento in vivo de un fármaco a través de los datos de disolución in vitro, es decir, correlaciones in vitro - in vivo (IVIVC). Las IVIVC pueden acortar la duración del desarrollo de los medicamentos, así como reducir el gasto y mejorar la calidad del producto. El principal objetiv…

“La conservazione ex situ dei fruttiferi mediante coltura in vitro: applicazione della crescita rallentata e della crioconservazione al nocciolo e al…

2014

Application of Cell Culture for the Production of Bioactive Compounds from Sponges:  Synthesis of Avarol by Primmorphs from Dysidea avara

2000

Among all metazoan phyla, sponges are known to produce the largest number of bioactive compounds. However, until now, only one compound, arabinofuranosyladenine, has been approved for application in humans. One major obstacle is the limited availability of larger quantities of defined sponge starting material. Recently, we introduced the in vitro culture of primmorphs from Suberites domuncula, which contain proliferating cells. Now we have established the primmorph culture also from the marine sponge Dysidea avara and demonstrate that this special form of sponge cell aggregates produces avarol, a sesquiterpenoid hydroquinone, known to display strong cytostatic activity especially against ma…

Effects of phorbol 12,13-diacetate on human isolated bronchus

2000

Protein kinase C appears to be involved in the regulation of airway contractility. Phorbol 12,13-diacetate (PDA; 0.01-10 microM), a protein kinase C activator, produced a transient relaxation followed by a sustained contraction of human isolated bronchus. Different protein kinase C inhibitors (calphostin C, staurosporine and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine) (H-7), nifedipine (NIF; 1 microM) or incubation with Ca(2+)-free medium, inhibited the spasmogenic response to phorbol, while ouabain (10 microM) suppressed only the initial relaxation. These results indicate that the initial relaxation, in response to PDA, is related to the activation of Na(+)/K(+)-ATPase, while the ensuin…