Chronic murine myocarditis due to Trypanosoma cruzi: an ultrastructural study and immunochemical characterization of cardiac interstitial matrix

In an attempt to define the mouse-model for chronic Chagas' disease, a serological, histopathological and ultrastructural study as well as immunotyping of myocardium collagenic matrix were performed on Swiss mice, chronically infected with Trypanosoma cruzi strains: 21 SF and mambaí (Type II); PMN and Bolivia (Type III), spontaneously surviving after 154 to 468 days of infection. Haemagglutination and indirect immunofluorescence tests showed high titres of specific antibodies. The ultrastructural study disclosed the cellular constitution of the inflammatory infiltrate showing the predominance of monocytes, macrophages with intense phagocytic activity, fibroblasts, myofibroblasts and abundant collagen matrix suggesting the association of the inflammatory process with fibrogenesis in chronic chagasic cardiomyopathy. Artertolar and blood capillary alterations together with dissociation of cardiac cells from the capillary wall by edema and inflammation were related to ultrastructural lesions of myocardial cells. Rupture of parasitized cardiac myocells contribute to intensify the inflammatory process in focal areas. Collagen immunotyping showed the predominance of Types III and IV collagen. Collagen degradation and phagocytosis were present suggesting a reversibility of the fibrous process. The mouse model seems to be valuable in the study of the pathogenetic mechanisms in Chagas cardiomyopathy, providing that T. cruzi strains of low virulence and high pathogenecity are used.

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Structural and elemental characterization of heart cells grown in a collagen matrix

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156948 ◽

1989 ◽

Vol 47 ◽

pp. 992-993

Author(s):

A. LeFurgey ◽

L.A. Hawkey ◽

M.C. Carney ◽

P. Ingram ◽

M. Lieberman

Keyword(s):

Liquid Nitrogen ◽

Collagen Matrix ◽

Cardiac Cells ◽

Heart Cells ◽

Embryonic Chick ◽

Culture Dish ◽

Diffusion Limitations ◽

Freeze Dried ◽

Quick Freezing

Cultured embryonic chick heart cells have been utilized as a model system for characterization of various membrane transport mechanisms. One advantage of this system is that the cells may be grown with differing geometries to minimize diffusion limitations and to optimize the growth configuration for particular techniques, such as ion-selective microelectrode measurements, fluorescent dye indicators, patch clamp, etc. A spontaneously contracting strand of cells embedded in a collagen matrix has recently been developed for measurements of cytoplasmic free ions by nuclear magnetic resonance (NMR) spectroscopy. These same strands, which provide the large numbers of cells needed for NMR, can be subdivided into small fragments ideal for cryopreservation prior to electron probe X-ray microanalysis (EPXMA). The aims in this study were to characterize the ultrastructure of cardiac cells within the strand, to demonstrate the quality of preservation obtainable by quick freezing methods, and to quantitatively map with EPXMA the distribution of physiologically relevant elements in thin, freeze-dried cryosections of the cells.Cells were isolated by serial trypsinization of 11-day old embryonic chick hearts. Strands of cells approximately 100 cm in length and 0.2 mm in diameter were obtained by extrusion of a cell-collagen mixture through polyethylene tubing into media within a culture dish. Three to five millimeter segments of 1-day old strands which contracted spontaneously were preserved by rapid immersion in liquid nitrogen-cooled liquid propane at 〜-185°C and stored in liquid nitrogen prior to being (a) cryosectioned for subsequent EPXMA or (b) freeze-substituted for conventional transmission electron microscopy (CTEM). Segments of strands were also chemically preserved in 2.5% glutaraldehyde in 0.1 M sodium cacodylate and processed as above for comparative CTEM. Cryosections of the frozen strands were cut at <-140°C with a dry glass knife and placed directly onto pre-cooled, carbon-coated, 200 mesh, fine bar nickel grids with a precooled implement. The grids were transferred to a liquid nitrogen cooled copper well for freeze drying at 10‒3 Torr over 24 to 48 hours. Prior to EPXMA, the grids were coated with 〜1OOÅ carbon.

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Faculty Opinions recommendation of Characterization of a new mouse model of empyema and the mechanisms of pleural invasion by Streptococcus pneumoniae.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13369983.14740098 ◽

2011 ◽

Author(s):

Adam Hill ◽

James Chalmers

Keyword(s):

Streptococcus Pneumoniae ◽

Mouse Model ◽

Pleural Invasion

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Characterization of Neurofibromas of the Skin and Spinal Roots in a Mouse Model

10.21236/ada469173 ◽

2007 ◽

Author(s):

Yuan Zhu

Keyword(s):

Mouse Model ◽

Spinal Roots

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Characterization of Neurofibromas of the Skin and Spinal Roots in a Mouse Model

10.21236/ada482942 ◽

2008 ◽

Author(s):

Yuan Zhu

Keyword(s):

Mouse Model ◽

Spinal Roots

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Gelatin and Glycerine-Based Bioadhesive Vaginal Hydrogel

Current Drug Delivery ◽

10.2174/1567201817666200129130031 ◽

2020 ◽

Vol 17 (4) ◽

pp. 303-311

Author(s):

Roberta Cassano ◽

Federica Curcio ◽

Delia Mandracchia ◽

Adriana Trapani ◽

Sonia Trombino

Keyword(s):

Differential Scanning Calorimetry ◽

Inflammatory Process ◽

Vaginal Mucosa ◽

Vaginal Infection ◽

Scanning Calorimetry ◽

Time Intervals ◽

Site Specific ◽

Release Studies ◽

Hiv Seropositive

Aim: The work’s aim was the preparation and characterization of a hydrogel based on gelatin and glycerine, useful for site-specific release of benzydamine, an anti-inflammatory drug, able to attenuate the inflammatory process typical of the vaginal infection. Objective: The obtained hydrogel has been characterized by Electronic Scanning Microscopy (SEM) and Differential Scanning Calorimetry (DSC). In addition, due to the precursor properties, the hydrogel exhibits a relevant mucoadhesive activity. Methods: The swelling degree was evaluated at two different pHs and at defined time intervals. In particular, phosphate buffers were used at pH 6.6, in order to mimic the typical conditions of infectious diseases at the vaginal level, particularly for HIV-seropositive pregnant women, and pH 4.6, to simulate the physiological environment. Results: The obtained results revealed that the hydrogel swells up well at both pHs. Conclusion: Release studies conducted at both pathological and physiological pHs have shown that benzydamine is released at the level of the vaginal mucosa in a slow and gradual manner. These data support the hypothesis of the hydrogel use for the site-specific release of benzydamine in the vaginal mucosa.

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