Matrix Protein Structural Analysis of Brain Aneurysms by Polarizing Microscopy

The wall of saccular brain aneurysms, lesions that develop at the fork regions of human brain arteries, is a layered multidirectional fabric of fibrous collagen. The wall tissue has the mechanical features of high elastic stiffness and a low tensile strength compared to adjacent arteries. Arterial blood pressure within the sac of an aneurysm stresses the wall in all tangential directions; thus an area of mechanical weakness may be characterized by an area lacking fibre strength, or an area with inadequately aligned fibres.The collagen fibres of the wall are birefringent, with many fibre types, similar to wound healing skin (types I, III, IV, V, VI) The known correlation between fibre birefringence and tissue strength for dermal wound healing3 provided the opportunity in this research to calculate strength maps to compare one lesion from another, and to make regional comparisons around a single lesion.

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Tissue-dependent expression of matrix proteins in human endothelin-1 transgenic mice

Clinical Science ◽

10.1042/cs103s039s ◽

2002 ◽

Vol 103 (s2002) ◽

pp. 39S-43S ◽

Cited By ~ 8

Author(s):

Anja SCHWARZ ◽

Michael GODES ◽

Christa THÖNE-REINEKE ◽

Franz THEURING ◽

Christian BAUER ◽

...

Keyword(s):

Blood Pressure ◽

Transgenic Mice ◽

Matrix Protein ◽

Collagen Type ◽

Matrix Proteins ◽

Collagen Type Iii ◽

Collagen Types ◽

Endothelin 1 ◽

Type Iii ◽

Arterial Blood

Endothelin-1 (ET-1) is a potent pro-fibrotic growth factor. However, little is known about its specific effects on the synthesis of matrix proteins in vivo. We used male 12-month-old ET-1 transgenic mice characterized by transgene expression in the kidney and (to a lesser extent) in the heart. Global cardiac and renal matrix protein synthesis was analysed after Sirius Red and periodate–Schiff staining. Specific expression of collagen types I, III and IV, laminin and fibronectin was examined using immunohistochemistry followed by computer-aided image analysis. Analysis of blood pressure revealed that mean arterial blood pressure was similar in ET-1 transgenic mice and controls. The total cardiac matrix protein content was increased in the myocardium of ET-1 transgenic mice. Analysis of specific cardiac matrix proteins showed increased cardiac expression of collagen type III (+211%; P<0.001) and laminin (+128%; P<0.01) in transgenic mice. The expression of collagen types I and IV and fibronectin was not altered. Global analysis of renal matrix proteins confirmed earlier studies showing pronounced interstitital fibrosis and glomerulosclerosis. Laminin expression was markedly increased in the glomerula (+152%; P<0.01) and even more so in the interstitium (+211%; P<0.001), whereas expression of collagen type III was reduced in glomerula (-48%; P<0.01) and interstitial tissue (-55%; P<0.01) of ET-1 transgenic mice. In conclusion, a primary overexpression of ET-1 does not cause uniformly enhanced synthesis of matrix proteins. In contrast, the effects of ET-1 on the matrix protein pattern is tissue-specific. The major renal and cardiac alterations in matrix proteins induced by ET-1 is a marked enhancement of laminin expression.

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Periodic Structure in the Matrix Protein of an Insect Virus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054121 ◽

1982 ◽

Vol 40 ◽

pp. 302-303

Author(s):

H.M. Mazzone ◽

W.F. Engler ◽

R. Zerillo ◽

G.F. Bahr

Keyword(s):

Inclusion Body ◽

Periodic Structure ◽

Matrix Protein ◽

Malacosoma Disstria ◽

Insect Virus ◽

Virus Particles ◽

The Matrix ◽

Nucleopolyhedrosis Virus

The nucleopolyhedrosis virus (NPV) of the forest tent cater - pillar (Malacosoma disstria Hubner) has been analyzed in our laboratories. As a representative of the Baculovirus class, the NPV has virus particles enclosed with in a proteinaceous structure, the inclusion body.

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Control of Autogenous Vein Grafts Prior to Reimplantation, By Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010009378x ◽

1972 ◽

Vol 30 ◽

pp. 106-107

Author(s):

John H. L. Watson ◽

John L. Swedo ◽

M. Vrandecic

Keyword(s):

Electron Microscopy ◽

Light And Electron Microscopy ◽

Physiological Saline ◽

Experimental Conditions ◽

Vein Grafts ◽

Arterial Blood ◽

Saphenous Veins ◽

Autogenous Vein ◽

Control Of Parameters ◽

Post Implantation

The ambient temperature and the nature of the storage fluids may well have significant effects upon the post-implantation behavior of venus autografts. A first step in the investigation of such effects is reported here. Experimental conditions have been set which approximate actual operating room procedures. Saphenous veins from dogs have been used as models in the experiments. After removal from the dogs the veins were kept for two hours under four different experimental conditions, viz at either 4°C or 23°C in either physiological saline or whole canine arterial blood. At the end of the two hours they were prepared for light and electron microscopy. Since no obvious changes or damage could be seen in the veins by light microscopy, even with the advantage of tissue specific stains, it was essential that the control of parameters for successful grafts be set by electron microscopy.

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Microvascular features that suggest effectors of blood-flow regulation in the brain: Evidence by SEM of corrosion casts of intracerebral vessels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158923 ◽

1990 ◽

Vol 48 (3) ◽

pp. 274-275

Author(s):

Enrico D.F. Motti ◽

Hans-Georg Imhof ◽

Gazi M. Yasargil

Keyword(s):

Blood Flow ◽

Perfusion Pressure ◽

Corrosion Casts ◽

Cerebral Microcirculation ◽

Pial Arteries ◽

Random Occurrence ◽

Brain Arteries ◽

Homogeneous Network ◽

The Brain

Physiologists have devoted most attention in the cerebrovascular tree to the arterial side of the circulation which has been subdivided in three levels: 1) major brain arteries which keep microcirculation constant despite changes in perfusion pressure; 2) pial arteries supposed to be effectors regulating microcirculation; 3) intracerebral arteries supposed to be deprived of active cerebral blood flow regulating devices.The morphological search for microvascular effectors in the cerebrovascular bed has been elusive. The opaque substance of the brain confines in vivo investigation to the superficial pial arteries. Most morphologists had to limit their observation to the random occurrence of a favorable site in the practically two-dimensional thickness of diaphanized histological sections. It is then not surprising most investigators of the cerebral microcirculation refer to an homogeneous network of microvessels interposed between arterioles and venules.We have taken advantage of the excellent depth of focus afforded by the scanning electron microscope (SEM) to investigate corrosion casts obtained injecting a range of experimental animals with a modified Batson's acrylic mixture.

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Morphometric analysis of peroxisomes in hepatocytes of alcohol-fed rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157486 ◽

1989 ◽

Vol 47 ◽

pp. 1100-1101

Author(s):

D.C. Dominguez ◽

J.T. Ellzey

Keyword(s):

Caloric Intake ◽

Volume Density ◽

Controlled Study ◽

Control Group ◽

Numerical Density ◽

Cacodylate Buffer ◽

Paired Control ◽

Experimental Group ◽

Liver Peroxisomes ◽

Single Lesion

Peroxisomes which participate in 1ipid metabolism have been shown to be altered in several metabolic disorders and toxic conditions. In alcoholic liver disease, the single lesion most frequently found is lipid accumu1ation in hepatocytes. However, the mechanisms for this 1ipid accumu1ation are not clear. The occurrence of modifications of liver peroxisomes due to excess alcohol consumption has not been subjected to a controlled study. We utilized a combination of cytochemica1 and morphometrictechniques to study the size and number of liver peroxisomes in rats fed an alcohol-supplemented diet compared to those of matched-paired control animals.Male Sprague-Daw1ey rats (400-500 g) received a liquid diet. The experimental group (N = 5/group) was fed a diet containing 30% ethanol-derived calories (EDC) and the control group was fed an isocaloric diet to 30% EDC. A pair feeding procedure was employed to control for caloric intake. Small pieces of liver randomly selected, were fixed in 2.3% -glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2, incubated in a DAB medium and postfixed with. 2% aqueous osmium tetroxide. EM photographs were taken from sections of 3 tissue blocks from each sample (7,200X) with a Zeiss EM10-A (60 kV). With the use of a point counting method and a digital planimeter the volume density (Vv) and numerical density (Nv) were determined.

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