Blood vessels surrounded by connective tissue (perivascular space) in the brain of Lepidosteus (Ganoidei) and some teleost fishes

1974 ◽  
Vol 153 (4) ◽  
Author(s):  
G. Merker ◽  
A. Oksche ◽  
H.O. Hofer
Neurographics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 186-188
Author(s):  
I. Page ◽  
D.J.T. McArdle ◽  
F. Gaillard

Dilated perivascular spaces in the brain have typical neuroimaging appearances. The classification of dilated perivascular spaces is based on their relationship to blood vessels and is divided into 3 subtypes. A fourth type has been described and termed “opercular perivascular space.” We report on an incidental finding of an opercular perivascular space on MR imaging. Dilated perivascular spaces are benign; it is important to be familiar with their characteristic appearance to prevent reporting them as a neoplasm.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lori A. Ray ◽  
Martin Pike ◽  
Matthew Simon ◽  
Jeffrey J. Iliff ◽  
Jeffrey J. Heys

Abstract Background Understanding molecular transport in the brain is critical to care and prevention of neurological disease and injury. A key question is whether transport occurs primarily by diffusion, or also by convection or dispersion. Dynamic contrast-enhanced (DCE-MRI) experiments have long reported solute transport in the brain that appears to be faster than diffusion alone, but this transport rate has not been quantified to a physically relevant value that can be compared to known diffusive rates of tracers. Methods In this work, DCE-MRI experimental data is analyzed using subject-specific finite-element models to quantify transport in different anatomical regions across the whole mouse brain. The set of regional effective diffusivities ($$D_{eff}$$ D eff ), a transport parameter combining all mechanisms of transport, that best represent the experimental data are determined and compared to apparent diffusivity ($$D_{app}$$ D app ), the known rate of diffusion through brain tissue, to draw conclusions about dominant transport mechanisms in each region. Results In the perivascular regions of major arteries, $$D_{eff}$$ D eff for gadoteridol (550 Da) was over 10,000 times greater than $$D_{app}$$ D app . In the brain tissue, constituting interstitial space and the perivascular space of smaller blood vessels, $$D_{eff}$$ D eff was 10–25 times greater than $$D_{app}$$ D app . Conclusions The analysis concludes that convection is present throughout the brain. Convection is dominant in the perivascular space of major surface and branching arteries (Pe > 1000) and significant to large molecules (> 1 kDa) in the combined interstitial space and perivascular space of smaller vessels (not resolved by DCE-MRI). Importantly, this work supports perivascular convection along penetrating blood vessels.


2021 ◽  
pp. 86-89

Perivascular spaces; also known as the Virchow-Robin Spaces, they are pleurally lined, interstitial fluid-filled areas that surround certain blood vessels in various organs, especially the perforating arteries in the brain, with an immunological function. Dilated perivascular spaces are divided into three types. The first of these is on the lenticulostriate artery, the second is in the cortex following the path of the medullary artery, and the third is in the midbrain. Perivascular spaces can be detected as areas of dilatation on MR images. Although a limited number of perivascular spaces can be seen in a normal brain, the increase in the number of these spaces has been associated with the incidence of various neurodegenerative diseases. Different theories have been suggested about the tendency of the perivascular spaces to expand. Current theories include mechanical trauma due to cerebrospinal fluid pulsing, elongation of penetrating blood vessels, unusual vascular permeability, and increased fluid exudation. In addition, the brain tissue atrophy that occurs with aging; It is thought to contribute to the widening of perivascular spaces by causing shrinkage of arteries, altered arterial wall permeability, obstruction of lymphatic drainage pathways and vascular demyelination. It is assumed that the clinical significance of the dilation tendencies of the perivascular spaces is based on shape change rather than size. These spaces have been mostly observed in brain regions such as corpus callosum, cingulate gyrus, dentate nucleus, substantia nigra and various arterial basins including lenticulostriate artery and mesencephalothalamic artery. In conclusion, when sections are taken on MR imaging, it is possible that perivascular spaces may be confused with microvascular diseases and some neurodegenerative changes. In addition, perivascular spaces can be seen without pathological significance. Therefore, it would be appropriate to investigate the etiological relationship by evaluating the radiological findings and clinical picture together.


1870 ◽  
Vol 16 (73) ◽  
pp. 52-58
Author(s):  
J. T. Sabben

In publishing the following cases, recently under my charge, of mental derangement dependent upon atheromatous deposit in the coats of the larger cerebral arteries, without any apparent disease of the brain substance, I desire, if possible, to define the symptoms of that condition during life, so as to enable them to be distinguished from those of general paralysis, with which I believe them often to be confused.


1969 ◽  
Vol 6 (2) ◽  
pp. 135-145 ◽  
Author(s):  
D. F. Brobst ◽  
G. C. Dulac

Fibromatous tumors were induced in the meninges of calves by inoculating the meninges with a suspension of bovine cutaneous papillomas or by implanting bovine cutaneous papillomas into the brain. Meningeal tumors were observed to occur as early as 20 days after inoculation. Meningeal tumors from calves killed 90 and 145 days after inoculation extended into the brain along the course of blood vessels. Metastasis, however, was not observed. Evidence that the induced meningeal tumors contained viral antigen was lacking.


In Vivo ◽  
2021 ◽  
Vol 35 (1) ◽  
pp. 313-317
Author(s):  
SATOSHI YOKOSE ◽  
YUKA KATO ◽  
KATSUTOSHI MATSUMOTO ◽  
PERRY R. KLOKKEVOLD ◽  
HENRY H. TAKEI ◽  
...  

2020 ◽  
Vol 9 (3) ◽  
pp. 64-71
Author(s):  
N. N. Shevlyuk ◽  
L. V. Khalikova ◽  
A. A. Khalikov

The aim of the study was to establish morphofunctional and immunohistochemical characteristics of large omentum in women with ovarian cancer.Material and methods. The large omenta of 48 women with ovarian cancer (low-grade differentiated seropapillary adenocarcinoma of high-grade malignancy) of II stage (n=20) and III stage (n=28) were studied. Histological sections were stained with overview histological and immunohistochemical methods (to reveal ki67, P53, CD34, CD7, CD4, CD8, CD61 proteins expression). Results. In patients, the size of the large omentum was characterized by high individual variability; in the presence of metastasis, the size of the omentum was reduced. Intensive development of blood vessels in the organ was noted, but in the presence of metastases stasis of blood corpuscles, leucocytic infiltration, and moderate edema of connective tissue were observed in the organ’s vessels. Areas of lymphoid tissue, both small lymphatic follicles and diffusely located lymphoid tissue, were revealed in the omentum. In most follicles, reactive centers were not marked, and the number of follicles was reduced in the presence of metastases in the omentum. The analysis of CD34+ cells distribution showed that they were identified both in the tumor and in the areas of the omentum adjacent to the tumor, which indicates a pronounced angiogenesis. An irregular distribution of CD7+ and CD8+ and CD4+ cells was revealed in the tumor tissues, as well as in the surroundings. Simultaneously with the expression of P53 protein, ki67 protein expression is revealed in the significant number of tumor cells (including endothelial cells of tumor blood vessels). The proportion of ki67+ cells in the tumor cell population was 60.1±3.3%. The presence of a large number of ki67+cells in the presence of P53 protein expression in them indicates the aggressiveness of the tumor, as well as a disturbance of apoptosis regulatory mechanisms in the cells. Ki67 expression was low in the omentum areas unaffected by metastases, and it was revealed in the certain areas of connective tissue in fibroblastic programmed differentiation cells. Conclusion. The results obtained indicate significant plasticity and reactivity of great omentum in the presence of tumor process in the body and confirm the important role of great omentum in protective reactions.


1941 ◽  
Vol 73 (1) ◽  
pp. 85-108 ◽  
Author(s):  
Philip D. McMaster

Minute amounts of Locke's or Tyrode's solution have been brought into contact with the interstitial connective tissue of the skin of the living mouse, at atmospheric pressure, in such a manner that the blood or lymphatic vessels are not entered directly. Under such circumstances these absorbable fluids enter the tissue spontaneously. Entrance is strikingly intermittent, not continuous, and so too when very slight pressures are brought to bear on the fluids (1). Hyperemia of the tissues, with accompanying dilatation of the blood vessels, increases the entrance of fluids at atmospheric pressure but it is still intermittent. By contrast, venous obstruction leads to intermittent backflow into the apparatus, but reflex hyperemia, following release of the obstruction, is attended by an increase of flow into the tissues in spite of the great reactive dilatation of vessels. The inflow is also intermittent. If the skin is deprived of circulation, fluid does not enter it at all at atmospheric pressure, though it moves in regularly and continuously if slight pressure is put upon it. Edema-forming fluids, described in the text, also enter in a continuous manner when forced into the skin of either living or dead animals. So too do serum and sperm oil. The findings indicate that the passage of interstitial fluid into the blood vessels may be intermittent under normal circumstances and its escape from them as well. The observed occurrence of intermittent flow in the blood vessels of several tissues (9, 15–25) will go far to account for the intermittent entrance of fluid into the skin.


1942 ◽  
Vol s2-83 (331) ◽  
pp. 299-316
Author(s):  
T. KERR

1. A general description is given of the pituitary of the perch (Perca fluviatilis L.), and histological details of its various parts. The subdivisions of the glandular component are confluent with each other but distinguished by their different cell types. The nervous lobe makes contact with all three of the subdivisions, but is separated from them by a layer of connective tissue, incomplete in particular areas. 2. The anterior glandular region (anterior lobe) has an anterior chromophil and a posterior chromophobe zone. The middle glandular region (transitional lobe) possesses brightly staining acidophils and basophils as well as chromophobes. The acidophils form a dorsal sheet, deeply indented by processes of the nervous lobe, the basophils lie ventrally and posteriorly, and chromophobes are common towards the extremities of the indentations. The posterior glandular region (intermediate lobe) is elaborately penetrated by nervous lobe processes; the cells are small and consist of amphiphils, dull basophils, and occasional dull acidophils. The possible homologies of these regions to the lobes of higher types are discussed. The nervous lobe is of loose glial tissue with many nuclei and blood vessels and some reticular and collagenous fibres. 3. Strongly acidophil spheres of various sizes and in various numbers occur in the middle glandular region. They originate in ‘sphere cells’ resembling eosinophil leucocytes and after enlarging become free in the tissues of the region. Later they appear to pass into the posterior processes of the nervous lobe to be the larger bodies of the Herring material. Finally these larger elements appear to break down to form a fine granulation, whose further fate could not be followed.


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