[A method for the topographic anatomical study of the fourth ventricle in relation to the structures of the cranial base and vault].
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Anatomy↗
Biomedical subjects
G F Dobrovol'skiĭ
Publications and source records attributed to G F Dobrovol'skiĭ.
[Ultrastructure of the cerebrospinal fluid-brain barrier of the cerebral ventricles and blood-brain barrier of the vascular plexus in experimental aseptic leptomeningitis].
The CSF-encephalic barrier of brain ventricles was examined at the submicroscopic level at different times of experimental aseptic leptomeningitis. In the acute period of the pathology, (3 to 7 days) the integrity of the bar was found to be disturbed because of acute inflammatory phenomena. In the subacute period (15 to 30 days), CSF hypertension was demonstrable. In the chronic period (90 days), the development of dystrophic and degenerative processes in the structures of the ependyma and vascular plexus were related to the disorders in CSF- and hemodynamics of the brain. Occlusion of the CSF tract was found to be associated with the impairment of the integrity of the blood- and CSF-encephalic barriers, marked edema end disintegration of the nerve tissue.
Acute Disease↗
[Arachnoid cysts (pathomorphological studies)].
Based on a macro- and microscopic analysis of the material of 2 section cases and 29 biopsies of persons operated on for arachnoidal cysts two types of cysts were distinguished: 1) arachnoidal cysts that occurred as a result of isolated congenital pathology of the leptomeninx; 2) cysts representing a manifestation of the combined developmental abnormality of the CNS occurring in the form of arachnoidal cysts coupled with intracerebral ones and with pathology of the adjacent cortical parts in the form of gross impairment of its architectonics and developmental abnormality of cerebral vessels.
Arachnoid↗
[The problem of the functional morphology of the cerebrospinal fluid circulatory system and its development in the works of M. A. Baron and his disciples].
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Central Nervous System↗
[Paravascular structures of the major arteries of the cerebral hemispheres (electron microscopy study)].
The ultrastructure of the paravasal formations of the magistral arteries in the brain hemispheres has been studied: the paravasal nerve trunks (components of the external nerve plexus of the arteries, running outside the adventitia and surrounded with liquor) and the artery-stabilizing constructions--strings in the human being and in the dog. The human para-arterial nerve trunks possess the vasa nervorum system, presented by blood capillaries situating at the border of endo- and perineurium, by powerfully developed perineurium, which includes into its composition a system of basal membranes and perineural cells. In the canine para-arterial nerve trunks these formation are absent. In the string composition there are collagenous-fibrillar base represented by tightly packed fasciculi of collagenous fibers, oriented in parallel to the long axis of the string, and by stellate cells. Both the paravasal nerve trunks and the strings are surrounded with flattened cells of the endothelial sheath. They are very much alike with the arachnoidendothelial cells lining the subarachnoidal space.
Animals↗
[Morphologic indices of the rat heart after colchicine application to the vagus nerve].
By means of the light optic and electron microscopic methods atrial ganglia, myocytes, vessels of the right cardiac chambers have been studied in rats 2 days--3 weeks after application of 100 mcg of colchicine on the right nervus vagus. Certain changes of the neural fibers have been described at the area of the application. In the myocardium the microcirculatory bed, focal edema and hypoxic alterations of the myocyte ultrastructure have been revealed. In the ventrical ganglia destruction of some terminals of the preganglionar fibers, chromatolysis and vacuolization of single neurocytes, as well as intraganglionar granule-containing cells have been found. The changes described take place for 7 days and they nearly completely disappear in 10 days. A suggestion is made that some phenomena, in particular, destruction of the preganglionar fibers and changes of the cardiac microcirculatory bed are connected with certain disturbances of the quick transport of substances in the nervus vagus fibers.
Animals↗
[Paracerebral barriers of the cerebral meninges].
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Animals↗
[M. A. Baron's concept of subarachnoid communications of the pia mater of the cerebral hemispheres].
In the pia mater of the human cerebral hemisphere certain specific structures named subarachnoid alveoli have been revealed. The best method for their revealing is the method of volumetric microscopy--tracheoscopy--but they can be detected in histological sections, as well. The subarachnoid alveoli are situated in the subarachnoid space between liquor canals. By their form they resemble honeycombs. Their walls have a carcass consisting of argyrophile and collagenous fibres to give the alveoli a definite form. The carcass is lined with arachnoid-endothelial cells. The alveoli are connected with the liquor canals by means of holes in the walls of the canals. The subarachnoid alveoli are connected with each other by means of holes in their walls. The arachnoid-endothelial cells of the subarachnoid alveoli are capable to accumulate colloid substances from the spinal liquor. The walls of the subarachnoid alveoli discharge macrophages into the lumen of the latter. Protective function of the subarachnoid alveoli system contributes to normalization of the spinal liquor composition both under normal and pathological conditions.
Adult↗
[Method of applying colchicine to the rat vagus nerve for the purpose of selective action on axonal transport].
A method of local application of colchicine deposited in a wax and paraffin alloy to the nerve is suggested. The doses of 25, 50, 75 and 100 micrograms were tested. Four days after application of 75 and 100 micrograms of colchicine, light microscopy demonstrated a non-uniform thickening of neurofibrils and the increase in their argyrophilic properties. Electron microscopy discovered the reduced number of microtubules, disordered arrangement of neurofilaments and accumulation of the latter ones beneath the neurolemma. The overall electric activity of the nerve was not disturbed. The method of colchicine application in vivo ensures the prolonged action of the drug without nerve compression or injury, thereby enabling one to assess consistently the sequels of the blockade of neurotrophic factors for metabolism of the innervated structures.
Animals↗
[Ultrastructure of the cerebral meninges].
Ultrastruct of the dog arachnoid membrane, pia (vascular) mater, internal layer of the dura mater, human arachnoid membrane, subarachnoid alveolar walls and canals transporting liquor into the subarachnoid space have been studied. From the literature analysed and from his own data the author considers the system of the meninges and intermeningeal spaces as a system of extracerebral barriers devided into 3 stdructural-functional groups: 1--barriers dealing with liquor outflow from the subarachnoid space into the blood stream (lgb-I lgb-II); 2--barriers dealing with metabolic processes between the liquor and the borderline tissues (lcb, lmb, lnb, etc.); 3--histo-haematic barriers between blood and tissue elements of the pia mater, dura mater and paravasal nerve trunks of the brain magistral arteries. Morphological substrates of some extracerebral barriers are described at a submicroscopical level.
Animals↗
[Role of the barrier system of the cerebral membranes in subarachnoid hemorrhage].
On the basis of literary and his own data the author distinguishes 3 stages of subarachnoidal hemorrhage, each having its own specific pathophysiological and pathomorphological features. The extracerebral barrier system can be divided into 3 structural and functional groups, such as: a) barriers between the cerebrospinal liquor and the blood; b) barriers between the liquor and the border tissues, and c) histohematic barriers. In the conditions of subarachnoidal hemorrhage accompanied with development of arterial spasm one observes disturbances of the liquor microcirculation because of blood clotting in the liquor and sticking of the blood clots in various parts of the subarachnoidal space, as well as changes in the ultrastructure of the morphological substrate of the extracerebral barrier system. All this, in the author's opinion, leads to damaging the innervation apparatus elements and smooth muscle cells of the cerebral arteries and arterioles; promotes the development of cerebral edema, etc. The data obtained make it possible to evaluate the role of the extracerebral barrier system of the meninges in cases of subarachnoidal hemorrhage with accompanying arterial spasm.
Animals↗
[Electron microscopic study of the process of the removal of autogenous blood erythocytes beyond the limits of the subdural space].
The internal plate of the dura mater and arachnoidea of the dob brain was studied by electron microscopy after introducing 0.3--0.5 ml of the autogenous blood into the subdural space. The arachnoidea of the excretory channels and structural elements of the internal plate of the dura mater (cells of the internal covering layer, the collagen fibril and microfibril layer, the wall of the blood capillaries of the internal capillary network) involve the morphological substratum of the liquor-blood barrier-I between the liquor and blood of the blood capillaries of the internal capillary network of the dura mater. It was established that red cells of the subdural space penetrate the thickness of the dura mater, where they concentrate around blood capillaries of the internal capillary network, rather than penetrate into the arachnoidea.
Animals↗
[Cerebrospinal fluid bearing channels of the pia meter].
The pia mater of the human brain hemispheres has liquor canals which form a continuous network communicating with the cisterns of the brain base. The wall of the liquor canals is formed by a fibro-collagenous framework covered from two sides with the arachnoidendothelium. In the canal walls there are openings, through which the lumens of the canals communicate with the lumens of alveoli. The liquor canals are divided into the circulatory and excretory ones. The circulatory canals are disposed in the depth of the cerebral sulci, the secretory canals--on the surface of the convolutions. The liquor moves along the circulatory canals from the cisterns of the brain base onto the surface of cerebral hemispheres. Excretory canals adjoin the arachnoid membrane which is part of its wall (the "roof"). In the "roof" of the liquor canals the fibrocollagenous basis and the number of layers of the arachnoid--endothelium are reduced, the intercellular spaces between the cells of the arachnoidendothelium are dilated. Through the roofs of the liquor canals the liquor is excreted from the subarachnoid space into the subdural space. Inside the liquor canals there are arteries of the pia mater hung up to the canal walls by trabeculae (cords) of a dense connective tissue.
Humans↗
[A fixation device for work with block preparations of the spine].
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Equipment Design↗
[Electron microscope study of the innervation of the large arteries of the base of the brain subsequent to subarachnoid hemorrhage, following aneurysmal rupture (a pathomorphologic and experimental study)].
The ultrastructure of the intraadventitial and paravasal nerve trunks of the superficial adventitial plexus in major vessels of the basis cerebri in man and in dogs under normal conditions and with a subarachnoidal hemorrhagic effusion was studied at the submucroscopic level. Unlike the ultrastructure of the intra-adventitial nerve trunks the paravasal ones, lying in the cerebrospinal fluid (CSF), have an endothelial sheath that substitutes the epineurium and also has a perineurium endowed with an abundantly developed system of basal membranes containing aplanated cells and bands of collagen fibrils. With a subarachnoidal hemorrhagic effusion was in evidence the disruption of the "CSF-neural barrier". The endothelial cells break" away and fall into the CSF, the basal membrane undergoes lysis, which, apparently, contributes to the penetration of various components of the subarachuoidally effused blood deep into the nerve trunks. This results in changes occurring in the ultrastructure of axones of the pulpous and, to a lesser extent,pulpousless nerve fibers.
Animals↗
[Neurinomas and neurofibromas of the jugular foramen: diagnosis and surgical treatment].
The paper analyzes the authors' experience in treating 16 patients with neurinomas and neurofibromas of the jugular foramen. A tumor was located intracranially (Type A) in 1 case, at the level of the base of the skull (Type B) in 7 cases, extracranially (type C) in 3 cases, and extra- and intracranially (Type D) in 5. All the patients were operated on. One-stage removal was performed in 15 patients, in 1 case a tumor was removed in 2 steps. By taking into account differences in the site of the tumors, the authors used the following accesses: retrosigmoid, supracondyllar, extreme lateral transcondylar, retroauricular transtemporal, extended retroauricular transtemporal, lateral cervical. While planning accesses, it is necessary to bear in mind not only the direction of growth of these tumors, but also the pathways of collateral venous blood flow.
Adolescent↗
[Prolonged spasm of the arteries of the base of the brain during experimental fibrinolysis in the subarachnoid space].
An ex tempore mixture of fibrinogen (1%--4 ml) and 0.2 ml thrombin solutions forming a compact clot of fibrin in the subarachnoid space was introduced into the cisterna magna of dogs. To dissolve the fibrin clot 2 ml of a fibrinolysin solution with an activity of 400 units were introduced into the same cisterna 10--15 minutes thereafter. A total of 26 experiments were set up, of which 13 were served as controls with separate introduction of the mixture ingredients. Through serial vertebral angiography with a 50 per cent urotrast solution it was found that following introduction of the fibrinogen and thrombin mixture the lumen of the basilar artery and of its branches contracts on the average up to 89.2 +/- 1 per cent. After introduction of fibrinolysis the diameter of the artery initially increases up to 116.3 +/- 2.5 per cent. In 3 hours time a pronounced spasm of the basilar artery and of its branches is seen to develop up to 80.9 +/- 3.6 per cent and after 24 hours -- up to 73.9 +/- 2.1 per cent. The spasm persists for up to 10 days, but its intensity gradually declines. During subsequent 11--18 days the diameter of the brain base arteries returns back to normal. In control experiments no development of protracted spasm was demonstrated. Hence, it is established that the appearance of fibrinolysis products formed in the spinal fluid consequent upon dissolution of a clot of fibrin containing no blood cells is attended by the development of a protracted spasm involving major arteries of the brain.
Animals↗
[Evaluation of disorders in the liquor circulation in craniocerebral trauma].
The modern methods of complex examinations of the brain in craniocerebral trauma are addressed and the possibilities of the topographic-and-anatomic substantiation in the forensic-medical (expert) evaluation of traumatic lesions of liquor-circulation structural elements are elucidated in the paper. Morphometry data characterizing the dislocation manifestations are presented with respect to the dislocation intensity and severity.
Adolescent↗