Intraorganic venous bed of the stomach cardia in children during the first 3 years of life

The intraorganic venous bed of the gastric cardial part has been studied in 27 organs, obtained from children corpses of both sex beginning from birth up to three years of life. They died from causes that were not connected with gastric or vascular system pathology. The results of the investigation prove the presence of mucous, submucous, muscular and serous-subserous venous plexuses in the wall of the gastric cardial part in children of the first three years of life. Every membrane of the stomach wall has its specific structure of the venous link in the microcirculatory bed. In the stomach mucous membrane already in a newborn there are complexly built microcirculatory pathways. Age changes are mostly expressed in the venous link of the gastric mucous membrane; this is probably connected with functional activity of the given layer of the organ. The largest venous vessels are situated in the gastric submucous base. By the end of the newborn period and, especially fully, during the successive age periods immune protection of the gastric wall is formed as an accumulation of lymphoid tissue to an antigenic effect of food. In these age groups certain structural mechanisms of blood outflow from the gastric wall appear.     

Microcirculatory pathways in normal human spleen, demonstrated by scanning electron microscopy of corrosion casts

Confusion regarding microcirculatory pathways in normal human spleen has arisen due to extrapolation from pathological material and from other mammalian spleens, not to mention difficulties in tracing intricate three-dimensional routes from the study of thin sections or cut surfaces of tissue. We examined microcirculatory pathways in normal human spleens freshly obtained from organ transplant donors. A modified corrosion casting procedure was used to obtain an open view of vessels and their connections. Our results demonstrate: 1) "arteriolar-capillary bundles" within lymphatic nodules and extensive branching of arterioles in the marginal zone (MZ); 2) the marginal sinus around lymphatic nodules; 3) the peri-marginal cavernous sinus (PMCS) outside the MZ or immediately adjacent to the nodule itself; the PMCS receives flow via ellipsoid sheaths and MZ, or directly from arterial capillaries, and drains into venous sinuses; 4) fast pathways for flow into venous sinuses via ellipsoid sheaths; 5) arterial capillary terminations in the reticular meshwork of the red pulp or MZ ("open" circulation); direct connections to venous sinuses also occur ("closed" circulation), although rarely; and 6) numerous open-ended venous sinuses in the MZ, allowing a large proportion of the splenic inflow to bypass the red cell filtration sites in the reticular meshwork and at venous sinus walls.     

Structure of the venous and lymphatic beds of the heart and their alteration in experimental pathology

The investigation performed has demonstrated that under a great deal of coronary, pulmonary and other organs' disorders, in the venous and lymphatic beds of the heart compensatory-adaptive and pathological changes occur. The earliest and deepest changes are noted in the microcirculatory bed. Most of morphological signs on vascular reconstruction are not specific and are observed at different kinds of clinical and experimental pathology. Changes in venous and lymphatic vessels of pathological conditions& do not only result from damage in the organ's wall or hemodynamical changes in the cavities of the cardiac vessels but they themselves can cause some disturbances in the miocardial microcirculation intensifying its hypoxia, congestive symptoms and enhancing the development of decompensation in the organ.     

MIcrocirculatory bed of various internal organs in modeling of the inter-atrial shunt

At modelling a congenital heart failure--defect of the interatrial septum during late stages of the experiment, dilatation of the pulmonary artery and certain changes in the microcirculatory bed of the lungs, oesophagus, stomach and colon are observed. It has been demonstrated histologically and morphometrically that in adaptive reactions of the blood bed an important role belongs to the arteriolar part and metabolic link of the microcirculatory bed of the organs investigated. The changes in the pulmonary vessels are insufficiently expressed and possibility of hypertension in the lesser circulation is not great.     

Venous stasis and state of the microcirculatory bed in the synovial membranes]

Microcirculatory bed of the synovial membranes was investigated in experiments on dogs during venous stasis. Ligation of the femoral vein and circulatory disturbances led to the alteration of the microcirculatory bed of the synovial membranes, to the overfilling of the venules. Capillary walls became thinner and there developed swellings and protrusions. The extent of the vascular wall changes depended on the calibre of the vessels. One month after the ligation of the vein congestive phenomena in the tissue of the joint capsule proved to decline. This indicated development of collateral venous circulation.     

Morphofunctional adjustments in the microvasculature of the conjunctiva of the human eye at different stages of the postnatal period of ontogenesis

By means of the biomicroscopy method under vital conditions, conjunctival microvessels in the eyeball have been investigated in 240 healthy boys 7-17 years of age at the state of rest and at the antiorthostatic action. The rearrangement of the conjunctival microcirculatory bed of the eyeball completes on the whole by 13-14 years of age and is characterized by transition from diffuse to a more refulate structure (the number of the main magistrals lessens, they become larger, the number of capillaries functioning simultaneously decreases, the role of the shunting blood stream becomes more important). With this process in ontogenesis, certain changes in reactivity of microvessels are connected. The quickest and the most adequate responses of the microvessels appear in the development by the time when the definitive composition of the conjunctival microcirculatory bed in the eyeball is formed. Since that time the microcirculatory system reaches its optimal level of functioning and all the processes are performed in the most economic regimen.     

VEGF, VEGFR-1 and VEGFR-2 immunoreactivity in the porcine arteries of vascular subovarian plexus (VSP) during the estrous cycle

Abstract: Vascular endothelial growth factor (VEGF) is an important angiogenic factor in the female reproductive tract. It binds to cell surface through ligand-stimulatable tyrosine kinase receptors, the most important being VEGFR-1 (flt-1) and VEGFR-2 (flk-1). The broad ligament of the uterus is a dynamic organ consisting of specialized complexes of blood vessels connected functionally to the uterus, oviduct and ovary. Endothelial cells form an inner coating of the vessel walls and thus they stay under the influence of various modulators circulating in blood including ovarian steriods involved in developmental changes in the female reproductive system. The aim of the present study was to immunolocalize VEGF and its two receptors: VEGFR-1 and VEGFR-2 in the broad ligament of the uterus in the area of vascular subovarian plexus during different phases of the estrous cycle in pig and to determine the correlation between immunoreactivity of the investigated factors and phases of the estrous cycle. The study was performed on cryostat sections of vascular subovarian plexus stained immunohistochemically by ABC method. Specific polyclonal antibodies: anti-VEGF, anti-VEGFR-1 and anti-VEGFR-2 were used. Data were subjected to one-way analysis of variance. Our study revealed the presence of VEGF and its receptors in endothelial and smooth muscle cells of VSP arteries. All agents displayed phase-related differences in immunoreactivity suggesting the modulatory effect of VEGF, VEGFR-1 and VEGFR-2 on the arteries of the VSP in the porcine broad ligament of the uterus.     

Results and prospects for the study of the morphologic basis of microcirculation of the blood

The survey of the works, performed during the 11th five-year period in studying general biological regularities of microcirculation, demonstrates certain success in investigations developed in the following directions: functional geometry of the hemo-microcirculatory bed; elaboration of quantitative and qualitative analysis methods of the microcirculatory system elements; functional morphology of the vascular endothelium; experimental analysis of adaptive mechanisms of the microcirculatory bed; clinical-morphological investigations of microcirculation. Formation of structural-functional units, ensuring specialization of microcirculation in organs, forms the base of the functional geometry of the microcirculatory bed. This makes necessary conditions for compartmentalization of some micro-region in an organ and spatial distribution of various liquid media in dependence of certain topology of microvessels. The most perspective ways in development of morphological investigations, concerning the general biological regularities of microcirculation, are discussed.     

The dynamics of morphofunctional changes in the microcirculation of the pelvic extremity after modeling the chief stages of its replantation]

Under study was the effect of autotransplantation in its "pure form" upon the morpho-functional reconstruction and structural mechanisms of adaptation of the blood and lymphatic links of the microcirculatory bed of extremities during early postoperation period up to 10 days. The pathophysiological state of the extremity sufficiently close to its autotransplantation was obtained by means of circular transection of soft tissues of the medial third of the femur together with the nerves and deep collecting lymphatic vessels. It was found that after modeling the main stages of replantation in the fascia and periosteum of the operated extremity there developed a spasm of the arteriolar link and dilatation of the venular and lymphatic links of the microcirculatory bed. The areas of leukocytic infiltration with the phenomena of diapedesis and microhemorrhages were revealed along the course of postcapillaries and venules in the paravasal connective tissue. The amount of functioning arteriole-venular anastomoses was increased. Against the background of pronounced oedema of soft tissues of the operated extremity the venous pressure increased and the rate of the capillary bloodflow in the skin and muscles decreased. The above changes tend to be reduced by the 10th day after modelling the main stages of replantation of the extremity.     

Morphofunctional characteristics of microcirculation in the skin of girls 5-17 years of age

In 261 girls year-to-year morphofunctional transformations of spatial composition of the skin microcirculatory bed have been studied at rest and after a dynamic local load. By means of biomicroscopy main regularities in development of the skin capillary network have been revealed in the nail torus in the postnatal ontogenesis. Formation of the microvessels reactivity during various age periods and maturation of mechanisms of the compensatory-adaptive reactions are connected with formation of the definitive composition of the microcirculatory bed, that in girls corresponds to 11-12 years. Qualitative transformations in the skin capillary network bring certain quantitative changes in the structural microcirculatory parameters--increasing diameter of microvessels and increasing density of functioning capillaries.     

The lymphatic bed of the liver in man and animal and its transformation in disordered bile outflow

The lymphatic bed has been studied in 141 hepatic preparations of the man, dog and white rat. Development of obturation in the common bile duct in the man and at modelling a similar process in the animals results in essential morphological adaptive-compensatory and destructive changes in the hepatic lymphatic bed. The adaptive-compensatory reconstruction is especially well seen at initial stages of the disease. It is manifested as a total dilatation of the bed, certain reserve elements get into work, the bed capacity increases. Then certain new structural units of the bed, collateral pathways develop. When the obturational process lasts long, certain destructive changes of the hepatic lymphatic bed elements take place. The change in the relief of endotheliocytes is their most characteristic sign. With increasing age of the patients the degree of the destructive rearrangements of the hepatic lymphatic bed increases. In the experiment carried out on the animals the lymphatic outflow from the thoracic duct is determined, being an indirect index of the hepatic lymph-forming function. An essential increase of the lymph volume, several times greater than in the control, gets from the duct into the venous bed. A connection is revealed between the morphological transformations of the bed components and its drainage function. The lymphatic bed of the liver performs also an active work concerning resorption and transport of bilirubin, its content in the organ rather increases, when the common bile duct is obturated.     

Lymphatic bed of layers of the abdominal wall in the human inguinal area]

Lymphatic bed in the layers of the inguinal area was studied in connection with age in 70 human corpses. Polychromic injection of arteries, veins and lymphatic bed, staining of preparations after van Gieson, Weigert, with hematoxylin-eosin and morphometry were the methods applied. It was stated that lymphatic capillaries penetrate through all the layers forming the abdominal wall of the human inguinal area; they arrange interconnected networks in dermis, in external and internal oblique and transversal muscles and in their aponeuroses, as well as in fasciae and in the peritoneum. The lymphatic bed in question changes during ontogenesis. Age transformations of the lymphatic capillaries are in connection with functional loading on the anterior abdominal wall. Intraorganic connections existing between the lymphatic vessels of the anterior abdominal wall and the organs of the small pelvis (urinary bladder, uterus, rectum, etc.) are revealed, they are of a rather great interest for physicians.     

Structural changes and hemodynamic relations in the microcirculatory bed of the mesentery of the white rat during the period of sexual maturation

Structural changes and hemodynamic relations have been studied in the microcirculatory bed of the white rat small intestine mesentery during sex maturation (from the 3d up to the 10th week of the postnatal development). All calculations are performed regarding the mesenteric segment limited with two intestinal arteries, which is considered as an elementary microvascular module. Complication of the microcirculatory bed construction takes place at the expense of increasing number (nearly five-fold) of microvessels in the segment and increase of the capillary network density. The hemodynamic factor plays a certain role for stimulating the process of the capillary growth. The definitive structure of the mesenteric microcirculatory bed is completed by the 7th week. The main rearrangement of the microcirculatory system during the developmental process from a simple arterio-venular loop up to a complex microcirculatory bed with a branching capillary network is performed within the limits of the mesenteric segment.     

Morphological characteristics of nerves of the vascular plexuses in the lateral cerebral ventricles of human fetuses

The vascular plexus of the lateral ventricle of the human brain includes the microcirculatory bed responsible for the blood supply and liquor production of the organ. Blood capillaries form a thick parviansiform network of the plexus. Innervation of the vascular plexus of the cerebral lateral ventricle in human embryos and fetuses develops synchronously with formation of the plexus itself. The structural complexity of the nervous apparatus increases at the expense of increasing number of nervous fasciculi and single nervous fibers. By the time of birth the nervous apparatus of the plexus acquires a definitive character. After birth further improvement of the nervous apparatus takes place. The role of the microcirculatory bed and of the nervous apparatus of the vascular plexus in ensuring functional loadings and their participation in reactions to certain pathological effects is substantiated.     

Formation of the microcirculatory bed of the muscle coat of the wall of the sigmoid colon during human fetal development]

During intrauterine life microcirculatory bed of the muscular coat is forming and developing in accordance with its differentiation, growth and functional changes at various steps of its ontogenesis. This step-like differentiation in the parts composing the microcirculatory bed and the whole microcirculatory network of longitudinal and circulatory layers of the muscular coat is genetically connected with differentiation taking place in the wall of the sigmoid colon during the developmental period studied and, in the end, reflects morphological maturation of the sigmoid colon at different stages of its individual ontogenesis.     

Structural interrelations of the air-blood barrier and terminal sections of the lymphatic link in the pulmonary microcirculatory bed in chronic hypervolemia

The interalveolar septa of the human lungs are known to have no lymphatic capillaries. The topography of the pulmonary lymphatic system origin under conditions of chronic hypervolemia is still not investigated. Lungs of 24 corpses of persons, died from non-pulmonary pathology (control) and lungs of 34 corpses of persons, died from congenital and acquired heart disease accompanied with pre- and postcapillary forms of the pulmonary circulation hypertension, have been investigated. Decreased efficiency of the microcirculation, increased permeability of the blood capillary walls against the background of hypoxia result in an elevated production of lymph. Intensified collagen formation in the blood vessel walls and in the interalveolar septa is the prerequisite for reorganization of the pulmonary lymphatic bed. Lymphatic capillaries are found to grow into some sclerotic interalveolar septa and into deep structures of the blood capillary walls. This demonstrates a high plasticity of the lymphatic link terminal parts of the microcirculatory bed in pathologically changed lungs.     

Lymphatic bed of the main bronchi in normal human subjects and in venous stasis]

The lymphatic bed of the main human bronchi has been studied in normal conditions and at venous stagnation. Different methods both with injections and without injections have been applied. Definite regularities in changes occurring in the lymphatic bed of the main human bronchi at venous congestion have been stated. The changes occurring in the lymphatic bed of the mucous membrane of the main human bronchi seem to be a response to those metabolic processes which develop at decompensative heart diseases.     

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.     

Morphological analysis of transportation pathways of microspheres after their introduction into the uterine horn cavity in cyclic pigs

Countercurrent transfer is thought to be one of the most important mechanisms involved in the transfer of substances between the uterus and oviduct. The present study was aimed at recognizing other putative transportation pathways from the uterine cavity through the oviduct onto the surface of and into internal ovarian structures. Microspheres (latex beads, 0.8 m in diameter) were introduced into the uterine horn cavity of pigs, for 30 min, at various days of the estrous cycle. The transportation pathways of the beads were then analyzed by light and electron microscopy. The transport of microspheres through the oviduct canal into ovarian tissues took place on each day of the estrous cycle. The largest numbers of microspheres passed through the tunica albuginea to the corpora lutea. Some of microspheres also reached the surface of the uterine ligament through the oviduct canal, where they attained the lumen of blood and lymphatic vessels, mainly of the vascular subovarian (VSP) and paraovarian lymphatic plexus (PLP), via the lymphatic stomata pathway. Transport of microspheres also took place simultaneously through the uterine and oviduct walls and from particular organs through blood and lymphatic vessels. Although the present results do not exclude the participation of countercurrent transfer between venous, lymphatic, and arterial vessels, they provide morphological evidence for the presence of direct transportation pathways of substances, released into the uterine lumen, into ovarian tissues through the oviduct canal.