Morphology of the microcirculatory bed of the vascular coat of the human eye]

Recently ophthalmologists got interested in microcirculatory bed of the choroid (the main collector of blood in the eye) because of the vascular layer was studied in 25 eyes of persons who had died suddenly and had no eye pathology during their lives. The age was from 11 to 70 years. V. V. Kuprianov's method of impregnation was used. Structural peculiarities of the choroid microcirculatory bed were presented; its changes were stated to depend on functional importance of the given segment of the eyeground and on the age of the patient. The data obtained could facilitate in studying different pathologic conditions in the eye in order to clarify the role of the choroid microcirculatory bed in genesis of ophthalmic diseases.     

Morphometric findings in the microcirculatory bed of the sigmoid serosa during the fetal period in man

During fetal life, formation and arrangement of the microcirculatory bed in the serous membrane of the sigmoid colon correspond to the growth and functioning of the latter at different stages of ontogenesis. Two periods in the development of the microcirculatory bed of the serous membrane of the sigmoid colon are revealed: the first period coincides with the first half of the fetal development when capillary growth is considerable, i.e. with the growth of metabolic part in the microcirculatory bed; the second period coincides with the second half of the fetal development when intensified growth of the sigmoid portion of the large intenstine and its transport sections in the microcirculatory bed (arterioles, precapillaries, postcapillaries, venules) are observed.     

Rearrangement of the microcirculatory bed of the skin pedicle flap during the development of complications]

Rearrangement of microcirculatory pathways in the skin was studied without injecting the vessels when the peduncles of a regular size and the peduncles with the ratio of their length to width as 5:1 were formed. In the first case, rearrangement of the microcirculatory bed was revealed to have an adaptive character. In the second case, continuously increasing gross morphological disorders resulting in venous congestion and contributing to necrosis of the peduncle were revealed.     

Innervation of the microcirculatory bed of the human trigeminal nerve]

The investigation of film preparations and histological sections of human trigeminal nerves impregnated with silver nitrate and treated after Gomori, Falck--Hillarp demonstrated a rich innervation in the intraneural blood vessels. The most various and complex interconnections of the neural structures were noted in arterioles and venules of the node capsule, epineurium and external layers of perineurium of the trigeminal nerve branches. On the vessel walls of these layers, neural plexus were revealed. Sensitive innervation of the neural blood vessels mainly performed by posvalent tissue-vascular receptors. In the walls of intraneural vessels, adrenergic and cholinergic neural plexus are revealed.     

The microcirculatory bed of the human heart

Using a complex approach in studying microcirculatory bed of the human heart, possibilities of scanning electron microscopy of corrosive preparations, those of silver nitrate impregnation after V. V. Kuprianov are demonstrated. The silver nitrate impregnation makes it possible to study the wall structure of the microcirculatory pathways, to analyse arrangement of nuclei in the endothelial and muscle cells of the microcirculatory links, to reveal together with the vessels the surrounding tissues. Scanograms of the corrosive preparations of the arterioles demonstrate "circulatory strips", that are absent in the venular part. The relief of the luminal casts of the microcirculatory bed vessels in the human heart is presented as impresses of nuclei of the endothelial and smooth muscle cells. Peculiarities in form and distribution of these nuclei in various links of the microbed are demonstrated.     

Morphofunctional characteristics of the microcirculatory bed of the human spinal dura mater]

Some morphofunctional peculiarities in microcirculatory pathways of the dura mater of the human spinal cord are described. They are concerned with the structure of arteriolo-venular anastomoses through which a rather large amount of arterial blood is transported into the venous bed. Around the vessels of arterial type running at an angle to the longitudinal axis of the vessel connective tissue fibres of the dura mater, there is a tissue layer intensively impregnated with silver salts and stained PAS-positively. The venous part of the dura mater microcirculatory pathways has a large number of accessory reservoirs in the form of venous "lakes". Functional importance of the peculiarities mentioned above for the dura mater and the perimedullar apparatus is clarified.     

Development of the lymphatic bed of the human esophageal wall]

The lymphatic capillaries are firstly determined in fetuses at the age of 3-4 months in the oesophagus submucous lamina. In fetuses of 5-6 months of age transition of the lymphatic capillaries from the submucous lamina into the mucous membrane proper is noted. In fetuses of 6 months of age perivascular lymphatic capillaries and vessels appear. They form peculiar paths around arterioles, venules, arterial branches and venous tributaries. The lymphatic bed of the oesophageal wall is rather well developed in mature fetuses and newborns. In adult and old persons a partial reduction of the lymphatic bed in the oesophageal wall is observed.     

The blood microcirculatory bed of the tunica muscularis of the human esophagus in postnatal ontogeny]

The analysis of morphological and morphometrical data of the muscular membrane and its blood microcirculatory bed has demonstrated that their development during the postnatal ontogenesis advances unevenly. An intensified growth and development of the muscular membrane morphological structures, including its blood microcirculatory bed occurs from 3 up to 30 years of life. Their maximal growth is noted from 12 up to 30 years of age. The stages of intensified development of the muscular membrane and its blood microcirculatory bed change into stages of retarded growth, where processes of involutive character preponderate. This is especially noticeable from 60 and more years of age. The stages noticed in the muscular membrane development and its blood microcirculatory bed are characterized both by general and topographical morphofunctional peculiarities specific for every stage of organogenesis.     

Expression of myosin light chains during fetal development of human skeletal muscle.

The expression of myosin light chains (MLCs) during the development of human skeletal muscle was investigated by using two different two-dimensional electrophoretic techniques. In both electrophoretic systems the predominant light chain 1 (LC1) expressed during the whole fetal period was found to co-migrate with the adult fast LC1 (LC1F). The main LC2 expressed during the whole fetal period was found to be different from the main fast LC2 (LC2F) and slow LC2 (LC2S) usually present in adult muscle, but co-migrated with a minor component often present in adult muscle. This fetal LC2 was phosphorylatable, and the phosphorylated form co-migrated with the main component of LC2F expressed in the adult. The adult fast LC3 appeared as early as week 20 of gestation, whereas the adult slow light chains (LC1S and LC2S) appeared only during the late fetal period. A minor component of LC1, previously described in humans as an 'embryonic LC' (LCemb.) [Strohman, Micou-Eastwood, Glass & Matsuda (1983) Science 221, 955-957], was only expressed in the early fetal period and was found to co-migrate with atrial LC1 (ALC1). We discuss the expression of these specific developmental forms of MLCs co-existing with immature myosin heavy chains during fetal life.     

Vascular anastomoses of the blood microcirculatory bed of the human heart

Using a complex of morphological techniques both injective and non-injective, scanning electron microscopy including, the hemomicrocirculatory bed and vascular anastomoses have been studied in various parts of the human heart. In most cases anastomoses between the microcirculatory links are realized at the level of capillaries, precapillary arterioles and postcapillary venules. Venulo-venular anastomoses are demonstrated in the myocardium. Existence of terminal arterioles is discussed.     

The formation of the microcirculatory bed of the neuromuscular systems of the tongue in human prenatal ontogeny]

A complex of adequate neurohistological and injection methods with use of mathematical analysis of the data obtained has been performed to study prenatal and early postnatal periods of ontogenesis of the microcirculatory bed of the human tongue neuromuscular systems. Certain changes of the degree in organization and structural-functional integration have been revealed; they demonstrate periodicity of the morphological changes of the vasculo-neural complex of the extra- and intrafusal part of the muscular tissue. In the neuromuscular spindles the microvascular network of capillaries is formed, their volumetric part changes in the process of development in greater degree than the microvascular bed of the extrafusal muscular fibers. In formation of the microcirculatory vascular bed of the neuromuscular spindles not only capillaries, getting into them together with nervous fibers, but also microvessels of the surrounding muscle tissue participate. This determines a higher level of the vascularization degree of the intrafusal muscle fibers.     

Structure and function of the microcirculatory bed in the preserved heart]

The morphological analysis of the state of the heart during hypertermal perfusion with different conservants reveals clear dependence of the microcirculation and the activity of the heart upon the type of the conservant. Perfusion with a salt solution and hemodilution is accompanied by pronounced disorders in microcirculation and unsatisfactory parameters of the cardiac activity. Conservation with cryoprecipitated plasma is characterized by comparatively less microcirculatory disorders, but fails to give a reliable safety of the heart. When using medium 199, changes in microcirculation were found to be minimal and parameters of cardiac activity were satisfactory. In the complex of non-specific changes in microcirculatory vessels the maximum structural lability was revealed in blood capillaries and vessels of the postcapillary-venular link.     

Use of hematoxylin to demonstrate the microcirculatory bed in full-thickness objects and sections of the wall of the gastrointestinal tract]

Slight modifications of the widely applied hematoxylin method of staining make it possible to reveal completely microcirculatory bed in total film preparations and in histological sections of the gastrointestinal wall. Hematoxylin staining of all elements in the vascular wall and the surrounding tissue helps to differentiate definitely every component of the microcirculatory bed and to demonstrate vascular-tissue and vascular-neural interconnections in film preparations and histological sections.     

Study of endothelium-dependent blood oscillations in the human skin microcirculatory bed

Cutaneous microcirculation parameters were studied with laser Doppler flowmetry in healthy volunteers. To investigate endothelial-dependent peripheral blood flow oscillations the iontophoresis of 1% acetylcholine solution was carried out. To estimate the contribution of rhythmical components in blood flow signal the continuous wavelet-transform spectral analysis was used. To reveal correlation between microcirculation parameters under study the correlation analysis was used. The microcirculation index was shown to be the factor producing cross-correlation dependences. The only positive significant correlation between the blood flow oscillation amplitude in the range of endothelial activity normalized to mean microcirculation index at rest and maximal microcirculation index during the iontophoresis of acetylcholine was revealed.     

Formation of ovarian follicles during fetal development in sheep

The origin of follicle (i.e., pregranulosa) cells that become the somatic component of primordial follicles is obscure. In addition, information regarding the structural changes that accompany the concomitant regression of ovigerous cords and the appearance of primordial follicles is lacking. In the present study, ovine ovaries collected at frequent time intervals between Day 38 and Day 100 of fetal life were examined by light and electron microscopy. To gain new information regarding the origin of follicular cells, incorporation of 5-bromo-2'-deoxyuridine was used to identify proliferating cells at selected stages of development. Based on the location and identity of proliferating cells, apoptotic cells, and sequential changes in histoarchitecture, we hypothesize 1) that most (i.e., >95%) of the granulosal cells in newly formed primordial follicles originate from the ovarian surface epithelium; 2) that the sequential events leading to follicle formation take place entirely within ovigerous cords, with the first follicles forming at the interface of the cortex and medulla; and 3) that the loss (i.e., >75%) of germ cells, but not of somatic cells, within the ovigerous cords is a means by which each surviving oocyte gains additional pregranulosal cells before follicle formation. Conceptual models detailing the chronology of developmental events involved in the formation of primordial follicles in sheep are discussed.     

Comparative evaluation of the adaptive mechanisms of the microcirculatory bed during dehydration

In total preparations of the white rat small intestine mesentery, impregnated with silver nitrate, as well as under conditions of vital microscopical observations at certain stages of alimentary experimental dehydration, analogous changes in the microcirculatory bed links have been demonstrated. Comparison of quantitative parameters in decreasing diameters of the microvessels, specific for dehydrated preparations has shown a great importance of these changes in the impregnated preparations at the expense of tissue condensation at their histological treatment. The advantages of a complex application of both methods for estimating dynamics of vascular, intervascular and extravascular changes are proved.     

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.     

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.