Functional and morphological basis for the nature of the microcirculatory bed reactions of the bulbar conjunctiva in experimental occlusion of the cranial mesenteric artery

A complex analysis on changes occurring in conjunctival microcirculation and a number of indices of hemodynamics, hemorheology and metabolism at different time of experimental occlusion in the cranial mesenteric artery has demonstrated certain objective and many-sided correlations that prove a systemic character of biomicroscopical changes in the conjunctiva. The degree of changes in the conjunctival microcirculation depends on duration of occlusion. After a 3 hours' occlusion revascularization is accompanied by reversible general microcirculatory disorders that are registered in bulboconjunctiva. In a 6 and 12 hours' occlusion revascularization is characterized by increasing general changes in microcirculation.     

Patterns in the development of the ultrastructure of elements of the microcirculatory system in the early stages of human embryogenesis

By means of transmissive electron microscopy methods, general regularities in development of the microcirculatory system have been studied at early stages of the human prenatal ontogenesis in functionally different organs. Ultrastructure of two cell types has been described in the mesenchyme of human embryos. Formation mechanisms of the primary blood vessels belonging to the protocapillary type are revealed. Structural peculiarities of the primary protocapillary network differentiating into various links of the secondary organospecific hemomicrocirculatory bed are distinguished. Certain stageness in development of the microcirculatory system is stated, its blood circulatory compartment including. Two stages are determined in development of the microcirculatory system: prevascular and vascular microcirculation. The latter includes the precirculatory and circulatory phases.     

Taxonomy of the microangiological changes in the ocular conjunctiva]

By means of biomicroscopical investigations of bulbar conjunctiva in healthy persons of different age certain characteristics on normal microcirculatory bed have been obtained. Morphometric analysis of the vital microscopical observations has revealed some age peculiarities in microcirculation of the conjunctiva. As a result of clinical examination of the persons, it has been stated that the phenomena noticed at biomicroscopy which characterize certain anomalies of microcirculatory parameters correlate with latent pathology, closely related diseases or developmental anomalies. Therefore, it is possible to consider the method of biomicroscopical investigation of the conjunctiva with a subsequent morphometric analysis of the data obtained as suitable for application not only for clinical but also for prophylactic examination of healthy persons.     

Potentially life-threatening primary acquired melanosis

Primary acquired melanosis is an acquired conjunctival pigmentation seen in Caucasians. It presents as a diffuse, patchy, unilateral area of pigmentation that can be flat or nodular. Other melanotic lesions such as ocular melanosis, argyrosis, congenital conjunctival melanosis can be confused with primary acquired melanosis. Diagnosis and management of primary acquired melanosis is critical since it is potential life-threatening. A 51-year-old while male presented with unilateral, diffuse, patchy pigmentation first noted 10 years prior. Slit lamp examination revealed a 4 mm x2 mm area of temporal bulbar conjunctival pigmentation extending to the limbus in the right eye. A biopsy was performed and pathologic examination disclosed primary acquired melanosis with atypia. Topical mitomycin-C therapy was initiated. Because of the large size and diffuse nature of the pigmentation, mitomycin-C was preferred since surgical excision would be destructive and has related risks of scarring, goblet cell loss, and associated side effects such as dry eye and ulceration. Two months, following treatment with mitomycin-C, significant clinical improvement was observed. A careful patient history is key in diagnosis primary acquired melanosis including a detailed history including onset, duration, stability, and progression of the pigmentation. All cases of primary acquired melanosis should be referred for biopsy. If atypia is found, traditional treatment includes surgical removal or cryotherapy. However, if the area is large side effects can occur. Mitomycin-C eliminates these potential side effects and can be used to successfully treat primary acquired melanosis.     

Morphologic changes in the microcirculatory bed at stages of prolonged experimental fasting in animals

In 40 white male rats with body mass 180-200 g, by means of silver nitrate impregnation, morphological changes have been studied in the blood microcirculatory bed of the small intestine mesentery, spinal trapezoid muscle and eye ball conjunctiva at various stages of a prolonged fasting. With an increasing time of the experiment, a gradual undirected character of the changes in the microvessels is noted. After 3 days of fasting the changes in diameters of the microvessels, comparing to the control ones, have not any significant values in all the organs studied. After 6 days of fasting significant changes in diameters in all the links of the microcirculatory bed of the eye ball conjunctiva and in that of the spinal trapezoid muscle are observed. The microvascular changes are mostly pronounced on the 9th day of fasting. The maximal decrease of the microvessel diameters is noted in the eye ball conjunctiva, and the minimal--in the small intestine mesentery. The changes in the spinal trapezoid muscle are of intermediate character. The highest points of the structural lability gradient fall on the capillary and postcapillary-venular links of the blood microcirculatory bed.     

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.     

Microcirculatory bed of the bulbar conjunctiva in 3- to 9-month-old fetuses

In 32 corpses of 3-9-month-old fetuses the diameter, length amount of the microcirculatory bed vessels and their wall thickness have been studied in different areas of the eye bulb conjunctiva by means of impregnation after Kuprianov. General morphofunctional vascular peculiarities have been revealed. They are connected with age and structure of the developing tissues in the eye bulb conjunctiva. Two stages of development have been defined: 3-6 and 7-9 months.     

Vascularization of the testes of the white rat in the high altitude conditions of the Pamir and Antarctica

By means of histometric and morphometric methods vascularization of the white rat testes has been studied at adaptation to living conditions in the Alpian Pamir (at the altitude of 4,000 m) and in the Antarctic Continent (at the altitude of 3,488 m). The leading factor in development of the parenchymatous rearrangements of the testes are certain disturbances of the microcirculatory link in the intraorganic bed. Different degree in manifestation of the morphological signs of the circulatory disturbances are revealed: plethora, interstitial tissue edema, degenerative changes in the spermatogenic epithelium cells and hence decreasing activity of spermatogenesis. The disturbances noted are essentially various in different stages of adaptation to the altitude. In contrast to the Pamir series of the experiment, in the group of the animals adapting to the living conditions of "Vostok" station, dilatation of the capillary lumens and signs of moderate plethora accompanying them remain up to the end of the observations.     

Morphofunctional features of different divisions of the microcirculatory bed of jejunal villi in the white rat

By means of injecting the vessels with vegetative peroxidase, scanning electron microscopy of corrosive preparations, biomicroscopy, transmissive electron microscopy and in serial semithin sections, spatial organization of the blood microcirculatory bed of the villus in the white rat jejunum has been studied and identification of various microvascular segments has been made. Increasing dimentions of the villus result only in multiplication of the outflow and inflow pathways of blood, while the number of the marginal capillary-distributers remains unchanged--one along each lateral part of the villus. The cause of this regularity should be sought in certain requirements to orientation of transport processes in the villose stroma and, first of all, in the conditions of the hemato-lymphatic transference at adaptation.     

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.     

A global view of the OCA2-HERC2 region and pigmentation

Mutations in the gene OCA2 are responsible for oculocutaneous albinism type 2, but polymorphisms in and around OCA2 have also been associated with normal pigment variation. In Europeans, three haplotypes in the region have been shown to be associated with eye pigmentation and a missense SNP (rs1800407) has been associated with green/hazel eyes (Branicki et al. in Ann Hum Genet 73:160-170, 2009). In addition, a missense mutation (rs1800414) is a candidate for light skin pigmentation in East Asia (Yuasa et al. in Biochem Genet 45:535-542, 2007; Anno et al. in Int J Biol Sci 4, 2008). We have genotyped 3,432 individuals from 72 populations for 21 SNPs in the OCA2-HERC2 region including those previously associated with eye or skin pigmentation. We report that the blue-eye associated alleles at all three haplotypes were found at high frequencies in Europe; however, one is restricted to Europe and surrounding regions, while the other two are found at moderate to high frequencies throughout the world. We also observed that the derived allele of rs1800414 is essentially limited to East Asia where it is found at high frequencies. Long-range haplotype tests provide evidence of selection for the blue-eye allele at the three haplotyped systems but not for the green/hazel eye SNP allele. We also saw evidence of selection at the derived allele of rs1800414 in East Asia. Our data suggest that the haplotype restricted to Europe is the strongest marker for blue eyes globally and add further inferential evidence that the derived allele of rs1800414 is an East Asian skin pigmentation allele.     

Effects of thermal factors on the state of microcirculation of the small intestine in acute ischemia

The influence of normo- (38 degrees C), hyper- (42 degrees C) and hypothermia (20 degrees C) on microcirculatory disturbances caused by acute local ischemia of the small intestine was investigated with the help of biomicroscopy as well as morphological methods. Ischemia was modeled by ligation of the intestine look eventrated through the abdominal wall incision of a rat onto the microscope stage for 1 h. It was shown that hyperthermia intensified microcirculatory disorders and stimulated destructive processes in tissues and hypothermia promoting microcirculation and decreasing metabolism and restrained the development of these processes. Important peculiarity of the microvascular response to ischemia, hyper- and hypothermia was revealed: heterogeneity of the reaction of different parts of microvascular bed. Appropriate evaluation of the microcirculation state in such conditions can be obtained taking into account not only the qualitative character of microvascular reaction but also an extent of this reaction manifestation in different parts of microvascular bed.     

Organ and tissue-specific properties of the microcirculatory bed of the heart

The auricular and ventricular microcirculatory bed has been studied in persons of mature age, not suffering from any cardio-vascular diseases during their life. As a whole, 48 objects have been studied. The microcirculatory bed has been revealed in sections of the cardiac wall 70-100 mcm thick using silver nitrate impregnation after V. V. Kuprianov. Organ- and tissue-specific properties of the vascular microcirculatory bed are revealed in interrelations of the vessels and the structural elements of the cardiac wall (myocardium, and connective tissue structures), in position of nuclei of the endothelial cells of the capillary wall and in places of the capillary branchings. Principle differences in structure of the auricular and ventricular microcirculatory bed are demonstrated. The notion the organ- and tissue-specific properties of the microcirculatory bed vessels is discussed.     

Topography of the borderline structures of the anterior portion of the inferior mediastinum and their vascularization

By means of silver nitrate impregnation after V. V. Kupriianov of blood vessels it has been revealed that the blood microcirculatory bed of the borderline structures in the anterior part of the inferior mediastinum, united by their topographical proximity and common sources of blood supply, are characterized by a high concentration of microvessels, arterioles, precapillaries, capillaries, postcapillaries and venules. In each structure investigated peculiar features of the blood microcirculatory bed organization are defined. Richness in vessels and their borderline position ensure potency of transudation and resorption of liquids from the inferior mediastinum in the cases, when the mediastinal part studied becomes the reservoir for pathological exudates (at traumas, at mediastinitis).     

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.     

Blood aggregation and the system of microcirculation in experimental atherosclerosis, its spontaneous regression and hemosorption

Blood aggregate state and microcirculation were studied during development and spontaneous regression of experimental atherosclerosis and following hemosorption. It has been shown that experimental atherosclerosis is not only accompanied by changes in blood lipid composition, but also by disturbances in the structure and function of microcirculatory bed. Normalization of blood lipid composition and recovery of blood aggregate state and microcirculatory bed structure and function were not observed during spontaneous regression. Repeated hemosorption enhances atherosclerosis regression, normalizes lipid composition of blood and biological membranes and promotes the recovery of microcirculation.     

Vascularization of the myenteric plexus in the small intestine of pigeons]

By means of light and electron microscopy vascularization of the myenteric plexus has been studied in the pigeon small intestine. Ganglia of the plexus, their cell composition, ultrastructure of neurons have been described. Links of the microcirculatory bed of the intramural ganglia are characterized, interrelations of capillaries with neurons are described, quantitative estimation of microhemovessels, surrounding the microcirculatory bed of the myenteric plexus in the intestinal wall in birds and mammalia.     

Tissue basophils in vascular plexuses of the lateral ventricles of the brain in humans and various mammals]

By means of histological and histochemical methods cell composition of vascular plexuses in the lateral ventricles of the rats, dogs and man has been investigated. Besides ependymocytes, endotheliocytes, pericytes, myocytes in the microcirculatory bed, described in literature, tissue basophils (TB) have been revealed and what is more--only in dog and man. The most variable forms and localizations of TB are observed in vascular plexuses of the lateral ventricles of the human brain. The following varieties of TB can be defined: small with ortochromic granularity and large ones with abundant metachromic granularity. Sometimes degranulating TB occur. According to their localization they are divided into stromal (+interstitial++), perivascular subepithelial and intraepithelial. The variable TB localization in the vascular plexuses of the brain can probably demonstrate their participation in performing functions of the hematoencephalic barrier.     

Lack of association between acupoint sensitization and microcirculatory structural changes in a mouse model of knee osteoarthritis: A pilot study

As a stimulating point in acupuncture, acupoint has unique microcirculatory features, and its dynamics vary greatly depending on health status. Acupoint sensitization is defined as the transformation of an acupoint from a “silenced status” (healthy) to an “activated status” (disease). Our previous study demonstrated that acupoint sensitization is associated with an increase in the level of local blood perfusion. However, the structural changes in microcirculation during acupoint sensitization have yet to be elucidated because the high‐resolution microcirculation imaging of acupoints has been difficult to obtain. In this study, the structural changes in microcirculation at the Zusanli (ST36), Yanglingquan (GB34) and nonacupoint sites on days 0, 7 and 21 were dynamically observed during acupoint sensitization in an experimental knee osteoarthritis mouse model by using optical‐resolution photoacoustic microscopy. The results showed that no significant differences in microvessel density, the distribution of vessel diameters or vascular tortuosity were observed at the GB34, ST36 or nonacupoint sites among days 0, 7 and 21. We proposed that acupoint sensitization may not be associated with the structural changes in microcirculation and that the microcirculatory changes during acupoint sensitization are more likely to be functional. The functional characteristics of the sensitized acupoints warrant further investigation.      

Development of the uterine microcirculatory bed in postnatal ontogeny

Age peculiarities of common structure of the microcirculatory pathways, specific volumes and amount of microvessels, zonal parameters of pericapillary microcirculation of metabolites, glycosamine glycans and glycoproteins contents, phosphatase and ATPase activity, collagen and elastic fibers of the microcirculatory bed vessels have been studied in 190 unchanged uteri, beginning from 36-week-old fetuses up to 35 years of age. The microcirculatory bed of myometrium during the period of postnatal ontogenesis investigated possesses a polymer-homonomous structural organization; its base make myoangiomas, including the terminal arteriole with precapillaries and collecting venule, that run from it. Similar structure of the myometrium microcirculatory pathways is already observed in fetuses of late antenatal period. In endometrium formed glanduloangionomas are revealed in the prepubertal age. Increase in glycosamine glycans contents is stated in the microvessel walls and in the uterine stroma during the process of its development. Compensatory-adaptive changes in the uterine microcirculatory bed are described during the newborn period up to the puberty. Functionally mature structures of the microcirculatory pathways in the submucosal and vascular layers of myometrium, endometrium and in the cervix uteri are found to be formed earlier than in other areas of the organ.