The aimof research was to study morphofunctional signs of the sensorimotor "dark neurons" formation in the cerebrum of sexually mature white rats under normal conditions and in 40 minutesafter the common carotid arteries (CCA) occlusion.

Material and methods.Acute ischemia was simulated in white Wistar rats by a 40-min CCA occlusion. The brain was fixed by immersion and perfusion methods. A comparative morphometric assessment of cyto-and gliocytoarchitectonics of the neocortex was carried out under normal conditions (n = 6), 1 (n = 6), 3 (n= 6), and in 7 days (n = 6) after the common carotid arteries (CCA) occlusion. The Nissl staining, hematoxylin and eosin staining, immunohistochemical typing NSE, MAP-2, HSP-70, p38, CASP3, GFAP and AIF1 were applied. The numerical density of normochromic and hyperchromic (dark) pyramidal neurons, oligodendrocytes, microgliocytes, and the relative area of edema –swelling zones were determined. Statistical hypotheses were tested by nonparametric methods using Statistica 8.0 software.

Results.The method of the brain fixation significantly influenced the content of the artifact dark neurons,which are similar in morphology and tinctorial properties to degeneratively altered dark neurons. The appearance of reversibly and irreversibly degeneratively altered dark neurons in the sensorimotor cortex after the CCA occlusion was accompanied by an increase in the relative area of edema  –swelling zones (control  –5.4%, 1st day  –17.6%). The maximum content of degeneratively altered dark neurons (53%) was found in layer V in 7 days after ischemia. According to the findings of immunohistochemical typing NSE, MAP-2, HSP-70, p38, CASP3, the specific proteins of the most degeneratively altered dark neurons were retained, ensuring their restoration and the neural network functioning. The total number density of sensorimotor neurons decreased by 26.4% (p =0.001) in layer III, and by 18.5% in layer V (Mann –Whitney U Test; p = 0.01) in 7 days after the intervention. The revealed changes were of a diffuse focal character. In the zones of degeneratively altered dark neurons accumulation, the content of astrocytes, microgliocytes and oligodendrocytes increased. The neuro-astroglial index (control  –1.62) increased to 2.72 in 3 days after the CCA occlusion. The peak in the number density of microgliocyte s was noted in 1 day, and the oligodendrocytes in 7 days after acute incomplete ischemia (Mann –Whitney U Test; p0.001).

Conclusion.After a 40-minute common carotid arteries occlusion, dark neurons were detected in layers III and V of the sensorimotor cortex with underlying hydropic dystrophy; their cytomorphological pro perties indicated the dynamics of their in vivo degenerative changes. Restoration of degeneratively altered dark neurons was accompanied  by  an  increase  in  the  number  of  satellite  oligodendrocytes,  astrocytes  and  microgliocytes. The  revealed changes were considered as one of the variants of reversible changes in neurons in response to moderate ischemic damage.

The aimof  this research was to study the variant anatomy of the obturator complex in terms of surgical treatment of stress urinary incontinence, as well as to determine the most atraumatic technique for conducting a surgical trocar for a transobturator suburethral sling.

Material and methods.A suburethral sling was implanted on 40 sagittally dissected samples of the female pelvis with preserved soft tissues using two techniques: the conventional one based on the use of external landmarks and the technique of the trocar rotation around the lower branch of the pubic bone developed at the University  Clinic  of  St.  Petersburg.  After  implantation  of  a  transobturator  suburethral  sling,  the  probability  of injury  to  the  branches  of  the  obturator  nerve  was  assessed  by  precision  preparation  for  each  of  the  presented techniques using 40 samples. It was also suggested to develop a protocol for atraumatic placement ofa sling for stress urinary incontinence.

Results. Based  on  the  results  obtained  and  study  of  the  topographic  relationships  of  the  trocar  and branches of the obturator nerve, it is concluded that the obturator complex has significant anatomical variability. This relates to both the muscular component  –the internal and external obturator muscles, and neurovascular structures. The obturator nerve has two types of branching: joint and separate. The latter is a risk factor for intraoperative nerve injury. The technique of suburethral sling implantation by rotating the surgical trocar around the inferior branch of the pubic bone is atraumatic and safe.

Conclusions.Variant anatomy of the obturator complex influences the probability of trauma in a transobturator suburethral sling implantation. In particular, the separate branching of the obturator nerve is a risk factor for its intraoperative injury. Further clinical studies are required to assess the outcomes of surgical t reatment of stress urinary incontinence taking into account the variant anatomy of the true pelvis.

The aimof this study was to determine the morphofunctional features of the spleen in rats under immobilization stress and administration of bacterial lipopolysaccharide.

Material and methods.60 white Wistar rats were divided into 4 groups. The animals of the first control group were injected with saline. The rats of the second control group were injected with lipopolysaccharide. In the rats of the third group, immobilization stress was induced and the animals of this group were injectedwith saline. In rats of the fourth group, immobilization stress was also caused and lipopolysaccharide was administered in the form of the drug Pyrogenal (Medgamal, Russia) in a dose of 100  µg/kg of body weight. Fragments of the spleen were fixed in a 10% solution of neutral formalin, dehydrated in alcohols of increasing strength, and embedded in paraffin. Thin paraffin sections 4–5 µm thick were stained with hematoxylin and eosin. The area of longitudinal sections  of  the  spleen,  the  area  of  the  white  and red  pulp  were  determined planimetrically.  Using  a  screw  m icrometer eyepiece, the width of the reactive center of the lymph nodes of the white pulp, the width of the mantle and  marginal  zone  of  the  nodules,  as  well  as  the  width  of  the  periarterial  lymphoid sheath  were  measured (40–50 measurements for each animal).

Results.It was found that on the 3rd day after the stress morphological signs of a sharp decrease in the activity of the white pulp were revealed. On the 8th day, pronounced recovery processes in the spleen were noted, however, complete restoration of the structure of the spleen did not occur. On the 3rd and 8th days after stress and  administration  of  lipopolysaccharide,  no  signs  of  inhibition  of  the  activity  of  the  white  and  red  pulp  were found in the spleen; morphological parameters of the spleen did not differ from the control values.

The aimof this research was to study an anogenital distance of the offspring of laboratory mice after prenatal exposure to estrogens.

Material  and  methods. The  study  included  sexually  mature  laboratory  mice  and  their  mothers  that were injected with various single doses of estrogen preparations intramuscularly at the E 11.5 gestation stage. The mice of the experimental group C-50 were injected with 2% oil solution of synestrol, dosage 50 μg/kg, the mice of the control group were injected with olive oil, dosage 0.2 μg/kg. The mice of the experimental group F-100 were injected with 0.4 ml of 0.0005% fulvestrant oil solution, dosage 100  μg/kg, the mice of the control group were injected with sterile castor oil, dosage 0.8 μg/kg. The body weight, the anogenital distance (AGD), the AGD index were measured in sexually mature offspring of laboratory mice, male and female. The data obtained were statistically processed.

Results.The  exposure  of  male  offspring  to  synestrol,  dosage  50  μg/kg,  caused  an AGD reduction  compared with the mice in the control group. Fulvestrant, dosage 100  μg/kg, blocked estrogen receptors; as a result, only androgen receptors worked, the fact leading to an increased masculinizing effect; with this effect a slight increase in AGD was observed in male offspring compared to the mice of the control group. The AGD parameters in female mice of the experimental group C-50 decreased compared with the mice of the control group; this parameter can be considered as a feminizing delayed effect. The female mice of the experimental group F-100 showed no statistically significant changes.

Conclusion.The study of dose-dependent effects of prenatal estrogen administration demonstrated both stimulating and inhibitory effects of hormones on the AGD parameters. The study of AGD dependence onthe prenatal effect of estrogens allows early identification of pathological changes in the reproductive system of the offspring.

The aimof this study is to study the recovery processes in the thyroid gland of Russian long-haired sheep in postnatal ontogenesis.

Material  and  methods. The  material  for  the  study  was  77  rams  of  the  Russian  long-haired  breed  of various ages. Fragments of the thyroid gland were fixed in a 10% solution of neutral formalin, in liquids of Shtive and Buena. Thin paraffin sections with a thickness of 4–5 μm were stained with hematoxylin and eosin, azan according to Heydenhein, and the PAS-reaction was applied. The average area of all follicles in the field of view was determined at a magnification of ×80 (ob. 10; oc. 8) using G.G. Autandilov ocular grid (50 fields of viewfor each animal). Based on the obtained absolute values of the area of the follicles and the interfollicular epithelium (mm 2 ), the relative value (%) of the area of the follicles and the interfollicular epithelium was determined. Using a screw eyepiece micrometer, the diameter of the nuclei of thyrocytes in the follicles and thyrocytes of the interfollicular epithelium was measured. The area of the nuclei was determined by the diameter of the nuclei. The mitotic index (MI) in ‰ was calculated . The number of dividing cells per thousand thyrocytes was calculated. At  least 20,000 cells were counted for each animal.

Results.It was found that in rams aged 15 days, the area of interfollicular epithelium was 86.5%, microfollicles occupied an area of 13.5%. Dividing cells were common, with the MI of follicular and interfollicular thyrocytes being 0.19‰. In rams at the age of 2 months, the number of small follicles increased, the areaof which was 19.7%. MI in follicles increased to 0.21‰, in interfollicular epithelium it decreased to 0.16‰. In rams at the age of 4 months, the area of follicles almost doubled, the area of interfollicular epithelium decreased by 16.1%. In rams aged 2–3 years, the area of interfollicular epithelium decreased, while MI decreased and was 0.13‰ in 3-year-old animals. In rams at the age of 4 and 5 years, there was a decrease in the functional activity of thefollicles. MI in large follicles was higher than in small follicles (0.12–0.13‰ versus 0.09‰).

The aimof the study is to establish age and gender patterns of morphometric parameters of the gallbladder in children and adolescents based on the findings of intravital imaging.

Material and methods.The authors analyzed computed tomograms of the abdominal cavity of 75 children having no visible pathologies of the abdominal organs. The participants were divided into 4 agegroups: early childhood,  first  childhood,  second  childhood,  adolescence.  The diagnostic  procedure was  performed  on 16-slice computed tomographs; a longitudinal size, a distance between the right and left walls, a distance between the anterior  and posterior  walls  and  a  volume  of  the  gallbladder  were  detected  in  the  study.  The data  obtained  were processed using variational and statistical methods,the mean value (M), standard error (m) and the significance of differences according to the Student's t-test were determined.

Results.The longitudinal size of the gallbladder averaged 4.5±0.1 cm in the entire sample, 4.3±0.1 cm in girls, and 4.6±0.1 cm in boys; there was detected an increase from 3.7±0.2 cm in group 1 to 4.8±0.3 cm in group 4 (p=0.023). The transverse size of the gallbladder was 1.8 ± 0.1 cm, while in girls  -1.8 ± 0.1 cm, and in boys  - 1.7  ±  0.1  cm.  The  value  of  this  parameter  increased in  all  examined  children  from  1.3  ±  0.1  cm  in  group  1  to 2.1 ± 0.1 cm in group 4 (p = 0.001). In patients of all groups the average value of the distance between the anterior and  posterior  walls  of  the  gallbladder  was  2.8±0.1  cm.  In  girls  this  parameter  was  2.8±0.1  cm,  and  in  boys  -2.9±0.1  cm.  This  parameter  increased  in  all  patients  from  2.4±0.1  cm  in  group  1  to  3.4±0.1  cm  in  group  4 (p=0.001). The volume of the gallbladder constituted 13.6±0.8 cm³, in girls this parameter was 12.8±1.0 cm³, and in  boys  - 14.2±1.3  cm³.  The  volume  of  the  gallbladder  increased  in  all  patients  from  7.3±1.1  cm³  in  group  1  to 19.4±1.9 cm 3 in group 4 (p=0.001).

Conclusion.The most significant increase in most studied parameters (p≤0.05) was noted in children of the first childhood group compared with children of the early childhood group, and in adolescents co mpared with children  from  the  second  childhood  group  without  differentiation  by  gender. A  significant  increase  in  the  morphometric parameters of the gallbladder was determined mainly in boys of the first childhood group compared with  children  of  the  early  childhood  group  and  in  adolescents  compared with  children  of  the  second  childhood group. In girls there was observed a tendency to a smooth increase in parameters from group to group; a significant increase was determined by the parameter “the distance between the anterior and posterior walls” in children of the second age group compared with children of the first age group (p=0.022). Most of the gallbladder morphometric parameters did not significantly differentiate in girls and boys of the same age group.

The aim of  the  study  was  to  analyze  the  microvasculation  of  the  liver  in  administration  of  tautomeric forms of orotic acid for a methionine-induced liver pathology to assess the efficacy of the modified drugs and the potentialof their clinical use.

Material and  methods. The  study  included  30  white  outbred  rats,  that  were  simulated  methionine induced hyperhomocysteinemia by the administration of methionine, dosage 0.15 g/100 g of the body we ight, via food  during  4  weeks.  Animals  with  hyperhomocysteinemia  were  divided  into  4  groups:  animals  of  group  1  received orotic acid (OA) in the initial form (oxo-tautomer), animals of group 2 received hydroxy–tautomer OA after mechanomodification for 1 hour, animals of group 3 received dihydroxy-tautomer OA after mechanomodification for 6 hours. Histological preparations of the liver were used to evaluate the area of hepatocytes; diameters and areas of the central vein, the interlobular vein and artery, the bile duct, and the Visotto coefficient were calculated.

Results. Morphometric  data  of  the  hepatic  microvascular  bloodstream  with  simulated  hyperhomocysteinemia evidenced a general increase in the diameter and area of blood vessels, changes affected the system of blood inflow and outflow at the organ level. Administration of OA had a normalizing effect on the liver bloodflow, but the effects were different: the most pronounced effect was detected in administration of the hydroxy-form of the preparation, this can be explained by a modificationin the dispersion of the preparation (without changing the crystal lattice), an increase in the rate of dissolution in water and aqueous solutions, an increasein the number of functionally active groups in the heterocycle of the hydroxy-form of OA. Thus, the hydroxy-tautomer of orotic acid had the greatest efficacy relating to vasodilation of microvessels of the liver bloodstream in hyperhomocysteinemia; the fact suggesting feasibility of its further study in the clinical environment.

The article reviews literature on the organization of the erythrocyte plasmalemma and its rearrangements at different periods of the cell lifespan. In the absence of a nucleus and organelles, the plasmalemma is the only structural element of erythrocytes involved in all processes of their vital activity. The plasmalemma supports the disk-like shape of the erythrocyte, provides its ability to reversible deformation, maintains intracellular homeostasis, participates in gas transport and energy metabolism, also transfers hormones, enzymes, antibodies, medicines and other substances on its surface. The polyfunctionality of the plasmalemma is provided by the peculiarities of its lipid, protein, and carbohydrate composition, as well as by the presence of a unique cytoskeleto n, morphologically associated with the erythrocyte membrane. The plasmalemma has the substantial modifications during the erythrocyte lifespan, namely, in maturation of reticulocytes, in the processes of functioning, aging, and cell death. Biochemical  rearrangements  of  the  plasmalemma  serve  as  triggers  for  events  such  as  membrane  vesiculation, eryptosis,  and  elimination  of  senescent  erythrocytes  by  macrophages.  Age-related  changes  in  the  erythrocyte plasmalemma  are  adoptive  in  nature  and  aimed  at  maintaining  cellular  homeostasis  and  functional  activity  of these formed elements during a four-month stay in the bloodstream.

The gastrointestinal tract is constantly exposed to various physical and chemical factors. In the intestine, the contact of bacteria and the epithelium largely depends on mucus, which mainly consists of highly glycosylated mucin-2 secreted by goblet cells in the epithelium. Goblet cells are located along the entire length of the small and large intestine and are responsible for the production and maintenance of a protective layer of mucus through the synthesis and secretion of high-molecular glycoproteins known as mucins. The article presents data on the embryogenesis of the small intestine in general and goblet cells, in particular, a literary review of the role of goblet cells in the morphology of the intestinal tract, the functional aсtivity of their secretion is carried out. Due to the unique nature of this highly polarized exocrine cell, the cellular mechanisms by which goblet cells  secrete their products are discussed.

This article reports on head-and-neck computed tomography angiography imaging findings and data of ultrasound examination of the extracranial carotid and vertebral arteries of 69-year-old patient with unilateral asymptomatic complete occlusion of extracranial internal carotid artery (ICA) in combination with unusually elongated styloid processes of temporal bone. The aim of the study was to specify the collateral pathways blood supply to the brain and to assess the possible clinical significance of an abnormally elongated styloid pro cess. Adequate cerebral blood flow was provided by anastomoses between the arteries at the base of the brain. This can explain the asymptomatic unilateral complete occlusion of the extracranial ICA. Occlusion of the artery was  not associated with the presence of a 5.5 cm styloid process.  Computed tomography angiography is a highly informative method for visualizing the individual morphological variants to clarify their clinical significance.

Eduard Germanovich Bykov, a famous Russian morphologist, Doctor of Medical Sciences, Honored Scientist of the Russian Federation, Honorary Professor of N.N. Burdenko Voronezh State Medical Academy (VSMA), a founder and leader of Voronezh school of histochemistry would have been 85 years old on June 10, 2021. A key issue of his scientific activity was careful selection of sample preparation protocols for histochem ical analysis in order to increase objectivity of differential diagnosis ofbiopsy material in vivo in clinical practice and to solve urgent problems of pathomorphogenesis of the whole range of diseases. Novelty and perspectives of the conducted research allowed Eduard Germanovich to become a scientific supervisor and consultant of a large number of dissertationists who performed their research in alma mater and in universities of other cities of the  USSR. From 1978 to 2008, Prof. Bykov was in charge of the Central Research Laboratory, N.N. Burdenko State Medical University,  organizing  work  of  laboratories  as  connecting  elements  between  fundamental  research  and  practical health  care.  Scientifically  based  methods  of  diagnosis,  therapy  and  rehabilitation  were  developed  an d  implemented into practical healthcare in the Central ResearchInstitute. Eduard Germanovich created Voronezh Scientific  School  "Human  Histochemistry.  Clinical  Histochemistry",  which  focused  on  preserving  the  vital  chemical characteristics of the object of study. Prof. Bykov was repeatedly awarded with certificates of honor from the University Administration and the Government of Voronezh Region for achievements in research, teaching and social work. In April 2010 he was awarded by the Russian Federation of Cosmonautics with Academician M.V. Keldysh medal for a significant contribution to the development of Russian cosmonautics. In 2011 Professor Eduard Bykov was awarded the title of "Honorary Professor" of N.N. Burdenko Voronezh State Medical Academy.

The two Grand Embassies to Europe and his view on the world helped Peter the Great to start reforms.Already as a child, he had abroad interest in medicine. Peter often followed a two-track policy. One for immediate application in the current practice and one for the development of specialists in collaboration with science. Peter established a medico-surgical hospital school in Moscow to prepare the students to become doctor medicinae and learn to make their own medical instruments along the line of the Leiden medical school. In Saint Pe tersburg, he opened a navy and an army hospital, intended to train students as a barber-surgeon for the army and navy. Also in Saint Petersburg Peter built the first factory for "mass" production to provide the military with medical instruments.His successors followed his two-track policy. Catherine the Great started to merge the two tracks. During the reign of Tsar Aleksander I and his brother Nicholas I, the merger came together and was further developed. They understood that strong cooperation between a physician and a designer is essential to create and produce useful medical instruments. If correctly designed, medical instruments and devices increase safety for the patient. We will shed light on the development and manufacture of medical instruments and appliances in Imperial Russia, an underdeveloped subject in the world medical history.