Anatomical variations in facies articularis calcanea on the talus in the Bulgarian population

The talus (talus) is a tarsal bone that supports the tibia and rests on the tarsus. On the lower surface of the talus, three articular surfaces are found: anterior, middle, and posterior, through which it is connected to the calcaneus and for which anatomical variations have been described. According to the Modified Boyan Classification, several types of variations are described: types A, B, and C (5). When three separate, fully demarcated articular surfaces are observed, the bone is designated as type A. The distance between the anterior and middle is used for further typing, with A1 being ≤2 mm, A2 being 2 to 5 mm, and A3 being ≥5 mm. In the presence of only two articular surfaces, the talus is defined as type B. In B1 and B2, there is a fusion between the anterior and middle facets, respectively incomplete and complete, and in B3, the middle surface is fused with the posterior one. In cases where there is only one articular surface on the lower side of the talus, it is classified as type C.In this study, 111 pieces of talus from the bone collection of the Department of Anatomy and Cell Biology at the Medical University of Varna were evaluated. The percentage distribution of the studied bones according to variations in facies articularis calcanea was: 89.20% for type B2; 5.40% for type B1; 4.50% for type A1; and 0.90% for type A2. No bones with one continuous articular surface (type C) were found, as were those with a distance between the anterior and middle facies articularis calcanea greater than 5 mm

A clinical case of variant testicular artery associated with an aberrant renal artery

The testicular arteries (AT) are long-paired blood vessels that typically arise from the abdominal aorta, below the beginning of the renal arteries, and above the inferior mesenteric artery. Variations of AT are relatively common. They can be classified based on different principles, such as the site of origin, their number, and their course. The overall incidence of AT originating from a site other than the abdominal aorta is about 4%. In such cases, its onset is usually related to the renal arteries. The presented clinical case involves an atypical origin of the left testicular artery, beginning with an accessory, aberrant a.renalis. The high incidence of variations regarding the renal vessels and their potential combination with abnormal testicular arteries require a thorough analysis of their anatomical features before interventions in the area.

A case of missing a. hepatica communis associated with aberrant origin of aa . hepaticae dextra and sinistra

A complex variation of truncus celiacus was discovered during routine anatomical dissection of a 65-year old female cadaver. After short course it divides into arteria gastrica sinistra, arteria lienalis and arteria gastroduodenalis. The missing arteria hepatica sinistra is replaced by a branch of arteria gastrica sinistra, and arteria hepatica dextra stems from arteria mesenterica superior. The left hepatic artery passes between the two sheaths of ligamentum hepatogastricum in its upper third and reaches porta hepatis via sulcus ligamenti venosi. The right hepatic is separated from the superior mesenteric artery just under the incisura pancreatica and crosses behind vena mesenterica superior. It continues in the free margin of ligamentum hepatoduodenale posteriorly to the ductus choledochus and to the right of vena portae. Uppon entrance in the hepatoduodenal ligament the artery separates arteria pancreaticoduodenalis superior posterior. Arteria gastroduodenalis has a similar anatomical course to the course of the `normal` arteria hepatica communis in the base of ligamentum hepatoduodenale. It separates arteria gastrica dextra, arteria pancreaticoduodenalis superior anterior and continues as expected into arteria gastroomentalis dextra. The incidence of the individual described variations (according literature data) is 10% - 19% for the left hepatic artery starting from the left gastric artery and 5% - 9% for the right hepatic artery starting from the superior mesenteric artery. The variations of the celiac trunk and the hepatic arteries are of greatest importance for the classical and minimum invasive surgical approach to the liver, gall bladder and hepatoduodenal ligament (e.g. cholecystectomy, tumor resection of liver, pancreas head or duodenum, aquisition of donor material for liver transplantation). The knowledge of the possible deviations in the hepatic arterial tree has also a significant impact on the interpretation of hepatic anatomy based on imaging data received by means of hepatic angiography, 3d computed tomography, CT angiography etc

Expression of transcription factor Coup-TF1 (NR2F1) in developing occipital cortex in humans

PURPOSES: We aimed to investigate the presence, distribution and abundance of transcription factor (TF) coup-tf1 (also known as NR2F1) in the germinative zones of human telencephalon during the fetal period. This transcription factor is of significance for the normal neuronal migration and differentiation of projection neurons in the mouse forebrain.MATERIALS AND METHODS: Brain tissue samples from spontaneously aborted human fetuses aged between 12  and 28  gestational weeks (g.w.) were fixed in paraformaldehyde and histologically investigated. Sections immunostained for coup-tf1 were scanned and its expression in different zones of the occipital lobe of developing pallium was evaluated. COUP-TF1 positive cells were counted and their percentage of all DAPI-stained nuclei was calculated in order to establish the abundance of the COUP-TF1-expressing cells among the total cell population.RESULTS: COUP-TF1 expression was prominent in all investigated zones of the developing human occipital lobe at stage 17 g.w. In all zones studied, COUP-TF1 positive cells presented a relatively high fraction (~71-95 %) of the cells counted with the highest value of 95.24% in the ventricular zone.CONCLUSIONS: The present data on the location, abundance and distribution pattern of coup-tf1-expressing cells in the human occipital lobe provide information on the possibility that this TF might participate to human to corticogenesis, similarly to the mouse.

Phenotype of De Novo Generated Cells in the Spinal Cord of Adult Macaque Monkeys

Neuronal stem and progenitor cells exist in the spinal cord of sexually mature mammals. Òhåy play an important role during repaining processes after in- jury, but their proliferation and differentiation are limited. In the present study we used the proliferative marker bromodeoxyuridine (BrdU) for a short (2 h) and three longer survival periods (2, 5 and 10 weeks) to investigate the quantity, topography and fate of de novo generated cells in intact spinal cord of adult pri- mates (macaque monkeys). We applied as well single or in combinations markers for mesenchymal cells or/ and neuronal stem/progenitor cells to demonstrate the phenotype of the proliferating cells. We found that af- ter the short period of BrdU application (2 h) the num- ber of BrdU+ cells is significantly elevated only in the cervical segments. Most of the cells in the ependymal layer are immunopositive for Vimentin or/and Nestin. This is an indice for their cellular belonging. A con- siderable number of Vimentin+ cells of the ependy- mal layer form long characteristic processes directed to underlying blood capillaries. Òhis indicates their participation as a component of the ependymal cellu- lar niche. The presence of BrdU+/Nestin+ cells in the central canal surrounding zone confirms the existence of dividing neuronal stem/progenitor cells cells in the spinal cord of adult primates

Еxpression of Transcriptional Factor SOX2 in Populations of Cortical Progenitors in Human Fetal Telencephalon

Cerebral cortex оf mammals is mainly generated during the embryonic period by stem cells and their derivative progenitors in the palium of the developing telencephalon. Various genes in complex interactions are involved in the processes of differentiation of the cerebral neurons. Transcriotional factor Sox2 plays a key role for self renewing and sustaining multipotency of embryonic neural stem/progenitor cells. Data about the expression and function of Sox2 in human fetal brain are insufficient and controversial.In the present sudy tissue samples of spontaneously aborted human fetuses aged between 12th to 28th gestational weeks (g. w.) were examined by a standard histological and immunohistochemical technique for paraffin sections. Sox2 expression was followed in the zones of cellular proliferation and migration in the occipital lobe of human fetal telencephalon mainly during 17th g. w. Within ventricular and outer subventricular zones we detected similar amount approximately 45% Sox2+ cells, whereas in the intermediate zone, cortical plate and marginal zone expression of Sox2 was not found.The data obtained on the location and expression dynamics of Sox2 contribute to a more complete understanding of neural stem/progenitor cell biology during embryonic neurogenesis in the human cerebral cortex

Quantity and Distribution of Proliferating Cells in the Juvenile and Adult Primate Spinal Cord

ÃŒultipotent progenitors exist in the adult mam- malian central nervous system, capable of producing both neurons and glia. Their proliferation in the spi- nal cord is limited. Generation of putative stem/pro- genitor cells has been reported in intact and injured spinal cord of rodents and in a limited number in monkeys with a spinal injury, but not in intact spi- nal cord in vivo. We recently reported de novo gener- ated cells in the intact spinal cord of macaque mon- keys. Here we extend these findings by showing data of intact juvenile and neonatal monkey spinal cord. We used bromodeoxyuridine (BrdU) to label the de novo generated cells in the experimental animals and stud- ied their quantity and distribution at different time- points after the BrdU infusion. As expected, we found a significant elevation of the BrdU-labeled cells at neo- natal stage. However, there was no difference between juvenile and adult stages. These results suggest that the survival of newly born cells in the intact primate spinal cord does not change after juvenile stage and this could be used to further study repair mechanisms in adult primate spinal cord

Proliferating cells in the adult primate cerebellar cortex after ischemia

INTRODUCTION: Brain ischemia is a devastating neurological condition with significant medical and social impact. Here we investigated the effect of experimental ischemia of different duration on the ability of the adult macaque cerebellum to produce new cells of specific phenotypes.MATERIAL AND METHODS: We used a well-established model of global brain ischemia in young adult Japanese monkeys applying bromodeoxyuridine (BrdU) for 5 days х 100 mg/kg daily. Animals were distributed into different experimental and control groups depending on postischemic survival periods: 4, 9, 15, 23, 44 days (D) and BrdU starting day. Immunohistochemical detection of BrdU+ cells, Iba1+ microglia and GFAP+ astroglia was performed on cryosections. Statistical evaluation of newly generated cells with phenotyping for microglia and astrocytes in various cortical layers of the cerebellum were done.RESULTS and CONCLUSIONS: The numbers of BrdU+ cells in some ischemic groups were significantly higher compared to control animals. By cerebrocerebellum, there was an increasing value by D4 group compared to the control, then slightly reducing in D9 and D15 groups and increasing again by D23 and D44 groups. In the spinocerebellum, an increase was detected only in D44 group. The newly generated cells were dispersed in all cerebellar cortical layers with highest concentration in Purkinje cell layer. Our data show that ischemia stimulates cellular proliferation in the cerebellum but this effect declines with time after ischemia. We found evidence for generation of new microglia but not for astroglia. Our data may contribute to a better understanding of regeneration in the cerebellum after brain ischemia

Rostro-caudal gradient in the expression of transcriptional factor SOX2 in the fetal human brain

Транскрипционният фактор Sox2 е ключов компонент в мрежа от гени, които контролират съдбата на различни видове стволови и прогениторни клетки в развиващия се мозък. Доказана е неговата важна роля за самообновяване и поддържане мултипотентността на ембрионалните неврални прогенитори при редица видове бозайници. Данните за експресията и функцията на Sox2 в човешкия фетален мозък обаче са твърде недостатъчни и противоречиви. В настоящото изследване беше проучена експресията и проследена динамиката на Sox2 в ростро-каудална посока в човешки фетален теленцефалон през 20-та гестационна седмица (г.с.). Чрез стандартна имунофлуоресцентна методика бяха визуализирани позитивните за този транскрипционен фактор клетки. Техният брой и относителен дял беше определен и след това сравнен между специфичните герминативни зони и на интересуващите ни нива и дялове на феталната крайномозъчна кора. Проучвайки експресията на Sox2 в трите основни герминативни зони на човешкия теленцефалон (вентрикулна, вътрешна субвентрикулна и външна субвентрикулна зона), установихме значителна разлика в броя на позитивните клетки в предно-задно направление. От рострално към каудално делът на Sox2 позитивните клетки във вентрикулната зона не показва съществена промяна, във вътрешната субвентрикулна зона има значително намаление, a при външнатa субвентрикулна зона има леко увеличение. Описаните различия във връзка с експресията на транскрипционния фактор Sox2 имат значение за пo-добрo разбиране на процесите на развитие, диференциация и миграция на невралните стволови/прогениторни клетки в крайния мозък при човека по време на феталната неврогенеза при нормални и патологични условия.Transcriptional factor Sox2 is a key component in a network of genes controlling the faith of diverse types of stem and progenitor cells in the developing brain. Its important role in self-renewal and maintenance of multipotency of embryonic neural progenitors is well established in a number of mammalian species. However, the data about the expression and function of Sox2 in the human fetal brain are scarce and controversial. In the present investigation, we studied Sox2 expression and its rostro-caudal dynamics in human telencephalon at 20th gestational week. Using a standard immunofluorescence technique positive cells for this transcriptional factor were visualized. Their numbers and relative portion were determined and compared in specific germinal zones at various levels and in different areas of the telencephalic cortex. When studying Sox2 expression we discovered significant differences in the numbers of positive cells in all three germinal zones (ventricular, inner subventricular and outer subventricular) in rostro-caudal direction. From rostrally to caudally the relative portion of Sox2 positive cells in the ventricular zone did not showed a significant change, in the inner subventricular zone there was a significant reduction and in the outer subventricular zone there was a slight increase. The differences described in the expression of transcriptional factor Sox2 may be of significance for a better understanding of processes related to the development, differentiation and migration of neural stem/progenitor cells in the human telencephalon during fetal neurogenesis in normal and pathological conditions