THE MEDICAL COLLECTIONS OF THE UNIVERSITY OF TARTU.

In the year 1999, a new and modern building Biomedicum was finished addressed to preclinic subjects of the Medical Faculty of the University of Tartu; the institutions of anatomy as well as pathological anatomy and forensic medicine moved there. However; no place was planned to exhibit the collections of specimens. Many of the specimens which had so far only been used for learning purposes found their place in the Old Anatomical Theatre, in the hope that this could be transformed as a museum. The medical collections of the Medical Faculty were opened up for a broader audience in October 2005. With the support of the national programme "The collections of humanities and natural sciences", the medical study specimens, models, moulages, and literature related to them in danger of being destroyed were collected from several subdivisions and buildings of the Medical Faculty. In 2012, the medical exhibition moved to the premises of Science Centre AHHAA and in the same time a specifc educational study began to be developed.

Expression of insulin signaling transmitters and glucose transporters at the protein level in the rat testis.

Insulin receptor substrate (IRS) proteins are key mediators in insulin signaling from the insulin receptor. It takes place through receptor-mediated tyrosine phosphorylation of IRS proteins. The aim of the present article is to demonstrate the distribution of IRS 1-3, glucose transporters 1-4 (GLUT 1-4), signal regulatory protein 1alpha (SIRP1alpha), PKB, and PI 3-kinase in the rat testis to see if signal transduction mediated by these proteins is active in testicular cells. Wistar rats were used as donors of testis tissue. Expression of these genes was studied at the protein level by using immunohistochemistry and Western blotting. IRS-1, IRS-2, GLUT 1, GLUT 2, GLUT 3, and SIRP1alpha were strongly expressed in the Sertoli cells (except GLUT 1), early spermatocytes, peritubular myoid cells, macrophage-like interstitial cells, and testicular endothelial cells in all the testes investigated by immunohistochemistry. IRS-2 was also expressed in the Leydig cells. Immunoblotting experiments demonstrated the presence of about 26-67 kDa reactive with anti- IRS-1, IRS-2, GLUT 1, GLUT 2, GLUT 3, PKB, and SIRP1alpha. The present results suggest that proteins like insulin and certain cytokines using IRS-1, IRS-2, GLUT 1, GLUT 2, GLUT 3, PKB, and SIRP1alpha in their signal transduction can have effects on the different types of testicular cells in the rat.

Experimental sepsis: characteristics of activated macrophages and apoptotic cells in the rat spleen.

Sepsis, being characterized by massive translocation of bacteria into tissues, induces the suppression of the function of both leukocytes and macrophages. The aim of the study was to count activated macrophages (AMs) and apoptotic (Ao) cells in the rat spleen during the period of experimental sepsis and to clarify the associations of these parameters with each other and with leukocyte migration and bacterial translocation into different organs. The Wistar rats were intraperitoneally inoculated with Escherichia coli (E. coli) and were sacrificed after 2, 6, 24, 48, and 120 h. Bacteria and leukocytes in tissues were specifically stained. AMs were identified by immunohistological staining and Ao cells by the TUNEL assay. The high counts of E. coli at 6 h were strongly associated with a low level of the total counts of leukocytes, accompanied by the high translocation of microbes into tissues. In the spleen, lymphocytes, macrophages, and neutrophils with pyknotic nuclei were identified. The count of AMs was highest at 24 h after the inoculation with E. coli; at the same time the Ao cell count began to rise and achieved the highest level 24 h later. Our investigation indicates that the molecular peculiarities of macrophages and their responses to the inflammation process are tissue-specific. In the spleen the activation process involving hematopoietic cells and macrophages was remarkable at the late stage of sepsis, characterized by a high count of Ao cells.

Expression of insulin receptor substrates 1-3, glucose transporters GLUT-1-4, signal regulatory protein 1alpha, phosphatidylinositol 3-kinase and protein kinase B at the protein level in the human testis.

Insulin receptor substrates (IRS) mediate the biological actions of insulin, growth factors and cytokines. This action is via receptor-mediated tyrosine phosphorylation of IRS proteins. The aim of present study was to demonstrate the distribution of IRS-1-3, the glucose transporter class I subfamily (GLUT-1-4), signal regulatory protein 1alpha (SIRP1alpha), protein kinase B (PKB) and phosphatidylinositol kinase (PI3-K) in the human testis to determine whether signal transduction mediated by these proteins is active in testicular cells. In the present study, the expression of IRS-1-3, GLUT-1-4, SIRP1alpha, P13-K and PKB was studied in the human testis at the protein level using immunohistochemistry and western blotting. A positive immunoreaction for IRS-1 was found in the human testis in peritubular myoid cells and macrophage-like interstitial cells. A positive immunoreaction for GLUT-3 was found in the human testis in Sertoli cells, peritubular myoid cells, early spermatocytes, macrophage-like interstitial cells and cells in the small vessels walls. Western blotting demonstrated IRS-1, IRS-2 and GLUT-3 proteins in the human testis. Expression of IRS-3, GLUT-1, GLUT-2, GLUT-4, SIRP1alpha, P13-K and PKB was not detected in the human testis. The results of the present study suggest that proteins like insulin and certain cytokines using IRS-1, IRS-2 and GLUT-3 in their signal transduction pathways can have effects on different cell types of the testis in humans.

Immunohistochemical detection of glucose transporters class I subfamily in the mouse, rat and human testis.

A family of glucose transporters (GLUT) mediates the cellular uptake of glucose at the plasma membrane by facilitated diffusion. We investigated the presence of isoforms GLUT1-4 of class I subfamilies in different types of cells in the mouse, rat and human testis by indirect immunofluorescence technique. Immunocytochemical analyses demonstrated that GLUT1 was expressed in the rat testis, GLUT2 in the mouse and rat testis, GLUT3 in the mouse, rat and human testis and GLUT4 was not presented in the testis at all. A very intensive positive immunoreaction for GLUT3 was found in Sertoli cells, peritubular myoid cells, macrophage-like interstitial cells, testicular endothelial cells and early spermatocytes. GLUT3 positive cells were not found in the luminal part of Sertoli cells, spermatids or Leydig cells. The present results suggest that glucose uptake in different testicular cells is mediated by GLUT1, GLUT2 and GLUT3 and the GLUT3 was the prominent glucose transporter type in the testicular cells.

Changes of activated macrophages and apoptotic cell count in the organs of rats during experimental sepsis.

OBJECTIVE: Leukocyte migration plays an important role in inflammation. The aim of our study was to detect the activated macrophage count and to define the apoptotic cell count in the rat's liver and lungs during different stages of sepsis and to clarify whether the activity of macrophages is associated with the apoptotic cell count in the course of the septic process. MATERIAL AND METHODS: Experimental sepsis was induced by inoculating Wistar rats intraperitoneally with E. coli cells. The liver and lung tissue was obtained 2, 6, 24, 48 and 120 hours after inoculation, and blood smears to detect the leukocyte volume were prepared at the same time. Macrophage activity was studied by immunohistochemical staining, using the ABC method. Apoptotic cell count was detected with the "In Situ Cell Death Detection Kit". RESULTS: Decrease in the total count of leukocyte and lymphocyte percentage and a rise in the percentage of neutrophils in the blood were evidences of a strong inflammation process in an organism. The count of activated macrophages in the liver was high, showing the maximum level at the end of the 2(nd) h after inoculation, after which it began to fall. Apoptotic cell count rose after a decrease in macrophage activity. In the lungs both changes - a decrease in activated macrophage level and a rise in the apoptotic cell count took place later on. CONCLUSION: Our investigations indicate that a decrease in the activated macrophage level is connected with an increased rise in the apoptotic cell count in both organs depending on the stage of the disease and occurs in the liver earlier than in the lungs but the process of cell apoptosis was more intensive in the lungs.