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Introduction. Congenital asplenia is an extremely rare condition that can be separate entity due to a specific defect of spleen development or may occur in the context of a malformation syndrome. The patients with asplenia have thrombocytosis and susceptibility to life-threatening infections. Case report. We report a 52-years-old female patient with isolated congenital asplenia with pseudothrombocytopenia and giant platelets. Estimation of platelets life with radioactive indium showed normal lenght of platelets life (9 days). Flow cytometric analysis of platelets showed normal expression of CD41 and CD42b antigens. The mean platelet diameter of asplenic patient measured on the ultrathin sections by the transmission electron microscope was significantly higher than in the healthy individuals (3.81 ± 1.16 μm vs. 2.37 ± 0.61 μm, p < 0.05). There were very few platelets of diameter more than 4 μm found in healthy individuals (around 1%) in comparison to > 40% of the patient’s platelets. The ultrastructural studies revealed normal morphology of megakaryocytes. The platelets were uniformly spheroid in shape with conspicuous pseudopodia and the centralization of granules. There were no marginal bands of microtubules inside the platelets. Conclusion. The first case of congenital asplenia with the pseudothrombocytopenia and giant platelets is presented. We discussed the pathogenesis of giant platelets and possible relation of observed ultrastructural changes of platelets with the severe three-vessel coronary artery disease in our patient.

Background/Aim. The number of patients with end-stage renal diseases treated with chronic dialysis is increasing over the last years. Long-term peritoneal dialysis is associated with progressive development of structural and functional alterations of peritoneal membrane. The aim of the study was to analyze ultrastructural alterations of mesothelial monolayer and submesothelial tissue in a modified nonuremic experimental model of peritoneal dialysis in rabbits. Methods. The study was performed on 5 healthy Chinchilla rabbits. Surgical procedures of implantation and removal of peritoneal catheter, prevention of catheter clothing, prevention of infection and dialysate instillation were performed according to previously described protocols. Peritoneal tissue samples were collected upon catheter placement and removal after a 5-week follow-up and processed for transmission electron microscopy (TEM) examination. Results. The rabbits tolerated anesthesia, surgical procedure and the applied regimen of dialysate instillations well. The animals recovered completely and no adverse effects were noted. In the animals treated with peritoneal dialysis instillations, TEM revealed alterations of the mesothelial monolayer and submesothelial tissue. The mesothelial cells in direct contact with dialysis fluid were prone to shrinking. They lost the typical cobblestone morphology and assumed a flattened shape. The mesothelial cells were often detached from the basement membrane. These cells showed euchromatic nuclei, higher number of microvilli in their apical part and very numerous vesicles. A higher quantity of collagen fibers was noticed in the peritoneal lamina propria in close relation to the basement membrane of mesothelium. The nuclei of the fibroblasts were also euchromatic. Numerous mitochondria, granules and vesicles were present in their cytoplasm. Conclusion. The used rabbit model of peritoneal dialysis is simple, practical to perform, reproducible, not expensive and not requiring advanced devices. It is suitable for obtaining peritoneal tissue samples for histological examination and can be used to analyze the effects of dialysis solutions on the rabbit peritoneal membrane. [Projekat Ministarstva nauke Republike Srbije, br. 145070]

Background/Aim. During peritoneal dialysis (PD) an exchange of substances between blood and dialysate takes place through specific histological structures of peritoneum. Peritoneal double-layered serous membrane has, so far, mostly been studied with electron microscopy on experimental animals. The aim of this study was to assess integrity of peritoneal tissue in end-stage renal disease (ESRD) and PD patients using standard light microscopy and immunohistochemical methods. Methods. Peritoneal tissue biopsies were performed on 25 persons: 8 healthy donors during nephrectomy, 9 ESRD patients upon insertion of PD catheter, and 8 PD patients upon removal of the catheter for medical indications. The samples were fixed and prepared routinely for immunocytochemical staining by standardized streptavidin biotin AEC method using a LSAB2® HRP kit (Dako®, Denmark) for collagen IV and analyzed by light microscopy. Results. We observed mesothelial detachment from lamina propria, duplicated basement membrane and much thicker blood vessel walls in ESRD and PD patients, compared to healthy subjects. Differences in histological structure, emphasized with immunostaining, indicated pathological alterations of peritoneal tissue in the renal patients. Conclusions. Imunohistochemistry can be used in studying histological alterations of peritoneal tissue in ESRD and PD patients. This method may indicate possible problems in filtration and secretion processes in this tissue.

Background. Incontinentia pigmenti (IP) is a rare, complex, X-linked genodermatosis in which skin changes are combined with defects of other organs. It appears almost exclusively in females and is usually lethal in men. It is estimated that according to the available reported cases, there have been approximately 900-1 200 affected individuals, out of which 60 males. The aim of the study was to report two additional individual male cases with IP. Case reports. We discovered two male patients with IP according to standard IP diagnostic criteria. The diagnosis was made by a dermatologist and confirmed by cutaneous histopathology and ultrastructural analysis. The pedigrees, karyotype analyses and routine laboratory findings were made. Two male probands were the only ones with IP in their families, with no history of miscarriages. Both probands had normal karyotype. In one proband, acrocentric chromosomes of the group D had tendency of forming associations. Histopathological and ultrastructural skin analyses revealed findings typical for IP. Conclusion. The detection of each male case is very valuable because of their rarity. Application of the standard diagnostic criteria is necessary for comparison and epidemiological analysis. Monitoring such probands allows a better determination of how genetic transmission occurs, and is important because of the different degrees of severity of IP.

The aim of the study was to investigate the morphology of mesothelial cells of the peritoneum of patients with terminal renal failure (TRF), taken by the biopsy immediately before the onset of peritoneal dialysis (PD), and to compare it with the findings in patients with PD. The samples were prepared in the way standard for light microscopy and transmission electron microscopy. In patients with TRF intracytoplasmatic inclusions could be observed, unusual protrusions of mesothelial apical surfaces, deformation of mesothelial cells and their detachment from the basal membrane, as well as the dilatated cisternae of granulated endoplasmatic reticulum with filamentous structures in some of them. In patients on PD cytoplasmic protrusions of different shapes and contents were observed at the surface of mesothelial cells, multiplication of basal membrane, occurrence of young forms of mesothelial cells as well as the detachment of those cells from the basal lamina.