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Biomedical subjects

G Basta-Jovanović

Publications and source records attributed to G Basta-Jovanović.

6 recordsLinked to original sources

Regulation of selectivity and translocation of aquaporins: an update.

All living beings need to solve the problem of controlled transport of water. To this purpose, a special group of integral membrane proteins called aquaporins has evolved. There are 13 known members of this family that act as channels for water and small solutes, such as glycerol and urea. Although they allow large flux of water, they successfully prevent passage of protons. Here, we present the review of the data from the literature on the selectivity mechanism of aquaporins. The regulation of aquaporin activity occurs through regulation of expression of their genes, changing the localization of the already existing proteins in the cells and direct regulation of the activity in situ. We present the review of new data on the mechanisms of direct regulation. Special emphasis is on the advances in comprehension of aquaporin-2 translocation in collecting tubule cells of the kidney. Four elements of this process are described: 1) the role of protein kinase A and phosphorylation of serine 256 on aquaporin-2, 2) the transport of vesicles along the microtubules toward the apical membrane, 3), the removal of cytoskeletal subapical obstruction and the role of Rho GTPase and ezrin-radixin-moesin proteins in this, and 4) elevation of the cytosolic Ca2+ concentration, the fusion of the vesicle with the apical membrane and the role of SNARE proteins in exocytosis.

Animals↗

[Ultrastructural changes in transplantation glomerulopathy].

Twenty-eight biopsy specimens were obtained from patients 3-95 months after kidney transplantation and studied by light, electron and in some cases also by immunofluorescence microscopy. Electron microscopic studies showed that the most frequent glomerular lesion was widening of lamina rata interna which is accompanied with subendothelial accumulation of finely granular material, formation of new subendothelial basement membrane and deposition of microfibrils and fine filaments. The mesangial changes were mainly those of mesangiolysis and mesangial sclerosis with deposition of mesangial matrix and microfibrils, but little cellular proliferation. Fragmented red blood cells were seen in nearly half of the patients. Arterial intimal thickening and occasionally also thrombosis produced ischaemic changes in the kidney and in the glomeruli and contributed to the process of transplant rejection.

Graft Rejection↗

[Electron microscopic analysis of eosinophilic renal cell carcinoma].

Renal cell carcinoma with cytoplasmic eosinophilic globules visualized on routine histologic preparations was analyzed. Eosinophilic globules in cytoplasm of the cells in renal cell carcinoma are very rate and till today we have not heard or found in the literature an attempt to analyze and describe them and that was the aim of our study. By electron microscopy, the globules most closely resembled non-membrane bound filamentous material that normally constitutes the cytoskeleton of normal and neoplastic renal epithelium.

Carcinoma, Renal Cell↗

[Cystic tumefaction in the minor pelvis--the agenesis-dysplasia syndrome (case report)].

UNLABELLED: Ectopic kidney often shows signs of parenchyma maldifferentiation. Multicystic or dysplastic kidney is usually associated with congenital urogenital and skeletal system anomalies. In the Unilateral form of the agenesia-dysplasis syndrome, the kidney, if it is present, is small dysplastic and usually cystically changed. Ipsilateral uterus horn or vaginal agenesia are the most frequently associated anomalies. Case report. A six years old girl was clinically examined due to recurrent urinary tract infections. On ultrasound, the left kidney was enlarged, while the right kidney was absent in normal position. Cystic mass 4x5 cm was seen in the pelvis. The right kidney was not seen on IVP. CT scan showed a cystic formation in the pelvis, described as cystically changed dysplastic kidney. Pelviceal mass was extirpated. Exploration of the genital system revealed vaginal arch blinded in the hypoplastic right uterus horn. On pathohystology tumefaction corresponded to the dysplastic kidney. IN CONCLUSION: unilateral renal aplasia or dysplasia may indicate genital anomalies having in mind the hereditary character of unilateral form of the agenesia-dysplasia syndrome therefore, it could be helpful in prenatal diagnosis of cystic pelvic mass of fetus in families with this syndrome.

Abnormalities, Multiple↗

[Adhesion molecules in kidney diseases (part I)].

Adhesive molecules are (glyco)proteins of the cellular membranes. All of them have their extramembranous, transmembranous and intracytoplasmatic parts. As receptor molecules, their extracellular parts bind the specific ligand. The ligand can be found on the surface of the other cell or in the extracellular matrix (basal membranes). The following families of adhesion molecules are: cadherins, selectins, integrins and members of immunoglobuline supergene family. Different members of the same family could have different times (in ontogenesis, in adult form) and space distribution (in different tissues, different tissue structures). The contact between the cells and basal membranes with these molecules is important for cell division, maintaining the tissue architecture, polarization and function of cells, migration of cells, endo- and exo-cytosis as well as for maintaining the structure and function of basal membranes. As above stated all this is important in the occurrence morphogenesis, haemostasis, inflammation, malignant cell transformation and metastasis. This knowledge is important for the better understanding of renal diseases.

Cell Adhesion Molecules↗

[Adhesion molecules in kidney diseases (part II)].

Different adhesion molecules are involved in the maintenance of tissue architecture, morphogenesis, immunosurveillance, inflammation, tumour growth, etc. Thus, this review will be directed to the role of cadherins, selectins, integrins and members of the immunoglobuline supergene family in the pathogenesis of glomerulonephritis, acute renal failure, reaction of renal rejection, development of renal tumours, their invasion and metastases. A better understanding of the role of adhesion molecules in nephropathology may provide new aspects of treatment of different forms of renal diseases including tumours.

Cell Adhesion Molecules↗