Microalbuminuria in Rats Treated with D-Nitroarginine Methyl Ether.

Microalbuminuria is an early symptom and prognostic marker of the progression of renal pathology. The analysis of the role of anionic components of the renal glomeruli in the albumin retention and the development of a model of minimal changes in the glomerular filter leading to the appearance of microalbuminuria are relevant. The effect of organic cations D-arginine methyl esters (D-AME) and D-nitroarginine (D-NAME) on the excretion of albumin by the kidneys in rats was studied. D-AME had no effect on urinary albumin excretion in rats. D-NAME caused microalbuminuria, which persisted for more than a day and sharply increased after injection of vasopressin. The number of anionic sites labeled with polyethyleneimine decreased in the structures of the glomerular filter. D-NAME-induced microalbuminuria can later serve as a model for studying nephroprotective or damaging factors.

[Posterior reversible encephalopathy syndrome in children with hematological diseases]. / Sindrom zadnei obratimoi entsefalopatii u detei s zabolevaniyami sistemy krovi.

OBJECTIVE: To assess risk factors (RF) and severity grade of Posterior reversible encephalopathy syndrome (PRES) in children with hematological diseases. MATERIAL AND METHODS: We analyzed cases of PRES in children during chemotherapy (CT) and after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We estimated the following RF: arterial hypertension, steroid therapy, CT, immunosuppressive therapy (IST), infection and renal injury. RESULTS: Thirty-five cases of PRES occurred in 32 patients (8 after allo-HSCT and 27 during CT) were included in this study. In the most of cases (94.3%), there were 2 and more RF. An increase in blood pressure level (88.6%), CT and IST (82.8%) administration, steroid therapy (71.4%) were the most significant for PRES development. Infectious process and the decline in renal function played a lesser role in this syndrome (31.4% and 14%). At the initial presentation of PRES, there were seizures (94.3%), a decrease of consciousness (28.6%), headache, vision disturbances and stomachache (20%). In the most of cases (91.4%), the 2nd and 3d grade according to the Common Terminology Criteria for Adverse Events (CTCAE 5.0) were observed. Brain magnetic resonance imaging (MRI) revealed the vasogenic edema of temporal (88.6%), occipital (74.3%), frontal (40%) lobes and the cerebellum (22.9%) more often than the cytotoxic edema (p=0.03). The cytotoxic edema was observed in the thalamus and the basal ganglia (2.9%) more often than in other parts of the brain (p<0.01). CONCLUSION: The majority of PRES cases are caused by more than two RF. Arterial hypertension does not have a leading role among its causes. There is a significant correlation between the grade of PRES according to CTCAE 5.0 score and RF number (p<0.05).

[Sturge-Weber syndrome in children. Clinical features, diagnosis and approaches to therapy on the example of three clinical cases]. / Sindrom Shturge-Vebera u detei. Osobennosti kliniki, diagnostiki i podkhodov k terapii paroksizmal'nykh sostoianii na primere trekh klinicheskikh nabliudenii.

Sturge-Weber syndrome belongs to the group of phacomotoses and is characterized by a combined lesion of the skin, eyes, nervous system and internal organs. The clinical course of Sturge-Weber syndrome is quite diverse. Of particular interest in the practice of pediatric neurology and neurosurgery is the fact that 72-90% of patients present with epilepsy. Of particular difficulty is the differential diagnosis of epileptic seizures and stroke-like episodes. The article presents clinical cases of patients with Sturge-Weber syndrome of various ages with epileptic seizures and transient ischemic attacks.

[EFFECT OF DIFFERENT PROTEINS ON THE REABSORPTION OF YELLOW FLUORESCENT PROTEIN IN THE KIDNEY OF BROWN FROG RANA TEMPORARIA].

Protein reabsorption in the proximal tubules (PT) of the frog kidney was studied by the methods of immunohistochemistry, fluorescent and confocal microscopy. Yellow fluorescent protein (YFP) was introduced in combination with other proteins. Reabsorption of YFP introduced simultaneously with ly- sozyme or green fluorescent protein (GFP) did not differ from the result of YFP injection only. Previous lysozyme injection did not change YFP absorption in contrast to YFP uptake reduced after GFP pretreat- ment. Lysozyme loading for 4 days resulted in a significant reduction in YFP absorption. The results show that receptor-mediated endocytosis in the frog kidney depends on the molecular nature of absorbable ligands, conditions of their competitive absorption and lysosomal accumulation in epithelial PT cells.

Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria.

The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes), and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

[Reabsorption of yellow fluorescent protein in the Rana temporaria kidney by receptor-mediated endocytosis].

The absorption of yellow fluorescent protein (YFP) and the expression of the endocytic receptors, megalin and cubilin, were investigated in the renal proximal tubules (PT) in frogs Rana temporaria after parenteral YFP injections. The methods of confocal microscopy and immunohistochemistry were used. The dynamics of YFP absorption was analyzed 2 h after injection. The logarithmic time dependence of the accumulation of YFP-containing endocytic vesicles in PT cells and the completion of absorption process 90-120 min after injection were shown. Unlike substantial megalin and cubilin expression 15-30 min after YFP introduction, immunolabeled endocytic receptors were not detected in PT cells after 2 h. The re-injection of YFP led to the appearance of apical endocytic vesicles containing megalin or cubilin colocalized with YFP. At the same time, the decrease of YFP uptake associated with reduction in the number of receptor-containing vesicles was demonstrated, suggesting a failure of megalin and cubilin expression. The decrease of absorption capacity of PT cells after YFP re-injection was similar to that found previously under conditions of the competitive absorption of green fluorescent protein (GFP) and YFP injected in different sequences. The data are the further demonstration of the proposed mechanism limiting the tubular protein absorption in the frog kidney and suggest the involvement of megalin and cubilin in uptake and vesicular transport of YFP.

Absorption capacity of renal proximal tubular cells studied by combined injections of YFP and GFP in Rana temporaria L.

The capacity for protein reabsorption in the renal proximal tubule (PT) was studied in Rana temporaria frogs by separate, simultaneous and sequential introduction of yellow fluorescent protein (YFP) and green fluorescent protein (GFP). The uptake patterns of YFP and GFP in PT epithelial cells were investigated 15-120min after their bolus intravenous and intraperitoneal injection. As shown by confocal microscopy, the tubular uptake of YFP and GFP was time- and dose-dependent. These proteins are absorbed in similar way and can be accumulated in the same endocytic vesicles after their combined injections. When GFP was injected 30 and 90min before YFP, and vice versa, the number of vesicles with pre-injected protein increased and the percentage of vesicles with colocalized GFP and YFP reduced. At the same time, the uptake rate of a protein injected later progressively and significantly decreased. Subcellular localization of endocytic receptors, megalin and cubilin, in renal PT cells after intravenous YFP introduction were revealed by immunofluorescent microscopy. Colocalization of internalized YFP with megalin or cubilin in the endocytic vesicles was demonstrated. The data suggest the possibility of protein uptake by receptor-mediated endocytosis and the existence of a mechanism limiting the protein absorption rate in wintering frogs.

[Morpho-functional changes in small intestine epithelium of frog Rana temporaria during hibernation].

Structure and function of small intestinal epithelium were studied in overwintering frogs Rana temporaria at various stages of hibernation. In the process of testing of absorption of arginine vasotocin (AVT) in experiments in vitro it is established that at the period of hibernation there is preserved the capability of the epithelium for absorption of this nonapeptide without hydrolysis. However, as compared with October-December, in January-February and later, a decrease of the AVT absorption takes place, which is the most pronounced in March-April. Changes in epithelial structures appear by the middle of winter and are progressing by spring. In April-May, as compared with the beginning of hibernation, the height of enterocytes, the length of microvilli, and the number of microvilli decrease by 33 %, 40 %, and 57 %, respectively. The absence of features of destruction indicates an adaptive character of the observed changes. Dynamics of the studied parameters indicates morphological plasticity of the small intestine epithelium of R. temporaria at the period of hibernation.

[Absorption of arginine-vasopressin and arginine-vasotocin in small intestine of the frog Rana temporaria].

Experiments in vitro demonstrated a partial absorption of arginine-vasopressin (AVP) in the frog small intestine. Dynamics and efficiency of the nonapeptide absorption are studied with use of hydroosmotic method of recording of the osmotic permeability of the frog urinary bladder epithelium and immunoenzyme analysis. In the process of absorption there were preserved intactness of the hormone cyclic structure and its physiological activity, like in the case of the arginine-vasotocin (AVT) absorption. The AVP absorption increased at its administration into the gut with inhibitor of proteases. By methods of immunoelectron and immunofluorescent microscopy with use of polyclonal antibody to AVP, location of the label to the hormone was shown in the enterocyte cytoplasm. Thus, there was obtained a morphological evidence for the AVP absorption and transepithelial transfer in the frog small intestine. These data enlarge the concept of the poorly studied properties of the absorbing epithelium of the vertebrate intestine with respect to absorption of intact molecules of polypeptides.

Tubular GFP uptake pattern in the rat and frog kidneys.

The renal tubular uptake of green fluorescent protein (GFP) after its bolus intravenous injection was studied in both frogs and rats. GFP fluorescence in the proximal tubule (PT) was revealed by fluorescent and confocal microscopy. Granular GFP fluorescence was observed nearby in the apical membrane of PT cells featuring distribution over the cytoplasm. GFP was internalized into endosomes and lysosomes as determined by immunocytochemistry in frogs. The tubular uptake and accumulation of GFP were dose- and time-dependent in both rats and frogs. Intralymphatic sac injection of arginine vasotocin (AVT) decreased the uptake of GFP in hydrated frogs. A high negative correlation between the AVT dose and the uptake of GFP was revealed. The effect of AVT was inhibited by a V(1)-receptor antagonist. A noted decrease in the average number of fluorescent PT profiles per kidney section and their irregular distribution after AVT injections suggest that not all of the glomeruli or preglomerular vessels are equally responsive to AVT. GFP may serve as a good marker for tubular uptake and intracellular traffic in the amphibian kidney for use in in vivo studies.

[Determination of ion content and localization of vasopressin and aquaporin receptors in the gerbil kidney after the flight aboard biosatellite "Foton M3"].

After 12 days on space fight, body mass of gerbils decreased by 32.9%; however, the effective systems of regulation did not let changes in the concentration of Na, K, Mg ions in fresh samples of the renal cortex. These data are viewed as a reflection of the regulation systems strategy to preserve the optimal conditions for functioning of the kidney, a vital body organ. The cations were reduced significantly in the renal medulla when calculated for dry mass and compared with the synchronous control. This could have changed the osmoregulating function of the kidney during space fight and, due to small cations accumulation, caused the drop of the cortex/medulla osmotic gradient. Locations of V1a-, V1b- and V2-receptors and aquaporin 1 and 2 in renal tubule cells of gerbils before and fight are described.

[Green fluorescent protein absorption and accumulation in the renal proximal tubule cells after its increased entry into blood].

The uptake of green fluorescent protein (GFP) by the proximal renal tubules was studied in the anaesthetized rats using laser confocal microscopy after GFP intravenous injection or administration into the small intestine lumen. The specific green fluorescence revealed in the proximal tubule cells after intravenous injection correlated with the logarithm of GFP dose injected intravenously (r = 0.96, p < 0.05). GFP fluorescence after its intravenous injection was higher than that one after GFP infusion into the small intestine (p < 0.05). Following the increase of injected GFP dose, the epitheliocyte cytoplasm, in addition to diffuse fluorescence, demonstrated large intensely fluorescent vesicles, that was confirmed by a graphical analysis. The reported changes in the intensity and pattern of specific fluorescence indicate the enhancement of GFP absorption by the cells of proximal tubules and GFP accumulation in the intracellular compartments during its increased entry into circulation.

[Dynamics of absorption of yellow fluorescent protein in intestine and reabsorption in kidney in rat postnatal ontogenesis].

In experiments of the 5, 12 and 25-day old rat pups and adult rats in has been shown that after administration of yellow fluorescent protein (YFP) into stomach, its partial absorption in the non-degraded state in the small intestine takes place, with subsequent transport to kidney with blood flow and accumulation in cells of the proximal nephron segment. With age of rats, intensity of the intestinal YFP absorption decrease; the YFP accumulation in the kidney is more active in rats of the younger age groups than in adult animals. No accumulation of YFP in liver was revealed. The obtained data indicate an intensive absorption of YFP in the non-hydrolyzed form in the rat pup small intestine in early postnatal ontogenesis and an important role of kidney in protein metabolism and in proteolysis of exogenous proteins.

[TolC mutant of Sinorhizobium meliloti strain SKHM1-188 fails to establish effective symbiosis with alfalfa].

The TolC mutant Tr63 of Sinorhizobium meliloti was generated by random Tn5 mutagenesis in the effective strain SKhM1-188. The mutant did not produce fluorescent halos in UV light on the LB medium containing calcofluor white, which suggests that modification occurred in the production of exopolysaccharide EPS1. Mutant Tr63 also manifested nonmucoidness both on minimal and low-phosphate MOPS media, and this was most likely connected with the absence of the second exopolysaccharide of S. meliloti (EPS2). The mutant was defective in symbiosis with alfalfa and formed on roots of host plants Medicago sativa and M. truncatula white round Fix- nodules or nodules of irregular shape. These nodules possessed the structure usually described for nodules of EPS1 mutants. According to the data of sequencing a DNA fragment of the mutant adjacent to the transposon, Tr63 contained a Tn5 insertion in gene SMc02082 located on the S. meliloti chromosome. This gene encodes the protein sharing homology with the TolC protein, a component of a type I secretion system responsible for the export of protein toxins and proteases in Gram-negative bacteria. The presence of proteins ExsH (endoglycanase of EPS1) and protein ExpE1 (essential for excretion of EPS2), which are known to be exported by the type I secretion system, was tested in cultural supernatants of mutant Tr63 and the parental strain by polyclonal antiserum analysis. It was ascertained that secretory proteins ExsH and ExpE1 are absent in the culture medium of mutant Tr63. The TolC protein of S. meliloti is assumed to be involved in the excretion of proteins ExsH and ExpE1.

Renal clearance of absorbed intact GFP in the frog and rat intestine.

Intestine absorption of intact green fluorescent protein (GFP) and its following accumulation in the renal proximal tubule cells after its intragastric administration have been established by confocal microscopy in the rat and frog. Reabsorbed GFP was revealed in the endosomes and lysosomes of the proximal tubule cells by the methods of GFP photooxidation and immunofluorescent microscopy. The GFP intestine absorption rate and GFP accumulation in the kidney were significantly higher in the frog than in the rat. No specific fluorescence was revealed in the liver and colon cells after the GFP intragastric administration. The data obtained indicate the ability of the small intestine in the frog and rat to absorb intact proteins and an important role of the kidney in exogenous protein metabolism.

[Kidney accumulation of yellow fluorescent protein after its absorption in the rat intestine].

Yellow fluorescent protein (3.6 ng) was administered through a catheter into the Wistar rat intestine lumen. By the method of confocal microscopy it has been established that as soon as in 3 min this protein appears in the epithelial cells of ileum, is absorbed into the blood and accumulated in cells of the nephron proximal segment, not being revealed in the liver, though. The protein accumulation in kidneys continues for several hours. The yellow fluorescent protein is homogeneously distributed in enterocytes, while in epithelial cells of the proximal tubule this protein is localized in vesicles. The data obtained indicate absorption of non-degraded yellow fluorescent protein in the intestine and role of kidney in metabolism not only of endogenous, but also of exogenous proteins.

[Clinical and biochemical characteristics of biliferous tract diseases in patients with diabetes mellitus].

The aim of the study was to investigate manifestations of biliferous tract diseases in patients with diabetes mellitus (DM) and to measure concentrations and the ratio of lipids in gall-bladder and liver bile in these patients. 125patients with DM and biliferous tract diseases were examined. Patients with chronic cholecystitis (CC), cholelithiasis, and biliary dyskinesia underwent clinical examination as well as biochemical and instrumental tests. The control group included 87 healthy individuals of comparable age and gender. CC was diagnosed in 35.2% of DM patients, cholelithiasis - in 17.6% patients. In liver and gall-bladder bile samples taken from patients with CC and cholelithiasis, fatty acids concentrations was not significantly different, cholesterol level was significantly higher, and phospholipids level was lower than in the control group. Thus, indices of cholesterol saturation in liver and gall-bladder bile portions were higher in patients with cholelithiasis than in the control group. The study revealed high biliferous tract diseases morbidity in patients with DM. Thomas-Hofmann index, which characterizes bile saturation with cholesterol, is significantly higher in patients with cholelithiasis and DM, then in healthy individuals.