205 research outputs found
Correction of retinal angiopathy of hypertensive type by minoxidil, sildenafil in experiment
For the study of retinoprotective properties of pharmacological agents a model of retinal angiopathy of hypertensive type was created against the background of N-nitro-L-arginine methyl ester (L-NAME) administration in a dose 12.5 mg/kg rat body weight for 28 days. Detection of preconditioning properties of pharmacological agents may be a new approach in the correction and prevention of retinal angiopathy, which is the initial part of hypertensive retinopath
The development of hypertensive neuroretinopathy model on wistar rats
A model of hypertensive neuroretinopathy was developed on Wistar line rats with administration of non-selective NO-synthase blocker N-nitro-L-arginine methyl ester (L-NAME) in a dose 12.5 mg/kg within 28 days on the background of single increased intraocular pressure (IOP) to 110 mmHg. As a result of the interim evaluation of pathology simulation mode the most optimal was a model of hypertensive neuroretinopathy with 5-minute increased IOP at day 26 of the experiment on the background of L-NAME for further study of neuroretinoprotective properties of pharmacological agent
Pharmacological preconditioning by recombinant erythropoietin as the possibility of increasing the stability of tissue of the retina to reperfusion ischemia in experiment
Ischemic injury was formed in laboratory rats by applying mechanical pressure (110 mm Hg) to the anterior eye chamber for 30 minutes. The experiment revealed that the recombinant erythropoietin (50 IU/kg) prevents the development of degenerative changes in retinal layers caused by ischemic injur
Role of catestatin in development and decompensation of heart failure: a literature review
The current literature review covers the role of sympathetic nervous system activation (SNS) and the significance of a new biomarker catestatin (CST), which is a chromogranin A-derived peptide, for assessing prognosis of patients with heart failure (HF). This review details the works devoted to CST metabolism and its role in clinical conditions with excessive catecholamine production, including the ability to counterbalance the adverse effects of SNS on cardiovascular system. The paper also presents the central results of studies on HF patients and shows the correlation of the CST level with HF functional class and stage. In addition, particular attention is paid on the possibilities and potential benefits of assessing the CST in addition to conventional management of patients hospitalized due to acute decompensated heart failure
Pharmacological correction of retinal ischemia/reperfusion by minoxidil
The objective of this paper was to increase the effectiveness of pharmacological correction of retinal ischemia-reperfusion by using minoxidil. Minoxidil at a dose of 0.5 mg/kg of rat mass protects the retina from ischemic-reperfusion injury. Protective effects of minoxidil are carried out by a preconditioning action, as evidenced by the lack of positive effects with the administration of glibenclamid
Comparison of the efficiency of zero and first order minimization methods in neural networks
To minimize the objective function in neural networks, first-order methods are usually used, which involve the repeated calculation of the gradient. The number of variables in modern neural networks can be many thousands and even millions. Numerous experiments show that the analytical calculation time of an N variable function’s gradient is approximately N/5 times longer than the calculation time of the function itself. The article considers the possibility of using zero-order methods to minimize the function. In particular, a new zero-order method for function minimization, descent over two-dimensional spaces, is proposed. The convergence rates of three different methods are compared: standard gradient descent with automatic step selection, coordinate descent with step selection for each coordinate, and descent over two-dimensional subspaces. It has been shown that the efficiency of properly organized zero-order methods in the considered problems of training neural networks is not lower than the gradient ones
Pharmacological correction of morphofunctional retinal injury using 11-amino acid fragment of darbepoetin in the experiment
The retinoprotective effect of the 11-amino acid fragment of darbepoetin PRK-002 on the models of hypertensive retinal angiopathy and hypertensive neuroretinopathy in Wistar rats was investigated in comparison with carbamylated darbepoetin and sulodexide. The study revealed angio- and neuroprotective activity of the 11-amino acid fragment of darbepoetin PRK-002 in correction of retinal injury formed on the background of hypertensio
CHEMOKINE MARKERS ASSOCIATED WITH EARLY REJECTION OF KIDNEY ALLOGRAFT
It is known at the present time that immunological biomarkers may become more sensitive, non-invasive methods of graft rejection diagnosis than those currently used. A growing amount of studies in animal models shows that chemokines, as active participants in the immune process, may be used to this purpose. Our earlier studies have shown an important prognostic significance of IL-6, IL-2, 17A and IL-1RA increase in pre-operative period as markers of acute kidney allograft rejection. When assessing changes in studied peripheral blood growth factors, we concluded that a sharp decrease in BDNF content is a diagnostically significant early sign of kidney allograft rejection. The aim of this study was to identify the prognostic role of serum chemokine levels at the preoperative stage, taking into account the production of anti-HLA antibodies during the post-transplant period as a risk factor of kidney allograft rejection. A comparative analysis of chemokine serum concentrations was performed in the patients with terminal-stage chronic kidney disease (CKD). In the patients from main clinical groups, the blood cytokine levels were measured 6 hours before transplantation, i.e., Eotaxin (CCL11), GRO-α (CXCL1), IL-8 (CXCL8), IP-10 (CXCL10), MCP-1 (CCL2), MIP-1α (CCL3), MIP-1β (CCL4), SDF-1α (CXCL12), RANTES (CCL5), MIG (CXCL9) by means of multiplex immunological assays, using appropriate test systems. The studies have shown significant changes in several chemokines in the CKD patients compared to age-matched controls. However, the following diagnostically significant biomarkers associated with early rejection of transplanted kidney should be considered: increased concentration of CCL2 and CCL4 chemokines, as well as an acute decrease in CCL11. Significantly decreased CXCL12 concentration in peripheral blood could be considered a marker of favorable posttransplant clinical course. Occurence of HLA antibodies in recipients is also associated with elevated serum levels of CXCL8, CXCL10, CCL4, and CCL5
CLINICAL AND IMMUNOHISTOCHEMICAL STUDIES IN THE DIAGNOSIS OF UNDIFFERENTIATED CONNECTIVE TISSUE DYSPLASIA IN PATIENTS WITH CHOLELITHIASIS
There were examined 132 patients in the age of 29-77 years old. Morphological features of abnormal shape or position of gallbladder were detected at 26.9% of patients with undifferentiated connective tissue dysplasia, and this may contribute to the formation of gallstones
LOCAL BARLEY ACCESSIONS FROM ETHIOPIA RESISTANT TO POWDERY MILDEW
The mlo11 allele associated with the loss of function of the Mlo locus and controlling mildew resistance in the majority of modern barley cultivars was identified in Ethiopian barley landraces. Twenty-seven accessions from Ethiopia were studied during laboratory experiments which resulted in identifying k-5448 as an accession resistant to powdery mildew. Three accessions (k-8555, k-8682 k-17554) were heterogeneous by the studied trait. With the help of molecular markers we showed that the resistant components of the selected forms are protected by the mlo11 gene
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