[Optical coherence tomography angiography in the diagnosis of retinal microvascular changes in chronic kidney disease (clinical observations)]. / Opticheskaya kogerentnaya tomografiya-angiografiya v diagnostike mikrovaskulyarnykh izmenenii setchatki pri khronicheskoi bolezni pochek (klinicheskie nablyudeniya).

One distinctive pathological sign of chronic kidney disease (CKD) is microcirculatory disorders, which mark it as a microvascular disease. Similarity in the blood supply of the retina and kidneys, in the anatomy of their vascularization lead to identical complications in these organs. The retinal-choroidal microvascular system is easily accessible for clinical and morphological assessment and can be examined by the reproducible and non-invasive method - optical coherence tomography (OCT) and OCT angiography (OCTA). The study of significant diagnostic tomographic retinal biomarkers in CKD and monitoring of their changes are of great clinical importance. The article presents clinical cases of changes in the retina and choroid depending of the stage of CKD. Retinal microvascular changes precede functional impairment. A significant decrease in retinal and choroidal thickness correlates with a decrease in the glomerular filtration rate (GFR) and the degree of albumin excretion in the urine. All clinical cases were observed to exhibit retinal microcirculation disorders, capillary rarefaction in both capillary plexuses accompanied by a decrease in vessel density and a decrease in the circularity index of the foveal avascular zone as a result of regression of the parafoveal capillary networks. OCTA allowed visualization of morphological changes at the microcirculatory level in the form of blunt ends of capillaries, their increased tortuosity and the presence of local areas of decreased perfusion. The severity of retinal microvascular changes varied depending on the stage of CKD and was not associated with either age or the presence of diabetes mellitus. Assessment of the retinal microvasculature can help with monitoring of microvascular lesions, early prediction of the risk of development and progression of decreased renal function, as well as allow avoiding aggressive diagnostic biopsy.

[Perinatal pathology in HIV-infection].

The analysis of the literature and that of own authors' data (structural changes in placenta, fetuses and deceased children) is given. Most typical changes associated with HIV infection (peculiar enlargement of the cells and changes in the size of the nuclei in the cells of different histogenesis) are described. The ways of perinatal infection, pathogenesis of intrauterine infection are discussed.

[Pathological anatomy of HIV infection according to data in Saint-Petersburg]. / Patologicheskaia anatomiia VICh-infektsii po materialam Sankt-Peterburga.

The results of postmortem investigation of 101 cases of HIV infection at its different stages in Saint-Petersburg are analyzed. The challenges to a pathologist performing the autopsy are discussed. There has been an increase in the number of deaths since 2000, among drug users in particular. Macrophacytic transformation and specific HIV-related encephalitis are among the most important changes directly associated with immunodeficiency virus. Among secondary infections, cryptococcosis, cytomegaly, pneumocystosis, and tuberculosis are most common and significant.

[Influence of end products of plasmin-mediated hydrolysis of fibrinogen and fibrin (EF and Ef fragments) on fibrinogen cross-linking]. / Vliianie konechnykh produktov plazminovogo gidroliza fibrinogena i fibrina--fragmentov EF i Ef na protsess perekrestnogo sshivaniia fibrinogena.

We studied the influence of the end products of plasmin-mediated hydrolysis of fibrinogen and nonstabilized fibrin (EF and Ef fragments) on covalent cross-linking of fibrinogen molecules catalyzed by a fibrin-stabilizing factor (factor XIIIa). The data on elastic and dynamic light scattering reveal no difference in the spatial structure of covalently linked fibrinogen molecules in the presence of the hydrolysis end products EF and Ef. In contrast to the inactive fragment EF, fragment Ef significantly accelerates the enzymatic reaction. This is also confirmed by electrophoresis of the reduced samples indicating a relatively fast accumulation of gamma-dimers and A alpha-polymers as compared to the control samples. Possible molecular mechanisms of this effect are discussed.

[Mechanism of cross-linking of fibrinogen and its early structural homolog fragment X]. / Mekhanizm perekrestnogo sshivaniia fibrinogena i ego rannego strukturnogo gomologa X-fragmenta.

We studied the mechanism of the cross-linking of fibrinogen as well as its closest structural homolog X fragment under the influence of a fibronectin-stabilizing factor (factor XIIIa). The data on elastic and dynamic light scattering indicate the formation of single-stranded polymers without any structural rigidity that acquire a ramified and compact structure upon reaching critical mass. The values of coefficients of translational diffusion, mean-mass molecular weight, averaged scattering factor, and the accumulation of gamma-dimers indicate that preincubation of fibrinogen and fragment X solutions significantly accelerates the enzymatic formation of a covalently bound macromolecular protein complex. We propose that enzymatic cross-linking proceeds only with the gradual accumulation of structurally imperfect molecules of fibrinogen and fragment X that are prone to intermolecular D-D end-to-end contacts.

[The structural transformations of X-oligomers]. / Strukturnye prevrashcheniia X-oligomerov.

Mechanism of self-assembly and the three-dimensional organization of the intermediate soluble forms of X-oligomers in the presence of non-denaturing urea concentration have been studied by dynamic light scattering, analytical ultracentrifugation, and viscometric methods. Swedberg and Kuhn-Mark-Hauwink analysis of the obtained hydrodynamic data accounting the concentration effect on translational friction demonstrated formation of equilibrium single-stranded rod-like protofibrils with end-to-end arrangement of the peripheral domains of X monomers. Upon elongation the single-stranded protofibrils form double-stranded structures through lateral aggregation. We infer that alpha C domains are involved in neither stabilization of the single-stranded structures nor their dimerization.

[Social and medical aspects of multimodality therapy for lymphogranulomatosis in children]. / Sotsial'nye i meditsinskie aspekty kompleksnoi terapii limfogranulomatoza u detei.

The high efficiency of treatment of lymphogranulomatosis in children by the currently available protocols determines the necessity of assessing them in terms of the quality of further life. The opportunity of creating a life and having the offspring, that of getting education and a profession are one of the main characteristics of the quality of life. The data on the reproductive function and social adaptation of 443 children receiving multimodality treatment for lymphogranulomatosis by 3 protocols (from 1976, 1978, and 1987). Two hundred and fifty eight individuals were 18 years old or more. Sixty four former patients have 88 children who are all healthy. The treatment performed in childhood intensively, which yielded a complete effect, exerts no substantial impact on the formation and performance of their reproductive function. The former patients have a high intellect, without limitations in getting professions, and they are easily adaptable to the changing social conditions.

[State of the reproductive function in women who had lymphogranulomatosis in childhood and adolescence]. / Sostoianie reproduktivnoi funktsii u zhenshchin, perenesshikh limfogranulematoz v detskom i molodnom vozraste.

As many as 33 women who received combined treatment (fully successful) at an age of 5-26 years for lymphogranulomatosis were examined. In 30 patients, the structure and function of the reproductive organs was within age norm. In 20 women, there were 20 deliveries at an age of 19-33 years, with the mean age amounting to 23 years; 10 boys and 10 girls were born. The children are healthy. The selective toxicity of the treatment as a whole and of each of its components with regard to the reproductive organs was not proved. In the authors' opinion, two cases of disease relapses in pregnant women do not form basis for recommending the woman do refrain from pregnancy in the long-term periods after the treatment of lymphogranulomatosis.

Mechanism of aggregation of fibrinogen molecules: the influence of fibrin-stabilising factor.

The physicochemical mechanism of aggregation of fibrinogen has been investigated in the presence and absence of fibrin-stabilising factor (factor XIIIa). Data from elastic and inelastic light-scattering and viscometry show that molecules of fibrinogen undergo a spontaneous modification of their carboxyl terminals and bind 'end to end' into flexible polymer chains. On attaining a critical length, the single-filament polymers twist into a coil and aggregate to form branched molecules in which the segments are packed sufficiently densely to resemble strongly hydrated globular particles. The formation, under the influence of factor XIIIa, of epsilon/gamma-glutamyl-lysine covalent bonds produces only insignificant changes in the spatial organisation of the fibrinogen aggregates. Covalent dimerisation of the gamma-chains restricts the structural flexibility of the polymers, but linking of the alpha-chains provides progressive compaction of the structure with increase in molecular weight. Electrophoresis of reconstituted samples shows that the coil-shaped chains of fibrinogen oligomers prevent the complete enzymatic linking of the gamma-chains. The results of this work suggest that the accelerated assembly of multimolecular aggregates, seen in the presence of factor XIIIa, may be explained by the stabilisation of intermediate complexes of fibrinogen, which makes the spontaneous transition from a stable native state to the activated state irreversible.

[The effect of fragment D on the aggregation of fibrinogen molecules in solution]. / Vliianie fragmenta D na agregatsiiu molekul fibrinogena v rastvore.

The mechanism of fibrinogen aggregation in the presence of fragment D has been studied. The values of translational diffusion coefficients, specific viscosity, average molecular masses, and Zimm factor of light scattering indicate that fragment D accelerated assembly of fibrinogen molecules that form flexible polymeric chains with tail-to-tail association due to spontaneous structural modification of COOH-terminal regions. Electrophoresis did not reveal the presence of fragment D in polymer fraction of non-reduced samples. The data obtained allowed to conclude that at initial stages fragment D forms unstable complexes with structurally modified fibrinogen molecules. These complexes serve as intermediates in the multistep process of assembly of supermolecular protein complex.

[The antifibrinolytic action of the D-dimer fragment]. / Antifibrinoliticheskoe deistvie fragmenta D-dimera.

The effect of D-dimer on the process of plasmin hydrolysis of unstabilized and crosslinked fibrin has been studied. Less degraded early, intermediate, and late products of fibrin cleavage have been revealed by electrophoresis of reduced and nonreduced samples. The molecular mechanism of antifibrinolytic effect of the D-dimer is supposed to be determined by shielding of peptide regions of monomer fibrin, localized both in N-terminal area of beta chain and in alpha, beta, and gamma chains between D and E domains. A notion has been proposed of autoinhibition of fibrinolytic reaction as a phenomenon related to the physical-chemical regulation of fibrinogen transformation into fibrin.

[Clinical biological possibilities of the early detection of the side effects of antibiotics]. / Kliniko-biologicheskie vozmozhnosti rannego vyiavleniia pobochnogo deistviia antibiotikov.

The study of the dynamics of biogenic amines in the blood of patients provided to a certain extent determination of the possible thread of the drug complications. In this respect the serotonin level was of special significance. As for the reaction of leucocyte agglomeration it may be used before the treatment if there is a doubt in the tolerance of the antibacterial drug prescribed. Increased serotonin blood levels in this case also serve a confirmation of the thread of the possible allergic or toxic reaction in the patient.