Short-term and medium-term clinical outcomes of multisystem inflammatory syndrome in children: a prospective observational cohort study.

Background: Even though the incidence of Multisystem Inflammatory Syndrome in children (MIS-C) is decreasing cases are still reported across the world. Studying the consequences of MIS-C enhances our understanding of the disease's prognosis. The objective of this study was to assess short- and medium-term clinical outcomes of MIS-C.

[Localization of crystallins in Muellerian cells in the grass frog retina].

Cell localization of 23 kDa- and 35 kDa-crystallins in the retina of adult common frogs Rana temporaria L. was studied using indirect immunofluorescence. Intense specific fluorescence of both crystallins was observed all over the retina, in both periphery and central area.

[The effect of para-aminobenzoic acid on the level of proliferative activity in the regenerating cornea of adult rats (a radioautographic study)].

[3H]-Thymidine radioautography showed that 0.005% p-aminobensoic acid (PABA) solution applied three times per day on penetrating wounds in central part of the adult rat cornea selectively stimulates proliferative activity of corneal stroma keratoblasts. In control rats, a curve showing changes in index of labeled nuclei in corneal stroma had two peaks, on the second and sixth day after injury (about 5 and 3%, respectively), whereas in animals receiving PABA treatment it had a single peak on the second day (about 12%).

[Melanotropic activity in the hypophysis and blood of Wistar rats in early postnatal development].

The activity of melanotropins in pituitary homogenates and blood of Wistar rats obtained from the nursery Stolbovaia (Russian Academy of Medical Sciences) was studied using the method of biological testing (Hogben, Slome, 1931; Golichenkov, 1980). In order to elucidate, to what extent the normal status of melanotropic activity is retained in albino rats, two experimental series were performed. Melanotropic activity was determined in (1) intact rats and (2) in rats receiving subcutaneous injections of parachlorophenylalanine, a specific inhibitor of serotonin synthesis.

[Emoxipin as an inhibitor of angiogenesis].

The effect of emoxypin on angiogenesis in rabbit cornea in aseptic inflammation induced by intracorneal implantation of a piece of quartz and on the development of the vessels of the chick embryo yolk sac was studied. 1% emoxypin pipetted thrice a day for 10-14 days inhibited corneal neovascularization and reduced the formation of new blood vessels. We observed an inhibitory effect on the development of vascular bed of the embryo yolk sac on incubation hour 64-72.

Image analysis of the lens opacities induced in developing chick embryo by glucocorticoid.

Glucocorticoid-induced cataracts in chick embryos were monitored by an image analysis system. Opacities in the lens visually showed a complex pattern with significant changes in the cortical and nuclear regions. An electronic image analyser produced an image in which contrast represented different zones of lens opacification in the frontal plane and documented objective lens findings such as the precise topography of the opacities, density and opacity measurements, geometric measurements of boundary surfaces and of regional areas.

[Immunohistochemical study of fibronectin localization during the formation of the vascular coat under the influence of the pigment epithelium in chick embryos].

The role of fibronectin (FN) in cell interactions of retinal pigment epithelium (RPE) and mesenchyme surrounding the optic cup during choroid formation in chick embryos was studied by indirect immunofluorescence using antibodies against FN. Experimental coloboma of retina and choroid was used as a model. During the initial stages of coloboma the regions structured like retina rudiment appear in the outer layer of the optic cup.

[Specific and nonspecific adhesion in the process of retinal cellular aggregation in chick embryos].

A study of aggregation of the retinal cells of 8 and 14 day old chick embryos has revealed two phases in this process. The first phase includes the decrease in the concentration of single cells and the increase in the concentration of aggregates. During the second phase the concentration of aggregates falls at the expense of fusion of smaller aggregates into larger ones.

[Biochemical characteristics of adhesion factors isolated from the retina of 8-day-old chick embryos].

While isoelectrofocusing the extracts obtained after dissociation of the retina of eight day old chick embryos, two active protein fractions were found: AF I with pI 3 and AF II with pI below 3. The content of these fractions in the extracts depended on the method of dissociation: treatment with EDTA increased the content of AF II, whereas trypsin treatment increased the yield of AF I. After electrophoresis in the denaturating conditions both fractions were divided in two components.

[Role of calcium-dependent and calcium-independent mechanisms in the adhesion of retinal and pigment epithelium cells in the chick embryo].

The mechanisms of adhesion of the retinal and pigment epithelium cells, as well of cell interaction within each of these tissues were studied during development. It was shown by means of separation of retina from pigment epithelium in different dissociation media that the adhesion of these tissues in 5-6 day old chick embryos is realized via a Ca2+-independent mechanism. The adhesion of these tissues decreases between days 7 and 16.

Mechanisms of repression and derepression of artificial transformation of pigmented epithelium into retina inXenopus laevis.

The present study shows that pigmented epithelium of tadpoles and adult frogs ofXenopus laevis, like that of the other Anurans and the Cyprinid fishes, cannot transform into retina without the action of retinal factors. Transformation of pigmented epithelium into retina occurs when a sheet of it is implanted into the lensless eye. Transformation of pigmented epithelium also occurs when a sheet of it is wrapped in Bruch's membrane of the adult frog and afterwards implanted into a lensless eye, thus suggesting that Bruch's membrane is permeable to the inducing factors.

[Role of Bruch's membrane in the process of metaplasia of the ocular pigmented epithelium of Xenopus laevis].

The metaplasia of pigmented epithelium into retina with the formation of nuclear and reticular layers took place in the experiments with wrapping a sheet of pigmented epithelium from tadpoles up in the Bruch's membrane of adult frogs X. laevis. The implant with de novo formed retina resembled the inverted eye.

[Metaplastic transformation of the tissue of the eye in tadpoles and adult Xenopus laevis frogs].

The pigment epithelium of the tadpoles and adults X. laevis, as well as of other anurans and cyprinids, is not capable of transformation into the retina without the special influences of agents produced by the retina. When implanting a layer of pigmented epithelium of tadpoles with the Bruch's membrane into the cavity of lensless eye of a tadpole, the transformation of pigment epithelium into retina proceeded in 40% of cases and when implanting the pigment epithelium of adults without the Bruch's membrane, the transformation proceeded in 68% of cases.

[The development of differentiation of pigment epithelium in teleosts and its stimulation to metaplasia].

The time was determined when pigmented epithelium acquires stable differentiation and the possibility was investigated for pigmented epithelium to transform in retina at different developmental stages in the Issyk-kul chebatchok Leuciscus bergi (Cyprinidae). By means of implantation of a layer of pigmented epithelium in pericardium it was established that the pigmented epithelium cells acquired stable differentiation rather early. When an already pigmented layer of pigmented epithelium was implanted in the cavity of a lensless eye, its cell transformed in retina under the influence of the whole retina.