Method of Reduction Background Fluorescence in Human Fetal Brain Tissue and Quantitative Estimate of the Effect of Photobleaching.

We developed a method of reducing the background fluorescence of samples made from formalin-fixed and paraffin-embedded blocks of the brain of the second-trimester human fetuses. For reducing excess background fluorescence, the samples were subjected to photobleaching using an LED lamp with blue and red emission peaks in the range of visible spectrum in a construction of an original design. The decrease in the background autofluorescence was checked by measuring the intensity of the emitted background fluorescence of the samples and relative abundance of immunopositive structures after immunohistochemical staining. It was found that the proposed method reliably reduced the background fluorescence of the samples, which improved the quality of multicolor immunofluorescence images of the cerebral cortex.

[AMYGDALA: NEUROANATOMY AND NEUROPHYSIOLOGY OF FEAR].

This work describes neuroanatomical and neurophysiological mechanisms of Pavlovian fear conditioning, focusing on contributions of the amygdala, a subcortical nuclear group, to control of conditioned fear responses. The mechanisms of synaptic plasticity at projections to the amygdala and within amygdala were shown to mediate the formation and retention of fear memory. This work reviews current data on anatomical organization of the amygdala, as well as its afferent and efferent projections, in respect to the role of the amygdala in auditory fear conditioning during which acoustic signals serve as the conditioned stimulus.

[Thymic mast cell localization at different stages of the ontogenesis in the mouse].

The aim of this research was to characterize the population of thymic mast cells (MC) which were demonstrated by histochemical methods, at different stages of mouse ontogenesis. First MCs appeared on day 19 of intrauterine life. MCs were localized to the thymic medulla during the whole embryonic period. Individual MCs could also be identified within the cortex. Single MCs were interspersed among other thymic medullary cells. In the newborn, young and mature animals, MCs were observed in the connective tissue of the capsule and in the interlobular septa, but some MCs were also found inside the thymic lobules. In the last-mentioned case, MCs were located in the subcapsular zone. The possible functional significance of MCs localization is discussed.

[Expression of the starfish complement component C3 gene homologue under the influence of bacterial lipopolysaccharide].

The fragment of a homologue of complement component C3 gene has been cloned and sequenced from the starfish, Asterias rubens. Phylogenetic analysis of ArC3-like gene demonstrates that ArC3-like gene has close similarity to C3 gene homologues of Deuterostomia invertebrate animals. High level of ArC3-like gene expression was identified in circulating cells (coelomocytes), in a gut's derivate (hepatopancreas) and in male gonada but not in stomach, female gonad and rectal gland of A. rubens starfish. ArC3-like gene expression was shown in all types of starfish coelomocytes: in lymphocyte-like cells, granular and nongranular amebocytes. Injection of bacterial lipopolysaccharide (LPS) solution into the coelomic cavity of starfish leads to the increase of ArC3-like gene expression in coelomocytes and hepatopancreas over the control level of sterile sea water injection. The level of ArC3-like gene expression increased in response to LPS reaching the maximum 6 h after the stimulation, and decreased to basal level 24 h after the stimulation. Injection of LPS solution stimulated the increase of ArC3-like gene expression level in hepatopancreas reaching the maximum 6-12 h after the stimulation, and the level of mRNA of ArC3-like gene had still been increased 48 h after LPS injection. The data demonstrates sustained positive regulation of ArC3-like gene expression under the influence of LPS.

Gene- and cell-based therapy of diabetes: between bench and bedside.

Pancreatic B cells are highly specialized in their ability to sense the glucose level and maintain the energy status of the organism through secretion of insulin, which is considered to be the primary anabolic hormone. Glucose exerts its effects on virtually all of the steps of insulin production: transcription of insulin gene, mRNA stability, translation, proinsulin processing, and insulin release via a highly regulated secretory pathway. Insulin therapy remains the only treatment of insulin-dependent diabetes (IDDM)--the chronic autoimmune disorder resulting in B-cell destruction. Yet, even regular daily insulin injections accompanied by the persistent control of blood glucose levels cannot provide for a glycemic control as precise as that existing in B cells, nor can it prevent the development of late complications. Different experimental approaches for IDDM treatment, their advantages and limitations, and their potential to be introduced into medical practice are discussed in this review. The alternative mostly experimental methods of IDDM treatment call for restoration of insulin-producing cells. The numerous experiments on insulin gene delivery into the non-islet tissues resulted in uncontrolled insulin secretion. The attempts to reproduce regulated glucose-dependent transcription of insulin gene in transduced cells could not reproduce so far the same complex and refined regulation of insulin production and release as that provided by B cells. Generation of pancreatic B cells from the embryonic or adult stem cells represents an appealing strategy that could potentially overcome the problems of the lack of donor material and graft rejection. The future experiments on identification and characterization of the factors involved into the differentiation of B cells will allow researches and clinicians to use stem cells for the safe and effective treatment of insulin-dependent diabetes in parallel with insulin- and immunomodulatory therapy.

70 kDa heat shock proteins from mollusc and human cells have common structural and functional domains.

1. Immunological and ATP-binding properties of 70 kDa heat shock proteins (hsp 70) from HeLa and sea bivalve mollusc cells were investigated. 2. Hsp 70 have similar antigenic and ATP-binding domains despite the taxonomic difference between the species.

[Changes in RNA synthesis in neurons depending on the intensity of their synaptic activity]. / Izmeneniia sinteza RHK v neironakh v zavisimosti ot intensivnosti ikh sinapticheskoi aktivatsii.

A prolonged synaptic activation of the frog spinal motoneurons increases the intensity of 3H-uridine incorporation into nuclei and nucleoli of the nerve cells. The higher the frequency of neuronal synaptic activation, the higher the incorporation intensity during the post-activation period.