Immunohistochemical Analysis and Electron Microscopy of Glial Cells in the Pancreas of Fetuses and Children.

Schwann cells forming peri-insular glial sheath of the pancreatic islets in some mammals can be involved in the pathogenesis of diabetes mellitus. Human pancreatic cells contain small elongated or oval cells of unknown origin with S100-immunopositive processes. We found that cells with processes located in pancreatic islets of human fetuses and children are similar to Schwann cells by their morphological and ultrastructural characteristics, immunopositive reaction for S100, and integration with nerve endings. In the pancreas of fetuses and children, Schwann cells are often seen in forming pancreatic islets and around the pancreatic ducts. The data suggests that Schwann cells can participate in the morphogenesis of human pancreatic islets.

Distribution of chromogranin A in human fetal pancreas.

Immunohistochemical study of distribution of chromogranin A (neuroendocrine cell marker) in the developing human pancreas was carried out. Immunopositive reaction to chromogranin A was detected in the primordial pancreas from the early period of development (8 weeks). The count of chromogranin A-positive cells in early fetuses significantly surpassed that of insulin- and glucagon-containing cells. Chromogranin A immunoreactive cells, but not cells reacting with antibodies to insulin and glucagon were detected in the pancreatic islets and pancreatic ducts during all periods of gestation. These results suggested that hormone synthesis by pancreatic endocrine cells was preceded by the expression of chromogranin A and hence, this marker could be used for studies of the mechanisms of development of the endocrine part of the pancreas.

[Non-esterified fatty acids of blood serum in type 1 diabetic women during late pregnancy].

Using gas chromatography a comparative study of the range and content of individual non-esterified fatty acids in serum of patients with diabetes mellitus type 1 in the third trimester of pregnancy, and healthy pregnant and non-pregnant women has been carried out. In groups of pregnant women there was activation of lipid metabolism, confirmed by corresponding changes in serum biochemical parameters, as well as in the content of non-esterified fatty acids. Intergroup differences in the non-esterified fatty acids were not found. However, there were significant differences between the examined groups in the quantitative content of non-esterified fatty acids.

Autoantibodies to neuron-specific proteins S100, GFAP, MBP and NGF in the serum of rats with streptozotocin-induced diabetes.

The appearance of autoantibodies to neuronal proteins (S100, GFAP, MBP, and NGF) in rat serum was analyzed by ELISA on days 5, 10, 17, 25, and 32 after streptozotocin injection. Simultaneously, blood glucose and insulin autoantibodies were assayed. Serum glucose level increased on the next day after streptozotocin injection and the level of autoantibodies to insulin significantly increased on day 5 indicating the development of diabetes. The levels of antibodies to specific neuronal proteins (S100, GFAP, MBP, and NGF) also increased at this term. It is concluded that diabetes with streptozotocin is associated with damage to the blood-brain barrier.

[Early morphogenesis of ciliated cells in human oral cavity].

Ciliated cells were found in the epithelium of the oral cavity of human embryos and fetuses starting from the seventh week of prenatal development. At the early stages of prenatal development (until the 13th week), cells with cilia cover most of the dorsal surface of the tongue and the soft palate, whereas they are found only near the gland ducts in the circumvallate and foliate lingual papillae after 17 weeks of development. The ultrastructure of the axoneme of cilia corresponds to the structure of motile cilia and is represented by nine microtubule doublets that surround the central pair of microtubule singlets. An immunohistochemical study performed on weeks 10-12 of development identified nerve endings associated with the ciliated cells. Until the 14th week of development, the cytoplasm of ciliated cells is immunopositive for NSE. The spatial distribution of ciliated cells in the tongue epithelium until the 13th week of development is not related to the morphogenesis of lingual papillae, and their role in the human oral cavity during the first trimester of pregnancy is unclear and requires further study.

[The proinsulin level in the blood of children with type 1 diabetes mellitus of various duration].

Proinsulin content was measured in the serum of 82 children (aged from 3 to 14 years) with type 1 diabetes mellitus of various duration. Three groups of patients characterized by low (54%), normal (42%) and high (4%) levels of this prohormone were recognized. No dependence the proinsulin level on the disease term was found. The serum proinsulin level may be used as a parameter specifying the pathogenesis of type 1 diabetes mellitus.

[The early embryonal anomalies of human brain].

The mechanisms of early embryonic pathology of the brain in man and animals were studied. Analysis of the biomechanical properties of development of nervous tissue and embryonal experiments demonstsrated that tangential neuroepithelial intention is the major source of positional information. Experimental changes in the neuroepithelial intention system resulted in various types of embryonal anomalies of the nervous system. Mechanical-dependent ion channels that have marked periods of sensitivity and determine the histogenetic direction of neuroblast cell differentiation were found to underline the mechanosensitivity of the neuroepithelium. Experimental findings were compared with unique autopsy data on early development of the human brain. Human embryos were examined from neurulation to month 6 of development. Different types of human embryonal brain anomalies were shown to occur with 3 types of neurulation disordes: 1) an open preneuropore is responsible for anomalies of the forebrain and etmoidal area; 2) arrested neurulation in the postneuropore leads to anomalies of the diencephalons, midbrain, and occipital region; 3) impaired neurulatuion in the caudal region is a cause of spinal cord anomalies. The above anomalies resulted from local compensatory responses of the neuroepithelium due to the lack of intentions that are characteristic of normal development of the neural tube.

[Supporting life of Pachydactylus turneri in a projected experiment aboard robotic spacecraft: choosing feed].

An experiment was carried out to validate and select feed to be supplied to Pachydactylus turneri in a 30-day orbital flight of robotic spacecraft BION-M1. Larvae of two Tenebrionidae species, i.e., Tenebrio molitor and Zophobas were tested for survivability, tolerance of hunger and cold, ability to stick to and move along different surfaces. Tenebrio molitor was shown to be best suited. A special feeder that will sustain the beetle over 30 days was designed. The experiment provided new data about Tenebrionidae biology and suggested the feeding technology for a 2-month space experiment with Pachydactylus turneri.

[Distal polyneuropathy in children with diabetes mellitus type 1].

To identify the association between distal peripheral neuropathy (DPN) and type 1 diabetes mellitus (T1D), 62 children and adolescents with different duration of T1D have been studied using electromyography (EMG). Subclinical symptoms of DPN occur with equal frequency in 74% of children with short duration of T1D (group 1) and in 72% of children with long duration of disease. In both groups, the highest frequency of disturbances of the neurophysiological parameters was found in the sural sensory nerve and the lowest frequency in the median motor nerve. Correlations between HbAlc levels and compound muscle action potential were revealed only in tibial and peroneal nerves and only in the early stages of T1D. However, this dependence disappears with increasing duration of the disease.

[Erythrocyte lipid composition at different stages of type 1 diabetes in children].

Complete profiles of phospholipid and ceramide molecular species from erythrocyte lipid extracts of children without carbohydrate metabolism disorders, and children with type 1 diabetes were compared by means of high performance liquid chromatography/mass spectrometry. For the first time a statistically significant increase (p<0.05) of lysophosphatidylcholine content in two groups of diabetic children with different duration of the disease (less than one year and more than one year) was found. Statistically significant changes in other lipid classes were not observed. The dependence of the content of phosphatidylcholine and phosphatidylethanolamine molecular species containing arachidonic acid residue (20:4) on the duration of the disease was found. The observed shift in lipid metabolism suggests of phospholipase A2 and chronic inflammatory process at different stages of diabetes mellitus, in cells (erythrocytes), which aer not involved in the immune response.

[Immunohistochemical study of human fetal vomerona structures the nasal septum, by applying neuron-specific beta3-tubulin antibodies].

The functioning of Jacobson's or vomeronasal organ (VNO) in man is the subject-matter of discussion today. It is generally taken that VNO as an anatomic structure also remains in the adult; however, its receptor apparatus still degenerates in the fetal stage of ontogenesis. Nevertheless, the data available in the literature on the time and specific features of degenerative changes in the human fetal VNO are conflicting and ambiguous. The authors examined the human fetal nasal septum from the 8th week of development to birth, by applying the traditional histological procedures and neuron-specific beta3-tubulin antibodies. An immunohistochemical study could first show the receptor apparatus of the human fetal VNO at weeks 8-26 of development. The immunohistochemical study on a series of sections could reveal the regularities of spatial receptor distribution depending on the time of fetal development. In addition, the developed human fetal vomeronasal nerve and ganglion at weeks 8-26 were described, in human fetuses at weeks 8-26. The neuron-specific marker test has shown the nerve fibers departing directly from the VNO wall, which is inconsistent with the data available in the literature on vomeronasal nerve degeneration in this sign just after the 18th week of development.

[Diabetic fetopathy in gravida with autoimmune hemolytic anemia complicated by steroid diabetes].

The authors made a clinicoanatomic analysis of fetal death in a 32-year-old diabetic gravida at 34-35 weeks gestational age. Fetal autopsy identified the characteristic signs of fetopathy: macrosomy, cardiomegaly, hepatomegaly, and brain weight reduction. Histological analysis revealed minute foci of leukomalacia with glial proliferation in the cerebral hemispheres; adipose and hyaline drop degeneration of cardiomyocytes in the heart, that of hepatocytes in the liver, the proximal renal tubular epithelial cells; hemorrhages in the respiratory portions of the lung. The pancreas displayed inflammation foci, hypertrophy and hyperplasia of the islets of Langerhans. Immunohistochemical studies identified cells with enlarged nuclei among the beta and alpha-cells. The placenta showed a large mass with pronounced changes. It has been demonstrated that steroid diabetes may lead to the development of diabetic fetopathy and placental changes, which are typical of maternal diabetes.

[Integrity principle of the evolution of associative centers in the vertebrate brain].

Principle trends in the evolution of brain associative centers are discussed. It is demonstrated that in various taxonomic groups the possibilities of adaptive changes, as far as the brain is concerned, go beyond the scope of biological, topographical, and dynamic coordinations, typical for other scopes and systems. The reason for such peculiarity of brain evolution is the multifunctional nature of nerve tissue. This property of nerve tissue allows vertebrates to implement the integrity principle and still preserve the flexibility of the brain, which is highly specialized morphologically and functionally.

[An approach to the identification of the phospholipid molecular species in human erythrocytes using HPLC with mass-spectrometric detection].

A modified RP-HPLC-MS approach has been proposed for a single run separation and identification of the molecular species of different phospholipid classes in a complex extract. This approach has been applied to the analysis of glycero- and sphingolipid composition of human erythrocytes and a number of ceramide fractions have been identified; these fractions was missed in previous studies employing similar methods. The fine experimental design leads to the decrease in the number of procedures needed for a complete phospholipid profiling of the sample.

Development of the olfactory bulbs in human fetuses (an immunohistochemical study).

An immunohistochemical study of the olfactory bulb (OB) in human fetuses was performed. Immunohistochemical markers for nervous system-specific protein complexes S-100 and SNAP-25 were used. At 20-22 weeks of development, the development of cells expressing protein S-100 was greater in the OB than in the neocortex (the areas of the gyrus rectus and the gyrus orbitalis longitudinalis internus). These quantitative differences indicate heterochronicity in glial differentiation in the OB and cerebral cortex. Immunopositive reactions for SNAP-25 were for the first time detected at the periphery of the OB and in glomeruli in human fetuses at 15-16 and 20-22 weeks of development. Immunohistochemical staining of the OB with antibodies to SNAP-25 indicated that the human olfactory system cannot function prior to 20-22 weeks of development. In the OB of fetuses at 28-29 weeks of development, the intensity of the immunohistochemical reaction showed topological differences. The reaction with antibodies to SNAP-25 in the OB of full-term fetuses was similar to the reaction in the OB of adult humans. The results of these immunohistochemical studies using the reaction for the protein complex SNAP-25 in fetuses of different ages suggest the that the primary olfactory center in humans starts to function no earlier than the 30th week of development.

[Neuroendocrine complexes in the pancreas of nutria (Myocastor coypus) (an immunohistochemical study)].

With the application of a double immunohistochemical labeling method, several types of neuroendocrine interactions were demonstrated in the pancreas of nutria. Two types of neuroinsular complexes were detected that have the organization typical to the mammals. It was found to be typical of nutria that several pancreatic islets were integrated with nerve cells and nerve fibers. The complexes detected that reflect the interactions between nervous elements and single endocrine cells or their small groups, are species-specific. The data obtained demonstrate the diversity of neuroendocrine interactions in the pancreas and possible influence of the nervous system on B-cell differentiation.

[Measurement of the endogenous alloxane in human blood].

To determine the endogenous alloxane content in blood of healthy donors we stabilized it by rapid lowering of pH in the sample to 2.0. Alloxane was then allowed to form a colored product in a reaction with o-phenylenediamine and its content was measured by spectrophotometry using an internal calibration curve. The experiment showed that the concentration of alloxane in blood of most of the healthy donors varied from 41 to 265 micromol/l. However, a small group of healthy people was had their blood alloxane level greatly exceeding the above-mentioned values.

[Evolution of brain development in amphibians].

Principal events in the early embryonic development of the nervous system, from neurulation to primary differentiation, are considered in different amphibian species. Attention is paid to numerous interspecific differences in the structure of neuroepithelium and the patterns of neurulation and embryonic brain segmentation. The data presented indicate that similarity in brain developmental patterns is apparently explained by universality of morphogenetic mechanisms rather than by the common origin of particular species. A hypothesis is proposed that similarity in the shape of the developing amphibian brain is determined by mechanisms of coding positional information necessary for histogenetic differentiation.

Lactate dehydrogenase isoenzymes in sympathetic neurons and satellite gliocytes in normal conditions and in blockade of nicotinic cholinoreceptors.

Integral cytophotometry was used to measure lactate dehydrogenase (LDH) and its H-and M-isoforms in neurons and satellite gliocytes in tissue sections from the cranial cervical sympathetic ganglion of the rabbit in normal conditions and after experimental partial and complete pharmacological blockade of nicotinic cholinoreceptors (n-CR). In normal conditions, both cell types showed both the H-and M-type isoforms, though the isoenzyme profiles differed--neurons showed a dominance of H-isoform activity while the M-isoform was more active in satellite gliocytes. In partial and complete blockade, the activity of LDH and its H-and M-isoforms decreased significantly in proportion to the number of blocked n-CR. In satellite gliocytes, increases in the extent of blockade were associated with decreases in the activity only of the M-isoform, while the activity of the H-isoform did not change. In partial blockade, the LDH isoenzyme profile of satellite gliocytes shifted towards the neuronal isoform, while in complete blockade there was no difference from the LDH isoenzyme profile of intact neurons. These data led to the suggestion that the formation of lactate in satellite gliocytes is induced by nicotinic cholinergic synapses directly involved in neuron-glial interactions and in controlling the activity of the LDH enzyme system in sympathetic neurons.

[Neurobiological mechanisms of the origin of terrestrial vertebrates].

Some trends in the phylogenetic changes of the vertebrate neural system in the course of their transition from aquatic to terrestrial mode of life are analyzed. Wide multifunctionality of the neural centers and heterotopic substitution of the brain functions are supposed to be prerequisites of transition of archaic amphibians to the land via a stable transitional environment. The latter include underground or vegetation aquatic-air labyrinths in which conditions of gradual acquisition of adaptations to the terrestrial mode of life occurred. The principal neurological adaptations to such mode of life and less dependence on aquatic environment developed during the long-term evolution in that environment. The neurobiological model of evolutionn of the archaic amphibians in the transitional environment of aquatic-air labyrinths suggested herewith is compared to other hypotheses of the tetrapod origin.