Ultrastructural Abnormalities in Induced Pluripotent Stem Cell-Derived Neural Stem Cells and Neurons of Two Cohen Syndrome Patients

Cohen syndrome is an autosomal recessive disorder caused by VPS13B (COH1) gene mutations. This syndrome is significantly underdiagnosed and is characterized by intellectual disability, microcephaly, autistic symptoms, hypotension, myopia, retinal dystrophy, neutropenia, and obesity. VPS13B regulates intracellular membrane transport and supports the Golgi apparatus structure, which is critical for neuron formation. We generated induced pluripotent stem cells from two patients with pronounced manifestations of Cohen syndrome and differentiated them into neural stem cells and neurons. Using transmission electron microscopy, we documented multiple new ultrastructural changes associated with Cohen syndrome in the neuronal cells. We discovered considerable disturbances in the structure of some organelles: Golgi apparatus fragmentation and swelling, endoplasmic reticulum structural reorganization, mitochondrial defects, and the accumulation of large autophagosomes with undigested contents. These abnormalities underline the ultrastructural similarity of Cohen syndrome to many neurodegenerative diseases. The cell models that we developed based on patient-specific induced pluripotent stem cells can serve to uncover not only neurodegenerative processes, but the causes of intellectual disability in general.

Female and Male Phenotypes of Iron Deficiency in CHF. Additional analysis of the «The Prevalence of Iron Deficiency in Patients With Chronic Heart Failure in the Russian Federation (J-CHF-RF)» study

Aim    To evaluate the incidence of iron deficiency (ID) in men and women with chronic heart failure (CHF) and to compare clinical and functional indexes in patient with and without ID depending on the gender.Material and methods    An additional analysis of the study "Prevalence of Iron Deficiency in Patients With Chronic Heart Failure in the Russian Federation (ID-CHF-RF)" was performed. The study included 498 (198 women, 300 men) patients with CHF, in whom, in addition to iron metabolism, the quality of life and exercise tolerance (ET) were studied. 97 % of patients were enrolled during their stay in a hospital. ID was defined in consistency with the European Society of Cardiology (ESC) Guidelines. Also, and additional analysis was performed according to ID criteria validated by the morphological picture of the bone marrow.Results    ID was detected in 174 (87.9 %) women and 239 (79.8 %) men (p=0.028) according to the ESC criteria, and in 154 (77.8 %) women and 217 (72.3 %) men (p=0.208) according to the criteria validated by the morphological picture of the bone marrow. Men with ID were older and had more severe CHF. They more frequently had HF functional class (FC) III and IV (63.4 % vs. 43.3 % in men without ID); higher concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and lower ET. HF FC III increased the probability of ID presence 3.4 times (p=0.02) and the probability of HF FC IV 13.7 times (p=0.003). This clinical picture was characteristic of men when either method of determining ID was used. In women, ID was not associated with more severe CHF.Conclusion    Based on the presented analysis, it is possible to characterize the male and female ID phenotypes. The male ID phenotype is associated with more severe CHF, low ET, and poor quality of life. In females of the study cohort, ID was not associated with either the severity of CHF or with ET.

[Iron deficiency in Russia heart failure patients. Observational cross-sectional multicenter study]

Aim    To evaluate the prevalence of iron deficiency (ID) in Russian patients with heart failure (HF).Material and methods    Iron metabolism variables were studied in 498 (198 women, 300 men) patients with HF. Data were evaluated at admission for HF (97 %) or during an outpatient visit (3 %). ID was determined according to the European Society of Cardiology Guidelines.Results    83.1 % of patients had ID; only 43.5 % of patients with ID had anemia. Patients with ID were older: 70.0 [63.0;79.0] vs. 66.0 years [57.0;75.2] (p=0.009). The number of patients with ID increased in parallel with the increase in HF functional class (FC). Among patients with ID, fewer people were past or current alcohol users (p=0.002), and a greater number of patients had atrial fibrillation (60.1 vs. 45.2 %, p=0.016). A multiple logistic regression showed that more severe HF (HF FC) was associated with a higher incidence of ID detection, whereas past alcohol use was associated with less pronounced ID. An increase in N-terminal pro-brain natriuretic peptide (NT-proBNP) by 100 pg/ml was associated with an increased likelihood of ID (odds ratio, 1.006, 95 % confidence interval: 1.002-1.011, p=0.0152).Conclusion    The incidence rate of HF patients is high in the Russian Federation (83.1 %). Only 43.5 % of these patients had anemia. The prevalence of ID in the study population increased with increases in HF FC and NT-proBNP.

[Homocysteine and markers of endothelial dysfunction in multiple sclerosis]

OBJECTIVE

To identify hyperhomocysteinemia and to assess its possible association with the course and other markers of endothelial damage in multiple sclerosis.

MATERIAL AND METHODS

Analysis of blood serum for homocysteine, for the content of adhesion molecules sPECAM-1, matrix metalloproteinase 9, blood plasma test for von Willebrand factor antigen in patients with multiple sclerosis. The values of these indicators were analyzed depending on the course and activity of the demyelinating process, the severity of neurological disorders, as also depending on the therapy received.

RESULTS

Hyperhomocysteinemia was found in more than half of patients with multiple sclerosis. A significantly higher homocysteine level was found in male patients, and hyperhomocysteinemia was associated with the activity of the process in patients with highly active multiple sclerosis.

CONCLUSION

The results of the study suggest a possible association of hyperhomocysteinemia with high process activity and disease progression, as well as with mechanisms of neurodegeneration. Determination of homocysteine concentration may be one potential marker for predicting the course of the disease.

[Thrombosis of the inferior vena cava and right portions of the heart in a relapsing retroperitoneal malignant tumour]

Presented herein is a clinical case report regarding successful treatment of a female patient with a relapsing malignant retroperitoneal tumour complicated by disseminated thrombosis of the inferior vena cava, right atrium and right ventricle of the heart. A relapse of the malignant uterine tumour had developed 3 years after the primary operation and was represented by a large-size mass ingrowing into the infrarenal segment of the inferior vena cava, aorta, as well as jejunum. Additional examination revealed the presence of a tumorous thrombus extending from the primary tumorous node in the lumen of the inferior vena cava to the right atrium and ventricle. The procedures performed consisted in removal of the tumour with resection of the inferior vena cava, aorta, and jejunum, followed by thrombectomy from the right portions of the heart under extracorporeal circulation. The postoperative period turned out uneventful, with no complications observed. The woman was discharged on POD 15. Twelve-month postoperative follow up revealed neither relapse nor progression of the disease. Currently, the patient continues undergoing specific treatment (second-line chemotherapy). Also discussed in the article are current challenges concerning both the classification of tumour thrombosis of the inferior vena cava in retroperitoneal sarcomas, and the choice of optimal strategy and policy of treatment.

[The differential diagnosis of constitutional delay of puberty and hypogonadotropic hypogonadism in boys]

BACKGROUND

The problem of differential diagnosis of constitutional delay of puberty/CDP and hypogonadotropic hypogonadism/HH in boys is discussed, as boys have similar genetic mechanisms and appearance.

AIMS

to determine accuracy of the criteria for the differential diagnosis of CDP and HH.

MATERIALS

The study included 56 boys 14.4±0.7 years old with delayed puberty (G1P1-3/testicular volume <3 сm3). We excluded patients with hypergonadotropic hypogonadism, treated with sex steroids or gonadotropins for 12 months, with endocrine/somatic diseases affecting puberty. At the first visit, we evaluated anthropometric data, bone age, testicular volume, hormones and the results of the gonadotropin-releasing hormone test (GnRH) agonist test and the human chorionic gonadotropin test (hCG) test. The HH was defined by a testicular volume <3 сm3 after 2 years follow-up. The patients were divided into two groups: the first group with CDP and testicles ≥3 cm3 (n=50) and the second group with HH and testicles <3 cm3 (n=6).

RESULTS

At the first visit in boys with CDP corrected target height was less (Me SDS –1.8 vs –0,4, р=0.02), bone age was less (Ме SDS –2.5 vs –0.2 р=0.03), testicular volume was more (Ме 1.9 vs 0.5, p=0.0003), hormones were significantly higher, such as LH (Ме 1.1 vs 0.1 mIU/ml, p=0.0002), FSH (Ме 1.9 vs 0.2 IU/l, p=0.00007), inhibin B (Ме 142.3 vs 31.3 pg/ml, p=0.00009), max LH (Ме 18.9 vs 0.6 mIU/ml, p=0.00007), max LH/FSH (Ме 2.3 vs 0.4, p=0.0002) on the GnRH agonist test and Δ testosterone (Ме 14.4 vs 1.1 nmol/l, p=0.0001) on the hCG test than in boys with HH. The LH ≥0.3 mIU/ml had 86% sensitivity, 100% specificity; max LH/FSH ≥1 – 92% sensitivity, 100% specificity; Δ testosterone ≥2.7 nmol/l on the hCG test – 98% sensitivity, 100% specificity for differential diagnosis of CDP and HH in boys. However, max LH ≥3.5 mIU/ml on the GnRH agonist test, FSH ≥0.5 IU/l, inhibin B ≥58 pg/ml had 100% sensitivity and specificity for diagnosis of CDP.

CONCLUSIONS

The inhibin B ≥58 pg/ml, LH ≥0.3 mIU/ml, FSH ≥0.5 IU/l or max LH ≥3.5 mIU/ml, max LH/FSH ≥1,0 on the GnRH agonist test, Δ testosterone ≥2.7 nmol/l on the hCG test have an excellent accuracy for the differential diagnosis of CDP and HH in prepubertal boys with delayed puberty.

Microporous Materials Based on Norbornadiene-Based Cross-Linked Polymers

New microporous homopolymers were readily prepared from norbornadiene-2,5, its dimer and trimer by addition (vinyl) polymerization of the corresponding monomers with 60–98% yields. As a catalyst Pd-N-heterocyclic carbene complex or Ni(II) 2-ethylhexanoate activated with Na⁺[B(3,5-(CF₃)₂C₆H₃)₄]⁻ or methylaluminoxane was used. The synthesized polynorbornenes are cross-linked and insoluble. They are glassy and amorphous polymers. Depending on the nature of the catalyst applied, BET surface areas were in the range of 420–970 m²/g. The polymers with the highest surface area were obtained in the presence of Pd-catalysts from the trimer of norbornadiene-2,5. The total pore volume of the polymers varies from 0.39 to 0.79 cm³/g, while the true volume of micropores was 0.14–0.16 cm³/g according to t-plot. These polymers gave CO₂ uptake from 1.2 to 1.9 mmol/g at 273 K and 1 atm. The porous structure of new polymers was also studied by means of wide-angle X-ray diffraction and positron annihilation lifetime spectroscopy.

A New Look at Etiological Factors of Idiopathic Scoliosis: Neural Crest Cells

Idiopathic scoliosis is one of the most common disabling pathologies of children and adolescents. Etiology and pathogenesis of idiopathic scoliosis remain unknown. To study the etiology of this disease we identified the cells' phenotypes in the vertebral body growth plates in patients with idiopathic scoliosis. Materials and methods: The cells were isolated from vertebral body growth plates of the convex and concave sides of the deformity harvested intraoperatively in 50 patients with scoliosis. Cells were cultured and identified by methods of common morphology, neuromorphology, electron microscopy, immunohistochemistry and PCR analysis. Results: Cultured cells of convex side of deformation were identified as chondroblasts. Cells isolated from the growth plates of the concave side of the deformation showed numerous features of neuro- and glioblasts. These cells formed synapses, contain neurofilaments, and expressed neural and glial proteins. Conclusion: For the first time we demonstrated the presence of cells with neural/glial phenotype in the concave side of the vertebral body growth plate in scoliotic deformity. We hypothesized that neural and glial cells observed in the growth plates of the vertebral bodies represent derivatives of neural crest cells deposited in somites due to alterations in their migratory pathway during embryogenesis. We also propose that ectopic localization of cells derived from neural crest in the growth plate of the vertebral bodies is the main etiological factor of the scoliotic disease.

[Apoptosis as a systemic adaptive mechanism in ischemic stroke]

This paper presents a literature review considering the role and mechanism of apoptosis in the pathogenesis of ischemic stroke (IS). The authors introduce a new concept: the functional request of the patient as a set of external (the nature and intensity of rehabilitation measures, characteristics of everyday life, diet, etc.) and internal (genetic factors, internal picture of the disease, availability of rental and other psychological facilities and etc.) attributes. This concept allows a new angle in understanding the pathogenesis of IS and creates fundamental and clinical potential for more successful approaches to therapy and rehabilitation after IS.

[Investigation of the surface layer of 3D-matrices for tissue engineering]

Electrospinning is a convenient and promising manufacturing method a variety of materials for tissue engineering. 3D matrices fabricated by electrospinning from solutions of polycaprolactone with human serum albumin or gelatin in 1,1,1,3,3,3-hexafluoroisopropanol were studied. The microstructure of the 3D matrices and surface of the fibers were investigated using scanning electron microscopy. Protein distribution in the surface layer was studied by modification of protein amino groups with N-(2-hydroxyethyl)phenazine and X-ray photoelectron spectroscopy. It was shown, that concentration of the proteins in the surface layer of fibers exceeded their concentration in the initial electrospun solution up to 12 times and the surface layer was enriched in the protein inversely to the concentration of the protein in solution. The minor part of the proteins was released from fibers during first 30-60 min after swelling in water. Treatment of matrices with proteinase K hydrolyzed about 1/3 of the surface exposed human serum albumin. Thus, both methods can be used to study the surface content of the materials produced by electrospinning from blends of synthetic and natural polymers, however X-ray photoelectron spectroscopy appears to be more convenient and informative.

THE FUNCTIONAL ROLE OF SMALL HEAT SHOCK PROTEIN Hsp67Bc IN DROSOPHILA MELANOGASTER

Heat shock proteins are universal agents protecting all known organisms from environmental stresses. These proteins are classified into six families differing in their structure and function, yet having a common purpose of maintaining cellular proteins in operating condition. The small heat shock protein family has the most diversified set of effects on the organism’s vital activity with a great number of its members’ features studied thoroughly in a fruit fly Drosophila melanogaster, which is regarded as a convenient model object. In this review, we represent and discuss data on the role of Drosophila melanogaster Hsp67Bc protein, which was earlier identified as the closest functional ortholog of human HSPB8 small heat shock protein.

Combination of cyclophosphamide and double-stranded DNA demonstrates synergistic toxicity against established xenografts

BACKGROUND

Extracellular double-stranded DNA participates in various processes in an organism. Here we report the suppressive effects of fragmented human double-stranded DNA along or in combination with cyclophosphamide on solid and ascites grafts of mouse Krebs-2 tumor cells and DNA preparation on human breast adenocarcinoma cell line MCF-7.

METHODS

Apoptosis and necrosis were assayed by electrophoretic analysis (DNA nucleosomal fragmentation) and by measurements of LDH levels in ascitic fluid, respectively. DNA internalization into MCF-7 was analyzed by flow cytometry and fluorescence microscopy.

RESULTS

Direct cytotoxic activity of double-stranded DNA (along or in combination with cyclophosphamide) on a solid transplant was demonstrated. This resulted in delayed solid tumor proliferation and partial tumor lysis due to necrosis of the tumor and adjacent tissues. In the case of ascites form of tumor, extensive apoptosis and secondary necrosis were observed. Similarly, MCF-7 cells showed induction of massive apoptosis (up to 45%) as a result of treatments with double-stranded DNA preparation.

CONCLUSIONS

Double-stranded DNA (along or in combination with cyclophosphamide) induces massive apoptosis of Krebs-2 ascite cells and MCF-7 cell line (DNA only). In treated mice it reduces the integrity of gut wall cells and contributes to the development of systemic inflammatory reaction.

[NESPRINS--nuclear envelope proteins ensuring integrity]

This review describes the nesprins (nuclear envelope spectrin-repeat proteins), which are recently discovered family of nuclear envelope proteins. These proteins play an important role in maintaining the cellular architecture and establish the link between the nucleus and other sub-cellular compartments. Many tissue-specific diseases including lipodystrophies, hearing loss, cardiac and skeletal myopathies are associated with nesprins mutations. These proteins comprise of multiple tissue specific isoforms which contain spectrin repeats providing interaction of nesprins with other nuclear membrane proteins, cytoskeleton and intranuclear matrix. We summarize recent findings and suggestions about nesprins structural organization and function inside the cell. Human diseases caused by abnormal nesprins expression are also described.

[Mesenchymal stromal cells synchronize the rhythm of protein synthesis under the effect of an exogenous signal]

A comparative study was performed of dense 5-hour cultures of rat hepatocytes and equal-density cultures of mesenchymal stromal cells (MSC) isolated from human adipose tissue of rat bone marrow. The cells were grown on collagen-coated class slides in serum-free medium. Unlike in hepatocytes, no rhythm of protein synthesis was initially revealed in MSC, but such a rhythm manifested itself when the culture medium was supplemented with melatonin (2 nM, 5 min). The results of experiments with cytoplasmic calcium chelator BAPTA-AM and protein kinase inhibitor H7 indicate that the mechanism of protein synthesis synchronization in MSC consists in calcium-dependent phosphorylation of cell proteins.

[Influence of allogenic and autologic multipotent stromal cells of adipose tissue upon bone tissue regeneration in the rabbit mandible angle defect]

Reconstructive surgery often collides with complicated task of defect recovery in the situation of deficit of maxillofacial skeleton tissues, that leads to necessary search of accessible cells source with osteogenic potentials and proper substrate for cell transplantation. In the study the regeneratory potential of stromal cells of adipose tissue was tested in the rabbit model of mandible through angle defect. Cells of allogenic and autologic nature stimulated reparative osteogenesis but their influence upon bone matrix maturation was different. When the construction with allogenic cells was transplanted reaction of its rejection was not detected on histological level.

[Use of mesenchymal stem cells for reparative processes activation in bone jaw tissue in experimental conditions]

In experiment on 12 Chinchilla rabbits dynamics of reparative regeneration was studied at the terms 2 and 4 months. Bone defect in mandible corner was closed by osteoplastic material Gapkol which was covered from inside by allogenic or autologic stem cells received from rabbit adipose tissue. The results of the ray tracing methods of study were verified by SEM and histological methods.

[Influence of Drosophila melanogaster genotype on biological effects of endocymbiont Wolbachia (stamm wMelPop)]

Comparative analyses of symbiotic bacteria Wolbachia (stamm wMelPop reducing lifespan of flies) morphology in normal and mutant strains of Drosophila melanogaster as well as the influence of Wolbachia on the host cell ultrastructure have been done. Wolbachia infected D. melanogaster mutation strains Trithorax-like -- Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ have been received by special flies crossing. Uninfected strain D. melanogaster white-1118 (w1118) have been obtained by antibiotic treatment of initially infected strain D. melanogaster [w]w1118. Complex of different methods and approaches let to investigate for the first time the morphology of cell structure before and after bacterial infection of insects and to value the bacterial presence effect on flies viability and reproduction of normal and mutant flies. Morphology af cytoplasmic compartments in early embryos and eggs layed by infected and uninfecyed females Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ have been analyzed. Electron microscopy has shown that D. melanogaster embryos contain typical Wolbachia contacting with different host organelles that verify preservation of their functional activity. Atificial mitochondria and Wolbachia (wMelPop) of unusual morphology with defective bacterial membranes have been visualised in D. melanogaster [w]Trl362/TM3, Sb1 Ser y+. Wolbachia presence in ovarium cells from strains [w]Trl362/TM3, Sb1 Ser y+ and [w]Trlen82/TM3, Sb1 Ser y+ did not influence on eggs quantity layed by females. We have demonstrated for the first time that lifespan of infected and uninfected strains: D. melanogaster Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ were similar. However the lifespan of imago from strain [w]w1118 was lower in comparison to those from strains Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+. It suggests that either chromosomal balancer TM3 or Trl mutation play an importance role in host-symbiotic relationship. Next experiments have revealed that lifespan of homozygotic flies decreased essentially and was close to lifespan of strain [w]w1118. Data obtained confirm that chromosomal balancer TM3 can affect on symbiont-host relationship.

[Evaluation of reparative regeneration of the jaw bone by microfocus roentgenography in an experiment]

In experiment on 16 grown-up chinchilla rabbits the dynamic of reparative regeneration was evaluated by digital microfocal rontgenography in the terms of 1, 2 and 4 months. Bone defect of the 8capital CHE, Cyrillic8 mm size in the region of mandible angle was caused by surgical laser Smart 2940 D+ on the right side and by physiodespenser Surgec XT on the left side. Surgical laser use let to reduce intact mother bone traumatisation and to improve remote results of bone tissue regeneration. After bone defect creation bone tissue regeneration was put into effect by all 3 callus types - endosteal, periosteal and intermediary.

[Comparison of fibroblasts-like cell differentiation capacities of human bone marrow, adipose tissue, hair papilla and dermal fibroblasts]

We compared the morphology and differentiation characteristics of the human cells from bone marrow, adipose tissue, hair papilla and skin dermis. All cell types showed fibroblastic morphology. Immunofluorescent analysis showed that adipose tissue derived stem cells (ADAS) and hair papilla cells (HPC) expressed CD105, CD49d and STRO-1, bone marrow mesenchymal stem cells (BMSC) were absent for CD49, dermal fibroblasts (DFb) expressed CD49 and STRO-1 at low level. Populations of ADAS, BMSC and HPC had similar capacities to lipid and bone differentiation. Following exposure to appropriate induction stimuli, these cells changed phenotype and expressed specific cell markers. However, the rate and extent of HPC differentiation were lower in comparison with populations of ADAS and BMSC. We propose that all investigated cell populations contain primitive progenitor cells with mesenchymal stem cell properties.

[Capabilities of digital microfocal x-ray study in the evaluation of reparative regeneration of bone tissue in an experiment]

Digital microfocal x-ray study was experimentally studied in animals to examine the time course of changes in their bone regeneration. Sixteen Chinchila rabbits whose bone defect in the angle of the mandibular ramus had been closed with the osteoplastic material Gapcol with the applied allogeneic, autologous stem cells isolated from rabbit adipose tissue and human plasma enriched with thrombocytic growth factors were examined. The capabilities of digital microfocal x-ray study versus x-ray computed tomography were compared in the evaluation of reparative regeneration of bone tissue. The results of radiation studies were verified with the data of scanning electron microscopy.

[Dynamics of the annulate lamellae in Drosophila syncytial embryos]

In eukaryotic cells, mitotic events are controlled by evolutionarily conserved cyclin-dependent kinases (cdk): these kinases phosphorylate cell proteins, which causes structural reorganization of the entire cell. Our recent studies of Drosophila syncytial embryos have demonstrated that cdk1 activity is a key factor that controls nuclear pore complex assembly/disassembly and affects the structure of cytoplasmic pores in the annulate. In this paper, we report a comparative analysis of these cytoplasmic organelles throughout the cell-cycle and throughout the development of Drosophila syncytial embryos. Based on the results obtained, it was presupposed that distribution of annulate lamellae containing cytoplasmic pores could reflect the inactivation of the mitotic kinase cdk1 in Drosophila syncytial embryos.

[Changes in Xenopus oocyte nucleus and cytoplasm organization after actin filaments depolymerization by latrunculin]

Actin-containing filaments have been visualized inside the Xenopus oocyte nuclei due to combination of fluorescence and transmission electron microscopy. It has been shown that these filaments contact with nucleoli, spherical bodies and nuclear pore complexes. The incubation of oocytes with actin-depolymerizing latrunculin causes membrane vesiculation in the cytoplasm, and disruption of the nucleoplasm and nuclear envelope integrity. We suppose that actin-containing filaments belong to crucial cell components which are involved in coordination of nuclear-cytoplasmic interactions as well as distribution and transport of intranuclear components in growing Xenopus oocytes.

[High temperature initiates changes of Wolbachia ultrastructure in the ovaries and early embryos of Drosophila melanogaster]

Electron microscopic analysis of Drosophila melanogaster (w1118) ovarian cells has demonstrated that stressful heat treatment of flies results in the appearance of electron dense granules and large lysosomes in the cytoplasm of ovarian cells, which is not related with the presence of Wolbachia, as these changes are observed in both the infected and uninfected flies. High temperature initiates essential envelope defects and other structural changes of symbiotic bacteria in the cytoplasm of ovarian cells. Some embryos developing from eggs of heat shocked flies die, however, bacteria in the survival embryos retain their typical morphology. Endosymbionts do not change their localization and their contacts with the mitochondria and endoplasmic reticulum in the ovarian cells and early embryos after heat shock treatment of the flies. The results obtained show that high temperature influences on both the host and the endosymbiont, but does not change their structural mutual interactions.

[Functional role of proteins containing ankyrin repeats]

This review describes and discusses new data about the structure and function of proteins which contain ankyrin-like repeats in their structure. These proteins have been found in cells of different organisms but they are not belonging to the cytoskeletal proteins. Many important functions of such proteins are provided by ankyrin repeats which maintain protein-protein interactions involved in the formation of transcription complexes, initiation of immuno-responses, biogenesis and assembly of cation channels in the membranes, regulation of some cell cycle stages, symbiotic interactions and many other processes. Mutations in genes encoding ankyrin-like proteins can cause defects in gene expression leading to diseases onset and progression in animals and humans. Therefore, the structure, dynamics and function of these proteins is an area of extensive research in modern biology.

[Structural organization and function of nuclear envelope]

Higher-eukaryotic membrane compartmentalization of different processes provides the control of functional activity in cells. The nuclear envelope that consists of outer and inner nuclear membranes, lamina, and nuclear pore complexes is one of the most significant and complex cell compartments. It separates DNA replication and transcription in the nucleus from RNA translation in the cytoplasm and regulates the nuclear-cytoplasmic transport of different molecules. This review describes and discusses the structural organization and biochemical composition of different nuclear envelope components (except nuclear pore complexes, which were discussed in our previous review) as well as its dynamics during mitosis in vitro and in vivo. Special attention is given to the role of lamina in a group of human genetic diseases, collectively referred to as laminopathies.

[Morphometrical analysis of endoplasmic reticulum dynamics in growing amphibian oocytes]

Morphological analysis of endoplasmic reticulum (ER) dynamics was carried out in early amphybian oocytes at different stages of their development. Comparative morphometric analysis of ER membrane relative surface area and relative volume has shown that at the 1st-2nd stages of oogenesis the accumulation of ER membranes occurred mainly in the peripheral region of the cell cytoplasm. At the 3rd-4th stages of oocyte growth characterized by active transcription, the increase in the relative volume of ER and relative surface area of ER membranes occurs in the middle and near-nuclear region of cytoplasm, and reduction of these parameters takes place in the peripheral part of the cell. Simultaneously observed fusion of numerous ER vesicles with the outer nuclear membrane may serve as an evidence of active formation of new fragments of nuclear envelope. The 5th-6th stages of oocyte development are characterized by an increase in the relative volume of ER in the whole oocyte. It has been supposed that the revealed reorganization of endoplasmic reticulum in growing amphibians oocytes might be due to yolk accumulation (vitellogenesis), redistribution of calcium ions, and synthesis and storage of lipids and proteins. These processes are necessary for the future embryo development, and also for assembly of new fragments of growing nuclear envelope.

[Structural organization, functions and dynamics of nuclear pores]

This review summarized data on the morphological and biochemical analysis of nuclear pore complexes, which are complex organelles providing the route of passive and active nuclear-cytoplasmic transport to different molecules in the eukaryotic cell. The morphology and functional role of nuclear pores in higher and lower eukaryotes, and molecular aspects of the import and export of molecules from the nucleus are described in addition to factors involved in the regulation of these process. Special attention has been paid to sequential steps of the nuclear pore assembly in vitro and in vivo.

Proteinase-Activated Type 1 Receptors are Involved in the Mechanism of Protection of Rat Hippocampal Neurons from Glutamate Toxicity

Survival of cultured rat hippocampal neurons was estimated 4, 24, and 48 h after 15-min exposure to the toxic effect of glutamate under conditions of pre- or coincubation with 10 nM thrombin. Thrombin inhibited glutamate-induced apoptosis in neurons 24 and 48 h after treatment, but had no effect on necrosis. Selective peptide agonist of proteinase-activated type 1 receptors simulated, but receptor antagonist suppressed the neuroprotective effect of thrombin. Our results suggest that peptide antagonist of type 1 receptors play a role in the mechanisms of neuronal protection from glutamate toxicity.

Cdk1 and okadaic acid-sensitive phosphatases control assembly of nuclear pore complexes in Drosophila embryos

Disassembly and reassembly of the nuclear pore complexes (NPCs) is one of the major events during open mitosis in higher eukaryotes. However, how this process is controlled by the mitotic machinery is not clear. To investigate this we developed a novel in vivo model system based on syncytial Drosophila embryos. We microinjected different mitotic effectors into the embryonic cytoplasm and monitored the dynamics of disassembly/reassembly of NPCs in live embryos using fluorescently labeled wheat germ agglutinin (WGA) or in fixed embryos using electron microscopy and immunostaining techniques. We found that in live embryos Cdk1 activity was necessary and sufficient to induce disassembly of NPCs as well as their cytoplasmic mimics: annulate lamellae pore complexes (ALPCs). Cdk1 activity was also required for keeping NPCs and ALPCs disassembled during mitosis. In agreement recombinant Cdk1/cyclin B was able to induce phosphorylation and dissociation of nucleoporins from the NPCs in vitro. Conversely, reassembly of NPCs and ALPCs was dependent on the activity of protein phosphatases, sensitive to okadaic acid (OA). Our findings suggest a model where mitotic disassembly/reassembly of the NPCs is regulated by a dynamic equilibrium of Cdk1 and OA-sensitive phosphatase activities and provide evidence that mitotic phosphorylation mediates disassembly of the NPC.

Effect of synthetic peptide thrombin receptor agonist encapsulated in microparticles based on lactic and glycolic acid copolymer on healing of experimental skin wounds in mice

PAR1 peptide thrombin receptor agonist (PAR1-AP) was encapsulated in microcorpuscles based on lactic and glycolic acid copolymer. The desorption profile of the preparation was studied in vitro and its wound-healing effects were studied on a model of cut skin wound in mice. The study showed that 90% PAR1-AP was desorbed over 6 h, but the peptide was detected in eluates from the microparticle surface after 23 h. The desorbed peptide retained its physiological activity and was capable of activating PAR1 receptors on human platelets. The study of the dynamics of experimental skin wound healing in mice showed lower number of macrophages in the wounds treated with PAR1-AP microparticles compared to the control (open wounds and wounds covered with microparticles) and higher number of fibroblasts on day 3 of tissue reparation. Hence, PAR1-AP desorbed from microparticles shortened the inflammation phase in the wound. On day 7 the best healing parameters were also observed in wounds treated with PAR1-AP microparticles, which attests to shortening of the proliferation phase and acceleration of wound healing.

Role of thrombin in activation of neurons in rat hippocampus

The effect of thrombin, an agonist of proteinase-activated receptor (PAR) family, was studied on cultured rat hippocampal neurons. Thrombin in a concentration range of 1 pM - 10 nM induced a transitory dose-dependent increase in intracellular free calcium concentration. Involvement of PAR1 in neural response to thrombin was corroborated in experiments with TFLLRN, a selective synthetic peptide agonist of these receptors. In a calcium-free medium and after treatment with cyclopiazonic acid (inhibitor of Ca(2+)-ATPase in the endoplasmic reticulum) activation of PAR not only mobilized Ca(2+) from intracellular stores, but also induced Ca(2+) entry into the cells. Thrombin decreased Ca(2+) signal triggered by activation of NMDA-subtype glutamate receptors.

[Structural organization and distribution of the symbiotic bacteria Wolbachia during spermatogenesis of Drosophila simulans]

Electron microscopy and morphometric analysis have shown that the symbiotic bacteria Wolbachia occur the testis cells during spermatogenesis and are absent in mature spermatids. Bacteria did not affect the structural organization of testis cells, which have a typical morphology during morphogenesis. Bacteria were distributed along the meiotic spindle microtubules near the mitochondria. They increased in number in spermatids at the stage of elongation. Endosymbionts aggregated at the spermatid distal end and contained many vacuoles but were absent at the spermatid proximal end near the nuclei. It was shown for the first time that the diameter of spermatids in a strongly infected line was two of three times that in a noninfected line. We hypothesize that the increase in the number of endosymbionts during spermatid elongation can affect the chromatin condensation in the spermatozoon.

[Structural organization and possible functional role of annulate lamellae containing cytoplasmic pores]

This review is devoted to annulate lamellae, a specific compartment of endoplasmic reticulum that occurs, presumably, in actively growing and rapidly dividing cells (oocytes, embryonic and tumor cells). We summarized both earlier and recent data on the dustribution of annulate lamellae in various cell types, on their morphology, and the distribution of interaction with intracellular structures at various treatments. As the annulate lamellae contain cytoplasmic pore complexes, a special attention was paid to their relation with nuclear pores. Possible functions of the annulate lamellae in intracellular processes and, particularly, in nuclear envelope assembly, are discussed.

[Effect of thrombin on survival of hippocampal neurons]

The effect of thrombin on the rat hippocampal neurons death in model of neurotoxicity induced by hemoglobin or glutamate, was studied. Thrombin (10 nM) was shown to inhibit 100-mkM glutamate--or 10-mkM hemoglobin-induced apoptosis of the rat hippocampal neurons. With the aid of PAR1 (protease-activated receptor1) agonist peptide and PAR1 antagonist, the PAR1 was found to be necessary for protective action of thrombin in hippocampal neurons in models of neurotoxicity induced by hemoglobin or glutamate. Because the prolonged elevation [Ca2+] ib neurons is a critical part of neurodestructive processes in CNS, the effect of thrombin on Ca2+-homeostatis of neurons after its injury by the inducer of neuronal apoptosis: a synthetic agonist of the NMDA receptors N-methyl-D-aspartate (NMDA), was studied. We hypothesized that thrombin via receptors PAR may prove to be neuroprotective for the hippocampus. Thrombin was shown to stimulate via PAR1 a transient increase in [Ca2+] in neurons in a concentration-dependent manner. Thrombin (1 nM) decreased the [Ca2+] signal induced by activation of the NMDA-subtype of glutamate receptors. This thrombin effect may be one of the reasons of the protective action of thrombin in hippocampal neurons.

Annulate lamellae play only a minor role in the storage of excess nucleoporins in Drosophila embryos

The nuclear pore complexes (NPCs), multiprotein assemblies embedded in the nuclear envelope, conduct nucleo-cytoplasmic traffic of macromolecules. Mimics of NPCs, called annulate lamellae pore complexes (ALPCs), are usually found in cytoplasmic membranous stacks in oocytes and early embryonic cells. They are believed to constitute storage compartments for excess premade nucleoporins. To evaluate the extent to which ALPCs store nucleoporins in early embryonic cells we took advantage of syncytial Drosophila embryos, containing both AL and rapidly proliferating nuclei in the common cytoplasm. Electron microscopic morphometric analysis showed that the number of ALPCs did not decrease to compensate for the growing number of NPCs during syncytial development. We performed Western blot analysis to quantify seven different nucleoporins and analyzed their intraembryonal distribution by confocal microscopy and subcellular fractionation. Syncytial embryos contained a large maternally contributed stockpile of nucleoporins. However, even during interphases, only a small fraction of the excess nucleoporins was assembled into ALPCs, whereas the major fraction was soluble and contained at least one phosphorylated nucleoporin. We conclude that in Drosophila embryos ALPCs play only a minor role in storing the excess maternally contributed nucleoporins. Factors that may prevent nucleoporins from assembly into ALPCs are discussed.

[Structural organization and distribution of symbiotic bacteria Wolbachia in early embryos and ovaries of Drosophila melanogaster and D. simulans]

Electron microscopic and morphometric analyses of Wolbachia distribution in early embryos of Drosophila flies have demonstrated that the number of bacteria in the embryo remains constant from fertilization to blastoderm, and that afterwards the symbionts could be observed only in the polar cells. Each bacterium has a three-layer envelope, makes contacts with microtubules and moves through the cytoplasm following the actively dividing nuclei. It has been found for the first time that Wolbachia could produce secretory vacuoles in the cytoplasm of early embryos. The relative volume of Wolbachia was five times as much in the embryos of Drosophila simulans as in those of D. melanogaster (Canton S), while the survival rate of D. simulans was half as much as that of D. melanogaster. It was shown that Wolbachia could form spore-like structures in D. simulans embryos. Ultrastructural investigations of Drosophila ovaries suggest that the bacteria may be present in all ovariol cells, including the oocyte, within whose cytoplasm they are delivered to the host. The highest number of symbionts was observed in germarium cells. In ovariol cells, the bacteria gradually decrease in number as oogenesis progresses. It has been determined for the first time that the symbionts are located closely to membranes of rough endoplasmatic reticulum in follicular and nurse cells of D. melanogaster. The data obtained suggest that Wolbachia may be involved in the regulation of oocyte maturation.

[Self-similarity in variability of human heart variability at various stages of ontogenesis]

We consider the potential of applying wavelet analysis to fluctuations found in physiological systems. We focus on cardiac interbeat interval time series (RR-intervals) from a group of young adults and children and fetus heart beat rate time series (antepartum cardiotocography), because the wavelet analysis of these heart rate dynamics may provide important practical diagnostic and prognostic information not obtainable with current approaches. We show that all the signals analyzed are self-similar and propose a method for estimating this scaling feature.

[Myelin-like structures as a possible source of the smooth endoplasmic reticulum in early amphibian oocytes]

A comparative study of amphibian oocyte ultrastructural organization has shown a significant accumulation of elements of the smooth endoplasmic reticulum in the oocyte cytoplasm at the third stage of development. The analysis of oocytes of two frog species, Xenopus laevis and Rana temporaria, at the first and second stages of their development enabled us to recognize in the cytoplasm of the oocyte some myelin-like structures (MLs) made of 30-40 densely packaged membranous layers and shaped as dense bodies. MLs are also present in the adjacent follicular cells and in the intercellular space. In the oocyte cytoplasm these structures are located near the nuclear envelope and other intracellular organelles. At the third stage of oogenesis, which is characterized by a high functional activity of the cells, MLs are seen to unwrap sequentially into double-layer membranes similar to the smooth endoplasmic reticulum cisternae. Intermediate steps of this process being also observed. It is supposed that MLs may play the role of membrane stocks to be used eventually for the formation of nascent endoplasmic membranes in the amphibian oocytes.

Receptors of the PAR family as a link between blood coagulation and inflammation

Blood coagulation plays a key role among numerous mediating systems that are activated in inflammation. Receptors of the PAR family serve as sensors of serine proteinases of the blood clotting system in the target cells involved in inflammation. Activation of PAR-1 by thrombin and of PAR-2 by factor Xa leads to a rapid expression and exposure on the membrane of endothelial cells of both adhesive proteins that mediate an acute inflammatory reaction and of the tissue factor that initiates the blood coagulation cascade. Certain other receptors (EPR-1, thrombomodulin, etc.), which can modulate responses of the cells activated by proteinases through PAR receptors, are also involved in the association of coagulation and inflammation together with the receptors of the PAR family. The presence of PAR receptors on mast cells is responsible for their reactivity to thrombin and factor Xa and defines their contribution to the association of inflammation and blood clotting processes.

[The role of PAR family receptors in activation of mast cells in the norm and in acute inflammation in rats]

Dose-dependent release of beta-hexoaminidase induced with thrombin was shown to be mediated by the PAR-1. This was further confirmed by means of agonist, antagonist and PAR desensitization. Acceleration of the mast cell mediator secretion by the Xa factor and PAR-2 agonist, was revealed. An increase in the mast cell release induced by thrombin and TRAP-6 was shown in the acute peritonitis model.

[Ultrastructure of skeletal muscle fibers in monkeys after space flight]

It is known that exposure of humans and animals to microgravity causes reduction in the cross-sected area of muscle fibers and muscle atrophy. These changes also involve ultrastructural alterations in muscle fibers. Therefore primates, that are physiologically close to humans, are to be examined to help a better understanding of the nature of these ultrastructural changes is muscles and muscle fibers. Although failed to find any relevant published data on the quantitative aspects of ultrastructural changes in muscle fibers of space-flown primates we believe that it is important to examine these aspects. The postflight study of monkey's m. soleus, and m. vastus lateralis did not reveal any significant changes in volume density of the myofibrillar apparatus. Mitochondria of m. soleus showed a distinct reduction in volume density, being more obvious in the subsarcolemmal zone than in the central one. Mitochondria of m. vastus lateralis showed a decrease (P > 0.05) in volume density. Following the flight, m. soleus and m. vastus lateralis of the monkeys showed a significant increase in the mean area of myofibrils, and a trend towards a decrease in the number of myofibrils per 100 micron 2. Besides, m. soleus showed a significant increase in the mean area of mitochondria, and a trend towards a decrease in the number of mitochondria per 100 micron 2. In m. vastus lateralis of the monkeys after space flight the number opf mitochondria tended to decrease and the mean area showed differential changes. It can be postulated that these phenomena may be associated with a reduction in the diffusion surface of mitochondria resulting from the diminished myofibrillar volume.

[AccBSI - a novel restriction endonuclease from Acinetobacter calcoaceticus BS]

The recognition site of a new restriction endonuclease from Acinetobacter calcoaceticus BS was determined. This is a nonpalindromic sequence. AccBSI restrictase cleaves DNA chains in the middle of the recognition sequence; therefore, ligation of its digestion fragments restored AccBSI recognition sites and generated palindromic sequences recognized by SacI and SacII restrictases.

Distribution of the total unsaturation in lipid components of plasma as a new differential diagnostic method in clinical analysis

Using ozonization and thin-layer chromatographic methods we determined the qualitative and quantitative correlation of unsaturation distribution (UD) in individual fractions of blood plasma lipids in children suffering from insulin-dependent diabetes mellitus (IDDM). The research was aimed at elucidation of biochemical criterion of the degree of metabolic disorders in children with IDDM and at development of methods for quantitative assessment of such disorders. Twenty children were examined during the compensation stage (group 1), and twelve during decompensation with ketoacidosis (group 2). The present investigation shows that in the case of insulin-dependent diabetes mellitus in children the total unsaturation distribution (TUD) in plasma lipid fractions were found to be decreased significantly compared to healthy controls. The pattern of TUD in plasma lipid fractions may serve as a new biochemical criterion for metabolic disorders and decompensation in IDDM.

[Visualization of DNA segments, interacting with reactive oligonucleotide derivatives in interphase nuclei and metaphase chromosomes]

Reaction of (pdT)16 derivatives, bearing 4-(N-2-chloroethyl-N-methylamino)benzylphosphamide group on its 5' end and biotin on its 3' end with DNA in interphase nuclei and metaphase chromosomes has been investigated by fluorescence and electron microscopy. The result obtained evidence that in interphase nuclei DNA in active chromatin (nucleolus) is the most available for specific modification. In metaphase chromosomes the modified DNA regions are situated on the surface of chromosome.

[Distribution of the total quantity of fatty acid double bonds in lipid components of the blood in children with diabetes mellitus]

Children suffering from insulin-dependent diabetes mellitus (IDDM) were examined for unsaturation, that is, total quantity of double bonds in individual fractions of blood serum lipids was assessed. Lipid fractions were isolated by thin-layer chromatography. Unsaturation was assessed by ozonation method. The research was aimed at elucidation of biochemical criteria of the degree of metabolic disorders in children with IDDM and at development of methods for quantitative assessment of such disorders. Thirty-two inpatients with IDDM aged 7 to 15 were examined over time. Control group included 10 healthy age-matched children. Twenty children were examined during compensation stage (group 1), twelve during decompensation with ketoacidosis (group 2). Total unsaturation parameters were found reliably decreased in children with IDDM both during compensation and decompensation stages vs. those in healthy controls. A relative decrease of unsaturated fatty acids in the fraction of unesterified fatty acids (p < 0.05) was characteristic of group 2, with the content of their fragments in triglyceride fraction being the maximal (p < 0.05). The pattern of total unsaturation distribution in serum lipid fractions may serve as an indicator for metabolic disorders and decompensation in IDDM.