[Gastroenterological symptoms in COVID-19 patients with mild severity of the disease: opportunities to optimize antidiarrheal therapy].

Background: The novel coronavirus infection COVID-19 can be manifested by damage to the organs of the gastrointestinal tract (GIT). Damage to the gastrointestinal tract by the SARS-CoV-2 virus leads to a violation of the microbial-tissue complex of the mucous membrane of the digestive tract. A common gastroenterological manifestation of COVID-19 is diarrhea.

[Comparative effectiveness of ursodeoxycholic acid preparations in the treatment of biliary sludge].

Unlabelled: In the clinical classification of cholelithiasis, biliary sludge (BS) is distinguished as the pre-stone stage. Ursodeoxycholic acid (UDCA) is a drug with an evidence base for effective and safe effects on BS. The therapeutic equivalence of various UDCA drugs remains an important issue for clinical practice.

Ex vivo culturing of whole, developing Drosophila brains.

We describe a method for ex vivo culturing of whole Drosophila brains. This can be used as a counterpoint to chronic genetic manipulations for investigating the cell biology and development of central brain structures by allowing acute pharmacological interventions and live imaging of cellular processes. As an example of the technique, prior work from our lab(1) has shown that a previously unrecognized subcellular compartment lies between the axonal and somatodendritic compartments of axons of the Drosophila central brain.

At the Fulcrum in Health and Disease: Cdk5 and the Balancing Acts of Neuronal Structure and Physiology.

Cdk5 has been implicated in a multitude of processes in neuronal development, cell biology and physiology. These influence many neurological disorders, but the very breadth of Cdk5 effects has made it difficult to synthesize a coherent picture of the part played by this protein in health and disease. In this review, we focus on the roles of Cdk5 in neuronal function, particularly synaptic homeostasis, plasticity, neurotransmission, subcellular organization, and trafficking.

Absence of the Cdk5 activator p35 causes adult-onset neurodegeneration in the central brain of Drosophila.

Altered function of Cdk5 kinase is associated with many forms of neurodegenerative disease in humans. We show here that inactivating the Drosophila Cdk5 ortholog, by mutation of its activating subunit, p35, causes adult-onset neurodegeneration in the fly. In the mutants, a vacuolar neuropathology is observed in a specific structure of the central brain, the 'mushroom body', which is the seat of olfactory learning and memory.

Cdk5 regulates the size of an axon initial segment-like compartment in mushroom body neurons of the Drosophila central brain.

The axon initial segment (AIS) is the specialized compartment of vertebrate axons where action potentials are initiated. Despite longtime attention to the unique functions of this compartment, the mechanisms that regulate AIS formation and maintenance are not known. Here, we identify a novel compartment in Drosophila mushroom body neurons that mirrors the molecular hallmarks of the vertebrate AIS as judged by accumulation of the anchoring protein Ankyrin1, presence of a specialized actin cytoskeleton, exclusion of both axon-specific and somatodendritic-specific cell surface proteins, and accumulation of a unique combination of voltage-gated ion channels.

Drosophila brain tumor metastases express both neuronal and glial cell type markers.

Loss of either lgl or brat gene activity in Drosophila larvae causes neoplastic brain tumors. Fragments of tumorous brains from either mutant transplanted into adult hosts over-proliferate, and kill their hosts within 2 weeks. We developed an in vivo assay for the metastatic potential of tumor cells by quantifying micrometastasis formation within the ovarioles of adult hosts after transplantation and determined that specific metastatic properties of lgl and brat tumor cells are different.

[Genetics of the cell cycle: adaptive modification of the cycB2g mutation expression in dividing cells of Drosophila melanogaster].

The effect of mutation CycB2g on mitosis in neural ganglia and imaginal disks was studied in third-instar larvae of Drosophila melanogaster. Chromosome condensation and segregation were shown to be impaired in dividing cells of mutant larvae. During the three-year period of maintenance of the mutation in heterozygote, frequencies of some defects decreased via cellular adaptive modification.

[Mitosis: regulation and organization of cell division].

Modern views on genetic, cytological and molecular bases of the structure and regulation of preparing and implementing mitotic chromosome segregation are discussed.

[Mutation of Indy(p115) increases the life expectancy of imago of Drosophila melanogaster depending on sex and genetic background].

The Indyp115 allele in heterozygous state almost doubles the life span of adult Drosophila melanogaster, and this effect largely depends on the strain used for obtaining heterozygotes. Male and female life span depends on Indyp115 to a different degree. Apart from Indyp115 heterozygotes, sexual dimorphism for life span was also observed in strain Hikone-AW, but not in OregonR and TM3 balancer.

[Key events in the cell cycle, their regulation and organization].

The review surveys the studies of molecular genetic mechanisms of the cell cycle control on various eukaryotic models. The major cell cycle phenomena are considered: (1) checkpoints and their role in preserving DNA integrity and fidelity of mitosis, (2) the cell oscillator model, and (3) the role of cyclins in timing of cell division and coordination of mitotic events. The main classes of regulatory proteins involved in the cell cycle are discussed in detail.

[Genetic control of mitosis: features of origin of sister chromatid sets in anaphase in Drosophila melanogaster mutant line aar(V158)].

The effect of mutation aarV158 on anaphase separation of chromatids was studied on fixed cells of neural ganglia of Drosophila melanogaster larvae. It was shown that mutation aarV158 causes three types of defective chromosome segregation manifested as (1) monopolar anaphase, (2) separation of chromatids to an abnormally short distance in anaphase, and (3) bridging and lagging of some chromatids or prolonged asynchronous separation of sister chromatid sets to the poles in anaphase. We believe that the former two types of defective segregation are caused by disturbed centrosome separation at the beginning of mitosis and the third type, by defects in chromatid separation during anaphase.

[A study of expression of cell cycle genes in Drosophila using an enhancer trap and radioautography].

The phase of expression of genes CycB, CycE, and chb were determined in the cell cycle of neuroblasts of D. melanogaster 3rd instar larvae using the previously described radioautographic method and software. CycB was expressed at G2 phase and upon transition from G2 phase to M phase, while CycE was expressed at the end of G1 phase and upon transition from G1 phase to S phase.

[Identification of Indy(p115) mutation in the Na+-dicarboxylate transporter gene in Drosophila melanogaster].

The P[lArB]-element insertional mutation (Indyp115) was obtained in the promoter region of the Na(+)-dicarboxylate transporter gene of Drosophila (gene Indy, I'm not dead yet) within the 75D region of chromosome 3. The expression pattern of the reporter beta-galactosidase was determined in various tissues of third-instar larvae and adult flies. Both males and females homozygous for this mutation were fertile, though their viability was reduced.

[Phase-specific elements of the regulatory zone of the Drosophila melanogaster string gene].

The phases of the reporter gene expression controlled by different fragments of the string (stg) gene regulatory region were determined in Drosophila neuroblasts by detection of beta-galactosidase activity and radioautography. In the D10 and D22 lines carrying the constructs pstg beta-E4.9 and pstg beta-E5.

[The effect of some mutations in the Trl gene on mitosis in embryonal and larval tissues and egg chamber morphology in Drosophila melanogaster].

A study was made of three insertional mutations (Trl13C, Trls2325, and TrlEP(3)3184) located in the second intron of the Trithorax-like (Trl) gene for the GAGA transcription factor (GAF). Their cytological effects were analyzed in oogenesis, early embryonic development, and in larval development (96-108 h) in cells of nervous ganglia and imaginal disks. Notwithstanding an interallelic difference in expression, all three P-element insertions proved to be dominant as far as the examined parameters were concerned.

[Graded pressure of the abdomen in the differential diagnosis of abdominal lesions].

With the aid of the submitted diagnostic option significant improvement is achieved in the accuracy of identification of injuries to the abdominal vegetative ganglia (by 27 to 32%) through the use of quantitative measurements of threshold pain sensitivity (TPS). It is the deeply situated tissues in sites of projection of abdominal vegetative ganglia and in high reflexogenous zones of neurometameres innervating organs of the abdominal cavity that are subjected to graded pressuration which is performed through the anterior abdominal wall using a device indicating pain sensitivity [3]. TPS is determined for each zone under study comparing it to TPS in healthy subjects.

[Genetic control of mitosis. Adaptive modifications of v158 mutation expression].

Cytogenetic parameters of mitosis were studied in the neural ganglions and imaginal disks of the third-instar Drosophila larvae of the marker lines ry506 and w; Cy/L; D/Sb; two wild-type lines Lausenne and Hikone-AW; and the v158 line mutant for the cell-cycle gene in the 85F locus. The control lines and their various tissues differ in a number of mitotic traits, which are believed to be the natural modifications of chromosome condensation and segregation and do not disturb homeostasis of the developing ry506, Lausenne, and Hikone-AW flies. Mutation v158 affects centromere disjunction.

Radial spindle and the phenotype of the maize meiotic mutant, dv.

The morphological phenotype of the maize meiotic mutant dv (divergent spindle) has been further analysed by visualization of the division spindle and examination of its fine structure in mother cells of pollen. Previous research showed that dv blocks convergence of spindle fibres at the poles. New observations reveal abnormalities caused by this mutation, with dv showing disturbances in nuclear envelope breakdown during vesiculation, preventing the spindle fibres from adopting a bipolar orientation (with convergence on the poles).

Abnormalities of spindle and cytokine behavior leading to the formation of meiotic restitution nuclei in intergeneric cereal hybrids.

Mobile stages of meiosis have been analysed by visualizing the spindle in fertile cereal F1 hybrids. We describe four different mechanisms of the formation of restitution nuclei in meiotic division: (1) centripetal migration of telophase chromosome groups from the poles of a curved spindle at early telophase; (2) centripetal migration of the chromosome groups at late telophase when cell plate formation has failed; (3) preferable migration of univalents to one of the poles although spindle appearance is morphologically normal; and (4) in the absence of chromosome segregation where kinetochore fibers have failed to form. Copyright 1999 Academic Press.

[Torsional tension in metaphase chromosome DNA].

The torsional tension in DNA of isolated metaphase chromosomes from murine fibroblasts was measured by the microfluorescent method. The method is based on the ability of a fluorescent dye ethidium bromide to compensate for the negative torsional tension in topologically closed DNA by intercalation between DNA base pairs. The value of the relative twist difference delta Tw/Tw = -0.

[Determination of the expression phase of chb(V40) gene in the cell cycle of Drosophila melanogaster].

Using autoradiography, we have determined cell cycle parameters in neuroblasts of III-rd instar larvae of D. melanogaster. The overall duration of the cell cycle is 9 h, tG1 = 4 h, tS = 3.