A transgenic cell line with inducible transcription for studying (CGG)n repeat expansion mechanisms.

There are more than 30 inherited human disorders connected with repeat expansion (myotonic dystrophy type I, Huntington's disease, Fragile X syndrome). Fragile X syndrome is the most common reason for inherited intellectual disability in the human population. The ways of the expansion development remain unclear. An important feature of expanded repeats is the ability to form stable alternative DNA secondary structures. There are hypotheses about the nature of repeat instability. It is proposed that these DNA secondary structures can block various stages of DNA metabolism processes, such as replication, repair and recombination and it is considered as the source of repeat instability. However, none of the hypotheses is fully confirmed or is the only valid one. Here, an experimental system for studying (CGG)n repeat expansion associated with transcription and TCR-NER is proposed. It is noteworthy that the aberrations of transcription are a poorly studied mechanism of (CGG)n instability. However, the proposed systems take into account the contribution of other processes of DNA metabolism and, therefore, the developed systems are universal and applicable for various studies. Transgenic cell lines carrying a repeat of normal or premutant length under the control of an inducible promoter were established and a method for repeat instability quantification was developed. One type of the cell lines contains an exogenous repeat integrated into the genome by the Sleeping Beauty transposon; in another cell line, the vector is maintained as an episome due to the SV40 origin of replication. These experimental systems can serve for finding the causes of instability and the development of therapeutic agents. In addition, a criterion was developed for the quantification of exogenous (CGG)n repeat instability in the transgenic cell lines' genome.

Viability of Bacteriophages in the Complex Hydrogel Wound Dressings in vitro.

Using bacteriophages to overcome the increasing resistance of microorganisms to antibiotics is a novel research venue of clinical importance. Among other challenges, this technique is expected to create and maintain an adequate local concentration of bacteriophages at the site of application. In addition, the possibility of combining the phage preparation with antioxidants and anesthetics may provide new options for stimulating the reparative process. The aim of the study was to assess the viability and lytic activity of bacteriophages incorporated into a hydrogel-based wound dressing that contains polyvinyl alcohol, phosphate buffer, with optional additions of succinic acid and lidocaine. Materials and Methods: A technique for incorporating bacteriophages into the complex hydrogel wound dressing ex tempore has been proposed. The bacteriolytic activity of phages inside the hydrogel was determined using standard microbiological techniques. Specifically, we used nutrient media with lawn cultures of Staphylococcus aureus added with the following antibacterial combinations: bacteriophages + succinic acid, bacteriophages + lidocaine, and bacteriophages + succinic acid + lidocaine. The lytic activity of bacteriophages was assessed within 1 to 7 days after the formation of the hydrogel. Results: In all samples containing bacteriophages, the presence of viable and lytically active phages was noted within 1 to 7 days, as evidenced by the "negative colonies" on the culture lawns. On days 1 to 3, no secondary growth was recorded in the phage-containing samples. In hydrogel samples containing phages, succinic acid, and lidocaine, secondary bacterial colonies were detected starting from day 4 indicating some reduction in the lytic activity. Conclusion: The results suggest that bacteriophages immobilized in the hydrogel maintain their viability and lytic activity, and this activity persists when the phages are combined with succinic acid and lidocaine.

[Decompensation of chronic internal hydrocephalus in an adult patient]. / Dekompensatsiya khronicheskoi vnutrennei gidrotsefalii u vzroslogo patsienta. Sluchai iz praktiki i obzor literatury.

We report a rare case of decompensated chronic internal hydrocephalus in an adult patient. A 35-year-old woman experienced acute intracranial hypertension in 3 weeks after relief of postoperative inflammation in the oral cavity (tooth extraction). MRI revealed severe internal hydrocephalus. Third ventriculostomy was followed by significant clinical improvement. However, postoperative survey and subsequent neuroimaging confirmed no reduction of ventricular system. Thus, decompensation of chronic hydrocephalus following dental intervention and subsequent oral inflammation was assumed. Impaired venous outflow from the brain and destabilization of CSF circulation can be considered as a pathogenetic mechanism.

[Use of phase-contrast magnetic resonance imaging to quantify cerebrospinal fluid dynamics in patients with communicating hydrocephalus].

OBJECTIVE: to determine differences in cerebrospinal fluid (CSF) flow velocities in patients with varying degrees of communicating hydrocephalus (CH) versus a group of healthy volunteers without hydrodynamic disorders. MATERIAL AND METHODS: The investigation enrolled 27 CH patients (17 and 10 patients with an Evans index of 0.31 and 0.46, respectively) and 62 healthy volunteers. Average, volumetric, and peak flow velocities were determined at different intracranial levels. RESULTS: Analysis of differences between the mean values indicated that the patients with CH were observed to have progressive cranial cavity CSF outflow obstruction that depended on the degree of dilation of the ventricular system and, probably, on impaired CSF reabsorption. These changes can provide an explanation for the clinical symptoms present in the patients and also serve as diagnostic criteria. CONCLUSION: The investigation showed that phase-contrast magnetic resonance imaging might be used to estimate the quantitative indicators of CSF in health and in varying degrees of CH. The velocity characteristics of antegrade and retrograde CSF flows are significantly different in health and in disease, which may be relevant to neurologists and neurosurgeons when planning therapy and surgery options.