The Effect of Repetitive Transcranial Magnetic Stimulation on Motor Symptoms in Hereditary Spastic Paraplegia.

Background: Hereditary spastic paraplegia (HSP) is a heterogeneous group of inherited disorders affecting predominantly the motor cortex and pyramidal tract, which results in slowly progressing gait disorders, as well as spasticity and weakness of lower extremities. Repetitive transcranial magnetic stimulation (rTMS) has been previously investigated as a therapeutic tool for similar motor deficits in a number of neurologic conditions. The aim of this randomized, controlled trial was to investigate the therapeutic potential of rTMS in various forms of HSP, including pure and complicated forms, as well as adrenomyeloneuropathy. Methods: We recruited 15 patients (five women and 10 men; mean age 43.7 ± 10.6 years) with the mentioned forms of HSP. The intervention included five sessions of bilateral 10 Hz rTMS over primary motor areas of the muscles of lower extremities and five sessions of similar sham stimulation. Results: One patient dropped out due to seizure, and 14 patients completed the study protocol. After real stimulation, the strength of the proximal and distal muscles of lower extremities increased, and the spasticity of the proximal muscles decreased. Change in spasticity was still present during follow-up assessment. No effect was observed regarding gait velocity. No changes were seen after sham stimulation. A post hoc analysis revealed an inverse relation between motor threshold and the change of the strength after active rTMS. Conclusions: rTMS may have potential in improving weakness and spasticity of lower extremities in HSP, especially of proximal muscles whose motor areas are located more superficially. This trial is registered with Clinicaltrials.gov NCT03627416.

The differences in sleep profile changes under continuous positive airway pressure (CPAP) therapy between non-obese, obese and severely obese sleep apnea patients.

Sleep disturbances in obstructive sleep apnea are caused mainly by repetitive apneas and hypopneas. An alternative factor contributing to disordered sleep may be the obesity, which is frequently associated with sleep apnea. The sleep disturbing effect of obesity was found previously in obese nonapneic subjects. The aim of this study was to evaluate the effect of obesity on sleep quality in sleep apnea patients in particular in patients under continuous positive airway pressure (CPAP) with successfully normalized respiration. We reviewed the archive data of 18 non-obese, 18 obese and 17 severely obese age and gender matched sleep apnea patients treated with CPAP. The polysomnographic parameters from the diagnostic night, from the second night under CPAP and from the follow up night (after three months of CPAP use) were compared. Before CPAP the apnea hypopnea index was worse in obese and in severely obese group and it normalised under CPAP in all groups. The severely obese group showed more light sleep and less REM sleep before CPAP and inversely - less light and more REM sleep in the second night under CPAP than the non-obese group. In the follow up, there was no differences in sleep profile between groups. This study indicates obesity does not affect the sleep independently of respiratory disorders. Before therapy it is associated with more severe sleep apnea and indirectly with worse sleep quality.

The influence of obesity on sleep quality in male sleep apnea patients before and during therapy.

Evidence exists that obesity, even in the absence of sleep related respiratory disorders, affects sleep negatively. In this study we examined the influence of obesity on sleep quality of male sleep apnea patients before and after breathing normalization with continuous positive airway pressure (CPAP). We compared the polysomnography from the diagnostic night, second night with CPAP, and a control night (three months later) in 13 non-obese, 13 obese, and 12 severely obese male obstructive sleep apnea patients. In the diagnostic polysomnography, obese and severely obese subjects showed increases in apnea-hypopnea index (AHI) and NREM-1 sleep, and decreases in min SaO(2), REM sleep, and partially slow wave sleep (SWS), when compared with the non-obese group. In the second night under CPAP, normalization of the AHI and a rebound of REM and SWS occurred, which was more pronounced in severely obese than in the non-obese and obese group. The polysomnography recorded three months thereafter revealed no differences in sleep stages between the groups. We conclude that after the long-term CPAP therapy, no effect of obesity on sleep quality is apparent.

Positron emission tomography findings in obstructive sleep apnea patients with residual sleepiness treated with continuous positive airway pressure.

Despite sufficient continuous positive airway pressure (CPAP) therapy, some patients with the obstructive sleep apnea syndrome (OSAS) still suffer from excessive daytime sleepiness (EDS). In some of them, no cause of the persistence of EDS can be found. Brain damage due to nocturnal hypoxemia is a potential cause for this unclear persistent sleepiness (UPS). This study was done to evaluate this hypothesis. Patients with UPS were identified among the OSAS patients, who came for a CPAP therapy checkup to our sleep laboratory. UPS was recognized when no explanation for persistent EDS could be yielded by standard diagnostic procedures. Out of 167 patients under CPAP therapy 13 had UPS. To investigate the brain morphology, positron emission tomography (PET) scanning with the tracer fluorine-18 fluorodeoxyglucose (FDG), called FDG-PET, were performed in 7 of the UPS patients. Abnormal PET findings were concentrated in frontal area (found in 4 patients). The frontal abnormality seems to distinguish the OSAS patients with UPS from the whole OSAS population, examined in previous studies.

Outcomes of CPAP treatment in a sleep laboratory specialized in neuropsychiatry.

The rapidly increasing number of sleep laboratories implicates their specialization into various fields of sleep medicine. In our sleep laboratory that specializes in neuropsychiatry, patients with the symptoms typical for the obstructive sleep apnea/hypopnea syndrome (OSAHS) were routinely redirected to a local respiratory clinic. Some patients, however, admitted to our center for other reasons revealed OSAHS in nocturnal polysomnography. The purpose of this retrospective study was to assess the outcome of CPAP in treating the sleepiness in this group of patients. Our material consisted of 36 patients who started CPAP therapy due to OSAHS diagnosed in our laboratory in the year 2000 and who came for a routine checkup in 2001. The sleepiness was assessed by using the Epworth Sleepiness Scale (ESS). After CPAP, the mean group ESS score decreased from 10.9 +/-4.4 to 8.5 +/-4.3 points (P<0.01). Some patients showed, however, persisting excessive sleepiness (PTS) after CPAP, defined as ESS >or=12. We overviewed the documentation of those patients in search for the possible causes of PTS. We identified the following causes: narcolepsy - 1 patient, insufficient CPAP pressure - 1 patient, low CPAP compliance, fewer than 2 h/night, - 2 patients. In 5 other patients we found CPAP compliance to be between 2.0 and 4.5 h/night, which is less likely to be the cause of PTS. In 1 patient no cause was identified. Our patients showed relatively mild sleepiness before CPAP and only a slight improvement under CPAP. The CPAP noncompliance seems the most prevailing reason for CPAP failure, but in some patients the cause of PTS could not be unraveled by using standard diagnostic tools and some additional measures are to be employed to resolve the issue.

Heptad-repeat regions of respiratory syncytial virus F1 protein form a six-membered coiled-coil complex.

The Respiratory Syncytial Virus (RSV) fusogenic glycoprotein F(1) was characterized using biochemical and biophysical techniques. Two heptad-repeat (HR) regions within F(1) were shown to interact. Proteinase-K digestion experiments highlight the HR1 region (located proximal to the fusion peptide sequence) of the F(1) protein to which an HR2-derived (located proximal to the membrane-spanning domain) peptide binds, thus protecting both the protein and peptide from digestion. Solution-phase analysis of HR1-derived peptides shows that these peptides adopt helical secondary structure as measured by circular dichroism. Sedimentation equilibrium studies indicate that these HR1 peptides self-associate in a monomer/trimer equilibrium with an association constant of 5.2 x 10(8) M(-2). In contrast, HR2-derived peptides form random monomers in solution. CD analysis of mixtures containing peptides from the two regions demonstrate their propensity to interact and form a very stable (T(m) = 87 degrees C), helical (86% helicity) complex comprised of three HR1 and three HR2 members.

A 43-nucleotide RNA cis-acting element governs the site-specific formation of the 3' end of a poxvirus late mRNA.

The 3' ends of late mRNAs of the ati gene, encoding the major component of the A-type inclusions, are generated by endoribonucleolytic cleavage at a specific site in the primary transcript [Antczak et al., (1992), Proc. Natl. Acad. Sci. USA 89, 12033-12037]. In this study, sequence analysis of cDNAs of the 3' ends of ati mRNAs showed these mRNAs are 3' polyadenylated at the RNA cleavage site. This suggests that ati mRNA 3' end formation involves cleavage of a late transcript, with subsequent 3' polyadenylation of the 5' cleavage product. The RNA cis-acting element, the AX element, directing orientation-dependent formation of these mRNA 3' ends, was mapped to a 345-bp AluI-XbaI fragment. Deletion analyses of this fragment showed that the boundaries of the AX element are within -5 and +38 of the RNA cleavage site. Scanning mutagenesis showed that the AX element contains at least two subelements: subelement I, 5'-UUUAU downward arrowCCGAUAAUUC-3', containing the cleavage site ( downward arrow), separated from the downstream subelement II, 5'-AAUUUCGGAUUUGAAUGC-3', by a 10-nucleotide region, whose composition may be altered without effect on RNA 3' end formation. These features, which differ from those of other elements controlling RNA processing, suggest that the AX element is a component of a novel mechanism of RNA 3' end formation.

Reovirus exists in the form of 13 particle species that differ in their content of protein sigma 1.

When electrophoresed in 0.7% agarose gels, populations of reovirus particles can be resolved into 13 well-defined bands that possess from 0 to 12 projection/spike-associated trimers of protein sigma 1. This state of affairs is not an artifact of purification, of the techniques used to demonstrate it, of aggregation, or of virus particle instability. Complexes of monoclonal antibody against protein sigma 1 with virus particles that possess only 1, or, to a lesser extent, 2 sigma 1 trimers are less stable (that is, more readily dissociated by sonication) than complexes of antibody and virus particles that possess 3 or more sigma 1 trimers. The specific infectivity of virus particles that possess 3 or more sigma 1 trimers is essentially the same; virus particles that possess only 2 sigma 1 trimers are about two-thirds as infectious; and particles that possess only 1 sigma 1 trimer still possess very significant infectivity (about one-third of maximum). Reovirus particles that possess no sigma 1 trimers (about 1 in 30) are essentially noninfectious. The reason reovirus particles do not possess a full complement of sigma 1 trimers is presumably the fact that only very small amounts of protein sigma 1 are synthesized in infected cells; and since possession of 3 such trimers is sufficient for maximal infectivity, and since the average number of sigma 1 trimers per reovirus particle is 7.1, there is presumably no selection for variants that synthesize larger amounts of sigma 1. On the contrary, such variants may well be at a selective disadvantage.

Site-specific RNA cleavage generates the 3' end of a poxvirus late mRNA.

The cowpox virus late mRNAs encoding the major protein of the A-type inclusions have 3' ends corresponding to a single site in the DNA template. The DNA sequence of the Alu I-Xba I fragment at this position encodes an RNA cis-acting signal, designated the AX element, which directs this RNA 3' end formation. In cells infected with vaccinia virus the AX element functions independently of either the nature of the promoter element or the RNA polymerase responsible for generating the primary RNA. At late times during virus replication, vaccinia virus induces or activates a site-specific endoribonuclease that cleaves primary RNAs within the AX element. The 3' end produced by RNA cleavage is then polyadenylylated to form the 3' end of the mature mRNA. Therefore, the poxviruses employ at least two mechanisms of RNA 3' end formation during the viral replication cycle. One mechanism, which is operative at early times in viral replication, involves the termination of transcription [Rohrmann, G., Yuen, L. & Moss, B. (1986) Cell 46, 1029-1035]. A second mechanism, which is operative at late times during viral replication, involves the site-specific cleavage of primary RNAs.

Reovirus genome segment assortment into progeny genomes studied by the use of monoclonal antibodies directed against reovirus proteins.

Using a panel of monoclonal antibodies (MABs) against reovirus proteins, we have identified proteins that associate with reovirus messenger RNA molecules prior to the generation of progeny double-stranded (ds) genome segments and proteins that are components of the structures within which progeny ds genome segments are generated. The following conclusions can be drawn from the results obtained. (1) Three proteins rapidly become associated with mRNA molecules to form single-stranded RNA-containing complexes (ssRCCs): the nonstructural protein microNS, the nonstructural protein sigma NS, and protein sigma 3. (2) Analysis of populations of ssRCCs in density gradients and by sequential exposure to various MABs indicates that some ssRCCs contain only microNS, others microNS and sigma NS or sigma 3, and others all three proteins. Each ssRCC contains one RNA molecule and, depending on the size of the RNA, 10-30 protein molecules. (3) The relative proportions of the individual RNA species in the ssRCC populations reflect the composition of the total mRNA population present in infected cells (which differs substantially from equimolarity). (4) RCCs that contain dsRNA, which become detectable as early as 4 hr after infection, contain not only microNS, sigma NS, and sigma 3, but also lambda 2. (5) The relative proportions of the 10 genome segments in dsRCCs are equimolar. This suggests that genome segment assortment into progeny genomes is linked to the transcription of plus strands into minus strands.

Studies on the mechanism of the antiviral activity of ribavirin against reovirus.

We have examined the mechanism by which ribavirin inhibits the multiplication of reovirus. At a concentration of 12.5 microM (3 micrograms/ml) ribavirin inhibits viral multiplication, ssRNA formation, dsRNA formation, and protein synthesis by about 90%; when much higher concentrations are used for brief periods of time, the primary target of ribavirin is seen to be viral ssRNA synthesis. When the effect of ribavirin triphosphate (RTP) was tested on the in vitro transcription by cores of the dsRNA genome segments into plus-stranded RNA, elongation, that is, the formation of intact mRNA molecules, was found to be inhibited to the greatest extent; initiation was at least 2.5 times less sensitive, and cap formation and methylation were almost unaffected. The inhibition of elongation and initiation was not competitive with respect to any of the four nucleoside triphosphates. Remarkably, the transcription of plus strands into minus strands by immature reovirus particles (the replicase reaction) was insensitive to RTP. A model is proposed that envisages RTP binding to a site close to the catalytic site of the transcriptase. This binding is postulated to inhibit the helicase function of the transcriptase and lower its affinity for template RNA so that the likelihood of premature termination is greatly increased. The helicase activity is not, of course, necessary for the transcription of plus strands into minus strands, which would account for the differential sensitivity of the transcriptase and the replicase to RTP.

[Use of low-temperature plasma in the preparation of synthetic polymers for modification by collagen]. / Zastosowanie plazmy niskotemperaturowej w przygotowaniu polimerów syntetycznych do modyfikowania kolagenem.

The physico mechanical properties of films, vascular prostheses and nets made of polyethylene terephthalate and polyethylene film treated with the low temperature plasma were investigated. The plasma was generated by glow discharge in air under the following conditions: gas pressure - , current - 0.4-0.6 A, time of treatment - 40-240 s. stated that the angles of wetting with water and collagen solution of films treated with plasma decreases considerably. Sharp decreasing of wetting angles is followed by quick rise of the between water and polymeric film, and also by the increasing of free surface energy. The increasing of the wettability does not change during the storing time. The breaking stress and extension of the films treated with plasma are the same or a little bit higher than those of the untreated ones. The collagen modified by radiation shows high adhesion to the polymeric materials treated with plasma. The value of this adhesion 6 x 10(5) mN/m for polyester film, is about 6 times higher than the value of adhesion obtained by other authors, if the polyester film was treated with air plasma generated by spark discharge method.