Comparison of combined therapy with ultrasound-associated interferential current in healthy subjects / Comparação da terapia combinada com corrente interferencial associada ao ultrassom em indivíduos saudáveis

ABSTRACT BACKGROUND AND OBJECTIVES: Although used in the therapeutic field, there is a shortage of studies that evaluate combined therapy or the association of electrical currents with therapeutic ultrasound, the present study aimed to compare the two forms in healthy individuals, analyzing the pain, number of accommodations and current intensity. METHODS: Thirty healthy volunteers took turns for three weeks in three groups. Nociception was evaluated by means of pressure and thermal stimuli in the lumbar spine and respective dermatomes. Then, the volunteer's dominant foot was submerged in cold water to evaluate the threshold of pain and its intensity. Shortly after, electroanalgesia (combined therapy, only current association with ultrasound, or placebo) was applied for 15 minutes. The application of the bipolar interferential current used a frequency of 4kHz, and amplitude modulation frequency of 100Hz, with one electrode on L3 and the other on S1. When combined therapy was used, the ultrasound head (1MHz) played the role of the electrode positioned over the L5-S1 region, in continuous form, at a dose of 0.4W/cm2. The intensity of the initial and final current was evaluated, as well as the number of accommodations. RESULTS: There was no significant difference between the pain thresholds of pressure and cold, but the combined therapy required more current intensity despite having a smaller number of accommodations. CONCLUSION: None of the therapies produced a difference in pain thresholds, but the combined therapy had fewer accommodations.

RESUMO JUSTIFICATIVA E OBJETIVOS: Apesar de utilizada no campo terapêutico, há escassez de estudos que avaliem a terapia combinada ou a associação de correntes elétricas ao ultrassom terapêutico. O objetivo deste estudo foi comparar as duas formas em indivíduos saudáveis, analisando o limiar de dor ao frio e à pressão, número de acomodações e intensidade da corrente. MÉTODOS: Trinta voluntários saudáveis revezaram em três grupos de forma cruzada durante três semanas. A nocicepção foi avaliada por meio de estímulos pressóricos e térmicos na coluna lombar e dermátomos. Em seguida, o voluntário teve seu pé submerso em água fria, e avaliado o limiar e a intensidade da dor. Logo após foi aplicado a eletroanalgesia (terapia combinada, apenas associação da corrente com ultrassom, ou placebo), por 15 minutos. Para corrente interferencial bipolar, foram utilizados frequência de 4kHz e frequência modulada pela amplitude de 100Hz, com um eletrodo sobre L3 e o outro sobre S1. Quando se utilizou a terapia combinada, o cabeçote do ultrassom (1MHz) fez o papel do eletrodo posicionado sobre a região de L5-S1, na forma contínua, com dose de 0,4W/cm2. Foi avaliada a intensidade da corrente inicial e final, além do número de acomodações. RESULTADOS: Não houve diferença significativa entre os limiares dolorosos à pressão e ao frio, mas a terapia combinada, apesar de ter apresentado menor número de acomodações, necessitou maior intensidade da corrente. CONCLUSÃO: Nenhuma das terapias produziu diferença nos limiares dolorosos, mas a terapia combinada apresentou menor número de acomodações.

The myotubularin-amphiphysin 2 complex in membrane tubulation and centronuclear myopathies.

Myotubularin (MTM1) and amphiphysin 2 (BIN1) are two proteins mutated in different forms of centronuclear myopathy, but the functional and pathological relationship between these two proteins was unknown. Here, we identified MTM1 as a novel binding partner of BIN1, both in vitro and endogenously in skeletal muscle. Moreover, MTM1 enhances BIN1-mediated membrane tubulation, depending on binding and phosphoinositide phosphatase activity. BIN1 patient mutations induce a conformational change in BIN1 and alter its binding and regulation by MTM1. In conclusion, we identified the first molecular and functional link between MTM1 and BIN1, supporting a common pathological mechanism in different forms of centronuclear myopathy.

Novel familial cases of ICCA (infantile convulsions with paroxysmal choreoathetosis) syndrome.

Epilepsy and paroxysmal dyskinesia are two episodic cerebral disorders that can share a common genetic basis. Rare families with infantile seizures and paroxysmal dyskinesia [predominantly paroxysmal kinesigenic dyskinesia (PKD)], co-inherited as a single autosomal dominant trait, have been described (infantile convulsions with paroxysmal choreoathetosis; ICCA syndrome) and a disease gene has been mapped at chromosome 16p12-q12 (ICCA region). We report the clinical picture of seven previously unreported families with ICCA syndrome. The identification of novel ICCA families should contribute to better knowledge regarding the clinical manifestations of ICCA syndrome as well as the search for the underlying genetic defect(s).

Nuclear localization of a novel human syntaxin 1B isoform.

The syntaxins are proteins associated with various intracellular membrane compartments. They are major participants in a large variety of physiological processes where membrane fusion occurs, including exocytosis. We have identified a novel syntaxin isoform generated by alternative splicing of the human STX1B gene. In contrast with the canonical syntaxins, this isoform (STX1B-DeltaTMD) lacked the classical C-terminal transmembrane domain and localized to the nucleus of various tumoral and non-tumoral cell types including human brain cortical neurons in vivo. The reversible blockade of STX1B-DeltaTMD nuclear import demonstrated that nuclear import occurred via a Ran-dependent pathway. A specific and glycine-rich C-terminus of 15 amino acids served as an unconventional nuclear localization signal. STX1B-DeltaTMD colocalized with Lamin A/C and NuMA (NUclear Mitotic Apparatus protein) in interphasic nuclei, and with NuMA and gamma-tubulin in the pericentrosomal region of the mitotic spindle in dividing cells. In a series of 37 human primary brain tumors, the ratio of STX1B-DeltaTMD to Lamin A/C transcripts was a significant prognostic marker of survival, independent of tumor staging. The characterization of STX1B-DeltaTMD as the first nucleoplasmic syntaxin with no transmembrane domain, illustrates the importance of alternative splicing in the emergence of unsuspected properties of the syntaxins in human cells, in both physiological and pathological conditions.

Molecular evolution of the human SRPX2 gene that causes brain disorders of the Rolandic and Sylvian speech areas.

BACKGROUND: The X-linked SRPX2 gene encodes a Sushi Repeat-containing Protein of unknown function and is mutated in two disorders of the Rolandic/Sylvian speech areas. Since it is linked to defects in the functioning and the development of brain areas for speech production, SRPX2 may thus have participated in the adaptive organization of such brain regions. To address this issue, we have examined the recent molecular evolution of the SRPX2 gene. RESULTS: The complete coding region was sequenced in 24 human X chromosomes from worldwide populations and in six representative nonhuman primate species. One single, fixed amino acid change (R75K) has been specifically incorporated in human SRPX2 since the human-chimpanzee split. The R75K substitution occurred in the first sushi domain of SRPX2, only three amino acid residues away from a previously reported disease-causing mutation (Y72S). Three-dimensional structural modeling of the first sushi domain revealed that Y72 and K75 are both situated in the hypervariable loop that is usually implicated in protein-protein interactions. The side-chain of residue 75 is exposed, and is located within an unusual and SRPX-specific protruding extension to the hypervariable loop. The analysis of non-synonymous/synonymous substitution rate (Ka/Ks) ratio in primates was performed in order to test for positive selection during recent evolution. Using the branch models, the Ka/Ks ratio for the human branch was significantly different (p = 0.027) from that of the other branches. In contrast, the branch-site tests did not reach significance. Genetic analysis was also performed by sequencing 9,908 kilobases (kb) of intronic SRPX2 sequences. Despite low nucleotide diversity, neither the HKA (Hudson-Kreitman-Aguadé) test nor the Tajima's D test reached significance. CONCLUSION: The R75K human-specific variation occurred in an important functional loop of the first sushi domain of SRPX2, indicating that this evolutionary mutation may have functional importance; however, positive selection for R75K could not be demonstrated. Nevertheless, our data contribute to the first understanding of molecular evolution of the human SPRX2 gene. Further experiments are now required in order to evaluate the possible consequences of R75K on SRPX2 interactions and functioning.

Familial generalized epilepsy in Bulgarian Roma.

AIMS: Gypsy communities constitute cultural and frequently inbred genetic isolates. Several genetic neurological disorders have been identified in these communities. Epilepsy appears as a fairly frequent medical condition among Bulgarian Gypsies, and many patients can be related to large pedigrees that may then be studied by conventional genetic linkage analyses. PATIENTS AND METHODS: We identified two large Wallachian Gypsy families from the Plovdiv and Varna regions of Bulgaria, with detailed clinical questionnaires and examination, and EEG recordings for many. Genetic linkage analysis was performed using microsatellite markers spaced across the human genome. RESULTS: Although phenotypes were not always easy to identify, epilepsy appears in both families as a dominant, or pseudo-dominant trait, with the characteristics of idiopathic generalized epilepsy with onset at various ages, with infrequent, generalized tonic-clonic seizures, some associated with fever in childhood, but without sensitivity to fever in later life. While few markers yielded LOD scores > 2, no locus showed significant linkage, assuming autosomal dominant or recessive modes of inheritance. CONCLUSION: Idiopathic generalized epilepsy, with a marked familial character, has not been reported to date in Bulgarian Gypsies. Both pedigrees studied here present with an identifiable epilepsy type inherited as a Mendelian trait. Despite the current lack of significant linkage, these families may constitute interesting ground for further genetic studies, on condition that more patients and families can be recruited. [Published with supplemental data on DVD].

SRPX2 mutations in disorders of language cortex and cognition.

The rolandic and sylvian fissures divide the human cerebral hemispheres and the adjacent areas participate in speech processing. The relationship of rolandic (sylvian) seizure disorders with speech and cognitive impairments is well known, albeit poorly understood. We have identified the Xq22 gene SRPX2 as being responsible for rolandic seizures (RSs) associated with oral and speech dyspraxia and mental retardation (MR). SRPX2 is a secreted sushi-repeat containing protein expressed in neurons of the human adult brain, including the rolandic area. The disease-causing mutation (N327S) resulted in gain-of-glycosylation of the secreted mutant protein. A second mutation (Y72S) was identified within the first sushi domain of SRPX2 in a male with RSs and bilateral perisylvian polymicrogyria and his female relatives with mild MR or unaffected carrier status. In cultured cells, both mutations were associated with altered patterns of intracellular processing, suggesting protein misfolding. In the murine brain, Srpx2 protein expression appeared in neurons at birth. The involvement of SRPX2 in these disorders suggests an important role for SRPX2 in the perisylvian region critical for language and cognitive development.

Large-scale expression study of human mesial temporal lobe epilepsy: evidence for dysregulation of the neurotransmission and complement systems in the entorhinal cortex.

Human mesial temporal lobe epilepsies (MTLE) are the most frequent form of partial epilepsies and display frequent pharmacoresistance. The molecular alterations underlying human MTLE remain poorly understood. A two-step transcriptional analysis consisting in cDNA microarray experiments followed by quantitative RT-PCR validations was performed. Because the entorhinal cortex (EC) plays an important role in the pathophysiology of the MTLE and usually discloses no detectable or little cell loss, resected EC and each corresponding lateral temporal neocortex (LTC) of MTLE patients were used as the source of disease-associated and control RNAs, respectively. Six genes encoding (i) a serotonin receptor (HTR2A) and a neuropeptide Y receptor type 1 (NPY1R), (ii) a protein (FHL2) associating with the KCNE1 (minK) potassium channel subunit and with presenilin-2 and (iii) three immune system-related proteins (C3, HLA-DR-gamma and CD99), were found consistently downregulated or upregulated in the EC of MTLE patients as compared with non-epileptic autopsy controls. Quantitative western blot analyses confirmed decreased expression of NPY1R in all eight MTLE patients tested. Immunohistochemistry experiments revealed the existence of a perivascular infiltration of C3 positive leucocytes and/or detected membrane attack complexes on a subset of neurons, within the EC of nine out of eleven MTLE patients. To summarize, a large-scale microarray expression study on the EC of MTLE patients led to the identification of six candidate genes for human MTLE pathophysiology. Altered expression of NPY1R and C3 was also demonstrated at the protein level. Overall, our data indicate that local dysregulation of the neurotransmission and complement systems in the EC is a frequent event in human MTLE.