SEARCH CONTENT

You are looking at 61 - 70 of 104,540 items :

  • General Interest x
Clear All
The Many Lives of Calamity Jane

Abstract

Coordination and timing in repetitive movements have been intensively investigated in diverse experimental settings for understanding the underlying basic mechanisms in healthy controls. On this basic research side, there are mainly two theoretical models: the Wing-Kristofferson (WK) model and the Haken-Kelso-Bunz (HKB) model. On the clinical side of the research, several efforts have been spent on quantitatively assessing gait and other repetitive movements such as tapping, especially as an outcome measure of clinical trials in diverse neurological disorders. Nevertheless, Parkinson’s disease (PD) remains the predominant disorder in the clinical literature in this context, as the tremor activity and the changes in the gait are both common symptoms in PD. Although there are motion recording systems for data acquisition in clinical settings, the tools for analysis and quantification of the extracted time-series offered by these systems are severely restricted. Therefore, we introduce a toolbox which enables the analysis of repetitive movements within the framework of the two main theoretical models of motor coordination, which explicitly focuses on varying clinical and experimental settings such as self-paced vs. cued or uni-manual vs. bi-manual measurements. The toolbox contains particular pipelines for digital signal processing. Licensed under the GNU General Public License (GNU-GPL), the open source toolbox is freely available and can be downloaded from the Github link: https://github.com/MehmetEylemKirlangic/RepetitiveMovementAnalysis. We illustrate the application of the toolbox on sample experiments of gait and tapping with a control subject, as well as with a Parkinson’s patient. The patient has gone through a brain surgery for deep brain stimulation (DBS); hence, we present the results for both stimulation ON and stimulation OFF modes. Sample data are freely accessible at: https://github.com/MehmetEylemKirlangic/DATA.

Abstract

Atrial fibrillation (AF), the most common type of arrhythmia, has a heritable component. Variants at locus 4q25 are best associated with the risk of AF development in genome-wide association studies. Left atrial volume is an independent predictor of recurrence of AF after successful sinus rhythm restoration. The aim of our study was to investigate potential association between genetic variants at 4q25 locus and the risk of AF and echocardiographic parameters. We included 241 AF patients and 119 control individuals into the study. Left ventricle ejection fraction (LVEF, %) and left atrial volume index (LAVI, ml/m2) were assessed by transthoracic echocardiography during outpatient visits. We selected five 4q25 genetic variants (rs6825911, rs1126483, rs10004516, rs6838973, rs2200733) for the analysis. Variant rs6838973 was found to be associated with reduced risk of AF in additive (CCTT) and dominant (CC vs. CT+TT) models of inheritance. On the other hand, additive (CC<CT<TT) and dominant (CC vs. CT+TT) models of rs2200733 were associated with greater risk of AF. The same variations were found to be associated with age of AF onset. Median LAVI was 39.0 ml/m2 (IQR = 10.0) and median LVEF was 56.0% (IQR = 13.0). Statistically significant association was observed only between LAVI and variant rs1126483 in the dominant model of inheritance (median LAVI in CC vs. CT+TT – 38 ml/m2 vs. 40 ml/m2, U = 1602.5, p = 0.032). No significant association was found for LVEF and the analysed genotypes.

Abstract

The most common reasons for major skin loss are thermal trauma — burns and scalds that can result in rapid, extensive, deep wounds as well as chronic non-healing wounds. Treatment using common techniques is poor and depending on the trauma level can result in death. There is a substantial need for skin integrity restoration. The main goal of this study was to develop an autologous 3D skin model that could eventually be translated into clinical applications. The study examined a variety of factors — extracellular matrix components, cell count, culture medium modification and role of structurally and functionally high-quality 3D skin dermis layer tissue culture production. The results of this study are an essential prerequisite to standardise the use of both clinical, as well as in vitro test systems. Dermal cell lines applied in the study were isolated form patient biopsies obtained at Pauls Stradiņš Clinical University Hospital. Blood plasma type AB was used for fibrin matrix formation. As catalysts, CaCl2 or calcium gluconate, and tranexamic acid were applied. 3D tissue functionality was assessed by evaluation of gene expression and changes in growth factor secretion. Fibrin matrix formulations with 1% and 1.5% CaCl2 and 5 mg, 7 mg and 10 mg tranexamic acid concentration were tested. Better matrix properties were observed with higher concentration of CaCl2 and tranexamic acid. Differences in levels of collagen gene expression and growth factor secretion were observed. Changes in levels of fibroblast growth factor and gene expression were observed in fibrin matrix samples and the surface-cultivated cell culture monolayer, but structural protein synthesis was not detected.

Abstract

Data from 35 patients were analysed to identify the main factors that may have predisposed the unfavourable clinical course in early diagnosed lower lip cancer. Of 35 patients who were sent to the Oncology Centre of Latvia, Rīga East University Hospital, with the diagnosis of early lower lip cancer, histologically diagnosis was confirmed for 22 patients. Sizes of the primary tumours were less than 2 cm (T1 size tumour). Vermilionectomy was carried out for 17 patients, wedge- or V-shaped resection was performed for 13 patients, and in five cases patients refused to receive surgical treatment and received radiation therapy instead. Review of the reports of the histological criteria for patients with aggressive course of the illness with relapses, regional metastases and also in cases of death, showed that vermilionectomy can be considered an effective diagnostic and therapeutic operation.

Abstract

Amateur sport has significant influence on peoples’ physical activity and affects the prevalence of non-communicable diseases. The population of competing amateur athletes has not been sufficiently studied, and there is a huge gap between functional results of untrained individuals and professional athletes. The aim of the study was to evaluate the exercise capacity and chrono-tropic, inotropic capacity in amateur athletes with different training programmes, as assessed by cardiopulmonary exercise testing. In a longitudinal prospective study, 600 amateur athletes who performed high dynamic load sports, according to the Mitchell Classification of Sports, were assessed. The individuals underwent standard maximum cardiopulmonary exercise testing on the ISO certified Master screen CPX system. The exercise capacity was dependent on the training programme organisation, regularity and duration, but it was not dependent on age. During maximum work-rate, the functional parameters of the cardiorespiratory system and inotropic capacity were significantly dependent on duration of the training programme. Chronotropic and inotropic capacity, as well as cardiorespiratory adaptation were significantly higher for competing amateur athletes of both genders than for untrained individuals. The study showed that amateur athletes with a training programme 300 minutes per week had higher exercise capacity, which was based on the individually suitable training programme, and higher aerobic and anaerobic capacity. Regular pre-competition medical assessment of amateur athletes can be used to objectively evaluate their health condition, adaptation, cardiac risk and make changes in the athletes’ training programme.

Abstract

Phylogenetic relationships between zokors living in different territories of Russia: Altai zokors Myospalax myospalax from “Altai” (Altai Republic and Altaiskii Krai) and “Priobie” from the River Ob zone (Tomsk oblast and Novosibirsk oblast) and subspecies M. m. tarbagataicus from Kazakhstan (ridge Tarbagatai) and M. aspalax and M. psilurus from Zabaikalskii Krai were determined on the basis of craniometrical and molecular analysis of the mitochondrial 12S rRNA gene. The comparison of the craniometrical and molecular data revealed significant differences between the Altai zokors of the “Priobie” (the River Ob zone) and “Altai” populations. The importance of geographic isolation to the formation of morphometric and genetic differentiation of distinct geographic forms of the investigated zokors is shown. Specific ecological and morphological adaptations and distinct genetic features of two forms of zokors indicate the existence of separate subspecies of the species M. myospalax.

Abstract

The aim of the present study was to determine if individuals of Rumex hydrolapathum Huds native to saline wetlands are able to tolerate high concentration of biogenous heavy metals Zn and Mn in substrate and to accumulate high concentration of these metals in aboveground parts. Plant physiological status was monitored by using non-destructive analysis of chlorophyll and chlorophyll a fluorescence. R. hydrolapathum plants accumulated up to 1840 mg·kg−1 Zn and 6400 mg·kg−1 Mn in older leaves. The usefulness of monitoring changes in chlorophyll concentration and chlorophyll a fluorescence parameters to predict physiological response of R. hydrolapathum plants to excess Zn and Mn was not supported, as the lack of significant changes indicated that the model species showed adaptation to increased amount of metals in actively photosynthesizing tissues. It appears that Zn and Mn tolerance of R. hydrolapathum is based primarily at the physiological level where metal accumulation in younger leaves and roots is restricted, and development of new leaves is promoted together with induction of senescence in older leaves that have accumulated the majority of Zn and Mn. R. hydrolapathum can be characterised as a very promising model species for further studies for practical phytoremediation needs.