Varkuti B.,University of Tübingen |
Varkuti B.,Institute for Infocomm Research |
Guan C.,Institute for Infocomm Research |
Pan Y.,Institute for Infocomm Research |
And 9 more authors.
Neurorehabilitation and Neural Repair | Year: 2013
Background. Robot-Assisted training may improve motor function in some hemiparetic patients after stroke, but no physiological predictor of rehabilitation progress is reliable. Resting state functional magnetic resonance imaging (RS-fMRI) may serve as a method to assess and predict changes in the motor network. Objective. The authors examined the effects of upper-extremity robot-Assisted rehabilitation (MANUS) versus an electroencephalography-based brain computer interface setup with motor imagery (MI EEG-BCI) and compared pretreatment and posttreatment RS-fMRI. Methods. In all, 9 adults with upper-extremity paresis were trained for 4 weeks with a MANUS shoulder-elbow robotic rehabilitation paradigm. In 3 participants, robot-Assisted movement began if no voluntary movement was initiated within 2 s. In 6 participants, MI-BCI-based movement was initiated if motor imagery was detected. RS-fMRI and Fugl-Meyer (FM) upper-extremity motor score were assessed before and after training. Results. The individual gain in FM scores over 12 weeks could be predicted from functional connectivity changes (FCCs) based on the pre-post differences in RS-fMRI measurements. Both the FM gain and FCC were numerically higher in the MI-BCI group. Increases in FC of the supplementary motor area, the contralesional and ipsilesional motor cortex, and parts of the visuospatial system with mostly association cortex regions and the cerebellum correlated with individual upper-extremity function improvement. Conclusion. FCC may predict the steepness of individual motor gains. Future training could therefore focus on directly inducing these beneficial increases in FC. Evaluation of the treatment groups suggests that MI is a potential facilitator of such neuroplasticity. © 2013 The Author(s).
Pandit L.,KS Hegde Medical Academy |
Ban M.,Addenbrookes Hospital |
Sawcer S.,Addenbrookes Hospital |
Singhal B.,Bombay Hospital |
And 6 more authors.
Multiple Sclerosis Journal | Year: 2011
Background: Multiple sclerosis (MS) is a chronic demyelinating neurodegenerative disorder with a strong genetic component. Objective: The prevalence of MS in India is low compared with white populations of Northern European descent. Methods: In order to ascertain whether disease susceptibility genes are the same across different populations, we completed the first investigation in the Indian MS population of 15 MS loci outside of the major histocompatibility (MHC) region that were previously identified and validated with MS susceptibility through genome-wide association and replication studies in white populations. Results: In total, 197 Indian patients and 197 unrelated controls were analyzed. The most associated single nucleotide polymorphism (SNP) within this study was rs6897932 in the IL7R gene, which showed a strong protective effect in this data set (rs 6897932, OR = 0.5543, 95% CI = 0.37-0.78, p = 0.0009727). Two other SNPs were nominally associated with MS in this dataset, namely CLEC16A rs 12708716 (p = 0.0082, OR = 1.478, 95% CI = 1.106-1.975) and CD226 rs763361 (p = 0.03971, OR = 1.353, CI = 1.014-1.805). For the majority of the remaining SNPs (7/14), the trend for association was in the same direction as in previous studies in the white population. Conclusions: Although the power of this study was limited, our preliminary data suggest that disease susceptibility genes in MS in the Indian population may be similar to those of western populations. © 2011 The Author(s).
Ruiz S.,University of Santiago de Chile |
Ruiz S.,University of Tübingen |
Birbaumer N.,University of Tübingen |
Birbaumer N.,Instituto Of Ricovero E Cura A Carattere Scientifico |
And 3 more authors.
Frontiers in Psychiatry | Year: 2013
Considering that single locations of structural and functional abnormalities are insufficient to explain the diverse psychopathology of schizophrenia, new models have postulated that the impairments associated with the disease arise from a failure to integrate the activity of local and distributed neural circuits: the "abnormal neural connectivity hypothesis." In the last years, new evidence coming from neuroimaging have supported and expanded this theory. However, despite the increasing evidence that schizophrenia is a disorder of neural connectivity, so far there are no treatments that have shown to produce a significant change in brain connectivity, or that have been specifically designed to alleviate this problem. Brain-Computer Interfaces based on real-time functional Magnetic Resonance Imaging (fMRI-BCI) are novel techniques that have allowed subjects to achieve self-regulation of circumscribed brain regions. In recent studies, experiments with this technology have resulted in new findings suggesting that this methodology could be used to train subjects to enhance brain connectivity, and therefore could potentially be used as a therapeutic tool in mental disorders including schizophrenia. The present article summarizes the findings coming from hemodynamics-based neuroimaging that support the abnormal connectivity hypothesis in schizophrenia, and discusses a new approach that could address this problem. © 2013 Ruiz, Birbaumer and Sitaram.
Birbaumer N.,University of Tübingen |
Birbaumer N.,Instituto Of Ricovero E Cura A Carattere Scientifico Irccs |
Ruiz S.,University of Tübingen |
Ruiz S.,Bernardo O'Higgins University |
And 3 more authors.
Trends in Cognitive Sciences | Year: 2013
Self-regulation and voluntary control of circumscribed brain regions using real-time functional MRI (rt-fMRI) allows the establishment of a causal functional link between localized brain activity and behavior and cognition. A long tradition of research has clearly shown the brain's ability to learn volitional control of its own activity and effects on behavior. Yet, the underlying neural mechanism of self-regulation is still not fully understood. Here, we propose that self-regulation of brain activity is akin to skill learning and thus may depend on an intact subcortical motor system. We elaborate on the critical role of the basal ganglia in skill learning and neurofeedback, and clarify that brain-self-regulation need not be an explicit and conscious process as often mistakenly held. © 2013.
Varghese V.M.,Sree Chitra Tirunal Institute for Medical Sciences and Technology |
Raj V.,Laboratory for Polymer Analysis |
Sreenivasan K.,Laboratory for Polymer Analysis |
Kumary T.V.,Sree Chitra Tirunal Institute for Medical Sciences and Technology
Journal of Materials Science: Materials in Medicine | Year: 2010
Scaffold free tissue constructs are preferred in tissue engineering as they overcome all the problems associated with scaffolds. Stimuli responsive polymers enable generation of scaffold free multilayered tissue constructs which would in turn reduce the use of biomaterials in vivo. In this study, we investigated cytocompatibility and thermoresponsiveness of a copolymer of N-Isopropylacrylamide and Methyl Methacrylate. Thermoresponsive surfaces were prepared by coating tissue culture polystyrene with the copolymer solution in isopropanol. Mammalian fibroblast cells (L929 cells) readily adhered on the copolymer. The viability and cellular activity was ensured through Neutral red staining, MTT assay, Tritiated thymidine uptake assay and Immunofluorescent staining for cytoskeletal organisation. Incubation under lower critical solution temperature of copolymer resulted in intact detachment of cells. To conclude, in-house synthesized cytocompatible smart culture substrate intended for tissue engineering was developed using a cost effective and simple technique. Moreover, presence of methyl methacrylate in the copolymer reduced the lower critical solution temperature facilitating extended in vitro manipulation time. As the copolymer is insoluble in water, the copolymer could be polymerised without additional crosslinkers. © Springer Science+Business Media, LLC 2010.
Singh G.,Christian Medical College and Hospital |
Manickam A.,Sree Chitra Tirunal Institute for Medical Sciences and Technology |
Sethuraman M.,Sree Chitra Tirunal Institute for Medical Sciences and Technology |
Rathod R.,Sree Chitra Tirunal Institute for Medical Sciences and Technology
Indian Journal of Critical Care Medicine | Year: 2015
We describe a case of Takotsubo cardiomyopathy in a case of pituitary macroadenoma in acute adrenal crisis. A 48-year-old man presented with acute onset altered sensorium, vomiting, and gasping. On admission, he was unresponsive and hemodynamically unstable. He was intubated and ventilated and resuscitated with fluids and inotropes. The biochemical evaluation revealed hyponatremia, hyperkalemia, and hypocortisolism. Hyponatremia was corrected with 3% hypertonic saline. Contrast enhanced computed tomography (CT) scan of the brain revealed a sellar-suprasellar mass with hypothalamic extension with no evidence of pituitary apoplexy. A diagnosis of invasive pituitary adenoma with the Addisonian crisis was made and steroid replacement was initiated. Despite volume resuscitation, he had persistent refractory hypotension, recurrent ventricular tachycardia, and metabolic acidosis. Electrocardiogram (ECG) showed ST elevation and T-wave inversion in lateral leads; cardiac-enzymes were increased suggestive of acute coronary syndrome. Transthoracic echocardiography showed severe regional wall motion abnormalities (RWMAs) involving left anterior descending territory and low ejection fraction (EF). Coronary angiogram revealed normal coronaries, apical ballooning, and severe left ventricular dysfunction, consistent with a diagnosis of Takotsubo's cardiomyopathy. Patient was managed with angiotensin-converting enzyme inhibitors and B-blockers. He improved over few days and recovered completely. At discharge, ECG changes and RWMA resolved and EF normalized to 56%. In patients with Addisonian Crisis with persistent hypotension refractory to optimal resuscitation, possibility of Takotsubo's cardiomyopathy should be considered. Early recognition of association of Takotsubos cardiomyopathy in neurological conditions, prompt resuscitation, and supportive care are essential to ensure favorable outcomes in this potentially lethal condition. © 2015 Indian Journal of Critical Care Medicine | Published by Wolters Kluwer - Medknow.
Remya N.S.,Sree Chitra Tirunal Institute for Medical Sciences and Technology |
Nair P.D.,Sree Chitra Tirunal Institute for Medical Sciences and Technology
Journal of Biomedical Materials Research - Part A | Year: 2016
Fetal-derived mesenchymal stem cells especially human umbilical cord matrix mesenchymal stem cells (hUCMSCs), with their ease of availability, pluripotency, and high expansion potential have emerged as an alternative solution for stem cell based cartilage therapies. An attempt to elucidate the effect of dynamic mechanical compression in modulating the chondrogenic differentiation of hUCMSCs is done in this study to add on to the knowledge of optimizing chondrogenic signals necessary for the effective differentiation of these stem cells and subsequent integration to the surrounding tissues. hUCMSCs were seeded in porous poly (vinyl alcohol)-poly (caprolactone) (PVA-PCL) scaffolds and cultured in chondrogenic medium with/without TGF-β3 and were subjected to a dynamic compression of 10% strain, 1 Hz for 1/4 h for 7 days. The results on various analysis shows that the extent of dynamic compression is an important factor affecting cell viability. Mechanical stimulation in the form of dynamic compression stimulates expression of chondrogenic genes even in the absence of chondrogenic growth factors and also augments growth factor induced chondrogenic potential of hUCMSC. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2554–2566, 2016. © 2016 Wiley Periodicals, Inc.
Manju S.,Sree Chitra Tirunal Institute for Medical Sciences and Technology |
Sreenivasan K.,Sree Chitra Tirunal Institute for Medical Sciences and Technology
Talanta | Year: 2011
A simple fluorescent sensing of glucose in aqueous fluids (e.g. tear fluid) using dually functionalized gold nanoparticles is presented. As a first step gold nanoparticles (AuNPs) were synthesized using oxidised dextran which acted both as reducing and stabilizing agent. Aminophenyl boronic acid was conjugated onto AuNPs by Schiff's base formation and the formed Schiff's base was stabilized by sodium borohydride reduction. Rhodamine B isothiocyanate (RBITC) was then assembled onto the modified AuNPs. The fluorescence of RBITC was nearly quenched and found to be revived when glucose was added. It is reasoned that the glucose binding induces restructuring of the surface assembly resulting in an overall increase in the size and thereby enhancing the distance between the gold core and fluorophore. TEM image and size measurements using dynamic light scattering (DLS) in fact, reflected this possibility. The increase in fluorescence was proportional with the concentration of glucose enabling quantitative detection. A good linearity was observed between the fluorescence intensity and glucose concentration in a range of 0.025-0.125 μM with detection limit of 0.005 ± 0.002 μM. The potential of the method was demonstrated by measuring glucose in real tear fluids collected from volunteers. The method is extremely sensitive and can be employed to measure low concentration of glucose in aqueous fluids such as tear. © 2011 Elsevier B.V. All rights reserved.
Nirmal R.S.,Sree Chitra Tirunal Institute for Medical Sciences and Technology |
Nair P.D.,Sree Chitra Tirunal Institute for Medical Sciences and Technology
European Cells and Materials | Year: 2013
Stem cell based tissue engineering has emerged as a promising strategy for articular cartilage regeneration. Foetal derived mesenchymal stem cells (MSCs) with their ease of availability, pluripotency and high expansion potential have been demonstrated to be an attractive cell source over adult MSCs. However, there is a need for optimisation of chondrogenic signals to direct the differentiation of these multipotent MSCs to chondrogenic lineage. In this study we have demonstrated the in vitro chondrogenesis of human umbilical cord matrix MSCs in three dimensional PVA-PCL (polyvinyl alcohol-polycaprolactone) scaffolds in the presence of the individual growth factors TGFβ1, TGFβ3, IGF, BMP2 and their combination with BMP2. Gene expression, histology and immunohistology were evaluated after 28 d culture. The induced cells showed the feature of chondrocytes in their morphology and expression of typical chondrogenic extracellular matrix molecules. Moreover, the real-time PCR assay has shown the expression of gene markers of chondrogenesis, SOX9, collagen type II and aggrecan. The expression of collagen type I and collagen type X was also evaluated. This study has demonstrated the successful chondrogenic induction of human umbilical cord MSCs in 3D scaffolds. Interestingly, the growth factor combination of TGF-β3 and BMP-2 was found to be more effective for chondrogenesis as shown by the real-time PCR studies. The findings of this study suggest the importance of using growth factor combinations for successful chondrogenic differentiation of umbilical cord MSCs.
PubMed | Sree Chitra Tirunal Institute for Medical Sciences and Technology
Type: Journal Article | Journal: Annals of cardiac anaesthesia | Year: 2017
Hypoxemia is common during one-lung ventilation(OLV), predominantly due to transpulmonary shunt. None of the strategies tried showed consistent results. We evaluated the effectiveness of ventilating the operated, non-dependent lung (NDL) with small tidal volumes in improving the oxygenation during OLV.30 ASA 1 and 2 patients undergoing elective, open thoracotomy were studied. After standard induction of anesthesia, lung seperation was acheived with left sided DLT. The ventilatory settings for two lung ventilation (TLV) were: FiO 2 of 0.5, tidal volume of 8-10ml/kg and respiratory rate of 10-12/min. After initiating OLV, the dependent lung alone was ventilated with the above settings for 15 minutes and an arterial blood gas (ABG) analysis was done. Then the NDL was ventilated with a separate ventilator, with FiO 2 of 1, tidal volume of 70 ml, I:E ratio of 1:10 and respiratory rate of 6/min for 15 minutes. The NDL ventilation was started early if the patients desaturated to <95%. ABG was done at 5 and 15 mins of NDL ventilation. We compared the PaO 2 values.The mean PaO 2 decreased from 232.2 67.2 mm of Hg (TLV-ABG1) to 91.2 31.7 mm of Hg on OLV (OLV-ABG1). The ABG after 5 minutes and 15 minutes after institution of NDL ventilation during OLV showed a PaO2 of 145.7 50.2 mm of Hg and 170.6 50.4 mm of Hg which were significantly higher compared to the one lung ventilation values.