148 research outputs found

    Effect of troponin C on the cooperativity in Ca2+ activation of cardiac muscle

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    AbstractThis study describes the effects of exchanging native cardiac troponin C (CTnC) from the right ventricular muscle of Syrian hamster for purified skeletal (S) TnC from fast twitch muscles in triggering cardiac contraction. Ca2+ sensitivity of the myocardium became decreased with STnC to 62% of the original value with CTnC. Furthermore, the slope of the pCa-force curve of cardiac muscle was found to be increased with STnC. The results show that the TnC moiety, as part of the switching mechanism during activation, also regulates thin-filament cooperativity in muscle. Modifications in both the Ca2+ sensitivity and cooperativity are associated with alterations in the primary structure of TnC

    Evaluation of antioxidative, analgesic and anti-inflammatory activities of methanolic extract of Myrica nagi leaves : an animal model approach

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    Myrica nagi (family Myricaceae) is commonly known as Kathphal (Hindi) and Bayberry (English) and it has a long history of usage in traditional medicine. It is popular actinorhizal plant for its symbiotic relationship with Frankia. This study was taken in force to estimate the analgesic, anti-inflammatory and anti-oxidative activities of methanolic extract of Myrica nagi (MMN) in an animal model. Anti-oxidative property of MMN was assessed by free radical scavenging assay (DPPH method). The acute toxicity test of methanolic extract of MMN revealed that the median lethal dose (LD50) was found to be 2080 mg/kg body weight in mice. The anti-inflammatory property was evaluated by carrageenan-induced acute inflammation in rats by measuring rat paw volume at different time intervals and toxicological analysis using mice. The analgesic effect was measured in Wistar rats using the acetic acid-induced writhing test and MMN at 200 mg/kg BW showed 54.56 % inhibition of writhing. MMN showed higher anti-oxidant activity in DPPH assays as compared to standard. High dose of MMN showed a significant reduction (21.71 %) in inflammation after 4 h of treatment, which was comparable to diclofenac (10 mg/kg BW; 32.75 %)-treated group. Significant reduction (p < 0.05) in the levels of inflammatory cytokine (IL-1 beta and TNF-alpha) markers were also observed in serum of MMN-treated animals as compared to control. Taken together, the phenolic compounds of MMN may serve as potential herbal drug for amelioration of acute inflammation due to their modulatory action on free radicals

    Chromosomal abnormalities and Y chromosome microdeletions in infertile men with varicocele and idiopathic infertility of South Indian origin

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    Various factors cause spermatogenesis arrest in men and, in a large number of cases, the underlying reason still remains unknown. Little attention is paid to determining the genetic defects of varicocele-related infertility. The objective of our present study was to investigate the chromosomal abnormalities and Y chromosome microdeletions in infertile men of South Indian origin with varicocele and idiopathic infertility. Metaphase chromosomes of 251 infertile men with varicocele and unexplained infertility were analyzed using Giemsa-Trypsin-Giemsa (GTG) banding and fluorescence in situ hybridization (FISH). The microdeletions in 6 genes and 18 sequence-tagged-sites (STS) in the Yq region were screened using polymerase chain reaction (PCR) techniques. Out of 251 infertile men, 57 (22.7%) men were with varicocele, of which 8.77% were azoospermic, 26.31% were severely oligozoospermic, 21.05% were mildly oligozoospermic, and 43.85% were oligoasthenoteratozoospermic (OAT), and 194 (77.29%), with idiopathic infertility, of which 51% were azoospermic, 13.40% were severely oligozoospermic, 19.07% were mildly oligozoospermic, and 16.4% were with OAT. Genetic defects were observed in 38 (15.13%) infertile individuals, including 14 (24.56%) men with varicocele and 24 (12.37%) men with idiopathic infertility. The frequencies of chromosomal defects in varicocele and idiopathic infertility were 19.3% and 8.76%, respectively, whereas Y chromosome microdeletions were 5.26% and 3.60%, respectively. Overall rate of incidence of chromosomal anomalies and microdeletions in 251 infertile men were 11.5% and 3.98%, respectively, indicating a very significant higher association of genetic defects with varicocele than idiopathic male infertility. Our data also demonstrate that, among infertile men with varicocele, severely oligozoospermic and OAT men with varicocele have higher incidences of genetic defects than mildly oligozoospermic and azoospermic men

    Socio-economic upliftment of farmers through model irrigated village approach in East Champaran (Bihar), India: A case study

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    In India, the precious freshwater resources are becoming scarcer due to the climate change effect coupled with their inappropriate planning and management at the field level. Development of water resources and sensitization of farming community/irrigators towards effective utilization of these resources is need of the hour and it is one of the most important factors in conservation and preservation water resources for future requirements. This case study has highlighted the direct and indirect benefits derived by implementation of National Innovations on Climate Resilient Agriculture (NICRA) scheme in Nawada, a village of the district East Champaran in Bihar state initiated by Krishi Vigyan Kendra, Piprakothi, East Champaran under Dr. Rajendra Prasad Central Agricultural University, Pusa, Bihar. Two groups of farmers of the village was chosen to evaluate the benefits derived from this scheme. Under this scheme, tube-wells were developed to facilitate assured irrigation. This study revealed that the total savings of approximate Rs.10,000 ($140) per hectare to irrigate wheat crop three times in Rabi season was achieved over conventional irrigation system. This scheme has also resulted in other intangible benefits which included a reduction in pollution, an increase in the number of crops- rabi , kharif and zaid  seasons and adequate time to carryout out other farm operations

    Enhanced Cardiac Regenerative Ability of Stem Cells After Ischemia-Reperfusion Injury Role of Human CD34+ Cells Deficient in MicroRNA-377

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    AbstractBackgroundMicroRNA (miR) dysregulation in the myocardium has been implicated in cardiac remodeling after injury or stress.ObjectivesThe aim of this study was to explore the role of miR in human CD34+ cell (hCD34+) dysfunction in vivo after transplantation into the myocardium under ischemia-reperfusion (I-R) conditions.MethodsIn response to inflammatory stimuli, the miR array profile of endothelial progenitor cells was analyzed using a polymerase chain reaction–based miR microarray. miR-377 expression was assessed in myocardial tissue from human patients with heart failure (HF). We investigated the effect of miR-377 inhibition on an hCD34+ cell angiogenic proteome profile in vitro and on cardiac repair and function after I-R injury in immunodeficient mice.ResultsThe miR array data from endothelial progenitor cells in response to inflammatory stimuli indicated changes in numerous miR, with a robust decrease in the levels of miR-377. Human cardiac biopsies from patients with HF showed significant increases in miR-377 expression compared with nonfailing control hearts. The proteome profile of hCD34+ cells transfected with miR-377 mimics showed significant decrease in the levels of proangiogenic proteins versus nonspecific control–transfected cells. We also validated that serine/threonine kinase 35 is a target of miR-377 using a dual luciferase reporter assay. In a mouse model of myocardial I-R, intramyocardial transplantation of miR-377 silenced hCD34+ cells in immunodeficient mice, promoting neovascularization (at 28 days, post–I-R) and lower interstitial fibrosis, leading to improved left ventricular function.ConclusionsThese findings indicate that HF increased miR-377 expression in the myocardium, which is detrimental to stem cell function, and transplantation of miR-377 knockdown hCD34+ cells into ischemic myocardium promoted their angiogenic ability, attenuating left ventricular remodeling and cardiac fibrosis

    Oral field cancerization: Genetic profiling for a prevention strategy for oral potentially malignant disorders

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    Background: Oral cancer therapy, such as radiation or surgical treatment, has pernicious long-term effects that patients suffer throughout their life, the disability being considerable with delayed diagnosis. It is well known that many oral cancers develop from oral potentially malignant disorders (OPMDs). Patients diagnosed with OPMDs may have an increased risk of developing cancer anywhere in the oral cavity. Early detection and intervention could be essential prevention strategies to inhibit oral cancer progression. OPMDs may not immediately develop into carcinoma. However, this condition provides a “field” of specific abnormalities wherein evolving altered genetic cells can be explained with the “field cancerization” concept. Purpose: This review aims to describe the “field cancerization” concept in oral cancer and OPMD, which is expected to contribute to a better clinical management strategy for oral cancer prevention. Review: “Oral field cancerization” describes oral cancers that develop in multifocal areas of pre-cancerous changes. It can be found as histologically abnormal tissue surrounding the tumor, suggesting that oral cancer often consists of multiple independent lesions. Conclusion: The oral field cancerization concept should prompt healthcare professionals to remind their patients that frequent oral examination with histological studies and molecular testing is mandatory for those at high risk of developing malignancies

    Improved control strategy of DFIG-based wind turbines using direct torque and direct power control techniques

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    This paper presents different control strategies for a variable-speed wind energy conversion system (WECS), based on a doubly fed induction generator. Direct Torque Control (DTC) with Space-Vector Modulation is used on the rotor side converter. This control method is known to reduce the fluctuations of the torque and flux at low speeds in contrast to the classical DTC, where the frequency of switching is uncontrollable. The reference for torque is obtained from the maximum power point tracking technique of the wind turbine. For the grid-side converter, a fuzzy direct power control is proposed for the control of the instantaneous active and reactive power. Simulation results of the WECS are presented to compare the performance of the proposed and classical control approaches.Peer reviewedFinal Accepted Versio

    Prognostic indicators and outcomes of hospitalised COVID-19 patients with neurological disease: An individual patient data meta-analysis

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    BACKGROUND: Neurological COVID-19 disease has been reported widely, but published studies often lack information on neurological outcomes and prognostic risk factors. We aimed to describe the spectrum of neurological disease in hospitalised COVID-19 patients; characterise clinical outcomes; and investigate factors associated with a poor outcome. METHODS: We conducted an individual patient data (IPD) meta-analysis of hospitalised patients with neurological COVID-19 disease, using standard case definitions. We invited authors of studies from the first pandemic wave, plus clinicians in the Global COVID-Neuro Network with unpublished data, to contribute. We analysed features associated with poor outcome (moderate to severe disability or death, 3 to 6 on the modified Rankin Scale) using multivariable models. RESULTS: We included 83 studies (31 unpublished) providing IPD for 1979 patients with COVID-19 and acute new-onset neurological disease. Encephalopathy (978 [49%] patients) and cerebrovascular events (506 [26%]) were the most common diagnoses. Respiratory and systemic symptoms preceded neurological features in 93% of patients; one third developed neurological disease after hospital admission. A poor outcome was more common in patients with cerebrovascular events (76% [95% CI 67-82]), than encephalopathy (54% [42-65]). Intensive care use was high (38% [35-41]) overall, and also greater in the cerebrovascular patients. In the cerebrovascular, but not encephalopathic patients, risk factors for poor outcome included breathlessness on admission and elevated D-dimer. Overall, 30-day mortality was 30% [27-32]. The hazard of death was comparatively lower for patients in the WHO European region. INTERPRETATION: Neurological COVID-19 disease poses a considerable burden in terms of disease outcomes and use of hospital resources from prolonged intensive care and inpatient admission; preliminary data suggest these may differ according to WHO regions and country income levels. The different risk factors for encephalopathy and stroke suggest different disease mechanisms which may be amenable to intervention, especially in those who develop neurological symptoms after hospital admission

    HLA-DQA1*05 carriage associated with development of anti-drug antibodies to infliximab and adalimumab in patients with Crohn's Disease

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    Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies.This article is freely available via Open Access. Click on Publisher URL to access the full-text
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