94 research outputs found
Reno productive activity of Ipomoea digitata in gentamicin induced kidney dysfunction
No full textKidneys endowed with million units termed as “nephrons†that act as natural sieves. The kidneys provide the final common pathway for the excretion of many drugs and their metabolites and therefore are frequently subjected to high concentrations of potentially toxic substances. Administration of several antibiotics like Gentamicin causes kidney dysfunction. Rats treated with Gentamicin developed significant kidney dysfunction was observed from increased level of urea, creatinine, sodium and decreased level of protein, potassium and non enzymatic antioxidants such as vitamin C and vitamin E. The plant, Ipomoea digitata is found to have nephroprotective activity. --------------------------------------------------------------------------------------------------------*Department of Biochemistry and Chemistry, Faculty of Science, PRIST University, Vallam, Tanjavur – 613 403, Tamilnadu, India**Department of Zoology, Annamalai University, Annamalainagar - 608 002, Tamilnadu, India1Corresponding author, Email: [email protected] This Article As: A. Kalaiselvan, T. Anand and M. Soundararajan.Reno productive activity of Ipomoea digitata in gentamicin induced kidney dysfunction. J. Ecobiotechnol. 2(2): 57-62
A retrospective study of clinical profile and outcomes of critically ill patients with heat-related illness
No full textBackground and Aims: Heat-related illness (HRI) due to high ambient temperatures is a common feature during the Indian summer. HRI often results in Intensive Care Unit (ICU) admissions and are associated with significant morbidity and mortality. However, published report on the effects of HRI among the Indian population is lacking. This study was undertaken to identify the profile of patients admitted to ICU with clinical features of HRI and study their clinical outcomes. Methods: This was a retrospective case series of patients admitted with features of HRI during the summer of 2012 in our multidisciplinary ICU. Data on demographics, co-morbid illness, admission severity of illness (Acute Physiology and Chronic Health Evaluation II [APACHE II]), organ failure scores (Sequential Organ Failure Assessment [SOFA]) and neuroimaging studies were collected. Outcome data studied included mortality, ICU length of stay (LOS), ventilator days and hospital LOS. Statistical analysis was performed using Student′s t-test, Chi-square test and multivariate analysis. Results: Twenty-six patients met the diagnostic criteria for HRI. Fifteen were males. The mean age was 53.12 18.6 years. Mean APACHE II score was 19.6 7.7 and mean SOFA score was 7.5 2.6. The common presenting symptoms were fever with neurological impairment (100%) and gastrointestinal symptoms (30%). Major organ systems involvement include neurological (100%), renal (57%), hepatic (34%) and coagulation abnormalities (26%). Most common metabolic abnormality noted was hyponatraemia (73%). Magnetic resonance imaging findings suggestive of heat stroke were seen in 5 of 26 patients. Mortality rate was 34%. 8 of 17 survivors had residual neurological impairment. Conclusion: HRI carries a high mortality and significant neurological morbidity
Groundnut (Arachis hypogaea L.) Leaf Area Estimation Using Allometric Model
No full textAbstract: Allometric relationship (LA = aL W , where a, b and c are the parameters) was fitted between bc the true leaf area and extreme linear measurements viz. length and width of groundnut (Arachis hypogeae L.) leaves to obtain the total leaf area without having to make the time-consuming area measurements directly. Groundnut (var. CO2) was raised at Coconut research station, Aliyar Nagar, Tamil Nadu Agricultural University, Coimbatore from which one hundred and twenty seven leaves were randomly selected at flowering stage. The allometric relationship between true leaf area and extreme linear measurements were fitted by ordinary least square (OLS) method. The predicted allometric model for the leaf area of groundnut was TLAm = 0.8955 L W . Also, using the same extreme linear 1.0842 0.7569 measurements and true leaf area, average 'K' factor was determined as 0.821 to use in the estimation of leaf area by using the formula TLAm = k * L * W. Both the model's predictability was tested for their validity using R and chi square tests. The allometric model fitted well to predict the true leaf area by 94%.
Studies on molecular mechanisms in calcium signaling and cellular energy consumption
No full textIon signaling plays fundamental role in cell survival. Na+ and Ca2+ are critical players in ion signaling. Cells spend the major amount of energy to maintain and regulate Na+ and Ca2+ gradients across the cell membrane. Any disruption in cellular energy consumption by plasma membrane ATPases affects ion signaling and vice versa. This thesis is a combination of four separate research studies. In the first study, We measured ATP consumption dynamics of Na+/K+-ATPase using a genetically encoded fluorescent indicator called Perceval HR. we demonstrate that PercevalHR is an excellent tool to visualize ATP:ADP in mammalian cells. In the second study, We studied the role of calcium signaling and TRP channels in angiotensin II type 1 receptor signaling cascade. We prove that low inhibition of CaV1.2 with physiological and therapeutically relevant concentration of Angiotensin II up regulate AT1R signaling. In the third study, We studied the role of the TRPM5 channel in regulating insulin secretion, and cytoplasmic free calcium concentration in the rat β-cells by usingtriphenyl phosphine oxide, a selective inhibitor of the channel. In the fourth study, We tested whether, the genetically engineered human β-cell line (EndoC-BH1) could be used as models for studying Ca2+signaling in the context of Type II Diabetes. We found that the EndoC-BH1 cells could be a relevant model to study stimulus-secretion coupling and Ca2+ signaling in the human β-cells.QC 20170328</p
Studies on Distortion of Dissimilar Thin Sheet Weld Joints Using Laser Beam Welding
No full textTo achieve reliable welds with minimum distortion for
the fabrication of components in aerospace industry laser beam
welding is attempted. Laser welding can provide a significant benefit
for the welding of Titanium and Aluminium thin sheet alloys of its
precision and rapid processing capability. For laser welding, pulse
shape, energy, duration, repetition rate and peak power are the most
important parameters that influence directly the quality of welds. In
this experimental work for joining 1mm thick TI6AL4V and AA2024
alloy and JK600 Nd:YAG pulsed laser units used. The distortions at
different welding power and speed of titanium and aluminium thin
sheet alloys are investigated. Test results reveal that increase in
welding speed increases distortion in weldmen
Effect of Butt Joint Distortion and Comparison Study on Ti/Al Dissimilar Metal Using Laser Beam Welding
No full textIn general, it is desirable to finish the weld quickly,
before a large volume of surrounding metal heats up and expands.
The welding process used, type, welding current and speed of travel,
thus, affect the degree of shrinkage and distortion of a weldment. The
use of mechanized welding equipment reduces welding time, metal
affected zone and consequently distortion. This article helps to define
what weld distortion is and then provide a practical understanding of
the causes of distortion, effects of shrinkage in butt joint welded
assemblies using TI6AL4VA and Aluminium AA2024 alloy sheet.
The beam offset position to the joint interface towards titanium and
aluminium side. The factors affecting distortion during welding is
also given. Test results reveal that welding speed is the significant
parameter to decide the extent of distortion. Also welding from Al
side reduces the distortion while Ti side increases the distortion
Optimizations of Friction Stir Welding Process Parameters for the Welding of Al-B4C Composite Plates using Generalized Reduced Gradient Method
No full textAbstractNow a days Friction stir Welding (FSW) has become very popular for joining of aluminium alloys and aluminium based composites. FSW produced the effective joints on the Metal matrix composites (MMCs) without defects like porosity, interfacial chemical reactions, reinforcement segregation etc., The desired mechanical properties of the weld can be achieved, depends on the FSW parameters such as rotational speed (N), welding speed (S), axial force (F) and the reinforcement content (%R) in the MMCs. In this study, a mathematical model was developed to predict the tensile strength friction stir welded Al/B4C joints using SYSTAT software. The central composite design of four factors and five levels has been used to conduct the experiments. The optimal process parameters were estimated from the developed regression equation using Generalized Reduced Gradient (GRG) method
Molecular mechanisms involved in the generation of calcium signals in insulin secreting cells
No full textIntracellular Ca 2+ regulates diverse cellular functions in almost all the cells. In the pancreatic ß-cells, Ca 2+ signals are critical for insulin secretion. An increase in the cytoplasmic free Ca 2+ concentration ([Ca 2+ ]i) triggers insulin secretion. Multiple mechanisms increase the [Ca 2+ ]i in the ß-cells, and in this respect depolarization of the plasma membrane and consequent Ca 2+ entry through the voltage-gated Ca 2+ channels is particularly important. For depolarization of ß-cells the closure of KATP channels is essential. In addition, cation channels belonging to Transient Receptor Potential (TRP) family are thought to play important roles in causing depolarization. Previous studies have reported that the Transient Receptor Potential Melastatin-like subtype 5 (TRPM5) channel, a Ca 2+ activated monovalent cation channel, is involved in the stimulus-secretion coupling in the mouse ß-cells. We aimed to study the role of the TRPM5 channel in regulating insulin secretion, and [Ca 2+ ]i in the rat ß-cells. Another focus of this thesis was to evaluate a new human inluinoma cell line as a model for studying Ca 2+ signaling in the ß-cells. Recently a genetically engineered human insulinoma cell line (EndoC-BH1) has been developed. We studied Ca 2+ signaling in the EndoC-BH1 cells, in an attempt to assess whether these cells could be used as a model for this purpose. For inhibiting the TRPM5 channels we used triphenyl phosphine oxide (TPPO), a selective and potent pharmacological inhibitor of the channel. We measured insulin secretion from the islets from Sprague-Dawley rats in batch incubations. For measuring [Ca 2+ ]i from single rat ß-cells and EndoC-BH1 cells, we used fura-2 based ratiometric microfluorometry. We found that TPPO did not inhibit insulin secretion triggered by KCl, or fructose but it significantly reduced insulin secretion in response to glucose, Larginine, and GLP-1. It also significantly inhibited the KATP channel-independent insulin secretion by glucose. TPPO significantly inhibited the [Ca 2+ ]i increase in response to L-arginine. It also inhibited the [Ca 2+ ]i increase triggered by glucose in a KATP channel independent mechanism. However, TPPO did not alter the [Ca 2+ ]i response triggered by KCl, fructose, glucose and GLP-1. We stimulated the EndoC-BH1 cells with gluocse, GLP-1, KCl, carbachol, Larginine, and tolbutamide. These agents that are known to increase [Ca 2+ ]i in the primary ß-cells also increased [Ca 2+ ]i in the these human insulinoma cells. Moreover, we found that GLP-1 was essential for eliciting Ca 2+ response in the EndoC-BH1 cells upon stimulation by tolbutamide and glucose. We conclude that in the rat islets, TRPM5 plays an important role in mediating insulin secretion by glucose, and L-arginine, and in potentiating the glucoseinduced insulin secretion by GLP-1. We also conclude that the EndoC-BH1cells responds by [Ca 2+ ]i increase upon stimulation by several well-known agonists.List of scientific papersI. Krishnan K, Ma Z, Björklund A, Islam M S. Role of transient receptor potential melastatin-like subtype 5 channel in insulin secretion from rat β-cells. Pancreas. [Accepted] https://pubmed.ncbi.nlm.nih.gov/24632551 II. Krishnan K, Ma Z, Björklund A, Islam M S. Calcium signaling in a genetically engineered human pancreatic β-cell line. [Submitted]</p
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