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301.
Thyroid dysfunction is associated with attention deficit and impairment of the motor system (muscle weakness and fatigue).
This paper investigates possible motor function deficit in thyroid patients, compared to the controls. Functional MRI studies
(fMRI) were carried out in five hypo and five hyperthyroid patients and six healthy volunteers. Whole brain imaging was performed
using echo planar imaging (EPI) technique, on a 1.5T whole body MR system (Siemens Magnetom Vision). The task paradigm consisted
of 8 cycles of active and reference phases of 6 measurements each, with right index finger tapping at a rate of 120 taps/min.
Post-processing was performed using statistical parametric mapping on a voxel-by-voxel basis using SPM99. Clusters of activation
were found in the contralateral hemisphere in primary somatomotor area (M1), supplementary motor area (SMA), somatosensory,
auditory receptive and integration areas, inferior temporal lobe, thalamus and cerebellum. Increased clusters of activation
were observed in M1 in thyroid subjects as compared to controls and with bilateral activation of the primary motor cortex
in two hyperthyroid patients. The results are explained in terms of increased functional demands in thyroid patients compared
to volunteers for the execution of the same task. 相似文献
302.
Carolina Cano Konrad Brunner Kumaran Baskaran Ralph Elsner Claudia E. Munte Hans Robert Kalbitzer 《Journal of biomolecular NMR》2009,45(4):397-411
The amount of experimental restraints e.g., NOEs is often too small for calculating high quality three-dimensional structures
by restrained molecular dynamics. Considering this as a typical missing value problem we propose here a model based data imputation
technique that should lead to an improved estimation of the correct structure. The novel automated method implemented in AUREMOL
makes a more efficient use of the experimental information to obtain NMR structures with higher accuracy. It creates a large
set of substitute restraints that are used either alone or together with the experimental restraints. The new approach was
successfully tested on three examples: firstly, the Ras-binding domain of Byr2 from Schizosaccharomyces pombe, the mutant HPr (H15A) from Staphylococcus aureus, and a X-ray structure of human ubiquitin. In all three examples, the quality of the resulting final bundles was improved
considerably by the use of additional substitute restraints, as assessed quantitatively by the calculation of RMSD values
to the “true” structure and NMR R-factors directly calculated from the original NOESY spectra or the published diffraction data. 相似文献
303.
Rangarajulu Senthil Kumaran Heehoon Jung Hyung Joo Kim 《Engineering in Life Science》2011,11(3):264-271
The fungus Colletotrichum capsici was isolated from the diseased fruits of Chilli plant, Capsicum annuum. The isolated test fungus was identified by its morphological and molecular characteristic features. For the first time, the fungus was screened for the production of taxol on modified liquid medium. The presence of taxol was confirmed by the spectroscopic and chromatographic methods of analyses. The amount of taxol produced by this fungus was quantified by HPLC. The maximum amount of fungal taxol production was recorded as 687 μg/L. The production rate was 13 740‐fold higher than that, previously reported for the fungus Taxomyces andreanae. The extracted fungal taxol showed a strong cytotoxic activity in an in vitro culture of human cancer cells indicating that the increase in taxol concentration induces increased cell death. A PCR‐based screening for taxadiene synthase (ts), a unique gene in the formation of the taxane skeleton, confirmed the molecular blueprint for taxol biosynthesis. The results show that the fungus C. capsici is an excellent candidate for an alternate source of taxol supply and can serve as a potential species for genetic engineering to enhance the production of taxol to a higher level. 相似文献
304.
Priyansh Gupta Keshavamurthy Vinay Anuradha Bishnoi Muthu Sendhil Kumaran Davinder Parsad 《Pigment cell & melanoma research》2023,36(1):33-41
Prospective data on correlation between dermoscopic features of vitiligo and disease activity are scarce. This study was conducted to sequentially determine the dermoscopic features of vitiligo and to evaluate their association with disease activity. A cohort of 30 patients with 60 active vitiligo patches on medical therapy was subjected to sequential clinical and dermoscopic examination at four weekly intervals till 16 weeks. Disease activity at each visit was assessed using serial clinical photographs and modified vitiligo activity severity index. The dermoscopic images were merged and analysed for a predefined set of dermoscopic parameters by two blinded dermatologists. Paired analysis of dermoscopic features was done between baseline, and stabilized vitiligo patches at 12 and 16 weeks. Pigment network changes (absent and reduced pigment network, p < .001), perifollicular depigmentation (p = .02), ill-defined margins (p = .04) and satellite lesions and micro-Koebner phenomenon (p < .001) were associated with active vitiligo while perifollicular repigmentation (p < .001) was associated with stabilizing and repigmenting vitiligo. Satellite lesions and micro-Koebner's phenomena were suggestive of unstable disease irrespective of site of target lesion, while perifollicular repigmentation was suggestive of stabilized/repigmenting disease only at non-acral sites. We found sequential dermoscopy to be useful to assess disease activity and potential for repigmentation in localized vitiligo. 相似文献
305.
Claude Mande Victor Van Cakenberghe Lucinda Kirkpatrick Anne Laudisoit Luc De Bruyn Guy-Crispin Gembu Erik Verheyen 《Biotropica》2023,55(5):920-932
Assessing how bats respond to habitat attributes requires an integrative approach to reliably predict direct community-level effects. We focused on hipposiderid and pteropodid bats because of their diverse resource use patterns, body size ranges, and dispersal abilities. We combined an array of bat species-level characteristics with key forest stand characteristics that may covary with habitat use. Twelve stations were sampled in the Lomami and Yangambi landscapes, Democratic Republic of the Congo. We investigated whether species-level flight ability of bats and forest stand characteristics can affect bat commuting flights and community-level estimates of both species detection and habitat occupancy. We captured bats for 108 trap-nights. Three sampling events (early evening, middle of the night, and early morning) were replicated for each survey night. Hipposiderids showed an early evening flight peak, while flight activity of pteropodids was constant throughout the night, but increased around the middle of the night. Species capture probability decreased with higher wing loading in hipposiderids and was negatively correlated with higher wing aspect ratio in pteropodids. Forest occupancy of hipposiderids increased along the gradient towards waterways, while pteropodid occurrence was not directly linked to measured forest stand variables. This suggests a consequence of habitat patterns at larger spatial scales, which would need clarifying through additional data collection. We discuss these findings in terms of resource-use strategies of clutter-tolerant and clutter-intolerant species. We argue that the occurrence of specific bat species and their habitat use patterns can serve as surrogate measures of ecosystem health. 相似文献
306.
The juvenile hormone esterase (JHE) activity in Galleria mellonella larvae was measured after exposure to different experimental conditions that affect larval-pupal transformation. The data show that stimulation of production of JHE is closely coupled with the developmental signals that intiate larval-pupal metamorphosis. Injury, which delays pupation, delays the appearance of JHE activity if the larvae are injured within 48 hr after the last larval moult. Chilling of day-0 larvae induces a supernumerary larval moult and inhibits the appearance of JHE. However, JHE activity increases in chilled larvae when their commitment for an extra larval moult is reversed by starvation. Starvation is effective in reversing the commitment for an extra larval moult if commenced within 48 hr after chilling, thereby suggesting a critical period for that commitment. These data suggest that the stimulus for JHE synthesis and/or release occurs approximately within 48 hr after the last larval ecdysis. A series of studies involving implantation of brain, suboesophageal ganglion and fat body into chilled, as well as chilled and ligated larvae suggest that a factor from the brain is involved in stimulation or production of JHE in Galleria larvae.JH, which suppresses JHE activity in day-3, -5 and early day-6 Galleria larvae, stimulates the production of JHE in late day-6 larvae, suggesting that reprogramming in larval fat body may occur on day 6 of the last larval stadium. 相似文献
307.
Kandaswamy Senthil Kumaran Ponnian Stanely Mainzen Prince 《Cell stress & chaperones》2010,15(6):791-806
Cardiac mitochondrial dysfunction plays an important role in the pathology of myocardial infarction. The protective effects
of caffeic acid on mitochondrial dysfunction in isoproterenol-induced myocardial infarction were studied in Wistar rats. Rats
were pretreated with caffeic acid (15 mg/kg) for 10 days. After the pretreatment period, isoproterenol (100 mg/kg) was subcutaneously
injected to rats at an interval of 24 h for 2 days to induce myocardial infarction. Isoproterenol-induced rats showed considerable
increased levels of serum troponins and heart mitochondrial lipid peroxidation products and considerable decreased glutathione
peroxidase and reduced glutathione. Also, considerably decreased activities of isocitrate, succinate, malate, α-ketoglutarate,
and NADH dehydrogenases and cytochrome-C-oxidase were observed in the mitochondria of myocardial-infarcted rats. The mitochondrial
calcium, cholesterol, free fatty acids, and triglycerides were considerably increased and adenosine triphosphate and phospholipids
were considerably decreased in isoproterenol-induced rats. Caffeic acid pretreatment showed considerable protective effects
on all the biochemical parameters studied. Myocardial infarct size was much reduced in caffeic acid pretreated isoproterenol-induced
rats. Transmission electron microscopic findings also confirmed the protective effects of caffeic acid. The possible mechanisms
of caffeic acid on cardiac mitochondria protection might be due to decreasing free radicals, increasing multienzyme activities,
reduced glutathione, and adenosine triphosphate levels and maintaining lipids and calcium. In vitro studies also confirmed
the free-radical-scavenging activity of caffeic acid. Thus, caffeic acid protected rat’s heart mitochondria against isoproterenol-induced
damage. This study may have a significant impact on myocardial-infarcted patients. 相似文献
308.
A method is described for degrading 3-hydroxybutyric acid to obtain specifically and in good yield each of its carbons as CO2. The hydroxybutyrate is dehydrated to crotonic acid which is reduced to butyric acid. The butyric acid is then degraded stepwise utilizing the Schmidt reaction. 相似文献
309.
310.
Elumalai Kumaran Meenakshisundaram Santhi Kalpattu K. Balasubramanian Shanmugasundaram Bhagavathy 《Carbohydrate research》2011,(13):1654
Montmorillonite K-10 clay-catalyzed substitution reactions of 3,4,6-tri-O-alkyl-2-C-hydroxymethyl-d-glycals, 3,4,6-tri-O-acetyl-d-glycals, 3,4,6-tri-O-alkyl-d-glycals, and 3,4-(dihydro-2H-pyran-5-yl)methanol with a few alcohols and phenols are described. The reactions of 2-C-hydroxymethyl-d-glycals with phenols were similar to those of 2-C-acetoxymethyl-d-glycals and afforded pyrano[2,3-b]benzopyrans. This montmorillonite K-10 clay-catalyzed transformation is facile both under ambient (Method 1) and microwave conditions (Method 2). Ferrier rearrangement of 3,4-(dihydro-2H-pyran-5-yl)methanol with p-cresol, 2,6-xylenol, and ethanol led to totally unexpected transformations. Reaction of 2-C-hydroxymethyl-d-galactal with 2,6-dimethylphenol in the presence of montmorillonite K-10 led to a novel domino transformation affording 4-(5′,6′-dihydro-4H-pyran-3′-ylmethyl)-2,6-dimethylphenol. In contrast, 3,4,6-tri-O-acetyl-d-glucal furnished the Ferrier rearrangement product, 2,6-dimethylphenyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside. Also, isomerization of 3,4,6-tri-O-alkyl-d-glycals to products of allylic rearrangement, 2,3-unsaturated-O-glycosides in good yields is reported. 相似文献