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21.
Several studies have shown the importance of the medial preoptic area in the regulation of sleep-wakefulness and of body temperature. The medial preoptic area has a rich noradrenergic innervation, coming mostly from the lateral tegmental noradrenergic system. The accumulating evidences show that the noradrenergic afferents to the medial preoptic area are involved in the induction of sleep. This hypnogenic mechanism operates through the postsynaptic alpha1 and alpha2-adrenergic receptors. Noradrenergic afferents are also involved in the thermoregulatory mechanisms, and the activation of these fibers brings about a fall in body temperature. Though the body temperature changes are brought about by the same receptor subtypes as those involved in hypnogenesis, observations suggest the possibility of separate sets of noradrenergic afferents in the medial preoptic area for sleep regulation and thermoregulation. In this review, we present the compelling evidences, which showed that the noradrenergic afferents of the medial preoptic area bring about a fall in body temperature and other thermoregulatory behavioral alterations associated with sleep. 相似文献
22.
Ramalingam Saraswathy N Sadasivam S Subha K Poorani N 《Indian journal of biochemistry & biophysics》2007,44(2):76-81
alpha-Galactosidase was strongly induced in the white-rot fungus Pleurotus florida by arabinose than its natural substrates and was purified to homogeneity by acetone precipitation, ultrafiltration and DEAE-Sepharose chromatography. The enzyme was a monomeric protein with a molecular mass of approximately equal to 99 kDa, as revealed by native-PAGE and SDS-PAGE. alpha-Galactosidase was optimally active at 55 degrees C for the hydrolysis of p-nitrophenyl-alpha-galactopyranoside (PNPalphaG) and lost its 20% and 50% of original activity in 30 min at 60 degres C and 70 degrees C, respectively. The pH optimum of the enzyme was between 4.6 and 5.0. It was stable in a wide pH range (pH 4.0 to 9.0) at 55 degrees C for 2 h. The Ag+ and Hg2+ strongly inhibited the enzyme activity. Galactose, glucose, maltose and lactose also inhibited the enzyme activity, whereas N-bromosuccinimide treatment resulted in near total loss of acitivity. The Km and Vmax values of the enzyme for PNPalphaG were found to be 1.1 mM, and 77 micromol min(-1) mg(-1), respectively. alpha-Galactosidase immobilized in agar was more effective for the degradation of raffinose than in the sodium alginate. TLC results indicated its potential for the removal of raffinose and stachyose in soymilk. 相似文献
23.
Dharmu I Ramamurty N Kannan R Babu M 《In vitro cellular & developmental biology. Animal》2007,43(8-9):306-314
The hemolymph-derived achatininH (lectin) from Achatina fulica showed a marked cytotoxic effect on MCF7, a human mammary carcinoma cell line. IC50 values as measured by the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay for achatininH ranged from 6 to 10 μg/ml in the MCF7 cells. MCF7 cells showed significant morphological changes leading to cell death. The
above cell death was observed after 48 h of treatment with 8 μg/ml when compared to untreated cells. Alterations in the tumor
marker enzymes, as well as in antioxidant enzymes, were observed after achatininH treatment. The specificity and purity of the achatininH was confirmed by the Western blot assay. AchatininH binding to MCF7 cells was detected by anti-achatininH, and visualization of the achatininH binding sites on confluent MCF7 cells was confirmed by flourescein isothiocyanate conjugated secondary antibody. MCF7-treated
cells fluoresced, indicating the presence of achatininH binding sites. Fluorescence-activated cell sorting analysis of the cell cycle showed a significant increase in S-phase in
MCF7 cells after 48 h of achatininH treatment. The cells were arrested in G2/M phase of the cell cycle after 48 h with significant changes in cell viability. Cellular damage was confirmed by agarose
gel electrophoresis with the characteristic appearance of a DNA streak in treated MCF7 cells indicating the ongoing apoptosis.
An erratum to this article can be found at 相似文献
24.
Jean-Marie Burel Sébastien Besson Colin Blackburn Mark Carroll Richard K. Ferguson Helen Flynn Kenneth Gillen Roger Leigh Simon Li Dominik Lindner Melissa Linkert William J. Moore Balaji Ramalingam Emil Rozbicki Aleksandra Tarkowska Petr Walczysko Chris Allan Josh Moore Jason R. Swedlow 《Mammalian genome》2015,26(9-10):441-447
25.
Josephine Anthony Vijaya Raghavan Rangamaran Dharani Gopal Kumar T. Shivasankarasubbiah Mary Leema J. Thilagam Magesh Peter Dhassiah Divya Shridhar M. Padinjattayil VinithKumar N. Valsalan Vijayakumaran Manambrakat Sivakumar Dakshinamurthy Sivaraman Thirunavukkarasu Kirubagaran Ramalingam 《Marine biotechnology (New York, N.Y.)》2015,17(1):66-80
26.
The phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit PI3K, mTOR or both are currently under development. The mTOR allosteric inhibitor, RAD001, and the PI3K/mTOR dual kinase inhibitor, BEZ235, are examples of these agents. We were interested in developing strategies to enhance mTOR-targeted caner therapy. In this study, we found that BEZ235 alone effectively inhibited the growth of rapamycin-resistant cancer cells. Interestingly, the combination of sub-optimal concentrations of RAD001 and BEZ235 exerted synergistic inhibition of the growth of human lung cancer cells along with induction of apoptosis and G1 arrest. Furthermore, the combination was also more effective than either agent alone in inhibiting the growth of lung cancer xenografts in mice. The combination showed enhanced effects on inhibiting mTOR signaling and reducing the expression of c-Myc and cyclin D1. Taken together, our results suggest that the combination of RAD001 and BEZ235 is a novel strategy for cancer therapy. 相似文献
27.
Surface functionalization of nanobiomaterials for application in stem cell culture,tissue engineering,and regenerative medicine
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Deepti Rana Keerthana Ramasamy Maria Leena Constanza Jiménez Javier Campos Paula Ibarra Ziyad S. Haidar Murugan Ramalingam 《Biotechnology progress》2016,32(3):554-567
Stem cell‐based approaches offer great application potential in tissue engineering and regenerative medicine owing to their ability of sensing the microenvironment and respond accordingly (dynamic behavior). Recently, the combination of nanobiomaterials with stem cells has paved a great way for further exploration. Nanobiomaterials with engineered surfaces could mimic the native microenvironment to which the seeded stem cells could adhere and migrate. Surface functionalized nanobiomaterial‐based scaffolds could then be used to regulate or control the cellular functions to culture stem cells and regenerate damaged tissues or organs. Therefore, controlling the interactions between nanobiomaterials and stem cells is a critical factor. However, surface functionalization or modification techniques has provided an alternative approach for tailoring the nanobiomaterials surface in accordance to the physiological surrounding of a living cells; thereby, enhancing the structural and functional properties of the engineered tissues and organs. Currently, there are a variety of methods and technologies available to modify the surface of biomaterials according to the specific cell or tissue properties to be regenerated. This review highlights the trends in surface modification techniques for nanobiomaterials and the biological relevance in stem cell‐based tissue engineering and regenerative medicine. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:554–567, 2016 相似文献
28.
29.
Indra D Ramalingam K Babu M 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2005,142(1):1-7
Collagenase (matrix metalloproteinase-1, EC:3.4.24.7) was isolated from the hepatopancreas of Achatina fulica and characterized for its enzymatic activity and immunological properties. Procollagenase was isolated using ammonium sulphate precipitation and gel filtration, followed by purification by reverse-phase high performance liquid chromatography in the presence of trifluoroacetic acid and by dialysis in neutral buffer. In the presence of SDS and beta-mercaptoethanol, the procollagenase resolved into two subunits with molecular masses of 63 and 28 kDa, respectively. The 63 kDa fragment retained its ability to bind and degrade gelatin, but the 28 kDa was inactive. Analysis by 2D gel electrophoresis revealed that the 63 kDa fragment was basic (pIs 7.6, 7.8 and 8.15), while the 28 kDa fragment was acidic (pI 4.7 and 5.1). Western blot analysis confirmed the identity of collagenase, as only matrix metalloproteinase-1 rabbit antibodies against human matrix metalloproteinase-1 (N-terminal region) recognized both the isolated procollagenase and the 63 kDa fragment. 相似文献
30.
This paper reviews the recent studies that led to the conclusion that the noradrenergic neurons projecting to the medial preoptic area (mPOA) are hypnogenic and that they mediate this action through α1 adrenergic receptors. Microinjection of noradrenaline (NA) into the mPOA induced arousal. Studies using α2 adrenergic drugs showed that the arousal induced by intrapreoptic injection of NA was due to its action on presynaptic α2 adrenergic receptors. A combination of lesion and chemical stimulation techniques demonstrated that when NA acted on the postsynaptic α1 receptors in the mPOA, it induced sleep. Intrapreoptic injection of α1 agonist, methoxamine could induce sleep, when the hypothermia, which was simultaneously produced, was behaviorally compensated for by the animal. Increased arousal produced by the destruction of noradrenergic fibers in the mPOA further confirmed the hypnogenic role of these fibers. 相似文献