1,720,991 research outputs found
Induction of matrix metalloproteinase-9 and -3 in nonsteroidal anti-inflammatory drug-induced acute gastric ulcers in mice: regulation by melatonin
No full textThe pathogenesis of gastric ulcer is associated with remodeling of
extracellular matrix (ECM) by various matrix metalloproteinases (MMPs).
However, how MMPs are regulated during nonsteroidal anti-inflammatory
drug (NSAID)-induced acute gastric ulceration is not well studied. In this
study, different NSAIDs (80 mg/kg b.w.) were applied to generate acute
gastric ulcer in the BALB/c mouse and the regulation of MMPs were
investigated. NSAIDs caused dose-dependent induction in MMP-9 and -3
activities and expressions in ulcerated gastric tissues along with significant
infiltration of inflammatory cells and disruption of gastric mucosal layer. In
addition, an increase in tumor necrosis factor (TNF)-a, interleukin (IL)-1b
and IL-8 expression, excessive generation of hydroxyl radical (•OH), and
protein oxidation and lipid peroxidation were observed in acute ulcerated
gastric tissues. In this study, the efficacy of melatonin on activities of MMP-9
and -3 during prevention of gastric ulcers was tested. Melatonin at a dose
of 60 mg/kg b.w. downregulated MMP-9 and -3 both at the enzyme and
protein levels in mouse gastric tissues during prevention as well as healing of
acute gastric ulcers. It also blocked oxidative stress via inhibition of protein
oxidation, lipid peroxidation, •OH generation and SOD-2 expression.
Moreover, it suppressed myeloperoxidase activity and expressions of TNF-a,
IL-1b and IL-8. This study documents for the first time that induction of
MMP-9 and -3 activities accompany NSAID-induced inflammation and
oxidative stress in gastric tissues and indicates that, melatonin may be a
preventive or therapeutic remedy for gastric ulcers
Curcumin arrests endometriosis by downregulation of matrix metalloproteinase-9 activity
No full text59-65Curcumin, a polyphenol derived from turmeric (Curcuma longa) possesses diverse pharmacological properties including antioxidant, anti-inflammatory and antiproliferative activities. Endometriosis is a gyneocological disorder characterized by growth of endometrial tissues outside uterus that involves aberrant matrix remodeling. In this study the effect of curcumin was studied on surgically developed endometriosis in mice. Endometriosis with varying severity was developed in mice by peritoneal implantation of uterine fragments. The changes in matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloprotease (TIMP)-1 were investigated in endometriotic tissues following curcumin pre- and post-treatment. Results showed that MMP-9 activity increased gradually in endometriotic tissues with severity and curcumin treatment reversed the MMP-9 activity near to control value. Curcumin administered either post- or pre-endometriosis arrested endometriosis in a dose-dependent manner. It inhibited both MMP-9 activity and its expression at the level of secretion, during regression of endometriotic lesion. In addition, the attenuated activity of MMP-9 was associated with decreased expression of tumor necrosis factor-α (TNF-α) during healing, suggesting the anti-inflammatory property of curcumin. Moreover, curcumin pretreatment prevented lipid peroxidation and protein oxidation in endometriotic tissues. We reported here for the first time the anti-endometriotic property of curcumin via MMP-9 dependent pathway that may lead to new therapeutic intervention
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Curcumin as Anti-Endometriotic Agent: Implication of MMP-3 and Intrinsic Apoptotic Pathway
No full textThe disease of reproductive women, endometriosis represents implantation of functional endometrial
glands outside uterine cavity. This invasive disorder is associated with dysregulation of matrix
metalloproteases (MMP)s and extracellular matrix (ECM) remodeling. In this study, we investigated the
role of MMP-3 on apoptosis during endometriosis. We also checked whether curcumin has potency to
regress endometriosis by modulating MMP-3 and apoptotic pathway. Mouse model of endometriosis
was designed by intraperitoneal inoculation of endometrial tissues to syngeneic female BALB/c. At 15th
day, stable endometriotic developments were observed with increased MMP-3 expression. TUNEL
positive cells were also found with endometriotic progression, which might resulted from destruction of
local immune cells. We speculate that increased MMP-3 activity might be involved in the Fas mediated
apoptosis. Curcumin treatment regressed endometriosis by inhibiting NFkB translocation and MMP-3
expression. It also accelerated apoptosis in endometriomas predominantly via cytochrome-c mediated
mitochondrial pathway. Involvement of mitochondria in apoptosis was further confirmed by atomic
force microscopy (AFM). These results were also supported by our therapeutic study, where curcumin
induced apoptosis both by p53 dependent and independent manner, while celecoxib followed only p53
independent pathway. Altogether, our study establishes the novel role of curcumin as a potent antiendometriotic
compound
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
N-glycolylneuraminic acid specific lectin from Pila globosa snail
No full textA N-glycolylneuraminic acid-specific lectin (PAL) has been
purified from an albumin gland extract of the apple snail, Pila globosa. Purification is conducted on a bovine submaxillary mucin-~$ar~s%-TB affinity matrix followed by gel filtration on a Sepharose 6B column. The lectin agglutinatz; rabbit erythrocytes. The hemagglutination activity is dependent on Ca concentration in a significant manner but with a remark able behaviour. The lectin is a trimeric glycoprotein of native Mr 440 kDa with 25% carbohydrate and is composed of three nonidentical subunits
of molecular weights 190, 145. and 105 kDa. It has a p1 of 7.0. The lectin exhibits a unique and strict specificity toward N-glycolylneuraminic
acid and this phenomenon discriminates it from other known sialic acid binding lectins. The uniqueness indicates the absolute need for a glycolyl substitution on the amino residue and of a glyceryl side chain on the exocyclic part and an axial-COOH group in neuraminic acid. The presence
of an acety
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