1,720,963 research outputs found
Effect of plant molluscicides on selected enzymes related to energy metabolism in Biomphalaria arabica snails molluscan hosts to Schistosoma mansoni in Saudi Arabia
No full textSchistosomiasis is one of the most important human parasitic diseases. One of the possible methods for the control is through the molluscan intermediate host of the parasite. Biomphalaria arabica, molluscan hosts to Schistosoma mansoni in Saudi Arabia were treated with sublethal concentrations (LC25) of dry powdered leaves Solanum nigrum. Effect of plant on ectonucleotidases (NTPdases) (ADPase & ATPase), sodium/potassium adenosine triphosphatase (Na+/K+ ATPase) and creatine kinase (CK) was traced. The plant molluscicide was potent in inhibiting the four investigated enzymes giving a percentage inhibition range between 45-55%. The effect of the inhibited enzymes on the compatibility of the snail hosts to schistosome parasite was discussed. In conclusion, the use of sublethal concentration of S. nigrum to disturb the biochemical profile of the snail hosts could be a promising and safe strategy to control the disease.King Saud Universit
Antimicrobial activity of Litchi chinensis and Nephelium lappaceum aqueous seed extracts against some pathogenic bacterial strains
No full textAbstractSeeds aqueous extracts from Litchi chinensis and Nephelium lappaceum were investigated for antibacterial activity by disc diffusion method and protein profile. Both seed aqueous extracts show moderate inhibition against pathogenic bacteria, both gram positive including Staphylococcus aureus, Streptococcus pyogenes, and Bacilllus subtillis and gram negative bacteria including Escherichia coli and Pseudomonas aeruginosa. Overall analysis of the antibacterial activity of tested samples revealed that the highest inhibitory activity was produced by Litchi chinensis (15±0.55mm) against S. pyogenes. Tris glycine SDS PAGE revealed major protein band approximately 15.5kDa and 22-kDa. Protein contents of Seeds of Litchi chinensis and Nephelium lappaceum were approximately 7.5 and 13.5mg/g, respectively
Liver injury from ampicillin-induced intestinal microbiota distresses in rats fed carbohydrate- and protein-rich diets
Get PDFPurpose: To investigate the effect of ampicillin on rat intestinal microflora and liver in the presence of high carbohydrate and protein diets.Methods: Male Wistar albino rats were divided into four groups. The first group served as the control, the second group was treated with ampicillin (50 mg/kg for 3 weeks) and fed with a standard diet, while the third and fourth groups were treated with the same dose of ampicillin and fed with acarbohydrateand protein-rich diets, respectively, to observe the effect of diet on gut flora and liver. Fecal specimens were collected and used for qualitative determination of gut microbiota composition. Serum hepatospecific markers (AST, ALT and ALP) were estimated. The antioxidant status of liver tissues was estimated for GSH, MDA, GST, LDH and vitamin C l, in addition to sodium and potassium.Results: Administration of orogastric dose of ampicillin for 3 weeks induced inhibition of E.coli, yeasts, total anaerobes, and anaerobic lactobacilli with new growth of P. vulgaris and K. pneumonia. The levels of serum AST, ALT and ALP showed significant (p ˂ 0.05) increase to 163, 112.38 and 115.35 %, respectively in ampicillin-treated animals, compared to control. Also significant (p ˂ 0.05) increase in lipid peroxidation (120 %) and LDH (111 %) coupled with significant (p ˂ 0.05) decrease in glutathione (74.57 %), vitamin C (63.49 %) and glutathione S-transferase (41.51 %) were observed in ampicillintreated groups. No significant variation (p ˂ 0.05) in sodium and potassium levels were found between control and the treated group after 3 weeks of treatment.Conclusion: These results confirm that extended ampicillin therapy disrupts gut flora, which results in liver injury; hence, overuse of antibiotics should be avoidKeywords: Ampicillin, Gut microbiota, Overgrowth, Dietary Strategies, Live
Antibacterial activities of extracts of leaf, fruit, seed and bark of Phoenix dactylifera
Get PDFThe antibacterial activities of different parts of local Phoenix dactylifera were investigated in vitro. Dried leaf, fruit, seed and tree bark were extracted with water, methanol and acetone. Antibacterial property of the extracts was evaluated against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa using the disc diffusion method. Overall analysis of the antibacterial activity of various extracts revealed that the highest inhibitory activity was produced by the fruit extract (18.2 ± 0.55 mm) as compared to the leaf, bark and seed extracts. All the extracts from the different parts of the plant showed antibacterial activity against most tested microorganisms. On the whole, aqueous extracts have the least antibacterial activity as compared to methanol and acetone extracts. The antibacterial activity against the Gram-positive strains was the highest in the acetone fruit extract against S. aureus (18.2 ± 0.55 mm). The most active extract against Gram-negative bacteria was methanol extract from the leaves with a 13.5 ± 0.33 mm inhibition zone for E. coli followed by 12.5 ± 0.88 mm for P. aeruginosa. Phytochemical analysis revealed the presence of carbohydrates and alkaloids in all parts, and flavonoids, steroids, saponins and tannins were present in some parts.Key words: Antibacterial activity, Phoenix dactylifera, disc diffusion assay, extracts, inhibition zone
Protective effects of quercetin on cadmium fluoride induced oxidative stress at different intervals of time in mouse liver
No full textQuercetin, a member of the flavonoid family is a major antioxidant acquired in humans by food consumption, while Cadmium fluoride (CdF2) is one of the naturally occurring chemicals having adverse effects. The protective effect of quercetin on time dependent oxidative damage induced in mice liver by CdF2 was studied in the following groups of mice consisting of six mice each: (i) control group; (ii) mice treated with single i.p injection of 2 mg/kg bw CdF2 for 24 h; (iii) mice treated with single i.p injection of 2 mg/kg bw CdF2 for 48 h; (iv) mice treated with single i.p injection of quercetin (100 mg/kg bw); (v) mice treated with i.p injection of 100 mg/kg bw of quercetin followed by i.p injection of CdF2 (2 mg/kg bw) for 24 h; and (vi) mice treated with i.p injection of 100mg/kg bw of quercetin followed by CdF2 (2 mg/kg bw) for 48 h. Administration of quercetin two hours before CdF2 significantly reduced the biochemical alterations in reduced glutathione, ascorbic acid, lipid peroxidation, super oxide dismutase, catalase and total protein (p<0.05). Histopathology also showed the protective effect of quercetin. The livers treated with CdF2 were atrophic, markedly nodular, inflamed and necrotic. However, this effect was reduced to a minimum in the mice pre-treated for two hours with quercetin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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