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Adebayo-Tayo B. C., Jonathan S. G.*, Popoola O. O. and Egbomuche R. C.
Abstract: Optimum culture condition for mycelia and exopolysaccharides production (EPS) by Pleurotus ostreatus in submerged liquid culture was investigated. The optimum temperature for mycelia yield and exopolysaccharide production was 25 and 15°C in day 14 with yields of 1.40 g/ml and 2700 mg/l respectively. Optimum pH was found to be 8 with respective yields of 2.5 g/ml and 2665 mg/l in day 12 for mycelia and EPS mannitol (9.75 g/litre) and raffinose stimulated the highest mycelia growth (3.0 g/ml) and EPS production (3000 mg/l) at day 14 respectively. Mycelia yield (2.10 g/ml) and EPS production (2700 mg/l) was optimally supported by urea. Glycine (1.0 g) and leucine (1.0 g) supported optimum production of mycelia yield (2.5 g/ml) and EPS concentration (2925 mg/l) respectively while folic acid and ascorbic acid induced the moderate mycelia yield and EPS concentration respectively. These results have shown that significant improvement in mycelia yield and EPS production by P. ostreatus could be enhanced through submerged cultivation under appropriate optimized conditions.[...] Read More.
Keywords: Culture, Pleurotus ostreatus, mycelia yield, exopolysaccharride-production.
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文章
Xiaozhi Zheng, Ping Ji and Jianqun Hu*
Abstract: Ultrasound-targeted microbubble destruction (UTMD) has been considered as a new approach to the gene therapy of proliferative vitreoretinopathy (PVR), but whether it affect the in vivo PVR model induction remains unknown. In this study, 90 Wistar rats were averagely divided into three groups according to the content of intravitreal injection: normal saline (Group 1), retinal pigmented epithelial -J cells and PRP (Groups 2 and 3). In Group 3, a condition of UTMD was used additionally on days 3 and 7 after injection. On days 14 and 28, the pathological changes of eye grounds were assessed, and the expression levels of transforming growth factor (TGF)- 2 and platelet -derived growth factor (PDGF)-BB were tested. In Group 3, proliferation in the eyes was significantly stronger and faster than that of Group 2 and the ratio of PVR was significantly higher than that of Group 2. The expression levels of TGF- 2 and PDGF-BB were significantly higher in Group 3 than in Group 2. These data suggested that UTMD promotes PVR induced by RPE- J cells and PRP which provide a new method for the development of rat PVR model. This also reminds us that the effects of UTMD should be taken into consideration when using UTMD as an approach to attenuate PVR.[...] Read More.
Keywords: Proliferative vitreoretinopathy, rat model, ultrasound-targeted microbubble destruction, retinal pigmented epithelial -J cells, platelet-rich plasma.
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Lida Lotfollahi,*, Jamileh Nowrouzi, Gholamreza Irajian, Faramarz Masjedian, Bahram Kazemi, Laleh Eslamian, Arash Falahat and Maryam Ramez
Abstract: Listeria monocytogenes is a causative agent of listeriosis. Clinical manifestation of invasive listeriosis is usually sever and include sepsis and meningoencephalitis. Uterian infection in listeriosis depend on gestational age varies from preterm labour, delivery of infected neonate to abortion. The present study investigated the incidence and antibiograms of the organism in clinical samples were collected from women with spontaneous abortions in Iran. Clinical samples were collected from patients with spontaneous abortions hospitalized in Shariati hospital in Tehran during December 2009 and November 2010. Antibiogram was done by disk-agar method. L. monocytogenes was isolated from 9 of 100 samples. Out of 9 isolates of L. monocytogenes 3 (16.66%), 0 (0%), 1 (4%), 3 (12%) and 2 (8%) were isolated from placental tissue, blood, urine, vaginal and rectal swabs respectively. Resistance to Penicillin G had the highest rate. Because of high incidence of L. monocytogenes in this study, in women with history of abortions or bad obstetric history, diagnosis procedures for detection of L. monocytogenes and on time treatment is recommended additionally because of high resistance rate of bacteria to Penicillin G in this study, antibacterial susceptibility before initiation of treatment is recommended.[...] Read More.
Keywords: Listeria monocytogenes, spontaneous abortion, antibiotic resistance.
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Manigeh Mehdinejad*, Azar Dokht Khosravi, Hamideh Yazdizadeh and Porandokht Afshari
Abstract: Bacterial vaginosis is caused by an imbalance of the organisms that naturally exist in the vagina. The importance of bacterial vaginosis with respect to pregnant women’s health is emphasized by the association between bacterial vaginosis and adverse outcome of pregnancy. The aim of present study was to evaluate the direct smear microscopy and culture for determination of bacteria from vaginal discharge of pregnant women. In total, 240 vaginal swabs were collected from 120 pregnant women and were screened for bacterial population. For each patient one swab was used for smear preparation and Gram staining and the second swab was used for cultivation. The prepared Gram-stained smears were observed for various morphotypes. Each morphotype was quantified on a scale from 0 to 4 and weighed to yield a score of 0 to 10, as per Nugent’s system. The bacteria grown in preliminary culture media were identified using standard identification tests. The majority of isolated bacteria in culture were Diphtheroid, Lactobacillus spp., Coagulase-negative Staphylococci and yeast. In Gram-stained smears, 78 (65%) Gram positive rods and 54 (45%) Gram positive cocci were detected. According to Nugent’s criteria, 64 cases (53.33%) were classified as having normal vaginal flora, 45 (37.5%) intermediate flora and 11 cases (9.2%) having bacterial vaginosis. The prevalence of bacterial vaginosis is not very high. However we recommend the regular screening of women with Gram stain method using Nugent’s criteria which is reliable, easy to perform and well suited for the routine clinical laboratory.[...] Read More.
Keywords: Vaginal discharge, bacterial vaginosis, Nugent’s criteria, Gram stain, culture.
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Lawal, A. K.*, Oso B. A., Sanni, A. I. and Akinola, S. O.
Abstract: An investigation was carried out to produce mutant isolates from Bacillus subtilis UG1 and Bacillus licheniformis OG4 isolated from vegetable proteins using a chemical mutagen N-methyl-N-nitrosoguanidine (NTG) at dosage concentration of 250 µg/ml. The mutant isolates obtained from wild strain of B. subtilis UG1 produced mutants (M1 to M9) and was screened for hyper producing effect. Mutant M1UG1 was obtained. The mutant isolates obtained from wild strain B. licheniformis OG4, produced 11 mutants (M1 to M11) and when screened for hyper producing effect mutant M6OG 4, was obtained. Hyper-producing mutant strains M1UG1 and M6OG4 produced L-glutamic acid of 23.0 mg/ml respectively. The quantity produced was higher than the glutamate obtained from Corynebacterium glutamicum ATCC 13032 (14 mg/ml). The developed mutant strain was better adapted to a shift in temperature range of 55 to 60°C, pH 9.0 and biotin concentration of 10 µg/ml. As part of the programme to increase glutamate yields and to use materials of agro-industrial wastes, the developed mutants M1UG1 and M 6OG4 were found to utilize the tested agro-industrial wastes maximally for growth and glutamic acid production.[...] Read More.
Keywords: L-glutamic acid, agro-industrial wastes, mutants, N-methyl-N-nitrosoguanidine (NTG), fermented vegetable proteins.
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Khandaghi Jalil*, Razavilar Vadood and Barzegari Abolfazl
Abstract: Although more than 100 serotypes of shigatoxigenic Escherichia coli (STEC) have been implicated in cases of human diseases, E. coli O157 is the most common serogroup connected with sporadic cases and large outbreaks of diseases in many countries. Rapid and sensitive identification of this dangerous pathogen is important for patient management and for prompt epidemiological investigations. PCR has become a very rapid and reliable tool for the molecular diagnosis of E. coli O157. PCR assays are usually aimed at detecting the shiga toxins, the intimin protein and enterohaemolysin. In the present study, a mPCR-based protocol is described as that which uses one primer set to detect the gene responsible for the production of the O- antigen synthesis (rfb O157) and four primer set to detect the major virulence factor genes including the Shigatoxin type 1 and 2 ( stx1 and stx2), intimin (eaeA) and enterohemolysin (EHEC hlyA) directly from 190 samples of animal faeces at the time of slaughter after overnight incubation of stool specimens in BPW. In this research, we use one primer set for detection of the gene responsible for the production of the O- antigen synthesis (rfb O157) and four primer set for detection of the Shigatoxin type 1 and 2 (stx1 and stx2), intimin (eaeA ) and enterohemolysin (EHEC hlyA) producing genes directly from 190 samples of animal faeces at the time of slaughter after overnight incubation of stool specimens in BPW. This study has established the presence of rather high prevalence of E. coli O157-positive animals at abattoirs (These consisted of 4.2% of cattle and 2.1% of sheep), providing an increased risk of transmission of E. coli O157 to the food chain and contamination of human.[...] Read More.
Keywords: Shigatoxigenic Escherichia coli (STEC), E. coli O157, shiga toxins, intimin, enterohaemolysin, mPCR.
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Sayed W. F.*, Salem W. M. and Ali M. S.
Abstract: Aqueous neem (Azadiracta indica) leaf extract was tested for its effect on Casuarina equisetifolia seed germination capacity, growth of Frankia and on some dominant rhizosphere microorganisms under casuarinas grown in soil contaminated with sewage water. Analysis was carried out to determine the main micro- and macroelement content of different extract amounts. The addition of extract amount between 10- 20 µl per 10 ml medium (1 - 2 µl ml-1) selectively stimulated Frankia growth and inhibited other non- beneficial bacteria and fungi in the rhizosphere such as Bacillus subtilis, Drechslera sp and Curvularia lunata. Slight increase was observed in Casuarina seed germination capacity with 1- 2 µ ml-1 of the extract, but with no significant differences, indicating at least no negative effect of the extract on seed germination. According to the results and as the roots and leaves of both Casuarina and neem release their active components in soil, and according to previous recommendations, we suggest a significant synergistic effect between Casuarina, rhizosphere microorganisms and neem trees for the benefits of Casuarina nodulation, growth performance and nitrogen fixation.[...] Read More.
Keywords: Neem, Casuarina, aqueous extract, Frankia, rhizospheric microorganisms.
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文章
Magdalena Frąc* and Stefania Jezierska-Tys
Abstract: Biochemical indices related with the transformations of C, N and P are frequently used in the diagnosis of soil quality. Such an assessment usually includes analysis of the following enzymes – the activity of dehydrogenases and of hydrolytic enzymes such as phosphatases, urease and protease. The objective of the study presented here was evaluation of dairy sewage sludge as an agent causing an improvement of soil quality or its degradation. Estimation of soil quality was performed on the basis of a comprehensive study comprising analyses of microbiological and biochemical parameters. The results of the study indicate a stimulating effect of dairy sewage sludge on the soil microorganisms, which was apparent also as an increase in the activity of the enzymes studied. That effect should be attributed to soil enrichment in organic matter, total nitrogen and minerals.[...] Read More.
Keywords: Dairy sewage sludge, enzymatic activity, microorganisms, soil.
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Jingwen Liu, Tianling Zheng*, Gunnar Bratbak and Runar Thyrhaug
Abstract: To investigate the influences of viral infection on cell cycle of marine algae, we examined the changes of expression and activity of G 2/M-phase cell cycle regulators in two unicellular marine algae Emiliania huxleyi and Chrysochromulina ericina after viral infection by immunoblot. The results revealed that the expression of cyclins could be altered by viral infection, thus inhibiting the progression of cell cycle. E. huxleyi virus (EhV) repressed the activity of p34cdc2/cyclinB complex by inactivating p34cdc2 kinase through phosphorylation of Cdc2, and block the life cycle of host cells at G2/M checkpoint. C. ericina virus (CeV) interfere with the activity of p34cdc2/cyclin B complex by the downregulation of cyclinB combined with the overexpression of kinase-active p34cdc2, resulting in a G2 cell cycle. The G 2/M cell cycle arrest caused by EhV infection indicated that EhV may transcribe its own genes without relying on the host cell cycle control. C. ericina cells blocked in a delayed G2 phase may partly turn into the second S phase to synthesize proteins useful for viral nucleic acid metabolism, suggesting that the replication of CeV viruses was dependent on cell cycle control. Our results indicated that algal virus infection selectively activates/inactivates certain components of the cell cycle with the aim to establish a more efficient environment for their gene expression and DNA replication.[...] Read More.
Keywords: Marine algal virus, cyclins expression, cell cycle arrest.
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Elias Tabatabaeizadeh, Gholamreza Hashemi Tabar,*, Nima Farzaneh and Hesam A. Seifi
Abstract: Bulk tank milk samples were collected from 47 dairy herds in Mashhad suburb. From 19 herds, one sample was collected at each season in 2009 and from the rest of the 28 dairy herds one sample was collected only at autumn, 2009 and samples was tested by ELISA method for detecting antibodies to Leptospira interrogans serovar hardjo. These herds, which had not been vaccinated against leptospirosis within the previous five years, were categorised according to the herds’ regions. Nine herds (19.15%) out of 47 had a positive ELISA result. The antibody level in the herd milk samples were affected by the herd size (P0.05). Larger herds were significantly more likely to have higher mean concentrations of antibody. It was concluded that a number of unvaccinated dairy herds in Mashhad suburb are exposed to infection with Leptospira hardjo.[...] Read More.
Keywords: Cattle, Leptospira, antibodies, ELISA, hardjo.
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