2,373 research outputs found
Attenuation of cisplatin-induced nephrotoxicity in rats using zerumbone
Zerumbone is a natural compound isolated from the fresh rhizomes of Zingiber zerumbet. This bioactive compound has shown a chemo-preventive, anti-inflammatory and free radical scavenging activities. This study examines the effect of zerumbone on the extent of tissue damage in cisplatininduced nephrotoxicity in rats. The rats received a single dose injection of 10 mg/kg cisplatin. Other groups of rats received zerumbone (100 and 200 mg/kg), corn oil or the vehicle, dimethyl sulfoxide (DMSO) intraperitoneally for 4 days prior to cisplatin-injections. All animals were decapitated 16 h after cisplatin injection. Trunk blood was collected and analyzed for blood urea nitrogen (BUN) and serum creatinine. Kidney tissue was kept for the quantification of malondialdehyde and glutathione levels. Histopathological investigations were carried out and the severity of lesions was scored to obtain quantitative data. Our study revealed that zerumbone reduced kidney damage and preserved renal functions as proved by microscopic observations and lesion scoring. The increased in kidney malondialdehyde (MDA) levels with simultaneous glutathione (GSH) reduction in cisplatin treated group was attenuated by zerumbone (p < 0.05). It was concluded that zerumbone is beneficial in cisplatininducedrenal dysfunction and organ damage in rats possibly via the prevention of lipid per oxidation and preservation of antioxidant glutathione
GC/MS determination of bioactive components and antibacterial properties of Goniothalamus umbrosusextracts
In this study, the antibacterial activity and chemical composition of Goniothalamus umbrosus leaves extracts were evaluated. The antibacterial activity was investigated using two gram-positive bacteria, Methicillin resistant Staphylococcus aureus (MRSA) and Bacillus subtilis B29, and two gram-negative bacteria, Pseudomonas aeruginosa 60690 and Salmonella choleraesuis. The activity was tested using disc diffusion and minimum inhibitory concentration assays. The chemical compositions of the ethyl acetate extract of G. umbrosus were investigated using Shimadzu gas chromatography–mass spectrometry (GC-17A) while the mass spectra of the compounds found in the extract was matched with the library. The results showed that the extracts demonstrated broad spectrum antibacterial effects against all tested bacteria. GC/MS analysis of ethyl acetate extract of G. umbrosus revealed the existence of 1-butyl-2-cyclohexen-1-ol (46.84%), benzaldehyde (4.42%) and globulol (4.07%). The results of this study offer a platform of using G. umbrosus as herbal alternative for the current synthetic antimicrobial agents
The Very Young Type Ia Supernova 2012cg: Discovery and Early-Time Follow-Up Observations
On 2012 May 17.2 UT, only 1.5 +/- 0.2 d after explosion, we discovered SN
2012cg, a Type Ia supernova (SN Ia) in NGC 4424 (d ~ 15 Mpc). As a result of
the newly modified strategy employed by the Lick Observatory SN Search, a
sequence of filtered images was obtained starting 161 s after discovery.
Utilizing recent models describing the interaction of SN ejecta with a
companion star, we rule out a ~1 M_Sun companion for half of all viewing angles
and a red-giant companion for nearly all orientations. SN 2012cg reached a
B-band maximum of 12.09 +/- 0.02 mag on 2012 June 2.0 and took ~17.3 d from
explosion to reach this, typical for SNe Ia. Our pre-maximum brightness
photometry shows a narrower-than-average B-band light curve for SN 2012cg,
though slightly overluminous at maximum brightness and with normal color
evolution (including some of the earliest SN Ia filtered photometry ever
obtained). Spectral fits to SN 2012cg reveal ions typically found in SNe Ia at
early times, with expansion velocities >14,000 km/s at 2.5 d past explosion.
Absorption from C II is detected early, as well as high-velocity components of
both Si II 6355 Ang. and Ca II. Our last spectrum (13.5 d past explosion)
resembles that of the somewhat peculiar SN Ia 1999aa. This suggests that SN
2012cg will have a slower-than-average declining light curve, which may be
surprising given the faster-than-average rising light curve.Comment: re-submitted to ApJL, 4 figures, 1 tabl
c-di-GMP Turn-Over in Clostridium difficile Is Controlled by a Plethora of Diguanylate Cyclases and Phosphodiesterases
Clostridium difficile infections have become a major healthcare concern in the last decade during which the emergence of new strains has underscored this bacterium's capacity to cause persistent epidemics. c-di-GMP is a bacterial second messenger regulating diverse bacterial phenotypes, notably motility and biofilm formation, in proteobacteria such as Vibrio cholerae, Pseudomonas aeruginosa, and Salmonella. c-di-GMP is synthesized by diguanylate cyclases (DGCs) that contain a conserved GGDEF domain. It is degraded by phosphodiesterases (PDEs) that contain either an EAL or an HD-GYP conserved domain. Very little is known about the role of c-di-GMP in the regulation of phenotypes of Gram-positive or fastidious bacteria. Herein, we exposed the main components of c-di-GMP signalling in 20 genomes of C. difficile, revealed their prevalence, and predicted their enzymatic activity. Ectopic expression of 31 of these conserved genes was carried out in V. cholerae to evaluate their effect on motility and biofilm formation, two well-characterized phenotype alterations associated with intracellular c-di-GMP variation in this bacterium. Most of the predicted DGCs and PDEs were found to be active in the V. cholerae model. Expression of truncated versions of CD0522, a protein with two GGDEF domains and one EAL domain, suggests that it can act alternatively as a DGC or a PDE. The activity of one purified DGC (CD1420) and one purified PDE (CD0757) was confirmed by in vitro enzymatic assays. GTP was shown to be important for the PDE activity of CD0757. Our results indicate that, in contrast to most Gram-positive bacteria including its closest relatives, C. difficile encodes a large assortment of functional DGCs and PDEs, revealing that c-di-GMP signalling is an important and well-conserved signal transduction system in this human pathogen
Current progress on removal of recalcitrance coloured particles from anaerobically treated effluent using coagulation–flocculation
The palm oil industry is the most important agro industries in Malaysia and most of the mills adopt anaerobic digestion as their primary treatment for palm oil mill effluent (POME). Due to the public concern, decolourisation of anaerobically treated POME (AnPOME) is becoming a great concern. Presence of recalcitrant-coloured particles hinders biological processes and coagulation–flocculation may able to remove these coloured particles. Several types of inorganic and polymers-based coagulant/flocculant aids for coagulation–flocculation of AnPOME have been reviewed. Researchers are currently interested in using natural coagulant and flocculant aids. Modification of the properties of natural coagulant and flocculant aids enhanced coagulation–flocculation performance. Modelling and optimization of the coagulation–flocculation process have also been reviewed. Chemical sludge has the potential for plant growth that can be evaluated through pot trials and phytotoxicity test
Melatonin Promotes Oligodendroglial Maturation of Injured White Matter in Neonatal Rats
OBJECTIVE:To investigate the effects of melatonin treatment in a rat model of white matter damage (WMD) in the developing brain. Additionally, we aim to delineate the cellular mechanisms of melatonin effect on the oligodendroglial cell lineage. METHODS:A unilateral ligation of the uterine artery in pregnant rat at the embryonic day 17 induces fetal hypoxia and subsequent growth restriction (GR) in neonatal pups. GR and control pups received a daily intra-peritoneal injection of melatonin from birth to post-natal day (P) 3. RESULTS:Melatonin administration was associated with a dramatic decrease in microglial activation and astroglial reaction compared to untreated GR pups. At P14, melatonin prevented white matter myelination defects with an increased number of mature oligodendrocytes (APC-immunoreactive) in treated GR pups. Conversely, melatonin was not found to be associated with an increased density of total oligodendrocytes (Olig2-immunoreactive), suggesting that melatonin is able to promote oligodendrocyte maturation but not proliferation. These effects appear to be melatonin-receptor dependent and were reproduced in vitro. INTERPRETATION:These data suggest that melatonin has a strong protective effect on developing damaged white matter through decreased microglial activation and oligodendroglial maturation leading to a normalization of the myelination process. Consequently, melatonin should be a considered as an effective neuroprotective candidate not only in perinatal brain damage but also in inflammatory and demyelinating diseases observed in adults
Prostate Cancer Cell Lines under Hypoxia Exhibit Greater Stem-Like Properties
Hypoxia is an important environmental change in many cancers. Hypoxic niches can be occupied by cancer stem/progenitor-like cells that are associated with tumor progression and resistance to radiotherapy and chemotherapy. However, it has not yet been fully elucidated how hypoxia influences the stem-like properties of prostate cancer cells. In this report, we investigated the effects of hypoxia on human prostate cancer cell lines, PC-3 and DU145. In comparison to normoxia (20% O2), 7% O2 induced higher expressions of HIF-1α and HIF-2α, which were associated with upregulation of Oct3/4 and Nanog; 1% O2 induced even greater levels of these factors. The upregulated NANOG mRNA expression in hypoxia was confirmed to be predominantly retrogene NANOGP8. Similar growth rates were observed for cells cultivated under hypoxic and normoxic conditions for 48 hours; however, the colony formation assay revealed that 48 hours of hypoxic pretreatment resulted in the formation of more colonies. Treatment with 1% O2 also extended the G0/G1 stage, resulting in more side population cells, and induced CD44 and ABCG2 expressions. Hypoxia also increased the number of cells positive for ABCG2 expression, which were predominantly found to be CD44bright cells. Correspondingly, the sorted CD44bright cells expressed higher levels of ABCG2, Oct3/4, and Nanog than CD44dim cells, and hypoxic pretreatment significantly increased the expressions of these factors. CD44bright cells under normoxia formed significantly more colonies and spheres compared with the CD44dim cells, and hypoxic pretreatment even increased this effect. Our data indicate that prostate cancer cells under hypoxia possess greater stem-like properties
The Myosin Va Head Domain Binds to the Neurofilament-L Rod and Modulates Endoplasmic Reticulum (ER) Content and Distribution within Axons
The neurofilament light subunit (NF-L) binds to myosin Va (Myo Va) in neurons but the sites of interaction and functional significance are not clear. We show by deletion analysis that motor domain of Myo Va binds to the NF-L rod domain that forms the NF backbone. Loss of NF-L and Myo Va binding from axons significantly reduces the axonal content of ER, and redistributes ER to the periphery of axon. Our data are consistent with a novel function for NFs as a scaffold in axons for maintaining the content and proper distribution of vesicular organelles, mediated in part by Myo Va. Based on observations that the Myo Va motor domain binds to intermediate filament (IF) proteins of several classes, Myo Va interactions with IFs may serve similar roles in organizing organelle topography in different cell types
Epistatic Association Mapping in Homozygous Crop Cultivars
The genetic dissection of complex traits plays a crucial role in crop breeding. However, genetic analysis and crop breeding have heretofore been performed separately. In this study, we designed a new approach that integrates epistatic association analysis in crop cultivars with breeding by design. First, we proposed an epistatic association mapping (EAM) approach in homozygous crop cultivars. The phenotypic values of complex traits, along with molecular marker information, were used to perform EAM. In our EAM, all the main-effect quantitative trait loci (QTLs), environmental effects, QTL-by-environment interactions and QTL-by-QTL interactions were included in a full model and estimated by empirical Bayes approach. A series of Monte Carlo simulations was performed to confirm the reliability of the new method. Next, the information from all detected QTLs was used to mine novel alleles for each locus and to design elite cross combination. Finally, the new approach was adopted to dissect the genetic basis of seed length in 215 soybean cultivars obtained, by stratified random sampling, from 6 geographic ecotypes in China. As a result, 19 main-effect QTLs and 3 epistatic QTLs were identified, more than 10 novel alleles were mined and 3 elite parental combinations, such as Daqingdou and Zhengzhou790034, were predicted
- …