Evaluation of Bioactivities and Phenolic Content of Selected Edible Mushrooms in Malaysia

Purpose: To determine the radical scavenging, metal chelating, antibacterial and cytotoxic activities of five edible mushrooms in Malaysia.Methods: Mushrooms (H. tessulatus, P. eryngii, P. florida, A. polytricha and F. velutipes) were ovendried and extracted with 90 % ethanol. Radical scavenging and metal chelating assays were based on the measurement of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferrozine absorbance at 517 and 562 nm, respectively. Mushrooms total phenolic and flavonoid contents were determined by spectrophotometric methods. Antimicrobial activity was measured using Kirby-Bauer Susceptibility Test. Cytotoxicity was assessed using brine shrimp toxicity assay.Results: Total phenolic and flavonoid contents ranged from 0.90 - 6.03 mg GAE per g of dry sample and 0.17 - 6.95 mg QE per g of dry sample, respectively. A. polytricha demonstrated the strongest radical scavenging and metal chelating activities. Moderate antimicrobial activity was found for extracts of both P. florida and A. polytricha. Cytotoxicity LD50 ranged from 46.9 - 115.8 μg/ml.Conclusion: The results suggest that A. polytricha is a suitable candidate for chemoprevention and would safe for use in large doses.Keywords: Cytotoxicity, Flavonoid, Free radical scavenging, Metal chelating, Mushroom, Phenoli

Pleomorphic adenocarcinoma of the lacrimal gland with multiple intracranial and spinal metastases

BACKGROUND: Pleomorphic adenoma of the lacrimal gland is known to undergo malignant transformation when incompletely excised. Even if such a malignant change occurs, intracranial direct invasion and leptomeningeal seeding are seldom encountered. CASE PRESENTATION: A 50-year-old woman presented with malignant transformation associated with both intracranial invasion and multiple intracranial and spinal disseminations in the third recurrence of pleomorphic adenoma of the lacrimal gland, 6 years after initial treatment. MRI demonstrated increased extent of orbital mass, extending to the cavernous sinus. The patient underwent intensity-modulated radiation therapy (IMRT) and Gamma Knife radiosurgery. Follow-up MRI showed multiple leptomeningeal disseminations to the intracranium and spine. CONCLUSION: It is important to recognize that leptomeningeal intracranial and spinal disseminations of pleomorphic adenocarcinoma can occur, although it is extremely rare. To our knowledge, we report the first case of pleomorphic adenocarcinoma of the lacrimal gland presumably metastasizing to the intracranium and spine

Possible Novel Therapy for Malignant Gliomas with Secretable Trimeric TRAIL

Malignant gliomas are the most common primary brain tumors. Despite intensive clinical investigation and many novel therapeutic approaches, average survival for the patients with malignant gliomas is only about 1 year. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has shown potent and cancer-selective killing activity and drawn considerable attention as a promising therapy for cancers, but concerns over delivery and toxicity have limited progress. We have developed a secretable trimeric TRAIL (stTRAIL) and here evaluated the therapeutic potential of this stTRAIL-based gene therapy in brain tumors. An adenovirus (Ad-stTRAIL) delivering stTRAIL was injected into intra-cranial human glioma tumors established in nude mice and tumor growth monitored using the magnetic resonance imaging (MRI). Ad-stTRAIL gene therapy showed potent tumor suppressor activity with no toxic side effects at therapeutically effective doses. When compared with 1, 3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a conventional therapy for malignant gliomas, Ad-stTRAIL suppressed tumor growth more potently. The combination of Ad-stTRAIL and BCNU significantly increased survival compared to the control mice or mice receiving Ad-stTRAIL alone. Our data indicate that Ad-stTRAIL, either alone or combined with BCNU, has promise as a novel therapy for malignant gliomas

“Excellence R Us”: university research and the fetishisation of excellence

The rhetoric of “excellence” is pervasive across the academy. It is used to refer to research outputs as well as researchers, theory and education, individuals and organisations, from art history to zoology. But does “excellence” actually mean anything? Does this pervasive narrative of “excellence” do any good? Drawing on a range of sources we interrogate “excellence” as a concept and find that it has no intrinsic meaning in academia. Rather it functions as a linguistic interchange mechanism. To investigate whether this linguistic function is useful we examine how the rhetoric of excellence combines with narratives of scarcity and competition to show that the hypercompetition that arises from the performance of “excellence” is completely at odds with the qualities of good research. We trace the roots of issues in reproducibility, fraud, and homophily to this rhetoric. But we also show that this rhetoric is an internal, and not primarily an external, imposition. We conclude by proposing an alternative rhetoric based on soundness and capacity-building. In the final analysis, it turns out that that “excellence” is not excellent. Used in its current unqualified form it is a pernicious and dangerous rhetoric that undermines the very foundations of good research and scholarship

Graphene Photonics and Optoelectronics

The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultra-wide-band tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres

Scoliotic posture as the initial symptom in adolescents with lumbar disc herniation: its curve pattern and natural history after lumbar discectomy

<p>Abstract</p> <p>Background</p> <p>There have been few studies focusing on the curve pattern of scoliosis caused by lumbar disc herniation (LDH) in adolescents and the natural history of scoliosis after discectomy. The current study was carried out to identify the curve pattern of scoliosis and investigate the effect of posterior discectomy on the curve improvement in adolescents with LDH.</p> <p>Methods</p> <p>This review focused on a group of 26 adolescents with LDH who initially presented to our clinic for evaluation of scoliosis, followed by posterior discectomy between 2000 and 2009. Radiographic measurements included curve pattern, specific curve features, trunk shift, and sagittal profile. The correlation between the side of disc herniation and the direction of lumbosacral curve and the trunk shift was evaluated.</p> <p>Results</p> <p>A typical curve pattern was initially identified in all of the patients as a short lumbosacral curve accompanied with a long thoracic or thoracolumbar curve toward the opposite side. 23 of 26 patients (88.5%) had a trunk shift more than 2.0 cm away from the midline, showing a poor coronal balance. A relatively straight sagittal profile was noted in all the patients. 84.6% (22/26) patients had a disc herniation at the convex side of lumbosacral curve. Similarly, 73.1% (19/26) patients showed a trunk shift toward the opposite side of disc herniation. All of the patients had an marked curve improvement immediately after discectomy. In the 17 patients with a more than 2-year follow-up, only two had a residual lumbosacral curve greater than or equal to 20 degrees. The mean ODI improved from 21.4% before surgery to 7.3% at the final follow-up.</p> <p>Conclusions</p> <p>A short lumbosacral curve accompanied with a long thoracic or thoracolumbar curve toward the opposite side, and a relatively straight sagittal profile have been noted in all the patients. The direction of lumbosacral curve and trunk shift was related to the side of disc herniation. A majority of patients have a small curve size while assosiated with a significant coronal imbalance. Earlier decompression can provide a greater opportunity for spontaneous correction of scoliosis.</p

Use of multiple methods for genotyping Fusarium during an outbreak of contact lens associated fungal keratitis in Singapore

<p>Abstract</p> <p>Background</p> <p>In Singapore, an outbreak of fungal keratitis caused by members of the <it>Fusarium solani </it>species complex (FSSC) was identified in March 2005 to May 2006 involving 66 patients. Epidemiological investigations have indicated that improper contact lens wear and the use of specific contact lens solutions were risk factors.</p> <p>Methods</p> <p>We assessed the genetic diversity of the isolates using AFLP, Rep-PCR, and ERIC-PCR and compared the usefulness of these typing schemes to characterize the isolates.</p> <p>Results</p> <p>AFLP was the most discriminative typing scheme and appears to group FSSC from eye infections and from other infections differently.</p> <p>Conclusion</p> <p>There was a high genomic heterogeneity among the isolates confirming that this was not a point source outbreak.</p

Chromatin signature of embryonic pluripotency is established during genome activation

available in PMC 2011 April 8.After fertilization the embryonic genome is inactive until transcription is initiated during the maternal–zygotic transition. This transition coincides with the formation of pluripotent cells, which in mammals can be used to generate embryonic stem cells. To study the changes in chromatin structure that accompany pluripotency and genome activation, we mapped the genomic locations of histone H3 molecules bearing lysine trimethylation modifications before and after the maternal–zygotic transition in zebrafish. Histone H3 lysine 27 trimethylation (H3K27me3), which is repressive, and H3K4me3, which is activating, were not detected before the transition. After genome activation, more than 80% of genes were marked by H3K4me3, including many inactive developmental regulatory genes that were also marked by H3K27me3. Sequential chromatin immunoprecipitation demonstrated that the same promoter regions had both trimethylation marks. Such bivalent chromatin domains also exist in embryonic stem cells and are thought to poise genes for activation while keeping them repressed. Furthermore, we found many inactive genes that were uniquely marked by H3K4me3. Despite this activating modification, these monovalent genes were neither expressed nor stably bound by RNA polymerase II. Inspection of published data sets revealed similar monovalent domains in embryonic stem cells. Moreover, H3K4me3 marks could form in the absence of both sequence-specific transcriptional activators and stable association of RNA polymerase II, as indicated by the analysis of an inducible transgene. These results indicate that bivalent and monovalent domains might poise embryonic genes for activation and that the chromatin profile associated with pluripotency is established during the maternal–zygotic transition.National Institutes of Health (U.S.) (grant 1R01 HG004069)National Institutes of Health (U.S.) (grant 5R01 GM56211)Human Frontier Science Program (Strasbourg, France) (LT-00090/2007)European Molecular Biology Organization (fellowship

Hrk1 Plays Both Hog1-Dependent and -Independent Roles in Controlling Stress Response and Antifungal Drug Resistance in Cryptococcus neoformans

The HOG (High Osmolarity Glycerol response) pathway plays a central role in controlling stress response, ergosterol biosynthesis, virulence factor production, and differentiation of Cryptococcus neoformans, which causes fatal fungal meningoencephalitis. Recent transcriptome analysis of the HOG pathway discovered a Hog1-regulated gene (CNAG_00130.2), encoding a putative protein kinase orthologous to Rck1/2 in Saccharomyces cerevisiae and Srk1 in Schizosaccharomyces pombe. Its function is not known in C. neoformans. The present study functionally characterized the role of Hrk1 in C. neoformans. Northern blot analysis confirmed that HRK1 expression depends on the Hog1 MAPK. Similar to the hog1Δ mutant, the hrk1Δ mutant exhibited almost complete resistance to fludioxonil, which triggers glycerol biosynthesis via the HOG pathway. Supporting this, the hrk1Δ mutant showed reduced intracellular glycerol accumulation and swollen cell morphology in response to fludioxonil, further suggesting that Hrk1 works downstream of the HOG pathway. However, Hrk1 also appeared to have Hog1-independent functions. Mutation of HRK1 not only further increased osmosensitivity of the hog1Δ mutant, but also suppressed increased azole-resistance of the hog1Δ mutant in an Erg11-independent manner. Furthermore, unlike the hog1Δ mutant, Hrk1 was not involved in capsule biosynthesis. Hrk1 was slightly involved in melanin production but dispensable for virulence of C. neoformans. These findings suggest that Hrk1 plays both Hog1-dependent and –independent roles in stress and antifungal drug susceptibility and virulence factor production in C. neoformans. Particularly, the finding that inhibition of Hrk1 substantially increases azole drug susceptibility provides a novel strategy for combination antifungal therapy