Medicinal mushroom modulators of molecular targets as cancer therapeutics

Empirical approaches to discover anticancer drugs and cancer treatments have made limited progress in the past several decades in finding a cure for cancer. The expanded knowledge of the molecular basis of tumorigenesis and metastasis, together with the inherently vast structural diversity of natural compounds found in mushrooms, provided unique opportunities for discovering new drugs that rationally target the abnormal molecular and biochemical signals leading to cancer. This review focuses on mushroom low-molecular-weight secondary metabolites targeting processes such as apoptosis, angiogenesis, metastasis, cell cycle regulation, and signal transduction cascades. Also discussed in this review are high-molecular-weight polysaccharides or polysaccharide–protein complexes from mushrooms that appear to enhance innate and cell-mediated immune responses, exhibit antitumor activities in animals and humans, and demonstrate the anticancer properties of selenium compounds accumulated in mushrooms.     

U wave: an important noninvasive electrocardiographic diagnostic marker

Study of U waves exemplifies important clinical role of noninvasive electrocardiography in modern cardiology. Present article highlights significance of U waves with a clinical case and also summarizes in brief the history of the same.     

Islet neogenesis: a potential therapeutic tool in type 1 diabetes

Current therapies for type 1 diabetes, including fastidious blood glucose monitoring and multiple daily insulin injections, are not sufficient to prevent complications of the disease. Though pancreas and possibly islet transplantation can prevent the progression of complications, the scarcity of donor organs limits widespread application of these approaches. Understanding the mechanisms of beta-cell mass expansion as well as the means to exploit these pathways has enabled researchers to develop new strategies to expand and maintain islet cell mass. Potential new therapeutic avenues include ex vivo islet expansion and improved viability of islets prior to implantation, as well as the endogenous expansion of beta-cell mass within the diabetic patient. Islet neogenesis, through stem cell activation and/or transdifferentiation of mature fully differentiated cells, has been proposed as a means of beta-cell mass expansion. Finally, any successful new therapy for type 1 diabetes via beta-cell mass expansion will require prevention of beta-cell death and maintenance of long-term endocrine function.     

Investigation of conformational changes induced by binding of pancreatic RNase to anti-RNase IgG derived Fab monomer using optical procedures

The conformational changes induced in Fab fragments of polyclonal anti-RNase antibody molecules obtained by digestion with papain as a result of binding of pancreatic RNase have been studied. The RNase-Fab complex (RN-Fab), being soluble, could be subjected to thermodynamic investigations using optical strategies, also because of the absence of tryptophan in RNase. Internalization of the chromophores (tryptophans and tyrosines) of Fab occurs when it binds to RNase, suggesting an increase in the compactness of Fab due to the binding of RNase.     

Proteomic characterization of lipid rafts markers from the rat intestinal brush border

To assess intestinal lipid rafts functions through the characterization of their protein markers, we have isolated lipid rafts of rat mucosa either from the total membrane or purified brush-border membrane (BBM) by sucrose gradient fractionation after detergent treatment. In both membrane preparations, the floating fractions (4-5) were enriched in cholesterol, ganglioside GM1, and N aminopeptidase (NAP) known as intestinal lipid rafts markers. Based on MALDI-TOF/MS identification and simultaneous detection by immunoblotting, 12 proteins from BBM cleared from contaminants were selected as rafts markers. These proteins include several signaling/trafficking proteins belonging to the G protein family and the annexins as well as GPI-anchored proteins. Remarkably GP2, previously described as the pancreatic granule GPI-anchored protein, was found in intestinal lipid rafts. The proteomic strategy assayed on the intestine leads to the characterization of known (NAP, alkaline phosphatase, dipeptidyl aminopeptidase, annexin II, and galectin-4) and new (GP2, annexin IV, XIIIb, Galpha(q), Galpha(11), glutamate receptor, and GPCR 7) lipid rafts markers. Together our results indicate that some digestive enzymes, trafficking and signaling proteins may be functionally distributed in the intestine lipid rafts.     

Opening up the advantages of the ruthenocenic bioprobes of ferroquine: distribution and localization in Plasmodium falciparum-infected erythrocytes

A ferrocene-quinoline conjugate named ferroquine (FQ or SSR97193) is active against both chloroquine-susceptible and chloroquine-resistant Plasmodium falciparum and P. vivax strains and/or isolates. FQ was shown to be efficient for the treatment of uncomplicated malaria in humans (phase IIb of clinical trials). However, the molecular basis of FQ's mechanism of action is still unknown because few approaches (such as radioactive labelling or immunofluorescence) are available for that purpose. Previous reports from our laboratory suggest that the intramolecular hydrogen bond in the lateral side chain plays a crucial role in the antimalarial activity of the drug. We used two ruthenocenic bioprobes of FQ (with and without an intramolecular hydrogen bond) to study their localization and quantification in Plasmodium falciparum-infected erythrocytes. We first used Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) analysis to trace ruthenoquine (RQ, with an intramolecular hydrogen bond) and methylruthenoquine (Me-RQ, without an intramolecular hydrogen bond) in the infected red blood cells (iRBCs). We showed that RQ accumulates faster in the digestive vacuole of the iRBCs than Me-RQ. We next examined the ruthenium distribution at the ultrastructural level by transmission electron microscopy (TEM). We showed that RQ accumulates faster in the parasitic digestive vacuole (DV) close to its membranes than Me-RQ.     

Molecular Identification of <Emphasis Type="Italic">Candida orthopsilosis</Emphasis> Isolated from Blood Culture

The incidence of candidemia and invasive candidiasis have increased markedly due to the increasing number of immunocompromised patients. There are five major medically important species of Candida with their frequency of isolation in the diminishing order namely Candida albicans, Candida parapsilosis, Candida tropicalis, Candida glabrata and Candida krusei. In addition, there are numerous other species of Candida which differ in their genetic makeup, virulence properties, drug susceptibilities and sugar assimilation capabilities. In this report, an unusual Candida species was isolated from the blood of two leukaemic patients. Conventional culture and biochemical tests identified the Candida species as C. parapsilosis. Using fungal-specific oligonucleotide primers ITS1 and ITS4, we managed to amplify the ribosomal RNA gene and its internal transcribed spacer region from the genomic DNA of these isolates. The PCR products were then purified and subjected to automated DNA sequencing using BLAST and CLUSTAL sequence analysis identified these isolates to be Candida orthopsilosis. Candida orthopsilosis is a new species recently identified in 2005, being morphologically indistinguishable from C. parapsilosis and was previously classified as a subspecies of C. parapsilosis. This report highlights the importance of complementing traditional culture and biochemical-based identification methods with DNA-based molecular assays such as PCR as the latter is more superior in terms of its discriminatory power and speed.     

Preparation of Secretory Vesicle-Free Plasma Membranes by Isopycnic Sucrose Gradient Fractionation of Neutrophils Purified by the Gelatin Method

Isolated human neutrophils serve as a model for the in vitro study of host defensive processes as well as the cell biology and biochemistry of primary human cells. We demonstrate that the requirements of the gelatinbased procedure for neutrophil isolation from whole blood induces the complete loss of secretory vesicles from in vitro isolated populations, whereas isolation by a dextran-based methodology results in the preservation of this organelle. Following density fractionation of cellular cavitates, examination of commonly employed plasma membrane marker activities yielded subcellular localization patterns that were indistinguishable between dextran- or gelatin-isolated populations, indicating both populations to be otherwise comparable in terms of the relative complexity and large-scale organization of plasma membranes. Given that the cell surface upregulation of secretory vesicles is implicated as an initial requirement of neutrophil activation as well as an intrinsic feature of neutrophil priming, we show that dextran and gelatin-isolated neutrophils may be considered to occupy functionally nonactivated and primed cellular states, respectively. These differences in phenotype can be exploited in specific ways. We suggest that the gelatin method has technical advantages with regard to the study of neutrophil plasma membranes. In particular, results from this study indicate the gelatin method to be a reliable and effective preparatory technique appropriate for tandem use with density fractionation procedures to achieve rapid isolation of plasma membranes that are uncontaminated by secretory organelles.     

Bio-separation, speciation and determination of chromium in water using partially pyrolyzed olive pomace sorbent

Speciation of Cr(III)/Cr(VI) from water using olive pomace (OP) was improved by partial pyrolysis of OP. The sorbents were characterized by physicochemical techniques. Sorption of Cr(III) on raw and partially pyrolyzed OP sorbents followed Freundlich isotherm and second-order rate kinetics. OP pyrolyzed at 150 °C (sorbent OP-150) exhibited maximum sorption capacity, favorability and the lowest sorption energy. Sorption was exothermic and spontaneous for the raw-OP and OP pyrolyzed at 100 or 150 °C; but endothermic and non-spontaneous for OP pyrolyzed at 200, 250, 300 or 400 °C. A speciation method of chromium was proposed, in which Cr(III) was selectively retained at pH 3 on sorbent OP-150; while total Cr was determined after reduction of Cr(VI). The method was selective with a detection limit for Cr(III) of 1.58 μg L⁻¹. The method was applied on natural and industrial waters (recoveries >97.7%, RSD’s <9%) and on tobacco leaves certified reference material (INCT-PVTL-6).     

New Insights into Plagiogrammaceae (Bacillariophyta) Based on Multigene Phylogenies and Morphological Characteristics with the Description of a New Genus and Three New Species

Plagiogrammaceae, a poorly described family of diatoms, are common inhabitants of the shallow marine littoral zone, occurring either in the sediments or as epiphytes. Previous molecular phylogenies of the Plagiogrammaceae were inferred but included only up to six genera: Plagiogramma, Dimeregramma, Neofragilaria, Talaroneis, Psammogramma and Psammoneis. In this paper, we describe a new plagiogrammoid genus, Orizaformis, obtained from Bohai Sea (China) and present molecular phylogenies of the family based on three and four genes (nuclear-encoded large and small subunit ribosomal RNAs and chloroplast-encoded rbcL and psbC). Also included in the new phylogenies is Glyphodesmis. The phylogenies suggest that the Plagiogrammaceae is composed of two major clades: one consisting of Talaroneis, Orizaformis and Psammoneis, and the second of Glyphodesmis, Psammogramma, Neofragilaria, Dimeregramma and Plagiogramma. In addition, we describe three new species within established genera: Psammoneis obaidii, which was collected from the Red Sea, Saudi Arabia; and Neofragilaria stilus and Talaroneis biacutifrons from the Mozambique Channel, Indian Ocean, and illustrate two new combination taxa: Neofragilaria anomala and Neofragilaria lineata. Our observations suggest that the biodiversity of the family is strongly needed to be researched, and the phylogenetic analyses provide a useful framework for future studies of Plagiogrammaceae.