EVALUATION OF ANTIOXIDANT ACTIVITY OF MAGNOLOL IN SACCHAROMYCES CEREVISIAE

Objective: To investigate the antioxidant activity of magnolol in Saccharomyces cerevisiae (S. cerevisiae) model.Methods: Antioxidant activity of magnolol was demonstrated in S. cerevisiae using spot assay, colony forming unit (CFU) assay, detection of reactive oxygen species (ROS) by fluorescent microscopy and spectrofluorometer, lipid peroxidation (LPO) and catalase (CAT) assay.Results: A dose-dependent increase in sensitivity of S. cerevisiae was observed with increase in hydrogen peroxide (H2O2) concentration. At 1.5 mmol concentration of H2O2, we observed 50 % of cell survivability in CFU and spot assay results. The sensitivity of S. cerevisiae to H2O2 was protected by magnolol treatment. In spot assay, magnolol pre-treatment showed the similar growth pattern as that of control and in CFU assay 75 % of survivability was observed. Fluorescence microscopic images and fluorescence intensity levels using 2´, 7´-dichlorodihydrofluoresceindiacetate (H2DCFDA) showed less number of fluorescence cells and 1.2 fold decrease in fluorescence intensity in magnolol pre-treated cells. The cellular protection in the cells pre–treated with magnolol followed by H2O2 was correlated with the decreased LPO and increase in CAT activity was recorded.Conclusion: The result of the present study demonstrates that magnolol protects S. cerevisiae cells from H2O2 induced oxidant mediated cell death

Nanoparticle-Mediated Drug Delivery for the Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are one of the foremost causes of high morbidity and mortality globally. Preventive, diagnostic, and treatment measures available for CVDs are not very useful, which demands promising alternative methods. Nanoscience and nanotechnology open a new window in the area of CVDs with an opportunity to achieve effective treatment, better prognosis, and less adverse effects on non-target tissues. The application of nanoparticles and nanocarriers in the area of cardiology has gathered much attention due to the properties such as passive and active targeting to the cardiac tissues, improved target specificity, and sensitivity. It has reported that more than 50% of CVDs can be treated effectively through the use of nanotechnology. The main goal of this review is to explore the recent advancements in nanoparticle-based cardiovascular drug carriers. This review also summarizes the difficulties associated with the conventional treatment modalities in comparison to the nanomedicine for CVDs

Increased tRNA modification and gene-specific codon usage regulate cell cycle progression during the DNA damage response

S-phase and DNA damage promote increased ribonucleotide reductase (RNR) activity. Translation of RNR1 has been linked to the wobble uridine modifying enzyme tRNA methyltransferase 9 (Trm9). We predicted that changes in tRNA modification would translationally regulate RNR1 after DNA damage to promote cell cycle progression. In support, we demonstrate that the Trm9-dependent tRNA modification 5-methoxycarbonylmethyluridine (mcm⁵U) is increased in hydroxyurea (HU)-induced S-phase cells, relative to G₁ and G₂, and that mcm⁵U is one of 16 tRNA modifications whose levels oscillate during the cell cycle. Codon-reporter data matches the mcm⁵U increase to Trm9 and the efficient translation of AGA codons and RNR1. Further, we show that in trm9Δ cells reduced Rnr1 protein levels cause delayed transition into S-phase after damage. Codon re-engineering of RNR1 increased the number of trm9Δ cells that have transitioned into S-phase 1 h after DNA damage and that have increased Rnr1 protein levels, similar to that of wild-type cells expressing native RNR1. Our data supports a model in which codon usage and tRNA modification are regulatory components of the DNA damage response, with both playing vital roles in cell cycle progression.National Institute of Environmental Health Sciences (R01 ES015037)National Institute of Environmental Health Sciences (R01 ES017010)National Institute of Environmental Health Sciences (P30 ES002109)Massachusetts Institute of Technology (Westaway Fund)Singapore-MIT Alliance for Research and Technolog

A Quantitative Systems Approach Reveals Dynamic Control of tRNA Modifications during Cellular Stress

Decades of study have revealed more than 100 ribonucleoside structures incorporated as post-transcriptional modifications mainly in tRNA and rRNA, yet the larger functional dynamics of this conserved system are unclear. To this end, we developed a highly precise mass spectrometric method to quantify tRNA modifications in Saccharomyces cerevisiae. Our approach revealed several novel biosynthetic pathways for RNA modifications and led to the discovery of signature changes in the spectrum of tRNA modifications in the damage response to mechanistically different toxicants. This is illustrated with the RNA modifications Cm, m[superscript 5]C, and m[superscript 2][subscript 2]G, which increase following hydrogen peroxide exposure but decrease or are unaffected by exposure to methylmethane sulfonate, arsenite, and hypochlorite. Cytotoxic hypersensitivity to hydrogen peroxide is conferred by loss of enzymes catalyzing the formation of Cm, m[superscript 5]C, and m[superscript 2][subscript 2]G, which demonstrates that tRNA modifications are critical features of the cellular stress response. The results of our study support a general model of dynamic control of tRNA modifications in cellular response pathways and add to the growing repertoire of mechanisms controlling translational responses in cells.National Institute of Environmental Health Sciences (ES002109)National Institute of Environmental Health Sciences (ES017010)National Institute of Environmental Health Sciences (ES015037)National Cancer Institute (U.S.) (CA026731)National Center for Research Resources (U.S.) (RR023783)Singapore-MIT Alliance for Research and Technolog

Molecular characterization, biofilm analysis and experimental biofouling study of Fusarium isolates from recent cases of fungal keratitis in New York State

BACKGROUND: To characterize Fusarium isolates from recent cases of fungal keratitis in contact lens wearers, and to investigate fungal association with MoistureLoc solution. METHODS: We studied six fungal isolates from recent cases of keratitis in New York State. The isolates were characterized by nucleotide sequencing and phylogenetic analyses of multiple genes, and then typed using minisatellite and microsatellite probes. Experimental fungal biofilm formation was tested by standard methods. MoistureLoc solutions were tested in biofouling studies for their efficacy in elimination of Fusarium contamination. RESULTS: Fusarium solani – corneal ulcers (2 isolates), lens case (1 isolate), and F. oxysporum – corneal ulcer (1 isolate), eye (1 isolate), were recovered from five patients. An opened bottle of MoistureLoc solution provided by a patient also yielded F. solani. Two distinct genotypes of F. solani as well as of F. oxysporum were present in the isolated strains. Remarkably, F. solani strains from the lens case and lens solution in one instance were similar, based on phylogenetic analyses and molecular typing. The solution isolate of F. solani formed biofilm on contact lenses in control conditions, but not when co-incubated with MoistureLoc solution. Both freshly opened and 3-month old MoistureLoc solutions effectively killed F. solani and F. oxysporum, when fungal contamination was simulated under recommended lens treatment regimen (4-hr). However, simulation of inappropriate use (15 – 60 min) led to the recovery of less than 1% of original inoculum of F. solani or F. oxysporum. CONCLUSION: Temporary survival of F. solani and F. oxysporum in MoistureLoc suggested that improper lens cleaning regimen could be a possible contributing factor in recent infections

Cryptococcus gattii in AIDS Patients, Southern California

A molecular analysis of pheromone genes showed a notable prevalence of Cryptococcus gattii isolates from AIDS patients in southern California

Bacterial and Mycotic Infections in immunocompromised hosts: Clinical and Microbiological Aspects

Causative organisms (Fungi) 2. Pathological Basis and Morphological Features 3. Gynecological Infections in Immunocompromised Hosts 4. Sexually Transmitted Diseases 5. Central Nervous System Infections in Immunocompromised Hosts 6. Skin and Soft Tissues Infections - 7. Sepsis in an Immunocompromised Host 8. Microsporidia Infections in Immunocompromised Hosts 9. Yeasts: Candida and Cryptococcus 10. Dimorph and Filamentous Fungi 11. Brucellosis: A Global Re-emerging Zoonosis: History, Epidemiology, Microbiology, Immunology and Genetic 12. Brucellosis: A Global Re-emerging Zoonosis: Clinical Aspects, Associations and Brucellosis in Specific Conditions 13. Brucellosis: A Global Re-emerging Zoonosis: Diagnosis, Treatment and PreventionThis book deals with bacterial and mycotic infections considering the particular aspects involved in the immunocompromised host. It is addressed to all people (microbiologists or pathologists) who for their activity have to face every day the clinical and microbiological features of these diseases. The immunocompromised hosts are a real problem for the peculiar characteristic that these subjects show and for the problems arisen in their treatment. We tried to examine most of infectious diseases such as the gynecological infections, the sexually transmitted diseases , the sepsis , the CNS infections and so on, stressing the diagnosis , the management and the prevention of the diseases and considering the newest aspects i.e. the formation of the bacterial biofilm in the devices or prostheses and the consequent resistance to the antimicrobial agents