ISOLATION, PURIFICATION and CHARACTERIZATION OF ACTIVE COMPOUND FROM ANDROGRAPHIS PANICULATA.L AND TESTING ITS ANTI-VENOM AND CYTOTOXIC ACTIVITY BY IN-VITRO and IN-VIVO STUDIES

We purified and characterized a 39-kDaBacillus subtilis168 nuclease that has been suggested in this laboratory to be involved in chromosomal DNA degradation induced by lethal heat and cold shock treatmentsin vivo. The nuclease activity was inhibitedin vitroby aurintricalboxylic acid but not by Zn2+. By the mutant analysis, we identified the 39-kDa nuclease as a product ofyokFgene. TheyokFgene contained a putative lipoprotein signal peptide motif. Afterin vivoexposure to lethal heat and cold stresses, the chromosomal DNA fragmentation was reduced in theyokFmutant, which demonstrated about a 2–10-fold higher survival rate than the wild type. TheyokFmutant was found to be more sensitive to mitomycin C than the wild type. The transformation efficiency of theyokFmutant was about 10 times higher than that of the wild type. It is suggested that whenB. subtiliscells are exposed to a stressful thermal shock resulting in membrane perturbation, YokF nuclease consequently dislocates into the cytoplasm and then attacks DNA.

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ENHANCED FLUORESCENCE IMAGING WITH DMSO-MEDIATED OPTICAL CLEARING

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545810001015 ◽

2010 ◽

Vol 03 (03) ◽

pp. 153-158 ◽

Cited By ~ 10

Author(s):

SANJEEV KARMA ◽

JAMES HOMAN ◽

CHARLES STOIANOVICI ◽

BERNARD CHOI

Keyword(s):

Fluorescence Emission ◽

Model Systems ◽

In Vivo Studies ◽

In Vivo Model ◽

Fluorescence Signal ◽

Optical Clearing ◽

Treated Site

Recent studies have demonstrated that topical application of glycerol on intact skin does not affect its optical scattering properties. Investigators from our research group recently revisited the use of dimethyl sulfoxide (DMSO) as an agent with optical clearing potential. We address the use of optical clearing to enhance quantitation of subsurface fluorescence emission. We employed both in vitro and in vivo model systems to study the effect of topical DMSO application on fluorescence emission. Our in vitro experiments performed on a tissue-simulating phantom suggest that DMSO-mediated optical clearing enables enhanced characterization of subsurface fluorophores. With topical DMSO application, a marked increase in fluorescence emission was observed. After 30 min, the fluorescence signal at the DMSO-treated site was 9× greater than the contralateral saline-treated site. This ratio increased to 13× at 105 min after agent application. In summary, DMSO is an effective optical clearing agent for improved fluorescence emission quantitation and warrants further study in preclinical in vivo studies. Based on outcomes from previous clinical studies on the toxicity profile of DMSO, we postulate that clinical application of DMSO as an optical clearing agent, can be performed safely, although further study is warranted.

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Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE): Biochemical Features and Therapeutic Approaches

Bioscience Reports ◽

10.1007/s10540-007-9043-2 ◽

2007 ◽

Vol 27 (1-3) ◽

pp. 151-163 ◽

Cited By ~ 43

Author(s):

M. C. Lara ◽

M. L. Valentino ◽

J. Torres-Torronteras ◽

M. Hirano ◽

R. Martí

Keyword(s):

Molecular Genetic ◽

In Vivo Studies ◽

Gene Encoding ◽

Mitochondrial Neurogastrointestinal Encephalomyopathy ◽

Mtdna Replication ◽

Biochemical Features

Over the last 15 years, important research has expanded our knowledge of the clinical, molecular genetic, and biochemical features of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). The characterization of mitochondrial involvement in this disorder and the seminal determination of its genetic cause, have opened new possibilities for more detailed and deeper studies on the pathomechanisms in this progressive and fatal disease. It has been established that MNGIE is caused by mutations in the gene encoding thymidine phosphorylase (TP), which lead to absolute or nearly complete loss of its catalytic activity, producing systemic accumulations of its substrates, thymidine (dThd) and deoxyuridine (dUrd). Findings obtained from in vitro and in vivo studies indicate that the biochemical imbalances specifically impair mitochondrial DNA (mtDNA) replication, repair, or both leading to mitochondrial dysfunction. We have proposed that therapy for MNGIE should be aimed at reducing the concentrations of these toxic nucleosides to normal or nearly normal levels. The first treatment, allogeneic stem-cell transplantation (alloSCT) reported in 2006, produced a nearly full biochemical correction of the dThd and dUrd imbalances in blood. Clinical follow-up of this and other patients receiving alloSCT is necessary to determine whether this and other therapies based on a permanent restoration of TP will be effective treatment for MNGIE.

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