Protective effect of various antioxidants on the toxicity of sulphur mustard administered to mice by inhalation or percutaneous routes

Protective effect of various antioxidants, trolox (water soluble analogue of vitamin E), quercetin (bioflavonoid) and glutathione reduced (GSH), was studied following sulphur mustard (SM) intoxication. SM, a blistering agent was administered to Swiss albino female mice through inhalation (1 LC50=42.3 mg/m3 for 1 h duration; 14 days observation for mortality) and percutaneous (1 LD50=154.7 mg/kg; 7 days observation for mortality) routes. The antioxidants were administered three times at the dose of trolox, 500 microg/kg; quercetin, 5 mg/kg and GSH, 400 mg/kg body weight by intraperitoneal injection, one immediately following SM exposure, then once each day for 2 days after SM treatment. The effect of antioxidants on survival, markers of oxidative damage and purine metabolites was investigated. Survival study animals were observed for 14 days. Oxidative markers (in blood, liver and lung) and purine metabolites (in blood and urine) were investigated 72 h after SM treatment. Survival time increased significantly following trolox and quercetin treatments through the inhalation route. Significant decrease in GSH and increase in the level of malondialdehyde (MDA) indicated oxidative damage to liver and lung tissues following SM inhalation and percutaneous exposure. Blood and urinary uric acid, end product of purine metabolism showed an increased following both routes of exposures. The antioxidants, trolox and quercetin protected the liver and lung tissues from oxidative damage caused by SM exposure through inhalation and percutaneous routes. This study showed that antioxidants could enhance survival time, protect liver and lung from oxidative damage and reduce accumulation of purine metabolites in blood following SM intoxication.     

Enhanced hydrolytic stability and water solubility of an aromatic nitrogen mustard by conjugation with molecular umbrellas

Chlorambucil, an aromatic nitrogen mustard, has been conjugated to putrescine- and spermidine-based scaffolds bearing one, two, and four persulfated cholic acid units. Those conjugates bearing two or four sterols show improved hydrolytic stability and water solubility relative to chlorambucil. A similar conjugate that contained only one sterol unit shows negligible improvement in hydrolytic stability but a significant increase in water solubility. Qualitatively, the hydrolytic stability within this series of conjugates parallels the shielding effects that have previously been found for related conjugates bearing a pendant, hydrophobic fluorescent probe. In vitro studies indicate that these conjugates possess modest to moderate activity against certain human lymphoblastic leukemia and human colon carcinoma cells.     

In vitro anti-inflammatory and antimicrobial potential of leaf extract from Artemisia nilagirica (Clarke) Pamp

In the present investigation, the bioactive compounds from the leaf extract of Artemisia nilagirica showed potent anti-inflammatory and antimicrobial activity. The leaf extract showed a maximum protection of human red blood cells (HRBC) with 74.63% at 20?µg/mL concentration, and the minimum hemolysis was 25.37% in a hypotonic solution with diclofenac as the control. The in vitro antimicrobial activity of plant extract against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Proteus vulgaris, Yersinia enterocolitica, Bacillus subtilis, and Candida albicans was evaluated at various concentrations (50, 100, 150, and 200?µg). The maximum zone of inhibition was observed against P. aeruginosa followed by B. subtilis, S. typhi, S. aureus and E. coli. The leaf extract also showed potent activity against C. albicans.     

Validation of Smartphone Based Retinal Photography for Diabetic Retinopathy Screening

Aim

To evaluate the sensitivity and specificity of “fundus on phone’ (FOP) camera, a smartphone based retinal imaging system, as a screening tool for diabetic retinopathy (DR) detection and DR severity in comparison with 7-standard field digital retinal photography.

Design

Single-site, prospective, comparative, instrument validation study.

Methods

301 patients (602 eyes) with type 2 diabetes underwent standard seven-field digital fundus photography with both Carl Zeiss fundus camera and indigenous FOP at a tertiary care diabetes centre in South India. Grading of DR was performed by two independent retina specialists using modified Early Treatment of Diabetic Retinopathy Study grading system. Sight threatening DR (STDR) was defined by the presence of proliferative DR(PDR) or diabetic macular edema. The sensitivity, specificity and image quality were assessed.

Results

The mean age of the participants was 53.5 ±9.6 years and mean duration of diabetes 12.5±7.3 years. The Zeiss camera showed that 43.9% had non-proliferative DR(NPDR) and 15.3% had PDR while the FOP camera showed that 40.2% had NPDR and 15.3% had PDR. The sensitivity and specificity for detecting any DR by FOP was 92.7% (95%CI 87.8–96.1) and 98.4% (95%CI 94.3–99.8) respectively and the kappa (ĸ) agreement was 0.90 (95%CI-0.85–0.95 p<0.001) while for STDR, the sensitivity was 87.9% (95%CI 83.2–92.9), specificity 94.9% (95%CI 89.7–98.2) and ĸ agreement was 0.80 (95%CI 0.71–0.89 p<0.001), compared to conventional photography.

Conclusion

Retinal photography using FOP camera is effective for screening and diagnosis of DR and STDR with high sensitivity and specificity and has substantial agreement with conventional retinal photography.     

Cardioprotective effect of alpha-mangostin, a xanthone derivative from mangosteen on tissue defense system against isoproterenol-induced myocardial infarction in rats

Increased oxidative stress and antioxidant deficit have been suggested to play a major role in isoproterenol-induced myocardial infarction. The present study was designed to evaluate the effect of alpha-mangostin on the antioxidant defense system and lipid peroxidation against isoproterenol-induced myocardial infarction in rats. Induction of rats with ISO (150 mg/kg body weight, ip) for 2 days resulted in a marked elevation in lipid peroxidation, serum marker enzymes (LDH, CPK, GOT, and GPT) and a significant decrease in the activities of endogenous antioxidants (SOD, CAT, GPx, GST, and GSH). Pre-treatment with alpha-mangostin (200 mg/kg of body weight per day) orally for 6 days prior to the ISO administration and 2 days along with ISO administration significantly attenuated these changes when compared to the individual treatment groups. These findings indicate the protective effect of alpha-mangostin on lipid peroxidation and antioxidant tissue defense system during ISO-induced myocardial infarction in rats.     

Analysis of Ppp1cc-null mice suggests a role for PP1gamma2 in sperm morphogenesis

Serine/threonine protein phosphatase 1 (PP1) consists of four ubiquitously expressed major isoforms, two of which, PP1gamma1 and PP1gamma2, are derived by alternative splicing of a single gene, Ppp1cc. PP1gamma2 is the most abundant isoform in the testis, and is a key regulator of sperm motility. Targeted disruption of the Ppp1cc gene causes male infertility in mice due to impaired spermiogenesis. This study was undertaken to determine the expression patterns of specific PP1 isoforms in testes of wild-type mice and to establish how the defects produced in Ppp1cc-null developing sperm are related to the loss of PP1gamma isoform expression. We observed that PP1gamma2 was prominently expressed in the cytoplasm of secondary spermatocytes and round spermatids as well as in elongating spermatids and testicular and epididymal spermatozoa, whereas its expression was weak or absent in spermatogonia, pachytene spermatocytes, and interstitial cells. In contrast, a high level of PP1gamma1 expression was observed in interstitial cells, whereas much weaker expression was observed in all stages of spermatogenesis. Another PP1 isoform, PP1alpha, was predominant in spermatogonia, pachytene spermatocytes, and interstitial cells. Examining the temporal expression of PP1 enzymes in testes revealed a striking postnatal increase in PP1gamma2 levels compared with other isoforms. Testicular sperm tails from Ppp1cc-null mice showed malformed mitochondrial sheaths and extra outer dense fibers in both the middle and principal pieces. These data suggest that in addition to its previously documented role in motility, PP1gamma2 is involved in sperm tail morphogenesis.     

Reduction of all-trans retinal to all-trans retinol in the outer segments of frog and mouse rod photoreceptors

The first step in the Visual Cycle, the series of reactions that regenerate the vertebrate visual pigment rhodopsin, is the reduction of all-trans retinal to all-trans retinol, a reaction that requires NADPH. We have used the fluorescence of all-trans retinol to study this reduction in living rod photoreceptors. After the bleaching of rhodopsin, fluorescence (excitation, 360 nm; emission, 457 or 540 nm) appears in frog and wild-type mouse rod outer segments reaching a maximum in 30-60 min at room temperature. With this excitation and emission, the mitochondrial-rich ellipsoid region of the cells shows strong fluorescence as well. Fluorescence measurements at different emission wavelengths establish that the outer segment and ellipsoid signals originate from all-trans retinol and reduced pyridine nucleotides, respectively. Using outer segment fluorescence as a measure of all-trans retinol formation, we find that in frog rod photoreceptors the NADPH necessary for the reduction of all-trans retinal can be supplied by both cytoplasmic and mitochondrial metabolic pathways. Inhibition of the reduction reaction, either by retinoic acid or through suppression of metabolic activity, reduced the formation of retinol. Finally, there are no significant fluorescence changes after bleaching in the rod outer segments of Rpe65(-/-) mice, which lack 11-cis retinal.     

Protein 14-3-3zeta binds to protein phosphatase PP1gamma2 in bovine epididymal spermatozoa

The protein phosphatase PP1gamma2 is critical in the regulation of sperm motility and fertility. Its activity is regulated by its binding proteins and by phosphorylation. We have recently shown that PP1gamma2 is phosphorylated and that the amount of phosphorylated PP1gamma2 increases during sperm epididymal maturation (Huang et al., Biol Reprod 2004; 70:439-447). Microsequencing revealed that protein 14-3-3 coeluted with phosphorylated PP1gamma2 during column chromatography of bovine sperm extracts. Western blot analyses confirmed the presence of protein 14-3-3 not only in bovine spermatozoa but also in spermatozoa of diverse species-bull, hamster, horseshoe crab, monkey, rat, turkey, and Xenopus. The binding between PP1gamma2 and protein 14-3-3 was confirmed by coimmunoprecipitation experiments and in pull-down assays with recombinant GST-14-3-3. Western blot analysis and protein 14-3-3 immunoprecipitates with antibodies against the consensus binding domain of protein 14-3-3 reveal that, in addition to PP1gamma2, at least two other protein 14-3-3 binding partners are present in spermatozoa. Fluorescence immunocytochemistry results indicate that phosphorylated PP1gamma2 and protein 14-3-3 both localize to the postacrosomal region of the head and principal piece of bovine spermatozoa. Together, these results provide conclusive evidence that protein 14-3-3 is present in mature spermatozoa and that PP1gamma2 is one of its binding partners.     

Mechanical and thermal properties of particle boards made from farm residues

Five farm residues were used for the manufacture of low-density particle boards in a hot platter press using urea formaldehyde as the binding material. Mechanical and thermal properties of the boards were evaluated. The maize-cob board was superior to other boards in mechanical and screw/nail holding strength, suggesting its use for interior applications, while paddy-straw board and coconut-pith board were found to be suitable for insulation purposes.     

Isolation and molecular characterization of AKAP110, a novel, sperm-specific protein kinase A-anchoring protein.

Agents that increase intracellular cAMP are potent stimulators of sperm motility. Anchoring inhibitor peptides, designed to disrupt the interaction of the cAMP-dependent protein kinase A (PKA) with A kinase-anchoring proteins (AKAPs), are potent inhibitors of sperm motility. These data suggest that PKA anchoring is a key biochemical mechanism controlling motility. We now report the isolation, identification, cloning, and characterization of AKAP110, the predominant AKAP detected in sperm lysates. AKAP110 cDNA was isolated and sequenced from mouse, bovine, and human testis libraries. Using truncated mutants, the RII-binding domain was identified. Alignment of the RII-binding domain on AKAP110 to those from other AKAPs reveals that AKAPs contain eight functionally conserved positions within an amphipathic helix structure that are responsible for RII interaction. Northern analysis of eight different tissues detected AKAP110 only in the testis, and in situ hybridization analysis detected AKAP110 only in round spermatids, suggesting that AKAP110 is a protein found only in male germ cells. Sperm cells contain both RI, located primarily in the acrosomal region of the head, and RII, located exclusively in the tail, regulatory subunits of PKA. Immunocytochemical analysis detected AKAP110 in the acrosomal region of the sperm head and along the entire length of the principal piece. These data suggest that AKAP110 shares compartments with both RI and RII isoforms of PKA and may function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction.