D-2-Amino-4-bromo-4-pentenoic acid

Cave ecosystems remain largely unstudied and risk being severely degraded as a result of anthropogenic activities. The Wonderfontein Cave, situated in the extensive gold mining region of the Witwatersrand Basin, is one such system that hosts a population of Clarias gariepinus, which is exposed to the influx of polluted mine water from the Wonderfontein Spruit River. The aim of this study was to investigate the bioaccumulation of metals, as well as relevant biomarkers, in C. gariepinus specimens sampled from the Wonderfontein Cave during high (April 2013) and low (September 2013) flow surveys. Results were also compared to a surface population associated with the Wonderfontein Spruit River. There were temporal differences in metal bioaccumulation patterns and this was attributed to the lack of dilution during the low flow period. Metals associated with acid mine drainage, i.e. Co, Mn and Zn were significantly higher in the Wonderfontein Cave population and were reflected in an increase in oxidative stress biomarkers (catalase, protein carbonyls and superoxide dismutase) and the induction of metallothionein, a biomarker of metal exposure.

Composite hydrogels were prepared by in situ incorporation of a natural macromolecule guar gum and nano sized bentonite clay in an acrylic network during copolymerization of acrylic acid, N,N-methylenebisacrylamide (MBA) and hydroxyethyl methacrlylate (HEMA) in water. The structure of the hydrogels was characterized and the hydrogels showing the best results in mechanical and swelling properties were used for the removal of low (5-50mg/L) and high (100-800mg/L) concentration of Cr (VI) ions from water. The composite hydrogel showed a high removal of 97.8% (4.89mg/g gel) and 91.4% (182.4mg/g gel) at an initial feed metal ion concentration of 5mg/L and 200mg/L, respectively.

The potentiality of collagen sponge as a skin substitute, derived from mrigal (Cirrhinus cirrhosus) scale has been explored in this study. Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the scale of mrigal were isolated and characterized. The yields of ASC and PSC were ∼3% and ∼7% based on the dry weight of scale while the hydroxyproline content was ∼90mg/g. Scanning electron microscope revealed progressive demineralization with EDTA on time dependent scale. Further, the D-Spacing in fibril bundles were calculated to be ∼67nm. Fourier transform infrared and circular dichroism spectra confirmed extracted protein to be collagen I, where both ASC and PSC comprised of two different α-chains (α1 and α2). The denaturation temperature (Td) of the collagen solution was 35°C closer to Td of mammalian collagen. In vitro cell culture studies on the extracted collagen sponge showed efficient cell growth and proliferation. Additionally, co-culture with fibroblast and keratinocyte cells showed development of stratified epidermal layer in vitro.

This study explored that lipoic acid treatment for 24 h significantly upregulated and promoted heat shock-induced catalase expression and downregulated GPx1 messenger RNA (mRNA) expression, indicating that lipoic acid exhibits antioxidant activity in the decomposition of hydrogen peroxide by upregulating catalase expression. Moreover, lipoic acid treatment for 3 h increased and promoted heat shock-induced interleukin (IL)-6 mRNA and protein levels and that for 24 h downregulated IL-6 mRNA expression, suggesting a dual effect of lipoic acid on IL-6 regulation. Lipoic acid alone failed to increase or reduce tumor necrosis factor (TNF)-α mRNA and protein levels, whereas heat shock alone downregulated TNF-α mRNA and protein expression. These data suggest that lipoic acid does not have a proinflammatory role and that heat shock acts as an anti-inflammatory agent by downregulating TNF-α expression in C2C12 myotubes. Moreover, lipoic acid or heat shock alone upregulated the IL-6 receptor (IL-6R-α) and glycoprotein 130 (gp130) mRNA expression followed by IL-6 expression; these data indicate that the regulation of lipoic acid or heat shock is mediated by IL-6R signaling, thus suggesting that C2C12 myotubes possesses a mechanism for regulating IL-6R and gp130 expression following lipoic acid treatment or heat shock.