Minimal chemical modification of reductive end of dextran to produce an amphiphilic polysaccharide able to incorporate onto lipid nanocapsules

In order to graft an amphiphilic polysaccharide to lipid nanocapsules, we present here a new method of dextran lipidation. The lipidation strategy is based on the formation of an oxime linkage between the amphiphilic hydroxylamine C16E20ONH2 and the reductive end of a 40 kDa dextran. This chemoselective reaction allows us to control the lipidation site and the number of lipid introduced on the dextran molecule. This new amphiphilic dextran was used to coat the surface of lipid nanocapsules. The coating efficiency was followed by dynamic light scattering and the presence of the polysaccharide was confirmed by (1)H NMR and observed by electronic microscopy.     

Bioconversion of Hydrocortisone by Cyanobacterium Fischerella ambigua PTCC 1635

Summary The bioconversion of hydrocortisone by a locally isolated strain of cyanobacterium Fischerella ambigua PTCC 1635 was investigated. Fischerella ambigua had not been previously examined for this potential. The fermentation led to production of 11β,17α, 20β, 21-tetrahydroxypregn-4-en-3-one and 11β-hydroxyandrost-4-en-3,17-dione. The metabolites were isolated and purified by chromatographic methods and identified using instrumental analyses.     

Calreticulin-melatonin. An unexpected relationship.

Increasing evidence suggests that melatonin can exert some effect at nuclear level. Previous experiments using binding techniques clearly showed the existence of specific melatonin binding sites in cell nucleus of rat liver. To further identify these sites, nuclear extracts from rat hepatocytes were treated with different percentages of ammonium sulfate and purified by affinity chromatography. Subsequent ligand blot analysis shows the presence of two polypeptides of approximately 60 and approximately 74 kDa that bind specifically to melatonin. N-Terminal sequence analysis showed that the 60 kDa protein shares a high homology with rat calreticulin, whereas the 74 kDa protein shows no homology with any known protein. The binding of melatonin to calreticulin was further characterized incubating 2-[125I]melatonin with recombinant calreticulin. Binding kinetics show a Kd = 1.08 +/- 0.2 nm and Bmax = 290 +/- 34 fmol.mg protein-1, compatible with other binding sites of melatonin in the cell. The presence of calreticulin was further identified by Western blot analysis, and the lack of endoplasmic reticulum contamination in our material was assessed by Western blot and immunostaining with anti-calnexin Ig. The results suggest that calreticulin may represent a new class of high-affinity melatonin binding sites involved in some functions of the indoleamine including genomic regulation.     

Role of the chest wall in detection of added elastic loads

Changes in respiratory mechanical loads are readily detected by humans. Although it is widely believed that respiratory muscle afferents serve as the primary source of information for load detection, there is, in fact, no convincing evidence to support this belief. We developed a shell that encloses the body, excluding the head and neck. A special loading apparatus altered pressure in proportion to respired volume (elastic load) in one of three ways: 1) at the mouth only (T), producing a conventional load in which respiratory muscles are loaded and airway and intrathoracic pressures are made negative in proportion to volume, 2) both at the mouth and in the shell (AW), where the same pattern of airway and intrathoracic pressure occurs but the muscles are not loaded because Prs (i.e., mouth pressure minus pressure in the shell is unchanged, and 3) positive pressure in proportion to volume at the shell only, loading the chest wall but causing no change in airway or thoracic pressures (CW). The threshold for detection (delta E50) with the three types of application was determined in seven normal subjects: 2.16 +/- 0.22, 2.65 +/- 0.54, and 6.21 +/- 0.85 (SE) cmH2O/l for T, AW, and CW, respectively. Therefore the active chest wall, including muscles, is a much less potent source of information than structures affected by the negative airway and intrathoracic pressure. The latter account for the very low threshold for load detection.     

Functional aspects of the superoxide dismutative action of Cu-penicillamine.

The superoxide dismutative action of Cu-penicillamine was examined by pulse radiolysis. The second order rate constand of the reaction wpith superoxide was 0.4 +/- o.2.10(9) M-1.s-1, comparable to the action of Fe and Mn-superoxide dismutases. No marked pH-dependence was seen. Neither ethylene diamine tetraacetic acid nor cyanide affected the catalytic action of Cu-penicillamine. The cyanide resistant reactivity as well as further X-ray photoelectron spectrometric measurements supported the suggestion of a Cu(I) stabilized sulphur radical being the active species involved in the catalysis of superoxide dismutation.     

The emu oil emulsified in egg lecithin and butylated hydroxytoluene enhanced the proliferation,stemness gene expression,and in vitro wound healing of adipose-derived stem cells

In recent decades, mesenchymal stem cells originated from adipose tissue (adipose-derived stem cells, ASCs) have gained increased attention for production of cell-based therapeutics. Emu oil as a natural compound showed antioxidant effects in previous studies. The goal of this study was to investigate the effect of crude emu oil on the proliferation, cell cycle progression, stemness genes expression, and in vitro wound healing potential of ASCs. An emulsion of emu oil was prepared using egg lecithin and butylated hydroxytoluene to improve bioavailability and solubility of emu oil in the expansion medium. The ASCs were treated using a series of emu oil concentrations in emulsion form, diluted in expansion medium (0.03–3 mg/ml). The emu oil-free emulsion was used as control treatment. The results revealed that emu oil (1.25 mg/ml) in emulsion form significantly (p?<?0.001) increased ASCs proliferation and colony formation. Additionally, emu oil caused upregulation of stemness marker genes (Sox2, Oct4, Nanog, and Nestin) (p?<?0.05). The cell cycle analysis after emu oil treatments showed an increase in the population of ASCs in S-phase of the cell cycle. Besides, an accelerated in vitro scratch wound healing was observed in emu oil-treated ASCs. Emu oil enhanced proliferation, colony formation, stemness genes expression, and in vitro wound healing of ASCs. These findings suggest that emu oil treatment could maintain the stemness of ex vivo cultivated ASCs and enhance their regenerative potential.