Humans ; Hydrocarbons, Chlorinated ; poisoning ; Propane ; analogs & derivatives ; poisoning

Acute Disease ; Humans ; Male ; Middle Aged ; Occupational Diseases ; therapy ; Plasma Exchange ; Propane ; analogs & derivatives ; poisoning

This paper reviews the research and commercialization progresses of biobased polymeric materials including polyhydroxyalkanoates (PHA), polylactides (PLA), poly (butylene succinate) (PBS) and its monomer succinate, and CO2 copolymer poly (propylene carbonate), especially these efforts made in China.
Bioengineering ; Butylene Glycols ; China ; Polyesters ; Polyhydroxyalkanoates ; Polymers ; Propane ; analogs & derivatives ; Succinic Acid

Air ; analysis ; Chromatography, Gas ; Propane ; analogs & derivatives ; analysis ; Reproducibility of Results ; Workplace

1,2,3-trichloropropane (TCP) is an industrially synthesized aliphatic chlorinated hydrocarbon and an intermediate product in the industrial production of epichlorohydrin, which can be used as a precursor for the manufacture of soil fumigant and organic solvents. Due to its biological toxicity, environmental persistence and strong environmental migration ability, 1,2,3-TCP is listed as an emerging organochlorine pollutant in the environment and regulated by many international organizations. Currently, the degradation of 1,2,3-TCP and the remediation of 1,2,3-TCP-contaminated sites receive great attention, but the degradation mechanism of 1,2,3-TCP has not been summarized in depth. This article discussed the origin of 1,2,3-TCP, its environmental impact and ecological effects, and the physical and chemical degradation techniques. This was followed by summarizing the degradation mechanisms of 1,2,3-TCP (e.g., aerobic co-biodegradation, anaerobic biodegradation). Specially, the pathways and mechanisms of microbial biodegradation and transformation of 1,2,3-TCP in anoxic environments (e.g., groundwater) were thoroughly reviewed. The feasibility of using 1,2,3-TCP as an electron acceptor by organohalide-respiring bacteria under anoxic conditions was predicted based on thermodynamic analysis. Last but not least, in situ bioremediation of 1,2,3-TCP contaminated sites was summarized, and prospects for future research were discussed.
Biodegradation, Environmental ; Environmental Restoration and Remediation ; Hydrocarbons, Chlorinated ; Propane/analogs & derivatives* ; Technology

OBJECTIVETo study the chemical constituents of Dregea sinensis var. corrugata.

METHODThe chemical constituents were isolated by various column chromatographic techniques. Structures were elucidated on the basis of NMR data.

RESULTEight compounds were isolated and their structures were elucidated as syringaresinol (1), syringaresinol-O-3-D-glycopyranoside (2), 3, 4'-dimethoxyl-4, 9, 9'-trihydroxyl-benzofuranneolignan-7'-ene (3), 3, 4'-di- methoxyl-4, 9-dihydroxyl-9'-hydroethyl-benzofuranneolignan-7'-ene (4), conifer-aldehyde (5), sinapic aldehyde (6), 3-hydoxy-1-(4-hydroxy-3-methoxy-phenyl)-propan-1-one (7), 3-hydroxy-1-(3-methoxy-4-hydroxyphenyl)-propan-1-one (8).

CONCLUSIONCompounds 1-8 were isolated from Dregea sinensis var. corrugata for the first time.

Apocynaceae ; chemistry ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Plants, Medicinal ; chemistry ; Propane ; analogs & derivatives ; chemistry ; isolation & purification

There is growing interest in biodiesel and this results in the accumulation of glycerol. The exploitation and application of glycerol has attracted more and more attention. In the current study, glycerol was biotransformed to produce 3-hydroxypropionaldehyde by genetic engineering bacteria. It is known that 3-hydroxypopionaldehyde has been widely used as an important intermediate for chemicals, effective antimicrobial agent, and fix agent for tissues. A pair of primers was designed on the basis of the sequence of both NH2-terminus and the amino acid sequence of glycerol dehydratase reported by NCBI, and a fragment about 1.6 kb was obtained by PCR amplification using the total genome DNA of Lactobacillus reuteri as template, then the fragment was cloned to the pMD18-T vector and sequenced. Two specific primers were designed according to the obtained sequence, and a fragment with length of 1674 bp was amplified using PCR with these two specific primers. Consequently, the resulting products were digested with EcoR I and Hind III and ligated using T4 DNA ligase to the pET28b vector digested with the same enzymes. The recombinant plasmid, named pET28b-dhaB, was transformed into E. coli BL21. The positive clones were induced with IPTG and the expression products were further analyzed by SDS-PAGE, indicating that protein with a molecule weight of around 65 kD was obtained. Furthermore, the glycerol dehydratase activity was evaluated and compared with the wild type strain as well.
Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Glyceraldehyde ; analogs & derivatives ; chemistry ; metabolism ; Hydro-Lyases ; biosynthesis ; genetics ; Lactobacillus reuteri ; enzymology ; genetics ; Propane ; chemistry ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

BACKGROUNDEndothelial cell senescence is accelerated under high glucose condition, which may contribute to the vascular complications in the diabetics. It has been proved that aspirin has multiple cytoprotective effects. This study aimed to investigate the effect of aspirin on high glucose-induced endothelial cell senescence and its possible mechanism.

METHODSHuman umbilical venous endothelial cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with different treatments including the normal glucose (5.5 mmol/L), high glucose (33 mmol/L) and aspirin (0.01 - 1.00 mmol/L) with high glucose. And 300 micromol/L L-NAME was added to the culture medium when needed. After 48 hours, SA-beta-gal staining was used to evaluate the senescence. Total nitric oxide (NO) production and NO synthase (NOS) activity were measured using Griess reaction and molecular probes of 3-amino-4-aminomethyl-2', 7'-difluorescein, diacetate. The level of intracellular reactive oxygen species was monitored by flow cytometry using 2', 7'-dichlorofluorescein diacetate. Endothelial NOS (eNOS), caveolin-1 protein expressions and caveolin-1/eNOS interaction were analyzed by immunoblotting and immunoprecipitation respectively. Asymmetric dimethylarginine (ADMA) concentration was determined by high-performance liquid chromatography.

RESULTSExposure to 33 mmol/L glucose for 48 hours significantly increased the number of SA-beta-gal positive cells. Co-incubation with aspirin markedly inhibited SA-beta-gal activity dose-dependently. Aspirin increased NOS activity with eNOS protein expression unchanged and increased NO levels and alleviated oxidative stress. Consistent with these findings, caveolin-1 expression, caveolin-1/eNOS interaction and ADMA accumulation were also decreased. All the inhibitory effects of aspirin on senescence were completely obliterated by L-NAME, the NOS inhibitor.

CONCLUSIONThe anti-senescent effects of aspirin are fulfilled by increasing NO production via the up-regulation of NOS activity and preventing caveolin-1 expression, caveolin-1/eNOS interaction and ADMA accumulation.

Anthracenes ; metabolism ; Anti-Inflammatory Agents, Non-Steroidal ; pharmacology ; Arginine ; analogs & derivatives ; metabolism ; Aspirin ; pharmacology ; Caveolin 1 ; metabolism ; Cells, Cultured ; Cellular Senescence ; drug effects ; Chromatography, High Pressure Liquid ; Endothelial Cells ; cytology ; drug effects ; metabolism ; Flow Cytometry ; Glucose ; pharmacology ; Humans ; Immunoblotting ; Immunoprecipitation ; NG-Nitroarginine Methyl Ester ; pharmacology ; Nitric Oxide Synthase Type III ; metabolism ; Propane ; analogs & derivatives ; metabolism ; Reactive Oxygen Species ; metabolism

BACKGROUNDPeripheral nerve regeneration across large gaps is clinically challenging. Scaffold design plays a pivotal role in nerve tissue engineering. Recently, nanofibrous scaffolds have proven a suitable environment for cell attachment and proliferation due to similarities of their physical properties to natural extracellular matrix. Poly(propylene carbonate) (PPC) nanofibrous scaffolds have been investigated for vascular tissue engineering. However, no reports exist of PPC nanofibrous scaffolds for nerve tissue engineering. This study aimed to evaluate the potential role of aligned and random PPC nanofibrous scaffolds as substrates for peripheral nerve tissue and cells in nerve tissue engineering.

METHODSAligned and random PPC nanofibrous scaffolds were fabricated by electrospinning and their chemical characterization were carried out using scanning electron microscopy (SEM). Dorsal root ganglia (DRG) from Sprague-Dawley rats were cultured on the nanofibrous substrates for 7 days. Neurite outgrowth and Schwann-cell migration from DRG were observed and quantified using immunocytochemistry and SEM. Schwann cells derived from rat sciatic nerves were cultured in electrospun PPC scaffold-extract fluid for 24, 48, 72 hours and 7 days. The viability of Schwann cells was evaluated by 3-[4,5-dimethyl(thiazol-2-yl)-2,5-diphenyl] tetrazolium bromide (MTT) assay.

RESULTSThe diameter of aligned and random fibers ranged between 800 nm and 1200 nm, and the thickness of the films was approximately 10 - 20 µm. Quantification of aligned fiber films revealed approximately 90% alignment of all fibers along the longitudinal axis. However, with random fiber films, the alignment of fibers was random through all angle bins. Rat DRG explants were grown on PPC nanofiber films for up to 1 week. On the aligned fiber films, the majority of neurite outgrowth and Schwann cell migration from the DRG extended unidirectionally, parallel to the aligned fibers. However, on the random fiber films, neurite outgrowth and Schwann cell migration were randomly distributed. A comparison of cumulative neurite lengths from cultured DRGs indicated that neurites grew faster on aligned PPC films ((2537.6 ± 987.3) µm) than randomly-distributed fibers ((493.5 ± 50.6) µm). The average distance of Schwann cell migration on aligned PPC nanofibrous films ((2803.5 ± 943.6) µm) were significantly greater than those on random fibers ((625.3 ± 47.8) µm). The viability of Schwann cells cultured in aligned PPC scaffold extract fluid was not significantly different from that in the plain DMEM/F12 medium at all time points after seeding.

CONCLUSIONSThe aligned PPC nanofibrous film, but not the randomly-oriented fibers, significantly enhanced peripheral nerve regeneration in vitro, indicating the substantial role of topographical cues in stimulating endogenous nerve repair mechanisms. Aligned PPC nanofibrous scaffolds may be a promising biomaterial for nerve regeneration.

Animals ; Biocompatible Materials ; chemistry ; Cells, Cultured ; Ganglia, Spinal ; cytology ; metabolism ; ultrastructure ; Immunohistochemistry ; Microscopy, Electron, Scanning ; Nanofibers ; chemistry ; Nerve Regeneration ; physiology ; Nerve Tissue ; cytology ; metabolism ; ultrastructure ; Polymers ; chemistry ; Propane ; analogs & derivatives ; chemistry ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; metabolism ; ultrastructure ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry