Application of Autogenous Dermis Combined With Local Flap Transplantation in Repair of Titanium Mesh Exposure After Cranioplasty.

OBJECTIVES: To investigate the clinical outcome of autogenous dermis combined with local flap transplantation in the treatment of titanium mesh exposure after cranioplasty. METHODS: We studied a total of 8 patients with titanium mesh exposure after cranioplasty. After debridement of the head wound, the autogenous dermal tissue from the lateral thigh was transplanted to the surface of titanium mesh, and the local skin flap was then applied after suturing and fixation to repair the wound on the surface of the dermis. To repair the lateral thigh dermal tissue area, a local skin flap was obtained, and a blade thick skin graft was used. RESULTS: Both dermal tissue and local skin flap survived. In the meanwhile, the donor skin area of the lateral thigh healed well, with only slight scar hyperplasia, and the titanium mesh was preserved. There was no recurrence after 6 months of follow-up. CONCLUSIONS: The application of autogenous dermis combined with local skin flap to repair titanium mesh exposure can effectively avoid skin flap necrosis, potential re-exposure of titanium mesh, sub-flap effusion, infection, and other problems. This method has an ideal effect, has easy access to materials, and reduces patients' economic burden. It is worth popularizing.

Comparison of modification of a bacterial uricase with N-hydroxysuccinimide esters of succinate and carbonate of monomethoxyl poly(ethylene glycol).

Uricase after modification with monomethoxy poly(ethylene glycol) (mPEG) is currently the sole agent to treat refractory gout. For formulating Bacillus fastidious uricase, succinimidyl carbonate of mPEG-5000 (SC-mPEG5k) and succinimidyl succinate of mPEG-5000 (SS-mPEG5k) were compared. SC-mPEG5k possessed higher purity, comparable reaction rate constant with glycine but lower hydrolysis rate, and stronger effectiveness to modify amino groups. The uricase possessed two types of amino groups bearing a 25-fold difference in reactivity with SC-mPEG5k or SS-mPEG5k at pH 9.2. Oxonate and xanthine concentration-dependently protected the bacterial uricase from inactivation during PEGylation. With SC-mPEG5k at a molar ratio of 200 to uricase subunits and oxonate of 50 µM, the PEGylated uricase (1) retained about 73% of the original activity, (2) displayed about 10% reactivity to rabbit anti-sera recognizing the native uricase, (3) elicited IgG in rats accounting for about 5% of that by the native uricase, (4) exhibited circulation half-life time of about 25 H in cock plasma in vivo, and (5) concurrently maintained uric acid at lowered levels for over 20 H. Hence, PEGylation with SC-mPEG under the protection of a competitive inhibitor was a practical approach to formulation of the bacterial uricase; protection of enzymes by competitive inhibitors during PEGylation may have universal significance.

Comparative transcriptome analysis provides insight into nitric oxide suppressing lignin accumulation of postharvest okra (Abelmoschus esculentus L.) during cold storage.

In plants, NO has been proved the function of improving abiotic stress resistance. However, the role of NO in the lignin metabolism of okra under cold stress has not been clarified. Here, histochemical staining and lignin content analysis showed that cold stress promoted the lignin accumulation of cold stored okra pods, and NO inhibited the lignin accumulation and delayed lignification process. To better understand the roles of NO in okra cold stress resistance mechanism, the full-length transcriptome data of 'Hokkaido' was analyzed. The SNP-treated okra transcriptome and cPTIO-treated okra transcriptome were obtained. A total of 41957 unigenes were screened out from three groups at 10 d, among which, 33, 78 and 18 DEGs were found in ddH2O-treat, SNP-treat and cPTIO-treat group, respectively. Transcriptomic data suggested that the genes involved in lignin biosynthesis showed downregulation under SNP treatment. Transcriptomic data and enzyme activity showed that exogenous NO significantly promoted the biosynthesis of endogenous NO by enhancing NOS activity. Transcriptomic data and plant hormone data showed that NO played an important role in the process of inhibiting the ethylene and ABA synthesis mechanism of okra and thereby reducing the endogenous ethylene and ABA content under chilling stress. Relevant physiological data showed that NO helped to the protection of ROS scavenging system and removed the MDA and H2O2 induced by cold stress. These results provided a reference for studying the molecular mechanism of nitric oxide delaying the lignification of okra, and also provided a theoretical basis for postharvest storage of vegetables.

Effects of modification of amino groups with poly(ethylene glycol) on a recombinant uricase from Bacillus fastidiosus.

After modification with monomethoxyl-poly(ethylene glycol)-5000, a recombinant intracellular uricase from Bacillus fastidiosus ATCC 29604 showed residual activity of about 65%, a thermo-inactivation half-life >85 h, a circulating half-life about 20 h in rats in vivo, consistent effects of common cations, and consistent optima for reaction temperature and pH. Thus, this uricase can be formulated via modification with monomethoxyl-poly(ethylene glycol).

Andrographolide sulfonate reduces mortality in Enterovirus 71 infected mice by modulating immunity.

Outbreaks of hand, foot and mouth disease (HFMD), which is caused by Enterovirus 71 (EV71), have erupted in recent years. Andrographolide sulfonate (Trade name: Xiyanping injection) has been recommended to treat severe HFMD in China because of its conventional antithermic and antitoxic activities, but its actual mechanism has not been revealed clearly until now. To explore its therapeutic efficacy and mechanism, a Xiyanping injection treatment mouse model was established. Based on the therapeutic model, routine clinical parameters and histopathologic changes were investigated, in the same time, viral loads, immune cells, inflammatory molecules and cell signaling pathways were determined. Xiyanping injection treatment protected mice from lethal EV71 challenge in a therapeutic regimen-dependent manner, which may mostly depend on its direct immunomodulatory activities on neutrophil and T lymphocyte. Reduced inflammatory molecular production of neutrophil and elevated T lymphocyte activity may result from its marked inhibition of some signaling pathways. Taken together, Xiyanping injection was an effective treatment for severe HFMD by improving hosts' immunity.

[Preparation and studies of the adsorbent double cross-linked agar beads entrapped attapulgite clay].

A method for preparing the double cross-linked agar beads entrapped attapulgite clay for hemopurification is reported. Attapulgite clay was coated with agar and cross-linked by epichlorohydrin. After the process of "drying-out", the cross-linked agar beads entrapped attapulgite clay (CAA) was cross-linked again by 10% toluene 2,4,-diisocyanate in acetone at 35 degrees C for 3 h and 30 min. The products withstood autoclaving at 121 degrees C for 30 min. The performance tests showed that the adsorption of the double cross-linked agar beads entrapped attapulgite clay (DCAA) on methylene blue was about 4 times the adsorption of CAA on methylene blue. The intensity of DCAA was raised 6 times, and the appearance of DCAA was denser. Investigation on the blood being in contact with DCAA showed: at 1 h of contact, the loss of leucocyte was <1%, of erythrocyte <5%, and of blood platelets <8%; at 2h of contact, the loss of leucocyte was <2%, of erythrocyte <10%, and of blood platelets <20%.

Intradermal injection of a fractional dose of an inactivated HFMD vaccine elicits similar protective immunity to intramuscular inoculation of a full dose of an Al(OH)3-adjuvanted vaccine.

Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) are the two major causative agents of hand, foot and mouth disease (HFMD), which erupts in the Asia-Pacific regions. A bivalent vaccine against both EV71 and CVA16 is highly desirable. In the present study, on the bases that an experimental bivalent vaccine comprising of inactivated EV71 and CVA16 induces a balanced protective immunity against both EV71 and CVA16, we compare the immunogenicity and reactogenicity of one fourth of a full dose of an intradermal vaccine administered by needle-free liquid jet injector with a full dose of an intramuscular vaccine administered by needle-syringe in monkeys. The results suggest that intradermal injection of a fractional dose of an inactivated HFMD vaccine elicits similar immunogenicity and reactogenicity to intramuscular inoculation of a full dose of an Al(OH)3-adjuvanted vaccine, regardless of whether monovalent or bivalent vaccines were used. Our results support the use of an intradermal bivalent vaccine strategy for HFMD vaccination in order to satisfy the requirements and reduce the costs.

Design and synthesis of pH-sensitive polymeric micelles for oral delivery of poorly water-soluble drugs.

pH-sensitive polymer poly (polylactide-co-methacrylic acid)-b-poly (acrylic acid) was synthesized using atom transfer radical polymerization and ring-opening polymerization and characterized by gel permeation chromatography and (1)H NMR. The polymers can self-assemble to form micelles in aqueous medium, which respond rapidly to pH change within the gastrointestinal relevant pH range. Critical micelle concentrations and pH response behavior of the polymeric micelle were investigated. Water-insoluble drug nifedipine was loaded and the drug-loading content can be controlled by tuning the composition of the polymers. The in vitro release studies indicate pH sensitivity enabled rapid drug release at the environment of simulated intestinal fluid (pH 7.36), the cumulative released amount of NFD reached more than 80% within 24 h, while only 35% in the simulated gastric fluid (pH 1.35). All the results showed that the pH-sensitive P(PLAMA-co-MAA)-b-PAA micelle may be a prospective candidate as oral drug delivery carrier for hydrophobic drugs with controlled release behavior.

[Change of leukocytic phagocytosis during repeat hemoperfusion with cross-linked agar beads entrapped attapulgite clay].

The leukocytic phagocytosis rate and the index of phagocytosis of rats on cross-linked agar beads entrapped attapulgite clay (CAA) hemoperfusion were studied. The results revealed that the leukocytic phagocytosis rate and the index of phagocytosis descended significantly after 1 hour and rose gradually after 6 hours. Finally it reached the normal level after 48 hours. Hemoperfusion repeated two times gave similar results. In conclusion, the function of leukocytic phagocytosis declined temporarily during CAA hemoperfusion. Many times hemoperfusion will not notably affect the body's defense system of rats.

Possible antioxidant mechanism of melanoidins extract from Shanxi aged vinegar in mitophagy-dependent and mitophagy-independent pathways.

Melanoidins are widely reported to have antioxidant activity; however, their mechanism has not been frequently studied. In this study, we found that melanoidins from Shanxi aged vinegar induced mitopahgy, the specific autophagic elimination of mitochondria, as assessed by up-regulation of the autophagy markers LC3-II and Beclin1 as well as degradation of the autophagy substrate p62 and mitochondrial proteins. Melanoidins reduced reactive oxygen species (ROS) in normal human liver cells and mouse livers through a mitophagy-dependent pathway, by the observation that the reducing ROS effect of melanoidins was partially lost when mitophagy was inhibited by chloroquine. Impaired Akt signaling was found in cells treated with melanoidins, which might explain the activation of autophagy induced by melanoidins. These results suggest that in addition to direct free radical scavenging activity, melanoidins decreased ROS levels through mitophagy in which damaged mitochondria, the source of ROS, were degraded.

Facile one-step coating approach to magnetic submicron particles with poly(ethylene glycol) coats and abundant accessible carboxyl groups.

PURPOSE: Magnetic submicron particles (MSPs) are pivotal biomaterials for magnetic separations in bioanalyses, but their preparation remains a technical challenge. In this report, a facile one-step coating approach to MSPs suitable for magnetic separations was investigated. METHODS: Polyethylene glycol) (PEG) was derived into PEG-bis-(maleic monoester) and maleic monoester-PEG-succinic monoester as the monomers. Magnetofluids were prepared via chemical co-precipitation and dispersion with the monomers. MSPs were prepared via one-step coating of magnetofluids in a water-in-oil microemulsion system of aerosol-OT and heptane by radical co-polymerization of such monomers. RESULTS: The resulting MSPs contained abundant carboxyl groups, exhibited negligible nonspecific adsorption of common substances and excellent suspension stability, appeared as irregular particles by electronic microscopy, and had submicron sizes of broad distribution by laser scattering. Saturation magnetizations and average particle sizes were affected mainly by the quantities of monomers used for coating magnetofluids, and steric hindrance around carboxyl groups was alleviated by the use of longer monomers of one polymerizable bond for coating. After optimizations, MSPs bearing saturation magnetizations over 46 emu/g, average sizes of 0.32 µm, and titrated carboxyl groups of about 0.21 mmol/g were obtained. After the activation of carboxyl groups on MSPs into N-hydroxysuccinimide ester, biotin was immobilized on MSPs and the resulting biotin-functionalized MSPs isolated the conjugate of streptavidin and alkaline phosphatase at about 2.1 mg/g MSPs; streptavidin was immobilized at about 10 mg/g MSPs and retained 81% ± 18% (n = 5) of the specific activity of the free form. CONCLUSION: The facile approach effectively prepares MSPs for magnetic separations.

Site-specific PEGylation of therapeutic proteins via optimization of both accessible reactive amino acid residues and PEG derivatives.

Modification of accessible amino acid residues with poly(ethylene glycol) [PEG] is a widely used technique for formulating therapeutic proteins. In practice, site-specific PEGylation of all selected/engineered accessible nonessential reactive residues of therapeutic proteins with common activated PEG derivatives is a promising strategy to concomitantly improve pharmacokinetics, allow retention of activity, alleviate immunogenicity, and avoid modification isomers. Specifically, through molecular engineering of a therapeutic protein, accessible essential residues reactive to an activated PEG derivative are substituted with unreactive residues provided that protein activity is retained, and a limited number of accessible nonessential reactive residues with optimized distributions are selected/introduced. Subsequently, all accessible nonessential reactive residues are completely PEGylated with the activated PEG derivative in great excess. Branched PEG derivatives containing new PEG chains with negligible metabolic toxicity are more desirable for site-specific PEGylation. Accordingly, for the successful formulation of therapeutic proteins, optimization of the number and distributions of accessible nonessential reactive residues via molecular engineering can be integrated with the design of large-sized PEG derivatives to achieve site-specific PEGylation of all selected/engineered accessible reactive residues.

A new practical system for evaluating the pharmacological properties of uricase as a potential drug for hyperuricemia.

The use of uricase-deficient mammals to screen formulations of engineered uricases as potential drugs for hyperuricemia involves heavy costs and presents a technical bottleneck. Herein, a new practical system was investigated to evaluate the pharmacological significance of a bacterial uricase based on its ability to eliminate uric acid in plasma in vitro, its pharmacokinetics in vivo in healthy rats, and the modeled pharmacodynamics in vivo. This uricase, before and after modification with the monomethyl ether of poly(ethylene glycol)-5000, effectively eliminated uric acid in vitro in rabbit plasma, but its action was susceptible to xanthine inhibition. After intravenous injection of the modified uricase without purification, a bi-exponential model fit well to uricase activities in vivo in the plasma of healthy rats; the half-life of the modified uricase was estimated without interference from the unmodified uricase leftover in the sample and was nearly 100-fold longer than that of the unmodified uricase. Using a model of the elimination of uric acid in vivo taking into account of uricase pharmacokinetics and xanthine inhibition, modeled pharmacodynamics supported that the half-life of uricase and its susceptibility to xanthine are crucial for the pharmacological significance of uricase. Hence, this practical system is desirable for doing preliminary screening of formulations of engineered uricases as potential drugs for hyperuricemia.