Cu2+-Ion-Substitution-Driven Microstructure and Microwave Dielectric Properties of Mg1-xCuxAl2O4 Ceramics.

In this work, Cu-substituted MgAl2O4 ceramics were prepared via solid-state reaction. The crystal structure, cation distribution, and microwave dielectric properties of Mg1-xCuxAl2O4 ceramics were investigated. Cu2+ entered the MgAl2O4 lattice and formed a spinel structure. The substitution of Cu2+ ions for Mg2+ ions contributed to Al3+ ions preferential occupation of the octahedron and changed the degree of inversion. The quality factor (Qf) value, which is correlated with the degree of inversion, increased to a maximum value at x = 0.04 and then decreased. Ionic polarizability and relative density affected the dielectric constant (εr) value. The temperature coefficient of the resonant frequency (τf) value, which was dominated by the total bond energy, generally shifted to the positive direction. Satisfactory microwave dielectric properties were achieved in x = 0.04 and sintered at 1550 °C: εr = 8.28, Qf = 72,800 GHz, and τf = -59 ppm/°C. The Mg1-xCuxAl2O4 solid solution, possessing good performance, has potential for application in the field of modern telecommunication technology.

Metabolic engineering of Escherichia coli for polyamides monomer δ-valerolactam production from feedstock lysine.

Nylon 5 and nylon 6,5 are recently explored as new commercial polyamides, of which the monomer includes δ-valerolactam. In this study, a novel catalytic activity of lysine 2-monooxygenase (DavB) was explored to produce δ-valerolactam from L-pipecolic acid (L-PA), functioning as oxidative decarboxylase on a cyclic compound. Recombinant Escherichia coli BS01 strain expressing DavB from Pseudomonas putida could synthesize δ-valerolactam from L-pipecolic acid with a concentration of 90.3 mg/L. Through the co-expression of recombinant apoptosis-inducing protein (rAIP) from Scomber japonicus, glucose dehydrogenase (GDH) from Bacillus subtilis, Δ1-piperideine-2-carboxylae reductase (DpkA) from P. putida and lysine permease (LysP) from E. coli with DavB, δ-valerolactam was produced with the highest concentration of 242 mg/L. α-Dioxygenases (αDox) from Oryza sativa could act as a similar catalyst on L-pipecolic acid. A novel δ-valerolactam synthesis pathway was constructed entirely via microbial conversion from feedstock lysine in this study. Our system has great potential in the development of a bio-nylon production process. KEY POINTS: • DavB performs as an oxidative decarboxylase on L-PA with substrate promiscuity. • Strain with rAIP, GDH, DpkA, LysP, and DavB coexpression could produce δ-valerolactam. • This is the first time to obtain valerolactam entirely via biosynthesis from lysine.

Histamine H4 receptor gene polymorphisms: a potential predictor of oral H1 antihistamine efficacy for allergic rhinitis.

BACKGROUND: Our study aimed to investigate the associations between Histamine H4 receptor (HRH4) gene polymorphisms (rs77485247, rs74604924, and rs77041280) and oral H1 antihistamine efficacy for the treatment of allergic rhinitis (AR) patients. METHODS: A total of 142 AR patients were selected as a case group and 160 healthy individuals were recruited as a control group. Single nucleotide polymorphisms (SNPs) in the HRH4 gene were detected using direct sequencing. Serum immunoglobulin E (IgE), specific IgE, and eosinophil cationic protein (ECP) levels were measured by enzyme-linked immunosorbent assay (ELISA). Clinical efficacy was evaluated by the visual analogue scale (VAS). The occurrence of adverse reaction was recorded. RESULTS: There were significant differences in the distribution frequencies of mutant genotype (TA + AA) and A allele of rs77485247, mutant genotype (AT + TT) and T allele of rs74604924, and mutant genotype (AT + TT) and T allele of rs77041280 between the case and control groups. AR patients with mutant genotype (TA + AA) of rs77485247 and AR patients with mutant genotype (AT + TT) of rs77041280 had higher specific IgE, ECP levels, and VAS scores after treatment and lower incidence of adverse reactions and total effective rate than those with TT genotype and those with AA genotype, respectively. However, for rs74604924, there were no differences was found between AR patients with mutant genotype (AT + TT) and those with AA genotype. CONCLUSION: Our findings provide evidence that HRH4 rs77485247 and rs77041280 polymorphisms may be associated with the risk of AR and the efficacy of H1 antihistamines for the treatment of AR patients.

A Novel Therapy for Laryngotracheal Stenosis: Treatment With Ethosomes Containing 5-Fluorouracil.

PURPOSE: The purpose of our article was to explore the effect of ethosomes containing 5-fluorouracil (5-FU) with different sizes on laryngotracheal stenosis treatment. METHODS: The physical characteristics of ethosomes containing 5-FU were investigated, including size, shape, and entrapment percentage. The effect of ethosomes containing 5-FU was evaluated on the airway stenosis rabbit model. The formation of fibrous/scar tissue was investigated by hematoxylin and eosin (HE) staining, and the permeation depth was observed under fluorescence microscope. RESULTS: The mean sizes of 5-FU ethosomes extruded by D=50 nm and D=100 nm pore were 60±10 nm and 110±13 nm, respectively. The 5-FU entrapment percentage of ethosomes was determined to be 15% (D=60±10 nm) and 32% (D=110±13 nm). After being treated by ethosomes containing 5-FU (D=60±10 nm), the fibroblast and collagenous fiber distributed sparsely in the deep scar tissue. The permeation capability of ethosomes containing 5-FU (D=60 nm) was significantly better than ethosomes (D=110 nm). Besides, the 5-FU ethosomes resulted in less stenosis than 5-FU only. CONCLUSIONS: Topical administration of 5-FU ethosomes may be a novel candidate therapy for laryngotracheal stenosis treatment.

Preparation of levofloxacin thermo-sensitive gel and clinical application in the treatment of suppurative otitis media.

CONCLUSION: The levofloxacin thermo-sensitive gel prepared using 17% poloxamer 407 (P407) can successfully treat suppurative otitis media (SOM) through the well-controlled release of levofloxacin targeted against the inflammation. OBJECTIVE: To evaluate the preparation method and therapeutic effect of levofloxacin thermo-sensitive gel used in the treatment of SOM. METHODS: The phase inversion temperatures of 16%, 17%, 18%, 19%, and 20% P407 or P407 solution with 3 mg/ml levofloxacin were determined and the one close to 34(°)C was selected as the optimal concentration. Then a model of SOM was induced by injection of 0.1 ml Staphylococcus aureus (1 × 10(8)/L) in the left ear of 32 Sprague Dawley (SD) rats. Normal saline injected in the right ear was used as the control. Then rats were treated with 0.1 ml normal saline (group A), levofloxacin (group B), P407 (group C), and levofloxacin thermo-sensitive gel (group D) (n = 8). The tympanic membranes were evaluated by otoscopy and hematoxylin and eosin (H&E) staining. RESULTS: The optimal concentration of P407 was 17% and the release of levofloxacin in thermo-sensitive gel followed zero-order kinetics. Levofloxacin thermo-sensitive gel and levofloxacin drops could both alleviate the local inflammation in the first 3 days, but levofloxacin drops could not inhibit the recurrence of SOM, while the levofloxacin gel performed continuous drug delivery into inflammation without recurrence.

[Preparation of ethosomes encapsulated with 5-fluorouracil and the effect of local administered 5-FU ethosome on laryngotracheal stenosis of rabbit].

OBJECTIVE: To evaluate the efficacy of Ethosomes encapsulated with 5-FU in treatment of laryngotracheal stenosis in rabbit models. METHOD: The 5-FU ethosome was prepared by the thin film hydration method, and the size distribution and the encapsulation efficiency was investigated. The tracheal mucosa was scraped about 0.5 cm in width with a nylon brush to induce the scar formation in the airway,then animals were divided into three groups: 5-FU ethosome group,5-FU group and saline group. Drugs were injected into scar by paracentesis under endoscope in each group respectively. The severity of stenosis was observed under laryngofiberoscope immediately, 7, 14, 21 days after administration. RESULT: Airway stenosis of 5-FU ethosome group was not significantly different compared with 5-FU group at 7 days after administration, but 5-FU ethosome significantly reduced the airway stenosis at 21 days after administration when compared with 5-FU group and no restenosis was noticed during the observation period. CONCLUSION: Ethosomes encapsulated with 5-FU was effective for laryngotracheal stenosis. It is a potentially new method for ameliorating airway stenosis originated from granulation tissue.

Expression of NMS and NMU2R in the pig reproductive axis during the estrus cycle and the effect of NMS on the reproductive axis in vitro.

Evidence has revealed that neuromedin S (NMS) and neuromedin U-receptor type-2 (NMU2R) mRNAs are expressed in the central nervous system and reproductive organs. Previous data indicated that variation of NMS and NMU2R was due to the phases of the adult rat hypothalamus estrus cycle. However, the expression and function of NMS in the pig reproductive axis remains unexplored. In this study, 16 virginal gilts were classified into four groups: proestrus, estrus, diestrus 1, and diestrus 2; the expression of NMS and NMU2R in the cyclic pig hypothalamus-pituitary-ovary axis was studied by reverse transcriptaion-polymerase chain reaction (RT-PCR), and the effect of NMS on the reproductive axis in vitro was detected by radioimmunoassay (RIA). The cloned pig NMS and NMU2R sequences were 82% and 90.2% identical to those of the corresponding human homologues, respectively. RT-PCR showed that NMS and NMU2R mRNA expression in the hypothalamus and pituitary changed with the estrus cycle, i.e., with the highest level in the proestrus group and the lowest in the estrus group. In the ovary, NMS and NMU2R expression was highest in the diestrus 2 group and the lowest in the proestrus group. In the in vitro study, different concentrations of NMS induced the release of gonadotropin-releasing hormone, luteinizing hormone, and estradiol at different levels of the reproductive axis. Taken together, the expression pattern of NMS during the estrus cycle and its role in reproductive hormones in vitro provide novel evidences of the potential roles of NMS in the regulation of pig reproduction.