Fluorescence enhancement reaction of flavoxate hydrochloride (FX) in strong alkali solution was studied, the mechanism of the reaction was investigated, and a novel fluorimetric method for analysis of FX in drug sample was established. FX has no intrinsic fluorescence, but it can slowly produce fluorescence in strong alkali solution. Heating can promote the fluorescence enhancement reaction. In 3D fluorescence spectra of the decomposition product of FX, two fluorescence peaks, located respectively at excitation wavelengths λex/ emission wavelength λem =223/410 nm, and 302/410 nm, were observed. Using quinine sulfate as a reference, fluorescence quantum yield of the decomposition product was measured to be 0.50. The structural characteriza- tion and spectral analysis of the decomposition product reveal that ester bond hydrolysis reaction of FX is firstly occurred during heating process, forming 3-methylflavone-8-carboxylic acid (MFA), then a cleavage reaction of the γ-pyrone ring of MFA occurred, producing α, β-unsaturated ketone. This product includes adjacent hydroxyl benzoic acid group in its molecule, which can form intramolecular hydrogen bond under alkaline condition, so that increase the conjugate degree and enhance the rigidity of the molecule, and thereby cause fluorescence enhancement. Based on this fluorescence enhancement reaction, a fluorimetric method was proposed for the determination of FX. A linear calibration curve covered the concentration range 0.020 3-0.487 µg · mL. The regression equation was I(F) = 23.9 + 5357.3 c, with correlation coefficient r = 0.999 7 (n = 8), detection limit D = 1.1 ng · mL(-1). The method was applied to the analysis of FX tablets, with a spiked recovery rate of 100.2%. The reliability of the method was verified by a UV-spectrophotometric method.
Alkalies ; Calibration ; Chemistry, Pharmaceutical ; Flavoxate ; analogs & derivatives ; chemistry ; Fluorescence ; Limit of Detection ; Reproducibility of Results ; Solutions ; Tablets

Aleutian mink disease parvovirus (AMDV) causes a persistent infection associated with immune complex disease, hypergammaglobulinemia, and high levels of antiviral antibodies. Despite the presence of an antibody, the virus is not cleared in vivo. Pre-existing antibodies may enhance viral infections, by Fc-receptor-mediated antibody-dependent enhancement (ADE), but the mechanism that underlies ADE has not been fully defined. Three models have been proposed, including: (1) interactions between antibody and FcR, complement C3 fragment and CR, or between C1q and C1qR, which promotes viral attachment to cells; (2) suppression of IFN-gamma-mediated host-cell antiviral gene expression by the upregulation of negative regulators of pathogen pattern recognition; and (3) the promotion of early IL-10 secretion. In addition, the role of cytokine IL-6 in ADE mediated disease development is discussed, to facilitate a better understanding of the pathogenesis of AMDV infection, as well as give insights into rational vaccine design approaches.
Aleutian Mink Disease ; immunology ; virology ; Aleutian Mink Disease Virus ; genetics ; immunology ; Animals ; Antibodies, Viral ; immunology ; Antibody-Dependent Enhancement ; Mink ; immunology ; virology

Evolution, Molecular ; Methicillin Resistance ; Staphylococcus aureus ; classification ; drug effects ; genetics ; isolation & purification

Objective To explore the clinical features and treatment of eosinophilic lymphoid granuloma(ELG) in children,in order to increase understanding of the disease.Methods Clinical features,laboratory examination,pathological examination,treatment and the-(rapeutic) effect of 5 patients with ELG were retrospectively studied,and the related literature were reviewed.Results Five cases were all boys.They all presented many subcutaneous swellings and lymphadenopathy.A case among them was associated with nephrotic syndrome,and 2 cases had the complication of eczema repeatedly,and 1 case ever had 2 times episodes of asthmatiform bronchitis.All of them had no hepatomegaly and splenomegaly,physically was well developed.Only chemotherapy was supplied to all the patients.During the course of therapy,4 cases among them recurred.After that,they were successfully treated with irradiation of lesion or cyclosporine(CsA).Conclusions ELG in children is as same as adult in clinicopathological features.It tends recur only with chemotherapy.We can get better curative effect with the synthetic treatment of chemotherapy,radiotherapy,operation or oral CsA and so on.

Objective To evaluate the safety,biocompatibility and efficacy of transcatheter closure of atrial septal defect(ASD)with no stainless-steel-screw occluder in canine model.Methods The device was constructed from superelastic Nitinol wires tightly woven into two flat disks and sewed with polyester fibers inside,with a pliable loop on the right-atrial-disk of the device,connecting to the delivery cable.ASD was created by transcatheter puncture and balloon dilatation and then closed by occluder under fluoroscopy in the catheterization laboratory.The location and the influence of the implanted device on function of tricuspid valve and mitral valve were evaluated by echocardiography.At 1,2,3 and 6 months after the operation,the animals were killed and autopsy was conducted.Results Eight dogs with puncture-produced ASD underwent ASD closing procedure successfully.The occluder showed no influence on the function of MV and AV demonstrated by echocardiogram.The two disks of the implanted device were covered with a smooth intact neogenesis layer in all dogs.Endocardial cells fully covered the surface of the two disk without inflammating reaction 3 months later. There was no evidence of corrosion on the surface of the nitinol wire removed from the dog after 6 months.Light microscopic examination of the liver,kidney,lung and spleen showed no evidence of embolization and inflammation.Conclusion Transcatheter ASD occlusion with new-type occluder is safe,feasible,effective and good biocompatibility with a good prospective clinical application.

Objective To investigate the effects ofYangyin Yiqi Mixture on pulmonary fibrosis caused by bleomycin in rats;To discuss its possible mechanism.Methods SD rats were randomly divided into normal control group, model group, dexamethasone acetate group, low-dose, middle-dose and high-doseYangyin Yiqi Mixture groups. Bleomycin was used to establish pulmonary fibrosis rat models through endotracheal instillation. One day after molding, each medication group received gavage with relevant medicine. Lung tissues were taken on the 7th, 14th and 28th day. Masson staining was used to observe pathological change;alkalinehydrolysis was used to detect HYP content;Western blot was used to detect the protein expressions of MMP-2 and TIMP-1.Results Compared with the normal control group, on 7th day, collagen in lung tissue of rats in model group markedly increased;the content of HYP in lung tissue significantly increased (P<0.01). On 28th day, collagen was deposited diffusely and the alveolar was destroyed;content of HYP in lung tissue increased significantly (P<0.01). Compared with model group, deposited collagen in lung tissue was alleviated, and the content of HYP were remarkable reduced in middle and high doseYangyin Yiqi Mixture groups and displayed dose-dependent. Western blot results showed that the protein expressions of MMP-2 and TIMP-1 increased quickly compared with the low expression of normal lung tissue in the 7th day of molding (P<0.05), and reached high expression in the 28th day. Compared with the model group, the level of MMP-9 in high-dose Yangyin Yiqi Mixture group decreased significantly in the 14th day;the expression of TIMP-1 decreased significantly in the 7th, 14th and 28th day (P<0.05).ConclusionYangyin Yiqi Mixture can effectively resist pulmonary fibrosis, which may be realized by inhibiting the expressions of TIMP-1 and MMP-9, regulating and promoting collagenic hydrolysis and restraining deposition of collagen.

Humans ; Male ; Middle Aged ; Pacemaker, Artificial ; adverse effects ; Tricuspid Valve Stenosis ; etiology

AIMTo elevate the encapsulation efficiency, decrease the burst release and improve the release of protein entrapped in poly (lactic-co-glycolic acid) (PLGA) microspheres. The bovine serum albumin (BSA) composite microspheres of alginate-chitosan-PLGA were prepared and the release characteristics of BSA from this composite microspheres were studied.

METHODSThe much smaller calcium alginate microcapsules were first prepared by a modified emulsification method in an isopropyl alcohol-washed way and coated with chitosan, then the alginate-chitosan microcapsules were further entrapped in PLGA to form the composite microspheres. The protein concentration was determined using a BCA protein assay kit. The release profiles were changed with various formulation factors.

RESULTSThe average diameter of the composite microcapsules was about 30 microm. Comparing with 60% to 70% of the conventional PLGA microspheres, the average encapsulation efficiency was more than 80%, and the burst releases in phosphate buffer solution of the composite microspheres decreased from 40% and 50% to 25% and further to 5% in saline solution.

CONCLUSIONThe novel composite microspheres were prepared, the drug encapsulation efficiency increased and the burst release decreased. The desired release profiles could be obtained by regulating the ratios of PLG and PLA in the composite microspheres.

Alginates ; chemistry ; Chitosan ; chemistry ; Drug Delivery Systems ; methods ; Lactic Acid ; chemistry ; Microspheres ; Particle Size ; Polyglycolic Acid ; chemistry ; Polymers ; chemistry ; Serum Albumin, Bovine ; chemistry

Anastomosis, Surgical ; Colon, Sigmoid/surgery* ; Colorectal Neoplasms/surgery* ; Humans ; Robotics

BackgroundThe three-dimensional configuration of the nasolacrimal canal is highly variable with age,gender,and race.But enlargement of the nasolacrimal canal has sparsely been reported in the literature.Objective Computed tomography dacryocystography was performed in patients with unilateral congenital nasolacrimal duct obstruction and normal children to analyze the difference of bilateral nasolacrimal canal.MethodsThis is a retrospective study.Axial scanwith sagittalandcoronalreconstructionwas appliedin computedtomography dacryocystography.Diameters of bilateral nasolacrimal canal of 20 unilateral congenital nasolacrimal duct obstruction patients and 20 normal children were measured.Written informed consent was obtained from each child ' s parents before examination.ResultsThe lacrimal sac,nasolacrimal duct and the peripheral tissue were clearly exhibited by computed tomography dacryocystography.The diameters of the origination,the middle part and the distal end of affected nasolacrimal duct were(5.5±1.4),(5.3±1.2),(5.3±1.6) mm,and normal ones were(3.9±0.8 ),(3.5± 0.8 ),( 3.9± 1.3 ) mm,respectively.These results were statistically significant ( t =5.200,6.967,2.932,P＜ 0.05 ).There was no statistically significant difference in bilateral nasolacrimal canal of normal children (t =0.346,0.281,0.312,P＞0.05 ).Conclusions Computed tomography dacryocystography can image lacrimal passage and their peripheral tissues clearly.The affected nasolacrimal canal diameters of unilateral congenital nasolacrimal duct obstruction were much larger than the fellow sides.The pathogenesis of this phenomenon need much research.