Validation of commercial dry-form broth microdilution panels and test reproducibility for susceptibility testing of dalbavancin, a new very long-acting glycopeptide

Results from dalbavancin dry-form commercial broth microdilution MIC panels (Sensititre, TREK Diagnostics) were compared with reference frozen-form MIC values to assure the validity and reproducibility of the extended shelf-life product. A collection of 402 organisms from four major organism groups were used in the validation trial and 10 strains for reproducibility replicate tests. A total of 98.6% commercial dalbavancin MIC results were within +/-1 log(2) dilution of reference values (76.2% were identical) and reproducibility trials produced identical MIC results in 88.9-92.2% of dalbavancin MIC comparisons. These dalbavancin MIC results demonstrated the acceptable accuracy of commercially-prepared broth microdilution products for use in subsequent clinical trials.     

Exposure to ozone aggravates nasal allergy-like symptoms in guinea pigs

The ability of O3 exposure to aggravate ovalbumin (OVA)-induced nasal allergy-like symptoms was studied in guinea pigs. Guinea pigs were exposed to filtered air or to 0.4 ppm O3 for 5 weeks. During the exposure, 1% OVA or saline was administered into the nasal cavities once a week. Sneezes and nasal secretions were measured for a 20-min period following OVA administration. The number of eosinophils infiltrating both nasal epithelium and subepithelium and titers of specific anti-OVA-IgG were measured 24 h after the last administration. Ozone increased OVA-induced sneezing and nasal secretion, as well as induced nasal hyper-responsiveness to physical stimuli. The number of eosinophils infiltrating the nasal subepithelium was increased by O3, and the titer of anti-OVA-IgG tended to increase in the O3-exposed animals. Thus, exposure to O3 aggravated nasal allergy-like symptoms by inducing nasal hyper-responsiveness, the infiltration of eosinophils, and by tending to increase the production of anti-OVA-IgG.     

冰片滴鼻对豚鼠鼻粘膜血管和脑血管通透性的影响研究

目的:研究不同浓度冰片滴鼻后对豚鼠鼻粘膜血管和脑血管通透性的影响。方法:将豚鼠随机分为系列浓度冰片(0.5%、1.0%、2.0%)组、组胺组和液体石蜡组,滴鼻给药后静脉注射2%伊文思蓝(EB),10min后处死豚鼠,取鼻粘膜和脑组织,测定并计算鼻粘膜和脑组织中EB含量。结果:与液体石蜡组比较,系列浓度冰片组鼻粘膜和脑组织中EB含量更高(P<0.05或P<0.01),并以2.0%冰片组最为明显。结论:冰片滴鼻可以明显增加豚鼠鼻粘膜血管和脑血管的通透性。     

A new rhinitis model using chemical mediators in rats

No good experimental model for studying rhinitis, has been hitherto available. In the present study, development of a new rhinitis model using chemical mediators was attempted, especially to establish an index of nasal congestion. Male Wistar rats were anesthetized with pentobarbital-Na. Nasal cavities were ventilated between both cannulae inserted into the nasopharynx and bilateral nostrils, with an artificial respirator. Intranasal resistance was recorded with a modification of a Konzett-R?ssler apparatus as a change in ventilation overflow (VO). To provoke rhinitis, some mediators were inhaled into the nasal cavities with an ultrasonic nebulizer for 5 min. To assess the capillary permeability of the nasal mucosa, exudation of Evans blue was determined by injecting the dye before inhalations of mediators. Inhalation of histamine (0.01, 0.1, 0.3%), bradykinin (0.01, 0.1%) and ACh (0.3%) markedly increased VO, while inhalation of serotonin (0.01, 0.1, 0.3%) did not increase VO. Histamine, bradykinin and high concentration of ACh significantly increased the dye exudation in the nasal cavities, although serotonin did not. From the above results, it is concluded that 1) a new rhinitis model in which symptoms of nasal blockage and increased capillary permeability in nasal mucosa are quantitatively determined, was established, and 2) histamine- and bradykinin-inhalations can cause rhinitis-like symptoms, although serotonin-inhalation can not.     

Usefulness of liposomes as an intranasal dosage formulation for topical drug application

The potential of liposomes as an intranasal dosage formulation for topical application was investigated in rats. When 5(6)-carboxyfluorescein (CF), a model absorbable drug, dissolved in phosphate-buffered saline (PBS) was administered intranasally, CF was rapidly absorbed into the systemic circulation and no adhesion of CF to the nasal mucosa was observed. The fraction of CF absorbed from the nasal mucosa reached about 48% 1 h after administration. On the other hand, only 3% of the dose was absorbed when CF was encapsulated in liposomes consisting of dipalmitoylphosphatidylcholine and cholesterol (DPPC-liposomes). In addition, the amount of CF adhering to the nasal mucosa after administration as DPPC-liposomes was 20- to 28-fold greater than that in PBS solution. In particular, positively charged liposomes markedly enhanced the adhesion of CF to the nasal mucosa. Differences in the lipid composition of liposomes did not affect the absorption of CF. However, the ability of liposomes to adhere to the nasal mucosa was consistent with the fluidity of the liposomal membrane. Furthermore, the action of liposomes on the anti-histaminic effect of diphenhydramine hydrochloride (DH) was studied in rats by measuring the amount of protein leaking into the nasal cavity under quasi-allergic conditions. The anti-histaminic effect of DH was strong but of short-duration when DH was administered as a PBS solution. However, liposomes prolonged the anti-histaminic effect of DH, suggesting that liposomes may adhere to the nasal mucosa and release DH slowly. In conclusion, liposomes suppress drug absorption into the systemic circulation and concurrently increase drug retention in the nasal cavity.     

Effect of mometasone furoate by topical application on allergic rhinitis model in rats

The effects of mometasone furoate on experimental allergic rhinitis in rats were studied in comparison with that of fluticasone propionate. Topical application of both drugs inhibited dose-dependently the increase of nasal symptoms (sneezing and nasal rubbing) after antigen challenge to the nasal cavity of actively sensitized rats. Mometasone furoate and fluticasone propionate at concentrations of 0.01 or 0.1% significantly inhibited both nasal rubbing and sneezing 1 h after topical application of both drugs. The relative potencies of mometasone furoate in nasal rubbing and sneezing compared to fluticasone propionate were 5.01 and 6.87, respectively. Mometasone furoate (0.02%) and fluticasone propionate (0.1%) significantly inhibited the increase of antigen-induced nasal rubbing even 6 h after topical application, indicating that both drugs have a long-lasting effect.     

Effects of muscarinic antagonists on experimental nasal secretion in guinea pigs

The effects of muscarinic antagonists on acetylcholine (ACh)- and histamine-induced nasal secretion were investigated in guinea pigs. Inhalations of flutropium (0.01 to 0.3%) and atropine (0.03 to 0.3%) into the nasal cavities dose-dependently inhibited the nasal secretion induced by ACh. The inhibitory action of flutropium was slightly stronger than that of atropine. Inhalations of pirenzepine (0.3%) and gallamine (0.3%) had no effect on the ACh-induced nasal secretion. However, 4-DAMP dose-dependently inhibited the nasal secretion induced by ACh. Inhalations of flutropium (0.3%) and diphenhydramine (0.3%) showed a similar inhibitory action on the histamine-induced nasal secretion. These results suggest that 1) inhalation into the nasal cavities of flutropium was effective in experimental model of ACh- and histamine-induced nasal secretion, 2) M3-cholinergic receptors may be dominant in the nasal secretion induced by ACh and 3) the experimental model of drug-induced nasal secretion in guinea pigs used in the present study can be employed to develop therapeutic drugs for nasal secretion.     

分光光度法测定果胶酶活性方法的研究

本文论述了用分光光度法测定发酵液等成份复杂的样品中果肢酶活性的新方法，标准曲线相关系数γ＝0．999；测定样品相对标准偏差1．90；回收率在90％以上。此方法准确、简便、易操作、需时短。     

Effects of fujibitol, a remedy for nasal symptoms, on experimental allergic rhinitis in rats

The effects of Fujibitol, a preparation of crude drugs in wide clinical use for treatment of chronic rhinitis and empyema, on experimental allergic rhinitis in rats were studied. Fujibitol inhibited nasal allergic symptoms, i.e. sneezing and nasal rubbing, induced by antigen in sensitized animals. An increase in dye leakage into the nasal cavity induced by antigen was also inhibited by Fujibitol. On the other hand, no inhibitory effects were observed on either the nasal allergic symptoms or increase in dye leakage into the nasal cavity induced by histamine. However, Fujibitol was effective in inhibiting histamine release from the nasal cavity induced by antigen. Oxatomide used as positive control drug showed potent inhibitory effects on nasal symptoms and dye leakage into the nasal cavity induced by histamine and antigen. These results suggested that Fujibitol showed a remarkable protective effect against experimental rhinitis induced by antigen via inhibition of histamine release from the nasal cavity.     

Comparative antimicrobial spectrum and activity of BMS284756 (T-3811, a desfluoroquinolone) tested against 656 Enterobacteriaceae, including preliminary in vitro susceptibility test comparisons and development

BMS284756 (T-3811), a novel des-F(6)-quinolone, was evaluated using isolates of Enterobacteriaceae from the SENTRY Antimicrobial Surveillance Program tested by Etest (AB BIODISK, Solna, Sweden), reference broth microdilution and disk diffusion (5-microg) methods. Ciprofloxacin, levofloxacin, gemifloxacin and gatifloxacin were also tested by broth microdilution as comparator antimicrobial agents within the same drug class. The 656 isolate collection included species from the genera Citrobacter, Enterobacter, Escherichia, Hafnia, Klebsiella, Morganella, Pantoea, Proteus, Providencia, Salmonella, and Serratia. BMS284756 was slightly less active than comparison fluoroquinolones against these isolates (MIC(90), 4 mg/l versus 0.06-2 mg/l). However, at a proposed susceptible breakpoint of < or =4 mg/l, 90.7% of the isolates processed were susceptible to BMS284756, demonstrating an equivalent spectrum of activity to all other agents except gemifloxacin (86.6%). In general, isolates requiring >4 mg/l of BMS284756 for inhibition of growth were also less susceptible to the comparators suggesting cross-resistance is common between des-F(6)- and fluoro-quinolones. Excellent correlation was observed between broth microdilution MIC results and 5-microg disk zone diameters (r=0.94), and between broth microdilution dilution and Etest MIC values (r=0.96). In conclusion, BMS284756 has an activity and spectrum similar to contemporary fluoroquinolones and in vitro test methods (NCCLS, Etest) appear accurate and reproducible     

In vivo studies on nasal preparations of ciprofloxacin hydrochloride

Gel formulations of ciprofloxacin hydrochloride (CPH) were prepared with bioadhesive polymers such as hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC) and methylcellulose (MC). They were administered into the nasal cavity of rabbits. A nasal aqueous suspension of CPH with glycerol was also applied. In addition, the effect of Tween 80 as penetration enhancer was examined. The agar plate diffusion technique was applied for the assay of CPH. The results were compared with oral and intravenous administrations. The bioavailability of the CPH gel formulation prepared with HPMC was almost identical to that of the oral route. Other nasal formulations with HEC and MC had bioavailabilities lower than oral preparations. The relative bioavailabilities for the formulation containing HEC and MC were 48.7 and 45.54%, respectively. To increase the bioavailabilities, 1% (w/w) of Tween 80 was added. The bioavailability of these gel formulations increased to 63.54 and 55.72%, respectively. Experiments carried out on rabbits showed that the nasal administration of CPH bioadhesive gel formulation containing HPMC may be an alternative to the oral route.     

Nasal congestion model in Brown Norway rats and the effects of some H1-antagonists

The aim of this study was to develop and characterize a new model for evaluating nasal congestion in rats by using whole body plethysmography (WBP)-free moving application. Brown Norway rats were sensitized with 10% toluene-2, 4-diisocyanate (TDI) solution, and nasal congestion was provoked with 5% TDI. An increase in the enhanced pause (Penh) was recognized after being challenged with TDI. In addition, a significant increase in the Penh was observed following the intranasal application of histamine in TDI sensitized rats. Histamine H1 antagonists, such as chlorpheniramine and ketotifen suppressed the increase of Penh during the early-phase response. On the other hand, epinastine suppressed the increase of Penh in both the early and late phase responses. In conclusion, we developed an allergic rhinitis model that includes nasal congestion symptoms in Brown Norway rats, and this model may be useful for evaluating the effects of drugs on nasal congestion.     

Effects of olopatadine hydrochloride on the increase of histamine and peptide-leukotrienes concentrations in nasal lavage fluid following the antigen-antibody reaction in actively sensitized guinea pigs

To investigate the mechanism for the amelioration by olopatadine hydrochloride (olopatadine) of allergic rhinitis, we determined its effects on the increase of chemical mediator concentrations in nasal lavage fluid following the intranasal antigen challenge in guinea pigs actively sensitized with DNP-Ascaris. The concentrations of histamine and peptide-leukotrienes increased 10 min after the challenge. Olopatadine at 10 mg/kg (p.o.) significantly prevented the increase of histamine and tended to inhibit the increase of peptide-leukotrienes. The inhibition by olopatadine of the nasal symptoms seems to involve the inhibitory effect on the releases of histamine and, possibly, p-LTs into the nasal cavity.     

In vivo evaluation of novel hyaluronan/chitosan microparticulate delivery systems for the nasal delivery of gentamicin in rabbits.

Biodegradable microparticles containing gentamicin were prepared using chitosan hydroglutamate (CH), hyaluronic acid (HA) and a combination of both polymers by a solvent evaporation method. These formulations were administered nasally via an insufflator. Gentamicin was also administered nasally into rabbits as a solution and powder (a physical mixture of gentamicin and lactose), intravenously (IV) and intramuscularly (IM). The resultant serum levels of gentamicin were determined by Fluorescence Polarisation Immunoassay (FPIA). The bioavailability of gentamicin was poor when administered as a nasal solution (1.1%) and dry powder (2.1%) when compared with IV. However, the microparticulate systems composed of CH and HA/CH considerably enhanced the bioavailability of gentamicin (31.4 and 42.9%, respectively,) with HA microparticles inducing a less significant enhancement (23.3%). Previous in vitro dissolution and frog palate studies indicated that these microparticulate formulations were all mucoadhesive and demonstrated prolonged drug release. Such findings were translated into an increase in the bioavailability of gentamicin when compared with a simple nasal solution in vivo. When HA and CH were combined in the HA/CH formulation, the polymers appeared to improve the absorption of incorporated gentamicin synergistically in comparison to the individual polymers, suggesting a promising nasal delivery system.     

Preparation and Characterisation of Mucoadhesive Nasal Gel of Venlafaxine Hydrochloride for Treatment of Anxiety Disorders

The aim of the present study is to prepare and evaluate mucoadhesive nasal gels of venlafaxine hydrochloride. Mucoadhesive nasal gels were prepared using polymers like carbopol 934 and sodium alginate and characterized in terms of viscosity, texture profile analysis, ex vivo drug permeation profiles and histopathological studies. The results show that values of viscosity, hardness and adhesiveness increase while those of cohesiveness decrease with corresponding increase in concentration of the polymers. Ex vivo drug permeation profiles showed that formulation containing 5% sodium alginate provided a better controlled release of the drug than the other formulations over a period of 12 h. Histopathological studies assured that gels containing different polymers did not produce any significant change in the nasal mucosae of goat even after 12 h permeation study. Mucoadhesive nasal gel of venlafaxine hydrochloride is a novel dosage form which delivers the drug directly into systemic circulation and provides controlled release of the drug.     

Effects of fexofenadine hydrochloride in a guinea pig model of antigen-induced rhinitis

Allergic rhinitis is an inflammatory disease of the nasal mucosa, induced by histamine, leukotrienes, and other substances released from mast cells. Fexofenadine hydrochloride, the active metabolite of terfenadine, is a novel, nonsedating antiallergic drug having H1 receptor antagonistic activity. Fexofenadine is effective for the treatment of allergic rhinitis. However, its mechanism of action in attenuating nasal congestion has not yet been elucidated. Therefore, we first examined the effects of fexofenadine on a guinea pig model of antigen-induced rhinitis. We also evaluated the effects of mepyramine, zafirlukast and ramatroban in this model; these drugs are an H1 receptor antagonist, a selective leukotriene antagonist and a selective thromboxane antagonist, respectively. Rhinitis was induced by ovalbumin (OVA) instillation into the nasal cavity of animals that had been sensitized by two earlier OVA injections (s.c. and i.p.). The nasal airway resistance was measured for 45 min after the challenge. Fexofenadine hydrochloride (20 mg/kg) and terfenadine (20 mg/kg) administered orally 70 min prior to the challenge significantly inhibited (fexofenadine, p < 0.001, terfenadine, p < 0.05) the increase in nasal airway resistance. Ramatroban (30 mg/kg) administered orally 60 min prior to the challenge also significantly inhibited (p < 0.05) the increase in nasal airway resistance. In contrast, mepyramine (3 mg/kg i.v.) and zafirlukast (3 mg/kg p.o.) failed to reduce the increase in nasal airway resistance. These results suggest that thromboxane may be involved in the increase in the nasal airway resistance in this model. Accordingly, fexofenadine may reduce the increase in nasal airway resistance by inhibiting the release of chemical mediators, including thromboxane, that are involved in the increase in nasal airway resistance in this model.     

Nasal administration of low molecular weight heparin

The main objective of this study was to determine if the systemic absorption of therapeutic amounts of heparin was possible following nasal administration. Sprague-Dawley rats received nosedrops containing a low molecular weight heparin (LMWH) or unfractionated heparin (UFH) formulated with or without tetradecylmaltoside (TDM). TDM is a nonionic surfactant that has been previously shown to be a potent absorption enhancer in studies with peptide drugs. LMWH/UFH absorption was determined by measuring plasma anti-Factor Xa activity. The inclusion of 0.25% TDM in nasal formulations containing LMWH resulted in a significant increase in the C(max) and area under the curve (AUC) of anti-Factor Xa activity when compared to LMWH formulated in saline alone. The addition of TDM to a nasal formulation containing UFH resulted in a much smaller increase in the C(max) and the AUC of anti-Factor Xa activity. The absolute bioavailability of LMWH was increased from 4.0 +/- 0.4% in the absence of TDM to 19 +/- 0.3% in the presence of TDM. The reversibility of the absorption enhancing effect of TDM was studied by applying LMWH nasally 60 or 120 min after the enhancer. The effect of TDM on the nasal epithelia appeared to be rapidly reversible. In conclusion, nasal delivery of LMWH, but not UFH, was successful when an absorption enhancer was included to increase nasal permeability.     

3种中和剂对常用消毒剂在Vero细胞上的中和效果

 目的  研究0.5%硫代硫酸钠、10%胰蛋白胨大豆肉汤（tryptic soy broth， TSB）培养基、10%Letheen肉汤培养基对实验室常用的4种消毒剂的中和效果，为疫苗生产和检定中科学选择中和剂提供依据。 方法  取生长良好的Vero细胞接种于96孔培养板，每组8个复孔，置于37 ℃、5% CO2培养过夜。将3种中和剂分别与杀孢子剂、0.5%“84”消毒液、酸性苯酸盐、碱性苯酚盐4种消毒剂中和后，接种于单层生长的Vero细胞，显微镜下观察细胞生长情况。结果  0.5%硫代硫酸钠分别与杀孢子剂、0.5%“84”消毒液中和后接种细胞，8孔细胞全部存活；而0.5%硫代硫酸钠分别与酸性苯酚盐和碱性苯酚盐的中和产物接种细胞后，细胞全部死亡。10% TSB培养基分别与酸性苯酚盐、碱性苯酚盐中和后接种细胞，8孔细胞全部存活；而10% TSB培养基分别与杀孢子剂和0.5%“84”消毒液的中和产物接种细胞后，细胞全部死亡。10%Letheen肉汤培养基接种细胞后，8个孔细胞全部死亡。结论  0.5%硫代硫酸钠可中和杀孢子剂和0.5%“84”消毒液的消毒作用，10%TSB培养基可中和酸性苯酚盐和碱性苯酚盐的消毒作用。10%Letheen肉汤培养对Vero细胞有毒性作用。     

吸收促进剂对人参皂苷Rg1鼻腔吸收的促进作用及鼻腔毒性

目的考察吸收促进剂对人参皂苷Rg1鼻腔黏膜的吸收促进作用以及对鼻腔黏膜毒性。方法采用大鼠在体鼻腔循环考察人参皂苷Rg1鼻腔吸收及吸收促进剂的促吸收作用，在体蟾蜍上腭纤毛法评价药物对纤毛运动的影响；考察吸收促进剂对家兔血红细胞的溶血作用、对鼻腔循环液中总蛋白和乳酸脱氢酶的影响及对鼻腔黏膜形态学的影响。结果人参皂苷Rg1鼻腔吸收必须加入吸收促进剂。各种吸收促进剂的促进作用为：1%去氧胆酸钠作用显著；1%甘草酸二钾和1%氮酮作用中等；1% Tween-80，2% β-环糊精、0.5%冰片、0.5%壳聚糖、5%羟丙-β-环糊精和0.1% EDTA等作用微弱。吸收促进剂对鼻腔黏膜毒性影响：1%去氧胆酸钠、1%氮酮和1%甘草酸二钾毒性大；1% Tween-80，2% β-环糊精及5%羟丙-β-环糊精等毒性中等；0.5%冰片、0.5%壳聚糖和0.1% EDTA毒性小。结论0.5%冰片与0.5%壳聚糖可安全有效地促进人参皂苷Rg1的鼻腔吸收。     

Diesel Exhaust Particulates Induce Nasal Mucosal Hyperresponsiveness to Inhaled Histamine Aerosol

The prevalence of allergic rhinitis is increasing in many countries.It has been reported that the prevalence rate of allergic rhinitiscaused by pollens in air-polluted areas are higher than thatin nonpolluted areas. Therefore, it is important to determinewhether air pollutants are related to the increase in the prevalencerate of allergic rhinitis. In this respect, it is necessaryto elucidate whether exposure to air pollutants affects thenasal mucosa and causes nasal mucosal hyperresponsiveness tochemical mediators released by antigen-antibody reactions. Inthe present study using, guinea pigs, we investigated effectsof diesel exhaust particulates on (1) nasal airway resistance,(2) increases in nasal airway resistance and secretion inducedby histamine aerosol, and (3) vascular permeability and theincrease in vascular permeability induced by histamine in dorsalskin, since vascular permeability is an important factor involvedin increased nasal airway resistance and secretion. Intranasalpressure and nasal secretion from the nostril were measuredas markers of nasal airway resistance and exocrine activityof the nasal mucosa, respectively. A 30-min administration ofa suspension of diesel exhaust particulates into the nasal cavitiescaused a significant increase in intranasal pressure. The administrationalso augmented an increase in intranasal pressure and nasalsecretion induced by histamine aerosol. In dorsal skin, dieselexhaust particulates increased vascular permeability. Dieselexhaust particulates also augmented vascular permeability inducedby histamine. In conclusion, diesel exhaust particulates arepotent in increasing nasal airway resistance and augmentingincreases in nasal airway resistance and nasal secretion inducedby histamine. These properties of diesel exhaust particulatesare likely derived in part from the augmentation vascular permeabilityby these particulates.