Preparation of Various Solid-Lipid Beads for Drug Delivery of Enrofloxacin

Solid-lipid beads were prepared to retard the release rate of enrofloxacin and to mask its bitter taste using carrageenan or sodium alginate as a shell material and either cacao butter or Witepsol W-35 as a solid lipid core. Sodium alginate was a better shell material than carrageenan and the highest loading efficiency was obtained using 2% sodium alginate. The alginate beads had a spherical morphology and a sturdy shell structure. The enrofloxacin release rate at room temperature was greatly reduced. Solid-lipid beads have the potential to mask the bitter taste of enrofloxacin and extend its release rate.     

A Comparison of Sodium Fusidate Ointment (‘Fucidin’)Alone Versus Oral Antibiotic Therapy in Soft-Tissue Infections

Summary

A Study Was Carried Out In 90 Patients With Superficial, Soft-Tissue Infections To Compare The Effectiveness Of Topical Treatment With 2 % Sodium Fusidate Ointment Used Alone, And Oral Antibiotic Therapy (Clindamycin, Erythromycin, Or Flucloxacillin) Plus A Placebo Ointment. The Results Showed That The Number Of Days For Healing To Take Place Was Significantly Shorter With Sodium Fusidate Ointment, And There Was Also A Highly Significant Preference For It Over Oral Antibiotic Therapy In The Subjective Assessment Of Clinical Response. Bacteriological Investigations Of Swabs From 58 Of The Patients Showed Staphylococcus Aureus To Be The Most Frequently Isolated Pathogen: 72% Of The Strains Were Penicillin-Resistant But All Were Sensitive To Sodium Fusidate. It Is Suggested That Oral Antibiotic Therapy Should Be Reserved For Those Cases Where There Is Evidence Of Systemic Spread Of The Infection And That Sodium Fusidate Ointment, With Or Without Surgical Drainage, Should Be The Standard Initial Treatment In The Out-Patient Andgeneral Practice Situation.     

The toxicity mechanism of sodium fluoride on fertility in female rats

Recognition of the harmful effects of sodium fluoride (NaF) on human reproduction is increasing, especially as it relates to female reproduction. However, the mechanism by which NaF interferes with female reproduction is unclear. The aims of the present study were to investigate the effects of fluoride exposure on female fertility and to elucidate the mechanisms underlying these effects. Female Sprague–Dawley rats were divided into three groups: one control group and two NaF-treated groups (100 and 200 mg/L in the drinking water for 12 weeks). Several parameters were evaluated, including: (i) fluoride concentrations; (ii) estrogen (E₂) and progesterone (P) concentrations; (iii) estrogen receptor alpha protein (ERα); (iv) progesterone receptor (PgR) protein; (v) follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) protein. The results indicated that administration of NaF lead to significant decreases in E₂ and P levels in the serum and in the expression of FSHR protein. In addition, fluoride exposure significantly increased Erα and PgR protein expression levels and LHR protein expression. These results suggest that the reproductive hormone reduction and the abnormalities of related receptor proteins expression are important factors underlying the decreased fertility observed in female rats that have been exposed to NaF.     

EFFECT OF DEPROTEINIZATION AND TUBULAR OCCLUSION ON MICROTENSILE BOND STRENGTH AND MARGINAL MICROLEAKAGE OF RESIN COMPOSITE RESTORATIONS

Dentin adhesion procedure presents limitations, especially regarding to lifetime stability of formed hybrid layer. Alternative procedures have been studied in order to improve adhesion to dentin. Objective: The aim of this study was to evaluate in vitro the influence of deproteinization or dentin tubular occlusion, as well as the combination of both techniques, on microtensile bond strength μTBS) and marginal microleakage of composite resin restorations. Material and Methods: Extracted erupted human third molars were randomly divided into 4 groups. Dentin surfaces were treated with one of the following procedures: (A) 35% phosphoric acid gel (PA) + adhesive system (AS); (B) PA + 10% NaOCl + AS; (C) PA + oxalate + AS and (D) PA + oxalate + 10% NaOCl + AS. Bond strength data were analyzed statistically by two-way ANOVA and Tukey''s test. The microleakage scores were analyzed using Kruskal-Wallis and Mann-Whitney non-parametric tests. Significance level was set at 0.05 for all analyses. Results: μTBS data presented statistically lower values for groups D and B, ranking data as A>C>B>D. The use of oxalic acid resulted in microleakage reduction along the tooth/restoration interface, being significant when used alone. On the other hand, the use of 10% NaOCl alone or in combination with oxalic acid, resulted in increased microleakage. Conclusions: Dentin deproteinization with 10% NaOCl or in combination with oxalate significantly compromised both the adhesive bond strength and the microleakage at interface. Tubular occlusion prior to adhesive system application seems to be a useful technique to reduce marginal microleakage.     

Evidence for the functional compartmentalization of spike generating regions of rat mdbrain dopamine neurons recorded in vitro

The regulation of spike generation in rat midbrain dopamine (DA) neurons was investigated using in vitro intracellular recordings. DA neurons fired long (greater than 1.8 ms) action potentials that exhibited comparatively depolarized spike thresholds (approx. −35 to −45 mV). Depolarization of the DA neuron increased the duration and the threshold of subsequent action potentials. The action potential was composed of two distinct components, a fast (0.8–1.5 ms duration) initial segment (IS) spike which triggered a slow (1.5–3 ms duration) somatodendritic (SD) component. Cobalt application (2 mM) blocked the SD spike component and revealed fast TTX-sensitive spikes. These fast spikes were also observed in untreated neurons following large hyperpolarizing pulses, and showed consistent changes in threshold and amplitude during membrane depolarization. Administration of 4-aminopyridine decreased the threshold of this TTX-sensitive spike, whereas tetraethylammonium (TEA) had no effect. When the fast spike was blocked by TTX, depolarization was ineffective in triggering further spike activity. However, after the administration of TEA (but not 4-AP), high threshold cobalt-sensitive spike activity could be triggered by relatively small depolarizations. TEA increased the duration of the SD portion of the action potential without altering the action potential threshold. The effect of 4-AP on spike threshold and the increase in SD spike duration caused by TEA were similar in nature to the changes in action-potential waveforms produced by polarizing the DA neuron membrane. Drawing from evidence gathered here and in previous in vivo studies, the properties of the TTX-sensitive fast spike are consistent with those of the IS spike component of the action potential, whereas the SD component is similar in nature to the high threshold calcium spike. One hypothesis that can be drawn from these studies is that dendritic and axonal spiking regions may exist in different functional subcompartments of the DA neuron, and may be independently modulated by pharmacologically distinct conductances. Under these conditions, synaptic influences could exist to modulate dendritic excitability and thus regulate putative dendritic spike-dependent functions, such as neuronal activity state, electrical coupling, and dendritic DA synthesis and release.     

过量氟对大鼠体内、外I型胶原蛋白的影响

为研究过量氟对大鼠骨中I型胶原蛋白的影响 ,经饮水投氟复制大鼠氟中毒模型 (NaF 2 2 1mg L) ,测定氟中毒大鼠血清中骨钙素含量 ,骨中无机质、胶原含量和胶原交联度 ;酶消化法分离大鼠颅骨成骨细胞 ,经 0 5mmol L和 1 0mmol LNaF染毒 4 8h后 ,用免疫组化方法观察过量氟对成骨细胞I型胶原表达水平的影响。结果表明 :大鼠染毒两个月后 ,氟中毒大鼠血清骨钙素含量、骨中无机质百分含量较对照组显著增加 (P<0 0 5 ) ;骨中胶原含量、胶原交联度较对照组显著下降 (P <0 0 5 ) ;体外成骨细胞染氟后 ,I型胶原蛋白分泌明显减少。提示过量氟可抑制I型胶原蛋白的合成 ;胶原蛋白减少是导致氟骨症的原因之一     

经皮穿刺腰椎间盘切除术与透明质酸钠联合治疗腰椎间盘突出症

目的　研究经皮穿刺腰椎间盘切除术 (PL D)与透明质酸钠联合治疗腰椎间盘突出症的疗效。方法　 48例患者随机分为两组 ,采用经皮穿刺 PL D联合透明质酸钠骶管注射 (治疗组 ) 2 6例 ,单纯经皮穿刺 PL D(对照组 ) 2 2例。术后每 3个月随访一次 ,至术后 2年 ,根据改良的 Macnab标准判断疗效。结果　治疗组痊愈 16例 ,显效 5例 ,有效 4例 ,无效 1例。显效率为 80 .77%。对照组痊愈 8例 ,显效 7例 ,有效 5例 ,无效 2例。显效率为6 8.18%。两组疗效比较 ,有统计学意义 (P<0 .0 5 )。结论　腰椎间盘切除术与透明质酸钠联合治疗具有疗程短、见效快及安全等优点 ,是穿刺治疗腰椎间盘突出症的一种理想方法     

The role of altered sodium currents in action potential abnormalities of cultured dorsal root ganglion neurons from trisomy 21 (down syndrome) human fetuses

Trisomy 21 (Down syndrome) results in abnormalities in electrical membrane properties of cultured human fetal dorsal root ganglion (DRG) neurons. Action potentials have faster rates of depolarization and repolarization, with decreased spike duration, compared to diploid neurons. In order to analyze the faster depolarization rate observed in trisomic neurons, we examined sodium currents of cultured human fetal DRG neurons from trisomy 21 and control subjects, using the whole-cell patch-clamp technique. The neurons were replated in culture to reduce dendritic spines. Two components of the sodium current were identified: (1) a fast, tetrodotoxin (TTX)-sensitive current; and (2) a slow, TTX-resistant component. The inactivation curves of both current types in trisomic neurons showed a shift of approximately 10 mV towards more depolarized potentials compared to control neurons. Thus, whereas essetially all of the fast sodium channels were inactivated at normal resting potentials in control neurons, approximately 10% of these channels were available for activation in trisomy 21 cells. Furthermore, the fast current showed accelerated activation kinetics in trisomic neurons. The slow sodium current of trisomic neurons showed slower deactivation kinetics than control cells. No differences were observed between trisomic and control neurons in the maximal conductance or current densities of either fast or slow current components. These data indicate that the greater rate of depolarization in trisomy 21 neurons at resting potentials is primarily due to activation of residual fast sodium channels that also have a faster time course of activation.     

阿魏酸钠颗粒人体生物利用度和生物等效性研究

目的在健康成年男性志愿者中比较阿魏酸钠颗粒与阿魏酸钠胶囊的相对生物利用度，评价二者的生物等效性。方法20名受试者单剂量交叉口服阿魏酸钠颗粒与阿魏酸钠胶囊，用HPLC法紫外检测器测定不同时间点的血药浓度，计算其药代动力学参数，评价两制剂的生物等效性。结果受试制剂及参比制剂Cmax分别为（3．91±1．88）、（5．00±2．71）mg·L^-1；Tmax分别为（0．34±0．08）、（0．33±0．15）h；t1／2（ke）分别为（0．68±0．19）、（0．66±0．18）h；AUC0-tn分别为（3．05±1．2）、（3．08±1．36）mg·h·L^-1；单次口服受试制剂的相对生物利用度F0-tn、F0-∝分别为（102．61±16．03）％、（102．26±15．54）％。对药动学参数AUC、Cmax、Tmax，等经统计学分析，无显著性差异。结论受试制剂和参比制剂具有生物等效性。     

润坦注射液对大鼠局灶性脑缺血再灌注后神经元凋亡的影响

目的研究润坦对局灶性脑缺血再灌注的神经保护效应.方法制备线栓法大脑中动脉闭塞再灌注模型,干预组每天给予润坦3 mg/kg,对照组给予等量生理盐水,每日对大鼠神经功能缺损进行评分,于再灌注12 h、24 h、48 h和5 d处死动物,切片作TUNEL原位凋亡检测.结果润坦可以显著改善术后第2 d大鼠的神经功能缺损(P＜0.05),降低致死率,减少再灌注24 h以后的细胞凋亡数目(P＜0.05).结论润坦可以抑制大鼠脑缺血再灌注后神经元凋亡,对急性期脑梗死可能有神经保护效应.