Microspheres of essential oil in polylactic acid and poly(methyl methacrylate) matrices and their blends

This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.

The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same.     

国产和日本产柱晶白霉素与其它常用抗生素的体外抗菌活性比较

用试管双倍稀释法测定国产与日本产柱晶白霉素对104株革蓝氏阳性球菌的体外抗菌活性并与9种常用抗生素进行比较。结果表明:国产和日本产柱晶白霉素对革蓝氏阳性球菌的抑菌率基本一致。国产柱晶白霉素的抑菌、杀菌作用强于红霉素;略优于氯霉素和四环素;与青霉素G、庆大霉素基本相似,但不及氨苄青霉素、苯唑青霉素、丁胺卡那霉素及强力霉素。     

高压脉冲电场对乳铁蛋白抑菌性能的影响

研究了高压脉冲电场(PEF)对乳铁蛋白(LF)的抑菌性能的影响。结果表明,LF质量浓度、电场强度、脉冲频率、脉冲数的增加,有利于LF抑菌能力的增强,而温度的升高会使之减弱。电场强度为35 kV/cm时,LF的抑菌能力达到最大值。LF的质量浓度越高,对电场强度的变化越敏感。当脉冲个数达到744时,LF的相对抑菌能力提高了34%。处理温度为15～55℃时,PEF处理的LF的相对抑菌性能增长了5%左右。当温度升高至65℃时,LF的相对抑菌能力下降显著,降低了约22%。     

人源性多肽pCM-19抗菌机制的初步研究

目的：初步分析人源性多肽pCM-19的抗菌作用机制。方法：利用荧光素掺入破损细胞膜的原理，采用流式荧光激活细胞分析（FACScan）和扫描电子显微镜分析pCM-19对靶菌膜的作用机制。结果：FACS分析法结果显示pCM-19处理后的大肠杆菌PI着染细菌比例明显高于未处理组，并且随作用时间的延长，PI着染BL-21菌比例增大，20min时达最高水平，20min以后反而降低；扫描电子显微镜观察到pCM-19处理后的大肠杆菌有明显的表面形态学的改变，如细菌体积缩小、细菌表面出现皱缩、凹陷似有孔洞形成。结论：人源性多肽pCM-19可能作用于细菌细胞壁和（或）细胞膜，通过改变其通透性而发挥杀菌作用。     

黑龙江省地产中药抗菌作用的实验研究

为开发我省地产中药资源，作者对地产中草药进行了较为全面系统的研究，本文仅报道我省几种地产中草药抗菌作用的实验研究，将抗菌效果好的艾叶、泽兰、大活、木贼、苦参和与之对照的紫丁香的抗菌作用进行对比，结果表明，紫丁香的抗菌作用效果好，毒副作用小。另外所试中３药因抗菌作用不如叶、泽兰、大活、木贼、苦参、紫丁香具有较好抗菌作用。是很有研究价值的中药。     

不同微生物诱导家蝇幼虫表达抗菌肽的特性

研究不同微生物诱导家蝇幼虫表达的抗菌肽特性.用3种不同的病源菌通过针刺感染的方法诱导家蝇幼虫表达抗菌肽,通过Sephadex G25分离,用Hult mark改进法和抑菌圈测定法作抑菌试验,用毛细管电泳（CE）分析不同微生物诱导得到的抗菌肽样品差异,检测抗菌肽的热稳定性和酸碱耐受性.发现不同微生物诱导产生的家蝇抗菌肽具有广谱抑菌性,但不同样品对不同病源菌抑菌活性有差异,不同测定抑菌效果的方法对抑菌结果有影响,各种抗菌肽样品CE蛋白谱具有明显不同.抗菌肽样品都具有热稳定性和酸碱耐受性.说明不同微生物诱导产生的家蝇抗菌肽类型以及抗菌肽含量与诱导源有关,抗菌肽为家蝇幼虫体内固有成分,诱导增加了抗菌肽的表达量同时刺激新抗菌肽的产生.用志贺氏菌、金黄色葡萄球菌、鼠伤寒沙门氏菌诱导家蝇幼虫可产生较多含量高活性好的抗菌肽.     

四种口服头孢菌素的体外抗菌活性的比较研究

本文报道口服Cefixime对900株需氧菌和厌氧菌的体外抗菌作用,并与其它口服的头孢克罗、头孢羟氨苄和头孢氨苄进行了比较。Cefixime对链球菌具较强作用,但对葡萄球菌的作用较差;对肠球菌无效。对肠杆菌科细菌的抗菌活性四者之中以Cefixime最强。Cefixime对头孢氨苄耐药株仍具高度活性,其MIC均值可降低60～1200倍以上。绿脓杆菌、硝酸盐阴性杆菌、鲁氏不动杆菌和产碱杆菌对Cefixime和其它3种头孢菌素的敏感性均较差。四者对厌氧菌的作用除厌氧球菌外其抗菌活性都很弱。Cefixime对β-内酰胺酶稳定,口服吸收良好,抗菌作用强,是一个值得进行临床研究的口服头孢菌素。     

甲氟哌酸体外抗菌活性及对耐药感染者的治疗

对天津市新近临床分离的414株细菌进行了甲氟哌酸(Pflx)和氟哌酸(Nflx)体外抗菌活性研究。结果显示Pflx对绝大多数肠杆菌和细菌、不动杆菌有良好抗菌活性,抑菌率>90％。对绿脓杆菌、MSSA及凝固酶阴性葡萄球菌有中度抗菌作用,抑菌率分别为85％、87.5％、87.5％。对MRSA和链球菌抗菌活性稍差,抑菌率在40％～68.42％之间。Nflx体外抗菌活性和Pflx相似。此外,18例药敏试验耐Pflx和Nflx细菌感染患者,经Pflx治疗,肺化脓症1例显效,余17例难治性尿路感染者1例痊愈、9例显效、5例进步、2例无效。     

Efficacy and functionality of silver-coated textiles in patients with atopic eczema

BACKGROUND: Microbial skin colonization with Staphylococcus aureus is known to play an important role in atopic eczema (AE). Recently, an antibacterial effect of silver-coated textiles on S. aureus colonization has been demonstrated. OBJECTIVES: To investigate clinical efficacy and functionality of silver-coated textiles in AE, a multicentre, double-blind, placebo-controlled trial was conducted. PATIENTS/METHODS: From November 2001 to August 2002, 68 consecutive outpatients clinically diagnosed with generalized AE were included in the study. Inclusion criteria were the clinical diagnosis of AE with a moderate severity as measured by the scoring of atopic dermatitis (SCORAD) index with at least 20. Patients were instructed to wear either silver-coated (verum, 35 patients + 2 dropouts) or cotton garments (placebo, 22 patients + 9 dropouts) directly on the skin for 2 weeks. Only basic skin care and ongoing therapy with topical steroids or oral antihistamines was permitted. Clinical severity was assessed using the 'SCORAD' before, during and at the end of study. Quality of life (QOL), wearing comfort (WC) and functionality (FU) of study clothes were measured in parallel. Patients documented their subjective and objective symptoms daily. RESULTS: In the verum group, eczema improved significantly after 1 week with further enhancement until the end of study (P = 0.03 and P < 0.001). Silver-coated textiles were comparable to cotton in WC and FU. Pruritus and self-assigned skin condition improved significantly more than with placebo (P < 0.001 and P = 0.003). CONCLUSIONS: In conclusion, silver-coated textiles are able to improve objective and subjective symptoms of AE significantly within 2 weeks, showing a good wearing comfort and functionality comparable to cotton.