Allergic contact dermatitis caused by topical antiacne drugs

Acne is a chronic inflammatory disease for which a long-lasting therapy, very often with topical drugs, is necessary. Despite the fact that several topical antiacne drugs (in particular, tretinoin, benzoyl peroxide, clindamycin and erythromycin) are used for many years, often on broad skin surfaces and for long periods of time, their potential for contact sensitization is low. Their potential for phototoxic and photoallergic reactions is also low. Much more frequent is irritant contact dermatitis caused by some of these drugs, in particular, retinoids and benzoyl peroxide, for which the short contact therapy has been recently suggested.     

EFFECT OF ERYTHROMYCIN ON GASTRIC DYSMOTILITY AND NEUROENDOCRINE PEPTIDES IN RATS WITH DIABETES MELLITUS

Objective To investigate the effect of erythromycin on the contractive activity of the isolated gastric antrum smooth muscle and somatostatin (SS), vasoactive intestinal peptide (VIP), motilin (MTL), and substance P (SP) in plasma and isolated gastric antrum tissue of diabetes mellitus (DM) rat models. Methods Thirty male Sprague-Dawley rats were divided into three groups: control group (n = 10), DM group (n =10), and erythromycin group (DM models with erythromycin treatment, n = 10). A single dose of streptozotocin (100 mg/kg,dissolved in 0.1 mol/L citric acid buffer, pH4.5) was injected intraperitoneally. After 48 to 72 hours, rats with blood glucose above 16.7 mmol/L and urine glucose level to be ( ) to ( ) over one week were considered successful DM models. The resting tension, mean contractile amplitude and frequency of spontaneous change in isolated longitudinal and circular gastric antrum smooth muscle strips were measured. SS, VIP, MTL, and SP levels in plasma and gastric antrum tissue were measured using radioimmunoassay. Results (1) In the isolated gastric antrum smooth muscle strips, the gastric motility parameters were lower in DM group than those in control group except circular smooth muscle contractile amplitude and longitudinal smooth muscle contractile frequency. The gastric motility parameters were significantly strengthened in erythromycin group, compared with DM group except longitudinal smooth muscle resting tension (P ＜ 0.01). (2) Plasma SS, VIP, and MTL concentrations in DM group were higher than those in control (P ＜ 0.05), while the SP level decreased (P ＜ 0.05). In the gastric antrum, SS of DM group was significantly higher than that of control group (P ＜ 0.01), while SP and MTL levels were lower than those of control group (P ＜ 0.05 and P ＜ 0.01, respectively). However, the level of VIP in gastric antrum tissue did not change among three groups. The plasma level of SS in erythromycin group was higher than that of DM group(P＜ 0.05). (3) The blood glucose was lower in erythromycin group than DM group (P ＜ 0.01).Conclusions Erythromycin has direct effects on contractive activity of gastric smooth muscle in diabetic rats, but there are few effects on neuroendocrine peptides. Gastric-motility disorders in diabetic rats have a correlation with the changes of neuroendocrine peptide levels in plasma and gastric antrum tissue.     

红霉素联合阿奇霉素短程治疗小儿支原体肺炎临床分析

目的探讨红霉素联合阿奇霉素短程治疗和红霉素、阿奇霉素常规治疗小儿支原体肺炎是否疗效相同;并作安全性比较.方法将56例患儿随机分为两组,对照组26例,观察组30例,并记录症状、体征及胸部X线、肝功能变化.结果两组治疗3 d后,症状均明显好转,且2周后复查X线阴影基本吸收,疗效无差异.结论红霉素联合阿奇霉素短程治疗与常规治疗疗效无差异,安全性相同.但前者可减少用药频率,缩短住院时间.     

Role of antibiotic ligand in nascent peptide-dependent ribosome stalling

Specific nascent peptides in the ribosome exit tunnel can elicit translation arrest. Such ribosome stalling is used for regulation of expression of some bacterial and eukaryotic genes. The stalling is sensitive to additional cellular cues, most commonly the binding of specific small-molecular-weight cofactors to the ribosome. The role of cofactors in programmed translation arrest is unknown. By analyzing nascent peptide- and antibiotic-dependent ribosome stalling that controls inducible expression of antibiotic resistance genes in bacteria, we have found that the antibiotic is directly recognized as a part of the translation modulating signal. Even minute structural alterations preclude it from assisting in ribosome stalling, indicating the importance of precise molecular interactions of the drug with the ribosome. One of the sensors that monitor the structure of the antibiotic is the 23S rRNA residue C2610, whose mutation reduces the efficiency of nascent peptide- and antibiotic-dependent ribosome stalling. These findings establish a new paradigm of the role of the cofactor in programmed translation arrest in which a small molecule is recognized along with specific nascent peptide sequences as a composite structure that provokes arrest of translation. A similar mechanism could be used by the ribosome to sense a variety of cellular metabolites.     

口服阿奇霉素与静脉滴注红霉素治疗小儿肺炎支原体感染的疗效比较

目的比较阿奇霉素口服、红霉素静脉滴注治疗小儿肺炎支原体感染的效果。方法 185例肺炎支原体感染患儿随机分为两组,常规组92例予以红霉素静脉滴注,实验组93例予以阿奇霉素口服,比较两组的临床疗效和不良反应。结果实验组的总有效率显著高于常规组(95.70%vs. 86.96%, P<0.05), X线症状消失时间、啰音消失时间、退热时间、咳嗽消失时间以及住院时长均显著少于常规组(P<0.05),不良反应发生率显著低于常规组(6.45%vs. 18.48%, P<0.05)。结论阿奇霉素口服治疗肺炎支原体感染的患儿效果明显优于红霉素静脉滴注,用药安全性较高。     

红霉素耐药葡萄球菌对克林霉素诱导性耐药的研究

目的：了解临床分离的红霉素耐药葡萄球菌对克林霉素诱导性耐药的发生率，比较双纸片扩散法（D试验）中纸片之间距离对试验结果的影响。方法VITEK-2微生物分析系统检测为红霉素耐药、克林霉素敏感或中介的葡萄球菌135株，其中金黄色葡萄球菌（SA）为55株，凝固酶阴性葡萄球菌（CNS）为80株。比较红霉素纸片与克林霉素纸片边距15 mm与26 mm对结果的影响。结果 D试验阳性率为57.0%，其中SA阳性率70.9%， CNS为47.5%（P＜0.01）。纸片边距15 mm组D试验阳性77株，26 mm组仅69株，漏检率10.4%（P＜0.05）。结论实验室应常规开展D试验，D试验中双纸片间距以15 mm为佳。     

A common clone of erythromycin-resistant Streptococcus pneumoniae in Greece and the UK

Objective  To investigate the possible genetic relationship among erythromycin-resistant Streptococcus pneumoniae strains isolated in Greece and the UK.
Methods  During 1995–97, 140 S. pneumoniae strains were isolated from clinical specimens submitted to the microbiology departments of the two main children's hospital in Athens. All erythromycin-resistant strains were further studied with respect to the presence of genes encoding for the two major mechanisms of macrolide resistance, their serotypes, and pulsed-field gel electrophoresis (PFGE) types, in comparison to a previously characterized UK erythromycin-resistant clone.
Results  Eleven of the 140 isolates (7.9%) were resistant to erythromycin; nine of these were susceptible to penicillin. Serotyping allocated seven, three and one isolates to serotypes 14, 19F and serogroup 6, respectively. The mef A gene was detected in seven isolates (five serotype 14 and two serotype 19F), erm B in two (one serotype 19F and the serogroup 6 isolate), whilst in the remaining two isolates no resistance gene could be detected by polymerase chain reaction (PCR). Pulsed-field gel electrophoresis of genomic DNA showed that five Greek serotype 14 isolates belonged to the same chromosomal type as the serotype 14 erythromycin-resistant UK clone.
Conclusions  The present study showed that erythromycin resistance among the S. pneumoniae isolates was mostly owing to the efflux mechanism and suggested a possible clonal spread of serotype 14 erythromycin-resistant S. pneumoniae strains between Greece and the UK.     

红霉素对家兔结肠平滑肌条收缩活动的兴奋作用

通过家兔结肠离体平滑肌条实验，观察红霉素（1．4、14μmol/L及0．14、1．4mmol/L)对结肠自发收缩活动的影响。结果表明：1．4μmol/L红霉素对结肠各部位肌条的收缩活动无明显影响；14μmol/L红霉素增加结肠头端环行肌（CMPC）和结肠尾端环行肌（CMDC）的收缩幅度和频率，但对结肠头端纵行肌（LMPC）和结肠尾端纵行肌（LMDC）的收缩活动无明显影响；0．14和1．4mmol/L红霉素明显增加结肠各部位肌条的收缩幅度（LMDC除外）和频率，同时增大CMPC、LMDC和CMDC的张力。异搏定（1μmol/L）部分阻断红霉素（0．14mmol/L）对LMPC和CMDC收缩幅度和频率的兴奋作用；六甲溴铵（10μmol/L）、阿托品（1μmol/L）和L－精氨酸（1μmol/L）不影响红霉素（0．14mmol/L)的兴奋作用。上述结果表明，红霉素兴奋家兔结肠头端和尾端纵行肌和环行肌的自发收缩活动，该兴奋作用部分与Ca^2 通道有关，但与胆碱能途径和NO合成无关。     

红霉素对兔消化间期胆囊运动的兴奋作用

为研究红霉素（ＥＭ）对兔胆囊（ＧＢ）运动的影响。动物禁食后静脉麻醉,同步记录ＧＢ内压及奥迪氏括约肌（ＳＯ）肌电,静脉注射ＥＭ后ＧＢ运动增强,注药后１０Ｓ内出现第１相效应,表现为ＧＢ内压同;注药后１０ｍｉｎ开始出现第２相效应,主要是ＧＢ位相性收缩增强。ＥＭ静牟效应同ＥＭ静脉注射个似。静脉脉注射阿托品或颈部迷走神经切断后静脉灌注或注射ＥＭ,ＰｈａｓｅＡ依然存在,而ＰｈａｓｅＢ消失。结果提示,ＥＭ先后引     

克林霉素诱导型耐药葡萄球菌的检测与分析

目的了解本地区葡萄球菌诱导型克林霉素的耐药率。方法用K-B琼脂扩散法检测葡萄球菌对红霉素和克林霉素的耐药性,用D-试验检测克林霉素诱导型耐药。结果61株耐红霉素的金黄色葡萄球菌对克林霉素耐药40株,敏感21株,其中克林霉素诱导型耐药8株;106株耐红霉素的凝固酶阴性的葡萄球菌(CNS)对克林霉素耐药62株,敏感44株,其中克林霉素诱导型耐药27株。结论对克林霉素敏感的菌株,应加做D-试验以免造成错误判断导致临床治疗失败。