Comparison of ethanol versus formalin fixation on preservation of histology and RNA in laser capture microdissected brain tissues

Although RNA can be retrieved from formalin-fixed, paraffin-embedded (FFPE) tissues, the yield is low, and the RNA is fragmented. Recent advances in gene expression profiling underscore the importance of identifying a fixative that preserves histology and mRNA. We demonstrated that, for immersion fixation of brains, 70% ethanol is superior to formalin for mRNA preservation. RNA yield from ethanol-fixed tissues was 70% of the yield from fresh frozen specimens, but only a negligible quantity was recovered from formalin-fixed tissues. RNA from ethanol-fixed brains showed integrity comparable to RNA from fresh frozen tissues, and RT-PCR using RNA from ethanol-fixed tissues was consistently successful. RNA from FFPE tissues composed of low-molecular weight fragments, and their use in RT-PCR failed repeatedly. The yield and quality of RNA from ethanol-fixed brains were unaffected after immersion at 4 degrees C for 2 weeks. In a blinded comparison to FFPE tissues, ethanol-fixed specimens were judged to show comparable histology and superior immunostaining. After laser capture microdissection (LCM), we failed to recover mRNA from FFPE tissues but retrieved mRNA from ethanol-fixed tissues for RT-PCR and cDNA microarray analysis. We conclude that 70% ethanol preserves RNA integrity and is suitable for expression profiling of brain tissues by LCM and cDNA microarray.     

Staphylococcus aureus adhesion to titanium oxide surfaces coated with non-functionalized and peptide-functionalized poly(L-lysine)-grafted-poly(ethylene glycol) copolymers

Implanted biomaterials are coated immediately with host plasma constituents, including extracellular matrix (ECM); this reaction may be undesirable in some cases. Poly(L-lysine)-grafted-poly(ethylene glycol) (PLL-g-PEG) has been shown to spontaneously adsorb from aqueous solution onto metal oxide surfaces, effectively reducing the degree of non-specific adsorption of blood and ECM proteins, and decreasing the adhesion of fibroblastic and osteoblastic cells to the coated surfaces. Cell adhesion through specific peptide-integrin receptors could be restored on surfaces coated with PLL-g-PEG functionalized with peptides of the RGD (Arg-Asp-Gly) type. To date, no study has examined the effect of surface modifications by PLL-g-PEG-based polymers on bacterial adhesion. The ability of Staphylococcus aureus to adhere to the ECM and plasma proteins deposited on biomaterials is a significant factor in the pathogenesis of medical-device-related infections. This study describes methods for visualizing and quantifying the adhesion of S. aureus to smooth and rough (chemically etched) titanium surfaces without and with monomolecular coatings of PLL-g-PEG, PLL-g-PEG/PEG-RGD and PLL-g-PEG/PEG-RDG. The different surfaces were exposed to S. aureus cultures for 1-24h and bacteria surface density was evaluated using scanning electron microscopy and fluorescence microscopy. Coating titanium surfaces with any of the three types of copolymers significantly decreased the adhesion of S. aureus to the surfaces by 89-93% for PLL-g-PEG, and 69% for PLL-g-PEG/PEG-RGD. Therefore, surfaces coated with PLL-g-PEG/PEG-RGD have the ability to attach cells such as fibroblasts and osteoblasts while showing reduced S. aureus adhesion, resulting in a selective biointeraction pattern that may be useful for applications in the area of osteosynthesis, orthopaedic and dental implantology.     

GDNF-induced seminomatous tumours in mouse--an experimental model for human seminomas?

Glial-cell-line-derived neurotrophic factor (GDNF) is a distant member of the transforming growth factor superfamily. It binds to and activates a receptor complex consisting of GFR-alpha1 and Ret receptor tyrosine kinase. In testis, GDNF is expressed by Sertoli cells. We have shown by transgenic loss- and gain-of-function mouse models that GDNF regulates the cell fate decision of undifferentiated spermatogonia. In the GDNF +/- mice, the spermatogonia differentiate in excess leading to the depletion of germ cells. In the mice overexpressing GDNF in testes, undifferentiated spermatogonia accumulate in the tubules, no sperm is produced, and the mice are infertile. After a year, the GDNF overexpressing mice frequently (89%) develop testicular tumours, and most of them are bilateral (56%). All these tumours show the same histological pattern. They are composed of round spermatogonial/gonocytic cells with only a scant cytoplasm. The tumours are locally invasive but do not metastasise. They express germ line markers, are positive for alkaline phosphatase, and aneuploid with a triploid peak. Thus, by several histological, molecular, and histochemical characteristics, the GDNF-induced tumours mimic classical seminomas in men, but the precursor lesions are apparently different in mouse and man.     

2018—2020年徐州市食源性疾病监测分析

目的 分析徐州市2018—2020年食源性疾病哨点医院主动监测结果,了解该地区食源性疾病流行特征。方法 收集2018—2020年徐州市食源性疾病哨点医院监测的病例信息,并对部分病例的粪便样本进行病原学检测。结果 3年共监测食源性疾病病例7 548例,其中25～45岁年龄组占比最高(26.81%);6—9月为发病高峰;肉与肉制品(20.72%)为主要的可疑暴露食品;可疑食物进食场所主要为家庭(80.49%);农民(26.75%)和散居儿童(24.95%)病例构成比较高。共采集1 835份腹泻病例粪便样本,其中诺如病毒检出率最高为(4.69%)。结论 徐州市食源性疾病高发期为6—9月,具有明显的季节性,好发于家庭,肉与肉制品为主要暴露食品,感染患者集中在>25～45岁年龄组,诺如病毒感染率较高。     

2017—2021年扬州市宝应县水痘流行病学特征分析

目的 分析2017—2021年扬州市宝应县水痘的流行特征,为水痘防制工作提供参考依据。方法 通过查阅监测系统相关数据的方式,采用描述性流行病学方法对2017—2021年扬州市宝应县水痘发病情况进行流行病学特征分析。结果 2017—2021年扬州市宝应县累计报告水痘病例3 841例,年均发病率为105.74/10万,5年发病率总体呈逐年上升趋势(χ2=112.92,P<0.01);有2个发病高峰期,主要集中在5—7月及10月至次年的2月,报告发病数分别占总病例数的27.65%、51.54%;人群以15岁及以下学生及幼托儿童为主,占79.24%;男性发病率略高于女性;城区发病率高于乡镇地区;突发公共卫生事件的发生主要集中在水痘发生的高峰期;疫苗首针剂的接种率总体呈现逐年上升的趋势(χ2=37.37,P<0.01)。结论 扬州市宝应县水痘的发生情况有明显的季节、年龄、职业和地区差异,加强15岁及以下人群的水痘二针剂疫苗的接种及防护知识宣传,这是预防水痘疫情发生和扩散的关键。     

经典名方中杜仲的本草考证

通过查阅历代本草、医籍、方书并结合近现代文献资料,笔者对杜仲药材的名称、基原、产地、品质评价、采收加工、炮制历史沿革及产地变迁情况进行了系统梳理及考证,以期为含杜仲的经典名方开发提供参考依据。经考证可知,历代本草均以杜仲为正名,基原为杜仲科植物杜仲Eucommia ulmoides的干燥树皮,古今一致;杜仲最早的产地为河南、山西、陕西、四川一带,自明代以来产地扩展至全国大部分地区,且推崇四川、陕西、重庆、贵州、湖北等地为杜仲的道地产区;近代以来总结其品质以皮厚、块大、粗皮刮净、断面多丝、内表面色暗紫为佳;杜仲的古代炮制加工方法主要有去粗皮切制生用和加酥蜜、姜汁、盐水、酒等辅料炮制,近现代以来炮制方法日趋简化,沿用的炮制方法主要为净制后切制生用、盐炙,建议挖掘不同杜仲炮制品的现代科学内涵,通过标准恢复传统主流炮制方法。基于宋代陈自明的三痹汤中杜仲“去皮,切,姜汁炒”的要求,根据考证结果,建议使用姜杜仲,即参考2020年版《中华人民共和国药典》炒法,以姜汁为辅料进行炮制后入药。     

Correction to: Cichorium intybus L. promotes intestinal uric acid excretion by modulating ABCG2 in experimental hyperuricemia

The study of sex differences in hyperuricemia can provide not only a theoretical basis for this clinical phenomenon but also new therapeutic targets for urate-lowering therapy. In the current study, we aimed to confirm that estradiol can promote intestinal ATP binding cassette subfamily G member 2 (ABCG2) expression to increase urate excretion through the PI3K/Akt pathway. The estradiol levels of hyperuricemia/gout patients and healthy controls were compared, and a hyperuricemia mouse model was used to observe the urate-lowering effect of estradiol and the changes in ABCG2 expression in the kidney and intestine. In vivo and in vitro intestinal urate transport models were established to verify the urate transport function regulated by estradiol. The molecular pathway by which estradiol regulates ABCG2 expression in intestinal cells was explored. The estradiol level of hyperuricemia/gout patients was significantly lower than that of healthy controls. Administering estradiol benzoate (EB) to both male hyperuricemic mice and female mice after removing the ovaries confirmed the urate-lowering effect of estradiol, and hyperuricemia and estradiol upregulated the expression of intestinal ABCG2. Estradiol has been confirmed to promote urate transport by upregulating ABCG2 expression in intestinal urate excretion models in vivo and in vitro. Estradiol regulates the expression of intestinal ABCG2 through the PI3K/Akt pathway. Our study revealed that estradiol regulates intestinal ABCG2 through the PI3K/Akt pathway to promote urate excretion, thereby reducing serum urate levels.     

大气颗粒物浓度对流感样病例发病关联性研究

目的 探讨大气颗粒物浓度对合肥市流感样病例发病情况的影响.方法 对2014-2017年合肥市流感监测流感样发病例数及同期大气颗粒物(PM2.5PM10),应用分布滞后非线性模型分析两者关系及其滞后效应.结果 流感样病例发病与PM2.5PM10呈正相关(r= 0.10,P＜0.001)与湿度呈负相关(r =-0.09,P = 0.001),其中PM2.5浓度对流感样病例人群的滞后3日和4日有显著影响,其超额死亡风险(ER)分别为0.115％(95％CI:0.016％～1.002％)、0.116％(95％CI:0.002％～1.002％),双污染模型中,纳入其他气态污染物后,模型均表现无统计学意义.结论 PM2.5可能是流感样病例发病的重要影响因素.     

新生儿尿布皮炎的影响因素及预防进展

本文就新生儿尿布皮炎发生的危险因素及预防的研究进展,从完善新生儿皮肤监测系统、ABCDE皮肤护理方案的实施和采用家长参与式护理模式等3个方面进行阐述,以期为降低新生儿尿布皮炎的发生率,提高患儿的舒适度,降低医疗花费,为保障新生儿家庭的护理安全提供参考和指导。