Encapsulation of selenium in chitosan nanoparticles improves selenium availability and protects cells from selenium-induced DNA damage response

Selenium, an essential mineral, plays important roles in optimizing human health. Chitosan (CS) is an effective, naturally oriented material for synthesizing nanoparticles with preferable properties such as biocompatibility, biodegradation and resistance to certain enzymes. We have recently shown that cellular exposure to selenium compounds activates ataxia-telangiectasia mutated (ATM)-dependent DNA damage responses, a tumorigenesis barrier. To test whether nanoencapsulation of selenium modulates the cellular response to selenium compounds, the HCT 116 cancerous and the MRC-5 normal cells were treated with Na₂SeO₃ and methylseleninic acid (MSeA) encapsulated in CS/polyphosphate nanoparticles. Analyses of cellular selenium levels demonstrate that (1) the nanoencapsulation enhances selenium levels in cells after exposure to Na₂SeO₃ and MSeA (1-10 μM); (2) cells retained more selenium when treated with Na₂SeO₃ than with MSeA; (3) selenium levels are greater in HCT 116 than in MRC-5 cells after Na₂SeO₃, but not MSeA, exposure. Survival analysis shows that CS encapsulation desensitizes HCT 116 and MRC-5 cells to Na₂SeO₃ or MSeA exposure. Immunofluorescent analysis demonstrates that CS encapsulation attenuates the selenium-induced ATM phosphorylation on Ser-1981, and the extent is greater in HCT 116 than in MRC-5 cells. Our results reveal features of selenium nanoencapsulation in CS, including increased selenium retention in cells and decreased cellular sensitivity and DNA damage response to selenium exposure.     

口服微生态制剂对早产低体重新生儿坏死性小肠结肠炎的预防效果

分析口服微生态制剂预防早产低体重新生儿坏死性小肠结肠炎（NEC）的效果。

采用随机数字表法将我院2021年2月至2022年3月收治入院的82例早产低体重新生儿分为观察组和对照组,各41例。对照组患儿予以常规对症治疗,观察组在此基础上予以口服微生态制剂预防治疗。对比两组早产儿NEC发生率和手术率,干预前后免疫球蛋白（IgG、IgM、IgA）水平变化情况,肠道菌群变化情况。

观察组患儿NEC发生率为7.32%,显著低于对照组的24.39%（P＜0.05）。干预后观察组患儿IgG、IgM、IgA水平高于对照组,组间差异均有统计学意义（均P＜0.05）。干预后观察组患儿肠道细菌总数、球菌总数、杆菌总数高于对照组（均P＜0.05）。干预7 d、14 d后,两组患儿体质量均有所增加,且观察组患儿体质量高于对照组（均P＜0.05）。观察组患儿达到完全肠内营养时间短于对照组（P＜0.05）。

口服微生态制剂可有效降低早产低体重新生儿NEC的发生率,促进早产儿肠道菌群稳定,增强患儿免疫能力,对改善早产低体重新生儿预后具有重要的意义。

     

微生态制剂对新生儿高胆红素血症的预防作用

目的 :探讨微生态制剂预防新生儿高胆红素血症的效果。方法 :74例正常足月新生儿随机分为干预组 39例和对照组 35例 ,出生后 12 h内干预组在常规预防的同时 ,加服微生态制剂金双歧。结果 :新生儿高胆红素血症干预组的发生率为 33.33% ,对照组的发生率为 5 7.14 % ,干预组的发生率较对照组低 (P<0 .0 5 )。结论 :微生态制剂金双歧预防新生儿高胆红素血症有一定效果。     

Reticulocytes: Plasmodium vivax target cells

Reticulocytes represent the main invasion target for Plasmodium vivax, the second most prevalent parasite species around the world causing malaria in humans. In spite of these cells' importance in research into malaria, biological knowledge related to the nature of the host has been limited, given the technical difficulties present in working with them in the laboratory. Poor reticulocyte recovery from total blood, by different techniques, has hampered continuous in vitro P. vivax cultures being developed, thereby delaying basic investigation in this parasite species. Intense research during the last few years has led to advances being made in developing methodologies orientated towards obtaining enriched reticulocytes from differing sources, thereby providing invaluable information for developing new strategies aimed at preventing infection caused by malaria. This review describes the most recent studies related to obtaining reticulocytes and discusses approaches which could contribute towards knowledge regarding molecular interactions between target cell proteins and their main infective agent, P. vivax.     

妇科手术造成泌尿系统损伤的原因及预防

目的：分析妇科手术致泌尿系统损伤的原因,并为预防提供理论依据,以改善患者的预后。方法：对我院2003年6月-2010年10月进行妇科手术治疗的13801例患者进行回顾性统计,分析出现泌尿系统损伤患者的相关资料,探讨其泌尿系统损伤情况,归纳影响妇科手术损伤泌尿系统的危险因素。结果：13801例患者共确诊122例术后泌尿系统损伤,损伤率0．88％;多因素分析显示,手术方式、盆腔粘连、导尿管阻塞及手术操作是影响妇科手术泌尿系统损伤的独立危险因素,有统计学意5C（P〈0．05）。结论：妇科手术致泌尿系统损伤的原因主要有手术方式的选择,患者出现盆腔粘连,导尿管受到阻塞及手术操作不当等。绝大部分损伤可在术前、术中得到避免,而对于术后出现泌尿系统损伤的患者,应进行及时有效的处理,以保证患者生活质量,改善预后。     

Seawater temperature, Gambierdiscus spp. variability and incidence of ciguatera poisoning in French Polynesia

In the context of global warming and climate change, ciguatera disease is put forward as an indicator of environmental disturbance. However, to validate this indicator, some unknown parameters such as the delay between environmental perturbation and outbreaks of ciguatera need to be investigated. The main goal of this study was to investigate the temporal link between the growth of Gambierdiscus spp., and one of its influencing factors and the declared cases of ciguatera disease in humans. Algal cell density and seawater temperature (SWT) were recorded monthly from February 1993 to December 2001 on the Atimaono barrier reef of Tahiti Island. Reports of ciguatera cases were obtained from three community health clinics near the study sites. The autoregressive integrated moving average model (ARIMA) shows: (1) SWT were positively associated with Gambierdiscus spp. growth at a lagtime of 13 and 17 months (p < 0.001); (2) Gambierdiscus spp. growth measured at a given time is related to a peak number of cases of ciguatera recorded 3 months after peak densities of this dinoflagellate (p < 0.001). These results allow the construction of a predictive model of the temporal link between ciguatera disease in humans and its etiologic agent: Gambierdiscus spp. This model constructed by using 1993–1999 data, then validated by 2000–2001 data, demonstrates an appreciable ability to predict changes in the incidence of ciguatera disease following algae blooms.     

H7N9 禽流感的研究现状及对未来的思考简

始发于2013年3月的人感染H7N9禽流感疫情给我国卫生、农业与经济带来了严峻而巨大的挑战,尽管目前疫情已经得到初步控制,但随后出现的散发病例提示H7N9卷土重来的势头已现端倪.对于H7N9禽流感,目前仍存在太多的不确定因素.基于此,本文将对目前H7N9禽流感的流行发展势态和研究现状进行综述,并在此基础上,提出一系列目前未知、但亟待解决的关键论题和研究方向,以作抛砖引玉之用.     

Percutaneous left atrial appendage closure for stroke prevention in atrial fibrillation

Background

Percutaneous left atrial appendage (LAA) closure can be an alternative to coumadin treatment in patients with atrial fibrillation (AF) at high risk for thromboembolic events and/or bleeding complications. We report the initial experience with this new technique.

Methods

Patients were eligible if they had AF with a high stroke risk (CHADS₂ score >1), and/or contraindication for coumadin therapy. The procedure was performed under general anaesthesia, using biplane fluoroscopy and (3D) transoesophageal echocardiography (TEE) guidance. Patients were discharged on coumadin until a TEE was repeated at 45 days after closure to evaluate LAA occlusion. If LAA occlusion was achieved, oral anticoagulation was discontinued and aspirin started.

Results

Percutaneous LAA closure was performed in 10 patients (50% male, age 61.6 ± 9.6 years). The median CHADS₂ score was 3 (range 2–4), median CHA₂DS₂-VASc score 3.5 (range 2–6) and HAS-BLED score 1.5 (range 1–4). Nine patients had a history of stroke and 2 patients had a history of major bleeding while on coumadin. Concomitant pulmonary vein isolation was performed in 9 patients. The device was successfully placed in all patients within a median of 56 min (38–137 min). Asymptomatic catheter thrombus occurred in one patient. At 45-day follow-up, no thromboembolic events occurred, TEE showed minimal residual flow in the LAA in three patients. In one patient the LAA device was dislocated, requiring successful percutaneous retrieval.

Conclusion

Device closure of the LAA may provide an alternative strategy to chronic coumadin therapy in patients with AF and high risk of stroke and/or bleeding complications using coumadin.     

手术后恶心呕吐的机制及其防治

在过去的几十年里,随着各种手术技术的不断提高和完善,已使外科手术的死亡率大幅降低,这使医生的注意力逐渐转向手术后的并发症和患者的满意程度上,如手术后恶心呕吐。恶心呕吐是术后严重的并发症之一,尽管术后恶心呕吐(Postoperativenausea and vomiting,PONV)是非致命性的并发症,但是PONV可导致严重的后果,并且增加了医疗费用,极大的影响了患者的满意程度。PONV高发率一直困扰着临床医生和患者。所以,探讨其发生及其风险因素是十分必要的。但是,术后恶心呕吐的病理生理学机制还不是十分清楚,本文总结了目前关于术后恶心呕吐发生机制的一些观点以及术后恶心呕吐的风险因素。虽然以往大量的文献报道了如何预防和治疗术后恶心呕吐,但迄今为止,5-HT3受体拮抗剂仍然是临床上使用的最主要的止吐药。目前,一些新药物,如NK-1受体拮抗剂、更加长效的5-HT3受体拮抗剂以及对于PONV高风险的病人实行的多模式管理和新技术的应用,正变得越来越突出。本文综述了现今手术后恶心呕吐的防治方法的最新进展。     

内镜清洗与消毒环节感染因素分析及预防措施研究

目的:总结我院内镜中心清洗与消毒过程中发生感染的主要危险因素,制定相应的预防措施,降低内镜感染发生率,确保患者医疗安全。方法:专人检查内镜清洗消毒全过程,统计各个环节发生感染的危险因素。随机抽取600例消毒后处于备用状态的内镜,采集内镜内腔及外表面标本,检测结果作为评估清洗消毒质量指标。结果:检测600例样本合格584例,合格率97.3%,胃镜、肠镜、十二指肠镜、气管镜和超声内镜合格率分别为98.6%,96.8%,95.6%,96.0%和97.2%;16例不合格样本中共检出病原菌28株,其中幽门杆菌13株,大肠埃希菌7株,铜绿假单胞菌4株,绿脓杆菌2株,金黄色葡萄球菌1株,肺炎克雷伯菌1株;16例检测不合格原因分析中,刷洗不彻底占37.5%,未按说明要求使用多酶及消毒液占18.75%,特殊感染患者用过的内镜未做特殊处理占12.5%,内镜干燥不充分及工作人员手卫生不达标各占6.25%。结论:内镜清洗消毒环节引发感染的危险因素众多,应加强对内镜中心所有人员的感染控制教育,定期对清洗消毒人员进行职业化培训,规范管理清洗消毒流程,建立可追溯性登记系统,从各个环节把关内镜清洗消毒的质量,是预防消化内镜中心发生感染的主要手段。