Mapping and ranking of potential cytotoxic T epitopes in the p53 protein: effect of mutations and polymorphism on peptide binding to purified and refolded HLA molecules

In many cancer cells, the p53 gene displays point mutations that result in stabilization and accumulation of the p53 protein. Therefore, p53 peptides could be presented to the immune system by tumor cells; thus, p53 might be a suitable target antigen for developing an immunotherapy against tumors using cytotoxic T lymphocytes (CTL). To map candidate CTL epitopes, we synthesized 150 peptides of 8–11 residues that contained putative anchor motifs required for binding to common HLA class I molecules. They were tested for their capacity to promote the assembly of purified and refolded HLA-A1, A2, B7 and B8 molecules. The following wild-type p53 peptides were found to be reactive with the HLA molecules tested: 196–205 and 226–234 bound moderately to HLA-A1; 25–35, 65–73, 129–137, 187–197, 263–272 and 264–272 bound strongly, and 187–195 and 256–264 moderately to HLA-A2; 26–35, 63–73, 189–197, 249–257 and 321–330 bound strongly to HLA-B7; and 135–143, 210–218 and 375–383 bound weakly to HLA-B8. We also analyzed the effects of p53 mutations occurring naturally in tumors on peptide/HLA assembly. We found substitutions that enhanced, diminished or had no effect on the peptide binding to HLA molecules. Polymorphism at position 72 mainly affected peptide/HLA-B7 binding, the proline allele P72 giving a less-reactive peptide (63–73) than the arginine allele R72. We have ranked potential p53 epitopes according to their reactivity for purified HLA molecules, allowing the selection of appropriate peptides and HLA molecules to attempt CTL induction in vitro.     

Sense of coherence and burnout in nursing home workers during the COVID-19 pandemic in Spain

Care staff in nursing homes work in a challenging environment, and the COVID-19 pandemic has exacerbated those challenges in an unprecedented way. On the other hand, the sense of coherence (SOC) is a competence that could help these professionals perceive the situation as understandable, manageable and meaningful. This study aims to analyse the extent to which potential risk and protective factors against burnout have affected nursing home workers during the COVID-19 pandemic and to assess the contribution of these factors to their burnout. Three hundred forty professionals who worked in nursing homes in Spain completed a survey and reported on their sociodemographic characteristics and their organisational characteristics of the job related to COVID-19, SOC and burnout. Multiple linear regression analyses were performed. The results showed that the SOC is highly related to the dimensions of burnout and is a protective factor against this. In addition, the increase in hours has a negative effect, facilitating inadequate responses to stressful situations; and whereas perceived social support and availability of resources have a protective effect, the deterioration in mental and physical health is the most important risk factor. This study could help better understand the psychological consequences of the effort that nursing home workers and can also help design mental health prevention and care interventions for workers that provide them with resources and supports that foster their coping skills.     

Particle Filtration Efficiency Testing of Sterilization Wrap Masks

ObjectivesNon-traditional materials are used for mask construction to address personal protective equipment shortages during the coronavirus disease 2019 (COVID-19) pandemic. Reusable masks made from surgical sterilization wrap represent such an innovative approach with social media frequently referring to them as “N95 alternatives.” This material was tested for particle filtration efficiency and breathability to clarify what role they might have in infection prevention and control.MethodsA heavyweight, double layer sterilization wrap was tested when new and after 2, 4, 6, and 10 autoclave sterilizing cycles and compared with an approved N95 respirator and a surgical mask via testing procedures using a sodium chloride aerosol for N95 efficiency testing similar to 42 CFR 84.181. Pressure testing to indicate breathability was also conducted.ResultsThe particle filtration efficiency for the sterilization wrap ranged between 58% to 66%, with similar performance when new and after sterilizing cycles. The N95 respirator and surgical mask performed at 95% and 68% respectively. Pressure drops for the sterilization wrap, N95 and surgical mask were 10.4 mmH₂O, 5.9 mmH₂O, and 5.1 mmH₂O, respectively, well below the National Institute for Occupational Safety and Health limits of 35 mmH₂O during initial inhalation and 25 mmH₂O during initial exhalation.ConclusionsThe sterilization wrap’s particle filtration efficiency is much lower than a N95 respirator, but falls within the range of a surgical mask, with acceptable breathability. Performance testing of non-traditional mask materials is crucial to determine potential protection efficacy and for correcting misinterpretation propagated through popular media.     

Postoperative Ileus after Stimulation with Probiotics before Ileostomy Closure

Loop ileostomy closure after colorectal surgery is often associated with Postoperative ileus, with an incidence between 13–20%. The aim of this study is to evaluate the efficacy and safety of preoperative stimulation of the efferent loop with probiotics prior to ileostomy closure in patients operated on for colorectal carcinoma. For this, a prospective, randomized, double-blind, controlled study is designed. All patients who underwent surgery for colorectal carcinoma with loop ileostomy were included. Randomized and divided into two groups, 34 cases and 35 controls were included in the study. Postoperative ileus, the need for nasogastric tube insertion, the time required to begin tolerating a diet, restoration of bowel function, and duration of hospital stay were evaluated. The incidence of Postoperative ileus was similar in both groups, 9/34 patients stimulated with probiotics and 10/35 in the control group (CG) with a p = 0.192. The comparative analysis showed a direct relationship between Postoperative ileus after oncological surgery and Postoperative ileus after reconstruction surgery, independently of stimulation. Postoperative ileus after closure ileostomy is independent of stimulation of the ileostomy with probiotics through the efferent loop. There seem to be a relationship between Postoperative ileus after reconstruction and the previous existence of Postoperative ileus after colorectal cancer surgery.     

Selection of Gut-Resistant Bacteria and Construction of Microbial Consortia for Improving Gluten Digestion under Simulated Gastrointestinal Conditions

This work aimed to define the microbial consortia that are able to digest gluten into non-toxic and non-immunogenic peptides in the human gastrointestinal tract. Methods: 131 out of 504 tested Bacillus and lactic acid bacteria, specifically Bacillus (64), lactobacilli (63), Pediococcus (1), and Weissella (3), showed strong gastrointestinal resistance and were selected for their PepN, PepI, PepX, PepO, and PepP activities toward synthetic substrates. Based on multivariate analysis, 24 strains were clearly distinct from the other tested strains based on having the highest enzymatic activities. As estimated by RP-HPLC and nano-ESI–MS/MS, 6 cytoplasmic extracts out of 24 selected strains showed the ability to hydrolyze immunogenic epitopes, specifically 57–68 of α9-gliadin, 62–75 of A-gliadin, 134–153 of γ-gliadin, and 57–89 (33-mer) of α2-gliadin. Live and lysed cells of selected strains were combined into different microbial consortia for hydrolyzing gluten under gastrointestinal conditions. Commercial proteolytic enzymes (Aspergillus oryzae E1, Aspergillus niger E2, Bacillus subtilis Veron HPP, and Veron PS proteases) were also added to each microbial consortium. Consortium activity was evaluated by ELISA tests, RP-HPLC-nano-ESI–MS/MS, and duodenal explants from celiac disease patients. Results: two microbial consortia (Consortium 4: Lactiplantibacillus (Lp.) plantarum DSM33363 and DSM33364, Lacticaseibacillus (Lc.) paracasei DSM33373, Bacillus subtilis DSM33298, and Bacillus pumilus DSM33301; and Consortium 16: Lp. plantarum DSM33363 and DSM33364, Lc. paracasei DSM33373, Limosilactobacillus reuteri DSM33374, Bacillus megaterium DSM33300, B. pumilus DSM33297 and DSM33355), containing commercial enzymes, were able to hydrolyze gluten to non-toxic and non-immunogenic peptides under gastrointestinal conditions. Conclusions: the results of this study provide evidence that selected microbial consortia could potentially improve the digestion of gluten in gluten-sensitive patients by hydrolyzing the immunogenic peptides during gastrointestinal digestion.     

弓形虫主要表膜P30抗原的免疫保护作用研究

目的 研究弓形虫主要表膜P30抗原免疫小鼠所诱导的免疫性保护作用及免疫保护机制。方法 将单克隆抗体免疫亲和层析分离纯化的P30抗原免疫C57BL／6纯系小鼠,然后用弓形虫RH株速殖子和Fukaya株包衰攻击感染,观察P30抗原免疫对急性弓形虫感染鼠死亡时间及慢性感染鼠脑内包囊形成的影响,同时对感染后不同时间鼠血清特异性抗体水平、IL－2及IFN－r细胞因子水平和脾T淋巴细胞亚群动态变化进行了测试分析。结果 显示P30抗原免疫可在一定程度上延长感染小鼠的存活时间,减少脑内包囊的形成数量,增强小鼠抵抗急慢性弓形虫感染的能力。在感染后不同时期免疫鼠血清中特异性抗休还清瘃IFN－r、IL－2水平均高于同期对照鼠,而且免疫鼠脾CD4^ t CD8^ T淋纠细胞尤其是CD8^ 细胞的数量在感染早期升高较快,至感染后4周达高峰,两者的比值随感染时间的延长而逐渐下降。结论 P30抗原免疫对感染小鼠具有明显的保护作用,是细胞免疫和体液免疫共同作用的结果,尤其是细胞免疫可能发挥着更为重要的作用。     

乙肝清胶囊对实验性肝损伤的保护作用

目的：通过本实验观察乙肝清胶囊的保肝降酶作用。方法：实验采用四氯化碳（CCl4）和D－氨基半乳糖（D－Gal）,造成动物急性实验性肝损伤,测定小鼠和大鼠血清GPT和LDH,并进行组织形态学观察。结果：乙肝清胶囊灌胃给药对CCl4和D－Gal急性肝损伤所引起的小鼠和大鼠GPT和LDH升高,均具有明显的抑制作用,且对小鼠和大鼠肝组织病理损伤具有一定保护作用,其1－2g/kg与联苯双酯15mg/kg作用效果接近。结论：乙肝清胶囊对化学物质的所引起的小鼠和大鼠急性肝损伤,具有保肝降酶作用。     

日本血吸虫多价DNA疫苗pBK-Sj26(Sj32)-Sj23免疫效果的观察

为了观察血吸虫病多价DNA疫苗的保护力,将小鼠分成5组空白对照组、空质粒对照组、单价抗原DNA疫苗pBK-CMV-Sj23组、多价抗原DNA疫苗pBK-CMV-Sj26-Sj23和pBK-CMV-Sj32-Sj23组.大量提取各组质粒DNA后,各组于0、3、5周在BALB/c小鼠股四头肌注射相应质粒DNA,9周用血吸虫尾蚴攻击感染,15周剖杀小鼠计算减虫率及减卵率.结果显示与对照组比较,实验组小鼠减虫率及减卵率有极显著性差异(P<0.01);与单价pBK-CMV-Sj23组比较,多价DNA疫苗组的减虫率及减卵率有显著性差异.提示血吸虫多价DNA疫苗诱导小鼠对血吸虫的保护力优于单价DNA疫苗.     

围术期肺保护策略的研究进展

术后肺部并发症(PPCs)是影响患者围术期预后的主要原因,需要麻醉科医师重点关注并有效防治。越来越多的证据表明,围术期实行肺保护策略可减少PPCs。近5年来,围术期肺保护策略研究已成为围术期医学关注的重点问题之一,围术期肺保护是加速康复外科的重要组成部分,其策略包括术前风险预测、术中肺保护性通气、术后镇痛及物理治疗等。本综述结合围术期肺保护策略最新进展进行阐述,以提高麻醉科医师对PPCs潜在风险的认识,为制定围术期个体化肺保护方案提供策略。未来还应进一步研究以阐明围术期肺保护策略对患者预后结局的影响。     

Personal protective equipment related skin reactions in healthcare professionals during COVID‐19

Since the outbreak of COVID‐19 pandemic, clinicians have had to use personal protective equipment (PPE) for prolonged periods. This has been associated with detrimental effects, especially in relation to the skin health. The present study describes a comprehensive survey of healthcare workers (HCWs) to describe their experiences using PPE in managing COVID‐19 patients, with a particular focus on adverse skin reactions. A 24‐hour prevalence study and multi‐centre prospective survey were designed to capture the impact of PPE on skin health of hospital staff. Questionnaires incorporated demographics of participants, PPE type, usage time, and removal frequency. Participants reported the nature and location of any corresponding adverse skin reactions. The prevalence study included all staff in intensive care from a single centre, while the prospective study used a convenience sample of staff from three acute care providers in the United Kingdom. A total of 108 staff were recruited into the prevalence study, while 307 HCWs from a variety of professional backgrounds and demographics participated in the prospective study. Various skin adverse reactions were reported for the prevalence study, with the bridge of the nose (69%) and ears (30%) being the most affected. Of the six adverse skin reactions recorded for the prospective study, the most common were redness blanching (33%), itchiness (22%), and pressure damage (12%). These occurred predominantly at the bridge of the nose and the ears. There were significant associations (P < .05) between the adverse skin reactions with both the average daily time of PPE usage and the frequency of PPE relief. The comprehensive study revealed that the use of PPE leads to an array of skin reactions at various facial locations of HCWs. Improvements in guidelines are required for PPE usage to protect skin health. In addition, modifications to PPE designs are required to accommodate a range of face shapes and appropriate materials to improve device safety.