Recently, we have identified proinsulin (P-Ins)73-90 as an immunodominant T cell epitope of HLA-DRB1*0401 (DR4) subjects with ␤-islet cell autoimmunity and of HLA-DR4͞CD4 double-transgenic mice immunized with human P-Ins. We have compared the fine specificities of one human CD4 T cell clone and two mouse T cell hybridoma clones recognizing this epitope, and, although these three clones all recognized the same core region (LALEGSLQK), there were major differences in how they interacted with the peptide (p)͞HLA complex, reflecting the fact that human P-Ins is a foreign antigen in the mouse and an autoantigen in the type 1 diabetes patient. The human T cell clone was forkhead transcription factor 3 (Foxp3)-positive, a marker for regulatory T cell lineages, and secreted predominantly IL-5, IL-10, and low levels of IFN␥ in response to P-Ins73-90. This finding is compatible with the previously detected regulatory cytokine pattern in subjects with ␤-cell autoimmunity. However, added N-or C-terminal amino acids drastically changed HLA and tetramer binding capacity as well as T cell reactivity and the cytokine phenotype of the P-Ins 73-90-specific human CD4 T cell clone, suggesting a potential for this P-Ins epitope as a target for therapeutic intervention in HLA-DR4-positive humans with ␤-islet cell autoimmunity or recent-onset type 1 diabetes.Foxp3 ͉ HLA-DRB1*0401 ͉ type 1 diabetes P roinsulin (P-Ins) is considered an important autoantigen in type 1 diabetes (T1D), because it is the only truly ␤-cellspecific target, and because autoreactivity to P-Ins is very common in T1D patients with the HLA-DRB1*0401 (DR4) DQ8 haplotype (1-6). The differences distinguishing autoreactive from foreign antigen reactive T cell responses to the same immunogenic epitope are still largely unknown (7). To understand the structural requirements for activation of self-reactive P-Ins 73-90 -specific T cells in T1D autoimmunity, we have isolated a Foxp3-positive CD4 ϩ T cell clone from a DR4-homozygous T1D patient and compared the fine specificity of this T cell receptor to those of two murine T cell hybridoma clones derived from HLA-DR4 transgenic mice, in which this epitope is a foreign antigen (8). P-Ins 73-90 is situated at the C terminus of the C peptide and also covers the enzymatic cleavage site of the insulin A chain (8). This site is proteolytically destroyed during the maturation of insulin before secretion and is, therefore, an indication that Proinsulin and not Insulin may be the actual autoantigenic target in T1D.In human studies using purified CD4 ϩ T cells from HLA-DR4-positive subjects with islet autoimmunity, P-Ins 73-90 was also identified as an immunodominant epitope. This epitope was recognized by approximately two thirds of autoantibody-positive subjects, one third of recently diagnosed T1D patients, and a few control subjects (5, 9). The cytokines seen in response to P-Ins 73-90 were predominantly IL-4 and IL-10 in subjects with ␤-cell autoimmunity (9). Moreover, in a consecutive follow up of three high-risk individuals, ...

Otolaryngology-head and neck surgery (OTL-HNS) residents face a variety of difficult, high-stress situations, which may occur early in their training. Since these events occur infrequently, simulation-based learning has become an important part of residents' training and is already well established in fields such as anesthesia and emergency medicine. In the domain of OTL-HNS, it is gradually gaining in popularity. Crisis Resource Management (CRM), a program adapted from the aviation industry, aims to improve outcomes of crisis situations by attempting to mitigate human errors. Some examples of CRM principles include cultivating situational awareness; promoting proper use of available resources; and improving rapid decision making, particularly in high-acuity, low-frequency clinical situations. Our pilot project sought to integrate CRM principles into an airway simulation course for OTL-HNS residents, but most important, it evaluated whether learning objectives were met, through use of a novel error identification model.

In this study, patients undergoing thyroidectomy in the winter months were more likely to develop postoperative hypocalcemia when compared with those operated in the summer. Further studies are needed to understand the role of vitamin D in the observed seasonal difference in hypocalcemia rates.

Objective The first pediatric tracheostomy tube change often occurs within 7 days after placement; however, the optimal timing is not known. The primary objective was to determine the rate of adverse events of an early tube change. Secondary objectives compared rates of significant peristomal wounds, sedation requirements, and expedited intensive care discharges. Study Design Prospective randomized controlled trial. Setting Tertiary children’s hospital between October 2018 and April 2020. Methods A randomized controlled trial enrolled children under 24 months to early (day 4) or late (day 7) first tracheostomy tube changes. Results Sixteen children were enrolled with 10 randomized to an early change. Median age was 5.9 months (interquartile range, 5.4-8.3), and 86.7% required tracheostomy for respiratory failure. All tracheostomy tube changes were performed without adverse events. There were no accidental decannulations. Significant wounds developed in 10% of children with early tracheostomy tube changes and 83.3% of children with late tracheostomy tube changes (odds ratio [OR], 45.0; 95% CI, 2.3-885.6; P = .01). This significant reduction in wound complications justified concluding trial enrollment. Hours of dexmedetomidine sedation ( P = .11) and boluses of midazolam during the first 7 days ( P = .08) were no different between groups. After the first change, 90% of the early group were discharged from intensive care within 5 weeks compared to 33.3% of patients in the late group (OR, 18.0; 95% CI, 1.2-260.9; P = .03). Conclusion The first tracheostomy tube change in children can occur without adverse events on day 4, resulting in fewer significant peristomal wounds and earlier intensive care discharge.