Evidence suggests that distinct splenic dendritic cell (DC) subsets activate either CD4+ or CD8+ T cells in vivo. This bias has been partially ascribed to differential antigen presentation; however, all DC subsets can activate both T cell lineages in vitro. Therefore, we tested whether the organization of DC and T cell subsets in the spleen dictated this preference. We discovered that CD4+ and CD8+ T cells segregated within splenic T cell zones prior to immunization. After intravenous immunization, the two major conventional DC populations, distinguished by 33D1 and XCR1 staining, migrated into separate regions of the T cell zone: 33D1+ DCs migrated into the CD4+ T cell area, whereas XCR1+ DCs migrated into the CD8+ T cell area. Thus, the post-immunization location of each DC subset correlated with the T cell lineage it preferentially primes. Preventing this co-localization selectively impaired either CD4+ or CD8+ T cell immunity to blood-borne antigens.

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Synaptic loss is critical in Alzheimer's disease (AD), but the dynamics of synapse turnover are poorly defined. We imaged dendritic spines in transgenic APPswe/PSen1∆E9 (APP/PS1) cerebral cortex. Dendritic spine turnover is increased far from plaque in aged APP/PS1 mice, and in young APP/PS1 mice prior to plaque formation. Dysregulation occurs in the presence of soluble Aβ oligomer and requires cellular prion protein (PrPC). APP/PS1 mice lack responsiveness of spine turnover to sensory stimulation. Critically, enhanced spine turnover is coupled with the loss of persistent spines starting early and continuing with age. To evaluate mechanisms of experience-independent supranormal spine turnover, we analyzed the transcriptome of young APP/PS1 mouse brain when turnover is altered but synapse density and memory are normal, and plaque and inflammation are absent. Early PrPC-dependent expression changes occur in synaptic and lipid-metabolizing genes. Thus, pathologic synaptic dysregulation underlying AD begins at a young age prior to Aβ plaque.

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Up to 90% of patients treated with an epidermal growth factor receptor inhibitor (EGFRi) experience cutaneous toxic effects that are negatively associated with quality of life and lead to treatment interruptions. The Skin Toxicity Evaluation Protocol With Panitumumab trial found reduced incidence of skin toxicity and quality of life impairment with preemptive use of doxycycline hyclate, topical corticosteroids, moisturizers, and sunscreen, demonstrating the benefit of prophylactic treatment for skin toxicity.OBJECTIVE To evaluate the association of a comprehensive skin toxicity program with adherence to prophylaxis guidelines for the prevention of EGFRi-associated cutaneous toxic effects. DESIGN, SETTING, AND PARTICIPANTSA retrospective cohort study was conducted of all adult patients receiving at least 1 dose of cetuximab at the Dana-Farber Cancer Institute in the calendar year 2012 (2 years after publication of the Skin Toxicity Evaluation Protocol With Panitumumab) or the calendar year 2017 (2 years after full implementation of the Skin Toxicities from Anticancer Therapies program). MAIN OUTCOMES AND MEASURESPrimary outcomes were rate of preemptive rash treatment and selection of preemptive agents. Secondary outcomes were incidence of rash, rates of rescue treatments, rates of cetuximab dose changes or interruptions, and overall survival at 2 years. RESULTSThere were 118 patients (85 men; median age, 62.4 years [range, 23.5-91.7 years]) treated with cetuximab in 2012 and 90 patients (70 men; median age, 62.5 years [range, 30.7-90.5 years]) treated with cetuximab in 2017; 11 patients (9%) in 2012 and 31 patients (34%) in 2017 were treated at Dana-Farber Cancer Institute affiliate sites. At cetuximab treatment initiation, 29 patients (25%) in 2012 and 42 patients (47%) in 2017 were prophylactically treated for skin toxicity (P < .001). From 2012 to 2017, preemptive tetracycline use (13 of 29 [45%] to 30 of 42 [71%]; P = .02) and topical corticosteroid use (2 of 29 [7%] to 24 of 42 [57%]; P < .001) increased and topical antibiotic use (23 of 29 [79%]to 18 of 42 [43%]; P = .002) decreased. There was no significant difference in incidence of rash by prophylaxis status. Patients prescribed prophylactic treatment were 94% less likely to require a first rescue treatment for rash (adjusted odds ratio, 0.06; 95% CI, 0.02-0.16; P < .001), 74% less likely to require a second rescue treatment for rash (adjusted odds ratio, 0.26; 95% CI, 0.08-0.83; P = .02), and 79% less likely to experience a cetuximab dose change or interruption (adjusted odds ratio, 0.21; 95% CI, 0.06-0.81; P = .02) than patients not prescribed prophylactic treatment, adjusting for treatment site and year.CONCLUSIONS AND RELEVANCE Dermatologists can add value to oncology care by raising awareness of appropriate treatment options and increasing adherence to evidence-based prophylaxis protocols for EGFRi-associated rash, which is associated with decreased interventions and toxicity-associated chemotherapy interruptions.

Background: A significant proportion of cancer survivors endorse ongoing health information needs and may use the internet to access information. We assessed patterns and predictors of general and health-specific internet use among cancer survivors. Methods: Using data from the National Health Interview Survey (NHIS), which was administered in 2013 through 2018, for adults reporting a cancer diagnosis, sample weight-adjusted estimates defined prevalence and multivariable logistic regressions defined adjusted odds ratios (aORs) of general and health-specific internet use, adjusting for relevant sociodemographic covariates, including healthcare satisfaction as the primary independent variable. The analysis for health-specific internet use was also repeated including a sex (female vs male)*healthcare satisfaction (very satisfied/somewhat satisfied vs somewhat dissatisfied/very dissatisfied) interaction term. Results: Among 12,970 survivors of cancer, general and health-specific internet use increased from 2013 to 2018 (from 63.2% to 70.8% and from 46.8% to 52.2%, respectively; P<.05 for both). Survivors who were very dissatisfied with healthcare were more likely to use the internet for health information compared with those who were very satisfied (59.5% vs 48.0%; aOR, 1.78; 95% CI, 1.20–2.64; P=.004). Younger age, female sex, higher educational attainment, and higher socioeconomic status were all associated with increased reported use of the internet for both general and health-specific purposes (P<.001 for all). There was a significant sex*healthcare satisfaction interaction (P=.009) such that for female survivors, healthcare dissatisfaction was associated with higher odds of health-specific internet use (61.4% vs 52.5%; P<.001; men, P=.97). No association was found between healthcare satisfaction and general internet use (P=.42). Conclusions: The increasing proportion of survivors of cancer using the internet for health-specific information may be associated with self-reported dissatisfaction with healthcare. Efforts are needed to improve both access to the internet and the quality of cancer-relevant online health information, and to enhance patients’ online health literacy.

Background/Aims: The importance of adjuvant radiotherapy in patients with close margin resections for mucoepidermoid carcinoma of the parotid gland remains unclear. Methods: Patients who underwent parotidectomy for mucoepidermoid carcinoma with or without adjuvant radiotherapy at a single academic tertiary care center from 2000 to 2014 were identified. Included patients had negative but close (≤2 mm) surgical margins without other high-risk histopathological factors including advanced T-stage, positive nodal disease, lymphovascular or perineural invasion, or high-grade histology. Results: Nineteen patients were identified, of whom 15 (79%) were observed postoperatively, while 4 (21%) underwent adjuvant radiotherapy. There were no significant differences in extent of parotidectomy, elective neck dissection, T staging, or tumor size between patients who were observed and those undergoing adjuvant radiation. There were no locoregional or distant recurrences in any patients at a mean follow up 74.3 months. Patients undergoing adjuvant radiation, however, had significantly more intermediate-grade as compared to low-grade histology (75% vs. 13%, difference 62%, 95% CI 4% to 100%). Conclusions: Patients with negative but close (≤2 mm) surgical margins without other high-risk histopathological factors have excellent long-term locoregional control with surgery alone. The effects of adjuvant radiotherapy for those who have intermediate-grade disease remain uncertain.