28 research outputs found
Contributions of the T Cell Receptor–associated CD3γ–ITAM to Thymocyte Selection
The immunoreceptor tyrosine-based activation motifs (ITAMs) in the CD3 chains associated with the T cell receptor (TCR) are crucial for TCR signaling. To probe the role of the CD3γ–ITAM in T cell development, we created knock-in mice in which the CD3γ chain of the TCR complex is replaced by a mutant signaling-deficient CD3γ chain, lacking the CD3γ–ITAM. This mutation results in considerable impairment in positive selection in the polyclonal TCR repertoire. When CD3γ–ΔITAM mice are crossed to mice expressing transgenic F5 TCRs, their thymocytes are completely unable to perform positive selection in vivo in response to intrathymic ligands. Also, the in vitro positive selection response of double-positive (DP) thymocytes with F5–CD3γ–ΔITAM mutant receptors to their agonist ligand and many of its variants is severely impaired or abrogated. Yet, the binding and dissociation constants of agonist ligands for the F5 receptor are not affected by the CD3γ–ΔITAM mutation. Furthermore, DP thymocytes with mutant receptors can respond to agonist ligand with normal antigen sensitivity and to normal levels, as shown by their ability to induce CD69 up-regulation, TCR down-regulation, negative selection, and ZAP70 and c-Jun NH2-terminal kinase activation. In sharp contrast, induction of extracellular signal-regulated kinase (ERK) activation and linker for activation of T cells (LAT) phosphorylation are severely impaired in these cells. Together, these findings underscore that intrinsic properties of the TCR–CD3 complex regulate selection at the DP checkpoint. More importantly, this analysis provides the first direct genetic evidence for a role of the CD3γ–ITAM in TCR-driven thymocyte selection
Atrial fibrillation in chronic heart failure patients with reduced ejection fraction: The CHECK-HF registry
Background: Atrial fibrillation (AF) is common in chronic heart failure (HF) patients and influences the choice and effects of drug and device therapy. In this large real-world HF registry, we studied whether the presence of AF affects the prescription of guideline-recommended HF therapy. Methods: We analyzed 8253 patients with chronic HF with reduced ejection fraction (HFrEF) from 34 Dutch outpatient clinics included in the period between 2013 and 2016 treated according to the 2012 ESC guidelines. Results: 2109 (25.6%) of these patients were in AF (mean age 76.8 ± 9.2 years, 65.0% were men) and 6.144 (74.4%) had no AF (mean age 70.7 ± 12.2 years, 63.6% were men). Patients with AF more often received beta-blockers (81.7% vs. 79.7%, p = 0.04), MRAs (57.1% vs. 51.7%, p < 0.01), diuretics (89.7% vs. 80.6%, p < 0.01) and digoxin (40.1% vs. 9.3%, p < 0.01) compared to patients without AF, whereas they less often receive renin-angiotensin-system (RAS)-inhibitors (76.1% vs. 83.1%, p < 0.01). The number of patients who received beta-blockers, RAS-inhibitor and MRA at ≥50% of the recommended target dose was comparable between those with and without AF (16.6% vs. 15.2%, p = 0.07). Conclusion: In this large cohort of chronic HFrEF patients, the prevalence of AF was high and we observed significant differences in prescription of both guideline-recommended HF between patients with and without AF
Neoadjuvant immunotherapy with nivolumab and ipilimumab induces major pathological responses in patients with head and neck squamous cell carcinoma
Surgery for locoregionally advanced head and neck squamous cell carcinoma (HNSCC) results in 30‒50% five-year overall survival. In IMCISION (NCT03003637), a non-randomized phase Ib/IIa trial, 32 HNSCC patients are treated with 2 doses (in weeks 1 and 3) of immune checkpoint blockade (ICB) using nivolumab (NIVO MONO, n = 6, phase Ib arm A) or nivolumab plus a single dose of ipilimumab (COMBO, n = 26, 6 in phase Ib arm B, and 20 in phase IIa) prior to surgery. Primary endpoints are feasibility to resect no later than week 6 (phase Ib) and primary tumor pathological response (phase IIa). Surgery is not delayed or suspended for any patient in phase Ib, meeting the primary endpoint. Grade 3‒4 immune-related adverse events are seen in 2 of 6 (33%) NIVO MONO and 10 of 26 (38%) total COMBO patients. Pathological response, defined as the %-change in primary tumor viable tumor cell percentage from baseline biopsy to on-treatment resection, is evaluable in 17/20 phase IIa patients and 29/32 total trial patients (6/6 NIVO MONO, 23/26 COMBO). We observe a major pathological response (MPR, 90‒100% response) in 35% of patients after COMBO ICB, both in phase IIa (6/17) and in the whole trial (8/23), meeting the phase IIa primary endpoint threshold of 10%. NIVO MONO’s MPR rate is 17% (1/6). None of the MPR patients develop recurrent HSNCC during 24.0 months median postsurgical follow-up. FDG-PET-based total lesion glycolysis identifies MPR patients prior to surgery. A baseline AID/APOBEC-associated mutational profile and an on-treatment decrease in hypoxia RNA signature are observed in MPR patients. Our data indicate that neoadjuvant COMBO ICB is feasible and encouragingly efficacious in HNSCC
Feedback preferences of patients, professionals and health insurers in integrated head and neck cancer care
Background: Audit and feedback on professional practice and health care outcomes are the most often used interventions to change behaviour of professionals and improve quality of health care. However, limited information is available regarding preferred feedback for patients, professionals and health insurers. Objective: Investigate the (differences in) preferences of receiving feedback between stakeholders, using the Dutch Head and Neck Audit as an example. Methods: A total of 37 patients, medical specialists, allied health professionals and health insurers were interviewed using semi-structured interviews. Questions focussed on: “Why,” “On what aspects” and “How” do you prefer to receive feedback on professional practice and health care outcomes?. Results: All stakeholders mentioned that feedback can improve health care by creating awareness, enabling self-reflection and reflection on peers or colleagues, and by benchmarking to others. Patients prefer feedback on the actual professional practice that matches the health care received, whereas medical specialists and health insurers are interested mainly in health care outcomes. All stakeholders largely prefer a bar graph. Patients prefer a pie chart for patient-reported outcomes and experiences, while Kaplan-Meier survival curves are preferred by medical specialists. Feedback should be simple with firstly an overview, and 1-4 times a year sent by e-mail. Finally, patients and health professionals are cautious with regard to transparency of audit data. Conclusions: This exploratory study shows how feedback preferences differ between stakeholders. Therefore, tailored reports are recommended. Using this information, effects of audit and feedback can be improved by adapting the feedback format and contents to the preferences of stakeholders
Substitution of hospital care with Primary Care Plus: differences in referral patterns according to specialty, specialist and diagnosis group
Reliability and usefulness of upper gastro intestinal contrast studies to assess pouch size in patients with weight loss failure after Roux-en-Y gastric bypass
Background: Weight loss failure or weight regain occurs in up to 25% of patients with a Roux-en-Y gastric bypass (RYGB). Post-operative anatomical changes, like pouch or stoma dilatation, might contribute. Aim of this study is to assess reliability and usefulness of upper gastro intestinal (UGI) contrast studies to detect pouch dilatation. Methods: Retrospective case-control study of patients with weight loss failure between 2010 and 2015 (failure group, n = 101) and a control group (n = 101) with adequate weight loss. Pouch dilatation was systematically reassessed. Clinical parameters were extracted from the electronic patient records. Results: Systematic reassessment showed 23/101 (23%) pouch dilatation in the failure group, compared to 11/101 (11%) in the control group (p = .024). Revision surgery was performed in 43/101 patients in the failure group. After this surgery, only 8% of patients with pouch dilatation achieved adequate weight loss, whereas 39% of patients without pouch dilatation achieved adequate weight loss (p = .07). There was no difference in return to adequate weight loss between patients treated surgically and conservatively (30% vs 28%). Conclusion: Systematic reassessment of UGI contrast studies showed 23% pouch dilatation in patients with weight loss failure after RYGB. However, low interobserver agreement and discrepancy in success rate of revision surgery greatly questions the reliability and usefulness of this diagnostic modality
Reliability and usefulness of upper gastro intestinal contrast studies to assess pouch size in patients with weight loss failure after Roux-en-Y gastric bypass
Background: Weight loss failure or weight regain occurs in up to 25% of patients with a Roux-en-Y gastric bypass (RYGB). Post-operative anatomical changes, like pouch or stoma dilatation, might contribute. Aim of this study is to assess reliability and usefulness of upper gastro intestinal (UGI) contrast studies to detect pouch dilatation. Methods: Retrospective case-control study of patients with weight loss failure between 2010 and 2015 (failure group, n = 101) and a control group (n = 101) with adequate weight loss. Pouch dilatation was systematically reassessed. Clinical parameters were extracted from the electronic patient records. Results: Systematic reassessment showed 23/101 (23%) pouch dilatation in the failure group, compared to 11/101 (11%) in the control group (p = .024). Revision surgery was performed in 43/101 patients in the failure group. After this surgery, only 8% of patients with pouch dilatation achieved adequate weight loss, whereas 39% of patients without pouch dilatation achieved adequate weight loss (p = .07). There was no difference in return to adequate weight loss between patients treated surgically and conservatively (30% vs 28%). Conclusion: Systematic reassessment of UGI contrast studies showed 23% pouch dilatation in patients with weight loss failure after RYGB. However, low interobserver agreement and discrepancy in success rate of revision surgery greatly questions the reliability and usefulness of this diagnostic modality
Patient preferences for treatment of lumbar disc herniation: a discrete choice experiment
OBJECTIVE Lumbar discectomy is a frequently performed procedure to treat sciatica caused by lumbar disc herniation. Multiple surgical techniques are available, and the popularity of minimally invasive surgical techniques is increasing worldwide. Clinical outcomes between these techniques may not show any substantial differences. As lumbar discectomy is an elective procedure, patients’ own preferences play an important role in determining the procedure they will undergo. The aims of the current study were to determine the relative preference weights patients apply to various attributes of lumbar discectomy, determine if patient preferences change after surgery, identify preference heterogeneity for choosing surgery for sciatica, and calculate patient willingness to pay for other attributes. METHODS A discrete choice experiment (DCE) was conducted among patients with sciatica caused by lumbar disc herniation. A questionnaire was administered to patients before they underwent surgery and to an independent sample of patients who had already undergone surgery. The DCE required patients to choose between two surgical techniques or to opt out from 12 choice sets with alternating characteristic levels: waiting time for surgery, out-of-pocket costs, size of the scar, need of general anesthesia, need for hospitalization, effect on leg pain, and duration of the recovery period. RESULTS A total of 287 patients were included in the DCE analysis. All attributes, except scar size, had a significant influence on the overall preferences of patients. The effect on leg pain was the most important characteristic in the decision for a surgical procedure (by 44.8%). The potential out-of-pocket costs for the procedure (28.8%), the wait time (12.8%), need for general anesthesia (7.5%), need for hospitalization (4.3%), and the recovery period (1.8%) followed. Preferences were independent of the scores on patient-reported outcome measures and baseline characteristics. Three latent classes could be identified with specific preference patterns. Willingness-to-pay was the highest for effectiveness on leg pain, with patients willing to pay €3133 for a treatment that has a 90% effectiveness instead of 70%. CONCLUSIONS Effect on leg pain is the most important factor for patients in deciding to undergo surgery for sciatica. Not all proposed advantages of minimally invasive spine surgery (e.g., size of the scar, no need of general anesthesia) are necessarily perceived as advantages by patients. Spine surgeons should propose surgical techniques for sciatica, not only based on own ability and proposed eligibility, but also based on patient preferences as is part of shared decision making
A 12-channel flexible receiver coil for accelerated tongue imaging
Objective: MRI of the tongue requires acceleration to minimise motion artefacts and to facilitate real-time imaging of swallowing. To accelerate tongue MRI, we designed a dedicated flexible receiver coil. Materials and methods: We designed a flexible 12-channel receiver coil for tongue MRI at 3T and compared it to a conventional head-and-neck coil regarding SNR and g-factor. Furthermore, two accelerated imaging techniques were evaluated using both coils: multiband (MB) diffusion-tensor imaging (DTI) and real-time MRI of swallowing. Results: The flexible coil had significantly higher SNR in the anterior (2.1 times higher, P = 0.002) and posterior (2.0 times higher, P < 0.001) parts of the tongue, while the g-factor was lower at higher acceleration. Unlike for the flexible coil, the apparent diffusion coefficient (P = 0.001) and fractional anisotropy (P = 0.008) deteriorated significantly while using the conventional coil after accelerating DTI with MB. The image quality of real-time MRI of swallowing was significantly better for hyoid elevation (P = 0.029) using the flexible coil. Conclusion: Facilitated by higher SNR and lower g-factor values, our flexible tongue coil allows faster imaging, which was successfully demonstrated in MB DTI and real-time MRI of swallowing