Type II NKT Cells Stimulate Diet-Induced Obesity by Mediating Adipose Tissue Inflammation, Steatohepatitis and Insulin Resistance

The progression of obesity is accompanied by a chronic inflammatory process that involves both innate and acquired immunity. Natural killer T (NKT) cells recognize lipid antigens and are also distributed in adipose tissue. To examine the involvement of NKT cells in the development of obesity, C57BL/6 mice (wild type; WT), and two NKT-cell-deficient strains, Jα18−/− mice that lack the type I subset and CD1d−/− mice that lack both the type I and II subsets, were fed a high fat diet (HFD). CD1d−/− mice gained the least body weight with the least weight in perigonadal and brown adipose tissue as well as in the liver, compared to WT or Jα18−/− mice fed an HFD. Histologically, CD1d−/− mice had significantly smaller adipocytes and developed significantly milder hepatosteatosis than WT or Jα18−/− mice. The number of NK1.1+TCRβ+ cells in adipose tissue increased when WT mice were fed an HFD and were mostly invariant Vα14Jα18-negative. CD11b+ macrophages (Mφ) were another major subset of cells in adipose tissue infiltrates, and they were divided into F4/80high and F4/80low cells. The F4/80low-Mφ subset in adipose tissue was increased in CD1d−/− mice, and this population likely played an anti-inflammatory role. Glucose intolerance and insulin resistance in CD1d−/− mice were not aggravated as in WT or Jα18−/− mice fed an HFD, likely due to a lower grade of inflammation and adiposity. Collectively, our findings provide evidence that type II NKT cells initiate inflammation in the liver and adipose tissue and exacerbate the course of obesity that leads to insulin resistance

Contraindications of sentinel lymph node biopsy: Áre there any really?

BACKGROUND: One of the most exciting and talked about new surgical techniques in breast cancer surgery is the sentinel lymph node biopsy. It is an alternative procedure to standard axillary lymph node dissection, which makes possible less invasive surgery and side effects for patients with early breast cancer that wouldn't benefit further from axillary lymph node clearance. Sentinel lymph node biopsy helps to accurately evaluate the status of the axilla and the extent of disease, but also determines appropriate adjuvant treatment and long-term follow-up. However, like all surgical procedures, the sentinel lymph node biopsy is not appropriate for each and every patient. METHODS: In this article we review the absolute and relative contraindications of the procedure in respect to clinically positive axilla, neoadjuvant therapy, tumor size, multicentric and multifocal disease, in situ carcinoma, pregnancy, age, body-mass index, allergies to dye and/or radio colloid and prior breast and/or axillary surgery. RESULTS: Certain conditions involving host factors and tumor biologic characteristics may have a negative impact on the success rate and accuracy of the procedure. The overall fraction of patients unsuitable or with multiple risk factors that may compromise the success of the sentinel lymph node biopsy, is very small. Nevertheless, these patients need to be successfully identified, appropriately advised and cautioned, and so do the surgeons that perform the procedure. CONCLUSION: When performed by an experienced multi-disciplinary team, the SLNB is a highly effective and accurate alternative to standard level I and II axillary clearance in the vast majority of patients with early breast cancer

Lack of evidence for aggregation-dependent enhancement of p56(lck) in the signal transduction upon major histocompatibility complex recognition by mature T cells

The kinase activity of lymphocyte-specific tyrosine kinase p56(lck) (Lck) upon physiological major histocompatibility complex (MHC) recognition by normal mature T cells was examined. Recognition of the target MHC molecules by T cells induced phosphorylation of the ζ-chain without obvious enhancement of the background Lck activity. There was no sign of enhancement of Lck through putative T-cell receptor (TCR)-independent class II MHC/CD4 interactions either. As has been reported, cross-linking of CD4 molecules by antibodies induced a marked enhancement of Lck activity. However, it did not have an immediate relevance to TCR-mediated signal transduction, as judged from the lack of detectable de novo phosphorylation of ζ-chain and the absence of functional responses of T cells. These results strongly favour the model in which TCR-mediated signal transduction does not involve aggregation-dependent enhancement of Lck, suggesting that the signal can be triggered simply by the recruitment of already active Lck with basal kinase activity through the formation of a TCR/MHC/CD4 ternary complex

Risk profile and 1-year outcome of newly diagnosed atrial fibrillation in Japan ― Insights from GARFIELD-AF ―

Background: Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective non-inter-ventional study of stroke prevention in patients with newly diagnosed non-valvular AF (NAVF) that is being conducted in 35 countries. Methods and Results: A total of 52,081 patients with a new diagnosis of NVAF were enrolled prospectively in GARFIELD-AF. Of these, 4859 (9.3%) were recruited in Japan (2010–2016). In cohort 1 (2010–2011), few patients were on non-vitamin K antagonist oral anticoagulants (NOAC) globally. From cohort 2 onwards (2011–2016), however, there was a rapid increase in NOAC use around the globe, especially in Japan. By the last year of enrolment (2015–2016), 67.9% of patients in Japan and 43.1% of patients globally were on NOAC ± antiplatelet therapy (AP). In Japan and globally, 17.0% and 12.2% of patients, respectively, did not receive stroke prevention treatment. Few patients in Japan (5.7%) received AP only. Compared with the other countries, the unadjusted rates of all-cause mortality and major bleeding were low, while rates of stroke/systemic embolism were similar after 1 year of follow-up. Conclusions: GARFIELD-AF continues to provide important information on the homogeneity and heterogeneity of baseline characteristics and treatment patterns in patients with newly diagnosed NVAF. This diversity reflects the differences in outcomes in Japan compared with the rest of the world