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Obesity plays an important role in human fertility in both genders. The same is true for vitamin D, for which accumulating evidence from observational human studies suggests a key role for both male and female fertility. In the latter case, however, robust data from relevant interventional studies are currently lacking. It is also not clear whether obesity and vitamin D deficiency, besides their independent effect on human infertility, act in synergy. Several pathogenetic mechanisms may be proposed as a linkage between vitamin D deficiency and obesity, with respect to infertility. In any case, the independent contribution of vitamin D deficiency in obese infertile states needs to be proven in interventional studies focusing on either vitamin D supplementation in obese or weight loss strategies in vitamin D-deficient infertile patients.

Thyroidology is a discipline of Endocrinology which has evolved markedly over the past few decades. However, its historical roots can be seen in the literature of, among others, ancient Greek medicine. In the present article, we present the descriptions of the thyroid gland by ancient Greek physicians and its depiction in ancient Greek art.

Peroxisome proliferator activated receptors (PPARs) are transcription factors that belong to nuclear hormone superfamily, with three distinct types identified: PPARapha (PPARα), PPARgamma (PPARγ), and PPARbeta/delta (PPARβ/δ). PPARs possess a critical role in the regulation of lipid metabolism, and thus play critical roles in the differentiation and fate of immune cells. PPARα is involved in lipid and carbohydrate metabolism and PPARα agonists, such as fibrates, have been used for the treatment of hypertriglyceridemia and cardiovascular diseases. PPARα has an anti-inflammatory role during infection, and similar to PPARγ, affects the polarization of macrophages. In acute myelogenous leukemia (AML), PPARα mutations correlate with chemoresistance, poor treatment outcomes and unfavorable prognosis. In experimental tumor models, it has been proposed that PPARα agonists might enhance anti-tumor T cell responses during PD-1 blocking immunotherapy. To dissect the mechanistic role of PPARα in tumor immunity, we used mice with global deletion of PPARα and examined tumor growth and profile of the immunological landscape, using various syngeneic tumor models. Significantly larger B16-F10 melanoma and MC-17 fibrosarcoma tumors were observed in PPARα KO mice compared with wild-type control, suggesting that PPARα deletion attenuated the immunological response against cancer. To dissect the role of PPARα in key populations of the innate and adaptive immune system involved in anti-tumor responses, we analyzed the immunological landscape of tumor, tumor draining lymph nodes (TDLN) and spleen, 14-16 days after tumor implantation. Assessment of CD4 + and CD8 + T cells, CD11b +F4/80 + tumor-associated macrophages (TAMs), CD11b +Ly6C hiLy6G - monocytic myeloid derived suppressor cells (M-MDSC), and CD11b +Ly6C loLy6G + polymorphonuclear myeloid derived suppressor cells (PMN-MDSC), by using flow cytometry, showed no quantitative differences between the two experimental groups. Functionally, MDSC from PPARα KO and WT mice showed comparable immunosuppressive properties as determined by suppression assay using splenocytes from OTI transgenic mice. However, PPARα KO TAMs demonstrated a less activated state, as determined by the lower expression levels of MHC-II that is critical for antigen presentation, and CD86 that is critical for T cell costimulation and prevention of T cell anergy and exhaustion. In agreement with these properties of TAMs, CD4 + T cells from TDLN of PPARα KO mice had diminished expression of activation markers, including PD-1, PD-L1 and ICOS, and numerically decreased central memory-like CD4 + T cells (T CM), compared to control tumor bearing mice. Furthermore, CD69, an emerging marker of T cell exhaustion, was significantly upregulated in CD4 + and CD8 + T cells from the TDLN of PPARα KO mice. To determine whether PPARα ablation altered the cell intrinsic properties of myeloid cells and/or T cells resulting in impaired anti-tumor function, we examined in vitro responses of isolated populations. In response to activation via TCR/CD3 and CD28, PPARα deficient T cells had no significant differences in expansion and cytokine production compared to control. In contrast, PPARα deficient Ly6C + monocytes isolated from the bone marrow displayed diminished responses to TLR-mediated signaling as determined by production of IL-6 and TNFα. Our in vitro and in vivo findings reveal a dominant role of PPARα in regulating the fate of innate immune cells thereby altering T cell responses and anti-tumor function. Our findings have implications for the development of new therapeutic approaches to enhance innate immune cell function for the improvement of cancer immunotherapy. Disclosures No relevant conflicts of interest to declare.

This cohort study investigates clinicopathologic and prognostic associations of hypercalcemia in patients with intrahepatic or extrahepatic cholangiocarcinoma.

4946 Establishing the diagnosis of Myelodysplastic Syndromes (MDS) is a challenging task for hematologists due to the heterogeneity of this clinical entity. Several attempts have been made to include findings from advanced technologies to the diagnostic criteria of MDS, but still in the majority of cases, morphology of peripheral blood and bone marrow remains the cornerstone for the diagnosis. Flow cytometry(FC) can identify abnormal antigen expression on myeloid cells. FC has been proposed as a complementary method in the diagnosis of low and intermediate risk MDS, particularly for patients not exhibiting characteristic karyotype abnormalities. On the other hand, recent literature suggests that these findings are not MDS-related, questioning the specificity of immunophenotyping for the diagnosis of MDS. The aim of the present study is to maximize the utility of FC data and simplify their interpretation for the diagnosis of MDS, by developing new analytical approaches of digital data, other than the conventional sequential biparametric analysis. The applied methodology was based on a mathematical model of scale analysis. Bone marrow(BM) samples from 50 subjects were analysed for the expression of CD45PC7, CD11bPC5, CD16FITC and CD13PE (antigens by Beckman Coulter, FC500 flow cytometer Beckman Coulter). 36 patients were diagnosed with MDS (23 low risk, 13 high risk) and 14 patients had other than an MDS diagnosis (ITP, chronic idiopathic neutropenia, systemic lupus erythematosus, LGL leukemia, age-related cytopenias, aplastic anemia, myelofibrosis etc). Additionally, 3 BM samples of patients with post-MDS acute myeloid leukemia(AML) were analysed. The data used for the development of the mathematical model were the following: two populations (neutro1, neutron2) were gated according to their CD45 and CD13/CD16 antigen expression (Figure 1i-1v).Seven subpopulations of Neutrophils were defined on CD11b/CD16 density plot N=g+h+i and O=k+j (Figure 1vi). In an attempt to identify correlations between data that cannot be routinely revealed by sequential biparametric analysis, we have developed the HeSK* ratio, which is given by: where x is the median of CD11b in gate O, y is the median of CD16 in gate O, z is the median of CD45 in gate neutro, pO is the percentage of gate O in the total CD11b/CD16 diagram gated in neutro, pN is the percentage of gate N in the total CD11b/CD16 gated in neutro and 1000 is an empirical parameter. The HeSK ratio combines fluorescence levels of CD16, CD11b and CD45 with the percentage of two distinct neutrophil populations (N and O), which differ in their maturation and differentiation stage. The ratio can quantify the abnormal differentiation profile of mature myeloid cells and thus distinguish MDS from non-MDS samples with statistical significance P<0. 0001 (Kruskal Wallis test) as indicated in graph 1. Descriptive statistics are shown in table 1. · HeSK ratio is based upon a novel FC analysis method that could change the conventional biparametric routine FC analysis and quantify patterns that are not evaluated properly. Mathematical modeling of antigen expression patterns optimizes the interpretation of single immunophenotype findings. · The present study proposes HeSK as a complementary diagnostic tool for MDS and a strong indicator for the classification of the patients according to their prognosis as well. *the name HeSK comes from the initials of the 4 main authors (H=Hala, e=Evgenia, S=Smirni, K=Kolliopoulou). Table 1 non MDS low risk MDS high risk MDS Number of values 14 23 13 Minimum 50,76 4,789 0,2850 25% Percentile 304,8 26,11 17,05 Median 2133 92,52 47,64 75% Percentile 10650 228,9 144,3 Maximum 55040 3043 671,7 Mean 10320 316,1 122,7 Std. Deviation 17860 647,9 185,1 Std. Error 4773 135,1 51,33 Figure 1 Figure 1. Disclosures: No relevant conflicts of interest to declare.

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