Few systematic studies have been published comparing the expression and distribution of endothelial cell (EC) markers in different vascular beds in normal human tissues. We investigated by immunohistochemistry the expression of CD31, CD34, von Willebrand factor (vWF), and Fli-1 in EC of the major organs and large vessels. Tissue samples obtained from autopsies and biopsy specimens were routinely processed and stained immunohistochemically for CD31, CD34, and vWF. Biopsy material was also stained immunohistochemically for Fli-1, D2-40, and Lyve-1. The expression pattern of the markers was heterogeneous in some of the organs studied. In the kidney, fenestrated endothelium of the glomeruli strongly expressed CD31 and CD34 but was only focally positive or completely negative for vWF. Alveolar wall capillaries of the lung strongly stained for CD31 and CD34 but were usually negative for vWF. The staining intensity for vWF increased gradually with the vessel caliber in the lung. Sinusoids of the spleen and liver were diffusely positive for CD31. They were negative for CD34 in the spleen and only expressed CD34 in the periportal area in the liver. Fli-1 was expressed in all types of EC but also in lymphocytes. D2-40 stained lymphatic endothelium only. Lyve-1 immunostaining was too variable to be applied to routinely processed tissues. The expression of EC markers CD31, CD34, and vWF in the vascular tree is heterogeneous with a specific pattern for individual vessel types and different anatomic compartments of the same organ. D2-40 labels lymphatic EC only.

Reaction‐based sensing: A fluorescent probe for the detection of hydrogen sulfide was prepared and evaluated on the basis of H2S‐mediated benzodithiolone formation. The probe showed good selectivity and sensitivity for hydrogen sulfide.

Tumor budding in colorectal cancer (CRC) is recognized as a valuable prognostic factor but its translation into daily histopathology practice has been delayed by lack of agreement on the optimal method of assessment. Within the context of the Swiss Association of Gastrointestinal Pathology (SAGIP), we performed a multicenter interobserver study on tumor budding, comparing hematoxylin and eosin (H&E) with pan-cytokeratin staining using a 10 high power field (10HPF) and hotspot (1HPF) method. Two serial sections of 50 TNM stage II-IV surgically treated CRC were stained for H&E and pan-cytokeratin. Tumor buds were scored by independent observers at six participating centers in Switzerland and Austria using the 10HPF and 1HPF method on a digital pathology platform. Pearson correlation (r) and intra-class correlation coefficients (ICC) comparing scores between centers were calculated. Three to four times more tumor buds were detected in pan-cytokeratin compared to H&E slides. Correlation coefficients for tumor budding counts between centers ranged from r = 0.46 to r = 0.91 for H&E and from r = 0.73 to r = 0.95 for pan-cytokeratin slides. Interobserver agreement across all centers was excellent for pan-cytokeratin [10HPF: ICC = 0.83 and 1HPF: ICC = 0.8]. In contrast, assessment of tumor budding on H&E slides reached only moderate agreement [10HPF: ICC = 0.58 and 1HPF: ICC = 0.49]. Based on previous literature and our findings, we recommend (1) pan-cytokeratin staining whenever possible, (2) 10HPF method for resection specimens, and (3) 1HPF method for limited material (preoperative biopsy or pT1). Since tumor budding counts can be used to determine probabilities of relevant outcomes and as such more optimally complement clinical decision making, we advocate the avoidance of cutoff scores.

Cancer‐testis (CT) antigens comprise families of tumor‐associated antigens that are immunogenic in patients with various cancers. Their restricted expression makes them attractive targets for immunotherapy. The aim of this study was to determine the expression of several CT genes and evaluate their prognostic value in head and neck squamous cell carcinoma (HNSCC). The pattern and level of expression of 12 CT genes (MAGE‐A1, MAGE‐A3, MAGE‐A4, MAGE‐A10, MAGE‐C2, NY‐ESO‐1, LAGE‐1, SSX‐2, SSX‐4, BAGE, GAGE‐1/2, GAGE‐3/4) and the tumor‐associated antigen encoding genes PRAME, HERV‐K‐MEL, and NA‐17A were evaluated by RT‐PCR in a panel of 57 primary HNSCC. Over 80% of the tumors expressed at least 1 CT gene. Coexpression of three or more genes was detected in 59% of the patients. MAGE‐A4 (60%), MAGE‐A3 (51%), PRAME (49%) and HERV‐K‐MEL (42%) were the most frequently expressed genes. Overall, the pattern of expression of CT genes indicated a coordinate regulation; however there was no correlation between expression of MAGE‐A3/A4 and BORIS, a gene whose product has been implicated in CT gene activation. The presence of MAGE‐A and NY‐ESO‐1 proteins was verified by immunohistochemistry. Analysis of the correlation between mRNA expression of CT genes with clinico‐pathological characteristics and clinical outcome revealed that patients with tumors positive for MAGE‐A4 or multiple CT gene expression had a poorer overall survival. Furthermore, MAGE‐A4 mRNA positivity was prognostic of poor outcome independent of clinical parameters. These findings indicate that expression of CT genes is associated with a more malignant phenotype and suggest their usefulness as prognostic markers in HNSCC.

The control of haematopoietic colony‐stimulating factors (CSF) gene expression by interleukin 1 (IL‐1) and tumour necrosis factor alpha (TNF‐alpha) in cultured endothelial cells was studied by RNA hybridization and nuclear gene transcription. Both IL‐1 and TNF‐alpha induced, with somewhat different kinetics, a slow but marked accumulation of granulocyte‐macrophage (GM)‐ and granulocyte (G)‐CSF mRNAs in endothelial cells; macrophage (M)‐CSF mRNA increased more rapidly but more moderately. Simultaneous treatment with maximally stimulating concentrations of both IL‐1 and TNF‐alpha had an additive effect on the accumulation of the three mRNAs, suggesting that both mediators act via independent pathways. The mechanism of CSF mRNA accumulation in endothelial cells was explored by nuclear run‐on experiments, which showed that both IL‐1 and TNF‐alpha increase GM‐CSF, G‐CSF and M‐CSF gene transcription to varying degrees.