Studies on the penetration of toxicologically or pharmaceutically relevant substances through the skin and, more specifically, through the stratum corneum (s.c.) often rely on the well-established method of tape stripping. Tape stripping involves the removal of skin layers by means of adhesive tape, which is usually followed by quantification of dermally applied substances in these layers. However, the amount of s.c. removed by each individual tape strip is still a matter of scientific debate. While some studies imply that the amount of s.c. adhering to each tape strip decreases with increasing depth into the s.c., others observed a constant removal rate. All these studies rely on the quantification of the amount of s.c. captured on individual or pooled tape strips. Here, we present an approach whereby we measured the amount of s.c. remaining on excised porcine skin in the process of tape stripping. Staining and bloating of the s.c. allowed to measure its thickness and to count individual s.c. layers, respectively. Histologically, we show that the s.c. remaining on the skin decreased linearly as a function of strips taken. We found that each tape strip removes about 0.4 µm of s.c., which corresponds to approximately one cellular layer. With a high coefficient of determination (r2 > 0.95), we were able to linearly correlate the thickness of the remaining s.c., the number of remaining cell layers and the number of tape strips applied. Furthermore, we elaborate on possible reasons for the discrepancies reported in the scientific literature regarding the amount of s.c. removed by each tape strip.

To the best of our knowledge, artificial intelligence stain generation is an urgent requirement for histopathology images. Pathological examinations usually only utilize hematoxylin and eosin (H&E) regular staining to show histomorphological characteristics, but to accurately diagnose the disease, functional staining (such as oil red O and Ki67) are also required to provide important auxiliary information. However, the same tissue section is usually stained with one stain, and additional functional staining is not only time-consuming but also causes inevitable morphological misalignment due to manual manipulation. This brings difficulties to the development of artificial intelligence pathological image analysis tools. In this work, we propose a histopathology staining transfer framework to generate virtual functional staining images from H&E regular staining images. Compared with the framework that emphasizes generation diversity in the natural image field, we use KL loss and histo loss to align and separate style feature spaces in different domains to obtain domain-variant style features. The proposed multiple virtual functional stain (MVFStain) abstracts staining conversion to domain mapping and comprehensively utilizes multiple staining information. We evaluated the proposed method on four datasets (lung lesion, lung lobes, breast, and atherosclerotic lesion). The experiment involves the translation of H&E to nine other functional stains: CC10, Ki67, proSPC, HER2, PR, ER, oil red O, α-SMA, and macrophages. The major quantitative results are divided into image quality and positive signal prediction. MVFStain is close to or even surpasses one-to-one image translation on psnr and HTI image quality metrics. The best psnr reaches 26.1919, and HIT reaches 0.9430. We used mIOD to evaluate the optical density of positive signals, and CNR and gCNR to evaluate the lesion detectability. The results show that the mIOD of positive signals of virtual staining was slightly lower than the ground truth and close the lesion detectability of artificial staining. These results prove that the potential exists to develop a successful clinical alternative to artificial functional stains.

Objective:To compare the diagnostic potential of HE staining, enzymatic histochemistry and immunohistochemistry in displaying lymphatic vessel of laryngeal carcinoma.Method：We recruited 3 patients who were pathologically diagnozed as laryngeal squamous cell carcinoma and were performed total laryngectomy in the First Affiliated Hospital of Shanxi Medical University from April to December 2016. According to the improved Kawamoto\'s Film Method, frozen specimens of whole laryngeal squamous cell carcinoma were made. Immunohistochemistry, using lymphatic endothelial cell specific marker D2-40, enzymatic histochemistry (5-nucleotidase) and HE staining were used to stain the frozen sections of laryngeal carcinoma. Then the staining results of lymphatic vessels in the specimens of laryngeal carcinoma were compared by the optical microscope. Result：The background of HE and D2-40 immunohistochemical staining were clear.5-Nase staining had a deeper background and more nonspecific staining. By immunohistochemistry,102（97.1%,102/105）blood vessels were identified, and 3(2.9%) were partly positive. While using 5-Nase,56（53,3%,56/105）blood vessels were identified. In 105 lumen structures that could not be clearly judged,95（90,5%）were positive by D2-40,while by 5-Nase staining,89（84.8%）were positive including a large number of glands.In addition, positive cells scattered in dots or clusters were observed in 5-Nase and D2-40 staining sections, but these cells or structures could not be identified by HE staining. Conclusion：D2-40 immunohistochemistry may have certain applied value in the study of lymphatic vessels associated with laryngeal carcinoma.

Hyperuricemia is related to a variety of pathologies, including chronic kidney disease (CKD). However, the pathophysiological mechanisms underlying disease development are not yet fully elucidated. Here, we studied the effect of hyperuricemia on tryptophan metabolism and the potential role herein of two important uric acid efflux transporters, multidrug resistance protein 4 (MRP4) and breast cancer resistance protein (BCRP). Hyperuricemia was induced in mice by treatment with the uricase inhibitor oxonic acid, confirmed by the presence of urate crystals in the urine of treated animals. A transport assay, using membrane vesicles of cells overexpressing the transporters, revealed that uric acid inhibited substrate-specific transport by BCRP at clinically relevant concentrations (calculated IC50 value: 365±13μM), as was previously reported for MRP4. Moreover, we identified kynurenic acid as a novel substrate for MRP4 and BCRP. This finding was corroborated by increased plasma levels of kynurenic acid observed in Mrp4(-/-) (107±19nM; P=0.145) and Bcrp(-/-) mice (133±10nM; P=0.0007) compared to wild type animals (71±11nM). Hyperuricemia was associated with >1.5 fold increase in plasma kynurenine levels in all strains. Moreover, hyperuricemia led to elevated plasma kynurenic acid levels (128±13nM, P=0.005) in wild type mice but did not further increase kynurenic acid levels in knockout mice. Based on our results, we postulate that elevated uric acid levels hamper MRP4 and BCRP functioning, thereby promoting the retention of other potentially toxic substrates, including kynurenic acid, which could contribute to the development of CKD.