How similar is "similar," or what is the best measure of soil spectral and physiochemical similarity?

Spectral similarity indices were used to select similar soil samples from a spectral library and improve the predictive accuracy of target samples. There are many similarity indices available, and precisely how to select the optimum index has become a critical question. Five similarity indices were evaluated: Spectral angle mapper (SAM), Euclidean distance (ED), Mahalanobis distance (MD), SAM_pca and ED_pca in the space of principal components applied to a global soil spectral library. The accordance between spectral and compositional similarity was used to select the optimum index. Then the optimum index was evaluated if it can maintain the greatest predictive accuracy when selecting similar samples from a spectral library for the prediction of a target sample using a partial least squares regression (PLSR) model. The evaluated physiochemical properties were: soil organic carbon, pH, cation exchange capacity (CEC), clay, silt, and sand content. SAM and SAM_pca selected samples were closer in composition compared to the target samples. Based on similar samples selected using these two indices, PLSR models achieved the highest predictive accuracy for all soil properties, save for CEC. This validates the hypothesis that the accordance information between spectral and compositional similarity can help select the appropriate similarity index when selecting similar samples from a spectral library for prediction.

LncRNA TP73-AS1 promotes malignant progression of hepatoma by regulating microRNA-103.

OBJECTIVE: The aim of this study was to investigate long non-coding RNA (lncRNA) TP73-AS1 expression in hepatocellular carcinoma (HCC) tissues and cells, and to further investigate whether it can accelerate the progression of HCC by regulating microRNA-103. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine TP73-AS1 expression in 60 pairs of HCC tissues and adjacent ones, and the association between lncRNATP73-AS1 level and clinical indicators of HCC as well as patients' prognosis was analyzed. Meanwhile, qRT-PCR was used to further verify TP73-AS1 expression in HCC cell lines. The lncRNA TP73-AS1 knockdown model was constructed using lentivirus in the HCC cell lines, including Bel-7402 and HepG2. Cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays were performed to figure out the influence of TP73-AS1 on the basic biological function of the HCC cells. Finally, the involved potential regulatory mechanism was explored using cell recovery experiments, and the relationship between TP73-AS1 and microRNA-103 was further studied. RESULTS: QRT-PCR results indicated that TP73-AS1 expression in HCC samples was conspicuously enhanced compared with paracancerous tissues, and patients with a relatively high level of TP73-AS1 had a higher tumor stage and a lower overall survival rate. Meanwhile, the proliferation ability of cells in the sh-TP73-AS1 group was strikingly lower than that in the control group, while cell apoptosis showed the opposite trend. Besides, qRT-PCR results indicated a negative correlation between microRNA-103 and TP73-AS1 in HCC tissue specimens. The results of the luciferase reporting assay revealed that TP73-AS1 could be targeted by microRNA-103 through binding site. In addition, the cell recovery experiment demonstrated that TP73-AS1 and microRNA-103 might have a mutual regulation, and the two of which could together affect the malignant progression of HCC. CONCLUSIONS: TP73-AS1 expression was conspicuously enhanced both in HCC tissues and cell lines, which were associated with advanced tumor stage and poor prognosis. In addition, TP73-AS1 could accelerate the proliferation of HCC cells by regulating microRNA-103.

[Clinical pathological characteristics of resectable papillary thyroid microcarcinoma].

Objective: To investigate the difference of prognostic factors and recurrence rates between papillary thyroid microcarcinoma (PTMC) and lager papillary thyroid carcinoma (PTC) and analyze the clinical pathological characteristics of PTMC suitable for surgery. Methods: A retrospective analysis on the clinicopathological features, expression level of of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E gene mutation and pigment epithelium-derived factor (PEDF), and postoperative follow-up results of the 251 PTC patients who underwent surgical treatment from October 2011 to October 2013, including 169 cases with PTMC and 82 with lager PTC (Tumor diameter>1 cm). Results: The BRAF V600E mutation rates of PTMC and lager PTC patients are 65.1%(110/169)and 78.0% (64/82) respectively, and the difference is statistically significant (P<0.05). The prevalence of extrathyroidal invasion (7.1%) and lymph nodes metastasis (27.2%) of the patients with PTMC were significantly lower than those of the patients with larger PTC (15.9% and 46.3%, respectively)(P<0.01). The follow-up durations for PTMC and lager PTC were (45.6±3.6) months and (45.0±3.4) months, respectively (P>0.05). There was no statistic significance for the difference in age, gender, coexistent hashimoto's thyroiditis, PEDF expression, and recurrence rate between the patients with PTMC and with larger PTC (P>0.05). The recurrence rate of the patients who have the high risk factors of PTMC was 1.6%(2/122)and that of larger PTC was 4.9% (4/82). Conclusions: Extrathyroid invasion, lymph node metastases and BRAF V600E gene mutation are the high risk factors of recurrent PTMC. The same treatment strategy should be considered for PTMC with coexistent high risk factors as that for larger PTC. For PTMC with BRAF V600E gene mutation, earlier surgical treatment is suggested. PTMC patients with BRAF V600E gene mutation and high cell subtype are suggested to undergo total thyroidectomy for the first operation in order to reduce the potential risk of recurrence.

The TrkB+ cancer stem cells contribute to post-chemotherapy recurrence of triple-negative breast cancers in an orthotopic mouse model.

Cancer stem cells (CSCs) are believed to have a crucial role in triple-negative breast cancer (TNBC) recurrence. However, the exact mechanisms that are functionally critical in CSCs-mediated recurrence remain unclear. Here, we showed that CSCs derived from recurrent TNBCs are endowed with increased self-renewal capacity as compared with those from the matched primary lesions. Using patient-derived specimens, we demonstrated the existence of paracrine brain-derived neurotrophic factor (BDNF) signaling between differentiated recurrent TNBC cells and CSCs characterized by the expression of TrkB, the receptor of BDNF. We showed that paclitaxel induced BDNF expression and apoptosis simultaneously in a cell cycle-dependent manner. BDNF promotes the self-renewal potential of the TrkB+CSCs through induction of KLF4. The TrkB+CSCs represent a particular subset indispensable for TNBC relapse. In line with this, TrkB is proved to be a superior predictor for TNBC recurrence. Using a genetically engineered mouse model of TNBC, we observed that ablation of the TrkB+CSCs potentially prevents relapse of malignant tumors. Further preclinical investigation of this promising approach may lead to development of a novel therapeutic strategy to improve the devastating prognosis of TNBC patients.

Nitric oxide contributes to both spinal nociceptive transmission and its descending inhibition in rats: an immunocytochemical study.

The present study was designed to determine if nitric oxide (NO) was involved both in the dorsal horn responses to the primary nociceptive inputs and the descending inhibitory action on these responses. The first part of the experiments showed that when formalin was injected into one hindpaw, the nociceptive c-fos expression in the lumbar dorsal horn ipsilateral to the injection was suppressed dose-dependently by intrathecal (i.t.) administration of Nomega-nitro-L-arginine (L-NNA), a nitric oxide synthase inhibitor. In the second part of the study, the formalin injection was carried out into two hindpaws of the rats with a sectioned dorsal quadrant at the thoracic spinal level, in these rats, there was a significant suppression of c-fos expression in the dorsal horn on the side with intact dorsal quadrant, reasonably owing to the preservation of the spinally descending inhibitory fibers from the supraspinal level; furthermore, this suppression could be canceled following i.t. L-NNA administration. The results suggest that endogenous NO not only facilitates the perception of nociceptive inputs at the spinal level but also enhances the descending inhibition upon the spinal nociception.