Comparative Study of Potential Habitats for Simulium qinghaiense (Diptera: Simuliidae) in the Huangshui River Basin, Qinghai-Tibet Plateau: An Analysis Using Four Ecological Niche Models and Optimized Approaches.

The Huangshui River, a vital tributary in the upper reaches of the Yellow River within the eastern Qinghai-Tibet Plateau, is home to the endemic black fly species S. qinghaiense. In this study, we conducted a systematic survey of the distribution of the species in the Huangshui River basin, revealing its predominant presence along the river's main stem. Based on four ecological niche models-MaxEnt with parameter optimization; GARP; BIOCLIM; and DOMAIN-we conduct a comparative analysis; evaluating the accuracy of AUC and Kappa values. Our findings indicate that optimizing parameters significantly improves the MaxEnt model's predictive accuracy by reducing complexity and overfitting. Furthermore, all four models exhibit higher accuracy compared to a random model, with MaxEnt demonstrating the highest AUC and Kappa values (0.9756 and 0.8118, respectively), showcasing significant superiority over the other models (p < 0.05). Evaluation of predictions from the four models elucidates that potential areas of S. qinghaiense in the Huangshui River basin are primarily concentrated in the central and southern areas, with precipitation exerting a predominant influence. Building upon these results, we utilized the MaxEnt model to forecast changes in suitable areas and distribution centers during the Last Interglacial (LIG), Mid-Holocene (MH), and future periods under three climate scenarios. The results indicate significantly smaller suitable areas during LIG and MH compared to the present, with the center of distribution shifting southeastward from the Qilian Mountains to the central part of the basin. In the future, suitable areas under different climate scenarios are expected to contract, with the center of distribution shifting southeastward. These findings provide important theoretical references for monitoring, early warning, and control measures for S. qinghaiense in the region, contributing to ecological health assessment.

The absence of muscle segment homeobox 2 leads to the pyroptosis of ameloblasts by inducing squamous epithelial hyperplasia in the enamel organ.

Muscle segment homeobox 2 (MSX2) has been confirmed to be involved in the regulation of early tooth development. However, the role of MSX2 has not been fully elucidated in enamel development. To research the functions of MSX2 in enamel formation, we used a Msx2-/- (KO) mouse model with no full Msx2 gene. In the present study, the dental appearance and enamel microstructure were detected by scanning electron microscopy and micro-computed tomography. The results showed that the absence of Msx2 resulted in enamel defects, leading to severe tooth wear in KO mice. To further investigate the mechanism behind the phenotype, we performed detailed histological analyses of the enamel organ in KO mice. We discovered that ameloblasts without Msx2 could secrete a small amount of enamel matrix protein in the early stage. However, the enamel epithelium occurred squamous epithelial hyperplasia and partial keratinization in the enamel organ during subsequent developmental stages. Ameloblasts depolarized and underwent pyroptosis. Overall, during the development of enamel, MSX2 affects the formation of enamel by regulating the function of epithelial cells in the enamel organ.

RUNX2 contributes to TGF-ß1-induced expression of Wdr72 in ameloblasts during enamel mineralization.

The elaborate modulation of the transforming growth factor ß (TGF-ß) superfamily signaling network plays an essential role in tooth morphogenesis and differentiation. In our previous studies, we have demonstrated that TGF-ß1 promotes enamel mineralization and maturation using TGF-ß1 gene conditional knockout (TGF-ß1-cKO) mice. However, the specific regulatory mechanisms of TGF-ß1 during enamel development remain unclear. Furthermore, we have previously found that the expression of WD repeat-containing protein 72(WDR72)in mouse enamel epithelium is decreased significantly in the absence of TGF-ß1. Therefore, the aim of the present study was to investigate how TGF-ß1 affects amelogenesis by regulating the expression of Wdr72. Histological examination showed that the absence of TGF-ß1 in ameloblastic epithelial cells resulted in a reduction in enamel mineralization and a delay in enamel matrix protein absorption. TGF-ß1, Runt-related transcription factor 2(RUNX2) and WDR72 were revealed to be colocalized in ameloblasts by immunohistochemistry, and it was also found that the expression of Runx2 and Wdr72 was markedly different between TGF-ß1-cKO mice and wild type(TGF-ß1-WT)mice. In addition, the effect of exogenous TGF-ß1 on Wdr72 was more significant when RUNX2 was present than when RUNX2 was absent. Furthermore, we found that there were binding sites for RUNX2 on the promoter of Wdr72 and that Wdr72 expression was regulated by RUNX2. Collectively, our results suggest that TGF-ß1 affects enamel mineralization by modulating RUNX2 and thus affecting the expression of Wdr72.

[Clinical observation of xenoskin to cover microskin graft in the treatment of patients with deep burns].

OBJECTIVE: To explore the feasibility of application of xenoskin as microskin graft covering. METHODS: Ten patients with deep and extensive burns were enrolled in the study. A white pig weighing about 50kg was cleaned and shaved(without boiled water treatment) after being slaughtered. After conventional disinfection, two pieces of skin with little amount of fat were removed from the pig and processed to full-thickness or split-thickness skin. Before operation they were perforated and autogeneic microskin was scattered onto it. After escharectomy they were grafted on the wound, and the wound was dressed and bandaged with pressure. The rejection of the xenoskin, the survival of the microskin grafts, the wound healing time,and the functional recovery of the patients 1 year after operation were observed. RESULTS: The porcine skin was intact, and stuck well to the wound within 2 post-operation weeks ( POW). But it turned to form a dry scab, and gradually separated from the autogeneic microskin during 4 - 5 POW. The xenoskin completely fell off and the wound healed during 6 - 8 POW . The wound healing time of the 10 patients was 42 - 56 days [ (50 +/- 5) d]. Though there were thin scars 1 year after operation, the elasticity and function of the skin were normal. CONCLUSION: It is feasible to use porcine skin as a substitute of alloskin to cover autogenous microskin.