Stem Cell Therapy in Inflammatory Bowel Disease: A Review of Achievements and Challenges.

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a group of chronic inflammatory diseases of the gastrointestinal tract. Repeated inflammation can lead to complications, such as intestinal fistula, obstruction, perforation, and bleeding. Unfortunately, achieving durable remission and mucosal healing (MH) with current treatments is difficult. Stem cells (SCs) have the potential to modulate immunity, suppress inflammation, and have anti-apoptotic and pro-angiogenic effects, making them an ideal therapeutic strategy to target chronic inflammation and intestinal damage in IBD. In recent years, hematopoietic stem cells (HSCs) and adult mesenchymal stem cells (MSCs) have shown efficacy in treating IBD. In addition, numerous clinical trials have evaluated the efficiency of MSCs in treating the disease. This review summarizes the current research progress on the safety and efficacy of SC-based therapy for IBD in both preclinical models and clinical trials. We discuss potential mechanisms of SC therapy, including tissue repair, paracrine effects, and the promotion of angiogenesis, immune regulation, and anti-inflammatory effects. We also summarize current SC engineering strategies aimed at enhancing the immunosuppressive and regenerative capabilities of SCs for treating intestinal diseases. Additionally, we highlight current limitations and future perspectives of SC-related therapy for IBD.

[Theoretical snow period and assessment of skiing climate suitability: With Changbai Mountain Ski Resort as an example]. / 理论雪期和滑雪气候适宜度评价­­ä»¥é•¿ç™½å±±æ»‘雪场为例.

To analyze the climatic characteristics of snow resources and quantitatively evaluate the climatic suitability of skiing, we proposed the concept of theoretical snow period from the perspective of climate based on the synoptic principle. We set threshold values of different suitability degrees of three indices closely related to skiing, including air temperature, wind speed, and precipitation. The conversion function of each index was designed after normalization. Based on grey relational theory and Euclidean distance method, we established evaluation model of ski sports climate suitability index, with Changbai Mountain Ski Resort as an example. The results showed that snow resource in Changbai Mountain area was rich. From 1981 to 2018, the average snowfall during the theoretical snow period was 64.6 mm. Under the background of climate change, the average number of snow days and snowfall decreased slightly over the years, with the starting time of snow season being delayed and the ending time being advanced. The number of snow days in the early winter (from the starting time of snow season to the end of December) was significantly less than that in the later winter (from the next January to the end of snow season). Climate in Changbai Mountain was highly suitable for skiing during the snow period. The most suitable and relatively suitable days with respect to air temperature, wind speed and precipitation accounted for 91.9%, 91.8%, and 94.6% of the total, respectively. The cumulative number of days for ski comprehensive weather suita-bility accounted for 99.7%, indicating that most days were suitable for skiing. The concept of theoretical snow period in this study had made up for the problems caused by the lack of meteorological observation data of the first and last snow event on the study of snow resources. The climate suitabi-lity evaluation model of skiing could help make management decision for the development and operation of ski resorts and scientific support for skiing enthusiasts.

Efficacy of low-dose versus high-dose simethicone with polyethylene glycol for bowel preparation: A prospective randomized controlled trial.

BACKGROUND AND AIM: Additional simethicone (SIM) can improve adequate bowel preparation and adenoma detection rate (ADR). However, there is no consensus on the optimal dose of SIM. In this study, we compared the adequate bowel preparation rate with supplementation of split-dose 2 L polyethylene glycol (PEG) with low-dose SIM (200 mg) versus high-dose SIM (1200 mg). METHODS: This was a prospective, randomized, observer-blinded trial involving consecutive subjects undergoing colonoscopy. The primary outcome was adequate bowel preparation as assessed by Boston Bowel Preparation Scale (BBPS) score. RESULTS: Four hundred subjects were randomly allocated to low-dose SIM or high-dose SIM group. Baseline characteristics were comparable in the two groups (P > 0.05). No significant between-group differences were observed with respect to total bubble scale (BS) (8.49 ± 1.00 vs 8.39 ± 1.10, P = 0.07), total BBPS score (8.70 ± 0.81 vs 8.29 ± 1.18, P = 0.98), ADR (33.68% vs 31.79%, P = 0.69) or withdrawal time (13 [range, 10-16] min vs 13 [10-15] min, P = 0.96). The intubation time in low-dose SIM group was significantly shorter than that in high-dose SIM group (8 (4-16) min vs 10 [6-17] min, P = 0.04). In addition, BS scores as well as diminutive ADR in right colon were superior in the low-dose SIM group (2.68 ± 0.59 vs 2.52 ± 0.73, P = 0.03 and 54.29% vs 30.30%, P = 0.046, respectively). CONCLUSION: Addition of low-dose SIM to split-dose 2 L PEG was as effective as addition of high-dose SIM with respect to adequate bowel preparation, ADR and patient tolerance. However, low-dose SIM was superior with respect to intubation time, right colon BS scores, right colon diminutive ADR and cost savings.

Sensing by Smell: Nanoparticle-Enzyme Sensors for Rapid and Sensitive Detection of Bacteria with Olfactory Output.

We present here a highly efficient sensor for bacteria that provides an olfactory output, allowing detection without the use of instrumentation and with a modality that does not require visual identification. The sensor platform uses nanoparticles to reversibly complex and inhibits lipase. These complexes are disrupted in the presence of bacteria, restoring enzyme activity and generating scent from odorless pro-fragrance substrate molecules. This system provides rapid (15 min) sensing and very high sensitivity (102 cfu/mL) detection of bacteria using the human sense of smell as an output.