Endoscopic minimally invasive treatment of congenital muscular torticollis in children.

BACKGROUND: This study aimed to investigate the clinical efficacy of minimally invasive endoscopic treatment of children with congenital muscular torticollis (CMT). METHODS: In total, 72 children (41 male, 31 female) with CMT who underwent endoscopic surgery at the Department of Orthopedics, Xi'an Children's Hospital, between January 2021 and January 2023 were included. Their mean age was 54 ± 36.1 (range, 12-141) months. Of these, 29 (40.3%) cases involved the left side while 43 (59.7%) involved the right side. Preoperative preparation involved precise body surface markings of the sternocleidomastoid muscle(SCM), clavicle, and important nerve and blood vessels, followed by the establishment of surgical channels through passive separation techniques. An arthroscope and a low-temperature plasma knife were utilized for accurate localization and surgical release of the clavicular and sternal heads of the SCM. The duration of surgery, blood loss, postoperative hospital stay, neck range of motion measurements, and any intraoperative or postoperative complications were analyzed using the rank sum test. Cervical and thoracic braces were applied for three months postoperatively, with follow-up assessments conducted using Cheng's scoring system. RESULTS: All patients successfully underwent endoscopic surgery, without the need for conversion to open surgery. No intra- or postoperative complications were observed. The average surgical duration was 56.4 ± 15.7 min, with minimal intraoperative bleeding (1-5 mL) and no need for blood transfusion. The mean postoperative hospital stay was 2.7 ± 0.8 days. Over a mean follow-up period of 22.2 ± 5.5 (range, 14-32) months, significant improvements were observed in neck rotation (from 20.2° [17.7° to 25°] to only 3.6° [2° to 6.7°]) and lateral flexion (from 19° [17° to 22.6°] to only 3° [2° to 7.8°]) restrictions (p < 0.05). According to Cheng's scoring system, 70 (97.2%) patients achieved excellent or good clinical outcomes, while 2 (2.8%) had average outcomes. The torticollis deformity was corrected during the follow-up period, and all surgical incisions healed without noticeable scarring. CONCLUSION: Endoscopic release is a safe, effective, and minimally invasive treatment option for CMT in children.

miR-192 enhances sensitivity of methotrexate drug to MG-63 osteosarcoma cancer cells.

Chemo-resistance remains a considerable obstacle encountered in osteosarcoma (OS) therapy. Evidence has implied that a reduction in the expression of microRNAs (miRs/miRNAs) leads to exacerbated chemo-resistance. Hence, to better understand the role of miR-192 in the pathogenesis of OS during methotrexate (MTX) treatment, we restore miR-192 in the MG-63 cells and investigate the mechanisms, which are associated with MTX-resistance in OS. Exogenetic overexpression of miR-192 was established by transfecting miR-192 mimics into MG-63 cells using Lipofectamine. Trypan blue dye exclusion test was performed to evaluate the proliferation of the MG-63 cells. Chemo-resistance to MTX was determined using the MTT method after 48 h. ELISA cell death assay was performed to evaluate the apoptosis rate. The quantitative RT-PCR (RT-qPCR) was applied to determine the mRNA expression levels before and after the transfection. Our results illustrated that miR-192 is down-regulated in OS tumor cells. Transfection of miR-192 noticeably alleviated the mRNA expression levels of MMP9, c-Myc, K-Ras, CXCR-4, and ADAMTS compared with the control groups (P-values< 0.05). MTX Combination treatment with miR-192 noticeably elevated the cytotoxic effect of MTX and alleviated its IC50 (P < 0.05). Moreover, miR-192 significantly increased the apoptotic effect of MTX. These results implied that miR-192 enhances the sensitivity of MG-63 cells to MTX. Collectively, our results elucidated that miR-192 contributes to chemo-sensitizing MG-63 cells to MTX, and could be considered as a promising agent to overcome MTX-resistance in OS.

Systematic metabolic engineering enables highly efficient production of vitamin A in Saccharomyces cerevisiae.

Vitamin A is a micronutrient critical for versatile biological functions and has been widely used in the food, cosmetics, pharmaceutical, and nutraceutical industries. Synthetic biology and metabolic engineering enable microbes, especially the model organism Saccharomyces cerevisiae (generally recognised as safe) to possess great potential for the production of vitamin A. Herein, we first generated a vitamin A-producing strain by mining ß-carotene 15,15'-mono(di)oxygenase from different sources and identified two isoenzymes Mbblh and Ssbco with comparable catalytic properties but different catalytic mechanisms. Combinational expression of isoenzymes increased the flux from ß-carotene to vitamin A metabolism. To modulate the vitamin A components, retinol dehydrogenase 12 from Homo sapiens was introduced to achieve more than 90 % retinol purity using shake flask fermentation. Overexpressing POS5Δ17 enhanced the reduced nicotinamide adenine dinucleotide phosphate pool, and the titer of vitamin A was elevated by almost 46 %. Multi-copy integration of the key rate-limiting step gene Mbblh further improved the synthesis of vitamin A. Consequently, the titer of vitamin A in the strain harbouring the Ura3 marker was increased to 588 mg/L at the shake-flask level. Eventually, the highest reported titer of 5.21 g/L vitamin A in S. cerevisiae was achieved in a 1-L bioreactor. This study unlocked the potential of S. cerevisiae for synthesising vitamin A in a sustainable and economical way, laying the foundation for the commercial-scale production of bio-based vitamin A.