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Background Since the implementation of the "universal two-child" policy, multiparous women has become the main labor and delivery population. Problems such as advanced maternal age, chronic comorbidities, obstetric complications and pregnancy after cesarean section have become increasingly prominent, bringing new challenges to obstetricians. Objective To analyze the current status of cesarean section in multiparous women under the new childbearing policy based on the revised Robson classification system, in order to provide data support for rational control of cesarean section rate, improvement of obstetric care. Methods A total of 19 170 women who delivered by cesarean section in the Tenth Affiliated Hospital, Southern Medical University from 2017 to 2020 were included and divided into the primipara group (n=5 630) and multiparous group (n=13 540). Maternal information including age, gravity, parity, previous deliveries, fetal position, pregnancy comorbidities and complications, maternal and fetal outcomes, was collected through the electronic medical records. The general information and maternal and neonatal outcomes of the two groups were compared. The revised Robson classification system was used to classify the parturients according to their obstetric characteristics (parity, fetal position, number of fetuses and gestational weeks of delivery). The distribution of parturients in the revised Robson classification system and the change of the proportion of parturients in each group with year were compared. Results The proportion of pregnancy after cesarean section was as high as 81.4% (11 026/13 540). The age, gravity, parity, proportion of age ≥35 years and gestational diabetes mellitus of the multiparous group were higher than the primipara group (P0.05) . Conclusion Advanced age and pregnancy after cesarean section are prominent features of multiparous women. Although the proportion of R3 class decreased by year, it is still the main population of cesarean section. In order to reduce cesarean section rate, it is necessary to effectively control the cesarean section of primipara women, and actively promote the vaginal trial of labor for women in R3 class. Meanwhile, the proportion of R2 and R8 in the multiparous women, which put forward new requirements for clinical practice of obstetrics.

Objective To explore the effect and underlying mechanism of long-term intake of sodium carboxymethyl cellulose (CMC-Na), a food additive, on radiation tolerance in mice. Methods Dietary intervention was performed on the mice by adding different concentrations of CMC-Na to drinking water at a dose of 0, 0.25% and 1%, respectively (Control and low-and high-dose groups) for 8 weeks, and then the mice were given a lethal radiation of 7 Gy 60Co gamma rays to establish a radiation damage model. Before and after the radiation intervention, the body weight was measured weekly in every mice, and death was observed and recorded in each group. After an 8-week intervention, the blood biochemical indicators of mice were assessed. ELISA, Qrt-Pcr, and Western blotting techniques to investigate changes in intestinal-related cytokines and proteins. What's more, HE staining, immunofluorescence assay and immunohistochemical staining were used to observe the changes of intestinal tissue morphology for pathological scores. Flow cytometry was employed to detect the proportion of intestinal stem cells. Results Flow cytometry showed that the proportion of intestinal stem cells was decreased in both dietary intervention groups when compared with the control group (P < 0.05), and the decrease was positively correlated with the dose of CMC-Na in drinking water and persisted after radiation damage. Higher death rate (P < 0.05) and obvious weight loss (P < 0.000 1) were observed in the high-dose intervention group, and impaired intestinal barrier function and a decrease in the content of the anti-inflammatory factor IL-10 were found in further research. Meanwhile, the expression levels of inflammatory factors such as TLR4, NF-κB, TNF-α and IL-1β were higher in the high-dose intervention group (P < 0.05), and the contents were further increased after radiation damage. The expression of certain inflammatory factors (NF-κB, TNF-α, and IL-1β) in the low-dose group exhibited a statistically significant increase compared to the control group (P < 0.05), yet remained lower than that observed in the high-dose group. Conclusion Long-term consumption of foods containing CMC-Na reduces the proportion of colonic stem cells in the intestinal tract, aggravates the radiation damage to the intestine, and reduces the radiation tolerance of mice.

Objective: To investigate the best defrosting method for frozen pork. Methods: Investigated the effects of three thawing methods, namely low-frequency electric field thawing, air thawing and hydrostatic thawing, on the juice loss rate, moisture content, water holding capacity, pH, colour difference, volatile saline nitrogen, total bacterial colony, textural characteristics, fat oxidation and protein oxidation of pork after thawing. Results: The low frequency electric field thawing resulted lower juice loss (1.09%), shear force (2 600.15 N), increase in thiobarbituric acid value (TBARS) (62.50%), good colour, pH close to that of fresh meat, less protein oxidation, richer taste material, less damage to the microstructure of the meat, better maintenance of muscle tissue and muscle fibre structure. The hydrostatic thawing resulted lower total bacterial colony count and llow protein oxidation. Conclusion: The quality, physicochemical properties and microstructure of pork under low frequency electric field thawing were better than the other two thawing methods.

Background: Irradiation disrupts the vascular niche where hematopoietic stem cells (HSCs) reside, causing delayed hematopoietic reconstruction. The subsequent recovery of sinusoidal vessels is key to vascular niche regeneration and a prerequisite for hematopoietic reconstruction. We hypothesize that resident bone marrow macrophages (BM-Mφs) are responsible for repairing the HSC niche upon irradiation injury. Methods: We examined the survival and activation of BM-Mφs in C57BL/6 mice upon total body irradiation. After BM-Mφ depletion via injected clodronate-containing liposomes and irradiation injury, hematopoietic reconstruction and sinusoidal vascular regeneration were assessed with immunofluorescence and flow cytometry. Then enzyme-linked immunosorbent assay (ELISA) and flow cytometry were performed to analyze the contribution of VEGF-A released by BM-Mφs to the vascular restructuring of the HSC niche. VEGF-A-mediated signal transduction was assessed with transcriptome sequencing, flow cytometry, and pharmacology (agonists and antagonists) to determine the molecular mechanisms of Piezo1-mediated responses to structural changes in the HSC niche. Results: The depletion of BM-Mφs aggravated the post-irradiation injury, delaying the recovery of sinusoidal endothelial cells and HSCs. A fraction of the BM-Mφ population persisted after irradiation, with residual BM-Mφ exhibiting an activated M2-like phenotype. The expression of VEGF-A, which is essential for sinusoidal regeneration, was upregulated in BM-Mφs post-irradiation, especially CD206+ BM-Mφs. The expression of mechanosensory ion channel Piezo1, a response to mechanical environmental changes induced by bone marrow ablation, was upregulated in BM-Mφs, especially CD206+ BM-Mφs. Piezo1 upregulation was mediated by the effects of irradiation, the activation of Piezo1 itself, and the M2-like polarization induced by the phagocytosis of apoptotic cells. Piezo1 activation was associated with increased expression of VEGF-A and increased accumulation of NFATC1, NFATC2, and HIF-1α. The Piezo1-mediated upregulation in VEGF-A was suppressed by inhibiting the calcineurin/NFAT/HIF-1α signaling pathway. Conclusion: These findings reveal that BM-Mφs play a critical role in promoting vascular niche regeneration by sensing and responding to structural changes after irradiation injury, offering a potential target for therapeutic efforts to enhance hematopoietic reconstruction.

PurposeRepairing the irradiation-induced osteogenic differentiation injury of bone marrow mesenchymal stem cells (BM-MSCs) is beneficial to recovering haematopoiesis injury in radiotherapy; however, its mechanism is elusive. Our study aimed to help meet the needs of understanding the effects of radiotherapy on BM-MSC osteogenic potential.Methods and materialsBalb/c mice and the BM-MSCs were used to evaluate the irradiation-induced osteogenic differentiation injury in vivo. The cellular and molecular characterization were applied to determine the mechanism for recovery of irradiation-derived haematopoiesis injuries.ResultsWe report a functional role of IL-12 in acute irradiation hematopoietic injury recovery and intend to dissect the possible mechanisms through BM-MSC, other than the direct effect of IL-12 on hematopoietic stem and progenitor cells (HSPCs). Specifically, we show that early use of IL-12 enhanced the osteogenic differentiation of BM-MSCs through IL-12Rβ1/TYK2/STAT3 signaling; furthermore, IL-12 induced osteogenesis facilitated bone formation and irradiation hematopoiesis recovery when transplanted BM-MSCs in the femur of Balb/c mice. For the mechanism of action, we found that IL-12 receptor beta 1 (IL-12Rβ1) expression of irradiated BM-MSCs was upregulated rapidly, coincidentally consistent with early use of IL-12 induced osteogenic differentiation enhancement. IL-12Rβ1 and tyrosine kinase 2 gene (Tyk2) silencing experiments and phosphotyrosine of signal transducer and activator of transcription 3 (p-STAT3) suppression experiments indicated the IL-12Rβ1/TYK2/STAT3 signaling was essential in IL-12-induced osteogenic differentiation enhancement of BM-MSCs.ConclusionThese findings suggested that IL-12 may exert BM-MSCs-based hematopoietic recovery by repairing osteogenic differentiation abilities damages through IL-12Rβ1/TYK2/STAT3 signaling pathway post-irradiation.

Coronavirus disease 2019 (COVID-19) has become a global pandemic with a high rate of transmission. Currently, there is a lack of vaccines and specific drugs for this newly-emerged virus. Timely diagnosis and treatment, as well as isolation of patients and virus carriers, contribute to the effective prevention and control of this epidemic. This review focuses on early stage COVID-19 diagnosis methods and strategies, highlighting the guiding role of laboratory indicators on treatment strategy formulation, and prognosis assessments.

Resistance to ionizing radiation (IR), which is a conventional treatment for osteosarcoma that cannot be resected, undermines the efficacy of this therapy. However, the mechanism by which IR induces radioresistance in osteosarcoma is not defined. Here, we report that CR6-interacting factor-1 (CRIF1) is highly expressed in osteosarcoma and undergoes nuclear-cytoplasmic shuttling of cyclin-dependent kinase 2 (CDK2) after IR. Osteosarcoma cells lacking CRIF1 show increased sensitivity to IR, which is associated with delayed DNA damage repair, inactivated G1/S checkpoint, and mitochondrial dysfunction. CRIF1 interacts with the DNA damage checkpoint regulator CDK2, and CRIF1 and CDK2 colocalize in the nucleus after IR. Nuclear localization of CDK2 is associated with phosphorylation changes that promote DNA repair and activation of the G1/S checkpoint. CRIF1 knockdown synergized with IR in an in vivo osteosarcoma model, leading to tumor regression. Based on these findings, we identify CRIF1 as a potential therapeutic target in osteosarcoma that can increase the efficacy of radiotherapy. More broadly, our findings may provide insights into the mechanism for other types of radioresistant cancers and be exploited for therapeutic ends.