Polysaccharide of Asparagus cochinchinensis (Lour.) Merr regulates macrophage immune response and epigenetic memory through TLR4-JNK/p38/ERK signaling pathway and histone modification.

BACKGROUND: Innate immune memory of macrophages is closely linked to histone modifications. While various studies have demonstrated that the polysaccharide of Asparagus cochinchinensis (Lour.) Merr (ACMP), extracted through alcohol-alkali extraction, enhances macrophages' non-specific immune function; no literature currently addresses whether ACMP's regulatory effect is related to innate immune memory and histone modification. PURPOSE: This study aims to investigate if ACMP induces innate immune memory emergence in macrophages via pattern recognition receptor (PRR). STUDY DESIGN: After co-incubating different doses of ACMP with RAW264.7 cells and BMDM cells, we observed changes in signaling pathways related to PRR and assessed the presence of innate immune memory phenomenon in the cells. METHODS: We observed the morphological characteristics of the ACMP using a scanning electron microscope, infrared spectrum, and HPLC pre-column derivatization method. We used q-PCR, Western blot, RNA-seq, and CUT&Tag-seq methods to examine ACMP's regulation of macrophage immune response and innate immune memory and explored its specific mechanism. RESULTS: ACMP, primarily composed of Man, GlcN, Rha, Fuc, GalA, Xyl, Glc, Gal, Ara, and, exhibited a molar ratio of each monosaccharide (1.41: 0.35: 0.49: 0.18: 1.00: 97.12: 0.36: 3.58: 1.14). ACMP regulated immunological function in macrophages through the TLR4-MAPK-JNK/p38/ERK pathway. ACMP induced elevated levels of chromosomal H3K4me1, enhancing TNF-α, IL-1ß, and other genes' responsiveness, allowing macrophages to develop innate immune memory to ACMP stimulation. CONCLUSION: This study first time demonstrates that ACMP regulates immunological function through the TLR4-MAPK-JNK/ERK/p38 signaling pathway, distinct from prior reports. ACMP induces innate immune memory in macrophages in response to its immune stimulation by promoting increased H3K4me1 on chromosomes. This mechanism may be crucial in how plant polysaccharides regulate macrophages and the body's immune function.

The growth and developmental of the myodural bridge and its associated structures in the human fetus.

Myodural bridge (MDB) is a dense connective tissue between suboccipital muscle and dura mater. However, there are few reports on the development and maturation of the human MDB. This study aims to explore the developmental relationship between suboccipital muscle and MDB. 30 head and neck specimens from human fetuses (F) ranging from the 12th to 41st week (W) were made into histological sections. The F12W sections showed evidence that the dura mater dominated by fibroblasts, attached to the posterior atlanto-axial membrane (PAAM) which completely sealed the atlanto-axial space. In the F13W stage, myofibrils of the suboccipital muscle fibers increased significantly in number. At the F14W stage, a gap was observed at the caudal end of the PAAM. Numerous myodural bridge-like structures were observed blending into the dura mater through the gap. At the F19W stage, muscle cells mature. Starting at the F21W stage, the MDB were observed as fibroblasts that cross the atlanto-axial interspace and attach to the dura mater. Therefore, the traction generated by the suboccipital muscles seems to promote the maturity of MDB. This study will provide new morphological knowledge to support future research on the function of the human MDB and regulating the development mechanism of MDB.

Clinical guideline on magnetically controlled capsule gastroscopy (2021 edition).

With the development and generalization of endoscopic technology and screening, clinical application of magnetically controlled capsule gastroscopy (MCCG) has been increasing. In recent years, various types of MCCG are used globally. Therefore, establishing relevant guidelines on MCCG is of great significance. The current guidelines containing 23 statements were established based on clinical evidence and expert opinions, mainly focus on aspects including definition and diagnostic accuracy, application population, technical optimization, inspection process, and quality control of MCCG. The level of evidence and strength of recommendations were evaluated. The guidelines are expected to guide the standardized application and scientific innovation of MCCG for the reference of clinicians.

Controlled fabrication of Ag@clay nanomaterials for ultrasensitive and rapid surface-enhanced Raman spectroscopic detection.

The nanostructure of Ag nanoparticles (NPs) plays a critical role in their surface-enhanced Raman scattering (SERS) activity. Despite many efforts to tune the nanostructure of Ag NPs, it remains a great challenge as Ag NPs tend to agglomerate and their nanostructure is difficult to control. Herein, newly-discovered clay-surfactant-Ag+ materials and interfacial processes were developed and used to prepare uniform spherical Ag@synthetic hectorite (Ag@Hct) nanomaterials for ultrasensitive SERS assay. Sodium dodecyl sulfate (SDS), an anionic surfactant, acted as a bridge to conjugate the positively charged edge of Hct NPs and Ag+via electrostatic interaction to form the bridging nanostructure of Hct-SDS-Ag+, which promoted the uniform dispersion of Hct NPs. Following this, Ag+ was reduced to Ag0 by the reductant, and Ag0 grew on the surface of disc-like Hct NPs to form spherical Ag@Hct nanomaterials with an average particle size of ∼24 nm. The prepared Ag@Hct nanomaterials showed an ultrasensitive SERS response to methylene blue (MB) with a detection limit of 10-12 M. The detection limit of MB in sewage was 10-11 M. The prepared Ag@Hct nanomaterials also exhibited great SERS enhancement for malachite green and crystal violet. This work provides a novel and simple approach to prepare Ag@Hct nanomaterials with uniform spheres and adjustable particle size, allowing more sensitive and reproducible detection of MB.

Pentoxifylline inhibits phosgene-induced lung injury via improving hypoxia.

Inhalation of high concentrations of phosgene often causes pulmonary edema, which obstructs the airway and causes tissue hypoxia. There is currently no specific antidote. This study was performed to investigate the effect behind pentoxifylline (PTX) treatment for phosgene-induced lung injury in rat models. Rats were exposed to phosgene. The protein levels of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), and occludin proteins in lung tissue were determined. The effect of both prophylactic and therapeutic administration of PTX (50 mg/kg and 100 mg/kg) was evaluated. The lung permeability index and HIF-1α protein level increased, the arterial blood oxygenation index (PaO2/FIO2 ratio) and occludin protein level decreased significantly 6 h after phosgene exposure (P < 0.05). PTX exerted protective effects by HIF-1α-VEGF-occludin signaling pathway to some extent. Moreover, prophylactic, but not therapeutic administration of PTX (100 mg/kg), exhibited a significant protective effect. Pretreatment with PTX protected against phosgene-induced lung injury, possibly by inhibiting differential expression of HIF-1α, VEGF, and occludin.

Comparison of Different Drying Methods for Asparagus [Asparagus cochinchinensis (Lour.) Merr.] Root Volatile Compounds as Revealed Using Gas Chromatography Ion Mobility Spectrometry.

Asparagus [Asparagus cochinchinensis (Lour.) Merr.] is a traditional herbal medicine plant commonly used to nourish yin, moisten dryness, and clear fire cough symptoms. Drying is an excellent option to conserve food materials, i.e., grains, fruits, vegetables, and herbs, reducing the raw materials volume and weight. This study aims to evaluate different drying approaches that could increase the value of asparagus, particularly as an ingredient in fast foods or as nutraceutical byproducts. The volatile components of asparagus roots were analyzed by using headspace-gas chromatography-ion mobility spectroscopy under different drying conditions, i.e., natural drying (ND) at ambient air temperature in the dark, well-ventilated room, temperature range 28-32°C, blast or oven drying at 50°C, heat pump or hot-air drying at temperature 50°C and air velocity at 1.5 ms-1 and vacuum freeze-drying at the temperature of -45°C and vacuum pressure of 10-30 Pa for 24 h. The findings revealed that the various drying processes had multiple effects on the color, odor index, and volatile compounds of the asparagus roots. As a result of the investigations, multiple characteristics of components, therefore, exploitation and comparison of various flavors; a total of 22 compounds were identified, such as alcohols, ketones, aldehydes, acids, esters, heterocyclic, and terpene. The present findings may help understand the flavor of the processed asparagus roots and find a better option for drying and processing.

Current research status on immune-related adverse events / 中华胃肠外科杂志

Immune checkpoint inhibitors have progressed rapidly over the past decade and have become one of the most promising oncology treatments. However, immune checkpoint inhibitors reduce T-cell tolerance and lead to a unique spectrum of immune-related adverse events (IRAE). IRAE can involve multiple systems, including endocrine, gastrointestinal, respiratory and skin systems and there is no predictive marker with high specificity and sensitivity. Mild IRAE can be alleviated by discontinuing immune checkpoint inhibitors while severe IRAEs require active intervention. The first-line treatment is glucocorticoids, and immunosuppressants can be considered in refractory cases. However the optimal choice of immunosuppressants is currently controversial. This review provides an overview of the epidemiology and possible mechanisms of immune-related adverse events, outlines some promising predictive biomarkers, and describes several immunotherapy-related organ toxicity and management.

SH3PXD2A-AS1/miR-330-5p/UBA2 ceRNA network mediates the progression of colorectal cancer through regulating the activity of the Wnt/ß-catenin signaling pathway.

Long non-coding RNAs have important roles in the occurrence and progression of various cancers. However, the molecular mechanism of lncRNAs in colorectal cancer (CRC) is not well illustrated. Thus, we used bioinformatics methods to find potential lncRNAs associated with CRC progression, and chose SH3PXD2A-AS1 as a candidate for further analysis. The roles of SH3PXD2A-AS1 in CRC cells were determined by CCK-8, transwell invasion, wound healing and flow cytometry assays. Besides, we established the CRC tumor models in nude mice to study the effect of SH3PXD2A-AS1 on the tumor growth. Based on the ceRNA hypothesis, we used miRDB and miRTarBase websites to identify the SH3PXD2A-AS1-related ceRNA regulatory network, and measured the roles of this network in CRC cells. The results revealed that the expression profiles of SH3PXD2A-AS1 from GEO and TCGA databases showed an aberrant high level in CRC tissues compared with colorectal normal tissues. SH3PXD2A-AS1 over-expression was also found in CRC cells. SH3PXD2A-AS1 knockdown inhibited the CRC cellular proliferation, invasion and migration but induced apoptosis. Besides, SH3PXD2A-AS1 knockdown also suppressed the growth of CRC tumors. Furthermore, SH3PXD2A-AS1 could function as a ceRNA of miR-330-5p. Additionally, UBA2 was proved to be a target gene of miR-330-5p. Moreover, SH3PXD2A-AS1 knockdown downregulated UBA2 expression through sponging miR-330-5p to inactivate the Wnt/ß-catenin signaling pathway, thereby inhibiting the cell growth and promoting apoptosis. Therefore, the SH3PXD2A-AS1/miR-330-5p/UBA2 network could regulate the progression of CRC through the Wnt/ß-catenin pathway. These findings offer new sights for understanding the pathogenesis of CRC and provide potential biomarkers for CRC treatment.

Surgically treated rare intestinal bleeding due to submucosal hematoma in a patient on oral anticoagulant therapy: A case report.

RATIONALE: Bleeding in the gastrointestinal tract is a common complication of oral anticoagulant therapy (AT), and it usually appears as mucosal erosion or ulcer; however, intestinal submucosal hematoma (ISH) is an uncommon cause of hemorrhage. PATIENT CONCERNS: This report presents the case of a 70-year-old woman with acute hematochezia induced by AT. She underwent computed tomography and endoscopy. DIAGNOSES: Colon submucosal hematoma. INTERVENTIONS: Conservative treatment had no effect, and the patient underwent emergency surgery. OUTCOMES: Surgical resection showed hemorrhage and necrosis in the left colon, and the patient recovered 24 hours after surgery and continued AT. LESSONS: The present case indicates that the ISH should be kept in mind as a complication of AT. It can be managed conservatively in some stable patients, but emergency surgery may be needed in some serious situations.

Comparative efficacy and safety between ablative therapies or surgery for small hepatocellular carcinoma: a network meta-analysis.

BACKGROUND: Major treatments for small hepatocellular carcinoma (SHCC) include percutaneous ethanol injection (PEI), percutaneous acetic acid injection (PAI), radiofrequency ablation (RFA), or surgical resection (SR). We aimed to compare these therapies concerning with effectiveness and safety. METHODS: Cochrane Library, PubMed, and Embase were searched for randomized controlled studies (RCTs) from inception to 30 April 2017. Odds ratios (OR) for proportion dead (PD), local recurrence (LR) and adverse events (AEs). RESULTS: Fourteen RCTs were identified. Compared with SR, PEI (OR 2.79, CrI 1.25, 6.45, p < 0.01) provided a significantly increased risk of PD. Similarly, PEI (OR 4.29, CrI 1.18, 18.35, p < 0.01) yielded more LR than SR. Also, SR significantly conferred more AEs than RFA (OR 0.10; CrI 0.02, 0.35, p < 0.01), PEI (OR 0.06; CrI 0.01, 0.31, p < 0.01). Besides, RFA conferred the highest efficacy for survival, time to recurrence, and new development of HCC. CONCLUSIONS: SR was superior to PEI. Although SR achieved highest cumulative ranking probabilities in clinical efficacy, it obtained a low benefit-to-risk ratio for patients. RFA was superior to the other ablative therapies. For tumor sizes > 2 cm or ≤ 2 cm in diameter, SR conferred non-significant effects compared with other therapies for SHCC.

Laparoscopic gastrectomy for elderly patients with gastric cancer: A systematic review with meta-analysis.

BACKGROUND: Laparoscopic gastrectomy (LG) has been widely applied in patients with gastric cancer (GC). However, the safety and application value of LG in elderly patients with GC was still unclear. In this study, we aimed to evaluate the feasibility and safety of LG for elderly patients with GC using the meta-analysis. METHODS: Studies comparing elderly patients and nonelderly patients who underwent LG for GC were reviewed and collected from the PubMed, EBSCO, Cochrane Library, and EMBASE. Outcomes such as operative results, postoperative recovery, and morbidity were compared and analyzed. The Review Manager 5.3 was used to portray the weighted mean difference (WMD) and odds ratio (OR) with a 95% confidence interval (CI). RESULTS: Eleven observational studies with a total of 3275 patients were included. Compared with nonelderly patients, elderly patients had shorter operation time (WMD -10.46; 95% CI -17.06 to -3.86; P = .002), less retrieved lymph nodes (WMD -2.34; 95% CI -3.77 to -0.92; P = .001), delayed time to first flatus (WMD 0.31; 95% CI 0.10-0.51; P = .003), longer postoperative hospital stays (WMD 1.06; 95% CI 0.07-2.05; P = .04), higher risk for overall postoperative complication (OR 1.34; 95% CI 1.08-1.67; P = .009), nonsurgical postoperative complication (OR 1.98; 95% CI 1.24-3.15; P = .004), and postoperative pulmonary complication (OR: 3.09; 95% CI 1.68-5.68; P < .001). There was no significance between nonelderly patients and elderly patients regarding the estimated blood loss, incidences of surgical postoperative complication, surgical site infection, and ileus (P > .05). CONCLUSION: Outcomes of LG for elderly patients were comparable to those in nonelderly patients. Age alone should not preclude LG in elderly patients.

Short-term outcomes of laparoscopic total gastrectomy for gastric cancer: a comparative study with laparoscopic distal gastrectomy at a high-volume center.

BACKGROUND: Laparoscopic distal gastrectomy (LDG) for gastric cancer has gradually gained popularity. However, laparoscopic total gastrectomy (LTG) has been reported rarely when compared with LDG. This study was designed to evaluate the surgical outcomes as well as the morbidity and mortality of LTG compared with LDG to confirm the feasibility and safety of LTG. MATERIAL AND METHODS: We reviewed the data of patients at our institution undergoing LTG (n = 448) or LDG (n = 956) for gastric cancer between January 2008 and July 2016. Then the clinical characteristics and perioperative clinical outcomes of the two groups were compared. RESULTS: Except for tumor size and stage, there were no statistically significant differences in the clinicopathological parameters between the groups. LTG was associated with significantly longer operation time, late time to postoperative diet, and longer hospital stay compared with the LDG group. Overall complications developed in 60 patients (13.4%) and surgical complications in 48 patients (10.7%) after LTG. Postoperative complications were less frequent in the LDG group than in the LTG group (8.4% versus 13.4%, p < .01), and fewer surgical complications were observed with LDG than with LTG (7.5% versus 10.7%, p = .05). CONCLUSIONS: The results of LTG were favorable even though are not inferior to those of LDG. LTG for gastric cancer is technically feasible and safe. However, because of the limits of this study, other high-quality studies are needed for further evaluation.

Application of Laparoscopic Gastrectomy in Obese Patients (BMI≥30 kg/m2) with Gastric Cancer: A Comparison With Open Gastrectomy Regarding Short-term Outcomes.

OBJECTIVE: Few studies have compared the surgical outcomes of laparoscopic (LG) and open (OG) gastrectomy in obese patients (BMI≥30 kg/m) with gastric cancer. The current study aimed to investigate the short-term outcomes of LG in this group of patients. METHODS: A total of 33 LG cases and 23 OG cases (BMI≥30 kg/m) were identified from our gastric cancer database. Clinicopathologic features, operative details, laboratory examination, and postoperative outcomes were compared between both groups. Regression analysis was used to determine the effects of BMI on intraoperative outcomes. RESULTS: The 2 groups had comparable clinicopathologic characteristics. LG was associated with significantly lesser blood loss, whereas both also groups had a similar operative time, and number of harvested lymph nodes. However, regression analysis indicated that increased BMI affected the operative time and blood loss in patients that underwent OG but had little effect on patients who received LG. The elevation of inflammatory factors (WBC, CRP) was lower in LG than in OG, postoperatively. Postoperative hepatic (alanine aminotransferase, total bilirubin, albumin) and renal (creatinine, blood urea nitrogen) functions in the LG group were not worse than in the OG group. The time to first flatus, initiation of diet, hospitalization, and postoperative complications seemed superior in LG than in OG, but these differences were not statistically significant. CONCLUSION: LG can be safely performed in obese gastric cancer patients. Compared with conventional OG, LG is less invasive and is characterized by less blood loss and milder surgical trauma. LG is also less adversely affected by increased BMI.

Totally laparoscopic versus open total gastrectomy for gastric cancer: A case-matched study about short-term outcomes.

Although surgical outcomes of totally laparoscopic total gastrectomy (TLTG) have been reported from several centers, the effectiveness of this technique has not been conclusively established. The aim of this study was to investigate the feasibility, safety, and efficacy of TLTG for gastric cancer.A prospectively collected and retrospectively analyzed data were used by comparing the short-term surgical outcomes of 124 patients who underwent TLTG with those of 124 patients who underwent open total gastrectomy (OTG) between March 2007 and March 2016.The 2 groups were well matched with respect to age, sex, body mass index, ASA score, and tumor stage. There was no significant difference with regard to the operation time but TLTG showed significantly less intraoperative blood loss (115.5 ±â€Š70.2 vs 210.5 ±â€Š146.7 mL, P < .01). Total numbers of retrieved lymph nodes were similar in the 2 groups. Postoperatively, no significant differences were found for morbidity or mortality. The time to first flatus, initiate oral intake, and postoperative hospital stay were significantly shorter in the TLTG group than in the OTG group (3.2 ±â€Š1.0 vs 4.1 ±â€Š1.2 days; 4.4 ±â€Š1.2 vs 5.6 ±â€Š2.0 days; and 8.9 ±â€Š3.1 vs 11.3 ±â€Š4.5 days, respectively; P < .01).TLTG for gastric cancer is technically safe, feasible, and minimally invasive compared with OTG. A prospective randomized trial is needed to establish the value of TLTG.

Capture and recycling of ammonium by dolomite-aided struvite precipitation and thermolysis.

The capture and reuse of NH4+ is an ideal solution to treat NH4+-containing wastewater. The capture and reuse process needs to be clean and cost-effective. Currently, however, there are many obstacles, particularly in the availability, cost, and recovery of the chemical sources required. Here, we demonstrate a clean and efficient method to capture and recycle NH4+ by a dolomite-aided struvite precipitation process. Dolomite calcined carefully in CO2 atmosphere was used as a Mg source to react with PO43- (KH2PO4) and NH4+ in model wastewater (2000 mg L-1 NH4+). The precipitation was performed at nMg2+:nNH4+:nPO43- = 1:1:1.2 and pH = 8.0 for 2 h; 89.7% of NH4+ was recovered in the form of struvite precipitate. The competition between K+ and NH4+ in the model wastewater led to the formation of K-struvite (MgKPO4·6H2O) and struvite (MgNH4PO4·6H2O). The formation of K-struvite resulted in a decrease in the NH4+ removal rate. When struvite was heated at 110 °C for 4 h, the NH4+ release rate from the thermolysis reached 75.7%. Thermolysis readily occurred as an unstable Ca2+-CO32--NH4+ system formed in the mixture of MgNH4PO4·6H2O and CaCO3. The elements Mg and P that were obtained during the struvite precipitation-thermolysis-reprecipitation process can be repeatedly used. After 6 cycles, under the conditions pH = 9.0, nMg2+:nNH4+:nPO43- = 1:1:1 and reaction time of 2 h, up to 78.3% of NH4+ was removed from the model wastewater.

Short-term outcomes of laparoscopic local resection for gastric submucosal tumors: a single-center experience of 266 patients.

BACKGROUND: Laparoscopic resections for submucosal tumors (SMTs) of the stomach have been developed rapidly over the past decade. Several types of laparoscopic methods for gastric SMTs have been created. We assessed the short-term outcomes of two commonly used types of laparoscopic local resection (LLR) for gastric SMTs and reported our findings. METHODS: We retrospectively analyzed the clinicopathological results of 266 patients with gastric SMTs whom underwent LLR between January 2006 and September 2016. 228 of these underwent laparoscopic exogastric wedge resection (LEWR), the remaining 38 patients with the tumors near the esophagogastric junction (EGJ) or antrum underwent laparoscopic transgastric resection (LTR). RESULTS: All the patients underwent laparoscopic resections successfully. The mean operation times of LEWR and LTR were 90.2 ± 37.2 min and 101.7 ± 38.5 min respectively. The postoperative length of hospital stays for LEWR and LTR were 5.1 ± 2.1 days and 5.3 ± 1.7 days respectively. There was a low complication rate (4.4%) and zero mortality in our series. CONCLUSION: ELWR is technically feasible therapy of gastric SMTs. LTR is secure and effective for gastric intraluminal SMTs located near the EGJ or antrum.

Intracorporeal esophagojejunostomy using the transorally inserted anvil (OrVil) after laparoscopic total gastrectomy for upper gastric cancer.

BACKGROUND: Totally laparoscopic distal gastrectomy gained wide popularity in recent years. Laparoscopic total gastrectomy with intracorporeal esophagojejunostomy (LTGIE) is much less performed. In this study, we reported our preliminary experience of LTGIE using the transorally inserted anvil (OrVil). METHODS: Clinical data of patients with upper gastric cancer who underwent LTGIE from January 2016 to January 2017 were retrospectively collected. The operative time, intraoperative blood loss, postoperative recovery time of intestinal function, the length of hospitalization and postoperative complications were summarized and compared between early and later cases. RESULTS: There were totally 26 patients underwent LTGIE using OrVil successfully. The mean total operation time and esophagojejunostomy time was 272.8 min and 45.3 min. The mean estimated blood loss was 113.8 ml. The mean first flatus time was 3.1±0.9 days and the postoperative length of hospitalization (LOH) was 13.0±6.4 days. Three patients suffered postoperative complications, including one abdominal fluid collection, one pulmonary embolism and one pulmonary infection. During the follow-up period, neither local recurrence nor anastomosis-related morbidity was observed. CONCLUSIONS: The LTGIE using OrVil is feasible and safe for upper gastric cancer. These preliminary results warrant further evaluation in a larger population to validate.

Lost Polarization of Aquaporin4 and Dystroglycan in the Core Lesion after Traumatic Brain Injury Suggests Functional Divergence in Evolution.

OBJECTIVE: To understand how aquaporin4 (AQP4) and dystroglycan (DG) polarized distribution change and their roles in brain edema formation after traumatic brain injury (TBI). METHODS: Brain water content, Evans blue detection, real-time PCR, western blot, and immunofluorescence were used. RESULTS: At an early stage of TBI, AQP4 and DG maintained vessel-like pattern in perivascular endfeet; M1, M23, and M1/M23 were increased in the core lesion. At a later stage of TBI, DG expression was lost in perivascular area, accompanied with similar but delayed change of AQP4 expression; expression of M1, M23, and DG and the ratio of M1/M2 were increased. CONCLUSION: At an early stage, AQP4 and DG maintained the polarized distribution. Upregulated M1 and M23 could retard the cytotoxic edema formation. At a later stage AQP4 and DG polarized expression were lost from perivascular endfeet and induced the worst cytotoxic brain edema. The alteration of DG expression could regulate that of AQP4 expression after TBI.

Recent advances in clay mineral-containing nanocomposite hydrogels.

Clay mineral-containing nanocomposite hydrogels have been proven to have exceptional composition, properties, and applications, and consequently have attracted a significant amount of research effort over the past few years. The objective of this paper is to summarize and evaluate scientific advances in clay mineral-containing nanocomposite hydrogels in terms of their specific preparation, formation mechanisms, properties, and applications, and to identify the prevailing challenges and future directions in the field. The state-of-the-art of existing technologies and insights into the exfoliation of layered clay minerals, in particular montmorillonite and LAPONITE®, are discussed first. The formation and structural characteristics of polymer/clay nanocomposite hydrogels made from in situ free radical polymerization, supramolecular assembly, and freezing-thawing cycles are then examined. Studies indicate that additional hydrogen bonding, electrostatic interactions, coordination bonds, hydrophobic interaction, and even covalent bonds could occur between the clay mineral nanoplatelets and polymer chains, thereby leading to the formation of unique three-dimensional networks. Accordingly, the hydrogels exhibit exceptional optical and mechanical properties, swelling-deswelling behavior, and stimuli-responsiveness, reflecting the remarkable effects of clay minerals. With the pivotal roles of clay minerals in clay mineral-containing nanocomposite hydrogels, the nanocomposite hydrogels possess great potential as superabsorbents, drug vehicles, tissue scaffolds, wound dressing, and biosensors. Future studies should lay emphasis on the formation mechanisms with in-depth insights into interfacial interactions, the tactical functionalization of clay minerals and polymers for desired properties, and expanding of their applications.

Expression patterns of transcription factor PPARγ and C/EBP family members during in vitro adipogenesis of human bone marrow mesenchymal stem cells.

In the past decades increasing lines of evidence have demonstrated that adipose tissue, as an endocrine organ plays a central role in metabolic homeostasis and its related maladies. CCAAT/enhancer-binding protein (C/EBP) family members and the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) were known to be the vital transcription factors in the regulation of adipogenesis. However, the exact mechanism for increased marrow fat in patients with bone metabolic diseases, such as osteoporosis, is still poorly understood. Herein, we studied the expression pattern of PPARγ and C/EBPs in human bone marrow mesenchymal stem cell (hBMSC) adipogenesis and evaluated the effects of individual components of an adipogenic cocktail on the differentiation and transcription factor expression. We furthermore examined whether the ERK signaling pathway was involved in mediating these effects. These findings showed that C/EBPß and C/EBPδ were detected in undifferentiated hBMSC and maintained during the whole process of adipogenesis, and could initiate the expression of PPARγ1 under the treatment of dexamethasone and IBMX. Subsequently, the activation of PPARγ1 by indomethacin, its exogenous ligand, activated C/EBPα, which, together with IBMX, up-regulated PPARγ2 expression and therefore the fullest adipogenesis. Insulin and its downstream signal pathway extracellular signal-regulated kinases (ERK), however, were found not necessary for hBMSC adipogenesis. Our results revealed some unique characteristics of human adipocyte formation, which may help to understand the molecular mechanisms of bone marrow adipogenesis and give insights into the treatment of osteoporosis.