Targeting ARNT attenuates chemoresistance through destabilizing p38α-MAPK signaling in glioblastoma.

Glioblastoma (GBM) is the most aggressive and lethal brain tumor in adults. This study aimed to investigate the functional significance of aryl hydrocarbon receptor nuclear translocator (ARNT) in the pathogenesis of GBM. Analysis of public datasets revealed ARNT is upregulated in GBM tissues compared to lower grade gliomas or normal brain tissues. Higher ARNT expression correlated with the mesenchymal subtype and poorer survival in GBM patients. Silencing ARNT using lentiviral shRNAs attenuated the proliferative, invasive, and stem-like capabilities of GBM cell lines, while ARNT overexpression enhanced these malignant phenotypes. Single-cell RNA sequencing uncovered that ARNT is highly expressed in a stem-like subpopulation and is involved in regulating glycolysis, hypoxia response, and stress pathways. Mechanistic studies found ARNT activates p38 mitogen-activated protein kinase (MAPK) signaling to promote chemoresistance in GBM cells. Disrupting the ARNT/p38α protein interaction via the ARNT PAS-A domain restored temozolomide sensitivity. Overall, this study demonstrates ARNT functions as an oncogenic driver in GBM pathogenesis and represents a promising therapeutic target.

Highly-reflective facet-coated multi-wavelength DFB laser array with exact wavelength spacings.

A distributed feedback (DFB) laser array of twenty wavelengths with highly reflective and anti-reflective (HR-AR) coated facets is both theoretically analyzed and experimentally validated. While the HR facet coating enhances high wall-plug efficiency, it inadvertently introduces a random facet grating phase, thereby compromising the lasing wavelength's predictability and the stability of the single-longitudinal-mode (SLM). In this study, two key advancements are introduced: first, the precisely spaced wavelength is achieved with an error of within ±0.2 nm using the reconstruction-equivalent-chirp (REC) technique; second, the random grating phase on the HR-coated facet is compensated by a controllable distributed phase shift through a two-section laser structure. The SLM stability can be improved while the wavelength can be continuously tuned to the standard wavelength grid. The overall chip size is compact with an area of 4000 × 500 µm2. The proposed laser array has a light power intensity above 13 dBm per wavelength, a high side mode suppression ratio above 50 dB, and low relative intensity noise under -160 dB/Hz. These attributes make it apt for deployment in DWDM-based optical communication systems and as a light source for optical I/O.

Development of an eco-friendly and fast HPLC method for quantitative analysis of four nucleosides in Cordyceps and related products.

An eco-friendly and fast HPLC method was developed for the determination of adenosine, inosine, guanosine and uridine in Cordyceps and related products (fermented mycelia of Hirsutella sinensis andPaecilomyces hepiali). The sample was ultrasonically extracted using 0.5% phosphoric acid solutions for 2.5 min. Sample separation was performed on a Poroshell SB-Aq column (50 mm × 4.6 mm, 2.7 µm) using eco-friendly mobile phase consisting of formic acid and ammonium formate aqueous solution at a flow rate of 1.0 mL·min-1. The detection wavelength was 260 nm. The developed HPLC method showed good linearity with correlation coefficients of 1.0000 in the test range. Good precision, repeatability and stability of this method were also observed (RSD ≤ 2.81%). The recovery ranged from 91.84%-105.19% (RSD ≤ 2.59%). Compared with reported methods, the current method did not use harmful organic solvent and took only 10.5 min. It obtained a high eco-score of 91 by the "Analytical Eco-Scale" tool. The developed method is eco-friendly and fast, which is suitable for the quality evaluation of Cordyceps and related products.

Alterations of the Bile Microbiome in Recurrent Common Bile Duct Stone.

OBJECTIVE: Common bile duct stone (CBDS) recurrence is associated with bile microbial structure. This study explored the structure of bile microbiome in patients with recurrent CBDS, and its relationship with the recurrence of CBDS. METHODS: Patients with recurrent CBDS (recurrence group) and controls without CBDS (control group) requiring endoscopic retrograde cholangiopancreatography (ERCP) were prospectively included. The control group was noncholelithiasis patients, mainly including benign and malignant biliary stenosis. Bile samples were collected, and bile microbiome structure was analyzed by the 16S rRNA encoding gene (V3-V4). RESULTS: A total of 27 patients in the recurrence group and 19 patients in the control group were included. The diversity of bile microbiome in the recurrence group was significantly lower than that in the control group (Shannon index: 2.285 vs. 5.612, P = 0.001). In terms of bile microbial distribution, patients with recurrent CBDS had significantly higher Proteobacteria (86.72% vs. 64.92%, P = 0.037), while Bacteroidetes (3.16% vs. 8.53%, P = 0.001) and Actinobacteria (0.29% vs. 6.74%, P = 0.001) are significantly lower compared with the control group at the phylum level. At the genus level, the recurrence group was mainly the Escherichia, and there was a variety of more evenly distributed microbiome in the control group, with significant differences between the two groups. CONCLUSION: The diversity of bile microbiome in patients with recurrent CBDS is lower. Patients with recurrent CBDS may have bile microbial imbalance, which may be related to the repeated formation of CBDS.

Constructing a Protective Pillaring Layer by Incorporating Gradient Mn4+ to Stabilize the Surface/Interfacial Structure of LiNi0.815Co0.15Al0.035O2 Cathode.

Nickel-rich layered oxides are regarded as very promising materials as cathodes for lithium-ion batteries because of their environmental benignancy, low cost, and high energy density. However, insufficient cycle performance and poor thermotic characteristics induced by structural degradation at high potentials and elevated temperatures pose challenging hurdles for nickel-rich cathodes. Here, a protective pillaring layer, in which partial Ni2+ ions occupy Li slabs induced by gradient Mn4+, is integrated into the primary particle of LiNi0.815Co0.15Al0.035O2 to stabilize the surface/interfacial structure. With the stable outer surface provided by the enriched Mn4+ gradient concentration and the pillar effect of the NiO-like phase, Mn-incorporated quaternary cathodes show enhanced structural stability and improved Li+ diffusion as well as lithium-storage properties. Compared with the severe capacity fade of a pure layered structure, the cathode with gradient Mn4+ exhibits more stable cycling behavior with a capacity retention of 80.0% after 500 cycles at 5.0 C.

Insulin protects against damage to pulmonary endothelial tight junctions after thermal injury: relationship with zonula occludens-1, F-actin, and AKT activity.

Intensive insulin therapy during critical illness protects the endothelium and thereby prevents organ failure. This study tested the hypothesis that insulin directly affects the attenuation of burn injury-induced damage to pulmonary endothelial tight junction and investigated the underlying mechanisms. Sprague Dawley rats with severe burn injury were randomized to treatment with insulin dissolved in normal saline (maintenance of blood glucose at a level between 5.0 and 7.0 mmol/L) or normal saline alone (in vivo treatment). Pulmonary damage was evaluated. Rat pulmonary microvascular endothelial cells were treated with 20% burn serum or 20% burn serum + insulin (in vitro treatment). Selected cultures were pretreated with phosphatidylinositol 3-kinase/protein kinase B (AKT) inhibitor (LY294002). Permeability was assessed by migration of bovine serum albumin across cell monolayers. Cells were stained with rhodamine phalloidin and were examined. Cell extracts were obtained to assess zonula occludens-1, occludin, and phosphorylated AKT levels by immunoblotting. Treatment with insulin attenuated the pulmonary edema, hemorrhage, and inflammatory cell infiltration of rats with severe burn injury. Burn serum significantly enhanced monolayer permeability to albumin, whereas treatment with insulin (10(-7 ) mol/L) limited this effect. Meanwhile, insulin (10(-7 ) mol/L) reduced burn serum-induced F-actin stress fiber formation and decreased zonula occludens-1 expression. LY294002 decreased cytoplasmic AKT phosphorylation and inhibited the protection effects of insulin. Through the phosphatidylinositol 3-kinase/AKT pathway, insulin independent of glucose toxicity can attenuate increased pulmonary endothelial permeability induced by burn injury. The effect is attributed to the attenuation of the architectural disruption of protein components of the endothelial tight junction. This result is useful in inhibiting multiple organ failure after burn injury.

[Intensive insulin treatment protected the cardiac myocytes against apoptosis in severely scalded rats].

OBJECTIVE: To investigate the effect of intensive insulin treatment, in the protection of myocardiocytes against apoptosis in severely scalded rats and its underlying mechanism. METHODS: Eighteen Sprague-Dawley (SD) rats were randomly divided into three groups (6/each) to receive: sham surgery, burn damage (on the back of the animals, degreeIII, to 30% of total body surface area), and burn damage+intensive insulin treatment. Tissue samples were collected from the left ventricle 6 hours after infliction of the burn damage for the examination of myocardial cell apoptosis [by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining] and the expression of apoptosis-related molecules caspase-3, Bax, and Bcl-2 (by immuno-histochemistry and Western blotting). RESULTS: In comparison with the animals in sham treated group, the myocardiocyte apoptosis rate in animals in burn damage only group increased significantly [(13.1 ± 3.4)% vs. (0.6 ± 0.4)%, P < 0.01]. The expression of caspase-3 and Bax both significantly increased while the level of Bcl-2 expression significantly decreased (immuno-histochemistry caspase-3: 13.72 ± 4.13 vs. 1.36 ± 0.95, Bax: 29.64 ± 5.42 vs. 2.24 ± 1.04, Bcl-2: 3.39 ± 1.52 vs. 8.01 ± 2.56; Western blotting caspase-3: 5.72 ± 2.13 vs. 1, Bax: 4.64 ± 1.42 vs. 1, Bcl-2: 0.69 ± 0.42 vs. 1, all P < 0.01). The animals received intensive insulin treatment showed significantly less myocardiocyte apoptosis [(6.7 ± 1.8)% vs. (13.1 ± 3.4)%, P < 0.01], significantly lower expression in caspase-3, Bax, and significantly higher level of Bcl-2 expression as compared to the animals in burn damage only group (immuno-histochemistry caspase-3: 8.88 ± 3.36 vs. 13.72 ± 4.13, Bax: 14.43 ± 3.69 vs. 29.64 ± 5.42, Bcl-2: 8.61 ± 3.72 vs. 3.39 ± 1.52; Western blotting caspase-3: 2.18 ± 0.86 vs. 5.72 ± 2.13, Bax: 2.87 ± 1.35 vs. 4.64 ± 1.42, Bcl-2: 3.57 ± 1.70 vs. 0.69 ± 0.42, P < 0.05 or P < 0.01). CONCLUSION: Intensive insulin therapy may protect myocardiocytes against apoptosis in severely burned animals through the regulation of the expression of apoptosis-related molecules caspase-3, Bax and Bcl-2.

Insulin-mediated inhibition of p38 mitogen-activated protein kinase protects cardiomyocytes in severe burns.

Thermal injury inhibits Akt activation and upregulates p38 mitogen-activated protein kinase, which in turn induces inflammation and increases apoptosis. This study aimed to elucidate the mechanism underlying the cytoprotective role of insulin in severe burns by examining the effects of insulin on inflammation and apoptosis mediated by p38 mitogen-activated protein kinase in burn serum-challenged cardiomyocytes. Neonatal rat cardiomyocytes were exposed to burn serum for 6 hours in the presence or absence of insulin and pretreated with inhibitors to p38 mitogen-activated protein kinase (SB203580) and Akt (LY294002). The authors examined expression of myocardial tumor necrosis factor-alpha, cardiac myofilament proteins caspase-3 and Bcl2, and apoptosis. Burn serum-induced upregulation of tumor necrosis factor was inhibited by both SB203580 and insulin. LY294002 reversed insulin-mediated downregulation of tumor necrosis factor. Both SB203580 and insulin inhibited apoptosis, resulting in fewer pyknotic nuclei and inhibition of caspase-3 activation and Bcl2 downregulation. LY294002 reversed insulin-mediated inhibition of apoptosis. Insulin decreases inflammatory cytokine expression and apoptosis via PI3K/Akt-mediated inhibition of p38 mitogen-activated protein kinase. The cytoprotective role of insulin suggests that it may have a potential role in strategies for treating thermal injuries.

Intensive insulin treatment attenuates burn-initiated acute lung injury in rats: role of the protective endothelium.

Nonmetabolic effects of intensive insulin therapy in critically ill patients have been reported, but the underlying mechanisms are unclear. This study was designed to test the hypothesis that intensive insulin treatment would attenuate burn-induced acute lung injury by protecting the pulmonary microvascular endothelium. The rat model of burn injury was achieved by exposure to 92°C water for 18 seconds. The rats were randomly allocated into the sham, burn/normal saline (NS), and burn/intensive insulin treatment groups. Blood glucose level was maintained between 5 and 7 mmol/L in rats in the burn/intensive insulin treatment group. Pulmonary injury was assessed by hematoxylin and eosin staining, scanning electron microscopy, bronchoalveolar lavage fluid protein concentrations, the lung wet:dry weight ratio, and lung myeloperoxidase activity. Pulmonary microvascular endothelial cells were examined by transmission electron microscopy. Western blotting was used to determine the protein expression of caspase-3. Intensive insulin treatment markedly attenuated the acute lung injury, revealed by improvements in histological features and significant decreases in bronchoalveolar lavage fluid protein concentrations, pulmonary wet:dry weight ratio, and myeloperoxidase activity at 12 hours after injury (P < .05 or P < .01 vs burn/NS). Moreover, the injured pulmonary microvascular endothelial cells showed significant improvements, whereas caspase-3 was markedly downregulated in the burn/intensive insulin treatment group when compared with the burn/NS group. Overall, intensive insulin treatment efficiently attenuated pulmonary microvascular endothelial cell dysfunction, decreased cell apoptosis, and inhibited acute lung injury after a burn. These findings may be useful in preventing organ failure after burn injury.

[Study on crosstalk between phosphatidylinositol 3 -kinase/Akt pathway and p38 mitogen-activated protein kinase pathway in cardiomyocyte with challenge of burn serum].

OBJECTIVE: To investigate the possibility of crosstalk between phosphatidylinositol 3-kinase (PI3-K)/Akt pathway and p38 mitogen-activated protein kinase (p38MAPK) pathway in cardiomyocyte with challenge of burn serum, and to explore their influence on cardiomyocyte injury after burn. METHODS: The model of murine cardiomyocyte with stimulation of burn serum was established. (1) The level of Akt and p38 phosphorylation in cardiomyocyte were examined with stimulation of 10% burn serum before stimulation and 1, 3, 6, 12, 24 hour after stimulation. (2) The levels of Akt and p38 phosphorylation in cardiomyocyte were determined with stimulation of burn serum (at concentration of 5%, 10%, 20%) or 10% burn serum plus insulin (at concentration of 1 x 10(-8), 1 x 10(-7), 1 x 10(-6)mol/L). The content of creatine kinase (CK) in supernate was also detected. (3) Addition to the inhibitor of p38 MAPK pathway (SB203580) and PI3K/Akt pathway (LY294002), the level of p38MAPK, PI3K/Akt and the content of CK in supernate were determined. RESULTS: (1) The level of p-p38 in cardiomyocyte was 4.0 +/- 0.8, 3.6 +/- 0.8, 5.1 +/- 1.6, 2.4 +/- 0.5, 3.0 +/- 0.6 at 1, 3, 6, 12, 24 hour (s) after stimulation of burn serum, which was obviously higher than that immediate after stimulation (1.0, P < 0.01). The level of p-Akt was 0.15 +/- 0.07, 0.64 +/- 0.10, 0.26 +/- 0.08, 0.38 +/- 0.11, 0.59 +/- 0.13, which was obviously lower than that before stimulation (1.00, P < 0.01). (2) With stimulation of different concentration of burn serum or burn serum plus insulin, the level of p-Akt and p-p38 changed in the opposite directions comparatively. The content of CK increased along with increase of burn serum concentration, but decreased obviously with treatment of insulin (P < 0.05 or 0.01). (3) Low level of p38 induced by burn serum was increased after treatment of LY294002, which neutralized the protection of insulin (P < 0.01). Low level of p-Akt induced by burn serum increased after treatment of SB203580 (P < 0.01), which inhibited the release of CK induced by burn serum. CONCLUSION: There is being crosstalk between PI3K/Akt pathway and p38 MAPK pathway in cardiomyocytes with challenge of burn serum, which may regulate cardiomyocytes.

[Effect of intensive insulin treatment on cardiac myocytes of severely scalded rats].

OBJECTIVE: To study the protective effect of intensive insulin treatment on cardiac myocytes of severely scalded rats. METHODS: Eighteen model Sprague-Dawley (SD) rats were subjected to 30% total body surface area (TBSA) full thickness injury, and they were divided into three groups with 6 rats in each group. The right jugular vein was cannulated for fluid resuscitation and administration of drugs. The rats in burn group were injected with normal saline, the intensive insulin group with injection of insulin to maintain plasma glucose content in normal range, and the sham burn group received physiologic dose of saline without burn injury. Plasma glucose was monitored after burn injury. Rats were sacrificed at 6 hours postburn to examine plasma myocardial enzymes spectrum as well as histological and ultrastructure changes in cardiac tissue. The expression of p-Akt was detected by western blotting. RESULTS: Plasma glucose level was significantly elevated in burn group within postburn 6 hours as compared with the sham burn group, and lowered in intensive insulin group (4.5 approximately 5.2 mmol/L vs. 7.6 approximately 8.4 mmol/L, P<0.05 or P<0.01). And the intensive insulin therapy could effectively inhibit the release of cardiac enzymes [lactate dehydrogenase (LDH): (2 369.3+/- 178.9) U/L vs. (2 684.1+/-335.0) U/L, P<0.05; alpha-hydroxybutyrate dehydrogenase (alpha-HBD): (576.7+/-219.2) U/L vs. (1 002.0+/-347.1) U/L, P<0.01; creatine kinase (CK): (1 041.9+/-623.2) U/L vs. (2 447.1+/-1 183.7) U/L, P<0.01]. The expression of p-Akt was significantly strengthened in the intensive insulin group (1.18+/-0.43 vs. 0.24+/-0.11, P<0.01). Light microscopic and electron microscopic examinations showed that intensive insulin therapy could alleviate the injury to myocardial cells and structural changes. CONCLUSION: Intensive insulin treatment possesses protective effect on cardiomyocytes after a severe burn, and it is related to its up-regulation of phosphorylation level of Akt in cardiomyocyte, thus inhibiting the damage to myocytes.

[The anti-apoptosis effect of intensive insulin treatment on cardiac myocytes in severe scald rats].

OBJECTIVE: To investigate the anti-apoptosis effect of intensive insulin treatment on cardiac myocytes and its underlying mechanism in severe scald rats. METHODS: Twelve SD rats were suffered from 30% TBSA full thickness scald, and they were divided into: IT group [with intravenous injection of isotonic saline including insulin (15 mU x kg(-1) x min(-1)) and 100 g/L glucose], B group [with treatment of isotonic saline (2 mL x kg(-1) x %TBSA(-1) x 8 h(-1)]. Six SD rats received sham burn as controls[sham(S)group, with treatment of fluid at physiologic dose]. + dp/ dtmax (the rate of the rise of left ventricular pressure) and -dp/ dtmax (the rate of the fall of left ventricular pressure)at 6 post burn hour (PBH)were recorded. Apoptosis were determined by TUNEL staining and DNA ladder. The phosphorylation f Akt and protein expression of Bcl-2 in cardiomyocyte were assayed by Western blotting. RESULTS: The + dp/ dtmax in the S group, IT group and B group at6 PBH were respectively (5.5 +/- 0.5) x 10(3) mm Hg/s, (3.4 +/- 0.4) x 10(3 mm Hg/s and (2.5 +/- 0.5) x 10(3) mm Hg/s (1 mm Hg = 0.133 kPa), the - dp/ dtmax were respectively (4.55 +/- 0.34) x 10(3) mmHg/s, (2.94 +/- 0.22) x 10(3) mm Hg/s and (2.05 +/- 0.19) x 10(3) mmHg/s.The +/- dp/dtmax in IT group was significantly higher than those in B group( P < 0.01). The apoptosis index in B group was (13.1 +/- 3.4)%, which was obviously higher than that in IT group (6.7 +/- 1.8)% and S group (0.6 +/- 0.4)% (P < 0.01). DNA ladder showed that no DNA fragmentation in S group, but obvious DNA fragmentation forming ladder pattern in B group, and no obvious ladder pattern in IT group. The phosphorylation of Akt and level of Bcl-2 protein in B group were markedly higher than those in IT group ( P < 0.05 or P < 0.01). CONCLUSION: Intensive insulin treatment can upregulate the activity of Akt and enhance the expression of Bcl-2, and they might constitute the mechanisms for anti-apoptosis in cardiomyocyte and protection of cardiac function.

[The protective effect of intensive insulin treatment on the myocardium in severely scalded rats].

OBJECTIVE: To study the protective effect of intensive insulin treatment on the myocardium of severely scalded rats, and to primarily explore its mechanism. METHODS: Eighteen SD rats were divided into three groups, with 6 rats in each group. The rats in burn and intensive insulin group were inflicted with 30% TBSA full-thickness injury on the back. Isotonic saline containing 0.12 U/ml insulin solution, and 100 g/L glucose solution were infused into the rats in the intensive insulin group to keep plasma glucose at the level of 4.0 - 6.6 mmol/L (the total fluid amount was 2 ml x kg(-1) x 8h(-1)). In sham burn group,fluid was given according to physiological demand. The same amount of isotonic saline was infused into the rats in burn group. The venous blood was obtained for the detection of plasma glucose contents, and the left ventricular systolic pressure (LVSP) and left ventricular end-diastolic pressure (LVEDP) were recorded via aortic ventricle cannula before scald and at 1, 2, 3, 4, 5, 6 post-scald hours (PSH). The tissue of the left ventricle was harvested at 6 PSH for the detection of troponin T expression in myocardiocytes. RESULTS: Plasma glucose level was increased to (7.6 +/- 1.7) mmol/L - (8.4 +/- 4.7) mmol/L in burn group during 1-6 PSH, which was significantly higher than that in intensive insulin group (4.5 +/- 0.9) mmol/L - (5.2 +/- 1.3) mmol/L, P < 0.01). Compared with the intensive insulin group, LVSP was markedly decreased in the burn group (60 +/- 11 mm Hg vs 72 +/- 8 mm Hg, P < 0.05) at 1 PSH,whereas LVEDP was increased significantly (21.3 +/- 11.3 mmHg vs 11.7 +/- 5.2 mmHg, P < 0.05). Intensive insulin treatment could significantly inhibit the loss of troponin T protein in myofilaments of myocardium. CONCLUSION: Intensive insulin treatment possesses a protective effect on myocardia function after severe burns, and it may be related to its preventive effect on the loss of contractile protein in cardiocytes.

[Protective effect of insulin on oxygen-radical induced hepatic injury in severely scalded rats].

OBJECTIVE: To investigate the protective effect of insulin on oxygen-radical induced hepatic injury in severely scalded rats in early stage of severe scald. METHODS: Eighty-four male Sprague-Dawley rats were randomly divided into three groups: i. e, normal group, saline group, and insulin group, with 28 rat in each group. The rats in the latter two groups were subjected to 30% TBSA full-thickness scald on the back, and received intra-peritoneal injection of 40ml/kg isotonic saline, and subcutaneous injection of 3 IU/kg insulin, respectively. The total anti-oxygen capability (T-AOC), the expression of superoxide dismutase (SOD), reactive oxygen species (ROS) and intercellular adhesion molecule (ICAM-1) in hepatic tissue, and serum alanine transaminase (ALT) were determined in each group at 6, 12, 24, 48 post-scald hours (PSH) with corresponding methods. RESULTS: The hepatic T-AOC and SOD content were obviously decreased, while the ROS content were markedly increased at 6 PSH in saline group compared with that in normal group (P < 0.05 or P < 0.01). The expression of ICAM-1 and serum content of ALT were significantly higher than that in normal group at 12 PSH and 48 PSH (P < 0.01). At 24 PSH, the hepatic T-AOC (386 +/- 75) U/g and SOD content (210 +/- 39 ) U/g were obviously higher in insulin group than those in saline group [(124 +/- 18), (111 +/- 9) U/g, respectively, P < 0.01), but the ROS content (154 +/- 29 ) U/g was much lower than that in saline group [(351 +/- 41) U/g, respectively, P < 0.01]. At 48 PSH, the serum content of ALT and hepatic expression of ICAM-1 in insulin group exhibited obvious difference when compared with those in saline group (P < 0.01). Meanwhile, Pathological examination showed that hepatic injury was alleviated by insulin administration after scald. CONCLUSION: Insulin administration early after severe scald exhibits protective effect on liver function by improving anti-oxygen radical ability of rat liver.

[Study of the anti-endotoxin effect of beta-1, 2, 3, 4, 6-penta-O-galloyl-D-glucopyranose in vitro].

OBJECTIVE: To study the anti-endotoxin effect of beta-1, 2, 3, 4, 6-penta-O-galloyl-D-glucopyranose (PGG) in vitro. METHODS: The affinity of PGG with lipid A was determined with biosensor technology, and the endotoxin-neutralizing effect was assayed with LAL. Human peripheral blood mononuclear cells (hPBMC) were separated from healthy donors and cultured in vitro. The effect of different concentrations of PGG on the release of TNF-alpha and hIL-6 from LPS-stimulated hPBMC were measured by ELISA method. RESULTS: Lipid A was combined with different concentrations of PGG. The combination speed was shortened with the increase in PGG concentration. The KD value between PGG and Lipid A was 5.2 x 10(-7) mol/L. The release of TNF-alpha and IL-6 of hPBMC under LPS stimulation (958 +/- 234 ng/L vs 1 351 +/- 99 ng/L) was obviously inhibited by PGG in the concentration of higher than 20 mg/L compared with that without PGG treatment (1 788 +/- 171 ng/L vs 1 965 +/- 232 ng/L, P < 0.05). CONCLUSION: PGG show an anti-endotoxin effect in vitro, which may be associated with its ability to combine and neutralize endotoxin.

[Experimental study on the antagonistic activity of cationic multi-peptide mastoparan-1 against lipopolysaccharide].

OBJECTIVE: To explore the mechanism of cationic multi-peptide mastoparan-1 (MP-1) on the protection of mice from lipopolysaccharide (LPS) challenge. METHODS: Thirty Kunming mice were divided randomly into MP-1, injury, protection groups with 10 mice in each group. The mice in MP-1 group were injected with 3 mg/kg MP-1 by tail vein, while those in injury group were injected with 20 mg/kg LPS by tail vein, and those in protection group 3 mg/kg MP-1 within 20 seconds after 20 mg/kg LPS injection were injected. The effects of MP-1 on the protection of mice from LPS challenge were observed. In vitro, the affinity of MP-1 and PMB to LPS was compared by biosensor and FAST fit construct and expressed as Kd. And the neutralizing activity of MP-1 and PMB in dose of 5, 10, 20, 40 micromol/L on LPS (2 microg/L) was detected by dynamic turbidimetric limulus test with LPS neutralizing 0 micromol/L MP-1 and PMB as control. The mRNA expression levels of TLR4, TNF-alpha and IL-6 in murine peritoneal macrophages (PM phi) after exposure to LPS (100 ng/ml) were assayed by RT-PCR. RESULTS: MP-1 could significantly protect mice from LPS challenging with protection rate of 90%. In vitro, MP-1 had a high affinity (Kd value: 484.0 nmol/L) and neutralizing ability with LPS, but it was lower than that of PMB (Kd value: 18.9 nmol/L). The neutralizing effect of 20 and 40 micromol/L MP-1 was obviously stronger than that in 0 micromol/L (P < 0.01). MP could obviously inhibit the expression of TLR4, TNF-alpha and IL-6 mRNA in LPS-stimulated murine PM phi. CONCLUSION: MP-1 can evidently protect mice from lethal LPS challenge, and the mechanism might be related to the activity of MP-1 which binding and neutralizing LPS, blocking the combination LPS with its receptors. So the murine macrophage activation induced by LPS was inhibited.

[Study on the injurious effect of a self designed micro-skin machine on the epithelia].

OBJECTIVE: To observe the injury on micro-skin induced by a self designed micro-skin machine. METHODS: Micro-skin was produced either with the machine or by hand. Cells at the edge of micro-skin were observed by transmission electron microscope. succinic dehydrogenase activity in supernatant of cultivated cells was analyzed, and the cell proliferation of micro-skin was assessed by (3)H-TdR. Twenty patients were enrolled in the study for the observation of the wound healing time between the two groups of micro-skin after being grafted. RESULTS: Transmission electron microscope examination revealed that the cellular injury at the edge of the micro-skin in machine-made group was mild compared with that in man-made group. (3)H-TdR rate was elevated but the activity of succinic dehydrogenase in the supernatant of cultured cells decreased in supernatant of cultured cells of machine produced micro-skin. Wound healing time was shortened in machine made group. (P < 0.05). CONCLUSION: The cellular injury at the edge of micro-skin in the machine made group was mild when compared with that in the man-made group with cell proliferation accelerated and wound healing time shortened.