St13 protects against disordered acinar cell arachidonic acid pathway in chronic pancreatitis.

BACKGROUND: Early diagnosis and treatment of chronic pancreatitis (CP) are limited. In this study, St13, a co-chaperone protein, was investigated whether it constituted a novel regulatory target in CP. Meanwhile, we evaluated the value of micro-PET/CT in the early diagnosis of CP. METHODS: Data from healthy control individuals and patients with alcoholic CP (ACP) or non-ACP (nACP) were analysed. PRSS1 transgenic mice (PRSS1Tg) were treated with ethanol or caerulein to mimic the development of ACP or nACP, respectively. Pancreatic lipid metabolite profiling was performed in human and PRSS1Tg model mice. The potential functions of St13 were investigated by crossing PRSS1Tg mice with St13-/- mice via immunoprecipitation and lipid metabolomics. Micro-PET/CT was performed to evaluate pancreatic morphology and fibrosis in CP model. RESULTS: The arachidonic acid (AA) pathway ranked the most commonly dysregulated lipid pathway in ACP and nACP in human and mice. Knockout of St13 exacerbated fatty replacement and fibrosis in CP model. Sdf2l1 was identified as a binding partner of St13 as it stabilizes the IRE1α-XBP1s signalling pathway, which regulates COX-2, an important component in AA metabolism. Micro-PET/CT with 68Ga-FAPI-04 was useful for evaluating pancreatic morphology and fibrosis in CP model mice 2 weeks after modelling. CONCLUSION: St13 is functionally activated in acinar cells and protects against the cellular characteristics of CP by binding Sdf2l1, regulating AA pathway. 68Ga-FAPI-04 PET/CT may be a very valuable approach for the early diagnosis of CP. These findings thus provide novel insights into both diagnosis and treatment of CP.

Danshensu alleviates pseudo-typed SARS-CoV-2 induced mouse acute lung inflammation.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can induce acute inflammatory response like acute lung inflammation (ALI) or acute respiratory distress syndrome, leading to severe progression and mortality. Therapeutics for treatment of SARS-CoV-2-triggered respiratory inflammation are urgent to be discovered. Our previous study shows that Salvianolic acid C potently inhibits SARS-CoV-2 infection. In this study, we investigated the antiviral effects of a Salvia miltiorrhiza compound, Danshensu, in vitro and in vivo, including the mechanism of S protein-mediated virus attachment and entry into target cells. In authentic and pseudo-typed virus assays in vitro, Danshensu displayed a potent antiviral activity against SARS-CoV-2 with EC50 of 0.97 µM, and potently inhibited the entry of SARS-CoV-2 S protein-pseudo-typed virus (SARS-CoV-2 S) into ACE2-overexpressed HEK-293T cells (IC50 = 0.31 µM) and Vero-E6 cell (IC50 = 4.97 µM). Mice received SARS-CoV-2 S via trachea to induce ALI, while the VSV-G treated mice served as controls. The mice were administered Danshensu (25, 50, 100 mg/kg, i.v., once) or Danshensu (25, 50, 100 mg·kg-1·d-1, oral administration, for 7 days) before SARS-CoV-2 S infection. We showed that SARS-CoV-2 S infection induced severe inflammatory cell infiltration, severely damaged lung tissue structure, highly expressed levels of inflammatory cytokines, and activated TLR4 and hyperphosphorylation of the NF-κB p65; the high expression of angiotensinogen (AGT) and low expression of ACE2 at the mRNA level in the lung tissue were also observed. Both oral and intravenous pretreatment with Danshensu dose-dependently alleviated the pathological alterations in mice infected with SARS-CoV-2 S. This study not only establishes a mouse model of pseudo-typed SARS-CoV-2 (SARS-CoV-2 S) induced ALI, but also demonstrates that Danshensu is a potential treatment for COVID-19 patients to inhibit the lung inflammatory response.

EMC6 regulates acinar apoptosis via APAF1 in acute and chronic pancreatitis.

Treatment of acute pancreatitis (AP) and chronic pancreatitis (CP) remains problematic due to a lack of knowledge about disease-specific regulatory targets and mechanisms. The purpose of this study was to screen proteins related to endoplasmic reticulum (ER) stress and apoptosis pathways that may play a role in pancreatitis. Human pancreatic tissues including AP, CP, and healthy volunteers were collected during surgery. Humanized PRSS1 (protease serine 1) transgenic (PRSS1Tg) mice were constructed and treated with caerulein to mimic the development of human AP and CP. Potential regulatory proteins in pancreatitis were identified by proteomic screen using pancreatic tissues of PRSS1Tg AP mice. Adenoviral shRNA-mediated knockdown of identified proteins, followed by functional assays was performed to validate their roles. Functional analyses included transmission electron microscopy for ultrastructural analysis; qRT-PCR, western blotting, co-immunoprecipitation, immunohistochemistry, and immunofluorescence for assessment of gene or protein expression, and TUNEL assays for assessment of acinar cell apoptosis. Humanized PRSS1Tg mice could mimic the development of human pancreatic inflammatory diseases. EMC6 and APAF1 were identified as potential regulatory molecules in AP and CP models by proteomic analysis. Both EMC6 and APAF1 regulated apoptosis and inflammatory injury in pancreatic inflammatory diseases. Moreover, APAF1 was regulated by EMC6, induced apoptosis to injure acinar cells and promoted inflammation. In the progression of pancreatitis, EMC6 was activated and then upregulated APAF1 to induce acinar cell apoptosis and inflammatory injury. These findings suggest that EMC6 may be a new therapeutic target for the treatment of pancreatic inflammatory diseases.

ATF6 aggravates acinar cell apoptosis and injury by regulating p53/AIFM2 transcription in Severe Acute Pancreatitis.

Background: There is no curative therapy for severe acute pancreatitis (SAP) due to poor understanding of its molecular mechanisms. Endoplasmic reticulum (ER) stress is involved in SAP and increased expression of ATF6 has been detected in SAP patients. Here, we aimed to investigate the role of ATF6 in a preclinical SAP mouse model and characterize its regulatory mechanism. Methods: Pancreatic tissues of healthy and SAP patients were collected during surgery. Humanized PRSS1 transgenic mice were treated with caerulein to mimic the SAP development, which was crossed to an ATF6 knockout mouse line, and pancreatic tissues from the resulting pups were screened by proteomics. Adenovirus-mediated delivery to the pancreas of SAP mice was used for shRNA-based knockdown or overexpression. The potential functions and mechanisms of ATF6 were clarified by immunofluorescence, immunoelectron microscopy, Western blotting, qRT-PCR, ChIP-qPCR and luciferase reporter assay. Results: Increased expression of ATF6 was associated with elevated apoptosis, ER and mitochondrial disorder in pancreatic tissues from SAP patients and PRSS1 mice. Knockout of ATF6 in SAP mice attenuated acinar injury, apoptosis and ER disorder. AIFM2, known as a p53 target gene, was identified as a downstream regulatory partner of ATF6, whose expression was increased in SAP. Functionally, AIFM2 could reestablish the pathological disorder in SAP tissues in the absence of ATF6. p53 expression was also increased in SAP mice, which was downregulated by ATF6 knockout. p53 knockout significantly suppressed acinar apoptosis and injury in SAP model. Mechanistically, ATF6 promoted AIFM2 transcription by binding to p53 and AIFM2 promoters. Conclusion: These results reveal that ATF6/p53/AIFM2 pathway plays a critical role in acinar apoptosis during SAP progression, highlighting novel therapeutic target molecules for SAP.

Long noncoding RNA CCAT2 functions as a competitive endogenous RNA to regulate FOXC1 expression by sponging miR-23b-5p in lung adenocarcinoma.

Long noncoding RNA (lncRNA) may regulate the process of tumor formation. Although lncRNA CCAT2 has been identified as a key point in many diseases, its pathophysiological mechanism in lung adenocarcinoma remains unknown. We measured the expression level of CCAT2 in lung adenocarcinoma cells and normal lung epithelial cell line BEAS-2B by quantitative real-time polymerase chain reaction (qRT-PCR). As well, cell migration and proliferation were detected by transwell detection and CCK8 assay. At the same time, the new target point of CCAT2 was confirmed with bioinformatics analysis and dual-luciferase reporter assay. In addition, potential mechanisms were studied by Western blot analysis and RNA immunoprecipitation (RIP) analysis. The expression of CCAT2 was upregulated obviously in lung adenocarcinoma cells. Cell function analysis showed that upregulation of CCAT2 significantly promoted cell proliferation and migration, and reduction of CCAT2 inhibited cell migration and proliferation. In addition, CCAT2 positively regulated the expression of FOXC1 by competitive binding with miR-23b-5p. These findings indicated that CCAT2 may act as a competitive endogenous RNA (ceRNA) to regulate FOXC1 expression by competitively binding miR-23b-5p in lung adenocarcinoma.

Potential of bone marrow mesenchymal stem cells in rejuvenation of the aged skin of rats.

The aim of the present study was to evaluate the anti-aging effects of bone marrow-mesenchymal stem cells (BM-MSCs) in a D-galactose-induced skin aging rat model. Male Sprague Dawley rats were randomly divided into four groups (n=10/group) as follows: Normal control group; skin aging model group; MSC-treated group by subcutaneous multi-point injection. The skin aging model was established by a daily subcutaneous injection of 15% D-galactose (1,000 mg/kg) for 8 weeks. Rats in the MSC-treated groups were administered 3×106/ml BM-MSCs/green fluorescent protein (GFP) for 4 weeks, administered once per week. Oxidative/antioxidative parameters were evaluated, and morphological and ultrastructure analyses were performed. Rats in the model group exhibited the typical changes of aging skin. Compared with the control group, rats in the model group had significantly increased malondialdehyde (MDA) content (P<0.01), and decreased serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities (P<0.05). MSC treatment markedly ameliorated aging-induced oxidative stress in the skin. Histologically, rats in the model group exhibited loosely arranged epidermal cell layers and disorganized collagen fibers. BM-MSC treatment significantly improved the histological abnormalities, which was similar to those in the control group. In addition, 7 days after the final cell transplantation, GFP-positive cells were observed by fluorescence microscopy to be distributed in the dermis. Injection of BM-MSCs significantly improved the D-galactose-induced histological abnormalities of the skin, by promoting an antioxidant response and ameliorating oxidative stress in aged skin. Thus, BM-MSCs may be beneficial in the rejuvenation of aged skin.

Synthesis and biological evaluation of substituted 1,2,3-benzotriazines and pyrido[3,2-d]-1,2,3-triazines as inhibitors of vascular endothelial growth factor receptor-2.

A novel series of substituted 1,2,3-benzotriazines and pyrido[3,2-d]-1,2,3-triazines were synthesized. The abilities of these compounds to inhibit the VEGFR-2 kinase activity and the proliferation of human microvascular endothelial cells (MVECs) were determined. 6-Methoxy-4-substituted-1,2,3-benzotriazines and 4-substituted-6-chloro-pyrido[3,2-d]-1,2,3-triazines have the abilities of inhibiting the VEGFR-2 kinase activity, but only the 4-substituted-6-chloro-pyrido[3,2-d]-1,2,3-triazines exhibit good growth inhibitory effects on MVECs. Compound 6-chloro-4-(3-trifluoromethylanilino)-pyrido[3,2-d][1,2,3]triazin (11d) is less half active than PTK787 to inhibit the VEGFR-2 kinase activity, but is more active than PTK787 to inhibit the growth of MVECs. The potential binding modes of 6d, 11d, and CTZ12 in complex with their putative intracellular target, VEGFR-2, were predicted using Surflex-Dock.

[Application of expansion bilateral delto-pectoral thin skin flap in the repair of extensive scar in faciocervical region].

OBJECTIVE: To contrive an effective method of repairing the scar in bilateral faciocervical region. METHODS: Between April 2009 and February 2012, 9 patients with large scars on face and neck due to burn and scald were treated. There were 5 cases with face scars and 4 cervical scars. Their average age was 33 years (range: 23-48 years). The disease duration was 6 months to 20 years (mean: 6.5 years). The scar area was 12 cm × 7 cm to 22 cm × 26 cm. The soft tissue expanders (600-800 ml in volume) were implanted in delto-pectoral zone in one-stage operation. In two-stage operation, after the resection of cervical scars, the defects were repaired with delto-pectoral perforator flaps. In 5 facial scar cases, skin flap pedicle division was performed at Week 3. After the resection of scars, all wounds were repaired by expansion flap. The donor sites were sutured directly. The area of removed scar and the status of flap blood supply were observed. And the texture of flaps and patient satisfaction score were followed up for 6-30 months. RESULTS: Mild congestion of flap occurred postoperatively 1 case. The other flaps survived successfully. The flaps of 2 cases appeared bulky after transposition and flap repair was performed at Month 6. The appearance, texture, and color of flaps were similar to those at the donor sites. And there was an excellent match of flaps and recipient place.The patient satisfaction score was 7.6 ± 2.3. All achieved satisfactory functional and aesthetic outcomes. CONCLUSION: The method has many advantages and its clinical application is both safe and effective.

[The comparison between the vascular endothelial cells special cdc42-deficient heterozygous mice and the non-knockout mice on lung tissue pathological change and vasopermeability in acute lung injury].

OBJECTIVE: To compare the change of lung tissue and vasopermeability between the vascular endothelial cells special cdc42-deficient heterozygous mice and the non-knockout mice in acute lung injury. METHODS: The mice with vascular endothelial cell-specific expression of cre recombinase were crossed with cdc42(flox/flox) mice. The cdc42(flox/+)Cre(+/-) F1 offspring mice were crossed back with cdc42(flox/flox) mice, resulting in the F2 generation mice with three genotypes, namely cdc42(flox/+)Cre(+/-), cdc42(flox/flox)Cre(-/-) and cdc42(flox/+)Cre(+/-). The heterozygous mice with cdc42(flox/+)Cre(+/-) genotype were selected as the model mice, with the other two genotype groups as the control. After intratracheal instillation of 2 mg/kg LPS to induce acute lung injury, the mice were sacrificed to examine the lung pathologies, lung wet/dry ratio and lung microvascular permeability. RESULTS: The heterozygous mice with cdc42 gene knockout (cdc42(flox/+)Cre(+/-)) showed no significant differences from the two control groups in the lung pathological score, lung wet/dry ratio or the lung microvascular permeability coefficient. CONCLUSION: There were no significant difference on lung tissue and vasopermeability between the vascular endothelial cells special cdc42-deficient heterozygous mice and the non-knockout mice.

The generation of the endothelial specific cdc42-deficient mice and the effect of cdc42 deletion on the angiogenesis and embryonic development.

BACKGROUND: High microvascular permeability plays an essential role in pathological process of multiple diseases such as septic shock, acute lung injury and acute respiratory distress syndrome, and burns. Inhibiting hyperpermeability is significant for controlling these conditions. Cdc42, as a main member of the small Rho GTPase family, plays a critical role in controlling and regulating the endothelial junctional permeability. We aimed to generate and identify endothelial specific cdc42-deficient mice by the Cre/loxp recombination approach, for examination in an animal model of the contribution of the cdc42 gene in the microvascular barrier function. METHODS: We crossed cdc42(Flox/Flox) mice with mice expressing endothelial cell-specific Cre recombinase, and the offspring with the genotype cdc42(Flox/+)Tie2Cre(+/-) were back-crossed with the cdc42(Flox/Flox) mice. The cdc42(Flox/Flox)Tie2Cre(+/-) mice in the F2 generation were the target mice. If the cdc42 deficient mice did not survive, we would observe the cdc42 deficient mice embryos, and compare them with wild-type mice embryos. RESULTS: Cdc42(flox/+)Cre(+/-) mice were mated with the cdc42(Flox/Flox) mice and among the living offspring there were no cdc42(Flox/Flox)Cre(+/-) target mice. We found the endothelial special cdc42 deficient embryos at the E7.5-E16.5 stage. We observed that cdc42 deficient embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos. CONCLUSIONS: Endothelial specific knockout of cdc42 caused embryonic lethality and the mice did not survive to birth. The target embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos. These results demonstrated that the cdc42 plays an important role in development of embryos and in development of microvessels as well as microvascular permeability.

[Clinical efficacy of keloids treated by surgical ablation and immediate postoperative adjuvant radiotherapy].

OBJECTIVE: To evaluate the clinical efficacy of intralesional excision and immediate postoperative adjuvant radiotherapy in the treatment of keloids. METHODS: Eighty-one patients with a combined total of 86 keloids were treated with 6 MeV electron beam radiotherapy after surgical intralesional excision of keloids. All received a total dose of 15 - 20 Gy for 5 consecutive days beginning the day of surgery. The time interval between keloid excision and the delivery of first fraction of radiotherapy was < 6 h. The post-operative follow-up period was 12 - 31 months. RESULTS: Forty-three cases yielded excellent outcomes and there were 18 fair cases. The overall effective rate was 85.9%. There were 10 recurrent cases. Only adverse effects such as delayed wound-healing and telangiectasias (11.3%) were found. Neither severe complications nor secondary malignancies occurred. CONCLUSION: Intralesional excision of keloid and postoperative electron radiotherapy are well-tolerated and efficacious in the prevention of keloid recurrence.

[Therapeutic effect of tiotropium bromide powder inhalation in patients with stable bronchiectasis].

OBJECTIVE: To observe the therapeutic effect of tiotropium bromide powder inhalation on stable bronchiectasis. METHODS: Twenty-two patients with stable bronchiectasis received inhalation of totropium bromide powder at the daily dose of 18 microg, and on days 1 and 28, the patients were examined for forced expiratory volume in one second (FEVl), predicted value [FEVl(%)], forced expiratory volume (FEV), and FEVl/FVC. The symptom score and BODE index were also recorded. RESULTS: After 1 month of inhalation therapy, the FEV1% of the patients showed a moderate increase but the increment was not statistically significant (t=-1.875, P>0.05); the symptom score and BODE index decreased significantly after the therapy (t=7.091, P<0.001; t=2.982, P<0.05). CONCLUSION: Long-term inhalation of tiotropium bromide powder can improve the clinical symptoms and BODE index and enhance the exercise tolerance and quality of life of the patients with bronchiectasis.

Ethyl 2-[(Z)-2-benzyl-hydrazin-1-yl-idene]-2-bromo-acetate.

In the title compound, C(11)H(13)BrN(2)O(2), the dihedral angle between the phenyl ring and the almost planar (r.m.s. deviation = 0.011 Å) C-C(Br)=N-N(H)- fragment is 74.94 (16)°. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, which generate C(6) chains propagating in [010]. Weak aromatic π-π stacking [centroid-centroid separation = 3.784 (3) Å] may also help to consolidate the packing.

Some insights into mechanism for binding and drug resistance of wild type and I50V V82A and I84V mutations in HIV-1 protease with GRL-98065 inhibitor from molecular dynamic simulations.

The single mutations I50V, V82A and I84V are considered as the key residue mutations of the HIV-1 protease drug resistance. The rank of calculated absolute binding free energies using MM-PBSA method is in excellent agreement with experimental result. Enthalpic and entropic balance is analyzed to explain resistance in I50V and V82A having a higher entropic contribution than in the wild type (WT) complex. The reduced van der Waals energy explains the drug resistance of I84V to GRL-98065. Detailed binding free energies between GRL-98065 and individual protein residues are calculated to provide insights into the inhibitor-protein binding and drug-resistant mechanism. Our results show I50V and V82A have larger structural changes than I84V compared with WT.

[Expression of the P450arom mRNA in the glandular tissue of the pubertal mammary hypertrophy].

OBJECTIVE: To investigate the expression status of the P450arom mRNA in breast tissue of pubertal mammary hypertrophy and then explore the possible etiology of pubertal mammary hypertrophy. METHODS: 15 patients were selected for pubertal mammary hypertrophy group. Breast hypertrophy tissue specimens were collected from the gland excised during reduction mammaplasty. 15 patients with pathologically simple fibroadenoma were used as another control group. Patient approval of participation in this study was obtained preoperatively. The expression of P450arom mRNA was detected by RT-PCR in all the cases above. RESULTS: There was no significant difference between the pubertal mammary hypertrophy groups and normal groups on the expression rates of P450arom mRNA. But among the positive cases, the expression of P450arom mRNA within breast tissue were 0.202 +/- 0.048 in pubertal mammary hypertrophy group; and 0.159 +/- 0.068 in normal group. There was significant difference between the pubertal mammary hypertrophy and normal groups (P < 0.05). CONCLUSION: The expression of P450arom mRNA in pubertal mammary hypertrophy are significantly higher than in normal mammary glandular tissue. The pubertal mammary hypertrophy may be related to the expression status of P450arom mRNA within breast tissue.

[Comparison of full-field digital mammography and magnetic resonance imaging for breast disease diagnosis].

OBJECTIVE: To compare the effectiveness of full-field digital mammography (FFDM) and magnetic resonance imaging (MRI) in the detection and diagnosis of breast diseases. METHODS: Forty-one patients with 47 breast lesions (20 malignant and 27 benign lesions) underwent preoperative FFDM and MRI, using the pulse sequences including T1WI, T2WI, T2WI/SPIR diffusion-weighted imaging (DWl), and 3D dynamic contrast-enhanced MRI. RESULTS: The imaging and pathological findings were compared, and the detection rates of the lesions by FFDM and MRI were 97.87% (46/47) and 74.46% (35/47), respectively (P<0.01). The sensitivity of FFDM and MRI was 70.00% (14/20) and 80.00% (16/20) (P>0.05), with specificity of 62.96%(17/27) and 88.89%(24/27) (P<0.05), respectively. CONCLUSION: MRI is superior to FFDM in the detection and diagnosis of breast diseases.

[Biological dressing with human hair keratin-collagen sponge-poly 2-hydroxyethyl methacrylate composite promotes burn wound healing in SD rats].

OBJECTIVE: To develop a composite material containing human hair keratin (HHK), collagen sponge (inner layer) and poly 2-hydroxyethyl methacrylate (PHEMA) film that allows sustained release of polydatin and test its effect as a biological dressing in promoting burn wound healing in SD rats. METHODS: Three HHK materials with fast, moderate, and low degradation rates were mixed at the ratio of 4:3:3 to prepare a reticular structure, which was processed into a composite material with bovine tendon-derived collagen sponge, and further complexed with HEMA film containing PD prepared by polymerization. Degree II burn wound was induced in SD rats by scalding and within postburn day 2-5, the wounds were cleansed and covered with the composite material or with glutaraldehyde-treated porcine skin (positive control). At week 1, 2, 4, 6 and 8 following wound dressing, 6 full-thickness skin samples were harvested from the wounds for histological observation and immunohistochemical detection of collagen and elastic fibers, and the wound healing time and healing rate were recorded. RESULTS: The prepared collagen sponge film was transparent and porous (50-300 microm in diameter) and allowed sustained PD release into normal saline within 48 h. Compared with the porcine skin, the composite material reduced exudation and maintained ideal moisture of the wound, and significantly shortened the wound healing time (P=0.000). On day 7, 14, and 21 following dressing, the composite material and porcine skin significantly increased the wound healing rate as compared with the negative control group (P=0.000), and on day 14, the composite achieved significantly greater healing rate than the porcine skin (P<0.05). CONCLUSION: HHK-collagen sponge-PHEMA/PD composite as a dressing material promotes burn wound healing in rats by allowing in vivo construction of tissue engineered epidermis. PHEMA is feasible for sustained drug delivery in this composite.

Effects of serum of the rats ventilated with high tidal volume on endothelial cell permeability and therapeutic effects of ulinastatin.

BACKGROUND: With the widespread use of ventilators in treating critically ill patients, the morbidity of ventilator-induced lung injury (VILI) is increasing accordingly. VILI is characterized by a considerable increase in microvascular leakiness and activation of inflammatory processes. In this study we investigated the effects of inflammatory mediators in VILI rat serum on endothelial cytoskeleton and monolayer cellular permeability, as well as the therapeutic effect of ulinastatin, to explore the pathogenesis and the relationship between biotrauma and lung oedema induced by VILI. METHODS: Thirty healthy male Sprague-Dawley rats were randomly divided into three groups: group A (normal tidal volume ventilation), group B (high tidal volume ventilation) and group C (high tidal volume ventilation plus ulinastatin). The serum of each rat after ventilation was added to endothelial cell line ECV-304 medium for two hours to observe the effects of serum and/or ulinastatin on endothelial fibrous actin and permeability. RESULTS: Compared to rats ventilated with normal tidal volume, serum of rats ventilated with high tidal volume caused a striking reorganization of actin cytoskeleton with a weakening of fluorescent intensity at the peripheral filament bands and formation of the long and thick stress fibres in the centre resulting in endothelial contraction and higher permeability. Prior treatment with ulinastatin lessened the above changes significantly. The changes of permeability coefficient of endothelial permeability after group A, B or C rats serum stimulation were (6.95 +/- 1.66)%, (27.50 +/- 7.77)% and (17.71 +/- 4.66)% respectively with statistically significant differences (P < 0.05) among the three groups. CONCLUSIONS: The proinflammatory mediators in the serum of the rats given high tidal volume ventilation increases endothelial permeability by reorganizing actin cytoskeleton, and pretreatment with ulinastatin lessens the permeability by inhibiting of proinflammatory mediators.

[Study on the protective effects of ZnSO4 on rat flaps with ischemia reperfusion injury].

OBJECTIVE: To observe the protective role of the ectogenesis zinc in the rat flap with ischemia-reperfusion injury and study the mechanism. METHODS: An abdominal island flap was created in Wistar rats. 48 rats were randomly divided into three groups, 16 per group: the non-ischemia-reperfusion group, the ischemia-reperfusion group and the ischemia-reperfusion (IR) group treated with zinc. The content of malondialdehyde (MDA) and the activity of myeloperoxidase (MPO) were measured. The expression of metallothionein (MT) was observed, and the image analysis was performed. The ultrastructure changes of the skin flap with ischemia-reperfusion injury and the flap viability were observed. RESULTS: Compared with the IR group, at 1 h and 24 h of reperfusion, the level of MDA in the adding-zinc-IR group decreased 11.3% and 33.2% (P < 0.05); the activity of MPO decreased 14.2% and 22.7% (P < 0.05); the content of MT increased 41.5% and 44% ( P < 0.01) respectively. In the ischemia-reperfusion injury flaps, MT was located in the cytoplasm of many kinds of cells. The ultrastructure changes of the skin flap of the adding-zinc-IR group were slighter than those of the IR group. The flap viability in the adding-zinc-IR group increased 27.2% (P < 0.05). CONCLUSIONS: MT could be induced by ectogenesis zinc in the flap of rats. The flap with ischemia-reperfusion injury was protected by MT through protecting the cells in the flap.

Preparation and bioactivity of human hair keratin-collagen sponge, a new type of dermal analogue.

OBJECTIVE: To develop a three-dimensional porous film of human hair keratin (HHK)-collagen sponge complex for use as a dermal substitute. METHODS: The three components F, B, and Z derived from healthy human hair were weaved into a meshwork and integrated with purified soluble type I collagen extracted from bovine tendons to prepare a highly porous film with vacuum freeze-drying followed by secondary cross-linking with glutaraldehyde. The film was grafted beneath the dorsal skin in 21 SD rats (experimental group), with simple collagen sponge serving as the negative control. The rats receiving surgical operation but without graft served as the blank control. The graft and its surrounding tissue were harvested on days 3, 7 and at weeks 2, 4, 6, 8, 12 after implantation for evaluation of tissue compatibility, vascularization and degradation. RESULTS: The prepared collagen sponge film was semitransparent and porous. Three to 7 days after grafting, inflammatory reaction was relieved gradually, and several fibroblasts and blood vessels were found adherent to the grafts in the experimental groups. At week 4, the wounds healed in the experimental groups, and the fibroblasts were actively secreting collagen and the film degraded obviously with the appearance of elastic fibers. At weeks 6 and 8, new collagen fibers thickened and assumed regular arrangement, and the collagen sponge films disappeared completely. In the control groups, the changes were less obvious and total HHK degradation occurred till week 12. CONCLUSION: The degradable and absorbable HHK-collagen sponge film has relatively satisfactory tissue compatibility and can accelerate wound healing by stimulating cell proliferation and vascularization, showing the potential as an optimal dermal substitute.