CSK may be a potential prognostic biomarker reflecting the immune status of gastric cancer

OBJECTIVE

C-terminal Src kinase (CSK), a sarcoma (Src) homologous family kinase, is one of the most important negative regulators. It acts as a tumor suppressor by inhibiting the activity of Src family tyrosine kinases. Paradoxically, CSK is highly expressed in a variety of common tumors. Therefore, we report the expression profile of CSK in pan-cancer patients, focusing on the prognostic value, immune infiltration pattern, and biological function of CSK in gastric cancer.

MATERIALS AND METHODS

We used the TCGA database to analyze CSK expression, clinical relevance, prognostic significance, assessment of the tumor immune microenvironment, and GO and Kegg enrichment analysis based on co-expressed genes using a bioinformatics approach.

RESULTS

CSK is a protective factor in gastric cancer, and its expression correlates with the level of immune cell infiltration and immune checkpoint molecules.

CONCLUSIONS

Our findings suggest that CSK is an independent prognostic factor in gastric cancer and may predict molecular targeting and immunotherapy and provide ideas for its therapeutic strategy.

Activating NO-sGC crosstalk in the mouse vascular niche promotes vascular integrity and mitigates acute lung injury

Disruption of endothelial cell (ECs) and pericytes interactions results in vascular leakage in acute lung injury (ALI). However, molecular signals mediating EC-pericyte crosstalk have not been systemically investigated, and whether targeting such crosstalk could be adopted to combat ALI remains elusive. Using comparative genome-wide EC-pericyte crosstalk analysis of healthy and LPS-challenged lungs, we discovered that crosstalk between endothelial nitric oxide and pericyte soluble guanylate cyclase (NO-sGC) is impaired in ALI. Indeed, stimulating the NO-sGC pathway promotes vascular integrity and reduces lung edema and inflammation-induced lung injury, while pericyte-specific sGC knockout abolishes this protective effect. Mechanistically, sGC activation suppresses cytoskeleton rearrangement in pericytes through inhibiting VASP-dependent F-actin formation and MRTFA/SRF-dependent de novo synthesis of genes associated with cytoskeleton rearrangement, thereby leading to the stabilization of EC-pericyte interactions. Collectively, our data demonstrate that impaired NO-sGC crosstalk in the vascular niche results in elevated vascular permeability, and pharmacological activation of this crosstalk represents a promising translational therapy for ALI.

Factors Influencing Length of Hospital Stay and Predictors Affecting Probability of Requiring Surgery in Severely Pediatric Burn Patients

Although many researches have explored the prognostic factors associated with length of hospital stay (LOS) of adult burn patients, fewer reports concerning pediatric burn patients have been conducted. The present study employed pediatric burn data to identify factors related to LOS and developed a novel model to assess the possibility of requiring surgery. A total of 750 children admitted for burns met the criteria for enrollment. We have analyzed the medical records using multivariable linear regression and logistic regression. The pediatric patients were stratified into medical (nonsurgical) and surgical groups, respectively. The median LOS was 27.11 ± 17.91 days (range: 6-107 days). Following multiple linear regression, surgery (P < .001; 95% confidence interval [CI]: 6.485, 11.918), percent total BSA (%TBSA) (P < .001; 95% CI: 0.271, 0.459), days to surgery (P < .001; 95% CI: 0.349, 0.648), etiology (P < .001; 95% CI: -15.801, -9.422), infection (P < .001; 95% CI: 4.163, 8.329), and erythrocyte loss (P < .001; 95% CI: 1.923, 4.017) were significantly associated with LOS. After logistic regression, the percent full thickness (%FT) (P < .001; odds ratio [OR]: 2.358; 95% CI: 1.680, 3.311), infection (P < .001; OR: 2.935; 95% CI: 2.014, 4.278), and erythrocyte loss (P < .001; OR: 0.572; 95% CI: 0.470, 0.696) within 5 days postadmission were independently related to the probability of requiring surgery. In conclusion, in pediatric patients admitted with burn size of TBSA ≥20%, factors independently influencing LOS were surgery, %TBSA, days to surgery, etiology, erythrocyte loss, and infection. Furthermore, the pivotal predictors of probability requiring surgery were %FT, infection, and erythrocyte loss.

Genistein-3'-sodium sulphonate protects against lipopolysaccharide-induced lung vascular endothelial cell apoptosis and acute lung injury via BCL-2 signalling

Under septic conditions, Lipopolysaccharide (LPS)‐induced apoptosis of lung vascular endothelial cells (ECs) triggers and aggravates acute lung injury (ALI), which so far has no effective therapeutic options. Genistein‐3′‐sodium sulphonate (GSS) is a derivative of native soy isoflavone, which has neuro‐protective effects through its anti‐apoptotic property. However, whether GSS protects against sepsis‐induced lung vascular endothelial cell apoptosis and ALI has not been determined. In this study, we found that LPS‐induced Myd88/NF‐κB/BCL‐2 signalling pathway activation and subsequent EC apoptosis were effectively down‐regulated by GSS in vitro. Furthermore, GSS not only reversed the sepsis‐induced BCL‐2 changes in expression in mouse lungs but also blocked sepsis‐associated lung vascular barrier disruption and ALI in vivo. Taken together, our results demonstrated that GSS might be a promising candidate for sepsis‐induced ALI via its regulating effects on Myd88/NF‐κB/BCL‐2 signalling in lung ECs.

Exosome-delivered syndecan-1 rescues acute lung injury via a FAK/p190RhoGAP/RhoA/ROCK/NF-κB signaling axis and glycocalyx enhancement

Acute lung injury (ALI) is characterized by protein-rich pulmonary edema, critical hypoxemia, and influx of pro-inflammatory cytokines and cells. There are currently no effective pharmacon therapies in clinical practice. Syndecan-1 in endothelial cells has potential to protect barrier function of endothelium and suppress inflammation response. Thus, the present study was to identify whether exosomes with encapsulation of syndecan-1 could achieve ideal therapeutic effects in ALI. Exosomes were isolated from the conditional medium of lentivirus-transfected mouse pulmonary microvascular endothelial cells (MPMVECs) and characterized by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and western blotting. ALI mouse models were induced via intratracheal administration of lipopolysaccharide (LPS) and treated with exosomes. Lung edema, inflammation, and glycocalyx thickness were examined. The possible mechanism was verified by immunoblotting in MPMVECs. The purified exosomes included SDC1-high-Exos and SDC1-low-Exos which loaded with up-regulated syndecan-1 and down-regulated syndecan-1 respectively. Compared with SDC1-low-Exos, administration of SDC1-high-Exos could ameliorate lung edema and inflammation, attenuate number of cells and protein levels in bronchoalveolar lavage fluid (BALF), and preserve glycocalyx. Furthermore, SDC1-high-Exos also mitigated the expression of pro-inflammatory cytokines such as IL-1β, TNF-α, and IL-6 following LPS challenge. In MPMVECs, SDC1-high-Exos decreased stress fiber formation and ameliorated monolayer hyper-permeability after LPS stimulation. Western blotting analysis demonstrated that FAK/p190RhoGAP/RhoA/ROCK/NF-κB signaling pathway may be involved in LPS-induced ALI. In conclusion, SDC1-high-Exos play a pivotal role in ameliorating LPS-stimulated ALI models and may be served as a potential therapeutic agent for clinical application in the future.

Fournier’s Gangrene With Septic Shock and Multiple Organ Dysfunction Syndrome

Fournier’s gangrene is a rare, rapidly progressing, and life-threatening infection associated with necrotizing fasciitis in the perineal, genital, and/or lower abdominal regions. Septic shock and multiple organ dysfunction syndrome due to the condition are even rarer events. We describe the case of a 58-year-old man who visited the emergency department with severely painful swelling in the scrotal, perianal, and lower abdominal regions. Physical examination combined with computed tomography and clinical findings led to the diagnosis of Fournier’s gangrene with septic shock and multiple organ dysfunction syndrome. Broad-spectrum antibiotics, fluid resuscitation, sedative administration, and several surgeries that included perineum reconstruction were performed successfully, and the patient fully recovered. Comprehensive, timely treatments are critical for treating Fournier’s gangrene.

HBP induces the expression of monocyte chemoattractant protein-1 via the FAK/PI3K/AKT and p38 MAPK/NF-κB pathways in vascular endothelial cells

Inflammation is characterized by early influx of polymorphonuclear neutrophils (PMNs), followed by a second wave of monocyte recruitment. PMNs mediate monocyte recruitment via their release of heparin binding protein (HBP), which activates CCR2 (CC-chemokine receptor 2) on monocytes. However, the pathways for such signal transmission remain unknown. Accumulating evidences have highlighted the importance of leukocyte-endothelial cell interactions in the initiation of inflammation. In this study, an interesting finding is that HBP enhances the secretion of monocyte chemotactic protein 1(MCP-1), ligand of CCR2, from a third party, the endothelial cells (ECs). HBP-induced increase in MCP-1 production was demonstrated at the protein, mRNA and secretion levels. Exposure of ECs to HBP elicited rapid phosphorylation of FAK/PI3K/AKT and p38 MAPK/NF-κB signaling. MCP-1 levels were attenuated during the response to HBP stimulation by pretreatment with a FAK inhibitor (or siRNA), a PI3K inhibitor, an AKT inhibitor, a p38 inhibitor (or siRNA) and two NF-κB inhibitors. Additionally, pretreatment with inhibitors to FAK, PI3K and AKT led to a decrease in HBP-induced phosphorylation of p38/NF-κB axis. These results showed that HBP induced MCP-1 expression via a sequential activation of the FAK/PI3K/AKT pathway and p38 MAPK/NF-κB axis. Interestingly, the patterns of HBP regulation of the expression of the adhesion molecular VCAM-1 were similar to those seen in MCP-1 after pretreatment with inhibitors (or not). These findings may help to determine key pharmacological points of intervention, thus slowing the progress of inflammatory-mediated responses in certain diseases where inflammation is detrimental to the host.

Relation between dynamic changes of platelet counts and 30-day mortality in severely burned patients

Thrombocytopenia is a common event in severely burned patients and associated with adverse outcome. The underlying relationship between the dynamic changes of platelet counts and mortality has not been well defined. We performed a 6-year retrospective chart of adult patients with a burn index of 50 or greater admitted to two burn centers and collected data on patient demographics, laboratory results, and patient outcomes. The mean daily increase in the platelet count (∆PC/∆t) from day 3 to day 10 was calculated, and 30-day mortality was determined. For the study, 141 survivors and 65 nonsurvivors were enrolled. The sequential changes in PCs presented a biphasic pattern after admission, with a slump to the nadir during the first 3 days and a subsequent recovery. With respect to 30-day mortality, compared with the AUC of APACHE-Ⅱ score (0.841), no significant difference was noted between ΔPC/ΔT and APACHE-Ⅱ score (p = 0.0648). The ΔPC/ΔT associated with the best discrimination between survivors and nonsurvivors was 20.57 × 10⁹/L due to the cutoff with optimal Youden index (0.453). By multiple logistic regression, ΔPC/ΔT ＜ 20.57 × 10⁹/L was one of the prognostic predictors of 30-day mortality. Furthermore, Kaplan-Meier estimates of hospital survival according to the size of ΔPC/ΔT revealed that a blunted increase with ΔPC/ΔT ＜ 20.57 × 10⁹/L was associated with increased 30-day mortality. A blunted daily increase in PCs, especially ΔPC/ΔT < 20.57 × 10⁹/L, is associated with increased 30-day mortality, which provides prognostic information for mortality risk assessment in severely burned patients.

GSK-3Beta-Dependent Activation of GEF-H1/ROCK Signaling Promotes LPS-Induced Lung Vascular Endothelial Barrier Dysfunction and Acute Lung Injury

The bacterial endotoxin or lipopolysaccharide (LPS) leads to the extensive vascular endothelial cells (EC) injury under septic conditions. Guanine nucleotide exchange factor-H1 (GEF-H1)/ROCK signaling not only involved in LPS-induced overexpression of pro-inflammatory mediator in ECs but also implicated in LPS-induced endothelial hyper-permeability. However, the mechanisms behind LPS-induced GEF-H1/ROCK signaling activation in the progress of EC injury remain incompletely understood. GEF-H1 localized on microtubules (MT) and is suppressed in its MT-bound state. MT disassembly promotes GEF-H1 release from MT and stimulates downstream ROCK-specific GEF activity. Since glycogen synthase kinase (GSK-3beta) participates in regulating MT dynamics under pathologic conditions, we examined the pivotal roles for GSK-3beta in modulating LPS-induced activation of GEF-H1/ROCK, increase of vascular endothelial permeability and severity of acute lung injury (ALI). In this study, we found that LPS induced human pulmonary endothelial cell (HPMEC) monolayers disruption accompanied by increase in GSK-3beta activity, activation of GEF-H1/ROCK signaling and decrease in beta-catenin and ZO-1 expression. Inhibition of GSK-3beta reduced HPMEC monolayers hyper-permeability and GEF-H1/ROCK activity in response to LPS. GSK-3beta/GEF-H1/ROCK signaling is implicated in regulating the expression of beta-catenin and ZO-1. In vivo, GSK-3beta inhibition attenuated LPS-induced activation of GEF-H1/ROCK pathway, lung edema and subsequent ALI. These findings present a new mechanism of GSK-3beta-dependent exacerbation of lung micro-vascular hyper-permeability and escalation of ALI via activation of GEF-H1/ROCK signaling and disruption of intracellular junctional proteins under septic condition.

Acinetobacter baumannii quorum-sensing signalling molecule induces the expression of drug-resistance genes

Quorum-sensing signalling molecules such as N-acyl homoserine lactones (AHLs) enable certain Gram-negative bacteria to respond to environmental changes through behaviours, such as biofilm formation and flagellar movement. The present study aimed to identify Acinetobacter baumannii AHLs and assess their influence on antibiotic resistance. A clinical isolate of A. baumannii strain S (AbS) was collected from the wound of a burn patient and high-performance liquid chromatography and tandem quadrupole or quadrupole time-of-flight high-resolution mass spectrometry was used to identify AbS AHLs. Antibiotic sensitivity was assessed in an AHL-deficient AbS mutant (AbS-M), and the expression of drug-resistance genes in the presence of meropenem in AbS, AbS-M and AbS-M treated with the AHL N-3-hydroxy-dodecanoyl-homoserine lactone (N-3-OH-C₁₂-HSL). AbS-M was more sensitive to meropenem and piperacillin than wild-type AbS, but resistance was restored by supplementation with N-3-OH-C₁₂-HSL. In addition, meropenem-treated AbS-M expressed lower levels of the drug-resistance genes oxacillinase 51, AmpC, AdeA and AdeB; treatment with N-3-OH-C₁₂-HSL also restored the expression of these genes. Overall, the results of the present study indicate that N-3-OH-C₁₂-HSL may be involved in regulating the expression of drug-resistance genes in A. baumannii. Therefore, this quorum-sensing signalling molecule may be an important target for treating multidrug-resistant A. baumannii infections.

Pseudomonas aeruginosa prevalence, antibiotic resistance and antimicrobial use in Chinese burn wards from 2007 to 2014

Objective To assess the application of antibacterial agents, alongside pathogen prevalence and Pseudomonas aeruginosa drug resistance, with the aim of understanding the impact of inappropriate antibacterial use. Methods This retrospective study assessed bacteria from wounds, catheters, blood, faeces, urine and sputum of hospitalized patients in burn wards between 2007 and 2014. The intensity of use of antibacterial agents and resistance of P. aeruginosa to common anti-Gram-negative antibiotics were measured. Results Annual detection rates of Staphylococcus aureus were significantly decreased, whereas annual detection rates of P. aeruginosa and Klebsiella pneumoniae were significantly increased. Multidrug-resistant strains of P. aeruginosa were increased. The intensity of use of some anti-Gramnegative antibiotics positively correlated with resistance rates of P. aeruginosa to similar antimicrobials. Conclusion In burn wards, more attention should be paid to P. aeruginosa and K. pneumoniae. The use of ciprofloxacin, ceftazidime and cefoperazone/sulbactam should be limited to counter the related increase in resistance levels.

Lipopolysaccharide Induces Human Pulmonary Micro-Vascular Endothelial Apoptosis via the YAP Signaling Pathway

Gram-negative bacterial lipopolysaccharide (LPS) induces a pathologic increase in lung vascular leakage under septic conditions. LPS-induced human pulmonary micro-vascular endothelial cell (HPMEC) apoptosis launches and aggravates micro-vascular hyper-permeability and acute lung injury (ALI). Previous studies show that the activation of intrinsic apoptotic pathway is vital for LPS-induced EC apoptosis. Yes-associated protein (YAP) has been reported to positively regulate intrinsic apoptotic pathway in tumor cells apoptosis. However, the potential role of YAP protein in LPS-induced HPMEC apoptosis has not been determined. In this study, we found that LPS-induced activation and nuclear accumulation of YAP accelerated HPMECs apoptosis. LPS-induced YAP translocation from cytoplasm to nucleus by the increased phosphorylation on Y357 resulted in the interaction between YAP and transcription factor P73. Furthermore, inhibition of YAP by small interfering RNA (siRNA) not only suppressed the LPS-induced HPMEC apoptosis but also regulated P73-mediated up-regulation of BAX and down-regulation of BCL-2. Taken together, our results demonstrated that activation of the YAP/P73/(BAX and BCL-2)/caspase-3 signaling pathway played a critical role in LPS-induced HPMEC apoptosis. Inhibition of the YAP might be a potential therapeutic strategy for lung injury under sepsis.

[Emphasize the diagnosis and treatment of infective endocarditis in patients with severe burn]

The incidence and mortality of infective endocarditis (IE) in patients with severe burn remain high, which are attributed to invasive procedures, bacteremia, and wound infection after burns. Clinical clues for IE in burns are usually masked by burn-related manifestations, so the diagnosis of IE may be delayed or missed. For burned patients with persistent bacteremia of unknown source, especially Staphylococcus aureus-induced bacteremia, the diagnosis of IE should be considered according to the Duke criteria, and early echocardiography performance is particularly important. Antibiotic therapy is the mainstay initial management, and early surgical intervention is strongly recommended once IE is clearly diagnosed in patients with burns. In order to lower the incidence and mortality of IE in burns, it is very important to take prophylactic procedures along with the whole course of burn management.

Yes-associated protein (YAP) signaling regulates lipopolysaccharide-induced tissue factor expression in human endothelial cells

BACKGROUND

Sepsis-induced acute lung injury (ALI) is characterized by fibrin deposition, which indicates the local activation of coagulation. Tissue factor (TF), expressed in the pulmonary microvasculature, acts as a critical initiator of blood coagulation and ALI in sepsis. The molecular mechanism of lipopolysaccharide (LPS)-induced TF expression in endothelial cells (ECs), however, has not been determined. In this study, we implicate the Rho-associated protein kinase (ROCK)/Yes associated protein (YAP)/early growth response (Egr-1) signaling pathway in LPS-induced TF expression in vitro and in sepsis-induced ALI in vivo.

METHODS

Human umbilical vein ECs incubated with LPS were pretreated with or without the ROCK inhibitor Y-27632, a YAP small, interfering RNA (siRNA) and an Egr-1 siRNA. ROCK, YAP and Egr-1 signaling-induced protein expression was investigated by Western blot. The LPS-induced activation of YAP was analyzed by an immunofluorescent assay. Furthermore, we intratracheally injected YAP siRNA to assess septic ALI in mice by hematoxylin and eosin staining.

RESULTS

LPS rapidly induced ROCK activation and increased TF expression in ECs. LPS caused YAP shuttling into the nuclei of ECs and combined with Egr-1 via the activation of ROCK. Furthermore, the LPS-mediated TF expression increase was prevented by ROCK inactivation, YAP knockdown and Egr-1 depletion, suggesting that LPS-induced TF expression is closely associated with the ROCK/YAP/Egr-1 signaling pathway in ECs. Finally, an intratracheal injection of YAP siRNA relieved lung injury in septic mice.

CONCLUSION

This study not only suggests that ROCK/YAP/Egr-1 signaling regulates TF expression after stimulation with LPS in ECs, but it also indicates that LPS-induced activation of YAP signaling plays an important role in septic ALI in mice. Our findings provide a new insight into the pathogenic mechanism of TF expression, which is closely linked to septic ALI, and YAP signaling is considered to be a novel target for therapeutic intervention under septic conditions.

Guidelines for burn rehabilitation in China

Quality of life and functional recovery after burn injury is the final goal of burn care, especially as most of burn patients survive the injury due to advanced medical science. However, dysfunction, disfigurement, contractures, psychological problems and other discomforts due to burns and the consequent scars are common, and physical therapy and occupational therapy provide alternative treatments for these problems of burn patients. This guideline, organized by the Chinese Burn Association and Chinese Association of Burn Surgeons aims to emphasize the importance of team work in burn care and provide a brief introduction of the outlines of physical and occupational therapies during burn treatment, which is suitable for the current medical circumstances of China. It can be used as the start of the tools for burn rehabilitation.

Coordinate regulation of residual bone marrow function by paracrine trafficking of AML exosomes

We recently demonstrated that acute myeloid leukemia (AML) cell lines and patient-derived blasts release exosomes that carry RNA and protein; following an in vitro transfer, AML exosomes produce proangiogenic changes in bystander cells. We reasoned that paracrine exosome trafficking may have a broader role in shaping the leukemic niche. In a series of in vitro studies and murine xenografts, we demonstrate that AML exosomes downregulate critical retention factors (Scf, Cxcl12) in stromal cells, leading to hematopoietic stem and progenitor cell (HSPC) mobilization from the bone marrow. Exosome trafficking also regulates HSPC directly, and we demonstrate declining clonogenicity, loss of CXCR4 and c-Kit expression, and the consistent repression of several hematopoietic transcription factors, including c-Myb, Cebp-β and Hoxa-9. Additional experiments using a model of extramedullary AML or direct intrafemoral injection of purified exosomes reveal that the erosion of HSPC function can occur independent of direct cell-cell contact with leukemia cells. Finally, using a novel multiplex proteomics technique, we identified candidate pathways involved in the direct exosome-mediated modulation of HSPC function. In aggregate, this work suggests that AML exosomes participate in the suppression of residual hematopoietic function that precedes widespread leukemic invasion of the bone marrow directly and indirectly via stromal components.

[Controlling infection and spread of carbapenems-resistant Klebsiella pneumoniae among burn patients]

The emergence and spread of carbapenems-resistant Klebsiella pneumoniae (CRKP) in burn ward is an important threat to burn management. CRKP isolates are resistant to almost all available antibiotics and are susceptible only to polymyxins and tigecycline. The mechanism of the drug resistance of CRKP is associated with the plasmid-encoded carbapenemase Klebsiella pneumoniae carbapenemase (KPC), a carbapenem-hydrolyzing β-lactamase. Antibiotics which can currently be used to treat CRKP infection include polymyxins, tigecycline, and some aminoglycosides. The efficacy of using antibiotics in combination is better than that of single-agent therapy for the treatment of CRKP infection in bloodstream. In order to control CRKP infection in burn patients, strategies for preventing CRKP dissemination in burn ward are strongly advocated.

Identification of quantitative trait loci conferring blast resistance in Bodao, a japonica rice landrace

Bodao, a japonica landrace from the Taihu Lake region of China, is highly resistant to most Chinese isolates of Magnaporthe oryzea, a form of rice blast. To effectively dissect the influence of genetics on this blast resistance, a population of 155 recombinant inbred lines (F2:8) derived from a cross of Bodao x Suyunuo was inoculated with 12 blast isolates. Using a quantitative trait locus (QTL) mapping approach, 13 QTL on chromosomes 1, 2, 9, 11, and 12 were detected from Bodao. Five QTL, including qtl11-1-1, qtl11-3-7, qtl11-4-9, qtl12-1-1, and qtl12-2-3, have not been previously reported. The qtl11-3-7 and qtl11-4-9 may be the two main effective QTL and resistant to 7 and 9 isolates, respectively. The results of the present study will be valuable for the fine mapping and cloning of these two new resistance genes.

The p38/mitogen-activated protein kinase pathway is implicated in lipopolysaccharide-induced microtubule depolymerization via up-regulation of microtubule-associated protein 4 phosphorylation in human vascular endothelium

BACKGROUND

Microtubules (MTs) play an important role in lipopolysaccharide (LPS)-induced overexpression of inflammatory cytokines and vascular barrier dysfunction; however, the mechanisms behind MT dynamics changes in the vascular endothelium under septic conditions are still not well understood.

METHODS

Human umbilical vein endothelial cells (HUVECs) stimulated with LPS were pretreated with or without the specific p38/mitogen-activated protein kinase (MAPK) inhibitor, SB203580. p38/MAPK cascade-induced signaling events and proteins expression were investigated by Western blotting assay. The interaction between p38/MAPK and microtubule-associated protein 4 (MAP4) was examined by immunoprecipitation. Furthermore, the effects of agonists on LPS-induced MT disruption and alteration of acetylated alpha-tubulin (Acet-tubulin) were analyzed by double-immunofluorescent assay and Western blotting analysis.

RESULTS

In the present study, our results indicated that LPS induced MT depolymerization, but the effects of LPS could be reversed in endothelial cells pretreated with taxol. Furthermore, phosphor-p38 and MAP4 interacted to form a complex after exposure to LPS. LPS-induced MAP4 phosphorylation was greatly suppressed by SB203580, suggesting that activation of p38/MAPK signaling affected MAP4 phosphorylation linked to MT acetylation after stimulation with LPS.

CONCLUSION

The present study demonstrated that the p38/MAPK signaling pathway might disrupt MT dynamics via phosphorylation of MAP4 in vascular endothelial cells challenged by LPS. Our findings provide novel insights into the pathogenic mechanism of MT disassembly and consider new targets for therapeutic intervention under sepsis or septic shock conditions.

[Clinical significance of continuous thrombocytopenia in predicting sepsis after severe burn]

OBJECTIVE

To explore the relationship between continuous thrombocytopenia and sepsis in patients with severe burns.

METHODS

Clinical data of 148 severely burned patients admitted to our,two burn centers from January 2007 to December 2011 and conforming to the study criteria were retrospectively analyzed. All patients were divided into sepsis group (n =44) and non-sepsis group (n = 104) according to the presence or absence of sepsis within post burn day (PBD) 30. The data of age, gender, total burn area, full-thickness burn area, fluid infusion volume within post burn hour (PBH) 24, plasma concentration of calcium ion on PBD 1, plasma concentration of albumin on PBD 1, platelet count on PBD 1, acute physiology and chronic health evaluation (APACHE) II score on admission, the presence or absence of hypovolemic shock or inhalation injury on admission, the presence or absence of disseminated intravascular coagulation (DIC) within PBH 48, operation or no operation within PBD 3, thrombocytopenia duration within PBD 10, and mortality were statistically compared between two groups to screen the independent risk factors of sepsis. Data were processed with t test, chi-square test, single factor Logistic regression analysis, and multi-factor Logistic regression analysis.

RESULTS

Between two groups, there were statistically significant differences in total burn area, full-thickness burn area, plasma concentration of calcium ion on PBD 1, plasma concentration of albumin on PBD 1, APACHE II score on admission, presence or absence of hypovolem- ic shock on admission, presence or absence of inhalation injury on admission, presence or absence of DIC within PBH 48, and mortality (with t values from 2.433 to 4.082, χ2 values from 8. 818 to 31.528, P < 0.05 or P < 0.01). Furthermore, the duration of thrombocytopenia within PBD 10 in sepsis group was (5.2 ± 2.4) d, which was significantly longer than that in non-sepsis group [(2.9 ± 1.9) d, t =6. 189, P <0.01]. There were no statistically significant differences in the other indexes between two groups (with t values from 0.971 to 1. 250, χ2 values respectively 0. 054 and 1.529, P values above 0.05). Single factor and multi-factor Logistic regression analysis indicated that APACHE II score on admission and duration of thrombocytopenia within PBD 10 were closely related to occurrence of sepsis (with odds ratio respectively 1. 140 and 1.569, P values below 0.01).

CONCLUSIONS

Duration of thrombocytopenia within PBD 10 is one of the risk factors for sepsis in severely burned patients, which can reflect pathophysiological changes in the body, thus providing predictive value for the occurrence of sepsis.

Guideline for diagnosis, prophylaxis and treatment of invasive fungal infection post burn injury in China 2013

Invasive fungal infection is one of the major complication of severe burns which can induce local or systemic inflammatory response and cause serious substantial damage to the patient. The incidence of fungal infection for burn victims is increasing dramatically during recent years. This guideline, organized by Chinese Society of Burn Surgeons, aims to standardize the diagnosis, prevention and treatment of burn invasive fungal infection. It can be used as one of the tools for treatment of major burn patients.

Guanine nucleotide exchange factor-H1 signaling is involved in lipopolysaccharide-induced endothelial barrier dysfunction

BACKGROUND

Gram-negative bacterial lipopolysaccharide (LPS) leads to the pathologic increase of vascular leakage under septic conditions. However, the mechanisms behind LPS-induced vascular hyperpermeability remain incompletely understood. In this study, we tested hypothesis that guanine nucleotide exchange factor-H1 (GEF-H1) signaling might be a key pathway involved in endothelial cells (ECs) barrier dysfunction.

METHODS

The roles of GEF-H1 signaling pathway in LPS-induced ECs barrier dysfunction were accessed by Evans blue dye-labeled albumin (EB-albumin) leak across the human umbilical vein EC (HUVEC) monolayers and Western blot assays. Furthermore, the effect of GEF-H1 signaling on LPS-induced alteration of cytoskeletal proteins and disruption of cell-cell junctions were analyzed by immunofluorescent analysis and Western blot assays, respectively.

RESULTS

We found that LPS could rapidly activated GEF-H1/RhoA/Rho-associated protein kinase (ROCK) signaling pathway in ECs. The LPS-mediated increase in EB-albumin flux across human HUVECs monolayers could be prevented by GEF-H1 depletion or ROCK inactivation. ECs permeability is controlled by actin filaments and cell-cell contact protein complexes. Actin stress fiber formation and/or cell-cell contact proteins loss cause vascular barrier disruption. Here, GEF-H1 knockdown or ROCK inactivation both not only significantly inhibited LPS-induced actin stress fiber formation, phosphorylation of myosin light chain, and myosin-associated phosphatase type 1, but also suppressed LPS-induced loss of occludin, claudin-1, and vascular endothelial (VE)-cadherin in ECs, which suggested that LPS-induced stress fiber formation and cell-cell junctions disruption were closely associated with GEF-H1/RhoA/ROCK signaling activation.

CONCLUSION

Our findings indicate that GEF-H1/RhoA/ROCK pathway in ECs plays an important role in LPS-mediated alteration of cell morphology and disruption of cell-cell junctions, consequently regulate LPS-induced vascular permeability dysfunction.

GEF-H1/RhoA signalling pathway mediates lipopolysaccharide-induced intercellular adhesion molecular-1 expression in endothelial cells via activation of p38 and NF-κB

The purpose of study is to investigate the effects of GEF-H1/RhoA pathway in regulating intercellular adhesion molecule-1 (ICAM-1) expression in lipopolysaccharide (LPS)-activated endothelial cells. Exposure of human umbilical vein endothelial cells (HUVECs) to LPS induced GEF-H1 and ICAM-1 expression in dose- and time-dependent up-regulating manners. Pretreatment with Clostridium difficile toxin B-10463 (TcdB-10463), an inhibitor of Rho activity, reduced LPS-related phosphorylation of p65 at Ser 536 in a dose-dependent manner. Inhibition of TLR4 expression significantly blocked LPS-induced RhoA activity, NF-κB transactivation, GEF-H1 and ICAM-1 expression. Coimmunoprecipitation assay indicated that LPS-activated TLR4 and GEF-H1 formed a signalling complex, suggesting that LPS, acting through TLR4, stimulates GEF-H1 expression and RhoA activity, and thereby induces NF-κB transactivation and ICAM-1 gene expression. However, GEF-H1/RhoA regulates LPS-induced NF-κB transactivation and ICAM-1 expression in a MyD88-independent pathway because inhibition of MyD88 expression could not block LPS-induced RhoA activity. Furthermore, pretreatment with Y-27632, an inhibitor of ROCK, significantly reduced LPS-induced p38, ERK1/2 and p65 phosphorylation, indicating that ROCK acts as an upstream effector of p38 and ERK1/2 to promote LPS-induced NF-κB transactivation and ICAM-1 expression. What is more, the p38 inhibitor (SB203580) but not ERK1/2 inhibitor (PD98059) blocked LPS-induce NF-κB transactivation and ICAM-1 expression, which demonstrates that RhoA mediates LPS-induced NF-κB transactivation and ICAM-1 expression dominantly through p38 but not ERK1/2 activation. In summary, our data suggest that LPS-induced ICAM-1 synthesis in HUVECs is regulated by GEF-H1/RhoA-dependent signaling pathway via activation of p38 and NF-κB.

Single-chain recombinant HLA-DQ2.5/peptide molecules block α2-gliadin-specific pathogenic CD4+ T-cell proliferation and attenuate production of inflammatory cytokines: a potential therapy for celiac disease

Celiac disease (CD) is a disorder of the small intestine caused by intolerance to wheat gluten and related proteins in barley and rye. CD4(+) T cells have a central role in CD, recognizing and binding complexes of HLA-DQ2.5 bearing gluten peptides that have survived digestion and that are deamidated by tissue transglutaminase (TG2), propagating a cascade of inflammatory processes that damage and eventually destroy the villous tissue structures of the small intestine. In this study, we present data showing that recombinant DQ2.5-derived molecules bearing covalently tethered α2-gliadin-61-71 peptide have a remarkable ability to block antigen-specific T-cell proliferation and inhibited proinflammatory cytokine secretion in human DQ2.5-restricted α2-gliadin-specific T-cell clones obtained from patients with CD. The results from our in vitro studies suggest that HLA-DQ2.5-derived molecules could significantly inhibit and perhaps reverse the intestinal pathology caused by T-cell-mediated inflammation and the associated production of proinflammatory cytokines.

Development of chitosan-collagen hydrogel incorporated with lysostaphin (CCHL) burn dressing with anti-methicillin-resistant Staphylococcus aureus and promotion wound healing properties

Methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly prevalent as nosocomial pathogens, especially in burn patients, which is the leading cause of their death. A drug delivery system of chitosan-collagen hydrogel incorporated with lysostaphin (CCHL) based on the lysostaphin gauze was developed for MRSA infected burn wounds. CCHL scaffold consisted of numerous interconnected sphericles and tubular bodies with an average diameter of 100-200 µm, 20-60-fold swelling, high water retention capacity, and cell proliferation properties. The minimal inhibitory concentration of CCHL was 0.053 U/mL. By the second week after its application on MRSA infected third-degree burn wounds, no bacteria could be detected and the burn wounds had started healing. Therefore, CCHL should be studied further as a promising candidate of burn treatment dressing against MRSA infections for clinics.

Calcium-sensing receptor and recovery from hypocalcaemia in thyroparathyroidectomized rats

BACKGROUND

Plasma ionized calcium (p-Ca(2+)) is kept within a very narrow range and deviations are rapidly corrected by flux of Ca(2+) between extracellular fluid and the labile calcium pool at the quiescent bone surface. The calcium sensing at the bone surface represents a physiological interesting model for the rapid minute-to-minute regulation of p-Ca(2+). Our aim was to study whether the calcium-sensing receptor (CaR) has a role in the rapid recovery of p-Ca(2+) from acute induced hypocalcaemia.

MATERIAL AND METHODS

Male Wistar rats were thyroparathyroidectomized (TPTX). Acute hypocalcaemia in the animals was induced by infusion of EGTA (40-50 mM EGTA, 3.0 mL h(-1) for 30 min). Thereafter the recovery of p-Ca(2+) was followed. Vehicle or the CaR activators, R-568 (2 mg as a bolus twice) or gentamycin were administrated intravenously.

RESULTS

EGTA infusion resulted in significantly lower nadir of hypocalcaemia in R-568- or gentamycin-treated rats compared to vehicle-treated rats (P < 0.01). During recovery phase p-Ca(2+) remained significantly lower in R-568 rats (P < 0.001). As such p-Ca(2+) levels recovered to basal levels in the vehicle group within 70 min after stopping EGTA, while R-568 or gentamycin rats remained significantly hypocalcaemic.

CONCLUSIONS

The CaR activators R-568 and gentamycin, both significantly delayed the recovery of p-Ca(2+) from acute EGTA-induced hypocalcaemia in TPTX rats. This novel finding suggests the existence of calcium sensing by bone of importance for the rapid minute-to-minute regulation of p-Ca(2+).

[Application of island myocutaneous flap for refractory wound in cervico-thoracic region]

OBJECTIVE

To introduce experiences in the application of island myocutaneous flap for refractory wound in cervico-thoracic region.

METHODS

From August 1994 to December 2004, 98 cases of refractory wound in cervico-thoracic region were treated; there 42 males and 56 females, aging 21-68 years. The course of disease was 3 hours to 13 months. The locations were anterior pectorial region(29 cases), cervical part (28 cases), nuchal region (18 cases), subaxillary and axillary region (15 cases), and thoracic wall (8 cases). The defect area ranged from 6 cm x 4 cm to 20 cm x 15 cm. According to location, peculiarity and etiological factor of wound, various island myocutaneous flaps were selected: 28 pectoralis major island myocutaneous flaps, 34 latissimus dorsi island myocutaneous flaps, 19 trapizius island myocutaneous flaps and 17 rectus abdominis island myocutaneous flap. The sizes of the dissected flap ranged from 8 cm x 6 cm to 35 cm x 15 cm.

RESULTS

Of 98 patients, the wound healed by first intention and the flap survived completely in 92 and the flap necrosed partially in 6. The good function and cosmetic results were obtained without severe complication. Eighty-three cases were followed up from 2 weeks to 5 years. The flap obtained satisfactory appearance, good function and cosmetic results.

CONCLUSION

Repairing refractory wound in cervico-nuchal region may select pectoralis major island myocutaneous flap, latissimus dorsi island myocutaneous flap, and trapizius island myocutaneous flap; repairing refractory wound on thoracic region may select latissimus dorsi island myocutaneous flap and rectus abdominis island myocutaneous flap. According to specific condition of wound, using suitable island myocutaneous flap for refractory wound in cervico-thoracic region may obtain satisfactory functional and cosmetic results.

Differences in the Outcomes and Treatments of Extensively Burned Patients between a Chinese Hospital and a Japanese Hospital

To know the therapeutic level at one's own institute is important and contributes to improving the treatment of patients. We compared the outcomes of extensively burned patients between a Chinese hospital and a Japanese hospital in order to identify the differences in the clinical treatment of severe burn patients. Thirty-four burn patients who were admitted to the National Defense Medical College Hospital (NDMC) in Japan and 95 burn patients who were admitted to the Changhai Hospital of the Second Military Medical University (SMMU) in China from January 1999 to December 2003 were studied. All patients were transported to the respective hospitals within 3 days after suffering burns and their total body surface area of burns was greater than 20%. Fourteen of the 34 patients (41.2%) at NDMC hospital and 1 of the 95 patients (1.1%) at SMMU hospital were injured by attempted suicide; namely, the suicide rate was significantly higher in the patients at NDMC hospital (p < 0.001). Moreover, the age (p = 0.005) and inhalation rate (p = 0.013) were significantly higher at NDMC hospital than those at SMMU hospital. Consequently, the survival rate at SMMU was higher than at NDMC in the patients with a burn surface area of greater than 80% or with a burn index of greater than 60. The excellent outcomes of the extensively burned patients at SMMU were in part due to the fact that Chinese doctors tend to perform an immediate tracheostomy and a traditional Chinese operation with alloskin, called microskin grafting or intermingled skin grafting.

Accurate classification of protein structural families using coherent subgraph analysis

Protein structural annotation and classification is an important problem in bioinformatics. We report on the development of an efficient subgraph mining technique and its application to finding characteristic substructural patterns within protein structural families. In our method, protein structures are represented by graphs where the nodes are residues and the edges connect residues found within certain distance from each other. Application of subgraph mining to proteins is challenging for a number reasons: (1) protein graphs are large and complex, (2) current protein databases are large and continue to grow rapidly, and (3) only a small fraction of the frequent subgraphs among the huge pool of all possible subgraphs could be significant in the context of protein classification. To address these challenges, we have developed an information theoretic model called coherent subgraph mining. From information theory, the entropy of a random variable X measures the information content carried by X and the Mutual Information (MI) between two random variables X and Y measures the correlation between X and Y. We define a subgraph X as coherent if it is strongly correlated with every sufficiently large sub-subgraph Y embedded in it. Based on the MI metric, we have designed a search scheme that only reports coherent subgraphs. To determine the significance of coherent protein subgraphs, we have conducted an experimental study in which all coherent subgraphs were identified in several protein structural families annotated in the SCOP database (Murzin et al, 1995). The Support Vector Machine algorithm was used to classify proteins from different families under the binary classification scheme. We find that this approach identifies spatial motifs unique to individual SCOP families and affords excellent discrimination between families.

[The role of Kupffer cells on the postburn production of TNFalpha, IL-1beta and IL-6 in severely scalded rats]

OBJECTIVE

To observe the role of Kupffer cells in the postburn production of TNFalpha, IL-1beta and IL-6 in severely scalded rats.

METHODS

(1) The production of TNFalpha, IL-1beta and IL-6 from rat Kupffer cells stimulated by burn serum was observed. (2) The postburn change in the expression of cytokine mRNA from rat Kupffer cells was monitored. (3) The change in the plasma cytokine contents in scalded rats was determined after the application of gadolinium chloride, a specific inhibitor of Kupffer cells.

RESULTS

Kupffer cells could be stimulated by burn serum to release cytokines TNFalpha, IL-1beta and IL-6. The mRNA expression of TNFalpha, IL-1beta and IL-6 from rat Kupffer cells increased significantly after injury. But the postburn plasma levels of TNFalpha, IL-1beta and IL-6 decreased obviously to 34.71%, 36.99% and 33.7% of those in scalding group, respectively, after the Kupffer cell activity was inhibited.

CONCLUSION

The plasma cytokines, i.e. TNFalpha, IL-1beta and IL-6, were primarily produced from Kupffer cells after injury in scalded rats, initiated by TNFalpha, IL-1beta and IL-6 mRNA transcription.

[Study on the intra- and extra-hepatocyte distribution of sodium ions in scalded rats during early postburn stage]

OBJECTIVE

To investigate the characteristics of the intra- and extra-hepatocyte sodium ions distribution in scalded rats during early postburn stage,with the aim of improving burn shock resuscitation regime and the resuscitation effects.

METHODS

Adult Sprague-Dawley rats were randomly divided into sham scalding (C, n = 12) and scalding (S, n = 7) groups. The rats in S group were subjected to 40% TBSA III degree scalding on the back and were catheterized via jugular vein for fluid resuscitation. The rats in C group were catheterized via jugular vein without fluid infusion and were sham scalded by warm water in temperature of 37 degrees. The changes in the intra- and extra-hepatocyte sodium ion contents were determined in vivo by (23)Na-magnetic resonance spectrum technology, while the existing state of the intra- and extra-hepatocyte sodium ion was determined by detecting (23)Na-magnetic resonance horizontal delaying time (T(2)).

RESULTS

The extra-hepatocyte sodium content in S group at 24 postburn hours (PBHs) was 17% less than that in C group. In addition, the T(2f) (fast T(2)) in S group remained stable but maintained a higher ratio during the observation time. This suggested that the sodium binding sites in extra-hepatocyte matrix increased relatively and that intra-hepatocyte sodium content increased by 57%. But the T(2) and the fast and slow parts of the T(2) kept stable, which implied that intra-hepatocyte catabolizing products were increased. This led to an increase in the sodium ion binding sites within intra-hepatocyte matrix in proportion to the sodium ion content.

CONCLUSION

During early postburn stage, the extra-hepatocyte sodium in a remote organ such as the liver exhibited relative deficiency due to its ingress into hepatocyte cytoplasm and to the increase of sodium combining sites.

[An experimental study on the recombinant composite skin graft consisting of human epithelium and acellular xeno-dermis]

OBJECTIVE

To observe the effects of the recombinant composite skin graft consisting of human epithelium and acellular xeno-dermis on full thickness skin loss wounds, so as to find a new wound covering material.

METHODS

Forty-two nude mice with full thickness skin loss on the back were grafted with the composite skin (compound skin grafting group, G) and human keratinocyte sheet (control group, C), respectively. The wound healing conditions, such as wound healing rate and wound contraction rate, were observed at different time points after the operation. Simultaneously, wound tissue samples were harvested for histological examination.

RESULTS

The wound healing rate in G group was much higher than that in C group. In contrast, the wound contraction rate in G group was obviously lower than that in C group (P < 0.05). It was indicated by histological examination that there was full differentiation of epithelium, orderly collagen proliferation and obvious reconstruction of the epithelial-dermal conjunction structure in G group. There was no obvious sign of acute immune rejection.

CONCLUSION

The wound covering with recombinant composite skin graft of human epithelium and acellular xeno-dermis could improve wound healing quality. The composite skin could be a new skin substitute.

[The effects of rhGH on macrophages in scalded mice]

OBJECTIVE

To investigate the effects of rhGH and IGF-1 on the CD14 mRNA expression and cytokine secretion of peritoneal macrophages (Mphi) in scalded rats.

METHODS

Reverse-transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosordent assay (ELISA) were employed to observe the postburn changes of CD14 expression and cytokines secretion of the Mphi treated in vivo and in vitro by rhGH and IGF-1.

RESULTS

It was demonstrated that in vivo postburn application of rhGH and IGF-1 could enhance the transcription of CD14 mRNA and the secretion of cytokines from the peritoneal Mphi in mice. But it seemed that there was no additive effect between the two factors. Additionally, rhGH (at 40 ng/ml) and IGF-1 (at all tested concentrations) could activate the secretion of TNF and IL-6 from cultured mice Mphi in vitro.

CONCLUSION

Postburn application of rhGH might activate Mphi by IGF-1 induction, enhancing Mphi CD14 expression, which promoted more secretion of cytokines, and promote the enhancement of immune function.

Inhibition of breast and brain cancer cell growth by BCCIPalpha, an evolutionarily conserved nuclear protein that interacts with BRCA2

BRCA2 is a tumor suppressor gene involved in mammary tumorigenesis. Although important functions have been assigned to a few conserved domains of BRCA2, little is known about the longest internal conserved domain encoded by exons 14-24. We identified a novel protein, designated BCCIPalpha, that interacts with part of the internal conserved region of human BRCA2. Human BCCIP represents a family of proteins that are evolutionarily conserved, and contain three distinct domains: an N-terminus acidic domain (NAD) of 30-60 amino acids, an internal conserved domain (ICD) of 180-220 amino acids, and a C-terminus variable domain (CVD) of 30-60 amino acids. The N-terminal half of the human BCCIP ICD shares moderate homology with regions of calmodulin and M-calpain, suggesting that BCCIP may also bind Ca. Human cells express both a longer, BCCIPalpha, and a shorter, BCCIPbeta, form of the protein, which differ in their CVD. BCCIP is a nuclear protein highly expressed in testis. Although BCCIPbeta expression is relatively consistent in cancer cells, the expression of BCCIPalpha varies in cancer cell lines. The BCCIPalpha gene is located at chromosome 10q25.3-26.2, a region frequently altered in brain and other cancers. Furthermore, expression of BCCIPalpha inhibits breast and brain cancer cell growth, but fails to inhibit HT1080 cells and a non-transformed human skin fibroblast. These results suggest that BCCIPalpha is an important cofactor for BRCA2 in tumor suppression.

Interactions in sheep between tall fescue ergot alkaloids and hepatotoxic carbon tetrachloride and Senecio pyrrolizidine alkaloids

The interaction between ergot alkaloids in endophyte-infected (E+) tall fescue (Festuca arundinacea) seed and pyrrolizidine alkaloids (PA) in tansy ragwort (TR; Senecio jacobaea) when simultaneously fed to sheep was investigated. Because of the hepatogenic effects of prolactin (PRL), it was hypothesized that low serum PRL induced by ergot alkaloids would increase the susceptibility of sheep to hepatotoxicity induced by PA. Sheep are normally resistant to PA-induced hepatotoxicity. Twenty-four wether lambs weighing 34.1 +/- 2.3 kg were used after being randomly assigned to 1 of 6 treatments of 4 wethers each. The diets offered were a control basal diet containing endophyte-free (E-) tall fescue seed, control + carbon tetrachloride (CCL4), E+ tall fescue basal diet, E+2CCl4, E(-)+TR, or E+2TR. The diets were composed of 50% alfalfa meal, 34.5% rolled barley, 5% soybean meal, 4% cane molasses, 0.5% trace mineralized salt and 6% tall fescue (E- or E+) seed. In the 2 TR treatments 25% of the alfalfa was replaced by TR. Interaction between ergot alkaloids in E+ tall fescue and PA in TR was assessed by gamma glutamyl transferase (GGTP) activity and/or sulfobromophthalein (BSP) clearance rate, both of which measure liver function. Serum GGTP activity was measured on days 14 and 28; plasma BSP clearance was monitored on days 28 and 70 by collection of blood at 4, 8 and 16 min after i.v. BSP injection. Serum PRL assays were performed on days 14, 70 and 84. Serum GGTP activity was elevated by CCl4 drenching on days 14 and 28. On day 28 TR feeding reduced GGTP activity, but there was no difference between the 2 TR treatments. There was no difference in the mean BSP half-times (t1/2) and % BSP retentions on day 28 among any of the 6 treatments. On day 70, there was no difference in the t1/2 or % BSP retention 4 min after BSP injection among any of the treatments. At 8 min after BSP injection, however, % BSP retention was significantly higher for the control +CCl4 than for the E+2CCl4 treatment. At 16 min after BSP injection, the E+ treatment had a higher mean % BSP retention value than the E+2CCl4 treatment; there were no differences among the other treatments. Serum PRL levels were reduced by E+ or CCl4 on all 3 dates of PRL evaluation. The lack of interaction between ergot alkaloids in E+ tall fescue seed and PA in TR as assessed by GGTP activity and/or BSP clearance in sheep may imply that the target sites o the 2 alkaloids are metabolically different. The low serum PRL with E+ did not increase susceptibility of sheep to CCl4 or PA.

[Activation of L-Arg: no pathway in canine brain by the damage from complete cerebral ischemia-reperfusion]

To ascertain whether complete cerebral ischemia-reperfusion activate L-Arg: NO pathway in canine brain, we anestherized nine adult dogs with ketamine and fentayle and randomly divided into two groups. Four dogs were nonischemic control group. Five dogs were complete cerebral ischemia-reperfusion group, they underwent a 18-minute cardiac arrest, and were resusciatation by standard CPR, supported by intensive care for 8 hours. At the end of each experiment, the parietal cortex was assayed for content of Nitrite and NADPH-positive neurons. Compared with the control group, the contents of Nitrite and NADPH-positive neurons of coxtex in complete cerebral ischemia-reperfusion group increased significantly (P < 0.01). The results suggest that complete cerebral ischemia-reperfusion activate the L-Arg: NO pathway in canine brain, and NO may play an important role in cerebral ischemia-reperfusion injury.

[Effects of thermal injury on heart sialic acid content in rats]

The myocardial sialic acid content, ATPase activities, and Ca2+ level were investigated in rats with full thickness burn of 30% TBSA. The results showed that the burned rats had a decreased level of myocardial sialic acid which was only 58.8% of controls at 3 h postburn. Myocardial Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase and Ca(2+)-ATPase activities were inhibited in burned rats. As compared to controls, the burned rats showed a higher level of Ca2+ in heart tissue. This study indicated that there were abnormal energy metabolism, dysfunction of ion pump, and paradox Ca2+ overload in burned rats, which may be associated with the decrease in sialic acid content in myocardium.

[Effects of thermal injury on production of nitric oxide in rat heart]

To elucidate the relationship between thermal injury and production of nitric oxide (NO), we measured the levels of heart No2-/NO3- (the stable and products of NO) and GMP in rats with full thickness burn of 30% TBSA. A higher level of heart tissue NO2-/NO3- was observed from 3 to 24 hours after burn injury. Parallel to the changes of NO2-/NO3-, there were increases of tissue cGMP level and heart tissue water content in burned rats. L-NMMA, a specific inhibitor of NO synthetase (NOS), can block the rise of heart NO2-/NO3- and the enhancement of heart water content. The results indicate that the heart injury caused by burn injury may be associated with induction of NOS and formation of NO.

[Effect of lysostaphin on phagocyte function in burn mice]

The ability of lysostaphin to prevent immunosuppression of phagocyte was assessed in burn mice. A full thickness burn covering 20% of TBSA was created on back of mouse, Lysostaphin was given intraperitoneally (400 micrograms/kg/day) for 3 days in treatment group. The results showed that lysostaphin treatment could restore the depression of phagocytosis of chick RBC by peritoneal macrophages. In the group treated by lysostaphin, peritoneal macrophage chemiluminescence expressed much greater peak value than that in both burn and normal groups. The a-value, which is a criterion of carbon clearance, was 1.63 x 10(-2) in lysostaphin treated mice, while that in burn and normal mice were 8.13 x 10(-4) and 2.76 x 10(-3), respectively. Results of the study indicated that lysostaphin was effective in improving phagocytosis by phagocytes.

[Changes in myocardial ATPase activity and Ca2+ content in burned rats]

The myocardial ATPase activity and Ca2+ content were investigated in rats with full thickness skin burn injury of 30% TBSA. The results showed that there were significant inhibitions of Na+, K(+)-ATPase,Ca2+, Mg(2+)-ATPase, and Ca(2+)-ATPase activities of myocardium after burn injury. The burn injury could result in increase of calcium content in myocardium. Burned rats also had a higher level of MDA in heart tissue when compared to controls. This study demonstrates that the membrane defects with respect to ATPase activity, oxygen free radical, and Ca2+ overload in myocardium may be associated with damage of myocardium after burns.

Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain

Objectives were to identify the PKC isoforms in cultured muscle cells, to examine roles of Ca(2+)-dependent proteinases (calpains) in processing of various muscle PKC isozymes and to obtain a mechanistic description of the processing of PKCs by examining the temporal relationships between phorbol ester-dependent translocation of muscle PKCs and calpains between cytosolic and membrane compartments. Using six isoform (alpha, beta, gamma, delta, epsilon, zeta)-specific polyclonal antibodies, PKC alpha, delta and zeta were detected in rat skeletal muscle and in L8 myoblasts and myotubes. PKC alpha and zeta were primarily localized in the cytosolic fraction of L8 myotubes whereas PKC delta was more abundant in the membrane fraction. Phorbol ester (TPA) caused rapid depletion of myotube PKC alpha and PKC alpha and PKC delta isoforms from the cytosolic compartment and rapid appearance of these isoforms in the membrane fraction. However, long-term exposure of myotubes to TPA eventually caused down-regulation of PKCs in the membrane compartment. Down-regulation of PKCs in the membrane fraction was partially blocked by calpain inhibitor II. However, the rapid TPA-dependent cytosolic depletion of PKCs was unaffected by calpain inhibitor. This suggests that calpains may be responsible for membrane-associated down-regulation of PKCs but not for cytosolic depletion. In the final study we assessed the effects of phorbol ester on compartmentation of m-calpain with PKCs in muscle cells. Like the PKCs, TPA caused rapid association of m-calpain with the membrane fraction followed by down-regulation. This demonstrates that phorbol esters cause translocation of both PKCs and calpains to membranes where processing of PKCs may occur via the limited proteolysis exerted by calpains.

[The character and clinical application of glutaraldehyde cross-linked collagen artificial skin]

The glutaraldehyde cross-linked collagen artificial skin was made with the modified Burke's method. It is an ideal artificial skin in that animal tests proved that it has the effect of bacteriostasis with strong adhesiveness and good porosity, is capable of decreasing vaporization and the loss of protein and electrolyte, and without rejection reaction. Clinical use of the artificial skin in 30 patients resulted in an average healing time of 24 +/- 3 days of the eschar-excised wound covered with the artificial skin and autograft of skin seeds. It is especially effective in Pseudomonas aeruginosa infected wound and chronic ulcer.

Dietary pyrrolizidine (Senecio) alkaloids and tissue distribution of copper and vitamin A in broiler chickens

The effect of feeding a diet containing 5% tansy ragwort (TR) (Senecio jacobaea), a poisonous plant containing pyrrolizidine alkaloids (PA), on the blood and liver levels of copper, zinc, iron and vitamin A in broiler chicks was examined. Serum and liver copper and liver iron concentrations were increased in chicks fed a diet with 5% TR, while serum and liver zinc and vitamin A decreased. When PA were removed from the diet, partial restoration of normal serum vitamin A level occurred, indicating that the ability to mobilize liver vitamin A is not irreversibly inhibited by PA. The decline in serum vitamin A occurred by 8 days of TR feeding with a concurrent decline in growth rate. When chicks were fed a diet high in vitamin A (25,000 IU/kg), followed by a basal diet containing TR, serum vitamin A levels were significantly (P < 0.01) decreased, while liver vitamin A level increased. This indicates that mobilization of previously stored vitamin A from the liver is impaired by PA. Prior feeding of a high vitamin A level resulted in protective effects against PA toxicity, as assessed by histopathology. This study shows that a dietary source of PA modifies metabolism and tissue distribution of minerals and vitamin A.