Treatment with Recombinant Trichinella spiralis Cathepsin B-like Protein Ameliorates Intestinal Ischemia/Reperfusion Injury in Mice by Promoting a Switch from M1 to M2 Macrophages.

Intestinal ischemia/reperfusion (I/R) injury, in which macrophages play a key role, can cause high morbidity and mortality. The switch from classically (M1) to alternatively (M2) activated macrophages, which is dependent on the activation of STAT6 signaling, has been shown to protect organs from I/R injuries. In the current study, the effects of recombinant Trichinella spiralis cathepsin B-like protein (rTsCPB) on intestinal I/R injury and the potential mechanism related to macrophage phenotypes switch were investigated. In a mouse I/R model undergoing 60-min intestinal ischemia followed by 2-h or 7-d reperfusion, we demonstrated that intestinal I/R caused significant intestinal injury and induced a switch from M2 to M1 macrophages, evidenced by a decrease in levels of M2 markers (arginase-1 and found in inflammatory zone protein), an increase in levels of M1 markers (inducible NO synthase and CCR7), and a decrease in the ratio of M2/M1 macrophages. RTsCPB reversed intestinal I/R-induced M2-M1 transition and promoted M1-M2 phenotype switch evidenced by a significant decrease in M1 markers, an increase in M2 markers, and the ratio of M2/M1 macrophages. Meanwhile, rTsCPB significantly ameliorated intestinal injury and improved intestinal function and survival rate of animals, accompanied by a decrease in neutrophil infiltration and an increase in cell proliferation in the intestine. However, a selective STAT6 inhibitor, AS1517499, reversed the protective effects of rTsCPB by inhibiting M1 to M2 transition. These findings suggest that intestinal I/R injury causes a switch from M2 to M1 macrophages and that rTsCPB ameliorates intestinal injury by promoting STAT6-dependent M1 to M2 transition.

Analysis of a novel cathepsin B circulating antigen and its response to drug treatment in Trichinella-infected mice.

In this paper, we cloned a novel full-length cDNA that encodes a Trichinella spiralis cathepsin B-like protease gene (TsCPB) using 3'-RACE PCR. The recombinant mature TsCPB protein (rTsCPB) was then expressed in an Escherichia coli expression system and purified with Ni-affinity chromatography. Real-time quantitative PCR revealed that TsCPB was expressed across all development stages of the parasite but had the highest expression level during the adult stage. Furthermore, rTsCPB was detected in Trichinella excretory-secretory products with anti-rTsCPB rabbit polyclonal antibodies. Interestingly, rTsCPB was strongly recognized by the T. spiralis-infected sera in Western blotting, implying that TsCPB protein appeared in the peripheral blood of Trichinella-infected mice as circulating antigens (CAg). We then analyzed the dynamic levels of TsCPB CAg and its antibodies in T. spiralis-infected sera by using an improved double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) and indirect ELISA, respectively. The results showed that TsCPB CAg can be detected much earlier compared to antibody detection in Trichinella-infected mice. In addition, we monitored the effects of albendazole drug therapy (a dosage of 370 mg/kg body weight, twice a day) on T. spiralis-infected mice by detecting the levels of TsCPB CAg and its antibody in the sera of drug-treated mice. The results showed that the levels of CAg dramatically decreased after successful drug treatment, while the antibody level remained unchanged. Overall, the novel Trichinella antigen TsCPB could be a promising novel circulating antigen molecule for the detection of Trichinella infection and for monitoring the efficacy of drug treatment of trichinellosis.

A bibliometric analysis of publications on burn sepsis using VOSviewer.

Background: Sepsis is one of the most common complications in burn patients and causes high morbidity, especially in those with severe burns. Nevertheless, there are no formal criteria for diagnosing and treating burn sepsis. Therefore, this bibliometric analysis is applied to reveal research trends in this field and predicts its possible hot spots. Methods: We screened relevant literature on burn sepsis that met the inclusion criteria of the Web of Sciences (WOS) database and analyzed publication trends and research hot spots in related fields using VOSviewer software. Results: From 1981 to 2022, we screened 2,486 documents that met the requirements and analyzed them bibliometrically. The American scholar Herndon DN had a much higher h-index [47] than other authors. Most published, cited, and h-indexed publications are from the USA (Np: 1193, Nc: 42154, H: 98). The second most publishing country is China, but the second most cited and h-indexed country is Germany. Burns also outperforms other journals in this field (Np: 376, Nc: 8019, H: 46). "Biomarkers" is a newly emerging keyword (cluster "clinical research," APY was 2018.16), and clinically relevant research in burn sepsis maybe a future research trend. Conclusions: Sepsis in burn patients has unique pathophysiological characteristics and the general diagnostic criteria for sepsis lack specificity. Consequently, we must establish a database and construct an intelligent predictive model to help achieve a more individualized and precise early diagnosis and treatment of burn sepsis. This may also be an important development direction for future research in this field.

HIF-1α inhibition promotes the efficacy of immune checkpoint blockade in the treatment of non-small cell lung cancer.

The response to immune checkpoint inhibitors (ICIs) monotherapy remains unsatisfactory in patients with NSCLC. Thus, combining ICIs with other potential modalities is of great significance to enhance the response of single drug alone. Here, we identified that HIF-1α inhibition was capable of promoting anti-tumor immunity in NSCLC. We applied NSCLC cell lines and mouse models to evaluate the synergy of combined HIF-1α inhibition and PD-1 blockade on tumor growth and the function of tumor infiltrating lymphocytes (TILs). Public datasets were utilized to investigate patients' prognosis based on expressions of HIF-1α and LOXL2 as well as EMT-associated markers and CD8+ TILs. Moreover, we explored the correlation between HIF-1α and LOXL2 levels and CD8+ TILs in tumor samples from patients with NSCLC by immunohistochemistry, as well as their association to patients' survival. In vitro, PX-478, an HIF-1α inhibitor, promoted tumor cell apoptosis induced by T cells when combined with ICIs. Furthermore, mice treated with PX-478 and anti-PD-1 antibodies exhibited a marked delay in tumor growth and prolonged survival, which correlated with increased TILs and granzyme B secretion. Besides, patients with high HIF-1α expression exhibited high levels of EMT-related markers and low TILs, indicating an immunosuppressive phenotype. Mechanistically, we observed that HIF-1α inhibition suppressed the EMT phenotypes induced by hypoxia and further alleviated tumor immunosuppression, which was related to blockage of HIF-1α/LOXL2 signaling pathway. In summary, we identified that HIF-1α inhibition could synergize with anti-PD-1 to impair tumor growth in vitro and in vivo. Our data suggest that HIF-1α inhibitors represent a promising treatment to enhance anti-tumor immunity and provide preclinical rationale to evaluate the combination of ICIs with HIF-1α inhibition clinically in NSCLC.

[Effect of bone marrow mesenchymal stem cells engraftment on secretion of inflammatory cytokine in the early stages of smoke inhalation injury in rabbits].

OBJECTIVE: To explore the effect of bone marrow mesenchymal stem cells (MSCs) engraftment on secretion of tumor necrosis factor-α (TNF-α), interleukins (IL-1ß, IL-6, IL-10) in peripheral blood and lung homogenates in the early stages of smoke inhalation injury. METHODS: MSCs were proliferated by the method of whole marrow culture and identified by flow cytometry. Fifty-six healthy New Zealand rabbits were randomly divided into control group (C group, n=8), smoke inhalation injury group (S group, n=24) and smoke inhalation injury+MSCs engraftment group (M group, n=24). The latter two groups were subdivided into 2, 4, 6 hours after injury subgroups, with 8 rabbits in each group. The levels of TNF-α, IL-1ß, IL-6 and IL-10 in peripheral blood and lung homogenates were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with C group, concent of pro-inflammatory and anti-inflammatory cytokines in peripheral blood at each time point in S group were increased significantly. The concent of pro-inflammatory cytokines in lung homogenate at each time point in S group was significantly higher than those in C group, and that of anti-inflammatory cytokines showed no significant changes. Compared with the S group, concent of pro-inflammatory cytokines in peripheral blood in M group was decreased significantly, and that of anti-inflammatory cytokines was increased significantly [6 hours TNF-α (µg/L): 1.7±1.7 vs. 4.1±1.6, IL-1ß (ng/L): 9.9±1.7 vs. 21.2±2.6, IL-6 (µg/L): 1.0±0.3 vs. 1.3±0.2, IL-10 (ng/L): 15.2±4.4 vs. 7.9±3.5, all P<0.05]. Concent of pro-inflammatory cytokines at each time point in M group was decreased significantly when compared with S group in lung homogenate, while only anti-inflammatory cytokine at 4 hours and 6 hours was increased significantly [6 hours TNF-α (ng/L): 503.0±156.4 vs. 587.7±171.2, IL-1ß (ng/L): 0.4±0.2 vs. 0.6±0.2, IL-6 (ng/L): 155.2±13.7 vs. 350.2±20.3, IL-10 (ng/L): 23.3±5.4 vs. 11.0±5.6, all P<0.05]. CONCLUSION: MSCs engraftment could decrease pro-inflammatory cytokines and increase anti-inflammatory cytokines in the early stages of smoke inhalation injury, thus ameliorates inflammatory response, which confers protective effect on smoke inhalation injury.

[The effect of bone marrow mesenchymal stem cells engraftment on lung tissue at early stage of smoke inhalation injury in rabbits].

OBJECTIVE: To explore the effect of bone marrow mesenchymal stem cells (MSCs) engraftment on lung tissue at early stage of smoke inhalation injury in rabbits. METHODS: MSCs were proliferated by the method of whole marrow culture and identified by flow cytometry. Forty-eight rabbits were randomly divided into smoke inhalation group (S group) and MSCs group (M group) after reproduction of rabbit smoke inhalation injury model. 10 ml of phosphate buffer saline (PBS) containing 1×10(7)/ml MSCs was intravenously injected in M group, meanwhile 10 ml PBS was injected intravenously in S group. Eight rabbits were sacrificed at 2, 6 and 24 hours after intervention, and the lung tissue was harvested for morphological and pathological observation, and lung injury score was used to evaluate smoke inhalation injury. RESULTS: Cultured cells were confirmed to be MSCs with flow cytometry. Lung injury in rabbits of M group was less serious in morphology and histopathology than that in S group. Though there was no significance in lung injury score between M group and S group at 2 hours after injury (4.0±0.7 vs. 4.5±0.6, P>0.05), the lung injury scores in M group at 6 hours and 24 hours after injury were significantly lower than those in S group (6 hours: 6.1±0.9 vs. 8.2±0.9, 24 hours: 4.6±0.9 vs. 10.4±0.8, both P<0.01). CONCLUSION: Intravenous engraftment of MSCs could ameliorate lung injury induced by smoke inhalation, and improve lung injury score significantly.

[Influence of heat shock preconditioning on structure and function of mitochondria in gastric mucosa of severely burned animals: experiment with rats].

OBJECTIVE: To investigate the influence of heat shock (HS) preconditioning on the ultra-structure of gastric mucosal cells and the activity of cytochrome oxidase (CCO) and superoxide dismutase (SOD) in mitochondria isolated from gastric mucosa of burned rats in order to investigate its protective mechanism on burn-induced acute gastric mucosal lesion. METHODS: Ninety-six Wistar rats were divided randomly into two groups:(1) burn model group (n =40) undergoing burning and made into model of acute gastric mucosal lesion; and then subdivided into 5 equal subgroups: 3, 6, 12, 24, and 48 h after burning; (2) normal control group (n = 8); (3) HS preconditioning + burn group (n = 40), undergoing burning 24 h after HS preconditioning; and (4) HS preconditioning group (n = 8), without burn as experimental control A number of rats were sacrificed and laparotomized before and 3, 6, 12, 24, and 48 h after the burning. Specimens were obtained from the gastric antrum, bodies if stomach and gastric lesion to undergo microscopy and determination of the ulcer index ( UI ). Streptavidin-peroxidase immunohistochemistry was used to detect the protein expression of heat shock protein (HSP)-60 and HSP-70. Mitochondria were isolated and the activities of CCO and SOD in mitochondria were measured. The dynamic postburn changes in micro and ultra structure of gastric mucosal cells of scalded rats were observed. RESULTS: The rats of the burn group showed conspicuous gastric mucosal lesions. The UI levels at every time point of the HS group were all the lowest in comparison with other groups. The expression levels of HSP70 and HSP60 of the HS group, especially those at the time points 3, 6, 12, and 24 h were significantly higher than those of the burn group (P <0.05 or P <0.01). The activities of mCCO and mSOD of the HS group did not decrease remarkably at any time point in comparison with the control groups, and the activities of mCCO and mSOD at the time points 6, 12, and 24 h of the HS group were all significantly higher than those of the burn group (P <0.05 of P <0.01). Electron microscopy showed that the ultrastructural lesion was mild and alteration of gastric mucosal mitochondria was not significant in the HS group compared with those of the burn group. A positive correlation was shown between SOD and HSP70 (r = 0.436, P <0.05) and also between CCO and HSP60 (r =0.679, P <0.05). CONCLUSION: HS preconditioning ameliorates the burn-induced acute gastric mucosal lesion and has a protective role to gastric mucosal mitochondria. The role of HS preconditioning on mitochondria is associated with the protection of the activity of antioxidase and CCO by HSP60 and 70.

Inhibiting eEF-2 kinase-mediated autophagy enhanced the cytocidal effect of AKT inhibitor on human nasopharyngeal carcinoma.

AIM: Our previous research showed that AKT inactivation via small molecule inhibitors did not induce significant apoptosis, but rather markedly increased autophagy in nasopharyngeal carcinoma (NPC). The purpose of the current study was to determine whether autophagy inhibition can enhance the anticancer efficacy of an AKT inhibitor (MK-2206). MATERIALS AND METHODS: NPC cell lines CNE-2 (Epstein-Barr virus negative) and C666-1 (Epstein-Barr virus positive) were used to conduct the research. Autophagy induction effects were evaluated via Western blotting. Eukaryotic elongation factor-2 (eEF-2) kinase was specifically and stably knocked down using shRNA. The growth and proliferation of the cells were assessed by Cell Counting Kit-8. In CNE-2 xenograft tumors, the antitumor effects of an AKT inhibitor (MK-2206) combined with an eEF-2 kinase inhibitor (NH125) were tested. RESULTS: MK-2206 induced eEF-2 kinase-dependent autophagy in NPC cell lines. Knockdown of eEF-2 kinase using shRNA blunted the autophagy activated by MK-2206. Compared with treatment with MK-2206 alone, shRNA or NH125 suppressed eEF-2 kinase and increased the growth-inhibitory effect of MK-2206 on the human NPC cell lines. The synergistic effects of eEF-2 kinase inhibition and MK-2206 were similar to those of the combination of hydroxychloroquine and MK-2206. Moreover, NH125 showed good synergistic effects with MK-2206 in vivo. CONCLUSION: eEF-2 kinase-mediated autophagy induced by AKT inhibition played a protective role in NPC cells. Inhibition of eEF-2 kinase may be an effective method for increasing the efficacy of an AKT inhibitor such as MK-2206 in NPC.

The efficacy of first-line chemotherapy in recurrent or metastatic nasopharyngeal carcinoma: a systematic review and meta-analysis.

BACKGROUND: The standard first-line chemotherapy for patients with recurrent or metastatic nasopharyngeal carcinoma (R/M NPC) has not been well established. We conducted a pooled meta-analysis to evaluate the efficacy of commonly used first-line chemotherapy in this disease. METHODS: Electronic databases including PubMed, Embase, and Corchrane library were searched for eligible literatures. Objective response rate (ORR), disease control rate (DCR), progression free survival (PFS), and overall survival (OS) were pooled with the 95% confidence interval (CI) using R software. RESULTS: Totally 973 patients were available for analysis from 14 phase II single arm clinical trials and 2 phase III randomized clinical trials. Four regimens were identified including 5-fluorouracil plus platinum (FP), gemcitabine plus platinum (GP), taxanes plus platinum (TP), and triplet combination regimen. Of these four regimens, triplet combination regimen demonstrated best short-term efficacy with a highest ORR (0.74; 95% CI, 0.62-0.87), DCR (0.91; 95% CI, 0.87-0.95), and 6-month PFS rate (0.83; 95% CI, 0.75-0.91), while 1-year OS rate (0.74; 95% CI, 0.61-0.87) was a little lower than TP regimen. Meanwhile, TP regimen showed best prognosis with a highest 1-year OS rate of 0.79 (95% CI, 0.65-0.92) and pretty good short-term efficacy with an ORR of 0.60 (95% CI, 0.48-0.72) and a DCR of 0.92 (95% CI, 0.86-0.98) comparable with triplet combination therapy. FP regimen had the lowest ORR (0.52; 95% CI, 0.38-0.65) and 1-year OS rate (0.63; 95% CI, 0.57-0.69). Efficacy of GP regimen fell between FP and TP regimens with an ORR of 0.54 (95% CI, 0.38-0.65), a DCR of 0.85 (95% CI, 0.71-0.93), a 6-month PFS rate of 0.69 (95% CI, 0.60-0.78) and a 1-year OS rate of 0.71 (95% CI, 0.61-0.80). CONCLUSIONS: Among four commonly used first-line chemotherapy regimens for R/M NPC, triplet combination regimen showed best short-term efficacy but failed to improve prognosis. TP regimen demonstrated fairly good short-term efficacy and best long-term efficacy, followed by GP regimen, while FP regimen was the lowest.

Roles of immunohistochemical staining in diagnosing pulmonary squamous cell carcinoma.

BACKGROUND: Differentiating morphologic features based on hematoxylin-eosin (HE) staining is the most common method to classify pathological subtypes of non-small-cell lung cancer (NSCLC). However, its accuracy and inter-observer reproducibility in pathological diagnosis of poorly differentiated NSCLC remained to be improved. MATERIALS AND METHODS: We attempted to explore the role of immunohistochemistry (IHC) staining in diagnosing pulmonary squamous cell carcinoma (SQCC) with poorly differentiated features by HE staining or with elevated serum adenocarcinoma-specific tumor markers (AD-TMs). We also compared the difference of epidermal growth factor receptor (EGFR) mutation rate between patients with confirmed SQCC and those with revised pathological subtype. Logistic regression analyses were used to test the association between different factors and diagnostic accuracy. RESULTS: A total of 132 patients who met the eligible criteria and had adequate specimens for IHC confirmation were included. Pathological revised cases in poor differentiated subgroup, biopsy samples and high-level AD-TMs cases were more than those with high/moderate differentiation, surgical specimens and normal-level AD-TMs. Moreover, biopsy sample was a significant factor decreasing diagnostic accuracy of pathological subtype (OR, 4.037; 95% CI 1.446-11.267, p=0.008). Additionally, EGFR mutation rate was higher in patients with pathological diagnostic changes than those with confirmed SQCC (16.7% vs 4.4%, p=0.157). CONCLUSIONS: Diagnosis based on HE staining only might cause pathological misinterpretation in NSCLC patients with poor differentiation or high-level AD-TMs, especially those with biopsy samples. HE staining and IHC should be combined as pathological diagnostic standard. The occurrence of EGFR mutations in pulmonary SQCC might be overestimated.

High PD-L1 expression was associated with poor prognosis in 870 Chinese patients with breast cancer.

BACKGROUND: To investigate the role of PD-L1 expression in tumor recurrence and metastasis in Chinese patients with breast cancer. METHODS: Suitable tissue samples were available from 870 patients with breast cancer. Paraffin-embedded tumor sections were stained with PD-L1 antibody. The correlations between PD-L1 expression and clinical characteristics, ER/PR/HER2 status and survival parameters were analyzed. Kaplan-Meier and univariate Cox proportional hazards model analyses were used to compare the survival of patients with high PD-L1 expression and patients with no PD-L1 expression. RESULTS: The median follow-up time was 98 months(range, 17-265 months).The positive rate of PD-L1 expression in breast cancer was 21.7% (189/870). PD-L1 high expression was inversely associated with larger tumor size, higher tumor grade, more positive lymph node number, as well as negative ER and PR status. PD-L1 expression was particularly higher in TNBC compared with non-TNBC, although no statistical significance was observed. Nomogram logistic regression results based on clinical and pathological features showed that the following factors were more likely associated with high PD-L1 expression: patient age younger than 35 years, larger tumor size, lymphovascular invasion and advanced stage. Our data indicated that patients with high PD-L1 expression had poor DFS, DMFS and overall survival compared with those with no PD-L1 expression. Univariate Cox proportional hazards model analysis showed that PD-L1 was an independent prognostic factor for tumor prognosis. CONCLUSIONS: PD-L1 expression is an important indicator of unfavorable prognosis in breast cancer patients.

[Effects of arginine enriched enteral nutrition on nutritional status and cellular immunity in burn patients].

OBJECTIVE: To investigate the effects of arginine enriched enteral nutrition (EN) on nutritional status and cellular immunity of severely burned patients. METHODS: Randomized, single blind, parallel and positive control investigation was employed in the study. Thirty severely burned patients were divided into enteral immune nutrition (EIN) group and EN group. Sixteen patients in EIN group received enteral nutrition enriched with arginine, while the other 14 patients in EN group received standard enteral nutrition. Nutritional support was continued for 14 days. Gastrointestinal reaction of patients in 2 groups was observed. Fasting venous blood was drawn from patients of both groups before receiving nutrition treatment and on the morning of 7th, 14th day of treatment. Level of serum protein, hepatic function parameters, renal function parameters, fasting-blood glucose, and subpopulations of T lymphocytes in peripheral blood were determined. RESULTS: (1) Incidence of gastrointestinal side effect in EIN group (25.0%) was close to that of EN group (21.4% , P > 0.05). (2) Compared with pre-treatment days, levels of prealbumin and transferrin in serum of patients in 2 groups on 7th and 14th post-treatment days were significantly increased (P < 0.05 or P < 0.01), but there was no significant difference between 2 groups. The level of total serum protein on 14th day of treatment of patients was significantly increased in both groups, and that of EIN group (66 +/- 7 g/L) was significantly higher compared with that in EN group (64 +/- 11 g/L, P < 0.05). The level of serum albumin (29 +/- 5, 32 +/- 5 g/L, respectively) of patients in EIN group on 7th and 14th day of treatment were significantly higher than that (26 +/- 4 g/L, P < 0.05) in pre-treatment days, however there was no significant difference in EN group. (3) There was no significant difference in respect of hepatic function, renal function, and fasting-blood glucose between pre-treatment and post-treatment periods in both groups (P > 0.05). (4) The ratio of CD4(+), CD8(+) on 14th day of treatment in EIN group was close to that of pretreatment level. In EN group, cell percentage of CD4(+) significantly decreased, while that of CD8(+) significantly increased (P < 0.05), and CD4(+) was significantly higher [(56 +/- 8)%] in EIN group than that in EN group [(55 +/- 12)%, P < 0.05]. In both groups, cell percentage of CD3(+) was significantly higher than that in pre-treatment days (P < 0.05), while there was no obvious change in CD4(+)/CD8(+). CONCLUSIONS: Arginine enriched enteral nutrition can effectively improve nutritional status and cellular immune function of burn patients.

[Experimental research on the effects of Chinese herb drugs on immune dysfunction in severely scalded rats].

OBJECTIVE: To observe the modulation effect of a concoction of Chinese herb drugs on immune dysfunction in severely burned rats. METHODS: One hundred healthy Wistar rats were randomly divided into A group (n = 30, with Chinese herb drug feeding after burns), B group (n = 30, with bouillon feeding after burns), C group (n = 30, with ordinary feeding after burns), and D group (n = 10, with sham burns as normal controls). The rats in A, B and C groups were subjected to 30% TBSA full-thickness burns and received conventional treatment. The rats in A group received 2 ml of Chinese herbal drug at 37 degrees C by gavage two times a day beginning from 2 postburn-hours(PBH). The rats in B group received 2 ml bouillon by gavage instead, and otherwise treatment was the same as A group, while the rats in C group were not fed by gavage. The activity of natural killer cell and T lymphocyte, and the levels of IgA, IgG, IgM, C3, C4 in A, B, C groups were examined on 3, 7, 14 PBD, and these indices were also determined in D group. RESULTS: Compared with D group, the amount of the CD3+, CD4+ lymphocyte, the ratio of the CD4+/CD8+, the level of IgA, IgG, IgM, C3, C4, the activity of NK cells, and the density of the sIgA in A, B, C groups were obviously decreased, but the amount of the CD8+ were obviously increased (P < 0.05 or P < 0.01). Furthermore, the above indices in A group improved more quickly when compared with B and C groups. CONCLUSION: The concoction of Chinese herb drugs can improve the distribution of T lymphocyte subsets, increase the activity of NK cells, promote the secretion of sIgA in intestinal mucous membrane and promote recovery of IgM, IgG, C3, C4 levels, thereby improves the immune function of the body.

[Protection of heat shock preconditioning on acute gastric mucosal lesion in scalded rats and its mechanism].

OBJECTIVE: To observe the influence of heat shock preconditioning on the expressions of heat shock protein (HSP) 60 and HSP 70 and on the activities of cytochrome oxidase (CCO) and superoxide dismutase (SOD) in mitochondria in gastric mucosa of severely scalded rats, and to investigate its protective mechanism on acute gastric mucosal lesion in rats with severe scald. METHODS: One hundred and forty-four Wistar rats were randomized into three groups, i. e. scald group ( n = 40, acute gastric mucosal lesion was made after scald, other 8 normal rats without scald were employed as blank control); HS group ( n =40, with heat shock preconditioning 20 h before scald), and other 8 rats preconditioned with heat shock but without scald were employed as experimental control I; actinomycin D group ( n = 40, with intraperitoneal injection of 0. 1 mg/kg actinomycin D 30 min before heat shock preconditioning and other treatment as HS group), and other 8 rats with merely actinomycin D injection were employed as experimental control II. Eight rats in each group were sacrificed and laparotomized at 3, 6, 12, 24 and 48 post-scald hours (PSH) , respectively to determine the index of gastric mucosal lesions (UI ) , the mRNA expressions of HSP70 and protein expression of HSP60 and HSP70, and the changes in the activities of SOD and CCO. RESULTS: UI of the scalded rats increased as the time elapses, reaching the peak (12. 8 +/- 1.9) at 24 PSH. In addition, UI in HS group was significantly lower than that in scald group at each time-point except that at 3 PSH ( P < 0. 05 or 0. 01). The extent of gastric mucosal lesion in rats in actinomycin D group was obviously aggravated compared with that in scald and HS groups ( P <0. 05). The HSP70 mRNA expression in both scald and HS groups was increased at each time-points except for 48PBH, while that in actinomycin D group was increased at 24 PBH and 48PBH. The expressions of HSP70 and HSP60 were greatly increased in HS group compared with those in scald group ( P < 0. 05 or 0. 01) , while those in actinomycin D group were significantly inhibited ( P < 0. 05). The activities of CCO and SOD were gradually decreased in gastric mucosa in scald group, but it was greatly improved by HS preconditioning at 6, 12, 24 PSH ( P < 0. 05 or 0. 01). CONCLUSION: Heat shock preconditioning is beneficial for the protection of acute gastric mucosal lesion of rats after severe scald, due to increase of HPS60 and HSP70 expression, and increase of CCO and SOD activities in mitochondria.

[Analysis of correlation factors affecting the incidence of burn shock].

OBJECTIVE: To analyze the correlation factors affecting the incidence of burn shock, so as to provide guidance for the clinical treatment of shock after burns. METHODS: Retrospective analysis of clinical data of 15 624 patients hospitalized in our department from 1973 to 2005 was undertaken . The incidence of shock during every 10 years, as well as the relationship between shock incidence and age, burn area, interval between injury and hospitalization, and complications were analyzed statistically. RESULTS: The incidence of shock during 1973-1980, 1981-1990, 1991-2000 and 2001-2005 periods was 14.69%, 13.50%, 9.38% and 7.88%, respectively, and there was significant difference of shock incidence between each 10 years and its succeeding period (P < 0.01). The occurrence of shock was closely related to age, length of time between injury and hospitalization, and burn area. The shock incidence of children under 7 years old or elderly more than 60 years old was obviously higher than other age groups, and there was positive relationship between burn area and shock incidence. Moreover, the shock incidence of the patients hospitalized later than 4 to 12 hours after burn shock was also markedly higher than those hospitalized earlier (P < 0.01). In addition, the incidence of sepsis, alimentary tract hemorrhage, acute renal failure, pulmonary failure, and cardiac failure in patients with shock was obviously higher than those without shock (P < 0.01). CONCLUSION: For the children and aged people, special attention should be paid in the prevention and resuscitation of burn shock. Early fluid resuscitation is vital for the prevention of organ complication, and it is beneficial to promote wound healing.