[Influence of family with sequence similarity 134, member B-mediated reticulophagy on lipopolysaccharide-induced apoptosis of mouse dendritic cells]

Objective: To investigate the influence of family with sequence similarity 134, member B (FAM134B)-mediated reticulophagy on lipopolysaccharide (LPS)-induced apoptosis of mouse dendritic cells (DCs), so as to provide a basis for improving the immune suppression of sepsis caused by wound infection and other factors. Methods: The experimental research methods were used. The DC line DC2.4 of the 3rd to 10th passage in the logarithmic growth stage was collected for experiments. DCs were divided into LPS stimulation 0 h (no stimulation) group, LPS stimulation 6 h group, LPS stimulation 12 h group, LPS stimulation 24 h group, and LPS stimulation 72 h group, which were cultured with 1 μg/mL LPS (the same concentration below) for the corresponding time. The protein expressions of FAM134B, microtubule-associated protein 1 light chain 3B (LC3B), and transporter protein SEC61B were determined by Western blotting, and the ratio of LC3B-Ⅱ/LC3B-Ⅰ was calculated (n=3). DCs were divided into phosphate buffer solution (PBS) group and LPS group for corresponding treatment. After 24 hours of culture, the expression of FAM134B and its co-localization with lysosomal probes and LC3B were detected using immunofluorescence method, while the number of autolysosomes in cells were observed through transmission electron microscope. DCs were divided into the FAM134B-knockdown group that were transfected with lentivirus containing small interfering RNA (siRNA) sequence of FAM134B gene and the empty vector group with empty lentivirus transfected. At post transfection hour 72, the fluorescence expression of cells was observed under the inverted fluorescence phase contrast microscope, meanwhile, the normally cultured DCs were set as blank control group, and the same observation was performed at the corresponding time point. DCs were divided into PBS alone group and LPS alone group, DCs successfully transfected with lentivirus containing siRNA sequence of FAM134B gene were divided into FAM134B-knockdown+PBS group and FAM134B-knockdown+LPS group, and DCs successfully transfected with empty lentivirus were divided into empty vector+PBS group and empty vector+LPS group. These cells were stimulated correspondingly and cultured for 24 hours. The protein expression of FAM134B was detected using Western blotting (n=3); the apoptotic rate of cells was determined by flow cytometry (n=3); the situation of apoptosis was observed by Hoechst staining, and the apoptotic rate was calculated (n=5); the protein expressions of cleaved cysteine aspartic acid specific protease-3 (caspase-3), B cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) were detected using Western blotting, and the ratio of Bax/Bcl-2 was calculated (n=5). Data were statistically analyzed with one-way analysis of variance (ANOVA), least significant difference test, and ANOVA for factorial design. Results: Compared with those in LPS stimulation 0 h group, the protein expressions of FAM134B of cells in LPS stimulation 12 h group and LPS stimulation 24 h group were significantly increased (P<0.05), the protein expressions of SEC61B of cells in LPS stimulation 6 h group, LPS stimulation 12 h group, LPS stimulation 24 h group, and LPS stimulation 72 h group were significantly decreased (P<0.05), and the ratios of LC3B-Ⅱ/LC3B-Ⅰ of cells in LPS stimulation 24 h group and LPS stimulation 72 h group were obviously increased (P<0.05). As the most significant changes of three proteins were seen in the cells of LPS stimulation 24 h group, 24 h was used as the duration of subsequent LPS stimulation. After 24 hours of culture, the expression of FAM134B and its co-localization with LC3B and lysosomal probes in the cells of LPS group were all significantly enhanced, with a significant increase in the number of autolysosomes in comparison with those in PBS group. Both the empty vector group and the FAM134B-knockdown group showed high intensity fluorescence in the cells at post transfection hour 72, but the blank control group showed no fluorescence in the cells at the corresponding time point. After 24 hours of culture, the protein expression of FAM134B of cells in FAM134B-knockdown+PBS group was significantly lower than the expressions in PBS alone group and empty vector+PBS group (with P values all <0.05), the protein expression of FAM134B of cells in FAM134B-knockdown+LPS group was significantly lower than the expressions in LPS alone group and empty vector+LPS group (with P values all <0.05), the protein expression of FAM134B of cells in LPS alone group was significantly higher than that in PBS alone group (P<0.05), while the protein expression of FAM134B of cells in empty vector+LPS group was significantly higher than that in empty vector+PBS group (P<0.05). After 24 hours of culture, flow cytometry assay revealed that the apoptotic rate of cells in PBS alone group, LPS alone group, empty vector+PBS group, empty vector+LPS group, FAM134B-knockdown+PBS group, and FAM134B-knockdown+LPS group were (13.3±0.8)%, (32.6±4.3)%, (17.0±1.5)%, (51.7±3.3)%, (52.4±3.1)%, and (62.3±2.6)%, respectively. After 24 hours of culture, compared with those in LPS alone group and empty vector+LPS group, the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2, and the apoptotic rates of cells detected by flow cytometry and Hoechst staining were significantly increased in FAM134B-knockdown+LPS group (P<0.05); compared with those in the corresponding PBS treatment group, namely, PBS alone group, empty vector+PBS group, and FAM134B-knockdown+PBS group, the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2, and the apoptotic rates of cells detected by flow cytometry and Hoechst staining were significantly increased in LPS alone group, empty vector+LPS group, and FAM134B-knockdown+LPS group (P<0.05). Conclusions: The activation of reticulophagy mediated by FAM134B in mouse DCs is enhanced and peaked in 24 hours under LPS stimulation, and the activated reticulophagy has a significant inhibitory effect on cell apoptosis.

[Novel strategy of sepsis immunomodulation targeting dendritic cells]

Dendritic cells (DCs) are the major antigen-presenting cells that play critical roles in regulating both innate and acquire immune responses. In the state of sepsis, the number of DCs is obviously decreased with inhibited antigen presenting ability as well as abnormal cytokine secretion, thereby resulting in an impairment of T lymphocyte activation. Previous studies have demonstrated that the depletion and dysfunction of DCs appear to be the main causes associated with the development of sepsis-induced immunosuppression. Based on the characteristic changes of DCs in sepsis and analysis of recent research progress, the authors propose a novel strategy of immunomodulation targeting the apoptosis, differentiation, and dysfunction of DCs, in order to provide new ideas for the prevention and treatment of severe burns and trauma complicated with sepsis.

[Rehabilitation strategy for the improvement of long-term outcomes of patients after sepsis]

Survivors of sepsis still face high risks of secondary infection and mortality after hospital discharge. Meanwhile, the persistent cognitive, psychological, and physical disorders affect their long-term outcomes and life qualities. In the current review, we analyze the factors for the poor outcomes and discuss the beneficial rehabilitation strategies to improve the long-term outcomes of patients after sepsis, including psychological intervention, early mobility, nutrition support, and immune modulation, etc.

[Early predictive value of high density lipoprotein cholesterol for secondary acute kidney injury in sepsis patients]

Objective: To investigate the changes of high density lipoprotein cholesterol (HDL-C) in sepsis patients and its early predictive value for secondary acute kidney injury (AKI) in such patients. Methods: A retrospective case series study was conducted. From June 2019 to June 2021, 232 sepsis patients who met the inclusion criteria were admitted to the Second Hospital of Hebei Medical University, including 126 males and 106 females, aged 24 to 71 years. According to whether complicating secondary AKI, the patients were divided into non-AKI group (n=158) and AKI group (n=74). Data of patients between the two groups were compared and statistically analyzed with independent sample t test or chi-square test, including the sex, age, body mass index (BMI), body temperature, heart rate, primary infection site, combined underlying diseases, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score and sepsis-related organ failure assessment (SOFA) score at admission, and the serum levels of C-reactive protein (CRP), procalcitonin, creatinine, cystatin C, and HDL-C measured at diagnosis of sepsis. The multivariate logistic regression analysis was performed on the indicators with statistically significant differences between the two groups to screen the independent risk factors for developing secondary AKI in 232 sepsis patients, and the joint prediction model was established based on the independent risk factors. The receiver operating characteristic (ROC) curve of the independent risk factors and the joint prediction model predicting secondary AKI in 232 sepsis patients were drawn, and the area under the curve (AUC), the optimal threshold, and the sensitivity and specificity under the optimal threshold were calculated. The quality of the above-mentioned AUC was compared by Delong test, and the sensitivity and specificity under the optimal threshold were compared using chi-square test. Results: The sex, age, BMI, body temperature, heart rate, primary infection site, combined underlying diseases, and CRP level of patients between the two groups were similar (P>0.05). The procalcitonin, creatinine, cystatin C, and scores of APACHE Ⅱ and SOFA of patients in AKI group were all significantly higher than those in non-AKI group (with t values of -3.21, -16.14, -12.75, -11.13, and -12.88 respectively, P<0.01), while the HDL-C level of patients in AKI group was significantly lower than that in non-AKI group (t=6.33, P<0.01). Multivariate logistic regression analysis showed that creatinine, cystatin C, and HDL-C were the independent risk factors for secondary AKI in 232 sepsis patients (with odds ratios of 2.45, 1.68, and 2.12, respectively, 95% confidence intervals of 1.38-15.35, 1.06-3.86, and 0.86-2.56, respectively, P<0.01). The AUCs of ROC curves of creatinine, cystatin C, HDL-C, and the joint prediction model for predicting secondary AKI in 232 sepsis patients were 0.69, 0.79, 0.89, and 0.93, respectively (with 95% confidence intervals of 0.61-0.76, 0.72-0.85, 0.84-0.92, and 0.89-0.96, respectively, P values all below 0.01); the optimal threshold were 389.53 μmol/L, 1.56 mg/L, 0.63 mmol/L, and 0.48, respectively; the sensitivity under the optimal threshold were 76.6%, 81.4%, 89.7%, and 95.5%, respectively; the specificity under the optimal threshold values were 78.6%, 86.7%, 88.6%, and 96.6%, respectively. The AUC quality of cystatin C was significantly better than that of creatinine (z=2.34, P<0.05), the AUC quality and sensitivity and specificity under the optimal threshold of HDL-C were all significantly better than those of cystatin C (z=3.33, with χ2 values of 6.43 and 7.87, respectively, P<0.01) and creatinine (z=5.34, with χ2 values of 6.32 and 6.41, respectively, P<0.01); the AUC quality and sensitivity and specificity under the optimal threshold of the joint prediction model were all significantly better than those of creatinine, cystatin C, and HDL-C (with z values of 6.18, 4.50, and 2.06, respectively, χ2 values of 5.31, 7.23, 3.99, 6.56, 7.34, and 4.00, respectively, P<0.05 or P<0.01). Conclusions: HDL-C level in sepsis patients with secondary AKI is significantly lower than that in patients without secondary AKI. This is an independent risk factor for secondary AKI in sepsis patients with a diagnostic value being superior to that of creatinine and cystatin C. The combination of the aforementioned three indicators would have higher predicative valuable for secondary AKI in sepsis patients.

[New understanding on the immunity for severe infections and complications in burns and trauma]

The mechanisms of burn/trauma related infection are complicated, involving uncontrolled inflammation, immune disorder, coagulation abnormality, and pathophysiological changes of multiple systems or organs. Although active management of primary diseases, application of antibiotics, and organ support treatment are the basis for the management of burn/trauma related infection, immune modulation opens up a new direction for the intervention of burn/trauma related infection and the relevant complications. In-depth understanding of inflammation-immune response and its regulatory mechanisms, and exploring new early warning biomarkers and immune interventional strategies are of great significance for improving the level of treatment of clinical burn/trauma related infections and improving the prognosis of patients.

[Deepening the understanding of the diagnostic system and therapeutic strategy for burn sepsis]

Burn patients with large area of skin defect are prone to cause wound infection, severe fluid loss, and hypermetabolism, etc, which lead to sequential dysfunction of multiple systems and easily induce severe systemic infections and sepsis. At present, sepsis has been the leading causes of death in severe burn patients, and its early diagnosis and timely treatment are critical for successful treatment of patients. As burn sepsis has unique pathophysiological characteristics, the diagnostic criteria for general sepsis lack specificity for burn sepsis. Therefore, to understand the pathogenesis of burn will help deepen the understanding of the diagnostic system and interventional way of burn sepsis, thus developing more precise and intelligent therapeutic strategy.

[Analysis on prediction power of HIV infection risk assessment tool in men who have sex with men in Guizhou province]

Objective: To evaluate the prediction power of HIV infection risk assessment tool and the applicability in MSM in Guizhou province. Methods: MSM were recruited through snowball sampling method. Questionnaire surveys were conducted among the MSM using HIV infection risk assessment tool, and combined with HIV serologic test results, the risk prediction power of HIV infection risk assessment tool was evaluated. Results: A total of 3 379 MSM were recruited from January 2018 to December 2019 in Guizhou. The HIV infection rate was 3.3%(111/3 379). The mean risk scores of HIV positive and HIV negative MSM were (12.15±3.08) and (12.07±3.07), respectively. The difference in risk score was significant between MSM with different HIV status (t=8.69, P<0.001). According to the principle of decision tree, individual risk scores were divided into following three categories: ≤11.96, 11.97-14.80 and >14.80, the HIV infection rate was 0.8%, 4.3% and 8.6% respectively, suggesting that the higher the individual risk score was, the higher the HIV infection rate was (trend χ²=88.18, P<0.001). Multivariate logistic regression analysis showed that the higher the individual risk score was, the higher the risk of HIV infection was. Compared to the total score ≤11.96, the aOR values at total scores of 11.97-14.80 and >14.80 were 6.34 (95%CI: 3.38-11.88) and 14.07(95%CI: 7.44-26.61), respectively. The risk of HIV infection in Miao ethnic group was higher than that in Han ethnic group (aOR=1.83, 95%CI:1.04-3.21), and the risk of HIV infection in those with education level of primary school and below was higher than that in undergraduates or those with education level of junior college and above (aOR=2.50, 95%CI:1.06-5.88), and the risk of HIV infection was higher in those who had bisexual behaviors than in those who had homosexual behaviors (aOR=1.95, 95%CI:1.19-3.19). The risk of HIV infection was higher in those who had never received HIV testing (aOR=1.53, 95%CI:1.01-2.33). The area under the receiver operating characteristic (ROC) curve and area under ROC (AUC) for HIV infection prediction was 0.751 (95%CI:0.710-0.792, P<0.001). The maximum Youden's index was individual risk score of 12.56, and the sensitivity of the risk assessment tool was 0.838, and its specificity was 0.412. Conclusions: The results of HIV infection risk assessment tool in Guizhou indicated that in MSM the higher the individual risk score, the higher the risk of HIV infection is. The tool can be used to evaluate the risk of HIV infection in MSM, but the specificity should be improved.

[A survey on sexual needs and factors of HIV risky sexual behaviors among elderly men at different ages in two communities of Qiandongnan Miao and Dong autonomous prefecture]

Objective: To understand sexual needs and factors of risky sexual behaviors among elderly men at different ages in two communities of Qiandongnan Miao and Dong autonomous prefecture and provide basis for targeted HIV prevention and intervention. Methods: Two communities in the prefecture were selected as study sites. Questionnaire surveys were carried out among elderly men aged 50 and over who visited or consulted in the communities from June to December 2018, and they were tested for HIV and syphilis antibodies. Results: Among 400 elderly men, 209 (52.2%) were 50-64 years old, and 191(47.8%) were above 65 years old. They were mainly Miao people, accounting for 66.3% (265/400), and 235 (58.8%) had an education no more than 6 years. HIV awareness of the two age groups were only 25.8% (54/199) and 26.2% (50/191), respectively. Among those aged 50-64, 142 (68.0%) felt normal sexual desire, and 153 (73.6%) reported penile erections or erections in most cases whenever sex, and 52.9% (110) ejaculated most of the time. HIV prevalence was 1.0% (4/400). Compared with the over 65-year-old group, the proportion of having sex with spouse/stable partners (89.5%, 179/200), proportion of no condom use with their spouse/stable sexual partners during the most recent sex (93.8%, 168/179), proportion of having casual sex (11.0%, 23/209) and commercial sex (3.8%, 8/209) were all higher among 50-64 age group. In comparison to those aged over 65 years old, average monthly income>3 000, and use of sex helper, aged 50-64 (OR=2.70, 95%CI: 1.22-5.95), average monthly income ≤1 000 yuan (OR=2.79, 95%CI: 1.25-6.21), and no use of sex helper (OR=3.78) (95%CI: 1.65-8.67) were related factors of HIV risky sexual behavior last time. Conclusion: Elderly men in the minority prefecture had low HIV awareness. Compared with those≥65 years old, the 50-64 age group had more active sexual behaviors and higher sexual needs. Those from 50-64 age group, with lower economic level and good sexual ability were more likely to have HIV risky sexual behaviors.

[Influence of Xuebijing injection and its component paeoniflorin on immune function and survival rate of septic rats]

Objective: To explore the influence of Xuebijing injection (hereinafter referred to as Xuebijing) and its component paeoniflorin on immune function of regulatory T cells (Tregs) of spleen and survival rate of septic rats. Methods: (1) CD4(+) CD25(+) Tregs and CD4(+) T cells were isolated and purified from spleens of three 9 to 12 weeks old Sprague-Dawley male rats (the same age, breed, and gender below) by immunomagnetic beads. According to the random number table (the same grouping method below), CD4(+) CD25(+) Tregs were divided into blank control group, simple CD3/CD28 group, simple endotoxin/lipopolysaccharide (LPS) group, LPS+ Xuebijing group, and LPS+ paeoniflorin group, with 6 wells in each group. The cells in simple CD3/CD28 group, simple LPS group, LPS+ Xuebijing group, and LPS+ paeoniflorin group were cultured in RPMI 1640 medium containing fetal bovine serum in volume fraction of 10%, 1.25 μg CD3, and 2.5 μg CD28 for 24 hours. Then 1 μg/mL LPS in the volume of 1 μL was added to the cells in simple LPS group, LPS+ Xuebijing group, and LPS+ paeoniflorin group. Moreover, 5 mg/mL Xuebijing in the volume of 1 μL and 80 μmol/L paeoniflorin in the volume of 1 μL were added to the cells in LPS+ Xuebijing group and LPS+ paeoniflorin group, respectively, which were cultured for another 72 hours. Cells in blank control group were routinely cultured in RPMI 1640 medium containing fetal bovine serum in volume fraction of 10% for 96 hours. The expressions of cytotoxic T lymphocyte antigen 4 (CTLA-4) and forkhead wing-link transcription factor 3 (Foxp3) and apoptosis of CD4(+) CD25(+) Tregs were measured by flow cytometry. The interleukin-10 (IL-10) level from culture supernatant of CD4(+) CD25(+) Tregs was determined by enzyme-linked immunosorbent assay (ELISA). CD4(+) T cells were divided into blank control' group, simple CD3/CD28' group, simple LPS' group, LPS+ Xuebijing' group, and LPS+ paeoniflorin' group, with 6 wells in each group. After being cocultured with the corresponding CD4(+) CD25(+) Tregs treated as before for 72 hours, the proliferative activity of CD4(+) T cells was measured by flow cytometry, and IL-4 level from culture supernatant of CD4(+) T cells was determined by ELISA. (2) One hundred and twenty rats were divided into sham surgery group, simple sepsis group, sepsis+ Xuebijing group, and sepsis+ paeoniflorin group, with 30 rats in each group. The septic rat model was reproduced by cecal ligation and puncture surgery in simple sepsis group, sepsis+ Xuebijing group, and sepsis+ paeoniflorin group. In sham surgery group, the rats were only performed with laparotomy to simulate surgery. In sepsis+ Xuebijing group, the rats were given post-surgical injection of 4 mL/kg Xuebijing through tail vein, twice a day. In sepsis+ paeoniflorin group, the rats received 978 μg paeoniflorin via tail vein, twice a day. The survival rates of rats in the four groups on post surgery day 1, 2, 3, 4, 5, 6, and 7 were observed and recorded. The surviving cure of Kaplan-Meier was drawn. Data were statistically analyzed with one-way analysis of variance, least significant difference t test. The surviving curve was analyzed by Log-rank (Mantel-Cox) test. Results: (1) Compared with those in blank control group, the expressions of CTLA-4 and Foxp3 of CD4(+) CD25(+) Tregs (t=27.19, 17.00, P<0.01) and IL-10 level from culture supernatant (t=40.76, P<0.01) were significantly increased in rats in simple LPS group. Compared with those in simple LPS group, the expressions of CTLA-4 and Foxp3 of CD4(+) CD25(+) Tregs (t(LPS+ Xuebijing group)=31.03, 11.27, t(LPS+ paeoniflorin group)=5.79, 5.64, P<0.01) and IL-10 level from culture supernatant (t=15.49, 4.20, P<0.01) was significantly decreased in LPS+ Xuebijing group and LPS+ paeoniflorin group. Compared with that in blank control group, the apoptosis rate of CD4(+) CD25(+) Tregs in simple LPS group was significantly declined (t=6.02, P<0.01). Compared with the rate in simple LPS group, the apoptosis rates of CD4(+) CD25(+) Tregs in LPS+ Xuebijing group and LPS+ paeoniflorin group were significantly increased (t=20.32, 8.60, P<0.01). (2) Compared with those in simple CD3/CD28' group, the proliferative rate of CD4(+) T cells was significantly decreased in simple LPS' group (t=22.47, P<0.01), while IL-4 level from culture supernatant was significantly elevated (t=3.51, P<0.01). Compared with those in simple LPS' group, the proliferative rates of CD4(+) T cells in LPS+ Xuebijing' group and LPS+ paeoniflorin' group were significantly increased (t=16.31, 11.48, P<0.01), while IL-4 level from culture supernatant showed no obvious change. (3) The post-operative 7-day survival rates of rats in sham surgery group, simple sepsis group, sepsis+ Xuebijing group, sepsis+ paeoniflorin group were 100% (30/30), 30% (9/30), 57% (17/30), and 47% (14/30), respectively. Compared with that in simple sepsis group, the survival rate within post-operative 7-day of rats in sepsis+ Xuebijing group was significantly higher (χ(2)=4.34, P<0.05), while the survival rate within post-operative 7-day of rats in sepsis+ paeoniflorin group showed no obvious change. Conclusions: Both Xuebijing and its component paeoniflorin are capable of reversing sepsis-induced inhibitory immune function and apoptotic resistant of Tregs in rats, and further improving the proliferative activity of T cells. In addition, the effect of paeoniflorin on improvement of survival rate of rats with sepsis is weaker than Xuebijing.

[Survival time and related factors on HIV/AIDS patients in Guizhou province from 1995 to 2018]

Objective: To examine the survival time and related factors on HIV/AIDS patients in Guizhou province from 1995 to 2018. Methods: A retrospective cohort study was conducted to analyze the HIV/AIDS case from 1995 to 2018 in Guizhou province with data gathered from the "Chinese National Comprehensive HIV/AIDS Prevention and care Information system". Survival rate was calculated by life table and survival time was estimated by Kaplan-Meier. Related factors on survival time were analyzed by Cox regression model. Results: A total of 53 232 HIV/AIDS cases were included in the study, with the mortality rate as 8.53/100 person-years (14 210/166 679.18), median survival time as 10.20 (95%CI: 9.91-10.48) years, and survival rates of 1, 5, 10 and 20 years as 0.85, 0.68, 0.51, 0.36, 0.19 respectively. Results from the multivariate Cox regression analysis showed that factors as: being male (compared with females, aHR=0.757, 95%CI: 0.727-0.788), with antiviral treatment (ART) (compared with those without ART, aHR=0.173, 95%CI: 0.165-0.181), CD(4)<200 cells/μl[compared with CD(4)(+)T cells (CD(4)) ≥200 cells/μl, aHR=0.410, 95%CI: 0.387-0.435], age ≥45 (compared with age<45, aHR=1.506, 95%CI: 1.193-1.901), illiterate (compared with having high school education or above, aHR=0.904, 95%CI: 0.832-0.982), unmarried (compared with divorced or widowed, aHR=0.896, 95%CI: 0.848-0.946), through heterosexual transmission (compared with homosexual transmission, aHR=0.555, 95%CI: 0.487-0.632), ethnic minorities (compared with Hans, aHR=1.185, 95%CI: 1.114-1.262), and farmers/migrant workers (compared with domestic/unemployed,aHR=0.874, 95%CI: 0.834-0.916,) etc., were related to the survival time of HIV/AIDS, in Guizhou province. Conclusions: The mortality rate of HIV/AIDS in Guizhou province appeared relatively high, but with no obvious downward trend seen in the last years. Factors as being male, age ≥45, low education level, ethnic minorities, CD(4)<200 cells/μl were identified as related to the HIV/AIDS survival time. We would suggest that treatment and follow-up management programs should be strengthened to improve the quality of life among these patients.

Novel treatment of refractory / recurrent pulmonary hepatoblastoma

BACKGROUND

There is no consensus about how to manage pulmonary metastasis in patients with hepatoblastoma. We reviewed a treatment with a combination of oxaliplatin, vincristine, and topotecan (OVT) paired with radiofrequency ablation (RFA) of 12 patients with multiple refractory / recurrent pulmonary hepatoblastoma.

METHODS

The medical records from patients with ≤21 years of age presenting with multiple deposits (≥2) of refractory / recurrent pulmonary hepatoblastoma were reviewed. The following data were extracted from each patient: age, gender, histological subtyping, cycles of OVT, tumor size, biomarkers, chemotherapy regimen and dosage, RFA details, treatment response, follow up, and patient outcomes. The primary outcome measure was the complete response (CR) of pulmonary diseases, and secondary outcomes were event-free survival rate and overall survival rate.

RESULTS

Of 12 assessable patients, three (25%) (95% CI, 46.3-104) patients achieved PR (partial resopnse) after they finished OVT. After RFA, five (41.7%) (95% CI, 8.95-74.4) patients achieved CR (complete response). The 2 year event-free survival rate was 33% (95% CI, 20.5-64.6). The 2 year overall survival for the study group was 41.7% (95% CI, 8.9-74.4). All toxicity events were handled satisfactorily and no toxic related deaths were observed.

CONCLUSIONS

Our review report shows that OVT combined with RFA can be a successful treatment modality for previously heavily treated refractory / recurrent pulmonary metastatic lesions from hepatoblastoma.

[Advances in the research of the relationship between skin regulatory T cells and wound healing and immune diseases]

As the body's largest organ, skin harbors a large amount of immune cells to regulate both innate and adaptive immune responses. Regulatory T cells (Tregs), as a subset of T lymphocytes with negative regulatory functions, play an important role in maintaining the immune homeostasis of different tissue. However, researches of skin Tregs are largely limited and uncompleted as compared with other tissue. In recent years, a comprehensive understanding is increasingly showing the specialized functions of Tregs in skin, including the orchestration of tissue wound healing, involvement in hair follicle recycling, and modulation of proper immune homeostasis. In this review, we outline the classification and characteristics of Tregs in skin, distribution, migration routes, immune effects, and relationship with wound healing, which aims to deepening our understanding towards the immunological effects of T lymphocytes subsets in skin and its regulatory pathways.

[Update in immune regulatory dysfunction of dendritic cells in sepsis]

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Further development of sepsis usually leads to septic shock or even death. Many previous studies have focused on the abnormal reactions of monocytes/macrophages, neutrophils, complement system, or cytokine inflammation in sepsis. Many evidences in recent years suggest that dendritic cells, as the most powerful antigen-presenting cells in innate immune system of body, play important role during the process of immune disorders of sepsis. In this article, I review the main classification, immune function, monitoring method, regulatory pathways of dendritic cells and their clinical significance in immune disorders of sepsis, so as to find new strategies for immune regulation of sepsis.

Unexpected vincristine-induced systemic capillary leak syndrome in patients with Wilm's tumor: A single institution experience

Capillary leak syndrome (CLS) is a rare but fatal disease, which has been reported following the infusions of interleukin-2, tumor necrosis factor, granulocyte-colony stimulating factor, certain monoclonal antibodies, and gemcitabine, suggesting that drugs can also cause CLS. In this study, seven Wilm's tumor cases with CLS had been presented, which was suggested to be caused following administration of vincristine (VCR). From January 1st, 2014 to December 31st, 2016, medical records from Wilm's tumor patients were reviewed to identify those diagnosed with CLS. Moreover, the following data were extracted for each patient, including age, gender, histological subtyping, tumor stage, risk group, biomarkers, chemotherapy regimen and dosage, surgery details, clinical manifestation of CLS, treatment regimen of CLS, and patient outcomes. From January 1st, 2014 to December 31st, 2016, a total of seven patients with Wilms tumor were identified with a diagnosis of VCR-associated CLS. Typically, for these seven cases in our study, the predominant features of CLS included interstitial pneumonia and pulmonary edema. Moreover, steroid therapy was demonstrated as the most effective therapy in our study. The clinical features of VCR-induced CLS are distinct, and pediatric oncologists should be aware of CLS that manifests as interstitial pneumonia and pulmonary edema during the VCR treatment for patients with Wilm's tumor.

[Mortality and influencing factors on injecting drug users with HIV/AIDS in Guizhou province, 1996-2015]

Objective: To understand the mortality and influencing factors on injecting drug users (IDUs) with HIV/AIDS, in Guizhou province, 1996-2015. Methods: A retrospective cohort study was conducted on IDUs with HIV/AIDS that were reported through national comprehensive HIV/AIDS information system, in Guizhou province during 1996-2015. Cox proportional hazard regression model was used to analyze the influencing factors on the mortality of HIV/AIDS. Results: A total of 3 958 cases of IDUs with HIV/AIDS were recruited in this study, with all-cause mortality rate of 44.01% (1 742/3 958) and total mortality rate of 7.80/100 person-years, respectively. The median survival time between diagnosis and death was 8.08 years. Mortality rate was 3.57/100 person-years in the group receiving antiretroviral therapy (ART). The mortality appeared to be 4.08/100 person-years in the group who were on methadone maintenance treatment (MMT). Data from the multiple regression analysis indicated that factors of gender, ethnicity, age when HIV/AIDS diagnosis was made, CD(4)(+)T lymphocyte (CD(4)) count at the first testing, ART and MMT were significantly associated with deaths among these people. The risk of death in females was 0.82 times (95%CI: 0.69-0.98) higher than that in males. The risk of deaths among the ethnic minority subjects was 1.39 times (95%CI: 1.21-1.60) higher than that of the Hans. The risk of death appeared to be 2.44 times higher (95%CI: 1.07-5.56) in the over-50-year of age group than in the <20 year-old group, when HIV/AIDS was diagnosed for the first time. The risk of death in CD(4) ≥500/μl group in the first time was 0.27 times (95%CI: 0.22-0.32) more than CD(4) <200/μl group in the firs time. The risk of death in cases who were treated with ART or MMT was 2.83 times (95%CI: 2.45-3.26) and 1.35 times (95%CI: 1.15-1.59) higher than those who did not receive any treatment, respectively. Conclusion: Higher risks on death seemed to be related to the following factors: being male, older age at the time of diagnosis, lower CD(4) at diagnosis, not on ART or MMT among the IDUs with HIV/AIDS in Guizhou province, between 1996-2015.

[Influence of vagus nerve on multiple organ function and immune reaction of T lymphocytes in septic rats]

Objective: To explore influence of vagus nerve on multiple organ function and immune reaction of T lymphocytes in septic rats. Methods: Forty Sprague-Dawley rats were divided into sham injury group, sepsis group, vagus nerve stimulation (VNS) group, and vagotomy (VGX) group, according to the random number table, with 10 rats in each group. Rats in sepsis group, VNS group, and VGX group were inflicted with sepsis by cecal ligation and puncture (CLP). Rats in VNS group were given electrical stimulation on left cervical vagus nerve for 15 min right after CLP. Rats in VGX group underwent vagotomy of left cervical vagus nerve at 30 min before CLP. At 24 h after CLP, serum of rats was collected to detect levels of alanine transaminase (ALT), aspartate aminotransferase (AST), glycocholic acid (CG), creatine kinase (CK), myocardial creatine kinase (CK-MB), blood urea nitrogen (BUN), and serum creatinine by fully automatic biochemistry analyzer. The left lung of rats was collected to determine wet or dry mass, and wet to dry (W/D) ratio was calculated. The right lung of rats was collected to measure the activity of pulmonary myeloperoxidase (MPO) by enzyme linked immunosorbent assay (ELISA). Spleen of rats was collected to determine the proliferative activity of CD4(+) T lymphocytes by cell counting kit 8, and real-time fluorescence quantitative polymerase chain reaction and ELISA were used to quantify mRNA expressions and levels of interleukin 2 (IL-2), interferon-γ, and IL-4, respectively. Data were processed with one-way analysis of variance and Tukey's honest significant difference test. Results: (1) The levels of serum ALT, AST, CG, CK, CK-MB, BUN, and creatinine, pulmonary W/D ratio, as well as MPO activity of rats in sepsis group were significantly higher than those in sham injury group and VNS group (P<0.01) and were significantly lower than those in VGX group (P<0.01). (2) The proliferative activity of CD4(+) T lymphocytes of rats in sepsis group was 0.93±0.03, which was significantly lower than 1.54±0.07 of rats in sham injury group (P<0.01). The proliferative activity of CD4(+) T lymphocytes of rats in VNS group was 1.15±0.15, which was significantly higher than that of rats in sepsis group (P<0.01). The proliferative activity of CD4(+) T lymphocytes of rats in VGX group was 0.75±0.06, which was obviously lower than that of rats in sepsis group (P<0.01). (3) In comparison with those of rats in sham injury group, the levels of IL-2 and interferon-γ in CD4(+) T lymphocytes of rats in sepsis group were markedly decreased (P<0.01), while the level of IL-4 was significantly increased (P<0.01). In comparison with those of rats in sepsis group, the levels of IL-2 and interferon-γ in CD4(+) T lymphocytes of rats in VNS group were obviously increased (P<0.01), while the level of IL-4 was markedly decreased (P<0.01). As compared with those of rats in sepsis group, the levels of IL-2 and interferon-γ in CD4(+) T lymphocytes of rats in VGX group were markedly decreased (P<0.01), while the level of IL-4 was significantly increased (P<0.01). (4) As compared with those of rats in sham injury group, expressions of IL-2 and interferon-γ mRNA in CD4(+) T lymphocytes of rats in sepsis group were markedly decreased (P<0.01), while expression of IL-4 mRNA was significantly increased (P<0.01). Expressions of IL-2 and interferon-γ mRNA in CD4(+) T lymphocytes of rats in VNS group were obviously increased when compared with those of rats in sepsis group (P<0.01), while expression of IL-4 mRNA was markedly decreased (P<0.01). In comparison with those of rats in sepsis group, expressions of IL-2 and interferon-γ mRNA in CD4(+) T lymphocytes of rats in VGX group were markedly decreased (P<0.01), while expression of IL-4 mRNA was significantly increased (P<0.01). Conclusions: Electrical stimulation of vagus nerve can significantly improve multiple organ dysfunction and reverse immunosuppression of T lymphocytes in septic rats, while vagotomy of vagus nerve may enhance the susceptibility of rats to sepsis.

[Precision evaluation of immune status and its significance in sepsis after burns or trauma]

Sepsis induced by major burns, trauma, and hemorrhage, remains a major cause of death of patients in intensive care units, and it may result in both the widespread activation and dysfunction of the innate as well as adaptive responses in host immune system. A large amount of information concerning subsets of innate and adaptive immune cells in sepsis has implicated that these cells, including neutrophils, macrophages, dendritic cells, T lymphocytes, regulatory T lymphocytes, and natural killer cells, have profound effects on immunoreactivity during acute insults or sepsis through modulating multiple receptor expressions or cytokine secretion, in turn contributing to the development and outcome of sepsis. It is of great significance that precision monitoring of immune function and the related indicators might help to assess the risk of secondary infection, the prognosis of septic patients, and guide the treatment of septic complications.

[Effects of rabbit adipose-derived mesenchymal stem cells on the healing of skin deep partial-thickness scald wound of rabbit]

OBJECTIVE

To investigate the effects of local injection of rabbit adipose-derived mesenchymal stem cells (ADSCs) on the healing of skin deep partial-thickness scald wound of rabbit.

METHODS

ADSCs were isolated from adipose tissue of one New Zealand rabbit and then sub-cultured. ADSCs of the third passage were used in the following experiments. Twenty-four rabbits were divided into ADSCs group (n=12) and control group (n=12) according to the random number table, and one deep partial-thickness scald wound with diameter of 5 cm on the two sides of the back near the buttocks was made. From post injury day (PID) 2, 2 mL suspension of EdU-labeled ADSCs with the number of 5×10(5) per mL was subcutaneously injected in wounds of rabbits in ADSCs group, while the rabbits in control group were given 2 mL serum-free DMEM until the wounds were healed. Wound healing processes of rabbits in two groups were observed every day, and the healing time was recorded. On PID 7, 14, 21, and 28, areas of wound of three rabbits in two groups were measured and the healing rates were calculated, respectively. The healed wound tissue was harvested to observe the morphology by HE staining, and the expression of collagen fiber was observed by Masson staining. The distribution of EdU-labeled ADSCs in healed wound tissue on PID 28 was observed by inverted fluorescence microscope. The expressions of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) of healed wound tissue on PID 7, 14, and 21 were detected by enzyme-linked immunosorbent assay. Data were processed with analysis of variance of factorial design and paired samples t test.

RESULTS

(1) The wound healing time of rabbits in ADSCs group was (19.5±1.1) d post injury, which was significantly shorter than that in control group [(23.3±1.5) d, t=4.50, P<0.05]. On PID 7, wounds of rabbits in two groups were dry with no obvious exudation, and redness and swelling around wounds disappeared gradually, the wound healing rate of rabbits in ADSCs group was (15.1±2.4)%, which was close to that in control group [(13.7±3.1)%, t=1.20, P>0.05]. On PID 14, wounds of rabbits in ADSCs group were dry and scabbed obviously, and the wound healing rate was (73.1±5.7)%, while wounds of rabbits in control group were little scabbed with little exudation, and the wound healing rate was significantly lower than that in ADSCs group [(52.9±5.1)%, t=8.06, P<0.01]. On PID 21, wounds of rabbits in ADSCs group were generally healed, and the wound healing rate was (95.6±3.0)%, while a few wounds still existed in rabbits of control group, and the wound healing rate was significantly lower than that in ADSCs group [(78.6±3.7)%, t=9.73, P<0.01]. On PID 28, wounds of rabbits in two groups were totally healed with the healing rate of 100%, and texture and microvascular responses of healed wound tissue in ADSCs group were better than those in control group. (2) On PID 7, fibroblasts in healed wound tissue of rabbits in two groups were all increased, and there were little vascular and collagen fiber proliferation with no obvious differences. On PID 14, the number of fibroblasts in healed wound tissue of rabbits in ADSCs group was more than that in control group, and the collagen fibers in healed wound tissue of rabbits in ADSCs group were arranged in dense and uniform, while those in control group were sparse and irregular. On PID 21, skin layers were differentiated in healed wound tissue of rabbits in two groups, and collagen fibers in healed wound tissue of rabbits in ADSCs group were still denser than that in control group. On PID 28, newborn skin was well differentiated in healed wound tissue of rabbits in ADSCs group, which was better than that in control group. There were a lot of thick collagen fibers in healed wound tissue of rabbits in two groups, and EdU-labeled ADSCs were involved in skin texture of rabbits in ADSCs group. (3) The expressions of VEGF and EGF in healed wound tissue of rabbits in two groups were similar on PID 7 (with t values respectively 0.70 and 0.91, P values above 0.05), which in ADSCs group were significantly higher than those in control group on PID 14 and 21 (with t values from 2.85 to 4.81, P values below 0.01).

CONCLUSIONS

The transplantation of ADSCs can promote the wound healing of skin deep partial-thickness scald wound of rabbit and shorten the wound healing time.

[A clinical study of serum protein markers in patients with 1-bromopropane poisoning]

Objective: To investigate the changes in protein expression in patients with 1-bromopropane (1-BP) poisoning using high-throughput proteomic technique and to screen out protein markers. Methods: Serum samples were collected from 3 patients with 1-BP poisoning and 15 controls. The label-free proteomic tech-nique was used for the quantitation and identification of proteins expressed in these samples, and the results were compared between the patients with 1-BP poisoning and the control population. The bioinformatics tools were used to analyze the function of differentially expressed proteins. Results: Compared with the control popula-tion, the patients with 1-BP poisoning had >2-fold upregulation of 38 proteins and >2-fold downregulation of 68 proteins. The differentially expressed proteins were mainly involved in immune response, signal transduction, and stress response. Conclusion: The proteins screened out may be potential protein markers for 1-BP poison-ing, which provides reliable and precise methods and thoughts for the diagnosis of 1-BP poisoning.

The tumor necrosis factor-alpha-induced protein 8 family in immune homeostasis and inflammatory cancer diseases

Within the immune system homeostasis is maintained by a myriad of mechanisms that include the regulation of immune cell activation and programmed cell death. The breakdown of immune homeostasis may lead to fatal inflammatory diseases. We set out to identify genes of tumor necrosis factor-alpha-induced protein 8 (TNFAIP8) family that has a functional role in the process of immune homeostasis. Tumor necrosis factor-alpha-induced protein 8 (TNFAIP8), which functions as an oncogenic molecule, is also associated with enhanced cell survival and inhibition of apoptosis. Tumor necrosis factor-alpha-induced protein 8-like 2 (TIPE2) governs immune homeostasis in both the innate and adaptive immune system and prevents hyper-responsiveness by negatively regulating signaling via T cell receptors and Toll-like receptors (TLRs). There also exist two highly homologous but uncharacterized proteins, TIPE1 and TIPE3. This review is an attempt to provide a summary of TNFAIP8 family associated with immune homeostasis and inflammatory cancer diseases.

Sensitive and selective liquid chromatography-mass spectrometry method for the quantification of rosiglitazone in human plasma

A sensitive and selective high-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (HPLC-ESI-MS-MS) method for determination of rosiglitazone in human plasma has been developed. After the addition of the internal standard, plasma samples were precipitated by acetonitrile. The compounds were separated on a proC18 column using a mixture of ammonium acetate buffer (0.02 M, pH 6.5) and acetonitrile (in the ratio of 47:53, v/v) as mobile phase. A Finnigan LCQdeca plus ion trap mass spectrometer connected to a Finnigan Surveyor HPLC was used to develop and validate the method. Linearity was established for the range of concentrations 1-1000 ng/ml with a coefficient of determination (r(2)) of 0.999. The intra-day accuracy for rosiglitazone ranged from 110.0 to 99.2% at low, medium and high levels. The inter-day accuracy was less than 15%. The lower limit of quantitation (LLOQ) was identified reproducible at 1.0 ng/ml with a precision of 5.7%. After validation, the method was used to study the pharmacokinetic profile of rosiglitazone in five healthy volunteers after administration of a single oral dose (4.0mg). The proposed method enabled the unambiguous evaluation and quantitation of rosiglitazone for pharmacokinetic, bioavailability or drug-drug interaction studies. A possible chromatography peak (m/z 121, its parent ion m/z 344) of N-demethyl rosiglitazone was observed at 3.49 min during determining rosiglitazone. This may be also a potential method for simultaneous determination of rosiglitazone and its metabolite N-demethyl rosiglitazone concentrations in plasma.

Effect of recombinant bactericidal/permeability-increasing protein on endotoxin translocation and lipopolysaccharide-binding protein/CD14 expression in rats after thermal injury

OBJECTIVE

To investigate the potential mechanisms underlying the in vivo effect of recombinant bactericidal/permeability-increasing protein (rBPI21) on endogenous bacteria or endotoxin translocation and lipopolysaccharide-binding protein/CD14 expression secondary to thermal injury.

DESIGN

Prospective, randomized, controlled animal study.

SETTING

College hospital animal research laboratory.

SUBJECTS

Thirty-six male Wistar rats weighing 250-300 g.

INTERVENTIONS

The rats were anesthetized, and a 35% total body surface area full-thickness burn was created. Animals were randomized to receive treatment with either rBPI21 or the control protein (albumin). rBPI21 (2 mg/kg body wt, BPI group) or a protein control preparation (burn group) in the same dose was administered in an intravenous bolus at 30 mins and 4 hrs after thermal injury. All animals were killed at 12 and 24 hrs postburn (six to ten rats for each interval). In addition, eight rats were taken as normal controls.

MEASUREMENT AND MAIN RESULTS

Our data showed that treatment with rBPI21 was effective in preventing endotoxin translocation secondary to severe burns. Meanwhile, tissue lipopolysaccharide-binding protein, CD14, and tumor necrosis factor-alpha mRNA expression in various organs were inhibited markedly by rBPI21 secondary to acute insults (p <.05-.01). Furthermore, significant reduction in serum aminoleucine transferase concentrations and elevation in intestinal diamine oxidase activities in the rBPI21-treated group were found compared with controls (p <.05-.01).

CONCLUSIONS

These findings indicate that endotoxin accumulated in local sites after thermal injury can markedly up-regulate lipopolysaccharide-binding protein/CD14 and tumor necrosis factor-alpha mRNA expression in various organs. Meanwhile, up-regulation of lipopolysaccharide-binding protein/CD14 expression would be the major molecular mechanism of increasing sensitivity to endogenous endotoxin response after burns. Early treatment with rBPI21may be effective in attenuating multiple organ damage resulting from gut-origin endotoxin translocation. This might be associated with the down-regulation effects of tissue lipopolysaccharide-binding protein and CD14 gene expression by the use of rBPI21.

Upconverting phosphor reporters in immunochromatographic assays

Immunochromatographic assays have become popular diagnostic tools in a variety of settings because they are sensitive, fast, and easy to use. Here, we describe the use of a novel reporter, upconverting phosphors (UCP), in this assay format. UCP are submicron-sized, inorganic crystals that are excited with infrared light and that emit photons in the visible range depending on the ion composition of the crystal. Using human chorionic gonadotropin (hCG) as a model analyte to describe the properties of phosphors in immunochromatographic assays, a detection limit of 10 pg hCG in a 100-microl sample has been achieved on a regular basis, with occasional detection of 1 pg hCG. This represents at least a 10-fold improvement over conventional reporter systems such as colloidal gold or colored latex beads. Quantitation of analytes is possible over at least 3 orders of magnitude. Furthermore, an example is given of how UCP can be used for analyte multiplexing using a two-plexed wick for the detection of mouse IgG and ovalbumin. Thus, UCP lateral flow assays can be used for applications that are currently limited by assay sensitivity, and they can increase the probability of a diagnosis by verifying the presence of several analytes in the same sample.

[The biological effect of tetrahydrobiopterin and its potential role in sepsis]

It is well known that overproduction of nitric oxide (NO) is the final common pathway in septic shock. Tetrahydrobiopterin (BH4), a low molecular weight pterdine, is an essential cofactor required for the activity of NO synthase (NOS). Existing evidences show that lipopolysaccharide and proinflammatory cytokines can cause significant rises in bipoterin levels, which in turn augments the synthesis of NO. Also inhibition of biosynthesis of BH4 can decrease NO formation, implying that BH4 may be involved in the pathophysiological alterations of sepsis. However, the precise mechanisms of BH4 in regulating NO formation are not yet fully understood. In this review, we focus on the biological effects and regulation of BH4, as well as its potential role in sepsis. The therapeutic significance of biopterin synthesis inhibitors in septic symptoms is also discussed.

High sensitivity immunoassays using particulate fluorescent labels

The use of polystyrene fluorescent microspheres as sensitive labels in direct-detection (not enzymatically amplified) heterogeneous equilibrium "sandwich" immunoassays in 96-well plates is described. With mouse IgG as a model antigen, a fluorescent particulate label is more sensitive than a corresponding soluble reporter. The limit of detection of mouse IgG in the multiparametrically optimized assay was 0.2 ng/ml (7.6 x 10(8) antigens/ml) for the particulate reporter and 50 ng/ml (1.9 x 10(11) antigens/ml) for the soluble reporter. The sensitivities of assays using the particulate label were dependent on the surface densities of the capture and reporter antibodies and the concentration of reporter beads. Sensitivity was improved by adding the preformed reporter antibody/fluorescent microsphere complex to trapped antigen on the well surfaces instead of sequentially adding the reporter antibody and then the fluorescent microspheres. Maximal (equilibrium) binding of the particulate reporter to captured antigen occurred after 20 h with a concentration of 1.4 x 10(9) reporter beads/ml. Thus, particulate fluorescent labels provide high sensitivity in direct-detection immunoassays.

The inflammatory basis of trauma/shock-associated multiple organ failure

Multiple alterations in inflammatory and immunologic function have been demonstrated in clinical and experimental situations after trauma and hemorrhage, in particular the activation of various humoral (e.g. complement, coagulation) and cellular systems (neutrophils, endothelial cells, macrophages). As a consequence of this activation process there is synthesis, expression and release of numerous mediators (toxic oxygen species, proteolytic enzymes, adherence molecules, cytokines), which may produce a generalized inflammation and tissue damage in the body. Mediators are responsible for ongoing interactions of different cell types and for amplification effects through their networks and feedback cycles, finally leading to a sustained inflammation and multiple organ damage in the body. In the setting of trauma/shock, many activators including bacterial as well as non-bacterial factors may be present that will induce local and systemic inflammatory responses. Although the potential role of bacteria/endotoxin translocation and its clinical relevance remains controversial, many lines of evidence support the concept that the gut may be the reservoir for systemic sepsis and subsequent MOF in a number of pathophysiologic states.

Monoclonal antibody to endotoxin attenuates hemorrhage-induced lung injury and mortality in rats

OBJECTIVES

To determine the possible role of enteric bacteria-derived endotoxin in the pathogenesis of the lung injury and mortality in rats following hemorrhagic shock and resuscitation.

DESIGN

Prospective, randomized study.

SETTING

Animal laboratory of an institute for research traumatology.

SUBJECTS

Male Sprague-Dawley rats, weighing 450 to 480 g.

INTERVENTIONS

Anesthetized rats were subjected to a prolonged hemorrhagic shock (mean arterial pressure of 30 to 35 mm Hg for 180 mins) followed by resuscitation. A murine monoclonal antibody to lipopolysaccharide from Escherichia coli and Salmonella, WN1 222-5, was administered at a total dose of 5 mg/kg i.v., starting at the onset of shock (WN1 group). The control group was treated similarly to the WN1 group but received saline at the same volume as WN1 222-5.

MEASUREMENTS AND MAIN RESULTS

The 48-hr mortality rate was significantly reduced by WN1 222-5 treatment (28.6% in the treatment group vs. 78.6% in the control group; p = .0169). The characteristic lung injury in this model was significantly reduced in the WN1 group, as assessed by microscopic histopathologic examination increase in lung wet weight (7.60 +/- 0.47 g/kg in the control group vs. 5.14 +/- 0.31 g/kg in the WN1 group; p = .0002), and pulmonary neutrophilic infiltration (myeloperoxidase activity: 1835 +/- 567 mU/g wet weight in the control group vs. 891 +/- 212 mU/g wet weight in the WN1 group).

CONCLUSIONS

These data suggest that a) endotoxin derived from enteric bacteria might play an important role in the pathogenesis of lung injury; and b) antiendotoxin agents, such as WN1 222-5, appear to protect against endogenous bacterial endotoxin-related disorders in severe hemorrhagic shock in rats.

IL-6 release after intestinal ischemia/reperfusion in rats is under partial control of TNF

Although there is much evidence to substantiate the view that tumor necrosis factor (TNF) plays a pivotal role in the pathogenesis of multiple organ injury subsequent to intestinal ischemia/reperfusion (I/R), it is still unclear whether TNF is involved in triggering the release of other inflammatory mediators in this condition. The current study was designed to determine the potential effects of TNF blockade, by means of monoclonal antibody (TNF MoAb) treatment, on plasma interleukin 6 (IL-6) in rats after acute intestinal I/R injury. Anesthetized rats underwent 75-min occlusion of superior mesenteric artery followed by 6 hr of reperfusion. The animals were treated with TNF MoAb or control protein at a dose of 20 mg/kg i.v. 30 min before the onset of I/R. Similar IL-6 responses in both the portal and the systemic circulation were observed in animals subjected to intestinal I/R, who showed a progressive increase in plasma IL-6 concentration upon release of the clamp. In animals receiving TNF MoAb before I/R, the subsequent IL-6 release following reperfusion was significantly blunted compared to the levels in controls (P < 0.05). The present study demonstrates that the activation and/or release of IL-6 in the setting of acute gut I/R may, at least in part, be mediated via TNF-dependent mechanisms, providing further evidence that a complex interaction exists between TNF and IL-6.

Influence of selective decontamination of the digestive tract on cell-mediated immune function and bacteria/endotoxin translocation in thermally injured rats

OBJECTIVE

To determine the influence of pretreatment with selective decontamination of the digestive tract (SDD) on systemic immunosuppression, and the relationship between bacteria/endotoxin translocation and abnormalities of immune function in thermally injured rats.

DESIGN, MATERIALS, AND METHODS

Animals were subjected to a 40% full-thickness scald injury, and divided into SDD-treated and control groups. The treatment group received SDD (polymyxin E, tobramycin, and 5-flucytosine) by gavage twice daily for 3 days before the experiment and continued for 5 days after thermal injury. The control group was given the same amount of water. The parameters reflecting cell-mediated immunity, including splenocyte proliferation in response to mitogens, interleukin 2 (IL-2) production, and lymphocyte subpopulation, were measured before injury and 1 and 5 days after burn, respectively.

MEASUREMENTS AND MAIN RESULTS

Thermal injury resulted in marked reduction in splenocyte proliferative response to T-cell mitogens, IL-2 production, and T-helper/suppressor cells (CD4/CD8) ratio. Prophylactic treatment with SDD significantly decreased the incidences of bacterial translocation and endotoxemia, prevented suppressive mitogenic response and inadequate IL-2 production (p < 0.05-0.01) but did not affect the abnormal ratio of CD4 to CD8 T lymphocytes in blood (p > 0.05).

CONCLUSIONS

These results suggest that bacteria/endotoxin translocation from the gut appears to be involved in cell-mediated immune dysfunction as a consequence of thermal injury. Pretreatment with SDD might attenuate postburn immunosuppression by preventing translocation events.

Significance of TNF in hemorrhage-related hemodynamic alterations, organ injury, and mortality in rats

To evaluate the role of tumor necrosis factor-alpha (TNF-alpha) in hemodynamic alterations, multiple organ damage, and mortality caused by hemorrhagic shock, we employed a monoclonal antibody to TNF-alpha (TNF-alpha MAb) in anesthetized rats subjected to prolonged hemorrhagic shock (mean arterial pressure of 30-35 mmHg for 180 min) followed by resuscitation over 50 min. Treatment of rats with 20.0 mg/kg TNF-alpha MAb 15 min after the end of resuscitation significantly decreased the total peripheral resistance index (P = 0.031) and provided remarkable protection from multiple organ damage compared with controls. The 48-h survival rate was significantly higher in the treatment group (73.3%) than in the control group (26.7%; P = 0.029). The results suggest that TNF-alpha induced by hemorrhagic shock in rats is an important mediator of pathophysiological alterations associated with cardiovascular abnormalities, multiple organ injury, and even lethality. Postresuscitation treatment with TNF-alpha MAb, even after an initial TNF-alpha formation had occurred, significantly attenuated the cardiovascular consequences and improved the survival rate. Thus monoclonal antibodies to TNF-alpha might provide new prospects in the treatment of hemorrhage-related disorders.

Monoclonal antibody to tumor necrosis factor-alpha attenuates hemodynamic dysfunction secondary to intestinal ischemia/reperfusion in rats

OBJECTIVE

To evaluate the effects of monoclonal antibody to tumor necrosis factor (TNF)-alpha on the hemodynamic alterations and survival rate in rats subjected to intestinal ischemia/reperfusion.

DESIGN

Prospective, randomized study.

SETTING

Animal laboratory of an institute for research in traumatology.

SUBJECTS

Male Sprague-Dawley rats, weighing 430 to 460 g.

INTERVENTIONS

Anesthetized rats underwent 75 mins of superior mesenteric artery occlusion followed by 6 hrs of reperfusion. The animals were treated intravenously with either TNF-alpha monoclonal antibody (TN3, 20 mg/kg) or the control protein (albumin, 20 mg/kg) 30 mins before the onset of ischemia.

MEASUREMENTS AND MAIN RESULTS

Pretreatment with TNF-alpha monoclonal antibody significantly attenuated the decreases in blood pressure and cardiac index (p < .01) compared with controls, for < or = 6 hrs after reperfusion. Stroke volume remained stable in the TNF-alpha monoclonal antibody-treated group and was significantly higher than in the control group at 0.5, 5, and 6 hrs after reperfusion (p < .05 at 0.5 and 5 hrs and p < .01 at 6 hrs). No differences in vascular resistance index values were observed between the two groups at any point in time (p > .05). After intestinal ischemia/reperfusion injury, both the portal and systemic TNF concentrations in the control animals were completely neutralized by TNF-alpha monoclonal antibody treatment. The 72-hr survival rate was significantly (p < .01) better in the treatment group (90%, 9/10) than in the control group (20%, 2/10).

CONCLUSIONS

These results suggest that intestinal ischemia/reperfusion injury can lead to increased TNF release into both the portal and the systemic circulation, which may be an important factor contributing to the development of hemodynamic dysfunction. Pretreatment with TNF-alpha monoclonal antibody significantly attenuates the cardiovascular consequences and improves the survival rate after acute intestinal ischemia/reperfusion injury.

Comparison of the efficacy of pentoxifylline and albifyllin (HWA 138) on endotoxin-induced cytokine production, coagulation disturbances, and mortality

We have evaluated two different xanthine derivatives, pentoxifylline (POF) and albifyllin (HWA), in rat endotoxemia for their ability to reduce 1) cytokine formation, 2) coagulation disturbances, and 3) mortality. The animals were injected with lipopolysaccharide (LPS) (15 mg/kg i.p.) and received HWA or POF (25, 50, or 100 mg/kg) or saline 30 min before LPS administration. The plasma tumor necrosis factor levels were significantly reduced and in a similar manner by pretreatment with HWA or POF in vivo as well as in vitro. Neither the coagulation disturbance nor the characteristic leukopenia that follow an LPS challenge were significantly influenced by the xanthine derivatives. At a dose of 100 mg/kg, the 6 day mortality was significantly reduced by HWA to 36% but only attenuated by POF to 55% as compared to 80% in the control group. The similar effect of both agents on cytokine formation and coagulation disturbances indicate that, at least to a substantial degree, other mechanisms may account for the significant protection of rats against endotoxin-induced mortality by HWA only. HWA 138 may, therefore, be a new powerful agent against endotoxin-related disorders and mortality.

Animal models as the basis of pharmacologic intervention in trauma and sepsis patients

With limited resources and the current concerns about using animals for research purposes, the needs must be clear when setting up trauma and sepsis experiments for pharmacologic interventions. Such interventions are performed typically for four reasons: (1) to study the pathophysiologic role of certain mediators (which can be influenced by pharmacologic agents); (2) to study the therapeutic efficacy of treatment strategies; (3) to study the overall safety of new drugs under trauma/sepsis conditions, which are adjunct studies to standard toxicology; (4) to test new diagnostic procedures in a defined trauma or sepsis setting. Intervention in the inflammatory response may be performed at several levels: (1) at the primary induction site (e.g., by antilipopolysaccharide or by preventing complement activation); (2) at the intermediate mediator level (e.g., by antitumor necrosis factor); (3) at the final mediator level (e.g. , by block of polymorphonuclear neutrophil elastase, and (4) at the target (e.g., by membrane stabilization or enhanced antioxidant defense).

Significance of NO in hemorrhage-induced hemodynamic alterations, organ injury, and mortality in rats

In an attempt to evaluate the role of nitric oxide (NO) in pathophysiological alterations and multiple organ damage caused by hemorrhagic shock, we employed NG-monomethyl-L-arginine (L-NMMA), an inhibitor of NO synthase, in anesthetized rats subjected to a prolonged hypovolemic insult (30-35 mmHg for 180 min). Infusion of 2.0 mg/kg L-NMMA at the end of resuscitation diminished the fall in mean arterial pressure (MAP) and significantly increased the cardiac index and stroke volume, together with remarkable protection from multiple organ damage compared with the controls. The 48-h survival rate was significantly improved from 26.7% in the control group to 68.8% in the treatment group (P < 0.05). In contrast, the high dose of 20.0 mg/kg L-NMMA resulted in a strong blood pressure response, but a marked reduction in cardiac index and stroke volume concomitant with an increased total peripheral resistance index within the observation period, and tended to increase damage to various organs at 2 h after treatment. In addition, marked elevation in both endotoxin and tumor necrosis factor levels were observed in animals subjected to shock insult. The results suggest that NO induced by hemorrhagic shock in rats is an important mediator for pathophysiological alterations associated with cardiovascular abnormalities, multiple organ dysfunction, and even lethality. Regulation of NO generation and use of NO inhibitors might provide new aspects in the treatment of hemorrhage-related disorders, whereas the administration of L-NMMA would be either deleterious or salutary in a dose-dependent manner.

Elevated serum neopterin level: its relation to endotoxaemia and sepsis in patients with major burns

The present study was conducted to determine the relationship between levels of neopterin and endotoxin in the circulation, and whether the neopterin level was related to the development of severe sepsis after extensive burns. This prospective study included 35 patients with burn size greater than 30% (30-98%), and 22 healthy volunteers who served as a comparison group. Neopterin levels increased in most patients on day 3 post-burn, but they were not significantly correlated with the extent of the burn surface (P > 0 center dot 05). A high serum neopterin level was found in patients with sepsis (n = 15), and a marked elevation persisted throughout the observation period. The difference between septic and non-septic patients (n = 20) became significant on 14 and 28 days post-burn. Although the presence of early endotoxaemia did not influence the alterations in serum neopterin, patients with endotoxaemia had much higher neopterin values than those who showed no endotoxaemia from the second week onward (P < 0 center dot 05-0 center dot 01). In addition, circulating endotoxin and neopterin levels were positively correlated in patients who developed endotoxaemia on day 14 (r = 0 center dot 368, P < 0 center dot 05) and day 21 (r = 0 center dot 439, P < 0 center dot 01) after major burns. These results suggest that thermal injury can lead to an elevation of serum neopterin independent of the burn surface area. The initial increase in the neopterin level may be a part of the acute-phase response to tissue injury itself, whereas the endotoxin release in the circulation may be responsible for the continuous induction of neopterin during the late stage. In addition, the presence of a constant high neopterin level is associated with a critical event in the development of severe burn sepsis.

Reduction of circulating prostaglandin E2 level by antiserum against core lipopolysaccharide in a rabbit model of multiple organ failure

OBJECTIVE

To determine the potential role of prostaglandin E2 (PGE2) in the development of multiple organ dysfunction or failure (MOF), the possible effects of antiserum directed against Re chemotype lipopolysaccharide (LPS, from Re mutant of Escherichia coli F515) on circulating PGE2 level and survival rate, and whether there is an elevation in the plasma LPS concentration that could account for the induction of arachidonic acid metabolite in a rabbit model of MOF caused by acute hypovolemic insult.

DESIGN, MATERIALS, AND METHODS

An animal model of MOF in rabbits, engendered by feeding live Escherichia coli O111:B4 before hemorrhagic shock (35-40 mm Hg for 60 min), was used in the present study. Re-LPS antiserum was given intravenously in the treatment group at the onset of hemorrhage and 4 hours after resuscitation. The animals that received equal volumes of normal rabbit serum and antiserum served as the control group.

MEASUREMENTS AND MAIN RESULTS

The circulating PGE2 level was not increased at the end of shock (p > 0.05), but it was found to be significantly elevated 24 hours after hemorrhage and resuscitation in both groups. However, Re-LPS antiserum administration markedly decreased peak PGE2 level (p < 0.05) and attenuated multiple organ damage caused by acute insult. Concomitantly, there were also lower LPS concentrations in the treatment group as compared with the control group (p < 0.05-0.01). The survival rate was significantly increased in antiserum-treated rabbits 96 hours postinjury (treatment vs. control: 58.0% vs. 11.1%, p < 0.01).

CONCLUSIONS

The results suggest that an excessive generation and release of PGE2 may be involved in the pathogenesis of immunosuppression and MOF following hemorrhage and resuscitation. Re-LPS antiserum has an inhibitory effect on overproduction of circulating PGE2 and the ability to improve survival with MOF. Gut-derived endotoxemia, bacterial translocation, or both, could account, at least in part, for the PGE2 formation and release in animals response to acute hypovolemic insult.

Role of gut-derived endotoxaemia and bacterial translocation in rats after thermal injury: effects of selective decontamination of the digestive tract

This study was performed to investigate: (1) the role of gut-derived endotoxin/bacterial translocation in the pathogenesis of sepsis, and (2) the possible effects of selective decontamination of the digestive tract (SDD) on mortality in rats following 40 per cent full-thickness scald injury. In the SDD-treated group, Enterobacteriaceae and yeasts were eradicated from the caecal mucosa, while the mucosal flora consisting of mainly anaerobes was well preserved, within 3 days. The incidence of bacterial translocation to the mesenteric lymph nodes (MLN) and viscerae was significantly lowered on postburn days 1, 3 and 5 (P < 0.05-0.01). Meanwhile, pretreatment with SDD resulted in reductions of the faecal endotoxin levels in different segments of intestinal tract to less than 0.5 per cent (0.04-0.45 per cent) of the untreated control; there was also a significant attenuation of the elevation of endotoxin concentrations in both portal and systemic blood. Intestinal diamine oxidase (DAO) activity returned to baseline on day 5 in rats receiving SDD but not in controls. The 5-day survival rate in the SDD-treated group was elevated by 26.7 per cent as compared with controls (P < 0.05). These data suggested that endotoxin/bacterial translocation took place early and commonly, which in turn contributed to postburn sepsis and mortality. SDD was effective in preventing gut origin endotoxaemia and bacterial translocation, and improving the survival rate in rats following severe thermal injuries.

Inhibitory effects of low-dose polymyxin B on hemorrhage-induced endotoxin/bacterial translocation and cytokine formation in rats

The current experiments were performed to determine the effects of a subtherapeutic dose of polymyxin B sulfate on gut origin endotoxemia/bacterial translocation, and tumor necrosis factor (TNF) and interleukin-1 (IL-1) release following hemorrhagic shock (30 mm Hg, 90 min) in rats. The results showed that significant portal and systemic endotoxemia took place in the control group (portal, 0.269 to 0.845 endotoxin units (EU)/mL; systemic, 0.164 to 0.655 EU/mL), but not in the treatment group (except 0.5 hour in portal blood: 0.207 +/- 0.094 EU/mL). Concomitantly, the incidence of bacterial translocation to the mesenteric lymph nodes and viscera were reduced significantly at 0.5, 2, 6, and 24 hours postresuscitation in animals receiving polymyxin B (p < 0.05 to 0.01), whereas there were no differences with respect to number of translocating bacteria between the two groups (p > 0.05). Marked elevation of plasma TNF levels and IL-1 activities of peritoneal macrophages were also found in untreated controls at 0.5 to 2 hours (p < 0.05) and 6 to 24 hours (p < 0.05 to 0.01), respectively, but prevented by administration of low-dose polymyxin B. The 48-hour survival rate was improved from 41.7% in the control group to 75.0% in the treatment ones (p > 0.05). These data suggest that pretreatment with a subtherapeutic dose of polymyxin B is effective to inhibit hemorrhage-induced endotoxin/bacterial translocation from the gut and excessive TNF and IL-1 production.

The association of circulating endotoxaemia with the development of multiple organ failure in burned patients

In this study, we examined the relationship of plasma endotoxin levels to the development of multiple organ failure (MOF), and the outcome in patients with thermal injury. A prospective cohort study of 17 patients admitted with burns covering more than 70 per cent of body surface area was undertaken. Circulating endotoxin concentrations were measured by modified limulus amoebocyte lysate assay in serial samples of plasma. Seven out of 17 burned patients developed MOF according to multiple criteria. The plasma endotoxin concentrations of patients with MOF were 0.512-1.127 EU/ml, which were significantly higher than that of 10 patients without MOF (0.216-0.553 EU/ml), on 3, 14, 21 and 28 days postburn (p < 0.05-0.01). A significantly higher incidence of positive endotoxin tests (> or = 0.120 EU/ml) was found in patients who developed MOF as compared to those patients who did not develop MOF during the observation period (p < 0.05). As the mean endotoxin levels increased, the incidence of MOF and death rate also increased, and persistent endotoxemia carried a poor prognosis. The present investigation provides further evidence that endotoxemia in severely burned patients commonly occurs. Circulating endotoxin has also been found to be strongly associated with the development of MOF and mortality following major burn injury.

Gut-derived endotoxemia and multiple system organ failure following gunshot wounds combined with hemorrhagic shock: an experimental study in the dog

The purpose of this study was to explore the causative effects of high-velocity bullet injury (5.56 mm, 930 m/sec) combined with hemorrhagic shock on gut-derived endotoxemia and multiple system organ dysfunction or failure. The concentration of endotoxin in both portal and systemic blood was markedly increased after gunshot wounds together with hemorrhagic shock (p < 0.05-0.01). The portal/systemic lipopolysaccharide ratio persistently decreased in the combined wound (CW) group at 24 to 72 hours after injury, and it was much lower in the CW group than that in the single gunshot wound (SW) group. Also, a significant increase of fecal endotoxin content was found in the CW group as compared to the SW group (118.30 +/- 75.36 vs. 8.89 +/- 3.32 micrograms/g, p < 0.01), which was paralleled with the population of gram-negative bacilli in the intestinal tract. The incidence of multiple system organ failure, multiorgan dysfunction (including single organ failure) in the CW group were 30.8% (4 of 13) and 38.5% (5 of 13), respectively. These results suggested that severe trauma could lead to gut origin endotoxemia and bacterial translocation, which might play an important role in the pathogenesis of sepsis and multiple system organ failure following gunshot wounds.

The potential etiologic role of tumor necrosis factor in mediating multiple organ dysfunction in rats following intestinal ischemia-reperfusion injury

Endogenous inflammatory cytokines may function as mediators in the development of remote organ damage in response to local ischemic insult. This study was designed to (a) explore the potential role of tumor necrosis factor (TNF) formation in the pathogenesis of systemic tissue injury, (b) determine the relationship between induction of TNF and gut-derived endotoxemia and/or bacterial translocation, and (c) evaluate the protective effect of anti-TNF monoclonal antibody (MoAb) for vital organs following intestinal ischemia-reperfusion in rats. Animals were subjected to superior mesenteric artery occlusion (SMAO) for 45 min. Systemic plasma TNF levels increased rapidly after the onset of reperfusion, reaching a peak value 2 h later (P < 0.01). TNF elevation was found to be associated with gut origin endotoxemia, where the maximal TNF levels occurred approximately 2 h after the initial appearance of endotoxin in portal vein. Prophylactic treatment with anti-TNF MoAb markedly blunted the elevation in plasma TNF levels and afforded protection from the development of hypotension, vital organs dysfunction, and metabolic acidosis. Significant improvement in 48-h survival rate was observed by administration of anti-TNF MoAb prior to inducing ischemia (P = 0.007). These findings suggest that intestinal ischemia-reperfusion could result in TNF production, which may play a key role in mediating subsequent septic response and systemic tissue injury. It seems likely that passage of endotoxin and bacteria from the gut can be responsible for the TNF formation

Pathogenesis of hemorrhage-induced bacteria/endotoxin translocation in rats. Effects of recombinant bactericidal/permeability-increasing protein

OBJECTIVES

This study was conducted to determine the role of gut-derived bacteria/endotoxin in the pathogenesis of the multiple-organ damage and mortality, the possible beneficial effect of recombinant bactericidal/permeability-increasing protein (rBPl21), and whether neutralizing endotoxemia by rBPl21 treatment influences tumor necrosis factor (TNF) formation in rats after hemorrhagic shock and resuscitation.

SUMMARY BACKGROUND DATA

Hypovolemic shock might be associated with bacterial or endotoxin translocation as well as systemic sepsis. Similar to bactericidal/permeability-increasing (BPl) protein, rBPl21 has been found to bind endotoxin and inhibit TNF production.

METHODS

A rat model of prolonged hemorrhagic shock (30 to 35 mm Hg for 180 min) followed by adequate resuscitation was employed. Recombinant bactericidal/permeability-increasing protein was administered at 5 mg/kg intravenously. The control group was treated similarly to the BPl group, but received thaumatin as a protein-control preparation in the same dose as rBPl21.

RESULTS

Immediately after resuscitation (230 min), plasma endotoxin levels in the control group (61.0 +/- 16.3 pg/mL) were almost neutralized by rBPl21 treatment (13.8 +/- 4.8 pg/mL, p < 0.05). Plasma TNF levels were not significantly influenced by rBPl21 treatment. The 48-hour survival rate was 68.8% in the treatment group versus 37.5% in the control group (p = 0.08). Microscopic histopathologic examination revealed relatively minor damage to various organs in the treatment group.

CONCLUSIONS

These data suggest that hemorrhagic shock may lead to bacterial/endotoxin translocation with concomitant TNF formation, endogenous endotoxemia may play an important role in the pathogenesis of multiple-organ failure after shock and trauma, TNF formation at an early stage might be related mainly to mechanisms other than Kupffer's cells activation via lipopolysaccharide, and rBPl21 might be a useful therapeutic agent against endogenous bacteria/endotoxin related disorders in severe hemorrhagic shock.

Exposure of workers to a mixture of toluene and xylenes. II. Effects

The health effects of exposure to a mixture of toluene and xylene isomers was studied on the fourth or fifth days of a working week in factories in China. The study population comprised 233 subjects (122 men and 111 women), who were exposed to the time weighted geometric mean (maximum) concentrations of toluene (3 (203) ppm) and xylenes (4 (103) ppm). For comparison, 241 non-exposed controls (116 men and 125 women) were recruited from the same regions. The prevalence of some subjective symptoms significantly increased in the exposed population, and the symptom profiles were similar to those found after exposure to toluene or xylenes alone. Haematology and serum biochemistry did not show notable changes. It seems reasonable to conclude that the effects of the toxicities of toluene and xylenes in combination are additive.

[Protective effect of monoclonal antibody of tumor necrosis factor-alpha for vital organs in a model suffering from intestinal ischemia and reperfusion injury]

Monoclonal antibody to tumor necrosis factor-alpha (TNFa-MAb), z8, was used to explore protective effect on multiple organ dysfunction caused by intestinal ischemia and reperfusion in rats. Systemic plasma TNF level rose rapidly after release of the clamp, on superior mesenteric artery, and reached peak level 2 hours later. Endotoxemia and bacteremia were associated with systemic TNF level, and portal endotoxin concentration increased significantly before elevation of TNF activity. Pretreatment with anti-TNFa antibody markedly attenuated the increase of TNF level and provided protection from the development of hypotension, vital organ dysfunction, and metabolic acidosis. As a result the survival rate in treatment group increased by 35.7%. Our results demonstrated that TNF might play an important role in mediating the pathophysiologic changes in the pathogenesis of multiple organ damage in this intestinal ischemia-reperfusion injury model, and monoclonal antibody to TNF offered significant protection against multiple organ dysfunction or failure after severe trauma.

[Endotoxemia in severely burned patients]

Plasma endotoxin was determined by modified synthetic chromogenic limulus amebocyte lysate assay in 35 severely burned patients (30% to 98% TBSA). The results showed that the level of circulating endotoxin markedly increased during the early stage after injury, with a peak value at the 3rd postburn days. The relationship between burn size and the endotoxin value was significant (P < 0.01); The incidence of endotoxemia in the 35 patients was 36.8% to 74.7%. The plasma endotoxin concentrations of 7 burned patients with multiple system organ failure (MSOF) raced from 0.512 to 1.127 EU/ml, significantly higher than those of 10 patients without MSOF (0.216-0.553 EU/ml) at 3, 14, 21 and 28 postburn days. Endotoxemia in severely burned patients commonly occurred and was closely related to the development of sepsis and MSOF after burn injury. Dynamic observation of the changes in circulating endotoxin concentration was valuable as a marker for predicting sepsis and MSOF in critically ill patients with burns.