[In vitro activity of ß-lactamase inhibitors avibanvctam and relebactam in combination with ß-lactams against multidrug-resistant Mycobacterium tuberculosis and mutations of resistance genes].

Objective: To evaluate the activity of six ß-lactams in combination with three ß-lactamase inhibitors against mycobacterium tuberculosis(MTB) in vitro. Methods: A total of 105 multidrug-resistant tuberculosis (MDR-TB) strains from different regions of Henan province from January to September 2020 were included in this study. Drug activity of six ß-lactams (biapenem, meropenem, imipenem, doripenem, ertapenem and tebipenem) alone or in combination with ß-lactamase inhibitors (clavulanic acid, avibactam and relebactam) was examined by minimum inhibitory concentration method (MICs) against 105 clinical isolates. Mutations of blaC, ldtmt1 and ldtmt2 were analyzed by PCR and DNA sequencing. Chi-square test was used to compare the antimicrobial activities of different ß-lactam drugs. Results: Out of the ß-lactams used herein, tebipenem was the most effective against MDR-TB and had an MIC50 value of 8 mg/L(χ2=123.70,P=0.001). Besides, after the addition of ß-lactamase inhibitors, the MICs of most ß-lactam drugs were reduced more evidently in the presence of avibactam and relebactam compared to clavulanic acid.Especially, relebactam decreased both the MIC50 and MIC90 of telbipenem by 16-fold, and diluted the MIC of 23 (21.90%) and 41 (39.04%) isolatesby 32-fold and 16-fold.In addition, a total of 13.33% (14/105) of isolates harbored mutations in the blaC gene, with three different nucleotide substitutions: AGT333AGG, AAC638ACC and ATC786ATT. For the strains with Ser111Arg and Asn213Thr substitution in BlaC, the MIC values of the meropenem-clavulanate combination were reduced compared with a synonymous single nucleotide polymorphism (SNP) group. Conclusions: Both avibactam and relebactam had better synergistic effects on ß-lactams than clavulanic acid. The combination of tebipenem and relebactam showed the most potent activity against MDR-TB isolates. In addition, the Ser111Arg and Asn213Thr substitution of BlaC may be associated with an increased susceptibility of MDR-TB isolates to meropenem in the presence of clavulanate.

[A randomized double-blinded placebo-controlled clinical trial of minodronate tablet in postmenopausal Chinese women with osteoporosis].

Objective: To verify the efficacy and safety of daily oral minodronate in postmenopausal women with established osteoporosis. Methods: In this randomized, double-blinded, placebo-controlled trial, 262 postmenopausal women were enrolled. Patients were randomized to receive daily oral minodronate 1 mg with supplements of 500 mg calcium and 200 U vitamin D3 (n=130) or placebo (n=132) with daily supplements of 500 mg calcium and 200 U vitamin D3, for 48 weeks. The primary endpoint was the average bone mineral density (BMD) change in the lumbar vertebrae 48 weeks post-treatment. Secondary outcome measures was the incidence of vertebral fractures. Safety assessments included the rate of adverse events. Results: At the end of 48 weeks treatment, the average BMD change rate from baseline were: full analysis set results: (3.52±4.82)% in the minodronate group and (2.00±5.74)% in the placebo group; per-protocol set results: (3.99±5.05)% in the minodronate group and (2.07±6.20)% in the placebo group; the differences were all significant (all P<0.05). Vertebral fracture occured in 3 patients (2.3%, 3/132) in the placebo group, and 1 case (0.8%, 1/130) in the minodronate group (P>0.05). The incidence of adverse events was 71.5% (93/130) in the minodronate group and 78.0% (103/132) in the placebo group (P>0.05). Conclusion: Minodronate is effective and safe in the treatment of postmenopausal osteoporosis without severe side effects.

[Emulation pulmonary nodules localization model:a novel non-invasive localization technique in resection of pulmonary nodules].

Objective: To explore the accuracy and efficiency of a novel 3D-printed emulation localization model of small pulmonary nodules in lung surgery. Methods: From April 2020 to April 2021, a total of 66 patients were selected in the study, who underwent localization and resection of pulmonary nodules with video-assisted thoracoscopic surgery (VATS) guided by the 3D-printed emulation localization model at Department of Thoracic Surgery, West China Hospital of Sichuan University. There were 13 males and 53 females, aged from 25 to 79 (52.7±11.4) years. Of all patients, 24 (36.4%) had single pulmonary nodule, and 42 (63.6%) had synchronous multiple pulmonary nodules. The chest high-resolution CT image data were utilized for digital reconstruction and 3D printing to make a tailored life-size emulation pulmonary nodules localization model, which was used to navigate real-time intraoperative localization of nodules. Clinical data including operative parameters, localization information, resection types and pathological findings of nodules were analyzed. The pulmonary nodules that doctors planned to resect were categorized into two categories:major nodules and additional nodules, according to their presence of invasion and radiological risk factors. The accuracy of localization and resection efficiency of nodules were evaluated in accordance with the categories of the nodules respectively. Results: On the basis of preoperative evaluation, there were 71 major nodules with median maximal diameter of 0.9 (0.6-1.3) cm, and 77 additional nodules with median maximal diameter of 0.5 (0.4-0.7) cm. All patients underwent VATS surgery, 52 of them (78.8%) were treated with uniportal VATS and 14 (21.2%) with triportal VATS. Among the patients with single nodule, 18 segmentectomies and 6 wedge resections were performed; whereas among the patients with multiple nodules, 5 segmentectomies, 14 wedge resections, and 23 combined pulmonary resections (including 2 cases of lobectomy+segmentectomy, 7 cases of lobectomy+wedge resections, and 14 cases of segmentectomy+wedge resections) were achieved. The median operative time was 93 (45-240) min, and the median resection time for all nodules was 51.4 (6.7-147.0) min. All major nodules were successfully resected and visibly dissected after removal, and all additional nodules were successfully resected with 85.7%(66/77) nodules visibly dissected. The accuracy rate of localization of both types of nodules was 100%. All major nodules were malignant, and the malignancy rate of additional nodules was 21.2%(14/66). Conclusion: This novel 3D-printed emulation localization model of small pulmonary nodules proved to be a non-invasive, accurate and efficient technique. Not only that, it has a unique advantage in localization of synchronous multiple pulmonary nodules.

MiR-124 promotes ischemia-reperfusion induced cardiomyocyte apoptosis by targeting sphingosine kinase 1.

OBJECTIVE: Ischemia-reperfusion (IR) injury of cardiomyocyte contributes to the cardiac dysfunction following myocardial infarction (MI). MiRNAs have been found to play a vital role in the pathogenesis of myocardial IR injury. In this study, the role of miR-124 in the myocardial IR injury was examined. MATERIALS AND METHODS: Myocardial ischemia rats' model was established to examine the expression level of miR-124. The primary rat cardiomyocytes were isolated to determine in vitro oxygen-glucose deprivation and reoxygenation model. The expression of miR-124 was analyzed by quantitative Real Time-PCR (qRT-PCR). The cell viability was assessed by Cell Counting Kit-8 (CCK-8) and LDH release assay. Cell apoptosis was evaluated by flow cytometry. The expression of cleaved caspase-3, Bcl-2, and Bax was assessed by Western blot. The expression of miR-124 was manipulated by transfection with miR-124 mimics and inhibitors. The Luciferase activity assay was performed to verify whether SphK1 was a direct target of miR-124. The mRNA and protein expression of SphK1 was assessed by qRT-PCR and Western blot. The ectopic expression of SphK1 was achieved by transfecting with overexpressing plasmid. RESULTS: Our results showed that miR-124 expression was elevated in the infarct zone. The expression level of miR-124 following OGD/R was also significantly increased. Our results showed that miR-124 mimics could enhance OGD/R-induced miR-124 increase while miR-124 inhibitors performed the opposite effect. Our findings also revealed that miR-124 mimics could augment OGD/R-induced cell death and apoptosis, while miR-124 inhibitors expressed the opposite effect. SphK1 was proposed to be a direct target of miR-124. SphK1 overexpression could abrogate the augmenting activities of miR-124 on OGD/R-induced cell injury. CONCLUSIONS: In the pathogenesis of MI, miR-124 promotes myocardial IR-induced cell death and apoptosis in cardiomyocyte by targeting SphK1.

[Analysis on prognosis and influencing factors of postoperative low anterior resection syndrome for rectal cancer patients undergoing laparoscopic anus-preserving radical resection].

Objective: To investigate the prognosis and influencing factors of postoperative low anterior resection syndrome (LARS) for rectal cancer patients undergoing laparoscopic sphincter-preserving radical resection. Methods: A retrospective case-control study was used in this study. Clinical data of 268 rectal cancer patients undergoing laparoscopic sphincter-preserving radical resection at Department of Gastrointestinal Surgery of The First Affiliated Hospital of Bengbu Medical College from January 2016 to January 2018 were retrospectively collected. Inclusion criteria: (1) operation procedure was total mesorectal excision (TME) and sphincter-preserving radical resection; (2) rectal cancer was confirmed by postoperative pathology; (3) age of patient was ≥ 18 years old. Exclusion criteria: (1) patient who had history of pelvic surgery and pelvic fractures, which would affect the anorectal function; (2) patient who had history of preoperative chronic constipation and irritable bowel syndrome, which would affect defecation; (3) patient who developed postoperative complications, such as anastomotic leakage, which would affect defecation function; (4) patient who received long-term use of drugs, which would affect the function of gastrointestinal tract or anus; (5) patient suffered from mental illness, who was unable to communicate properly; (6) patient who was lack of clinical data or had incomplete clinical data. Patients were followed up at 3, 6 and 12 months postoperatively, and LARS was diagnosed and graded according to the LARS score scale. The LARS score ranged from 0 to 42 points, and 0 to 20 was difined as no LARS, 21 to 29 was mild LARS, and 30 to 42 was severe LARS. LARS score >20 points at any time point was defined as postoperative LARS. Severe LARS transferring into mild LARS and mild LARS transferring into no LARS was defined as symptom improvement. Incidence and outcomes of LARS were evaluated. The factors associated with LARS outcomes were analyzed using χ(2) test and logistic regression model. Results: A total of 268 patients were enrolled. The incidence of LARS was 42.9% (115/268), 32.5% (87/268) and 20.1% (54/268) at 3, 6, and 12 months postoperatively respectively, and no new case of LARS was found after 3 months postoperatively. The incidence of mild LARS was 25.7% (69/268), 17.2% (46/268) and 8.6% (23/268) at 3, 6, and 12 months postoperatively respectively, and mild LARS incidence at 6 months was significantly lower than that at 3 months (χ(2)=5.857, P=0.016), and was significantly higher than that at 12 months (χ(2)=8.799, P=0.003). The incidence of severe LARS was 17.2% (46/268), 15.3% (41/268) and 11.6% (31/268) at 3, 6, and 12 months postoperatively respectively, without significant difference among 3 time points (all P>0.05). The improvement rate within one year after surgery in patients with mild LARS diagnosed at 3 months was significantly higher than that in patients with severe LARS (88.4% vs. 32.6%, χ(2)=38.340, P<0.001). Univariate analysis showed that female, distance from anastomosis to anal verge < 5 cm and tumor diameter ≥ 5 cm were associated with unsatisfied LARS outcomes (all P<0.05). Logistic regression analysis showed that distance from anastomosis to anal verge <5 cm was an independent risk factor for LARS outcome (OR=3.589, 95% CI: 1.163 to 2.198, P<0.001). Conclusions: The incidence of LARS after laparoscopic sphincter-preserving radical resection decreases with time. The improvement rate within postoperative 1-year of severe LARS is lower than that of mild LARS. Low anastomotic position may lead to impaired improvement of LARS.

[Study on characteristics and prognosis of organ failure in patients with hepatitis B virus-associated acute-on-chronic liver failure].

Objective: To evaluate the incidence, and the characteristics of organ failure in relationship to prognosis in hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) patients using chronic liver failure-sequential organ failure assessment (CLIF-SOFA) score for judgments of clinical treatment and prognosis. Methods: Clinical data of 316 patients who were diagnosed as HBV-ACLF during hospitalization from February 2015 to February 2016 were retrospectively analyzed. Intrahepatic and extrahepatic organ failures were assessed according to CLIF-SOFA score, and the relationship between clinical characteristics and prognosis was analyzed. Continuity variables were analyzed by analysis of variance, or Kruskal-Wallis H test. Comparison of the categorical data were done using χ (2) or Fisher's exact test, and the predictive efficacy of various prognostic scores was compared using the area under the receiver operating characteristic curve (AUROC) and Z-test. Results: Of 316 cases (87.3% men) of HBV-ACLF, the mean age was (45 ± 11) years old. 78.8% of patients with underlying liver disease had hepatitis B virus induced cirrhosis. Mortality rates in patients without liver transplantation at 28 days, 90 days and 180 days were 20.5% (63/307), 36.7% (110/300) and 39.2% (116/296), respectively. According to the CLIF-SOFA score, 89.9% (284 patients) had organ failure at baseline, of which 97.5% had liver failure (Total bilirubin ≥ 12 mg/dl) and only 2.5% had coagulation, kidney, circulation or respiratory failure without liver failure. Besides liver failure, the incidence of extrahepatic organ failure was coagulation (23.1%), kidney (5.7%), brain (3.8%), circulation (1.3%) and respiratory failure (0.3%). With increasing number of organ failure, the mortality rate of two and three or more organ failures were 69.6% and 69.2%, respectively, which was significantly higher than that of single organ failure and non-organ failure patients (27% and 6.9%, respectively; P < 0.001). Liver failure with coagulation failure (International normalized ratio≥2.5 or platelet count≤20×10(9)/L) had worst prognosis with a mortality rate of up to 75% at 90 days. Conclusion: According to the CLIF-SOFA score, the main organ failure in patients with HBV-ACLF in China is liver failure. The mortality rate in patients with two or more organ failures is as high as 70% within 3 months. Therefore, timely manner liver transplantation should be considered.

[Advances in the application of regional citrate anticoagulation for continuous renal replacement therapy in patients with liver failure].

Currently, continuous renal replacement therapy (CRRT) is one of the most important means of organ support methods in critical care medicine. Anticoagulation is an essential part of the treatment process due to its prolonged duration. Patients with liver failure often have coagulation dysfunction and heparin anticoagulant can increase the risk of bleeding, but without heparin anticoagulant, coagulation can easily occur. In addition, an increased volumetric load, hemodynamic instability, nursing workload and other problems are major issues. Therefore, regional citrate anticoagulation (RCA) is the main anticoagulant method for CRRT therapy in patients with liver failure. This article reviews the mechanism, indications, advantages and disadvantages of using RCA to CRRT in hepatic failure.

Identification of critical microRNAs in gastrointestinal stromal tumor patients treated with Imatinib.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Imatinib mesylate was considered to be a breakthrough drug in clinical treatment of GIST, but GIST patients showed resistance against it. We aimed to identify critical microRNAs (miRNAs) related to imatinib resistance in imatinib-treated GIST patients. Microarray datasets under the accession number of GSE63159 and GSE45901 were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed miRNAs (DEMs) that are related to imatinib resistance were identified. GO function and KEGG pathway enrichment analyses were performed, and lncRNA-miRNA-target gene regulatory networks were constructed. Finally, the critical miRNAs and their target genes that are related to imatinib resistance or sensitivity were identified. In total, 20 DEMs in the GSE63159 dataset (7 significantly up-regulated and 13 down-regulated) and 23 DEMs in the GSE45901 dataset (8 up-regulated and 15 down-regulated) were identified. In lncRNA-miRNA-target gene regulatory networks, five critical miRNAs and 109 target genes were identified. GO function and KEGG pathway enrichment analysis showed that the target genes of DEMs were mainly involved in several signaling pathways, such as focal adhesion and the GnRH signaling pathway. Among the five miRNAs, the overexpression of hsa-miR-28-5p and hsa-miR-125a-5p had significant correlation to imatinib resistance or imatinib sensitivity in GIST patients. Hsa-miR-28-5p and hsa-miR-125a-5p may be involved in the development and progression of GIST, and they may be able to serve as prognostic markers for imatinib-response in GIST patients.

[Comparison of the efficacies of cross priming amplification and RealAmp with XpertMTB/RIF for the diagnosis of pulmonary tuberculosis at peripheral microscopic center].

Objective: To compare the efficacies of cross priming amplification (CPA) and RealAmp with XpertMTB/RIF for the diagnosis of pulmonary tuberculosis(TB) at peripheral microscopic centers. Methods: From December of 2014 to December of 2015, 3 193 patients suspected with TB were enrolled consecutively at 3 county level TB clinical clinics in Zhongmu, Xinmi and Dengzhou of Henan province. Totally 3 193 collected sputum samples were detected by smear microscopy, L-J media culture, CPA, RealAmp and Xpert MTB/RIF. The culture positive samples were tested by MPB64 for strain identification. The sensitivity and specificity of CPA, RealAmp and Xpert MTB/RIF were calculated according to L-J solid culture results and clinical diagnosis results. Results: The sensitivity of CPA, RealAmp and Xpert MTB/RIF were 85.5%(413/483), 85.5%(413/483) and 87.9%(422/480), respectively, compared with L-J solid culture, the difference among the 3 methods being not significant(χ(2)=1.6, P>0.05). The specificity of CPA, RealAmp and Xpert MTB/RIF were 96.8%(2 624/2 170), 93.2%(2 527/2 170) and 95.3%(2 567/2 170) compared with culture; and there was a significantly statistic difference among the 3 methods(χ(2)=37.8, P<0.001). The sensitivity of smear microscopy, culture, CPA, RealAmp and Xpert MTB/RIF was 21.7%(300/1 383), 34.9%(483/1 383), 34.6%(478/1 383), 39.2%(542/1 383) and 38.1%(526/1 381) compared with clinical diagnosis. The sensitivity of CPA, RealAmp and Xpert MTB/RIF was higher than that of smear (χ(2) =31.9, P<0.01), but there was no significantly statistic difference between the 3 molecular methods(χ(2)=2.9, P>0.05). The specificity of smear microscopy, L-J solid culture, CPA, RealAmp and Xpert MTB/RIF was 100%(1 810/1 810), 100%(1 810/1 810), 98.8%(1 789/1 810), 98.8%(1 756/1 810) and 97.0%(1 788/1 810), and there was no significantly statistic difference among the 3 molecular methods(χ(2)=0.16, P>0.05). Conclusion: The capability of CPA and RealAmp for diagnosing pulmonary TB was similar to Xpert MTB/RIF.The former 2 methods were more suitable to apply to the diagnoses of pulmonary TB in peripheral laboratories.

Mechanical behavior of mother-of-pearl and pearl with flat and spherical laminations.

Laminated structure reduces the common inverse relationship of strength and toughness in many biological materials. Here the mechanical behavior of pearl and nacre with spherical and flat laminations was investigated and compared with the geological aragonite counterpart. The biological ceramics demonstrate higher strength, better reliability, and improved damage resistance owing to their laminated arrangement. Kinking and delamination occur in pearl to resist damage in addition to the crack-tip shielding mechanisms as in nacre, such as crack deflection, bridging, and platelet pull-out. The fracture mechanisms were interpreted in terms of the stress state using finite element simulation. This study may help clarify the compressive mechanics of laminated sphere between platens and advance the understanding on the mechanical behavior of biological and bio-inspired laminated materials.

Analysis of 15 patients with abnormal liver function as the first systemic lupus erythematosus symptom.

OBJECTIVE: To understand the clinical characteristics of patients with abnormal liver function as the first symptom of systemic lupus erythematosus (SLE). METHODS: Here, 15 patients admitted to a hospital from January 2010 to December 2013 with initial presentation of lupus-related hepatitis or cirrhosis were included. Their SLE-DAI scores and clinical and laboratory data were collected. All cases received liver protection therapy and active SLE controlling treatment with methylprednisolone combined with rapamycin. RESULTS: When hepatic abnormalities were the most prominent feature during the first visit, the patient was more likely to receive an incorrect diagnosis or be diagnosed with SLE late. Of the 15 cases, only 7 (46.7%) were identified as SLE within a week of presentation of abnormal liver function ; meanwhile, the 7 remaining patients (46.7%) were not correctly diagnosed until more than 2 weeks later and as late as 4 months ; in addition, 1 patient was not diagnosed with SLE until 8 years after the initial presentation of abnormal liver function. In the 3-month follow-up after active treatment, liver function was completely restored in 10 cases with no cirrhosis and significantly improved in 3 patients who still had cirrhosis. Another case showed no improvement in liver function and was self-discharged, and another died from chronic liver failure. CONCLUSION: Liver injury caused by SLE is not uncommon, and it is easy to tentatively diagnose it as hepatitis, delaying the correct diagnosis of SLE. In such patients, physicians should perform a thorough differential diagnosis as soon as possible and administer proper treatment. Corticosteroid conjugated with immunosuppressants with no or little liver toxicity would be suitable for patients with SLE-induced liver injury. (Acta gastroenterol. belg., 2016, 79, 441-446).

Reduced cortisol in the absence of bacterial infection in patients with hepatitis B virus cirrhosis.

In liver cirrhosis with bacterial infection, hepatoadrenal syndrome has been described recently as a progressive impairment in the adrenocortical reserve, with deficient production or action of glucocorticoids resulting in adrenal insufficiency. The aim of this study was to explore the characteristics of cortisol in hepatitis B virus (HBV) cirrhosis patients in the absence of bacterial infection. Fasting peripheral venous blood samples were collected from 107 patients with HBV cirrhosis in the absence of bacterial infection and 18 patients with chronic hepatitis B (CHB) infection at 7 a.m. in the morning. The carbohydrate, cortisol-binding globulin, routine chemistry, liver function, and hepatitis B indicators were tested, and free cortisol was calculated. Cortisol (COR) levels were 18.72 ± 6.60 µg/dL in the CHB group and 14.20 ± 7.55 µg/dL in the HBV cirrhosis group (P = 0.002). COR levels were 15.11 ± 5.56, 14.88 ± 6.96, and 12.68 ± 8.36 µg/dL in Child-Pugh class A, B, and C cirrhotic patients, respectively (P = 0.006). Adrenocorticotropic hormone levels were 35.42 ± 24.49, 26.57 ± 15.72, and 19.65 ± 10.72 pg/mL in Child-Pugh class A, B, and C cirrhotic patients, respectively (P = 0.000). Patients with HBV cirrhosis had significantly lower serum COR levels compared with those of CHB patients, even if they are in the absence of bacterial infection. COR levels negatively correlated with Child-Pugh scores. The hypothalamic-pituitary-adrenal axis might be damaged in patients with HBV cirrhosis.

Factors influencing the degree of enhancement of prostate cancer on contrast-enhanced transrectal ultrasonography: correlation with biopsy and radical prostatectomy specimens.

OBJECTIVES: This study was designed to identify factors that influenced the degree of enhancement of prostate cancer on contrast-enhanced transrectal ultrasonography (CETRUS). METHODS: 139 patients suspected of prostate cancer were evaluated with CETRUS followed by systematic and targeted transrectal ultrasound-guided biopsies. The degree of enhancement of the lesions was objectively measured using peak intensity with time-intensity curve analysis software. Ultrasound findings were correlated with clinical characteristics as well as biopsy and radical prostatectomy findings. RESULTS: Prostate cancers were detected in 230 biopsy sites from 91 patients. The mean peak intensity value of prostate cancer was significantly higher than that of the benign lesions (9.82 ± 3.73 vs 7.51 ± 2.97; p<0.001), and the peak intensity value of the cancer foci varied across the prostate. The mixed model analysis revealed that the location and Gleason score of tumour foci were the influencing factors of the peak intensity value, and the former had a stronger influence upon peak intensity than the latter (p=0.000 and 0.040, respectively). However, age, prostate volume or serum prostate-specific antigen of the patient had no significant influence on the peak intensity value (p>0.05). Furthermore, the peak intensity value of tumours larger than 5 mm diameter was significantly higher than tumours of 5 mm or smaller diameter (9.28 ± 2.46 vs 6.69 ± 2.65; p<0.001). CONCLUSIONS: The prostate cancer lesions with a higher Gleason score and larger tumour size which were located in the lateral peripheral zone (PZ) were more likely to show a marked enhancement. Lesions with lower peak intensity that are located in the medial PZ should also be treated as suspicious.

Correlation between promoter methylation of glutathione-S-tranferase P1 and oxidative stress in acute-on-chronic hepatitis B liver failure.

Promoter methylation of glutathione-S-transferase P1 (GSTP1) may be involved in liver damage caused by oxidative stress in acute-on-chronic hepatitis B-induced liver failure (ACHBLF). This study aimed to explore GSTP1 promoter methylation status and oxidative stress in such patients. DNA was extracted from peripheral blood mononuclear cells (PBMCs) of patients with acute-on-chronic liver hepatitis B-induced liver failure, chronic hepatitis B (CHB) and normal controls, followed by sodium-bisulfite treatment and methylation-specific PCR (MSP) analysis. Plasma malondialdehyde (MDA) adducts levels were detected by enzyme-linked immunosorbent assay as oxidative stress marker. Model for end-stage liver disease (MELD) score was employed to estimate the severity of the liver failure. Eleven of 35 patients with acute-on-chronic liver failure and 3 of 35 patients with stab le hepatitis B displayed GSTP1 promoter methylation, and the difference was significant (χ2) = 5.71, P = 0.02). No differences in standard liver function tests were found in patients with acute-on-chronic liver failure with and without GSTP1 promoter methylation although the levels of total bilirubin were greater in those with methylation. The levels of MDA adducts were significantly higher in patients with liver failure when compared to those with CHB (12.44 ± 5.38 pmol/mg vs 8.42 ± 5.49 pmol/mg, P < 0.01), and in the patients with liver failure who had promoter methylation the levels were higher than in those who did not (15.2 ± 4.68 pmol/mg vs 11.17 ± 5.29 pmol/mg, P < 0.01). The MELD score was not significantly different between methylated and unmethylated patients with liver failure (P > 0.05), although MDA adducts were correlated with MELD scores in patients with acute-on-chronic liver failure (r = 0.579, P < 0.01). GSTP1 promoter methylation may facilitate oxidative stress-associated liver damage in ACHBLF, and oxidative stress is correlated with ACHBLF severity.

Interactions between monocytes and smooth-muscle cells can lead to extracellular matrix degradation.

BACKGROUND: Chronic infiltration of the airway wall with inflammatory cells characterizes both asthma and chronic bronchitis. Remodeling of the airway wall is also a feature of both diseases. OBJECTIVE: We hypothesized that collagen degradation may take place during coculture of monocytes with smooth-muscle cells (SMCs) and that this degradation might be altered by agents that modify the inflammatory regimen. METHODS: Monocytes (4.5 x 10(5)/mL) were cast into collagen gels containing human airway SMCs (4.5 x 10(5)/mL) and released into serum-free Dulbecco's modified Eagle's medium containing neutrophil elastase. Collagen content was quantified as total insoluble hydroxyproline on day 5. Zymography and immunoblotting were used to detect matrix metalloproteinases. RESULTS: Monocytes cocultured with SMCs in 3-dimensional native type I collagen gels produced TNF-alpha and IL-1beta and resulted in collagen degradation (30.5 vs 17.9 mg per gel) through inducing matrix metalloproteinase 1, 2, and 9 by means of SMCs. PGE(2) was significantly increased in coculture (0.9 vs 10.5 ng/mL). Indomethacin (1 micromol/L) completely inhibited PGE(2) production but augmented collagen degradation (17.9 vs 2.3 microg per gel), and this was blocked by the addition of exogenous PGE(2). Dexamethasone also inhibited collagen degradation in coculture. CONCLUSION: The current study supports the concept that interactions among cells present in the airway inflammatory milieu that characterize airway disease can lead to alterations in tissue structure and suggests mechanisms by which therapeutic strategies can be designed to modify tissue remodeling.

Retinoic acid attenuates cytokine-driven fibroblast degradation of extracellular matrix in three-dimensional culture.

Proteolytic degradation of extracellular matrix is thought to play an important role both in emphysema and in tissue development and repair. Retinoic acid has been suggested to modify tissue injury, and in an animal model of emphysema may induce alveolar repair. Since cytokines can induce matrix metalloproteinase (MMP) production in fibroblasts and neutrophil elastase (NE) can activate MMPs, we hypothesized that retinoic acid could attenuate collagen degradation by modifying MMP production and activation. To evaluate this, human lung fibroblasts were cast into native type I collagen gels and floated in medium containing cytomix (TNF-alpha, IL-1beta, and IFN-gamma) alone or in combination with NE in the presence and absence of retinoic acid (1 microM). After 5 d, cytomix with elastase induced significant degradation of the collagen gels assessed by quantifying total hydroxyproline (41.6 +/- 1.6 microg versus 3.3 +/- 1.5 microg, P < 0.01). Retinoic acid significantly inhibited this degradation (23.3 +/- 1.5 microg versus 3.3 +/- 1.5 microg, P < 0.01). Gelatin zymography and Western blot revealed that MMP-1, MMP-3, and MMP-9 were induced by cytomix and that co-exposure to NE resulted in increased production of activated forms of these enzymes. Retinoic acid attenuated the induction and activation of MMP-1 and MMP-3. The current study, therefore, suggests that in addition to stimulating anabolic effects, retinoic acid may modulate proteolytic processes thought to contribute to tissue destruction in emphysema.

Synergistic neutrophil elastase-cytokine interaction degrades collagen in three-dimensional culture.

Proteolytic degradation of extracellular matrix is thought to play an important role in many lung disorders. In the current study, human lung fibroblasts were cast into type I collagen gels and floated in medium containing elastase, cytomix (combination of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma), or both. After 5 days, gel collagen content was determined by measuring hydroxyproline. Elastase alone did not result in collagen degradation, but in the presence of fibroblasts, elastase reduced hydroxyproline content to 75.2% (P < 0.01), whereas cytomix alone resulted in reduction of hydroxyproline content to 93% (P < 0.05). The combination of elastase and cytomix reduced hydroxyproline content to 5.2% (P < 0.01). alpha(1)-Proteinase inhibitor blocked this synergy. Gelatin zymography and Western blot revealed that matrix metalloproteinase (MMP)-1, -3, and -9 were induced by cytomix and activated in the presence of elastase. Tissue inhibitor of metalloproteinase (TIMP)-1 and -2 were also induced by cytomix but were cleaved by elastase. We conclude that a synergistic interaction between cytomix and elastase, mediated through cytokine induction of MMP production and elastase-induced activation of latent MMPs and degradation of TIMPs, can result in a dramatic augmentation of collagen degradation. These findings support the notion that interaction among inflammatory mediators secreted by mononuclear cells and neutrophils can induce tissue cells to degrade extracellular matrix. Such a mechanism may contribute to the protease-anti-protease imbalance in emphysema.

Cytokine inhibition of fibroblast-induced gel contraction is mediated by PGE(2) and NO acting through separate parallel pathways.

Contraction of three-dimensional collagen gels is a model of the contraction that characterizes normal healing and remodeling after injury. In the current study, we evaluated the hypothesis that a number of inflammatory factors, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, and interferon (IFN)-gamma, modulate this process by induction of prostaglandin (PG) E(2) and nitric oxide (NO) production and that these secondary mediators function in an autocrine or paracrine manner to modulate contraction. Human fetal lung fibroblasts (HFL) were cultured in type I collagen gels and floated in medium containing TNF-alpha, IL-1 beta, or IFN-gamma alone or in combination (cytomix). All cytokines inhibited the contraction significantly. The potency order was IL-1 beta, TNF-alpha, IFN-gamma. The cytomix was no more potent than was IL-1 beta alone. PGE(2) production was increased by TNF-alpha (5.0 versus 0.16 ng/ml, P < 0.01), IL-1 beta (5.3 versus 0.16 ng/ml, P < 0.01), and cytomix (5.9 versus 0.16 ng/ml, P < 0.01), and was completely inhibited by indomethacin. Indomethacin (P < 0.05) and L-NG-monomethyl arginine citrate (L-NMMA) (P < 0.05) alone both partially attenuated the inhibition of contraction caused by cytokines alone or by cytomix. Indomethacin and L-NMMA together attenuated inhibition more than either alone (P < 0.05). Exogenous PGE(2) and exogenous NO donors (DETA nononate and 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium chloride) inhibited the contraction significantly. The protein kinase A inhibitor KT5270 and the protein kinase G inhibitor Rp-pCPT-cGMPS attenuated the inhibition induced by PGE(2) and NO, respectively. In summary, PGE(2) and NO appear to function in parallel as autocrine/paracrine mediators of cytokine-driven fibroblast inhibition of the contraction of collagen gels and may contribute to remodeling during repair and inflammation in lung disorders.

Persistence of TGF-beta1 induction of increased fibroblast contractility.

Fibroblast contraction of collagen gels is regarded as a model of wound contraction. Transforming growth factor (TGF)-beta added to such gels can augment contraction consistent with its suggested role as a mediator of fibrotic repair. Since fibroblasts isolated from fibrotic tissues have been suggested to express a "fibrotic phenotype," we hypothesized that TGF-beta exposure may lead to a persistent increase in fibroblasts' contractility. To evaluate this question, confluent human fetal lung fibroblasts were treated with serum-free Dulbecco modified Eagle medium (DMEM), with or without 100 pM [corrected] TGF-beta1, TGF-beta2, or TGF-beta3 for 48 h. Fibroblasts were then trypsinized and cast into gels composed of native type I collagen isolated from rat tail tendons. After 20 min for gelation, the gels were released and maintained in serum-free DMEM. TGF-beta-pretreated fibroblasts caused significantly more rapid gel contraction (52.5+/-0.6, 50.9+/-0.2, and 50.3+/-0.5% by TGF-beta1, -beta2, and -beta3 pretreated fibroblasts, respectively) than control fibroblasts (74.0+/-0.3%, P < 0.01). This effect is concentration dependent (50-200 nM), and all three isoforms had equal activity. The effect of TGF-beta1, however, persisted for only a short period of time following the removal of TGF-beta, and was lost with sequential passage. These observations suggest that the persistent increase in collagen-gel contractility, mediated by fibroblasts from fibrotic tissues, would not appear to be solely due to previous exposure of these cells to TGF-beta.

Glucocorticoids and TGF-beta1 synergize in augmenting fibroblast mediated contraction of collagen gels.

TGF-beta plays a central role in the initiation and progression of pulmonary fibrosis. Glucocorticoids are frequently used to treat fibrotic diseases, but beneficial effects are often modest. Both TGF-beta and glucocorticoids have been reported to increase fibroblast contraction of native collagen gels, a model of fibrotic tissue remodeling. Therefore, we sought to determine how glucocorticoids interact with TGF-beta in this system. In this study, human fetal lung fibroblasts (HFL-1) were pretreated with or without TGF-beta for 72 h before they were cast into type I collagen gels. Various concentrations of glucocorticoids (budesonide or hydrocortisone) were added at the time of casting. Gel size was then monitored at different times after gel release. The surrounding media were collected for the assay of prostaglandin E2 (PGE2) and the cell lysates were analyzed for cyclooxygenase (COX) expression by immunoblot. Glucocorticoids alone significantly enhanced fibroblast-mediated contraction of collagen gels (P < 0.01) and dose-dependently inhibited PGE2 release by HFL-1 fibroblasts. TGF-beta significantly augmented gel contraction but also induced a 30% increase in PGE2 release and increased the expression of COX-1. Glucocorticoids inhibited TGF-beta1 induced-PGE2 release, and enhanced TGF-beta augmented gel contraction without significantly affecting TGF-beta augmented COX-1 expression. Indomethacin, a COX inhibitor, increased TGF-beta augmented gel contraction but had no further effect when added together with glucocorticoids. Thus, glucocorticoids can synergize with TGF-beta in augmenting fibroblast mediated collagen gel contraction through the inhibition of PGE2 production. Such interactions between glucocorticoids and TGF-beta may account, in part, for the lack of response of fibrotic diseases to glucocorticoids.