Serum interleukin-33 combined with FEF75% z-score and FeNO improves the diagnostic accuracy of asthma in children.

OBJECTIVE: To investigate the diagnostic efficacy of serum IL-33 single indicator and combined indicators for asthma in children. METHODS: 132 children were initially diagnosed with asthma during acute exacerbation and 100 healthy children were included. Serum IL-33 concentration differences were compared between asthmatic and normal children. Correlations between IL-33 with pulmonary function parameters, FeNO, peripheral blood EOS counts and serum total IgE were analyzed in asthmatic children. ROC curves were used to assess IL-33 diagnostic efficacy and its combined indicators. To prevent overfitting of the predictive model, the hold-out cross-validation method was used. RESULTS: (1) Serum IL-33 concentrations were significantly higher in children with asthma than in normal children (p < 0.001). (2) IL-33 concentration was negatively correlated with FVC z-score, FEV1 z-score and FEF75% z-score in asthmatic children (p < 0.05). (3) The area under the ROC curve of IL-33 was 0.821, which was higher than those of FeNO, FVC z-score, and FEV1 z-score. (4) Cross-validation of the combined indicators showed that IL-33 significantly improved asthma diagnostic efficacy. The combination of IL-33, FEF75% z-score, and FeNO showed the highest diagnostic efficacy, with the AUC, sensitivity, and specificity of the combined indicator being 0.954, 90.1%, and 89. 0%, respectively, and good extrapolation of the predictive model. CONCLUSION: Serum IL-33 is higher in children with asthma and increases with the severity of pulmonary ventilation obstruction. A single indicator of serum IL-33 demonstrates moderate diagnostic accuracy, and its combination with FEF75% z-score and FeNO significantly improves the diagnostic accuracy in childhood asthma.

Serum interleukin-33 combined with FEF75% z-score and FeNO improves the diagnostic accuracy of asthma in children

Abstract Objective To investigate the diagnostic efficacy of serum IL-33 single indicator and combined indicators for asthma in children. Methods 132 children were initially diagnosed with asthma during acute exacerbation and 100 healthy children were included. Serum IL-33 concentration differences were compared between asthmatic and normal children. Correlations between IL-33 with pulmonary function parameters, FeNO, peripheral blood EOS counts and serum total IgE were analyzed in asthmatic children. ROC curves were used to assess IL-33 diagnostic efficacy and its combined indicators. To prevent overfitting of the predictive model, the hold-out cross-validation method was used. Results (1) Serum IL-33 concentrations were significantly higher in children with asthma than in normal children (p < 0.001). (2) IL-33 concentration was negatively correlated with FVC z-score, FEV1 z-score and FEF75% z-score in asthmatic children (p < 0.05). (3) The area under the ROC curve of IL-33 was 0.821, which was higher than those of FeNO, FVC z-score, and FEV1 z-score. (4) Cross-validation of the combined indicators showed that IL-33 significantly improved asthma diagnostic efficacy. The combination of IL-33, FEF75% z-score, and FeNO showed the highest diagnostic efficacy, with the AUC, sensitivity, and specificity of the combined indicator being 0.954, 90.1%, and 89. 0%, respectively, and good extrapolation of the predictive model. Conclusion Serum IL-33 is higher in children with asthma and increases with the severity of pulmonary ventilation obstruction. A single indicator of serum IL-33 demonstrates moderate diagnostic accuracy, and its combination with FEF75% z-score and FeNO significantly improves the diagnostic accuracy in childhood asthma.

CCNB1 is a novel prognostic biomarker and promotes proliferation, migration and invasion in Wilms tumor.

BACKGROUND: Wilms tumour (WT) is a mixed type of embryonal tumour that usually occurs in early childhood. However, our knowledge of the pathogenesis or progression mechanism of WT is inadequate, and there is a scarcity of beneficial therapeutic strategies. METHODS: High-throughput RNA sequencing was employed in this study to identify differentially expressed genes (DEGs) in clinical tumor samples and matching normal tissues. The STRING database was utilized to build a protein-protein interaction (PPI) network, and the Cytohubba method was used to identify the top 10 highly related HUB genes. Then, the key genes were further screened by univariate COX survival analysis. Subsequently, the XCELL algorithm was used to evaluate the tumour immune infiltration. RT-PCR, WB, and IF were used to verify the expression level of key genes in clinical tissues and tumour cell lines. Finally, the function of the key gene was further verified by loss-of-function experiments. RESULTS: We initially screened 1612 DEGs, of which 1030 were up-regulated and 582 were down-regulated. The GO and KEGG enrichment analysis suggested these genes were associated with 'cell cycle', 'DNA replication'. Subsequently, we identified 10 key HUB genes, among them CCNB1 was strongly related to WT patients' overall survival. Multiple survival analyses showed that CCNB1 was an independent indicator of WT prognosis. Thus, we constructed a nomogram of CCNB1 combined with other clinical indicators. Single gene GSEA and immune infiltration analysis revealed that CCNB1 was associated with the degree of infiltration or activation status of multiple immune cells. TIDE analysis indicated that this gene was correlated with multiple key immune checkpoint molecules and TIDE scores. Finally, we validated the differential expression level of CCNB1 in an external gene set, the pan-cancer, clinical samples, and cell lines. CCNB1 silencing significantly inhibited the proliferation, migration, and invasive capabilities of WIT-49 cells, also, promoted apoptosis, and in turn induced G2 phase cell cycle arrest in loss-of-function assays. CONCLUSION: Our study suggests that CCNB1 is closely related to WT progression and prognosis, and serves as a potential target.

Bufalin reverses ABCB1-mediated resistance to docetaxel in breast cancer.

Background: Docetaxel (DCT) is widely used in clinical practice, but the drug resistance of breast cancer patients has become an important reason to limit its clinical efficacy. Chan'su is a commonly used traditional Chinese medicine for the treatment of breast cancer. Bufalin (BUF) is a bioactive polyhydroxy steroid extracted from chan'su and has strong antitumor activity, but there are few studies on reversing drug resistance in breast cancer. The aim of this study is to determine whether BUF can reverse the drug resistance to DCT and restore efficacy in breast cancer. Methodology: The reversal index of BUF was detected by Cell Counting Kit-8 (CCK-8) assays. The effects of BUF on enhancing the apoptosis of DCT were detected by flow cytometry and Western Blot (WB), and the main differential expression levels of sensitive and resistant strains were detected by high-throughput sequencing. Rhodamine 123 assay, WB and ATP Binding Cassette Subfamily B Member 1 (ABCB1) ATPase activity experiments were used to detect the effect of BUF on ABCB1. The nude mouse orthotopic model was constructed to investigate the reversal effect of BUF on DCT resistance in vivo. Results: With BUF intervention, the sensitivity of drug-resistant cell lines to DCT was increased. BUF can inhibit the expression of ABCB1 protein, increase the drug accumulation of DCT in drug-resistant strains, and reduce the ATPase activity of ABCB1. Animal experiments show that BUF can inhibit the growth of drug-resistant tumors in an orthotopic model of breast cancer and decrease the expression of ABCB1. Conclusion: BUF can reverse ABCB1-mediated docetaxel resistance in breast cancer.

Transurethral Retrograde Fishing the Double J Urethral Stent: A Tertiary Children Hospital's Experience With a New Technical Strategy.

Purpose: The purpose of this study is to provide a new strategy for non-cystoscopic double J urethral stent (JJS) removal, the transurethral retrograde fishing the double J urethral stent (TURFJJS), that avoids general anesthesia in pediatric populations. Methods: We retrospectively reviewed the JJS removal records of patients having ureteropelvic junction obstruction (UPJO). We analyzed differences in the removal success rates, operation-related severe complications, total cost, duration, and parental satisfaction between TURFJJS and traditional cystoscopic double J urethral stent removal (CJJSR) procedures. Results: A total of 324 patients with UPJO were included in this study. CJJSR yielded a success rate of 100%. TURFJJS achieved a success rate of 94.3%. The TURFJJS was just an outpatient procedure, and its total cost was about 800 Chinese yuan (US$ 124). There were no severe JJS removal-related complications using TURFJJS. Parental satisfaction was 98.2 and 92.5% for the CJJSR and TURFJJS protocols, respectively. Conclusion: TURFJJS is safe, effective, cost-effective, and well-tolerated in pediatric patients, minimizing or eliminating the need for general anesthesia, additional hospitalization, and waste of time. TURFJJS should be widely used in pediatric urology.

Macrophage polarization induced by quinolone antibiotics at environmental residue level.

Widespread use of quinolone antibiotics leads to serious residues in the environment and toxicity effects. This paper studied the effects of three typical quinolone antibiotics ciprofloxacin, norfloxacin and pipemidic acid on the polarization of macrophages RAW264.7 cells. The experimental concentrations were 0.01, 0.1, 1, 10, 100 and 1000 µg/L according to the environmental residual level. By MTT assay, phagocytosis assay and migration assay, macrophages were found to exhibit hormesis effect of low dose promotion and high dose inhibition. The detection of macrophages surface markers showed that 0.1 µg/L antibiotics increased the secretion of pro-inflammatory cytokines and induced macrophages to be M1-type, and 1000 µg/L antibiotics significantly increased the secretion of anti-inflammatory cytokines and induced macrophages to be M2-type. In order to explore the relationship between low-dose excitatory effects and polarization, the mechanism of 0.1 µg/L antibiotics inducing macrophages to M1-type was further studied. Results showed that 0.1 µg/L quinolone antibiotics activated the key proteins in the PI3K/Akt, Notch1, JNK and JAK2/STAT3 signaling pathways to cause the secretion of pro-inflammatory cytokines and induce inflammation. In order to eliminate inflammation, macrophages number feedback increased, phagocytosis and migration function enhanced, showing hormesis effect. In vitro macrophages experiment confirmed that quinolone antibiotics with environmental residual concentration had immunotoxicity.

Long Non-Coding RNA XIST Promotes Wilms Tumor Progression Through the miR-194-5p/YAP Axis.

PURPOSE: Although the long non-coding RNA (lncRNA) X inactive-specific transcript (XIST) has been reported to have an anti-tumor effect in multiple malignant tumors, its role in Wilms tumor (WT) progression has not been characterized. Thus, we investigated the underlying mechanism by which XIST regulates WT progression. PATIENTS AND METHODS: We performed microarray analysis and real-time quantitative PCR (RT-qPCR) to detect the expression levels of XIST lncRNA, microRNA-194-5p (miR-194-5p), and YAP (yes-associated protein in Hippo pathway) in tumor and matched adjacent normal tissues and blood collected from 49 WT patients. We also conducted bioinformatics analyses to identify differentially expressed genes. We measured the effects of XIST overexpression and knockdown on cell proliferation, apoptosis, migration, and invasion, and its association with the miR-194-5p/YAP pathway in the rhabdoid G401cell line using flow cytometry, transwell assays, immunohistochemistry, Western blot analysis, and the dual luciferase reporter gene assay. RESULTS: We found that XIST lncRNA levels were increased in blood and tissue samples of WT patients, and this upregulation was significantly correlated with TNM staging and shorter survival time. Notably, we found that XIST upregulation correlated with miR-194-5p downregulation and YAP upregulation in WT tissues, suggesting that XIST regulates the miR-194-5p/YAP pathway. Conversely, XIST downregulation inhibited WT cell proliferation, migration, and invasion and induced apoptosis. Our study revealed the oncogenic role of the lncRNA XIST in WT and demonstrated its role as a competitive endogenous RNA that regulates the miR-194-5p/YAP pathway. CONCLUSION: Our study demonstrates XIST's potential as a clinical prognostic biomarker and therapeutic target for WT.

Retrospective analysis of outcomes in patients with clear cell sarcoma of the kidney: A tertiary single-institution experience.

BACKGROUND: Clear cell sarcoma of the kidney (CCSK) is a rare and aggressive tumor. This study aims to describe the clinical characteristics and outcomes of CCSK patients in one of the largest pediatric medical centers in China. METHODS: We included all patients diagnosed with CCSK between January 2008 and March 2019 at the Children's Hospital of Chongqing Medical University, China. The patients' demographics, clinical presentation, and management were reviewed. Follow-up was continued until December 2019. RESULTS: In total, 41 CCSK patients (66% male) with a median age of 24 months (range 3-108 months) were identified. The stage distributions of stages I, II, III and IV were 42%, 34%, 24% and 0%, respectively. Preoperative chemotherapy was administered to 7/41 patients. All patients underwent radical nephrectomy and postoperative chemotherapy. The median number of lymph nodes sampled was 4 (range 1-12). Radiotherapy was applied in 8/41 patients. The 5-year event-free survival (EFS) and overall survival (OS) were 63.9% and 78.8%, respectively. Of the 41 patients, 11 patients experienced relapse at a median time of 19 months (range 5-72 months). The most common site of recurrence was the tumor bed (9/11). Young age was a significant adverse prognostic factor for EFS. CONCLUSIONS: The overall outcome of CCSK patients in our hospital is poorer than that in developed regions. More research is needed to clarify the underlying causes of poorer outcomes in young patients and improve outcomes. TYPE OF STUDY: Retrospective study. LEVEL OF EVIDENCE: LEVEL IV.

Trans-uretero-cystic external urethral stent for urinary diversion in pediatric laparoscopic pyeloplasty: A novel approach.

PURPOSE: We present a new approach for urine drainage in pediatric patients following laparoscopic pyeloplasty, the trans-uretero-cystic external urethral stent (TEUS). METHODS: We retrospectively identified 85 children who underwent laparoscopic pyeloplasty from July 2015 to June 2017. The included children were assigned to group A (double-J stent) or group B (TEUS). In group A, the double-J stent was removed by a cystoscopy under anesthesia after 1 month, while in group B, the external stent was removed after 5 to 7 days. We examined the durations of operation, hospital stay and the frequency of stent-related complications including urinary leakage, stent dislocation, stent occlusion, and urinary tract infection. RESULTS: The operation time was significantly longer for patients in group B than for those in group A. No significant difference was observed between the groups regarding stent-related complications. In group A, 4 patients need auxiliary stent re-insertion for the management of complications, 2 developed urinary tract infection, and 2 had stent occlusion. In group B, none needed auxiliary stent re-insertion for complications and avoided re-operation. CONCLUSIONS: In children, the outcome of external stent implantation was similar to that using double-J stent, and the use of the former approach may be beneficial for younger children.

MiR-155-5p exerts tumor-suppressing functions in Wilms tumor by targeting IGF2 via the PI3K signaling pathway.

BACKGROUND: MicroRNA-155-5p (miR-155-5p) has been reported to play an oncogenic role in different human malignancies; however, its role in Wilms tumor (WT) remains unclear. METHODS: Differentially expressed miRNAs (DE-miRNAs) and mRNAs (DEGs) in WT blood and tissues were identified by using miRNA microarray and RNA-sequencing. Bioinformatics prediction and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to predict the potential functions of DE-miRNAs. DE-miRNAs and DEGs in WT obtained from Gene Expression Omnibus (GEO) and Therapeutically Applicable Research to Generate Effective Treatments (TARGET) were identified by using the "edgeR" package. RT-qPCR was used to explore miR-155-5p and IGF2 expression and their clinical significance in WT specimens. A rhabdoid cell line (G401) and Ewing sarcoma cell line (SK-NEP-1) were used. Immunohistochemical staining, western blotting and dual-luciferase reporter assays were performed to study the mechanisms involved. The CCK-8, flow cytometry, wound healing and transwell assays were performed to identify the effects of miR-155-5p and IGF2 knockdown on cell proliferation, apoptosis, migration and invasion, respectively. RESULTS: MiR-155-5p was downregulated in both blood and tissues from WT patients who did not receive chemotherapy before surgery but was upregulated in tissues from WT patients who had received chemotherapy before surgery. IGF2, PI3K, AKT and mTOR were found to be upregulated in WT tissues. Additionally, miR-155-5p and IGF2 were significantly correlated with TNM stage and lymphatic metastasis in WT patients. Molecular mechanism exploration indicated that IGF2 was downregulated by miR-155-5p via direct binding to its 3' untranslated region in cell lines. Furthermore, IGF2, PI3K, AKT and mTOR expression was inversely correlated with miR-155-5p expression, and PI3K, AKT and mTOR expression was positively correlated with IGF2 expression in cell culture. Functional studies demonstrated that miR-155-5p upregulation and IGF2 knockdown suppressed cell proliferation, migration and invasion and induced cell apoptosis. Moreover, the tumor-suppressing effects of miR-155-5p in cells were abrogated by miR-155-5p inhibitor treatment. CONCLUSIONS: Taken together, these findings suggest that miR-155-5p functions as a tumor suppressor in WT through inactivating the PI3K/AKT/mTOR signaling pathway by directly targeting IGF2. Thus, miR-155-5p might be a novel therapeutic target for WT.

Long non-coding RNA ANRIL-mediated inflammation response is involved in protective effect of rhein in uric acid nephropathy rats.

BACKGROUND: The aim of this study was to investigate the role of long non-coding RNAs (LncRNAs) antisense non-coding RNA in the INK4 locus (ANRIL) in anti-inflammation of rhein in uric acid nephropathy (UAN) rats. METHODS: Rat models of UAN were induced by adenine and potassium oxonate. Enzyme-linked immunosorbent assay (ELISA) was performed to assess inflammation factor in serum and supernatant. ANRIL mRNA level was detected using real-time reverse transcription PCR (qRT-PCR). Immunostaining was used to observe pathological changes of renal tissues in rats. RESULTS: ANRIL and inflammatory factor levels were highly expressed in patient with UAN. Furthermore, rhein showed an observable effect on anti-inflammatory and renal protection in UAN rats, rhein inhibited expressions of ANRIL in vivo or in vitro. Besides, ANRIL-mediated inflammatory response attenuated protective effect of rhein. CONCLUSIONS: ANRIL-mediated inflammatory response attenuated the protective effect of rhein in UAN rats. This study showed an understanding of the role and mechanism of ANRIL in UAN, which provides a new target and therapy for the prevention and treatment of UAN.

LncRNA ANRIL promotes NLRP3 inflammasome activation in uric acid nephropathy through miR-122-5p/BRCC3 axis.

This study is designed to explore the mechanism by which long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) plays a pathogenic role in uric acid nephropathy (UAN). The expressions of ANRIL, miR-122-5p, BRCA1-BRCA2-containing complex subunit 3 (BRCC3) and NOD-like receptor protein 3 (NLRP3) were determined in UAN patients and uric acid-treated HK-2 cells by qRT-PCR. Protein levels of BRCC3 and NLRP3 were examined by western blot. The levels of inflammatory cytokines were quantified by ELISA. CCK-8 assay was used to assess cell viability. Apoptosis was detected by Annexin V-FITC/PI double-labeled flow cytometry and TUNEL assay. The interaction between ANRIL, miR-122-5p and BRCC3 were studied using luciferase reporter assay. The role of ANRIL in renal injury was evaluated in experimental rats. ANRIL and BRCC3 were highly expressed while miR-122-5p was down-regulated in serum of UAN patients and uric acid-treated tubular epithelial cells. Luciferase reporter assay and in vitro rescue experiment confirmed that ANRIL promoted NLRP3 inflammasome activation by up-regulating BRCC3 expression via sponging miR-122-5p. Furthermore, in vivo experiment validated that knockdown of ANRIL alleviated renal injury of UAN rats. ANRIL exerted pathogenic effect in UAN to promote NLRP3 inflammasome activation via miR-122-5p/BRCC3 axis.

[Expression of miR-155-5p in Wilms tumor and its regulatory role in proliferation, migration and apoptosis of Wilms tumor cells in vitro].

OBJECTIVE: explore the expression of miR-155-5p in Wilms tumor and its effect in regulating the proliferation, migration and apoptosis of Wilms tumor cells. METHODS: Specimens of tumor tissues and paired adjacent tissues were obtained from 40 patients with Wilms tumor for detection of the expression levels of miR-155-5p using RT-qPCR. Wilms tumor cell line G401 was transfected with miR-155-5p mimics and miR-155-5p inhibitor to induce miR-155-5p over-expression and its inhibition, respectively, and the changes in the cell proliferation, migration and apoptosis were assessed using cell counting kit-8 (CCK-8), wound healing assay and fl ow cytometry. RESULTS: RT-qPCR showed that the expression of miR-155-5p decreased significantly in Wilms tumor tissues as compared with normal kidney tissues and was significantly associated with TNM stage (P < 0.05). In G401 cells, over-expression of miR-155-5p significantly inhibited the cell proliferation and migration and promoted cell apoptosis (P < 0.05), and down-regulation of miR-155-5p obviously enhanced the proliferation and migration and suppressed apoptosis of the cells (P < 0.05). CONCLUSIONS: miR-155-5p is down-regulated in Wilms tumor and its expression level is correlated with TNM stage. miR-155-5p participates in the progression of Wilms tumor by inhibiting the proliferation and migration and promoting apoptosis of the tumor cells, and may serve as a novel biomarker for diagnosis, therapy and prognostic evaluation of Wilms tumor.

Weicao capsule ameliorates renal injury through increasing autophagy and NLRP3 degradation in UAN rats.

Uric acid nephropathy (UAN) is one of the most common metabolic diseases and leads to kidney damage. This study aimed to evaluate the effect of Weicao capsule on renal injury of UAN rats and to examine whether the mechanism was associated with induction of autophagy and degradation of nucleotide binding oligomerization domain (Nod)-like receptor (NLR) protein 3 (NLRP3) inflammasome. Sixty Sprague-Dawley rats were randomly allocated into 6 groups: Control, Model, Allopurinol, and Weicao (0.55/1.1/2.2 g/kg) group. The data showed activation of renal NLRP3 inflammasome in UAN rats, with elevation in serum levels of interleukin (IL)-1ß and IL-18, and subsequent deterioration of renal injury. Fortunately, Weicao had a markedly therapeutic effect on UAN rats, including improving renal function-related indexes, ameliorating hyperuricemia-related inflammation, decreasing crystals in renal tissue and alleviating renal interstitial fibrosis. Additionally, Weicao exerted anti-proliferative and anti-apoptosis effects on rat renal tubular epithelial cell NRK-52E in macrophages from UAN rats. Our investigation into the mechanism revealed that Weicao suppressed the activated NLRP3 inflammasome. Furthermore, Weicao induced autophagy, as evidenced by a dose-dependent increase in levels of renal autophagy-related proteins in UAN rats. Moreover, autophagy inhibitor 3-MA and NLRP3 activator ATP blocked the effect of Weicao on autophagy induction and NLRP3 inflammasome degradation. In conclusion, Weicao had similar effects as allopurinol and exerted anti-inflammatory and renal-protective effect in a concentration-dependent manner in UAN rats, most likely through increasing autophagy and NLRP3 degradation. Our study provides new insight into the underlying mechanism of Weicao in the treatment of UAN.

Protective Effects of Adiponectin Against Diabetic Renal Injury in a Mouse Model of Diabetes.

BACKGROUND/AIMS: Adiponectin (Apn) has shown anti-diabetic and anti-inflammatory potential. In the study, we studied and tested the protective effects of Apn against diabetic renal injury and the possible mechanism of these effects. METHODS: After 1 week of adaptive feeding, 30 mice were randomly divided into 5 groups: the control group, the model group, the Apn (L) group, the Apn (M) group and the Apn (H) group. All mice were marked and weighed. Following 4 weeks of a pro-diabetic high-fat diet, the model group and Apn groups were injected intraperitoneally with a high dose of STZ (85 mg/kg), while the normal control group was injected with sodium citrate. Fasting blood glucose was measured daily, starting 3 days after STZ injection. After confirming the success of the diabetic model by measuring blood glucose of more than 16.7 nM for 3 successive days, we observed the animal models for an additional 4 weeks. After body weights were measured, urinary albumin, urinary protein, SOD activity and malondialdehyde (MDA) were measured by ELISA, BCA and biochemical assay respectively . Moreover, plasma insulin was assayed by radioimmunoassay, insulin expression in pancreatic ß cells was assayed by immunohistochemistry and receptor for advanced glycation end products (RAGE) and corresponding PKC and PKA signaling in the kidney cortex were also assayed by Western blot and Real-time PCR. RESULTS: The results showed that Apn can significantly reduce MDA and enhance SOD activity. Moreover, Apn promoted the synthesis and secretion of insulin by islet ß-cells and reduced RAGE accumulation in the kidney, which was associated with down-regulated PKC expression and upregulated PKA expression. CONCLUSION: Apn has protective effects against hyperglycemia and can effectively enhance antioxidation, promote the secretion of insulin and reduce the accumulation of glycosylated products in T2DM mice; these effects were associated with inhibition of PKC and promotion of PKA signaling.

Fluorogenic and chromogenic probe for rapid detection of a nerve agent simulant DCP.

A fluorogenic and visual probe was devised to detect diethyl chlorophosphate (DCP), a nerve agent simulant. The probe, N-(rhodamine B)-lactam-2-aminoethanol (RB-AE), undergoes oxazoline formation following phosphorylation in the presence of DCP, which gives rapid and clear fluorescence and color change in the assay solutions.

Pharmacological characterization of 3-azabicyclo[3,2,1] octane-1-yl-l-leucyl-d-tryptophanyl-d-4-Cl-phenylalanine: A novel ET(A) receptor-selective antagonist.

BACKGROUND AND OBJECTIVES: Pulmonary hypertension is a kind of disease associated with a very high rate of mortality. There are not many effective drugs for the treatment of pulmonary hypertension. Treatment with ET-1 receptor antagonists was proved to be effective in the treatment of pulmonary hypertension. Aiming at developing new endothelin A receptor (ET(A)) antagonist for treatment of pulmonary hypertension, 242 peptide compounds were synthesized by structural optimization of a selective ET(A) receptor antagonist BQ-123. Among these, -azabicyclo[3,2,1]octane-1-yl-l-Leucyl-d-tryptophanyl-d-4-Cl-phenylalanine, named ETP-508, was selected for further harmacological characterization. METHODS: Radioligand binding assay was performed to study the binding affinity of ETP-508 for ET(A) and ET(B) receptors. The biological activity of ETP-508 was evaluated in isolated rat aortic ring experiment and in systemic arterial pressure experiment. In addition, hypotensive effect of ETP-508 was investigated on hypoxia-induced pulmonary hypertension. RESULTS: ETP-508 binds to endothelin ET(A) receptor with >10,000-fold higher affinity than to endothelin B receptor in rat lung tissue preparation. ETP-508 inhibited endothelin-1 (ET-1)-induced contraction of isolated rat aortic ring and shifted the cumulative concentration-contraction response curve to ET-1 to right with no change in the maximal response. In vivo, ETP-508 inhibited the increased effect of ET-1 on mean systemic arterial pressure. Pre-treatment with ETP-508 by intravenous infusion significantly inhibited chronic hypoxia-induced pulmonary hypertension and right ventricular hypertrophy. ETP-508 also significantly inhibited the increase in lung ET-1 expression level, hemoglobin, red-cell count and red-cell hematocrit as induced by hypoxia. Furthermore, ETP-508 partially reversed pre-established pulmonary hypertension and right ventricle hypertrophy by chronic hypoxia. CONCLUSION: These results indicated that ETP-508 is a novel highly selective ET(A) receptor antagonist and may have a great potential to be developed as a drug of anti-pulmonary hypertension.