Rational engineering strategies for achieving high-yield, high-quality and high-stability of natural product production in actinomycetes.

Actinomycetes are recognized as excellent producers of microbial natural products, which have a wide range of applications, especially in medicine, agriculture and stockbreeding. The three main indexes of industrialization (titer, purity and stability) must be taken into overall consideration in the manufacturing process of natural products. Over the past decades, synthetic biology techniques have expedited the development of industrially competitive strains with excellent performances. Here, we summarize various rational engineering strategies for upgrading the performance of industrial actinomycetes, which include enhancing the yield of natural products, eliminating the by-products and improving the genetic stability of engineered strains. Furthermore, the current challenges and future perspectives for optimizing the industrial strains more systematically through combinatorial engineering strategies are also discussed.

Platelet count trends and response to fondaparinux in a cohort of heparin-induced thrombocytopenia suspected patients after pulmonary endarterectomy.

A definitive diagnosis of heparin-induced thrombocytopenia (HIT) is difficult to make, especially in patients undergoing cardiac surgery. In this retrospective cohort study, we assessed the platelet count trends and the response to fondaparinux in a population of patients of suspected HIT after pulmonary endarterectomy (PEA). Patients enrolled in this study were over the age of 18 years, and survived longer than 7 days after PEA between January 1, 2011 and December 31, 2015. HIT likelihood was assessed by the 4 T's score and interpreted by our institutional algorithm. 54 patients were operated, and 49 patients met the inclusion criteria. Six patients met the criteria for suspected HIT and were treated with fondaparinux until the platelet recovered. No significant difference was observed of clinical characteristics between intermediate to high HIT likelihood patients (HIT SUSPECTED) and low HIT likelihood patients (NO HIT SUSPECTED). HIT SUSPECTED patients reached platelet count lowest later (about 5.5 days after PEA), while NO HIT SUSPECTED patients is about 4.0 days after PEA. Percentage of platelet counts decrease (> 50%) was larger than NO HIT SUSPECTED patients (< 50%). There was no difference in mortality or residual pulmonary hypertension between HIT SUSPECTED and NO HIT SUSPECTED patients. Two HIT SUSPECTED patients who used heparin after PEA died, the other four survived by replacing heparin or low molecular weight heparin with fondaparinux. Suspected HIT patients should be surveilled carefully. Platelet counts trends may have some hints in the prevention of HIT. Fondaparinux may be effective for patients with suspected HIT.

FadR1, a pathway-specific activator of fidaxomicin biosynthesis in Actinoplanes deccanensis Yp-1.

Fidaxomicin, an 18-membered macrolide antibiotic, is highly active against Clostridium difficile, the most common cause of diarrhea in hospitalized patients. Though the biosynthetic mechanism of fidaxomicin has been well studied, little is known about its regulatory mechanism. Here, we reported that FadR1, a LAL family transcriptional regulator in the fidaxomicin cluster of Actinoplanes deccanensis Yp-1, acts as an activator for fidaxomicin biosynthesis. The disruption of fadR1 abolished the ability to synthesize fidaxomicin, and production could be restored by reintegrating a single copy of fadR1. Overexpression of fadR1 resulted in an approximately 400 % improvement in fidaxomicin production. Electrophoretic mobility shift assays indicated that fidaxomicin biosynthesis is under the control of FadR1 through its binding to the promoter regions of fadM, fadA1-fadP2, fadS2-fadC, and fadE-fadF, respectively. And the conserved binding sites of FadR1 within the four promoter regions were determined by footprinting experiment. All results indicated that fadR1 encodes a pathway-specific positive regulator of fidaxomicin biosynthesis and upregulates the transcription levels of most of genes by binding to the four above intergenic regions. In summary, we not only clearly elucidate the regulatory mechanism of FadR1 but also provide strategies for the construction of industrial high-yield strain of fidaxomicin.

Renin-angiotensin system regulates pulmonary arterial smooth muscle cell migration in chronic thromboembolic pulmonary hypertension.

Pulmonary arterial smooth muscle cell (PASMC) migration plays a key role in vascular remodeling, which occurs during development of chronic thromboembolic pulmonary hypertension (CTEPH). Activation of the renin-angiotensin system (RAS) contributes to vascular remodeling observed in many diseases, including idiopathic pulmonary arterial hypertension. However, the role of RAS imbalance in CTEPH has not been characterized. Here, we hypothesize that RAS imbalance regulates vascular remodeling by promoting PASMC migration in CTEPH. Serum renin and angiotensin II levels in patients with CTEPH were quantified by ELISA. The pulmonary endarterectomy tissues were stained and analyzed by immunohistochemistry. PASMCs were isolated and verified by immunofluorescence staining. PASMC migration was determined by Transwell assay. Phosphorylation and protein level were detected by Western blotting. Serum levels of renin and angiotensin II were increased in patients with CTEPH {renin [median (25th percentile, 75th percentile) in pg/ml], 1,199.94 [690.85, 1,656.90] vs. 595.43 [351.48, 936.43], P < 0.001; angiotensin II [in pg/ml], 63.97 [45.97, 345.24] vs. 56.85 [11.20, 90.37], P < 0.05}. The migration of PASMCs isolated from patients with CTEPH was enhanced compared with control. Angiotensin II promoted the migration of PASMCs via activation of angiotensin II receptor 1 and phosphorylation of ERK1/2, whereas angiotensin-(1-7) counteracted this effect through activation of the Mas receptor and ERK1/2. These results demonstrate that the renin-angiotensin system regulates migration of PASMCs from patients with CTEPH via the ERK1/2 pathway. Our findings suggest that angiotensin-(1-7) or reagents targeting the renin-angiotensin system will be beneficial in the development of novel therapies for CTEPH.

Circular RNA hsa_circ_0001564 regulates osteosarcoma proliferation and apoptosis by acting miRNA sponge.

Circular RNAs (circRNAs) is a novel type of non-coding RNAs generated from back splicing, which has been verified to mediate multiple tumorigenesis. However, the role of circRNA in osteosarcoma is still unclear. In the present study, we preliminarily screened the circRNAs expression profiles in osteosarcoma and investigated the potential regulation mechanism. The circRNAs expression profiles in osteosarcoma were screened using circRNA microarray analysis, and results showed that there were 1152 circRNAs up-regulated and 915 circRNAs down-regulated in tumor tissue compared to adjacent tissue. Hsa_circ_0001564, located at 5q35.3 and its associated-gene symbol is CANX, was one of the significantly overexpressed circRNAs in osteosarcoma tissue, as well as in osteosarcoma cell lines. In functional experiments, hsa_circ_001564 knockdown significantly suppressed the proliferation activity, induced cell cycle arrest in G0/G1 phase, and promoted apoptosis in HOS and MG-63 cells. Subsequently, we explored the probable mechanism of hsa_circ_001564, and fortunately, bioinformatics analysis revealed that miR-29c-3p contained the complementary binding region with hsa_circ_0001564, which was confirmed by dual-luciferase reporter assay. Moreover, rescue experiments illustrated that miR-29c-3p could reverse the oncogenesis effect of hsa_circ_001564. Our study discovers that hsa_circ_0001564 acts as miR-29c-3p sponge to mediate the tumorigenicity, which could act as a potential biomarker for the osteosarcoma and provide a novel insight for competing endogenous RNAs (ceRNAs) mechanism in osteosarcoma.

Circular RNA GLI2 promotes osteosarcoma cell proliferation, migration, and invasion by targeting miR-125b-5p.

Circular RNAs are novel identified type of endogenous non-coding RNAs, which exert vital functions in human and animals. However, the in-depth role of circular RNAs in the progression of tumorigenesis, especially osteosarcoma, is still undefined. Our preliminary study had found that cir-GLI2 was significantly upregulated in osteosarcoma tissues compared to adjacent non-tumor tissue. Moreover, cir-GLI2 silencing could effectively suppress the proliferation, migration, and invasion capacity of osteosarcoma cells, indicating the tumor-promoting role. Besides, bioinformatics analysis and luciferase reporter assay predicted the direct binding to miR-125b-5p, which has been reported to function as a tumor suppressor in osteosarcoma. Furthermore, functional experiments validated that cir-GLI2 exerted the tumor-promoting effects on osteosarcoma cells via negatively targeting miR-125b-5p. In conclusion, our study demonstrated that cir-GLI2 acts as an oncogenic circular RNA in osteosarcoma genesis, providing a novel diagnostic and therapeutic target for osteosarcoma.

A Case of Pulmonary Hypertension Due to Fistulas Between Multiple Systemic Arteries and the Right Pulmonary Artery in an Adult Discovered for Occulted Dyspnoea.

BACKGROUND: Pulmonary hypertension (PH) can be caused by a fistula between the systemic and pulmonary arteries. Here, we report a case of PH due to multiple fistulas between systemic arteries and the right pulmonary artery where the ventilation/perfusion scan showed no perfusion in the right lung. METHODS: A 32-year-old male patient was hospitalised for community-acquired pneumonia. After treatment with antibiotics, the pneumonia was alleviated but dyspnoea persisted. Pulmonary hypertension was diagnosed using right heart catheterisation, which detected the mean pulmonary artery pressure as 37mmHg. The anomalies were confirmed by contrast-enhanced CT scan (CT pulmonary angiography), systemic arterial angiography and pulmonary angiography. RESULTS: Following embolisation of the largest fistula, the haemodynamics and oxygen dynamics did not improve, and even worsened to some extent. After supportive therapy including diuretics and oxygen, the patient's dyspnoea, WHO function class and right heart function by transthoracic echocardiography all improved during follow-up. CONCLUSIONS: Pulmonary hypertension can be present even when the right lung perfusion is lost. Closure of fistulas by embolisation, when those fistulas act as the proliferating vessels, may be harmful.

Stabilization of the angiotensin-(1-7) receptor Mas through interaction with PSD95.

The functions and signalling mechanisms of the Ang-(1-7) [angiotensin-(1-7)] receptor Mas have been studied extensively. However, less attention has been paid to the intracellular regulation of Mas protein. In the present study, PSD95 (postsynaptic density 95), a novel binding protein of Mas receptor, was identified, and their association was characterized further. Mas specifically interacts with PDZ1-2, but not the PDZ3, domain of PSD95 via Mas-CT (Mas C-terminus), and the last four amino acids [ETVV (Glu-Thr-Val-Val)] of Mas-CT were determined to be essential for this interaction, as shown by GST pull-down, co-immunoprecipitation and confocal co-localization experiments. Gain-of-function and loss-of-function studies indicated that PSD95 enhanced Mas protein expression by increasing the stabilization of the receptor. Mas degradation was robustly inhibited by the proteasome inhibitor MG132 in time- and dose-dependent manners, and the expression of PSD95 impaired Mas ubiquitination, indicating that the PSD95-Mas association inhibits Mas receptor degradation via the ubiquitin-proteasome proteolytic pathway. These findings reveal a novel mechanism of Mas receptor regulation by which its expression is modulated at the post-translational level by ubiquitination, and clarify the role of PSD95, which binds directly to Mas, blocking the ubiquitination and subsequent degradation of the receptor via the ubiquitin-proteasome proteolytic pathway.

Wnt5a inhibits hypoxia-induced pulmonary arterial smooth muscle cell proliferation by downregulation of ß-catenin.

Chronic hypoxia-induced pulmonary arterial hypertension (HPH) is closely associated with profound vascular remodeling, especially pulmonary arterial medial hypertrophy and muscularization due to hyperplasia of pulmonary artery smooth muscle cells (PASMCs). Aberrant Wnt signaling has been associated with lung diseases, but its role in pulmonary hypertension is unclear. This study evaluated the effect of Wnt5a on hypoxia-induced proliferation of human PASMCs and its possible mechanism. The results show that hypoxia (3% O(2), 48 h) induced proliferation of human PASMCs, accompanied with a significant decrease in Wnt5a gene expression, increase in ß-catenin and Cyclin D1 expression, as well as ß-catenin nuclear translocation. Treatment with recombinant mouse Wnt5a significantly inhibited hypoxia-induced proliferation of human PASMCs, upregulation of Cyclin D1 and ß-catenin expression, as well as the nuclear translocation of ß-catenin. These effects were inhibited by Wnt5a antibody. Knocking down ß-catenin or Cyclin D1 gene expression inhibited hypoxia-induced human PASMC proliferation, whereas overexpression of ß-catenin increased hypoxia-induced human PASMC proliferation and counteracted the inhibitory effect of Wnt5a. These results suggest that Wnt5a has an antiproliferative effect on hypoxia-induced human PASMC proliferation by downregulation of ß-catenin and its target gene Cyclin D1. Hypoxia-induced downregulation of Wnt5a may be a way to facilitate hypoxia-induced human PASMC proliferation. The results of this study will help to understand the novel strategies for PH treatment involving Wnt signaling.

[Study on the axial strain sensor of birefringence photonic crystal fiber loop mirror based on the absolute integral of the monitoring peak].

In the present paper, the theoretical expression of the wavelength change and the axial strain of birefringence fiber loop mirror is developed. The theoretical result shows that the axial strain sensitivity of birefringence photonic crystal fiber loop mirror is much lower than conventional birefringence fiber loop mirror. It is difficult to measure the axial strain by monitoring the wavelength change of birefringence photonic crystal fiber loop mirror, and it is easy to cause the measurement error because the output spectrum is not perfectly smooth. The different strain spectrum of birefringence photonic crystal fiber loop mirror was measured experimentally by an optical spectrum analyzer. The measured spectrum was analysed. The results show that the absolute integral of the monitoring peak decreases with increasing strain and the absolute integral is linear versus strain. Based on the above results, it is proposed that the axial strain can be measured by monitoring the absolute integral of the monitoring peak in this paper. The absolute integral of the monitoring peak is a comprehensive index which can indicate the light intensity of different wavelength. This method of monitoring the absolute integral of the monitoring peak to measure the axial strain can not only overcome the difficulty of monitoring the wavelength change of birefringence photonic crystal fiber loop mirror, but also reduce the measurement error caused by the unsmooth output spectrum.

Analysis of clinical features between active and inactive patients of Takayasu's arteritis with pulmonary arteries involvement.

BACKGROUND: The aim of this study was to investigate the clinical characteristics of patients between active and inactive Takayasu's arteritis with pulmonary artery involvement (PTA) and to identify better markers of disease activity in these patients. METHODS: Sixty-four PTA patients in Beijing Chao-yang hospital (2011 to 2021) were included. According to National Institutes of Health criteria, 29 patients were in active stage and 35 were in inactive stage. Their medical records were collected and analyzed. RESULTS: Compared with inactive group, patients in active group were younger. More patients in active stage presented fever (41.38% vs 5.71%), chest pain (55.17% vs 20%), increased C-reactive protein (2.91 vs 0.46 mg/L), erythrocyte sedimentation rate (35.0 vs 9 mm/h), and platelet count (291 vs 221 × 109/L). Pulmonary artery wall thickening was more common in active group (51.72% vs 11.43%). These parameters were restored after treatment. The incidence of pulmonary hypertension was comparable between groups (34.48% vs 51.43%), but patients in active group had lower pulmonary vascular resistance (PVR) (361.0 vs 891.0 dyn·s·cm-5) and higher cardiac index (2.76 ± 0.72 vs 2.01 ± 0.58 L/min/m2). On multivariate logistic regression analysis, chest pain [odds ratio (OR) 9.37, 95%CI (1.98-44.38), P = 0.005], increased platelet count (>242.5 × 109/L) [OR 9.03, 95%CI (2.10-38.87), P = 0.003] and pulmonary artery wall thickening [OR 7.08, 95%CI (1.44-34.89), P = 0.016] were independently associated with disease activity. CONCLUSION: Chest pain, increased platelet count, and pulmonary artery wall thickening are potential new indicators of disease activity in PTA. Patients in active stage may have lower PVR and better right heart function.

Long-term Outcomes and Predictors of Chronic Thromboembolic Pulmonary Hypertension After Pulmonary Endarterectomy.

BACKGROUND: Pulmonary endarterectomy (PEA) is the preferred treatment for CTEPH patients which can significantly improve symptoms and pulmonary hemodynamics. Therefore, this retrospective study evaluated the long-term outcomes after pulmonary endarterectomy (PEA) and analyze the predictors of long-term outcomes for chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: From 2002-2020, 76 CTEPH patients successfully discharged after PEA in Beijing Chaoyang Hospital were followed-up by scheduled clinical visits or telephone interviews. The follow-up time lasted for 18 years and median time was 7.29 years. RESULTS: The survival rate at 1,3,5,10,15 years postoperatively was 100.00%, 97.10%, 95.40%, 89.80% and 82.90%, respectively. Multivariate logistics regression analysis showed that postoperative mPAP (hazard ratio: 1.144; 95%confidence interval: 1.018-1.285; P = 0.023) was associated with a higher risk of late death, right atrium right and left diameters (hazard ratio: 1.113; 95%confidence interval, 1.006-1.231; P = 0.038) were associated with a higher risk of major adverse events. CONCLUSION: Pulmonary endarterectomy is an effective way to treat CTEPH. Long-term outcome is excellent for patients who undergoing pulmonary endarterectomy who survived from peri-operation time. Postoperative mPAP is a significant prognostic factor for long-term death and right atrium right and left diameters is a significant prognostic factor for major adverse events. That shows patients with high postoperative mPAP and right atrium right and left diameter should be followed up closely.

Effect of EZH2 on pulmonary artery smooth muscle cell migration in pulmonary hypertension.

Pulmonary hypertension (PH) is a life­threatening disease that often involves vascular remodeling. Although pulmonary arterial smooth muscle cells (PASMCs) are the primary participants in vascular remodeling, their biological role is not entirely clear. The present study analyzed the role of enhancer of zeste homolog 2 (EZH2) in vascular remodeling of PH by investigating the behavior of PASMCs. The expression levels of EZH2 in PASMCs in chronic thromboembolic pulmonary hypertension (CTEPH), a type of PH, were detected. The role of EZH2 in PASMC migration was investigated by wound­healing assay following overexpression and knockdown. Functional enrichment analysis of the whole­genome expression profiles of PASMCs with EZH2 overexpression was performed using an mRNA Human Gene Expression Microarray. Quantitative (q)PCR was performed to confirm the results of the microarray. EZH2 expression levels increased in CTEPH cell models. The overexpression of EZH2 enhanced PASMC migration compared with control conditions. Functional enrichment analysis of the differentially expressed genes following EZH2 overexpression indicated a strong link between EZH2 and the immune inflammatory response and oxidoreductase activity in PASMCs. mRNA expression levels of superoxide dismutase 3 were verified by qPCR. The results suggested that EZH2 was involved in the migration of PASMCs in PH, and may serve as a potential target for the treatment of PH.

Genome-based rational engineering of Actinoplanes deccanensis for improving fidaxomicin production and genetic stability.

Microbial fermentation is currently still the major way to produce structural complicated clinical drugs. Yet, the low productivity and genetic instability of producing strains remain the bottlenecks in microbial pharmaceutical industry. Fidaxomicin is a microbial drug against the Clostridium difficile infection. Here, a genome-based combinatorial engineering strategy was established to improve both fidaxomicin production and the genetic stability of Actinoplanes deccanensis YP-1. Guided by genomic analysis, several genetic instability-associated elements were cumulatively deleted, generating a more genetically stable mutant. Further rational engineering approaches including elimination of a pigment pathway, duplication of the fidaxomicin gene cluster, overexpression of a positive regulator and optimization of the fermentation medium, led to an overall 27-folds improvement in fidaxomicin production. Taken together, the genome-based rational combinatorial engineering strategy was efficient to enhance the fidaxomicin production and ameliorate the genetic stability of YP-1, it can also be widely used in other industrial actinomycetes for strain improvement.

Inhibition of SOC/Ca2+/NFAT pathway is involved in the anti-proliferative effect of sildenafil on pulmonary artery smooth muscle cells.

BACKGROUND: Sildenafil, a potent phosphodiesterase type 5 (PDE5) inhibitor, has been proposed as a treatment for pulmonary arterial hypertension (PAH). The mechanism of its anti-proliferative effect on pulmonary artery smooth muscle cells (PASMC) is unclear. Nuclear translocation of nuclear factor of activated T-cells (NFAT) is thought to be involved in PASMC proliferation and PAH. Increase in cytosolic free [Ca2+] ([Ca2+]i) is a prerequisite for NFAT nuclear translocation. Elevated [Ca2+]i in PASMC of PAH patients has been demonstrated through up-regulation of store-operated Ca2+ channels (SOC) which is encoded by the transient receptor potential (TRP) channel protein. Thus we investigated if: 1) up-regulation of TRPC1 channel expression which induces enhancement of SOC-mediated Ca2+ influx and increase in [Ca2+]i is involved in hypoxia-induced PASMC proliferation; 2) hypoxia-induced promotion of [Ca2+]i leads to nuclear translocation of NFAT and regulates PASMC proliferation and TRPC1 expression; 3) the anti-proliferative effect of sildenafil is mediated by inhibition of this SOC/Ca2+/NFAT pathway. METHODS: Human PASMC were cultured under hypoxia (3% O2) with or without sildenafil treatment for 72 h. Cell number and cell viability were determined with a hemocytometer and MTT assay respectively. [Ca2+]i was measured with a dynamic digital Ca2+ imaging system by loading PASMC with fura 2-AM. TRPC1 mRNA and protein level were detected by RT-PCR and Western blotting respectively. Nuclear translocation of NFAT was determined by immunofluoresence microscopy. RESULTS: Hypoxia induced PASMC proliferation with increases in basal [Ca2+]i and Ca2+ entry via SOC (SOCE). These were accompanied by up-regulation of TRPC1 gene and protein expression in PASMC. NFAT nuclear translocation was significantly enhanced by hypoxia, which was dependent on SOCE and sensitive to SOC inhibitor SKF96365 (SKF), as well as cGMP analogue, 8-brom-cGMP. Hypoxia-induced PASMC proliferation and TRPC1 up-regulation were inhibited by SKF and NFAT blocker (VIVIT and Cyclosporin A). Sildenafil treatment ameliorated hypoxia-induced PASMC proliferation and attenuated hypoxia-induced enhancement of basal [Ca2+]i, SOCE, up-regulation of TRPC1 expression, and NFAT nuclear translocation. CONCLUSION: The SOC/Ca2+/NFAT pathway is, at least in part, a downstream mediator for the anti-proliferative effect of sildenafil, and may have therapeutic potential for PAH treatment.

Endogenous automatic nerve discharge promotes nerve repair: an optimized animal model.

Exogenous electrical nerve stimulation has been reported to promote nerve regeneration. Our previous study has suggested that endogenous automatic nerve discharge of the phrenic nerve and intercostal nerve has a positive effect on nerve regeneration at 1 month postoperatively, but a negative effect at 2 months postoperatively, which may be caused by scar compression. In this study, we designed four different rat models to avoid the negative effect from scar compression. The control group received musculocutaneous nerve cut and repair. The other three groups were subjected to side-to-side transfer of either the phrenic (phrenic nerve group), intercostal (intercostal nerve group) or thoracodorsal nerves (thoracic dorsal nerve group), with sural nerve autograft distal to the anastomosis site. Musculocutaneous nerve regeneration was assessed by electrophysiology of the musculocutaneous nerve, muscle tension, muscle wet weight, maximum cross-sectional area of biceps, and myelinated fiber numbers of the proximal and distal ends of the anastomosis site of the musculocutaneous nerve and the middle of the nerve graft. At 1 month postoperatively, compound muscle action potential amplitude of the biceps in the phrenic nerve group and the intercostal nerve group was statistically higher than that in the control group. The myelinated nerve fiber numbers in the distal end of the musculocutaneous nerve and nerve graft anastomosis in the phrenic nerve and the intercostal nerve groups were statistically higher than those in the control and thoracic dorsal nerve groups. The neural degeneration rate in the middle of the nerve graft in the thoracic dorsal nerve group was statistically higher than that in the phrenic nerve and the intercostal nerve groups. At 2 and 3 months postoperatively, no significant difference was detected between the groups in all the assessments. These findings confirm that the phrenic nerve and intercostal nerve have a positive effect on nerve regeneration at the early stage of recovery. This study established an optimized animal model in which suturing the nerve graft to the distal site of the musculocutaneous nerve anastomosis prevented the inhibition of recovery from scar compression.

Papillary Solitary Fibrous Tumor/Hemangiopericytoma: An Uncommon Morphological Form With NAB2-STAT6 Gene Fusion.

Solitary fibrous tumor/hemangiopericytomas (SFT/HPCs) are mesenchymal tumors characterized by "staghorn" blood vessels and collagen deposition. Little is known about SFT/HPCs with papillary architecture. We summarized the clinicopathologic features of 12 patients with papillary SFT/HPCs (8 males and 4 females; median age: 59 years), including 8 previously reported cases. Tumors were present in the meninges (75%, 9/12), adrenal gland (8%, 1/12), orbit (8%, 1/12), or spinal canal (8%, 1/12). Six tumors (50%) had a true papillary architecture with fibrovascular cores and 6 tumors (50%) had a pseudopapillary architecture with vascular cores. Nuclear staining for STAT6 was present in all tested tumors (10/10). RT-PCR indicated NAB2 ex6-STAT6 ex17 fusion in 4 tumors (80%, 4/5) and NAB2 ex4-STAT6 ex2 fusion in 1 tumor (20%, 1/5). Five patients (42%, 5/12), all with tumors in the meninges, developed local recurrence at a median of 61 months after surgery (range: 56-165 months; mean: 88.6 months). These results indicated that the papillary architecture is a morphological form of SFT/HPCs. The recognition of this pattern, with appropriate immunohistochemical analysis and assessment of NAB2-STAT6 fusion, should facilitate the distinction of these rare neoplasms from morphologically similar tumors in the meninges, lung, pleura, and soft tissue.

[Study on the differential expression of lipid metabolism-related genes in young LDLR knockout mice liver].

OBJECTIVE: To clarify the differential expression of the genes related to the lipid metabolism in the early stage of atherosclerosis in the young LDLR-/- mice of different ages. METHODS: A RT-PCR assay was used to analyse the gene expression patterns in the livers of LDLR-/- mice and wild type (WT) mice from 14 to 90 days. The characteristics of early lipid deposition in intima were evaluated using biochemical and pathological techniques. RESULTS: In LDLR-/- mice, when compared to WT mice, the mRNA level of the apolipoprotein A IV (apoA IV), fatty acid translocase (Fat/CD36) and carnitine palmitoyl transferase I (CPT I) changed prominently at the age of 14-days (P < 0.05). At 30 days, the mRNA level of apolipoprotein A I (apoA I) was up regulated, but apolipoprotein F (apoF), CD36 and CPT I were down regulated (P < 0.05). At 60 days, the mRNA levels of apoA I, CPT I and liver X receptor alpha (LXRalpha) were up regulated, but apoA IV was down regulated (P < 0.05). At 90 days, the level of the apoA I was higher, but the expression of the apoA IV, apoF and acyl-coenzymeA oxidase 1 (ACOX1) were down regulated (P < 0.05), whereas the expression of apolipoprotein A V (apoA V), apolipoprotein E (apoE), peroxidase proliferator-activated receptor alpha (PPARalpha) and angiopoietin-like protein 3 (angptl 3) had no significant changes (P > 0.05). The serum levels of TC (P < 0.05), TG (P < 0.05) and LDLC (P < 0.05) in LDLR-/- mice were significantly higher than those in wild type mice with the same age. CONCLUSIONS: The mRNA levels of the apoA I, apoA IV, apoF, FAT/CD36, CPT I, ACOX1 and LXRalpha of the LDLR-/- mice were significantly changed compared to the WT mice. The genes may be of some relevance to the complicated lipid metabolism network, and have effect in the early stage of atherogenesis.

Identification of haptoglobin as a potential diagnostic biomarker of acute pulmonary embolism.

: Acute pulmonary embolism is a common disease, which is associated with high mortality and morbidity. There is significant relationship between haptoglobin and pulmonary embolism, however, the usefulness of haptoglobin as a biomarker for the diagnosis of pulmonary embolism remains poorly defined. The aim of the present study was to investigate the change and clinical diagnostic value of haptoglobin in pulmonary embolism. A comparative proteomic analysis was used for clinical screening of serum proteins in 18 patients (9 patients with pulmonary embolism and 9 controls). ELISA was used to validate the dysregulated proteins in 48 patients (24 patients with pulmonary embolism and 24 controls). Immunohistochemical staining was performed to detect the expression of haptoglobin in pulmonary artery of both groups. The diagnostic value of the differential protein and its association with the severity of pulmonary embolism were evaluated. Eight proteins showed significant changes in serum of pulmonary embolism patients. Haptoglobin, as one of the eight differential proteins, was significantly overexpressed in the serum of pulmonary embolism patients. In accordance, the expression of haptoglobin was increased in pulmonary artery of pulmonary embolism patients. The ROC curve showed that serum haptoglobin was a specific parameter in the diagnosis of pulmonary embolism with an area under the curve of 0.764 (95% confidence interval, 0.622-0.906; P < 0.01); in particular, the haptoglobin level at least 256.74 mg/l was the most useful cut-off value, with the sensitivity of 62% and specificity of 83%. Increased haptoglobin level may be an acceptable diagnostic parameter for pulmonary embolism.

Phrenic and intercostal nerves with rhythmic discharge can promote early nerve regeneration after brachial plexus repair in rats.

Exogenous discharge can positively promote nerve repair. We, therefore, hypothesized that endogenous discharges may have similar effects. The phrenic nerve and intercostal nerve, controlled by the respiratory center, can emit regular nerve impulses; therefore these endogenous automatically discharging nerves might promote nerve regeneration. Action potential discharge patterns were examined in the diaphragm, external intercostal and latissimus dorsi muscles of rats. The phrenic and intercostal nerves showed rhythmic clusters of discharge, which were consistent with breathing frequency. From the first to the third intercostal nerves, spontaneous discharge amplitude was gradually increased. There was no obvious rhythmic discharge in the thoracodorsal nerve. Four animal groups were performed in rats as the musculocutaneous nerve cut and repaired was bland control. The other three groups were followed by a side-to-side anastomosis with the phrenic nerve, intercostal nerve and thoracodorsal nerve. Compound muscle action potentials in the biceps muscle innervated by the musculocutaneous nerve were recorded with electrodes. The tetanic forces of ipsilateral and contralateral biceps muscles were detected by a force displacement transducer. Wet muscle weight recovery rate was measured and pathological changes were observed using hematoxylin-eosin staining. The number of nerve fibers was observed using toluidine blue staining and changes in nerve ultrastructure were observed using transmission electron microscopy. The compound muscle action potential amplitude was significantly higher at 1 month after surgery in phrenic and intercostal nerve groups compared with the thoracodorsal nerve and blank control groups. The recovery rate of tetanic tension and wet weight of the right biceps were significantly lower at 2 months after surgery in the phrenic nerve, intercostal nerve, and thoracodorsal nerve groups compared with the negative control group. The number of myelinated axons distal to the coaptation site of the musculocutaneous nerve at 1 month after surgery was significantly higher in phrenic and intercostal nerve groups than in thoracodorsal nerve and negative control groups. These results indicate that endogenous autonomic discharge from phrenic and intercostal nerves can promote nerve regeneration in early stages after brachial plexus injury.