[Construction of cochlear progenitor cells with recombinant short-hairpin RNA lentiviral vector inhibiting the expression of the β-catenin gene]

Objective: To construct a recombinant short-hairpin RNA (shRNA) lentiviral vector targeting the β-catenin gene in cochlear precursor cells (CPCs) in mice, and to investigate its inhibitory effect. Methods: PCR was used for the multiplication of the β-catenin gene, and shRNA oligo was designed based on the β-catenin gene to construct an interference vector. Gateway Technology was used to construct shRNA lentiviral vector which carried the β-catenin gene, and then 293FT cells were transfected with the constructed lentiviral vector and helper plasmids pLV/helper-SL3, pLV/helper-SL4, and pLV/helper-SL5. The virus supernatant was collected to obtain viral particles, and then mouse CPCs were transiently infected with the recombinant lentivirus with four different concentrations (0, 5, 10, and 20 μl) . The shRNA control group was established. Quantitative real-time PCR and Western blot were used to investigate the inhibitory effect of shRNA β-catenin lentiviral vector on β-catenin. Results: The recombinant shRNA β-catenin lentiviral vector was successfully constructed, and the virus titers of shβ-catenin and shβ-catenin-control were 5.05×10(7) and 4.34×10(7), respectively. The results of in vitro experiments showed that in CPCs transfected with four different concentrations of recombinant lentivirus, the content of β-catenin protein gradually decreased with the increase in concentration, and there was a significant difference between groups (P<0.05) ; the CPCs transfected with shβ-catenin had significantly lower mRNA expression of β-catenin than those in the shβ-catenin-control group (P<0.05) . Conclusion: The constructed lentiviral vector targeting the β-catenin gene has a high infection efficiency, and the successful construction of lentiviral vectors provides a technical support for analyzing the role of β-catenin in the differentiation of CPCs into auditory hair cells.

Structural and Energetic Effects of O2'-Ribose Methylation of Protonated Purine Nucleosides

The chemical difference between DNA and RNA nucleosides is their 2'-hydrogen versus 2'-hydroxyl substituents. Modification of the ribosyl moiety at the 2'-position and 2'-O-methylation in particular, is common among natural post-transcriptional modifications of RNA. 2'-Modification may alter the electronic properties and hydrogen-bonding characteristics of the nucleoside and thus may lead to enhanced stabilization or malfunction. The structures and relative glycosidic bond stabilities of the protonated forms of the 2'-O-methylated purine nucleosides, 2'-O-methyladenosine (Adom) and 2'-O-methylguanosine (Guom), were examined using two complementary tandem mass spectrometry approaches, infrared multiple photon dissociation action spectroscopy and energy-resolved collision-induced dissociation. Theoretical calculations were also performed to predict the structures and relative stabilities of stable low-energy conformations of the protonated forms of the 2'-O-methylated purine nucleosides and their infrared spectra in the gas phase. Low-energy conformations highly parallel to those found for the protonated forms of the canonical DNA and RNA purine nucleosides are also found for the protonated 2'-O-methylated purine nucleosides. Importantly, the preferred site of protonation, nucleobase orientation, and sugar puckering are preserved among the DNA, RNA, and 2'-O-methylated variants of the protonated purine nucleosides. The 2'-substituent does however influence hydrogen-bond stabilization as the 2'-O-methyl and 2'-hydroxyl substituents enable a hydrogen-bonding interaction between the 2'- and 3'-substituents, whereas a 2'-hydrogen atom does not. Further, 2'-O-methylation reduces the number of stable low-energy hydrogen-bonded conformations possible and importantly inverts the preferred polarity of this interaction versus that of the RNA analogues. Trends in the CID_50% values extracted from survival yield analyses of the 2'-O-methylated and canonical DNA and RNA forms of the protonated purine nucleosides are employed to elucidate their relative glycosidic bond stabilities. The glycosidic bond stability of Adom is found to exceed that of its DNA and RNA analogues. The glycosidic bond stability of Guom is also found to exceed that of its DNA analogue; however, this modification weakens this bond relative to its RNA counterpart. The glycosidic bond stability of the protonated purine nucleosides appears to be correlated with the hydrogen-bond stabilization of the sugar moiety.

Structural Basis for S100B Interaction with its Target Proteins

The S100B protein is an intra- and extracellular signaling protein that plays a role in a multitude of cellular processes and abnormal S100B is associated with various neurological diseases and cancers. S100B recognizes and binds effector proteins in a calcium-dependent manner. S100B has been shown to interact with the actin capping protein CapZ, protein kinase C, Hdm2 and 4, RAGE receptor, and p⁵³, among others. These protein partners interact with a common area on the S100B protein surface, validating the method of using the consensus sequence for S100B target search. In addition, each S100B target protein distinguishes itself by additional contacts with S100B. This perspective suggests that the combination of sequence homology search and structural analysis promises to identify newer S100B-binding partners beyond the use of the consensus sequence alone as the given example in the XPB subunit of the TFIIH general transcription factor. XPB is a helicase required for both transcription and DNA repair. Inherited xpb mutations are associated with human disease Xeroderma Pigmentasum, Cockayne syndrome, and trichothiodystrophy. S100B protein is likely associated with much more biological pathways and processes. We believe that S100B will attract more and more attentions in the scientific community and S100B related studies will have important implications in human health and medicine.

Assessment of left atrial function and dyssynchrony by real time three-dimensional echocardiography predicts recurrence of paroxysmal atrial fibrillation after radiofrequency ablation

OBJECTIVE

Left atrial volume and function are associated with recurrence of paroxysmal atrial fibrillation (AF) after radiofrequency ablation. A relationship between left atrial mechanical dyssynchrony and AF recurrence is presently unclear. The aim of this study was to investigate whether left atrial volume, function, and dyssynchrony were associated with AF recurrence in patients with normal left ventricular function, and normal or mildly enlarged left atrium, if assessed by the Real-time three-dimensional echocardiography (3DE).

PATIENTS AND METHODS

We included 88 patients with AF who had their first pulmonary vein isolation. There were 67 patients without and 21 patients with AF recurrence after radiofrequency ablation. Real-time 3DE was performed in the sinus rhythm the day before radiofrequency ablation. Left atrial volumes (maximum, minimum and preA), functions (passive, active and reservoir) and dyssynchrony were calculated. The latter was quantified by the standard deviation of time to minimum systolic volume (Tmsv-SD) from the end-diastole.

RESULTS

There was no difference between left atrial volume and function in patients with or without AF recurrence. However, significant differences in left atrial Tmsv-SD were observed in patients with AF recurrence.

CONCLUSIONS

In patients with normal left ventricular function, and normal/mildly enlarged left atrium, left atrial Tmsv-SD assessment by Real-time 3DE is a useful predictor of AF recurrence after radiofrequency ablation.

[Analysis of drug sensitivity of Staphylococcus aureus in patients with chronic sinusitis]

Objective:To investigate the prevalence and drug sensitivity of nasal Staphylococcus aureus infection in patients with chronic sinusitis and healthy controls.Method:Bacterial culture and drug sensitivity test were performed in 71 patients with CRS (experimental group) and 103 healthy controls (control group). The infection rate of Staphylococcus aureus and the sensitivity of the drug were analyzed based on these results.Result:Twenty-nine Staphylococcus aureus strains were isolated from 71 cases of patients in the experimental group, and the positive rate was 40.85%; 12 Staphylococcus aureus strains were isolated from 103 cases of patients in the control group, and the positive rate was 11.65%. There was no significant difference between the experimental group and the control group in the sensitivity of the strains to aminoglycosides and glycopeptides.A total of 13 strains of methicillin resistant Staphylococcus aureus (MRSA) were detected, and there was no strains which had resistance to quinolones, aminoglycosides and vancomycin.Conclusion:The incidence of CRS may be related to the infection of Staphylococcus aureus. The use of antibiotics in the treatment of CRS should be based on the results of bacterial culture and drug sensitivity test.

Associations between air pollution, climate factors and outpatient visits for eczema in West China Hospital, Chengdu, south-western China: a time series analysis

BACKGROUND

Eczema is one of the most common inflammatory dermatoses that can be provoked as a result of external and internal factors. With dense population and rapid economic development of China, air pollution is still a serious problem and the prevalence of eczema has been elevating.

OBJECTIVE

To determine the association and lagged effects between environmental factors and the outpatient visits for eczema.

METHODS

Data of daily outpatient visits for eczema at the clinics of dermatology in West China Hospital within the last 5 years were collected. Data of environmental factors of Chengdu during the same period, including temperature, relative humidity, barometric pressure, wind speed and air pollutants concentrations like sulphur dioxide (SO₂ ), nitrogen dioxide (NO₂ ) and particular matter (PM₁₀ ), were gathered. The distributed lag nonlinear model was used to statistically examine the relationship between eczema and environmental factors and their lagged effects.

RESULTS

Correlation analysis showed that eczema outpatient visits were positively correlated with the air pollutants and were negatively correlated with relative humidity. The barometric pressure and wind speed influenced the outpatient visits in association with air pollutants.

CONCLUSION

This study provides evidence that environmental factors like relative humidity and multiple air pollutants influence the incidence and prevalence of eczema and have lagged effects.

Analysis of sensitive skin barrier function: basic indicators and sebum composition

OBJECTIVES

Sensitive skin (SS) is a condition characterised by high reactivity, low tolerance, and susceptibility to allergies of the skin. Owing to changes in the environment and marketing strategies, as well as the increasing public awareness about skin care, attention to skin condition is gradually increasing. The aim of this study is to explore the differences in the skin barrier of SS and normal skin (NS).

METHODS

A questionnaire survey was conducted and basic indicators of the skin barrier were analysed. It was found that sebum secretion in the SS group was lower than that in the NS group, suggesting that the development of SS might be associated with sebum secretion and its specific components. Next, an ultra performance liquid chromatography-quadruple time-of-flight mass spectrometer was used to identify facial sebum components in female volunteers.

RESULTS

The results showed that the sebum of female volunteers with SS had high levels of ceramides, glycerophosphoethanolamines, and diacylglycerols, and low levels of glucosylceramides, glycerophosphoserines, glycerophosphocholines, and triacylglycerols.

CONCLUSION

Analysis of lipid functions suggested that the main reason for SS development in women might be a barrier dysfunction caused by excessive apoptosis and lack of water. Therefore, anti-allergy additives in cosmetic products that could inhibit apoptosis of keratinocytes and methods to maintain the stability of water molecules in the skin should be further studied.

[Lung transplantation for connective tissue disease-associated interstitial lung disease recipient]

Objective: To investigate the timing and complications of lung transplantation for the treatment of connective tissue disease-associated interstitial lung disease (CTD-ILD). Method: The clinical data of connective tissue-associated disease lung transplantation recipients from September, 2015 to February, 2017 were collected. Results: 11 patients with CTD-ILD were evaluated by lung transplantation and were treated with lung transplantation. Including 2 cases dermatomyositis/polymyositis and interstitial lung disease (PM/DM-ILD), 4 cases rheumatoid arthritis and interstitial lung disease (RA-ILD), 4 cases of primary Sjgren's syndrome and interstitial lung disease (pSS-ILD), 1 case of systemic sclerosis and interstitial lung disease (SSc-ILD). There are 6 cases are CTD-ILD-PAH patients of all. There were 5 males and 6 females, aged 37-70 years, with an average age of (52.73±9.53) years. 7 patients received single lung transplantation, 4 patients received double lung transplantation. 3 patients died in the early postoperative period, one for pulmonary embolism, one for septic shock and heart failure, one for severe primary graft failure (PGD). The remaining patients were followed up (4-24 months) with good survival, no acute and chronic rejection and other complications were observed. The survival rate was similar to that of other disease sources. Conclusion: There is no recurrence, acute and chronic rejection and other complications were observed in CTD-ILD and/or PAH lung transplant recipients. And the survival rate was comparable to that of other disease sources.Lung transplantation is a safe and effective choice for selected CTD-ILD patients.

Genetic variants of microRNA processing genes and risk of non-syndromic orofacial clefts

OBJECTIVE

MicroRNA (miRNA) processing genes play important roles in the craniofacial development. The aim of this study was to explore the associations between single nucleotide polymorphisms (SNPs) of miRNA processing genes with the risk of non-syndromic orofacial clefts (NSOC).

METHODS

We genotyped 12 potentially functional SNPs from seven miRNA processing genes (GEMIN3, DROSHA, DGCR8, GEMIN4, PIWIL1, XPO5, and DICER) in a case-control study of 602 NSOC cases and 605 controls.

RESULTS

Two SNPs were associated with the susceptibility of CL/P: rs10719 in DROSHA led to an increased risk of cleft lip with or without palate (CL/P) (GA/AA: p = .024, OR = 1.33, 95% CI = [1.04, 1.70]; GG + GA/AA: p = .037, OR = 1.29, 95% CI = [1.02, 1.63]), while rs493760 in DROSHA (CC/TT: p = .049, OR = 0.58, 95% CI = [0.34, 0.99]) could reduce the risk of CL/P. In addition, rs10719 (A)-rs493760 (C) haplotype contributed to a decreased risk of CL/P (OR = 0.77, 95% CI = [0.63, 0.94]), whereas the rs10719 (G)-rs493760 (C) haplotype contributed to the increased risk of cleft palate only (CPO) (OR = 2.70, 95% CI = [1.15, 6.35]). However, there was no difference observed in these SNPs after the Bonferroni correction.

CONCLUSION

Taken together, our results provided the potential evidence that rs10719 and rs493760 might contribute to the risk of CL/P and suggested potential genetic basis and mechanisms of CL/P. The lack of association between these SNPs and CPO might be due to the limited sample size of CPO subgroup.

Release of the tourniquet immediately after the implantation of the components reduces the incidence of deep vein thrombosis after primary total knee arthroplasty

Objectives

The length of the tourniquet time during total knee arthroplasty (TKA) is related to the incidence of post-operative deep vein thrombosis (DVT). Our aim in this study was to investigate the effect of the early release of the tourniquet on the incidence of DVT in patients undergoing TKA.

Methods

A total of 200 patients who underwent TKA between November 2015 and November 2016 were prospectively enrolled. The tourniquet was inflated before surgery and released immediately after the introduction of the components (early release group). This group was compared with a retrospective cohort of 200 primary TKAs, in which the tourniquet was released after the dressings had been applied (late release group). The presence of a DVT was detected using bilateral lower limb ultrasonography. Peri-operative clinical and follow-up data were collected for analysis.

Results

The incidence of DVT in the early release group (9 of 196, 4.6%) was significantly lower compared with the late release group (24 of 200, 12%; odds ratio (OR) 0.35, 95% confidence interval (CI) 0.16 to 0.78, p = 0.008). The incidence of proximal DVT in the early release group (1 of 196 (0.5%)) was significantly lower than in the late release group (8 of 196, 4%; OR 0.12, 95% CI 0.02 to 0.99, p = 0.020). Although the mean intra-operative blood loss was higher in the early release group, the mean post-operative drainage, total blood loss, transfusion requirements and complications were not significantly different in the two groups.

Conclusion

In patients who undergo TKA, releasing the tourniquet early is associated with a decreased incidence of DVT, without increasing the rate of complications.

Cite this article: Bone Joint Res 2017;6:535–541.

[A retrospective analysis of clinical characteristics and prognostic factors for 124 cases of primary gastric lymphomas]

目的

探讨原发胃淋巴瘤（PGL）的临床特征、治疗方法及预后。

方法

以2009年7月至2016年1月收治的124例PGL患者为研究对象，回顾性分析患者的临床资料，并探讨患者初诊时临床特征与预后的关系。

结果

124例PGL患者中包括弥漫大B细胞淋巴瘤（DLBCL）93例、黏膜相关淋巴组织（MALT）淋巴瘤25例、外周T细胞淋巴瘤非特指型4例、套细胞淋巴瘤和结外NK/T细胞淋巴瘤各1例。93例原发胃DLBCL（PG-DLBCL）患者中，非生发中心型（non-GCB）48例，生发中心型（GCB）45例，其中10例（10.8%）为MALT淋巴瘤转化的DLBCL。胃幽门螺杆菌检测：DLBCL患者阳性率51.2%（21/41），MALT淋巴瘤患者阳性率43.5%（10/23）。单因素分析结果显示临床分期Ⅲ~Ⅳ期（P=0.002）、B症状（P=0.001）、高国际预后指数（P<0.001）、HGB<100 g/L（P<0.001）、白蛋白<35 g/L（P=0.001）、LDH升高（P<0.001）、β₂微球蛋白升高（P=0.003）、未联合利妥昔单抗（P=0.006）是影响PG-DLBCL患者无进展生存（PFS）的不良因素。多因素分析结果显示临床分期Ⅲ~Ⅳ期（HR=5.113，95%CI 1.087~24.048，P=0.039）、LDH升高（HR=5.111，95%CI 1.651~15.827，P=0.005）是影响患者PFS的独立危险因素。在PG-DLBCL non-GCB型组，是否接受利妥昔单抗治疗对患者PFS率的影响差异有统计学意义（P=0.013）。MALT淋巴瘤转化与非转化的DLBCL患者PFS率差异无统计学意义（P=0.373）。

结论

PGL以DLBCL和MALT淋巴瘤多见，PG-DLBCL是一组高度异质性的恶性肿瘤，临床分期Ⅲ~Ⅳ期和LDH升高是影响PG-DLBCL患者PFS的独立危险因素。

Intrinsic functional connectivity of cortico-basal ganglia-thalamo-cortical circuitry underlying psychomotor retardation in major depressive disorder

Introduction

Psychomotor retardation (PMR) in depression is analogous to the hypokinesia in Parkinson's disease, which is associated with the unbalanced direct and indirect pathways of cortico-basal ganglia-thalamo-cortical (CBTC) circuitry. This study hypothesized PMR in major depressive disorder (MDD) should be associated with the hyperactivity of CBTC indirect pathways.

Objectives

To substantiate the hypothesis that the PMR symptom of MDD might attribute to the hyperactivity of the ortico-basal ganglia-thalamo-cortical indirect pathway which could inhibit psychomotor performance.

Methods

We investigated the intrinsic stiato-subthalamic nucleus (STN)-thalamic functional connectivity (FC), three pivotal hubs of the indirect pathway, in 30 MDD patients with PMR (PMR group) and well matched 30 patients without PMR (NPMR group) at baseline, and 11 patients of each group at follow-up who remitted after antidepressant treatment.

Results

The results showed increased STN-striatum FC of PMR group at baseline and no more discrepancy at follow-up, and significant correlation between PMR severity and thalamo-STN FC.

Conclusions

Our findings suggested the increased STN- striatum FC should be considered as a state biomarker to distinguish MDD patients with PMR from patients without PMR at acute period, and thalamo-STN FC could be identified as the predictor of the PMR severity for MDD patients.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Perioperative factors associated with hidden blood loss in intertrochanteric fracture patients

BACKGROUND

The actual total blood loss after a hip fracture has been found to be considerably larger than that observed during surgery and collected in drainage postoperatively. However, no previous studies have offered reasonable explanations for the deficit between a large hemoglobin drop and a small intraoperative blood loss. The aim was to quantify blood loss associated with hip injuries and surgery, and to identify the relative risk factors for perioperative hidden blood loss.

MATERIALS AND METHODS

Eighty-nine patients with a femoral intertrochanteric fracture were operated on between August 2012 and October 2013. The patients were accepted to undergo DHS (AO/ASIF) surgery or PFN-a (AO/ASIF) surgery and were randomly assigned to one of the two groups according to whether they had a wound drain or not. Admission information collected included: age, gender, body mass index (BMI), the American Society of Anesthetists system (ASA grading), plasma albumin (ALB), specific gravity of urine (SGU), fracture type (FT), surgery type (ST), and time from admission to surgery in hours (TAS). Blood samples for HB (hemoglobin) analysis were obtained upon admission, at 1 h preoperatively, and at successive postoperation days. The hidden blood loss was calculated by deducting the observed perioperative blood loss from the calculated total blood loss based on the hematocrit changes.

RESULTS

A total of 82 patients with a mean admission lapse time of 4 h after injury remained for the final analysis. One-way analysis of variance (ANOVA) of HBL shows the significant difference was observed in BMI subgroups, ALB subgroups, SGU subgroups, and ST subgroups, but no difference was observed in other subgroups. A multivariate linear regression investigating the relationship between HBL and all factors show that decreased albumin at admission and PFN-a surgery were variables associated with increased HBL.

CONCLUSIONS

Several readily available preoperative factors in the form of non-drainage, BMI < 25 kg/m², admission specific gravity of urine >1.020, surgery type PFN-a, and admission albumin <30 g/L were associated with a greater likelihood of more HBL. In addition, the latter two are independent risk factors for greater HBL in patients with intertrochanteric fractures.

EGR2 mutations define a new clinically aggressive subgroup of chronic lymphocytic leukemia

Recurrent mutations within EGR2 were recently reported in advanced-stage chronic lymphocytic leukemia (CLL) patients and associated with a worse outcome. To study their prognostic impact, 2403 CLL patients were examined for mutations in the EGR2 hotspot region including a screening (n=1283) and two validation cohorts (UK CLL4 trial patients, n=366; CLL Research Consortium (CRC) patients, n=490). Targeted deep-sequencing of 27 known/postulated CLL driver genes was also performed in 38 EGR2-mutated patients to assess concurrent mutations. EGR2 mutations were detected in 91/2403 (3.8%) investigated cases, and associated with younger age at diagnosis, advanced clinical stage, high CD38 expression and unmutated IGHV genes. EGR2-mutated patients frequently carried ATM lesions (42%), TP53 aberrations (18%) and NOTCH1/FBXW7 mutations (16%). EGR2 mutations independently predicted shorter time-to-first-treatment (TTFT) and overall survival (OS) in the screening cohort; they were confirmed associated with reduced TTFT and OS in the CRC cohort and independently predicted short OS from randomization in the UK CLL4 cohort. A particularly dismal outcome was observed among EGR2-mutated patients who also carried TP53 aberrations. In summary, EGR2 mutations were independently associated with an unfavorable prognosis, comparable to CLL patients carrying TP53 aberrations, suggesting that EGR2-mutated patients represent a new patient subgroup with very poor outcome.

Acceptability and feasibility of a social entrepreneurship testing model to promote HIV self-testing and linkage to care among men who have sex with men

OBJECTIVES

HIV self-testing (HIVST) offers an opportunity to increase HIV testing among people not reached by facility-based services. However, the promotion of HIVST is limited as a consequence of insufficient community engagement. We built a social entrepreneurship testing (SET) model to promote HIVST linkage to care among Chinese men who have sex with men (MSM) in Guangzhou.

METHODS

The SET model includes a few key steps. Each participant first completed an online survey, and paid a US$23 (refundable) deposit to receive an HIVST kit and a syphilis self-testing (SST) kit. After the testing, the results were sent to the platform by the participants and interpreted by Center for Disease Control and Prevention (CDC) staff. Meanwhile, the deposit was returned to each participant. Finally, the Community based organizations (CBO) contacted the participants to provide counselling services, confirmation testing and linkage to care.

RESULTS

During April-June 2015, a total of 198 MSM completed a preliminary survey and purchased self-testing kits. The majority were aged < 34 years (84.4%) and met partners online (93.1%). In addition, 68.9% of participants had ever been tested for HIV, and 19.5% had ever performed HIVST. Overall, feedback was received from 192 participants (97.0%). Of these participants, 14 people did not use the kits; among those who did use the kits, the HIV and syphilis prevalences were 4.5% (eight of 178) and 3.7% (six of 178), respectively. All of the screened HIV-positive individuals sought further confirmation testing and were linked to care.

CONCLUSIONS

Using an online SET model to promote HIV and syphilis self-testing among Chinese MSM is acceptable and feasible, and this model adds a new testing platform to the current testing service system.

Effect of polychlorinated biphenyls on osmoregulatory response and apoptosis in GIFT tilapia, Oreochromis niloticus

In the present study, GIFT tilapia Oreochromis niloticus were exposed to polychlorinated biphenyls (PCBs) for 7, 14, and 21 days. Over the duration of the exposure, genotoxicity and the activity of Na⁺/K⁺-ATPase (NKA) and Ca⁺/Mg⁺-ATPase (CMA) were measured in the gill, kidney, and intestine, to evaluate changes in osmoregulatory response in O. niloticus. Our results showed significant decreases in organic NKA (except in gill tissues after 0.5 mg/L PCB-exposure) and CMA activity. The results of the genotoxicity assay showed significant increases in atp1a1a, nkcc2 (only in gill tissue), and fxyd7 (except after 21 days of 5 mg/L PCB exposure). We found significant increases in caspase proteins in the liver in the 5-mg/L PCB exposure group, and the transcripts showed dose-dependent increases between treatment groups over the exposure duration. This study presents evidence that chronic exposure to PCB could result in organic osmoregulatory response and hepatic apoptosis in GIFT tilapia.

Processable PMR Poly(Pyrrolone-Imide)s Matrix Resins and their Short Carbon Fiber-Reinforced Composites

Processable poly(pyrrolone-imide)s (PPI) were prepared via PMR process from diethyl ester of 4,4′-(hexafluoroisopropylidene)diphthalic acid (6FDE), 3,3′, 4,4′-tetraaminodiphenyl ether (TADPE), p-phenylenediamine ( p-PDA) and monoethyl ester of cis-5-norbornene- endo-2,3-dicarboxylic acid (NE) using methyl alcohol as solvent. The homogenous PPI matrix resin solutions with 32 wt.% solid content had the low absolute viscosities in the range of 80-90 mPa s at 25 °C. The matrix resin solutions were stable for a period of > 2 months at the refrigerator temperature (4 °C) and showed good adhesion on carbon fibers. The matrix resin solutions could be thermally converted to B-stage end-capped prepolymer, which was then thermally processed to yield the fully-cured PPI. Experimental results demonstrated that the fully-cured PPI exhibited good thermal stability with glass transition temperatures of >400 °C and the thermal decomposition temperature of 525-537 °C. The onset temperatures of the DMA storage modulus curve for PPI-20 was as high as 395 °C and the storage modulus retention was 71% at 370 °C. The short carbon fiber-reinforced PPI composites (CF/PPI) were also fabricated. The CF/PPI composites showed excellent thermal stabilities and good mechanical properties, with glass transition temperature in the range of 413-421 °C and the storage modulus retention of 76-87% at 370 °C.

The four and a half LIM domains 2 (FHL2) regulates ovarian granulosa cell tumor progression via controlling AKT1 transcription

The four and a half LIM domains 2 (FHL2) has been shown to play important roles in the regulation of cell proliferation, survival, adhesion, motility and signal transduction in a cell type and tissue-dependent manner. However, the function of FHL2 in ovarian physiology and pathology is unclear. The aim of this study was to determine the role and functional mechanism of FHL2 in the progression of ovarian granulosa cell tumors (GCTs). Immunohistochemical analysis indicated that FHL2 was overexpressed in GCT tissues. Cellular localization of FHL2 in GCT cells was cell cycle dependent. Knockdown of FHL2 suppressed GCT cell growth, reduced cell viability and inhibited cell migration. Consistently, ectopic expression of FHL2 in GCT cells with very low endogenous FHL2 promoted cell growth, improved cell viability and enhance cell migration. Importantly, overexpression of FHL2 promoted GCT progression in vivo. Mechanistic studies indicated that FHL2 regulates AKT1 gene expression in vitro and in vivo. Knockdown of FHL2 or AKT1 in GCT cell lines induced very similar phenotypes. Ectopic expression of constitutively active AKT1 rescued FHL2 knockdown-induced arrest of GCT cell growth and reduction of GCT cell viability, suggesting that FHL2 regulates GCT cell growth and viability through controlling AKT1 expression. Finally, co-immunoprecipitation and chromatin immunoprecipitation analyses indicated that FHL2 functions as a co-activator of NFκB and AP-1 to regulate AKT1 gene transcription. In conclusion, results from the present study indicate that FHL2 exerts its oncogenic action in GCT cells via controlling AKT1 gene expression. FHL2 is a promising target for the development of novel drugs against ovarian granulosa cell tumor.