Role of C/EBP Homologous Protein in Vascular Stenosis After Carotid Artery Injury

The study aims to explore the fluctuating expression of C/EBP Homologous Protein (CHOP) following rat carotid artery injury and its central role in vascular stenosis. Using in vivo rat carotid artery injury models and in vitro ischemia and hypoxia cell models employing human aortic endothelial cells (HAECs) and vascular smooth muscle cells (T/G HA-VSMCs), a comprehensive investigative framework was established. Histological analysis confirmed intimal hyperplasia in rat models. CHOP expression in vascular tissues was assessed using Western blot and immunohistochemical staining, and its presence in HAECs and T/G HA-VSMCs was determined through RT-PCR and Western blot. The study evaluated HAEC apoptosis, inflammatory cytokine secretion, cell proliferation, and T/G HA-VSMCs migration through Western blot, ELISA, CCK8, and Transwell migration assays. The rat carotid artery injury model revealed substantial fibrous plaque formation and vascular stenosis, resulting in an increased intimal area and plaque-to-lumen area ratio. Notably, CHOP is markedly elevated in vessels of the carotid artery injury model compared to normal vessels. Atorvastatin effectively mitigated vascular stenosis and suppresses CHOP protein expression. In HAECs, ischemia and hypoxia-induced CHOP upregulation, along with heightened TNFα, IL-6, caspase3, and caspase8 levels, while reducing cell proliferation. Atorvastatin demonstrated a dose-dependent suppression of CHOP expression in HAECs. Downregulation of CHOP or atorvastatin treatment led to reduced IL-6 and TNFα secretion, coupled with augmented cell proliferation. Similarly, ischemia and hypoxia conditions increased CHOP expression in T/G HA-VSMCs, which was concentration-dependently inhibited by atorvastatin. Furthermore, significantly increased MMP-9 and MMP-2 concentrations in the cell culture supernatant correlated with enhanced T/G HA-VSMCs migration. However, interventions targeting CHOP downregulation and atorvastatin usage curtailed MMP-9 and MMP-2 secretion and suppressed cell migration. In conclusion, CHOP plays a crucial role in endothelial injury, proliferation, and VSMCs migration during carotid artery injury, serving as a pivotal regulator in post-injury fibrous plaque formation and vascular remodeling. Statins emerge as protectors of endothelial cells, restraining VSMCs migration by modulating CHOP expression.

The critical role and molecular mechanisms of ferroptosis in antioxidant systems: a narrative review

Background and Objective

Ferroptosis is a recently discovered form of cell death which differs from other forms of cell death in terms of morphology, biochemistry, and regulatory mechanisms. Ferroptosis is regulated by a complex system and the precise molecular mechanisms are still being elucidated. Over the past few years, extensive research has revealed that the essence of ferroptosis is iron-dependent accumulation of lipid hydroperoxides induced by oxidative stress, and the System Xc-glutathione (GSH)-glutathione peroxidase 4 (GPX4) pathway is the main ferroptosis prevention system. Meanwhile, other antioxidant systems have also been implicated in regulating ferroptosis, including the transsulfuration pathway, mevalonate pathway, ferroptosis inhibitory protein 1 (FSP1)-Coenzyme Q10 (CoQ10) pathway, dihydroorotate dehydrogenase (DHODH)-dihydroubiquione (CoQH2) pathway, and GTP cyclohydrolase-1 (GCH1)-tetrahydrobiopterin (BH4) pathway. This article reviews the molecular mechanisms of ferroptosis and its critical role in antioxidant systems, aiming to reveal that antioxidation is an important method of inhibiting ferroptosis and to provide a new direction for the treatment of ferroptosis-related diseases.

Methods

We searched all original papers and reviews about the molecular mechanisms of ferroptosis in antioxidant systems using PubMed to November 2021. The search terms used included: ‘ferroptosis’, ‘ferroptosis inducers’, ‘ferroptosis inhibitors’, ‘ferroptosis and GSH’, ‘ferroptosis and GPX4’, ‘ferroptosis and System Xc-’, ‘SLC7A11’, ‘P53’, ‘NRF2 and ferroptosis’, ‘iron metabolism’, ‘lipid peroxidation’, ‘antioxidant systems’, ‘transsulfuration pathway’, ‘mevalonate pathway’, ‘FSP1-CoQ10’, ‘DHODH-CoQH2’, and ‘GCH1-BH4’.

Key Content and Findings

We first introduced the origin of ferroptosis and its common inhibitors and inducers. Next, we discussed the molecular mechanisms of ferroptosis and its role in antioxidant systems in existing studies. Finally, we briefly summarized the relationship between ferroptosis and diseases. It reveals that antioxidation is an important method of inhibiting ferroptosis.

Conclusions

This review discusses the recent rapid progress in the understanding of the molecular mechanisms of ferroptosis and its role in several antioxidant systems.

[Analysis of the cognitive effects of monocular blindness and related influencing factors]

Objective: To investigate the cognitive effects of monocular blindness and related influencing factors. Methods: A cross-sectional study was conducted. The patients with monocular blindness (the age of onset <16 years) were enrolled from Beijing Tongren Eye Center, Beijing Tongren Hospital between January 2018 and June 2020. The Montreal cognitive assessment (MoCA) scale was applied to assess seven cognitive domains including visuospatial and executive function, naming, attention, etc. Based on MoCA scores, all the patients were classified into two groups: normal cognitive functions and cognitive impairment. Spearman's correlation was used to perform the single factor analysis of the influencing factors of cognitive functions. Multivariate linear regression analyses were applied to identify the independent influencing risk factors. Results: A total of 45 patients with monocular blindness were enrolled. There were 25 males and 20 females, with age at testing being (27±10) years.The incidence of cognitive impairment in 45 patients was 60.0% (27/45). The abnormal items ranking from a high to low rate were language (95.6%, 43 cases), delayed recall (75.6%, 34 cases), visuospatial and executive function (60.0%, 27 cases), abstract (44.4%, 20 cases), attention (35.6%, 16 cases), naming (20.0%, 9 cases), and orientation (0%). There were statistically significant differences (all P<0.05) in total score (21.9±3.3 vs. 27.4±1.4), visuospatial and executive function (3.2±1.7 vs. 4.6±0.7), naming (2.7±0.6 vs. 2.9±0.2), attention (5.3±1.0 vs. 5.8±0.4), language (1.1±0.8 vs. 1.8±0.8), abstract (1.1±0.8 vs. 1.8±0.5) and delayed recall (2.3±1.3 vs. 4.4±0.8) between two groups of patients with and without cognitive impairment. Spearman's correlation analysis showed visuospatial and executive functions, attention, abstract and MoCA total score were positively correlated with education years (correlation coefficients being 0.355, 0.424, 0.434 and 0.370, respectively; all P<0.05). Multiple linear regression showed that duration of blindness was correlated with naming (β=-0.325), and years of education correlated with attention (β=0.472), abstract ability (β=0.441) and MoCA total score (β=0.390) (all P<0.05). Conclusions: Monocular blindness may affect language, delayed memory and visuospatial executive functions. The duration of blindness is an independent risk factor, and higher education is a protective factor of the cognitive impairment.

Permanent His-bundle pacing in the right atrium in a patient with a Mobitz II atrioventricular block: a case presentation

Background

This case report presents a patient diagnosed with sick sinus syndrome who was successfully treated with permanent His-bundle pacing (PHBP).

Case presentation

A 36-year-old man was transferred to our hospital due to recurrent syncope. He was diagnosed with sick sinus syndrome based on the 24-h Holter and a history of syncope. He was admitted to hospital and successfully treated with PHBP. The postoperative examination showed that the pacing rhythm, pacemaker pacing and perception function were normal. He was discharged without any complications after a successful pacemaker implantation.

Conclusions

We described a case in which PHBP may become an optimal approach to the management of patients with sick sinus syndrome. Right ventricular pacing has been attempted with inconsistent efficacy outcomes. HBP provides a promising alternative pacing option that might provide symptom resolution to patients with sick sinus syndrome.

[Ultrasonic manifestations and axis length of blind microphthalmia]

Objective: To discuss the ultrasonic manifestations of blind microphthalmia, and to explore the correlation between axis length and complicity of intraocular structure of blind microphthalmia. Methods: Retrospective case series study. The data of ultrasonic imaging and axis length of 162 patients (162 eyes) with blind microphthalmia diagnosed in Tongren Eye Center, Beijing Tongren Hospital from July 2013 to July 2018 were collected. According to the degree of internal structure disorder, all affected eyes were divided into groups of the normal, the abnormal and the indistinguishable. The binocular axial length in these patients were compared. The relationship between the axial length and the age of the patients, and the structural changes of the blind microphthalmia with a basic structure were analyzed. Statistical methods were mainly performed by paired t-test, one-way linear regression analysis and one-way analysis of variance. Results: The disease was unilateral in all the 162 patients. The age ranged from 1 month to 58 years old. And 139 cases (85.80%) were under 12 years old. There were 90 males and 72 females. The mean axial length of the affected eyes (162 eyes) was (13.17±3.77) mm, while the mean axial length of the control eyes (162 eyes) was (21.85±2.01) mm. There was significantly statistical difference in the ocular size between them (t=-27.369; P<0.01). There was no significant correlation between the axial length of the affected eye and age in patients with unilateral blind microphthalmia (r=0.027; P>0.05), while there was a significant correlation between the axial length of the control eye and age (r=0.590; P<0.01). The axial length of the groups of the normal (14 eyes), the abnormal (91 eyes) and the indistinguishable (57 eyes) was (17.80±2.19) mm, (14.81±2.92) mm and (10.05±2.46) mm, respectively, and the difference was statistically significant (F=72.800; P<0.01), and there was also significant difference between the two groups (all P<0.01). Ocular ultrasonic imaging showed that 105 eyes (64.81%) had a basic ocular structure, 83 eyes (51.23%) had retinal detachment, 15 eyes (9.26%) had bulbar ossification, and 10 eyes (6.17%) had optic disc abnormality. Conclusions: Blind microphthalmia mostly has a basic ocular structure and is often associated with retinal detachment. The axial length of the affected eye is correlated with the degree of intraocular structural disorder. (Chin J Ophthalmol, 2021, 57: 825-829).

Perforation of the atrial wall and aortic sinus after closure of an atrial septal defect with an Atriasept occluder: a case report

Background

While the perforation of the atrial wall and aortic sinus after closure of an atrial septal defect (ASD) is rare, it’s life-threatening, with rapid progress and high mortality. To the best of our knowledge, 21 similar cases have been reported since 1976.

Case presentation

We report a 16-year-old male whose atrial septal defect (ASD) was closed using a 12-mm Amplatzer septal occluder (ASO). Atrial wall and aortic sinus perforation occurred 3 months after transcatheter closure, and the patient was discharged after emergency operation. He was discharged on the 12th postoperative day in good overall condition.

Conclusions

With this case report, we want to illustrate that although percutaneous closure of ASD is regarded as a routine procedure, we should not forget the potentially lethal complications, especially cardiac erosion. Therefore, we should carefully evaluate the risk of erosion before surgery, and careful lifelong follow-up is needed.

Intrinsical localization of both topological (anti-kink) envelope and gray (black) gap solitons of the condensed bosons in deep optical lattices

By developing quasi-discrete multiple-scale method combined with tight-binding approximation, a novel quadratic Riccati differential equation is first derived for the soliton dynamics of the condensed bosons trapped in the optical lattices. For a lack of exact solutions, the trial solutions of the Riccati equation have been analytically explored for the condensed bosons with various scattering length a_s. When the lattice depth is rather shallow, the results of sub-fundamental gap solitons are in qualitative agreement with the experimental observation. For the deeper lattice potentials, we predict that in the case of a_s>0, some novel intrinsically localized modes of symmetrical envelope, topological (kink) envelope, and anti-kink envelope solitons can be observed within the bandgap in the system, of which the amplitude increases with the increasing lattice spacing and (or) depth. In the case of a_s<0, the bandgap brings out intrinsically localized gray or black soliton. This well provides experimental protocols to realize transformation between the gray and black solitons by reducing light intensity of the laser beams forming optical lattice.

[Ocular manifestations and surgical treatment of the linear nevus sebaceous syndrome]

Objective: To report the clinical and pathological features and surgical treatment of the linear nevus sebaceous syndrome. Methods: It was a retrospective case series study. The clinical records of 11 patients (14 eyes) who were diagnosed as linear nevus sebaceous syndrome between April 2009 and February 2018 at Beijing Tongren Hospital were analyzed. Data collected included sex, age, clinical manifestations, disease site, pathological features, surgical treatment and therapeutic effects. Results: There were six males and five females, aged 6 months to 7 years (mean, 2.8 years). The nevus sebaceous was located at the head (9 patients), face (5 patients) and neck (3 patients). The most common ocular manifestations were blepharocoloboma (13 eyes) and external ocular mass (9 eyes). Surgical treatment was performed in 9 patients (11 eyes), including lid reconstruction in all these eyes, corneal and conjunctival mass resection in four patients (4 eyes), eyelid tumor resection in 5 patients (5 eyes), and symblepharon separation and conjunctival sac reconstruction in 3 patients (5 eyes). Pathological examinations of the external ocular, corneal and conjunctival masses (6 eyes) confirmed the diagnosis of complex choristoma. All operated patients had improved appearance. Conclusions: Linear nevus sebaceous syndrome has characteristic cutaneous lesions and ocular manifestations. Histopathologically, all epibulbar lesions prove to be complex choristomas. The appearance of patients with linear nevus sebaceous syndrome can be significantly improved by oculoplastic surgery. (Chin J Ophthalmol, 2020, 56: 846-852).

[Clinical features and surgical management of orbitotemporal neurofibromatosis]

Objective: To report the clinical features and surgical treatment of orbitotemporal neurofibromatosis. Methods: It was a retrospective case series study. The clinical records of 24 patients who were treated for orbitotemporal neurofibromatosis between April 2007 and July 2017 at Beijing Tongren Hospital, Capital Medical University were analyzed. Data collected included sex, age, laterality, periorbital deformities, surgical treatment, follow-up time, complication and recurrence. Results: Sixteen males and 8 females were included. Age at surgery was (15±7) years (4-30 years). All patients were unilaterally involved. Twenty-three patients (96%) had upper lid involvement and ptosis. Nine patients (38%) had lower lid involvement. Fourteen patients (58%) had lateral canthal disinsertion. Three patients (13%) had brow involvement, 10 patients (42%) had conjunctival involvement and 2 patients (8%) had lacrimal gland infiltration. All patients had tumor debulking procedure. Twenty-two patients (92%) had correction of ptosis. Fourteen patients (58%) required lid reconstruction and lateral canthus reattachment surgery. Three patients (13%) had correction of brow ptosis.One patient (4%) had skull and orbit reconstruction. The median follow-up time was 3.5 (1.0-10.0) years. All patients had improved appearance. Ptosis recurred in 6 patients, but were corrected with surgery. On the last follow-up, 7 patients were free of ptosis. In 14 patients, mild ptosis was noted, but the upper lid did not cover the pupil. In 2 patients the pupil was half covered. Only in 1 patient who had not received ptosis correction surgery the pupil was covered completely. Conclusions: The periorbital deformities of orbitotemporal neurofibromatosis include upper eyelid infiltration with ptosis, lateral canthal disinsertion and infiltration of lower eyelid, brow, conjunctiva and lacrimal gland. The appearance of patients with orbitotemporal neurofibromatosis can be significantly improved through oculoplastic surgery. (Chin J Ophthalmol, 2019, 55: 828-833).

Abnormal circadian rhythms are associated with plaque instability in acute coronary syndrome patients

AIM

Acute coronary syndrome (ACS), a leading cause of morbidity and mortality worldwide, is among the most serious cardiovascular diseases. Circadian rhythms are present in almost all organisms. In clinical practice, we have found that ACS is closely related to these circadian rhythms. However, the relationship between circadian rhythms and plaque instability in ACS patients is incompletely understood. The aim of this study is to provide new insights into the relationship between circadian rhythms and plaque instability in ACS patients.

METHODS

We enrolled patients with ACS and individuals with normal coronary artery function in this study. The Athens Insomnia Scale (AIS), Pittsburgh Sleep Quality Index (PSQI), International Physical Activity Questionnaire (IPAQ) and Healthy Diet Score (HDS) were used to evaluate circadian rhythms. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess the mRNA expression levels of muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 (Bmal1), circadian locomotor output cycles kaput (Clock), Cryptochrome1 (Cry1), Period2 (Per2), nuclear receptor subfamily 1, group D, member 1 (Rev-erbα), and matrix metalloproteinases MMP2 and MMP9.

RESULTS

AIS scores and PSQI scores were significantly higher in patients with ST segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction (NSTEMI), and unstable angina pectoris (UA) than in the normal controls (NCs) (P < 0.05). The IPAQ scores of the NCs and patients with UA were significantly higher than in patients with STEMI and NSTEMI (P < 0.05). Notably higher HDS scores were recorded for the NCs compared to those of patients with UA, NSTEMI, and STEMI (P < 0.05). Consistent with these findings, compared with the NCs, the lowest levels of Bmal1, Clock, Cry1, Per2 and Rev-erbα mRNAs were detected in patients with STEMI, followed by patients with NSTEMI and then patients with UA (P < 0.05). Furthermore, the levels of MMP2 and MMP9 mRNA were significantly higher in the patients with STEMI, NSTEMI, and UA than those in the NCs (P < 0.05). In addition, we found that the levels of MMP mRNA negatively correlated with the levels of clock genes mRNAs (P < 0.05, respectively).

CONCLUSIONS

Based on our data, the circadian rhythms and clock genes are correlatively with the occurrence of ACS, and the expression levels of clock genes are negatively correlated with plaque stability in ACS patients.

UCP2 protect the heart from myocardial ischemia/reperfusion injury via induction of mitochondrial autophagy

Uncoupling protein 2 (UCP2), located in the mitochondrial inner membrane, is a predominant isoform of UCP that expressed in the heart and other tissues of human and rodent tissues. Nevertheless, its functional role during myocardial ischemia/reperfusion (I/R) is not entirely understood. Ischemic preconditioning (IPC) remarkably improved postischemic functional recovery followed by reduced lactate dehydrogenase (LDH) release with simultaneous upregulation of UCP2 in perfused myocardium. We then investigated the role of UCP2 in IPC-afforded cardioprotective effects on myocardial I/R injury with adenovirus-mediated in vivo UCP2 overexpression (AdUCP2) and knockdown (AdshUCP2). IPC-induced protective effects were mimicked by UCP2 overexpression, while which were abolished with silencing UCP2. Mechanistically, UCP2 overexpression significantly reinforced I/R-induced mitochondrial autophagy (mitophagy), as measured by biochemical hallmarks of mitochondrial autophagy. Moreover, primary cardiomyocytes infected with AdUCP2 increased simulated ischemia/reperfusion (sI/R)-induced mitophagy and therefore reversed impaired mitochondrial function. Finally, suppression of mitophagy with mdivi-1 in cultured cardiomyocytes abolished UCP2-afforded protective effect on sI/R-induced mitochondrial dysfunction and cell death. Our data identify a critical role for UCP2 against myocardial I/R injury through preventing the mitochondrial dysfunction through reinforcing mitophagy. Our findings reveal novel mechanisms of UCP2 in the cardioprotective effects during myocardial I/R.

Down-Regulation of miR-327 Alleviates Ischemia/Reperfusion-Induced Myocardial Damage by Targeting RP105

BACKGROUND/AIMS

Micro RNAs (miRNAs) play a very important role in myocardial ischemia/ reperfusion injury (MIRI), including in inflammation, apoptosis, and angiogenesis. Previous studies have demonstrated up-regulation of miR-327 in renal ischemia/reperfusion injury and MIRI. Via TargetScan, we found RP105 is a possible target gene of miR-327; our previous studies have also confirmed that RP105 acted as a cardioprotective protein in MIRI by reducing inflammation. However, the regulatory effect of miR-327 on RP105 has not previously been proposed. In our study, we aimed to identify the regulatory effect of miR-327 on RP105 protein in MIRI rats.

METHODS

Sixty male Sprague-Dawley rats were randomly divided into five groups, which were pre-treated with saline (sham and ischemia/reperfusion group), adenovirus-expressing miR-327-RNAi (Ad-miR-327-i group), control (Ad-NC group), or pri-miR-327 (Ad-miR-327 group) treatments. Three days later, the rat MIRI model was established by ischemia for 30 min, followed by reperfusion for 3 h. Myocardium and plasma were harvested and assessed.

RESULTS

miR-327 was increased by nearly 3-fold both in myocardium and plasma, which down-regulated RP105 in a 3'-untranslated region-dependent manner, and down-regulation of miR-327 via adenovirus transfection indirectly suppressed the TLR4/ TLR2-MyD88-NF-κB signaling axis activation via up-regulation of RP105, which subsequently resulted in reduced myocardial infarct size, attenuated cardiomyocyte destruction, and alleviated inflammation. In contrast, up-regulation of miR-327 induced the opposite effect.

CONCLUSION

Down-regulation of miR-327 exerts a cardioprotective effect against MIRI by reducing inflammation, which may constitute a promising molecular therapeutic target for treating MIRI.

The Effects of High Mobility Group Box-1 Protein on Peripheral Treg/Th17 Balance in Patients with Atherosclerosis

BACKGROUND

Atherosclerosis (AS) is defined as chronic inflammation of the vessel wall. The major objective of the this study was to explore the mechanism of Treg/Th17 imbalance and the role of high mobility group box-1 protein (HMGB1) on the balance in AS.

METHODS

We detected the apoptotic ratios of Treg and Th17 cells in peripheral blood mononuclear cells (PBMCs) from subjects with AS and normal coronary arteries (NCA) by flow cytometry. The effects of recombinant HMGB1 (rHMGB1) on the proportion, apoptosis and differentiation of Treg and Th17 cells were analyzed using flow cytometry, qRT-PCR and ELISA.

RESULTS

The frequencies of apoptotic Treg cells in the PBMCs from the subjects with AS were significantly higher than in those with NCA (p < 0.01). Stimulation of rHMGB1 obviously increased the level of Th17 cells and acid- related orphan receptor C (RORC) mRNA, and markedly decreased Treg cell frequency and the mRNA expression of factor forkhead family protein 3 (Foxp3) in the PBMCs. rHMGB1 played an obvious role in elevating Treg cell apoptosis ratio (p < 0.01). rHMGB1 treatment significantly decreased Treg cell ratio and IL-10 level, and increased Th17 cell ratio and IL-17A level induced from naïve CD4+ T cells.

CONCLUSIONS

HMGB1 may modulate Treg/Th17 balance in patients with AS through inducing Treg cell apoptosis and promoting cell differentiation of Th17.

[Etiological and drug sensitivity analysis of lacrimal canaliculitis]

Objective: To analyze the etiology and drug sensitivity of lacrimal canaliculitis. Methods: Retrospective study of case series. The general information, culture results and drug sensitivity results of 52 patients (including 10 males and 42 females with an average age of 60.3 years) clinically diagnosed with lacrimal canaliculitis during 2011 and 2016 at Beijing Tongren Hospital of Capital Medical University have been analyzed. The enumeration data have been tested with Chi-square method. Results: The positive rate of bacterial culture was 78.8%, and the fungal culture tests of all cases showed negative results. Sixty strains of bacteria were isolated from 41 patients whose bacterial culture tests showed positive results, Gram-positive bacteria have been confirmed as the main among the isolated bacteria with Streptococcus (18.3%), Propionibacterium (18.3%), and Streptococcus (15.0%) identified as the three common genera. Thirteen cases (25.0%, all the 13 patients were female) involved with mixed infection, 13.3% (8/60) of the isolated strains were multi-drug resistant bacteria. The drug sensitive rate of the bacteria to fluoroquinolones antibiotics(79.3%, 230/290) was higher than that to cephalosporins(62.1%, 36/58) and aminoglycoside antibiotics(56.3%, 98/174), and such differences are of statistical significance (χ(2)=7.977, 27.738, P<0.05). Except for the fact that gram-positive bacteria are mostly sensitive to vancomycin, the sensitive rate of the bacteria to gatifloxacin was the highest and that to tobramycin was the lowest. Conclusion: Lacrimal canaliculitis tend to affect women and elderly patients. Staphylococcus, Propionibacterium, and Streptococcus are the three most common genera. Gatifloxacin may be the preferred antibiotic. Antibiotics combination therapy should be applied for multi-drug resistant bacteria. (Chin J Ophthalmol, 2018, 54: 111-114).

[Value of CT in evaluating the risk of benign and malignant thyroid nodules]

Objective: To evaluate the value of CT in the risk assessment of thyroid benign nodules (BN) and malignant nodules (MN). Methods: The CT signs of 461 pieces of MN in 447 cases and 548 pieces of BN in 484 cases were retrospectively analyzed, the diagnoses were confirmed by histology, including nodular morphology, cookie bite sign, microcalcification, enhanced range narrow/blurred, cystic changes and enhanced.The signs of CT were analyzed by univariate and multivariate regression analysis.The positive CT signs were calculated to assess sensitivity and specificity in the diagnosis of BN and MN. Results: Univariate and multivariate analysis showed that irregular nodular morphology (χ(2)=509.263, P<0.001, OR=5.297), cookie bite sign (χ(2)=504.619, P<0.001, OR=3.467), microcalcification (χ(2)=97.793, P<0.001, OR=1.730), enhanced range reduction/blur (χ(2)=361.967, P<0.001, OR=5.729) were more common in MN.Cysts changes (χ(2)=223.208, P<0.001, OR=7.537) and enhancement signs (χ(2)=65.983, P<0.001, OR=10.782) were more common in BN.The sensitivity and specificity of irregular nodular morphology in the diagnosis of MN were 80.5% and 90%, those in cookie bite sign were 74.2% and 94.3%, microcalcification were 35.6% and 90.1%, enhanced range reduction/blur were 80.7% and 79.4%.The sensitivity and specificity of capsule-based and high-enhanced BN diagnosis were 42.2% and 98.1%, 19.0% and 97.4%, respectively. Conclusions: Irregular shape, cookie bite sign, microcalcification and enhanced range of narrowing/blur are significant CT signs in the assessment of MN, and cystic changes and enhancement are significant CT signs in the evaluation of BN.The diagnostic efficiency of various CT signs varies greatly, and combination of multiple CT signs can improve the diagnostic efficiency.

[Developing and application of an autoverification system for clinical chemistry and immunology test results]

Objective: To develop and validate an autoverification system for biochemistry and immunology test results for application in routine work. Methods: Algorithms was designed and translated into the laboratory information system. Parameters including verify limit, delta check, logic relation between tests was set up in the system. Verification rate of every test and the causes of fails were analyzed, according to which the system and parameters were modified. The autoverified reports were evaluated by chief technicians. Only when all of the autoverified results pass the evaluation, the system applied for routine work of releasing the results. Autoverification rate and turnaround time(TAT) were calculated for evaluation of the efficiency of the system. Results: A brand new autoverification system was developed and applied for routine work. The autoverification rate for each single test was 91.1%-96.6%. The autoverification rate for reports was 74%. With the autoverification system, the media of TAT reduced from 111.6(53.9-270.7) min to 87.2(45.4-202.4) min, whereas the time from instrument finishing analysis to releasing the reports reduced from 18.6(1.0-99.3) min to 0.1(0-58.3)min. The number of staff specified for results validation reduced from three to one. Conclusions: The newly developed system can be used for autoverification of biochemistry and immunology test results. The autoverification system can greatly reduce TAT and raise working efficiency. It's essential to employ carefully designed algorithm, appropriate parameters and comprehensive evaluation when developing a new autoverification system.

RNAi-Mediated Down-Regulation of CD47 Protects against Ischemia/Reperfusion-Induced Myocardial Damage via Activation of eNOS in a Rat Model

BACKGROUND/AIMS

Oxidative stress is strongly implicated in the pathogenesis of myocardial damage caused by ischemia reperfusion (I/R). Previous studies have confirmed that cardiac CD47 drives left ventricular heart failure. However, the role for CD47 in myocardial I/R injury (MIRI) has not previously been proposed. This study was designed to investigate whether down-regulation of CD47 using RNA interference (RNAi) technology can relieve inhibition of nitric oxide signaling and attenuate myocardial damage in a rat model of I/R.

METHODS

Male Sprague-Dawley rats (n = 40) were randomly allocated to four groups and pre-treated either with saline (Sham and I/R groups), or adenovirus expressing either control (Ad-EGFP-N) or CD47-targeting (Ad-EGFP-CD47) RNAi. After four days, the rat MIRI model was established by occluding the left anterior descending coronary artery for 30 min, followed by reperfusion for 3 h. Heart tissue was harvested and assessed by immunohistochemistry, western blot, and quantitative RT-PCR. Outcome measures included infarct size, myocardial enzyme (creatine kinase, creatine kinase-MB, and lactate dehydrogenase) levels in serum, markers of oxidative stress, and morphological changes to the myocardium.

RESULTS

Delivery of Ad-EGFP-CD47 RNAi into the myocardium remarkably decreased CD47 expression levels. Down-regulation of CD47 was significantly associated with reduced infarct size and serum levels of myocardial enzymes, increased activity of endothelial nitric oxide synthase, increased levels of nitric oxide, and decreased levels of oxidative stress.

CONCLUSION

These data indicate that down-regulation of CD47 exerts a protective effect against MIRI, which may be attributable to attenuation of oxidative stress via activation of the eNOS/NO signaling pathway.

[Effects and related mechanism of quercetin on thrombin-induced proliferation and migration of rat vascular smooth muscle cells]

OBJECTIVE

To investigate the effects and related mechanism of quercetin on thrombin-induced proliferation and migration of rat vascular smooth muscle cells(VSMCs).

METHODS

Third to fifth generation VSMCs were divided into three groups, including control group (with PBS on the base of medium DMEM), thrombin group (with 1 U/ml thrombin on the base of medium DMEM) and quercetin group (treated with 100 μmol/L quercetin before 1 U/ml thrombin on the base of medium DMEM). The proliferation and migration capacitities were tested by CCK-8 kit and transwell chamber, respectively. The protein level of phospho-extracellular signal regulated kinase 1/2 and phosphor-p38 were measured by Western blot.

RESULTS

(1) According to the CCK-8 results, optical density value was significantly higher in thrombin group than that of control group(2.59±0.16 vs. 1.97±0.18, P<0.01), which could be significantly attenuated by pretreatment with quercetin(2.13±0.19, P<0.01), and there was no significant difference between quercetin group and control group(P>0.05). (2) The transwell results showed that the migrated VSMCs were significantly higher in thrombin group than in control group (1 337±162 vs. 99±26, P<0.01), which could be significantly reduced by pretreatment with quercetin (926±111, P<0.05), but still significantly higher than control group (P<0.01). (3) The protein expressions of phospho-extracellular signal regulated kinase 1/2 and phosphor-p38 were significantly upregulated in thrombin group compared to control group (both P<0.05), which could be significantly downregulated by pretreatment with quercetin (P<0.05).

CONCLUSION

Quercetin can effectively attenuate thrombin-induced vascular smooth muscle cells proliferation and migration, possibly through inhibiting the phosphorylation of extracellular signal regulated kinase 1/2 and p38 pathway.

Clinical effects of combined treatment by optimal dose of furosemide and spironolactone on diastolic heart failure in elderly patients

Diastolic heart failure (DHF) is characterized by symptoms including reduced ventricular relaxation and compliance, resulting in congestion of pulmonary and systemic circulation. The curative effects of regular cardiac agents are ineffective. Thus, new agents are required to treat chronic cardiac failure. The aim of the present study was to examine the clinical effects of the combined treatment by optimal dose of furosemide (20 mg/day) and spironolactone (40 mg/day) on elderly patients with diastolic heart failure (DHF) [New York Heart Association (NYHA) 1–2 grade]. A total of 93 patients diagnosed with DHF between February, 2013 and February, 2014 were enrolled in the present study. The patients were randomly divided into the furosemide group (20 mg/day, n=27), optimal dose group (20 mg/day furosemide+40 mg/day spirolactone, n=36), and large dose group (40 mg/day furosemide+100 mg/day spirolactone, n=30). Following treatment for one month, a comparison and analysis of the NYHA class, left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVEDD), left ventricular wall segmental motion among the three groups were performed. The re-hospitalization rate of heart failure and incidence of electrolyte disorder among the three groups was compared and their differences analysed. Compared with pretreatment, the NYHA classifications of the three groups after treatment were reduced and differences were statistically significant (P<0.05). By contrast, for the NYHA classification after treatment there was no statistical significance (P>0.05). Compared with pretreatment, LVEF of the optimal dose group increased, LVEDD decreased, and the average systolic myocardial peak velocity and early diastolic myocardial peak velocity of ventricular wall motion were reduced, with differences being statistically significant (P<0.05). By contrast, in the furosemide and large dose groups no statistical significance was identified before and after the treatment (P>0.05). Improvement of the optimal dose group following treatment was more significant than the remaining two groups, and differences were statistically significant (P<0.05). The re-hospitalization rate of heart failure and incidence of electrolyte disorder in the optimal dose group following treatment were significantly less than the other two groups, and differences were statistically significant (P<0.05). In conclusion, the optimal dose (20 mg/day furosemide+40 mg/day spirolactone) significantly improved the clinical symptoms of elderly DHF patients (NYHA 1–2 grade) and ameliorated their long-term prognosis.

RP105 Protects Against Apoptosis in Ischemia/Reperfusion-Induced Myocardial Damage in Rats by Suppressing TLR4-Mediated Signaling Pathways

BACKGROUND

Myocardial apoptosis is heavily implicated in the myocardial damage caused by ischemia-reperfusion (I/R). Toll-like receptor 4 (TLR4) is a potent inducer of these apoptotic cascades. In contrast, the radioprotective 105 kDa protein (RP105) is a specific negative regulator of TLR4 signaling pathways. However, the precise mechanisms by which RP105 inhibits myocardium apoptosis via TLR4-associated pathways during I/R is not fully understood.

METHODS

We utilized a rat model of myocardial ischemic reperfusion injury (MIRI). Animals were pre-treated with Ad-EGFP adenovirus, Ad-EGFP-RP105 adenovirus, saline, or nothing (sham). After three days, rats underwent a 30min left anterior descending coronary artery occlusion and a 4h reperfusion. Mycardial tissue was assessed by immunohistochemistry, TUNEL-staining, Western blot, quantitative RT-PCR, and a morphometric assay.

RESULTS

RP105 overexpression resulted in a reduction in infarct size, fewer TUNEL-positive cardiomyocytes, and a reduction in mitochondrial-associated apoptosis cascade activity. Further, RP105 overexpression repressed I/R-induced myocardial injury by attenuating myocardial apoptosis. This was mediated by inhibiting TLR4 activation and the phosphorylation of P38MAPK and the downstream transcription factor AP-1.

CONCLUSION

RP105 overexpression leads to the de-activation of TLR4, P38MAPK, and AP-1 signaling pathways, and subsequently represses apoptotic cascades and ensuing damage of myocardial ischemic reperfusion. These findings may become the basis of a novel therapeutic approach for reducing of cardiac damage caused by MIRI.

The HMGB1-TLR4 axis contributes to myocardial ischemia/reperfusion injury via regulation of cardiomyocyte apoptosis

Toll-like receptor 4 (TLR4) and its ligand high mobility group box 1 (HMGB1), are known for playing central roles in ischemia-reperfusion injury in myocardium. However, the detailed mechanisms of TLR4 and HMGB1 are not fully understood. The aim of this study was to investigate the effects and possible mechanisms of the HMGB1-TLR4 axis and cardiomyocyte apoptosis on myocardial ischemic damage. Artificial oxygen ventilated anesthetized C3H/HeN mice and C3H/HeJ mice were subjected to 30 min of left anterior descending coronary artery occlusion followed by 6h of reperfusion. The myocardial infarct size, HMGB1 levels, apoptosis index, Bax, Bcl-2 and TNF-α mRNA levels were assessed. The results showed that a lowered amount of cardiomyocyte apoptosis and infarct size in the myocardium of TLR4-mutant mice after myocardial I/R and that TLR4 deficiency notably inhibited the expression of HMGB1 and TNF-a, both of which were up-regulated by ischemia/reperfusion. These findings suggest that the HMGB1-TLR4 axis plays a pathogenic role in triggering cardiomyocyte apoptosis during myocardial I/R injury and that the possible mechanism for this process is the result of released cytokines and inflammatory response involved in the HMGB1/TLR4-related pathway.

High mobility group [corrected] box 1 mediates neutrophil recruitment in myocardial ischemia-reperfusion injury through toll like receptor 4-related pathway

This study aimed to explore the role of high mobility group [corrected] box 1 (HMGB1) and its receptor toll like receptor 4 (TLR4) on neutrophils in myocardial ischemia reperfusion (I/R) injury. We constructed TLR4-mutant (C3H/HeJ) and control (C3H/HeN) mouse models of myocardial I/R injury and subjected the mice to 30 min of ischemia and 6h of reperfusion. Light microscope was used to observe structural changes in the myocardium. HMGB1 levels were measured using quantitative real-time PCR and immunohistochemistry. Neutrophil accumulation, TNF-a expression and IL-8 levels were analyzed via myeloperoxidase (MPO) biochemical studies, quantitative real-time PCR and ELISA, respectively. The results demonstrated that fewer neutrophils infiltrated in the myocardium of TLR4-mutant mice after myocardial I/R and that TLR4 deficiency markedly decreased the ischemic injury caused by ischemia/reperfusion, and inhibited the expression of HMGB1, TNF-a, and IL-8, all of which were up-regulated by ischemia/reperfusion. These findings suggest that HMGB1 plays a central role in recruiting neutrophils during myocardial I/R leading to worsened myocardial I/R injury. This recruitment mechanism is possibly due to its inflammatory and chemokine functions based on the TLR4-dependent pathway.

Giant orbital paramagnetism in toroidal carbon nanopeapods

The electronic structure and the magnetic response of toroidal carbon nanopeapods (TCNPs) are investigated within the sp(3) tight-binding formalism. It is found that in the presence of mirror symmetry, there exists a level crossing at the Fermi level in the energy spectrum of a TCNP, leading to giant orbital paramagnetism (GOP), in spite of the curvatures and hybridizations of the outer toroidal carbon nanotube (TCN). When the mirror symmetry is broken by rotating the inner C(60)s, however, two level crossings appear at the Fermi level, and the GOP changes into a very small diamagnetic response. The results reveal the GOP in a filled TCN, depending on the characteristics of the filling materials and temperature.

RNA interference and ischemic injury

In the early period of 21st century, RNA interference (RNAi) had emerged as one of the most important discoveries. This highly conserved endogenous gene silencing mechanism has been largely exploited as a powerful tool to determine biological functions of each gene. Both direct introduction of chemically synthesized small interference RNA (siRNA) and a plasmid or viral vectors encoding for siRNA can allow especially stable RNA knockdown. Recently, it has been widely used in the production of therapeutic drugs against hepatitis or immuno-deficiency viruses in human beings. Here, we provide a brief overview of the RNAi mechanism and the technology of RNAi on ischemic injury.

Activated protein C protects myocardium via activation of anti-apoptotic pathways of survival in ischemia-reperfused rat heart

Activated protein C (APC) is known to be beneficial on ischemia reperfusion injury in myocardium. However, the protection mechanism of APC is not fully understood. The purpose of this study was to investigate the effects and possible mechanisms of APC on myocardial ischemic damage. Artificially ventilated anaesthetized Sprague-Dawley rats were subjected to a 30 min of left anterior descending coronary artery occlusion followed by 2 hr of reperfusion. Rats were randomly divided into four groups; Sham, I/R, APC preconditioning and postconditioning group. Myocardial infarct size, apoptosis index, the phosphorylation of ERK1/2, Bcl-2, Bax and cytochrome c genes and proteins were assessed. In APC-administrated rat hearts, regardless of the timing of administration, infarct size was consistently reduced compared to ischemia/reperfusion (I/R) rats. APC improved the expression of ERK1/2 and anti-apoptotic protein Bcl-2 which were significantly reduced in the I/R rats. APC reduced the expression of pro-apoptotic genes, Bax and cytochrome c. These findings suggest that APC produces cardioprotective effect by preserving the expression of proteins and genes involved in anti-apoptotic pathways, regardless of the timing of administration.

Odd-even width effect on persistent current in zigzag hexagonal graphene rings

The electronic structure and thus the persistent current of zigzag hexagonal graphene rings are investigated within the tight-binding formalism. The flux-dependent energy spectrum is grouped into bands with six levels per band due to inter-valley scattering at the corners of the ring. It is found that the degeneracy at the Fermi level is determined by the even or odd quality of the ring width N. The sample ring becomes metallic at odd N but semiconducting at even N, showing up a strange odd-even width effect. In metallic rings, the persistent current within a flux period is linearly changed with magnetic flux varphi, while it is a sinusoidal periodical function of varphi in semiconducting rings. In addition, with increasing N, the persistent current exponentially decreases (increases) at odd (even) N, but finally falls into the consistence with each other at enough large N, showing that the odd-even effect may be experimentally observable only in narrow rings.

[The effect of protease-activated receptor2 on rat apoptotic cardiomyocytes underwent ischemia reperfusion injury]

OBJECTIVE

To investigate the effect of protease-activated receptor 2 (PAR-2) on rat apoptotic cardiomyocytes underwent ischemia reperfusion (I/R) injury.

METHODS

Healthy male Sprague-Dawley rats were randomly divided into five groups (n = 8 each): sham-operation group, I/R (ligating the left coronary artery for 30 minutes and followed by 120 minutes reperfusion) group and three SLIGRL-NH2 groups treated with intravenous PAR-2 agonist SLIGRL-NH2 at different doses (0.5, 1, 3 mg/kg) 5 minutes before reperfusion. Apoptic cardiomyocytes was detected by TUNEL staining and by DNA ladder on agarose gel electrophoresis. Bax and Bcl-2 expression in myocardium was analyzed by immunohistochemical technique. The mRNA expression of PAR-2 was determined by Real-time quantitative polymerase chain reaction (RT-PCR).

RESULTS

(1) The apoptosis index and the expression of Bcl-2 and Bax were significantly increased in IR group and SLIGRL-NH2 groups than those in sham group (P < 0.05-0.01). (2) Compared with I/R group, the apoptosis index and the expression of Bax were significantly reduced while the expression of Bcl-2 and PAR-2 mRNA were significantly upregulated by SLIGRL-NH2 in a dose-dependent manner. (3) DNA Agarose gel electrophoresis demonstrated that DNA ladder existed in I/R and 0.5 mg/kg SLIGRL-NH2 group, but not in 1, 3 mg/kg SLIGRL-NH2 groups.

CONCLUSIONS

PAR-2 agonist SLIGRL-NH2 could reduce myocardial apoptosis by upregulating the Bcl-2 and PAR-2 mRNA level and downregulating Bax expression in a dose-dependent manner in this rat I/R model.

Visible photon-avalanche upconversion in Ho3+ singly doped beta-Na(Y1.5Na0.5)F6 under 980 nm excitation

Visible IR-to-green photon-avalanche upconversion is reported in an Ho3+ singly doped beta-Na(Y1.5Na0.5)F6 crystal under 980 nm excitation. Upconverted green, red, and IR emissions are observed at 540, 645, and 751 nm, respectively. Temporal evolution and excitation power dependent upconversion intensity are measured, suggesting that a photon-avalanche mechanism is responsible for the upconversion process. It is believed that an efficient cross relaxation (5S2,5I8)-->(5I6,5I6) mainly performs the population of 5I6 excited state, resulting in the intense photon-avalanche upconversion emission in the synthesized samples.

[Myocardial toll like receptor 4 expression in a rat model of myocardial ischemia reperfusion injury]

OBJECTIVE

To explore the role of TLR4 in myocardial ischemia reperfusion injury (MI/RI) by observing the dynamic TLR4 expression changes at mRNA and protein levels early after myocardial ischemia reperfusion.

METHODS

Male SD rats were randomly divided into Sham and IR group and the rats were killed according to different reperfusion time (0, 0.5, 1, 2, 4 and 8 hours). Myocardial changes under light microscope and transmission electronic microscope were observed. TLR4 expressions at protein and mRNA levels were detected by immunohistochemistry and realtime RT-PCR respectively. Myocardial TNF-alpha was determined by ELISA.

RESULTS

(1) Myocardial injury was observed in IR but not in Sham group and histopathological and ultrastructural changes in IR group remained unchanged up to 8 hours after reperfusion. (2) Positive TLR4 protein staining was visualized in both Sham and IR groups and significantly increased and peaked at 1 hour of reperfusion in IR group. (3) Compared to Sham group, TLR4 mRNA level was upregulated in myocardium in IR group and peaked at 1 hour of reperfusion. (4) Concentration of TNF-alpha in IR group was significantly higher than that of Sham group at corresponding time points (all P < 0.05), and myocardial TLR4 mRNA level correlated positively with myocardial TNF-alpha (r = 0.728, P < 0.01).

CONCLUSION

Expression of TLR4 in myocardium during early after myocardial ischemia reperfusion was upregulated and actived TLR4 might play an important role in MI/RI through promoting myocardial TNF-alpha excretion.

Raman frequency shift in oxygen-functionalized carbon nanotubes

Based on density functional theory, the geometrical and electronic structures of oxygen-functionalized single-wall carbon nanotubes (O-SWCNs) are obtained, of which the vibrational properties are calculated in terms of lattice dynamics theory. Both bond expansion and contraction are found to coexist in O-SWCNs. A distinct Raman shift is observed in the radial breathing mode (RBM) and the G modes, depending not only on the tube diameter and chirality but also on oxygen coverage and adsorption configurations. With the oxygen coverage increasing, interestingly, a nonmonotonic upshift and downshift is observed in the G modes, which is attributed to the competition between the bond expansion and contraction. In addition, the resonance Raman effect at different oxygen coverage, which may be observable in O-SWCNs, is discussed.

Lattice Dynamics of Carbon Chain Inside a Carbon Nanotube

Based on the density functional theory, we obtain the optimum geometry of carbon chain inside a carbon nanotube. The phonon spectrum and specific heat of such a chain and nanotube hybrid system are calculated in terms of lattice dynamics theory. Some new phonon branches that have been obtained come from the coupling vibrations of the nanotube and the chain. The bending and stretching modes of the chain appear at about 520 cm(-1)and 1935 cm(-1) at Gamma point, respectively. It is found that the softening of G modes results mainly from the chain induced variations in the bond length on nanotube, independent of van der Waals interaction, while the stiffening of radial breathing mode is developed by the competition between the two factors. In the low-frequency region, the vibrational density of states are very different from that of the bare nanotube. Its specific heat implies the underlying quantized phonon structures and much large thermal conductivity in the hybrid system. In addition, the chain-length dependent vibration modes are calculated, from which it is expected that a finite chain of about 14 carbon atoms in the nanotube may produce the experimental Raman peak at about 1850 cm(-1).

Electronic structure of carbon nanotori: the roles of curvature, hybridization, and disorder

An efficient and reasonable procedure is proposed for calculating the electronic structure of carbon nanotori in terms of rotational symmetry, within the tight binding formalism. It is shown that the curvature induced σ(*)-π(*) hybridization effects play an important role in determining the electronic structure of this novel nanostructure. The energy gap of the carbon nanotorus exhibits a well defined oscillation feature with increasing size of the torus, converging to that of the corresponding infinite nanotube, while its density of states spectrum evolves from the characteristic of a zero dimensional system to that of a quasi-one dimensional system. Effects of disorder on the electronic properties are also discussed.

Liver ischemia contributes to early islet failure following intraportal transplantation: benefits of liver ischemic-preconditioning

Early graft failure following intraportal islet transplantation (IPIT) represents a major obstacle for successful islet transplantation. Here, we examined the role of islet emboli in the induction of early graft failure and utilized a strategy of ischemic-preconditioning (IP) to prevent early islet destruction in a model of syngeneic IPIT in STZ-induced diabetic mice. Numerous focal areas of liver necrosis associated with the islet emboli were observed within 24 h post-IPIT. Pro-inflammatory cytokines, IL-1beta and IL-6, were significantly increased 3 h after IPIT, while TNF-alpha was elevated for up to 5 days post-IPIT. Caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling positive cells were observed in the transplanted islets trapped in areas of necrotic liver at 3 h and 1 day post-IPIT. Hyperglycemia was corrected immediately following IPIT of 200 islets, but recurrence of hyperglycemia was observed within 14 days associated with a poor response to glucose challenge. IP, a procedure of pre-exposure of the liver to transient ischemia and reperfusion, protected the liver from embolism-induced ischemic injury and prevented early islet graft failure. These data suggest that islet embolism in the portal vein is a major cause of functional loss following IPIT that can be prevented by liver IP.

[Adenosine protects cardiomyocytes from hypoxia/reoxygenation injury]

The aim of this study was to investigate the protective effect of adenosine (ADO) on cardiomyocytes following hypoxia/reoxygenation (H/R) and its molecular mechanism. Primary cultured cardiomyocytes of neonatal rats were divided into two groups, namely H/R (control) and ADO (1.0 micromol/L) groups. The morphologic changes in cardiomyocytes were observed under an inverted phase-contrast microscope. The following parameters of the two groups were determined: lactate dehydrogenase (LDH) activity, intracellular calcium concentration and malondialdehyde (MDA) content. Tumor necrotic factor (TNF-alpha) assay was performed using an ELISA kit and NF-kappaB in the nucleus was analyzed by electrophoretic mobility shift assay (EMSA). The results are as follows: (1) after H/R injury, cardiomyocytes contracted, tending to get round in shape and its pseudopods decreased, while marked morphological changes were not observed in ADO group; (2) LDH leakage maintained at a lower level in ADO group than that in the control group during H/R (both P<0.01); (3) ADO significantly reduced the concentration of calcium in cells and prevented calcium overload during H/R (both P<0.01); (4) ADO markedly reduced the content of MDA during H/R (both P<0.01); (5) ADO inhibited the production of TNF-alpha during H/R (both P<0.01); and (6) ADO down-regulated NF-kappaB binding activity of cardiomyocytes during H/R (both P<0.01) The results suggest that (1) exogenous ADO attenuates H/R injury of cultured cardiomyocytes; (2) exogenous ADO inhibits the production of TNF-alpha after H/R injury; (3) exogenous ADO prevents the activation of NF-kappaB, which may be the molecular mechanism of down-regulation of TNF-alpha expression.

Activation of the novel prothrombinase, fg12, as a basis for the pregnancy complications spontaneous abortion and pre-eclampsia

PROBLEM

Impaired trophoblast invasion during the first trimester of pregnancy is linked to spontaneous abortion, and defective invasion in the second trimester to hypertension + proteinuria (pre-eclampsia). Hypertension developing during the third trimester of human pregnancy represents, in part, a corrective response in the mother to provide adequate placental perfusion for fetal growth when trophoblast has not to invaded and converted the myometrial porprtion of maternal spiral arteries into to low resistance-high capacitance conduits. Deportation of vesicles from hypoxemic trophoblast is thought to cause hypertension plus proteinuria, vascular damage and a systemic coagulopathy. Trophoblast invasion may be inhibited by local cytokines, such as TGF-betas but Thl-type cytokines associated with pre-eclapmsia and spontaneous abortions (e.g., IL-1, TNF-alpha, IFN-gamma) are not known to inhibit migration at in situ concentrations. Trophoblast invasion is also inhibited by the binding of surface integrins to fibronectin and fibrin, and fibrin production is stimulated by these Th1 cytokines via up-regulation of prothrombinases(s) such as fg12 which directly and via TNF-alpha-facilitated inflamation compromise trophoblast cell integrity. We, therefore, asked if fg12 expression and TNF-alpha are increased in first trimester human miscarriage and in third trimester pre-eclampsia.

METHODS

fg12 mRNA was detected using in situ hybridization and fg12 protein by immunohistochemistry. TNF-alpha mRNA and protein were similarly tested. The techniques were validated using uterine sections from day 8.5 of CBA x DBA/2 pregnancies, and then were applied to sections of placentae from normal and pre-eclamptic pregnancies with and without intrauterine fetal growth restriction (IUGR). Fibrin was detectectd by immunohistochemistry.

RESULTS

Expression of fg12 protein correlated with fg12 mRNA expression in mouse uteri and in placentae from normal human pregnancies. Increased expression of fg12 and TNF-alpha mRNA and protein, and increased fibrin deposition was detected in placental trophoblast.

CONCLUSIONS

Activation of fg12 prothrombinase by Th1-type cytokines in pregnancy may lead to spontaneous abortion, or in ongoing pregnancy, to pre-eclampsia and/or IUGR.

Fgl2 prothrombinase expression in mouse trophoblast and decidua triggers abortion but may be countered by OX-2

Spontaneous abortion of normal karyotype embryos in mice and in humans is associated with an increase in uterine T helper (Th) 1 type proinflammatory cytokines, tumour necrosis factor (TNF)-alpha, interferon-gamma and interleukin (IL)-1, and a deficiency of Th2/3 type cytokines, IL-4, IL-10, and transforming growth factor (TGF)-beta2. In mice, Th1 cytokines up-regulate a novel prothrombinase, fgl2, which via thrombin, leads to activation of polymorphonuclear leukocytes that terminate the pregnancy. Here we show that Th1 cytokines up-regulate fgl2 mRNA in fetal trophoblast and secondary decidua of CBA/JxDBA/2 and CBA/JxBALB/c matings, and promote fibrin deposition. This pattern is accompanied by a high rate of abortion. However, the spontaneous abortion rates in abortion-prone CBAxDBA/2 matings and in low abortion rate CBAxBALB/c matings were significantly lower than that expected from the frequency of implantations with high levels of fibrin and fgl2 mRNA(hi). As the glycoprotein OX-2 occurs in the pregnant rat uterus and can deviate cytokine responses to Th2/3, we investigated OX-2 in pregnant CBA/J mice. We found OX-2 mRNA was present at the same sites as fgl2 mRNA, but was reduced in response to Th1 cytokines. Furthermore, anti-OX-2 raised the abortion rate to predicted levels, while recombinant OX-2 dramatically reduced the abortion rate. Fgl2 prothrombinase may provide a mechanism explaining pregnancy loss, and conversely, successful pregnancy may be due in part to OX-2-dependent activation of maternal tolerance mechanisms at the feto-maternal interface.

The emerging role of immunoregulation of fibrinogen-related procoagulant Fgl2 in the success or spontaneous abortion of early pregnancy in mice and humans

PROBLEM

Abortion of chromosomally normal embryos in the CBA X DBA/2 mating combination is triggered by release of Th1 cytokines (tumor necrosis factor [TNF]-alpha, interferon [IFN]-gamma, and interleukin [IL]-1), which cause abortion via a novel prothrombinase, Fgl2, and polymorphonuclear leukocytes. The site of activation may be maternal vascular endothelium on arteries and veins nourishing the placenta. Activation of coagulation is also prominent in spontaneous abortion of chromosomally normal human embryos. We asked where is Fgl2 up-regulated in the uterus in murine abortions, and if similar Fgl2 expression occurs in human pregnancy failure.

METHODS

Control CBA X DBA/2 pregnant mice, or from mice injected with TNF-alpha + IFN-gamma on day 7.5 of gestation, were removed on day 8.5, fixed, sectioned, and subject to in situ hybridization for Fgl2. Sections were also stained for fibrin. Elective first trimester termination samples or biopsies taken early in the course of a recurrent miscarriage were similarly fixed, sectioned, and analyzed by in situ hybridization. Control and cytokine-treated mice were anticoagulated with heparin, an activator of antithrombin III, and/or the direct anti-thrombin inhibitor hirudin.

RESULTS

Low level Fgl2 expression localized to basal decidua remote from the embryo was noted in control mice; cytokine treatment, which causes greater than 80% of abortions, produced a striking up-regulation in this area as well as in a band at the junction of decidua and myometrium. Trophoblast also became strikingly positive. Fgl2 expression was associated with increased fibrin staining. Anticoagulation significantly protected against abortions, but doses were limited by the complication of retroplacental hemorrhage. In tissue from normal first trimester pregnancy, minimal Fgl2 positivity was seen in some villous syncytiotrophoblast, in villous stroma, cytotrophoblast, and in some cells in decidua. In spontaneous abortion of normal embryo, striking Fgl2 positivity was seen in syncytiotrophoblast and extravillous cytotrophoblast, in association with areas of thrombus formation.

CONCLUSIONS

Fgl2 appears to be physiologically expressed and may protect against the internal danger of maternal and/or fetal bleeding during pregnancy and at parturition; a role in inhibiting transplacental traffic is also possible. External dangers in the form of stress, endotoxin, and antigens eliciting Th1 cytokine responses upregulate Fgl2 prothrombinase in trophoblast as well as in decidua, which results in spontaneous abortion of immunogenetically "weaker" embryos.

Expression of the fgl2 and its protein product (prothrombinase) in tissues during murine hepatitis virus strain-3 (MHV-3) infection

Murine Hepatitis Virus Strain 3 (MHV-3) produces fulminant hepatitis with 80-90% mortality in Balb/cJ mice. Previous studies in our laboratory have shown that peritoneal macrophages from MHV-3 infected mice produce a procoagulant (PCA) which has the ability to cleave prothrombin to thrombin (prothrombinase) encoded by the gene fgl2 located on chromosome 5. PCA accounts for sinusoidal thrombosis and hepatic necrosis and the necrosis and mortality can be prevented by treatment of animals with a monoclonal antibody to PCA. These present studies were designed to examine the expression of this gene (mRNA by Northern analysis and in situ hybridization) and the gene product PCA (immunochemistry) in tissues recovered from MHV-3 infected Balb/cJ mice in an attempt to explain the liver specific nature of MHV-3 disease. Fgl2 gene expression was detected as early as 8 hours after MHV-3 infection which persisted to 48 hours in the liver, spleen and lungs whereas no gene expression was seen in the brain or kidneys despite the fact that equivalent viral titers were detected in all tissues at all times. In the liver, fgl2 gene expression was confined to endothelial and Kupffer cells with no expression in hepatocytes. Immunochemistry localized the PCA protein to Kupffer cells and endothelial cells and necrotic foci within the liver. No PCA protein was detected by immunochemistry in any other tissues at any time during the course of MHV-3 infection. These results explain the liver specific nature (fulminant hepatitis) of MHV-3 infection and provides further evidence for the role of PCA in the pathogenesis of fulminant hepatitis. MHV-3 induces selective transcription of the gene fgl2 and only hepatic reticuloendothelial cells produce functional protein (PCA) which is known to account for fulminant hepatic failure produced by MHV-3.

Resistance of naive mice to murine hepatitis virus strain 3 requires development of a Th1, but not a Th2, response, whereas pre-existing antibody partially protects against primary infection

Murine hepatitis virus strain 3 (MHV-3) produces a host-strain-dependent spectrum of disease. The development of liver necrosis has been shown to be related to production of a unique macrophage procoagulant activity (PCA), encoded by the gene fgl-2, in susceptible mice. These studies were designed to examine the influence of Th1/Th2 cells on resistance/susceptibility and production of macrophage procoagulant activity (PCA) in resistant (A/J) and susceptible (Balb/cJ) strains of mice following infection with MHV-3. Immunization of A/J mice with MHV-3 induced a Th1 cellular immune response and one Th1 cell line (3F9.1) protected susceptible mice and inhibited production of PCA by macrophages both in vitro and in vivo. In contrast, immunization of Balb/cJ mice with an attenuated variant of MHV-3 derived from passaging MHV-3 in YAC-1 cells resulted in a Th2 response. Transfer of spleen cells and T cell lines from immunized Balb/cJ mice failed to protect naive susceptible syngeneic mice from infection with MHV-3 and augmented production of IL-1 beta, TNF-alpha and PCA by macrophages to MHV-3 in vitro. Serum from immunized Balb/cJ mice contained high titered neutralizing antibody which protected naive Balb/cJ animals from lethal primary MHV-3 infection. These results demonstrate that susceptible Balb/cJ mice generate a Th2 response following MHV-3 infection and that these Th2 cells neither inhibit MHV-3-induced macrophage PCA production nor protect naive mice from MHV-3 infection. The results suggest that antibody protects against primary infection, but could not eradicate ongoing infection. Ribavirin, a synthetic guanosine analogue prolonged survival to MHV-3 infection, inhibited production and transcription of the macrophage pro-inflammatory cytokines IL-1 beta and TNF-alpha and Th2 cytokines while preserving Th1 cytokine production. Thus, this data defines the differential role of Th1/Th2 lymphocytes in primary and secondary MHV-3 infection and further defines the importance of macrophage inflammatory mediators in the pathogenesis of MHV-3 infection.

Resistance to murine hepatitis virus strain 3 is dependent on production of nitric oxide

The strain-specific spectrum of liver disease following murine hepatitis virus type 3 (MHV-3) infection is dependent on inflammatory mediators released by macrophages. Production of nitric oxide (NO) by macrophages has been implicated in resistance to a number of viruses, including ectromelia virus, vaccinia virus, and herpes simplex virus type 1. This study was undertaken to define the role of NO in MHV-3 infection. Gamma interferon-induced production of NO inhibited growth of MHV-3 in a murine macrophage cell line (RAW 264.7). Viral inhibitory activity was reproduced by the NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP), whereas N-acetyl-DL-pencillamine (NAP), an inactive analog of SNAP, had no effect. Electron microscopy studies confirmed the inhibitory effects of NO on viral replication. Peritoneal macrophages isolated from A/J mice known to be resistant to MHV-3 produced a fivefold-higher level of NO and higher levels of mRNA transcripts of inducible NO synthase in response to gamma interferon than macrophages from susceptible BALB/cJ mice. SNAP inhibited growth of MHV-3 in macrophages from both strains of mice to similar degrees. In vivo inhibition of NO by N-monomethyl-L-arginine resulted in loss of resistance to MHV-3 in A/J mice. These results collectively demonstrate a defect in the production of NO in macrophages from susceptible BALB/cJ mice and define the importance of endogenous NO in resistance to MHV-3 infection in resistant A/J mice.

Ribavirin inhibits viral-induced macrophage production of TNF, IL-1, the procoagulant fgl2 prothrombinase and preserves Th1 cytokine production but inhibits Th2 cytokine response

Ribavirin, a synthetic guanosine analogue, possesses a broad spectrum of activity against DNA and RNA viruses. It has been previously shown to attenuate the course of fulminant hepatitis in mice produced by murine hepatitis virus strain 3. We therefore studied the effects of ribavirin on murine hepatitis virus strain 3 replication, macrophage production of proinflammatory mediators including TNF, IL-1, and the procoagulant activity (PCA), fgl2 prothrombinase; and Th1/Th2 cytokine production. Although ribavirin had inhibitory effects on viral replication (<1 log), even at high concentrations complete eradication of the virus was not seen. In contrast, at physiologic concentrations (up to 500 microg/ml), ribavirin markedly reduced viral-induced parameters of macrophage activation. With ribavirin treatment, the concentrations of PCA, TNF-alpha and IL-1beta all decreased to basal concentrations: PCA from 941 +/- 80 to 34 +/- 11 mU/10(6) cells; TNF-alpha from 10.73 +/- 2.15 to 2.74 +/- 0.93 ng/ml; and IL-1beta from 155.91 +/- 22.62 to 5.74 +/- 0.70 pg/ml. The inhibitory effects of ribavirin were at the level of gene transcription as evidenced by Northern analysis. Both in vitro and in vivo, ribavirin inhibited the production of IL-4 by Th2 cells, whereas it did not diminish the production of IFN-gamma in Th1 cells. In contrast, ribavirin had no inhibitory effect on TNF-alpha and IL-1beta production in LPS-stimulated macrophages. These results suggest that the beneficial effects of ribavirin are mediated by inhibition of induction of macrophage proinflammatory cytokines and Th2 cytokines while preserving Th1 cytokines.

Inhibition of amiloride-sensitive sodium-channel activity in distal lung epithelial cells by nitric oxide

Distal lung epithelial cells (DLECs) play an active role in fluid clearance from the alveolus by virtue of their ability to actively transport Na+ from the alveolus to the interstitial space. The present study evaluated the ability of activated macrophages to modulate the bioelectric properties of DLECs. Low numbers of lipopolysaccharide (LPS)-treated macrophages were able to significantly reduce amiloride-sensitive short-circuit current (Isc) without affecting total Isc or monolayer resistance. This was associated with a rise in the flufenamic acid-sensitive component of the Isc. The effect was reversed by the addition of N-monomethyl-L-arginine to the medium, implying a role for nitric oxide. We hypothesized that macrophages exerted their effect by expressing inducible nitric oxide synthase (iNOS) in DLECs. The products of LPS-treated macrophages increased the levels of iNOS protein and mRNA transcripts in DLECs as well as causing a rise in iNOS activity. Immunofluorescence microscopy of LPS-stimulated macrophage-DLEC cocultures with anti-nitrotyrosine antibodies provided evidence for the generation of peroxynitrite in macrophages but not in DLECs. These data indicate that activated macrophages in the lung may contribute to impaired resolution of acute respiratory distress syndrome and suggest a novel mechanism whereby nitric oxide might alter cell function by altering its ion-transporting phenotype.

Fulminant hepatic failure in murine hepatitis virus strain 3 infection: tissue-specific expression of a novel fgl2 prothrombinase

Activation of the immune coagulation system has been implicated in the pathogenesis of fulminant liver failure caused by murine hepatitis virus strain 3 (MHV-3). The recent discovery of the fgl2 gene, which encodes for MHV-3-induced prothrombinase (fgl2 prothrombinase), allows for fundamental studies to determine the molecular basis for fulminant liver failure. Transcription of the fgl2 gene and translation of the protein it encodes were examined in the liver and other organs of susceptible mice following MHV-3 infection. No constitutive expression of the fgl2 gene or the fgl2 prothrombinase was detected. Within 12 to 24 h of MHV-3 infection, however, fgl2 gene transcripts were detected in large amounts in the liver, spleen, and lungs, all of which are rich in reticuloendothelial cells, but were only focally present in small amounts in the kidney and brain. There was sequential detection of fgl2 prothrombinase in the liver, where it was localized specifically to the endothelium of intrahepatic veins and hepatic sinusoids; this was allowed by fibrin deposition, which resulted in confluent hepatocellular necrosis. These results provide further evidence for the role of the selective expression of this novel fgl2 prothrombinase in the pathogenesis of MHV-3-induced fulminant liver failure.

Function of reduced-size liver transplant in the rat

We have studied the function of partial orthotopic liver transplantation in the rat by evaluating prothrombin time (PT), liver blood flow, basal and glucose-stimulated insulin secretion and glucose tolerance, and the reticuloendothelial function (RES) in hepatectomized rats subjected to partial liver transplantation. A graft corresponding to 68% of a normal liver was transplanted to totally hepatectomized rats. Comparison was made between control rats and rats subjected to 32% liver resection. PT was not significantly different in the transplanted group compared with liver-resected and control rats. Laser Doppler flowmetry showed that at 28 days after surgery, blood flow had increased in the transplanted livers. Furthermore, on the third day after transplantation, basal plasma insulin was increased and the plasma insulin response to glucose was exaggerated, suggesting reduced insulin action and impaired insulin degradation. Finally, uptake of radioactive-labeled E. coli bacteria, as a measure of RES function, was not compromised in transplanted animals. Based on these results, we conclude that reduced-size liver transplant in out-bred rats results in fast normalization of liver function after surgery although, immediately after surgery, glucose intolerance is seen.

Effect of bile obstruction on liver regeneration following major hepatectomy: an experimental study in the rat

The regeneration of the liver following resection is regulated by a variety of factors and it might be expected that jaundice influences the process. We therefore evaluated the regenerative response to major hepatectomy in bile-obstructed rats. Two weeks after ligation of the common bile duct, a standardized 77% hepatectomy was undertaken. The jaundiced animals showed an augmented liver regeneration compared to nonjaundiced individuals (p < 0.01). However, blood clearance of radiolabelled Escherichia coli bacteria was impaired (p < 0.01) in animals with bile obstruction at 7 days after the hepatectomy, accompanied by reduced bacterial uptake in the liver as a sign of impaired reticuloendothelial system function.