Dissecting molecular mechanisms underlying ferroptosis in human umbilical cord mesenchymal stem cells: Role of cystathionine γ-lyase/hydrogen sulfide pathway

BACKGROUND

Ferroptosis can induce low retention and engraftment after mesenchymal stem cell (MSC) delivery, which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension (PAH) therapy. Interestingly, the cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway may contribute to mediating ferroptosis. However, the influence of the CSE/H2S pathway on ferroptosis in human umbilical cord MSCs (HUCMSCs) remains unclear.

AIM

To clarify whether the effect of HUCMSCs on vascular remodelling in PAH mice is affected by CSE/H2S pathway-mediated ferroptosis, and to investigate the functions of the CSE/H2S pathway in ferroptosis in HUCMSCs and the underlying mechanisms.

METHODS

Erastin and ferrostatin-1 (Fer-1) were used to induce and inhibit ferroptosis, respectively. HUCMSCs were transfected with a vector to overexpress or inhibit expression of CSE. A PAH mouse model was established using 4-wk-old male BALB/c nude mice under hypoxic conditions, and pulmonary pressure and vascular remodelling were measured. The survival of HUCMSCs after delivery was observed by in vivo bioluminescence imaging. Cell viability, iron accumulation, reactive oxygen species production, cystine uptake, and lipid peroxidation in HUCMSCs were tested. Ferroptosis-related proteins and S-sulfhydrated Kelch-like ECH-associating protein 1 (Keap1) were detected by western blot analysis.

RESULTS

In vivo, CSE overexpression improved cell survival after erastin-treated HUCMSC delivery in mice with hypoxia-induced PAH. In vitro, CSE overexpression improved H2S production and ferroptosis-related indexes, such as cell viability, iron level, reactive oxygen species production, cystine uptake, lipid peroxidation, mitochondrial membrane density, and ferroptosis-related protein expression, in erastin-treated HUCMSCs. In contrast, in vivo, CSE inhibition decreased cell survival after Fer-1-treated HUCMSC delivery and aggravated vascular remodelling in PAH mice. In vitro, CSE inhibition decreased H2S levels and restored ferroptosis in Fer-1-treated HUCMSCs. Interestingly, upregulation of the CSE/H2S pathway induced Keap1 S-sulfhydration, which contributed to the inhibition of ferroptosis.

CONCLUSION

Regulation of the CSE/H2S pathway in HUCMSCs contributes to the inhibition of ferroptosis and improves the suppressive effect on vascular remodelling in mice with hypoxia-induced PAH. Moreover, the protective effect of the CSE/H2S pathway against ferroptosis in HUCMSCs is mediated via S-sulfhydrated Keap1/nuclear factor erythroid 2-related factor 2 signalling. The present study may provide a novel therapeutic avenue for improving the protective capacity of transplanted MSCs in PAH.

[Analysis of work stress and its influencing factors among nursing staff in Tianjin City]

Objective: To explore the current situation of work stress among nursing staff in Tianjin City and analyze its influencing factors. Methods: From August to October 2020, 26002 nursing staff from tertiary hospitals, secondary public hospitals, secondary private hospitals, primary hospitals, and other medical institutions in Tianjin City were selected as objects, and their general situation and working stress situation were surveyed by the general information questionnaire and the Nurse's Work Stressor Scale. Single factor analysis and multiple linear regression analysis were used to explore the influencing factors of work stress among nursing staff. Results: The average age of 26002 nursing staff was (33.86±8.28) years old, and the average working years were (11.84±9.12) years. There were 24874 women (95.66%) and 1128 men (4.34%). The total score of work stress was (79.82±21.69), and the average score of workload and time allocation dimension was the highest (2.55±0.79). The results of multiple linear regression analysis showed that marital status (β=-0.015, P=0.014), employment form as contract system (β=0.022, P=0.001), post as clinical nursing (β=0.048, P<0.001), education level (β=0.024, P<0.001), age (β=0.050, P<0.001), working years (β=0.075, P<0.001), and professional title (β=0.036, P<0.001) were the influencing factors of work stress, which explained 22.8% of the total variation in work stress of nursing staff (F=24.25, P<0.001) . Conclusion: The work stress among nursing staff in Tianjin City is high, the corresponding departments and nursing managers should adopt scientific management methods to reduce the workload of nursing staff according to the influencing factors of work stress, so as to create a good atmosphere for further promoting the healthy development of nursing career and nursing industry in the new era.

Mammalian Ste20-like kinase 1 inhibition as a cellular mediator of anoikis in mouse bone marrow mesenchymal stem cells

BACKGROUND

The low survival rate of mesenchymal stem cells (MSCs) caused by anoikis, a form of apoptosis, limits the therapeutic efficacy of MSCs. As a proapoptotic molecule, mammalian Ste20-like kinase 1 (Mst1) can increase the production of reactive oxygen species (ROS), thereby promoting anoikis. Recently, we found that Mst1 inhibition could protect mouse bone marrow MSCs (mBMSCs) from H₂O₂-induced cell apoptosis by inducing autophagy and reducing ROS production. However, the influence of Mst1 inhibition on anoikis in mBMSCs remains unclear.

AIM

To investigate the mechanisms by which Mst1 inhibition acts on anoikis in isolated mBMSCs.

METHODS

Poly-2-hydroxyethyl methacrylate-induced anoikis was used following the silencing of Mst1 expression by short hairpin RNA (shRNA) adenovirus transfection. Integrin (ITGs) were tested by flow cytometry. Autophagy and ITGα5β1 were inhibited using 3-methyladenine and small interfering RNA, respectively. The alterations in anoikis were measured by Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling and anoikis assays. The levels of the anoikis-related proteins ITGα5, ITGβ1, and phospho-focal adhesion kinase and the activation of caspase 3 and the autophagy-related proteins microtubules associated protein 1 light chain 3 II/I, Beclin1 and p62 were detected by Western blotting.

RESULTS

In isolated mBMSCs, Mst1 expression was upregulated, and Mst1 inhibition significantly reduced cell apoptosis, induced autophagy and decreased ROS levels. Mechanistically, we found that Mst1 inhibition could upregulate ITGα5 and ITGβ1 expression but not ITGα4, ITGαv, or ITGβ3 expression. Moreover, autophagy induced by upregulated ITGα5β1 expression following Mst1 inhibition played an essential role in the protective efficacy of Mst1 inhibition in averting anoikis.

CONCLUSION

Mst1 inhibition ameliorated autophagy formation, increased ITGα5β1 expression, and decreased the excessive production of ROS, thereby reducing cell apoptosis in isolated mBMSCs. Based on these results, Mst1 inhibition may provide a promising strategy to overcome anoikis of implanted MSCs.

Left ventricular apical aneurysm in Fabry disease: implications for clinical significance and risk stratification

Funding Acknowledgements

Type of funding sources: None.

Background

More than 50% of patients with Fabry disease (FD) present with cardiac phenotype, and left ventricular hypertrophy (LVH) is the most frequent manifestation. Among FD patients with LVH, a rare and novel presentation of left ventricular apical aneurysm (LVAA) has been reported.

Purpose

This study aimed to investigate the clinical incidence of LVAA and its impacts on prognosis among FD patients.

Methods

We retrospectively analyzed 268 FD patients at a tertiary medical center between January 2003 to September 2020. Two patients with ischemic LVAA were excluded. LVH and LVAA were confirmed either by echocardiography (Figure 1A) or cardiovascular magnetic resonance imaging (Figure 1B). The primary endpoints were a composite of heart failure (HF) hospitalization, sustained ventricular tachycardia (VT), stroke, and death. 

Results

Of 266 FD patients, there were 105 (39.5%) patients had LVH, and 11 (10.3%) of them had LVAAs (age 67.5 ± 9.5 years, 8 males [72.7%]). After a mean follow-up of 49.3 ± 34.8 months, 8 patients experienced primary endpoints, including 5 (45.5%) HF hospitalizations, 3 (27.3%) VT, 1 (9.1%) stroke, and 4 (36.4%) deaths. The risk for composite adverse events was significantly higher in patients with LVAA compared with those without (8 [72.7%] vs 17 [18.1%]), leading to significantly lower event-free survival in patients with LVAA (Log-Rank P &lt; 0.001, Figure 2). The presence of LVAA was independently associated with an increased risk of composite adverse events (hazard ratio: 3.59; confidence interval: 1.30-9.91, P = 0.01) after adjusting for age, gender, advanced HF, renal function, dyslipidemia, atrial fibrillation, left ventricular ejection fraction of &lt;40%, average E/e’, and LV mass index.

Conclusions

LVAA presents in around 10% of patients with Fabry cardiomyopathy and is strongly associated with an increased risk of adverse events. The identification of this phenotype would be useful to identify high-risk patients with Fabry cardiomyopathy, among whom more aggressive treatments may be considered. Abstract Figure. Apical aneurysm in Fabry cardiomyopathy  Abstract Figure. KM curve of composite adverse events

A Healable and Mechanically Enhanced Composite with Segregated Conductive Network Structure for High-Efficient Electromagnetic Interference Shielding

The cationic waterborne polyurethanes microspheres with Diels-Alder bonds were synthesized for the first time. The electrostatic attraction not only endows the composite with segregated structure to gain high electromagnetic-interference shielding effectiveness, but also greatly enhances mechanical properties. Efficient healing property was realized under heating environment. It is still challenging for conductive polymer composite-based electromagnetic interference (EMI) shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness (EMI SE), especially undergoing external mechanical stimuli, such as scratches or large deformations. Herein, an electrostatic assembly strategy is adopted to design a healable and segregated carbon nanotube (CNT)/graphene oxide (GO)/polyurethane (PU) composite with excellent and reliable EMI SE, even bearing complex mechanical condition. The negatively charged CNT/GO hybrid is facilely adsorbed on the surface of positively charged PU microsphere to motivate formation of segregated conductive networks in CNT/GO/PU composite, establishing a high EMI SE of 52.7 dB at only 10 wt% CNT/GO loading. The Diels-Alder bonds in PU microsphere endow the CNT/GO/PU composite suffering three cutting/healing cycles with EMI SE retention up to 90%. Additionally, the electrostatic attraction between CNT/GO hybrid and PU microsphere helps to strong interfacial bonding in the composite, resulting in high tensile strength of 43.1 MPa and elongation at break of 626%. The healing efficiency of elongation at break achieves 95% when the composite endured three cutting/healing cycles. This work demonstrates a novel strategy for developing segregated EMI shielding composite with healable features and excellent mechanical performance and shows great potential in the durable and high precision electrical instruments.

Detection of Hole Pockets in the Candidate Type-II Weyl Semimetal MoTe_{2} from Shubnikov-de Haas Quantum Oscillations

The bulk electronic structure of T_{d}-MoTe_{2} features large hole Fermi pockets at the Brillouin zone center (Γ) and two electron Fermi surfaces along the Γ-X direction. However, the large hole pockets, whose existence has important implications for the Weyl physics of T_{d}-MoTe_{2}, has never been conclusively detected in quantum oscillations. This raises doubt about the realizability of Majorana states in T_{d}-MoTe_{2}, because these exotic states rely on the existence of Weyl points, which originated from the same band structure predicted by density functional theory (DFT). Here, we report an unambiguous detection of these elusive hole pockets via Shubnikov-de Haas (SdH) quantum oscillations. At ambient pressure, the quantum oscillation frequencies for these pockets are 988 and 1513 T, when the magnetic field is applied along the c axis. The quasiparticle effective masses m^{*} associated with these frequencies are 1.50 and 2.77 m_{e}, respectively, indicating the importance of Coulomb interactions in this system. We further measure the SdH oscillations under pressure. At 13 kbar, we detected a peak at 1798 T with m^{*}=2.86m_{e}. Relative to the oscillation data at a lower pressure, the amplitude of this peak experienced an enhancement, which can be attributed to the reduced curvature of the hole pockets under pressure. Combining our experimental data with DFT+U calculations, where U is the Hubbard parameter, our results shed light on why these important hole pockets have not been detected until now.

Endobronchial valve for treatment of persistent air leak complicating spontaneous pneumothorax

INTRODUCTION

Endobronchial one-way valves have been proposed as treatment for persistent air leak complicating spontaneous pneumothorax in which surgical intervention is not feasible. However, published data on efficacy, safety, and factors associated with success are scanty.

METHODS

This is a retrospective study of 37 patients at a general hospital from 2008 to 2016. The impact of endobronchial valve implantation on the time to air-leak cessation after bronchoscopy was evaluated.

RESULTS

The median patient age was 71 years. The majority of patients were males (92%), were ever-smokers (83%), had at least one co-morbidity (97%), and had secondary spontaneous pneumothorax (89%). Nineteen patients (51%) had a mean of 2.6 endobronchial valves implanted (range, 1-6). The air leak ceased within 72 hours for only eight patients (22% of the complete cohort), with immediate air-leak cessation after completion of endobronchial valve implantation. All six successful cases that had computed tomographic data of the thorax were shown to have bilateral intact interlobar fissures. The median (interquartile range) Charlson co-morbidity index was 1 (0.25-1) and 2 (1-3) for the success group and failure group, respectively (P=0.029). All patients in the no-endobronchial valve group survived, whereas three patients in the endobronchial valve group died within 30 days of endobronchial valve implantation.

CONCLUSION

Only a small proportion of cases of endobronchial valve implantation for air leak complicating pneumothorax had unequivocal success. Intact bilateral interlobar fissures appear to be a necessary, though not sufficient, condition for success. Patients with fewer medical co-morbidities and immediate air-leak cessation after endobronchial valve implantation have a higher likelihood of success.

Zinc ion rapidly induces toxic, off-pathway amyloid-β oligomers distinct from amyloid-β derived diffusible ligands in Alzheimer's disease

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease in the elderly. Zinc (Zn) ion interacts with the pathogenic hallmark, amyloid-β (Aβ), and is enriched in senile plaques in brain of AD patients. To understand Zn-chelated Aβ (ZnAβ) species, here we systematically characterized ZnAβ aggregates by incubating equimolar Aβ with Zn. We found ZnAβ40 and ZnAβ42 both form spherical oligomers with a diameter of ~12–14 nm composed of reduced β-sheet content. Oligomer assembly examined by analytical ultracentrifugation, hydrophobic exposure by BisANS spectra, and immunoreactivity of ZnAβ and Aβ derived diffusible ligands (ADDLs) are distinct. The site-specific ¹³C labeled solid-state NMR spectra showed that ZnAβ40 adopts β-sheet structure as in Aβ40 fibrils. Interestingly, removal of Zn by EDTA rapidly shifted the equilibrium back to fibrillization pathway with a faster kinetics. Moreover, ZnAβ oligomers have stronger toxicity than ADDLs by cell viability and cytotoxicity assays. The ex vivo study showed that ZnAβ oligomers potently inhibited hippocampal LTP in the wild-type C57BL/6JNarl mice. Finally, we demonstrated that ZnAβ oligomers stimulate hippocampal microglia activation in an acute Aβ-injected model. Overall, our study demonstrates that ZnAβ rapidly form toxic and distinct off-pathway oligomers. The finding provides a potential target for AD therapeutic development.

Integrin alpha5beta1 suppresses rBMSCs anoikis and promotes nitric oxide production

BACKGROUND

Cell based therapy has been heralded as a novel, promising therapeutic strategy for cardiovascular diseases including pulmonary arterial hypertension (PAH). However, the low survival rate after transplantation due to cell death via anoikis is a major obstacle in stem cell therapy. Cells adhesion via Integrin alpha5beta1 (ITGA5B1) has a tendency to exert higher maximum forces. The present study aimed to evaluate the potential protective effect of ITGA5B1 on rat bone marrow mesenchymal stem cells (rBMSCs) from anoikis.

METHODS

Mononuclear cells were isolated by density gradient centrifugation with Ficoll, and rBMSCs cell surface markers were evaluated by flow cytometry. Osteogenic and adipocyte differentiation was determined by Alizarin Red S and Oil Red O staining respectively. The expression of Integrin A5 (ITGA5), Integrin B1 (ITGB1), eNOS and actived-caspase-3 mRNA or protein was confirmed by qPCR and western-blot. Cell adhesion, cell viability, anoikis and the migration of rBMSCs were also evaluated. Nitric oxide (NO) production was detected by the greiss assay.

RESULTS

Co-infected with Integrin A5 and B1 lentivirus to rBMSCs increased ITGA5 and ITGB1 mRNA and protein expression. ITGA5B1 enhanced the cell adhesion, cell viability, cell migration and NO production but reduced the cell anoikis in rBMSCs/ITGA5B1 groups.

CONCLUSION

Transduction of rat rBMSCs with ITGA5B1 lentivirus could prevent cell anoikis and increase NO production.

Optimising the utility of pleural fluid adenosine deaminase for the diagnosis of adult tuberculous pleural effusion in Hong Kong

INTRODUCTION

Pleural fluid adenosine deaminase level can be applied to rapidly detect tuberculous pleural effusion. We aimed to establish a local diagnostic cut-off value for pleural fluid adenosine deaminase to identify patients with tuberculous pleural effusion, and optimise its utility.

METHODS

We retrospectively reviewed the medical records of consecutive adults with pleural fluid adenosine deaminase level measured by the Diazyme commercial kit (Diazyme Laboratories, San Diego [CA], United States) during 1 January to 31 December 2011 in a cluster of public hospitals in Hong Kong. We considered its level alongside early (within 2 weeks) findings in pleural fluid and pleural biopsy, with and without applying Light's criteria in multiple scenarios. For each scenario, we used the receiver operating characteristic curve to identify a diagnostic cut-off value for pleural fluid adenosine deaminase, and estimated its positive and negative predictive values.

RESULTS

A total of 860 medical records were reviewed. Pleural effusion was caused by congestive heart failure, chronic renal failure, or hypoalbuminaemia caused by liver or kidney diseases in 246 (28.6%) patients, malignancy in 198 (23.0%), non-tuberculous infection in 168 (19.5%), tuberculous pleural effusion in 157 (18.3%), and miscellaneous causes in 91 (10.6%). All those with tuberculous pleural effusion had a pleural fluid adenosine deaminase level of ≤100 U/L. When analysis was restricted to 689 patients with pleural fluid adenosine deaminase level of ≤100 U/L and early negative findings for malignancy and non-tuberculous infection in pleural fluid, the positive predictive value was significantly increased and the negative predictive value non-significantly reduced. Using this approach, neither additionally restricting analysis to exudates by Light's criteria nor adding closed pleural biopsy would further enhance predictive values. As such, the diagnostic cut-off value for pleural fluid adenosine deaminase is 26.5 U/L, with a sensitivity of 87.3%, specificity of 93.2%, positive predictive value of 79.2%, negative predictive value of 96.1%, and accuracy of 91.9%. Sex, age, and co-morbidity did not significantly affect prediction of tuberculous pleural effusion using the cut-off value.

CONCLUSION

We have established a diagnostic cut-off level for pleural fluid adenosine deaminase in the diagnosis of tuberculous pleural effusion by restricting analysis to a level of ≤100 U/L, and considering early pleural fluid findings for malignancy and non-tuberculous infection, but not Light's criteria.

[Chinese expert consensus for non-antiinfective effects and clinical use of macrolides]

Important/potential value of macrolides has been proved in the management of chronic respiratory diseases by increasing basic and clinical trials.Through three face-to-face discussions, 10 experts examined important data and drafted this consensus related to macrolides: (1) mechanism of non-antiinfective effects; (2) clinical use in chronic respiratory diseases; (3) cautions of long-term use.The mechanism out of non-antiinfective effects includes anti-inflammatory effect, modifying airway secretion, immune-regulation related to antibacterial effect, corticoid saving effect and anti-viral effect.The efficacy of long-term use of low-dose macrolides is definitely confirmed in diffuse panbronchiolitis, chronic rhinosinusitis. It is considerably used in bronchiectasia, cystic fibrosis, severe asthma and chronic obstructive pulmonary disease. Further studies should be conducted in cryptogenic organizing pneumonia and respiratory viral infection. It should be paid attention to its possible adverse effects (including drug interactions, cardiac toxicity, ototoxicity and disturbance of intestinal flora) and drug resistance in long-term use.A Chinese consensus for non-antiinfective effects and clinical use of macrolides is developed for the first time, which aims to expand their rational use and the further research.

Quasilinear quantum magnetoresistance in pressure-induced nonsymmorphic superconductor chromium arsenide

In conventional metals, modification of electron trajectories under magnetic field gives rise to a magnetoresistance that varies quadratically at low field, followed by a saturation at high field for closed orbits on the Fermi surface. Deviations from the conventional behaviour, for example, the observation of a linear magnetoresistance, or a non-saturating magnetoresistance, have been attributed to exotic electron scattering mechanisms. Recently, linear magnetoresistance has been observed in many Dirac materials, in which the electron–electron correlation is relatively weak. The strongly correlated helimagnet CrAs undergoes a quantum phase transition to a nonmagnetic superconductor under pressure. Here we observe, near the magnetic instability, a large and non-saturating quasilinear magnetoresistance from the upper critical field to 14 T at low temperatures. We show that the quasilinear magnetoresistance may arise from an intricate interplay between a nontrivial band crossing protected by nonsymmorphic crystal symmetry and strong magnetic fluctuations.

The electronic structure of the helimagnet CrAs is unusual due to its nonsymmorphic crystal symmetry. Here, the authors observe quasilinear magnetoresistance close to a pressure-driven superconducting transition, which may arise from the interaction of the band structure and magnetic fluctuations.

Correlates of disease-specific knowledge in Chinese patients with COPD

Background

This study aimed to determine the associations of various sociodemographic factors with the level of disease-specific knowledge among Hong Kong Chinese patients with COPD.

Methods

A cross-sectional survey of 100 Chinese adults with COPD recruited from outpatient clinics was conducted from September 2009 to September 2010. Data on the knowledge specific to COPD and patients’ sociodemographics were collected from face-to-face interviews. Primary outcome of disease-specific knowledge was measured using 65-item Bristol COPD Knowledge Questionnaire (BCKQ), summing up the 65 items as the BCKQ overall score. Associations of sociodemographic factors with the BCKQ overall score were evaluated using the linear regression model.

Results

The mean BCKQ overall score of our patients was 41.01 (SD: 10.64). The knowledge in topics of “Smoking” and “Phlegm” achieved the first (3.97, SD: 0.82) and second (3.91, SD: 1.17) highest mean scores, respectively, while the topic of “Oral steroids” returned the lowest mean score of 1.89 (SD: 1.64). The BCKQ overall score progressively declined (P<0.001) with increase in education level, with the highest BCKQ overall score of 46.71 at no formal education among all subgroups. Compared to nondrinkers, current drinkers were associated with lower total BCKQ score.

Conclusion

We found that among COPD patients in outpatient clinics, impairments in the level of COPD knowledge were evident in patients who were current drinkers or had higher level of education.

Abstract 5346: Identification of essential genes for the development of hepatitis B virus-associated hepatocellular carcinoma

Background and Aim: Hepatocellular carcinoma (HCC) is a highly lethal and prevalent cancer, posing a grave threat to human health globally. Hepatitis B virus (HBV) infection is considered as a major risk factor for this cancer, especially in the Asia-Pacific region. Unfortunately, the molecular mechanisms of hepatocarcinogenesis remain obscure, which hinders the development of effective therapies for the disease. In the present study, we attempted to elucidate the molecular details of HBV-induced hepatocarcinogenesis by investigating differentially regulated genes at multiple developmental stages of HCC in a HBV transgenic mouse model. Materials and Methods: The transgenic mice which overproduced HBV large envelope polypeptide in hepatocytes and developed liver tumors spontaneously were used in this study. To unravel transcriptomics dynamics underlying hepatocarcinogenesis, RNA prepared from livers of both transgenic and wild type mice of different ages (at months 2, 12, 18 and 19) were subjected to RNA sequencing. Selected target genes were first validated by quantitative PCR (qPCR) using a larger set of mouse liver tissues (n=96) collected from 8 time points. Clinical implications of the selected genes were then explored in a set of human liver samples comprising 18 normal, 29 cirrhosis and 96 pairs of HCC. RNA and protein expression levels were determined by qPCR, immunohistochemical staining and Western blotting, respectively. Results: Upon analysis of 20,209 gene transcripts, 2574 and 1035 transcripts were found to be up-regulated (≥2 folds) and down-regulated (≤2 folds) in tumors, respectively, when compared with the wild type controls. Among these, 133 most prominent genes that exhibited concordant differential expression throughout the stages of tumor progression were chosen for validation in mouse liver tissues. Correlation analysis showed a high correlation between RNA sequencing and qPCR data (r=0.7495; P&lt;0.0001), indicating a high validity of the data. Forty-six biologically informative genes were further validated in human liver samples. By Gene Ontology analysis, the target genes were revealed to play roles in a variety of biological processes including stress and inflammation responses, metabolic and apoptotic processes. Immunohistochemical staining and Western blotting demonstrated significant differential expression of these genes between HCC and non-tumorous livers. Statistical analyses revealed their significant correlation with clinicopathological parameters including venous infiltration, tumor size and overall survival, implicating their roles in hepatocarcinogenesis. Conclusion: This study has demonstrated a systematic strategy for identifying crucial genes for HBV-associated HCC, which may have profound implications in combating this deadly cancer.

Citation Format: CT Lam, ZF Yang, JC Lau, MN Ng, WC Yu, DW Ho, ST Fan. Identification of essential genes for the development of hepatitis B virus-associated hepatocellular carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5346. doi:10.1158/1538-7445.AM2014-5346

Outcome of adult critically ill patients mechanically ventilated on general medical wards

OBJECTIVE. A significant number of critically ill mechanically ventilated patients are not admitted to the Intensive Care Unit but are cared for on general wards. This study looked at the outcome of these patients. DESIGN. Case series. SETTING. A 1100-bed tertiary hospital in Hong Kong. PATIENTS. All adult patients admitted in a 2.5-year period who received invasive mechanical ventilation on general medical wards without admission to Intensive Care Unit or other special care areas. INTERVENTIONS. Invasive mechanical ventilation. MAIN OUTCOME MEASURES. The observed number of deaths, the expected number of deaths as derived from the Mortality Probability Model II system admission model, and other morbidity measures. RESULTS. Among 755 patients studied, the observed number of deaths was 673, which amounts to a mortality of 89.1%. The expected number of deaths was 570. The risk-standardised mortality ratio was 1.18 (95% confidence interval, 1.09-1.28; P<0.0005). Patients with chronic obstructive pulmonary disease had the lowest mortality rate of 70.8% (P<0.005). The post-cardiac arrest subgroup had the highest mortality of 99.0%. CONCLUSIONS. There was a worse-than-predicted survival in the absence of Intensive Care Unit care for the critically ill patients who received mechanical ventilation on general wards. Patients with chronic obstructive pulmonary disease warranted more Intensive Care Unit admissions. Early discontinuation of invasive support should be seriously considered in the post-cardiac arrest patients.

Treatment of patients with chronic obstructive pulmonary disease as practised in a defined Hong Kong community: a cross-sectional pilot survey

OBJECTIVES

To examine the characteristics of chronic obstructive pulmonary disease patients of the Kwai-Tsing area, Hong Kong, and the chronic treatments they received. DESIGN. Cross-sectional survey.

SETTING

Four clinic settings in Hong Kong: Respiratory Specialist Clinic, Princess Margaret Hospital (group 1); Medical Specialist Clinics, Princess Margaret Hospital (group 2); General Outpatient Clinics, Princess Margaret Hospital (group 3); South Kwai Chung Chest Clinic, Department of Health (group 4).

PATIENTS

Thirty physician-diagnosed chronic obstructive pulmonary disease patients in each of the above groups with post-bronchodilator 1-second forced expiratory volume/forced vital capacity ratios of less than 70% predicted values, who had been followed up at any of the participating clinics for at least 6 months.

RESULTS

There were 111 male and nine female patients. The median age was 72.5 years and 79% had at least one medical co-morbidity. The mean duration of their chronic obstructive pulmonary disease was 9.8 years, and their mean post-bronchodilator 1-second forced expiratory volumes were 45% (for males) and 58% (for females) of predicted values. There were significantly fewer stage I and more stage IV patients in group 1. Influenza vaccination coverage within the previous 1 year was 54% and did not differ significantly between groups. Chronic obstructive pulmonary disease education was given significantly more often to group 1 patients. Short-acting beta agonists were used to treat all patients but long-acting bronchodilators and pulmonary rehabilitation were used almost exclusively in group 1. Overall, long-acting bronchodilators and pulmonary rehabilitation were offered to 16% and 5%, respectively, of those for whom these were indicated (according to international guidelines).

CONCLUSION

In general there was insufficient education and under-treatment for chronic obstructive pulmonary disease patients. Management of such patients warrants improvements by way of increased accessibility to structured education programmes, pulmonary rehabilitation programmes, long-acting bronchodilator drugs, and respiratory specialist care.

Management and prevention of spontaneous pneumothorax using pleurodesis in Hong Kong

BACKGROUND

The practice of pleurodesis for the management and prevention of spontaneous pneumothorax (SP) is uncertain.

DESIGN

A retrospective multicentre analysis of patients admitted to 12 hospitals in Hong Kong with SP in 2004 and who subsequently underwent pleurodesis for the same episode.

RESULTS

Pleurodesis was performed in 394 episodes. Initial medical chemical pleurodesis was performed for 258 (65.5%) patients ('initial medical group'), while 136 (34.5%) underwent initial surgical pleurodesis ('initial surgical group'). Secondary spontaneous pneumothorax (SSP; 237 episodes, 60.2%) was the most common indication for pleurodesis; it was also performed after a first episode of primary spontaneous pneumothorax (PSP) in 22 episodes (5.6%). Tetracycline derivatives (172 episodes, 66.7%) were the most popular sclerosing agents in the initial medical group. Those in the initial medical group were older and were more likely to be males, have SSP, chronic obstructive pulmonary disease and a history of past pleurodesis (P < 0.05) compared to the initial surgical group. Compared to the tetracycline group, more patients who initially received talc slurry had the procedure performed by surgeons, had larger (≥2 cm) pneumothorax or required suction during initial drainage (P < 0.05).

CONCLUSIONS

Despite the availability of international guidelines, there is considerable variation in pleurodesis for SP.

Minocycline and talc slurry pleurodesis for patients with secondary spontaneous pneumothorax

SETTING

Few studies have evaluated the sclerosing efficacy of minocycline, and none have specifically compared its sclerosing efficacy and safety profiles with talc slurry in secondary spontaneous pneumothorax (SSP).

DESIGN

A retrospective analysis was conducted in patients with SSP who underwent chemical pleurodesis from January to December 2004 with minocycline or talc slurry in 12 public hospitals of Hong Kong.

RESULT

There were 121 episodes of minocycline pleurodesis and 64 episodes of talc slurry pleurodesis. Immediate procedural failure were similar in the minocycline and talc slurry groups (21.5% vs. 28.1%, P = 0.31). Presence of interstitial lung disease, ≥ 2 previous episodes of pneumothorax, requiring mechanical ventilation during pleurodesis and persistent air leak before pleurodesis were independently associated with procedural failure. Pain was experienced in respectively 44.6% and 37.5% of the minocycline and the talc slurry groups. Pain was more common in patients receiving high doses of talc (≥ 5 g; P = 0.03). Respiratory distress was found in respectively 1.7% and 1.6% of the minocycline and talc slurry groups.

CONCLUSION

Minocycline and talc slurry had comparable sclerosing efficacy in SSP, with immediate success rates of >70%. Pain was the most common adverse effect and respiratory distress was uncommon. Both appeared to be effective and safe for chemical pleurodesis in SSP.

Management of patients admitted with pneumothorax: a multi-centre study of the practice and outcomes in Hong Kong

OBJECTIVE

To examine the management practice of pneumothorax in hospitalised patients in Hong Kong, especially the choice of drainage options and their success rates, as well as the factors associated with procedural failures.

DESIGN

Retrospective study.

SETTING

Multi-centre study involving 12 public hospitals in Hong Kong.

PATIENTS

All adult patients admitted as an emergency in the year 2004 with a discharge diagnosis of 'pneumothorax' were included. Data on the management and outcomes of the various types of pneumothoraces were collected from their case records.

RESULTS

Altogether these patients had 1091 episodes (476 primary spontaneous pneumothoraces, 483 secondary spontaneous pneumothoraces, 87 iatrogenic pneumothoraces, and 45 traumatic pneumothoraces). Conservative treatment was offered in 182 (17%) episodes, which were more common among patients with small primary spontaneous pneumothoraces (71%). Simple aspiration was performed to treat 122 (11%) of such episodes, and had a success rate of 15%. Aspiration failure was associated with having a pneumothorax of size 2 cm or larger (odds ratio=3.7; 95% confidence interval, 1.2-11.5; P=0.03) and a smoking history (4.1; 1.2-14.3; P=0.03). Intercostal tube drainage was employed in 890 (82%) episodes, with a success rate of 77%. Failure of intercostal tube drainage was associated with application of suction (odds ratio=4.1; 95% confidence interval, 2.8-5.9; P<0.001) and presence of any tube complications (1.55; 1.0-2.3; P=0.03). Small-bore catheters (<14 French) were used in 12 (1%) of the episodes only. Tube complications were encountered in 214 (24%) episodes.

CONCLUSION

Notwithstanding recommendations from international guidelines, simple aspiration and intercostal tube drainage with small-bore catheters were not commonly employed in the management of hospitalised patients with the various types of pneumothoraces in Hong Kong.

Polymorphisms and functional activity in superoxide dismutase and catalase genes in smokers with COPD

Increased oxidative stress has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study investigated the risk of COPD and the substitution of alanine 16 with valine (Ala16Val) polymorphism of manganese-superoxide dismutase (Mn-SOD) and the cytosine to thymidine transition of nucleotide -262 (-262C>T) polymorphism of the catalase gene, and the activity of erythrocyte SOD and catalase. The subjects were stable COPD patient ever smokers (n = 165) and healthy controls, matched for age and cigarette consumption. Genotyping of Mn-SOD at Ala16Val and the catalase gene at -262C>T was performed, and the functional activity of SOD and catalase in erythrocytes determined. There were no significant differences in the distribution of the different genotypes or allele frequencies between patients and controls for both the Mn-SOD and catalase genes. Among healthy controls or COPD patients, no differences were observed in erythrocyte SOD and catalase activity, irrespective of genotype. Significantly higher erythrocyte catalase activity was found in COPD patients than in healthy controls. The T/T catalase genotype and Ala/Ala Mn-SOD genotype were uncommon in the present Chinese population. The increase in erythrocyte catalase activity in Chinese patients with chronic obstructive pulmonary disease probably indicates dysfunction of the oxidant/antioxidant defence system, but it is unclear whether this increase is compensatory or a pathogenic factor.

The placentas of patients with severe acute respiratory syndrome: a pathophysiological evaluation

Aims

The pathology of the placentas delivered from pregnant women who had severe acute respiratory syndrome (SARS) in Hong Kong was studied.

Methods

The pathology of the placentas was retrospectively studied in detail and compared with control sets. The clinical data of the women and neonates were also reviewed.

Results

A total of seven placentas were studied. The placentas from two women convalescent from SARS in the first trimester were normal. In three placentas delivered in the acute stage of SARS, there were increases in intervillous or subchorionic fibrin which might be related to disturbances in maternal placental blood flow due to the hypoxic respiratory disease. Extensive fetal thrombotic vasculopathy (FTV) with sharply demarcated zones of avascular fibrotic villi was noted in the placentas of two patients convalescent from SARS in the third trimester. Both pregnancies had intrauterine growth retardation, oligohydramnios and newborns small for gestation. The aetiology of the FTV might be related to thrombotic tendency due to SARS or placental hypoxia.

Conclusions

This report highlights placental pathology that was probably the result of pathophysiological alteration of the maternal fetal unit during SARS. Further studies are required to delineate the relationship between severe maternal respiratory disease, placental pathology and pregnancy outcome.

Prevalence of helminthes in adult dogs in Heilongjiang Province, the People’s Republic of China

The prevalence of helminthes in adult dogs was investigated in Heilongjiang Province, the People's Republic of China, between 1996 and 2004. A total of 178 adult farm dogs from representative geographical locations in Heilongjiang Province were killed and examined for the presence of helminthes using a helminthological approach. The worms were examined, counted, and identified to species according to existing keys and descriptions. A total of 17 species of helminthes were found to infect dogs, and they represented two phyla, three orders, 13 families, and 15 genera. All dogs were infected by more than one helminth species. Clonorchis sinensis (26.4%), Paragonimus westermani (7.9%), and Metagonimus yokogawai (6.2%) were the most common trematode species; Mesocestoides lineatus (20.2%), Taenia hydatigena (19.7%), and Dipylidium caninum (14.6%) were the most common cestodes species; and Ancylostoma caninum (66.3%), Toxocara canis (36.5%), and Trichinella nativa (21.9%) were the most common nematode species. The results of the present investigation provide relevant "base-line" data for assessing the effectiveness of future control strategies against helminth infection in dogs in Heilongjiang Province, China.

Absence of association between angiotensin converting enzyme polymorphism and development of adult respiratory distress syndrome in patients with severe acute respiratory syndrome: a case control study

BACKGROUND

It has been postulated that genetic predisposition may influence the susceptibility to SARS-coronavirus infection and disease outcomes. A recent study has suggested that the deletion allele (D allele) of the angiotensin converting enzyme (ACE) gene is associated with hypoxemia in SARS patients. Moreover, the ACE D allele has been shown to be more prevalent in patients suffering from adult respiratory distress syndrome (ARDS) in a previous study. Thus, we have investigated the association between ACE insertion/deletion (I/D) polymorphism and the progression to ARDS or requirement of intensive care in SARS patients.

METHOD

One hundred and forty genetically unrelated Chinese SARS patients and 326 healthy volunteers were recruited. The ACE I/D genotypes were determined by polymerase chain reaction and agarose gel electrophoresis.

RESULTS

There is no significant difference in the genotypic distributions and the allelic frequencies of the ACE I/D polymorphism between the SARS patients and the healthy control subjects. Moreover, there is also no evidence that ACE I/D polymorphism is associated with the progression to ARDS or the requirement of intensive care in the SARS patients. In multivariate logistic analysis, age is the only factor associated with the development of ARDS while age and male sex are independent factors associated with the requirement of intensive care.

CONCLUSION

The ACE I/D polymorphism is not directly related to increased susceptibility to SARS-coronavirus infection and is not associated with poor outcomes after SARS-coronavirus infection.

Re-emergence of fatal human influenza A subtype H5N1 disease

Human disease associated with influenza A subtype H5N1 re-emerged in January, 2003, for the first time since an outbreak in Hong Kong in 1997. Patients with H5N1 disease had unusually high serum concentrations of chemokines (eg, interferon induced protein-10 [IP-10] and monokine induced by interferon gamma [MIG]). Taken together with a previous report that H5N1 influenza viruses induce large amounts of proinflammatory cytokines from macrophage cultures in vitro, our findings suggest that cytokine dysfunction contributes to the pathogenesis of H5N1 disease. Development of vaccines against influenza A (H5N1) virus should be made a priority.

Home mechanical ventilation in Hong Kong

Home mechanical ventilation (HMV) is increasingly used to treat chronic respiratory failure. This present study was aimed to examine the trend, the disease categories treated and the outcomes of HMV use in Hong Kong. In the year 2002, all adult respiratory units in Hong Kong were invited to report to a multicentre retrospective survey of HMV use. A total of 249 patients (156 males, mean age 62.7 +/- 13.8 yrs) were treated since 1980, with 197 (79%) continuing with HMV at the time of the survey. Cumulative number of HMV grew as a cubic function of time since 1980. Currently, there are 2.9 users per 100,000 population. The predominant mode of HMV was noninvasive ventilation by bilevel pressure support ventilators (n=236). Chronic obstructive pulmonary disease accounted for 48.6% of all cases. The overall 3-yr HMV continuation rate was 66.2%. Death was the main reason for discontinuation. A rapidly rising trend of home mechanical ventilation use is observed in Hong Kong. In contrast to other series, chronic obstructive pulmonary disease was the major group treated and bilevel pressure support ventilation was the predominant mode chosen. Most patients tolerate home mechanical ventilation reasonably well, with approximately two-thirds continuing with its use at 36 months.

Outbreak of severe acute respiratory syndrome in Hong Kong Special Administrative Region: case report

OBJECTIVE

To describe the outbreak of severe acute respiratory syndrome in Hong Kong.

DESIGN

Descriptive case series.

SETTING

Hong Kong, Special Administrative Region, China

RESULTS

The outbreak started with a visitor from southern China on 21 February. At the hospitals where the first cases were treated the disease spread quickly among healthcare workers, and then out into the community as family members became infected. By 1 April, 685 cases had been reported with 16 deaths. Symptoms include high fever and one or more respiratory symptoms (including cough, shortness of breath, and difficulty breathing). Changes in lung tissue suggest that part of the lung damage is due to cytokines induced by the microbial agent, which has led to empirical treatment with corticosteroids, broad spectrum antiviral agent, and antibacterial cover. There is strong evidence that a novel coronavirus is the pathogen. Precautions for droplet infection should be instituted, including the wearing of masks and rigorous disinfection and hygiene procedures. On 27 March the Department of Health announced drastic measures, including vigorous contact tracing and examination, quarantine of contacts in their homes, and closure of all schools and universities.

CONCLUSION

The rapidity of the spread of the disease and the morbidity indicate that the agent responsible is highly infectious and virulent. Strict infection control measures for droplet and contact transmission by healthcare workers, a vigilant healthcare profession, and public education are essential for disease prevention.

Clinical and electrophysiological characteristics in children with atrioventricular nodal reentrant tachycardia

Atrioventricular (AV) nodal reentrant tachycardia is one of the most common supraventricular tachycardias in childhood. However, information about AV nodal reentrant tachycardia in childhood is limited, especially about the variant and multiple forms. The purpose of this retrospective study was to investigate the clinical and electrophysiological characteristics in pediatric patients with AV nodal reentrant tachycardia. Forty-eight pediatric patients with AV nodal reentrant tachycardia were included (ages 11-18 years; 25 males and 23 females). The age of onset and duration of symptoms were significantly younger and shorter in pediatric patients, respectively. A higher incidence of antegrade dual AV nodal pathways was found in adult patients than pediatric patients (72.9 vs 52.1% p = 0.003). Both antegrade and retrograde slow pathway functions were better in pediatric than adult patients. There was no significant difference between children and adults in the occurrence of variant and multiple forms of AV nodal reentrant tachycardia. This study demonstrated that pediatric patients have different electrophysiologic characteristics from those of adult patients.

Respiratory insufficiency in a Chinese adult with mitochondrial myopathy

Mitochondrial myopathy is an important but uncommon cause of respiratory insufficiency in adults. We report the first case of respiratory insufficiency associated with adult-onset mitochondrial myopathy seen in a Chinese adult in Hong Kong. The patient presented with peripheral oedema and shortness of breath over 2 to 3 days. There was a history of gradual progressive limb weakness over approximately 2 years, hypertrophic cardiomyopathy, intermittent diarrhoea, and weight loss. The diagnosis was made by skeletal muscle biopsy and molecular study, which revealed the A3243G point mutation.

Role of right middle pulmonary vein in patients with paroxysmal atrial fibrillation

INTRODUCTION

Elimination of the ectopic foci from pulmonary veins (PVs) has proved to be a curative therapy for focal atrial fibrillation (AF). However, information about the importance of the right middle PV (RMPV) in initiation of AF and radiofrequency ablation of AF is limited.

METHOD AND RESULTS

Forty-three patients (34 men and 9 women; age 65+/-12 years) with drug-refractory paroxysmal AF underwent electrophysiologic study and catheter ablation for treatment of AF. Three-dimensional magnetic resonance angiography (MRA) of the PVs and left atrium (LA) was performed to determine the anatomic patterns of RMPV. Diameter of PV ostium was measured at the junction of the LA and each PV. MRA findings showed the following: (1) 36 (84%) of 43 patients had a discrete RMPV; (2) there are three drainage patterns of RMPV, including joining the proximal part (<1 cm from the ostium) of the right superior PV (RSPV), joining the right inferior PV (RIPV), and a separate RMPV ostium in the LA wall; and (3) the ostial diameter of RMPV was significantly smaller than RSPV and RIPV (P < 0.01). Electrophysiologic studies demonstrated that five AF foci arose from RMPV. The coupling interval between the ectopic beat of AF and sinus beat was longer in RMPV than RSPV (262+/-45 msec vs 212+/-47 msec; P = 0.043). All AFs from RMPV were ablated successfully. PV stenosis or AF recurrence from RMPV was not found during follow-up of 10+/-4 months.

CONCLUSION

RMPV was detected by MRA in >80% of paroxysmal AF patients. Ectopy from RMPV can initiate AF, and radiofrequency ablation of RMPV foci is feasible and safe.

Mechanisms of transition between double paroxysmal supraventricular tachycardias

INTRODUCTION

Coexistence of double tachycardias in one patient has been infrequently reported. Furthermore, the mechanisms of transition between double paroxysmal supraventricular tachycardias have not been well studied.

METHODS AND RESULTS

Thirty-five patients with two paroxysmal supraventricular tachycardias were studied. Group IA consisted of 3 patients with spontaneous transition between AV reciprocating tachycardia (AVRT) and AV nodal reentrant tachycardia (AVNRT). Group IB consisted of 13 patients without spontaneous transition between AVRT and AVNRT. Group IIA consisted of 5 patients with spontaneous transition between AVNRT and atrial tachycardia (AT). Group IIB consisted of 14 patients without spontaneous transition between AVNRT and AT. The absolute values of differences between the two tachycardia cycle lengths were significantly smaller in patients with than in those without transition between the two tachycardias (25+/-8 msec vs 90+/-46 msec, P < 0.05, IA vs IB; 21+/-25 msec vs 99+/-57 msec, P < 0.01, IIA vs IIB). The cutoff point of 25 msec had 80% positive predictive value for transition between the two tachycardias. Transition between two tachycardias occurred due to a spontaneous premature atrial complex (30%), conduction block at one limb of tachycardia (20%), or tachycardia-induced tachycardia (50%). Absence of transition between two tachycardias might be explained by the absence of a spontaneous premature atrial complex, longer cycle length of the first tachycardia, larger difference between two tachycardia cycle lengths, or induction of each tachycardia under different situations.

CONCLUSION

Double supraventricular tachycardias with similar tachycardia cycle lengths are vulnerable to transition between different tachycardias.

Effects of cavotricuspid isthmus ablation on atrioventricular node electrophysiology in patients with typical atrial flutter

BACKGROUND

The atrial musculature in the cavotricuspid isthmus is a part of posterior inputs to the AV node. In patients with typical atrial flutter, effects of radiofrequency ablation of this isthmus on AV node conduction are still unknown.

METHODS AND RESULTS

This study included 16 patients with clinically documented typical atrial flutter. Group 1 had 8 patients without and group 2 had 8 patients with dual AV nodal pathway physiology. Electrical pacing from the interatrial septum and low right atrium was performed to evaluate antegrade AV node function before and after ablation of the cavotricuspid isthmus. In group 1, the AV node conduction properties were similar before and after ablation. In group 2, the AV node Wenckebach cycle length and maximal AH interval during low right atrium (356+/-58 versus 399+/-49 ms, P=0.008; 303+/-57 versus 376+/-50 ms, P=0.008) and interatrial septum (365+/-62 versus 393+/-59 ms, P=0.008; 324+/-52 versus 390+/-60 ms, P=0.008) pacing were significantly longer after ablation. Elimination of the slow pathway after ablation was noted in 2 patients, including 1 with AV nodal reentrant echo beats.

CONCLUSIONS

Radiofrequency ablation of the cavotricuspid isthmus was effective in eliminating typical atrial flutter without injury of antegrade fast AV node conduction. The atrial musculature in the cavotricuspid isthmus significantly contributed to the slow AV node conduction.

Synergistic effect of cadmium chloride and acetaldehyde on cytotoxicity and its prevention by quercetin and glycyrrhizin

Cadmium chloride at concentrations of 10-50mM and acetaldehyde (AA) at 1-5mM showed synergistic toxic effects on V79 cells in vitro. Furthermore, synergistic effects of these chemicals were also observed in mutagenicities of the Hprt gene within certain dose ranges (cadmium chloride 5-10mM, and AA 1-2.5mM). Moreover, lipid peroxide formation, malondialdehyde (MDA) formation, detected by 2-thiobarbituric acid (TBA) reaction and the mitochondrial membrane potentials detected by rhodamine 123 uptake were significantly increased with the combined effect of cadmium and AA in V79. Thus, the cytotoxicity and genotoxicity displayed by combination of these chemicals can be considered to be associated with oxidative stress. Further, these effects were efficiently reduced by quercetin and less efficiently with glycyrrhizin.

Correlation of serum basic fibroblast growth factor levels with clinicopathologic features and postoperative recurrence in hepatocellular carcinoma

BACKGROUND

Basic fibroblast growth factor (bFGF) is an important positive regulator of tumor angiogenesis. This study evaluated the role of serum bFGF as a biological marker of tumor invasiveness and postresection recurrence in hepatocellular carcinoma (HCC).

METHODS

Concentrations of bFGF in preoperative serum samples in 88 patients undergoing resection of HCC were measured by a quantitative enzyme-linked immunosorbent assay. A single pathologist performed histopathologic examination of all tumor specimens. All patients were prospectively monitored for tumor recurrence.

RESULTS

The preoperative serum bFGF levels ranged from <0.22 to 71.2 pg/mL (median 10.8 pg/mL). There was significant correlation between high serum bFGF levels and large tumor >5 cm, presence of venous invasion or advanced pTNM stage. Patients with a serum bFGF level >10.8 pg/mL had worse disease-free survival than those with a level <10.8 pg/mL (median disease-free survival 11.2 versus 20 months, P = 0.044). Serum bFGF level >10.8 pg/mL (P = 0.035) and tumor size >5 cm (P = 0.004) were independent preoperative factors that predicted early recurrence after resection of HCC.

CONCLUSIONS

This study supports a role of bFGF in tumor growth and invasion in HCC. A high preoperative serum bFGF level appears to be predictive of invasive tumor and early postoperative recurrence. The clinical implications of serum bFGF level in HCC warrant further investigation.

Acquired pulmonary vein stenosis after radiofrequency catheter ablation of paroxysmal atrial fibrillation

INTRODUCTION

Elimination of the initiating focus within the pulmonary vein (PV) using radiofrequency (RF) catheter ablation is a new treatment modality for treatment of drug-refractory atrial fibrillation. However, information on the long-term safety of RF ablation within the PV is limited.

METHODS AND RESULTS

In 102 patients with drug-refractory atrial fibrillation and at least one initiating focus from the PV, series transesophageal echocardiography was performed to monitor the effect of RF ablation on the PV. There were 66 foci in the right upper PV and 65 foci in the left upper PV. Within 3 days of ablation, 26 of the ablated right upper PVs (39%) had increased peak Doppler flow velocity (mean 130+/-28 cm/sec, range 106 to 220), and 15 of the ablated left upper PVs (23%) had increased peak Doppler flow velocity (mean 140+/-39 cm/sec, range 105 to 219). Seven patients had increased peak Doppler flow velocity in both upper PVs. No factor (including age, sex, site of ablation, number of RF pulses, pulse duration, and temperature) could predict PV stenosis after RF ablation. Three patients with stenosis of both upper PVs experienced mild dyspnea on exertion, but only one had mild increase of pulmonary pressure. There was no significant change of peak and mean flow velocity and of PV diameter in sequential follow-up studies up to 16 (209+/-94 days) months.

CONCLUSION

Focal PV stenosis is observed frequently after RF catheter ablation applied within the vein, but usually is without clinical significance. However, ablation within multiple PVs might cause pulmonary hypertension and should be considered a limiting factor in this procedure.

Pulmonary vein dilation in patients with atrial fibrillation: detection by magnetic resonance imaging

INTRODUCTION

The positive relationship between left atrial (LA) size and atrial fibrillation (AF) is well recognized; however, there is little information on the association of pulmonary vein (PV) diameter and AF. The purpose of this study was to investigate by magnetic resonance angiography the change of PV and LA size in patients with no history of AF, patients with paroxysmal AF (PAF), and patients with chronic AF (CAF).

METHODS AND RESULTS

The study included 47 patients. Group I included 15 patients with normal sinus rhythm and no history of documented AF. Group II included 24 patients with drug-refractory PAF who underwent electrophysiologic study and radiofrequency ablation of PV foci. Group III included 8 patients with CAF who were converted to sinus rhythm by external electrical cardioversion. Age and concomitant heart diseases were similar among the three groups. We measured the diameter of each PV at its junction with the LA in addition to LA dimensions by gadolinium-enhanced magnetic resonance angiography with three-dimensional reconstruction. Significant dilation of both superior PVs (P < 0.01) and transverse diameter of LA (P < 0.01) was seen in the three groups. There were no significant changes of both inferior PVs, corrected PV (PV/LA) diameter, or longitudinal diameter of LA among the three groups. Only 28% patients showed arrhythmogenic foci from the largest PV.

CONCLUSION

Significant dilation of both superior PVs with simultaneous LA enlargement was demonstrated i

A prospective longitudinal study of quality of life after resection of hepatocellular carcinoma

HYPOTHESIS

Hepatic resection improves quality of life (QOL) in patients with resectable hepatocellular carcinoma (HCC).

DESIGN

A prospective longitudinal study.

SETTING

A university teaching hospital.

PATIENTS

Sixty-six consecutive patients undergoing resection of HCC, and 10 patients with unresectable HCC found after surgical exploration who were subsequently treated with transarterial chemoembolization (control group).

MAIN OUTCOME MEASURE

Serial measurements of preoperative and postoperative QOL using the Functional Assessment of Cancer Therapy-General (FACT-G) Questionnaire for up to 2 years after surgery (at 3, 6, 9, 12, 18, and 24 months).

RESULTS

Among the 66 patients with resectable HCC, the mean postoperative QOL scores at 3 months after surgery were significantly higher than the mean preoperative QOL scores in domains related to physical, social, and emotional well-being and relationship with physicians. The mean total QOL score increased from 83.5 (SD, 9.4) before surgery to 94.1 (SD, 7.7) at 3 months after surgery (P <.001). No significant change of QOL scores at 3 months after surgery was observed in the control group. Twenty patients in the resected group died of early recurrence within 2 years after surgery, but their mean postoperative QOL scores remained higher than the preoperative QOL scores for most assessment times. In contrast, in the control group, the mean total QOL scores became significantly lower than the preoperative scores, starting 9 months after surgery. Forty-six patients in the resected group completed all QOL assessments. At all postoperative assessments, their mean QOL scores were higher than preoperative scores. Recurrence developed in 13 of the 46 patients within the 2-year study, and there was significant deterioration of QOL over time among these 13 (P <.001), whereas no significant change in QOL over time was observed among the 33 recurrence-free patients. Of various clinicopathologic factors, only advanced pTNM stage was significantly predictive of deterioration of QOL over time after resection of HCC.

CONCLUSIONS

Hepatic resection results in significant enhancement of QOL in patients with HCC. Development of recurrence is the main factor leading to deterioration in QOL over time after resection of HCC.

Electrophysiologic characteristics in initiation of paroxysmal atrial fibrillation from a focal area

OBJECTIVES

We investigated the electrophysiologic characteristics in the initiation of paroxysmal atrial fibrillation (PAF) from a focal area.

BACKGROUND

The electrophysiologic characteristics in the initiation of PAF are still not clear.

METHODS

The study group consisted of 77 patients (M/F = 65/12, age 66 +/- 12 years) with frequent episodes of PAF; we analyzed: 1) 15 cycle lengths of electrical activity before the onset of atrial fibrillation (AF); 2) coupling interval (CI) of the first ectopic beat just before the initiation of AF; and 3) the prematurity of an ectopic beat (prematurity index [PI] = CI/mean of preceding 15 cycle lengths).

RESULTS

A total of 111 episodes of sustained AF were identified. Two patterns of AF initiation were observed: group I (59/111, 53%) included the episodes preceded by cycle length oscillation, and group II (52/111, 47%) included the episodes initiated by a single ectopic beat with preceding cycle length relatively constant. The PI of group I episodes was significantly greater than that of group II (0.41 +/- 0.12 vs. 0.34 +/- 0.10, p < 0.01). The CI (267 +/- 54 ms vs. 217 +/- 55 ms, p < 0.05), AF1 (194 +/- 36 ms vs. 153 +/- 37 ms, p < 0.05) and PI (0.49 +/- 0.13 vs. 0.37 +/- 0.11, p < 0.01) of the AF episodes from the superior vena cava (SVC) were significantly longer and greater than those of AF episodes from pulmonary veins (PVs).

CONCLUSIONS

In patients with PAF originating from PVs or the SVC, two major initiating patterns were found. Moreover, the electrophysiologic characteristics in the initiation of AF originating from the SVC were also different from those of AF initiating from the PVs.

Serum vascular endothelial growth factor predicts venous invasion in hepatocellular carcinoma: a prospective study

OBJECTIVE

To evaluate the correlation between serum vascular endothelial growth factor (VEGF) level and the clinicopathologic features in patients with hepatocellular carcinoma (HCC).

SUMMARY BACKGROUND DATA

VEGF is an important angiogenic factor regulating tumor angiogenesis. A high serum VEGF level has been shown to be associated with tumor progression and metastasis in several human cancers, but its significance in HCC is unclear. The correlation between serum VEGF level and tumor pathologic features in patients with HCC has not been studied before.

METHODS

Preoperative serum samples and tumor specimens were prospectively collected in 100 patients undergoing resection of HCC. Serum VEGF level was measured by enzyme-linked immunosorbent assay, and tumor VEGF expression was assessed by immunohistochemical study. Histopathologic examination was performed by a pathologist without prior knowledge of the serum VEGF level or tumor VEGF expression.

RESULTS

Preoperative serum VEGF levels ranged from 15 to 1,789 pg/mL (median 269). When serum VEGF levels were compared between groups categorized by different clinicopathologic variables, significant correlation was found between a high serum VEGF level and absence of tumor capsule, presence of intrahepatic metastasis, presence of microscopic venous invasion, and advanced stage. There was a positive correlation between the serum VEGF level and tumor expression of VEGF as well as platelet count. When the 75th percentile serum VEGF level (500 pg/mL) was used as a cutoff level, the frequency of venous invasion in patients with a high serum VEGF level was significantly greater compared with patients with a low serum VEGF level. By multivariate analysis, a serum VEGF level of more than 500 pg/mL and tumor size more than 5 cm were independent preoperative factors predictive of microscopic venous invasion. During a median follow-up of 11.6 months, 48% of patients with a serum VEGF level of more than 500 pg/mL and 27% of those with a serum VEGF level of 500 pg/mL or less developed postoperative recurrence.

CONCLUSIONS

These results show that a high preoperative serum VEGF level is a predictor of microscopic venous invasion in HCC, suggesting that the serum VEGF level may be useful as a biologic marker of tumor invasiveness and a prognostic factor in HCC.

Mechanism of spontaneous transition from typical atrial flutter to atrial fibrillation: role of ectopic atrial fibrillation foci

Paroxysmal AF has been known to be initiated by ectopic beats, especially in the pulmonary veins (PVs), and radiofrequency catheter ablation could cure it. We considered that the spontaneous transition from typical atrial flutter to AF also could be initiated by ectopic beats. Twenty patients (18 men, mean age 66 +/- 14 years) with episodes of spontaneous transition from typical atrial flutter to AF were included in this study. They underwent detailed mapping of both atria. All the patients had spontaneous AF initiated by ectopic beats, and all of them had typical atrial flutter and spontaneous transition from typical atrial flutter (12 patients with counterclockwise atrial flutter and 8 patients with clockwise atrial flutter) to AF. The transition was initiated by ectopic beats from the PVs (17 foci, 85%), crista terminalis (2 foci, 10%), and superior vena cava (1 focus, 5%). After successful ablation of AF foci, typical atrial flutter was induced again, but no spontaneous transition was found after at least 10 minutes of observation. We concluded that paroxysmal AF and spontaneous transition from typical atrial flutter to AF were initiated by ectopic beats, and successful catheter ablation of the ectopic foci can eliminate paroxysmal AF and spontaneous transition from typical atrial flutter to AF.