Telemedicine acceptance by older adults in Hong Kong during a hypothetical severe outbreak and after the COVID-19 pandemic: a cross-sectional cohort survey

INTRODUCTION

Telemedicine services worldwide have experienced unprecedented growth since the early days of the coronavirus disease 2019 (COVID-19) pandemic. Multiple studies have shown that telemedicine is an effective alternative to conventional in-person patient care. This study explored the public perception of telemedicine in Hong Kong, specifically among older adults who are most vulnerable to COVID-19.

METHODS

Medical students from The Chinese University of Hong Kong conducted in-person surveys of older adults aged ≥60 years. Each survey collected socio-demographic information, medical history, and concerns regarding telemedicine use. Univariate and multivariate logistic regression analyses were conducted to identify statistically significant associations. The primary outcomes were acceptance of telemedicine use during a hypothetical severe outbreak and after the COVID-19 pandemic.

RESULTS

There were 109 survey respondents. Multivariate logistic regression analyses revealed that the expectation of government subsidies for telemedicine services was the strongest common driver and the only positive independent predictor of telemedicine use during a hypothetical severe outbreak (P=0.016) and after the COVID-19 pandemic (P=0.003). No negative independent predictors of telemedicine use during a hypothetical severe outbreak were identified. Negative independent predictors of telemedicine use after the COVID-19 pandemic included older age and residence in the New Territories (both P=0.001).

CONCLUSION

Government support, such as telemedicine-specific subsidies, will be important for efforts to promote telemedicine use in Hong Kong during future severe outbreaks and after the COVID-19 pandemic. Robust dissemination of information regarding the advantages and disadvantages of telemedicine for the public, especially older adults, is needed.

GNG5 is an unfavourable independent prognostic indicator of gliomas

Gliomas are the most common primary brain tumours, and glioblastomas (GBMs) are subgrouped into four distinct molecular subtypes. This study aimed to identify the potential gene related to glioma progression. Weighted gene co‐expression network analysis (WGCNA) was used to explore the related gene. Correlation, ROC, survival and Cox regression analyses were performed. Blue module was strongly associated with WHO grade (r = .65, P = 1e‐19). GNG5 in gliomas was overexpressed compared with normal samples and associated with clinicopathologic characteristics. GNG5 was frequent in Mesenchymal subtype and lowly expressed in Proneural subtype of GBMs. Survival and Cox regression analyses showed that glioma patients with GNG5 overexpression had shorter survival time, and GNG5 was an independent prognostic indicator of overall survival. Overall, GNG5 expression is closely associated with clinicopathologic characteristics and is an independent prognostic indicator for glioma patients, as well as a promising subtype‐associated biomarker in molecular classification of gliomas.

Integrated Transcriptome Analyses and Experimental Verifications of Mesenchymal-Associated TNFRSF1A as a Diagnostic and Prognostic Biomarker in Gliomas

Gliomas are the most prevalent malignant primary brain tumors with poor outcome, and four different molecular subtypes (Mesenchymal, Proneural, Neural, and Classical) are popularly applied in scientific researches and clinics of gliomas. Public databases contain an abundant genome-wide resource to explore the potential biomarker and molecular mechanisms using the informatics analysis. The aim of this study was to discover the potential biomarker and investigate its effect in gliomas. Weighted gene co-expression network analysis (WGCNA) was used to construct the co-expression modules and explore the biomarker among the dataset CGGA mRNAseq_693 carrying 693 glioma samples. Functional annotations, ROC, correlation, survival, univariate, and multivariate Cox regression analyses were implemented to investigate the functional effect in gliomas, and molecular experiments in vitro were performed to study the biological effect on glioma pathogenesis. The brown module was found to be strongly related to WHO grade of gliomas, and KEGG pathway analysis demonstrated that TNFRSF1A was enriched in MAPK signaling pathway and TNF signaling pathway. Overexpressed TNFRSF1A was strongly related to clinical features such as WHO grade, and functioned as an independent poor prognostic predictor of glioma patients. Notably, TNFRSF1A was preferentially upregulated in the Mesenchymal subtype gliomas (Mesenchymal-associated). Knockdown of TNFRSF1A inhibited proliferation and migration of glioma cell lines in vitro. Our findings provide a further understanding of the progression of gliomas, and Mesenchymal-associated TNFRSF1A might be a promising target of diagnosis, therapy, and prognosis of gliomas.

Identification of biomarkers and construction of a microRNA-mRNA regulatory network for ependymoma using integrated bioinformatics analysis

Ependymomas (EPNs) are one of the most common types of malignant neuroepithelial tumors. In an effort to identify potential biomarkers involved in the pathogenesis of EPN, the mRNA expression profiles of the GSE25604, GSE50161, GSE66354, GSE74195 and GSE86574 datasets, in addition to the microRNA (miRNA/miR) expression profiles of GSE42657 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) between EPN and normal brain tissue samples were identified using the Limma package in R and GEO2R, respectively. Functional and pathway enrichment analyses were conducted using the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction network was constructed using the Search Tool for Retrieval of Interacting Genes database, which was visualized using Cytoscape. The targeted genes of DEMs were predicted using miRWalk2.0 and a miRNA-mRNA regulatory network was constructed. Following analysis, a total of 948 DEGs and 129 DEMs were identified. Functional enrichment analysis revealed that 609 upregulated DEGs were significantly enriched in ‘PI3K-Akt signaling pathway’, while 339 downregulated DEGs were primarily involved in ‘cell junction’ and ‘retrograde endocannabinoid signaling’. In addition, 6 hub genes [cyclin dependent kinase 1, CD44 molecule (Indian blood group) (CD44), proliferating cell nuclear antigen (PCNA), MYC, synaptotagmin 1 (SYT1) and kinesin family member 4A] and 6 crucial miRNAs [homo sapiens (hsa)-miR-34a-5p, hsa-miR-449a, hsa-miR-106a-5p, hsa-miR-124-3p, hsa-miR-128-3p and hsa-miR-330-3p] were identified as biomarkers and potential therapeutic targets for EPN. Furthermore, a microRNA-mRNA regulatory network was constructed to highlight the interactions between DEMs and their target DEGs; this included the hsa-miR-449a-SYT1, hsa-miR-34a-5p-SYT1, hsa-miR-330-3p-CD44 and hsa-miR-124-3p-PCNA pairs, whose expression levels were confirmed using reverse transcription-quantitative polymerase chain reaction. In conclusion, the present study may provide important data for the investigation of the molecular mechanisms of EPN pathogenesis.

Examining the biomarkers and molecular mechanisms of medulloblastoma based on bioinformatics analysis

Medulloblastoma (MB) is the most common malignant brain tumor in children. The aim of the present study was to predict biomarkers and reveal their potential molecular mechanisms in MB. The gene expression profiles of GSE35493, GSE50161, GSE74195 and GSE86574 were downloaded from the Gene Expression Omnibus (GEO) database. Using the Limma package in R, a total of 1,006 overlapped differentially expressed genes (DEGs) with the cut-off criteria of P<0.05 and |log₂fold-change (FC)|>1 were identified between MB and normal samples, including 540 upregulated and 466 downregulated genes. Furthermore, the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were also performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool to analyze functional and pathway enrichment. The Search Tool for Retrieval of Interacting Genes database was subsequently used to construct a protein-protein interaction (PPI) network and the network was visualized in Cytoscape. The top 11 hub genes, including CDK1, CCNB1, CCNB2, PLK1, CDC20, MAD2L1, AURKB, CENPE, TOP2A, KIF2C and PCNA, were identified from the PPI network. The survival curves for hub genes in the dataset GSE85217 predicted the association between the genes and survival of patients with MB. The top 3 modules were identified by the Molecular Complex Detection plugin. The results indicated that the pathways of DEGs in module 1 were primarily enriched in cell cycle, progesterone-mediated oocyte maturation and oocyte meiosis; and the most significant functional pathways in modules 2 and 3 were primarily enriched in mismatch repair and ubiquitin-mediated proteolysis, respectively. These results may help elucidate the pathogenesis and design novel treatments for MB.

Silencing SATB1 overcomes temozolomide resistance by downregulating MGMT expression and upregulating SLC22A18 expression in human glioblastoma cells

Glioblastoma multiforme (GBM) is the most common malignant tumor of the central nervous system and has a very poor prognosis. Currently, patients were treated by resection followed by radiotherapy plus concurrent temozolomide (TMZ) chemotherapy. However, many patients are resistant to TMZ-induced DNA damage because of upregulated expression of the DNA repair enzyme O⁶-methylguanine-DNA methyltransferase (MGMT). In this study, upregulation of SATB1 and MGMT, and downregulation of SLC22A18 resulted in acquisition of TMZ resistance in GBM U87 cells. Inactivation of special AT-rich sequence-binding protein 1 (SATB1) using short hairpin RNA (shRNA) downregulated MGMT expression and upregulated solute carrier family 22 member 18 (SLC22A18) expression in GBM cells. This suggested SATB1-mediated posttranscriptional regulation of the MGMT and SLC22A18 protein levels. Immunohistochemical analysis of malignant glioma specimens demonstrated a significant positive correlation between the levels of MGMT and SATB1, and a negative correlation between the levels of SLC22A18 and SATB1. Importantly, in recurrent, compared with the primary, lesions in 15 paired identical tumors, the SATB1 and MGMT protein levels were increased and the SLC22A18 levels were decreased. Finally, in TMZ-resistant GBM, SATB1 knockdown enhanced TMZ efficacy. Consequently, SATB1 inhibition might be a promising strategy combined with TMZ chemotherapy to treat TMZ-resistant GBM.

Low Adherence to Immunosuppressants Is Associated With Symptom Experience Among Kidney Transplant Recipients

PURPOSE

The purpose of this study was to investigate the relationship between immunosuppressant-related symptom experience (SE) and adherence to immunosuppressant regimens among kidney transplant (KT) recipients.

METHODS

A total of 239 KT recipients on an immunosuppressant regimen who were followed up after transplantation participated in this study. Data was collected through a self-reported questionnaire survey (medication adherence, SE, and quality of life) and medical record review.

RESULTS

Low adherence in the immunosuppressant group was associated with longer time since KT, less comorbidity (<3), and a higher rehospitalization rate. Low adherence among KT recipients showed significantly greater overall symptom occurrence (P = .001) and symptom distress (P = .002) levels than patients with high or medium adherence after adjusting for a number of covariates. The most common symptom both in terms of occurrence (96.4%) and distress (91.1%) among poorly adherent KT recipients was tiredness.

CONCLUSION

Low adherence to an immunosuppressant regimen was significantly associated with high SE among KT recipients. Strategies to decrease immunosuppressant-related SE are needed to improve adherence to immunosuppressants.

Needs assessment for master of nursing programmes among Bangladesh nurses

AIM

This study aimed to assess the intent to enrol in a master of nursing programme among Bangladesh nurses, identify preferred programme options and measure the association among intent to enrol in the programme, clinical competency and job satisfaction.

BACKGROUND

Personal and professional aspects of potential students pursuing graduate education are beneficial in devising educational strategies. However, considering the pressing needs for higher nursing education, there are no masters of nursing programmes in Bangladesh.

METHODS

This study used a descriptive correlational design. Nurses working in Bangladesh public sector were recruited to participate in a self-administered survey (n = 260). The questionnaire consisted of perception of job satisfaction, clinical competency and the need for educational options, including the intent to enrol in a master of nursing programme, preferred specialty area, curriculum content and career goals after graduation. Data were analysed using descriptive statistics and point-biserial correlation.

RESULTS

Ninety per cent of the respondents reported that they intended to enrol in a master of nursing programme. Intention was significantly correlated with clinical competency but not with job satisfaction. The most preferred specialty areas were nursing management and education. Half of the respondents responded that teaching at nursing schools was a career goal after graduation.

DISCUSSION

The results of the needs assessment for the programme reflected the unique interest and priorities of the current status of Bangladesh.

CONCLUSIONS

The results indicate a strong motivation to enrol in a master of nursing programme, confidence in clinical competence and high demand for programme in nursing management and education. These findings should be considered to design the programme in order to meet the interest of Bangladesh nurses.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Educational needs assessments should take precedence to ensure the best possible educational outcome and to produce competent nurses who will contribute in achieving the Millennium Development Goals of Bangladesh.

Loss of speech after living-related donor liver transplantation: detection of the lesion by diffusion tensor image

INTRODUCTION

Loss of speech after living-related liver transplantation is uncommon. Either immunosuppressive agents, related sequelae, or a neurological event may cause it.

CASE REPORT

A 46-year-old man developed dysarthria and dysphagia on the 10th day after living-related donor liver transplantation for alcoholic cirrhosis with Child-Pugh class C. Brain magnetic resonance images and electroencephalograms could not detect any lesion, but the diffusion tensor image showed a subacute lacunar infarction at right midbrain. The patient's speech improved 1 month after rehabilitation.

CONCLUSIONS

Some unexpected neurological events, such as loss of speech, may occur after liver transplantation. The differential diagnosis becomes very important before active treatment. Magnetic resonance imaging supplemented with diffusion tensor imaging is an effective imaging study in establishing the diagnosis.

Right mini-parasternotomy may be a good minimally invasive alternative to full sternotomy for cardiac valve operations-a propensity-adjusted analysis

AIM

Limited realworld data existed for miniparasternotomy approach with good sample size in Asian cohorts and most previous studies were eclipsed by case heterogeneity. The goal of this study was to compare safety and quality outcomes of cardiac noncoronary valve operations by miniparasternotomy and full sternotomy approaches on riskadjusted basis.

METHODS

From our hospital database, we retrieved the cases of non-coronary valve operations from 1 January 2005 to 31 December 2012, including re-do, emergent, and combined procedures. Estimated EuroScore-II and propensity score for choosing mini-parasternotomy were adjusted for in the regression models on hospital mortality, complications (pneumonia, stroke, sepsis, etc.), and quality parameters (length of stay, ICU time, ventilator time, etc.). Non-complicated cases, defined as survival to discharge, ventilator use not over one week, and intensive care unit stay not over two weeks, were used for quality parameters.

RESULTS

There were 283 miniparasternotomy and 177 full sternotomy cases. EuroScore-II differed significantly (medians 2.1 vs. 4.7, p<0.001). Propensity scores for choosing miniparasternotomy were higher with lower EuroScore-II (OR=0.91 per 1%, p<0.001), aortic regurgitation (OR=2.3, p=0.005), and aortic non-mitral valve disease (OR=3.9, p<0.001). Adjusted for propensity score and EuroScore-II, mini-parasternotomy group had less pneumonia (OR=0.32, p=0.043), less sepsis (OR=0.31, p=0.045), and shorter non-complicated length of stay (coefficient=7.2 (day), p<0.001) than full sternotomy group, whereas Kaplan-Meier survival, non-complicated ICU time, non-complicated ventilator time, and 30-day mortality did not differ significantly.

CONCLUSION

The propensity-adjusted analysis demonstrated encouraging safety and quality outcomes for mini-parasternotomy valve operation in carefully selected patients.

In vitro and in vivo radiosensitization induced by hydroxyapatite nanoparticles

BACKGROUND

Previous study showed that hydroxyapatite nanoparticles (nano-HAPs) inhibited glioma growth in vitro and in vivo; and in a drug combination, they could reduce adverse reactions. We investigated the possible enhancement of radiosensitivity induced by nano-HAPs.

METHODS

In vitro radiosensitization of nano-HAPs was measured using a clonogenic survival assay in human glioblastoma U251 and breast tumor brain metastatic tumor MDA-MB-231BR cells. DNA damage and repair were measured using γH2AX foci, and mitotic catastrophe was determined by immunostaining. The effect of nano-HAPs on in vivo tumor radiosensitivity was investigated in a subcutaneous and an orthotopic model.

RESULTS

Nano-HAPs enhanced each cell line's radiosensitivity when the exposure was 1 h before irradiation, and they had no significant effect on irradiation-induced apoptosis or on the activation of the G2 cell cycle checkpoint. The number of γH2AX foci per cell was significantly large at 24 h after the combination modality of nano-HAPs + irradiation compared with single treatments. Mitotic catastrophe was also significantly increased at an interval of 72 h in tumor cells receiving the combined modality compared with the individual treatments. In a subcutaneous model, nano-HAPs caused a larger than additive increase in tumor growth delay. In an orthotopic model, nano-HAPs significantly reduced tumor growth and extended the prolongation of survival induced by irradiation.

CONCLUSIONS

These results show that nano-HAPs can enhance the radiosensitivity of tumor cells in vitro and in vivo through the inhibition of DNA repair, resulting in an increase in mitotic catastrophe.

Predictive value of the SLC22A18 protein expression in glioblastoma patients receiving temozolomide therapy

Background

Our previous study showed that SLC22A18 downregulation and promoter methylation were associated with the development and progression of glioma and the elevated expression of SLC22A18 was found to increase the sensitivity of glioma U251 cells to the anticancer drug 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). In this study, we investigated the predictive value of SLC22A18 promoter methylation and protein expression in glioblastoma multiforme (GBM) patients receiving temozolomide (TMZ) therapy.

Patients and methods

SLC22A18 promoter methylation and protein expression were examined by methylation-specific polymerase chain reaction (MSP) and Western blotting respectively, then we compared SLC22A18 promoter methylation and protein expression in tumor cell explants in regard to prediction of TMZ response and survival time of 86 GBM patients.

Results

SLC22A18 promoter methylation was detected in 61 of 86 (71%) samples, whereas 36 of 86 (42%) cases were scored positive for SLC22A18 protein expression. Overall SLC22A18 promoter methylation was significantly related to SLC22A18 protein expression, but a subgroup of cases did not follow this association. Multivariate Cox regression analysis indicated that SLC22A18 protein expression, but not promoter methylation, was significantly correlated with TMZ therapy. SLC22A18 protein expression predicted a significantly shorter overall survival in 51 patients receiving TMZ therapy, whereas no differences in overall survival were observed in 35 patients without TMZ therapy.

Conclusions

These results show that lack of SLC22A18 protein expression is superior to promoter methylation as a predictive tumor biomarker in GBM patients receiving temozolomide therapy.

Relationship between SATB1 expression and prognosis in astrocytoma

Special AT-rich-sequence-binding protein 1 (SATB1), a new type of gene regulator, has been reported to be expressed in various human cancers and may be associated with malignancy. The aim of this study was to investigate the expression of SATB1 in astrocytoma and to determine its prognostic value for the overall survival of patients with astrocytoma. The expression of SATB1 protein and messenger RNA (mRNA) in human astrocytoma specimens was examined using immunohistochemistry and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The relationship between SATB1 expression and O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status was also investigated. Spearman's correlation coefficient was used to describe the association between SATB1 expression and the clinical parameters of astrocytoma patients. SATB1 protein and mRNA were expressed at significant levels in astrocytoma specimens. SATB1 expression was positively correlated with astrocytoma pathological grade but negatively correlated with the life span of astrocytoma patients. SATB1 expression was also significantly lower in astrocytoma specimens with MGMT promoter methylation than in those without MGMT promoter methylation. Our findings suggest that SATB1 may have an important role as a positive regulator of astrocytoma development and progression and that SATB1 might be a useful molecular marker for predicting the prognosis of patients with astrocytoma and could be a novel target for treating astrocytoma.

Upregulation of SATB1 is associated with the development and progression of glioma

Background

Special AT-rich sequence-binding protein-1 (SATB1) has been reported to be expressed in several human cancers and may have malignant potential. This study was aimed at investigating the expression and potential role of SATB1 in human glioma.

Method

The relationship between SATB1 expression, clinicopathological parameters, Ki67 expression and MGMT promoter methylation status was evaluated, and the prognostic value of SATB1 expression in patients with gliomas was analyzed. SATB1-specific shRNA sequences were synthesized, and U251 cells were transfected with SATB1 RNAi plasmids. Expression of SATB1 mRNA and protein was investigated by RT-PCR and immunofluoresence staining and western blotting. The expression of c-Met, SLC22A18, caspase-3 and bcl-2 protein was determined by western blotting. U251 cell growth and adherence was detected by methyl thiazole tetrazolium assay. The apoptosis of U251 cells was examined with a flow cytometer. The adherence, invasion, and in vitro angiogenesis assays of U251 cells were done. The growth and angiogenesis of SATB1 low expressing U251 cells was measured in an in vivo xenograft model.

Results

Of 70 tumors, 44 (62.9%) were positive for SATB1 expression. SATB1 expression was significantly associated with a high histological grade and with poor survival in univariate and multivariate analyses. SATB1 expression was also positively correlated with Ki67 expression but negatively with MGMT promoter methylation in glioma tissues. SATB1 shRNA expression vectors could efficiently induce the expression of SLC22A18 protein, increase the caspase-3 protein, inhibit the expression of SATB1, c-Met and bcl-2 protein, the growth, invasion, metastasis and angiogenesis of U251 cells, and induce apoptosis in vitro. Furthermore, the tumor growth of U251 cells expressing SATB1 shRNA were inhibited in vivo, and immunohistochemical analyses of tumor sections revealed a decreased vessel density in the animals where shRNA against SATB1 were expressed.

Conclusions

SATB1 may have an important role as a positive regulator of glioma development and progression, and that SATB1 might be a useful molecular marker for predicting the prognosis of glioma.

Hydroxyapatite nanoparticles inhibit the growth of human glioma cells in vitro and in vivo

Hydroxyapatite nanoparticles (nano-HAPs) have been reported to exhibit antitumor effects on various human cancers, but the effects of nano-HAPs on human glioma cells remain unclear. The aim of this study was to explore the inhibitory effect of nano-HAPs on the growth of human glioma U251 and SHG44 cells in vitro and in vivo. Nano-HAPs could inhibit the growth of U251 and SHG44 cells in a dose- and time-dependent manner, according to methyl thiazoletetrazolium assay and flow cytometry. Treated with 120 mg/L and 240 mg/L nano-HAPs for 48 hours, typical apoptotic morphological changes were noted under Hoechst staining and transmission electron microscopy. The tumor growth of cells was inhibited after the injection in vivo, and the related side effects significantly decreased in the nano-HAP-and-drug combination group. Because of the function of nano-HAPs, the expression of c-Met, SATB1, Ki-67, and bcl-2 protein decreased, and the expression of SLC22A18 and caspase-3 protein decreased noticeably. The findings indicate that nano-HAPs have an evident inhibitory action and induce apoptosis of human glioma cells in vitro and in vivo. In a drug combination, they can significantly reduce the adverse reaction related to the chemotherapeutic drug 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU).

Correlation of low SLC22A18 expression with poor prognosis in patients with glioma

We investigated the expression of the putative tumor suppressor SLC22A18 to evaluate it as a prognostic marker in glioma patients. Immunohistochemical and Western blot analyses of clinical tissue samples obtained from 120 patients with glioma were performed. Low expression of SLC22A18 was observed in 71.7% of patients. Loss of SLC22A18 expression in glioma was significantly related to pathological grade (p = 0.003). High pathological grade (World Health Organization III-IV) was correlated with negative (low or absent) expression of SLC22A18, which was correlated with a significantly shorter overall patient survival than in those with positive (high) expression (p = 0.007). Multivariate Cox regression analysis indicated that SLC22A18 expression level is an independent survival prognostic factor for patients with glioma (p = 0.011). Western blotting analysis confirmed decreased expression of SLC22A18 in glioma tissues compared with adjacent brain tissues. This study suggests that SLC22A18 functions as a tumor suppressor in glioma and represents a candidate biomarker for long-term survival in this disease.

Effect of 5-Aza-2'-deoxycytidine on SLC22A18 in glioma U251 cells

SLC22A18 [solute carrier family 22 (organic cation transporter) member 18] is located within the 11p15.5 cluster, and may be a new tumor suppressor gene; evidence of SLC22A18 hypermethylation is documented in several types of human cancers. In order to determine whether SLC22A18 hypermethylation is involved in glioma, we determined the SLC22A18 gene protein expression, mRNA expression and methylation status in glioma U251 cells before and after treatment with 5-Aza-2'‑deoxycytidine (5-Aza-CdR), and observed the change in growth. Glioma U251 cells treated with 5-Aza-CdR were analyzed by flow cytometry to identify any change in their cell cycle profiles. Tumors induced via the injection of untreated U251 cells were measured. Immunohistochemistry, reverse transcriptase-polymerase chain reaction (RT-PCR) and PCR-based methylation assay were carried out to determine SLC22A18 gene protein expression, mRNA expression and methylation status in glioma U251 cells before and after treatment with 5-Aza‑CdR. The treated cells showed an increase in their proportion in G1, from 79.2 to 83.5%, and a decrease in S phase, from 12.4 to 5.8%. The apoptotic rate increased from 6.4 to 15.8%. Tumors induced via the injection of untreated U251 cells were approximately 1.46 cm³ in size, whereas the tumors induced by U251 cells treated with 5-Aza-CdR averaged 0.88 cm³ in size. The expression levels of SLC22A18 protein and mRNA in U251 cells were increased following treatment with 5x10⁻⁷ M 5-Aza‑CdR. Prior to 5-Aza-CdR treatment, the SLC22A18 gene demonstrated hypermethylation and therefore could not be cleaved by HpaII and MspI. It is known that only the DNA digested with HpaII or MspI can be amplified. Following treatment with 5-Aza‑CdR, the SLC22A18 gene became demethylated, and could then be cleaved by both of the enzymes, and this failed to be amplified. 5-Aza-cdR may induce glioma U251 cell division and apoptosis and enhance demethylation and protein and mRNA expression of SLC22A18. The hypermethylation of SLC22A18 may be related to the transcriptional silencing of this gene. The growth inhibitory effects of 5-Aza-CdR treatment in vivo remain recognizable.

Promoter methylation and downregulation of SLC22A18 are associated with the development and progression of human glioma

Background

Downregulation of the putative tumor suppressor gene SLC22A18 has been reported in a number of human cancers. The aim of this study was to investigate the relationship between SLC22A18 downregulation, promoter methylation and the development and progression of human glioma.

Method

SLC22A18 expression and promoter methylation was examined in human gliomas and the adjacent normal tissues. U251 glioma cells stably overexpressing SLC22A18 were generated to investigate the effect of SLC22A18 on cell growth and adherence in vitro using the methyl thiazole tetrazolium assay. Apoptosis was quantified using flow cytometry and the growth of SLC22A18 overexpressing U251 cells was measured in an in vivo xenograft model.

Results

SLC22A18 protein expression is significantly decreased in human gliomas compared to the adjacent normal brain tissues. SLC22A18 protein expression is significantly lower in gliomas which recurred within six months after surgery than gliomas which did not recur within six months. SLC22A18 promoter methylation was detected in 50% of the gliomas, but not in the adjacent normal tissues of any patient. SLC22A18 expression was significantly decreased in gliomas with SLC22A18 promoter methylation, compared to gliomas without methylation. The SLC22A18 promoter is methylated in U251 cells and treatment with the demethylating agent 5-aza-2-deoxycytidine increased SLC22A18 expression and reduced cell proliferation. Stable overexpression of SLC22A18 inhibited growth and adherence, induced apoptosis in vitro and reduced in vivo tumor growth of U251 cells.

Conclusion

SLC22A18 downregulation via promoter methylation is associated with the development and progression of glioma, suggesting that SLC22A18 is an important tumor suppressor in glioma.

Elevated expression of solute carrier family 22 member 18 increases the sensitivity of U251 glioma cells to BCNU

Previous studies showed that solute carrier family 22 member 18 (SLC22A18) is involved in tumorigenesis. The aim of this study was to examine the role of SLC22A18 in glioma cells. Glioma U251 cells were transfected with the human SLC22A18 gene. Transfection of the empty vector pcDNA3.1 was used as a negative control. Sensitivity to BCNU was measured by Annexin V staining. The expression of caspase-3 and bcl-2 was determined by immunohistochemistry. The transfection was confirmed by PCR, RT-PCR and Western blotting. Augmented apoptotic cell death was observed in the SLC22A18-transfected cells, compared to the non-transfected cells or cells with the empty vector. Caspase-3 expression increased in U251-SLC22A18 cells, whereas the bcl-2 expression decreased. These results indicated that SLC22A18 has a pro-apoptotic function in glioma cells.

Expression of HGF and VEGF in the cerebral tissue of adult rats with chronic hydrocephalus after subarachnoid hemorrhage

The hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) are important cytokines with modulatory actions in the nervous system. The present study aimed to investigate the role and expression of HGF and VEGF in the cerebral tissue of adult rats with chronic hydrocephalus after subarachnoid hemorrhage. Adult female Wistar rats were randomly divided into 4 groups: a control group (n=20) and 3 experimental subgroups (n=60). Subarachnoid hemorrhage was induced by the injection of 0.4 ml of non-heparinized autologous arterial blood into the cisterna magna of experimental animals on day 0 with a second injection 2 days later. The rats were sacrificed within 24 h of magnetic resonance imaging (MRI) examination at 2, 4, or 6 weeks. The excised brains were studied by RT-PCR, immunohistochemical and Western blot analyses as we examined HGF and VEGF mRNA and protein expression. Chronic hydrocephalus was induced in 21 rats after subarachnoid hemorrhage. After 2 weeks, the expression of HGF and VEGF in the cerebral tissue was significantly increased in the experimental group compared to the controls, especially in periventricular white matter. Our results indicate that HGF and VEGF participate in the pathological injury and repair of cerebral tissue in rats with chronic hydrocephalus after subarachnoid hemorrhage.

c-Met antisense oligodeoxynucleotides increase sensitivity of human glioma cells to paclitaxel

Cell culture, tissue chemistry and flow cytometry were used to determine whether antisense c-Met oligodeoxynucleotides enhanced the sensitivity of human glioma cells to paclitaxel. A combination of paclitaxel with antisense c-Met oligodeoxynucleotides inhibited cell growth, induced apoptosis and induced c-Met protein expression in U251 and SHG44 human glioma cells more significantly than either paclitaxel or the oligodeoxynucleotides on their own (P<0.01). Thus, c-Met antisense oligodeoxynucleotides increase the sensitivity of human glioma cells to paclitaxel. Combined use of the two agents could be a novel and attractive strategy in human glioma treatment.

c-Met-targeted RNA interference inhibits growth and metastasis of glioma U251 cells in vitro

Angiogenesis plays an essential role in tumor growth and metastasis and is a promising target for cancer therapy. c-Met, a receptor tyrosine kinase, and its ligand, hepatocyte growth factor (HGF), are critical in cellular proliferation, motility, invasion, and angiogenesis. The present study was designed to determine the role of c-Met in growth and metastasis of glioma U251 cells using RNA interference (RNAi) technology in vitro. We constructed three kinds of shRNA expression vectors aiming at the c-Met gene, then transfected them into glioma U251 cells by lipofectamine(TM) 2000. The level of c-Met mRNA was investigated by real-time polymerse chain reaction (RT-PCR). The protein expression of c-Met was observed by immunofluoresence staining and western blotting. U251 cell growth and adherence was detected by methyl thiazole tetrazolium assay. The apoptosis of U251 cells was examined with a flow cytometer. The adherence, invasion, and in vitro angiogenesis assays of U251 cells were done. We got three kinds of c-Met specific shRNA expression vectors which could efficiently inhibit the growth and metastasis of U251 cells and the expression of c-Met in U251 cells. RT-PCR, immunofluoresence staining and western blotting showed that inhibition rate for c-Met expression was up to 90%, 79% and 85%, respectively. The expression of c-Met can be inhibited by RNA interference in U251 cells, which can inhibit the growth and metastasis of U251 cell and induce cell apoptosis. These results indicate that RNAi of c-Met can be an effective antiangiogenic strategy for glioma.

Stabilization of hepatocyte growth factor mRNA by hypoxia-inducible factor 1

Hypoxia regulates expression of hepatocyte growth factor (HGF) by increasing its transcription and by stabilizing its mRNA. Despite the pivotal role of hypoxia-inducible factor 1 (HIF-1) in transcriptional activation of hypoxia-responsive genes, it is not known whether HIF-1 mediates hypoxia-induced stabilization of HGF mRNA. We constructed adenoviral vectors expressing either the wild-type HIF-1alpha (Ad2/HIF-1alpha/FL), a constitutively stable hybrid form of HIF-1alpha (Ad2/HIF-1alpha/VP16), or no transgene (Ad2/CMVEV). In rat glioma (C6) cells, human glioma (U251) cells human cardiac, vascular smooth muscle, and endothelial cells, infection with Ad2/HIF-1alpha/VP16 or Ad2/HIF-1alpha/FL increased HGF expression at both the mRNA and protein levels. Under normoxic conditions, the half-life of HGF mRNA was 43 min in C6 and U251 cells. Hypoxia and Ad2/HIF-1alpha/VP16 increased the half-life of HGF mRNA to 3.2 and 2.8 h, respectively, while Ad2/CMVEV had no effect. These studies are the first to demonstrate that overexpression of HIF-1alpha increases HGF mRNA stability. Our results also suggest that stabilization of HGF mRNA by hypoxia is mediated, at least in part, by HIF-1.

c-Met antisense oligodeoxynucleotides as a novel therapeutic agent for glioma: in vitro and in vivo studies of uptake, effects, and toxicity

BACKGROUND

c-Met, a receptor tyrosine kinase, and its ligand, hepatocyte growth factor, are critical in cellular proliferation, motility, and invasion and are known to be overexpressed in gliomas. The aim of our study was to investigate the uptake and effects of c-Met antisense oligodeoxynucleotides (ASODNs) on rat and human glioma cells in vitro and the uptake and toxicity of these nucleotides in rat carcinomatosis and brain tumor models.

MATERIALS AND METHODS

The three human cell lines (U87, BT325, SHG44) and the C6 rat glioma cell line were cultured. To study the uptake of oligodeoxynucleotides (ODNs) by glioma cells in vitro, cultured glioma cells readily incorporated caroboxyfluorescein-5-succimidyl ester (FAM) labeled phosphorothioate oligodeoxynucleotides, as demonstrated by immunofluorescence microscopy and flow cytometry. To study the effect of ASODNs treatment on c-Met expression in vitro, Expression of c-Met was assessed by immunofluorescence microscopy and reverse transcriptase polymerase chain reaction (RT-PCR) analysis. For animal studies of ODNs toxicity and uptake, eight rats underwent placement of cisternal catheters, under general anesthesia. Four rats were given 24 mug FAM-labeled ASODNs while the others were given a saline control injection. After a 24 h observation period, rats were sacrificed by barbiturate overdose, and their brains were studied.

RESULTS

For all cell lines, fluorescence was seen to increase with increasing ASODNs concentration. Cells treated in similar fashion were also analyzed by flow cytometry to graphically illustrate the differing fluorescence. Multiple glioma cell lines were tested, with similar results. c-Met ASODNs was found to be successfully incorporated from the media into cultured human glioma cells, even at concentrations as low as 2 muM. In addition, maintenance of the pH-dependent green fluorescence color, as seen by immunofluorescence microscopy and by using flow cytometry, indicated that the FAM was not contained within lysosomes. Immunofluorescence microscopy and RT-PCR analysis showed decreases in c-Met expression with oligodeoxynucleotides treatment. Uptake into tumor cells was also demonstrated in vivo, with no detectable toxicity at concentrations exceeding expected therapeutic levels.

CONCLUSION

These data are encouraging for further study of c-Met antisense oligodeoxynucleotides as a therapeutic modality for glioma.

Single-center experience of pediatric heart transplantation in taiwan

Heart transplantation (HTx) is a treatment for end-stage heart failure or a complex or inoperable congenital defect. The long-term survival and the adequate donor to recipient body weight (D/R BW) ratio remain to be determined. From March 1995 to May 2004, 14 children (6 months-16 years of age) underwent HTx due to underlying diseases of idiopathic dilated cardiomyopathy (n = 10; 71.4%), congenital heart disease (n = 3; 21.4%), and Kawasaki disease (n = 1; 7.1%). Donor-recipient body weight ratio ranged from 0.89 to 3.9. Big heart syndrome was present in one patient when D/R BW ratio was more than 3. Actuarial survival was 92.9% at 5 years after transplantation. Only the one patient who had Kawasaki disease died due to early primary graft failure. HTx is a feasible method with good long-term survival rates for end-stage heart failure or for complex or inoperable congenital defects. After careful pretransplant evaluation, a high D/R BW ratio (more than 3) is acceptable.

Heart retransplantation for heart allograft failure in Chinese heart transplant recipients: NTUH experience

We investigated the short- and long-term results after heart retransplantation in terms of different causes of heart allograft failure. We sought to establish the data of heart retransplantation in Chinese compared with Western counterparts due to differences in heart allograft vasculopathy. From March 1995 to May 2005, eight heart transplantation recipients with allograft failure underwent retransplantation. Heart allograft failure was due to coronary vasculopathy (CAV) in six patients (75%) and acute rejection in two patients (25%). The mean interval to retransplantation was 32 to 84 months (mean 54.3 months). There were five patients who survived after heart retransplantation for CAV and no patient survived after an earlier diagnosis of acute rejection. Heart retransplantation is a feasible method with acceptable long-term survival rate for heart allograft failure. After careful pretransplant evaluation, retransplantation is acceptable. The survival after retransplantation for CAV is notably great than that after acute rejection. Heart retransplantation is the only way for patients who have cardiac allograft failure to achieve long-term survival.

Successful Treatment of Hepatitis B Virus Infection With Lamivudine After Heart Transplantation

Patients with hepatitis B virus (HBV) infection have a higher morbidity and mortality after heart transplantation (HT). HBV infection is endemic in Taiwan. We studied the effect of lamivudine treatment of HBV infection after HT. From July 1987 to July 2005, 252 patients underwent HT. All recipients and donors underwent routine screening of hepatitis B surface antigen (HBsAg), hepatitis B e antigen, antibody to hepatitis B surface antigen, antibody to hepatitis B core antigen, antibody to hepatitis B e antigen, and an alanine aminotransferase (ALT) level before HT. When ALT was two times greater than the upper limit of normal or serum bilirubin was higher than 3 mg/dL in HBsAg-positive patients, HBV-DNA were checked by a branched DNA assay or polymerase chain reaction. When HVB-DNA was greater than 100,000 copies/mL, lamivudine (100 mg per day) was prescribed indefinitely. There were 14 patients under lamivudine treatment after HT, among whom, none suffered severe adverse reactions from lamivudine. Four patients died: one due to end-stage cirrhosis while awaiting liver transplantation at 14 months after HT. Two died of sudden death at 54 months and 138 months after HT. Another died of diffuse B cell lymphoma at 62 months after HT. All the survivors have normal ALT and undetectable HBV-DNA after lamivudine treatment. But the YMDD mutant was detected in two patients. With successful treatment of HBV infection in HT, it is not necessary to exclude HBV infection patients from HT.

Sparing Immunosuppression in Heart Transplant Recipients With Severe Sepsis

This study described an analysis of severe sepsis among heart transplantation recipients who were treated by sparing all immunosuppressants. Sepsis leading to multiple organ failure (MOF) in heart transplantation has a high mortality. This retrospective study of 190 patients who underwent heart transplantation from 1993 to 2004 included 12 who had severe sepsis with MOF who were treated by sparing all immunosuppressants. Half of them survived after sparing all immunosuppressants with intensive endomyocardial biopsy. Only one case needed pulse therapy for an acute rejection episode. The most common bacterial infectious episodes were caused by methicillin-resistant Staphylococcus aureus (n = 3). All sepsis episodes occurred in the first month after heart transplantation except in one case, which occurred 6 years after heart transplantation. There was a 50% survival rate of heart transplantation recipients who experienced MOF due to severe sepsis and were treated by sparing all immunosuppressants under a program of intensive endomyocardial biopsy.

Simultaneous Heart and Kidney Transplantation for Combined Cardiac and Renal Failure

Simultaneous heart and kidney transplantation (SHKT) is feasible for combined cardiac and renal failure. Herein we reviewed our 10-year experience in SHKT. Six patients underwent SHKT from June 1995 to December 2004. Their ages ranged from 13 to 63 years old with a mean of 45.5 +/- 15.8 years. They were all men except one girl, who was the youngest (aged 13) who suffered from dilated cardiomyopathy with congestive heart failure and chronic renal failure due to systemic lupus erythematosus. Because of aggravating heart failure, she changed from hemodialysis to peritoneal dialysis. Because of intractable heart failure, she underwent SHKT from a 24-year-old female donor. All received hemodialysis before SHKT. The indications for heart transplantation included dilated cardiomyopathy (n = 3), ischemic cardiomyopathy (n = 1), cardiac allograft vasculopathy (n = 1), and cardiac allograft failure (n = 1). The immunosuppressive protocol and rejection surveillance were these employed for heart transplantation. No operative mortality was noted in this study. The 1-year and 5-year survival rates were the same, 83%. The 10-year survival rate was 55%. No cardiac or renal allograft rejection was noted. No renal allograft loss was noted. There were two late mortalities: the one, who underwent redo heart transplantation for coronary artery vasculopathy died of cardiac allograft failure 1 year after SHKT. The other patient died of massive ischemic necrosis of the intestine at 6 years after SHKT. Our experience showed that SHKT had good short- and long-term results without increasing immunosuppressive doses. End-stage failure of either the heart or the kidney did not preclude heart plus kidney transplantation.

[The expression of hepatocyte growth factor and its receptor in brain astrocytomas]

OBJECTIVE

To investigate the expression of hepatocyte growth factor (HGF) mRNA and its receptor (c-Met) mRNA in brain astrocytomas and their relationships with tumor proliferation, angiogenesis, clinical pathology and prognosis.

METHODS

The expression of HGF mRNA, c-Met mRNA in the resected tumor tissues of 76 patients with brain astrocytomas, 43 males and 33 females, aged 20 - 71, were detected by in situ hybridization. Immunohistochemistry technique was used to test the expression of proliferating cell nuclear antigen (PCNA) protein and the microvessel density (MVD) was determined by immunohistochemistry with monoclonal antibody against CD34.

RESULTS

The positive rates of expression of HGF, c-Met and PCNA in low pathologic grades of brain astrocytoma were 34.5%, 44.8% and 15% +/- 9% respectively, and in high pathologic grades of brain astrocytoma were 34.5%, 44.8% and 48% +/- 12% respectively (P < 0.05). MVD in low and high pathologic grades of brain astrocytoma were 17 +/- 7 and 31 +/- 13 respectively (P < 0.05). The expression of HGF, c-Met, PCNA and CD34 was not related to sex, age, position of tumor and diameter of tumor. The expression of c-Met was related to the expression of HGF, PCNA and the MVD in the tumor tissues of these patients. The pathological grade, position of tumor, HGF, c-Met, PCNA, MVD had a significant influence on the survival time.

CONCLUSION

HGF/c-Met plays an important role in the formation and progression of the brain astrocytoma and can promote tumor proliferation and intratumoral microvascular formation, and is closely related to the prognosis of the patients.

Constitutional activation of IL-6-mediated JAK/STAT pathway through hypermethylation of SOCS-1 in human gastric cancer cell line

The interleukin-mediated Janus kinase (JAK)/STAT pathway plays a crucial role in carcinogenesis. Recently, increased STAT3 activity was found in hepatocellular carcinoma and multiple myeloma in which there was silencing of SOCS-1 (suppressor of cytokine signalling-1) by gene promoter hypermethylation. We investigated the expression level of interleukin-6 (IL-6) and SOCS-1 in gastric cancer cell lines. Expression of SOCS-1 correlated with IL-6 level in most of the cell lines, except for AGS cells in which SOCS-1 was absent despite a high level of IL-6 production. Methylation analysis by methylation-specific polymerase chain reaction and bisulphite sequencing revealed that CpG island of SOCS-1 was densely methylated in AGS cells. Demethylation treatment by 5'aza-deoxycytidine restored SOCS-1 expression and also suppressed constitutive STAT3 phosphorylation in AGS cells. Moreover, methylation of SOCS-1 was detected in 27.5% (11 of 40) of primary gastric tumours samples, 10% (one of 10) of adjacent noncancer tissues but not in any (zero of nine) normal gastric mucosa. Methylation of SOCS-1 also correlated with the loss of mRNA expression in some primary gastric cancers. In conclusion, this is the first report to demonstrate that hypermethylation of SOCS-1 led to gene silencing in gastric cancer cell line and primary tumour samples. Downregulation of SOCS-1 cooperates with IL-6 in the activation of JAK/STAT pathway in gastric cancer.

Management of aortic aneurysm infected with Salmonella

BACKGROUND

This study reviewed the clinical outcomes of patients with an aortic aneurysm infected with Salmonella treated by a single centre over 6 years.

METHODS

Data were collected by a retrospective case-note review.

RESULTS

Between September 1995 and December 2001, 121 patients with non-typhoid Salmonella bacteraemia were treated, of whom 24 patients had an aortic aneurysm infected with Salmonella. Ten had a suprarenal and 14 an infrarenal aortic infection. The most common responsible pathogen was group C Salmonella (12 patients). All of the 20 patients who had combined medical and surgical therapy survived, whereas two of four who had medical therapy alone died. There were two late deaths during a mean follow-up of 23 (range 3-63) months.

CONCLUSION

The incidence of aortic infection in patients with non-typhoid Salmonella bacteraemia was high in Taiwan. Timely surgical intervention and prolonged intravenous antibiotic therapy resulted in excellent outcomes.

Fish allergy in atopic children

The prevalence of fish allergy among 11 atopic children with elevated levels of specific immunoglobulin (Ig) E for cod was determined. None of the children had a history of fish allergy. All of the children had asthma and allergic rhinitis and 5 of them had also atopic dermatitis. The children underwent allergy skin tests (codfish, tuna, catfish, salmon, flounder, and bass), specific IgE tests (salmon, trout, tuna, eel, and mackerel), and food challenge tests. Skin tests in cod-specific IgE-positive children were positive for codfish in 4 children, tuna in 2, catfish in 2, salmon in 6, flounder in one, and bass in 2. Three children had elevated specific IgE for salmon, 5 for trout, 8 for tuna, 4 for eel, and 4 for mackerel. Oral fish challenge with 10 g of fish did not result in positive reaction in any of the children. In conclusion, a positive food challenge test provided the only definitive confirmation of fish allergy, whereas positive allergy skin tests or positive specific IgE tests were less reliable. Skin tests and in vitro specific IgE assays were not correlated with clinical symptoms of fish allergy, and the results of these 2 tests did not correlate with each other in this study.

Reactive oxygen species activity, mucosal lipoperoxidation and glutathione in Helicobacter pylori-infected gastric mucosa

BACKGROUND AND AIM

Helicobacter pylori is considered as the major pathogen in Helicobacter pylori-associated gastroduodenal disease, but the mechanism of its action has not been fully explained. This study was performed to assess the reactive oxygen species activity and the damage in Helicobacter pylori-infected gastric mucosa.

METHODS

Gastric biopsy specimens were obtained from 308 patients undergoing endoscopy. Gastric mucosal damage was assessed by using luminol enhanced chemiluminescence, thiobarbituric acid-reactive substance, and mucosal glutathione.

RESULTS

The chemiluminescence and thiobarbituric acid-reactive substance-equivalent levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (43.8 +/- 134.9 c.p.m./microg tissue, 157.0 +/- 96.2 nmol/g tissue, respectively) were significantly higher than in those with Helicobacter pylori-negative mucosa (6.8 +/- 20.3 c.p.m./microg tissue, 110.0 +/- 51.6 nmol/g tissue, respectively; P=0.000, P=0.016, respectively). The glutathione levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (159.3 +/- 76.6 nmol/microg tissue) were significantly lower than in those with Helicobacter pylori-negative gastric mucosa (212.3 +/- 134.3 nmol/microg tissue; P=0.008). After the data were divided according to the presence of Helicobacter pylori, there were no significant differences in chemiluminescence, thiobarbituric acid-reactive substance, and glutathione among the different macroscopic findings within Helicobacter pylori-positive and -negative gastric mucosa.

CONCLUSIONS

Helicobacter pylori infection plays a pathological role in many gastrointestinal diseases through excessive mucosal-reactive oxygen species production, pronounced membrane damage, and the depletion of gastric anti-oxidants.

Survival after early surgical revascularization in patients with both acute myocardial infarction and cardiogenic shock

BACKGROUND AND PURPOSE

Previous studies have reported encouraging results with percutaneous transluminal coronary angioplasty (PTCA) in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock. However, PTCA is often unsuccessful and the mortality rate is more than 80%. The success rate of early surgical revascularization in patients with cardiogenic shock and failed PTCA is not clear. This study assessed the effect of early surgical revascularization on survival chances in patients with cardiogenic shock and failed PTCA.

PATIENTS AND METHODS

Nineteen patients referred to our hospital by cardiologists due to cardiogenic shock and failed PTCA were included in this study. During the period from February 1995 through August 1997, seven patients were treated using mechanical circulatory support with extracorporeal membrane oxygenation (ECMO) and no surgical revascularization, and from August 1997 through June 1999, 12 patients underwent emergency surgical revascularization. The patient characteristics and in-hospital mortality were compared between groups.

RESULTS

Ten patients were treated after acute infarction and nine were treated after cardiac intervention. No significant differences were found between the two groups in age, sex, hypertension, diabetes, smoking, and previous infarction. The in-hospital mortality rates were 100% in patients receiving mechanical circulatory support with ECMO and 25% in patients who underwent emergency surgical revascularization (p = 0.003). In the emergency revascularization group, four of 12 patients had surgical revascularization more than 18 hours after AMI and the in-hospital mortality rate was 25%.

CONCLUSION

Surgical revascularization improved survival in patients with cardiogenic shock and failed PTCA.

The dilemma of "to-be or not-to-be": needs and expectations of the Taiwanese cadaveric organ donor families during the pre-donation transition

There has been little study of the Chinese cadaveric donor family's decisions to donate organs within the Chinese cultural framework. A convenience sample of 25 cadaveric donor family members (12 men, 13 women) who gave their consent to donation at National Taiwan University Hospital agreed to participate in this study and completed in-depth interviews. Data were analyzed by a three-steps within-method qualitative triangulation method. The factors influencing the donor family's decisions to donate organs, the needs of donor families, and their expectations of health care providers during the pre-donation transition--the critical period of time between signing a donation and consent to organ harvesting--were examined. The background context and a conceptual framework were further developed to discuss and depict this phenomenon. This project aims to broaden the horizon on organ donation and contribute to the understanding of some of the psychodynamic issues in the Chinese family in Taiwan.

Lamivudine treatment for hepatitis B reactivation in HBsAg carriers after organ transplantation: a 4-year experience

BACKGROUND

Reactivation of hepatitis B after organ transplantation in hepatitis B surface antigen (HBsAg) carriers may be fatal. In this study, we reported our experience of lamivudine treatment in HBsAg carriers who had post-transplant reactivation of hepatitis B.

METHODS

The patients were 15 men and one woman. Nine received kidney transplants, six received heart transplants, and one received a lung transplant. They developed a reactivation of hepatitis B 1-101 months (median, 14 months) after transplantation. They received lamivudine 100 mg daily on a compassionate-use basis, and had regular follow ups. The median pretreatment total serum bilirubin level was 3.0 mg/dL, and the alanine aminotransferase level was 357 U/L. Four of the 16 patients were positive for HBeAg. The serum hepatitis B virus (HBV) DNA levels were > 3000 pg/mL in 13 (81%) patients. Three were coinfected with hepatitis C virus.

RESULTS

The overall survival rate was 75%. All four fatal cases had a pretreatment total serum bilirubin level of > or = 3 mg/dL. Serum HBV-DNA soon became undetectable in 12 survivors. Of the 12 survivors, after a median treatment period of 101 weeks, a lamivudine-resistant strain with variation in the YMDD motif of the HBV polymerase gene developed in three (25%). None had significant adverse reactions to lamivudine treatment.

CONCLUSIONS

These results indicated that lamivudine is effective in the treatment of post-transplant hepatitis B reactivation, including patients with dual chronic hepatitis B and C. Early recognition of HBV reactivation and prompt lamivudine treatment are important to prevent mortality.

Hepatitis B virus infection in heart transplant recipients in a hepatitis B endemic area

BACKGROUND

Hepatitis B virus (HBV) infection is hyperendemic in Taiwan. It is almost impossible for us to reject organ donors or recipients with positive serum hepatitis B surface antigen (HBsAg). We report our experience with HBV infection in heart transplant recipients with particular attention to outcome of recipients who were HBsAg+ or who had received donor hearts from HBsAg+ donors.

METHODS

We performed a retrospective review of medical records.

RESULTS

In the study, we included 101 heart recipients with post-transplant survival of more than 6 months. According to pre-transplant HBV serology markers, we divided patients into 4 groups. Group 1 (n = 8) had been HBsAg+ at the time of heart transplantation. Of these, 6 patients had HBV reactivation in the post-transplant follow-up and needed lamivudine treatment. Complete response was achieved in all 6 patients; however, HBV recurrence occurred in 1 patient after 8 months of lamivudine treatment. The recurrence remained under partial control. Group 2 (n = 16) was HBV naïve at the time of heart transplantation. Of these, 2 received HBsAg+ donor hearts under perioperative hepatitis B immunoglobulin prophylaxis. HBV infection was successfully prevented in 1 patient, but the other contracted HBV hepatitis, which was successfully treated with lamivudine. In Group 2, 10 patients received donor hearts from anti-HBs+ donors, and none contracted HBV hepatitis after transplantation. Group 3 (n = 55) had protective anti-HBs antibody at the time of heart transplantation either from previous HBV vaccination (n = 10) or from natural HGB infection (n = 45). HBsAg+ donor hearts were transplanted into 2 patients with anti-HBs from previous HBV vaccination, and into 8 patients with anti-HBs form natural HBV infection. However, none of these 10 patients who received HBsAg+ donor hearts had HBV hepatitis after transplantation. Group 4 (n = 22) was HBs-, anti-HBs-, and anti-HBc+ at the time of heart transplantation. Of these, 7 patients received HBsAg+ donor hearts. Six patients experienced no HBV hepatitis after heart transplantation, and serum HBV DNA by polymerase chain reaction (PCR) at the time of heart transplantation was negative in all 6 patients. One patient had HBV hepatitis after transplantation, and serum HBV DNA by PCR at the time of heart transplantation also was positive.

CONCLUSION

HBV reactivation after the heart transplantation was common but usually well controlled with lamivudine treatment. Therefore, HBV carrier status should not contraindicate heart transplantation. HBsAg+ donor hearts were safely transplanted into anti-HBs+ recipients; therefore, HBsAg+ itself was not a contraindication to heart donation. Patients with HBsAg-, anti-HBs-, anti-HBc+, and negative HBV DNA in the serum by PCR could be protected from HBV infection from HBsAg+ donor hearts. However, patients with HBsAg-, anti-HBs-, anti-HBc+, and positive HBV DNA in the serum by PCR should be recognized as HBV carriers and closely followed for potential HBV flare-up after heart transplantation.

Mechanical bridge with extracorporeal membrane oxygenation and ventricular assist device to heart transplantation

The aim of this study was to evaluate the effect of double bridges with extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VADs) in clinical heart transplantation. Between May 1994 and October 2000, 134 patients underwent heart transplantation at the National Taiwan University Hospital. Ten patients received ECMO or VAD support as bridges to transplantation. The ages ranged from 3 to 63 years. The indications included cardiac arrest under cardiopulmonary resuscitation in 2 and profound cardiogenic shock refractory to conventional therapy in 8 patients. Usually ECMO was first set up as rescue therapy. If ECMO could not be weaned off after short-term (usually 1 week) support, suitable VADs (HeartMate or Thoratec VAD) were implanted for medium-term or long-term support. Five patients received ECMO support as emergency rescue for 2 to 9 days, and then moved to Thoratec VAD for 8, 49, and 55 days, respectively, or centrifugal VAD for 31 days, or HeartMate VAD for 224 days. They all survived. The survival rate of double bridges with ECMO and VAD was 100%. In postcardiotomy cardiogenic shock, circulatory collapse from acute myocardial infarction or myocarditis, ECMO is the device of choice for short-term support. If heart transplantation is indicated, VADs should replace ECMO for their superiority as a bridge to heart transplantation. Our preliminary data of double bridges with ECMO and VAD revealed good results and were reliable and effective bridges to transplantation.

Conversion of extracorporeal membrane oxygenation to non-pulsatile left ventricular assist device. Is it out-of-date for non-pulsatile LVAD?

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) provides an immediate support for acute deterioration of hemodynamic and pulmonary status, but what is the best decision for these critical patients? Biventricular assist device (BVAD) or left ventricular assist device (LVAD)? We proposed a protocol of step-by-step conversion from ECMO to LVAD after assurance of the reversibility of right ventricle and pulmonary function.

METHODS

After femoral venoarterial ECMO was inserted for the critical patients, the left atrial drainage was added to the ECMO firstly and the femoral arterial inflow was shifted to the ascending aorta for preventing possible peripheral vascular complications. Temporary clamp of right heart drainage was tried to test right heart function 24 to 48 hours later. The sweep gas flow of oxygenator could be reduced gradually to test the pulmonary function. Therefore, the right heart drain and the oxygenator could be withdrawn to become a non-pulsatile LVAD or shift to pneumatic LVAD directly. There were four clinical experiences with successful conversion without temporary right ventricular assist device.

RESULTS

All of them were able to convert their ECMO to LVAD smoothly in 8.0+/-2.5 days. Three of them were shifted to non-pulsatile LVAD, and one was converted to HeartMate. All but one could be weaned from the ventilator. No BVAD was needed in these patients. Due to the shortage of donor hearts, only one had the chance to undergo heart transplantation.

CONCLUSIONS

The protocol did provide a good guideline for decision-making for those under ECMO support necessitating bridge to transplantation.

Development of a totally implantable pulsatile centrifugal pump as a ventricular assist device

The Taita No. 1 ventricular assist device (T-VAD) is a totally implantable pulsatile impeller centrifugal pump driven by a magnetically suspended motor. The flow can achieve 2.01 +/- 0.17 L/min against a pressure of 100 mm Hg under 0.266 +/- 0.017 amp and 13.55 +/- 0.41 voltage. The speed was around 3,500 rpm. It consumed less than 6 W of power, resulting in less heat production and mechanical bearing complications. The impeller vane was designed to have both radial and axial curves according to the stream surface and stream lines to reduce thrombosis and hemolysis. Eight calves weighing 80 to 100 kg (mean 87 +/- 12 kg) were used for experiments. With the calves under general anesthesia, left posterolateral thoracotomy was performed to connect the inflow tube with the atrial appendage and to anastomose the outflow tube with the descending aorta. The calves usually awoke and stood up within hours after discontinuation of anesthetics. The mean survival of the calves was 75 +/- 42 days (range 33-148 days). The terminations of experiments were mainly due to infection. During the course of pumping, no significant deterioration of liver or renal function was noted. The evaluation of serum samples from the implanted calves indicated that hemolysis was not associated with use of the T-VAD. The average daily free hemoglobin level was 8.08 +/- 3.05 mg/dl, which was less than the set limit of 20 mg/dl. The red blood cell and platelet count and hemoglobin of implanted animals were within the normal range. In our results, the T-VAD provided competent pulsatile function without severe blood damage or organ dysfunction.

Physiologic analysis of cardiac cycle in an implantable impeller centrifugal left ventricular assist device

The purpose of this study was to determine the physiologic relationship between the cardiac cycle and the nonpulsatile impeller centrifugal Taita No.1 left ventricular assist device (T-LVAD) in a chronic animal study. The relationship of the cardiac cycle, pump flow, aortic pressure, left ventricle pressure, and pump power were analyzed by 5 phases in 4 stages. The isovolumetric ventricular phase is from mitral valve closure (MVC) to aortic valve opening (AVO) and is called Stage 1. The ejection phase is from AVO to aortic valve closure (AVC) and is called Stage 2. The isovolumetric relaxation phase is from AVC to MVC and is called Stage 3. The passive filling and atrial contraction phase is from MVC to mitral valve opening (MVO) and called Stage 4. Based on evidence from the physiologic volume change of the left ventricle, the change of pump flow of the T-LVAD in a cardiac cycle by variable voltages of pump control was evaluated using animal models. After left posteriolateral thoracotomy via the fifth intercostal space under general anesthesia, the nonpulsatile centrifugal T-LVAD was implanted into 2 healthy calves. The inflow of the T-LVAD was inserted into the left ventricle through the mitral valve via the left atrial appendage. The arterial blood pressure waveform was measured and recorded on the outflow of the T-LVAD. The 4 phases of a cardiac cycle were defined as MVC-AVO (Stage 1), AVO-AVC (Stage 2), AVC-MVO (Stage 3) and MVC-MVO (Stage 4) according to the outflow pressure of the outflow of the T-LVAD and differential pressure between the outflow and inflow of the T-LVAD. We carried out the real-time waveform measurement for electrocardiogram, the outflow pressure, the T-LVAD flow and the speed, as well as open loop and constant voltage (V). In a cardiac cycle, the sensing current of the T-LVAD was inverse to the speed. The flow of the T-LVAD at the 4 stages was measured individually and analyzed with different control voltages from 10 to 18 V. The highest flow ratio of MVC-AVC/AVC-MVC was noted when the T-LVAD worked on 14 V. By using analysis methodology of the flow ratio of a cardiac cycle, the optimal physiologically effective control of the T-LVAD might be achieved.

Application of extracorporeal membrane oxygenation in adult burn patients

Adult respiratory distress syndrome (ARDS) has been the major cause of mortality in burn injury. The authors reported the experience of using extracorporeal membrane oxygenation (ECMO) to treat adult burn patient with ARDS. Three patients with burn or electric injury, around 48.9% of body surface area over second-degree burns, developed ARDS after resuscitation. All had positive blood culture and depended on a ventilator more than 5 days before ECMO. Venovenous (VV) ECMO was started at the beginning of severe respiratory failure with an oxygen index of 61.6 +/- 15.5 cm H2O/mm Hg (> or =40 cm H2O/mm Hg), partial arterial oxygen tension to inspired oxygen fraction (Pa(O2)/Fi(O2)) of 46.1 +/- 7.0 mm Hg (< or =200 mm Hg), positive end expiratory pressure (PEEP) of 15.7 +/- 1.6 cm H2O (> or =10 cm H2O), alveolar-arterial difference in oxygen concentration (A-a D(O2)) of 618.9 +/- 19.3 mm Hg (> or =300 mm Hg), and lung compliance of 17.3 +/- 4.6 ml/cm H2O (< or =30 ml/cm H2O). The VV type had to be converted to the newly designed veno-venoarterial (V-VA) ECMO due to the myocardial dysfunction. Two of three patients survived. The duration of ECMO was 160.2 +/- 51.1 h. Two patients received debridement of escar during ECMO support and desmopressin infusion, and no increased bleeding or coagulopathy was found. The respiratory parameters were significantly improved after ECMO, especially in the survivors. ECMO is also suitable for ARDS in adult burn injury.

Growth of endothelial cells on different concentrations of Gly-Arg-Gly-Asp photochemically grafted in polyethylene glycol modified polyurethane

To improve endothelial cell adhesion and growth on the surface of polyethylene glycol modified polyurethane (PU-PEG), cell adhesive peptide Gly-Arg-Gly-Asp (GRGD) was photochemically grafted to the surface. The surface grafted GRGD-N-Succinimidyl-6-[4'-azido-2'-nitrophenylamino]hexanoate (SANPAH) on a PU-PEG surface was performed by adsorption and subsequent ultraviolet irradiation. Fourier transform infrared spectra (FTIR) and electron spectroscopy for chemical analysis (ESCA) confirmed the GRGD grafted to form a PU-PEG-GRGD surface. The composition fraction of nitrogen calculated from ESCA analysis for the PU-PEG-GRGD surface was well correlated with the concentration of GRGD to be immobilized. Human umbilical vein endothelial cells (ECs) were well adhered and growing on the PU-PEG-GRGD surface. Moreover, the viability of ECs growing on PU-PEG-GRGD surfaces, analyzed by MTT test, was also well correlated with the GRGD concentrations immobilized on the surface. With photochemical techniques, we could manipulate different contents of GRGD to form multiple regions of PU-PEG-GRGD surface that could enhance the growth of ECs on the surface, and the enhancement efficiency was well correlated with GRGD contents.

Preliminary result of an algorithm to select proper ventricular assist devices for high-risk patients with extracorporeal membrane oxygenation support

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is not suitable for long-term support because of its high incidence of complications. Conversion from ECMO to ventricular assist device (VAD) is reasonable, and we have developed a simple algorithm for selecting proper VADs for these ECMO-supported patients.

METHODS

We converted 12 patients who were receiving ECMO support to VAD for bridge to transplantation. Group I (n = 6) was converted directly from ECMO to VAD. Group II (n = 6) underwent stage conversion. We added left atrial drainage to ECMO because of lung edema or marked left heart distension. We discontinued drainage after recovery of right heart function. Group II had more unfavorable risk factors for VAD before ECMO.

RESULTS

Three patients (50%) in Group I received biventricular VADs. The other 3 patients were converted to left ventricular assist device (LVAD), but only 1 (16.7%) experienced successful conversion. We successfully converted 5 patients (83.3%) in Group II to LVAD without right VAD, and 4 of them could be weaned from the ventilator. The multiple-organ dysfunction score gradually improved in Group II despite additional surgery. Two patients in each group received heart transplantation and survived long term.

CONCLUSION

Using a conversion protocol provides a good guideline for making decisions. According to the protocol, right heart and pulmonary function can be clearly assured before shifting to LVAD in these critical ECMO-supported patients.

Successful resuscitation of acute massive pulmonary embolism with extracorporeal membrane oxygenation and open embolectomy

Acute massive pulmonary embolism is usually fatal if not treated aggressively, but the management is not standardized. Open pulmonary embolectomy retains a role in the treatment of this disastrous disease. Extracorporeal membrane oxygenation has been used for cardiopulmonary support in some patients with life-threatening pulmonary embolism. This article details our experience of a 58-year-old woman suffering from acute cardiopulmonary collapse caused by massive pulmonary embolism. Under extracorporeal membrane oxygenation support, the patient received pulmonary angiography and underwent open embolectomy for a definitive treatment.

Heart transplantation and the Batista operation for children with refractory heart failure

Medically refractory heart failure may be present in children with cardiomyopathy (CMP) or complex congenital heart disease (CHD). In adults, the surgical management of this condition is either heart transplantation or the Batista operation. From March 1995 to January 2000, a total of 6 children, aged from 1 to 16 years, with medically refractory heart failure associated with CMP or complex CHD underwent cardiac transplantation and one of them also had the Batista operation as a bridge to transplantation. One of the 6 patients died of intractable sepsis 17 days after the operation, but the other 5 were discharged with satisfactory hemodynamics. Immunosuppressive agents, including azathioprine, cyclosporin or FK-506, were given. One patient experienced moderate acute rejection, but it was controlled by FK-506, OKT-3 and solumedrol. However, another suffered from lymphoproliferative disease 8 months after transplant, but it was controlled by intravenous immunoglubulin, alpha-interferon and acyclovir. Cardiac function during serial follow-up (range, 1 month to 5 years) revealed normal systolic and diastolic function and none received any anticongestive medications. Almost all patients received an oversized donor heart. The left ventricle (LV) mass was remodeled, initially as an decrease and later as an increase. The patient who underwent the Batista operation was discharged 1 month after the operation with an increased LV ejection fraction (from 10% to 22%). She was successfully bridged to heart transplantation 7 months after the Batista operation. The results of cardiac transplantation in growing children are satisfactory and remain the mainstay of surgical treatment for medically refractory heart failure in these patients. However, with a shortage of donor hearts, the Batista operation may be adopted as a bridge to heart transplant with a fair response.