Spray nozzle for topical anaesthesia during flexible bronchoscopy: a randomised controlled trial

Background

The effectiveness of using a spray nozzle to deliver lidocaine for superior topical airway anaesthesia during non-sedation flexible bronchoscopy (FB) remains a topic of uncertainty when compared with conventional methods.

Methods

Patients referred for FB were randomly assigned to receive topical lidocaine anaesthesia via the bronchoscope's working channel (classical spray (CS) group) or through a washing pipe equipped with a spray nozzle (SN group). The primary outcome was cough rate, defined as the total number of coughs per minute. Secondary outcomes included subjective perceptions of both the patient and operator regarding the FB process. These perceptions were rated on a visual analogue scale, with numerical ratings ranging from 0 to 10.

Results

Our study enrolled a total of 126 (61 CS group; 65 SN group) patients. The SN group exhibited a significantly lower median cough rate compared with the CS group (4.5 versus 7.1 counts·min-1; p=0.021). Patients in the SN group also reported less oropharyngeal discomfort (4.5±2.7 versus 5.6±2.9; p=0.039), better tolerance of the procedure (6.8±2.2 versus 5.7±2.7; p=0.011) and a greater willingness to undergo a repeat FB procedure (7.2±2.7 versus 5.8±3.4; p=0.015) compared with those in the CS group. From the operator's perspective, patient discomfort (2.7±1.7 versus 3.4±2.3; p=0.040) and cough scores (2.3±1.5 versus 3.2±2.4; p=0.013) were lower in the SN group compared with the CS group, with less disruption due to coughing observed among those in the SN group (1.6±1.4 versus 2.3±2.3; p=0.029).

Conclusions

This study illustrates that employing a spray nozzle for the delivery of lidocaine provides superior topical airway anaesthesia during non-sedation FB compared with the traditional method.

Upfront liquid next-generation sequencing in treatment-naïve advanced non-small cell lung cancer patients: A prospective randomised study in the Taiwanese health system

BACKGROUND

Next-generation sequencing (NGS) of plasma cell-free DNA identifies driver mutations in advanced non-small cell lung cancer (NSCLC) and may complement routine molecular evaluation. The utility of liquid NGS at the start of tumour workup is undetermined.

METHODS

This is a randomised study of patients with suspected advanced NSCLC. All patients received blood liquid NGS testing at their first clinic visit and underwent standard histological diagnosis and tissue genotyping, encompassing polymerase chain reaction based methods for EGFR mutation, immunohistochemical (IHC) staining for ALK fusion and BRAF V600E mutation, and an IHC screening followed by confirmation using fluorescence in situ hybridization confirmation for ROS1 fusion. They were then randomly assigned to receive NGS results either after tissue genotyping (Group A) or as soon as possible after histological diagnosis of advanced NSCLC (Group B). The study measured time to start of systemic treatment as the primary endpoint and secondary endpoints included biomarker discovery rate, objective response rate (ORR), and progression-free survival (PFS).

RESULTS

This study enroled 180 patients with suspected advanced NSCLC, randomised into two groups. 63 patients in Group A and 59 in Group B with advanced NSCLC were confirmed as advanced NSCLC and analysed. Most had adenocarcinoma (Group A: 77.8%, Group B: 79.7%). The prevalence of EGFR mutations in the two groups was similar (Group A: 57.1%; Group B: 56.6%). Other driver alterations were rare. The median time to treatment was shorter in Group B (20 days) than in Group A (28 days). ORR and PFS did not differ between groups significantly. Liquid NGS had high concordance with tissue testing and identified driver mutations in 42.6% (20/47) of tissue-negative cases.

CONCLUSION

Performing liquid NGS at the initial clinic visit for suspected advanced NSCLC identifies more patients suitable for targeted therapies and shortens time to the start of treatment.

Effects of Early Short-Course Corticosteroids on Immune-Related Adverse Events in Non-Small Cell Lung Cancer Patients Receiving Immune Checkpoint Inhibitors

INTRODUCTION

In real-world practice, most non-small cell lung cancer (NSCLC) patients receiving combined immunochemotherapy are exposed to short-course corticosteroids following immune checkpoint inhibitor (ICI) infusion to prevent chemotherapy-related adverse events. However, whether this early short-course corticosteroid use prevents immune-related adverse events (irAEs) remains unknown.

METHODS

Between January 1st, 2015, and December 31st, 2020, NSCLC patients who received at least one cycle of ICI with or without chemotherapy were enrolled. Early short-course corticosteroids were defined as corticosteroids administered following ICI injection and before chemotherapy on the same day and no longer than 3 days afterward. The patients were categorized as either "corticosteroid group" or "non-corticosteroid group" depending on their exposure to early short-course corticosteroid. The frequencies of irAEs requiring systemic corticosteroid use and irAEs leading to ICI discontinuation were compared between the two groups, and exploratory survival analyses were performed.

RESULTS

Among 252 eligible patients, 137 patients were categorized as "corticosteroid group" and 115 patients as "non-corticosteroid group." The corticosteroid group enriched patients in the first-line setting (n = 75, 54.7%), compared to the non-corticosteroid group (n = 28, 24.3%). Thirty patients (21.9%) in the corticosteroid group and 35 patients (30.4%) in the non-corticosteroid group developed irAEs requiring systemic corticosteroid use (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.35-1.18; p = 0.15). Eight patients (5.8%) in the corticosteroid group, as compared with 18 patients (15.7%) in the non-corticosteroid group, permanently discontinued ICI due to irAEs (OR, 0.34; 95% CI, 0.12-0.85; p = 0.013).

CONCLUSION

Early short-course corticosteroids following each ICI injection may reduce the rate of irAEs that lead to ICIs discontinuation, warranting further investigation of its prophylactic use to mitigate clinically significant irAEs.

Behçet's disease-induced massive small intestinal bleeding successfully treated with adalimumab

We herein report a case of Behçet's disease in a 27-year-old female who suffered from generalized skin rashes for one week. After hospitalization, massive bloody stools accompanying hypovolemic shock occurred. Emergency abdominal computed tomography-angiography failed to detect the bleeding source. Esophagogastroduodenoscopy also demonstrated no definite bleeding points. Ileocolonoscopy showed multiple large and deep ulcers with some blood coating and mild oozing in the terminal ileum. We initially performed epinephrine injection and hemoclips for her intestinal bleeding. However, massive bloody stools still continued. Thus, we prescribed a loading dose of 160 mg adalimumab followed by weekly 80 mg adalimumab subcutaneous injections to the patient. Following this treatment, her gastrointestinal bleeding gradually subsided and completely stopped within a few days. After three-week therapy with adalimumab, capsule endoscopy showed several healing ulcers without bleeding in the distal to the terminal ileum. She continues to be treated with adalimumab, azathioprine, and mesalazine without recurrent bleeding.

MiR-503 pleiotropically regulates epithelial-mesenchymal transition and targets PTK7 to control lung cancer metastasis

OBJECTIVE

In lung cancer patients, most deaths are caused by the distant dissemination of cancer cells. Epithelial-mesenchymal transition (EMT) and collective cell migration are distinct and important mechanisms involved in cancer invasion and metastasis. Additionally, microRNA dysregulation contributes significantly to cancer progression. In this study, we aimed to explore the function of miR-503 in cancer metastasis.

METHODS

Molecular manipulations (silencing or overexpression) were performed to investigate the biological functions of miR-503 including migration and invasion. Reorganization of cytoskeleton was assessed using immunofluorescence and the relationship between miR-503 and downstream protein tyrosine kinase 7 (PTK7) was assessed using quantitative real-time PCR, immunoblotting, and reporter assays. The tail vein metastatic animal experiments were performed.

RESULTS

Herein, we demonstrated that the downregulation of miR-503 confers an invasive phenotype in lung cancer cells and provided in vivo evidence that miR-503 significantly inhibits metastasis. We found that miR-503 inversely regulates EMT, identified PTK7 as a novel miR-503 target, and showed the functional effects of miR-503 on cell migration and invasion were restored upon reconstitution of PTK7 expression. As PTK7 is a Wnt/planar cell polarity protein crucial for collective cell movement, these results implicated miR-503 in both EMT and collective migration. However, the expression of PTK7 did not influence EMT induction, suggesting that miR-503 regulates EMT through mechanisms other than PTK7 inhibition. Furthermore, we discovered that PTK7 mechanistically activates focal adhesion kinase (FAK) and paxillin, thereby controlling the reorganization of the cortical actin cytoskeleton.

CONCLUSION

Collectively, miR-503 is capable of governing EMT and PTK7/FAK signaling independently to control the invasion and dissemination of lung cancer cells, indicating that miR-503 represents a pleiotropic regulator of cancer metastasis and hence a potential therapeutic target for lung cancer.

Monitoring of T790M in plasma ctDNA of advanced EGFR-mutant NSCLC patients on first- or second-generation tyrosine kinase inhibitors

BACKGROUND

The T790M mutation is the major resistance mechanism to first- and second-generation TKIs in EGFR-mutant NSCLC. This study aimed to investigate the utility of droplet digital PCR (ddPCR) for detection of T790M in plasma circulating tumor DNA (ctDNA), and explore its impact on prognosis.

METHODS

This prospective study enrolled 80 advanced lung adenocarcinoma patients treated with gefitinib, erlotinib, or afatinib for TKI-sensitizing mutations between 2015 and 2019. Plasma samples were collected before TKI therapy and at tri-monthly intervals thereafter. Genotyping of ctDNA for T790M was performed using a ddPCR EGFR Mutation Assay. Patients were followed up until the date of death or to the end of 2021.

RESULTS

Seventy-five of 80 patients experienced progressive disease. Fifty-three (71%) of 75 patients underwent rebiopsy, and T790M mutation was identified in 53% (28/53) of samples. Meanwhile, plasma ddPCR detected T790M mutation in 23 (43%) of 53 patients. The concordance rate of T790M between ddPCR and rebiopsy was 76%, and ddPCR identified 4 additional T790M-positive patients. Ten (45%) of 22 patients who did not receive rebiopsy tested positive for T790M by ddPCR. Serial ddPCR analysis showed the time interval from detection of plasma T790M to objective progression was 1.1 (0-4.1) months. Compared to 28 patients with rebiopsy showing T790M, the overall survival of 14 patients with T790M detected solely by ddPCR was shorter(41.3 [95% CI, 36.6-46.0] vs. 26.6 months [95% CI, 9.9-43.3], respectively).

CONCLUSION

Plasma ddPCR-based genotyping is a useful technology for detection and monitoring of the key actionable genomic alteration, namely, T790M, in patients treated with gefitinib, erlotinib, or afatinib for activating mutations, to achieve better patient care and outcome.

Real-world treatment patterns and outcomes among patients with advanced non-small-cell lung cancer with spindle cell and/or giant cell carcinoma

Objectives

A definitive diagnosis of pulmonary sarcomatoid carcinoma cannot be made with small biopsies. In clinical practice, a diagnosis of advanced non-small-cell lung cancer with spindle cell and/or giant cell carcinoma (NSCLCsg), or possible sarcomatoid carcinoma, is acceptable. Therefore, we aimed to investigate the treatment patterns and outcomes of advanced NSCLCsg.

Materials and methods

Between 01 January 2012 and 01 April 2021, patients with pathologically proven advanced NSCLCsg were enrolled. The choice of treatment was based on clinician discretion.

Results

In all, 101 patients with advanced NSCLCsg were enrolled. In total, 77 (76.2%) patients received at least one line of systemic therapy; 44 patients (43.1%) had received platinum doublet chemotherapy; 27 (26.7%) patients had been treated with targeted therapies; and 23 patients (22.8%) had been given an immune checkpoint inhibitor (ICI). The median overall survival (OS) was 6.3 months [95% confidence interval (CI): 3.6-9.0 months]. Excluding patients without systemic therapy, patients who had received an ICI had better OS (median: 18.2 months) than those who had not (median 3.8 months, log-rank test p = 0.002). No significant difference in OS was detected between patients who had or had not received platinum doublet chemotherapy (log-rank test p = 0.279), or targeted therapy (log-rank test p = 0.416). Having received any systemic therapy [hazard ratio (HR): 0.33, 95% CI: 0.18-0.61, p < 0.0001) and ICI (HR: 0.38, 95% CI: 0.19-0.78, p = 0.008) were independent factors for better OS. Patients with programmed death ligand-1 (PD-L1) expression ⩾50% had better OS than those with PD-L1 expression <50% (HR: 0.51, 95%: 0.30-0.86, p = 0.012).

Conclusion

Although advanced NSCLCsg has a poor survival outcome, our results showed that ICI may prolong OS in patients with advanced NSCLCsg. Further prospective studies are warranted to gain more understanding of the role of ICI in this specific patient population.

Serial Plasma Cell-Free Circulating Tumor DNA Tests Identify Genomic Alterations for Early Prediction of Osimertinib Treatment Outcome in EGFR T790M-Positive NSCLC

Introduction

Recent advances in the detection of genomic DNA from plasma samples allow us to follow tumor DNA shedding in plasma during systemic treatment. Osimertinib is the standard of care for patients with NSCLC with acquired EGFR T790M mutations. We assessed changes in serial plasma cell-free circulating tumor DNA (ctDNA) genomic alterations to predict osimertinib efficacy.

Methods

We prospectively collected plasma from patients having EGFR-mutated advanced NSCLC previously treated with EGFR tyrosine kinase inhibitor therapy and with acquired EGFR T790M mutation detected by standard methods. Plasma samples were collected before starting osimertinib treatment, 4 weeks after osimertinib treatment, and on progression. ctDNA was analyzed using the Guardant360 assay.

Results

A total of 15 eligible patients received osimertinib. Before starting treatment, EGFR-activating mutations were detected in the ctDNA of all patients, and EGFR T790M was detected in 93% of the cases. Osimertinib treatment was associated with an objective response rate of 53% and a median progression-free survival of 7.3 months. A total of 12 of the 15 patients had undetectable plasma T790M and decreased activating mutation allelic frequency (AF) at week 4. None of the 12 patients had disease progression within 16 weeks. For the remaining three patients, with detectable plasma T790M (n = 2) or increased activating mutation AF (n = 1) at week 4, two had progressive disease within 16 weeks (p = 0.03).

Conclusions

In patients with EGFR-mutated advanced NSCLC, persistent EGFR T790M or increasing activating mutation AF as detected in ctDNA 4 weeks after the start of osimertinib treatment may predict disease progression within 16 weeks.

Monitoring levels of vimentin-positive circulating cancer stem cells and tumor cells in patients with advanced EGFR-mutated non-small cell lung cancer

OBJECTIVES

Circulating tumor cells (CTCs) are associated with tumor spread, whereas cancer stem cells may be related to drug resistance. However, few studies have analyzed the levels of circulating cancer stem cells (CCSCs) and CTCs in patients with advanced non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Treatment-naïve patients with EGFR-mutated NSCLC who received epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy were recruited prospectively. The cell surface vimentin antibody was used for CTC detection and CD133 antibody for CCSC detection. CCSC and CTC levels were measured as cell count per 4 mL of blood, before treatment, after 2 and 12 weeks of treatment, and at disease progression. Data on clinical characteristics and outcomes were also collected.

RESULTS

At diagnosis (n = 29), the median CCSC and CTC levels were 0 (interquartile range, 0-2) and 3 (2-9), respectively. After 12 weeks, the CCSC and CTC levels were lower than those at diagnosis (CCSC: 0 (0-0), p = 0.14; CTC: 1 (0-4), p = 0.048). At disease progression, the median CCSC and CTC levels were 0 (0-1) and 1 (0-2), respectively. Patients with higher CCSC and CTC levels at diagnosis had a numerically shorter progression-free survival.

CONCLUSION

In patients with EGFR-mutated NSCLC, CCSC and CTC levels became lower after 12 weeks of EGFR-TKI therapy and remained low at disease progression. High pre-treatment CCSC and CTC levels may be associated with a trend towards poor treatment outcomes.

miR-146b-5p Enhances the Sensitivity of NSCLC to EGFR Tyrosine Kinase Inhibitors by Regulating the IRAK1/NF-κB Pathway

Although patients with non-small cell lung cancer harboring activating mutations in the epidermal growth factor receptor (EGFR) show good clinical response to EGFR tyrosine kinase inhibitors (TKIs), patients eventually develop acquired resistance. Previous studies have shown that several microRNAs (miRNAs) are involved in EGFR TKI resistance. Here, we aimed to investigate whether miR-146b-5p sensitizes the EGFR TKI-resistant lung cancer cells. Clinical analysis showed that miR-146b-5p expression in lung cancer cells isolated from pleural effusions of treatment-naive patients was significantly higher than that after acquiring resistance to EGFR TKI treatment. Ectopic expression of miR-146b-5p in EGFR TKI-resistant cells enhanced EGFR TKI-induced apoptosis. The same results were observed in EGFR-dependent and -independent osimertinib-resistant primary cancer cells (PE3479 and PE2988). Mechanically, miR-146b-5p suppressed nuclear factor κB (NF-κB) activity and NF-κB-related IL-6 and IL-8 production by targeting IRAK1. A negative correlation was observed between miR-146b-5p and IRAK1 in clinical specimens. In rescue experiments, restoration of IRAK1 expression reversed the effects of miR-146b-5p on EGFR TKI sensitivity and recovered NF-κB-regulated IL-6 and IL-8 production. In conclusion, miR-146b-5p/IRAK1/NF-κB signaling is important in promoting EGFR TKI resistance, and miR-146b-5p may be a useful tool for overcoming EGFR TKI resistance.

Association of Programmed Death-Ligand 1 Expression with Fusion Variants and Clinical Outcomes in Patients with Anaplastic Lymphoma Kinase-Positive Lung Adenocarcinoma Receiving Crizotinib

BACKGROUND

Programmed death-ligand 1 (PD-L1) expression is associated with clinical outcomes of epidermal growth factor receptor (EGFR) mutant lung adenocarcinoma (ADC) treated with tyrosine kinase inhibitors (TKIs). However, whether PD-L1 expression plays a role in anaplastic lymphoma kinase (ALK)-positive lung ADC is unknown. We aimed to evaluate the impact of PD-L1 in patients with ALK-positive lung ADC receiving crizotinib.

MATERIALS AND METHODS

PD-L1 expression was identified by immunohistochemistry (IHC). Reverse transcriptase-polymerase chain reaction was used for ALK variant detection, and immunofluorescence-based multiplex staining was applied for exploring immune cells in tumor microenvironments.

RESULTS

A total of 78 patients with ALK-positive advanced ADC were enrolled in our study, of whom 52 received crizotinib. Compared with EGFR/ALK wild-type tumors, PD-L1 expression was lower in ALK-positive ADC. ALK fusion variants were identified in 32 patients, and those with variant 3 and 5 (short variants) had higher PD-L1 expression than those with other variants. The crizotinib objective response rate (ORR) and progression-free survival (PFS) was better in tumors with negative PD-L1 expression (ORR/PFS in PD-L1 0% vs. 1%-49% vs. 50%-100%: 60.7%/11.8 months vs. 38.5%/6.5 months vs. 36.4%/4.0 months, p = .007/.022). The multivariate Cox proportional hazards model revealed that PD-L1 0% (vs. ≥1%) was an independent factor for longer PFS (adjusted hazard ratio 0.322, 95% confidence interval 0.160-0.650, p = .002). Multiplex IHC in three cases showed a varied extent of immune cell infiltrations in tumors with different PD-L1 expression.

CONCLUSION

Positive PD-L1 expression was associated with unfavorable clinical outcomes in patients with ALK-positive lung ADC receiving crizotinib.

IMPLICATIONS FOR PRACTICE

Not all lung adenocarcinoma with sensitizing driver mutations experienced durable responses to small-molecule tyrosine kinase inhibitors (TKIs). Similar to the negative impact of programmed death-ligand 1 (PD-L1) in epidermal growth factor receptor mutant tumors treated with TKIs, this study demonstrated that positive PD-L1 expression was also associated with worse response rate and shorter progression-free survival of anaplastic lymphoma kinase (ALK)-positive adenocarcinoma treated with crizotinib. Among different ALK fusion partners, tumors with short variants (V3 and V5) had higher PD-L1 compared with long variants (V1, V2, and V6). Testing PD-L1 before initiating crizotinib for ALK-positive lung cancer could be a simple method to provide important prognostic information.

Complex EGFR mutations with secondary T790M mutation confer shorter osimertinib progression-free survival and overall survival in advanced non-small cell lung cancer

OBJECTIVES

Osimertinib is active against epidermal growth factor receptor (EGFR) T790M-mutated non-small cell lung cancer (NSCLC). However, its efficacy against complex EGFR mutations with T790M has not been evaluated.

MATERIALS AND METHODS

In order to detect complex EGFR mutations, we consecutively sequenced cancer tissues by RNA reverse transcription polymerase chain reaction. Patients with advanced NSCLC with activating EGFR mutation and secondary T790M who received osimertinib were enrolled. Patients' clinicopathologic characteristics, prior treatment details, and osimertinib treatment outcomes were analyzed.

RESULTS

Totally, 165 sequenced patients were analyzed. Eleven (7%) of them had complex EGFR mutations with T790M. The osimertinib response rate was 27%. They had a shorter progression-free survival (PFS) (median, 2.9 and 9.7 months, p < 0.001) and overall survival (OS) (median, 17.8 and 31.0 months, p = 0.01) than patients with a single EGFR mutation with T790M. After osimertinib failure, seven patients received rebiopsy with molecular analysis. Four lost the T790M, two transformed to small cell and one acquired C797S. Moreover, taking the median as the demarcation, patients received shorter prior EGFR tyrosine kinase inhibitor (TKI) treatment duration had a shorter osimertinib PFS (median, 7.3 and 13.8 months, p < 0.001) and OS (median, 21.5 and 36.7 months, p = 0.003). Multivariate Cox regression analysis confirmed complex EGFR mutations and prior EGFR TKI treatment duration were independent factors for osimertinib PFS and OS.

CONCLUSIONS

Complex EGFR mutations and shorter prior EGFR TKI treatment duration may confer shorter osimertinib PFS and OS in advanced NSCLC with secondary T790M mutation.

P3115Effect of calcitriol attenuates doxorubicin-induced cardiac dysfunction in mice model: focus on endothelial-to-mesenchymal transition

Objective

Doxorubicin (DOX) is an effective anti-neoplasm drug, but the early and late cardiac toxicity limits its clinical use. The Endothelial-to-mesenchymal transition (EndMT) has been found to involve in the process of heart failure. It's unclear whether EndMT plays a role in DOX-induced cardiomyopathy (DoIC). Calcitriol is an active form Vitamin D3, which blocks the growth of cancer cells via inhibiting Smad pathway. This study investigated the cardiac protective effect of calcitriol via inhibiting of EndMT in DoIC.

Methods/Findings

C57BL/6 mice and endothelial-specific labeled mice were administered Dox twice weekly for 4 weeks [intraperitoneally (i.p.), 32 mg/kg cumulative dose]and were subsequently treated with/without calcitriol for 12 weeks. The cardiac echography revealed diastolic dysfunction at 13 weeks following the first DOX treatment and was accompanied by increased of myocardial fibrosis and up-regulated pro-fibrotic proteins.(Figure A-C) Calcitriol attenuated DOX-induced myocardial fibrosis, down-regulated pro-fibrotic proteinsand diastolic function. Endothelial fate tracing revealed that endothelium-derived cells contributed DOX-induced cardiac remodelling through EndMT and Calcitriol attenuated this process without attenuating Dox-induced cardiac myocyte and endothelial cell damage.(Figure D) In vitro, we examined if calcitriol would inhibit EndMT and fibroblast-to-myofibroblast transition (FMT) through the Smad pathway. Human umbilical vein endothelial cells (HUVECs) and mouse cardiac fibroblasts were treated with TGF-beta with or without calcitriol. Morphological, immunofluorescence staining, and western blot analyses were carried out to evaluate EndMT and FMT. Calcitriol attenuated EndMT and FMT by inhibiting the Smad2 pathway. Taken together, calcitriol didn't reduced Doxorubicin induced damage of cardiomocyte and endothelial cells. But calcitriol inhibit doxorubicin induced heart failure by attenuating cardiac fibrosis through inhibiting Smad pathway.

Conclusion

Calcitriol attenuated DOX-induced cardiomyopathy partial through inhibiting EndMT process.

Acknowledgement/Funding

CMRPG8E0661-3

Cranial Irradiation for Patients with Epidermal Growth Factor Receptor (EGFR) Mutant Lung Cancer Who Have Brain Metastases in the Era of a New Generation of EGFR Inhibitors

BACKGROUND

Immediate whole brain radiation (WBRT) has been the standard for patients with lung cancer with brain metastases. The study aims to evaluate the effect of immediate cranial irradiation in patients with epidermal growth factor receptor (EGFR) mutant lung cancer in the era of a new generation of EGFR inhibitors.

MATERIALS AND METHODS

Medical records of 198 patients with EGFR mutant non-small cell lung cancer and brain metastases at initial metastatic diagnosis were reviewed. Patients were categorized into four groups: immediate WBRT, immediate cranial stereotactic radiosurgery (SRS), delayed radiation upon progression of cranial lesions (DRT), and never cranial irradiation (NRT). Overall survival (OS) and progression-free survival related to EGFR inhibitors were analyzed.

RESULTS

The SRS group had the fewest brain metastases and fewest extracranial lesions, and the DRT and NRT groups had the smallest brain metastases. Median survival were 18.5, 55.7, 21.1, and 18.2 months for the WBRT, SRS, DRT, and NRT groups, respectively. Patients who had received EGFR T790M inhibitors survived longer (41.1 vs. 19.8 months). In multivariate analysis, the OS of patients in the SRS group was longer than that in the NRT group (adjusted hazard ratio [aHR]: 0.315). Patients who had fewer extracranial lesions and who had received EGFR T790M inhibitor treatments also survived longer (aHR: 0.442 and 0.357, respectively).

CONCLUSION

Immediate stereotactic radiosurgery but not whole brain radiation was associated with longer survival. Because of patient heterogeneity and the introduction of EGFR T790M inhibitors, the timing and modality of cranial irradiation should be determined individually, and cranial irradiation may be omitted for selected patients.

IMPLICATIONS FOR PRACTICE

Immediate whole brain radiation has been the standard for patients with lung cancer with brain metastases. In this study, it was observed that, for patients with epidermal growth factor receptor (EGFR) mutant advanced lung cancer who had brain metastases, there was no difference in survival between patients who never received cranial irradiation and those who received whole brain radiation immediately. Patients who received immediate stereotactic radiosurgery or who had ever received EGFR T790M inhibitors survived longer. Patients who received immediate stereotactic radiosurgery have fewer brain metastases. These findings suggest that the timing and modality of cranial irradiation should be determined individually, and cranial irradiation may be omitted in selected patients.

Oncogenic Function of a KIF5B-MET Fusion Variant in Non-Small Cell Lung Cancer

A kinesin family member 5b (KIF5B)-MET proto-oncogene, receptor tyrosine kinase (MET) rearrangement was reported in patients with lung adenocarcinoma but its oncogenic function was not fully evaluated. We used one-step reverse transcription-polymerase chain reaction for RNA samples to screen for the KIF5B-MET fusion in 206 lung adenocarcinoma and 28 pulmonary sarcomatoid carcinoma patients. Genomic breakpoints of KIF5B-MET were determined by targeted next-generation sequencing. Soft agar colony formation assays, proliferation assays, and a xenograft mouse model were used to investigate its oncogenic activity. In addition, specific MET inhibitors were administered to evaluate their anti-tumor activities. A KIF5B-MET fusion variant in a patient with a mixed-type adenocarcinoma and sarcomatoid tumor was identified, and another case was found in a pulmonary sarcomatoid carcinoma patient. Both cases carried the same chimeric gene, a fusion between exons 1-24 of KIF5B and exons 15-21 of MET. KIF5B-MET-overexpressing cells exhibited significantly increased proliferation and colony-forming ability. Xenograft tumors harboring the fusion gene demonstrated significantly elevated tumor growth. Ectopic expression of the fusion gene stimulated the phosphorylation of KIF5B-MET as well as downstream STAT3, AKT, and ERK1/2 signaling pathways. The MET inhibitors significantly repressed cell proliferation; phosphorylation of downstream STAT3, AKT, and ERK1/2; and xenograft tumorigenicity. In conclusion, the KIF5B-MET variant was demonstrated to have an oncogenic function in cancer cells. These findings have immediate clinical implications for the targeted therapy of subgroups of non-small cell lung cancer patients.

Tumor PD-L1 Expression and Clinical Outcomes in Advanced-stage Non-Small Cell Lung Cancer Patients Treated with Nivolumab or Pembrolizumab: Real-World Data in Taiwan

Background: Immunotherapy that targets programmed death protein-1 (PD-1) provides improved treatment efficacy and survival in patients with metastatic non-small cell lung cancer (NSCLC), especially those with high tumor expression of PD-L1. However, data on this treatment are mostly from clinical trials enrolling highly selected patients. The real-world experience of anti-PD-1 treatment and the usefulness of tumor PD-L1 expression in prediction of treatment response are largely unknown.

Methods: We retrospectively reviewed patients with stage IIIB/ IV NSCLC who received monotherapy with nivolumab or pembrolizumab, and evaluated response using RECIST 1.1 criteria. Factors associated with treatment response, progression free survival (PFS), and overall survival (OS) were determined.

Results: Seventy-four NSCLC patients out of 116 examined patients were included, most of whom had adenocarcinoma (48/74, 64.9%) and received immunotherapy as a third-line or subsequent treatment (51/74, 68.9%). The median PFS and OS were 1.8 and 7.9 months, respectively. The objective response rate was 32%, but only 47 of 74 patients were evaluable. Through multivariate analysis, epidermal growth factor receptor (EGFR) mutation was independently associated with a poor treatment response. Good performance status (ECOG≤1) and smoking were independently associated with better PFS and OS. Data on tumor PD-L1 expression were available in 43 patients (58%); higher PD-L1 expression correlated with better treatment response and longer PFS. Severe treatment-related adverse events were uncommon.

Conclusion: The efficacy and safety of anti-PD-1 medications for advanced NSCLC were comparable in real-world and clinical settings, except in those with poor ECOG scores. Prediction of treatment response from tumor PD-L1 expression seemed practical.

IL-8 confers resistance to EGFR inhibitors by inducing stem cell properties in lung cancer

Epidermal growth factor receptor (EGFR)-targeted strategy is limited by resistance. We identify the potential genes involved in EGFR TKI (tyrosine kinase inhibitor) resistance and study the therapeutic mechanism in the non-small cell lung cancers. Potential genes involved in resistance were examined by analyzing datasets from a pair of EGFR TKI-sensitive (PC9) and TKI-resistant cells (PC9/gef). Blood specimens from patients taking EGFR TKI as first-line treatment were used to examine the correlation between drug's efficacy and IL-8 level. The effects of IL-8 on gefitinib-induced apoptosis, stemness, and in vivo tumorigenicity were investigated using established cell lines. We identified IL-8 was up-regulated in gefitinib-resistant cells, and high plasma IL-8 level was correlated with shorter progression-free-survival time. IL-8 overexpression suppressed gefitinib-induced apoptosis in gefitinib-sensitive cells. By contrast, suppression of IL-8 enhanced gefitinib-induced cell death in gefitinib-resistant cells. IL-8 also increased stem-like characteristics including aldehyde dehydrogenase activity, expression of stemness-related genes, clonogenic activity, side-population, and in vivo tumorigenicity. Consistently, knockdown of IL-8 leads to loss of stem cell-like characteristics in gefitinib-resistant cells. Our study demonstrates an important role for IL-8, and suggests IL-8 is a potential therapeutic target for overcoming EGFR TKI resistance.

BMVC test, an improved fluorescence assay for detection of malignant pleural effusions

The diagnosis of malignant pleural effusions is an important issue in the management of malignancy patients. Generally, cytologic examination is a routine diagnostic technique. However, morphological interpretation of cytology is sometimes inconclusive. Here an ancillary method named BMVC test is developed for rapid detection of malignant pleural effusion to improve the diagnostic accuracy at low cost. A simple assay kit is designed to collect living cells from clinical pleural effusion and a fluorescence probe, 3,6-Bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC), is used to illuminate malignant cells. The fluorescence intensity is quantitatively analyzed by ImageJ program. This method yields digital numbers for the test results without any grey zone or ambiguities in the current cytology tests due to intra-observer and inter-observer variability. Comparing with results from double-blind cytologic examination, this simple test gives a good discrimination between malignant and benign specimens with sensitivity of 89.4% (42/47) and specificity of 93.3% (56/60) for diagnosis of malignant pleural effusion. BMVC test provides accurate results in a short time period, and the digital output could assist cytologic examination to become more objective and clear-cut. This is a convenient ancillary tool for detection of malignant pleural effusions.

Changes in the expression of the Alzheimer’s disease-associated presenilin gene in drosophila heart leads to cardiac dysfunction

Mutations in the presenilin genes cause the majority of early-onset familial Alzheimer’s disease. Recently, presenilin mutations have been identified in patients with dilated cardiomyopathy (DCM), a common cause of heart failure and the most prevalent diagnosis in cardiac transplantation patients. However, the molecular mechanisms, by which presenilin mutations lead to either AD or DCM, are not yet understood. We have employed transgenic Drosophila models and optical coherence tomography imaging technology to analyze cardiac function in live adult Drosophila. Silencing of Drosophila ortholog of presenilins (dPsn) led to significantly reduced heart rate and remarkably age-dependent increase in end-diastolic vertical dimensions. In contrast, overexpression of dPsn increased heart rate. Either overexpression or silencing of dPsn resulted in irregular heartbeat rhythms accompanied by cardiomyofibril defects and mitochondrial impairment. The calcium channel receptor activities in cardiac cells were quantitatively determined via real-time RT-PCR. Silencing of dPsn elevated dIP3R expression, and reduced dSERCA expression; overexprerssion of dPsn led to reduced dRyR expression. Moreover, overexpression of dPsn in wing disc resulted in loss of wing phenotype and reduced expression of wingless. Our data provide novel evidence that changes in presenilin level leads to cardiac dysfunction, owing to aberrant calcium channel receptor activities and disrupted Wnt signaling transduction, indicating a pathogenic role for presenilin mutations in DCM pathogenesis.

Catechin stimulates osteogenesis by enhancing PP2A activity in human mesenchymal stem cells

SUMMARY

Using human mesenchymal stem cells, we identified catechin from a panel of herbal ingredients and Chinese traditional compounds with the strongest osteogenic effects. Catechin increased alkaline phosphatase activity, calcium deposition, and mRNA expression of Runx2 and osteocalcin. We further clarified the signaling pathway that catechin mediated to stimulate osteogenesis.

INTRODUCTION

Human mesenchymal stem cells (hMSCs), useful as a species specific cell culture system for studying cell lineage differentiation, were examined as a tool to identify novel herbal ingredients and Chinese traditional compounds for enhancing osteogenesis.

METHODS

Immortalized and primary hMSCs were induced in osteogenic induction medium in the presence of a variety of herbal ingredients and Chinese traditional compounds and osteogenic differentiation was evaluated by histochemical assays and quantitative RT-PCR.

RESULTS

Using immortalized hMSCs, we first identified catechin, 18β-glycyrrhetinic acid, baishao, and danggui with osteogenic properties, which enhanced calcium deposition at the dose without significant cytotoxic effects. Primary hMSCs were then applied for confirming the osteogenic effects of catechin, which increased alkaline phosphatase activity, calcium deposition, and mRNA expression of Runx2 and osteocalcin. We further found the extracellular signal-regulated kinase (ERK) pathway was downregulated upon stimulation with catechin. Catechin increased the level and activity of protein phosphatases 2A (PP2A) that dephosphorylates ERK kinase (MEK) and ERK. Further, PP2A inhibitor, okadaic acid, abolished the effect of catechin-mediated inactivation of ERK and stimulation of osteogenesis. The blocking effect of okadaic acid on osteogenesis was further reversed by PD98059, a specific inhibitor of MEK. Co-immunoprecipitation revealed the association of PP2A to both MEK and ERK.

CONCLUSIONS

These studies propose catechin enhanced osteogenesis by increasing the PP2A level that inhibits the MEK and ERK signaling in hMSCs. These results prove the concept of using hMSCs as a convenient tool for rapid and consistent screening of the osteogenic herbal ingredients and traditional Chinese compounds.

Disposition of asarone after intravenous administration to rabbits assessed using HPLC

A simple and sensitive high-performance liquid chromatography (HPLC) method for the determination of asarone in rabbit plasma has been developed. Up to 0·1 mL of plasma containing asarone was deproteinated by acetonitrile, which contained an internal standard (indomethacin). The supernatant was injected into a Nucleosil 7C18 column using acetonitrile-water-triethylamine (55:45:0·1 v/v, pH 5·4–5·5, adjusted with orthophosphoric acid) as the mobile phase and UV detection at 257 nm, followed by UV spectrum identification (between 200 and 380 nm) with a photodiode array detector. The method is rapid, easily reproduced, selective and sensitive. It was applied to pharmacokinetic studies of asarone in rabbit, after 5, 10, or 20 mg kg−1 intravenous administration. Rapid distribution followed by a slower elimination phase was observed from the plasma concentration–time curve. The plasma disposition at each dose fitted well to a two-compartment open model and the terminal disposition became much slower as the dose was increased, suggesting a nonlinear dose-dependent plasma asarone disposition.

Localized cyclotron mode driven by fast alpha particles under a nonuniform magnetic field

Resonance requires precise synchronization. Surprisingly, relativistic cyclotron instability can survive under a magnetic field with its nonuniformity larger than the requirement of synchronism. Localized eigenmode observed in a hybrid simulation is found to be consistent with that predicted by an analytical theory including both profile and eigenvalue. Half of the spatial area of the wave profile is located where the frequency mismatch is negative as against to the positive requirement generally believed. The consequence on the alpha dynamics is also demonstrated.

Hepatic cerebrospinal fluid pseudocyst: a case report and review of the literature

An abdominal pseudocyst is a rare, but important complication in patients with a ventriculo-peritoneal (VP) shunt insertion. Several predisposing factors for this complication have been suggested, including infection, obstruction or dislodgement, but the pathophysiology is still unknown. However, the abdominal inflammatory process is accepted widely as a hypothesis for the formation of an abdominal pseudocyst. In this study, we report the case of a 21-year-old male that presented with a high-grade fever, poor appetite, shortness of breath and unconsciousness 1 week after receiving a VP shunt insertion for obstructive hydrocephalus. Ultrasonography and computed tomographic scans of the abdomen revealed a well-defined large hepatic cyst surrounding the peritoneal tube of the VP shunt. A hepatic cerebrospinal fluid (CSF) cyst was diagnosed and Staphylococcus epidermis was cultured via CSF. After externalization of the VP shunt and adequate antibiotic treatment, the hepatic cyst was resolved. There was no recurrence observed in the regular follow up.

Community-Acquired Thoracic Empyema in Older People

OBJECTIVES

To compare the clinical characteristics of community-acquired thoracic empyema in older and younger patients and to analyze the effect of various factors on outcome.

DESIGN

A retrospective, comparative observational study.

SETTING

A university-affiliated tertiary medical center.

PARTICIPANTS

Forty-six patients aged 65 and older (older group) and 86 patients aged 18 to 64 (younger group).

MEASUREMENTS

Demographic, clinical, and microbiological data were reviewed.

RESULTS

Older patients were more likely to have dyspnea but less likely to have chest pain or fever (P<.05 for all). The causative organisms were similar between the two groups, with anaerobes and facultative streptococci the most common pathogens. Older patients had increased morbidity and longer hospital stay (median 29.5 vs 20 days, P<.001), but the in-hospital mortality was not significantly different between the two groups (13% vs 8%, P=.37). Multivariate analysis showed that coexisting malignancy (odds ratio (OR)=10.33, P=.01), lack of fever higher than 38 degrees C (OR=17.97, P=.03), and isolation of fungi from pleural fluid (OR=32.66, P=.01) were independently and significantly associated with in-hospital deaths.

CONCLUSION

The microbiology and mortality of community-acquired thoracic empyema were similar between the two age groups. Difference in chronological age did not explain in-hospital death. This finding highlights the importance of effective treatment to obtain better outcomes for older patients.

Central venous catheter-associated fungemia due to Wangiella dermatitidis

Central venous catheter-related Wangiella dermatitidis infection has been increasingly reported in the recent literature. We report a case of central venous catheter (Port-A-Cath)-related fungemia caused by W. dermatitidis in a 58-year-old woman with lung cancer. Two W. dermatitidis isolates were recovered from 2 blood samples drawn from a peripheral vein and the Port-A-Cath 4 months after its placement. The minimum inhibitory concentrations of 2 isolates to fluconazole and amphotericin B using the standard broth microdilution method were 48 microg/mL and 0.19 microg/mL, respectively. The Port-A-Cath was removed and the fungemia responded to amphotericin B treatment. W. dermatitidis should be categorized as a pathogen that can cause central venous catheter-associated fungemia, particularly in immunocompromised patients.

Ultrasonographic evaluation of liver/spleen movements and extubation outcome

INTRODUCTION

The diaphragm plays a pivotal role in weaning and successful extubation. We hypothesized that ultrasonographic evaluation of the movements of the diaphragm by measuring liver/spleen displacement during spontaneous breathing trials is a good predictor for extubation outcome.

PATIENTS AND METHODS

The studied subjects were intubated patients receiving mechanical ventilation who were scheduled to be extubated. The displacement of liver/spleen was measured by ultrasonography before extubation. The patients were classified into a success group (SG) or failure group according to the extubation outcome. The baseline data and organ displacements in these two groups were analyzed. The sensitivity and specificity for the mean organ displacements and weaning parameters to predict successful extubation were calculated.

RESULTS

We included 55 patients, 32 of whom (58%) were in the SG. The baseline data are similar for these two groups, but the mean values of liver and spleen displacements were higher in the SG. Using a cutoff value of 1.1 cm, the sensitivity and specificity to predict successful extubation were 84.4% and 82.6%, respectively, better than traditional weaning parameters in this study.

CONCLUSION

The displacement of the liver/spleen, measured by ultrasonography, is a good predictor for extubation outcome.

Cloning and sequencing of complete cDNA of Japanese encephalitis virus YL strain in Taiwan

We determined the complete nucleotide sequence of the YL strain of Japanese encephalitis virus and its amino acid sequence was deduced. Our results displayed that the genome of YL strain contained a single open reading frame of 10,296 nucleotides (nts) which was flanked by untranslated region (UTR) containing 95 bases at the 5'-end and 586 bases at the 3'-end, respectively. Comparison of sequences showed that the overall amino acid sequence and 3' UTR of YL were similar to those of the virulent strain JaGAr0l. However, some significant amino acid differences of viral envelope (E) protein were observed between YL and JaGAr01; the amino acid sequence of E protein in YL strain possessed RGG(387-389) tripeptide instead of RGD(387-389) in JaGAr01 and in other strains; and another amino acid is K(138) in YL, not E(138) found in others. These differences suggested that the YL strain impairs in viral attachment to the cell surface and loses neuroinvasiveness, and therefore this strain was used as a live attenuated vaccine.

Ultrasound in the diagnosis and management of pleural disease

The authors summarize the current applications of chest ultrasonography in the diagnosis and management of various pleural diseases. Ultrasound has been proved to be valuable for the evaluation of a wide variety of chest diseases, particularly when the pleural cavity is involved. Chest ultrasound can supplement other imaging modalities of the chest and guides a variety of diagnostic and therapeutic procedures. Pleural effusion, pleural thickening, pleural tumors, tumor extension into the pleura and even the chest wall, pleuritis, and pneumothorax can be detected easily and accurately with chest ultrasound. Many ultrasound features and signs of these diseases have been well characterized and widely applied in clinical practice. Under real-time ultrasound guidance the success rates of invasive procedures on pleural diseases increase significantly whereas the risks are greatly reduced. The advantages of low-cost, bedside availability and no radiation exposure have made ultrasound an indispensable diagnostic tool in modern pulmonary medicine.

The effects of the cyclosporin A, a P-glycoprotein inhibitor, on the pharmacokinetics of baicalein in the rat: a microdialysis study

1. Baicalein is a bioactive flavonoid isolated from the root of Scutellaria baicalensis Georgi, a medicinal herb that has been used since ancient times to treat bacterial infections. As little is known concerning its pharmacokinetics, this study focussed on its pharmacokinetics as well as the possible roles of the multidrug transporter P-glycoprotein on its distribution and disposition. 2. Three microdialysis probes were simultaneously inserted into the jugular vein, the hippocampus and the bile duct of male Sprague-Dawley rats for sampling in biological fluids following the administration of baicalein (10, 30 and 60 mg kg(-1)) through the femoral vein. The P-glycoprotein inhibitor cyclosporin A was used to help delineate its roles. 3. The study design consisted of two groups of six rats in parallel: control rats which received baicalein alone and the cyclosporin A treated-group in which the rats were injected cyclosporin A, a P-glycoprotein inhibitor, 10 min prior to baicalein administration. 4. Cyclosporin A treatment resulted in a significant increase in elimination half-life, mean residence time and area under the concentration versus time curve (AUC) of unbound baicalein in the brain. However, AUC in the bile was decreased. 5. The decline of baicalein in the hippocampus, blood and bile suggested that there was rapid exchange and equilibration between the peripheral compartment and the central nervous system. In addition, the results indicated that baicalein was able to penetrate the blood-brain barrier as well as undergoing hepatobiliary excretion. 6. Although no direct transport studies were undertaken and multiple factors may affect BBB penetration and hepatobiliary excretion, strong association of the involvement of P-glycoprotein in these processes is indicated.

Hepatobiliary excretion of fluconazole and its interaction with cyclosporin A in rat blood and bile using microdialysis

In order to investigate the hepatobiliary excretion of Fluconazole, we develop a rapid and sensitive method using high-performance liquid chromatography coupled with microdialysis for the simultaneous determination of unbound fluconazole in rat blood and bile. Microdialysis probes were inserted into both the jugular vein toward the right atrium and bile duct of male Sprague-Dawley rats for biological fluid sampling after administration of fluconazole at 10 mg/kg through the femoral vein. Fluconazole and dialysates were separated using a Zorbax phenyl column maintained at ambient temperature. The detection limit of fluconazole was 50 ng/ml. Biological fluid sampling thereby allowed the simultaneous determination of fluconazole levels in blood and bile. The disposition of fluconazole in the blood and bile fluid suggests that there was rapid exchange and equilibration between the blood and hepatobiliary system. In addition, to investigate the mechanism of P-glycoprotein related hepatobiliary excretion of fluconazole, we examined the drug-drug interaction of fluconazole and cyclosporin A in the aspect of pharmacokinetics. These results indicate that the plasma level of fluconazole was no different than that in bile, and that fluconazole undergoes hepatobiliary excretion, maybe unrelated to the P-glycoprotein transported system.

Pharmacokinetic study of levofloxacin in rat blood and bile by microdialysis and high-performance liquid chromatography

The aim of this study was to develop a rapid and sensitive method for the simultaneous determination of unbound levofloxacin in rat blood and bile using high-performance liquid chromatography coupled with microdialysis for further pharmacokinetic study. Microdialysis probes were simultaneously inserted into the jugular vein toward the right atrium and the bile duct of male Sprague-Dawley rats for biological fluid sampling after administration of levofloxacin 3 mg/kg through the femoral vein. Levofloxacin and dialysates were separated using a Merck LiChrospher reversed-phase C18 column maintained at ambient temperature. The mobile phase was comprised of acetonitrile-1 mM 1-octanesulfonic acid (40:60, v/v, pH 3.0 adjusted with orthophosphoric acid). The fluorescence response for levofloxacin was observed at excitation and emission wavelengths of 292 and 494 nm, respectively. The detection limit of levofloxacin was 50 ng/ml. Intra-day and inter-day precision and accuracy of levofloxacin measurements fell well within the predefined limits of acceptability. The disposition of levofloxacin in the blood and bile fluid suggests that there was rapid exchange and equilibration between the blood and hepatobiliary systems, and the plasma level of levofloxacin was greater than that of the bile. Thus, levofloxacin undergoes hepatobiliary excretion but might not be related to the P-glycoprotein transport system.

Determination and pharmacokinetic study of meropenem in rat bile using on-line microdialysis and liquid chromatography

Meropenem is a carbapenem antibiotic with a wide spectrum of activity against both Gram-positive and Gram-negative bacteria. Because of its clinical efficacy, meropenem is an excellent choice for the treatment of serious infections in both adults and children. The knowledge of tissue concentrations of antibiotic in an infection site is valuable for the prediction of treatment outcome. To investigate the biliary disposition of meropenem, we utilized a minimally invasive sampling technique with a shunt linear microdialysis probe for continuous sampling in the biliary excretion studies. Analysis of meropenem in the dialysates was achieved using a LiChrosorb RP-18 column (Merck, 250 x 4.6 mm I.D.; particle size 5 microm) maintained at ambient temperature. The mobile phase was 50 mM monosodium phosphoric acid-methanol (80:20, v/v, pH 3.0). The UV detector wavelength was set at 298 nm. The area under the concentration-time curve and elimination half-lives of meropenem were about 6144 +/- 1494 min microg/ml and 61 +/- 17 min, respectively. This study represents a successful application of the microdialysis technique, which is an effective method for pharmacokinetic and biliary drug excretion studies.

Determination and pharmacokinetic profile of omeprazole in rat blood, brain and bile by microdialysis and high-performance liquid chromatography

The disposition and biliary excretion of omeprazole was investigated following i.v. administration to rats at 10 mg/kg. We used a microdialysis technique coupled to a validated microbore HPLC system to monitor the levels of protein-unbound omeprazole in rat blood, brain and bile, constructing the relationship of the time course of the presence of omeprazole. Microdialysis probes were simultaneously inserted into the jugular vein toward right atrium, the brain striatum and the bile duct of the male Sprague-Dawley rats for biological fluid sampling after the administration of omeprazole (10 mg/kg) through the femoral vein. The concentration-response relationship from the present method indicated linearity (r2>0.995) over a concentration range of 0.01-50 microg/ml for omeprazole. Intra-assay and inter-assay precision and accuracy of omeprazole fell well within the predefined limits of acceptability. Following omeprazole administration, the blood-to-brain coefficient of distribution was 0.15, which was calculated as the area under the concentration versus time curve (AUC) in the brain divided by the AUC in blood (k=AUCbrain/AUCblood). The blood-to-bile coefficient of distribution (k=AUCbile/AUCblood) was 0.58. The decline of unbound omeprazole in the brain striatum, blood and bile fluid suggests that there was rapid exchange and equilibration between the compartments of the peripheral and central nervous systems. In addition, the results indicated that omeprazole was able to penetrate the blood-brain barrier and undergo hepatobiliary excretion.

Analytical approaches for traditional chinese medicines exhibiting antineoplastic activity

Traditional Chinese medicines have attracted great interest in recent researchers as alternative antineoplastic therapies. This review focuses on analytical approaches to various aspects of the antineoplastic ingredients of traditional Chinese medicines. Emphasis will be put on the processes of biological sample extraction, separation, clean-up steps and the detection. The problems of the extraction solvent selection and different types of column chromatography are also discussed. The instruments considered are gas chromatography, capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) connected with various detectors (ultraviolet, fluorescence, electrochemistry, mass, etc.). In addition, determinations of antineoplastic herbal ingredients, including camptothecin, taxol (paclitaxel), vinblastine. vincristine, podophyllotoxin, colchicine, and their related compounds, such as irinotecan, SN-38, topotecan, 9-aminocamptothecin, docetaxel (taxotere) and etoposide, are briefly summarized. These drugs are structurally based on the herbal ingredients, and some of them are in trials for clinical use. Evaluation of potential antineoplastic herbal ingredients, such as harringtonine, berberine, emodin, genistein, berbamine, daphnoretin, and irisquinone, are currently investigated in laboratories. Other folk medicines are excluded from this paper because their antineoplastic ingredients are unknown.

Effect of caffeic acid phenethyl ester, an antioxidant from propolis, on inducing apoptosis in human leukemic HL-60 cells

Caffeic acid phenethyl ester (CAPE) is an active component isolated from propolis. The aim of this study was to investigate the mechanism of CAPE-induced apoptosis in human leukemic HL-60 cells. It was found that CAPE entered HL-60 cells very quickly and then inhibited their survival in a concentration- and time-dependent manner. CAPE induced characteristic DNA fragmentation and morphological changes typical of apoptosis in these cells. Estimation of the apoptotic percentage showed a time-dependent increase after CAPE (6 microg/mL) treatment (up to 66.7 +/- 2.0% at 72 h). Treatment with CAPE caused rapid activation of caspase-3 after 4 h, down-regulation of Bcl-2 expression after 6 h, and up-regulation of Bax expression after 16 h. These results suggest that CAPE is a potent apoptosis-inducing agent; its action is accompanied by activation of caspase-3, down-regulation of Bcl-2, and up-regulation of Bax in human leukemic HL-60 cells.

Effect of P-glycoprotein modulators on the pharmacokinetics of camptothecin using microdialysis

1. By performing microdialysis, this study investigated the pharmacokinetics of unbound camptothecin in rat blood, brain and bile in the presence of P-glycoprotein mediated transport modulators (cyclosporin A, berberine, quercetin, naringin and naringenin). Pharmacokinetic parameters of camptothecin were assessed using a non-compartmental model. 2. Camptothecin rapidly crosses the blood-brain barrier (BBB) within 20 min after camptothecin administration. The disposition of camptothecin in rat bile appeared to have a slow elimination phase and a peak concentration after 20 min of camptothecin administration. The area under the concentration versus time curve (AUC) for camptothecin in bile significantly surpassed that in blood, suggesting active transport of hepatobiliary excretion. 3. In the presence of cyclosporin A camptothecin AUC, in the brain, was significantly elevated but no significant change in the presence of berberine, quercetin, naringin and naringenin. 4. With treatment by smaller doses of quercetin (0.1 mg x kg(-1)), naringin (10 mg x kg(-1)) and naringenin (10 mg x kg(-1)), they significantly diminished the camptothecin AUC in bile, but was not altered by the treatment of berberine (20 mg x kg(-1)), a higher dose of quercetin (10 mg x kg(-1)), and cyclosporin A treated (20 mg x kg(-1)) and pretreated groups. 5. The distribution ratio (AUC(bile)/AUC(blood)) of camptothecin in bile was decreased in the cyclosporin A, quercetin, naringin and naringenin treated groups. However, the distribution ratio in the brain was increased in the cyclosporin A groups, but was decreased in the groups treated with quercetin, naringin and naringenin. These results revealed that P-glycoprotein might modulate hepatobiliary excretion and BBB penetration of camptothecin.

Simultaneous determination of unbound ropivacaine in rat blood and brain using microdialysis

To investigate the pharmacokinetics of ropivacaine in rat blood and brain, a sensitive HPLC method and microdialysis were developed for the simultaneous determination of unbound ropivacaine in rat blood and brain. Adult, male Sprague-Dawley rats (290-350 g) were anesthetized with sodium pentobarbital (50 mg/kg, i.p.). Two microdialysis probes were inserted, one into the jugular vein toward right atrium, and one into the brain striatum of rats. Ropivacaine (5 mg/kg, i.v.) was then administered via the femoral vein. Blood and brain dialysates were collected and eluted with a mobile phase containing methanol-acetonitrite-20 mM monosodium phosphoric acid (pH 5.5) (10:40:50, v/v/v) in a liquid chromatographic system. Separation of ropivacaine was achieved by a CN column (Phenomenex Luna, 250x4.6 mm, particle size 5 microm; Torrance, CA, USA) within 10 min. The UV detector wavelength was set at 205 nm and the detection limit of ropivacaine was 20 ng/ml. The intra- and inter-day accuracy and precision of the analyses were less than 10% in the ranges of 0.02-5 microg/ml. The pharmacokinetic data were calculated from the individual animal measurements of dialysate concentration versus time. This method exhibits no endogenous interference and its sensitivity is sufficient for the determination of biological samples. The present results confirm that microdialysis sampling followed by LC separation with UV detection represents a viable approach for the measurement of free ropivacaine in rat brain and plasma.

Eosinophilic meningitis caused by Angiostrongylus cantonensis: report of 17 cases

PURPOSE

To describe two outbreaks of Angiostrongylus cantonensis infection that occurred in Kaohsiung, Taiwan, during 1998 and 1999, and to characterize the source of the outbreaks and the clinical manifestations of the disease.

SUBJECTS AND METHODS

We performed a retrospective cohort study among Thai laborers with eosinophilic meningitis who ate raw snails (Ampullarium canaliculatus), as well as an environmental surveillance of larvae in snails.

RESULTS

We enrolled 17 Thai laborers in whom severe headache and eosinophilia developed within 4 to 23 days after eating raw snails. Twelve (71%) developed eosinophilic meningitis. Third-stage larvae were found in the cerebrospinal fluids of 2 patients and in all 12 tested snails. Specific antibodies to A. cantonensis were detected in serum from 16 of the patients and in cerebrospinal fluid from 5 of the patients. Central nervous system manifestations included headache (n = 17 [100%]), fever (n = 11 [65%]), Brudzinski's sign/stiff neck (n = 11 [65%]), hyperesthesia (n = 3 [18%]), cranial nerve palsy (n = 2 [12%]), diplopia (n = 2 [12%]), and ataxia (n = 1 [6%]). Laboratory findings included peripheral eosinophilia (n = 15 [88%]) and cerebrospinal fluid eosinophilia (n = 12 [71%]); elevated immunoglobulin (Ig) E levels (n = 13 [100%]); and transient increases in white blood cell count (n = 7 [41%]) and in serum levels of creatine kinase (n = 7 [41%]), transaminase (n = 3 [18%]), and lactate dehydrogenase (n = 2 [12%]). The severity of illness and eosinophilia were correlated with the number of ingested snails. Meningeal and basal ganglion enhancement was noted on magnetic resonance imaging in several patients. Treatment with mebendazole combined with glucocorticosteroids appeared to shorten the course of the infection, but not the number of relapses. The eosinophil count fell to normal within 3 months, but IgE levels remained elevated for as long as 6 months. All patients recovered with minimal neurologic sequelae.

CONCLUSION

Eosinophilic meningitis caused by A. cantonensis should be considered in patients who have headache or central nervous system manifestations after eating raw snails.

Effect of cyclosporine, a P-glycoprotein inhibitor, on the pharmacokinetics of cefepime in rat blood and brain: a microdialysis study

In clinical application, cefepime and cyclosporine are regularly combined in the treatment of organ transplant patients, so the interaction of these two drugs can be hypothesized. Therefore, the pharmacokinetics of cefepime alone and in combination with cyclosporine in rat using microdialysis coupled with HPLC-UV on-line system was evaluated in the study. Cefepime at three doses (20, 50, and 100 mg/kg) showed linear kinetics. After addition of cyclosporine, the mean residence time was increased from 34.9 min to 48.6 min (p<0.05, n=6), and the area under the concentration versus time curve (AUC) increased from 4775 min microg/ml to 6960 min microg/ml (p<0.01, n=6). While in the brain, AUC increased from 64.3 min microg/ml to 110.2 min microg/ml. In summary, cyclosporine (20 mg/kg) could significantly alter the simultaneously administered cefepime (50 mg/kg) unbound drug pharmacokinetic parameters in both blood and brain.

On-line microdialysis coupled with microbore liquid chromatography with ultraviolet detection for continuous monitoring of free cefsulodin in rat blood

A microdialysis method followed by a microbore liquid chromatographic ultraviolet detection procedure has been performed for the assay of unbound cefsulodin in rat blood. A microdialysis probe was inserted into the jugular vein for blood sampling. This method involves an on-line design for submitting dialysate into the liquid chromatographic system. The chromatographic conditions consisted of a mobile phase of methanol-100 mM monosodium phosphoric acid (10:90, v/v, pH 5.0) pumped through a microbore reversed-phase column at a flow-rate of 0.05 ml/min. Detection wavelength was set at 265 nm. Microdialysis probes, being laboratory-made, were screened for acceptable in vivo recovery while chromatographic resolution and detection were validated for response linearity as well as intra- and inter-day variabilities. The method was then applied to pharmacokinetics profiling of cefsulodin in the blood following intravenous administration of cefsulodin (20 mg/kg) in rats. Pharmacokinetics were calculated from the corrected data for dialysate concentrations of cefsulodin versus time. Based on pharmacokinetic calculation, cefsulodin best fitted to a two-exponential disposition. This study provided specific pharmacokinetic information for protein-unbound cefsulodin and demonstrated the applicability of this continuous sampling method for pharmacokinetic study.

Measurement and pharmacokinetic analysis of unbound cephaloridine in rat blood by on-line microdialysis and microbore liquid chromatography

A technique involving rapid sampling of cephaloridine in rat blood was achieved using a combination of microdialysis and sensitive microbore liquid chromatography. A microdialysis probe was inserted into the jugular vein/right atrium of a Sprague-Dawley rat. Then after a real-time collection of the analyte by microdialysis, the dialysate was automatically injected into a liquid chromatographic system via an on-line injector. Following a 2 h stabilization period after the surgical procedure, cephaloridine (20 mg/kg, i.v.) was then administered via the femoral vein. Isocratic elution of cephaloridine was carried out with a mobile phase containing methanol-20 mM monosodium phosphate (25:75, v/v, pH 5.5), and the flow rate of the mobile phase was 0.05 mL/min within 10 min. Intra- and inter-assay accuracy and precision of the assay were each less than 10%. The in vivo recovery of the cephaloridine from the microdialysate was 49.7 +/- 8.0% and 42.4 +/- 8.4% for 0.5 and 1 microg/mL standards (n = 6), respectively. Based on the pharmacokinetic analysis, the elimination half-life was 32.2 +/- 8.6 min by cephaloridine administration (20 mg/kg, i.v., n = 6).

Determination of pyruvate and lactate in primary liver cell culture medium during hypoxia by on-line microdialysis–liquid chromatography

A microdialysis sampling device was constructed for the measurement of pyruvate and lactate in primary liver cell culture medium during hypoxia. It was composed of a Petri dish, a dialysis membrane and two transmission tubes within a hypoxia chamber. The dialysis membrane was located in the Petri dish such that it was immersed in the culture medium. Dialysates were collected and introduced by an on-line injector to a liquid chromatographic system for analysis of pyruvate and lactate. The detection limit of this assay was 0.2-2.0 microM with acceptable intra- and inter-assay reproducibilities. In order to validate the assay, primary liver cells were incubated in the Petri dish within a hypoxia chamber in an incubator. The baseline concentrations of pyruvate and lactate in primary liver cell culture medium were 10.6+/-5.6 and 607+/-143 microM, respectively. These levels drastically changed during hypoxia and reperfusion. In conclusion, the present assay provides a sensitive, direct measurement of pyruvate and lactate in culture medium while minimizing pretreatment procedures for sample preparation.

Simultaneous monitoring of extracellular glucose, pyruvate, lactate and glutamate in gerbil cortex during focal cerebral ischemia by dual probe microdialysis

The aim of this study was to monitor dynamic changes in energy-related metabolites in the cortex of gerbils subjected to cerebral ischemia by a dual probe microdialysis technique. Focal cerebral ischemia was produced in anesthetized gerbils by occlusion of the right common carotid artery and the right middle cerebral artery for 60 min. Two microdialysis probes were inserted into both sides of the cortex to simultaneously monitor extracellular glucose, lactate, pyruvate and glutamate. Dynamic and comparative changes in these analytes, on the ipsilateral and contralateral sides of the brain, were simultaneously monitored by liquid chromatography and a microdialysis analyzer. The present study demonstrated decreases in glucose and pyruvate, increases in lactate and glutamate on the ipsilateral side whereas all analytes remain constant on the contralateral side of cortex during cerebral ischemia. In vitro recovery of each microdialysis probe was performed to ensure the quality of experiments. The detection limits of pyruvate, glutamate, lactate and glucose were 0.2, 1.0, 2.0 and 20 microM, respectively. The intra- and inter-assay correlations were less than 5% in standard mixtures and pooled brain dialysates.

Determination and pharmacokinetic study of unbound cefepime in rat bile by liquid chromatography with on-line microdialysis

Biliary excretion and intestinal reabsorption in enterohepatic circulation play major dispositional roles for some drugs. To investigate biliary excretion of drug, we inserted a microdialysis probe into the bile common duct of rat between the liver and the duodenum. In order to avoid the obstruction of bile fluid or bile salt waste, a shunt linear microdialysis probe was used for simultaneous and continuous sampling following intravenous administration of cefepime (50 mg/kg, i.v.). Separation and quantitation of cefepime in the dialysates were achieved using a LiChrosorb RP-18 column (Merck; 250x4.6 mm I.D., particle size 5 microm) maintained at ambient temperature. Samples were eluted with a mobile phase containing 100 mM monosodium phosphoric acid (pH 3.0)-methanol (87:13, v/v). The UV detector wavelength was set at 270 nm. The result indicates that the elimination half-life of cefepime in bile was 64.01+/-9.32 min. This study also served as an example for the microdialysis application in the biliary excretion study of drug.