Jessica A. Yu

Biglycan Induces the Expression of Osteogenic Factors in Human Aortic Valve Interstitial Cells via Toll-Like Receptor-2

Objective—Although biglycan (BGN) and oxidized low-density lipoprotein (oxLDL) accumulation has been observed in calcific, stenotic aortic valves, their role in the pathogenesis of calcific aortic valve disease is poorly understood. We hypothesized that soluble BGN induces the osteogenic response in human aortic valve interstitial cells via Toll-like receptor (TLR) 2 and TLR4 and mediates the proosteogenic effect of oxLDL. Methods and Results—Aortic valve interstitial cells of stenotic valves express higher levels of BGN. Stimulation of cells from normal valves with BGN increased the expression of bone morphogenetic protein-2 (BMP-2) and alkaline phosphatase (ALP) among the chondrogenic/osteogenic markers examined and caused accumulation of calcium deposits. TLR2 silencing, but not TLR4 silencing, reduced BMP-2 and ALP levels after BGN stimulation although coimmunoprecipitation revealed that BGN interacts with both TLR2 and TLR4. BGN induced the phosphorylation of extracellular signal-regulated protein kinase-1/2, p38 mitogen-activated protein kinase and nuclear factor-&kgr;B. Inhibition of extracellular-regulated kinase-1/2 markedly reduced the upregulation of BMP-2 and ALP expression by BGN whereas inhibition of p38 mitogen-activated protein kinase or nuclear factor-&kgr;B had a moderate effect. Stimulation of aortic valve interstitial cells with oxLDL upregulated BGN expression and release. Knockdown and neutralization of BGN reduced the effect of oxLDL on BMP-2 and ALP expression. Conclusion—Extracellular soluble BGN induces the expression of BMP-2 and ALP in human aortic valve interstitial cells primarily via TLR2 and contributes to the proosteogenic effect of oxLDL. These findings highlight the potential role of soluble BGN and oxLDL in the development of calcific aortic valve disease.

Lady Windermere revisited: treatment with thoracoscopic lobectomy/segmentectomy for right middle lobe and lingular bronchiectasis associated with non-tuberculous mycobacterial disease §

OBJECTIVE Lady Windermere syndrome is a well-known but poorly understood female predominant phenotype of isolated right middle lobe and lingular bronchiectasis associated with non-tuberculous mycobacterial (NTM) infection. Despite lengthy multidrug antibiotic treatment, the presence of damaged parenchymal tissue leads to symptomatic disease recurrence, often with resistant organisms. The use of surgical resection as an adjunct to medical therapy may alter this cycle, although little is known about the use of thoracoscopic lung resection in this patient population. METHODS This is a retrospective review of a prospectively collected database of patients with pulmonary NTM disease from July 2004 to December 2009. All patients had focal bronchiectasis of the right middle lobe and lingula, treated with targeted antimicrobial therapy for several months prior to resection. RESULTS A total of 134 patients underwent 172 operations, with 38 patients having staged bilateral resections. The cohort was predominately female (96%) and Caucasian (95%), with a mean age of 59 years (range 34-81 years). Using a thoracoscopic approach in all patients, 102 middle lobectomies and 70 lingulectomies were performed. Conversion to open thoracotomy occurred in five cases (3%). Secondary procedures were performed in 20 cases (12%). There was no operative mortality. Postoperative morbidity was noted following 12 operations (7%), primarily consisting of prolonged air leak. The mean length of stay was 3.3 days (range 1-15 days). CONCLUSIONS Although medical therapy remains the primary treatment modality for patients with pulmonary NTM disease, the selective use of pulmonary resection may reduce the incidence of symptomatic disease recurrence. The addition of thoracoscopic resection to treatment regimens for patients with Lady Windermere syndrome can be accomplished with minimal morbidity and mortality.

Thoracoscopic Lobectomy and Segmentectomy for Infectious Lung Disease

BACKGROUND The potential benefits of thoracoscopic lobectomy and segmentectomy for early stage non-small cell lung cancer have been well documented in the literature. However, little is known about the use of these techniques in patients requiring resection for infectious or inflammatory lung disease. METHODS Using a prospectively collected database, we performed a retrospective review of consecutive operations from July 2004 to June 2010. All patients who underwent elective thoracoscopic lobectomy or segmentectomy for focal bronchiectasis or cavitary lung disease associated with active pulmonary infection were included. RESULTS In all, 212 resections were performed in 171 patients. The average age was 59 years (range, 26 to 82 years). Patients were predominately white (93%) and female (93%). Indications for surgery included recurrent active infection, hemoptysis, or antibiotic intolerance associated with focal bronchiectasis (86%), cavitary disease (7%), or both (7%). Operations included 126 lobectomies, 73 segmentectomies, 10 lobe plus segmental resections, and 3 bilobectomies. Conversion to thoracotomy occurred in 10 patients. The operative mortality rate was zero. Complications occurred in 9%, consisting largely of prolonged air leak and atrial fibrillation. The mean hospital length of stay was 3.7 days. CONCLUSIONS Thoracoscopic lobectomy and segmentectomy for individuals with infectious lung disease can be accomplished safely with minimal morbidity and mortality. These techniques may provide the optimal surgical approach for patients with focal bronchiectasis or cavitary lung disease requiring resection.

Lung cancer cell invasion and expression of intercellular adhesion molecule-1 (ICAM-1) are attenuated by secretory phospholipase A2 inhibition

OBJECTIVE Invasive lung tumors are associated with intercellular adhesion molecule-1 (ICAM-1) expression. Secretory phospholipase A(2) (sPLA(2)) enzymes produce inflammatory mediators that stimulate ICAM-1 expression, and upregulation of PLA(2) activity can enhance metastasis. We hypothesize a link between sPLA(2) activity, ICAM-1 expression, and tumor cell invasion. We propose that inhibition of sPLA(2) modulates ICAM-1 expression in cancer cells and attenuates their invasiveness. METHODS Human lung adenocarcinoma cells (A549) were treated with an ICAM-1 blocking antibody and assayed for invasion. Lung cancer cells (A549 and H358) were then treated with an sPLA(2) inhibitor and evaluated by immunoblotting for ICAM-1 expression. Next cells (A549) treated with sPLA(2) inhibitor were assayed for invasion. Finally, sPLA(2) messenger RNA and protein expression were evaluated by quantitative reverse-transcriptase polymerase chain reaction and immunofluorescence microscopy, respectively. Statistical analysis was performed by the Student t test or analysis of variance, as appropriate. RESULTS Antibody blockade of ICAM-1 decreased lung cancer cell invasion. sPLA(2) inhibition significantly reduced ICAM-1 expression and invasion. sPLA(2) inhibition also significantly decreased sPLA(2) mRNA expression and immunofluorescent staining of sPLA(2). CONCLUSIONS sPLA(2) plays a significant role in mediating the inflammatory signals that induce ICAM-1 expression in lung cancer cells. Inhibition of the enzyme can significantly decrease ICAM-1 expression and subsequent cancer cell invasion. This lays the groundwork for further investigation into the cellular mechanisms of sPLA(2) and its role in lung cancer.

Techniques of Bronchial Sleeve Resection

A bronchial sleeve resection can be considered for lesions arising from a lobar bronchus so as to preclude a standard lobectomy, yet without enough distal involvement as to warrant a pneumonectomy. Limited bronchial resection allows maximal conservation of pulmonary function in patients with benign or malignant disease, without compromising oncologic outcome. This article defines the indications and preoperative management of candidate patients and discusses key anesthetic considerations and surgical techniques for this complex airway reconstruction. The essential component of a successful operation is a tension-free bronchial anastomosis. Open communication and careful discussion of airway management between anesthesiologist and surgeon will help ensure a good outcome.

Surgical treatment of atypical mycobacterial infections.

Surgical evaluation in nontuberculous mycobacterial (NTM) infections plays an essential role as part of multidisciplinary management of this complex pulmonary process. Resection of damaged lung parenchyma combined with appropriate antimicrobial therapy may interrupt a cycle of disease progression and relapse in select patients. Relevant technical considerations for managing both minimally invasive and open anatomic resection in this unique population are discussed. Results of anatomic resection of NTM damaged lung in the modern era are also summarized.

Group IIa secretory phospholipase expression correlates with group IIa secretory phospholipase inhibition–mediated cell death in K-ras mutant lung cancer cells

OBJECTIVE There are currently no targeted therapies against lung tumors with oncogenic K-ras mutations that are found in 25% to -40% of lung cancers and are characterized by their resistance to epidermal growth factor receptor inhibitors. The isozyme group IIa secretory phospholipase A(2) (sPLA(2)IIa) is a potential biomarker and regulator of lung cancer cell invasion; however, the relationship between K-ras mutations and sPLA(2)IIa has yet to be investigated. We hypothesize that sPLA(2)IIa modulates lung cancer cell growth in K-ras mutant cells and that sPLA(2)IIa expression in human lung tumors is increased in K-ras mutant tumors. METHODS Baseline sPLA(2)IIa expression in K-ras mutant lung cancer cell lines (A549, SW1573, H358, H2009) was assessed. Cells were treated with a specific sPLA(2)IIa inhibitor and evaluated for apoptosis and cell viability. Nuclear factor kappa-b (NF-κB) and extracellular signal-regulated kinase 1/2 activity were detected by Western blot. Human tumor samples were evaluated for sPLA(2)IIa mRNA expression by quantitative reverse-transcription polymerase chain reaction. RESULTS Cytotoxicity of sPLA(2)IIa inhibition correlates with sPLA(2)IIa expression. Apoptosis in response to sPLA(2) inhibition parallels attenuation in NF-κB activity. In addition, sPLA(2)IIa expression in human tumors correlates with squamous cell pathology and increasing stage of K-ras mutant lung tumors. CONCLUSIONS Baseline sPLA(2)IIa expression predicts response to sPLA(2)IIa inhibition in some K-ras mutant lung cancer cells. This finding is independent of p53 mutation status. Furthermore, squamous tumors and advanced-stage K-ras mutant tumors express more sPLA(2)IIa. These data support a role for sPLA(2)IIa as a potential global therapeutic target in the treatment of lung cancer.

Assessment of the Relationship Between Contegra Conduit Size and Early Valvar Insufficiency

BACKGROUND Contegra bovine jugular vein (BJV) conduit results vary widely, and little attention has been directed at assessment of early conduit insufficiency. Conduit insufficiency is graded subjectively, and criteria vary. Several studies have used branch pulmonary artery flow reversal (BPAFR) to define severe conduit insufficiency. BJV valves are larger than human pulmonary valves of similar diameter. We hypothesize that anatomic differences between BJV and human pulmonary valves limit the use of BPAFR in the evaluation of BJV competence. Our purposes were to (1) assess the prevalence of early and 6-month BJV conduit insufficiency in our patients, (2) determine if conduit size affects BJV competence, and (3) determine if BPAFR is a specific discriminator of severe conduit insufficiency. METHODS We reviewed 135 BJV conduits. One cardiologist blinded to original reports reviewed postoperative and 6-month echocardiograms. Conduits were grouped by size: group 1, 12 to 14 mm (n=51), and group 2, 16 to 22 mm (n=84). Moderate or greater insufficiency was considered clinically significant. RESULTS Early conduit insufficiency was common in group 1 (37%) and rare in group 2 (5%, p<0.0001). After excluding conduits with significant insufficiency, BPAFR occurred in 18% (group 1, 27%; group 2, 13%; p=0.02). At follow-up, insufficiency worsened in group 1 but was stable in group 2. CONCLUSIONS Early conduit insufficiency is common and worsens with follow-up in small BJVs. Conduit insufficiency is limited in larger sizes and remains stable. BJV exhibits BPAFR commonly in the absence of significant conduit insufficiency. BPAFR should not be used as a primary criterion for grading insufficiency in BJV conduits.

Analysis of efficacy and cost-effectiveness of high-dose arabinoside versus daunorubicin chemotherapy in older adult patients with acute myeloid leukemia by cytogenetic risk profile: retrospective review from China

High-dose arabinoside (HiDAC) and daunorubicin (DNR)-based chemotherapy are the primary consolidation treatment options for older adults (50–60 years old) with acute myeloid leukemia in China. We analyzed the event-free survival (EFS) and hospital treatment charges of older adult patients with different cytogenetic risk profiles. In patients with a better/intermediate risk profile, the average total treatment cost of HiDAC was similar to that of DNR (P = 0.11). A 5-year follow-up of patients with better/intermediate cytogenetic risk profiles revealed that the median EFS of patients who received HiDAC was significantly longer than for patients who received the DNR-based regimen (27 vs. 20 months, P = 0.03). Average cost per year of life saved was 18,746.84 USD for HiDAC, compared to 32,733.37 USD for DNR. In contrast, for patients with a poor cytogenetic risk profile, the average total treatment cost for HiDAC was higher than for DNR (P < 0.005). In addition, the median EFS in the HiDAC protocol group was significantly lower than in the DNR group (11 vs. 20 months, P = 0.003). Meanwhile, in this risk group, the average cost per year of life saved was 103,237.70 USD compared to 32,277.93 USD, respectively, in the HiDAC and DNR regimens. We conclude that HiDAC is a more efficacious and cost-effective consolidation treatment regimen in the better/intermediate risk group, while the DNR-based regimen is more cost-effective in the poor risk group.

Cancer Stem Cell Phenotype Is Supported by Secretory Phospholipase A2 in Human Lung Cancer Cells

BACKGROUND Lung cancer stem cells (CSCs) are a subpopulation of cells that drive growth, invasiveness, and resistance to therapy. Inflammatory eicosanoids are critical to maintain this malignant subpopulation. Secretory phospholipase A2 group IIa (sPLA2) is an important mediator of the growth and invasive potential of human lung cancer cells and regulates eicosanoid production. We hypothesized that sPLA2 plays a role in the maintenance of lung CSCs. METHODS Cancer stem cells from lung adenocarcinoma cell lines H125 and A549 were isolated using aldehyde dehydrogenase activity and flow cytometry. Protein and mRNA levels for sPLA2 were compared between sorted cells using Western blotting and quantitative reverse transcriptase-polymerase chain reaction techniques. Chemical inhibition of sPLA2 and short-hairpin RNA knockdown of sPLA2 were used to evaluate effects on tumorsphere formation. RESULTS Lung CSCs were isolated in 8.9%±4.1% (mean±SD) and 4.1%±1.6% of H125 and A549 cells respectively. Both sPLA2 protein and mRNA expression were significantly elevated in the CSC subpopulation of H125 (p=0.002) and A549 (p=0.005; n=4). Knockdown of sPLA2 significantly reduced tumorsphere formation in H125 (p=0.026) and A549 (p=0.001; n=3). Chemical inhibition of sPLA2 resulted in dose-dependent reduction in tumorsphere formation in H125 (p=0.003) and A549 (p=0.076; n=3). CONCLUSIONS Lung CSCs express higher levels of sPLA2 than the non-stem cell population. Our findings that viral knockdown and chemical inhibition of sPLA2 reduce tumorsphere formation in lung cancer cells demonstrate for the first time that sPLA2 plays an important role in CSCs. These findings suggest that sPLA2 may be an important therapeutic target for human lung cancer.