Medical Applications of a Small Sample X-Ray Fluorescence System

A quantitative x-ray fluorescence (XRF) analytical system has been developed with the emphasis on small sample size. The system employs a two kilowatt tungsten anode x-ray tube, and an 80 mm2 lithium drifted silicon x-ray detector arranged in a compact geometry. Operation at 55 kV and 20 m A give a sensitivity of 153 counts/min/ng at Z=42 (molybdenum). A computer controlled target changer makes it capable of analyzing 32 targets automatically. The sample target is rotated during irradiation, so that the average sample position is defined to 0.2 mm. Several sets of 5 to 9 calibration targets have exhibited a standard deviation of less than 1%.

Association between diabetes and esophageal cancer, independent of obesity, in the United States Veterans Affairs population

In the past 30 years, the incidence of esophageal adenocarcinoma (EAC) has increased more rapidly than any other cancer in the United States. The prevalence of obesity and diabetes mellitus has drastically increased as well. We explored the potential association between obesity, diabetes mellitus, and EAC. By means of retrospective interrogation of an administrative database from fiscal year 2005-2009, we identified two cohorts. The cancer cohort was defined as patients with adenocarcinoma of the distal esophagus or gastric cardia. The comparison cohort contained patients with gastroesophageal reflux disorder (GERD; diagnosis coupled with a procedure code for fundoplication). Patient data, including demographic measures, diagnoses of obesity, diabetes mellitus, dyslipidemia, alcohol abuse, and nicotine dependence were examined. A logistic regression model identified risk factors for development of EAC. The sample included 2,836 patients identified as having either EAC (1,704) or fundoplication with GERD (1,132). Although slightly higher percentages of the benign cohort were obese, the cancer cohort had more diabetics (30.8% vs. 14.8%; chi-square = 94.5; P < 0.0001). In a logistic regression analysis adjusting for comorbidity and lifestyle factors, diagnosis of diabetes mellitus was significantly associated with esophageal cancer as opposed to GERD without cancer (OR = 2.2; 95% confidence interval [CI] 1.7-2.8). Nicotine dependence was also identified as a risk factor (OR = 1.7; 95% CI 1.4-2.0). We identified a potential association between diabetes mellitus and adenocarcinoma of the esophagus or gastric cardia. This association appears to be independent of obesity. Additionally, nicotine dependence was identified as a risk factor for EAC.

BNIP3L (Nix) expression in colon cancer

e15097

Background: Microenvironmental adaptation to hypoxic conditions is critical for a cell to survive in a growing solid tumor. BNIP3L (Nix) mediates apoptosis during hypoxia in cancer cell lines, and Nix knockdown promotes tumor growth in-vivo through decreased apoptosis and increased proliferation, suggesting a means by which cells can adapt. Little is known specifically about Nix expression and its importance in human colon cancer. To gain insight into expression of this gene in colon tumors, the present study analyzed mRNA microarray data from 227 colon tumors and 22 normal colon tissue samples and queried differential expression of Nix. These results were compared to the protein levels present in human colon tumors. Methods: mRNA expression of 227 human colon tumors (made available by the Expression Project for Oncology (expO)) and 22 normal colon samples (retrieved from the Gene Expression Omnibus (GEO)) was analyzed. These samples were hybridized to the Affymetrix GeneChip Human Genome U133 Plus 2.0 Array, assaying 17,726 NCBI Entrez genes. Immunohistochemistry was performed on human tissue microarray CO701 (US Biomax, Inc.) containing 62 tumor samples. Results: Nix mRNA levels were shown to increase from normal to cancer (log-fold change of 0.961, Benjamini-Hochberg FDR adjusted p < 0.001). IHC demonstrated variable levels of Nix present in colon tumors: 38/62 (61.3%) of tumors stained positive for Nix while 24/62 (38.7%) were negative. Conclusions: We have shown that mRNA levels of Nix are upregulated in the transition from normal colon tissue to cancer but that protein levels in tumors demonstrate variable expression. This suggests that silencing of Nix occurs at various stages of tumorigenic progression and results in isolated populations of cells within a growing tumor that are uniquely resistant to apoptosis. Better understanding of Nix in the context of a growing colon tumor is needed and could lead to development of more successful therapeutics.

No significant financial relationships to disclose.

Risk factors associated with atrial fibrillation after noncardiac thoracic surgery: analysis of 2588 patients

OBJECTIVE

The purpose of this study was to identify risk factors associated with the onset of atrial fibrillation after thoracic surgery to allow more targeted interventions in patients with the highest risk.

METHODS

A comprehensive prospective database was used to identify patients undergoing major thoracic surgery from January 1, 1998, through December 31, 2002. Data collection was performed at point of contact: at preoperative evaluation, the time of the operation, discharge, and postoperative visits. All patients undergoing resection of a lung, the esophagus, the chest wall, or a mediastinal mass were included in this study. Univariate and multivariate analyses of factors associated with the development of atrial fibrillation were analyzed.

RESULTS

There were 2588 patients who met the inclusion criteria. The overall incidence of atrial fibrillation was 12.3% (n = 319). Categories of disease were primary lung cancer, pulmonary metastasis, esophageal cancer, intrathoracic metastasis, benign lung disease, other mediastinal tumors, mesothelioma, chest wall tumors, benign esophagus, and "other." Patients with atrial fibrillation had increased mean lengths of hospital stay, mortality rates, and mean hospital charges. Univariate analysis evaluated age, sex, disease category, comorbidities, preoperative therapy, and procedure, and significant variables were entered into the multivariate analysis. Significant variables (relative risk; 95% confidence interval) in the multivariate analysis were male sex (1.72; 1.29-2.28), age 50 to 59 years (1.70; 1.01-2.88), age 60 to 69 years (4.49; 2.79-7.22), age 70 years or greater (5.30; 3.28-8.59), history of congestive heart failure (2.51; 1.06-6.24), history of arrhythmias (1.92; 1.22-3.02), history of peripheral vascular disease (1.65; 0.93-2.92), resection of mediastinal tumor or thymectomy (2.36; 0.95-5.88), lobectomy (3.89; 2.19-6.91), bilobectomy (7.16; 3.02-16.96), pneumonectomy (8.91; 4.59-17.28), esophagectomy (2.95; 1.55-5.62), and intraoperative transfusions (1.39; 0.98-1.98).

CONCLUSIONS

The significant variables identified by means of multivariate analysis were associated with the occurrence of atrial fibrillation. Preventive therapies in selected populations might reduce the incidence of atrial fibrillation.

Histone deacetylase inhibitor downregulation of bcl-xl gene expression leads to apoptotic cell death in mesothelioma

It has been shown that mesothelioma expresses the antiapoptotic protein BCL-XL, but not BCL-2, rendering bcl-xl gene expression a potential therapeutic target. Sodium butyrate (NaB) is a histone deacetylase inhibitor capable of alteration of bcl-2 family protein expression in other tumor types. Mesothelioma cell lines (REN, I-45) were exposed to NaB, and viability (colorimetric assay) and apoptosis (TUNEL, Hoescht staining, flow cytometry) were evaluated. Effects on bcl-2 family protein, fas-fas ligand, and caspases were examined by Western blot analysis and functional assay. An RNase assay evaluated bcl-2 family messenger RNA (mRNA) expression. Overexpressing BCL-XL mesothelioma clones were created by plasmid transfer. Cells were sensitive to NaB at low IC(50) (REN, 0.3 mM; I-45, 1 mM) and demonstrated apoptosis (percentage of cells below G1 phase by flow cytometry [sub-G1]: REN, 38.5%; I-45, 30.9%). A significant decrease in BCL-XL protein expression was noted with BAK, BAX, and BCL-2 unchanged, and this was corroborated at the transcriptional level with selectively decreased bcl-xl mRNA production after sodium butyrate exposure. Fas expression and fas-fas ligand sensitivity were unchanged. Caspases demonstrated low-level activation. Stable overexpressing BCL-XL clones were proportionally resistant to the NaB effect. This study suggests that mesothelioma cells are sensitive to the induction of apoptosis related to the attenuation of antiapoptotic bcl-xl gene and protein expression. Additional study of the therapeutic benefit of targeting bcl-xl gene expression in mesothelioma is warranted.

Pulmonary granuloma caused by Pseudomonas andersonii sp nov

Pulmonary granuloma is a common lesion for which gram-negative bacteria are rarely implicated as a cause. Hence, most physicians are unaware of this etiology. We isolated a gram-negative bacterium from a surgically resected pulmonary granuloma in a 42-year-old, nonimmunocompromised woman. Within the necrotizing granuloma, numerous organisms also were demonstrated by Gram stain, suggesting a cause-disease relationship. Characterization of the bacterium by sequence analysis of the 16S ribosomal gene, cellular fatty acid profiling, and microbiologic studies revealed a novel bacterium with a close relationship to Pseudomonas. We propose a new species for the bacterium, Pseudomonas andersonii. These results suggest that the differential diagnosis of a lung granuloma also should include this gram-negative bacterium as a potential causative agent, in addition to the more common infections caused by acid-fast bacilli and fungi. This bacterium was shown to be susceptible to most antibiotics that are active against gram-negative bacteria.

Significant augmentation of pro-apoptotic gene therapy by pharmacologic bcl-xl down-regulation in mesothelioma

The ratio of pro-apoptotic (PAP) and anti-apoptotic (AAP) bcl-2 proteins is important in apoptosis regulation. We sought to determine if inhibition of the AAP bcl-xl by sodium butyrate (SB) would augment apoptotic cellular death in mesothelioma when combined with adenoviral pro-apoptotic gene therapy (PAGT) by simultaneously increasing PAP and decreasing AAP in these cells. Human mesothelioma cell lines were exposed to AdBax, AdBak, Adp53, and SB alone as well as all vectors combined with SB at varying doses and time points. Cell death was assessed, and apoptosis evaluated by morphology and FACS. Isobologram analysis evaluated additive or synergistic effect. Cellular death and apoptosis were augmented by PAGT/SB combinations compared to monotherapy. Following AdBax/SB and AdBak/SB, a decrease of the AAP bcl-xl was noted in combination with increases in PAP bax and bak. By isobologram analysis, additive or synergistic cell killing was noted with both combinations. SB treatment did not significantly augment cell killing or apoptosis in combination with Adp53. PAGT/SB was more effective than monotherapy in induction of apoptotic cell death. Synergy may be due to the ability of SB to decrease bcl-xl with marked increases in PAP engendered by PAGT. Combination therapy with agents that down-regulate AAP in addition to PAGT may prove useful clinically.

Treatment of stage I and II non-small-cell lung cancer

BACKGROUND

The appropriate staging and treatment of patients with stage I and II non-small-cell lung cancer (NSCLC) are important in that the potential for a lost curative opportunity in this population is greater than for those presenting with advanced NSCLC.

METHODS

Treatment options -- surgery, radiation therapy, and chemotherapy -- for stage I and II NSCLC are reviewed, and the impact of newer staging modalities on patient survival is discussed, including altering both the lead-time and clinicopathologic stage biases that exist in the diagnosis and treatment of NSCLC. Some predictions are also made regarding how that standard may change for clinicians in the near future, and methods for further improvements in posttreatment survival in this group are discussed.

RESULTS

Whenever possible, patients with early-stage NSCLC should be treated with surgical resection. Patients for whom resection is not an option may benefit from radiation as definitive therapy. Positive results with neoadjuvant chemotherapy have led to an ongoing randomized trial (Intergroup S9900) to compare surgery alone to neoadjuvant chemotherapy plus surgery.

CONCLUSIONS

Staging bias may affect the overall low survival of early-stage NSCLC. However, true stage-specific survival may improve with newer imaging modalities. Future advances, including closed transthoracic radiation, thermal ablative therapy techniques, and gene therapy, may supplant the need to surgically resect these tumors to achieve local control.

Preoperative chemotherapy for lung cancer does not increase surgical morbidity

BACKGROUND

Preoperative chemotherapy (C+S) for non-small cell lung cancer (NSCLC) has increased in an attempt to improve survival. Patients receiving C+S potentially may have an increase in postoperative morbidity and mortality compared with surgery alone (S). We reviewed our experience with C+S and S in a tertiary referral center.

METHODS

Three hundred eighty consecutive patients underwent lobectomy or greater resection for NSCLC between August 1, 1996, and April 30, 1999: 335 patients (259 S; 76 C+S) were analyzed; 45 additional patients were excluded for prior NSCLC, other chemotherapy for other malignancy, or radiation. We compared morbidity and mortality overall, and by subset analysis (clinical stage, pathological stage, procedure, and by protocol use) for both C+S and S patients.

RESULTS

Demographics, comorbidities, and spirometry were similar. We noted no significant difference in overall or subset mortality or morbidity including pneumonia, acute respiratory distress syndrome, reintubation, tracheostomy, wound complications, or length of hospitalization.

CONCLUSIONS

C+S did not significantly affect morbidity or mortality overall, based on clinical stage, postoperative stage, or extent of resection. The potential for enhanced survival in resectable NSCLC justifies continued study of C+S.

Surgical resection of non-small cell carcinoma after treatment for small cell carcinoma

BACKGROUND

Development of non-small cell lung carcinoma (NSCLC) in patients previously treated for small cell carcinoma (SCLC/NSCLC) is well described; however, little is known about clinical outcome.

METHODS

A single-institution 20-year review was performed. Patient characteristics and survival for SCLC/ NSCLC patients were compared with those for control patients matched for stage, resection, and previous malignancy.

RESULTS

One thousand four hundred four patients with small cell carcinoma were identified, and 29 underwent therapy for metachronous NSCLC: 11 of 29 patients underwent surgical resection, 10 of these 11 (90%) were stage I. Compared with surgically treated stage I NSCLC patients, SCLC/NSCLC patients were more likely to have squamous histology (70% versus 35%, p = 0.026); and subanatomic resection (90% versus 17.4%, p < 0.0005). The SCLC/NSCLC patients had significantly poorer survival when compared with stage I NSCLC patients undergoing any resection (24.53 versus 74.43 months, p = 0.003) and stage I NSCLC patients receiving wedge resection (24.53 versus 58.39 months, p = 0.006). Survival was similar to NSCLC patients with a history of previous treated extrathoracic solid malignancy.

CONCLUSIONS

Surgical resection for SCLC/NSCLC patients is feasible, but poorer prognosis is noted when compared with stage-matched control patients. Surgical candidates should be carefully chosen, and alternative local control modalities considered.

Adenovirus-mediated Bak gene transfer induces apoptosis in mesothelioma cell lines

OBJECTIVE

Conventional treatment for mesothelioma is largely ineffective. We therefore evaluated the novel approach of adenoviral gene transfer of the proapoptotic Bcl-2 family member Bak in mesothelioma cancer cell lines, which are sensitive and resistant to adenoviral p53.

METHODS

Binary adenoviral Bak (Ad/GT-Bak and Ad/GV16) and LacZ (Ad/GT-LacZ and Ad/GV16) vectors were used for transduction of the mesothelioma cell lines I-45 (p53 resistant) and REN (p53 sensitive). Protein levels were determined by Western blotting. Apoptosis was assessed by morphologic changes, caspase-3 cleavage, and fluorescence-activated cell sorter analysis of subdiploid populations. Cell viability was determined with the XTT assay. Statistical analysis was performed with analysis of variance and the Student t test.

RESULTS

High levels of Bak gene transfer were seen after coadministration of Ad/GT-Bak and Ad/GV16 in both mesothelioma cell lines. Apoptosis was induced 24 hours after Bak but not LacZ gene transfer ([Bak: I-45, 36%; REN, 25%] vs [LacZ: I-45, 1%; REN, 3%], P <.05]) in p53-sensitive (REN) and p53-resistant (I-45) cell lines. Cellular viability was significantly decreased 48 to 72 hours after Bak gene transfer compared with control vector in both cell lines (72 hours: Bak I-45, 1.4% +/- 1.0%, and Bak REN, 4.7% +/- 1%, vs Lac-Z I-45, 83% +/- 3%, and Lac-Z REN, 100% +/- 1%; P <.05).

CONCLUSIONS

Adenovirus-mediated overexpression of the Bak gene induces apoptosis and decreased cellular viability in p53-sensitive and p53-resistant mesothelioma cells. These data suggest that the gene transfer of proapoptotic Bcl-2 family members may represent a novel gene therapy strategy to treat mesothelioma.

A single-institutional, multidisciplinary approach to primary sarcomas involving the chest wall requiring full-thickness resections

OBJECTIVE

Primary sarcomas involving the chest wall requiring full-thickness excision are rare. We reviewed our experience with these lesions in a tertiary referral cancer center by using multidisciplinary approaches.

METHODS

A 10-year retrospective study identified 51 patients referred with primary sarcomas of the chest wall: 40 for initial treatment and 11 after previous unsuccessful surgical excisions elsewhere (secondary referral). Presenting symptoms were pain alone in 23 (45%) of 51 patients, pain with an associated mass in 8 (16%) patients, and an asymptomatic mass alone in 13 (25%) patients. Median symptom duration was 241 days in the primary group and 225 days in the recurrent group. Tumor locations were the sternum (n = 11), the rib alone (n = 36), and the posterior rib with extension into vertebral bodies (n = 4). Histologic types included the following: chondrosarcomas (n = 15), malignant fibrous histiocytomas (n = 9), osteosarcomas (n = 4), Ewing sarcomas (n = 3), desmoid tumors (n = 7), and other types (n = 13). The median tumor volume of those referred initially was 311 cm(3) compared with 84 cm(3) in patients with recurrent lesions.

RESULTS

Twenty-six (51%) of 51 patients received treatment before resection, including chemotherapy alone (n = 22), radiation alone (n = 3), and combined chemotherapy and radiation therapy (n = 1). The complete sternum was removed in 6 of 11 patients, and the average number of ribs requiring resection was 3.8. Four patients had vertebral body resections. Prosthetic meshes alone were required in 16 of 51 patients, and meshes with methylmethacrylate were required in 18 of 51 patients. Muscle flap reconstructions by plastic surgery were required in 24 patients. Negative margins were obtained in 47 of 51 patients. There were no perioperative deaths with morbidities occurring in 12 (24%) of 51 patients (wound [n = 3], prolonged air leak [n = 1], prolonged ventilator requirement [n = 1], arrhythmias [n = 3], doxorubicin (Adriamycin)-induced cardiomyopathy [n = 1], and other [n = 3]). Postoperative treatment was administered to 13 patients (chemotherapy alone, n = 9; chemotherapy with radiation therapy, n = 4). The cumulative 5-year survival of all patients was 64% (initial referral, 61.3%; secondary referral, 72.7%). The average follow-up is 44.7 months.

CONCLUSIONS

A combined aggressive multidisciplinary approach to primary sarcomas of the chest wall resulted in no treatment-related deaths and a cumulative 5-year survival of 64% in patients referred to our tertiary care cancer center.

Bilateral sequential lung transplant for ectodermal dysplasia

A case of bilateral sequential lung transplantation for anhidrotic ectodermal dysplasia is presented. The patient was a 16-year-old male with end-stage lung disease secondary to chronic severe respiratory infection. Although a relatively rare disease, the common association of fatal pulmonary compromise in those affected with this disorder warrants consideration of lung transplantation as a viable therapeutic option.

Outpatient management of malignant pleural effusion by a chronic indwelling pleural catheter

BACKGROUND

Previous studies have shown that a chronic indwelling pleural catheter (PC) safely and effectively relieved dyspnea, maintained quality of life, and reduced hospitalization in patients with malignant pleural effusions. Outpatient management of malignant pleural effusion with a PC may reduce length of stay and early (7-day) charges compared with inpatient management with chest tube and sclerosis.

METHODS

A retrospective review of consecutive PC patients (n = 100; 60 outpatient, 40 inpatient) were treated from July 1, 1994 to September 2, 1998 and compared with 68 consecutive inpatients treated with chest tube and sclerosis between January 1, 1994 and December 31, 1997. Hospital charges were obtained from date of insertion (day 0) through day 7.

RESULTS

Demographics were similar in both groups. Pretreatment cytology was positive in 126 of 168 patients (75%), negative in 21 (12.5%), and unknown in 21 (12.5%). Primary histology included lung (n = 61, 36%), breast (n = 39, 23%), lymphoma (n = 12, 7%), or other (n = 56, 34%). Median survival was 3.4 months and did not differ significantly between treatment groups. Overall median length of stay was 7.0 days for inpatient chest tube and inpatient PC versus 0.0 days for outpatient Pleurx. No mortality occurred related to the PC. Eighty-one percent (81/100) of PC patients had no complications. One or more complications occurred in 19 patients (19%). Patients treated with outpatient PC (n = 60) had early (7-day) mean charges of $3,391 +/- $1,753 compared with inpatient PC (n = 40, $11,188 +/- $7,964) or inpatient chest tube (n = 68, $7,830 +/- $4,497, SD) (p < 0.001).

CONCLUSIONS

Outpatient PC may be used effectively and safely to treat malignant pleural effusions. Hospitalization is not required in selected patients. Early (7-day) charges for malignant pleural effusion are reduced in outpatient PC patients compared with inpatient PC patients or chest tube plus sclerosis patients.

Prodrug/drug sensitivity gene therapy: current status

The prodrug strategy has its own particular real and theoretic obstacles. Clinical strategies and research efforts have tried to approach these problems. The bystander effect, whereby nontransduced cells are affected by simple proximity to those that have received the novel gene, has enabled many prodrug systems to be more efficient than anticipated. Several prodrug gene therapy systems have been developed, including the HSVtk/GCV and CD/5-FC systems. Preclinical work serves as the foundation for clinical trials examining the use of prodrug gene therapy systems. At least 21 prodrug gene therapy trials have been approved for patient enrollment in the United States and Europe. Recent work has demonstrated the success of prodrug gene therapy, which might lead to combination therapies using vector transfer of both prodrug/suicide as well as immune-enhancing genes to tumors.

Cadherin and catenin expression in normal human bronchial epithelium and non-small cell lung cancer

Cadherins are transmembrane cell adhesion molecules (CAMS) that mediate cell-cell interactions and are important for maintenance of epithelial cell integrity. This function is dependent on an indirect interaction between the cytoplasmic domain of the cadherin molecule with three cytoplasmic proteins known as alpha-, beta-, and gamma-catenin (-cat). Growing evidence suggests that alterations in cadherin or catenin expression or function may be important to the development of an invasive or metastatic phenotype. Immunohistochemical techniques were used to study the expression of the two major epithelial cadherins, E-cadherin (E-cad) and P-cadherin (P-cad) as well as alpha- and gamma-cat in normal bronchial epithelium and in a series of carefully TMN-staged pulmonary adenocarcinomas (n = 21) and squamous cell carcinomas (n = 7). The cadherin profile of normal pseudostratified bronchial epithelium was heterogeneous. Basilar cells strongly expressed P-cad, alpha- and gamma-cat, while columnar cells moderately expressed E-cad, alpha- and gamma-cat. In contrast to other epithelial tumors, E-cad on non-small cell lung carcinomas was actually upregulated, however, a decrease in P-cad expression was noted in 68%. At least one cadherin or catenin was downregulated, compared to normal bronchial epithelium, in 82% of tumors examined. With the exception of an association between loss of P-cad expression and poorly differentiated state, changes in cadherin and catenin expression levels were not significantly correlated to tumor stage, cell type, or nodal status. These findings illustrate that alteration of expression of cadherins and catenins are often found in non-small cell lung carcinoma when compared to the progenitor bronchial epithelium, and may play a role in the development of the malignant phenotype.

Management of exsanguinating hemoptysis during cardiopulmonary bypass

BACKGROUND

Large-volume hemoptysis during cardiopulmonary bypass is an infrequent, but life-threatening event. Rapid airway clearance and control are the primary prerequisites for successful management.

METHODS

The cases of 3 patients with different sources of exsanguinating hemoptysis during cardiopulmonary bypass managed initially with rigid bronchoscopy were reviewed.

RESULTS

In all patients, airway control was rapidly established and weaning from cardiopulmonary bypass CPB was accomplished. Two patients survived the operative procedure. The other patient died in the operating room of unremitting bilateral pulmonary hemorrhage.

CONCLUSIONS

Major hemoptysis during cardiopulmonary bypass is best dealt with initially by rapid airway control and cessation of bypass in an expeditious manner. An algorithm for suggested management is provided. The rigid bronchoscope is the optimal tool for initial management and it should always be available. Definitive treatment is determined by the cause and the persistence of hemorrhage once these maneuvers have been performed.

Diffuse airway narrowing from carcinoma metastatic to the bronchial submucosa: identification by chest CT

The differential diagnosis of dyspnea in patients with prior malignancy and nondiagnostic chest radiographs is broad. We report a case of breast carcinoma diffusely metastatic to the bronchial submucosa presenting as obstructive airway disease. Chest radiographs failed to suggest metastatic disease as the cause of dyspnea. CT, however, revealed the unusual finding of diffusely thickened and narrowed airways. Carcinoma confined to airway submucosa was identified using bronchial biopsy. We suggest that diffuse airway narrowing from submucosal metastasis can be demonstrated by CT and should be added to the differential diagnosis of dyspnea in cancer patients with nondiagnostic chest radiographs and evidence of airflow obstruction.

Mediastinoscopic subtotal removal of mediastinal cysts

STUDY OBJECTIVE

Evaluate the use of mediastinoscopy in the surgical diagnosis and treatment of mediastinal cystic masses in adults.

DESIGN

Case reports and literature review.

SETTING

Academic department of surgery.

PATIENTS

Three consecutive adults with mediastinal masses identified on plain radiographs and CT.

INTERVENTIONS

Operative mediastinoscopy.

MEASUREMENTS AND RESULTS

All patients were successfully treated with removal of cyst wall, establishment of diagnosis, and same-day hospital discharge.

CONCLUSIONS

Simple mediastinoscopic removal of mediastinal cysts offers the same potential for diagnosis and treatment as more conventional methods, with a potential for less morbid and more cost-effective care.

Severe acute extrinsic airway compression by mediastinal tumor successfully managed with extracorporeal membrane oxygenation

The successful use of femoral venoarterial extracorporeal membrane oxygenation to support an adult patient with extrinsic airway compression secondary to a large mediastinal tumor is presented. Extracorporeal membrane oxygenation was continued until a combination of chemotherapy and radiation therapy allowed sufficient tumor shrinkage to permit decannulation. This method should be considered and available before manipulation of the airway in similar patients.

Resection of a pulmonary malignancy invading the intrapericardial inferior vena cava

Resection of extensive lung cancers invading thoracic vascular structures (T4 lesions) can yield long-term survival provided the margins and nodes are free of tumor. We report the resection of the suprahepatic inferior vena cava for direct tumor involvement by a pulmonary malignancy. The resection was performed without bypass, and the cava was subsequently reconstructed with a 22-mm-diameter Dacron graft. Patency was documented on postoperative magnetic resonance angiograms. The patient was discharged home on postoperative day 10 without complications and remains well 8 months after the operation. Potentially curative resections and reconstructions of suprahepatic inferior vena cava involved with pulmonary malignancies are possible and can be done without cardiopulmonary bypass.

Loss of alpha-v integrin expression and recurrence in node-negative lung carcinoma

BACKGROUND

Despite "curative" resection, metastases develop in many patients with node-negative (N0) non-small cell lung carcinoma. Alternative biologic markers for this tumor would be useful. Integrins are cell adhesion molecules that are thought to be important in tumor progression, and expression of these molecules previously has been shown to be altered in non-small cell lung carcinoma. We evaluated alterations in integrin expression and clinical outcome.

METHODS

Immunohistochemical staining of tumor specimens was performed, and clinical data were reviewed retrospectively.

RESULTS

Data were complete for 42 patients. Half of all patients (21/42) and 9 of 26 patients with negative nodes experienced tumor recurrence during follow-up. Neither histologic type nor tumor differentiation status correlated with recurrence. However, loss of the alpha v integrin subunit was associated significantly with recurrence in the N0 group. Seventy-five percent of patients with negative nodes who exhibited recurrence lost alpha v expression, compared with only 10% of patients with negative nodes who did not exhibit recurrence (p = 0.012). Alterations of other integrin subunits did not correlate significantly with prognostic follow-up variables.

CONCLUSIONS

Loss of alpha v expression may serve as a marker for patients with node-negative non-small cell lung carcinoma who are at high risk for recurrence, potentially directing additional therapies.

Thoracoscopic management of descending necrotizing mediastinitis

Descending necrotizing mediastinitis (DNM) is a lethal process originating from odontogenic, pharyngeal, or cervical infectious sources that descends along fascial planes into the mediastinum. Despite earlier use of antibiotics and surgical drainage, the mortality (>50%) has changed little since the first large series reported in the preantibiotic era. The surgical management remains controversial, with support ranging from cervical drainage alone to cervical drainage and routine thoracotomy. We report a case of thoracoscopic drainage and debridement of a mediastinal abscess resulting from descending necrotizing mediastinitis. The decreased morbidity of this approach compared with posterolateral thoracotomy and the improved drainage of the mediastinum compared with cervical drainage support this method as an attractive management of patients with DNM.

Upper abdominal aortic injury during spinal surgery

We describe a rare case of iatrogenic injury to the upper abdominal aorta during spine surgery. The case is reviewed, and diagnosis as well as management of this injury is discussed. No similar previous reports of iatrogenic injury to the upper abdominal/lower thoracic aorta were identified in the literature. Reports of iatrogenic injury to the lower abdominal aorta during spinal surgery have been frequent. With more aggressive operative treatment of spinal disorders, injury to the upper abdominal/lower thoracic aorta may become more common. Timely diagnosis and treatment are essential to prevent both early and delayed complications and death.

Treatment of pleural mesothelioma in an immunocompetent rat model utilizing adenoviral transfer of the herpes simplex virus thymidine kinase gene

Previously, we have treated malignant mesothelioma (MM) growing in the peritoneal cavity of immunodeficient mice utilizing a recombinant adenovirus vector carrying the herpes simplex virus-thymidine kinase gene (Ad.RSVtk) followed by administration of the anti-viral drug ganciclovir (GCV). To mimic more closely the clinical situation in human MM, a syngeneic model of pleural MM was developed in immunocompetent Fischer rats. Administration of Ad.RSVtk into the pleural space of animals with established multifocal tumor followed by systemic GCV therapy resulted in significant tumor regression at 20 days in HSVtk/GCV-treated animals (average tumor weight 0.6 +/- 0.2 gram; n = 12) versus control animals (average weight 5.4 +/- 0.2 grams; n = 21; p < 0.001). In additional studies, Ad.RSVtk/GCV-treated animals had a mean survival of 34 days (average tumor weight 1.0 +/- 0.3 gram at death) versus 26 days in control animals (average tumor weight 6.2 +/- 0.6 grams at death). A significant reduction in tumor burden was also seen when more advanced, bulkier disease was treated. These studies demonstrate the Ad.RSVtk/GCV system is effective in the treatment of pleural-based tumors in an immunocompetent host. However, there are limitations to this treatment approach that result in only small increments in survival.

The role of immunosuppression in the efficacy of cancer gene therapy using adenovirus transfer of the herpes simplex thymidine kinase gene

OBJECTIVE

To determine whether the immune system limits or improves the therapeutic efficacy of an adenovirus vector expressing the herpes simplex thymidine kinase (HSVtk) gene in a subcutaneous tumor model.

BACKGROUND DATA

Enhanced immune reactions against tumors may be therapeutically useful. However, recent studies with adenoviral vectors show that immune responses limit the efficacy and persistence of gene expression. The effect of the immune response on cancer gene therapy with HSVtk gene delivery by an adenovirus vector followed by treatment with ganciclovir is unclear.

METHODS

After adenoviral transduction of a Fischer rat syngeneic mesothelioma cell line with the HSVtk gene in vitro, subcutaneous flank tumors were established. The ability of the HSVtk/ganciclovir system to inhibit tumor growth was compared among normal Fischer rats, immunodeficient nude rats, and Fischer rats immunosuppressed with cyclosporin.

RESULTS

HSVtk/ganciclovir therapy was more effective in nude rats and immunosuppressed Fischer rats than in immunocompetent Fischer rats.

CONCLUSION

These results indicate that the immune response against adenovirally transduced cells limits the efficacy of the HSVtk/ganciclovir system and that immunosuppression appears to be a useful adjunct. These findings have important implications for clinical trials using currently available adenovirus vectors as well as for future vector design.

Pleural-based mesothelioma in immune competent rats: a model to study adenoviral gene transfer

BACKGROUND

Despite multimodality approaches, pleural-based malignant mesothelioma remains a disease with a very poor prognosis. Novel therapeutic strategies such as gene therapy clearly are needed to improve the survival of patients with this neoplasm. To aid in the evaluation of new treatment strategies, animal models that closely mimic human disease are required. This article describes the establishment of a pleural-based model of malignant mesothelioma in immune-competent Fischer rats.

METHODS

Via a modified left anterior lateral thorocotomy, a syngeneic malignant mesothelioma cell line, called II-45, was placed into the pleural cavity of Fischer rats.

RESULTS

Placement of II-45 cells into the pleural cavity of Fischer rats results in a model of pleural mesothelioma that closely resembles the disease seen in patients and is highly reproducible, with animals dying within 1 month. We also demonstrate the feasibility of adenoviral-mediated gene transfer to normal mesothelial cells lining the pleural cavity, as well as to malignant cells deep within the substance of pleural-based malignant mesothelioma.

CONCLUSIONS

The model described here offers the opportunity to study a variety of new treatment modalities, especially somatic gene transfer, against pleural-based malignant mesothelioma in an immune competent setting.

Integrin expression in non-small cell carcinoma of the lung

Alteration of integrin expression in a number of different malignant diseases has been recognized, with a trend of downregulation of collagen-laminin binding integrin expression in epithelial tumor types noted. This study evaluated the expression of a panel of integrin subunits that included subunits that form receptors that bind to collagen and laminin (alpha 2, alpha 3, alpha 6 beta 4) and subunits that form receptors that bind to fibronectin and fibrinogen (alpha 5, alpha V, beta 3, beta 6) in 51 specimens of non-small cell carcinoma (NSCCA) of the lung by use of immunohistochemistry. Integrin expression was then correlated with histologic type (squamous vs. adenocarcinoma), absence or presence of hilar or mediastinal nodal metastasis at resection, and cellular differentiation (well or poorly differentiated). In general, downregulation of the collagen-laminin binding subunits was noted in tumor cells of the NSCCA specimens when compared to the progenitor normal bronchial epithelium. No differences were noted in integrin expression between squamous cell and adenocarcinoma or between node-positive or node-negative tumors. However, downregulation of the integrin subunit alpha 3 was noted to be significantly more common in poorly differentiated tumors (p = 0.02) and several of the other collagen-laminin binding subunits also appeared to be more downregulated in poorly differentiated tumors. No upregulation was seen in the alpha 5 subunit of the fibronectin receptor or the beta 3 subunit of the vitronectin receptor, however, approximately 50% of tumors showed upregulation of the beta 6 subunit, the great majority of these being well-differentiated, node-negative tumors. Downregulation of the collagen-laminin integrins may thus be associated with differentiation of NSCCA, but not metastasis, and may serve as an adjunctive prognostic marker of disease. The beta 6 subunit appears to be associated with malignant transformation, but may serve as a positive prognostic factor.

Gene therapy using adenovirus carrying the herpes simplex-thymidine kinase gene to treat in vivo models of human malignant mesothelioma and lung cancer

Previous studies have shown adenoviral transfer of the herpes simplex virus thymidine kinase (HSVtk) gene followed by the anti-viral drug ganciclovir (GCV) can be used to successfully treat established human mesothelioma tumors growing within the peritoneal cavities of severe combined immune deficient (SCID) mice. These findings raised a number of questions important to the applicability, efficiency, and safety of this treatment strategy. In this report, we have further characterized the use of recombinant adenovirus carrying the HSVtk gene to treat mesothelioma and other localized malignancies. Our results indicate that the Ad.RSVtk/GCV system is effective in causing tumor regression in animals inoculated with another mesothelioma cell line and a lung cancer cell line and that animals with bulky disease can be successfully treated. Effects are seen at a wide range of virus doses and significant anti-tumor activity is present at doses of ganciclovir that are clinically achievable. Finally, this treatment approach appears safe, with limited dissemination of virus using a sensitive RT-PCR detection system. These studies further characterize the use of adenoviral transfer of the HSVtk gene to treat experimental mesothelioma and suggest that clinical trials using this approach may be feasible.

Treatment of experimental human mesothelioma using adenovirus transfer of the herpes simplex thymidine kinase gene

OBJECTIVE

The authors demonstrate the ability of an adenovirus vector expressing the herpes simplex thymidine kinase (HSVtk) gene to treat human malignant mesothelioma growing within the peritoneal cavity of severe combined immunodeficient (SCID) mice.

BACKGROUND DATA

Introduction of the HSVtk gene into tumor cells renders them sensitive to the antiviral drug ganciclovir (GCV). This approach has been used previously to treat experimental brain tumors. Although malignant mesothelioma is refractory to current therapies, its localized nature and the accessibility of the pleural space make it a potential target for a similar type of in vivo gene therapy using adenovirus.

METHODS

An adenovirus containing the HSVtk gene (Ad.RSVtk) was used to transduce mesothelioma cells in vitro. These cells were then injected into the flanks of SCID mice. Ad.RSVtk was also injected directly into the peritoneal cavity of SCID mice with established human mesothelioma tumors. Mice were subsequently treated for 7 days with GCV at a dose of 5 mg/kg.

RESULTS

Mesothelioma cells transduced in vitro with Ad.RSVtk formed nodules when injected in the subcutaneous tissue. These tumors could be eliminated by the administration of GCV, even when as few as 10% of cells were transduced to express HSVtk (bystander effect). Administration of Ad.RSVtk into the peritoneal space of animals with established multifocal human mesothelioma followed by GCV therapy resulted in the eradication of macroscopic tumor in 90% of animals and microscopic tumor in 80% of animals when evaluated after 30 days. The median survival of animals treated with Ad.RSVtk/GCV was significantly longer than that of control animals treated with similar protocols.

CONCLUSION

These results indicate that an adenoviral vector containing the HSVtk gene is effective in treating established malignant mesothelioma in an in vivo setting and raise the possibility of using adenovirus transfer of HSVtk for clinical trials in mesothelioma and other localized tumors.

Differential sensitivity of thoracic malignant tumors to adenovirus-mediated drug sensitization gene therapy

Malignant mesothelioma may prove to be an attractive candidate for somatic gene therapy with replication-deficient recombinant adenovirus transfer of a toxic, or drug sensitization gene. Transfer of the herpes simplex thymidine kinase type I gene (HSVtk), followed by exposure to the acyclic nucleoside drug ganciclovir, has been shown to be an effective tumor cell killing system. To study generalized applicability, we tested a number of thoracic malignant cell lines for their sensitivity to gancyclovir after infection with an adenoviral vector containing the HSVtk gene (Ad.RSVtk). Using the concentration of gancyclovir required to kill 50% of the cells (IC50) as a measure of sensitivity, we detected variable sensitivity among cell lines, with mesothelioma most sensitive (IC50 = 0.075 to 2.8 mumol/L gancyclovir), and non-small-cell carcinoma lines having an intermediate sensitivity (IC50 = 1.5 to 100 mumol/L). In contrast, an ovarian carcinoma line was extremely resistant (IC50 > 2000 mumol/L). To study the possible mechanisms for these differences, we studied cell lines with regard to their ability to be infected with an adenoviral vector containing a marker gene (Ad.CMVlacZ) and expression of the vitronectin receptor alpha v (an integrin cell adhesion molecule shown to be required for adenovirus internalization after initial binding). We found that the degree of lacZ transduction correlated with HSVtk sensitivity, whereas vitronectin receptor expression did not, suggesting that differences in initial viral binding ability, rather than internalization, may explain the sensitivity differences seen in vitro.

Wilms' tumor 1 susceptibility (WT1) gene products are selectively expressed in malignant mesothelioma

The distinction between malignant mesothelioma and other neoplastic processes involving the pleura is difficult, partly due to the lack of specific markers expressed on mesothelioma. Because of evidence suggesting that the Wilms' tumor susceptibility gene (WT1), unlike other tumor suppressor genes, is restricted mostly to mesenchymally derived tissues, we hypothesized that the WT1 gene products could serve as a potential marker for mesothelioma. The expression of WT1 mRNA was analyzed in 19 malignant mesothelioma cell lines and 9 tumors and compared with the expression of WT1 in 10 non-small cell lung cancer lines and 9 lung cancer specimens. WT1 mRNA was detectable by Northern analysis in 16 of 19 mesothelioma cell lines and in 5 of 8 malignant mesothelioma tumors. In contrast, WT1 mRNA was not detected by Northern analysis in non-small cell lung cancer lines or carcinomas. Immunoprecipitation with an anti-WT1 monoclonal antibody showed that a 52- to 54-kd protein was present in 4 mesothelioma cell lines. Immunostaining with this antibody localized the WT1 protein to the nucleus in two mesothelioma lines and in 20 of 21 mesothelioma tumors examined. This distinctive pattern of nuclear immunoreactivity was absent in 26 non-mesothelioma tumors involving the lung, including 20 non-small cell lung carcinomas. The detection of WT1 mRNA or protein may thus provide a specific molecular or immunohistochemical marker for differentiation of mesothelioma from other pleural tumors, in particular, adenocarcinoma.

Thoracoscopic removal of mediastinal parathyroid adenoma

Mediastinal parathyroid tissue hyperfunctions in as much as 25% of the patients with primary hyperparathyroidism, and this may be responsible for causing conventional operative procedures to fail in as much as one-third of the cases. When lesions prove to not be accessible through a cervical incision, or when a mediastinal adenoma is diagnosed before cervical procedures, median sternotomy and angiographic ablation have been considered the only options for removal. However, thoracoscopy has theoretic advantages over both. Two patients underwent successful thoracoscopic removal of a hyperfunctioning ectopic mediastinal parathyroid adenoma and their cases are presented here.

Successful adenovirus-mediated gene transfer in an in vivo model of human malignant mesothelioma

Malignant mesothelioma remains a frustrating clinical problem with uniformly poor responses to current therapeutic regimens. However, the localized nature of the disease, the potential accessibility of the tumor, and the relative lack of distant metastases make it a particularly attractive candidate for somatic gene therapy. The purpose of this study was to evaluate the ability of an adenoviral vector system to transfer genetic material to human mesothelioma cells in vitro and in vivo. Using a replication-deficient recombinant adenovirus carrying the Escherichia coli lacZ marker gene, we found that human mesothelioma cell lines were susceptible to adenovirus infection. Furthermore, surprisingly effective gene transfer was accomplished within tumor implants of human mesothelioma growing within the peritoneal cavity of immunodeficient mice after intraperitoneal administration of virus. These studies demonstrate that adenoviral vectors hold promise as vehicles to deliver gene therapy in human malignant mesothelioma.

Use of recombinant adenovirus to transfer the herpes simplex virus thymidine kinase (HSVtk) gene to thoracic neoplasms: an effective in vitro drug sensitization system

Transfer of the herpes simplex virus thymidine kinase (HSVtk) gene into tumor cells using retroviral vectors followed by administration of ganciclovir provides a potential strategy for the treatment of malignancy. Because of the limitations of using retroviral vectors for clinical application, the feasibility of using a recombinant adenovirus containing HSVtk was examined. Cell lines derived from human malignant mesotheliomas and non-small cell lung cancers infected with a recombinant adenovirus containing HSVtk showed strong expression of HSVtk protein as determined by immunohistochemical staining. Infection with a recombinant adenovirus containing HSVtk rendered cells sensitive to doses of ganciclovir that were 2-3 logs lower than uninfected cells or those infected with a control virus. A strong "bystander effect" was noted in mesothelioma lines; there was no diminution in the efficacy of ganciclovir treatment until the ratio of infected:uninfected cells fell below 1:10. This study thus demonstrates in vitro efficacy of an adenovirus-transduced HSVtk drug sensitization gene therapy system in thoracic malignancies. Recombinant adenovirus transfer of the HSVtk gene followed by ganciclovir may have promise as an in situ treatment for tumors.

Tetracycline pleurodesis--associated acute renal failure

Chemical pleurodesis is a frequently performed procedure for pneumothorax and effusion and significant adverse effects are unusual. We present a previously unreported case of acute renal failure associated with tetracycline pleurodesis. Recent studies have shown that intrapleural drug administration may lead to therapeutic serum levels. Systemic toxic drug effects may therefore be noted with chemical pleurodesants such as tetracycline. Alternative methods of pleurodesis should always be considered if a sensitivity or metabolic abnormality is suspected.

A survey of exposures, practices and recommendations of surgeons in the care of patients with human immunodeficiency virus

Policy makers face a conflict between satisfying concerns of health care workers (HCW) about the occupational risk of human immunodeficiency virus (HIV) infection and ensuring adequate care for patients. This conflict is particularly severe in the field of surgery. We mailed a questionnaire on the surgical care of patients infected with HIV to 1,461 surgeons in New York City and Philadelphia, and 551 (37.7 per cent) responded. Although 1.9 per cent currently were testing all patients for HIV, 42.6 per cent of surgeons believed that all patients in their hospital should be tested. Of the surgeons who responded, 6.3 per cent refused to treat any patient infected with HIV. Less than 50 per cent recommended the use of barrier precautions on all patients in their hospital. Surgeons in New York City were significantly more likely than those in Philadelphia to favor separate facilities for HIV-infected patients. Surgeons considering themselves at higher occupational risk were more likely than those at lower risk to favor widespread testing, separate facilities and use of precautions. Surgeons reported a wide range of opinions. Their approach to the use of barrier precautions differs from the Centers for Disease Control recommendations. The patterns observed suggest that distinct policies may be appropriate for different hospitals.

Prophylaxis of serious cytomegalovirus infection in renal transplant candidates using live human cytomegalovirus vaccine. Interim results of a randomized controlled trial

We report the interim results of a randomized, double-blind, placebo-controlled, clinical trial of prophylactic, live, attenuated cytomegalovirus (CMV) vaccination (Towne strain of CMV) of renal transplant candidates (RTCs). One hundred seventy-two RTCs were treated and subsequently underwent transplantation and followed up for at least one year and up to five years after transplantation. Eighty-eight RTCs received vaccine, and 84 received placebo. Results were analyzed according to the prevaccination serologic status (anti-CMV antibody titer) of the recipient (R- or R+) and the donor (D- or D+). The overall incidence of CMV disease was highest in the R-D+ group and almost absent in the R-D- group. There was no difference in the incidence of CMV infection or disease between vaccinated and respective placebo control recipients in either the R-D+, R+D+, R+D-, or R-D- groups. In contrast, the severity of CMV disease was significantly decreased in R-D+ vaccinees vs R-D+ placebo-treated recipients. Moreover, in the R-D+ group, one- and five-year cadaver renal allograft actuarial survival rates were 73% and 62%, respectively, for CMV vaccinees vs 40% and 25%, respectively, for control placebo patients. We conclude that seronegative cadaver RTCs may benefit from vaccination with live, attenuated, Towne strain CMV vaccine before transplantation.

Elemental analysis in murine central nervous system: elevation of rubidium subsequent to Newcastle disease virus encephalopathy

The Cg strain of Newcastle disease virus (NDV) produces neurologic signs and death in mice. This illness is unusual because of the lack of typical features of a viral encephalitis. Specifically, there is a paucity of infectious virus, detectable cellular inflammatory reaction, cytopathic effect, and viral antigen by immunofluorescence. We previously showed an elevation of alpha-aminoisobutyric acid in the CNS of moribund NDV-infected mice, indicating cellular membrane dysfunction. In an attempt to further our understanding of the pathogenesis of the illness, we evaluated CNS concentrations of sodium, potassium, iron, copper, zinc, magnesium, selenium, and rubidium. Elemental analysis revealed no difference between infected and control mice for all elements except for rubidium, which was significantly elevated in infected mice. Elevation in rubidium was detected in infected mice by X-ray fluorescence and atomic absorption spectrophotometry, whereas rubidium concentrations for control mice were similar by both methods. Neurologic symptoms correlated directly with rising rubidium concentrations. Our data suggest that abnormal trace element levels during viral infection may be one mechanism responsible for the clinical symptoms.