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Biomedical subjects

G A Patterson

Publications and source records attributed to G A Patterson.

At least 91 records · Page 5Linked to original sources

Clinical-pathologic analysis of 40 patients with large cell neuroendocrine carcinoma of the lung.

BACKGROUND: The identification, classification, and appropriate treatment of patients with pulmonary carcinomas demonstrating neuroendocrine differentiation remains controversial. METHODS: Patients undergoing resection of lung cancer at Washington University since 1986 were reviewed to identify all large cell neuroendocrine carcinomas. Cases were segregated into large, small, or mixed cell categories, and graded as moderate ("atypical carcinoid") or poorly differentiated (all higher grade lesions). All patients' charts were reviewed and referring physicians contacted to ascertain cancer treatment after resection and follow-up status. RESULTS: Forty patients were identified with large cell neuroendocrine carcinoma: 8 moderate and 32 high-grade. Average follow-up was 19.8 months. Stage distribution was as follows: I, 25; II, 6; III, 6; and VI, 3. Fifteen patients have no evidence of disease, 15 are dead of disease, and 6 are alive with disease. Five-year survival of the stage I patients is 18%; all-stage 5-year survival is 13%. Of the 15 patients who died of their disease, 80% had stage I or II disease. Postoperative chemotherapy, radiation therapy, or both were given to 9 of 26 patient in stage I, with six deaths (67%). Six of 17 patients (35%) with stage I disease died after no postoperative intervention. CONCLUSIONS: Large cell neuroendocrine carcinomas identified by histologic examination have a remarkably poor prognosis even in very early stage disease. Adjuvant therapy did not improve survival.

Aged↗

Retrieval by other procurement teams provides favorable lung transplantation outcome.

BACKGROUND: During the last 4 years, we have increasingly used lungs retrieved by other procurement teams. We therefore investigated whether the use of those lungs affected the outcome of lung transplantation. METHODS: We analyzed the results of 159 consecutive lung transplantations performed at our institution between July 1, 1992, and December 31, 1995. The transplants were divided into three groups: distant donor lungs retrieved by our team (DB group, n = 68); distant donor lungs retrieved by other teams (DX group, n = 46); and local donor lungs retrieved by our team (LB group, n = 44). One transplantation with a local donor lung retrieved by another team was excluded from the analysis. RESULTS: No significant differences were noted between the three groups in alveolar-arterial oxygen gradient immediately after transplantation (DB group, 359 +/- 18 mm Hg; DX group, 329 +/- 23 mm Hg; LB group, 327 +/- 20 mm Hg) and at 24 hours; days on ventilator; days in the intensive care unit; length of hospital stay; 30-day mortality; and actuarial 1-year survival (DB group, 81%; DX group, 87%; LB group, 89%). CONCLUSIONS: The use of donor lungs retrieved by other teams achieves an equivalently satisfactory outcome after lung transplantation as lungs retrieved by our team.

Adult↗

Inhaled nitric oxide at the time of harvest improves early lung allograft function.

BACKGROUND: Inhalation of nitric oxide (NO) has been shown to have beneficial effects on a variety of acute lung injuries, including lung allograft reperfusion injury. The purpose of the present study was to investigate the effects of inhaled NO at the time of harvest on function of canine left lung allografts after transplantation. METHODS: Ten dogs underwent left lung allotransplantation. Donor lungs were flushed with modified Euro-Collins solution and stored for 21 hours at 1 degree C. Immediately after transplantation, the contralateral main pulmonary artery and bronchus were ligated to assess isolated allograft function. Hemodynamics and arterial blood gases (inspired oxygen fraction, 1.0) were assessed intermittently for 6 hours prior to sacrifice. Allograft myeloperoxidase activity and wet to dry weight ratio were assessed. Donor animals were divided into two groups. Group I animals (n = 5) received no NO. In group II (n = 5), donors received inhaled NO (60 ppm) at the time of harvest. RESULTS: Pulmonary vascular resistance decreased to 79.6% of baseline because of inhalation of 60 ppm NO in group II donor animals. Thiobarbituric acid-reactive materials were reduced during the storage period in group II, a finding suggesting less oxidant injury during storage in donor lungs treated with NO. Throughout the 6-hour assessment, oxygenation in group II was superior to that in group I (p < 0.05). At 360 minutes of assessment, mean arterial oxygen tension in groups I and II was 88.9 +/- 11.4 mm Hg and 169.1 +/- 33.0 mm Hg, respectively. Myeloperoxidase activity was significantly decreased in group II (p < 0.05), data indicating reduced neutrophil sequestration. Wet to dry weight ratio was significantly lower in group II. CONCLUSIONS: These data suggest that inhaled NO at the time of harvest improves early function of preserved lung allografts by attenuating oxidant injury during storage and subsequent neutrophil sequestration.

Administration, Inhalation↗

Ex vivo adenoviral-mediated gene transfer to lung isografts during cold preservation.

BACKGROUND: Although whole-organ gene transfer has been reported in heart and liver transplant models, it has not been well characterized in lung grafts. The aim of this study was to determine the feasibility of ex vivo gene transfer to rat lung isografts during cold preservation using an adenoviral vector. METHODS: F344 rats, divided into four groups, underwent orthotopic left lung transplantation. In group I, lung grafts were flushed with adenovirus carrying the beta-galactosidase gene. After storage at 10 degrees C, grafts were implanted in recipient animals. Group II underwent the same procedure but graft storage was at 4 degrees C. Groups III (10 degrees C) and IV (4 degrees C) served as controls. On postoperative day 5, recipients were sacrificed, and native and transplanted lungs were examined. RESULTS: In group I, all animals showed successful, albeit patchy, gene expression. This occurred in 2 of 4 animals in group II, the other 2 showing no expression. Transduced cells were consistent morphologically with endothelial cells and pneumocytes. A minimal mononuclear inflammatory infiltrate was present. Control groups showed no transduction. CONCLUSIONS: It is feasible to perform ex vivo adenoviral-mediated gene transfer to rat lung isografts during cold preservation.

Adenoviridae↗

Improvement in staging of esophageal cancer with the addition of positron emission tomography.

BACKGROUND: Positron emission tomography with the glucose analogue 2-[18F]fluoro-2-deoxy-D-glucose (FDG) has been used to detect and stage a variety of malignancies. We hypothesized that FDG-positron emission tomography would improve staging of patients with esophageal cancer and thereby facilitate selection of candidates for resection. METHODS: Fifty-eight patients (42 men and 16 women) with biopsy-proven esophageal cancer were evaluated with both FDG-positron emission tomography and computed tomography. RESULTS: In all but 2 patients, increased FDG uptake was identified at the site of the primary tumor. Six patients were not operative candidates. Seventeen patients were not candidates for resection because of metastatic disease. Positron emission tomography identified the metastatic disease in all 17 (12 of whom underwent confirmatory biopsy), whereas computed tomography was positive for metastases in only 5. The remaining 35 patients underwent surgical exploration, were judged to have resectable disease and had esophagectomy. Pathologic examination of resected specimens identified lymph node metastases in 21 patients. These nodes were detected by positron emission tomography in 11 patients and by computed tomography in 6. CONCLUSIONS: Positron emission tomography improved staging and facilitated selection of patients for operation by detecting distant disease not identified by computed tomography alone.

Adenocarcinoma↗

Pulmonary embolectomy after single-lung transplantation.

Single-lung transplantation for pulmonary hypertension results in a significant ventilation/perfusion mismatch with dramatic shift of blood flow, but not ventilation, to the replacement organ. This raises concern that the patient may be precariously dependent on the function of the transplanted lung. We report the successful management of a massive central pulmonary embolus to the transplanted lung in a 43-year-old woman 4 years after single-lung transplantation for primary pulmonary hypertension.

Adult↗

Liposome-mediated gene transfer to lung isografts.

OBJECTIVES: Our objective were to determine the feasibility, efficacy, and safety of in vivo and ex vivo liposome-mediated gene transfer to lung isografts. METHODS: Fischer rats were divided into three main groups: (1) Nontransplant setting: Liposome-chloramphenicol acetyl transferase cDNA was intravenously injected, and lungs were harvested at different time points: 2, 6, 12, and 24 hours; 2, 5, 8, and 21 days (n = 3). Chloramphenicol acetyl transferase activity was determined in lungs, hearts, livers, and kidneys. The distribution and type of transfected cells were evaluated by in situ hybridization. Lung toxicity was assessed by arterial oxygen tension, histology, and tumor necrosis factor-alpha levels. (2) In vivo graft transfection: Left lungs were transplanted 6 hours, 4 hours, and 15 minutes after intravenous injection and were assessed for chloramphenicol acetyl transferase activity and arterial oxygen tension on postoperative day 2. (3) Ex vivo graft transfection: Grafts were infused ex vivo with either 660 micrograms (n = 3) or 330 micrograms (n = 3) of DNA complexed to liposomes and stored at 10 degrees C for 4 hours. Chloramphenicol acetyl transferase activity was assessed 44 hours after transplantation. RESULTS: Transgene expression was detected in endothelial cells, macrophages, and interstitial cells. Chloramphenicol acetyl transferase activity was present as early as 2 hours, increased significantly between 6 hours and 8 days, and then decreased to minimal levels by 21 days. Chloramphenicol acetyl transferase activity was greatest in donor lungs and hearts and minimal in livers and kidneys. Arterial oxygen tension was normal in treated animals. Inflammation was minimal, and tumor necrosis factor-alpha levels increased only sevenfold in treated animals. CONCLUSION: In vivo and ex vivo liposome-mediated gene transfer to lung isografts allows significant transgene expression with minimal effects on graft function.

Animals↗

Successful in vivo and ex vivo transfection of pulmonary artery segments in lung isografts.

OBJECTIVE: Gene transfer to lung grafts may be useful in ameliorating ischemia-reperfusion injury and rejection. Efficient gene transfection to the whole organ may prove problematic. Proximal pulmonary artery endothelial transfection might provide beneficial downstream effects on the whole graft. The aim of this study was to determine the feasibility of transfecting proximal pulmonary artery segments in lung isografts. METHODS: Male Fischer rats were divided into six groups. In vivo transfection: In group I (n = 7), a proximal segment of the left pulmonary artery was isolated and injected with saline solution by means of a catheter inserted through the right ventricle. After an exposure period of 20 minutes, clamps were removed and blood flow was restored. In group II (n = 7), the isolated arterial segments were injected with adenovirus carrying the Escherichia coli LacZ gene encoding for beta-galactosidase. Ex vivo transfection: In group III (n = 5), arterial segments were injected ex vivo with saline solution and in group IV (n = 5) with the adenovirus construct. In group V (n = 6), arteries were injected with saline solution and in group VI (n = 11) with liposome chloramphenicol acetyl transferase cDNA. In groups I to IV, animals were killed on postoperative day 3 and transgene expression was assessed by Bluo-Gal staining. In groups V and VI, animals were killed on postoperative day 2 and transgene expression was assessed by chloramphenicol acetyl transferase activity assay. RESULTS: Transgene expression was detected grossly and microscopically in endothelial and smooth muscle cells of pulmonary artery segments from all surviving animals of groups II and IV. In group VI, chloramphenicol acetyl transferase activity was significant in all assessed arterial segments. CONCLUSION: Significant transgene expression is observed in proximal pulmonary artery segments after both in vivo and ex vivo exposure.

Animals↗

Adenovirus mediated gene transfer into rat lung grafts at the time of harvest.

OBJECTIVE: New methods to introduce genetic material into cells in vivo may revolutionize current treatment modalities. Expression of functional genes in lung allografts could be used as a prophylactic strategy for reperfusion injury and rejection. We studied the feasibility of ex vivo adenovirus mediated transfection of rat lung allografts. METHODS: In group I (n = 3) donor rat lungs (Fisher) were flushed with Low Potassium Dextran Glucose (LPDG) solution (20 ml, 20 degrees C). 4 x 10(11) viral particles of adenovirus 5 containing the E. coli lacZ reporter gene coding for beta-galactosidase (AdCMV-beta-Gal) were added to the last milliliter of the flush solution. Lung grafts were stored for 3.5 h at room temperature followed by syngenic orthotopic transplantation (Fisher to Fisher) using a microsurgical cuff technique. On postoperative day 5 the heart lung block was extracted and flushed with x-Gal (beta-Gal substrate) and kept in x-Gal for 3 h at 37 degrees C. Color development was observed macroscopically and plastic embedded sections were used for histologic examination. Group II grafts (n = 3) served as controls and were flushed without adenovirus. RESULTS: X-Gal stained the transfected lung grafts blue, indicating high reporter gene expression. Control lungs did not stain with x-Gal. In group I histological examination demonstrated transfection predominantly in type II pneumocytes. Surprisingly endothelial cells showed no beta-Gal activity. CONCLUSION: This study demonstrates that ex vivo transfection of lung grafts at the time of harvest is a feasible method of gene transfer and results in gene expression after transplantation.

Adenoviridae↗

Treatment of long-standing thoracostoma and bronchopleural fistula without pulmonary resection in high risk patients.

A chronic bronchopleural fistula and a fibrotic postthoracotomy space in a patient with poor functional respiratory reserve is a difficult problem. The classic management of bronchopleural cutaneous fistulas has been with further pulmonary resection to healthy bronchus, repair of the bronchus directly, and a thoracoplasty or myoplasty technique to obliterate the cavity. In a high risk patient, further pulmonary resection and thoracoplasty may be contraindicated. Myoplasty techniques alone without control of the fistula have limited success. In the last 4 years, we have treated six patients with right-sided thoracostomas after a primary open drainage procedure for bronchopleural fistula and empyema. The air leak was controlled with inversion of the sinus tract, fibrin glue, and muscle flap cavity obliteration. An average of two muscle flaps per patient were used, including the contralateral latissimus dorsi muscle. An 83 percent success rate has been achieved with this procedure in patients who otherwise would not be considered surgical candidates. Attention to the details described, including direct suture closure of the bronchial sinus, obliteration of the cavity by local muscle flaps, and avoidance of mechanical positive pressure ventilation, will make extended thoracotomy, pulmonary resection, and thoracoplasty unnecessary in these high risk patients.

Adult↗

Staging of esophageal cancer with 18F-fluorodeoxyglucose positron emission tomography.

OBJECTIVE: The objective of this study was to assess the performance of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in the staging of cancer in patients with esophageal carcinoma. MATERIALS AND METHODS: The findings of FDG PET and of CT in the chest and upper abdomen of 36 patients with newly diagnosed esophageal carcinoma were compared with pathologic findings obtained either during a curative surgical procedure with tissue sampling (n = 29) or by tissue sampling alone (n = 7). RESULTS: Abnormal FDG uptake was identified on PET in the esophageal tumors of all patients. In 29 patients who underwent curative esophagectomy, PET and CT accurately revealed the extent of nodal disease in 76% (22/29) and 45% (13/29) of patients, respectively. In the seven patients who underwent tissue sampling instead of complete esophagectomy, PET revealed metastatic disease in five patients, all of whom avoided needless surgery. CT failed to reveal metastatic disease in these five patients. In addition, PET incidentally revealed an unsuspected primary long carcinoma in one patient. CONCLUSION: FDG PET is more sensitive than CT for revealing regional and distant metastases in patients with esophageal carcinoma. The use of PET in the staging of esophageal cancer may prove to be cost-effective by decreasing the number of unnecessary surgeries in patients with unresectable tumors.

Adenocarcinoma↗

Inducible nitric oxide synthase is expressed during experimental acute lung allograft rejection.

BACKGROUND: We recently demonstrated that inhibition of nitric oxide (NO) production ameliorated acute pulmonary allograft rejection. This study examined whether inducible NO synthase (iNOS) was expressed in the transplanted lung during acute rejection. METHODS: With a rat left lung transplant model, tissue from syngeneic (Fischer 344 to Fischer 344) and allogeneic (Brown Norway to Fischer 344) transplants were harvested on postoperative day 4 and analyzed for iNOS mRNA expression (ribonuclease protection assay), iNOS enzyme activity (conversion of L-[3H]-arginine to NO and L-[3H]-citrulline), and serum nitrite/nitrate levels. RESULTS: The iNOS mRNA was expressed in allograft lungs but was not detected in isografts or controls. The iNOS protein was present in allograft lungs, as demonstrated by high levels of L-[3H]-citrulline production compared with minimal iNOS enzyme activity in isograft and control lungs (10.1 +/- 2.4 vs 0.6 +/- 0.2 and 0.7 +/- 0.2 pmol L-[3H]-citrulline.mg-1.min-1, respectively; n = 6, p < 0.001). Allografts had significantly elevated systemic serum nitrite/nitrate levels compared with isografts and controls (38 +/- 6 vs 18 +/- 2 and 16 +/- 1 mumol/L, respectively; n = 6; p < 0.005). CONCLUSIONS: These results, together with our previous demonstration that iNOS inhibition ameliorated lung allograft rejection, suggest that (1) iNOS expression and increased NO production contributed to acute rejection of the transplanted lung, (2) iNOS inhibition may offer an alternative in management of acute lung allograft rejection, and (3) increased NO production, detected by the presence of iNOS mRNA or protein or noninvasively by measuring serum nitrite/nitrate levels, may serve as an early marker of acute allograft rejection.

Animals↗

Pulmonary hemodynamics modify the rat pulmonary artery response to injury. A neointimal model of pulmonary hypertension.

Hemodynamic factors have profound influences on blood vessels. To test the hypothesis that hemodynamic conditions modify the pattern of remodeling in response to injury, monocrotaline (MCT) injury in Sprague-Dawley rats was followed 1 week later by left pneumonectomy to increase blood flow to the right lung. Right pulmonary artery remodeling in these MCT plus pneumonectomy animals was compared with animals receiving MCT or pneumonectomy alone. Neointimal changes developed in more than 90% of all right lung intra-acinar vessels 5 weeks after MCT injury (4 weeks after pneumonectomy). Neointimal lesions did not develop in untreated animals or in animals receiving MCT or pneumonectomy only. Animals with a neointimal pattern of remodeling developed severe right ventricular hypertrophy (RVH) whereas animals with a medial hypertrophy pattern of remodeling (MCT only) developed moderate RVH compared with control animals. Neointimal lesions and RVH were similar whether injury preceded pneumonectomy or vice versa. To exclude the possibility that neointimal lesions resulted from injury plus post-pneumonectomy compensatory lung growth, rather than injury plus increased flow, a left subclavian-pulmonary artery anastomosis was substituted for pneumonectomy. Neointimal lesions and severe RVH developed in these animals but were not seen in animals receiving either MCT or anastomosis only. These studies demonstrate an important role for hemodynamics in determining the pattern of pulmonary vascular remodeling after injury.

Actins↗

Carbohydrate selectin inhibitor CY-1503 reduces neutrophil migration and reperfusion injury in canine pulmonary allografts.

BACKGROUND: Neutrophil adhesion is initiated by the interaction of rapidly expressed endothelial selectins with oligosaccharide structures (sialyl Lewis(x) on polymorphonuclear neutrophils (PMN). The carbohydrate sialyl Lewis X analogue CY-1503 blocks selectin receptors, thereby inhibiting PMN rolling and subsequent firm adhesion and migration. METHODS: We evaluated the inhibitory effect of CY-1503 on PMN migration and reperfusion injury in canine left lung allografts. Donor lungs were flushed with modified Euro-Collins solution (1500 ml, 4 degrees C) and preserved for 21 hours at 1 degree C. Left lung allotransplantation was subsequently performed in 14 mongrel dogs. Immediately after transplantation and allograft reperfusion, the recipient contralateral right pulmonary artery and bronchus were ligated to permit assessment of isolated allograft function during a 6-hour postreperfusion period (FIO2 = 1.0). Allograft gas exchange (q 15 minutes) and hemodynamics (q 60 minutes) were assessed. After sacrifice, allograft bronchoalveolar lavage fluid (BALF) PMN count and allograft tissue myeloperoxidase (MPO) activity were measured. Two groups were studied: In group I (n = 7) CY-1503 was added to the donor lung flush (20 mg/L) and given to the recipient (35 mg/kg intravenous bolus) before reperfusion, followed by a continuous infusion (5.25 mg/kg/h intravenously) during the 6-hour assessment period. Group II animals (n = 7) received no CY-1503. RESULTS: Gas exchange in group I was superior throughout the assessment period (p < 0.01 at 6 hours after reperfusion). BALF PMN count in group I was reduced to 0.57 +/- 0.3 x 10(6) PMN/ml compared with 3.9 +/- 1.3 x 10(6) PMN/ml in group II (p < 0.05). Group I allograft MPO activity was 0.21 +/- 0.06 compared with 0.40 +/- 0.02 delta OD/mg/ min in controls (p < 0.02). Two animals in each group died early after reperfusion as a result of graft failure and were excluded from analysis. CONCLUSIONS: Our observations indicate that selectin inhibition effectively reduces PMN adhesion, migration, and subsequent reperfusion injury in preserved canine lung allografts.

Animals↗

Preharvest nitroprusside flush improves posttransplantation lung function.

BACKGROUND: Morbidity as a result of early allograft dysfunction remains a significant problem in clinical lung transplantation. We previously demonstrated that nitroprusside (NP), a potent nitric oxide donor, administered before storage and again during reperfusion, reduced lung reperfusion injury. The purpose of the present study was to determine whether these observations were storage effects, reperfusion effects, or both. MATERIALS AND METHODS: Fifteen dogs underwent left lung allotransplant. Donor lungs were flushed with modified Euro-Collins solution and stored for 21 hours at 1 degree C. Immediately after transplantation, the contralateral right main pulmonary artery and bronchus were ligated to assess isolated allograft function. Hemodynamics and arterial blood gas analysis (FIO2 1.0) were assessed for 6 hours before sacrifice. Allograft myeloperoxidase (MPO) activity and wet to dry weight (W/D) ratio were assessed. Animals were divided into three groups for timing of NP administration. Group I (n = 5) animals received no NP. In group II (n = 5), donor lungs received NP (10 mg/L) in the flush solution only. In group III (n = 5), recipient animals received NP (0.2 mg/kg) just before reperfusion, as well as a continuous infusion (0.1 mg/kg/hr) during the assessment period. RESULTS: Significant improvement in gas exchange was apparent in groups II and III compared with group I, but there was no significant difference between groups II and III. After 6-hour reperfusion, mean PaO2 values were 85.46 +/- 13.32 mm Hg in group I, 298.74 +/- 61.25 mm Hg in group II (p < 0.05), and 311.12 +/- 43.39 mm Hg in group III (p < 0.05). Systemic vascular resistance was significantly lower in group III than in group I (p < 0.05). MPO activities decreased in groups II (p < 0.05) and III (p < 0.05), indicating reduced neutrophil sequestration. W/D ratio was significantly lower in groups II and III. CONCLUSION: Both methods of NP administration are effective, but NP administration in the recipient is accompanied by a decrease in systemic vascular resistance. From a clinical point of view, NP administration in the flush solution is a sufficiently effective and practical method to reduce lung allograft reperfusion injury.

Analysis of Variance↗

Increased concentration of soluble human leukocyte antigen class I levels in the bronchoalveolar lavage of human pulmonary allografts.

BACKGROUND: Human leukocyte antigen (HLA) class I antigens, are glycoproteins expressed on the cell surface and are also secreted (sHLA) into the surrounding fluids. This study investigates whether pulmonary allograft rejection is associated with an increased amount of sHLA class I in the bronchoalveolar lavage (BAL) fluid. METHODS: Enzyme-linked immunosorbant assays were used to measure sHLA class I levels in BAL samples from 66 lung transplant recipients. RESULTS: Analysis of pulmonary allograft recipients revealed that the mean concentration of sHLA class I was significantly higher in samples from recipients with acute rejection than in recipients with no evidence of rejection. Seventy-two percent of the patients with rejection had sHLA levels above the normal range for patients with infection or rejection. Conversely, sHLA levels were within normal limits in 94% of the control population. Time kinetic analysis revealed that in subjects with rejection, sHLA class I levels peaked in the first 2 weeks after transplantation and decreased thereafter. Increased levels of sHLA were found in patients with acute rejection but not in those with chronic rejection. Fifty-nine percent (n = 10) of the patients with infection had sHLA levels within the normal (no infection or rejection) range. The remaining 41% (n = 7) with infection had sHLA above the normal range. Fifty-seven percent (n = 4) of the latter group had cytomegalovirus infection. These results were confirmed in a prospective study carried out by analyzing paired samples obtained during and after rejection. Eight of the nine patients had high BAL sHLA class I during acute rejection, and low BAL sHLA class I levels after resolution of the acute rejection. CONCLUSION: Our data demonstrate that measurement of sHLA class I levels in BAL samples is a sensitive indicator of acute rejection.

Acute Disease↗