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Biomedical subjects

C D Wright

Publications and source records attributed to C D Wright.

At least 19 recordsLinked to original sources
PubMed2001

Mediastinal tumors: diagnosis and treatment.

Mediastinal tumors are uncommon and often asymptomatic if benign. Tumors have a predilection for arising in one of three mediastinal compartments; anterior, middle, or posterior. If symptoms are present, they are usually compressive in origin. Computed tomography is almost always the imaging modality of choice. Benign-appearing lesions are usually resected for cure. Malignant-appearing lesions usually require biopsy by the least invasive route appropriate for the suspected tumor type.

Castleman Disease↗
PubMed2001

Superior sulcus tumors.

Superior sulcus tumors (also known as Pancoast's tumors) are an unusual presentation of non-small cell lung cancer (NSCLC) that are often initially misdiagnosed. Accurate and thorough staging is necessary prior to treatment and typically includes magnetic resonance imaging if a surgical approach is being considered. Standard therapy has been induction radiation therapy followed by resection, which results in a 5-year survival of about 30%. Complete resection remains the key to long-term survival in localized NSCLC but is difficult to achieve with superior sulcus tumors due to early invasion of bone and to vascular and nervous structures at the apex of the chest. Complete resection has been enhanced by using an anterior trans-cervicomediastinal approach that facilitates resection of anterior-based tumors that invade the subclavian vessels. Recently, induction chemoradiotherapy has been reported to enhance complete resection rates and improve survival compared with historical controls and is likely to become the new standard treatment for localized superior sulcus tumors.

Antineoplastic Agents↗
PubMed2001

Trial of a novel synthetic sealant in preventing air leaks after lung resection.

BACKGROUND: Postoperative air leaks are a major cause of morbidity after lung resections. This study was designed to evaluate the efficacy and safety of a new synthetic, bioresorbable surgical sealant in preventing air leaks after pulmonary resection. METHODS: In a multicenter trial, 172 patients undergoing thoracotomy were randomized intraoperatively in a 2:1 ratio to receive surgical sealant applied to sites at risk for air leak after standard methods of lung closure (treatment group) or to have standard lung closure only (control group). The primary outcome variable was the percentage of patients free of air leakage throughout hospitalization. Secondary outcome variables were the control of air leaks intraoperatively and the time to postoperative air leak cessation. Time to chest tube removal, time to hospital discharge, and safety outcomes were also evaluated. RESULTS: Air leaks were identified before randomization in 89 of 117 patients in the treatment group and in 39 of 55 patients in the control group. Application of the sealant resulted in control of air leaks in 92% of treated patients (p < or = 0.001). A significantly higher percentage of treated patients than control patients remained free of air leaks during hospitalization (39% versus 11%, p < or =0.001). The mean times to last observable air leak were 30.9 hours in the treatment group and 52.3 hours in the control group (p = 0.006). In the treatment group, trends were observed for reduced time to chest tube removal and earlier discharge. No significant difference was identified in postoperative morbidity and mortality between the two groups. CONCLUSIONS: Air leaks after lung resection occur in most patients. The application of this novel surgical sealant appears to be effective and safe in preventing postoperative air leaks.

Acrylates↗
PubMed2001

Limitations of randomized clinical trials for evaluating emerging operations: the case of lung volume reduction surgery.

Although unanswered questions remain, scores of observational studies and several small randomized clinical trials (RCTs) indicate that lung volume reduction surgery (LVRS) offers safe and effective palliation for a relatively well defined subset of patients with advanced emphysema. Nonetheless, Medicare and other insurers stopped reimbursement for the procedure. Subsequently, two multicenter RCTs on LVRS, the National Emphysema Treatment Trial (NETT) and the Overholt-BlueCross Emphysema Surgery Trial (OBEST), were launched with the stipulation that the procedure would not be paid for outside these trials. Thus access to LVRS has been denied to patients who could benefit but do not wish to participate in an RCT. Emerging operations, unlike new drugs or devices, pass through evolutionary changes and frequently fail to produce data that meet the scientific rigor required by randomized studies. In such a setting, the observational approach is more appropriate. Indeed, almost all operations in the present surgical armamentarium have been evaluated and have evolved through observational studies without the use of RCTs. By the time new operations are standardized and qualify for RCTs, benefits for certain patients may be demonstrated and randomization could involve unacceptable health hazards. Patients from this population should be offered the choice between participating in RCTs and having the operation outside the study. Imposition of financial restrictions that bars access to a therapy with known benefit is a questionable practice.

Bias↗
PubMed2001

Impact of hospital volume on clinical and economic outcomes for esophagectomy.

BACKGROUND: Several complex surgical procedures had a reduction in mortality when they were performed at high volume centers. We hypothesized esophagectomy procedures for cancer performed at high volume hospitals in the state of Massachusetts would show a similar relationship. METHODS: Data were obtained from the Massachusetts Health Data Consortium on discharge information for all acute care hospitals in Massachusetts regardless of payer from 1992 to 2000. The influence of hospital volume was related to days in the intensive care unit, length of stay, discharge disposition, hospital mortality, and total cost. Hospitals were stratified to low volume hospitals (< 6 cases per year) and high volume hospitals (> 6 cases per year). RESULTS: One thousand one hundred ninety-three patients underwent esophagectomy during this 8-year study period in Massachusetts. Three high volume hospitals performed 56.5% of all resections (674 of 1,193). Sixty-one low volume hospitals performed 43.5% of the resections (519 of 1,193) with an average volume of only 1 case of esophagectomy per year. High volume hospitals were associated with a 2-day decrease in median length of stay (p < 0.001), a 3-day reduction in median intensive care unit stay (p < 0.001), an increased rate of home discharges (as opposed to rehabilitation hospitals) (p < 0.001), and a 3.7-fold decrease in hospital mortality (9.2% vs 2.5%; p < 0.001). The odds ratio of death at a low volume hospital was 4.3 (95% confidence interval, 2.3 to 7.7; p < 0.001). The median cost was $755 dollars greater at high volume hospitals (p = not significant). CONCLUSIONS: Hospitals that perform a high volume of esophagectomies have better results with early clinical outcomes and marked reductions in mortality compared with low volume hospitals.

Aged↗
PubMed2001

Resection for bronchogenic carcinoma involving the carina: long-term results and effect of nodal status on outcome.

OBJECTIVE: Bronchogenic carcinoma in close proximity to or involving the carina remains a challenging problem for thoracic surgeons. The operative procedures to allow complete resection are technically demanding and can be associated with significant morbidity and mortality. Little is known about long-term survival data to guide therapy in these patients. METHODS: We conducted a single-institution retrospective review. RESULTS: We have performed 60 carinal resections for bronchogenic carcinoma: 18 isolated carinal resections for tumor confined to the carinal or proximal main stem bronchus; 35 carinal pneumonectomies; 5 carinal plus lobar resections, and 2 carinal resections for stump recurrence after prior pneumonectomy. Thirteen patients (22%) had a history of lung or airway surgery. The overall operative mortality was 15%, improved from the first half of the series (20%) to the second half (10%), and varied according to the type of resection performed. Adult respiratory distress syndrome was responsible for 5 early deaths, and all late deaths were related to anastomotic complications. In 34 patients, all lymph nodes were negative for metastatic disease; 15 patients had positive N1 nodes, and 11 patients had positive N2/N3 nodes. Complete follow-up was accomplished in 90%, with a mean follow-up of 59 months. The overall 5-year survival including operative mortality was 42%, with 19 absolute 5-year survivors. Survival was highest after isolated carinal resection (51%). Lymph node involvement had a strong influence on survival: patients without nodal involvement had a 5-year survival of 51%, compared with 32% for patients with N1 disease and 12% for those with N2/N3 disease. CONCLUSIONS: This constitutes one of the largest single-institution reports on carinal resection for bronchogenic carcinoma involving the carina. Morbidity and mortality rates are acceptable. The overall survival including operative mortality is 42%. Positive N2/N3 lymph nodes may be a contraindication to surgery because of poor prognosis.

Adenocarcinoma↗
PubMed2001

Temperature distributions in laser-heated biological tissue with application to birthmark removal.

The time-dependent temperature distributions produced within thermally homogeneous media heated by a moving laser beam with Gaussian and uniform power density profiles are examined using a time-domain method based on Green's functions. Regions of finite length, width, and depth within the medium having exponential power absorption are considered. The temperature distribution is written as a single integral with respect to time of simple functions and the resulting expressions have been used to model the heating of blood vessels for birthmark (port-wine stain) removal. The temperature distributions obtained are in good agreement with those produced using Monte Carlo optical and finite difference thermal models.

Dermatologic Surgical Procedures↗
PubMed2000

Stage III thymoma: pattern of failure after surgery and postoperative radiotherapy and its implication for future study.

PURPOSE: With the conventional approach of surgery and postoperative radiotherapy for patients with Masaoka Stage III thymoma, progress has been slow for an improvement in the long-term survival rate over the past 20 years. The objective of this study was to evaluate the pattern of failure and survival after surgery and postoperative radiotherapy in Stage III thymoma and search for a new direction for better therapy outcome. METHODS AND MATERIALS: Between 1975 and 1993, 111 patients with thymoma were treated at Massachusetts General Hospital. Of these, 32 patients were determined to have Masaoka Stage III thymoma. The initial treatment included surgery for clinically resectable disease in 25 patients and preoperative therapy for unresectable disease in 7 patients. Surgical procedure consisted of thymectomy plus resection of involved tissues. For postoperative radiotherapy (n = 23), radiation dose consisted of 45-50 Gy for close resection margins, 54 Gy for microscopically positive resection margins, and 60 Gy for grossly positive margins administered in 1.8 to 2.0 Gy of daily dose fractions, 5 fractions a week, over a period of 5 to 6.6 weeks. In preoperative radiotherapy, a dose of 40 Gy was administered in 2.0 Gy of daily dose fractions, 5 days a week. For patients with large tumor requiring more than 30% of total lung volume included in the target volume (n = 3), a preoperative radiation dose of 30 Gy was administered and an additional dose of 24-30 Gy was given to the tumor bed region after surgery for positive resection margins. RESULTS: Patients with Stage III thymoma accounted for 29% (32/111 patients) of all patients. The median age was 57 years with a range from 27 to 81 years; gender ratio was 10:22 for male to female. The median follow-up time was 6 years. Histologic subtypes included well-differentiated thymic carcinoma in 19 (59%), high-grade carcinoma in 6 (19%), organoid thymoma in 4 (13%), and cortical thymoma in 3 (9%) according to the Marino and Müller-Hermelink classification. The overall survival rates were 71% and 54% at 5 and 10 years, respectively. Ten of the 25 patients who were subjected to surgery as initial treatment were found to have incomplete resection by histopathologic evaluation. The 5- and 10-year survival rates were 86% and 69% for patients (n = 15) with clear resection margins as compared with 28% and 14% for those (n = 10) with incomplete resection margins even after postoperative therapy, p = 0.002. Survival rates at 5 and 10 years were 100% and 67% for those with unresectable disease treated with preoperative radiation (n = 6) and subsequent surgery (n = 3). Recurrence was noted in 12 of 32 patients and 11 of these died of recurrent thymoma. Recurrences at pleura and tumor bed accounted for 77% of all relapses, and all pleural recurrences were observed among the patients who were treated with surgery initially. CONCLUSION: Incomplete resection leads to poor results even with postoperative radiotherapy or chemoradiotherapy in Stage III thymoma. Pleural recurrence is also observed more often among patients treated with surgery first. These findings suggest that preoperative radiotherapy or chemoradiotherapy may result in an increase in survival by improving the rate of complete resection and reducing local and pleural recurrences.

Adult↗
PubMed2000

Anti-inflammatory effects of mutant forms of secretory leukocyte protease inhibitor.

The secretory leukocyte protease inhibitor (SLPI) is found in a variety of secreted fluids in mammals and is a known inhibitor of serine proteases. Wild-type (WT) SLPI has recently been shown to block nuclear factor kappaB (NF-kappaB) activation in rat lungs and to interfere with the ensuing inflammatory response and recruitment of neutrophils after an intrapulmonary deposition of IgG immune complexes. In this study, WT SLPI and SLPI mutants with various degrees of protease-inhibitory capacity (for trypsin, chymotrypsin, and elastase) were evaluated for their ability to suppress the lung-vascular leak, neutrophil accumulation, and NF-kappaB activation in the lung inflammatory model. The SLPI mutant with Gly(72) (replacing Leu(72) ) lost its ability to block in vivo activation of NF-kappaB, as well as its ability to suppress the lung vascular leak and neutrophil recruitment. The Phe(72) and Gly(20) mutants were as effective as the WT SLPI in suppressing NF-kappaB activation and neutrophil recruitment. The Lys(72) mutant had the most suppressive effects of the lung vascular leak and for neutrophil recruitment into the lung. The in vivo suppressive effects of SLPI mutants on lung vascular permeability, neutrophil recruitment, and NF-kappaB activation appear to be most closely related to their trypsin-inhibiting activity. These data suggest that the suppressive effects of SLPI on the intrapulmonary activation of NF-kappaB and neutrophil recruitment into the lung may be linked to their antiprotease activity, directed, perhaps, at the intracellular proteases.

Acute Disease↗
PubMed2000

Secretory leukocyte protease inhibitor, an inhibitor of neutrophil activation, is elevated in serum in human sepsis and experimental endotoxemia.

OBJECTIVES: To document changes in serum secretory leukocyte protease inhibitor (SLPI) in human sepsis and in experimental endotoxemia in vivo. To compare changes in serum SLPI in human sepsis with changes in interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha. To determine whether or not changes in SLPI correlate with the severity of multiple organ dysfunction syndrome as measured by the maximal multiple organ dysfunction score. Finally, because neutrophils have been implicated in tissue injury associated with organ dysfunction, to determine whether recombinant human SLPI blocks activation of isolated human neutrophils. DESIGN: Case-control study and ex-vivo cellular assay. SETTING: Surgical intensive care unit and clinical research center of university hospitals; laboratory of a medical school. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There was a significant dose-dependent elevation (50.2+/-4.0 ng/mL, p = .01) in plasma SLPI 12 hrs after administration of lipopolysaccharide to seven healthy adults (36.4+/-2.3 ng/mL). Further, serum concentrations of SLPI (132+/-15 ng/mL) were elevated in septic surgical patients compared with healthy controls (43+/-2 ng/mL, p < .01) and nonseptic surgical controls (69+/-10 ng/mL, p = .01). Serum SLPI concentrations correlated (r2 = .71, p < .01) better with organ dysfunction as measured by maximal multiple organ dysfunction score than did serum IL-6 (r2 = .49, p < .01), IL-10 (r2 = .05, p = .22), or TNF-alpha (r2 = .02, p = .44). We found that recombinant human SLPI in vitro inhibits TNF-alpha-induced hydrogen peroxide production by human neutrophils (ID50 = 1-2 microg/mL). CONCLUSIONS: Serum SLPI is elevated in human sepsis and experimental endotoxemia. Maximal concentrations of serum SLPI correlate significantly with maximal multiple organ dysfunction scores in patients with sepsis. Secretory leukocyte protease inhibitor may function to limit ongoing neutrophil-mediated tissue injury associated with organ dysfunction.

Adolescent↗
PubMed1999

Inhibition of allergen-induced pulmonary responses by the selective tryptase inhibitor 1,5-bis-[4-[(3-carbamimidoyl-benzenesulfonylamino)-methyl]-phenoxy]-pen tane (AMG-126737).

Emerging evidence suggests that mast cell tryptase is a therapeutic target for the treatment of asthma. The effects of this serine protease are associated with both pathophysiologic pulmonary responses and pathologic changes of the asthmatic airway. In this study, the tryptase inhibitor 1,5-bis-[4-[(3-carbamimidoyl-benzenesulfonylamino)-methyl]-p henoxy]-pentane (AMG-126737) was evaluated for its pharmacologic effects against allergen-induced airway responses. AMG-126737 is a potent inhibitor of human lung mast cell tryptase (Ki = 90 nM), with greater than 10- to 200-fold selectivity versus other serine proteases. Intratracheal administration of AMG-126737 inhibited the development of airway hyperresponsiveness in allergen-challenged guinea pigs with an ED50 of 0.015 mg/kg. In addition, the compound exhibited oral activity in the guinea pig model. The in vivo activity of AMG-126737 was confirmed in a sheep model of allergen-induced airway responses, where the compound inhibited early and late phase bronchoconstriction responses and the development of airway hyperresponsiveness. These results support the proposed role of tryptase in the pathology of asthma and suggest that AMG-126737 has potential therapeutic utility in this pulmonary disorder.

Allergens↗
PubMed1999

Potent selective nonpeptidic inhibitors of human lung tryptase.

Human lung tryptase, a homotetrameric serine protease unique to mast cell secretory granules, has been implicated in the pathogenesis of asthma. A hypothesis that tethered symmetrical inhibitors might bridge two adjacent active sites was explored via a rationally designed series of bisbenzamidines. These compounds demonstrated a remarkable distanced-defined structure-activity relationship against human tryptase with one series possessing subnanomolar potencies. Additional evidence supporting the concept of active-site bridging is also presented.

Asthma↗
PubMed1999

Inhibition of murine neutrophil serine proteinases by human and murine secretory leukocyte protease inhibitor.

Human secretory leukocyte protease inhibitor (SLPI) is a predominant physiologic inhibitor of elastase and cathepsin G, proinflammatory serine proteases released by activated neutrophils. In order to fully evaluate the potential pharmacologic efficacy of human SLPI in animal models of inflammation, it is critical to know the potency of the inhibitor for corresponding proteases from the species of interest. In this report, we compare the inhibitory activity of human and murine SLPI against elastase and cathepsin G from both species. Human and murine neutrophil elastase and cathepsin G display comparable Km values for their specific peptide substrates. Murine SLPI inhibits murine neutrophil elastase and cathepsin G with Ki values of 5 and 0.12 nM, respectively, while human SLPI inhibits the both murine serine proteases with Ki's of 0.02 nM. In contrast, murine SLPI inhibits human neutrophil elastase and cathepsin G with Ki values of 1.4 and 90 nM, respectively, while human SLPI inhibits the proteases with Ki's of 0.3 and 10 nM, respectively. These results demonstrate species-specific variations in the protease inhibitory activities of SLPI. Such variations should be considered in the evaluation of the activity of human SLPI in murine pharmacologic models.

Animals↗
PubMed1999

Induction immunosuppression for lung transplantation with OKT3.

BACKGROUND: The use of OKT3, an anti-CD3 monoclonal antibody, for immunosuppressive therapy for lung transplantation has been restricted because of concerns regarding infectious risk and cardiopulmonary instability after its administration. METHODS: Fifty-two patients received OKT3 (5 mg/d intravenously for 10 days) for induction of immunosuppressive therapy, along with azathioprine (1.5 mg x kg(-1) x d(-1) intravenously) and enteral cyclosporine (12 mg x kg(-1) x d(-1)). Maintenance steroid therapy was begun on postoperative day 8. Prophylactic antifungal therapy (fluconazole or amphotericin B) and ganciclovir was used in all patients. Serial transbronchial biopsy and measurements of pulmonary function were used to assess patients for evidence of infection or rejection. Cytomegalovirus infection was diagnosed by biopsy or the presence of cytomegalovirus antigenemia. RESULTS: The 30-day mortality rate was 4%; the in-hospital mortality rate was 8%. Acute graft failure was seen in 6 patients. The median length of intubation was 5 days, and the median hospital stay was 30 days. Systemic and pulmonary artery systolic pressures, cardiac index, and ratio of arterial partial oxygen pressure to fraction of inspired oxygen showed no significant alteration after OKT3 dosage. Gram-negative pulmonary infections were identified in 12 patients. Aspergillus infection was seen in 7 patients. Cytomegalovirus infection in 8 patients responded to ganciclovir and did not affect mortality. Respiratory syncytial viral infection was seen in 7 patients. Acute rejection was never seen during OKT3 administration. No episodes of acute rejection were identified in 14 patients at any time postoperatively. In the remainder, episodes of acute rejection responded to steroid or antithymocyte globulin therapy. At a median length of follow-up of 31 months, freedom from obliterative bronchiolitis was 69%+/-9% at 36 months. The overall survival rate was 88%+/-5% at 12 months, 82%+/-6% at 24 months, and 74%+/-7% at 36 months after transplantation. CONCLUSIONS: OKT3 is a safe and effective agent for induction immunosuppressive therapy in lung transplant recipients that limits the incidence of acute rejection and may decrease the incidence of obliterative bronchiolitis.

Adolescent↗
PubMed1999

Long-segment colon interposition for acquired esophageal disease.

BACKGROUND: Long-segment colon interposition has been used for esophageal replacement for acquired esophageal disease. The indications for use, morbidity, and functional results of these conduits have been debated. METHODS: We reviewed the medical records, office visits, and operative reports of patients undergoing long colon interposition for acquired esophageal disease at our institution from 1956 to 1997. RESULTS: Long colon interposition was performed in 52 patients for caustic injury (n = 20), gastroesophageal disease (n = 16), previous irradiation (n = 8), primary motility disorders (n = 4), and acquired absence of the esophagus (n = 4). From 1976 to 1997, acquired diseases accounted for 62% of long colon interposition. The left colon was used in 46 patients and the right colon in 6. The in-hospital mortality rate was 4%. Early complications included graft ischemia in 5 patients, anastomotic leak in 3, and small bowel obstruction in 1. Late complications included anastomotic stenosis requiring dilation in 26 patients, with 2 requiring surgical revision, and bile reflux requiring surgical diversion in 1 patient. Swallowing function was excellent in 24% of patients, good in 66%, and poor in 10%. CONCLUSIONS: Long colon interposition can be performed safely, with acceptable long-term functional results in patients with acquired esophageal disease.

Adult↗
PubMed1999

Bronchoalveolar carcinoma: clinical, radiologic, and pathologic factors and survival.

BACKGROUND: The principal feature of bronchoalveolar carcinoma is that it spreads along airways or aerogenously with multifocality, but many issues are unresolved. METHODS: We studied 119 patients with pathologically confirmed bronchoalveolar carcinoma. Symptoms, smoking status, radiologic findings, the size of tumor, operative procedures, and complications were reviewed. We studied the pathologic features: presence or absence of aerogenous spread, patterns of growth, cell type, nuclear grade, mitosis, rate of bronchoalveolar carcinoma in adenocarcinoma, and lymphocyte infiltration. The correlation among clinical, radiologic, and pathologic findings was examined, and the factors affecting survival were analyzed. RESULTS: Symptomatic patients had more infiltrative radiographic features, and asymptomatic patients tended to have more mass-like features (P <.0001). Tumors with radiographically infiltrating lesions tended to have mucinous histologic features (P =.006). Tumors with mass lesions by radiograph tended to have nonmucinous and sclerosing histologic features (P =.003). Aerogenous spread was seen in 94% of specimens. The presence of a variety of cell types suggested multiple clonal origin. The overall survival in those patients undergoing resection was 69.1% at 5 years and 56.5% at 10 years. The significant factors affecting survival were radiologic presence of a mass or infiltrate, pathologic findings of the presence of sclerosis, association with a scar, the rate of bronchoalveolar carcinoma in adenocarcinoma, lymphocyte infiltration grade, nodal involvement, and status of complete resection. Mitosis or nuclear grade of tumor cells did not correlate with survival. CONCLUSIONS: Bronchoalveolar carcinoma showed good overall survival with appropriate surgical procedures. Certain radiologic or pathologic findings correlated with survival. These findings may enhance the ability to predict long-term survival.

Adenocarcinoma, Bronchiolo-Alveolar↗