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Biomedical subjects

M Blair Marshall

Publications and source records attributed to M Blair Marshall.

17 recordsLinked to original sources
PubMed2006

Inactivation of TGF-beta signaling in lung cancer results in increased CDK4 activity that can be rescued by ELF.

Escape from TGF-beta inhibition of proliferation is a hallmark of multiple cancers including lung cancer. We explored the role of ELF, crucial TGF-beta adaptor protein identified from endodermal progenitor cells, in lung carcinogenesis and cell-cycle regulation. Interestingly, elf-/- mice develop multiple defects that include lung, liver, and cardiac abnormalities. Four out of 6 lung cancer and mesothelioma cell lines displayed deficiency of ELF expression with increased CDK4 expression. Immunohistochemistry and Western blot analysis of primary human lung cancers also showed decreased ELF expression and overexpression of CDK4. Moreover, rescue of ELF in ELF-deficient cell lines decreased the expression of CDK4 and resulted in accumulation of G1/S checkpoint arrested cells. These results suggest that disruption in TGF-beta signaling mediated by loss of ELF in lung cancer leads to cell-cycle deregulation by modulating CDK4 and ELF highlights a key role of TGF-beta adaptor protein in suppressing early lung cancer.

Animals↗
PubMed2006

Modified central line for pneumothorax.

Pneumothoraxes, whether spontaneous or iatrogenic, frequently require drainage. Although the recent trend has been toward a catheter-based approach, many thoracic surgeons continue to use chest tubes. Tube thoracostomy is associated with significant pain at the time of insertion and during continued drainage. Pneumothorax catheters are less painful but more expensive, and some have been associated with significant failure. After disappointing experience with pneumothorax catheters, we have modified a central line to use in lieu of a pneumothorax kit. We have found this technique to be effective, safe, reliable, and inexpensive.

Catheterization↗
PubMed2006

Anterior surgical approaches to the thoracic outlet.

OBJECTIVES: The anatomy of the thoracic outlet is complex, and the optimum surgical approach to pathologic disease at this location is controversial. Although the Dartevelle approach to the apex seems to be a safer and more direct approach, this technique has not been widely adopted in the United States. We have used this approach for pathologic disease at the thoracic outlet and modified it. Our experience is described in this article. METHODS: A retrospective review was performed on all patients who underwent an anterior approach between December 1997 and May 2003. RESULTS: There were 42 patients who underwent anterior approaches to pathologic disease at the level of the outlet. Diagnosis included apical non-small cell lung cancers (20 patients), osteosarcoma (2 patients), spinal cord compression (5 patients), solitary metastasis (4 patients), and benign lesions (11 patients). There were 22 female and 20 male patients with ages ranging from 26 to 82 years (mean age, 54.6 years). There were 25 complications in 14 patients and 1 in-hospital death. A transmanubrial approach was used in 14 patients, the standard Dartevelle technique was used in 8 patients, and a transclavicular approach with reapproximation of the clavicle was used in 20 patients. Reapproximation failed in 5 patients (3/3 patients who underwent fixation with mini-plates and 2/17 patients with sternal wires). CONCLUSIONS: The anterior approach is a useful adjunct to a thoracic surgeon's armamentarium. When a transclavicular approach is optimal, division and reapproximation of the clavicle are feasible. In our experience, reapproximation with wires is superior to plates and screws.

Adult↗
PubMed2005

Invited commentary.

Explore the source record for details and available documents.

Carcinoma, Non-Small-Cell Lung↗
PubMed2005

Comparative study of subxiphoid versus video-thoracoscopic pericardial "window".

BACKGROUND: It remains undefined whether surgical subxiphoid drainage or thoracoscopic pericardial "window" is the optimal operative approach to pericardial effusion. We hypothesized that the true window into the pleural space created by the latter might improve the duration of freedom from recurrent effusion. METHODS: We conducted a retrospective chart review of indications, preoperative and intraoperative variables, morbidity, recurrence, and survival. RESULTS: Fifty-six patients underwent the subxiphoid procedure and 15 underwent the thoracoscopic procedure. Echocardiographic evidence of tamponade was present before 8 of 10 thoracoscopic procedures (80%) and 43 of 56 subxiphoid procedures (81%) for which descriptions of hemodynamics were available. In addition, non-pericardial procedures were performed in 10 (67%) and 18 (32%) patients, respectively (p = 0.020). Anesthesia time was longer at thoracoscopy (117.1 +/- 32.4 vs 81.1 +/- 25.5 minutes; p < 0.001). Procedural morbidity was higher after thoracoscopy (4 [27%] vs 1 [2%]; p = 0.006), but was generally minor. Hospital mortality tended to be higher after the subxiphoid procedure (7 [13%] vs 0 [0%]; p = 0.332), but none of the deaths was procedure-related. Follow-up was complete for 65 patients (92%). Recurrence occurred in 1 thoracoscopy patient (8%) and 5 subxiphoid patients (10%) (p = 1.000). Mean time to recurrence by Kaplan-Meier analysis trends were longer after thoracoscopy (36.1 vs 11.4 months; p = 0.16), and multivariate analysis identified the thoracoscopic approach as an independent predictor of freedom from recurrence (relative risk, 0.41; p = 0.014). CONCLUSIONS: Operative time and minor procedural morbidity are higher with thoracoscopic pericardial window, but long-term control of effusion seemed to be better than after subxiphoid surgical drainage.

Female↗
PubMed2005

Catamenial pneumothorax: optimal hormonal and surgical management.

OBJECTIVE: To provide further information addressing the etiology, optimal hormonal management and surgical management in catamenial pneumothorax (CP). METHODS: We retrospectively analyzed records of all female patients operated on for spontaneous pneumothorax at a university hospital between January 1993 and March 2002. RESULTS: In eight of 24 patients, pneumothoraces were timed with menses. In all, the right side was involved. Seven patients were on hormonal medications pre-operatively and six post-operatively. All six patients taking estrogen/progesterone replacement had recurrences pre-operatively and two of three had recurrences post-operatively while on these medications. No patient suffered a pneumothorax either pre- or post-operatively while taking a gonadotropin releasing hormone agonist (two and three patients, respectively). Intraoperative findings included diaphragmatic implants [5] diaphragmatic fenestrations [4], apical blebs [2] and visceral pleural implants [2]. All pathology was specifically addressed at the time of surgery. Pleural space management included mechanical pleurodesis in seven and pleurectomy with talc insufflation in 1. Follow-up ranged from 27 to 63 months with a mean of 48 months. Three patients developed post-operative recurrences. One was managed without intervention and two required additional procedures. CONCLUSION: Catamenial pneumothorax is under appreciated, representing up to one-third of women with spontaneous pneumothorax. Hormonal agents that allow for menses are ineffective. Gonadotropin releasing hormone agonists should be considered as part of the pre-operative or post-operative management in high risk patients. Our findings suggest that an additional intervention to augment pleural symphysis at the level of the diaphragm should be performed.

Adult↗
PubMed2005

Mediastinal Castleman disease mimicking mediastinal pulmonary sequestration.

We describe a 39-year-old woman who presented with anterior mediastinal Castleman disease that mimicked an anterior mediastinal pulmonary sequestration due to the presence of both prominent systemic arterial feeding vessels and a systemic draining vein as seen on computed tomography and magnetic resonance imaging.

Adult↗
PubMed2004

Lung cancer in transplant recipients: a single-institution experience.

HYPOTHESIS: That aggressive surgical treatment of lung cancer (LC) is justified by stage-based outcome in immunosuppressed solid organ transplant recipients. DESIGN: Case series. SETTING: University hospital. PATIENTS: Lung cancer developed in 15 patients (0.28%) among a solid organ transplant recipient population of 5400 accrued at our institution over a 25-year period. MAIN OUTCOME MEASURES: Smoking prevalence, subtypes and stages of LC represented, operative morbidity, and survival. RESULTS: The mean time from transplantation to the diagnosis of LC was 76 months (range, 9-192 months). Eight patients received kidneys; 3, lungs; and 4, hearts. Only 11 patients (73%) had a smoking history (mean, 66 pack-years). The following carcinomas developed in our patient population: adenocarcinoma, 6 patients; squamous cell, 5; large cell undifferentiated, 2; bronchoalveolar, 1; and small cell, 1. Eight patients (53%) presented with inoperable stage IIIB or IV disease. The remaining patients presented in stages IA (n = 2), IB (n = 1), IIB (n = 2), and IIIA (n = 2); all underwent resection. No major postoperative complications occurred. All patients with stage IIIB or greater disease with or without treatment died quickly (mean survival, 1.4 months; range, 0.33-3.0 months). All patients with stage IIB or less remain alive a mean of 37 months after resection. Patients with stage IIIA survived only a mean of 6.0 months despite resection. CONCLUSIONS: Regarding LCs in transplant recipients compared with LCs in the nontransplant population, we find that (1) there is an increased incidence among nonsmokers; (2) death occurs rapidly in unresected patients; (3) resection carries a low morbidity rate; and (4) resection seems to offer a high chance of cure in those with cancers staged IIB or less.

Adult↗
PubMed2004

Evolving options in the management of esophageal perforation.

Esophageal perforation remains a devastating event that is difficult to diagnose and manage. The majority of injuries are iatrogenic and the increasing use of endoscopic procedures can be expected to lead to an even higher incidence of esophageal perforation in coming years. Accurate diagnosis and effective treatment depend on early recognition of clinical features and accurate interpretation of diagnostic imaging. Outcome is determined by the cause and location of the injury, the presence of concomitant esophageal disease, and the interval between perforation and initiation of therapy. The overall mortality associated with esophageal perforation can approach 20%, and delay in treatment of more than 24 hours after perforation can result in a doubling of mortality. Surgical primary repair, with or without reinforcement, is the most successful treatment option in the management of esophageal perforation and reduces mortality by 50% to 70% compared with other interventional therapies.

Esophageal Perforation↗
PubMed2004

Simple technique for maximal thoracic muscle harvest.

We present a modification of technique for standard muscle flap harvest, the placement of cutaneous traction sutures. This technique allows for maximal dissection of the thoracic muscles even through minimal incisions. Through improved exposure and traction, complete dissection of the muscle bed can be performed and the tissue obtained maximized. Because more muscle bulk is obtained with this technique, the need for a second muscle may be prevented.

Humans↗
PubMed2003

Weerda diverticuloscope: novel use to remove embedded esophageal foreign bodies.

Embedded sharp foreign bodies of the cervical esophagus represent a clinical challenge. Initial attempts at removal are usually undertaken by nonsurgical endoscopists who are often successful with blunt objects. Unsuccessful attempts with sharp objects, however, can result in distal migration, mucosal damage, and frank perforation. Thoracic surgeons are often called on for cervical esophagotomy after endoscopic attempts have failed. This report describes the novel use of a Weerda diverticuloscope for removal of a dental appliance with metallic hooks embedded in the cervical esophagus.

Adult↗
PubMed2003

Bronchial sleeve resection for posttransplant stricture.

Nonanastomotic bronchial stenosis is a rare complication of lung transplantation. We report a case of a bilateral lung transplant recipient who experienced recalcitrant stenosis of the bronchus intermedius. All attempts at conservative management failed, and the stricture was successfully treated by a parenchymal-sparing segmental sleeve resection. Although rare, this is an important technique in the management of this difficult problem.

Bronchi↗
PubMed2002

Transcervical thymectomy for myasthenia gravis achieves results comparable to thymectomy by sternotomy.

BACKGROUND: It remains controversial whether transcervical thymectomy offers results equivalent to thymectomy by way of a median sternotomy in the treatment of myasthenia gravis. Furthermore, preoperative prognostic factors have not been clearly defined. METHODS: This study is a retrospective chart review and interview of 78 patients completing transcervical thymectomy for myasthenia gravis between 1992 and 1999. RESULTS: There were 24 men and 54 women. Mean age was 40 years (range, 13 to 78 years). Twelve patients were in Osserman class 1, 25 in class 2, 30 in class 3, and 11 in class 4 (mean, 2.5). There was no perioperative mortality and 6 (7.7%) morbidities. Mean length of stay was 1.5 days and mean follow-up, 54.6 months. The crude cumulative complete remission (asymptomatic off medications for 6 months) rate was 39.7% (n = 31). Only 8 patients (10.3%) failed to improve after transcervical thymectomy. Kaplan-Meier estimates of complete remission were 31% and 43% at 2 and 5 years, respectively. Eight patients with thymoma had a 5-year estimated complete remission rate of 75% in contrast to 43% in 38 patients with thymic hyperplasia and 36% in 32 patients with neither thymoma nor hyperplasia (p = 0.01). Twelve patients with ocular myasthenia had a 5-year estimated complete remission rate of 57%, whereas patients with mild-to-moderate (n = 55) or severe (n = 11) generalized symptoms had 5-year complete remission rates of 43% and 30%, respectively (p = 0.21). CONCLUSIONS: Overall, extended transcervical thymectomy offers results that are comparable to those published for the transsternal procedure. Patients with milder disease (including isolated ocular disease) and taking no preoperative immunosuppressive agents appear to experience higher remission rates. In contrast to previous studies, we also find that small thymomas predict better responses to thymectomy.

Adolescent↗
PubMed2002

Suction vs water seal after pulmonary resection: a randomized prospective study.

STUDY OBJECTIVE: To evaluate whether suction or water seal is superior in the management of chest tubes after pulmonary resection. DESIGN: A prospective, randomized, controlled trial. After an initial, brief period of suction, patients were randomized to water seal or - 20 cm H(2)O suction. SETTING: University hospital. PATIENTS: Sixty-eight patients who underwent wedge resection, segmentectomy, or lobectomy were included in the study. Those patients who underwent reoperative surgery or lung volume reduction surgery were excluded. RESULTS: There were 34 patients in each group. The two groups were evenly matched for age, sex, operation performed, severity of lung disease, and nutritional status. Fifteen patients in each group (44%) had an air leak at the completion of surgery. The duration of the air leak was shorter in the water seal group than in the suction group (mean +/- SEM, 1.50 +/- 0.32 days vs 3.27 +/- 0.80 days, respectively; p = 0.05). The mean times to removal of chest tubes were 3.33 +/- 0.35 days in the water seal group and 5.47 +/- 0.98 days in the suction group (p = 0.06). The length of stapled parenchyma was measured for each patient and averaged 24.9 cm for the water seal group and 18.5 cm for the suction group (p = 0.18). When corrected for the length of staple lines, the duration of air leaks and days with chest tube were dramatically lower in the water seal group (p = 0.02 and p = 0.02, respectively). CONCLUSION: Placing chest tubes on water seal after a brief period of suction after pulmonary resection shortens the duration of the air leak and likely decreases the time that the chest tubes remain in place. Adoption of this practice may result in lower morbidity and lower hospital costs.

Aged↗
PubMedDate not supplied

Differentially expressed apoptotic genes in early stage lung adenocarcinoma predicted by expression profiling.

OBJECTIVE: In undiseased lung epithelial cells, apoptosis is an evolutionarily conserved and genetically regulated form of cell suicide which plays an important role in development and in the maintenance of tissue homeostasis. Neoplastic lung cells develop the ability to deregulate growth by alterations in these genes which control apoptosis. Genomic profiling was used to compare gene expression levels in early stage lung adenocarcinomas and nonneoplastic pulmonary tissue in order to comprehensively identify alterations in the process of apoptosis. METHODS: RNA extracted from node negative, poorly differentiated lung adenocarcinomas (15 patients) and nonneoplastic pulmonary tissue (5 patients) was hybridized to oligonucleotide microarray filters containing 44,363 genes. Ontological classification was used to extract genes involved with apoptosis. Further analysis discovered a subset of differentially expressed genes for further study. RESULTS: Of the 308 apoptotic genes on the microarray filters, 24 genes were predicted to be differentially expressed in lung adenocarcinomas. Alterations in several genes (i.e., Akt, BcL-xL, PTEN, FAS) are consistent with the literature. We also identified 10 novel genes that have not been described in nonsmall cell lung cancer (i.e., RIP, Caspase 1, PDK-1). CONCLUSIONS: These results identified several potential apoptotic genes altered in lung cancer.

Adenocarcinoma↗