Breast reconstruction.
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Breast Implants↗
Biomedical subjects
M Bains
Publications and source records attributed to M Bains.
The role of thoracotomy in managing postchemotherapy residual thoracic masses in patients with nonseminomatous germ cell tumours.
OBJECTIVE: To evaluate the clinical outcome and identify prognostic variables in patients with nonseminomatous germ cell tumours undergoing postchemotherapy thoracotomy for residual masses, as the role of this procedure is controversial. PATIENTS AND METHODS: Of 385 patients who underwent postchemotherapy retroperitoneal lymph node dissections between 1988 and 1998, 105 also had 130 thoracotomies. The clinical presentation, chemotherapy regimens, marker status, primary tumour histology, pathology of all resected masses, and clinical outcome of these 105 patients were analysed. RESULTS: The overall discordance rate for synchronous thoracic and retroperitoneal masses was 28%; that for asynchronous thoracic and retroperitoneal masses was 57%. Independent prognostic factors for residual thoracic teratoma or cancer were teratoma (mature or immature) in the primary tumour or retroperitoneal teratoma or cancer. Although three of 12 patients with residual thoracic cancer remained with no evidence of disease, residual thoracic cancer is an independent prognostic factor (P < 0.001) against disease-free survival. CONCLUSION: Postchemotherapy thoracotomy yields important prognostic information, and is therapeutic for most patients with teratoma and a subset with residual viable cancer. The prognostic criteria predictive of fibrosis are not sufficiently accurate to omit resection of residual thoracic masses.
Antineoplastic Combined Chemotherapy Protocols↗
Role of postchemotherapy adjunctive surgery in the management of patients with nonseminoma arising from the mediastinum.
PURPOSE: To evaluate the role of postchemotherapy surgery in patients with nonseminomatous germ cell tumors arising from the anterior mediastinum. PATIENTS AND METHODS: Thirty-two patients with nonseminoma arising from a mediastinal primary site were treated on a clinical trial at our center, and they underwent postchemotherapy surgery. The results of postchemotherapy surgical resection, frequency of viable tumor found during postchemotherapy surgery, and prognostic factors for survival were assessed. RESULTS: Complete resection of all gross residual disease was achieved in 27 patients (84%). Histologic analysis of resected residua postchemotherapy revealed viable tumor in 66%, teratoma in 22%, and necrosis in 12% of the specimens. Viable tumor included embryonal carcinoma, choriocarcinoma, yolk sac carcinoma, seminoma, and teratoma with malignant transformation to nongerm cell histology (eg, sarcoma). Clinical characteristics associated with a shorter survival after surgery included the presence of viable tumor in a resected specimen (P =.003) and more than one site resected during surgery (P =.06). There were no statistically significant differences in survival for patients who underwent surgical resection with normal markers compared with patients with elevated serum tumor markers (P =.33). A trend toward shorter survival was found in patients with increasing tumor markers before surgery compared with patients with normal and declining serum tumor markers (P =.09). CONCLUSION: Surgical resection of residual mass after chemotherapy plays an integral role in the management of patients with primary mediastinal nonseminoma. Teratoma and viable tumor were found in the majority of resected residua after chemotherapy. Because patients who undergo conventional salvage chemotherapy programs rarely achieve long-term disease-free status, selected patients with elevated markers after chemotherapy are considered candidates for surgical resection.
Adolescent↗
VATS port site recurrence: a technique dependent problem.
OBJECTIVES: Video-assisted thoracic surgery (VATS) has become an accepted approach for the diagnosis and treatment of thoracic malignancies. Port site tumor recurrence is a reported complication of VATS. However, the true incidence of this problem is unknown. To try to determine the incidence of port site recurrence, we analyzed our experience with patients undergoing VATS wedge resection for malignancy. METHODS: Data were obtained from our prospective VATS database. The analysis was confined to patients undergoing VATS wedge resection for malignancy, excluding those having a pleural biopsy only. Parameters analyzed included demographic factors, surgical technique, and port site recurrences identified by physical examination, CT scan, or both. RESULTS: From 1992 to 1996, 410 patients (182 men, 228 women; median age = 61 years) underwent a VATS wedge resection for malignancy. The procedure was performed for diagnosis or staging in 90% of cases. Access incisions plus port sites were used in 97 (24%) patients; port sites only were used in 313 (76%) patients. Conversion to thoracotomy was necessary in 102 patients (25%) either for definitive resection (58 patients) or because VATS was not technically adequate (44 patients). Specimens were retrieved via access incisions or port sites with or without a specimen bag. The operative mortality was 0.25%. With long-term follow-up (median = 25 months) available for 374 patients (91%), only one port site recurrence was identified (0.26%). CONCLUSION: Our experience confirms the safety of VATS wedge resection in cancer patients. The incidence of port site tumor recurrence is low when oncologic principles are respected. In our institution, these principles include performing VATS wedge resection only for lesions that can be widely removed; converting to thoracotomy for definitive or extensive cancer operation; and using meticulous technique for the extraction of specimens from the pleural space.
Adult↗
Clinical microbiological case: refractory chest wall infection following reconstructive surgery in a patient with relapsed lung cancer.
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Adult↗
Chest wall resection for locally recurrent breast cancer: is it worthwhile?
OBJECTIVE: The effectiveness of chest wall resection for locally recurrent breast cancer as cancer treatment remains poorly defined, possibly because of the general impression that locally recurrent disease is a harbinger of rapidly progressive metastatic disease and that extensive surgical treatment in these patients is inappropriate. Reports to date have focused on technical feasibility, not long-term outcome. METHODS: We reviewed our experience with 38 women who underwent chest wall resection for locally recurrent breast cancer between October 1987 and May 1997. Overall survival was calculated by the Kaplan-Meier method and the significance of prognostic variables evaluated by log-rank and Cox regression analyses. RESULTS: The operative mortality rate was 0%. Overall survival at 1, 3, and 5 years after chest wall resection was 74%, 41%, and 18%, respectively, and the proportion of patients free of local recurrence at 1, 3, and 5 years was 59%, 42%, and 13%, respectively. Regional nodal disease and size of largest tumor nodule (>4 cm) were significant predictors of local re-recurrence (P <.01, P =.04); lymph node metastasis was the only predictor of long-term survival (P <.01). Patients with and without synchronous sites of metastatic disease had near-identical 3-year survivals. CONCLUSIONS: Chest wall resection for locally recurrent breast cancer has a low mortality. However, a significant number of patients have the development of local re-recurrence or metastases, and 5-year survival is limited. It is unlikely that complete resection of all locally recurrent disease improves survival. Future studies should focus on the quality of palliation achieved.
Adult↗
Pediatric chest wall Ewing's sarcoma.
BACKGROUND: Chest wall tumors of primitive neuroectodermal origin (PNET, Ewing's sarcoma [ES]) are rare and have a poor prognosis. Multimodality therapy has improved survival results, and long-term survival is possible. Whether adjuvant radiation therapy is uniformly beneficial remains unclear. METHODS: A retrospective analysis of the authors' institutional experience between 1979 and 1998 was performed. RESULTS: Twenty consecutive patients with PNET-ES of the chest wall were identified. The median age was 12 years (range, 2.5 to 21 years). Median follow-up was 3 years (range, 7 months to 19.4 years). Seven patients presented with a mass, 12 with pain, 1 with respiratory distress, and 1 with a neuropathy. Initial therapy consisted of biopsy and neoadjuvant chemotherapy followed by chest wall resection in 12 patients. Of the remaining 8 patients, 6 underwent biopsy, followed by chest wall resection and adjuvant chemotherapy, 1 underwent biopsy, chemotherapy, and resection of a lung nodule, and 1 underwent biopsy, chemotherapy, and a laminectomy and decompression procedure. All 20 patients were included in institutional-based trials using multiagent chemotherapy. Fifteen patients received radiation therapy with a median dose of 3,000 cGy. At last follow-up, 11 patients are alive and disease free, with a median survival of 7.5 years (range, 7 months to 19.4 years). Seven of 11 (64%) survivors had neoadjuvant therapy followed by chest wall resection. Seven of 11 (64%) survivors had radiation therapy. There was no surgical mortality. Twelve patients had treatment-related complications, 3 of which were related to surgical resection. There were no survivors among patients with recurrent disease. Three of the patients who died of disease had both local and distant recurrences, 4 patients had distant recurrence only, and one patient had local recurrence only. Only 4 of 9 (44%) patients who died were treated initially with chemotherapy followed by chest wall resection. All but 1 of those that died (89%) received initial radiation therapy. All 9 patients who did not survive received additional salvage radiotherapy as well. CONCLUSIONS: Long-term survival is possible with ES-PNET after complete chest wall resection. This may be facilitated by neoadjuvant chemotherapy. Long-term survival without radiation therapy is possible, and consideration of radiation therapy should be made on a case-by-case basis.
Adolescent↗
Role of putative loops 2 and 3 in imipenem passage through the specific porin OprD of Pseudomonas aeruginosa.
Mutant proteins with eight amino acid deletions in putative surface loops 2 and 3 of the imipenem-specific porin OprD of Pseudomonas aeruginosa failed to reconstitute imipenem susceptibility in an oprD-deficient background. The loop 3 deletion prevented the ability of imipenem to inhibit KCl conductance through the OprD channel, as previously shown for a loop 2 deletion. This suggests that both loops 2 and 3 have a role in imipenem binding to the OprD channel.
Amino Acid Sequence↗
The amino terminus of Pseudomonas aeruginosa outer membrane protein OprF forms channels in lipid bilayer membranes: correlation with a three-dimensional model.
Pseudomonas aeruginosa OprF forms 0.36-nS channels and, rarely, 2- to 5-nS channels in lipid bilayer membranes. We show that a protein comprising only the N-terminal 162-amino-acid domain of OprF formed the smaller, but not the larger, channels in lipid bilayers. Circular dichroism spectroscopy indicated that this protein folds into a beta-sheet-rich structure, and three-dimensional comparative modeling revealed that it shares significant structural similarity with the amino terminus of the orthologous protein Escherichia coli OmpA, which has been shown to form a beta-barrel. OprF and OmpA share only 15% identity in this domain, yet these results support the utility of modeling such widely divergent beta-barrel domains in three dimensions in order to reveal similarities not readily apparent through primary sequence comparisons. The model is used to further hypothesize why porin activity differs for the N-terminal domains of OprF and OmpA.
Amino Acid Sequence↗
Functional expression in Escherichia coli and membrane topology of porin HopE, a member of a large family of conserved proteins in Helicobacter pylori.
HopE is one of the smallest members of a family of 31 outer membrane proteins in Helicobacter pylori and has been shown to function as a porin. In this study it was cloned into Escherichia coli where it was expressed in the outer membrane, as confirmed by indirect immunofluorescence using HopE-specific antibodies. HopE purified from E. coli reconstituted channels in planar bilayer membranes that were the same size as those formed by HopE purified from H. pylori. A model of the membrane topology of HopE was constructed and indicated that this protein formed a beta-barrel with 16 transmembrane amphipathic beta-strands. The accuracy of this model was tested by linker insertion mutagenesis, assuming that, like other porins, amino acid insertions were not tolerated in the transmembrane beta-strands but were tolerated in the adjoining loop regions. Generally, the results obtained with a series of 12 insertions of the sequence RSKDV and two substitutions were consistent with the topological model. The preponderance of amino acids that were conserved in the extended family of HopE paralogs were predicted to be within the membrane and comprised 45% of all residues in the membrane.
Amino Acid Sequence↗
Paclitaxel, ifosfamide, and cisplatin second-line therapy for patients with relapsed testicular germ cell cancer.
PURPOSE: To evaluate the dose, toxicity, and efficacy of paclitaxel in combination with ifosfamide and cisplatin as salvage therapy for patients with relapsed testicular germ cell tumors (GCTs). PATIENTS AND METHODS: Thirty patients with previously treated GCTs were treated with paclitaxel and ifosfamide plus cisplatin (TIP) as second-line therapy. All had favorable prognostic features for response (testis primary tumor site and prior complete response to first-line chemotherapy program). Four cycles of paclitaxel, ifosfamide 5 g/m(2), and cisplatin 100 mg/m(2) were given 21 days apart with granulocyte colony-stimulating factor support, followed by resection of radiographic residua. The dose of paclitaxel was increased among cohorts with dose levels of 175, 215, and 250 mg/m(2); the largest dose was selected for the phase II part of the trial. RESULTS: Twenty-three (77%) of 30 patients achieved a complete response to chemotherapy alone, and one patient achieved a durable partial response with normal tumor markers. Therefore, 24 (80%) achieved a favorable response. Eleven patients with normalized markers after chemotherapy underwent resection of residual tissue, with only necrosis found in 10 and mature teratoma in one. Two patients relapsed, and 22 (73%) of the favorable responses remain durable at a median follow-up duration of 33 months. Myelosuppression was the major toxicity, and two patients had grade 3 neurotoxicity. CONCLUSION: Four cycles of TIP was associated with a high proportion of patients who achieved a complete response, a lack of relapse, and relative tolerability as an ifosfamide-containing salvage regimen for testicular GCTs. The high durable complete response proportion emphasizes the importance of patient selection according to prognostic factors for a favorable outcome to conventional-dose salvage therapy.
Adult↗
Sequential dose-intensive paclitaxel, ifosfamide, carboplatin, and etoposide salvage therapy for germ cell tumor patients.
PURPOSE: To evaluate the efficacy and toxicity of sequential, dose-intensified chemotherapy with paclitaxel/ifosfamide and carboplatin/etoposide administered plus peripheral blood-derived stem-cell (PBSC) support for patients with germ cell tumors (GCT) who have unfavorable prognostic features in response to conventional-dose salvage programs. Carboplatin was dose escalated by target area under the curve (AUC; in [milligrams per milliliter] x minutes) among patient cohorts, and pharmacokinetic studies were performed for comparison. PATIENTS AND METHODS: Thirty-seven previously treated patients who had cisplatin-resistant GCT and unfavorable prognostic features for response to conventional-dose salvage therapy were treated. Two cycles of paclitaxel 200 mg/m(2) plus ifosfamide 6 g/m(2) were given 2 weeks apart with leukapheresis, followed by three cycles of carboplatin plus etoposide given 14 to 21 days apart with reinfusion of PBSCs. The dose of etoposide was 1, 200 mg/m(2), and the carboplatin target AUC ranged among cohorts from 12 to 32 (mg/mL) x min. Pharmacokinetic studies of carboplatin were performed for comparison of target to measured AUC. RESULTS: Twenty-one patients (57%) achieved a complete response and an additional two patients (5%) achieved a partial response with normal tumor markers; therefore, 23 (62%) achieved a favorable response. Eight patients relapsed, and 15 (41%) of the favorable responses remained durable at a median follow-up of 30 months. Myelosuppression was the major toxicity; 58% of carboplatin/etoposide cycles were associated with hospitalization for nadir fever. The AUC of carboplatin measured in serum was lower than the target AUC; this may be related to underestimation of the glomerular filtration rate used in the dosing formula. CONCLUSION: Dose-intense therapy with sequential, accelerated chemotherapy of paclitaxel/ifosfamide and carboplatin/etoposide administered with PBSC support was relatively well tolerated. The durable complete response proportion was substantial in patients with unfavorable prognostic features for achieving durable complete response to conventional-dose salvage programs. Optimal dosing of carboplatin in the high-dose setting warrants further investigation.
Adolescent↗
Induction chemotherapy employing dose-intense cisplatin with mitomycin and vinblastine (MVP400), followed by thoracic surgery or irradiation, for patients with stage III nonsmall cell lung carcinoma.
BACKGROUND: Cisplatin-based induction chemotherapy before surgery or irradiation has improved the survival of patients with Stage III nonsmall cell lung carcinoma (NSCLC). Encouraged by earlier results with preoperative MVP (cisplatin [120 mg/m(2) or 25 mg/m(2)/week], vinblastine, and mitomycin) for Stage IIIA patients with clinically apparent mediastinal (N2) disease, the authors conducted a Phase II trial of the safety and efficacy of induction MVP400 with the dose intensity of cisplatin doubled from 25 to 50 mg/m(2) per week. METHODS: From October 1992 to March 1996, 37 patients with Stage IIIA (26) or Stage IIIB (11) NSCLC began the MVP400 induction chemotherapy program. Four doses of cisplatin (100 mg/m(2)), 7 doses of vinblastine, and 2 doses of mitomycin were given over 9 weeks. Patients received either surgery or irradiation after induction treatment. RESULTS: Overall, the response rate was 65% (95% confidence interval, 49-81%) with a complete resection rate of 67%. The median survival was 17 months, with 66% of patients alive at 1 year. Complete resection and Stage IIIA involvement were favorable prognostic indicators for survival. No Stage IIIB patients underwent a complete resection. Myelosuppression was the most common side effect. There were no treatment-related deaths. CONCLUSIONS: Although high response and complete resection rates were again demonstrated, results with the MVP400 regimen were not improved over those achieved with MVP regimen tested earlier with Stage IIIA (N2) patients. The authors continue to recommend MVP as an induction chemotherapy regimen for clinical trials.
Adult↗
Pulmonary metastasectomy for head and neck cancers.
BACKGROUND: Distant metastases from carcinomas that arise from the head and neck region are infrequent. The most common site is the lung. To evaluate the results of resection of pulmonary metastases for head and neck cancers, we reviewed our own cases of these metastases. METHODS: Between November 1966 and March 1995, 83 patients with pulmonary metastases from head and neck cancers underwent 94 thoracic operations. All patients had obtained or had obtainable locoregional control of their primary head and neck cancers. Kaplan-Meier and Cox regression models were used to analyze the prognostic factors for survival after metastasectomy. RESULTS: Median age was 53 years (range, 17-77). Fifty-nine were male and 24 were female. Forty-one patients had squamous cell cancers, and 36 had glandular tumors that consisted mostly of thyroid and adenoid cystic carcinomas. The median disease-free interval from the time of treatment of the head and neck primary cancers to the development of pulmonary metastases was 27 months. Sixty-eight (82%) patients had complete resection. Overall operative mortality rate was 2%. Overall actuarial survival rate after metastasectomy was 50% at 5 years. Patients with glandular tumors had a 5-year survival rate of 64% compared with 34% for patients with squamous cell cancers. When the patients with glandular tumors were analyzed according to their histology, patients with adenoid cystic carcinomas had an 84% 5-year survival, but none remained disease-free. Patients with thyroid cancers fared similarly whether they were treated medically or surgically. On multivariate analysis, the adverse prognostic factors for patients with squamous cell cancers were incomplete resection, age greater than 50 years, and disease-free interval less than or equal to 2 years. CONCLUSIONS: Approximately 30% of patients with pulmonary metastases from squamous cell cancers of the head and neck who underwent complete resection of all their metastases can expect to achieve long-term survival. The role of pulmonary resection for patients with glandular tumors is unclear.
Adenocarcinoma↗
Negative regulation of the Pseudomonas aeruginosa outer membrane porin OprD selective for imipenem and basic amino acids.
Pseudomonas aeruginosa OprD is a specific porin which facilitates the uptake of basic amino acids and imipenem, a carbapenem antibiotic. Resistance to imipenem due to the loss of OprD is an important mechanism for the loss of clinical effectiveness. To investigate the negative regulatory mechanisms influencing oprD expression, a gene upstream of the coregulated mexEF-oprN efflux operon, designated mexT, was cloned. The predicted 304-amino-acid mature MexT protein showed strong homology to LysR-type regulators. When overexpressed it induced the expression of the mexEF-oprN efflux operon while decreasing the level of expression of OprD. The use of an oprD::xylE transcriptional fusion indicated that it acted by repressing the transcription of oprD. Salicylate, a weak aromatic acid known to reduce porin expression and induce low levels of multiple antibiotic resistance in Escherichia coli, was able to induce imipenem resistance and reduce the expression of OprD but not multiple antibiotic resistance or OprN expression in P. aeruginosa. This was also demonstrated to occur at the level of transcription. Acetyl salicylate and benzoate, but not catechol, were also able to reduce the levels of OprD in the P. aeruginosa outer membranes. These OprD-suppressing compounds increased imipenem resistance even in a mexT-overexpressing and nfxC mutant backgrounds, suggesting that such resistance is independent of the MexT repressor and that oprD is influenced by more than a single mechanism of repression.
Amino Acids↗
Resection of lung cancer invading the diaphragm.
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Aged↗
Magnetic resonance imaging of the postpneumonectomy chest: normal and abnormal findings.
To determine the normal findings at magnetic resonance imaging (MRI) of the postpneumonectomy space (PPS), and to evaluate the utility of MRI in detection of recurrent tumor in the postpneumonectomy chest, 32 MRI scans were performed in 31 patients at varying time intervals after pneumonectomy. Eleven patients also had 12 computed tomography (CT) scans performed at the same time to evaluate possible tumor recurrence. Of the 32 scans, 5 demonstrated complete obliteration of the fluid containing PPS, and 4 showed gas in the PPS; the remainder (n = 23) demonstrated persistence of fluid-filled spaces of varying size. The presence of a fibrotic rim of tissue was constant. In 11 patients with clinically suspected tumor recurrences, both CT and MRI were obtained: the two modalities performed with similar accuracy in diagnosing tumor recurrence at 16 sites; CT detected opposite-lung metastatic nodules not seen on MRI in one patient, and a rib metastasis described as "indeterminate" on MRI in a second patient. MRI detected a focus of recurrence in the PPS that was indeterminate on CT. There is considerable variability in the amount of fluid seen in the PPS on MRI. CT remains the procedure of choice for routine follow-up or in suspected tumor recurrence in the postpneumonectomy patient; MRI can be helpful if the CT scan is nondiagnostic or equivocal.
Adult↗
Cloning and characterization of the major outer membrane protein gene (ompH) of Pasteurella multocida X-73.
The major outer membrane protein (OmpH) of Pasteurella multocida X-73 was purified by selective extraction with detergents, followed by size exclusion chromatography. The planar lipid bilayer assay showed that OmpH has pore-forming function. The average single channel conductance in 1.0 M KCl was 0.62 nS. The gene (ompH) encoding OmpH has been isolated and sequenced by construction of a genomic library and PCR techniques. The coding region of this gene is 1,059 bp long. The predicted primary protein is composed of 353 amino acids, with a 20-amino-acid signal peptide. The mature protein is composed of 333 amino acids with a molecular mass of 36.665 kDa. The ompH gene encoding mature protein has been expressed in Escherichia coli by using a regulatable expression system. The ompH gene was distributed among 15 P. multocida serotypes and strain CU. Protection studies showed that OmpH was able to induce homologous protection in chickens. These findings demonstrate that OmpH is a protective outer membrane porin of strain X-73 and is conserved among P. multocida somatic serotypes.
Amino Acid Sequence↗