Biomedical subjects

R Bueno

Publications and source records attributed to R Bueno.

At least 37 records · Page 2Linked to original sources

PubMed1999

Patterns of recurrence and outcome for patients with clinical stage II non-small-cell lung cancer.

Forty-six patients with pathologic clinical stage II non-small-cell lung carcinoma underwent resection with or without adjuvant radiotherapy from 1989 through 1994. These patients were analyzed to determine patterns of recurrence and survival. Surgery consisted of pneumonectomy for 11 patients, bilobectomy for two patients, lobectomy for 29 patients, and wedge or segmental resection for four patients. Adjuvant radiotherapy was delivered to 29 patients, and the median total dose was 54 Gy (range, 44-60 Gy). Median follow-up time was 23 months for all patients and 25 months for surviving patients. Twenty-six of 46 patients have had recurrence. The site of first recurrence was locoregional for 9 of 46 patients (20%) and distant for 17 of 46 patients (37%). The median time to locoregional recurrence was 18 months for patients treated with radiotherapy and 13 months for patients treated without radiotherapy. An isolated locoregional recurrence (with no simultaneous distant recurrence) was seen in 2 of 28 evaluable patients (7%) treated with radiotherapy compared with 3 of 17 patients (18%) not treated with radiotherapy. For all patients, the 3-year disease-free survival rate was 52%, and the overall survival rate was 52%. Among patients treated with radiotherapy, the 3-year disease-free survival and overall survival rates were 56% and 56%, respectively, compared with 46% and 43%, respectively, for patients who did not receive radiotherapy (p values were not significant). The locoregional recurrence rate was 33% for patients with adenocarcinoma and 15% for those with squamous cell carcinoma. The distant recurrence rates by histologic characteristic were 56% and 20%, respectively. For patients with clinical stage II non-small-cell lung cancer, postoperative radiotherapy appears to improve locoregional control. However, the preponderance of recurrences remains distant. Further study is warranted with special emphasis on control of systemic disease.

Adult↗

PubMed1999

Multimodality treatment of malignant superior vena caval syndrome.

Malignant superior vena caval (SVC) syndrome due to non-small cell lung cancer is invariably fatal, with most therapy directed toward palliating the manifestations of the disease. A cure, by means of any modality, is unusual. We report a patient with SVC syndrome secondary to documented ipsilateral peritracheal nodal involvement (stage IIIB disease) who underwent neoadjuvant chemoradiotherapy and resection. At surgery, his superior vena cava was not involved and his tumor had been downstaged to stage I (T1 nanoseconds). He remains alive and free of disease 60 months after surgery. Neoadjuvant chemoradiotherapy may be used to downstage malignant SVC syndrome to resectable lesions in good functional candidates.

Carcinoma, Non-Small-Cell Lung↗

PubMed1999

Mesothelioma clinical presentation.

OBJECTIVES: Clinical teaching of treatment for mesothelioma DESIGN: Case presentation SETTING: Postgraduate course. PATIENT: A 52-year-old man with chest pain INTERVENTIONS: Multimodality therapy consisted of surgery, intrapleural chemotherapy, chemotherapy, and radiation therapy. RESULTS: Patient is alive and well 2 years after surgery. CONCLUSIONS: Aggressive trimodality therapy for mesothelioma is presented as a successful treatment option.

Antineoplastic Agents↗

PubMed1999

New surgical options for elderly lung cancer patients.

To understand the size of the aging population in the United States, the imminent need to include the elderly in clinical studies on lung cancer, and the safe potential of video-assisted thoracic surgery, and to change awareness of the elderly's need for and ability to undergo treatment for lung cancer, clinical studies of video-assisted thoracic surgery in patients > or = 70 years of age are presented. The elderly are a fast-growing part of the American population who are at high risk for lung cancer and should be included in clinical studies. Age alone should not be a contradiction to thoracic surgical interventions when video thoracoscopy is performed as treatment.

Age Factors↗

PubMed1999

Management of the solitary pulmonary nodule: role of thoracoscopy in diagnosis and therapy.

OBJECTIVES: The solitary pulmonary nodule remains a common clinical problem. The essential question is whether the lesion is malignant or not. This discussion presents the clinical practice and looks at the problem. DESIGN: Didactic. SETTING: Academic tertiary-care hospital. PATIENTS: Prospective thoracic database. INTERVENTIONS: Minimally invasive technique. RESULTS: The workup and treatment of the solitary pulmonary nodule is presented with particular emphasis on the role of minimally invasive techniques. A small single-institution series is referenced. CONCLUSIONS: The approach is safe and highly effective in diagnosing and often in treating solitary pulmonary nodules.

Carcinoma, Non-Small-Cell Lung↗

PubMed1998

Left ventricular pseudoaneurysm after epicardial patch electrode placement.

There are many known complications of implantable cardioverter-defibrillator placement. We treated a patient in whom a left ventricular pseudoaneurysm developed secondary to epicardial patch electrode placement and cardioverter-defibrillator implantation. The presenting symptoms, diagnostic evaluation, and surgical repair are described.

Aged↗

PubMed1997

No-cut thoracoscopic lung plication: a new technique for lung volume reduction surgery.

BACKGROUND: Lung volume reduction surgery (LVRS) using a linear cutting stapler or laser ablation via median sternotomy or thoracoscopy is a current therapy for symptomatic emphysema. The primary causes of morbidity and mortality (as high as 20%) are existing comorbidities and prolonged air leaks secondary to visceral pleural division. We report a novel technique using minimally invasive techniques designed to achieve volume reduction while preserving the visceral pleura. A novel lung grasper and a knifeless stapler are used to permanently plicate lung tissue without cutting visceral pleura. STUDY DESIGN: This prospective analysis involves a consecutive series of patients who had LVRS using this method. Between May 1995 and September 1996, 32 patients underwent 50 unilateral, staged bilateral, or bilateral thoracoscopic lung plication procedures. The indications for LVRS were standard; they included severe limiting dyspnea (forced expiratory volume in one second [FEV1] = 0.68 +/- 0.05), hyperinflated lungs with flattened diaphragms on chest x-ray, and diffuse emphysema seen on chest computed tomography scan. Ventilation and perfusion scanning was used to identify potential ventilation and perfusion mismatch target areas of lung for plication. RESULTS: The right lung was plicated first in 25 of 32 patients (78%), and upper lobe plications predominated (77%). A mean of 9.3 +/- 0.8 staple firings were used for each unilateral plication procedure. There were no perioperative deaths. Two patients (4%) required axillary thoracotomies to repair air leaks. Mean chest tube duration was 6.3 +/- 0.5 days. Median hospital stay was 7 days (range 3-15). An Intensive Care Unit stay was required following 8 procedures (17%). Postoperative morbidity occurred in 18 (39%) of 46 procedures, including 5 cases of atrial fibrillation and 4 persistent (> 7 days) air leaks. A minimum 2 month followup was available for 22 patients (32 of 46 procedures), demonstrating a clear chest x-ray with significant improvement in ipsilateral diaphragmatic contour. Twelve patients had unilateral reduction, and 10 patients had bilateral reduction in either a staged (n = 7) or sequential at one operation (n = 3) fashion. Twenty-five (78%) of 32 procedures were associated with improved pulmonary function, with a mean increase in FEV1, in patients in this subgroup of procedures, of 43 +/- 7% for each ipsilateral plication at a mean followup of 3.8 +/- 0.5 months. For the entire group of 32 procedures, the mean improvement in measured FEV1 was 29 +/- 7%. Supplemental oxygen requirement was significantly reduced in 9 of 16 patients following plication. CONCLUSION: These data suggest that minimally invasive surgical techniques coupled with a no-cut lung plication can achieve significant lung volume reduction with favorable postoperative morbidity and mortality. Lung plication appears to hold promise as an alternative technique of LVRS.

Humans↗

PubMed1997

Current Therapy for Mesothelioma.

BACKGROUND: Diffuse malignant pleural mesotheliomas (DMPMs) are highly lethal tumors that are becoming more common. Standard management approaches have provided limited effectiveness. METHODS: The literature on management has been revised, and the authors present their data on outcomes for 120 patients treated with an aggressive trimodality approach. RESULTS: An aggressive trimodality approach including extrapleural pneumonectomy followed by chemoradiation produces low mortality and acceptable morbidity. The five-year survival rate in patients with epithelial histology and negative nodes approaches 40%. CONCLUSIONS: Nodal status and histologic subtype are major predictors for survival in patients with early DMPM. A uniformly accepted staging system would allow comparison of treatment approaches from various institutions. More effective management interventions are required.

Journal Article↗

PubMed1997

Mediastinoscopy, thoracoscopy, and video-assisted thoracic surgery in the diagnosis and staging of lung cancer.

The intrathoracic staging of lung cancer involves assessment of the primary tumor and potential sites of metastases. Imaging studies of the chest are sensitive in detecting intrathoracic abnormalities, but specific staging information generally requires a tissue biopsy. The instruments used to obtain this information include the bronchoscope, mediastinoscope, and thoracoscope. The complementary application of these instruments can provide valuable staging information while limiting the morbidity of surgical staging.

Fiber Optic Technology↗

PubMed1996

Bronchoplasty in the management of low-grade airway neoplasms and benign bronchial stenoses.

BACKGROUND: Parenchyma-sparing bronchoplastic procedures have altered the management of benign bronchial stenoses and low-grade neoplasms of the airway. Reliable techniques are available to allow sleeve resection of any lobe or the main bronchus and thus maximize preservation of lung parenchyma. METHODS: Between 1972 and 1995 we performed 100 bronchoplastic procedures on 99 patients. Seventy-eight patients had low-grade or benign tumors including carcinoid, mucoepidermoid, and fibrous histiocytomas. Seven patients had inflammatory lesions including histoplasmosis and tuberculosis. Two patients had idiopathic stenosis. Thirteen patients had stenoses due to prior trauma or previous operation. Resection involved the bronchus alone in 51 cases. Sleeve lobectomies were done in 49 patients. RESULTS: There were two postoperative deaths in complicated patients. Major complications occurred in 3 patients. Sixteen patients presented preoperatively with postobstructive pneumonia but had no major postoperative complications. Long-term follow-up (mean, 88 months) reveals only one instance of tumor recurrence (adenoidcystic carcinoma) and progressive stenosis in 1 patient with idiopathic stenosis. CONCLUSIONS: Lung-sparing bronchoplastic operations are the procedures of choice in anatomically suited patients with low-grade malignant tumors of the airway and benign bronchial stenosis.

Adolescent↗

PubMed1996

Insecticide susceptibility of Aedes aegypti and Aedes albopictus in the Lower Rio Grande Valley of Texas and Mexico.

In response to a potential dengue fever outbreak in south Texas during 1995, the susceptibilities of Aedes aegypti and Aedes albopictus to commonly used mosquito adulticides were assessed. Larvae collected from the Lower Rio Grande Valley of Texas and Mexico were reared to adults and tested against susceptible laboratory strains at Texas A&M University. Resistance ratios at both the LC50 and LC95 rates were all less than 10, indicating that adult populations of both species are still susceptible to malathion, chlorpyrifos, resmethrin, and permethrin.

Aedes↗

PubMed1995

Trends in hepatitis A virus infection with reference to the process of urbanization in the greater Madrid area (Spain).

Hepatitis A is an infection transmitted by the fecal-oral route. Endemicity within a specific country is directly related to sanitation and hygienic standards, while being inversely related to socioeconomic conditions. We studied how the process of urbanization witnessed in Madrid had influenced the transmission of hepatitis A infection. In the Madrid Autonomous Region, this process first began in the early sixties and was not brought to a close until the late seventies. Catalytic models were used to estimate the annual infection rate, lambda, on the basis of seroprevalence data stratified by age. A cohort effect related to a fall-off in infancy-related hepatitis A virus (HAV) is to be observed in the results for the last few years. The model permits four birth cohort-based groups to be differentiated by lambda: individuals born pre-1960, lambda = 0.082 (95% CI 0.095-0.070); those born in the early sixties, lambda = 0.052 (95% CI 0.060-0.042); whose members were born in the late sixties, lambda = 0.033 (95% CI 0.041-0.025); and those born in the late seventies, lambda = 0.017 (95% CI 0.020-0.013). The first group includes those born before the urbanization process had started. The second and third groups coincide with the development stage of that process, hence exhibiting transitional rates. The fourth group reflects the process in its consolidation stage. This reduction in the transmission of infection has changed the manner of presentation, so that while isolated cases or small outbreaks tend to be more common nowadays, occasionally epidemics may evolve explosively. The average age at presentation has risen and the likelihood of symptomatic infection is higher.

Adult↗

PubMed1995

Distributions of melanoma growth stimulatory activity of growth-regulated gene and the interleukin-8 receptor B in human wound repair.

The alpha-chemokines have been implicated as regulators of proliferation and differentiation of normal keratinocytes and as mediators of keratinocyte maturation and migration in inflammatory processes that involve the skin. Using the cutaneous wound repair model, we examined the sites and temporal sequence of the appearance of melanoma growth stimulatory activity or growth-regulated gene (MGSA/GRO;ligand) and the type B interleukin (IL)-8 receptor (IL-8RB) to which MGSA/GRO binds. Human burn tissues (n = 44) representing days 2 to 12 after injury were obtained during surgical debridement, fixed in 4% paraformaldehyde, and embedded in paraffin. Immunolocalizations were performed with polyclonal antisera for both ligand and receptor, as well as a monoclonal antibody for the IL-8 RB. Western blot analysis confirmed the presence of the IL-8 RB in immunoprecipitates of epidermal keratinocyte lysates. In normal skin, MGSA/GRO protein was restricted to sites populated by differentiated keratinocytes (suprabasal compartments, inner root sheath cells, and dermal sweat ducts). MGSA/GRO protein was barely detectable within epithelial margins and islands of burn wounds where the migrating/proliferating keratinocyte populations reside, but staining intensities increased as cells matured into the outer layers. Weak diffuse staining was detected in areas of neutrophilic infiltration (granulation tissue and overlying exudates). By contrast, in normal skin the IL-8 RB was detected in specific locations within epidermal and dermal compartments of healing wounds. In the dermis, polyvalent antibodies detected receptor immunoreactivity most prominently in dermal sweat ducts and endothelium of capillaries, whereas this immunoreactivity was inconspicuous in sections stained with the monoclonal antibody. Receptor immunostaining was noted in migrating/proliferating keratinocytes in epithelial margins and islands but was in the outer layers or in hypertrophic epidermis adjacent to wounds. This same pattern was observed in epidermal appendages such as hair follicles and eccrine sweat ducts. In granulation tissues, IL-8 RB was noted in numerous fibroblasts and in subpopulations of macrophages and smooth muscle. The presence of both MGSA/GRO and its receptor in human burn wounds implicate this cytokine as an autocrine or paracrine mediator of epidermal regeneration in both the inflammatory and proliferative phases of cutaneous wound repair.

Animals↗

PubMed1994

Two alternatively spliced forms of the human insulin-like growth factor I receptor have distinct biological activities and internalization kinetics.

Two alternatively spliced human insulin-like growth factor I (IGF I) receptor mRNA transcripts have been described that differ by three nucleotides (CAG) starting at position 2829. This results in an amino acid coding sequence change from Thr-Gly to Arg in the extracellular portion of the receptor beta subunit. To investigate the functional significance of this sequence difference, we obtained full-length cDNAs for the CAG+ and CAG- receptor forms, transfected CHO cells, and isolated multiple clones expressing approximately equal numbers of receptors (0.57-0.73 x 10(6) receptors/cell). The two receptors bound IGF I with similar affinity (Kd approximately 1.7 nM), but the CAG- form exhibited an approximately 2-fold increase in IGF I stimulation of receptor autophosphorylation, insulin receptor substrate-1 (IRS-1) tyrosine phosphorylation, thymidine incorporation, and IRS-1-associated phosphatidylinositol 3-kinase activity. In contrast to its higher signaling activity, the rate of receptor-mediated internalization of IGF I by the CAG-receptor was decreased by 50% in comparison with the CAG+ receptor. We conclude that proteins corresponding to the two alternatively spliced human IGF I receptor transcripts are biologically active, but have distinct signaling properties. These experiments further indicate a previously unrecognized role for the extramembranous portion of the beta subunit in receptor signaling and internalization.

Alternative Splicing↗

PubMed1993

Evidence for two insulin-like growth factor I receptors with distinct primary structure that are differentially expressed during development.

We have previously presented evidence for two IGF I receptor species in rat skeletal muscle. One form of IGF I receptor is selectively expressed in fetal and early postnatal life, and the second is present in both fetal and adult animals. These two IGF I receptors were shown to have similar tryptic phosphopeptide maps but to differ in beta subunit molecular weight (105,000 for the fetal vs. 95,000 for the adult type receptor). In this study, we have used specific antibodies to investigate the structural relationships between the two IGF I receptors. Anti-IGF I receptor beta subunit antibodies were generated against synthetic peptides corresponding to residues 1284-1293 and 1308-1318 of the cloned human IGF I receptor, and the capacity of these antibodies to interact with the two IGF I receptors was investigated. Both anti-peptide antibodies selectively immunoprecipitated the higher molecular weight fetal receptor and not the adult receptor from rat muscle. Human placenta and muscle were shown to contain two receptors similar to those observed in rat muscle. In human muscle, the anti-peptide antibodies and the human-specific monoclonal alpha subunit antibody alpha-IR3 also selectively immunoprecipitated the fetal type receptor. The presence of a 95,000 M(r) IGF I receptor beta subunit distinct from the insulin receptor beta subunit in human muscle was confirmed by the demonstration of an IGF I sensitive receptor with a beta subunit of this size after insulin receptor immunodepletion. These data strongly support the conclusion that the fetal and adult type IGF I receptors differ in primary structure. The fetal receptor corresponds to the cloned and sequenced IGF I receptor, and the primary structure of the adult type receptor has not yet been established.

Aging↗

PubMed1992

Insulin-like growth factor I receptor gene structure.

The insulin-like growth factor I (IGF I) receptor is a tyrosine kinase-containing transmembrane protein that plays an important role in cell growth control. We have isolated and characterized human genomic DNA clones containing the entire coding sequence of the IGF I receptor. Results of restriction analysis and sequencing of multiple overlapping clones were consistent with the existence of a single IGF I receptor gene. The complete receptor coding sequence is contained in 21 exons. There is striking homology with the insulin receptor gene in overall size (approximately 100 kilobases) and in the number and size of individual exons. An exon analogous to the alternatively spliced exon 11 of the insulin receptor gene could not be detected. An alternative internal splice site corresponding to a known alternatively spliced mRNA transcript was shown to be located at the 5' end of exon 14. Knowledge of the structure of the IGF I receptor gene should facilitate further studies on the structural determinants of receptor function, the relationships between insulin and IGF I receptors, and the molecular basis for multiple IGF I receptor species.

Amino Acid Sequence↗

PubMed1991

The use of AIDS surveillance data for short-term prediction of AIDS cases in Madrid, Spain.

The paper presents a preliminary attempt to predict the numbers of AIDS cases in the Community of Madrid (CAM) up to 1992. Using AIDS case surveillance data gathered by CAM, and a statistical procedure that includes a distribution for reporting delays, the numbers of new diagnoses, reports, AIDS deaths and numbers of patients alive is predicted. Approximate confidence limits for the numbers of new diagnoses are given. We emphasise that these predictions are tentative given the nature of the reporting delays, and discuss the use of such predictions and the requirements for their improvement.

Acquired Immunodeficiency Syndrome↗

PubMed1987

Latissimus dorsi flap: a valuable resource in lower arm reconstruction.

Lower arm reconstruction of soft tissue defects and after ablation for cancer leaves the reconstructive surgeon few alternatives. We have used latissimus dorsi muscle (n = 1) and musculocutaneous flaps (n = 3) with good functional and cosmetic results. Defects in one patient with traumatic amputation, another with extravasation of doxorubicin, and two with cancer were closed without complications to donor site, recipient site, or flap. Skin paddle size averaged 182 sq cm in the three musculocutaneous flaps. Mean follow-up was six months.

Aged↗