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Biomedical subjects

S G Peters

Publications and source records attributed to S G Peters.

At least 19 recordsLinked to original sources
PubMed2000

Steroid therapy of a proliferating hemangioma: histochemical and molecular changes.

OBJECTIVES: Hemangioma is a primary tumor of the microvasculature in which angiogenesis is initially excessive, followed by regression of the newly formed vessels. Intervention is necessary in up to 20% of cases, high-dose systemic or intralesional steroids being the first-line treatment. As the mechanism of action of steroids is unknown, we undertook an investigation of the cellular and molecular effects of their action. STUDY DESIGN: A unique opportunity to study the effect of steroid treatment was presented when biopsy material was obtained from an infant with an ulcerated proliferating hemangioma before and after intralesional triamcinolone injection, which resulted in an accelerated regression of the lesion. Histochemical quantitation of mast cells, molecular analysis by reverse transcriptase-polymerase chain reaction (RT-PCR) for 7 growth factor transcripts and differential display RT-PCR (DD RT-PCR) were conducted. RESULTS: After steroid therapy, the mast cell number increased (untreated = 2.22 +/-.27 [standard error of the mean ¿SEM¿]; treated = 8.7 +/-.71 [SEM] mast cells per field, respectively; P <.0001; n = 40 fields for each group), and the transcriptional expression of cytokines: platelet-derived growth factor-A and -B; interleukin-6; transforming growth factor-beta1 and -beta3 decreased, while that of basic fibroblast growth factor (bFGF) and vascular endothelial cell growth factor remained unaltered. Elevated urinary bFGF levels noted in cases of proliferating hemangioma, persisted even after steroid treatment. Using DD RT-PCR an amplicon that shared 100% sequence homology with the human mitochondrial cytochrome b gene was detected in the hemangioma biopsy after steroid treatment. CONCLUSIONS: The regression of this hemangioma subsequent to steroid therapy was accompanied by a significant increase in mast cell density, reduced transcription of several cytokines, and an enhanced expression of the mitochondrial cytochrome b gene.

Anti-Inflammatory Agents↗
PubMed1998

Security and confidentiality in an electronic medical record.

The maintenance of privacy and confidentially must remain a core principle of the interaction between patients and medical staff. Traditionally, the single paper copy of the medical history has been treated with systematic handling, careful tracking, and respect for the integrity and confidentiality of the contents. The widespread availability of computerized information requires that these principles be maintained in the electronic environment. Security measures should protect sensitive data without hindering medical practice. At Mayo, we have established data security policies and standards for the handling of all electronic information. Dissemination and communication of these standards and guidelines are an ongoing challenge. Technical maneuvers can be employed to protect data integrity, identify users, and monitor compliance. Personnel policies must be updated to reflect the responsibilities and liabilities of the electronic environment. Practice efficiencies and access to clinical data must be balanced by individual responsibility and accountability for privileged patient information.

Computer Security↗
PubMed1997

Native lung complications after single lung transplantation for emphysema.

We reviewed the impact of the presence of the native diseased contralateral lung on the outcome after single lung transplantation for emphysema. Twenty consecutive recipients of single lung transplants for emphysema were reviewed for complications related to the native lung. Five patients (25%) suffered major complications arising in the native lung and resulting in serious morbidity and mortality. The timing of onset varied from 1 day to 43 months after transplantation. We conclude that the susceptibility of the native lung to complications such as those described in this report is an additional fact to be considered in choosing the ideal transplant procedure for patients with obstructive lung disease.

Adult↗
PubMed1997

Lung transplantation: selection of patients and analysis of outcome.

Lung transplantation is an important option for patients with respiratory failure and limited life expectancy. Herein we review the current indications for and outcome after lung transplantation. These results are compared with the natural history of various respiratory diseases, estimated from available databases. Candidates for lung transplantation are generally younger than 60 years of age, have a limited life expectancy because of end-stage lung disease, and have no other major organ dysfunction. Single lung transplantation is performed most commonly for emphysema, pulmonary fibrosis, and pulmonary hypertension. Survival after single lung transplantation is approximately 70% at 1 year, 60% at 2 years, and 40% at 3 years. The median duration of survival for patients with end-stage lung diseases ranges from approximately 2 to 6 years, with wide variation based on the diagnosis and severity of illness. Currently, prolongation of the average survival has not been clearly substantiated after lung transplantation. Further evaluation of outcomes, functional status, and quality of life after lung transplantation is necessary.

Humans↗
PubMed1997

Posttransplantation physiologic features of the lung and obliterative bronchiolitis.

Obliterative bronchiolitis remains the major obstacle to long-term survival after lung transplantation. Herein we provide a brief review of the key literature as well as our own experience with this condition. Obliterative bronchiolitis has occurred in up to two-thirds of all lung transplant recipients. The characteristic physiologic changes include declines in (1) forced expiratory volume in 1 second, (2) forced vital capacity, and (3) diffusing capacity of the lungs for carbon monoxide. Lung biopsy in patients with obliterative bronchiolitis reveals occlusion of bronchioles in a patchy but extensive distribution. Mucous plugging and bronchiectasis may also be seen. Furthermore, intimal thickening of pulmonary vessels together with mild arteriosclerotic changes of the muscular and elastic pulmonary arterioles may be observed. To date, the main risk factor for the development of obliterative bronchiolitis is recurrent, severe, and persistent acute lung rejection. The recommended management is prevention because the established fibrotic condition may necessitate retransplantation.

Bronchiolitis Obliterans↗
PubMed1997

Medical management and complications in the lung transplant recipient.

Lung transplantation has evolved as a viable therapy for patients with end-stage lung disease. Improvements in surgical techniques, avoidance of rejection by effective strategies of immunosuppression, and other aspects of medical management allow successful lung transplantation, with 1-year survivorship of 70 to 93%. In this review, we address the medical management of patients who have undergone lung transplantation. The immunosuppressive protocol used at Mayo Clinic Rochester is presented, along with a discussion of the mechanisms of action and potential complications associated with the various drugs used. The recognition and treatment of early graft dysfunction, infection, rejection, stenosis of the airway anastomosis, and posttransplantation lymphoproliferative disorder are also reviewed. Careful surveillance of patients after lung transplantation helps maintain graft function and facilitates identification, treatment, and potential avoidance of complications.

Clinical Protocols↗
PubMed1997

Colchicine versus prednisone as treatment of usual interstitial pneumonia.

OBJECTIVE: To assess the results with colchicine and prednisone as initial single-drug therapy in patients with usual interstitial pneumonia (UIP). MATERIAL AND METHODS: We reviewed the serial pulmonary function test results in 22 patients with typical clinical and high-resolution computed tomographic features of UIP who were treated with colchicine as initial single-agent therapy and compared them with a group of 22 historical patients with UIP of similar severity diagnosed by open-lung biopsy who were given prednisone as initial single-drug therapy. RESULTS: No significant difference was detected in the rate of decline of pulmonary function or in the time to "failure" between the two study groups. A trend was suggested for more rapid decline of pulmonary function in the prednisone-treated than in the colchicine-treated group. The design of this study does not allow distinction between a possible beneficial effect of colchicine and a possible adverse effect related to weaning from high-dose prednisone. Colchicine was well tolerated; few side effects other than mild diarrhea were noted in those patients able to take the drug long enough to return for pulmonary function testing at 3 months. In comparison, the side effects of prednisone were more serious and were not always reversible with cessation of therapy. CONCLUSION: This study lends further support to the assumption that colchicine may be a satisfactory and less hazardous substitute for prednisone in the treatment of patients with UIP.

Aged↗
PubMed1994

Evolving strategies in lung transplantation for emphysema.

Evolving strategies of pulmonary preservation, bronchial revascularization, immunosuppression, and infectious disease management were used in 15 initial consecutive patients undergoing lung transplantation for emphysema. There were 10 women and 5 men with a mean age of 49 years (range, 36 to 60 years). All patients required supplemental oxygen therapy. One bilateral, 9 left, and 5 right transplantations were performed. Mean preoperative forced expiratory volume in 1 second and total lung capacity were 16% and 146%, respectively, of predicted. Quadruple drug immunosuppression was used. Actuarial 1-year survival in this initial series is 93.3% +/- 6.4% (Kaplan-Meier) with one early cardiac death at day 71. Mean forced expiratory volume in 1 second and diffusing capacity for carbon monoxide at discharge were 43% and 62%, respectively, of predicted. Rehabilitation has been excellent, and all survivors are active and free of supplemental oxygen. During the study, the following treatment strategies have evolved: (1) University of Wisconsin solution has replaced Euro-Collins' solution for pulmonary preservation; (2) direct bronchial revascularization with the internal thoracic artery now is used; (3) an algorithm-based variable dose OKT3 induction regimen has resulted in a major reduction in dosage; and (4) infectious disease management focuses on the prophylaxis of cytomegalovirus and fungal infection using prolonged ganciclovir and early itraconazole therapy as well as the avoidance of Epstein-Barr virus mismatches. Single-lung transplantation for emphysema has excellent early results with continuing evolving management strategies.

Adenosine↗
PubMed1993

Clinical manifestations of lung cancer.

The initial clinical manifestations of lung cancer are diverse and may occur with or without symptoms. Manifestations of pulmonary malignant lesions are produced by local growth or invasion, metastatic disease, or paraneoplastic processes. Patterns of local invasion such as Pancoast's syndrome or the superior vena cava syndrome are relatively uncommon but well recognized. Metastatic lung cancer can involve almost any anatomic area by hematogenous, lymphatic, or, occasionally, interalveolar dissemination. Complications related to malnutrition, infection, electrolyte disturbances, and coexisting diseases influence the initial manifestations. Although individual tumor cell types are associated with characteristic features, no constellation of findings is pathognomonic for a specific histologic variant. Because successful treatment of pulmonary carcinoma depends on early detection, awareness of the typical clinical manifestations is important.

Humans↗
PubMed1993

Paraneoplastic syndromes associated with lung cancer.

Paraneoplastic phenomena associated with primary lung cancer have diverse initial manifestations and epitomize the systemic nature of human malignant disease. The spectrum of clinical features in patients with paraneoplastic syndromes ranges from mild systemic or cutaneous disease to hypercoagulability and severe neuromyopathic disorders. Although the diagnosis is often one of exclusion, an improved understanding of the pathogenesis involved in some of these syndromes has provided another means of recognizing the disorders and perhaps treating the affected patients. Proposed mechanisms of paraneoplastic processes include the aberrant release of humoral mediators such as hormones and hormone-like peptides, cytokines, and antibodies. In this update, we review the potential mechanisms, diagnosis, and treatment of paraneoplastic syndromes associated with lung cancer.

Endocrine System Diseases↗
PubMed1993

Pulmonary manifestations of extrathoracic malignant lesions.

Two of the most common thoracic manifestations of extrapulmonary malignant tumors are thoracic metastatic lesions and pulmonary thromboembolism. Recognition of the broad array of patterns of pulmonary metastatic involvement is essential for optimal management of oncology patients. In addition to the "typical" pattern of multiple bilateral nodules, patients may have solitary nodules, reticulonodular infiltrates, hilar and mediastinal adenopathy, endobronchial obstruction, pleural disease, or even normal roentgenographic findings. An awareness of the association between cancer and pulmonary thromboembolism is also valuable. The mechanisms potentially responsible for the thrombotic events associated with malignant disease are discussed, and diagnostic issues are reviewed.

Humans↗
PubMed1993

Colchicine in the treatment of pulmonary fibrosis.

There is no standard or known optimal treatment for idiopathic pulmonary fibrosis. Corticosteroids have been used with widely variable benefit. Colchicine has been reported to suppress fibroblast growth factors and to inhibit collagen deposition. A potential role has been proposed for colchicine in the treatment of fibrotic pulmonary diseases. We retrospectively assessed the outcome of 23 patients with idiopathic pulmonary fibrosis in whom colchicine was used as empiric treatment. Eighteen patients had received prior corticosteroid therapy. By clinical and pulmonary function criteria, five patients (22 percent) improved following colchicine, nine (39 percent) remained stable, and nine (39 percent) worsened. The average duration of follow-up was 22 months. Despite limitations of this retrospective analysis, colchicine may be of benefit in pulmonary fibrosis and should be considered for further clinical trials.

Adult↗
PubMed1992

Intubation of critically ill patients.

Respiratory failure is one of the most common causes for admission to an intensive-care unit. Any patient with loss of central nervous system control of breathing, neuromuscular respiratory failure, or impairment of gas exchange may require tracheal intubation and mechanical ventilation. Tracheal intubation provides a conduit for ventilatory support, maintains the patency of an airway that has potential for obstruction, protects the airway from the contents of the stomach, and allows access to the trachea for pulmonary hygiene. Although the mechanics of intubation are easily learned, many factors must be considered in critically ill patients. Herein we summarize the principles of tracheal intubation in acutely ill patients.

Critical Care↗
PubMed1992

Outcome of recipients of bone marrow transplants who require intensive-care unit support.

To determine the outcome and prognostic factors associated with bone marrow transplantation (BMT), we reviewed the clinical course of 35 adult recipients of such a transplant who were admitted to our intensive-care unit (ICU). This constituted 24% of patients who underwent BMT for treatment of hematologic disorders during the study period. The reasons for admission to the ICU were postsurgical care in 5, respiratory failure in 25, shock in 4, and renal failure in 1. The in-hospital mortality was 20% for the postsurgical patients and 87% for the others. None of the postsurgical patients required mechanical ventilation, whereas 90% of the others did, and the associated mortality was 93%. Infection was the cause of the respiratory failure in all but 3 of the 25 patients and was associated with 95% mortality. Complications that involved multiple organs increased the mortality to 100%. No significant differences were found in age, sex, type of BMT, serologic tests for cytomegalovirus, history of graft-versus-host disease, conditioning regimen for BMT, and duration of stay in the ICU and the hospital between survivors and nonsurvivors. The APACHE II (acute physiology and chronic health evaluation) prognostic scoring system underestimated mortality and had no correlation with the duration of stay in the ICU or the hospital. Vasopressors, total parenteral nutrition, and transfusion of blood components in the ICU had no influence on the outcome. Open-lung biopsy was helpful in making specific diagnoses, and pulmonary artery catheters were used in most patients to guide therapy but did not improve survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Academic Medical Centers↗