Foam sclerosants are more stable at lower temperatures.

OBJECTIVES: Sclerosant foams are aqueous and break down under the influence of gravity, pressure, and temperature. The aim of this study was to investigate the effects of temperature on foam stability. METHODS: Sodium tetradecyl sulphate (STS) and polidocanol (POL) liquid and foam (1 + 4, liquid-plus-air fraction) were investigated in a range of concentrations (0.5%, 1.5%, 3.0%) and temperatures. Surface tension was measured by the Du Nuoy ring method. Liquid drainage from foam was measured and documented by serial photography. Both pre- and post-cooling variations were investigated. RESULTS: Surface tension decreased at higher temperatures. Surface tension of POL was higher than STS at concentrations tested. POL foam half-time increased significantly at higher concentrations while the half-time of STS foam was not affected by concentration. Heating the sclerosant foam above the ambient temperature reduced its half-time while cooling below the ambient temperature prolonged the half-time. Both pre- and post-cooling of the foams resulted in significant prolongation of half-times when compared to no cooling. Maximum stability of the two sclerosant foams tested was achieved at 10 °C. CONCLUSIONS: Foam sclerosants are more stable at cooler temperatures.

Sclerosant foam structure and stability is strongly influenced by liquid air fraction.

OBJECTIVES: To determine the effects of sclerosant foam preparation and composition on foam structure, the time course of liquid drainage, and foam coarsening. METHODS: Sodium tetradecyl sulphate (STS) and polidocanol (POL) foams were investigated in a range of concentrations (0.5-3%) and liquid-plus-air fractions (LAF; 1 + 2 to 1 + 8). Foam was injected into a vein simulation model (polyvinyl chloride tubing, inner diameter 3 mm, constant pressure 5-7 mmHg) filled with saline or blood. Liquid drainage, bubble count, and diameter were measured and documented by serial photography. RESULTS: Liquid drainage was faster in the vertical position than the horizontal one. In all variations, very small bubbles (diameter <30 µm) were generated initially that coarsened to form micro-foams (<250 µm). By 3 minutes mini-foams (>250 µm) and by 7.5 minutes macro-foams (>500 µm) were formed. Following injection, the upper regions of foam coarsened faster as liquid drained to the bottom of the vessel. Wet preparations produced significantly smaller bubbles. Low concentration POL foam produced significantly higher bubble counts and coarsened slower than STS. CONCLUSIONS: Foam structure is strongly influenced by the LAF. Despite the initial formation of micro-bubbles in the syringe, mini- and macro-bubbles are formed in target vessels with time post-injection.

Alterations in central hemodynamic in patients with COPD after acute high intensity exercise.

The present study investigated the relationship between central hemodynamics and lung function and the response to an acute bout of exercise in COPD. METHODS: Based on the severity of COPD, moderate group (MOD, n = 12) and more mild group (MLD, n = 12) underwent central hemodynamic assessments pre- and post-peak exercise. RESULTS: In the entire cohort (n = 24), central diastolic blood pressure (cDBP) was associated with pulmonary function. Post-exercise, cDBP remained elevated (p < 0.01), however, peripheral diastolic blood pressure (pDBP) was reduced (p = 0.02). Prior to exercise, the MOD showed higher cDBP and heart rate (HR) than the MLD (p = 0.02 and p = 0.01, respectively), but no difference in central aortic/arterial stiffness (p > 0.05). These findings remained similar post-exercise. CONCLUSION: Central diastolic blood pressure is linked to pulmonary function in COPD and it is elevated after exercise-induced reductions in pDBP. Central diastolic blood pressure is higher in the MOD than the MLD, however, there was no difference in central aortic/arterial stiffness between groups.

A retroviral vector expressing human interferon gamma upregulates MHC antigen expression in human breast cancer and leukemia cell lines.

The use of cytokines to modify antigen expression on syngeneic murine tumor cells has led to immunization of the host from subsequent challenges with the parent tumor cell line. To determine whether this approach can be applied to human malignancies we introduced the human interferon gamma gene (IFN gamma) into the human breast cancer cell lines MDA-MB-435 and MDA-MB-231 using retroviral-mediated gene transfer. Retroviral transfer of the IFN gamma gene was associated with decreased growth, decreased tumor invasiveness, IFN gamma production, and upregulation of MHC antigens. While the MDA-MB-435 produced higher levels of IFN gamma than MDA-MB-231, MHC class I and class II antigens were upregulated in both cell lines. Introduction of this vector into the human leukemia cell line K562 led to increased expression of MHC class I antigens, but not class II. Our findings suggest that expression of interferon gamma in breast cancer cells may lead to increased recognition of breast cancer cells by the host immune system. Furthermore, these data suggest that further development of this approach to cancer immunotherapy is warranted.

Adjuvant bleomycin, etoposide and cisplatin in pathological stage II non-seminomatous testicular cancer. the Indiana University experience.

Two cycles of bleomycin, etoposide, and cisplatin (BEP) were evaluated as adjuvant chemotherapy for patients with pathological stage II non-seminomatous germ cell tumours. Between 1985 and 1995, 86 patients with pathological stage II non-seminomatous testicular cancer were treated with two cycles of BEP. At retroperitoneal lymph node dissection (RPLND) 49 patients (57%) had pathological stage II(A) (microscopic nodal metastases) and 37 (43%) had stage II(B) (gross nodal metastases). After RPLND, the patients received bleomycin, 30 units weekly for 8 weeks, etoposide (100 mg/m(2)) and cisplatin (20 mg/m(2)) each for 5 days every 28 days for two cycles as adjuvant chemotherapy. 4 patients were lost to follow-up. 10 patients (12%) developed granulocytopenic fever during their chemotherapy. Of the 82 evaluable patients all remained with no evidence of disease except for a single patient with a cervical nodal relapse of teratoma. This was resected and he remains disease free. Median follow-up has been 85 months (range: 42-173 months). In patients with fully resected stage II non-seminomatous germ cell tumour, two cycles of BEP were almost universally effective in preventing relapse.

Mitochondrial disease: a pulmonary and critical-care medicine perspective.

The clinical spectrum of mitochondrial diseases has expanded dramatically in the last decade. Abnormalities of mitochondrial function are now thought to participate in a number of common adult diseases, ranging from exercise intolerance to aging. This review outlines the common presentations of mitochondrial disease in ICUs and in the outpatient setting and discusses current diagnostic and therapeutic options as they pertain to the pulmonary and critical-care physician.

Lung infections: role of apoptosis in host defense and pathogenesis of disease.

Apoptosis is a form of cell death that has gained enormous attention during the past few years, and its mechanisms, important to biology and medicine, are being unraveled at an accelerating pace. Apoptosis of lung cells occurs during lung infections and may be either a host defense mechanism or reflect the pathogenesis of the infection. In the first part of this review, the biochemistry and physiology of apoptotic pathways and its regulators are discussed. This is followed by an overview of apoptotic mechanisms in selected lung infections. The implications of apoptosis in host immunity, pathogenesis, and treatment of pulmonary infections will be discussed in this context.

COPD may increase the incidence of refractory supraventricular arrhythmias following pulmonary resection for non-small cell lung cancer.

PURPOSE: This study investigated the association of COPD and postoperative cardiac arrhythmias, specifically supraventricular tachycardia (SVT), as well as mortality in patients undergoing pulmonary resection for non-small cell lung cancer (NSCLC). METHODS: A retrospective chart review of 244 patients who had undergone lung resection for NSCLC at Indiana University Hospital between 1992 and 1997 was undertaken. COPD, which was defined as an FEV(1) of < or = 70% predicted and an FEV(1)/FVC ratio of < or = 70% based on the results of a preoperative pulmonary function test (PFT), was diagnosed in 78 of the 244 patients (COPD group). In the remaining 166 patients, the results of preoperative PFTs did not meet these criteria (non-COPD group). Both groups were otherwise well-matched with respect to multiple variables, including age, comorbid conditions, extent of pulmonary resection, and final pathologic stage. The incidence of cardiac arrhythmias and operative mortality were compared between the two groups using univariate and multivariate analysis. RESULTS: Seventy-six patients (31.9%) experienced new onsets of postoperative SVT, with 58 of these patients (76.3%) demonstrating atrial fibrillation. The COPD group had a 58.7% incidence of SVT (n = 44) compared to a 27.0% incidence (n = 44) in the non-COPD group (p < 0.0 0 1). Moreover, following initial digoxin therapy, the COPD group required more second-line antiarrhythmic therapy than did the non-COPD group (66.7% vs 37.8%, respectively; p = 0.0 03). Overall, there were 16 operative deaths (6.6%), and the mortality rate was significantly higher in the COPD group (14.1%) than in the non-COPD group (3.0%; p = 0.0 04). Patients who developed SVT had a significantly longer hospital course than did patients who did not (p < 0.0001). Thirteen of the 16 patients who died experienced SVT; however, SVT was not an independent risk factor for death. Finally, of the 19 variables evaluated, major resection (ie, pneumonectomy and bilobectomy) and COPD were identified as independent risk factors for the development of cardiac arrhythmias (p = 0.0 033 and p = 0.0 009, respectively). CONCLUSION: Patients with COPD, as defined by the results of preoperative PFTs, are at significantly higher risk for SVT, and in particular SVT refractory to digoxin, following pulmonary resection for NSCLC. Although SVT was not an independent risk factor for death, a significantly longer hospitalization was observed.

Management of myxedematous respiratory failure: review of ventilation and weaning principles.

Respiratory failure in myxedema is a complex medical emergency and may require prolonged ventilatory assistance. Appropriate management of this medical problem requires an understanding of its effects on the central nervous system and peripheral neuromusculoskeletal system. Weaning of these patients can be very protracted and requires a diligent multidisciplinary approach. Because of its infrequency, ventilatory management of severe hypothyroidism has not been studied in a controlled fashion. The first part of this review discusses the mechanisms of respiratory failure in myxedema. The second part explores strategies in mechanical ventilation and weaning of myxedematous patients.

Unilateral bronchiectasis and esophageal dysmotility in congenital adult tracheoesophageal fistula.

Tracheoesophageal fistulas (TEF) in adults are most commonly neoplastic, and very rarely congenital in nature. We report a 45-year-old Hispanic male with TEF and initial presentation of minimal hemoptysis. The patient had radiographic evidence of unilateral upper lobe (RUL) bronchiectasis, massive esophageal dilatation, and dysmotility. However, there was no evidence of esophageal malignancy, achalasia, or Chagas' disease. Bronchoscopy revealed a large TEF in the posterior wall of trachea, which was not visualized on esophagram or esophagoscopy. Bronchoalveolar lavage (BAL) cultures grew Mycobacterium avium complex (MAC). Our report illustrates that idiopathic, or congenital, TEF can be associated with esophageal dysmotility, adulthood bronchiectasis, and atypical mycobacterial superinfection.

Primary care diagnosis of thyroid disease.

Recent diagnostic advances include sensitive thyroid-stimulating hormone (TSH) assays, more accurate free thyroxine assays, and fine-needle aspiration biopsy. The workup of patients with suspected thyroid dysfunction generally begins with a TSH assay; guidelines are provided for subsequent thyroid tests. Aspiration biopsy is appropriate for those with a nodular goiter.

Role of electromyography in amyotrophic lateral sclerosis.

We reviewed the role of electrodiagnostic testing in amyotrophic lateral sclerosis (ALS) in a large ALS clinic. Over 31 months, 133 patients with a clinical diagnosis of ALS were tested. In most, nerve conduction studies were normal, and needle electrode examination showed active denervation in the upper and lower limbs or the limbs and bulbar muscles (Lambert's criteria). However, 50 of 133 patients did not fulfill Lambert's criteria at presentation because of abnormal nerve conduction studies (11 patients), abnormal F-wave latencies (6 patients), or insufficiently distributed fibrillation potentials (40 patients). This study reveals that a large proportion of patients with a clinical diagnosis of ALS fail to have classical findings on initial electrodiagnostic studies, and reveals several caveats of electrodiagnostic testing in these patients: (1) Conduction studies may be unreliable in motor nerves with markedly low compound muscle action potential (CMAP) amplitudes. (2) Sensory nerve action potential (SNAP) amplitudes may be abnormal in a small percentage of otherwise typical ALS patients. However, better controls for elderly subjects are needed. (3) Needle electrode examination may not show widespread active denervation early in the disease. (4) Some patients may have a mild polyneuropathy. (5) The classic diagnostic criteria may need to be modified to allow earlier acceptance of many ALS patients into therapeutic trials.

Pleural fluid and serum eosinophilia: association with fluoxetine hydrochloride.

We report the case of a patient who was treated with fluoxetine hydrochloride (Prozac) for depression. Approximately 8 weeks into the treatment, an eosinophilic pleural effusion and serum eosinophilia developed. An extensive workup for the etiology of eosinophilic pleural effusion was unrevealing. Pleural biopsy showed a nonspecific inflammatory reaction and mild fibrosis. The pleural effusion and eosinophilia resolved within a few weeks of cessation of the drug. Fluoxetine can be associated with pleural and serum eosinophilia, possibly through an allergic-mediated reaction.