Inhibition of TNF-alpha processing and TACE-mediated ectodomain shedding by ethanol.

Alcohol (EtOH) is a well-documented immunosuppressant. Acute EtOH-induced immunosuppression is partially due to suppression of tumor necrosis factor alpha (TNF-alpha) secretion. We investigated the mechanism of acute EtOH-induced TNF-alpha suppression in two monocytic cell lines, Mono Mac 6 and DRM. EtOH inhibited TNF-alpha secretion in a dose-dependent manner. However, TNF-alpha transcription was not affected by EtOH. Enzyme-linked immunosorbent assay and confocal microscopy showed that EtOH treatment increased cell-associated TNF-alpha. Ectodomain shedding of TNF-alpha from the cell surface is mediated by TNF-alpha converting enzyme (TACE). In contrast with TNF-alpha, EtOH did not inhibit interleukin-8 (IL-8) secretion, which does not require shedding. Furthermore, TNF p75 receptor shedding, a biomarker for TACE activity, was inhibited by EtOH in both cell lines. EtOH also inhibited TNF p75 receptor shedding in TACE-reconstituted fibroblasts, suggesting that EtOH inhibits the shedding process. These data show that acute EtOH exposure can posttranscriptionally suppress TNF-alpha production, resulting in specific defects in immune defense.

Left atrial leiomyosarcoma: manifestation as unexplained pulmonary vascular disease.

Primary, left-sided cardiac tumors are a rare cause of unexplained pulmonary hypertension. We describe herein two patients with leiomyosarcoma of the left atrium, who were initially seen with symptoms suggestive of primary pulmonary hypertension, venoocclusive disease, or multiple, small thromboemboli. Postmortem examination showed extension of the leiomyosarcoma into the pulmonary veins, which resulted in pulmonary venous hypertension. Although unusual, the occurrence of left-sided cardiac neoplasms should be included in the differential diagnosis of patients who are initially seen with unexplained pulmonary hypertension. An open lung biopsy should be considered and may indicate a venous origin for the hypertension.

Aerosol bronchodilator delivery methods. Relative impact on pulmonary function and cost of respiratory care.

Thirty-six acutely III, hospitalized patients with acute exacerbations of obstructive airway disease and a greater than 10% increase in forced expiratory volume in 1 s after administration of aerosolized bronchodilator were randomized to receive either metaproterenol sulfate delivered by updraft-compressor nebulization (UDN) or terbutaline sulfate delivered by metered-dose inhaler (MDI) with a spacer. Serial analyses of pulmonary function measurements were performed with the use of 95% confidence intervals for the percentage response ratios of MDI to UDN. The response to MDI was at least equivalent to that of UDN, and MDI use was associated with no prolongation of hospital stay. Equivalent bronchodilation was achieved with MDI therapy with a lower daily charge for therapy for each patient and less respiratory therapist time. In hospitalized bronchodilator-responsive patients with acute exacerbations of obstructive airway disease, the MDI/spacer combination is the preferred approach when the status of the patient allows its use.

Use of transient CD4 lymphocyte depletion to prolong transgene expression of E1-deleted adenoviral vectors.

E1-deleted adenoviral vectors are increasingly being utilized for in vivo gene transfer. The potential use of these vectors is limited by transient expression of the transgene and a markedly reduced rate of transduction following readministration, presumably due to a host immune response to the vector. We hypothesized that CD4+ lymphocytes are necessary to generate an immune response to these vectors and that administration of a depleting anti-CD4 antibody (GK1.5) might prolong transgene expression in vivo. We found that pretreatment of mice with a single injection (transient depletion) or weekly injections of GK1.5 (persistent depletion), markedly prolonged expression of an adenovirus-encoded tumor necrosis factor (TNF) inhibitor or luciferase gene compared to controls. Moreover, mice treated with GK1.5 showed no antiadenoviral antibody response to repeat administration of the vector and a second adenoviral transgene could be expressed in these animals. However, control mice developed a significant neutralizing antibody response that prevented transgene expression with administration of a second adenovirus. These findings demonstrate that manipulation of the host immune response may expand potential applications of gene transfer utilizing adenoviral vectors.

The treatment of malignant mesothelioma with a gene modified cancer cell line: a phase I study.

Malignant mesothelioma is a tumor of the pleura for which there is no satisfactory treatment. It is almost universally fatal, regardless of the stage of the tumor at the time of diagnosis. Current treatment modalities include surgery, chemotherapy, and radiation therapy, although in some series none of these modalities is superior to no treatment at all. Because of the dismal prognosis for patients with malignant mesothelioma, a new mode of treatment is desperately needed. A promising area of research into the treatment of various malignancies is gene therapy. Recent studies have demonstrated the utility of exposing tumor cells to cells transduced to express the Herpes simplex virus gene for thymidine kinase (HSV-tk). By virtue of their expression of HSV-tk, the transduced cells are rendered susceptible to the antiviral drug, ganciclovir (GCV). and nearby tumor cells are killed by a phenomenon termed the bystander effect. In this protocol we propose a Phase I trial to study the safety and determine the maximal tolerated dose of an HSV-tk-transduced ovarian cancer cell line (PA1-STK cells) infused into the pleural cavities of patients with malignant pleural mesothelioma, followed by systemic administration of ganciclovir. The hope is that administration of ganciclovir will result in killing of the HSV-tk transduced ovarian cancer cells as well as the nearby malignant mesothelioma cells. This is a standard dose-escalation protocol.

Regulation of tumor necrosis factor cytotoxicity by calcineurin.

Cyclosporin (CsA) inhibits mitochondrial death signaling and opposes tumor necrosis factor (TNF)-induced apoptosis in vitro. However, CsA is also a potent inhibitor of calcineurin, a phosphatase that may participate in cell death. Therefore, we tested the hypothesis that calcineurin regulates TNF cytotoxicity in rat hepatoma cells (FTO2B). TNF-treated FTO2B cells appeared apoptotic by DNA fragmentation, nuclear condensation, annexin V binding, and caspase activation. We studied two calcineurin inhibitors, CsA and FK506, and found that each potently inhibited TNF cytotoxicity. Western blot demonstrated calcineurin in FTO2B homogenates. In a model of mitochondrial permeability transition (MPT), we found that CsA prevented MPT and cytochrome c release, while FK506 inhibited neither. In summary, we present evidence that calcineurin participates in an apoptotic death pathway activated by TNF. CsA may oppose programmed cell death by inhibiting calcineurin activity and/or inhibiting mitochondrial signaling.

Calcium channel blockers in hypoxic pulmonary hypertension.

Hypoxia is the major cause of pulmonary hypertension and right ventricular hypertrophy in chronic obstructive pulmonary disease, cystic fibrosis, kyphoscoliosis, chronic mountain sickness, and the obesity-hypoventilation and sleep apnea syndromes. Pulmonary hypertension develops in these patients because the long-standing vasoconstriction produced by hypoxia causes muscular hypertrophy of the pulmonary arteries and arterioles. These pathologic changes may regress if alveolar hypoxia is corrected and hypoxic pulmonary vasoconstriction is continuously inhibited. Intermittent inhibition of hypoxic pulmonary vasoconstriction does not reverse these pathologic changes. Since patient noncompliance with oxygen therapy makes it difficult to achieve continual relief of alveolar hypoxia, a drug that inhibits hypoxic vasoconstriction may be useful. Experimental findings indicate that hypoxic pulmonary vasoconstriction requires calcium influx and can be inhibited by certain slow-channel calcium blockers. Studies also demonstrate that slow-channel calcium antagonists can attenuate the pulmonary hypertension and right ventricular hypertrophy produced in rats by chronic hypoxia. Recently, two studies have shown that nifedipine inhibits hypoxic pulmonary vasoconstriction in patients with chronic obstructive pulmonary disease. If further studies demonstrate that these short-term effects are sustained, certain slow-channel calcium blockers may become a useful adjuvant to low-flow oxygen therapy in the treatment of hypoxic pulmonary hypertension.

Comparison of Xe-133 washout and single-breath imaging for the detection of ventilation abnormalities.

The Xe-133 ventilation studies of 115 patients were analyzed to determine the relative abilities of the single-breath and washout phases to detect regional ventilation abnormalities. All Xe-133 images were obtained in the posterior projection before 6-view perfusion studies with Tc-99m human albumin microspheres. There were 275 regions with matching V-P abnormalities in the patients. The washout portion of the study detected 258 of these regions (94%) and the single breath detected 175 (64%) (p less than 0.01). The discrepancies were confined to regions with nonsegmental perfusion defects, where the single breath detected 139 matches and the washout 216. The discrimination ratio between normal areas and areas of obstructive lung disease improved from 2 to 1 after 1 min washout to 30 to 1 after 5 min. The late phases of Xe-133 washout are useful in detecting ventilation abnormalities, especially those associated with nonsegmental perfusion defects.

Inhibition of hypoxic pulmonary vasoconstriction by nifedipine.

Nifedipine is a potent slow channel calcium antagonist and systemic vasodilator recently reported to attenuate hypoxic pulmonary vasoconstriction in man. Other systemic vasodilators have also been shown to attenuate hypoxic pulmonary vasoconstriction, but their effects in some species may be mediated by reflex beta-adrenergic discharge. We evaluated the effect of nifedipine on the relation between pulmonary arterial pressure and blood flow during hyperoxia (inspired partial pressure of oxygen [PO2] 200 mm Hg) and hypoxia (inspired PO2 50 mm Hg) in denervated ventilated pig lungs perfused in situ with the animal's own blood. Ten lungs were ventilated with alternating 15 minute periods of hyperoxia and hypoxia. Hypoxia shifted the pulmonary artery pressure (x axis)-blood flow (y axis) relationship to the right and decreased its slope, indicating vasoconstriction. Nifedipine, given as a 0.1, 1, or 10 microgram/kg bolus into the pulmonary artery, caused a dose-dependent reduction of hypoxic pulmonary vasoconstriction. It is concluded that nifedipine is a potent pulmonary vasodilator acting locally within the lung and that it might be useful in the therapy of hypoxic pulmonary hypertension from chronic lung disease in man.

Postpartum acute myocardial infarction: a rare occurrence of uncertain etiology.

Two women who had an acute myocardial infarction during the early postpartum period are described, and the findings in nine other women previously reported on are summarized. Attention is called to the atypical nature of ischemic heart disease and myocardial infarction in these patients when compared with myocardial infarction during pregnancy and with ischemic heart disease in men. Postpartum infarcts most often occur in women in their 20s during their first pregnancy, frequently a pregnancy complicated by the preeclampsia-eclampsia syndrome, and are associated with a high mortality rate. In one of our patients and one patient previously reported on, the results of coronary arteriography were normal, suggesting that coronary arterial thromboembolism or spasm was a cause of the infarction. Because postpartum myocardial infarction may be unrelated to atherosclerotic narrowing, detailed angiographic studies in such patients appear warranted. These cases indicate the variety and complexity of ischemic heart disease in women.

Right ventricular ejection fraction measured by first-pass intravenous krypton-81m: reproducibility and comparison with technetium-99m.

Study of the effects of various diseases and therapeutic manipulation of pulmonary vascular resistance on the right ventricle has been restricted by methodologic limitations. The radioactive gas in solution, krypton-81m was used to study the right ventricle and the technique was compared with a technetium-99m method. In 22 subjects, first-pass krypton-81m right ventricular ejection fraction, acquired both in list mode and electrocardiogram-gated frame mode, correlated well (r = 0.81 and 0.86, respectively, p less than 0.01) with that determined by technetium-99m first-pass studies over a broad range of ventricular function. The reproducibility of the technique was excellent (r = 0.84 and 0.95 for each acquisition mode, respectively). Krypton-81m first-pass studies provide accurate and reproducible estimates of right ventricular function. Use of krypton allows multiple measurements, with or without perturbations, over a short period of time.

Frequency and prognostic significance of pericardial effusion in primary pulmonary hypertension. PPH Study Group. Primary pulmonary hypertension.

Pericardial effusion was noted in 43 of 79 patients (54%) with severe primary pulmonary hypertension. Larger effusion was associated with hemodynamic and echocardiographic evidence of right heart failure, impaired exercise tolerance, and a poor 1-year prognosis.

Serine/threonine phosphorylation in cellular signaling for alveolar macrophage phagocytic response to endotoxin.

Protein serine/threonine (ser/thr) phosphorylation is an early signaling event in macrophage activation. We investigated the changes in stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK) activity and effects of phosphatase inhibition on alveolar macrophage (AM) function in rats challenged with intratracheal endotoxin. Animals were sacrificed 90 min post intratracheal lipopolysaccharide (LPS, 100 microg/rat) challenge. AMs were incubated with or without phosphatase inhibitors at 37 degrees C for 30 min. Phagocytosis, CD18 expression, SAPK/JNK and phosphatase activities of AMs were determined. LPS challenge activated SAPK/JNK activity and enhanced phagocytosis of AMs without altering phosphatase activity in these cells. Inhibition of phosphatase 1 and 2A activity with okadaic acid and calyculin A exerted a bi-phasic effect on AM phagocytic function. Okadaic acid at a concentration of 1 microM increased the mean channel fluorescence intensity (MCF) and the percentage of cells engaged in phagocytosis (percent phagocytosis) in AMs from saline-treated rats. This inhibitor at concentrations of 0.5 and 1 microM enhanced both the MCF and percent phagocytosis of AMs from LPS-challenged rats. Calyculin A at a concentration of 10 nM increased the MCF phagocytosis of AMs from LPS-challenged rats. At higher concentrations (20 and 30 nM), calyculin A showed a suppression on both the MCF and percent phagocytosis of AMs in both saline and LPS groups. AM CD18 expression was not altered following LPS challenge. Phosphatase inhibitors at doses that enhanced AM phagocytosis showed either no effect (okadaic acid) or inhibition (calyculin A) of AM CD18 expression. These results suggest that ser/thr phosphorylation and dephosphorylation participate in mediating the phagocytic response of AMs to LPS.

Modulation of the lung host response by granulocyte colony-stimulating factor in rats challenged with intrapulmonary endotoxin.

The effects of granulocyte colony-stimulating factor (G-CSF) on the functional activities of circulating and lung-recruited neutrophils (PMNs) and alveolar macrophages (AMs) were studied in rats to further elucidate the mechanisms underlying G-CSF-enhanced pulmonary host defense. Animals received G-CSF or vehicle twice a day for 2 days, followed by an intratracheal challenge with endotoxin or saline. G-CSF up-regulated CD11b/c expression and mean channel fluorescence intensity of phagocytosis in circulating PMNs. G-CSF also enhanced phagocytic activities, reflected by both the percentage of phagocytosis and mean channel fluorescence intensity in lung-recruited PMNs and AMs in intratracheal endotoxin-challenged rats. The endotoxin-induced increase in pulmonary production of tumor necrosis factor-alpha and cytokine-induced neutrophil chemoattractant was not affected by G-CSF pretreatment. These data demonstrate that G-CSF-enhanced pulmonary recruitment of PMNs is primarily based on the effects of G-CSF on the PMNs themselves, rather than the generation of certain chemotactic stimuli, i.e., cytokine-induced neutrophil chemoattractant and tumor necrosis factor-alpha. The enhanced phagocytic activities of lung-recruited PMNs and AMs also augment pulmonary host defenses in G-CSF-pretreated animals.

Cardiac augmentation by phasic high intrathoracic pressure support in man.

Left ventricular performance can be significantly influenced by changes in intrathoracic pressure. In man, sustained increases in intrathoracic pressure unload the left ventricle, but since venous return decreases, increased intrathoracic pressure is associated with a decreased cardiac output. In a canine model of acute ventricular failure, it has been shown that phasic increases in intrathoracic pressure, which do not decrease venous return, improve steady-state cardiac output. We thus studied the cardiovascular effects of phasic high intrathoracic pressure support (PHIPS) in seven patients with shock in our intensive care unit whose condition was not responsive to conventional types of therapy. The PHIPS was generated by abdominal and chest wall binding during positive-pressure ventilation. As compared to the state before PHIPS, the PHIPS was associated with an increase in esophageal pressure (6.6 +/- 1.1 mm Hg; p less than 0.01) and in mean arterial pressure (43.0 +/- 6.1 to 51.0 +/- 7.7 mm Hg; p less than 0.01) while not changing arterial pressure relative to esophageal pressure. Cardiac output also increased from 3.6 +/- 0.5 to 4.2 +/- 0.6 L/min (p less than 0.05), while left ventricular filling pressures remained constant. In one subject a gated cardiac blood pool scan demonstrated a PHIPS-associated increase in ejection fraction and decreased end-diastolic volume. These results are consistent with the hypothesis that PHIPS, by increasing intrathoracic pressure, augments left ventricular performance by reducing left ventricular afterload. This appears to be a promising area for future research.

Upper airways obstruction with bilateral vocal cord paralysis.

In ten patients with bilateral vocal cord paralysis, we demonstrated variable extrathoracic airway obstruction. The ratio of forced expiratory flow at 50 percent vital capacity to forced inspiratory flow at the same lung volume (VE50/VI50) was 1.65 +/- 0.77 (mean +/- 1 SD). There was marked variability of inspiratory flow obstruction with a mean VI50 of 1.63 +/- 0.75 liters/ sec and a range from 0.9 liters/sec to 3.2 liters/sec. Nine of the ten patients required tracheostomy for symptoms of dyspnea. Follow-up flow volume loops were obtained to document the effects of surgical intervention and tracheostomy.

The effects of acute ethanol ingestion on pulmonary diffusing capacity.

Single breath diffusing capacities for carbon monoxide (DLco) were measured in 12 normal supine subjects before and after ingestion of 15 to 30 ml of 95 percent ethanol (ETOH) to determine if alcohol could acutely change the DLco. Both DLco and specific DLco (DLco/alveolar volume) were significantly decreased 90 minutes after the ingestion of alcohol. This change may be due to a direct effect of alcohol on the alveolar capillary interface by possibly interfering with a carbon monoxide carrier molecule. Another plausible explanation for the reduced diffusing capacity after ingestion of alcohol may be redistribution of blood from the lung to the periphery secondary to the hemodynamic effects of alcohol.

Severe viral pneumonia in young adults.

Three patients with primary group-A influenzal pneumonia had diffuse pulmonary infiltrates, arterial oxygen tensions (PaO2) less than 50 mm Hg while breathing oxygen at 1 atm (fractional concentration of oxygen in the inspired gas (FIo2) equals 1.0), and right-to-left pulmonary shunts greater than 45 percent of total pulmonary blood flow. At an FIo2 of 1.0, end-expiratory pressure (EEP) was added in increments of 2 to 5 cm H2O every 30 to 60 minutes until the PaO2 was above 200 mm Hg and right-to-left shunting had fallen to less than 25 percent. The FIo2 was then lowered to 0.5. Using this systematic approach, all three patients required an FIo2 of 1.0 for less than 12 hours, minimizing the risk of oxygen toxicity. Two of the three patients did not require mechanical ventilation and breathed spontaneously while on continuous positive airway pressure (CPAP), and one of them tolerated an EEP of 31 cm H2O. Two patients survived, and one died of a neurologic complication of cardiopulmonary arrest, despite clearing on the chest x-ray film and improved gas exchange. Therapy with CPAP can be safely used in adults and has practical as well as theoretic benefits over continuous positive-pressure ventilation.

Response of patients with chronic obstructive lung disease to the regular administration of nebulized isoproterenol. A double-blind crossover study.

The effect of the regular use of neublized isoproterenol in 14 patients with symptomatic chronic obstructive lung disease (COLD) was evaluated in a double-blind crossover 16-week study. FEV1, FVC and SGaw were measured before and 45 minutes after bronchodilator therapy every two weeks, while arterial blood gases were measured every eight weeks, before and 45 minutes after bronchodilator therapy. When the patients were considered as a group, there was no significant difference in mean symptom scores or objective pulmonary functions during the drug and placebo periods. Four patients had significantly higher (p less than .05) and two patients significantly lower mean values for at least one of the pulmonary function tests during the isoproterenol period. The patient who is most likely to benefit from isoproterenol on a regular basis appears to have the following characteristics; (1) consistent improvement in pulmonary function tests 45 minutes after use of nebulized bronchodilator; (2) moderate rather than severe COLD; and (3) a relatively normal DLCO.

Effect of prostacyclin on microvascular pressures in a patient with pulmonary veno-occlusive disease.

Continuous-infusion prostacyclin improves symptom scores and decreases mortality in patients with primary pulmonary hypertension, but use of prostacyclin in patients with pulmonary veno-occlusive disease may precipitate pulmonary edema. A patient with pulmonary veno-occlusive disease received a graduated intravenous infusion of prostacyclin and pulmonary capillary pressures were calculated during prostacyclin dose ranging. Calculated capillary pressure increased with low-dose prostacyclin (< or = 6 ng/kg/min) but decreased with higher doses. These data suggest that the post-capillary pulmonary venules in our patient had reversible vasomotor tone, but required a higher dose of prostacyclin to vasodilate than did the precapillary arterioles.