F. Charles Hiller

Intracavitary amphotericin B in the treatment of symptomatic pulmonary aspergillomas

The optimal treatment of pulmonary aspergillomas is not established. Surgical resection is often impossible because of severe, underlying pulmonary impairment, and medical treatment has given negative or inconclusive results. Six patients with symptomatic pulmonary aspergillomas were treated with percutaneous instillation of intracavitary amphotericin B. Four patients who received the full course of therapy showed improvement and stabilization or reversal of progressive roentgenographic changes. Also, follow-up serologic studies of Aspergillus spp. precipitins were obtained in three and were negative. One patient did not tolerate this treatment because of repeated systemic reactions. Another patient did not respond clinically or roentgenographically. Intracavitary amphotericin B therapy should be considered in patients with symptomatic pulmonary aspergilloma, particularly when surgical resection is not feasible.

Efficacy of Gamma-Hydroxybutyrate versus Placebo in Treating Narcolepsy-Cataplexy: Double-Blind Subjective Measures

The efficacy of gamma-hydroxybutyrate (GHB) versus placebo for treating narcolepsy was evaluated in 20 patients with narcolepsy, 10 men and 10 women, using a double-blind counterbalanced crossover design. Each patient completed a daily sleep-wake log and questionnaire during a 14-day baseline, a 29-day placebo period, a 29-day GHB period (50 mg GHB/kg/night given 25 mg/kg h.s. and 25 mg/kg 3 hr later), and a 6-day washout period after each treatment. Cataplexy frequency was significantly lower during GHB treatment than during placebo treatment (p = 0.022). Compared to baseline values, the number of cataplexy attacks per day declined by 52% and 69% during GHB treatment weeks 1 and 4, respectively. The number of subjective arousals from sleep was less with GHB than with placebo (p = 0.035), and the number of sleep attacks was not significantly different during GHB versus placebo treatment. GHB did not have a significant effect on subjective estimates of sleep onset latency, total sleep time, Stanford Sleepiness Scale ratings at morning wake-up, methylphenidate usage, or the number of naps per day. The results indicate that GHB is efficacious for reducing the frequency of cataplexy attacks and subjective nocturnal arousals in patients with narcolepsy within the first 4 weeks of treatment.

Postoperative evaluation of sleep apnea after uvulopalatopharyngoplasty

Uvulopalatopharyngoplasty (UPPP) is an operation that is frequently performed for the treatment of obstructive sleep apnea (OSA). While UPPP usually eliminates or decreases snoring and often reduces excessive daytime sleepiness, the decrease in the number of episodes of apnea and hypopnea, and the improvement in oxygen saturation (SaO2) have been less predictable. We compared preoperative and postoperative polysomnography (PSG) in 27 patients with OSA and found that no single PSG parameter could accurately reflect the changes in respiration seen after UPPP. We suggest that a combination of indices including the apnea index, the apnea and hypopnea index, the frequency and severity of decreases in SaO2, and the lowest SaO2 be used to assess the effect of UPPP. Using this combination we determined that 30% of our patients were markedly improved, 33% were somewhat improved, and 37% were unimproved. To rely soley on the patients subjective improvement often results in overestimating the therapeutic results of surgery, whereas to rely only on one PSG parameter may underestimate or overestimate the degree of improvement.

Regulation of the β2-Adrenergic Receptor and its Mrna in the Rat Lung by Dexamethasone

Glucocorticoids increase beta 2-adrenergic responsiveness and receptor density in the lung, but the underlying mechanisms have not been clearly elucidated. To determine whether changes in beta 2-adrenergic receptor gene expression are involved in vivo, we measured beta 2-adrenergic receptor mRNA levels and beta 2-adrenergic receptor density in lungs from Sprague-Dawley rats treated with a daily injection of dexamethasone (1 mg/kg subcutaneously) for 1, 3, or 7 days. Animals were sacrificed either 2 or 24 h after receiving the last injection. beta 2-Adrenergic receptor mRNA levels were significantly (p < .05) elevated compared to saline-treated controls in the lungs of animals sacrificed 2 h after dexamethasone injection for 1 day (174 +/- 12%), 3 days (236 +/- 18%), and 7 days (220 +/- 11%). Receptor mRNA levels measured 24 h after dexamethasone injection did not differ significantly from the control group. Induction of beta 2-adrenergic receptor mRNA by dexamethasone was transient, since no significant cumulative or sustained increase in receptor mRNA levels was observed during the study period. Treatment with dexamethasone increased beta 2-adrenergic receptor density as expected, but no significant increase in receptor density was detected until 24 h after the third daily injection of dexamethasone, when levels reached 2045 +/- 150 fmol/mg protein compared to 1292 +/- 34 fmol/mg protein in the control group. Receptor density then remained at this elevated level through 7 days of treatment. These results show that dexamethasone up-regulates both the beta 2-adrenergic receptor and its mRNA in vivo in the lung. The induction of beta 2-adrenergic receptor mRNA levels indicates that glucocorticoids may regulate receptor density in the lung through modulation of gene expression. However, the difference between the time course of induction for the beta 2-adrenergic receptor and its mRNA suggests that additional translational or post-translational mechanisms may also be involved.

Deposition of sidestream cigarette smoke in the human respiratory tract.

The intake of sidestream cigarette smoke can be calculated if ventilation and smoke concentration are known. However, respiratory tract dose of smoke particulates cannot be determined unless the deposition fraction of inhaled smoke is known. The deposition fraction of mainstream smoke is 70-90%, far higher than expected for most particles in the size range, 0.2-0.5 micron, which is also the range for cigarette smoke. The deposition fraction of sidestream smoke was measured in five normal male subjects. The deposition, the dose of smoke particulates to the respiratory tract can be estimated. The deposition fraction of sidestream smoke is much lower than for mainstream smoke.

Effect of propellant on the pharmacokinetics and pharmacodynamics of inhaled albuterol in asthmatic subjects

Hydrofluoroalkane (HFA) propellants have largely replaced chlorofluorocarbon (CFC) propellants in metered dose inhalers (MDI). It is important to document the pharmacokinetics (PK) and pharmacodynamics (PD) of medications delivered using HFA propellants compared to CFC propellants. Six adult asthmatics with mild to moderate asthma were selected for the study. Each subject inhaled 180 microg of albuterol from an MDI with holding chamber. Venous blood was collected for measuring albuterol levels at intervals over 12 h, and spirometric measurements of airflow were measured over the same time period. Plasma samples were analyzed using a GC/MS assay developed in our laboratory. PK and PD parameters were calculated by nonlinear regression using WinNonlin. There were no statistically significant differences between PD parameters for HFA versus CFC propellants. The area under the plasma albuterol concentration versus time curve (AUC) was 72% greater for the HFA formulation, indicating a greater lung bioavailability (p = 0.015). This difference in bioavailability did not result in a statistically significant difference in FEV(1) values between the two propellants.

Deposition of sidestream cigarette smoke in the human respiratory tract II. Deposition of ultrafine smoke particles

Sidestream cigarette smoke was generated into an inhalation chamber from which five normal male volunteers inhaled the smoke. Size distribution of the smoke aerosol was: count median diameter, 0.11 micron, mass median diameter 0.43 micron. Deposition fraction measured as concentration difference for each size fraction between inhaled and exhaled aerosol for each size interval was: 0.075 micron, 0.24 +/- 0.04; 0.13 micron, 0.15 +/- 0.04; 0.24 micron, 0.10 +/- 0.04; and 0.42 micron, 0.07 +/- 0.02. The declining deposition fraction as size approaches 0.5 micron is consistent with previous theoretical and experimental data.

Enhanced β2-adrenergic receptor (β2AR) signaling by adeno-associated viral (AAV)-mediated gene transfer

Backgroundβ2-Adrenergic receptors (β2AR) play important regulatory roles in a variety of cells and organ systems and are important therapeutic targets in the treatment of airway and cardiovascular disease. Prolonged use of β-agonists results in tolerance secondary to receptor down-regulation resulting in reduced therapeutic efficiency. The purpose of this work is to evaluate the signaling capabilities of the β2AR expressed by a recombinant adeno-associated viral (AAV) vector that also included an enhanced green fluorescent protein (EGFP) gene (AAV-β2AR/EGFP).ResultsBy epifluorescence microscopy, ~40% of infected HEK 293 cells demonstrated EGFP expression. β2AR density measured with [3H]dihydroalprenolol ([3H]DHA) increased either 13- or 77-fold in infected cells compared to mock infected controls depending on the culture conditions used. The [3H]DHA binding was to a single receptor population with a dissociation constant of 0.42 nM, as would be expected for wild-type β2AR. Agonist competition assays with [3H]DHA showed the following rank order of potency: isoproterenol>epinephrine> norepinephrine, consistent with β2AR interaction. Isoproterenol-stimulated cyclic AMP levels were 5-fold higher in infected cells compared to controls (314 ± 43 vs. 63.4 ± 9.6 nmol/dish; n = 3). Receptor trafficking demonstrated surface expression of β2AR with vehicle treatment and internalization following isoproterenol treatment.ConclusionsWe conclude that HEK 293 cells infected with AAV-β2AR/EGFP effectively express β2AR and that increased expression of these receptors results in enhanced β2AR signaling. This method of gene transfer may provide an important means to enhance function in in vivo systems.

EXPRESSION OF FUNCTIONAL ß2-ADRENERGIC RECEPTORS IN A RAT AIRWAY EPITHELIAL CELL LINE (SPOC1) AND CELL DENSITY-DEPENDENT INDUCTION BY GLUCOCORTICOIDS

The beta 2-adrenergic receptor (beta 2AR) signal transduction system regulates many key functions of airway epithelium. In this study, we have pharmacologically characterized the beta 2AR and determined the impact of glucocorticoids on beta 2AR gene transcription in SPOC1 cells, a continuous cell line derived from the tracheal epithelium of rats. [125I]Cyanoiodopindolol assays demonstrated that binding to SPOC1 cell membranes was saturable (Bmax = 62.6 +/- 6 fmol/mg protein) and of high affinity (Kd = 6.3 +/- 0.8 pM). From competition experiments, the rank order of potency of agonists (isoproterenol > epinephrine >> norepinephrine) and the high affinity (Ki = 0.37 +/- 0.05 nM) of the beta 2-selective antagonist ICI 118,551 suggested the predominance of the beta 2AR subtype. Two isoforms of the alpha subunit of Gs (45 and 52 kDa) were identified by Western blot analysis. Isoproterenol-stimulated cyclic AMP levels increased in a dose-dependent manner, confirming that SPOC1 cell beta 2ARs are functionally coupled to adenylyl cyclase. The effect of glucocorticoids on beta 2AR expression was assessed in radioligand and transient transfection assays. Dexamethasone treatment of SPOC1 cells increased both beta 2AR protein and beta 2AR-luciferase fusion gene expression 1.6- to 3.1-fold, with the greatest increase demonstrated in cells cultured at low density compared to cells grown at high density.

Effect of single intravenous doses of histamine2-receptor antagonists on volume and pH of gastric acid secretions in critically ill patients

Abstract The effects of single doses of cimetidine, famotidine, and ranitidine on gastric acid and fluid secretions in 12 critically ill, mechanically ventilated patients were evaluated in a prospective, randomized, crossover, single-blind trial. Each patient received an intravenous dose of cimetidine 300 mg, famotidine 20 mg, or ranitidine 50 mg diluted in 50 mL of normal saline and infused over 30 minutes. Each agent was administered in crossover fashion on consecutive days after the pH returned to baseline. Analysis of gastric fluids and pH measurements were determined from gastric samples collected every 15 minutes. Cimetidine, famotidine, and ranitidine treatment resulted in significant increases in gastric pH and decreased fluid production and total aspirated fluid volume. Famotidine maintained a gastric pH ⩾4.0 for a mean duration of 16.5 ± 4.1 hours, significantly longer ( P P