New Limit for Neutrinoless Double-Beta Decay of

The CUPID-Mo experiment at the Laboratoire Souterrain de Modane (France) is a demonstrator for CUPID, the next-generation ton-scale bolometric 0νßß experiment. It consists of a 4.2 kg array of 20 enriched Li_{2}^{100}MoO_{4} scintillating bolometers to search for the lepton-number-violating process of 0νßß decay in ^{100}Mo. With more than one year of operation (^{100}Mo exposure of 1.17 kg×yr for physics data), no event in the region of interest and, hence, no evidence for 0νßß is observed. We report a new limit on the half-life of 0νßß decay in ^{100}Mo of T_{1/2}>1.5×10^{24} yr at 90% C.I. The limit corresponds to an effective Majorana neutrino mass ⟨m_{ßß}⟩<(0.31-0.54) eV, dependent on the nuclear matrix element in the light Majorana neutrino exchange interpretation.

First Germanium-Based Constraints on Sub-MeV Dark Matter with the EDELWEISS Experiment.

We present the first Ge-based constraints on sub-MeV/c^{2} dark matter (DM) particles interacting with electrons using a 33.4 g Ge cryogenic detector with a 0.53 electron-hole pair (rms) resolution, operated underground at the Laboratoire Souterrain de Modane. Competitive constraints are set on the DM-electron scattering cross section, as well as on the kinetic mixing parameter of dark photons down to 1 eV/c^{2}. In particular, the most stringent limits are set for dark photon DM in the 6 to 9 eV/c^{2} range. These results demonstrate the high relevance of Ge cryogenic detectors for the search of DM-induced eV-scale electron signals.

Transfusion-related acute lung injury after intravenous immunoglobulin treatment in a lung transplant recipient.

Three weeks after single-lung transplantation for pulmonary fibrosis, a patient with high serum levels of de novo donor-specific antibodies received high-dose intravenous immunoglobulin (IVIG) infusion (scheduled dose: 2 g/kg on 2 days) to prevent antibody-mediated rejection. Within the first hours after completion of infusions, he experienced acute lung injury involving the transplanted lung. Given the clinical evolution and the absence of an alternative diagnosis, transfusion-related acute lung injury (TRALI) was diagnosed. The IVIG administered on each day was from the same batch. At day 110, because of an increase in the serum titers of donor-specific antibodies, IVIG therapy was reintroduced but from a different batch, with excellent clinical tolerance. The lung injury was explored biologically, but no mechanism was revealed. Given the increasing use of IVIG in solid-organ recipients, clinicians should be aware of possible TRALI after IVIG infusion.

Incidence and management of mTOR inhibitor-associated pneumonitis in patients with metastatic renal cell carcinoma.

The administration of mammalian target of rapamycin (mTOR) inhibitors can give rise to a potentially life-threatening adverse event, often referred to as 'non-infectious pneumonitis' (NIP), which is characterized by non-infectious, non-malignant, and non-specific inflammatory infiltrates. Patients usually present with cough and/or dyspnoea. We provide a brief description of the mechanism of action of mTOR inhibitors and their overall safety in patients with metastatic renal cell carcinoma (mRCC) and review the literature on mTOR inhibitor-associated NIP in patients with solid tumours. The review was used to derive questions on the diagnosis, management, and monitoring of mRCC patients with NIP, and to develop a decision tree for use in routine clinical practise. A key recommendation was the subdivision of grade 2 NIP into grades 2a and 2b, where grade 2a is closer to grade 1 and grade 2b to grade 3. This subdivision is important because it takes into account the nature and severity of clinical symptoms potentially related to NIP, either the onset of new symptoms or the worsening of existing symptoms, and thus determines the type and frequency of follow-up. It also helps to identify a subgroup of patients in whom treatment, if effective, may be continued without dose adjustment.

Bleomycin induces pleural and subpleural fibrosis in the presence of carbon particles.

The pathological changes in idiopathic pulmonary fibrosis (IPF) typically start in subpleural lung regions, a feature that is currently not explained. IPF, as well as bleomycin-induced lung fibrosis, are more common in smokers. We hypothesised that carbon particles, which are major components of cigarette smoke that are transported to alveoli and pleural surface, might be involved in the development of subpleural fibrosis through interaction with pleural mesothelial cells. Carbon particles were administered to mice in combination with bleomycin through intratracheal and/or intrapleural injection and fibrosis was assessed using histomorphometry. Carbon administered to the chest cavity caused severe pleural fibrosis in the presence of bleomycin, whereas bleomycin alone had no fibrogenic effect. The pleural response was associated with progressive fibrosis in subpleural regions, similar to IPF in humans. Matrix accumulation within this area evolved through mesothelial-fibroblastoid transformation, where mesothelial cells acquire myofibroblast characteristics. In contrast, carbon did not exaggerate bleomycin-induced pulmonary fibrosis after combined intratracheal administration. This represents a novel approach to induce a robust experimental model of pleural fibrosis. It also suggests that carbon particles might be involved as a cofactor in the initiation and/or progression of (subpleural) pulmonary and pleural fibrosis. Mesothelial cells appear to be critical contributors to this fibrotic process.

Evaluating noninvasive ventilation using a monitoring system coupled to a ventilator: a bench-to-bedside study.

Empirically determined noninvasive ventilation (NIV) settings may not achieve optimal ventilatory support. Some ventilators include monitoring modules to assess ventilatory quality. We conducted a bench-to-bedside study to assess the ventilatory quality of the VPAPIII-ResLink (ResMed, North Ryde, Australia). We tested the accuracy of minute ventilation (MV) and leak calculations given by VPAPIII-ResLink compared to those measured by a bench model at varied leak levels and ventilator settings. We systematically assessed NIV efficacy using this system from 2003 to 2006. Ventilation was considered inadequate if leak (>24 L x min(-1)), continuous desaturation (>30% of the trace) or desaturation dips (>3%) were present. On the bench test, both methods were highly correlated (r = 0.947, p>0.0001 and r = 0.959, p<0.0001 for leak and MV, respectively). We performed 222 assessments in 169 patients (aged 66.42+/-16 yrs, 100 males). Abnormalities were detected on 147 (66%) out of 222 occasions. Leak was the most common abnormality (34.2%) followed by desaturation dips (23.8%). The most effective therapeutic solutions were a chin strap if leak was detected (61.2%) and expiratory positive airway pressure increase for desaturation dips (59.5%). In 15.7% of cases, when abnormalities persisted, a polygraphy was performed. The systematic use of this device enables NIV to be optimised, limiting the indication of sleep studies to complex cases.

[Pulmonary embolism by cyanoacrylate following embolisation of an arteriovenous malformation]. / Embolie pulmonaire de cyanoacrylate après embolisation d'une malformation artérioveineuse.

INTRODUCTION: Symptomatic complications can occur after intravascular injection of cyanoacrylate glue. We report a case of pulmonary embolism following embolisation of an arteriovenous malformation (AVM). CASE REPORT: A 46-year-old woman was found to have an internal iliac AVM which was obliterated using N-butyl-2 cyanoacrylate (NBCA) mixed with lipiodol. The early clinical course was uneventful. On the third post-operative day she complained of sudden, transient chest tightness. On admission one hour later the chest pain had disappeared. Physical examination was normal. A chest roentgenogram showed multiple, dense, branched opacities scattered throughout both lung fields which were confirmed on HRCT, suggesting diffuse scattered embolism of iodine- labelled NBCA. The radiological signs persisted 6 months later. CONCLUSION: Endovascular treatment of arteriovenous malformations with NBCA can be responsible for symptomatic pulmonary embolism. This is not detectable radiologically in the absence of contrast medium. Radiologists should be aware of these often asymptomatic, but sometimes fatal, embolic complications.

[Difficult weaning due to tracheal compression by an esophageal bezoar]. / Difficulté de sevrage par compression trachéale due à un bézoard.

INTRODUCTION: Bezoars result from the aggregation of ingested materials (food, drugs, hair) that accumulate at a certain anatomic level in the gastrointestinal tract. It is a rare condition, which is favoured by a reduction in intestinal motility, or by a primary abnormality reducing the patency of gastrointestinal tract. CASE REPORT: We present a case when acute respiratory symptoms revealed an oesophageal bezoar. The patient presented with compression of the posterior tracheal wall by an oesophageal bezoar. The diagnosis was confirmed by oesophageal endoscopy. Treatment consisted in endoscopy-guided fragmentation and removal of the bezoar followed by topical lavage. CONCLUSION: Oesophageal bezoars may account for compression of the posterior tracheal wall causing acute respiratory failure or difficult weaning from the ventilator. The close anatomic proximity between the gastrointestinal and respiratory tract may explain the impact of oesophageal bezoars on the respiratory tract.

[Severe drug rash with eosinophilia and systemic symptoms after treatment with minocycline]. / Syndrome d'hypersensibilité médicamenteuse avec manifestations systémiques sévères après traitement par minocycline.

INTRODUCTION: Lung involvement is rarely observed in the DRESS syndrome (Drug rash with eosinophilia and systemic symptoms). We report here a severe minocycline induced hypersensitivity syndrome with initial respiratory distress. CASE REPORT: A 19 year old man was admitted to the intensive care unit for acute respiratory distress with fever (400C), lymph node enlargement, hepatomegaly, splenomegaly and eosinophilia (1640/mm3). Bilateral alveolar opacities were observed on the chest x-ray. Sedation and mechanical ventilation rapidly became necessary because of severe hypoxaemia (47 mm Hg) and the sudden onset of severe aggressive behaviour. The diagnosis of DRESS was immediately suspected as the patient had been treated for acne with minocycline for 28 days, and IV corticosteroids (2 mmg/kg/day) were initiated. Skin lesions were delayed and appeared 3 days later. The outcome was uncertain for the following 6 weeks with serious disturbance of hepatic and renal function. Serology for human herpes virus (HHV6) was initially negative but became positive. One year later, after progressive withdrawal of corticosteroid therapy, the patient had made a complete recovery with no sequelae. CONCLUSION: The DRESS syndrome can cause considerable morbidity with multiple, severe visceral functional disturbances. Respiratory physicians should be aware of this syndrome as lung involvement can be serious and may precede cutaneous symptoms.

Development of 100 Mo -containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search.

This paper reports on the development of a technology involving 100 Mo -enriched scintillating bolometers, compatible with the goals of CUPID, a proposed next-generation bolometric experiment to search for neutrinoless double-beta decay. Large mass ( ∼ 1 kg ), high optical quality, radiopure 100 Mo -containing zinc and lithium molybdate crystals have been produced and used to develop high performance single detector modules based on 0.2-0.4 kg scintillating bolometers. In particular, the energy resolution of the lithium molybdate detectors near the Q-value of the double-beta transition of 100 Mo (3034 keV) is 4-6 keV FWHM. The rejection of the α -induced dominant background above 2.6 MeV is better than 8 σ . Less than 10 µ Bq/kg activity of 232 Th ( 228 Th ) and 226 Ra in the crystals is ensured by boule recrystallization. The potential of 100 Mo -enriched scintillating bolometers to perform high sensitivity double-beta decay searches has been demonstrated with only 10 kg × d exposure: the two neutrino double-beta decay half-life of 100 Mo has been measured with the up-to-date highest accuracy as T 1 / 2 = [6.90 ± 0.15(stat.) ± 0.37(syst.)] × 10 18 years . Both crystallization and detector technologies favor lithium molybdate, which has been selected for the ongoing construction of the CUPID-0/Mo demonstrator, containing several kg of 100 Mo .

Minocycline pneumonitis and eosinophilia. A report on eight patients.

We identified eight patients (six women and two men) who had pulmonary infiltrates during treatment with minocycline hydrochloride between 1989 and 1992 in French referral centers for drug-induced pulmonary diseases. Clinical files, chest roentgenograms, computed tomographic scans, pulmonary function, and bronchoalveolar lavage data were reviewed. Minocycline treatment was given for acne (n = 4), genital infection (n = 3), and Lyme disease (n = 1). The duration of treatment averaged 13 +/- 5 days (mean +/- SE); the total dose, 2060 +/- 540 mg. Patients presented with dyspnea (n = 8), fever (n = 7), dry cough (n = 5), hemoptysis (n = 1), chest pain (n = 2), fatigue (n = 3), and rash (n = 3). Chest roentgenograms showed bilateral infiltrates in all cases. Pulmonary function was measured in five patients; four had airflow obstruction and two had mild restriction. Blood gas tests demonstrated hypoxemia in seven patients (58 +/- 3 mmHg). Seven patients had blood eosinophilia (1.76 +/- 0.2 x 10(9)/L). Bronchoalveolar lavage (performed in seven patients) showed an increased proportion of eosinophils (0.30 +/- 0.07). The Cd4+/CD8+ ratio was determined in four cases and was low in three. Transbronchial lung biopsy, performed in two patients, showed interstitial pneumonitis in both patients, with marked infiltration by eosinophils in one patient. The outcome was favorable in all patients. Because of severe symptoms, steroid therapy was required in three patients. Rechallenge was not attempted. We conclude that minocycline can induce the syndrome of pulmonary infiltrates and eosinophilia, that presenting symptoms may be severe and may culminate in transient respiratory failure, and that the disease has a favorable prognosis.

[Drug-induced lung disease in general practice]. / Poumons et médicaments: aspects utiles pour le praticien.

Adverse medical side effects are an important health issue causing morbidity and mortality. Lungs, being a complex system are also involved. Cough, bronchospasms and buccopharyngeal oedema are the main drug-induced reactions at the airways level. With regard to pulmonary parenchyma, this can result in almost all forms of interstitial lung disease such as usual interstitial pneumonia, non specific interstitial pneumonia, lung oedema, eosinophilic lung disease. Certain drugs are often involved and cause specific clinical pictures (amiodarone, methotrexate). Lung vasculature, pleura and thoracic wall can also be affected. Drug-induced pulmonary disease is an exclusion diagnosis and the main therapeutic action is to stop administration of the suspected drug. On the Internet www.pneumotox.com is a helpful tool for the clinical practice.

The lung in inflammatory bowel disease.

Respiratory involvement in patients with inflammatory bowel disease (IBD) has been reported mainly since 1976. This form of involvement should clearly be separated from interstitial lung disease due to sulfasalazine or mesalamine, although the distinction may be difficult in some cases. We report the data of an ongoing Registry containing 33 cases (23 cases receiving no drug therapy) with ulcerative colitis or, less often, Crohn's disease, who developed varied bronchopulmonary problems. In several cases, the exact diagnosis and the relation of the bronchopulmonary disease to IBD had not been established for many years, thus delaying effective treatment with steroids. In most cases (28/33), respiratory involvement followed the onset of IBD (8 of these 28 cases were postcolectomy), and in the remainder, respiratory manifestations predated the IBD. Patterns of involvement included: 1) Airway inflammation, in the form of subglottic stenosis, chronic bronchitis, severe chronic bronchial suppuration, bronchiectasis, and chronic bronchiolitis. In cases with large airway involvement, endoscopy showed exuberant inflammatory tissue in the airways and narrowing of tracheal and/or bronchial lumen. Histologically, airways were heavily infiltrated by a dense aggregate of inflammatory cells, and there were mucosal ulcerations. 2) Varied patterns of interstitial lung disease, mainly bronchiolitis obliterans with organizing pneumonia, and pulmonary infiltrates and eosinophilia. (3) Miscellaneous other forms of involvement including striking neutrophilic necrotic parenchymal nodules (corresponding histologically to sterile aggregates of neutrophils), and serositis. Steroids were very effective in the majority of cases. Inhaled steroids were of durable benefit in patients with chronic bronchitis, but less often so in those with chronic bronchial suppuration, bronchiectasis, or chronic bronchiolitis. Steroids administered orally led to marked improvement in patients with interstitial lung disease and necrotic nodules, but lacked effectiveness in several patients with severe airway inflammation or chronic bronchiolitis. Intravenous steroids were required in the initial management of life-threatening complications such as asphyxiating subglottic stenosis or extensive interstitial lung disease. Bronchial lavages with methylprednisolone were effective in some patients with severe airway inflammation. Patients with IBD can develop varied inflammatory complications in the lung, and a sizable fraction of these complications is steroid-sensitive.

Amiodarone pneumonitis. Bronchoalveolar lavage findings in 15 patients and review of the literature.

UNLABELLED: Amiodarone (Am) pneumonitis is currently a common and potentially severe adverse reaction, the accurate diagnosis of which remains difficult to establish. OBJECTIVES: To determine the contribution of bronchoalveolar lavage (BAL) in the diagnostic workup of patients suspected of having Am pneumonitis. METHODS: Diagnosis of Am pneumonitis was established on the basis of (1) development of recent symptoms and pulmonary opacities while receiving the drug, (2) exclusion of other possible causes, and (3) improvement following cessation of Am and/or steroid therapy. (4) Confirmatory changes were obtained by histopathologic examination in eight cases. BAL was performed in each patient at the time of initial evaluation. RESULTS: Am pneumonitis was diagnosed in 15 consecutive patients between 1985 and 1991. The disease was associated with significant morbidity and mortality. Six patients died; four died of Am pneumonitis. A neutrophilic BAL was found in nine patients (average PMN = 26.6 percent). A mixed pattern (lymphocytic + neutrophilic) was seen in four patients (average: Ly = 19.9 percent; PMN = 11.9 percent). Two patients had a normal BAL. No patient had a lymphocytic pattern. A low CD4+/CD8+ ratio was seen in two patients. A literature survey indicated 70 cases of Am pneumonitis with detailed information on BAL. The BAL pattern was mixed in 23 (33 percent), neutrophilic in 18 (26 percent), lymphocytic in 15 (21 percent), and normal in 14 (20 percent). No correlation was found between BAL pattern and prognosis. Also, BAL pattern was related neither to daily or total dose of Am nor to duration of treatment with Am. CONCLUSION: The cellular profile of BAL in Am pneumonitis is highly variable, and no cellular pattern of BAL seems to be predictive of a detrimental outcome or of irreversible fibrosis. Aside from excluding other illnesses, and due to its extreme variability, the contribution of BAL differential in the initial workup of patients suspected of having Am pneumonitis is limited.

D-Penicillamine-induced severe pneumonitis.

We report the first histologically described case of severe D-penicillamine-induced pneumonitis. It occurred in a 73-year-old woman who suffered from rheumatoid arthritis and had previously demonstrated gold intolerance. Pathologic study disclosed marked interstitial and alveolar damage resembling that described with certain chemotherapeutic agents. We assess the drug's responsibility, discuss possible pathogenetic pathways, and provide suggestions regarding the patient on a D-penicillamine schedule.

A 1-year comparison of turbuhaler vs pressurized metered-dose inhaler in asthmatic patients.

An open, randomized, parallel-group study was conducted to investigate whether asthmatic patients, considered adequately treated with a corticosteroid and/or short-acting beta 2-agonist via pressurized metered-dose inhaler (pMDI), could be transferred to a corresponding nominal dose of budesonide and/or terbutaline via Turbuhaler, an inspiratory flow-driven multidose dry powder inhaler (Astra Draco; Lund, Sweden), without a decrease in the effect of treatment. One thousand four patients (555 women; mean age, 44 years; mean peak expiratory flow [PEF], 102% predicted normal value) were randomized and treated with either pMDI (current therapy) or Turbuhaler for 52 weeks. The variables studied were asthma-related events, morning PEF, and inhaler-induced clinical symptoms. Asthma-related events were defined in two ways: (1) sum of health-care contacts plus doublings or additions of steroids, and (2) number of 2 consecutive days with PEF less than 80% of baseline. Baseline was obtained from a 2-week run-in period while receiving previous therapy. No statistically significant difference was found in asthma-related events according to definition 1. According to definition 2, there was a statistically significant difference between the groups in favor of Turbuhaler (p = 0.008). The mean number of events was 1.7 with Turbuhaler and 2.2 with pMDI. The mean number of weeks per patient with a PEF less than 90% of baseline was 4.5 with Turbuhaler compared with 6.0 with pMDI (p = 0.002). The sum of inhaler-induced symptoms after 1 year of use was statistically significantly lower with Turbuhaler (0.40) than with pMDI (0.75) (p = 0.0001). In conclusion, budesonide and terbutaline in Turbuhaler offered a superior alternative to corticosteroids and bronchodilators delivered by pMDIs in the maintenance treatment of asthma.

Effects of drug-induced pulmonary phospholipidosis on lung mechanics in rats.

Chronic administration of amphiphilic drugs to rats induces pulmonary phospholipidosis (P), a disease characterized by accumulation of phospholipids and large foamy macrophages in alveolar spaces. We investigated whether P induced by chlorphentermine (CPH) causes changes in lung volumes and mechanics in this species. Groups of rats were fed CPH (50 mg.kg-1.day-1) for 1, 2, 3, 5, 9, and 14 wk. After each treatment period, lung volumes and mechanics were studied in the anesthetized, paralyzed, supine rat. Partial pressure-volume (PV) curves were developed at 3 and 6 ml above functional residual capacity (FRC; PV3, PV6), followed by maximal [up to total lung capacity (TLC)] PV curves. FRC was determined by saline displacement. Lungs were then fixed for histopathological examination. A subgroup of animals was allowed a recovery period of 6 wk, after the 9 wk of CPH administration. Pair-fed rats served as controls (CTR) at each time point. Lung weight increased in CPH-treated (CPH-T) rats from 1.5 +/- 0.2 (SD) g at week 1 to 5.8 +/- 1.4 g at week 14, reflecting the development of P. TLC, FRC, transpulmonary pressure at FRC, the shape of maximal PV curves, and static expiratory lung compliance computed from maximal PV data points did not change in CPH-T rats. However, partial PV curves of CPH-T lungs (particularly PV3) were shifted downward and to the right of those of CTR at 2, 3, 5, and 9 wk, indicating increased recoil pressure in phospholipidotic lungs at these time points.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of two oral antibiotics, roxithromycin and amoxicillin plus clavulanic acid, in lower respiratory tract infections.

In a randomized, multicenter, open-label study, 490 ambulatory adult patients with lower respiratory tract infection (LRTI) were randomized to roxithromycin (ROX) 150 mg b.i.d. orally (n = 244) or amoxicillin plus clavulanic acid (AMX + CA) as 500 mg AMX + 125 mg CA t.i.d orally (n = 24). Clinical results were analyzed in 477 patients with acute bronchitis (79%), chronic bronchitis (CB) (14%), and pneumonia (7%). There were significantly more patients with underlying disease (cardiovascular diseases, p = 0.045; and alcoholism, (p less than 0.001), and more patients over the age of 65 years (p = 0.045) in the ROX group. Overall clinical efficacy was similar in both groups: 88% (206:235) in the ROX group and 85% (205:242) in the AMX + CA group. Side effects were reported in 67 cases (28%) in the AMX + CA group and in 21 cases (9%) in the ROX group (p less than 0.0001), causing withdrawal in 21 and three cases, respectively (p less than 0.001). Thus, despite being administered to a significantly older and more ill group of patients with LRTI, roxithromycin was as effective as amoxicillin plus clavulanic acid and better tolerated.

On the many advantages of local-electrode atom probes.

Local extraction electrodes offer several crucial advantages for operation of atom probes. Because of the proximity of the local extraction electrode to the specimen, the electric field produced at the specimen apex by a given voltage is enhanced and the voltage required for field evaporation is reduced. In a voltage-pulsed atom probe, the absolute magnitude of the energy uncertainty is correspondingly reduced. High mass resolution (m/deltam > 1000) may therefore be obtained by accelerating the evaporated ions to a greater total potential after the local extraction electrode. The low extraction voltage may also be pulsed rapidly (100 ps rise time) and at high repetition rates (up to 10(5) pulses per second) using currently available solid-state pulsers. Furthermore, a local electrode and intermediate electrodes may be used as optical elements to control the image magnification. All of these benefits may be applied to any type of atom probe. Local-electrode atom probes (LEAP) should be especially advantageous for developing three-dimensional atom probes with high mass resolution and a large field of view. A sample has been developed that consists of many microtips formed on a planar sample using ion beam mask etching. Microtip samples are especially suited to LEAP. Analysis of electrically insulating samples may also be possible with microtip samples in a LEAP. This combination of features suggests flexible, high speed, high mass resolution atom probes that can work with either conventional needle-shaped specimens or the new style of planar microtip specimens.

Comparative pharmacokinetics of tetrahydropyranyl-doxorubicin and doxorubicin in rat isolated lung.

Rat isolated perfused lungs (Sprague-Dawley rats, n = 20) were studied to compare the pulmonary uptake of a new anthracycline, tetrahydropyranyl-doxorubicin (THP-DXR) with that of doxorubicin (DXR). Lung perfusions were initiated with a constituted medium containing either drug at concentrations of 1, 10 or 100 microM. Lungs were perfused by recirculation for 60 min. Thirteen perfusate samples were collected over 60 min and subjected to HPLC for assay. The perfusate concentration of THP-DXR decreased to 24 +/- 5% of the initial concentration and to 8 +/- 2%, 20 and 60 min after the beginning of the infusion, respectively. Corresponding values for DXR were 77 +/- 16 and 52 +/- 15%, respectively (P less than 0.05). During the THP-DXR perfusion, the area under the perfusate concentration vs time curve (AUC) was decreased to one-third and the clearance was increased 3-fold (P less than 0.05). The pulmonary concentration of THP-DXR reached 0.032 +/- 0.01 mumol g-1 60 min after the beginning of a perfusion of 1 microM of the drug. This concentration increased to 0.379 +/- 0.11 mumol g-1 when the initial dose concentration was 10 microM. Corresponding lung concentrations for DXR were 0.013 +/- 0.001 and 0.150 +/- 0.04 mumol g-1, respectively (P less than 0.05). The perfusate concentration/initial concentration ratio decreased by the same amount whether a 1 or 10 microM initial concentration of either drug was used. An initial concentration of 100 microM of THP-DXR, unlike DXR, consistently induced oedema in the perfused lung. No metabolite of either drug was revealed during the course of our study.(ABSTRACT TRUNCATED AT 250 WORDS)