Local application of engineered insulin-like growth factor I mRNA demonstrates regenerative therapeutic potential in vivo

Insulin-like growth factor I (IGF-I) is a growth-promoting anabolic hormone that fosters cell growth and tissue homeostasis. IGF-I deficiency is associated with several diseases, including growth disorders and neurological and musculoskeletal diseases due to impaired regeneration. Despite the vast regenerative potential of IGF-I, its unfavorable pharmacokinetic profile has prevented it from being used therapeutically. In this study, we resolved these challenges by the local administration of IGF-I mRNA, which ensures desirable homeostatic kinetics and non-systemic, local dose-dependent expression of IGF-I protein. Furthermore, IGF-I mRNA constructs were sequence engineered with heterologous signal peptides, which improved in vitro protein secretion (2- to 6-fold) and accelerated in vivo functional regeneration (16-fold) over endogenous IGF-I mRNA. The regenerative potential of engineered IGF-I mRNA was validated in a mouse myotoxic muscle injury and rabbit spinal disc herniation models. Engineered IGF-I mRNA had a half-life of 17-25 h in muscle tissue and showed dose-dependent expression of IGF-I over 2-3 days. Animal models confirm that locally administered IGF-I mRNA remained at the site of injection, contributing to the safety profile of mRNA-based treatment in regenerative medicine. In summary, we demonstrate that engineered IGF-I mRNA holds therapeutic potential with high clinical translatability in different diseases.

Prospective randomised treatment with recombinant human growth hormone in cystic fibrosis

AIM

To evaluate the efficacy and safety of treatment with recombinant growth hormone (rGH) in patients with cystic fibrosis (CF).

METHODS

Twenty patients with CF (aged 10-23 years) were randomised to age and sex matched treatment and control groups. The treatment group received daily subcutaneous injections of 1 IU/kg/wk rGH for 12 months. Pulmonary function (forced expiratory volume in one second (FEV1) and airway resistance), exercise capacity measured with a bicycle ergometer, body composition (dual energy x ray absorptiometry), and weight were assessed at the beginning of the study and after 6 and 12 months.

RESULTS

rGH treatment did not improve weight and pulmonary function, but lean body mass increased significantly in the treatment group. Exercise capacity increased in the treatment group from 143 (16) W (mean (SD)) to 164 (19) W after 12 months of rGH treatment.

CONCLUSION

Treatment of CF patients with rGH for one year improved the exercise capacity significantly but not pulmonary function. The improved exercise capacity needs confirmation in a larger population before such an expensive treatment is justified.

Inhalation of alpha(1)-protease inhibitor in cystic fibrosis does not affect surfactant convertase and surface activity

The inhalation of alpha(1)-protease inhibitor (alpha(1)-PI) was assessed in a pilot study to restore the protease-antiprotease balance in the lungs of cystic fibrosis (CF) patients. In addition, the effect of this treatment on the surface active properties of lung surfactant and the metabolic conversion of aggregate forms was studied. Eight young adults with CF inhaled 100 mg of alpha(1)-PI twice daily over 8 weeks and bronchoalveolar lavages (BAL) were obtained before and 12 h after the last inhalation. Large aggregate (LA) forms of surfactant were isolated from the in vivo material by ultracentrifugation and their conversion into small aggregates (SA) was assessed by an in vitro surface area cycling assay. Although alpha(1)-PI partially restored the protease-anti-protease imbalance and reduced BAL protein content, no effects were noted on the impaired minimal surface tension and on the in vivo and in vitro conversion of LA to SA. Antiserum against the specific carboxyl esterase ES-2, previously identified in mice and rats as the putative surfactant convertase, did not detect a protein of the appropriate size in CF BAL. Whereas short-term inhalation of alpha(1)-PI was beneficial for the proteolytic aspects of CF lung injury, this appeared not to be the case for surfactant conversion and surface activity.

Surfactant protein A and other bronchoalveolar lavage fluid proteins are altered in cystic fibrosis

Inflammation and proteolytic processes play an important role in the progression of cystic fibrosis (CF) lung disease. The goal of this study was to describe bronchoalveolar lavage fluid (BALF) protein pattern of CF patients in comparison to controls and to assess if there is proteolytic degradation of surfactant protein A (SP-A), an important innate host defence component of the lungs. BALFs from 17 clinically stable CF patients and from eight healthy children were separated by two-dimensional gel electrophoresis. Silver staining was used to show BALF proteins and Western blotting to detect SP-A isoforms. In CF, BALF proteins of a low molecular weight < or = 20 kD were more abundant than in controls. Various proteins were seen in CF which were not present in controls and vice versa. Degradation of SP-A was present in 15 of 17 CF BALFs but in none of the controls, in contrast polymeric isoforms were seen in all controls and in four of 17 CF patients. Proteolytic damage to surfactant protein A and significant changes of normal bronchoalveolar lavage fluid proteins occur in lungs of cystic fibrosis patients. Identification of altered bronchoalveolar lavage fluid proteins may give new insights into pathogenic mechanisms and provide new targets for therapy.

Reduced proteolysis of surfactant protein A and changes of the bronchoalveolar lavage fluid proteome by inhaled alpha 1-protease inhibitor in cystic fibrosis

In cystic fibrosis (CF), the chronic neutrophilic inflammation of the airways results in proteolytic degradation of lung tissue early in the course of the disease. Inhalation of alpha 1-protease inhibitor (alpha 1-PI) may restore the protease-antiprotease imbalance and thus lead to less tissue damage. To monitor its impacts on bronchoalveolar lavage (BAL) fluid protein pattern (proteome) and on surfactant protein A (SP-A), eight young adults with CF inhaled 100 mg of alpha 1-PI twice daily over eight weeks. BAL fluids were obtained before and after inhalation. Total protein, the number and amount of proteins with a molecular mass < 20 kDa were reduced compared to pretreatment values. Degradation products of SP-A were shown by immunoblotting, being reduced after alpha 1-PI treatment. This pilot study demonstrates that inhalation of alpha 1-PI is associated with biochemical changes consistent with reduced proteolysis. The display of the BAL proteome by two-dimensional electrophoresis may be helpful to quantify the overall molecular changes associated with proteolytic or other lung injuries and offers the possibility to monitor directly therapeutic interventions.

Bronchodilator responsiveness in a ventilator-dependent infant with severe tracheobronchomalacia

A neonatal case of severe, ventilator-dependent tracheobronchomalacia (TBM) is described. The extent of the malacic segment was determined by endoscopy and tracheobronchography. Additionally, relevant and ever increasing reversible peripheral airway obstruction was documented by measuring the mechanical properties of the respiratory system before and after salbutamol. With the combination of endoscopically guided aortopexy and salbutamol infusion, the infant was eventually weaned from mechanical ventilation at the age of 86 days. We speculate that in ventilator-dependent infants with severe TBM the determination of bronchodilator responsiveness may have clinical consequences.

Genotype-phenotype association in infants with cystic fibrosis at the time of diagnosis

The relationship between the most common disease-causing mutations, the clinical manifestation, and lung function was prospectively assessed in 60 infants (33 females, 27 males) with cystic fibrosis at time of diagnosis (age: 7.2 months; range: 0.8-23.8 months). Lung function was assessed by infants whole-body plethysmography. Age at time of diagnosis was independent from the genotype. Weight gain from birth until the time of diagnosis expressed in percent predicted of a normal population was lower in the 3905insT group (57.9 +/- 19.0%) compared with deltaF508 homozygotes (62.5 +/- 20.6%; n.s.) and the R553X group (85.9 +/- 10.9%; p < 0.005). Differences regarding lung function within the genetic groups are mainly related to pulmonary hyperinflation, measured by thoracic gas volume (TGV), present in 8 of 9 infants with 3905insT, differentiating this frameshift mutation (TGV of 7.0 +/- 3.6 SD-S) from the R553X mutation (TGV 2.1 +/- 4.6 SD-S; p < 0.02). It is concluded that the variable disease findings in infants with cystic fibrosis is clinically and functionally reflected by features already present at time of diagnosis. The degree of pulmonary hyperinflation is, at least partly, influenced by the genotype.

Clinical and physiological improvement after inhalation of low-dose beclomethasone dipropionate and salbutamol in wheezy infants

Twenty-nine of initially 42 infants with recurrent wheeze (20 male and 9 female) with an age range of 2.1-25.2 months were randomly assigned to receive either 100 micrograms beclomethasone dipropionate (BDP) combined with 200 micrograms salbutamol (group BDP-S, n = 9), 200 micrograms salbutamol (group S, n = 8), or placebo (group P, n = 6) 3 times daily for a 6 weeks' treatment period. Six infants had to be treated openly with BDP-S (group O, n = 6) because of deterioration in the disease state. Ten babies were excluded because of incomplete data and poor drug compliance and further 3 because of needed rescue medication. The drugs were inhaled from a metered dose inhaler through a baby-adapted spacer device, the Babyhaler. Control was assessed by symptom diaries, and infant whole-body plethysmography. Values of thoracic gas volume (TGV), airway conductance (Gaw) and specific airway conductance (sGaw) were calculated numerically independent of age and body length in percent predicted and in standard deviation scores using regression equations taken from healthy infants previously evaluated. Functional improvement was considered to have occurred when either TGV, and/or Gaw improved more than 2 SD from baseline. There was a significant improvement in the symptom score (p < 0.05), particularly concerning cough, in addition to a significant decrease in pulmonary hyperinflation (TGV: p < 0.05) and improvement of Gaw (p < 0.01) and sGaw (p < 0.01) in the BDP-S group when compared to the P group. No significant differences were found between the BDP-S and S group and/or between the S and P groups.

CONCLUSIONS

In wheezy infants BDP improves clinical status and lung function, when given in combination with salbutamol by a baby-adapted spacer device.

Pulmonary surfactant in cystic fibrosis

Cystic fibrosis (CF) leads to a chronic inflammation of the airways with significant air flow limitations developing early in the course of the disease. As a well-functioning pulmonary surfactant is necessary to keep the alveoli and the small conducting airways open during expiration, we hypothesized that the biochemical and biophysical properties of surfactant may be impaired in CF. Bronchoalveolar lavage fluid obtained during a clinically stable period was analysed from 20 CF patients (5.9-20 yrs) and 17 healthy children and adults. CF patients had significantly elevated total and polymorphonuclear neutrophil cell counts, whereas the concentrations of total protein and phospholipids did not differ from controls. The percentage of surface active phospholipids, phosphatidylcholine and phosphatidylglycerol, and the concentration of surfactant protein A were significantly reduced in CF patients. Surfactant protein B was unchanged. Although the relative proportion of large aggregates was higher in CF, their surface active properties were inferior, as assessed in the pulsating bubble surfactometer. Because the capacity of CF lavage fractions to inhibit surfactant function was the same as that of controls, impaired minimal surface tension was more likely to be due to the biochemical alterations detected, than to inhibition of a well-functioning surfactant. The impaired pulmonary surfactant system in clinically stable patients with cystic fibrosis is in agreement with the view that surfactant dysfunction may contribute to lung disease in cystic fibrosis.

[PFAPA syndrome: periodic fever, adenitis, pharyngitis and aphthous stomatitis]

A syndrome involving periodic fever, pharyngitis, adenitis and aphthous stomatitis is described in 8 children. Attacks are characterized by abrupt onset of fever and, in addition to the above symptoms, by malaise, headache and abdominal pain. Mild leukocytosis and elevation of the erythrocyte sedimentation rate are found in the laboratory. Patients exhibit normal growth and development and are otherwise healthy. PFAPA is clinically benign, with no long-term sequelae. Recognition and diagnosis of the syndrome eliminate the need for intensive work-up. The cause remains unknown. No evidence linking bacterial, viral, or fungal pathogens to this syndrome has been found. No patient has exhibited atypical lymphocytosis or neutropenia, and all patients had normal levels of immunoglobulin. All had received antibiotics early in the course of their illness but without effect. Cimetidine has been discussed in the literature as a possible treatment, but the results are controversial.

Antipyretic effect of parenteral paracetamol (propacetamol) in pediatric oncologic patients: a randomized trial

The antipyretic efficacy of propacetamol, an intravenous prodrug of paracetamol, was evaluated in two pediatric prospective randomized studies. In the first, we-compared one standard intravenous dose of propacetamol (30 mg/kg) to one standard intravenous dose of acetylsalicylic acid (ASA, 15 mg/kg) in 10 nononcologic patients with bacterial illnesses. In the second study, we compared two intravenous doses of propacetamol (30 mg/kg versus 15 mg/kg) in 24 oncologic patients with fever and neutropenia. No statistically significant differences in antipyretic efficacy were found between standard doses of propacetamol and ASA; even when half-doses of propacetamol (15 mg/kg) were used, good antipyretic efficacy was observed, which was not statistically different from that observed with the full dose. The use of propacetamol seems promising for patients (such as oncologic patients) who cannot receive enteral paracetamol formulas.

[Invasive Pseudomonas aeruginosa and Ecthyma gangrenosum infection in a child without risk factors]

BACKGROUND

Pseudomonas aeruginosa sepsis, well known in immunocompromised patients, is rare in previously healthy children.

CASE REPORT

A previously healthy 4 month-old boy was admitted with the suspicion of meningococcal septicemia. Three days prior to admission, he had developed high fever and two 4 cm-diameter skin lesions on his right leg, with dark red colour and a central haemorrhagic blister. He subsequently developed generalized seizures; meningitis and urinary tract infection were excluded. Despite topical therapy with an antistaphylococcal drug skin lesions extended, particularly at the level of the head. The patient was given oral amoxicillin-clavulanate, but his condition worsened; he was transferred to our intensive care unit with septic shock and a diagnosis of meningococcemia. Blood cultures grew Pseudomonas aeruginosa. Despite intensive therapy and appropriate antibiotic therapy, the patient died.

CONCLUSION

To allow early diagnosis and adequate treatment, it is mandatory to diagnose Ecthyma gangrenosum as the most frequent manifestation of invasive infection with Pseudomonas aeruginosa.

Proteases and antiproteases in cystic fibrosis: pathogenetic considerations and therapeutic strategies

The association between abnormal chloride transport, resulting from mutations in the cystic fibrosis transmembrane regulator (CFTR) gene, and the immunologic processes involved in the development of CF lung disease is poorly understood. However, neutrophil-dominated inflammation on the respiratory epithelial surface is a common finding in CF patients and suggests a mechanism for the immunologic abnormalities described in CF. Of particular importance for the pathophysiology of CF are proteases such as neutrophil elastase (NE) which are released from neutrophils in CF airways and cause direct structural damage to respiratory tissue. In healthy individuals, the deleterious effects of excess protease activity in the respiratory system are inhibited by antiproteases such as alpha 1-antitrypsin (alpha 1AT) and secretory leukoprotease inhibitor (SLPI). However, in CF, antiproteases are outnumbered by proteases and this protective mechanism is rendered ineffective. Restoration of this protease/antiprotease balance through antiprotease replacement therapy is currently under clinical investigation and preliminary results are promising.

Chronic metabolic alkalosis: not uncommon in young children with severe cystic fibrosis

The acid-base balance of 199 patients with cystic fibrosis, seen from 1987 through 1992 at the Bern Outpatient Clinic, were evaluated. Simple metabolic alkalosis was demonstrated in 16 and mixed metabolic alkalosis and respiratory acidosis in 9 patients. When compared with 10 patients with simple respiratory acidosis and 16 with normal hydrogen ion balance, those with simple metabolic alkalosis were significantly younger. The need for pancreatic enzymes was significantly higher and the relative underweight significantly more severe in patients with either simple or mixed metabolic alkalosis and respiratory acidosis. The results indicate the rather common occurrence of chronic metabolic alkalosis in cystic fibrosis. It is observed in young patients, in patients who need high doses of pancreatic enzymes and in the those with poor nutritional status.

Mycobacterium genavense invasive infection in two children with AIDS: long-term followup

Mycobacterium genavense is a rare cause of opportunistic infection in immunocompromised hosts. Follow up of two cases of M. genavense invasive infection in children with haemophilia A and AIDS are presented. One patient died 18 months after diagnosis of M. genavense infection of an indirectly related cause, probably of Pneumocystis carinii pneumonia. The second patient still attends our outpatient clinic and the infection is under control. Both presented with abdominal lymphomas and pain and a wasting syndrome. A combination of several drugs against atypical mycobacteria is used for treatment.

Protease-antiprotease imbalance in the lungs of children with cystic fibrosis

Cystic fibrosis (CF) is characterized in the lung by chronic purulent bronchitis culminating in pulmonary insufficiency. There is evidence to suggest that neutrophil elastase (NE) released by neutrophils on the respiratory epithelial surface plays a major role in the pathogenesis of this lung disease. This study sought to determine the age of onset of the chronic neutrophil-dominated inflammation in CF and the consequences to the NE-anti-NE screen on the respiratory epithelial surface of the CF lung. NE and anti-NE defensive molecules were evaluated in respiratory epithelial lining fluid (ELF) in 27 children with stable CF (1 to 18 yr of age). Despite normal antigenic concentrations of alpha 1-antitrypsin (alpha 1AT) and secretory leukoprotease inhibitor (SLPI), 25 of 27 children with CF had neutrophil-dominated inflammation (> 500 neutrophils/microliters ELF). Active NE was found in ELF in 20 of 27 children, including two of four aged 1 yr. Western blot analysis showed the majority of alpha 1AT and SLPI molecules to be complexed and/or degraded. These observations demonstrate that a chronic imbalance of the NE-anti-NE protective screen develops early on the respiratory epithelial surface in persons with CF and is likely well established by 1 yr of age, with resultant potential for lung damage.

Recombinant secretory leukoprotease inhibitor augments glutathione levels in lung epithelial lining fluid

Secretory leukoprotease inhibitor (SLPI), a 12-kDa serine antiprotease, serves as the major inhibitor of neutrophil elastase (NE) on the epithelial surface of the upper airways. As a control for studies to evaluate the aerosol administration of recombinant SLPI (rSLPI) to augment the anti-NE defenses of the lung, the status of antioxidants in respiratory epithelial lining fluid (ELF) was evaluated. Unexpectedly, aerosol administration of rSLPI caused an elevation in ELF glutathione, a major component of the epithelial antioxidant screen; i.e., rSLPI may provide not only augmentation of anti-NE defenses but also antioxidant defenses. To evaluate this concept, rSLPI (100 mg) was aerosolized to sheep, and SLPI, glutathione, anti-NE capacity, and anti-H2O2 capacity were evaluated in respiratory ELF over a 30-h period. As expected, aerosolization of rSLPI increased ELF SLPI levels and anti-NE capacity. Strikingly, postaerosol levels of glutathione in ELF were also increased (5-fold 24 h after aerosol), with a concomitant increase in ELF anti-H2O2 capacity; i.e., the rSLPI augmented the antioxidant screen of ELF. This suggests that rSLPI may be particularly well suited for therapy in lung diseases characterized by excess of both serine proteases and oxidants on the respiratory epithelial surface.

Effect of blood pressure on hemorrhage volume and survival in a near-fatal hemorrhage model incorporating a vascular injury

STUDY HYPOTHESIS

In a model of near-fatal hemorrhage that incorporates a vascular injury, stepwise increases in blood pressure associated with aggressive crystalloid resuscitation will result in increased hemorrhage volume and mortality.

DESIGN

This study used a swine model of potentially lethal hemorrhage in the presence of a vascular lesion to compare the effects of resuscitation with mean arterial pressures of 40, 60, and 80 mm Hg. Twenty-seven fully instrumented immature swine (14.8 to 20 kg), each with a surgical-steel aortotomy wire in place, were bled continuously from a femoral artery catheter to a mean arterial pressure of 30 mm Hg. At that point the aortotomy wire was pulled, producing a 4-mm aortic tear and uncontrolled intraperitoneal hemorrhage. When the animal's pulse pressure reached 5 mm Hg, the femoral artery hemorrhage was discontinued and resuscitation was begun.

INTERVENTIONS

Saline infusion was begun at 6 mL/kg/min and continued as needed to maintain the following desired endpoints: group 1 (nine) to a mean arterial pressure of 40 mm Hg, group 2 (nine) to a mean arterial pressure of 60 mm Hg, and group 3 (nine) to a mean arterial pressure of 80 mm Hg. After 30 minutes or a total saline infusion of 90 mL/kg, the resuscitation fluid was changed to shed blood infused at 2 mL/kg/min as needed to maintain the desired mean arterial pressure or to a maximum volume of 24 mL/kg. Animals were observed for 60 minutes or until death.

MEASUREMENTS AND MAIN RESULTS

Data were compared using repeated-measures analysis of variance with a post hoc Tukey-Kramer, Fisher's exact test, and Kruskal-Wallis. Mortality was significantly greater in group 3 (78%) compared with either group 1 (11%; P = .008) or group 2 (22%; P = .028). Mean survival times were significantly shorter in group 3 (44 +/- 12 minutes) compared with either group 1 (58 +/- 6 minutes; P = .007) or group 2 (59 +/- 3 minutes; P = .006). The average intraperitoneal hemorrhage volumes were 13 +/- 14 mL/kg, 20 +/- 25 mL/kg, and 46 +/- 11 mL/kg for groups 1, 2, and 3, respectively (group 1 versus 2, P = .425; group 1 versus 3, P < .001; group 2 versus 3, P = .014). Group 2 animals demonstrated significantly greater oxygen deliveries compared with groups 1 and 3.

CONCLUSION

In a model of near-fatal hemorrhage with a vascular injury, attempts to restore blood pressure with crystalloid result in increased hemorrhage volume and markedly higher mortality.

Comparison of midazolam and diazepam for conscious sedation in the emergency department

STUDY OBJECTIVE

To compare the efficacy of diazepam and midazolam when used for conscious sedation in emergency department patients.

DESIGN

Prospective, randomized, double-blind, multicenter trial.

SETTING

Three university EDs.

TYPE OF PARTICIPANTS

Patients requiring one of the following procedures: abscess drainage, joint reduction, extensive suturing, chest tube insertion, or lumbar puncture.

INTERVENTIONS

Diazepam (2.5 mg/mL) or midazolam (1 mg/mL) was administered until the desired level of sedation was achieved to a maximum of 5 mL. Fentanyl citrate was administered if needed for pain.

MEASUREMENTS AND MAIN RESULTS

Thirty-three patients received diazepam and 36 received midazolam. Patients receiving midazolam had a greater degree of early sedation (P < .05), a higher 90-minute alertness scale score (P < .05), more patients ready for discharge at 90 minutes (P = .05), significantly less recall for the procedure (P < .02), and less pain on injection (P < .01) than patients who were given diazepam.

CONCLUSIONS

Diazepam and midazolam are both effective for conscious sedation in ED patients. Midazolam causes less pain on injection, a significantly greater degree of early sedation, and a more rapid return to baseline function.

Consequences of unbalanced protease in the lung: protease involvement in destruction and local defense mechanisms of the lung

Complex mechanisms regulate sequestration, retention and migration of neutrophils in the lung. Neutrophils can migrate into the lung without producing significant damage under some circumstances, whereas at other times great structural alteration occurs. A potential explanation lies in the phenomenon of priming, a state of altered responsivity of neutrophils. A wide variety of molecules are able to induce this higher degree of responsiveness including PAF, TNF, GM-CSF, and IL-1. Enhanced cellular responses include secretion, adhesion and synthetic function. Unprimed neutrophils can migrate through lung tissues, secreting but little of their contents, in the context of "normal" inflammatory response. On the other hand neutrophils primed before the emigration phase, injury to the tissue they are migrating through would be likely by virtue of releasing toxic mediators. One of these mediators is neutrophil elastase, a potent protease. It is the purpose of this review to highlight the duality function of neutrophils as (i) one of the bodies highly effective host defense weapons and (ii) mediator of destruction and host defense impairment in the lung by releasing mediators such as neutrophil elastase.

Modulation of airway inflammation in cystic fibrosis. In vivo suppression of interleukin-8 levels on the respiratory epithelial surface by aerosolization of recombinant secretory leukoprotease inhibitor

Based on the knowledge that neutrophil elastase (NE) in cystic fibrosis (CF) epithelial lining fluid (ELF) can induce human bronchial epithelial cells to express the gene for interleukin 8 (IL-8), an 8.5-kD neutrophil chemoattractant, we have evaluated CF ELF for the presence of IL-8, and investigated the ability of aerosolized recombinant secretory leukoprotease inhibitor (rSLPI) to suppress NE, and hence IL-8, levels on the respiratory epithelial surface in CF. Enzyme-linked immunoassay revealed 21.9 +/- 4.8 nM IL-8 in CF ELF compared with none in normals. Active NE was detectable in ELF of all individuals with CF and was significantly decreased (P < 0.03) after aerosolization of rSLPI. Human bronchial epithelial cells exposed to CF ELF recovered before rSLPI therapy expressed IL-8 mRNA transcripts, but ELF recovered after rSLPI therapy induced far less bronchial epithelial cell IL-8 gene expression. Consistent with this, rSLPI aerosol therapy caused a marked reduction in CF ELF IL-8 levels (P < 0.05) and neutrophil number (P < 0.02). There was also a clear association between CF ELF active NE and IL-8 levels (r = 0.94). These data suggest that rSLPI therapy not only suppresses respiratory epithelial NE levels, but also breaks a cycle of inflammation on the CF epithelial surface.

Intravenous recombinant secretory leukoprotease inhibitor augments antineutrophil elastase defense

Secretory leukoprotease inhibitor (SLPI), a 12-kDa serine antiprotease, normally protects the upper airway epithelial surface from attack by neutrophil elastase (NE). In the context that a variety of inflammatory lung diseases are characterized by large neutrophil burdens with resultant high levels of NE in the lung, recombinant SLPI (rSLPI), a molecule identical to natural SLPI, may be an effective means to augment the anti-NE protective screen of the lung. To determine whether intravenous rSLPI will augment respiratory tract and epithelial surface levels of SLPI and anti-NE capacity, rSLPI was administered intravenously to sheep and SLPI levels were quantified in plasma, lung lymph (as a measure of lung interstitial levels), lung epithelial lining fluid (ELF), and urine. rSLPI (1 g) was administered over 10 min, and after 30 min plasma levels of SLPI were 8 microM and decreased with a half-life of 1.8 h. Lymph SLPI levels paralleled the plasma levels: 4 h after infusion the lymph-to-plasma ratio was 0.8. ELF SLPI levels paralleled the lymph levels: 4 h after infusion the ELF-to-lymph ratio was 0.3. Western analysis demonstrated intact SLPI in lymph and ELF, and functional analysis showed increases in lymph and ELF anti-NE capacity that paralleled the levels of SLPI. As might be expected from a protein with a molecular mass of 12 kDa, urine excretion was high, with 20% of the SLPI excreted over 5 h. However, if the rate of infusion was slowed, SLPI excretion decreased significantly, with a 3-h infusion associated with 9% excretion and a 12-h infusion associated with less than 0.2% excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

A new baby-spacer device for aerosolized bronchodilator administration in infants with bronchopulmonary disease

The response of salbutamol (Ventolin, Glaxo), topically administered from a metered dose inhaler (MDI) through a new baby-spacer-device (Babyhaler, Glaxo) was studied in 14 infants (8 wheezy infants, 3 infants with cystic fibrosis and 3 infants after respiratory distress syndrome), age 2.9-18.8 months. Changes in thoracic gas volume (TGV) as an estimate of pulmonary hyperinflation and changes in airway conductance (Gaw) as an estimate of bronchial obstruction were assessed by whole-body plethysmography. After baseline measurements, 1 puff of 100 micrograms salbutamol was given repeatedly at 5 min intervals until 600 micrograms have been inhaled and TGV and Gaw were measured after each inhalation at 5, 10, 15, 20, 25 and 30 min. Significant improvement in lung function was achieved in 57.1% of infants after 400 micrograms and in 92.9% of infants after 600 micrograms salbutamol. The study shows usefulness of bronchodilator treatment in infants with bronchopulmonary disease by a system with a MDI and baby-spacer-device. However a special dose-time relationship must be respected.

Aerosol alpha 1-antitrypsin treatment for cystic fibrosis

In cystic fibrosis neutrophil-dominated inflammation on the respiratory epithelial surface results in a chronic epithelial burden of the destructive enzyme, neutrophil elastase. alpha 1-antitrypsin (alpha 1AT), the main inhibitor of neutrophil elastase in lung, was given in aerosol form to 12 cystic fibrosis patients. It suppressed neutrophil elastase in the respiratory epithelial lining fluid (ELF) and restored the ELF anti-neutrophil elastase capacity when ELF alpha 1AT reached 8 mumol/l. This treatment also reversed the inhibitory effect of cystic fibrosis ELF on pseudomonas killing by neutrophils, which suggests that it may augment host defence in cystic fibrosis.

Alpha 1-antitrypsin deficiency and liver disease

Alpha 1-antitrypsin (alpha 1AT) deficiency, one of the most common lethal hereditary disorders among Caucasians, is associated with emphysema in adults, while in children it is associated with liver disease. Produced in the liver and released into the plasma, alpha 1AT serves as the body's major inhibitor of neutrophil elastase, a powerful proteolytic enzyme capable of degrading extracellular structural proteins. The pathogenesis of the liver disease associated with alpha 1AT deficiency is not as well understood, but is clearly linked to specific mutations in coding exons of the alpha 1AT gene, and the resulting accumulation of alpha 1AT within hepatocytes. At present, therapy for the liver disease associated with alpha 1AT deficiency is symptomatic, with liver transplantation as a last resort. New strategies are being developed to suppress the accumulation of alpha 1AT by transferring the normal gene into the liver.

Dose-response relationships and time course of the response to systemic beta adrenoreceptor agonists in infants with bronchopulmonary disease

The lung function response to three doses of salbutamol 0.075 mg/kg given at 10 minute intervals by gastric tube was studied in 31 infants aged 2-22 months with bronchopulmonary disease (eight after the respiratory distress syndrome, 15 with wheezy bronchitis, and eight with cystic fibrosis). Lung function was measured by whole body plethysmography. Seven of 31 infants had normal lung function and 10 of the remaining 24 had an increase in thoracic gas volume (TGV), 10 an increase in airway resistance (Raw), and four an increase in both the TGV and Raw. The response of TGV and Raw to salbutamol was analysed by circular statistics, enabling analysis of coupled, directional data. Thirty minutes after administration of the first dose of salbutamol there was a reduction in TGV or Raw in 21 of the 24 infants, 11 showing a decrease in TGV ("volume responder") and 10 a fall in Raw ("flow responder"). These results indicate that in most infants with bronchopulmonary disease an improvement in lung function can be documented after systemic administration of beta agonists if both TGV and Raw are measured.

Short-time response characteristics of salbutamol in infants with broncho-pulmonary diseases

The effects of salbutamol 0.225 mg/kg given systemically on lung function in infants have been measured by whole-body plethysmography in 60 children with broncho-pulmonary diseases (24 after respiratory distress syndrome, 21 with wheezy bronchitis and 15 with cystic fibrosis). A therapeutic action was demonstrated in 74% of the tests, taking into account changes in end-expiratory resting level (state of inflation) and associated changes in airway resistance. There was a significant decrease in thoracic gas volume as an estimate of pulmonary hyperinflation, which was due to improved alveolar ventilation and to a consequential decrease in end-expiratory resting level. The improvement in airway resistance, as an estimate of airway obstruction, reflects a substantial relaxation of bronchial smooth muscle increasing the diameter of the airways. The extent to which similar results may be achieved by topical administration of nebulised beta agonists remains to be determined.