Flow cytometric analysis of duodenal intraepithelial lymphocytes (celiac lymphogram): A diagnostic test for celiac disease

Celiac disease (CD) diagnosis in adults and certain cases of children mainly relies on the assessment of histopathological features in duodenal biopsies. However, none of the histological findings that characterize CD are pathognomonic. This, in addition to the clinical heterogeneity of the disease and the presence of seronegative forms, makes the diagnosis of CD still a challenge. A hallmark of the celiac mucosa is the elevated number of TCRγδ intraepithelial lymphocytes (IEL) in the epithelium, which may remain increased even long after gluten withdrawal. Active disease is also characterized by the decreased CD3- IEL subset. The use of flow cytometry enables a precise cell counting and phenotyping, allowing the ascertainment of both TCRγδ+ and CD3- IEL subsets, what is known as the "IEL lymphogram." Although determination of this lymphogram has become a routine evaluation tool in numerous hospitals, standardization of the technical method will guarantee an accurate performance in order to become a pivotal technique for CD diagnosis. Here we describe the protocol to process duodenal biopsies in order to obtain the IELs from the mucosa and to characterize lymphocyte populations by flow cytometry to obtain the IEL lymphogram.

Severe tracheobronchial stenosis in a patient with Crohn's disease

Tracheobronchial involvement in Crohn's disease is rare, usually associated with symptoms of tracheobronchitis, and typically responds well to steroids. The authors report a case of a 29-yr old patient with Crohn's disease, who presented with dyspnoea, fever, and a productive cough. Computed tomography of the chest revealed extensive nodular tracheobronchial stenosis, that was accompanied by severe mucosal inflammation at bronchoscopy. High-dose oral steroids diminished the mucosal inflammation, but had limited efficacy on the underlying tracheobronchial stenosis. It is speculated that this relative ineffectiveness of steroids may be due to the persistence of the untreated inflammatory process.

[Role of surgery in the treatment of obstructive respiratory insufficiency]

Within 15 years, the prognosis of chronic obstructive respiratory failure has been deeply modified by advances in surgical treatment. In case of emphysema, lung volume reduction permits an improvement in the functional status in a significant number of patients, at least for several years. Moreover, lung transplantation, mainly single lung transplantation, provide currently an actuarial survival rate of 50% at five years.

Myosin heavy chain gene expression changes in the diaphragm of patients with chronic lung hyperinflation

In striated muscle, chronic increases in workload result in changes in myosin phenotype. The aim of this study was to determine whether such changes occur in the diaphragm of patients with severe chronic obstructive pulmonary disease, a situation characterized by a chronic increase in respiratory load and lung volume. Diaphragm biopsies were obtained from 22 patients who underwent thoracic surgery. Myosin was characterized with electrophoresis in nondenaturing conditions, SDS-glycerol PAGE, and Western blotting with monoclonal antibodies specific for slow and fast myosin heavy chain (MHC) isoforms. Flow volume curves, total lung capacity, and functional residual capacity were measured before surgery in 20 patients. We found that the human diaphragm is composed of at least four myosin isoforms, one slow and three fast, resulting from the combination of three MHC species. Chronic overload was associated with an increase in the slow beta-MHC species at the expense of the fast species (beta-MHC, 78.2 +/- 4.6 and 50.0 +/- 6.5% in emphysematous and control patients, respectively; P < 0.005). Linear correlations were found between beta-MHC percentage and forced expiratory volume in 1 s (r = -0.52; P < 0.02), total lung capacity (r = 0.44; P < 0.05), and functional residual capacity (r = 0.65; P < 0.003). The human adult diaphragm is composed of a balanced proportion of slow and fast myosin isoforms. In patients with chronic obstructive pulmonary disease, the proportion of fast myosins decreases, whereas that of slow myosin increases. This increase appears to be closely related to lung hyperinflation and may reflect an adaptation of the diaphragm to the new functional requirements.

Early release of proinflammatory cytokines after lung transplantation

BACKGROUND

Systemic hypotension may complicate the early postoperative period after lung transplantation. A release of proinflammatory cytokines secondary to lung ischemia/reperfusion injury could be involved in the pathogenesis of this early hemodynamic failure (EHF).

STUDY OBJECTIVE

To assess prospectively whether the occurrence of EHF is associated with a release of cytokines in the systemic circulation.

DESIGN

Blood samples were taken daily during the first postoperative week in 26 patients who underwent a double or a single-lung transplantation. These patients were divided into three groups: 7 patients who experienced EHF and subsequently died (EHF group); 15 patients without EHF (control group); and 4 patients without EHF but with an identified sepsis (sepsis group). The serum levels of interleukin (IL)-1beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 were compared among the three groups.

RESULTS

In the EHF group, the levels of each cytokine peaked at day 1 postoperatively. Cytokine levels at day 1 were significantly higher in the EHF group than in the control group (p<0.0006) or in the sepsis group (p<0.003 except for TNF-alpha).

CONCLUSION

We conclude that EHF is associated with a massive release of proinflammatory cytokines that could play a determinant role in the pathogenesis of this complication.

[Selection criteria of candidates for lung transplantation]

Amongst the elements which contributed to the success of the early lung transplants at the beginning of the 1980's we feel that the careful selection of candidates probably played a predominant role. If some of the selection criteria initially described remain somewhat intangible, others have either been eased or have been invalidated. The experience acquired over the last 15 years has enabled to precise the optimal moment to include patients on the waiting list and to refine the choice for the type of surgical procedure according to the underlying disease. This article aims to review the different selection criteria for candidates for transplantation and stresses those which have recently undergone change.

[Pneumopathy caused by minocycline]

BACKGROUND

Minocycline has been identified as a pathogenic agent in drug-induced pneumonia. We report a new case.

CASE REPORT

A 38-year-old female asthmatic patient was given minocycline (100 mg/j) for facial acne. She was allergic to penicillin. Other treatments were theophylline, salbutamol and inhaled budesonide. Severe bilateral hypoxemia pneumonia developed with high eosinophil blood counts within a few days of treatment onset. The lung disease regressed with minocycline withdrawal.

DISCUSSION

This case is exceptional because the minocycline-induced lung disease continued to progress despite high-dose corticosteroids in this asthmatic patient.

Expiratory flow limitation in stable asthmatic patients during resting breathing

Application of negative pressure at the mouth during tidal expiration (NEP) provides a simple, rapid, noninvasive method for detecting expiratory flow limitation during spontaneous breathing. Patients in whom NEP elicits an increase in flow throughout expiration are not flow-limited (FL). In contrast, patients in whom application of NEP does not elicit an increase in flow during most or part of tidal expiration are considered FL. We have used the NEP technique to assess the prevalence of expiratory flow limitation during resting breathing in sable asthmatic patients in both the seated and supine positions. In patients in the sitting position, we have also assessed flow limitation with the conventional method, based on comparison of tidal and maximal expiratory flow-volume (MEFV) curves. We studied 13 patients (FEV1 range: 48 to 94% predicted) with both the NEP and conventional techniques. According to the NEP technique, none of the patients was FL in the seated and only two were FL in the supine position. By contrast, on the basis of the conventional method, six of the patients would have been classified as FL in the sitting position. We conclude that: (1) most stable asthmatic patients do not exhibit tidal expiratory flow limitation during resting breathing; and (2) the conventional method for assessing flow limitation may lead to erroneous conclusions.

[Lung volume reduction surgery in emphysema]

Lung volume reduction surgery in emphysema has, as an objective, the reduction of dyspnoea and an increase in the exercise tolerance in patients with respiratory insufficiency suffering from diffuse emphysema. In principle the resection of the most diseased areas of emphysema leads to improvement in the mechanical properties of the emphysematous lung and correct pulmonary hyperinflation. The respiratory function benefits both objective and subjective, produced by surgery are real but transitory and inconstant depending in particular on the evolutionary profile of the emphysematous disease. The indications should be further refined and an objective comparison of different surgical techniques has not been achieved. The impact on the quality of life for these patients is unknown.

[Pulmonary transplantations. Current assessment]

After fifteen years of experience, 3-year survival rates after lung transplantation have reached 60% for heart-lung, two-lung and single-lung procedures. At 7 years, the rate is currently 41%. Lung transplantation has thus become the ultimate treatment for end-stage respiratory failure, and, as we were able to establish in 1988, single lung transplantation is now the indication of choice. Most of the early complications after transplantation, including edema and post-operative shock, though relatively frequent, can generally be controlled. There is however the problem of acute rejection during the first three months following transplantation due to herpes or cytomegalovirus infections which respond poorly to antiviral therapy. Immunosuppressive therapy generally can control acute rejection, but subsequent chronic episodes may account for 25% of long-term failures. Episodes of chronic rejection usually occur after nine months but onset may be retarded beyond 3 years. The real problem today is the small number of donors and the long waiting lists. In France, where 200 lung transplantations are needed annually, the number of donors is dramatically insufficient.

Bronchial Kaposi's sarcoma after single lung transplantation

Kaposi's sarcoma (KS) has been reported in 6% of malignancies of solid organ transplant recipients. Most of the observations have been in recipients of renal allografts but, so far, KS has not been described in lung transplantation. We report a case of bronchial KS occurring in a black patient 6 months after single lung-transplantation. Skin lesions were absent and, interestingly, KS lesions were observed solely in the trachea and the native lung. Following reduction of the immunosuppressive regimen a complete remission was obtained 1 year later. Up to the present time, this clinical remission is very encouraging, but close surveillance remains necessary to detect rejection episodes or the reappearance of KS following manipulation of the immunosuppressive therapy.

[Tuberculosis: epidemiological, bacteriological and therapeutic changes]

The regular decline in the incidence of tuberculosis up to 1985 left us with the hope that the disease might one day be totally irradicated. But from 1985 on the number of cases has remained unchanged at about 8000 new cases per year in France. Resistant strains have also been identified, requiring new treatment strategies. Polyresistant strains may develop because of non-compliance to standard treatment or, particularly in immunosuppressed patients with AIDS, infection with atypical mycobacteria such as Mycobacterium avium. In developed countries, prophylactic measures for tuberculosis should be based on early diagnosis, rapid initiation of a proven treatment protocol not only to obtain cure but also to reduce contagion, and avoiding contract between high-risk patients. Chemoprophylaxy should be prescribed in case of doubt about contact as the tuberculin test is no longer discriminate due to widespread vaccination. For AIDS patients, the treatment protocol is the same as for normal subjects but should be prolonged. In case of M. avium infection, the most effective treatment combines pyrazinamide, clarithromycin and a third anti-tuberculosis drug.

Expiratory flow limitation in COPD patients after single lung transplantation

Expiratory flow limitation and dyspnea during resting breathing are common in patients with severe chronic obstructive pulmonary disease (COPD). Although single lung transplantation (SLT) is used to treat end-stage COPD, its effects on flow limitation and dyspnea are not well established. We assessed expiratory flow-limitation and dyspnea in 13 COPD patients after SLT at rest in the sitting and supine positions by applying negative pressure at the mouth during tidal expiration (negative expiratory pressure [NEP] technique). If NEP increases flow throughout the control tidal volume (VT), flow limitation is absent (not flow limited [NEL]). If NEP does not increase flow during part of the control VT, flow limitation is present. After SLT, lung function improved in all but one patient. Twelve patients were NFL during resting breathing in both positions studied. The patient whose lung function did not improve after SLT was flow-limited (FL) both when seated and supine. This patient also exhibited moderately severe chronic dyspnea (Medical Research Council [MRC] score = 3). In the nine other patients in whom dyspnea was assessed, it was slight (MRC score = 1). In conclusion, after SLT for end-stage COPD, expiratory flow limitation at rest is uncommon in both the seated and supine positions. This is consistent with the finding that after SLT the degree of chronic dyspnea is generally slight.

Progressive obstructive lung disease associated with microscopic polyangiitis

Small airway involvement and progressive severe airflow obstruction are unexpected features in patients with microscopic polyangiitis. We report the case of a patient with microscopic polyangiitis and circulating anti-neutrophil cytoplasmic antibodies (ANCA), who developed pulmonary hyperinflation and airflow obstruction over a 7-yr period. Systemic manifestations of this vasculitis improved under corticosteriods and cyclophosphamid therapy, a treatment that did not influence either the very high level of anti-myeloperoxidase antibodies or the ventilatory impairment. Small airway involvement was suspected on the basis of pathologic small airway lesions and a mild emphysematous pattern on computed tomography (CT) scan, which was out of proportion with the severity of the obstructive lung disease.

Lung volume reduction in patients with severe diffuse emphysema. A retrospective study

BACKGROUND

For most authors, surgery of emphysema is restricted to resection of large bullae, whereas resection of small bullae or lung volume reduction is generally considered to have poor results.

STUDY OBJECTIVE

To report our experience of lung volume reduction in patients with severe emphysema without large bullae.

PATIENTS

Thirteen patients were operated on from 1982 to 1992. Before surgery, they all had severe diffuse emphysema with a dyspnea grade 4 or 5 and mean FEV1 values of 18 +/- 5% of predicted. Seven patients had a PaCO2 greater than 42 mm Hg. On radiologic evaluation, they had either small bullae or, most often, areas of destroyed lung.

INTERVENTION

The surgical procedure was unilateral in 11 patients and bilateral in 2.

MEASUREMENTS AND RESULTS

Postoperative assessment included dyspnea grading, FEV1 measurements, and blood gas analysis followed at 6- to 12-month intervals. There was no perioperative mortality and the morbidity was limited. At 6, 12, 18, 24, and 36 months postoperatively, a symptomatic improvement was observed in 92%, 85%, 54%, 31%, and 31% of the patients, respectively, with FEV1 increasing by at least 20% in 92%, 46%, 46%, 31%, and 24% of the patients, respectively.

CONCLUSION

Our data show that lung volume reduction may result in symptomatic and spirometric improvement in patients with severe emphysema without large bullae.

[Pulmonary emphysema: surgical indications]

Surgery for pulmonary emphysema, with the exception of lung transplantation, is limited at present to resection of the emphysematous areas. The resection of a unique bulla within an otherwise healthy parenchyma can be indicated in case of complications but rarely in asymptomatic patients. When the bullae are large (i.e. volume greater than one-third of the hemithorax) in a patient suffering from diffuse emphysema, bullectomy is the ideal indication. Mortality varies from 0 to 10%, essentially due to infection or acute respiratory failure. In most patients, the subjective improvement in terms of dyspnea and the objective improvement as measured by spirometry remains significative up to 5 years after surgery. Inversely, surgical resection is classically considered to be contraindicated in patients with small poorly-limited bullae. Recent data would however question this idea since subjective and objective improvement after reduction of the lung volume is still present 1 year after surgery in most patients, even those with severe obstruction. The mechanism is probably related to increased elastic recoil. Even if only temporary improvement can be achieved for a few years, the persisting course of emphysema would suggest that volume reduction should always be entertained as an alternative before lung transplantation.

Refractory hypoxemia during liver cirrhosis. Hepatopulmonary syndrome or "primary" pulmonary hypertension?

We report an uncommon mechanism of severe hypoxemia in two cirrhotic patients under long-term beta-blocker therapy. Our patients presented with profound hypoxemia refractory to oxygen therapy, normal lung radiography and pulmonary function tests, and evidence of right-to-left anatomic shunt. Although these features are highly suggestive of hepatopulmonary syndrome, pulmonary hypertension was present, and a right-to-left shunt through a patent foramen ovale was demonstrated by contrast-enhanced echocardiography. No cause of pulmonary hypertension other than portal hypertension was identified. Pulmonary hypertension and intracardiac right-to-left shunt eventually regressed after discontinuation of beta-blocker therapy. We conclude that "primary" pulmonary hypertension associated with portal hypertension may because of severe hypoxemia during liver cirrhosis. Differential diagnosis of hepatopulmonary syndrome relies upon contrast-enhanced echocardiography and may be of critical importance because of possible therapeutic implications.

[Treatment of severe acute asthma]

Severe acute asthma remains associated with significant mortality. Medical treatment of acute severe episodes includes oxygentherapy, inhaled or intravenous beta-2-agonists, and high doses of systemic corticosteroids. The benefit of additional treatment with other agents such as nebulized ipratropium bromide, epinephrine and intravenous aminophylline is still not well defined. Mechanical ventilation, which remains necessary in case of life-threatening acute respiratory failure, addresses specific problems: PaCO2 may be allowed to remain elevated and ventilator settings should be chosen that avoid barotrauma under appropriate sedation. The use of inhalation anesthesics, helium or even extracorporeal life support necessitates further study to determine the optimal therapeutic strategy in those particular situations.

[Asthma and its treatment during pregnancy]

Asthma occurs in 0.4 to 4.0% of pregnant women and is considered to be the most frequent respiratory disease during pregnancy. Physiological modifications during pregnancy, including hyperventilation due to increased progesterone levels and lower residual volume and functional capacity resulting from increased uterine volume can interfere with the asthmatic disease and require adapted management. Results of studies evaluating the interaction between asthma and pregnancy provide a wide variety of results. For some authors, manifestations of asthma may worsen during pregnancy requiring reinforced medical treatment in as many as 42% of the patients. For others bronchial hyperreactivity is significantly diminished during pregnancy. These findings should be examined in light of several individual factors including the spontaneous clinical course of asthma itself and more rigorous control during pregnancy. It is thus very difficult to predict the effect of pregnancy on clinical manifestations of asthma in any given patient or from one pregnancy to another. Certain authors have observed a correlation between IgE levels and the gravity of asthma in pregnant women: normally IgE levels tend to decline during pregnancy but may remain unchanged or increase if asthma manifestations worsen. Therapeutic options remain unchanged during pregnancy although only drugs proven safe for the fetus may be used. If carefully managed, pregnancy in the asthmatic patient usually reaches term with no major problem.

Latent pulmonary function abnormalities in children with Crohn's disease

Recently, latent pulmonary involvement has been described in adult patients with inflammatory bowel disease. It is unknown, however, whether this also occurs in children, and whether the pulmonary abnormalities differ between the acute phase and remission. The incidence of pulmonary abnormalities has been investigated in 26 children with acute or quiescent Crohn's disease in terms of the following parameters: clinical pulmonary symptoms, chest roentgenograms and pulmonary function tests, including lung transfer factor for carbon monoxide (TLCO). One child had a severe digital clubbing. Chest radiographs were normal in all subjects. No significant differences were found between acute and quiescent phase for pulmonary volumes and expiratory flows, but TLCO (% predicted) was significantly decreased during the active phase of the disease as compared to remission (53 +/- 15 vs 81 +/- 19% predicted). These data suggest that latent pulmonary involvement is also present in a paediatric population with active Crohn's disease, despite a short disease history and absence of smoking. Although the nature of this abnormality remains unclear, this extradigestive epiphenomenon should be taken into account with respect to the aetiopathogenesis of Crohn's disease.

Silica exposure and chronic airflow limitation in pottery workers

We assessed the relationship between exposure to silica dust and chronic airflow limitation in an epidemiological survey conducted among pottery workers and controls who were of the same socioeconomic status (average age: 35 y; 78% males). Data were collected by questionnaire for respiratory symptoms, allergy, respiratory history, smoking habits, and occupation. Lung function was measured with a computer-equipped Gauthier spirometer. We excluded subjects with silicosis or doubtful chest x-ray, and two exposure levels were defined. No differences were observed between exposed subjects and controls with respect to respiratory conditions. Mean pulmonary function values for men and women were significantly lower, after adjustment for age, height, and smoking habits, in even indirectly exposed pottery workers, compared with controls. These results suggest that exposure to silica dust is a risk factor for chronic airflow limitation and is independent of radiographic changes.

Tracheal malacoplakia

Malacoplakia is a rare granulomatous disease well described in the urinary tract but which rarely involves the lung. We report for the first time, to our knowledge, tracheal localization of this unusual disorder. The larynx and probably kidneys were also involved. Differential diagnosis, physiopathology, and treatments are discussed.

Single-lung retransplantation for late graft failure

In lung or heart-lung recipients, an irreversible graft-failure may develop in connection with chronic rejection, infection or bronchial complications. A limited number of transplant-recipients have undergone a retransplantation procedure in several centres. First results are discouraging, especially in the case of early retransplantation. We decided, 3 yrs ago, to evaluate the feasibility and benefits of single-lung retransplantation in lung-transplant recipients with late graft-failure. Eight consecutive single-lung retransplantations were performed in patients with previous single-lung (n = 7), or double-lung (n = 1) transplant. Primary graft and native lung were removed in 5 and 3 patients, respectively. The delay between the two surgical procedures was 16 +/- 10 months (range 6-37 months). Three patients died within 3 months. Long-term survivors experienced stable and satisfactory functional results (forced expiratory volume in one second (FEV1 63 +/- 21% predicted; range 40-103% predicted), with survival values ranging 8-20 months. One patient died of septic shock 16.5 months after retransplantation. The remaining four patients are alive. These data suggest that the retransplantation option could be considered in selected patients with late graft-failure. The final decision for retransplantation, however, is largely influenced by the current shortage of donor lungs.

Single-lung retransplantation for late graft failure

In lung or heart-lung recipients, an irreversible graft-failure may develop in connection with chronic rejection, infection or bronchial complications. A limited number of transplant-recipients have undergone a retransplantation procedure in several centres. First results are discouraging, especially in the case of early retransplantation. We decided, 3 yrs ago, to evaluate the feasibility and benefits of single-lung retransplantation in lung-transplant recipients with late graft-failure. Eight consecutive single-lung retransplantations were performed in patients with previous single-lung (n = 7), or double-lung (n = 1) transplant. Primary graft and native lung were removed in 5 and 3 patients, respectively. The delay between the two surgical procedures was 16 +/- 10 months (range 6-37 months). Three patients died within 3 months. Long-term survivors experienced stable and satisfactory functional results (forced expiratory volume in one second (FEV1 63 +/- 21% predicted; range 40-103% predicted), with survival values ranging 8-20 months. One patient died of septic shock 16.5 months after retransplantation. The remaining four patients are alive. These data suggest that the retransplantation option could be considered in selected patients with late graft-failure. The final decision for retransplantation, however, is largely influenced by the current shortage of donor lungs.

Acute effects of zolpidem, triazolam and flunitrazepam on arterial blood gases and control of breathing in severe COPD

Patients with severe chronic obstructive pulmonary disease (COPD) commonly complain of insomnia, but hypnotic drugs are generally not recommended due to their depressant effect on the respiratory centres. The aim of this study was, therefore, to compare the effects of a single dose of the benzodiazepine hypnotics, triazolam 0.25 mg and flunitrazepam 1 mg, and a new imidazopyridine compound, zolpidem 10 mg, in hypercapnic COPD patients. Twelve stable COPD patients (mean +/- SD arterial oxygen tension (PaO2) 9.3 +/- 0.8 kPa and arterial carbon dioxide tension (PaCO2) 5.9 +/- 1.9 kPa) were included in the study. The following measurements were performed before and 2 h after drug administration: PaO2 and PaCO2, minute ventilation (VE), mouth occlusion pressure (P0.1), rebreathing CO2 tests with ventilatory response to carbon dioxide stimulation (delta VE/delta PACO2) and mouth occlusion pressure response to carbon dioxide stimulation (delta P0.1/delta PACO2). The measurements were performed in a randomized, double-blind fashion, each patient receiving a single dose of each drug on three different days, separated by a one week interval. No difference was noted between control measurements and those taken 2 h after administration of zolpidem in the following parameters: PaCO2, PaCO2, VE, P0.1, delta VE/delta PACO2 and delta P0.1/PACO2. Two hours after administration of triazolam and flunitrazepam, a significant difference was noted in VE for triazolam and for flunitrazepam. After flunitrazepam administration, a significant decrease in PaCO2 (6 +/- 1.8 at baseline versus 7 +/- 0.4 kPa), and delta VE/PACO2 (0.44 +/- 0.20 at baseline versus 0.31 +/- 0.21 l.min-1 x kPa) were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute effects of zolpidem, triazolam and flunitrazepam on arterial blood gases and control of breathing in severe COPD

Patients with severe chronic obstructive pulmonary disease (COPD) commonly complain of insomnia, but hypnotic drugs are generally not recommended due to their depressant effect on the respiratory centres. The aim of this study was, therefore, to compare the effects of a single dose of the benzodiazepine hypnotics, triazolam 0.25 mg and flunitrazepam 1 mg, and a new imidazopyridine compound, zolpidem 10 mg, in hypercapnic COPD patients. Twelve stable COPD patients (mean +/- SD arterial oxygen tension (PaO2) 9.3 +/- 0.8 kPa and arterial carbon dioxide tension (PaCO2) 5.9 +/- 1.9 kPa) were included in the study. The following measurements were performed before and 2 h after drug administration: PaO2 and PaCO2, minute ventilation (VE), mouth occlusion pressure (P0.1), rebreathing CO2 tests with ventilatory response to carbon dioxide stimulation (delta VE/delta PACO2) and mouth occlusion pressure response to carbon dioxide stimulation (delta P0.1/delta PACO2). The measurements were performed in a randomized, double-blind fashion, each patient receiving a single dose of each drug on three different days, separated by a one week interval. No difference was noted between control measurements and those taken 2 h after administration of zolpidem in the following parameters: PaCO2, PaCO2, VE, P0.1, delta VE/delta PACO2 and delta P0.1/PACO2. Two hours after administration of triazolam and flunitrazepam, a significant difference was noted in VE for triazolam and for flunitrazepam. After flunitrazepam administration, a significant decrease in PaCO2 (6 +/- 1.8 at baseline versus 7 +/- 0.4 kPa), and delta VE/PACO2 (0.44 +/- 0.20 at baseline versus 0.31 +/- 0.21 l.min-1 x kPa) were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

[Bronchiolitis obliterans after lung transplantation]

Lung transplantation has become a realistic treatment in some patients with severe respiratory impairment or severe pulmonary arterial hypertension. Immunosuppression therapy is about the same in all transplantation units and includes cyclosporin, corticosteroids and azathioprine. The diagnosis of acute rejection episodes has been greatly facilitated by the histological study of transbronchial biopsies obtained by endoscopy. Improvements in the short-term prognosis of these patients have made it possible to individualize an unusual and delayed complication: bronchiolitis obliterans. This progressive and diffuse obstruction followed by destruction of the transplant's bronchioles is interpreted as a consequence of chronic rejection. The diagnosis of bronchiolitis obliterans is difficult and rests essentially on degradation of the respiratory function resisting to increased immunosuppression. Some viral infections perhaps contribute to its development, and it may be so severe as to require another lung transplantation.

Pulmonary lymphangiomyomatosis treated by single lung transplantation

Pulmonary lymphangiomyomatosis is a rare disease resistant to almost all medical treatments to date. We describe the case of a 44-yr-old woman with end-stage pulmonary lymphangiomyomatosis who was treated by single-lung transplantation. The patient is doing well in her sixteenth post-transplantation month and has a marked improvement in her pulmonary function tests and walking distance as compared with preoperative values, and she is enjoying an unrestricted life-style.

Comparative study of azithromycin and amoxicillin/clavulanic acid in the treatment of lower respiratory tract infections

Forty-eight patients with acute bronchitis and four with pneumonia were randomly assigned to receive five doses (500 mg on day 1, plus 250 mg/day on days 2-5) of azithromycin; 54 patients with acute bronchitis and four with pneumonia were assigned 30 doses (625 mg every eight hours for ten days) of amoxicillin/clavulanic acid (CA). The two regimens were equally effective, with clinical improvement or cure in 92% and 87% of patients respectively, bacteriological cure in 89% and 86%, with 91% and 89% of pathogens eliminated. Minor side effects occurred in 6% and 12% of patients in the two groups, respectively. No major abnormalities in laboratory safety parameters were seen in either group.

Single-lung transplantation in emphysematous patients

We report six single-lung transplantations in emphysematous patients with end-stage disease. Compression of the graft or ventilation/perfusion imbalance were not observed. Rejection episodes were generally documented through transbronchial biopsies and the radiological changes related to acute infections or rejections were restricted to the transplanted lung. Three patients died from CMV pneumonia, status epilepticus and fibrosis of the graft following bronchography, respectively. The three remaining patients are well, with documented improvement of pulmonary function tests and arterial blood gases. Bronchial complications were observed in all patients and have in some cases required dilatation or insertion of a stent. Although requiring a longer follow up, single transplantation is feasible and beneficial in patients with end-stage emphysema.

Expiratory flushing of airways: a method to reduce deadspace ventilation

A jet of fresh gas entering the trachea during the last part of expiration, expiratory flushing of airways (EFA), may during mechanical ventilation bring the fresh gas interface into the trachea to reduce deadspace. EFA, delivered in a variety of modes, was tested in healthy dogs. EFA allowed tidal volume, peak and mean airway pressure to be reduced by about 25%. EFA was administered in the form of pulses with frequencies 2-8 Hz, and as a continuous flow. The mode was of little importance. EFA was found to be efficient and should be clinically tested.

Expiratory flushing of airways: a method to reduce deadspace ventilation

A jet of fresh gas entering the trachea during the last part of expiration, expiratory flushing of airways (EFA), may during mechanical ventilation bring the fresh gas interface into the trachea to reduce deadspace. EFA, delivered in a variety of modes, was tested in healthy dogs. EFA allowed tidal volume, peak and mean airway pressure to be reduced by about 25%. EFA was administered in the form of pulses with frequencies 2-8 Hz, and as a continuous flow. The mode was of little importance. EFA was found to be efficient and should be clinically tested.

[Bronchial tolerance to inhalation of beclomethasone. Histologic and microbiologic study in asthmatic patients]

The aim of the present study was to investigate the effects of a three months' treatment with beclomethasone dipropionate on the bronchial mucosa of asthmatic patients. Eleven patients suffering from a mild chronic asthma treated with inhaled salbutamol and theophylline were randomly assigned to receive either 1000 mu g of beclomethasone dipropionate (6 patients) or an aerosolized placebo (5 patients) in a double-blind manner. Bronchial biopsies and bronchial secretions were obtained through a fiberoptic procedure at the beginning and the end of the study. Repeated clinical and spirometric investigations were performed each month. Inter- and intra-group mean changes of clinical symptoms and of spirometric values were not significantly different. Pathogens were rarely found in bronchial aspirates and their occurrence did not seem to be influenced by the beclomethasone therapy. Sixty percent of the bronchial biopsies displayed pathological changes of the mucosa that observed at the beginning and at the end of the study; however, no sign of mucosal atrophy was noted.

Effects of steroids on diaphragmatic function in rats

The present study was undertaken to determine the effects of 8 days of corticosteroid administration on diaphragmatic atrophy and contractile properties. One hundred sixty rats were divided into a pair-fed (PF) group (n = 80) and a steroid-treated (ST) group (n = 80). The treated rats received a single injection of Kenacort 80 retard (0.1 mg/kg intramuscularly). The experimental period was 8 days. Steroid treatment resulted in a 30% decrease in body weight in the ST group when compared with the PF group. Diaphragmatic mass in the ST group decreased in proportion to body weight (30%) as did the weight of the extensor digitorum longus (EDL). The soleus muscle was unaffected. The diaphragmatic atrophy was associated with a significant decrease (p less than 0.001) in normalized tetanic force as assessed both in vivo and in vitro. Diaphragmatic strength was determined in vivo by measuring transdiaphragmatic pressure (Pdi) during bilateral electrical stimulation of the phrenic nerves at different frequencies (0.5, 10, 20, 30, 50, and 1000 Hz). The force-frequency relationship was also studied in vitro using direct stimulation of costal diaphragmatic strips. In both preparations, twitch and low-frequency force were unaffected, whereas normalized tetanic force in the ST group was markedly reduced compared with that in the PF group (p less than 0.001). Soleus and EDL muscles were also studied in vitro. Although steroid treatment had no effect on the soleus, in the EDL, a slight (11%) decrease in normalized tetanic tension was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Preventive effects of indomethacin on diaphragmatic contractile alterations in endotoxemic rats

We evaluated the effects of a sublethal Escherichia coli endotoxemia with and without concomitant administration of indomethacin on diaphragmatic strength in an in vivo rat model. Ninety-six rats were inoculated subcutaneously on two successive days with 0.3 and 0.6 mg/100 g body weight of E. coli lipopolysaccharide, respectively (E animals, n = 64), or saline (C group, n = 32). E animals were divided into two groups based on subcutaneous administration of endotoxin alone (E group, n = 32) or endotoxin plus indomethacin (2.5 mg/kg body weight/day) (EI group, n = 32). Diaphragmatic strength was evaluated in 14 animals from each group 2 days after the first endotoxin or saline administration. Diaphragmatic strength was assessed by measuring the transdiaphragmatic pressure (Pdi) during electrical stimulation of the phrenic nerves at different frequencies (0.5, 10, 20, 30, 50, and 100 Hz). Lung histologic examination and measurements of lung weights were performed 1 and 2 days after the first endotoxin or saline administration in nine animals of each group each day. A slight increase in the number of neutrophils without alveolar septal thickening and alveolar edema was observed in the lungs of endotoxin-inoculated animals. No differences in the lung weight to body weight ratio nor in the dry to wet weight ratio of the lungs were noted between C, E, and EI groups. Diaphragmatic weight was not different in the three groups, whereas the weights of the extensor digitorum longus, tibialis anterior, and soleus muscles were significantly reduced in E compared with C and EI animals.(ABSTRACT TRUNCATED AT 250 WORDS)

The respiratory response to CO2 and O2 in patients with coma due to voluntary intoxication with barbiturates and carbamates

We have investigated the respiratory response to CO2 and to O2 in comatose subjects self intoxicated with barbiturates and carbamates. The chemical drive of 12 such patients with coma was compared with that of comparable normal subjects. The ventilatory response to CO2 was depressed but the P0.1 response was of the same order of magnitude as in normals. O2 had little effect on the ventilatory parameters and occlusion pressure. There was no difference between the two groups of patients, indicating that the respiratory changes observed were more dependent on the intensity of the intoxication than on the nature of the drugs. In addition, mechanical factors seem mainly responsible for the depressed ventilatory response to CO2.

The respiratory response to CO2 and O2 in patients with coma due to voluntary intoxication with barbiturates and carbamates

We have investigated the respiratory response to CO2 and to O2 in comatose subjects self intoxicated with barbiturates and carbamates. The chemical drive of 12 such patients with coma was compared with that of comparable normal subjects. The ventilatory response to CO2 was depressed but the P0.1 response was of the same order of magnitude as in normals. O2 had little effect on the ventilatory parameters and occlusion pressure. There was no difference between the two groups of patients, indicating that the respiratory changes observed were more dependent on the intensity of the intoxication than on the nature of the drugs. In addition, mechanical factors seem mainly responsible for the depressed ventilatory response to CO2.

The transition between apnoea and spontaneous ventilation in patients with coma due to voluntary intoxication with barbiturates and carbamates

We have investigated the transition from apnoea to spontaneous breathing in five comatose patients self intoxicated with barbiturates and carbamates. All patients were apnoeic on admission, and were studied throughout the course of recovery. The transition between the first respiratory movements and a stable and nearly normal ventilation (stable respiratory activity) ranged from 15 to 105 min, a very short time compared to the duration of the apnoeic state that lasted 6 to 72 h from admission. Minute ventilation and occlusion pressure during the first respiratory movements were 6.3 +/- 2.7 l.min-1 and 1.35 +/- 0.45 kPa, respectively. These values increased by roughly 50 and 100% by the time stable respiratory activity was achieved. The increase in minute ventilation was entirely due to an increased inspiratory flow, in relation to a proportionate increase in occlusion pressure, and without significant changes in the respiratory times or in the effective elastance. We conclude that the transition between apnoea and stable respiratory activity is characterized by its rapidity, by the fact that respiratory times are fixed throughout the recovery process, and by the fact that effective elastance is high.