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Biomedical subjects

M Badier

Publications and source records attributed to M Badier.

At least 37 records · Page 2Linked to original sources
PubMed1998

Does norepinephrine modify the effects of inhaled nitric oxide in septic patients with acute respiratory distress syndrome?

UNLABELLED: Hypoxia-related pulmonary vasoconstriction enhanced by norepinephrine could be deleterious in patients with the acute respiratory distress syndrome (ARDS) and sepsis. A prospective study compared the effects of nitric oxide on cardiorespiratory parameters, including the evaluation of right ventricular function in patients with ARDS and sepsis who were receiving or not receiving norepinephrine. METHODS: During a 15-month period, 27 patients with ARDS and sepsis were prospectively investigated (group 1: 15 patients not receiving norepinephrine; group 2: 12 patients receiving norepinephrine). Right ventricular ejection fraction was measured by thermodilution. After baseline measurements, nitric oxide was administered at increasing inspiratory concentrations. RESULTS: The ratio of oxygen tension in arterial blood to the fractional concentration of oxygen in inspired gas increased in the two groups. After logarithmic transformation of the data, an analysis of variance was performed that did not show any difference between the two groups. A dose-dependent decrease in mean pulmonary arterial pressure was observed in the two groups. This decrease and the increase in right ventricular ejection fraction induced by inhaled nitric oxide were more marked when patients received norepinephrine (P < 0.0001). CONCLUSION: Norepinephrine did not influence the beneficial effects of inhaled nitric oxide administered to patients with ARDS and sepsis on oxygenation.

Acute Disease↗
PubMed1998

Rhinitis alone or rhinitis plus asthma: what makes the difference?

This paper examines the clinical expression of asthma in a group of patients displaying rhinitis according to age, sex, associated symptoms, smoking, familial history of asthma, atopy, type of sensitization to aeroallergens (pollens and/or indoor allergens), total serum immunoglobulin E (IgE), and blood eosinophils. A total of 117 adults with rhinitis were analysed on the basis of symptoms. Among them, 51 also displayed asthma, defined as a history of recurrent episodes of dyspnoea with a reversible airflow obstruction or a positive methacholine challenge. The logistic regression analysis carried out in a stepwise approach, combining several factors, showed that various parameters affected the risk of having asthma associated with rhinitis. A further analysis was made in 74 rhinitis patients comparing 42 subjects without nonallergic airway hyperresponsiveness (NAAH) to 32 patients with asthma and NAAH. Atopy, high total serum IgE levels, elevated blood eosinophil count and maternal asthma were associated with asthma. Furthermore, in atopic patients, pollen sensitization was more closely related to rhinitis alone, whereas sensitization to indoor allergens was a major determinant for the association of asthma with the symptoms of rhinitis. The same risk factors as those found in the clinical part of the study discriminated the patients with rhinitis without NAAH from those with rhinitis, asthma and NAAH. In conclusion, this study gives new insights into the relationships between asthma and rhinitis.

Adult↗
PubMed1998

Possible interaction between exposure to environmental tobacco smoke and therapy in children with asthma.

1. The aim of the study was to determine the carbachol and albuterol responsiveness in treated and untreated asthmatic and allergic children exposed to environmental tobacco smoke assessed by urinary cotinine measurements. 2. Forty-six asthmatic and allergic children with normal spirometric values were recruited. The doubling dose, concentration of carbachol producing a 2-fold increase in specific airway resistance (SRaw) was determined and 200 micrograms of albuterol were administered via a Volumatic(R) spacer. The percentage of bronchodilatation was defined as the difference between the largest obtained SRaw and the post-beta2 SRaw divided by the largest SRaw. Data were compared by a Mann-Whitney U-test. 3. The 23 children with a high urinary cotinine, compared with the 23 children without urinary cotinine, had a decreased doubling dose (108.2+/-14.7 micrograms versus 160.9+/-19.5 micrograms; P=0.04) and an increased percentage of bronchodilatation (74.8+/-1.4% versus 68.8+/-1.8%; P=0.03). A prophylactic anti-inflammatory treatment induced a weaker bronchial reactivity to carbachol and a slightly greater bronchodilatation in children exposed to environmental tobacco smoke. 4. Environmental tobacco smoke increases bronchial reactivity in asthmatic and allergic children. This effect might be reduced by anti-inflammatory therapy. The bronchodilator response may be enhanced in exposed children and may be caused by one or several direct interactions between tobacco smoke compounds and albuterol.

Adolescent↗
PubMed1997

Functional consequences of acute and chronic hypoxia on respiratory and skeletal muscles in mammals.

Reduced oxygen supply to contracting muscles affects not only the metabolic paths but also modifies the gain of sensorimotor reflex loops initiated from the activation of specialized nervous endings that detect the changes in muscle metabolism and membrane outflow of potassium. Large differences are found between skeletal muscles and the diaphragm with respect to their sensitivity to acute or chronic hypoxia. The diaphragm tolerates much more hypoxemia than do skeletal muscles, namely those constituted by a large proportion of slow twitch oxidative fibers. Acute hypoxemia or ischemia accentuates the inhibitory influences exerted by the afferent paths from muscle metaboreceptors. This adaptative response may be responsible for enhanced muscle wisdom phenomenon during fatiguing contractions under hypoxic conditions. Prolonged and severe chronic hypoxemia markedly reduces muscle force generation by skeletal muscles and their endurance to fatigue. Restoration of normal PaO2 levels in these individuals immediately improves maximal muscle performance, perhaps through more efficient excitation-contraction coupling. Recent data on the consequences of hypoxia on muscle metabolism and the associated changes in sensorimotor control strongly suggest that local acidosis cannot entirely explain all electromyogram changes found during and after fatiguing exercise.

Acute Disease↗
PubMed1997

Impairment of muscle energy metabolism in patients with sleep apnoea syndrome.

Impairment of muscle energy metabolism has been demonstrated in normal subjects with chronic hypoxaemia (altitude chronic respiratory failure). The purpose of this study was to verify the hypothesis that a comparable condition could develop in patients with sleep apnoea syndrome (SAS), considering that they are exposed to prolonged and repeated hypoxaemia periods. Muscle metabolism was assessed in 11 patients with SAS performing a maximal effort on cycloergometer. In comparison with normal subjects, SAS patients reached lower maximal loads [144 +/- 7 vs. 182 +/- 10 W (P < 0.005)] and lower peak oxygen uptakes [26.4 +/- 1.2 vs 33.2 +/- 1.4 ml kg-1 min-1 (P < 0.005)]. Abnormal metabolic features were found: maximal blood lactate concentration was significantly lower than in normal subjects [0.034 +/- 0.004 vs. 0.044 +/- 0.002 mmol l-1 W-1 (P < 0.05)]; and lactate elimination rate, calculated during a 30-min recovery period, was reduced [0.127 +/- 0.017 vs, 0.175 +/- 0.014 mmol l-1 min-1 (P < 0.025)]. The extent of these anomalies correlated with the severity of SAS. The patients also showed higher maximal diastolic blood pressures than normal subjects [104 +/- 5 vs. 92 +/- 4 mmHg (P < 0.05)]. These results can be interpreted as indications of an impairment of muscle energy metabolism in patients with SAS. Decrease in maximum blood lactate concentration suggests an impairment of glycolytic metabolism, while decrease in the rate of lactate elimination indicates a defect in oxidative metabolism. Since no respiratory pathology apart from SAS was found in this group of patients, it seems legitimate to link the genesis of these impairments to repeated bouts of nocturnal hypoxaemia.

Ammonia↗
PubMed1996

Combined electromyography--31P-magnetic resonance spectroscopy study of human muscle fatigue during static contraction.

Metabolic changes measured by 31P-magnetic resonance spectroscopy and surface electromyograms were simultaneously recorded during isometric contraction of forearm flexor muscles sustained at 60% of maximal force until exhaustion. Throughout the fatigue trial, energy in the low-frequency (L) band continuously increased whereas energy in the high-frequency (H) band first increased and fell only prior to exhaustion. PCr content decreased linearly. Intracellular pH (pHi) transiently increased during the first 22 s of trial. The triggering of acidosis was associated with critical PCr values (35-70% of initial content) and decreased electromyogram (EMG) energy in the H band. Linear relationships were only found between energy in the L band, pHi, and PCr content. The interindividual variability of metabolic and EMG changes was high despite standardized conditions of contraction. Maximal PCr consumption was correlated with the maximal pHi decrease measured at the end of the trial. Overall, there was no correlation between H/L EMG ratio and changes in muscle metabolism.

Adult↗
PubMed1996

A randomized, single-blind crossover comparison of the effects of chronic DDD and dual sensor VVIR pacing mode on quality-of-life and cardiopulmonary performance in complete heart block.

The aim of this study was to compare DDD and dual sensor VVIR (activity and QT) pacing modes in complete AV block (CAVB). Eighteen patients (14 men and 4 women, aged 70 +/- 6.5 years) implanted with a dual chamber, dual sensor pacemaker for CAVB with normal sinus node chronotropic function were studied. A quality-of-life and cardiovascular symptom questionnaire, and a treadmill exercise test were completed after a period of VVIR and a period of DDD pacing, each lasting 1 month. Overall quality-of-life and cardiovascular symptoms did not significantly differ, though three patients felt discomfort during VVIR mode. There was no significant statistical difference in cardiopulmonary parameters. DDD and VVIR modes yielded the following respective data: maximum heart rate = 105.7 +/- 21.8 beats/minute versus 107.6 +/- 21.6 beats/minute (NS); maximum workload = 60 +/- 33.4 W versus 59.3 +/- 37.8 W (NS); treadmill duration = 10.1 +/- 3.8 minute versus 10.1 +/- 3.6 minute (NS); oxygen consumption at anaerobic threshold = 14.6 +/- 4.1 mL/kg per minute versus 14.9 +/- 4.6 mL/kg per minute (NS); maximum minute ventilation = 49.6 +/- 9L/min versus 46 +/- 12 L/min (NS); and respiratory quotient = 1.08 +/- 0.15 versus 1.08 +/- 0.13 (NS). We conclude that, during a 1-month follow-up period, no difference was found between DDD and dual sensor VVIR (QT and activity) pacing modes in CAVB patients with regard to quality-of-life and cardiopulmonary performance, though a trend toward an increased sense of well being was noted with the DDD mode.

Aged↗
PubMed1996

Balance between alveolar macrophage IL-6 and TGF-beta in lung-transplant recipients. Marseille and Montréal Lung Transplantation Group.

Acute inflammation in the lung is characterized by a phase of tissue injury followed by a phase of tissue repair. When the latter is excessive, fibrosis occurs. Alveolar macrophages (AM) can produce cytokines involved in both phases of acute lung inflammation, notably interleukin-6 (IL-6), involved in injury and transforming growth factor-beta (TGF-beta), mediating repair. We hypothesized that AM were activated in both phases, and studied IL-6 and TGF-beta production by AM during complications of lung transplantation, acute rejection (AR), and cytomegalovirus pneumonitis (CMVP). In addition, we analyzed these cytokines in bronchiolitis obliterans (BO), a fibrotic complication of lung transplantation linked to previous AR and CMVP. At the onset of AR and CMVP, IL-6 secretion increased, whereas AM TGF-beta content was increased, but not its secretion. In contrast, with time, IL-6 reached control value whereas TGF-beta secretion rose significantly. In BO, IL-6 was not oversecreted, but TGF-beta increased, notably before functional abnormalities occurred. These results show that during acute complications of lung transplantation, AM display an early activation with oversecretion of IL-6, which is involved in tissue injury, counterbalanced by a late activation in which TGF-beta predominates, mediating tissue repair. The results provide new insights into the pathogenesis of BO, which is linked to acute complications of lung transplantation through this biphasic AM activation.

Adolescent↗
PubMed1995

Maximal force and endurance to fatigue of respiratory and skeletal muscles in chronic hypoxemic patients: the effects of oxygen breathing.

The consequences of chronic hypoxemia on maximal force and endurance time to sustained 80% of maximal isometric contraction of two skeletal muscles (adductor pollicis and vastus lateralis) and the diaphragm were studied in patients with chronic obstructive pulmonary disease (COPD). Compared to normal subjects, COPD patients have lower values of Fmax for the two skeletal muscle groups and Pmax (diaphragm). Endurance time was also shorter for the diaphragm and adductor pollicis. Chronic hypoxemia was associated with an accentuation in integrated EMG changes in both low and high frequency bands for adductor pollicis and diaphragm. Inhalation of oxygen enriched gas mixture for a 15-min period increased markedly Fmax and PImax values, prolonged the endurance time to sustained thumb adduction, and reduced the EMG changes in the low frequency band for adductor pollicis. The present observations provide evidence for altered maximal performances of skeletal muscles in chronic hypoxemic patients and also point out the virtues of oxygen breathing in these patients.

Adult↗
PubMed1995

[Lung transplantation and respiratory function tests. Functional outcome in the presence and absence of chronic rejection].

Between may 1988 and march 1993, twenty five double lung transplants were performed and five heart/lung transplants. Lung function tests (EFR) were performed on these patients for a period of 19.2 +/- 3.4 months. The aim of this study was two-fold. First, to report our overall results and to estimate the role of the single breath nitrogen washout test (N2 slope) in the early detection of chronic rejection (RC). Secondly, to assess the diagnostic value of EFR in the discrimination of acute rejection (RA) and of cytomegalovirus pneumonitis (PCMV). There were 41 episodes of RA and 21 episodes of PCMV and they were analysed as a function of the presence or absence of RC. In the absence of RC, RA produced no change in EFR and PCMV was accompanied by a pure restrictive ventilatory defect. On the otherhand, RA and PCMV lead to a worsening of obstruction and an hypoxaemia which characterises RC. The diagnosis of RC was made, on average, 14.4 +/- 2.9 months after surgery. However, from the sixth month the nitrogen slope was significantly increased and other parameters of EFR (particular maximal flows at low lung volume) remained normal. Thus, our results suggest that the N2 slope, measured in the absence of any evidence of acute rejection, constitutes an early test for chronic rejection. When its pathological rise is compared to the results of histology (presence or absence of RC), it shows a sensitivity of 0.94 and a specificity of 0.93.

Acute Disease↗
PubMed1994

EMG changes in respiratory and skeletal muscles during isometric contraction under normoxic, hypoxemic, or ischemic conditions.

The consequences of general hypoxemia (PaO2 = 51 mmHg) on two muscle groups (adductor pollicis and diaphragm) sustaining 80% maximal isometric voluntary contraction were studied in healthy individuals. For adductor pollicis, contractions were also executed after 10-s or 3-min rest ischemia. Compared to control, i.e., normoxic, sustained isometric workloads, significant shortening of endurance time occurred only when adductor pollicis contracted under hypoxemic conditions. In both muscle groups, a 3-min ischemia test as well as hypoxemia reduced the rate of changes in integrated surface EMG in a low frequency band and lowered, or did not modify, the rate of change in the high above low frequency ratio. Recovery of normal patterns of EMG changes was prolonged only after the adductor pollicis contracted under hypoxemic conditions. The present data show that both hypoxemia and prolonged rest ischemia reduced the rate of changes in quantitative EMG activity, with the more significant effects being measured under hypoxemia.

Adult↗
PubMed1994

Effect of recombinant human erythropoietin treatment in uremic patients on oxygen affinity of hemoglobin.

Anemia of chronic renal failure is associated with a reduced affinity of hemoglobin for oxygen (Hb-O2 affinity). It has been reported that the correction of renal anemia by recombinant human erythropoietin (rhuEPO) treatment could be associated paradoxically with a further decrease in Hb-O2 affinity. We investigated changes in the compensatory mechanisms of chronic renal anemia during 25 weeks of rhuEPO treatment, in 19 chronic hemodialyzed (HD) patients. There was no significant variation of mean standard P50 (P50std). Average 2,3-diphosphoglycerate (DPG) increased after 13 weeks and remained stable. The large interindividual variations prompted us to study delta P50std and delta Hb. We demonstrated a negative correlation between delta P50std and delta Hb. Thus, P50std increased in patients who did not immediately correct their anemia and decreased in patients whose Hb values rose. These data showed that the major factor influencing variations of Hb-O2 affinity in chronic HD patients treated by rhuEPO is the variation of Hb concentrations. In our study, it was demonstrated that the most important rise in P50std and 2,3-DPG occurred in patients who were late responders to rhuEPO.

Adult↗
PubMed1994

Monitoring of alveolar macrophage production of tumor necrosis factor-alpha and interleukin-6 in lung transplant recipients. Marseille and Montreal Lung Transplantation Group.

Bronchiolitis obliterans (BO), a common complication in lung transplant recipients, is a fibrotic process probably related to acute rejection (AR) and cytomegalovirus pneumonitis (CMVP). Because the pathogenesis of pulmonary fibrotic diseases involves activation of alveolar macrophages (AM), the present study was carried out to determine if AM were activated during AR, CMVP, and BO. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were measured in 157 AM supernatants obtained from 29 transplant recipients by immunoradiometric assay. Five groups were analyzed: AR (n = 21), CMVP (n = 12), BO (n = 15), bacterial pneumonia (BP) (n = 8), and control subjects (n = 70). Cytokines were also assayed 15 d (n = 15) and 30 d (n = 9) after AR and 30 d (n = 9) after CMVP. Cytokine secretion was elevated during AR (TNF-alpha = 3,709 +/- 1,409 pg/10(6) cells, IL-6 = 5,482 +/- 2,058 pg/10(6) cells, p < 0.005), and they returned to control values within 15 d. A similar pattern was observed during CMVP (TNF-alpha = 5,000 +/- 2,773 pg/10(6) cells, IL-6 = 12,280 +/- 3,939 pg/10(6) cells, p < 0.005), and values returned to control levels within 30 d. During BP, cytokine production values were higher than control values, but to a lesser extent than in AR and CMVP (TNF-alpha = 2,502 +/- 1,072, p < 0.05; IL-6 = 3,734 +/- 1,440, p < 0.005). In contrast, cytokine secretion during BO was not statistically different from that of control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

[Tracheobronchial healing after lung and heart-lung transplantations. Apropos of 64 anastomoses].

The authors report an analysis concerning the healing of tracheo-bronchial anastomoses after lung- and heart-lung transplantation. The present study includes 64 anastomoses selected from a total of 80 cases. Sixteen had to be excluded because of early post-operative death; none of these deaths was related to an air-way complication. Bronchial healing was assessed by bronchoscopic follow-up; the appearance of the suture-line was classified according to Couraud's grades. The initial reference was the examination at 2 weeks, which was compared to subsequent follow-up. At the initial assessment, 42 anastomoses were grade 1, 4 were grade II, and 18 were grade III. The subsequent anatomic result was satisfactory for 52 sutures (81%). The complications were malacia in 2 cases, stenoses treated with a stenting device in 4 cases, dehiscence in 6 cases. The duration of ischemia and postoperative mechanical respiratory support, as well as the proximal or distal site of the anastomosis appeared to be of significant prognostic value.

Adolescent↗
PubMed1993

[Bronchial provocation tests. Comparison of 2 inhalation methods].

This study was performed to compare two methods of aerosols delivery and inhalation in a bronchial provocation test with carbachol : the stocked method (S) where the aerosol is previously stocked in a spirometer bell before inhalation and the dosimeter method (D) where the aerosol is directly inhaled after nebulization. Fourteen subjects (seven normal and seven asthmatic) underwent bronchial challenges with the two techniques. Bronchial sensitivity was calculated on SRaw-dose response curves to carbachol. SGaw-dose response curves were also constructed and the slopes of these curves were used to measure bronchial reactivity. Within subjects sensitivity values were lower with the D method than with the S method (40 +/- 5 micrograms (S E) versus 450 +/- 50 micrograms respectively in asthmatics, 340 +/- 30 micrograms versus 2350 +/- 130 micrograms respectively in healthy subjects). Reactivity values were higher with the dosimeter method (2,7 +/- 0,7 x 10(-5) versus 27 +/- 4 x 10(-5) in healthy and 10 +/- 1 x 10(-5) versus 106 +/- 16 x 10(-5) in asthmatics). The dosimeter method had greater efficacy, was less time consuming and appeared to be a useful method for carrying out standardised non-specific bronchoprovocation test.

Adult↗
PubMed1993

EMG power spectrum of respiratory and skeletal muscles during static contraction in healthy man.

Changes in EMG power spectrum during isometric voluntary contraction maintained until exhaustion in the range of 20-80% MVC were studied in three skeletal muscles (adductor pollicis or AP, vastus lateralis, and medialis) and two respiratory muscles (diaphragm and rectus abdominis). Quantitative EMG analysis consisted of computation of the median frequency (MF) of power spectra and also the continuous measurement of EMG power in two bands of high (EH) and low (EL) frequencies using bandpass filters. This allowed the calculation of the H/L ratio and its time constant of decay rate (TC delta H/L) throughout the sustained static contraction. The main results were: (1) highly significant, positive correlations between TC delta H/L and the maximal MF changes and also the endurance time to fatigue; (2) EMG changes were determined early, within the first 10-20 s of contraction; and (3) EL always increased throughout the fatiguing isometric contraction, but EH changes markedly varied within the five muscle groups studied. These observations are discussed in terms of the differences in muscle fiber composition and also the variations in motor unit recruitment.

Abdominal Muscles↗
PubMed1993

Pulmonary function changes 100 days and one year after bone marrow transplantation.

The pulmonary function of patients receiving autologous or allogeneic bone marrow transplantation (BMT) was studied before, 100 days after and 1 year after BMT. The 117 patients studied before transplantation showed a slight reduction in average total lung capacity (TLC) and transfer coefficient (KCO). These reductions were related to haematological disease, previous pulmonary disease or irradiation, or use of toxic lung chemotherapy. Studies 100 days after BMT showed TLC and KCO decreases of 5% and 8%, respectively. These decreases were related to different factors in autologous and allogeneic BMT. The results were influenced by previous pulmonary status in autologous BMT patients and the occurrence of GVHD in allogeneic BMT patients. Seventy patients underwent pulmonary function testing 1 year after BMT. The decrease in TLC values was greater in autologous BMT than in allogeneic BMT patients (107 +/- 3% to 100 +/- 3% versus 113 +/- 3% to 112 +/- 2%, respectively) although TLC remained normal in both groups. KCO values dropped significantly in both populations. Relapse of the initial disease was an important factor impairing lung function in the autologous group. TLC and KCO changes were strongly related to mortality in both groups. These results emphasise the need for frequent pulmonary function tests after BMT to detect and quantify lung function changes.

Adult↗