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M Montes de Oca

Publications and source records attributed to M Montes de Oca.

At least 19 recordsLinked to original sources
PubMed2005

[Changes in exercise tolerance, health related quality of life, and peripheral muscle characteristics of chronic obstructive pulmonary disease patients after 6 weeks' training].

OBJECTIVE: This study was designed to assess changes in skeletal muscle characteristics after 6 weeks' high-intensity physical training of patients with moderate to severe chronic obstructive pulmonary disease (COPD) and to determine how the changes were related to improvements in exercise tolerance and health related quality of life (HRQL). PATIENTS AND METHODS: Ten patients with a mean (SD) age of 60 (10) years and a forced expiratory volume in 1 second of 32% (9%) were enrolled. The effect of training on the 6-minute walk test, HRQL questionnaires, and skeletal muscles was examined for the 8 patients who completed the program. The structural and chemical characteristics of skeletal muscles before and after training were studied in vastus lateralis muscle biopsies. RESULTS: Training significantly modified the 6-minute walk test (P<.01), HRQL (P<.05), and citrate synthetase activity (P<.05). Changes in distances walked during the 6-minute walk test were significantly related to changes in the mean area of fibers (r=0.81). CONCLUSIONS: The results of this study indicate that 6 weeks of high-intensity physical training of COPD patients produces moderate changes in skeletal muscles which could partly explain improvements observed in exercise tolerance after respiratory rehabilitation.

Aged↗
PubMed2005

Skeletal muscle inflammation and nitric oxide in patients with COPD.

In chronic obstructive pulmonary disease (COPD) the presence of systemic inflammation has been associated with peripheral muscle abnormalities and weight loss. To study whether inflammatory factors are important in these processes, the present study compared the skeletal muscle levels of nitrite, nitrate, nitrotyrosine, neuronal, endothelial and inducible nitric oxide synthases (nNOS, eNOS, and iNOS, respectively), and inflammatory markers (tumour necrosis factor (TNF)-alpha, CD154 and CD163) in 15 patients (forced expiratory volume in one second 43+/-11%) and 14 controls. All these markers were also compared between patients with normal and low body weight. Nitrite (12.5+/-2.6 versus 17.0+/-3.4 micromol.mg(-1) protein), nitrate (20.7+/-2.4 versus 24.4+/-4.5 micromol.mg(-1) protein) and eNOS (31.9+/-4.6 versus 43.6+/-7.5 ng.mg(-1) protein) were lower in COPD patients than in controls. Nitrotyrosine (25.6+/-5.4 versus 6.6+/-3.3 ng.mg(-1) protein), iNOS expression (32+/-9.5 versus 7.16+/-2.7 ng.mg(-1) protein), TNF-alpha (257+/-160 versus 48.3+/-4.4 pg.mg(-1) protein) and CD163 (6.4+/-2.1 versus 0.8+/-0.4 ng.mg(-1) protein) were higher in COPD patients than in controls. CD154 levels were 15.7+/-7.0 ng.mg(-1) protein in COPD patients and undetectable in controls. Similar levels of all these markers were observed in COPD patients with normal and low body weight. In conclusion, these findings suggest the presence of an inflammatory process in the muscle tissue of chronic obstructive pulmonary disease patients, and argue in favour of its participation in the pathogenesis of skeletal muscle abnormalities.

Aged↗
PubMed2004

[Antifungal susceptibility of Acremonium species using E-test and Sensititre].

Filamentous fungi have become a common cause of severe infections, especially in immunocompromised patients. In recent years, the number and diversity of the infections caused by Acremonium species have increased and numerous species have been implicated. As is the case for most emerging pathogens, the optimal therapeutic approach to Acremonium species remains to be determined. We used two methods to determine the in vitro susceptibility to amphotericin B, itraconazole and fluconazole for 15 clinical isolates of eight different species of Acremonium. The MICs were determined according to protocol M38-A of the National Committee for Clinical Laboratory Standards (NCCLS) document, using the Sensititre and E-test microdilution methods. Amphotericin B was effective in vitro for few species using the Sensititre method. However, high MICs were obtained with E-test. Fluconazole and itraconazole were ineffective according to both methods. Acremonium species are generally resistant to the most commonly used antifungal agents. Consequently, Acremonium susceptibility testing is recommended to assist in choosing adequate treatment of infections caused by this filamentous fungus.

Acremonium↗
PubMed2003

[Evaluation of exercise tolerance in patients treated with praziquantel for chronic schistosomiasis with no signs of cardiopulmonary impairment].

OBJECTIVE: The purpose of this study was to evaluate whether a progressive cycle ergometer test (PCET) can detect minimal functional abnormalities that might indicate compromise of the pulmonary vascular bed in patients treated with praziquantel for chronic schistosomiasis who have no clinical signs of cardiopulmonary impairment. PATIENTS AND METHOD: We studied 9 patients (whose mean (SD) age was 38 (18) years and 10 control subjects aged 32 (14) years. Both groups were evaluated by spirometry and a PCET to determine maximum oxygen consumption, heart rate, minute ventilation and gas exchange. Echocardiograms were used to rule out the presence of associated heart disease. RESULTS: Lung function was similar among patients and controls. Slight decreases in maximum oxygen consumption and heart rate reserve were observed with effort during the PCET, with normal respiratory response. No echocardiographic abnormalities that might indicate the presence of pulmonary vascular occlusive disease were observed. CONCLUSIONS: The results showed that the resting lung function is normal in these patients. However, there was a slight decrease in exercise tolerance, probably related to physical detraining. The data obtained during exercise indicated that pulmonary vascular occlusive disease is unlikely in these patients. Abnormalities may appear in later stages of the disease or in patients who do not receive early medical treatment.

Adult↗
PubMed2001

[Chronic obstructive pulmonary disease: evaluation of exercise tolerance using three different exercise tests].

The clinical usefulness of simple exercise tests in patients with chronic obstructive pulmonary disease (COPD) continues to give rise to debate. Questions remain about whether these tests assess maximum effort or only exercise tolerance (submaximal effort). To determine the levels of stress reached during the six-minute walking (6MW) test and stair climbing (SC) test and their relation to maximum aerobic capacity, 50 patients with COPD (FEV1 49 +/- 19%) were studied. Data collected included spirometric variables and VO2, heart rate (HR), ventilatory response and dyspnea during the progressive effort ergometric cycle (PEEC) test. Two 6MW and SC tests were completed on two separate days, with distance, number of steps, HR and dyspnea recorded. HR was higher during the PEEC test. Among the simple tests, SC caused a faster HR than did the 6MW test. Likewise, a significant linear relation was observed between VO2/kgpeak during the 6MW test (r2 = 0.27; p < 0.05) and the SC test (r2 = 0.33; p < 0.01). We therefore conclude that exercise tolerance in patients with COPD can be evaluated using simple stress tests. The SC test is probably the best simple way to determine maximum functional capacity, whereas the 6MW test can be reserved for measurement of exercise tolerance.

Aged↗
PubMed2000

Respiratory muscle recruitment and exercise performance in eucapnic and hypercapnic severe chronic obstructive pulmonary disease.

If chronic hypercapnia in patients with severe COPD occurs as a consequence of respiratory muscle (RM) weakness or fatigue, we would expect that ventilatory muscle recruitment (VMR) and exercise performance in stable hypercapnic patients would differ from those in eucapnic patients. We evaluated exercise performance and RM function at rest and during exercise in 19 eucapnic (PCO(2) 40 +/- 3 mm Hg), and 13 hypercapnic (PCO(2) 52 +/- 10 mm Hg) patients with severe COPD. A metabolic cart was used to determine V E, V O(2), V CO(2), and HR. Gastric (Pg) and esophageal (Ppl) balloons were used to measure Pg, Ppl, and Pdi. Ventilatory muscle recruitment pattern (VMR) was partitioned using end-inspiratory and end-expiratory Pg and Ppl. Hypercapnic patients had lower FEV(1) (0.60 +/- 0.24 versus 0.95 +/- 0.31 L, p < 0.001), MVV (28 +/- 11 versus 41 +/- 13 L, p < 0.001), resting PO(2) (61 +/- 11 versus 70 +/- 11 mm Hg, p < 0.001), peak PO(2) (60 +/- 20 versus 75 +/- 22 mm Hg, p < 0.005), and V E(max) (24 +/- 10 versus 32 +/- 12 L/min, p < 0.001). Patients in both groups had similar FRC (5.7 +/- 1.6 versus 5.0 +/- 1.5 L), V O(2)max (0.58 +/- 0.30 versus 0.76 +/- 0.32 L/min), Watts (45 +/- 48 versus 71 +/- 59), V E/MVV (88 +/- 33 versus 79 +/- 14), and HRmax (117 +/- 17 versus 128 +/- 18 beats/min). PI(max) (67 +/- 28 versus 65 +/- 32 cm H(2)O) and PE(max) (98 +/- 34 versus 96 +/- 40 cm H(2)O) were also similar in both groups. VMR (DeltaPg/DeltaPpl) at rest (-0.28 +/- 0.51 versus 0 +/- 0.35) and during exercise (0.4 +/- 0.2 versus 0.39 +/- 0.15) was equally affected in both groups. We conclude that exercise capacity and ventilatory muscle recruitment are similarly impaired in eucapnic and hypercapnic patients with severe COPD. These findings make inability of the lung to increase ventilation and not respiratory muscle dysfunction a more attractive explanation for CO(2) retention in stable hypercapnic patients.

Aged↗
PubMed1999

Ventilatory drive at rest and perception of exertional dyspnea in severe COPD.

BACKGROUND: The reasons for exertional dyspnea in severe COPD are not well established, but they are not solely related to the mechanical load. We tested the hypothesis that breathlessness may be determined, in part, by the response of an individual's central output. METHODS: In 26 patients with severe COPD (FEV1 < 50% predicted) and 22 matched control subjects, we assessed at rest the ventilatory and mouth occlusion pressure (P0.1) response to hyperoxic progressive hypercapnia. At rest and during a symptom-limited exercise test, routine cardiopulmonary variables were measured, and respiratory muscle function was evaluated using esophageal and gastric pressure. Dyspnea was assessed with a visual analog scale. RESULTS: Dyspnea with or without leg discomfort limited exercise in 73% of patients. Peak exercise dyspnea correlated only with dyspnea at rest (r = 0.5, p < 0.008) and P0.1 response to CO2 (deltaP0.1/delta[end-tidal PCO2]PETCO2) (r = 0.48, p = 0.02). Multiple regression analysis including resting and exercise data as independent variables revealed that 47% of the variance for dyspnea at peak exercise was explained by a model including dyspnea at rest and deltaP0.1/deltaPETCO2. Again, deltaP0.1/deltaPETCO2 was the only predictor for the change in dyspnea from rest to peak exercise (delta Dyspnea, r2 = 0.28, p = 0.005). There was no correlation between exercise dyspnea and any metabolic variable, pulmonary function, or respiratory muscle function test. CONCLUSION: In severe COPD, exertional dyspnea is not simply related to respiratory muscle load or mechanical impairment, but also to an individual's central motoneural output to the respiratory system.

Adult↗
PubMed1998

Mouth occlusion pressure, CO2 response and hypercapnia in severe chronic obstructive pulmonary disease.

The resting mouth occlusion pressure 0.1 s after onset of inspiration (P0.1) and minute ventilation (V'E) and their response to CO2 in patients with chronic obstructive pulmonary disease (COPD) remain controversial. The ventilatory drive and the factors that predict resting arterial CO2 tension (Pa,CO2) were studied in 19 eucapnic and 14 hypercapnic severe COPD patients, and 20 controls. The CO2 response was evaluated by the Read technique. The V'E, and P0.1 as a function of end-tidal CO2 tension (Pet,CO2) was used to study the ventilatory (deltaV'E/deltaPet,CO2) and P0.1 response (deltaP0.1/deltaPet,CO2). In the patients, respiratory muscle function and pleural occlusion pressure 0.1 s after onset of inspiration (Ppl,0.1) were evaluated with simultaneous measurement of pleural (Ppl) and gastric (Pga) pressures. Hypercapnic patients had lower forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and arterial O2 tension (Pa,O2). Resting P0.1 was higher in patients than in controls, whereas deltaP0.1/deltaPet,CO2 was similar in the three groups. There was no difference in resting P0.1 (3.6+/-2.0 versus 4.3+/-2.8 kPa (2.7+/-1.5 versus 3.2+/-2.1 cmH2O), p=0.2) and Ppl,0.1 (1.4+/-2.3 versus 5.2+/-3.3 kPa (4.08+/-1.7 versus 3.9+/-2.5 cmH2O), p=0.22) between eucapnic and hypercapnic COPD, whereas deltaV'E/deltaPet,CO2 was lower in the hypercapnic group (0.29+/-0.24 versus 0.66+/-0.5 L x min(-1) x kPa, p<0.001). By logistic regression only FEVI and increased diaphragmatic load, and not respiratory drive, predicted resting Pa,CO2. Irrespective of CO2 level, baseline central drive (represented by the mouth occlusion and pleural pressures) and CO2 response are preserved in most patients with severe chronic obstructive pulmonary disease. Effective ventilation is inadequate in the more severely obstructed patients and this results in hypercapnia. Neuroventilatory coupling failure is an attractive explanation for chronic hypercapnia in these patients.

Aged↗
PubMed1997

Lung reduction surgery in severe COPD decreases central drive and ventilatory response to CO2.

BACKGROUND AND OBJECTIVES: Lung volume reduction surgery (LVRS) improves ventilatory function in selected patients with severe COPD. The reasons for the observed benefits include the following: increased elastic recoil, improved airflow, and lesser dynamic hyperinflation and decreased lung volumes. We reasoned that these changes could also alter respiratory drive. METHODS: Respiratory central drive was prospectively assessed using the mouth occlusion pressure (P0.1), and the P0.1 response to increasing CO2 (P0.1/PETCO2 [end-tidal CO2 pressure]), in eight sequential patients before and 3 to 5 months after LVRS. Results were compared with those from 13 control subjects. RESULTS: LVRS decreased total lung capacity from 7.44+/-1.8 L to 5.92+/-1.3 L (p<0.05) and residual volume from 4.97+/-1.5 L to 3.56+/-1.1 L (p<0.05). It also significantly improved FEV1 from 0.85+/-0.26 L to 0.99+/-0.26 L (p<0.05). Baseline P0.1 (3.4+/-1.8 vs 1.4+/-0.4 cm H2O, p<0.01) and P0.1/PETCO2 (0.24+/-0.07 vs 0.11+/-0.04 cm H2O/mm Hg, p<0.05) were higher in patients than in control subjects. After LVRS, P0.1 decreased from 3.4+/-1.8 to 1.3+/-0.75 cm H2O (p<0.01) and P0.1/PETCO2 from 0.24+/-0.07 to 0.16+/-0.06 cm H2O/mm Hg (p<0.05). These postoperative values were similar to those of control subjects. There were no correlations between changes in the factors known to influence central drive (PaO2, PaCO2, age, weight, height, FVC, and FEV1) and changes in P0.1. CONCLUSIONS: We conclude that decreased ventilatory drive should be added to the list of benefits of LVRS, and may help explain the symptomatic improvement reported by many patients after this surgery.

Age Factors↗
PubMed1997

[Progress of respiratory muscle dysfunction in patients with severe chronic obstructive disease].

The altered function of respiratory muscle function in chronic obstructive pulmonary disease (COPD) has been documented by short term studies but not by prospective follow-up. To evaluate the progression of muscle dysfunction and its relation to hyperinflation, air flow obstruction and generalized muscle weakness, we studied seven patients upon admission and 10 to 25 months later. We measured peak inspiratory (PImax) and expiratory (PEmax) pressures in the mouth, peak pleural inspiratory pressure (Pplimax) and peak transdiaphragmatic pressure (Pdimax). Pdimax was measured using gastric (Pg) and esophageal (Ppl) balloons. The slope of excursion of Pg and Ppl measured at the end of inspiration and expiration (Pg/Ppl) was used to assess respiratory muscle recruitment. Nutritional status was indexed as the ratio of weight to height (W/H). FEV1 remained unchanged (1.0 +/- 0.1 to 0.8 +/- 0.3 L), while functional residual capacity (FRC) increased from 7.1 +/- 1.0 to 8.9 +/- 2.0 L (p < 0.05). W/H, PImax, Pplimax and PEmax remained unchanged, while Pdimax decreased significantly from 83 +/- 35 to 47 +/- 16 cmH2O. Diaphragm loading (TTDI and Pdi/Pdimax) were found to increase and Pg/Ppl shifted toward increased use of accessory muscles. The last finding was significantly related to changes in FRC (r = 0.87; p < 0.05). We conclude that diaphragm function deteriorates progressively in patients with severe COPD, even though overall inspiratory muscle strength is preserved, apparently as a consequence of the effect of mechanical factors (hyperinflation) but not of air flow obstruction or generalized muscle weakness.

Data Interpretation, Statistical↗
PubMed1996

Respiratory muscle and cardiopulmonary function during exercise in very severe COPD.

Chronic obstructive pulmonary disease (COPD) is thought to limit exercise capacity through a decreased ventilatory reserve, with cardiovascular factors playing a minimal role. We assessed respiratory muscle (RM) and cardiopulmonary function during exercise in very severe COPD (FEV1 0.79 +/- 0.17 L). We determined minute ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2), heart rate (HR), respiratory rate (RR), and O2 pulse with a metabolic cart. RM function was assessed from esophageal and gastric pressures. Dyspnea was assessed with a visual analog scale (VAS). Exercise capacity (peak VO2 = 36 +/- 31%), ventilatory reserve (VE/maximum voluntary ventilation [MW] = 89 +/- 31%), HR = 76 +/- 15%, and O2 pulse (O2Pmax = 45 +/- 15%) were abnormal. Peak VO2 correlated with O2Pmax(r = 0.82), the change in end-inspiratory pleural pressure (deltaPpli) (r = -0.74), maximal transdiaphragmatic pressure (Pdimax) (r = 0.68), and VEmax (r = 0.58). There were similar correlations with exercise endurance time. Multiple regression analysis revealed O2Pmax to be the best predictor of peak VO2. Thereafter, only VEmax and deltaPpli remained significant (r2 = 0.87). O2Pmax correlated with inspiratory muscle function (Pplimax, r = -0.58; Pdimax, r = 0.53; deltaPpli, r = -0.47; and PImax, r = -0.47). By multiple regression analysis, the predictors of O2Pmax were Pplimax and deltaPpli (r2 = 0.47). In very severe COPD, the impressive swings in intrathoracic pressure resulting from deranged ventilatory mechanics are the most likely cause of exercise limitation and reduced O2 pulse. The contributions of factors such as deconditioning, hypoxemia, and concurrent heart disease remain unknown.

Aged↗
PubMed1993

Childhood-onset systemic lupus erythematosus: antiphospholipid antibodies in 37 patients and their first-degree relatives.

OBJECTIVE: Antiphospholipid antibodies (aPL) are noted with increased frequency in patients with systemic lupus erythematosus (SLE). The main manifestations found to be associated with aPL are arterial and venous thrombotic events, thrombocytopenia, and recurrent pregnancy loss. This study is an attempt to define the incidence of aPL in patients with childhood-onset SLE and in their relatives and to correlate their presence with clinical manifestations, and especially, to evaluate the risk of thrombosis in aPL-positive subjects. METHODOLOGY: We studied 37 unrelated patients and 107 of their first-degree relatives. VDRL, IgG and IgM anticardiolipin, and IgG antiphosphatidylethanolamine antibodies were studied in all probands during periods of clinical remission and in first-degree relatives at the time of interview. Lupus anticoagulant had only been studied in probands during an SLE flare-up. RESULTS: Thirty-eight percent of probands and 19% of relatives were positive for at least one aPL, with little overlap between the different aPL studied. -No aPL-negative proband developed thrombosis. Two of the aPL-positive probands had thrombotic events before testing, and a third one showed thrombosis after testing. Only two probands had high levels of IgG aCL and showed thrombosis. The occurrence of aPL positivity in relatives was not always related to its presence in probands. None of the aPL-positive relatives had had thrombosis, but recurrent fetal loss was noted in one aPL-positive mother with SLE. Although there was a high frequency of SLE, SLE-like disease, auto-immune disorders or positive serological findings for lupus in first-degree relatives, many of these relatives did not test positive for aPL. CONCLUSION: The high levels of IgG aCL may be considered a risk factor for thrombosis. Findings in relatives suggest a multifactorial origin for autoimmune disease and antibody production.

Abortion, Habitual↗
PubMed1991

[Unfavorable outcomes in disseminated lupus erythematosus in children. Cooperative study in the Paris region].

Pediatric cases of systemic lupus erythematosus with an unfavorable outcome (terminal renal failure requiring chronic hemodialysis, or death) assembled during a retrospective multicenter study of pediatric SLE in the Paris metropolitan area were analyzed. Seven patients (6 girls, 1 boy) were entered into a chronic hemodialysis program. Four had diffuse proliferative glomerulonephritis, the pattern of glomerular disease classically responsible for end-stage renal failure. The other three patients had membranous glomerulonephritis with active segmental lesions, a form of glomerulopathy whose severe prognosis deserves to be emphasized. Nine other patients (8 girls, 1 boy) died. In six patients, death occurred as a result of a flare with malignant hypertension and progressive renal failure (1 case), pancreatitis (1 case), encephalopathy (2 cases) or cardiomyopathy (2 cases). An infectious disease (tuberculosis, mumps) was apparently the cause of the two cases of encephalopathy. One girl died as a result of a hemorrhagic syndrome with a cerebral hematoma. Two other girls died at home. Overall, among 111 children with SLE 14% had an unfavorable outcome. Sex and age at onset seemed to have no bearing on prognosis. Patients with renal involvement were apparently more likely to have an unfavorable outcome. Lastly, although the influence of ethnic origin is unproven, children living in foreign countries of French overseas territories, but treated in France have an increased risk for unfavorable outcomes.

Adolescent↗