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Biomedical subjects

R Moreno

Publications and source records attributed to R Moreno.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Reiter's syndrome exacerbated by indomethacin].

A 26-year-old man, with a personal history of drug abuse and positive serology for HIV, had Reiter's syndrome for six years. He experienced progressive worsening of his cutaneous lesions after initiation of indomethacin therapy. The skin lesions were almost completely resolved after the discontinuance of the drug and its reintroduction resulted in a similar deterioration. To our knowledge, indomethacin has not been reported to aggravate Reiter's syndrome. This case study documents anti-inflammatory drugs as possible causal factors for triggering Reiter's syndrome. Possible implicated mechanisms are also discussed.

Adult↗
PubMed1988

Weekly cuirass ventilation improves blood gases and inspiratory muscle strength in patients with chronic air-flow limitation and hypercarbia.

We studied the effects of an 8-h, once-a-week schedule of cuirass ventilation (CV) in 5 patients with advanced chronic air-flow limitation and chronic hypercarbia (PaCO2, 58.6 +/- 10.1 mm Hg; mean +/- SD). Repeated measurements of arterial blood gases, maximal inspiratory mouth pressure (P1max), 12-min walking distance, and respiratory cycle were performed during a 1-month run-in period. Quality of life and transdiaphragmatic pressure were measured once. All patients completed the planned 4-month study. Four of them were ventilated for longer periods because CV could not be discontinued at the end of the study. PaCO2 showed a significant fall starting during the first month; PaO2 significantly increased from the second month, whereas P1max significantly rose from the third month on. Maximal transdiaphragmatic pressure increased in the 2 patients with abnormal baseline values. The fall in PaCO2 was associated with an increase in tidal volume because of a longer inspiratory time. Significant improvements in quality of life and in the 12-min walking distance were observed. We conclude that weekly CV improves blood gases, inspiratory muscle strength, and clinical conditions of patients with chronic air-flow limitation and chronic hypercarbia, probably because of correction of chronic inspiratory muscle fatigue.

Blood Gas Analysis↗
PubMed1987

A rabbit model of hypersensitivity to plicatic acid, the agent responsible for red cedar asthma.

We describe a rabbit model for the study of the immunogenicity and allergenicity of plicatic acid (PA), the small molecular weight compound in western red cedar responsible for occupational asthma in exposed workers. Specific anti-PA IgE as well as IgG antibodies could be raised, depending on the method of immunization. The sensitized rabbits reacted to antigenic challenge with PA-protein conjugates intravenously, with increases in respiratory frequency and pulmonary resistance. This animal model may be used for the further elucidation of the mechanism of occupational asthma induced by small molecular weight chemical compounds.

Animals↗
PubMed1986

Inspiratory muscle function in unilateral diaphragmatic paralysis.

Pulmonary function has been extensively studied in unilateral diaphragmatic paralysis (UDP), but there is scarce information regarding inspiratory muscle function in this condition. We therefore studied inspiratory muscle function in 8 patients with UDP (Group 1: age 48.3 +/- 2.1 yr of age, means +/- SD) as well as in 7 patients with UDP and concomitant cardiopulmonary disease (Group 2: 60.6 +/- 13 yr of age). Twelve young normal subjects were also studied (32.3 +/- 7.7 yr of age). Maximal static transdiaphragmatic and inspiratory mouth pressure were measured at FRC. Gastric (Pga), esophageal (Pes), and transdiaphragmatic (Pdi) pressure swings were measured during quiet breathing. There was no difference in inspiratory muscle function in left-sided versus right-sided UDP. Paradoxical gastric pressure swings were observed in 4 patients from Group 1 and in 5 from Group 2. In 2 patients from Group 1 and 1 from Group 2, Pga did not change during quiet breathing. In the remaining 3 patients, Pga swings were similar to those observed in the normal subjects. Maximal Pdi was reduced in half of the patients from Group 1 and in all of the patients from Group 2. Maximal inspiratory pressure was below normal values in 2 patients from Group 1 and in all patients from Group 2. We conclude that unilateral diaphragmatic paralysis is associated with an abnormal pattern of use of respiratory muscles during quiet breathing, characterized by the use of intercostal and accessory inspiratory muscle or compensatory use of abdominal expiratory muscles. Inspiratory muscle strength was impaired in some of the patients, and it worsened when cardiopulmonary disease was present.

Adult↗
PubMed1986

In vivo human tracheal pressure-area curves using computerized tomographic scans. Correlation with maximal expiratory flow rates.

In order to develop a simple technique to measure in vivo pressure-area (P-A) curves of the extrathoracic trachea in humans, we studied 14 normal male subjects. Valsalva and Mueller maneuvers were performed at FRC, and tracheal cross-sectional area (TXSA) was measured using computed tomography. Extrathoracic tracheal transmural pressure (TMP) was obtained as airway opening minus atmospheric pressure (Pat). Tracheal "compliance" (TC) was measured on the "inflation" limb of the P-A curve. Tracheal compliance was not a significant predictor of maximal expiratory flow rates, and TXSA at zero TMP was a significant predictor of peak expiratory flow rate but not of FEV1 or Vmax50. P-A curves showed an unexpected configuration characterized by a plateau or an increase in TXSA with TMP lower than -15 cm H2O. P-A curves obtained in 5 subjects using extrathoracic esophageal pressure as tracheal external pressure instead of atmospheric pressure did not show a plateau or an increase in TXSA with Mueller maneuvers. In these 5 subjects, TC using esophageal pressure rather than Pat did not aid in the prediction of flow. We conclude that extrathoracic tracheal external pressure is not Pat because this pressure is probably affected by transmission of pleural pressure to the cervical interstitial tissue as well as by the contraction of cervical accessory inspiratory muscles. Therefore, true tracheal compliance cannot be simply measured since it requires placement of an esophageal balloon.

Adult↗
PubMed1985

Inspiratory muscle dysfunction and unexplained dyspnea in systemic lupus erythematosus.

The role of inspiratory muscle dysfunction in lung volume restriction and unexplained dyspnea was studied in 16 consecutive patients with systemic lupus erythematosus. Maximal mouth inspiratory pressure (PIM) and maximal transdiaphragmatic pressure (Pdi max) were measured. Pdi and its components were determined during quiet breathing. No significant association was found between the activity of the disease, several serologic markers, and the inspiratory muscle dysfunction. No specific anti-skeletal muscle antibody was found in these patients. Significant correlations were found between the degree of dyspnea and PIM (r = -0.69, P less than 0.01) and Pdi max (r = -0.75, P less than 0.001); however, dyspnea did not correlate with specific lung compliance. Vital capacity correlated significantly with the degree of dyspnea (r = -0.813, P less than 0.001) and with Pdi max (r = 0.544, P less than 0.05). No correlation was found between vital capacity and specific lung compliance. We conclude that inspiratory muscle dysfunction can be an important mechanism in the pathogenesis of the lung volume restriction and dyspnea in patients with systemic lupus erythematosus.

Adolescent↗
PubMed1985

Inspiratory muscle function in patients with severe kyphoscoliosis.

In 9 patients with severe kyphoscoliosis we studied inspiratory muscle function by measuring transdiaphragmatic pressure (Pdi) and its components: gastric (Pga) and esophageal (Pes) pressures during quiet breathing. Maximal Pdi and maximal inspiratory mouth pressure (Pimax) were also measured. The results showed that Pimax and Pdimax were significantly lower in patients than in normal subjects. During quiet breathing, all patients had positive swings in Pga, indicating an active contraction of the diaphragm, but Pes was significantly more negative, suggesting the recruitment of intercostal and accessory inspiratory muscles. We did not find significant correlations between Pimax, Pdimax, delta Pga/delta Pes, FVC, PaO2, or PaCO2 and the degree of spinal deformity. The FVC tended to correlate with Pimax (r = 0.63) and with Pdimax (r = 0.53). The Pdi correlated with PaO2 (r = 0.66) and with PaCO2 (r = -0.76; p less than 0.05). A significant correlation was also observed between Pimax and PaO2 (r = 0.785; p less than 0.05) and between Pimax and PaCO2 (r = -0.86; p less than 0.01). We conclude that impairment of inspiratory muscle function is related to the development of ventilatory failure in kyphoscoliosis.

Adult↗
PubMed1985

Acute effect of ketotifen on the dose-response curve of histamine and methacholine in asthma.

This study was designed to assess the acute effect of 1 mg of orally administered ketotifen on the dose-response curve to both histamine and methacholine, in 15 patients with bronchial asthma. From this curve we measured the concentration that produced a 20% fall in FEV1 (PC20) and reactivity, defined as the slope of the curve beyond the threshold dose. Results were analysed comparing the change in log PC20 and in reactivity before and after a double-blind administration of ketotifen and placebo. Ketotifen, compared to placebo, significantly increased the histamine PC20 (P less than 0.001) and reduced reactivity (P less than 0.001). After adjusting for starting FEV1 the difference of effect between ketotifen and placebo was still significant, although to a lesser degree (P less than 0.01). In contrast, ketotifen did not modify the methacholine dose-response curve. No significant changes were observed in FEV1 after ketotifen. The results suggest that acute administration of ketotifen has a selective action on histamine-activated pathways of bronchoconstriction.

Adolescent↗