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Biomedical subjects

I Sanchez

Publications and source records attributed to I Sanchez.

At least 19 recordsLinked to original sources
PubMed1992

Efficacy of salbutamol and ipratropium bromide in decreasing bronchial hyperreactivity in children with cystic fibrosis.

A proportion of patients with cystic fibrosis (CF) suffer from increased airway hyperreactivity but their response to bronchodilators is variable. Adrenergic agents may produce an increase, no change or a decrease in forced expiratory volume in 1 second (FEV1). We hypothesized that the variable response might be related to poor aerosol distribution caused by the presence of secretions. Therefore, in 11 children with CF and airway hyperreactivity the influence of pretreatment with either 0.9% saline, salbutamol, or ipratropium bromide on the methacholine challenge test was evaluated in a double-blind, randomized, cross-over study. FEV1 (mean +/- S.E.) did not change following pretreatment with saline, salbutamol, or ipratropium (1.64 +/- 0.22, 1.63 +/- 0.16 and 1.67 +/- 0.19, respectively). All patients demonstrated airway hyperreactivity with a PC20 below 8 mg/mL (geometric mean, 0.41 mg/mL) after saline pretreatment. Salbutamol inhalation significantly increased the PC20 to 1.24 mg/mL (P less than 0.01), but ipratropium bromide was found to be even more effective than salbutamol (PC20 = 7.37 mg/mL) (P less than 0.0001). We conclude that the variable response to bronchodilator is not secondary to impaired aerosol distribution since ipratropium bromide effectively blocked the response to methacholine. The improvement in PC20 without a change in baseline FEV1 following salbutamol suggests that the adrenergic agent altered the contractile mechanism of smooth muscle.

Adolescent↗
PubMed1992

Response to inhaled bronchodilators and nonspecific airway hyperreactivity in children with cystic fibrosis.

We tested the hypothesis that children with CF who have a significant response to bronchodilator (BD) would respond positively to standard methacholine (Mch) challenge. Our objective was to correlate the response to BD with the concentration that produced a 20% fall (PC20) in forced expiratory volume in 1 second (FEV1). We studied 22 patients (12 males), aged 10.5 +/- 0.7 years (mean +/- SE), with a Shwachman-Kulczycki score 82 +/- 2.6 and baseline FEV1 of 80 +/- 4.5% predicted. Baseline expiratory flows, static lung volumes, and airway resistance were measured before and 30 min after inhaled salbutamol. On a separate day, within 2 weeks, a Mch challenge was given, with doubling concentrations from 0.03 to 8.0 mg/mL. A positive challenge was defined as a PC20 less than or equal to 2.0 mg/mL, and a positive response to BD as a greater than 6% of FEV1 increase. Mch challenge yielded 17 responders (R) with a PC20 of 0.5 +/- 0.1 mg/mL, and 5 nonresponders (NR) with a PC20 of 8.8 +/- 2.9 mg/mL. Baseline FEV1 was 77 +/- 5.3% predicted in R compared to 89 +/- 6.3% in NR (P = less than 0.001). History of springtime rhinitis was positive in 9/17 R and 2/5 NR. No significant correlation was found between baseline FEV1 and PC20, or between change in FEV1 post-BD and PC20. A greater than 6% increase in FEV1 was seen in 14/17 R (83% sensitivity) and in none of the 5 NR (100% specificity). In R, 8/17 patients had baseline FEV1 less than 80% predicted, compared to 1/5 in NR.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Rigid bronchoscopy in the pediatric age group: diagnostic effectiveness.

Over a 15-year period, 277 diagnostic bronchoscopic procedures were carried out at the Winnipeg Children's Hospital using rigid bronchoscopic instrumentation. The objective of the review is to examine contribution to final diagnosis made by the procedure. The patient population included 60% male and 40% female patients ranging from the first day of life to 18 years (mean age, 6 years). Indications for bronchoscopy fell into two large groups, including 60% of patients with evidence of lower airway disease and 30% of patients with evidence of upper airway obstruction. In patients with upper airway obstruction, half were found to have a congenital underlying cause and half were due to an acquired lesion. In 85% of patients, a specific diagnosis was reached and this proved to correlate positively with the preoperative diagnosis in 80% of patients and negatively in 20%. Definitive treatment in patients with upper airway obstruction included surgical intervention in one third of patients. Patients with lower airway disease were diagnosed as having consolidation in 43%, atelectasis in 39%, and bronchiectasis in 18%. Disease localized most frequently to the left lower and right upper lobes and in only 10 of 168 patients was a congenital cause determined. Among 168 patients, 30 had surgical treatment as the definitive management with the majority of patients treated medically. Bronchoscopy was shown to contribute to diagnosis in 88% of patients examined. Bronchoscopy was carried out with a complication rate of 3% and no mortality.

Adolescent↗
PubMed1992

Tracheal sounds in upper airway obstruction.

A boy with subglottic narrowing secondary to laryngotracheitis presented with noisy breathing. Acoustic measurements of tracheal sounds at standardized air flows correlated well with the clinical course and with spirometric assessments. This indicates the potential value of respiratory sound characterization in patients with upper airway obstruction.

Child↗
PubMed1992

Effects of betamethasone and thyroid hormone on fetal rat lung maturation in vivo.

We studied the effect of maternal administration at various intervals of betamethasone, triiodothyronine (T3), or both, on fetal rat lung maturation. T3 alone did not enhance choline incorporation to phosphatidylcholine by 20-day fetal lung explants, or morphometric lung maturation. Betamethasone, and betamethasone plus T3, increased both of those parameters over control and T3 values. However, addition of T3 offered no advantage over administration of betamethasone alone. Significant enhancement of morphometric lung maturation was already present after only 24 h of exposure to beta-methasone, or to the combination of hormones. However, choline incorporation to phosphatidylcholine only increased significantly by 36 h of exposure to betamethasone with or without T3.

Animals↗
PubMed1991

Respirosonography in infants with acute bronchiolitis.

Respirosonography was used to analyze lung sounds and breathing patterns in 16 infants with acute bronchiolitis who were treated with nebulized salbutamol (albuterol). Wheezing was measured as a proportion of respiratory time (time spent wheezing [Tw]/total time [Ttot]). A decrease of 10% or greater in Tw/Ttot or a reduction in Tw/Ttot to less than 2% was considered a positive response to salbutamol. Seven infants responded to the salbutamol, and nine did not. In responders, Tw/Ttot decreased from 47% +/- 26% to 20% +/- 25% (mean +/- SD), and the respiratory rate decreased from 65 +/- 8 to 57 +/- 7 breaths per minute. In nonresponders, mean Tw/Ttot either did not change or increased, and there was no significant change in respiratory rate (53 +/- 10 breaths per minute before salbutamol inhalation and 56 +/- 9 breaths per minute after salbutamol inhalation). Complex repetitive waveforms, different from the sinusoidal waveforms of typical wheezing, were observed in 14 of 16 infants. Our findings add supportive evidence to the clinical impression that some infants with bronchiolitis respond to salbutamol. Respirosonography provides a noninvasive method for objective clinical assessment of young, wheezy children.

Acoustics↗
PubMed1991

Sleep quality in children with asthma treated with theophylline or cromolyn sodium.

The effect of theophylline and cromolyn sodium on sleep was studied in 10 children with asthma who were 10 to 17 years of age (mean 13.5 +/- 2.4 years). Theophylline or cromolyn sodium was taken for 14 days in a double-blind, crossover, placebo-controlled trial. Theophylline blood levels before sleep were 10.2 +/- 4 micrograms/ml during the theophylline period. There was no difference in pulmonary function between the two periods. Theophylline did not disrupt sleep as measured by sleep latency, total sleep time, sleep efficiency, movement time, microarousals, and arousals. Apneic episodes (greater than or equal to 10 seconds) were of central origin and less frequent during the theophylline period (p less than 0.05). Arterial oxygen desaturation (greater than 5% decrease from baseline saturation when awake) was less frequent during the theophylline treatment (p less than 0.05). We conclude that theophylline treatment of the children's asthma did not disrupt sleep and appeared to have a protective effect in regard to apnea, hypopnea, and arterial oxygen saturation.

Adolescent↗
PubMed1991

Effect of theophylline on lung function tests, sleep quality, and nighttime SaO2 in children with cystic fibrosis.

The effect of theophylline (T) was studied in 12 children with cystic fibrosis (CF) (seven males and five females) aged 7 to 17 yr (mean, 11.8 +/- 2.8). T or placebo (P) was taken for 10 days in a double-blind, crossover controlled trial. During Nights 9 and 10 of each study period, the subjects slept in a sleep laboratory, where complete polysomnographs were recorded. Patients were subdivided according to T blood levels above or below 10 micrograms/ml: five children had a mean serum T of 11.7 +/- 1.6 micrograms/ml (Group 1), and seven patients had serum T levels of 6.7 +/- 1.5 micrograms/ml (Group 2). There was no difference in pulmonary function between the two periods, but Group 2 had significantly better baseline lung function (p less than 0.01). During sleep while on T, Group 1 had a higher mean SaO2 (93.1 +/- 0.3% T versus 90.7 +/- 0.3% P; p less than 0.0001), less time with a decrease greater than 5% in SaO2 from baseline (43.7 +/- 7.9 min T versus 85.8 +/- 7.9 min P; p less than 0.01), and a lower heart rate (HR), (77.9 +/- 5.1 bpm T versus 86.1 +/- 4.2 bpm P; p less than 0.01). Group 2 did not show differences in these parameters. T significantly disrupted sleep as measured by sleep efficiency and total wake time independently of serum level (p less than 0.01). There was no significant effect of T on the incidence of apnea, hypopnea, or body movements during sleep.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1990

Reduction of primary postoperative adhesion formation under calcium channel blockade in the rabbit.

Preliminary studies in a hamster model have demonstrated calcium channel blocking agents to be potent inhibitors of primary post-traumatic peritoneal adhesion formation. The present investigation was designed to extend these observations to an extensively studied model, the rabbit, and to evaluate the optimal route of administration of these drugs for intraabdominal surgery. Rabbits were subjected to a standardized traumatic lesion of the left uterine horn. Subsequently, animals were divided into the following treatment groups: subcutaneous vehicle control (n = 7), intraperitoneal (ip) vehicle control (n = 8), subcutaneous verapamil treatment (n = 6), low-dose (2.5 micrograms/kg/hr) ip verapamil treatment (n = 10), and high-dose ip (25 micrograms/kg/hr) verapamil treatment (n = 6). All animals were reexplored at 1 week postop for evaluation of adhesion formation (scale: 0 to 4+). Calcium channel blockade-treated animals formed significantly fewer adhesions (0.45) than controls (3.93) (P less than 0.01). There was no significant difference between animals treated with sc with verapamil sc and those treated with low- or high-dose verapamil ip (0.33 vs 0.20 vs 1.0). These data confirm our preliminary results, suggesting that calcium channel blockade potently modulates peritoneal healing and regeneration. Furthermore, intraperitoneal delivery and systemic administration appear equipotent in this model. Further study of these agents as potential adjuvants for intraperitoneal surgery is indicated.

Abdomen↗
PubMed1990

Detergent-based isolation of marginal bands of microtubules from nucleated erythrocytes.

We have developed a new, detergent-based method for the isolation of marginal bands (MBs) of microtubules from non-mammalian vertebrate erythrocytes. The critical step in MB isolation is selective removal of the "membrane skeleton" network (MS), within which the MB is enclosed. To test potential MS solubilizing agents systematically, we prepared dogfish (Mustelus canis) erythrocyte cytoskeletons in the presence of protease inhibitors and stored them at -20 degrees C in medium containing 50% glycerol and 10 microM taxol to stabilize the MB. Using this as a standard starting material, we found that low concentrations of sodium dodecyl sulfate (SDS) (0.025-0.1%) in the presence of Triton X-100 (0.1-0.4%) released both MBs and nuclei intact from cytoskeletons. Either detergent alone was ineffective. MB release from cytoskeletons was blocked by excess Triton X-100 and slowed by glycerol, and this was useful for stopping the release reaction during quantitative time-course studies. Most MBs (greater than 90%) were liberated from cytoskeletons in 5 to 30 min, depending upon detergent concentrations and other conditions, and they were sufficiently stable for mass isolation by differential centrifugation. Added standard proteins were not proteolyzed during MB release, nor was release blocked by protease inhibitors, indicating that endogenous proteases were not involved. As observed in thin sections and negatively stained whole mounts (transmission electron microscopy) and in critical-point dried preparations (scanning electron microscopy), the isolated MBs consisted principally of bundled microtubules, with some additional adhering material. SDS-polyacrylamide gel electrophoresis showed the isolated MBs to be composed primarily of four tubulin region polypeptides, with the same stoichiometry as in the whole cytoskeleton. As determined by immunofluorescence microscopy, isolated MBs bound antibody to both chicken brain and erythrocyte tau, in addition to anti-tubulin. Thus, proteins of the tau family may be involved in bundling of MB microtubules. Unlike previous MB isolation methods, that employed here is applicable to erythrocytes of diverse species, including the marine toad (Bufo marinus) and the chicken (Gallus domestica), both of which should be of value for comparative studies.

Animals↗
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↗
PubMedDate not supplied

Limit for qualitative detection of benzoylecgonine in urine using EMIT reagents and the Hitachi 705 automatic analyzer.

The limit of detection for the cocaine metabolite (hydrolysis product), benzoylecgonine, using Syva EMIT reagents and the Hitachi 705 automatic analyzer has been found to be 10 ng/mL at the 99% confidence level. For this determination 30 controls were prepared from a single urine pool known to be negative for cocaine metabolite. Urine samples of 90 patients were found to be drug-free when analyzed by selected ion monitoring gas chromatography/mass spectrometry for ecgonine methyl ester and benzoylecgonine at sensitivities of less than 0.4 ng/mL and 1.3 ng/mL, respectively. To test matrix effects on the limit of detection, these samples were screened with the Hitachi 705. Results for eight of the known negative samples fell above the 10-ng/mL limit of detection while only one presumptive positive resulted at an arbitrary 20-ng/mL cutoff. Detection limits were also determined using 20 different negative patients' urine samples fortified with benzoylecgonine. At the 99% confidence level using EMIT d.a.u. and 705 reagents the detection limits were found to be 44 ng/mL and 35 ng/mL, respectively. It was found that 62% of patients' samples positive for benzoylecgonine fell below the 300-ng/mL cutoff and above a cutoff at 50 ng/mL.

Cocaine↗
PubMedDate not supplied

[Mumps uveitis].

Explore the source record for details and available documents.

Female↗