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Biomedical subjects

M Schatz

Publications and source records attributed to M Schatz.

At least 55 records · Page 3Linked to original sources
PubMed1992

Prevalence of dust mites in the homes of people with asthma living in eight different geographic areas of the United States.

The density and species prevalence of dust mites were determined at various times over a 5-year-period in 252 homes of dust mite sensitive people with asthma who lived in eight geographic areas of the United States (Cincinnati, Ohio; New Orleans, La.; Memphis, Tenn.; Galveston, Texas; Greenville, N.C.; Delray Beach, Fla.; San Diego and Los Angeles, Calif.). The most common dust mites found in the homes were Dermatophagoides farinae (DF), D. pteronyssinus (DP), Euroglyphus maynei (EM), and Blomia tropicalis. All homes in all locations contained Dermatophagoides spp. mites, but few homes were populated exclusively by either DF or DP alone. Most homes (81.7%) were coinhabitated by both DF and DP. In coinhabited homes one species was predominant and usually made up at least 75% of the total mite population. Prevalence of the dominant or only species present varied between homes within a geographic area. EM occurred in significant numbers in 35.7% of homes in New Orleans, Memphis, Galveston, Delray Beach, and San Diego. Blomia tropicalis occurred in these same cities but in low densities. For all dust samples, only 13 homes of the 252 sampled had 100 or fewer mites/gm dust, which is considered to be the threshold for sensitivity. Most homes had average mite densities of 500 or more mites/gm dust. The results of the present study suggest a significant and widespread occurrence of both DF and DP. Therefore extracts of both mite species should be considered for diagnostic tests and immunotherapy. Significant levels of EM were present in some areas. Thus sensitivity to EM should be considered in these areas.

Adolescent↗
PubMed1991

Increased transient tachypnea of the newborn in infants of asthmatic mothers.

OBJECTIVE: To compare the incidence of transient tachypnea of the newborn (TTN) in infants of asthmatic vs nonasthmatic mothers. RESEARCH DESIGN: Case-control analysis. SETTING: Group model health maintenance organization. PATIENTS: A volunteer sample of 294 pregnant asthmatic women and 294 pregnant nonasthmatic women with normal pulmonary function test results, matched on the basis of age and smoking status. All subjects entered the study before their third trimester of pregnancy. Subjects with multiple gestations and abortions (less than 20 weeks' gestation) were excluded. INTERVENTION: Asthma was treated in the allergy department. Routine obstetric, neonatal, and pediatric care was provided to all patients by staff physicians. MEASUREMENTS/RESULTS: Transient tachypnea occurred in 11 infants (3.7%) of asthmatic women and in one control infant (0.3%). There were no significant differences between asthmatic and matched control subjects in previously defined TTN risk factors, such as the occurrence of longer labors, failure to progress, cesarean sections, premature births, male sex, Apgar scores of less than 7 at 1 minute, or birth weight greater than 4 kg. Although infants of asthmatic mothers were more likely to exhibit wheezing by age 15 months compared with control infants (12.0% vs 3.2%), none of the infants with TTN manifested wheezing by age 15 months. No relationships could be identified in the asthmatic cohort between the occurrence of TTN and asthma severity or medication use (during the pregnancy in general or during labor and delivery in particular). CONCLUSION: Although the mechanism is uncertain, maternal asthma appears to increase the risk of infant TTN.

Adult↗
PubMed1991

Facilitated referral to asthma specialist reduces relapses in asthma emergency room visits.

Facilitated asthma-specialist care delivered by allergists was compared to generalist care on the rate of relapse of asthma emergency room (ER) visits and hospitalizations and on asthma control in a prospective, controlled study of San Diego Kaiser Health Plan members with asthma. Subjects with asthma between the ages of 6 and 59 years presenting for acute ER care for asthma were systematically assigned by alternating, consecutively, the day of their ER visit to receive either (1) facilitated referral to an asthma specialist within the allergy department and concomitant comprehensive ongoing asthma care (intervention group, n = 149) or (2) continued outpatient management from generalist physicians (control group, n = 160). The course of their asthma was evaluated blindly during the subsequent 6 months by review of medical records, initial and follow-up questionnaires, and spirometry. Compared to the control group, the intervention group noted (1) a 75% reduction in the number of, and percent of, subjects with asthma awakenings per night (p less than or equal to 0.0001), (2) an almost 50% reduction in asthma ER relapses (p = 0.017) resulting from a reduction in the frequency of multiple relapse (p = 0.005), and (3) a greater use of inhaled corticosteroids (p less than 0.00001) and cromolyn (p = 0.002). Thus, facilitated referral of subjects with asthma to specialists in asthma therapy after acute ER therapy appears to reduce asthma ER relapses and to improve asthma outcome.

Adult↗
PubMed1990

Intrauterine growth is related to gestational pulmonary function in pregnant asthmatic women. Kaiser-Permanente Asthma and Pregnancy Study Group.

Asthmatic mothers have been reported to deliver infants of lower mean birth weight than nonasthmatic mothers. This study examined the relationship between intrauterine growth and serial gestational spirometry in 352 pregnant asthmatic women who were prospectively treated and observed during pregnancy. A small (r = 0.11) but significant (p less than 0.04) direct correlation was demonstrated between infant birth weight and individual mean percent predicted FEV1 during pregnancy. In addition, lower maternal mean FEV1 during pregnancy was associated with increased incidences of birth weight in the lower quartile of the infant population (p = 0.002) and ponderal indices less than 2.2 (suggestive of asymmetric intrauterine growth retardation) (p less than 0.05), but not with increased incidences of preterm (less than 38 weeks) or low birth weight (less than 2,500 g) infants. Although lower mean birth weight occurred in infants of smoking compared with nonsmoking asthmatic mothers (p less than 0.02), the relationships of lower FEV1 to birth weight in the lower quartile of the population (odds ratio 3.0, p = 0.002) and ponderal indices less than 2.2 (odds ratio 2.8, p less than 0.05) were shown by multivariate analysis to be above and beyond the influence of smoking and also independent of the effects of age, parity, acute asthmatic episodes, and asthma medications. These data support the hypothesis that lower maternal gestational FEV1 during pregnancy is related to intrauterine growth retardation and suggest that the goals of gestational asthma therapy should include optimization of pulmonary function in addition to achievement of symptomatic control.

Asthma↗
PubMed1989

Involvement of glutathione peroxidase activity in the stimulation of 5-lipoxygenase activity by glutathione-depleting agents in human polymorphonuclear leukocytes.

We recently demonstrated activation of 5-lipoxygenase activity in human polymorphonuclear leukocytes (PMN) on preincubation of the cells with glutathione-depleting agents, namely 1-chloro-2,4-dinitrobenzene (Dnp-C1) and azodicarboxylic acid bis[dimethylamide] (diamide). In this paper we show that Dnp-C1, but not diamide, impairs the reduction of added organic peroxides in whole PMN. Also, since co-incubation of fatty acid hydroperoxides with arachidonate caused activation of 5-lipoxygenase, we propose that Dnp-C1 increases the peroxide level in PMN which is required for the onset of lipoxygenase activity. This could be substantiated in PMN homogenates by a glutathione-dependent depression of arachidonate 5-lipoxygenation. At higher arachidonate concentrations and in the presence of Ca2+ the glutathione effect was not observed but additional glutathione peroxidase also blocked this maximally stimulated 5-lipoxygenase. Together with other experiments, it became obvious that the formation of leukotrienes, but also of 15-lipoxygenase products, requires a sharply defined threshold level of fatty acid hydroperoxides which are generated by the lipoxygenases and counteracted by glutathione-dependent peroxidase(s). Dnp-C1 influences this equilibrium by removing glutathione and thereby inhibiting glutathione-dependent peroxidase activity. From our data we conclude that it is the physiological function of the peroxidase activity in PMN to determine an efficiently regulated threshold level of hydroperoxide products, below which no activation of 5-lipoxygenase or 15-lipoxygenase can occur.

Arachidonate 15-Lipoxygenase↗
PubMed1989

Effect of combined maternal and infant food-allergen avoidance on development of atopy in early infancy: a randomized study.

The effect of maternal and infant avoidance of allergenic foods on food allergy was examined in a prenatally randomized, controlled trial of infants of atopic parents. The diet of the prophylactic-treated group (N = 103) included (1) maternal avoidance of cow's milk, egg, and peanut during the third trimester of pregnancy and lactation and (2) infant use of casein hydrolysate (Nutramigen) for supplementation or weaning, and avoidance of solid foods for 6 months; cow's milk, corn, soy, citrus, and wheat, for 12 months; and egg, peanut, and fish, for 24 months. In the control group (N = 185), mothers had unrestricted diets, and infants followed American Academy of Pediatrics feeding guidelines. The cumulative prevalence of atopy was lower at 12 months in the prophylactic-treated (16.2%) compared to the control (27.1%) group (p = 0.039), resulting from reduced food-associated atopic dermatitis, urticaria and/or gastrointestinal disease by 12 months (5.1% versus 16.4%; p = 0.007), and any positive food skin test by 24 months (16.5% versus 29.4%; p = 0.019), caused primarily by fewer positive milk skin tests (1% versus 12.4%; p = 0.001). The prevalences of allergic rhinitis, asthma, and inhalant skin tests were unaffected. Serum IgE levels in the prophylactic-treated group were marginally lower only at 4 months. Thus, reduced exposure of infants to allergenic foods appeared to reduce food sensitization and allergy primarily during the first year of life.

Adult↗
PubMed1988

The safety of inhaled beta-agonist bronchodilators during pregnancy.

To assess the safety of inhaled beta-agonist bronchodilators during pregnancy, perinatal outcomes in 259 prospectively managed women with asthma using these medications during pregnancy were compared to perinatal outcomes in 101 concurrently followed pregnant subjects with asthma not using inhaled bronchodilators and to perinatal outcomes in 295 concurrently followed pregnant control subjects without asthma. No significant differences between women with asthma using inhaled bronchodilators and subjects not receiving inhaled bronchodilators were found in the following parameters: perinatal mortality, congenital malformations, preterm births, low birth weight infants, mean birth weight, small for gestational age or low ponderal index infants, Apgar scores, labor/delivery complications, or postpartum bleeding. Increased incidences of maternal chronic and pregnancy-induced hypertension and transient tachypnea of the neonate were observed in the pregnancies of subjects with asthma using regular inhaled bronchodilators compared to control subjects, but a logistic regression analysis within the sample of subjects with asthma did not significantly associate the use of inhaled bronchodilators with these outcomes. In the light of the known substantial perinatal risks of severe, uncontrolled asthma and the relatively sparse evidence of human gestational safety for alternative asthma medications, these data support the use of inhaled beta-agonist bronchodilators as part of the management of asthma during pregnancy.

Administration, Inhalation↗
PubMed1988

The course of asthma during pregnancy, post partum, and with successive pregnancies: a prospective analysis.

We studied 366 pregnancies in 330 prospectively managed women with asthma to determine the effect of pregnancy on asthma. Asthma activity was assessed by (1) daily symptom and medication diaries and (2) monthly auscultation and spirometry during pregnancy and for 3 months post partum. At 3 months post partum, subjects were asked to assess the overall course of their asthma during pregnancy compared to the usual course for them, and the course of their asthma during the 3 months post partum compared to the asthma during pregnancy. Asthma worsened during pregnancy in 35% of the women, improved in 28%, and was unchanged in 33%. Based on diary-card analysis, asthma was significantly less frequent and less severe during the last 4 weeks of pregnancy than during any other gestational interval. In women whose asthma improved during pregnancy, diary-card analysis revealed a gradual improvement with progressive pregnancy, whereas in women whose asthma worsened during pregnancy, there was an increase in asthma symptoms during 29 to 36 weeks gestation. During labor and delivery, asthma symptoms occurred in 10% of women with approximately equal proportions of these women receiving either no treatment or inhaled bronchodilators; only two subjects required intravenous aminophylline. During the 3 months post partum, asthma reverted toward its prepregnancy course in 73% of women. In 34 subjects prospectively studied for two successive pregnancies, there existed a significant concordance between the asthma course during the first and second pregnancies. The mechanistic and clinical implications of these findings are discussed.

Asthma↗
PubMed1988

Prevention of chymopapain anaphylaxis by screening chemonucleolysis candidates with cutaneous chymopapain testing.

With chymopapain at a concentration of 10 mg/ml, the authors skin tested 540 chemonucleolysis candidates; six were positive, and 534 were negative. None of the positive patients received therapeutic injections of chymopapain. There were no instances of unequivocal anaphylaxis to chymopapain in the patients with negative skin tests treated with chymopapain. When this 0% incidence of systemic reactions in skin test negative patients is compared with the historical rate of 1%, this difference is statistically significant (p less than 0.05). Restriction of chymopapain treatment to patients with negative prick tests can reduce the incidence of systemic reactions.

Anaphylaxis↗
PubMed1987

Longitudinal effects of pregnancy on the pharmacokinetics of theophylline.

The effects of pregnancy on the disposition of theophylline were assessed in 10 patients throughout pregnancy and post-partum. The clearance relative to total theophylline concentrations was only slightly affected during the first two trimesters (2.61 +/- 0.63 l/h and 2.85 +/- 1.05 l/h), while a statistically significant reduction was evident late in pregnancy (2.05 +/- 0.49 l/h). Post-partum clearance values (2.16 +/- 2.81 l/h) suggest an ongoing suppression relative to pre-pregnancy levels. A similar pattern was evident with clearance values based on free theophylline plasma concentrations (p = 0.12). Absolute volume of distribution increased in concert with gestation, suggesting that theophylline partitions into the enlarged tissue spaces. In addition, theophylline binding to plasma proteins decreased, albeit insignificantly, during the second (fraction bound = 29%) and third (32%) trimesters compared to post-partum values (41%). Increases in half-life during the third trimester (13.00 +/- 2.31 h vs 9.53 +/- 3.53 h post-partum) were highly significant. This change reflects the net effect of reduced clearance and increased distribution. Breast feeding had no effect on the disposition of theophylline, although the transfer of this compound into breast milk was confirmed.

Asthma↗
PubMed1987

Interrelationships between asthma and pregnancy: clinical and mechanistic considerations.

Asthma appears to be one of the most common potentially serious medical problems to complicate pregnancy. There is abundant literature suggesting that asthma and pregnancy may have reciprocal influences on each other. This article will review the literature dealing with the effect of asthma on pregnancy and the effect of pregnancy on asthma. For each of the bidirectional relationships, a review of clinical observations will be followed by a review of potentially relevant mechanistic considerations.

Asthma↗
PubMed1987

Prevention of chymopapain anaphylaxis by screening chemonucleolysis candidates with cutaneous chymopapain testing. A preliminary report.

The risk of anaphylaxis in candidates for chemonucleolysis for herniated lumbar discs is approximately 1%. An investigation was designed to eliminate or reduce the incidence of chymopapain anaphylaxis. The procedure was to restrict chemonucleolysis to patients who are prick test-negative to chymopapain at a concentration of 10 mg/ml. The authors skin-tested 292 chemonucleolysis candidates; five were positive and 287 were negative. None of the positive patients were injected with chymopapain. There were no instances of unequivocal chymopapain anaphylaxis in the skin test-negative group. This 0% incidence of anaphylaxis in skin test-negative patients was compared with a population estimate of 1%, based on historical data. The resulting value of p = 0.08 value fell short of the conventional level of significance of 0.05. The p value will reach 0.05 when the series of skin test-negative patients without anaphylaxis reaches 360. It is important that this information is readily available to physicians concerned about anaphylactic reactions to chymopapain.

Adult↗