Embryonic origins of the relation of gastroesophageal reflux disease and airway disease.

The human tendency to have gastroesophageal reflux is a result of the upright stance, with the head and pelvis in the same plane, and bipedal locomotion. Compared with quadrupedal mammals, human embryologic developments shift in orientation, so that the ventral surface becomes anterior, the dorsal surface becomes posterior, anterior becomes dorsal, and posterior becomes ventral. Shifts in the position of the stomach and esophagus lead to relatively ineffective cardioesophageal sphincter mechanisms. This lends itself to reflux and reflux-associated problems. By the end of fetal development, all of the changes are present.

Safe administration of influenza vaccine to patients with egg allergy.

OBJECTIVES: Specific recommendations for administering the influenza vaccine to patients with egg allergy are based on limited scientific data. The objectives of this investigation were to determine the safety of a 2-dose administration of an influenza vaccine to patients with egg allergy and to evaluate the usefulness of skin testing with the influenza vaccine before administration. STUDY DESIGN: In this multicenter clinical trial, clinical histories of egg allergy were confirmed by skin testing with egg and, if possible, by oral challenges with egg. Subjects with egg allergy received the vaccine in 2 doses, 30 minutes apart; the first dose was one tenth and the second dose nine tenths of the recommended dose as determined by age. Subjects without egg allergy were recruited as control subjects and received 1 age-determined dose of the vaccine. Skin prick tests with the influenza vaccine were performed on all subjects. RESULTS: From 1994 to 1997, 83 subjects with egg allergy and 124 control subjects were evaluated. The content of ovalbumin/ovomucoid was 0.1, 1.2, and 0.02 micrograms/mL, respectively in the 1994-95, 1995-96, and 1996-97 influenza vaccines. Results of vaccine skin prick tests were positive in 4 subjects with egg allergy and in 1 control subject. All patients with egg allergy tolerated the vaccination protocol without any significant allergic reactions. CONCLUSIONS: These results demonstrate that patients with egg allergy, even those with significant allergic reactions after egg ingestion, can safely receive an influenza vaccine in a 2-dose protocol when the vaccine preparation contains no more than 1.2 micrograms/mL egg protein.

Corticosteroid-sparing effect of azelastine in the management of bronchial asthma.

The objective of this double-blind trial was to evaluate the corticosteroid-sparing effect of azelastine in patients with chronic bronchial asthma. A total of 193 subjects received either 6 mg of azelastine twice per day or placebo (in a 2:1 ratio) in combination with beclomethasone dipropionate (6 to 16 inhalations per day). The number of daily inhalations of the corticosteroid was reduced until maximum reduction or elimination was achieved. Patients then entered a 12-wk maintenance period, during which patients were maintained on their lowest possible dose of inhaled corticosteroid. Compared with placebo, the azelastine group had a statistically significantly greater overall median reduction in inhaled corticosteroids (4.9 puffs/day for azelastine versus 3.1 puffs/day for placebo; p < or = 0.010) during the maintenance period. The azelastine group also had a statistically significantly higher percentage of patients with reductions of > or = 50% and > or = 75% from the baseline level (53 and 31%, respectively, for azelastine versus 34 and 14%, respectively, for placebo; p < or = 0.028). The results demonstrated that azelastine, 6 mg twice per day, can reduce the need for inhaled corticosteroids in patients with chronic bronchial asthma and not lead to a deterioration in pulmonary function.

Associations and interactions between the esophagus and the lower respiratory tract.

There are important interactions between the esophagus and the lower respiratory tract (LRT). These occur because of their physical proximity and the functional activities. Malfunctions or lack of coordination between these organs leads to serious human illness such as asthma, aspiration pneumonia, and gastroesophageal reflux.

Gastroesophageal reflux and respiratory disorders.

Gastroesophageal reflux is an important cause of chronic respiratory diseases. Asthma in particular has an interesting and frequent association with GER. Asthma appears to promote GER, and GER can provoke asthma. It behooves the clinician to be aware of this association when treating patients with one of or both of these disorders. Any patient whose respiratory status is worsening without another recognized cause needs to have GER causation considered. Asthmatics whose disease requires systemic steroids or who cannot be controlled are suspect for GER provoked problems. Recognition and treatment of GER will often cause worthwhile improvement of the respiratory illness. This response can often be dramatic.

The role of antihistamine therapy in vascular headaches.

Migraine (vascular) headache is a complex syndrome that involves vascular hyperreactivity. The functions of systemic mediators in migraine are not fully understood. It is unclear which mediators provoke this probably atopic disorder and which represent an attempt to correct an imbalance. However, it has been demonstrated fairly conclusively that increased histamine levels correlate with migraine attacks in susceptible persons. Recent studies showing that histamine seems to have many different receptors and to adopt different conformations for different receptors may serve as a useful guide to future scientific investigation. Further impetus may come from ongoing studies of H3 histamine receptors, which indicate that H3 agonists offer promise as prophylactic agents for people who suffer from vascular headaches.

Use of enzyme-developed immunoblots scanned by densitometry to compare lot-to-lot variability of Russian-thistle extracts.

Two different lots of Russian-thistle extracts from five commercial sources were evaluated by isoelectric focusing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblots of Immobilon transfers from these separations. The immunoblots were developed by an enzyme-linked method and scanned with a densitometer. The two lots of a standardized extracts produced scans that suggested uniformity in allergenic components. Several of the nonstandarized extract lots also appeared quite comparable. With further refinement, immunoblotting with densitometric analysis appears to offer an attractive way to standardize allergen extracts.

Inhibition of dermographia, histamine, and dextromethorphan skin tests by ketotifen. A possible effect on cutaneous vascular response to mediators.

Forty-one subjects with dermographia were studied for a 4-week period. Twenty subjects received ketotifen therapy, the other 21 received chlorpheniramine (H1) for 2 weeks, and then chlorpheniramine plus cimetidine (H1 + H2). Both groups had significant suppression of dermographia and skin wheals caused by dextromethorphan and histamine after 2 weeks. The inhibition by ketotifen of dermographia, histamine wheal, and the dextromethorphan wheal increased from week 2 to week 4. During the first 2 weeks, ketotifen's activity was comparable to chlorpheniramine. Ketotifen's activity increased during the second 2 study weeks to match the additional chlorpheniramine. These results suggest that ketotifen may have additional pharmacologic activities besides H1 antagonism, including possible inhibition of mast cell mediator release. As a consequence, cutaneous vascular hyperresponsiveness may decrease. Ketotifen appears promising as treatment for allergic skin disorders.

Gastroesophageal reflux and asthma.

Gastroesophageal reflux provokes asthma in many patients. Conversely, asthma predisposes to gastroesophageal reflux. In many patients, reflux therapy will ameliorate asthma. Recognition of this relationship is facilitated by physician awareness, clinical history, selected laboratory tests, and ultimately, a careful monitoring of the response to antireflux therapy. With the introduction of effective medical antireflux therapy, the opportunity to benefit these patients has increased. Surgical management of reflux-provoked asthma remains an effective and useful alternative in selected patients.

Gastroesophageal reflux and respiratory disorders: a review.

Gastroesophageal reflux is an important cause of chronic pulmonary disease. Particularly, chronic bronchitis and asthma are two common conditions in which there may be a chicken-and-egg association between the pulmonary problems and the gastroesophageal reflux. This interesting relationship needs to be considered in any patient with chronic pulmonary disease in whom the condition is progressing in spite of adequate medical therapy, in whom the history strongly supports this concept, and in whom laboratory tests suggest a causal relationship. Recognition and treatment of gastroesophageal reflux, either medical or surgical, can lead to improvement in the pulmonary condition of a large number of patients.

Albuterol treatment for children with asthma: a comparison of inhaled powder and aerosol.

A dose-ranging study and a 12-week treatment study were conducted in children with asthma, aged 4 to 12 years, to assess the efficacy and safety of albuterol inhaled as either an aerosol or as dry powder. Both studies were double-blind and placebo-controlled with randomized assignment to treatment. The dose-ranging study in 30 patients indicated that similar single doses of albuterol aerosol and powder had comparable effects with the intermediate doses (i.e., 180 micrograms of aerosol and 200 micrograms of powder) providing effective bronchodilation with minimal adverse effects. In the subsequent 12-week, parallel-group study, 204 children received albuterol as either aerosol, 180 micrograms, or powder, 200 micrograms four times a day. Both formulations were equally effective with no untoward cardiovascular effects and only one incident of mild tremor. Among those children who expressed a preference for one of the delivery systems, significantly more children preferred the powder (44% versus 26%, p less than 0.01). Albuterol taken four times a day as either aerosol or dry powder is both effective and well tolerated in children with asthma.