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Biomedical subjects

S C Bukantz

Publications and source records attributed to S C Bukantz.

At least 37 records · Page 2Linked to original sources
PubMed1988

The Hymenoptera venom study I, 1979-1982: demographics and history-sting data.

The Hymenoptera venom study, a study based on case histories, skin test results and adverse reactions, immunotherapy and adverse reactions, and treatment efficacy, for 3236 Hymenoptera-allergic subjects, was begun in 1979 after the Food and Drug Administration approval of Hymenoptera venoms. Eighty-four Fellows and Members of the American Academy of Allergy and Immunology participated in the study. All subjects had a history of an adverse reaction to one or more Hymenoptera insects. The mean age was 30 1/2 years (range 1 to 83 years). Male subjects accounted for 61.5% and female subjects, 38.5%; 3.1% were beekeepers and 32.3% were atopic. Demographic data were similar for subgroups. There was an average of 2.7 history stings per subject. At least one systemic reaction (SR) was reported by 2866 subjects (89%); 2219 (69%) experienced an SR after their most recent sting before entry into the study, and 70% had experienced only a single SR. Moderate to severe SRs were equally likely after stings of yellow jacket, white-faced hornet, and yellow hornet (65%), honeybee (67%), or wasp (70%), although historical SRs were reported more often after stings of yellow jacket, white-faced hornet, or yellow hornet (30%) than after honeybee (19%) or wasp (14%) stings. No association was noted between the number of stings per episode and severity of the SR. Fifty-one percent of SRs were reported as occurring within 10 minutes of sting; however, the onset of a moderate to severe SR sometimes occurred at 301 or more minutes after a sting episode. Of 2219 subjects with an SR after their most recent sting before entry into the study, 68% received epinephrine for treatment.

Animals↗
PubMed1988

Effects of ketotifen on the responsiveness of peripheral blood lymphocyte beta-adrenergic receptors.

The effects of ketotifen therapy on the responsiveness of lymphocyte beta-adrenergic receptors was evaluated by measuring cyclic AMP elevations caused by isoproterenol in cells isolated from patients treated with ketotifen for more than 1 year. Binding of 3H-dihydroalprenolol to beta-receptors was also evaluated. The isoproterenol-induced rise in cyclic AMP relative to each individual's baseline level was greater in patients on current ketotifen therapy than in other asthmatic patients or non-asthmatic subjects. Ketotifen therapy increased the apparent equilibrium dissociation constant for specific 3H-dihydroalprenolol binding to the receptors. Receptor numbers in symptomatic asthma patients on standard drug therapy were decreased. The results indicate that long term ketotifen therapy is associated with increased responsiveness of beta-receptors to stimulation by catecholamines and that this alteration may involve changes in the receptors themselves, their membrane environment, adenylate cyclase or components of the adenylate cyclase coupling system.

Adolescent↗
PubMed1987

Fatalities from immunotherapy (IT) and skin testing (ST)

The Committee on Allergen Standardization of the American Academy of Allergy and Immunology obtained information about 46 fatalities that had occurred during immunotherapy (IT) or skin testing (ST) since 1945. Sufficient information for complete analysis was provided for 30 patients (six for ST and 24 for IT). Of the 30 fatalities, there were 15 male and 15 female fatalities ranging in age from 7 to 70 years (x = 33 years). Known errors of administration accounted for three and possibly an additional three fatalities. Ten fatalities occurred during seasonal exacerbation of the patient's disease, four in patients who had been symptomatic at the time of the injection, two of whom had been receiving beta-adrenergic blockers. Of the 24 fatalities associated with IT, four had experienced previous reactions, 11 manifested a high degree of sensitivity, and four had been injected with newly prepared extracts. Fifteen of the 30 fatalities had received pollen extracts as part of the fatal injection. Of the six fatalities associated with ST, five were due to intradermal testing without prior puncture testing. The signs and symptoms were variable and did not indicate that death was imminent nor predict the cause of death. The time to onset of the reaction was less than 30 minutes in 22/30, more than 30 minutes in 3/30, and not reported in 5/30. The cause of death in 14/16 patients with asthma was respiratory. Epinephrine had been administered to 18, not administered to three, and was either not recorded or unknown in the remaining nine patients. Since seven to 10 million allergen injections are administered yearly, the risk of a fatal reaction is low and may be lessened even further as additional precautions are taken in the selection and treatment of allergic patients and in improved treatment of the anaphylactic reactions.

Adult↗
PubMed1987

Melkersson-Rosenthal syndrome.

Two patients were referred to the University of South Florida College of Medicine Allergy and Immunology Clinic for evaluation of "angioedema." Patient 1 presented with intermittent severe lip edema, and patient 2 presented with lip and facial swelling together with facial palsy. Multiple symptomatic treatments had been ineffective. Both patients were ultimately found to have Melkersson-Rosenthal syndrome, a rare granulomatous disorder of undetermined cause that must be considered in a differential diagnosis of facial edema. The patients are presented in detail to call attention to the diagnosis of the condition in order that unnecessary treatment, with attendant side effects, may be avoided.

Adult↗
PubMed1986

The treatment of mild to severe chronic idiopathic urticaria with astemizole: double-blind and open trials.

Astemizole is a new H1 histamine-receptor antagonist that has a long elimination half-life and high H1-receptor affinity. This double-blind study evaluated the safety and efficacy of astemizole in the treatment of chronic idiopathic urticaria (more than or equal to 3 months). Seventeen male and 34 female adult patients with chronic idiopathic urticaria entered the 2-month study. After a 48- to 72-hour washout, half the subjects were prerandomized to receive astemizole (10 mg), and the other half received placebo. Placebo-treated patients who were unable to complete the full 8 weeks because of uncontrolled chronic urticaria symptoms were entered into a 2-month open astemizole trial. Treatment with astemizole, as measured at the end point of each patient's treatment and compared to placebo, resulted in significant improvement of pruritus, erythema, number of wheals, frequency of urticarial attacks, and control of urticaria (p less than or equal to 0.03). The overall response to astemizole was significantly better than for placebo, according to both the investigator's and the patient's global evaluations (p less than 0.01) and as indicated by dropouts caused by treatment failure with placebo (p = 0.005). Six of 26 (24%) of the placebo-treated patients in the double-blind study had good to excellent results on the basis of global assessments. Thirteen of 16 patients with placebo-treatment failures who received astemizole in the open trial improved significantly from baseline symptoms of pruritus, erythema, and number of wheals (p less than or equal to 0.05). No significant side effects were reported except mild sedation in three astemizole-treated subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

A multicenter trial of the prophylactic effect of ketotifen, theophylline, and placebo in atopic asthma.

Three hundred seventy-four patients with asthma were entered into a year-long, double-blind, double-placebo controlled study comparing the prophylactic effect of ketotifen (229 patients), theophylline (73 patients), and placebo (72 patients). The ketotifen group was larger to allow the accumulation of additional long-term safety data. The primary measure of therapeutic effect was a decrease in concomitant medication without a significant increase in symptomatology or a decrement in pulmonary functions. A patient daily diary was used to document symptoms (cough, shortness of breath, and wheeze) and concomitant medications taken during the 2-week baseline and the subsequent 12 monthly periods. After 2 months of study-drug therapy, the ketotifen patients had a greater decrease in both concomitant medication and symptomatology than either of the other groups. This delay in the onset of therapeutic activity has been observed in other studies and is characteristic of this compound. The principal side effect observed with ketotifen is initial sedation, which was found to be self-limiting and of little concern to the patient after the first month.

Adolescent↗
PubMed1985

Effects of ergometrine on airway smooth muscle contractile responses.

A 26-year-old asthmatic female developed severe asthma within a few hours of receiving three oral doses of 0.4 mg ergometrine maleate for the control of postpartum haemorrhaging. This experience and two previous reports of bronchospasm in asthmatic subjects following ergometrine suggested that ergometrine altered airway smooth muscle tone. In the present investigation the effect of ergometrine was studied on canine tracheal smooth muscle strips. Ergometrine (10(-9) M-10(-4) M) induced contraction of canine tracheal smooth muscle. The concentration causing 50% of maximal contraction (EC50) was 4.73 X 10(-8) M. The acetylcholine EC50 was not altered by ergometrine (10(-9) M or 10(-8) M); however, acetylcholine (10(-4) M and 10(-3) M) induced contractions were enhanced by ergometrine (10(-8) M). The data suggest that ergometrine maleate may cause broncho-constriction in some patients with asthma.

Acetylcholine↗
PubMed1984

The site of action of Ptychodiscus brevis toxin within the parasympathetic axonal sodium channel h gate in airway smooth muscle.

The red tide toxin produced by Ptychodiscus brevis ( PBTX ) may cause cough, sneezing, and asthma. Previous in vitro studies with isolated canine tracheal smooth muscle demonstrated that PBTX stimulates sodium channels of parasympathetic nerve endings and thus causes a contractile response. The present study investigated the mechanism of the PBTX effect on canine tracheal smooth muscle. Repeated exposure of the muscle strip to PBTX (final concentration 46 micrograms/ml) followed by washout of the toxin resulted in reestablishment of baseline tension but a failure of contraction on further addition of PBTX . However, veratridine and scorpion toxin (SCT), which are voltage-sensitive sodium channel activators, still induced contraction. Furthermore, the contraction caused by veratridine was enhanced by a high dose of PBTX , whereas contraction caused by SCT was not. Responses to veratridine and SCT as well as PBTX (previously reported) were blocked by tetrodotoxin (a sodium channel blocker), while acetylcholine responsiveness remained intact. These results indicate that PBTX receptors in parasympathetic nerves influence Na+ flux at the h gate, that these receptors differ from the veratridine and SCT receptors, and that the conformational change in the receptors induced by PBTX affects the tissue response to veratridine.

Animals↗
PubMed1983

Pharmacokinetics and bioavailability of three dyphylline preparations.

The pharmacokinetics and bioavailability of 3 oral dyphylline preparations, solution (S), regular (R) and sustained release (SR), were studied in 8 healthy subjects (mean age 25 years). A single dose of each preparation, 20 mg X kg-1, was given at one week intervals and multiple serum samples obtained over 24 h. Drug levels were measured by high performance liquid chromatography. No adverse effects were found. The dyphylline half-life for the solution was 2.16 +/- 0.18 h and for the tablet 2.59 +/- 0.56 h. The mean clearance rate for S was 13.6 +/- 1.7 h-1 and volume of distribution 43.0 +/- 3.91. Peak concentration (Cmax, micrograms X ml-1), time of peak (Tmax, h), area under the curve (AUC, micrograms X ml-1 X h) and relative bioavailability (RB, %), were determined for three preparations: Cmax S, 33.7 +/- 3.7; R, 27.7 +/- 4.2; SR, 10.4 +/- 1.5 Tmax: S, 0.33 +/- 0.0; R, 0.66 +/- 0.0; SR, 2.13 +/- 1.1 AUC: S, 108.4 +/- 12.1; R, 113.9 +/- 25.2; SR, 104.0 +/- 30.8 RB: Reference Product R, 105.00 +/- 16.00; SR, 100.00 +/- 25.00 The data confirm the short half-life of dyphylline, demonstrate a lack of toxicity for the 20 mg X kg-1 dose and establish bioequivalence for the products studied.

Adult↗
PubMed1983

Theophylline kinetics in a geriatric group.

The influence of age, sex, and smoking on theophylline disposition was studied in 38 healthy subjects ranging in age from 26 to 81 yr. There were 8 young (less than 60 yr) and 30 geriatric (greater than 60 yr) subjects, including 28 men (8 smokers) and 10 women (3 smokers). A crossover experimental design was used. A single dose of theophylline elixir (5 mg/kg lean body weight [LBW]) was given as a reference product to all subjects. One week later a sustained-release (SR) theophylline tablet (8 and 6 mg/kg LBW) was given to the young and the geriatric subjects. Serum theophylline concentrations were determined by HPLC. Theophylline elimination (t1/2 beta) is shorter in the geriatric group (6.93 and 8.14 hr); total body theophylline clearance is greater in the geriatric group (44.39 and 32.97 ml/kg/hr), and the apparent volume of distribution is also greater in the geriatric group (26.29 and 22.97 l). Sex and smoking did not influence any of the parameters studied. In 93% of the geriatric subjects, serum theophylline levels of 8 to 20 micrograms/ml were reached at steady state with the SR tablet. Theophylline dose reduction based on an arbitrary age limit is not, therefore, invariably indicated.

Adult↗
PubMed1983

Study of oxtriphylline SA in 50 asthmatics.

Fifty clinically stable patients with asthma on maintenance theophylline therapy, mean dose of 15 mg kg-1 per day, were switched to an equivalent dose (X 1.56) of oxtriphylline SA for seven doses. All subjects remained clinically stable after the change during the study period. Oxtriphylline SA appears to be useful for the maintenance treatment of asthma and can be safely substituted for other theophylline maintenance regimens.

Adult↗
PubMed1982

Effects of toxin of red tide, Ptychodiscus brevis, on canine tracheal smooth muscle: a possible new asthma-triggering mechanism.

The red tide toxin produced by Ptychodiscus brevis becomes airborne by the thrashing action of the surf and wind and induces cough, rhinorrhea, watery eyes, and sneezing in normal humans and wheezing in asthmatic patients. The mechanism of the contractile response induced by P. brevis toxin (PBTX) was investigated with isolated canine tracheal smooth muscle. Tetrodotoxin and atropine blocked the contractile effect of PBTX, and neostigmine potentiated the contraction. Mepyramine, phentolamine, methysergide, and chlorisondamine did not inhibit the effect of PBTX. This is the first description of a naturally occurring airborne substance that causes smooth muscle contraction by stimulating the axon sodium channels, resulting in the release of acetylcholine at postganglionic parasympathetic efferent nerve endings. The in vitro effect of PBTX on canine tracheal smooth muscle indicates that PBTX is capable of causing respiratory irritation and thus may precipitate an asthmatic attack. It is possible, however, that the mechanism is vivo may also include stimulation of a cough receptor reflex and/or stimulation of sodium channels of afferent vagus nerve fibers. In vitro evidence suggests that isoproterenol, atropine, and verapamil may be used to eliminate or prevent the respiratory symptoms that follow exposure to airborne red tide toxin. The use of high-pressure liquid chromatography separated fractions indicates that the neurotoxic component, not the hemolytic component, is responsible for contractions.

Acetylcholine↗