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Biomedical subjects

H Harving

Publications and source records attributed to H Harving.

15 recordsLinked to original sources
PubMed1991

Measurement of PC20 histamine with the use of two different nebulizers and measurement of FEV1 and PEF.

Histamine challenge was performed in 19 patients using two nebulizers (PARI and Wright) and FEV1 and PEF were measured to determine PC20 histamine. FEV1 and PEF gave identical PC20 histamine values. The PARI nebulizer gave PC20 histamine values that were 2.5 doubling concentrations lower than the Wright nebulizer. The reproducibility of histamine challenge with the PARI nebulizer was studied in 15 patients and the results suggested that the challenge was reproducible within one doubling concentration of histamine.

Adolescent↗
PubMed1991

Lung function and bronchial reactivity in asthmatics during exposure to volatile organic compounds.

The purpose of the present study was to investigate whether vapors of organic solvents at low concentrations could exert an adverse effect in the lower airways. Under controlled conditions in a climate chamber, 11 persons with bronchial hyperreactivity to histamine and bronchial asthma were exposed for 90 min to a mixture of organic solvents at levels of zero, 2.5, and 25 mg/m3. During exposure to 25 mg/m3 a decrease in FEV1 to 90.7% of baseline value was measured. This was significantly different from the initial value (p less than 0.05), but not significantly different from the value found after sham exposure (FEV1, 97.4% of initial value). The decline in FEV1 during exposure to 25 mg/m3 was most pronounced in persons with high bronchial sensitivity. No changes were found in histamine reactivity after exposure, and no late reactions were registered. Ratings of discomfort showed different individual patterns ranging from no response to reactions towards both of the concentrations. The ratings indicated development of tolerance during exposure. Volatile organic compounds in concentrations found in both the work and the home environments may influence lung function and are probably of importance as bronchial irritants.

Adult↗
PubMed1990

Pulmonary function and bronchial reactivity in asthmatics during low-level formaldehyde exposure.

This study evaluated whether formaldehyde, at concentrations similar to those found in the indoor environment, could produce adverse effects on the lower airway of 15 asthmatic persons with documented bronchial hyperresponsiveness who were exposed for 90 min in a climate chamber to clean air containing formaldehyde vapor at levels of 0.85 mg/m3, 0.12 mg/m3, and 0.008 mg/m3. No significant changes in forced expiratory volume in 1 sec (FEV1), airway resistance (Raw), specific airway resistance (SRaw), and flow-volume curves could be detected during formaldehyde exposure. Furthermore, histamine challenge tests performed immediately after formaldehyde exposure showed no evidence of changes in bronchial reactivity. No late reactions were registered during the first 14-16 hr after exposure. The results suggest that residential levels of formaldehyde are of minor importance in the emergence of pulmonary symptoms. Discrepancies between the present study and previous data may be due to differences in environmental conditions.

Adolescent↗
PubMed1990

House dust mites and atopic dermatitis. A case-control study on the significance of house dust mites as etiologic allergens in atopic dermatitis.

The occurrence of house dust mites was measured in homes of 24 patients with atopic dermatitis, 30 patients with mite-sensitive asthma and 32 patients with asthma not related to house dust mites. Patients with mite-positive asthma and patients with atopic dermatitis had significantly higher exposure to house dust mites compared with patients with mite-negative asthma. For atopic dermatitis the higher exposure to house dust mites corresponded to a relative risk of 4.7 and a clear dose-response relationship was demonstrated between exposure and risk of disease in the subgroups of patients with atopic dermatitis. The present epidemiologic results support the idea that house dust mites may be an etiologic factor in a proportion of adult patients with atopic dermatitis.

Allergens↗
PubMed1989

Atopic dermatitis and the indoor climate. The effect from preventive measures.

Nine patients with atopic dermatitis (AD) were clinically evaluated before and after moving to new houses with improved air exchange, low relative humidity and optimal temperature control. During a 2-year period three clinical and subjective assessments were performed each month of disease activity, and compared with changes in suspended and respirable dust particles, room temperature, air exchange rate, concentration of house-dust mites in bedrooms, and the concentration of organic solvents in the indoor air. Ten matched patients with AD, who did not move, served as a control group. The skin condition of patients moved improved significantly after moving. The indoor climate was improved on: 1) air exchange rate, 2) relative humidity, and 3) room temperature, but the amounts of house dust mites, respirable air particles and organic solvents were unchanged. The clinical and subjective improvement in AD could not be correlated to any single indoor environmental factor. The present investigation supports the current concept, that AD may be a multifactorial disease, and that the indoor climate may be a contributing factor affecting the eczema.

Adolescent↗
PubMed1988

Terbutaline sustained-release tablets in nocturnal asthma--a placebo-controlled comparison between a high and a low evening dose.

The effects of oral treatment with terbutaline sustained-release (SR) tablets (Bricanyl Depot) were studied in nine patients who had bronchial asthma and marked diurnal variation in ventilatory function. In a randomized and double-blind study, the patients were treated with terbutaline SR 7.5 mg b.i.d., terbutaline SR 7.5 mg in the morning and 15 mg in the evening and terbutaline SR placebo b.i.d. Each treatment was given for 1 week. The nocturnal decline in the peak expiratory flow rate (PEFR) was 45% during the placebo period, 27% after the lower and 22% after the higher terbutaline SR evening dose (P less than 0.01 for both treatments compared to placebo). The mean morning PEFR was significantly higher with the high evening dose than with the low evening dose (P less than 0.01). Mild to moderate side effects were noted. The sustained-release preparation of terbutaline seems to be of clinical value in preventing or relieving nocturnal asthma and early morning dipping. The flexible dose technique, with a higher evening dose, results in further improvements in these patients.

Adult↗
PubMed1986

Red wine asthma: a controlled challenge study.

Drinking red wine may provoke bronchospasm in subjects with asthma. In order to reveal some of the possible agents involved in this reaction, 18 patients with a history of red wine-induced asthma were studied. They received, in a double-blind fashion, red wine with low sulfur dioxide (SO2) and high amine, high SO2 and high amine and low SO2 and low amine content. In each challenge, the wine was administered in stepwise increasing quantities until a total of 385 ml or a fall in peak expiratory flow of greater than 15% was reached. Nine subjects demonstrated a significant fall in peak flow in one or more challenges. In all cases the most severe reaction was observed after the wine with high SO2 content. The study suggests that SO2 is the most important factor in red wine-induced asthma. It is recommended that wine labels provide information on the SO2 content.

Adult↗
PubMed1985

Procaterol and terbutaline in bronchial asthma. A double-blind, placebo-controlled, cross-over study.

Procaterol, a new beta-2 adrenoceptor stimulant, was studied in a double-blind, placebo-controlled, cross-over trial in patients with bronchial asthma. Oral procaterol 50 micrograms b.d., procaterol 100 micrograms b.d., and terbutaline 5 mg t.i.d., were compared when given randomly in 1-week treatment periods. The best clinical effect was found with terbutaline. Both anti-asthmatic and tremorgenic effects of procaterol were dose-related. Procaterol appeared effective in the doses tested, and a twice daily regimen would appear to be suitable with this drug.

Adolescent↗
PubMed1978

Effect of dantrolene sodium on the spastic external urethral sphincter recorded by sphincterometry.

An improved method of sphincterometry is described, which is easy to perform in men and also may be used in women. It gives reproducible results in the individual patient. The maximum pressure was found by radiographic and reflexological examinations of the external urethral sphincter. When 0.5 mg./kg. body weight dantrolene sodium was injected intravenously the resistance of the external urethral sphincter was found to be reduced significantly, presumably reflecting a reduction of reflex activity.

Dantrolene↗
PubMed1978

Human anal reflexes.

By perianal electrical stimulation and EMG recording from the external anal sphincter the anal reflex was constantly present in normal subjects. The latency decreased within certain limits with increasing stimulation to an average minimum latency of 50 ms (SD 10.5). There was no difference between the minimum latency in normal subjects and patients with suprasegmental lesions of the CNS. The latency may be prolonged in patients with lesion of the reflex arc. By stimulation over the posterior tibial nerve behind the medial malleolus a reflex reaction could be picked up constantly from the anal sphincter in normal subjects. This reflex had a longer latency but a lower threshold than the reflex reaction from the tibialis anterior muscle. The average minimum latency from the anal sphincter was 93 ms (SD 21.1) and from the tibialis anterior muscle 64 ms (SD 7.9). In the absence of the anal reflex it may be possible to localise the defect to the afferent or efferent parts of the reflex by using types of stimulation. Preliminary studies of spinal shock revealed a perianally elicited anal reflex in all cases, but also a response to peripheral stimulation in some of the cases, more frequently found in the anal sphincter than in the tibialis anterior muscle.

Anal Canal↗