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Biomedical subjects

A B Murray

Publications and source records attributed to A B Murray.

At least 55 records · Page 3Linked to original sources
PubMed1986

Predictive value of skin prick tests and radioallergosorbent tests for clinical allergy to dogs and cats.

The predictive value and post-test probability of disease were compared for skin prick tests and radioallergosorbent tests (RASTs) in 168 children suspected of clinical allergy to dogs and cats. The skin tests included negative and positive (histamine) controls. The results of RASTs with the same allergen extracts were expressed in relation to the results with allergen-specific pooled reference serum. All the tests were performed blind. The predictive values of positive test results were comparable and low (53% to 76%), whereas the predictive values of negative test results were comparable and high (88% to 95%). The post-test probability of clinical allergy to dog or cat allergen, based on the prevalence rates in the referral population (15.1% and 22.5% respectively), increased to between 46% and 67% for positive test results and decreased to between 4% and 8% for negative results, which suggests that the primary role of skin prick tests and RASTs is in eliminating the diagnosis of clinical allergy.

Adolescent↗
PubMed1986

The effect of cigarette smoke from the mother on bronchial responsiveness and severity of symptoms in children with asthma.

The effect of parental smoking was assessed in 94 consecutively observed children, aged 7 to 17 years, who had a history of asthmatic wheezing. The 24 children whose mothers smoked, when they were compared with children whose mothers did not smoke, had 47% more symptoms, a 13% lower mean FEV1 percent, a 23% lower mean FEF25-75%, and fourfold greater responsiveness to aerosolized histamine. A dose response was evident. There was a highly significant correlation between the results of the tests and the number of cigarettes the mother smoked while she was in the house. The differences between the children of smoking and nonsmoking mothers were greater in older than in younger subjects. The smoking habits of the father were not correlated with the severity of the child's asthma.

Adolescent↗
PubMed1986

Retrovirus-induced osteopetrosis in mice. Ultrastructural evidence of early virus production in osteoblasts and osteocytes.

Newborn female strain NMRI mice were given injections of a mouse retrovirus (OA MuLV) known to induce osteopetrosis, osteoma, and lymphoma. Femur metaphyses and lumbar vertebrae were investigated ultrastructurally 3 d, 7 d and 28 d after infection. Budding, immature and mature virus was observed associated with osteoblasts and osteocytes, but not with osteoclasts or chondrocytes, 28 d after infection with the virus. No production of virus particles was observed in bone-tissue in mock-treated controls. Thus, the primary target cell for OA virus in bone appears to belong to the osteoblastic/osteocytic cell lineage.

Animals↗
PubMed1985

Sensitization to house dust mites in different climatic areas.

With the use of local meteorologic data, the mean monthly indoor relative humidity (RH) was calculated for the area of residence of each of 774 children with respiratory symptoms who were referred to our allergy clinic. Seven hundred fourteen children lived in areas in which the mean indoor RH was 50% or more for 4 or more mo per year ("humid" areas), and 60 children lived where this RH was present for no more than 2 mo per year ("dry" areas). Of those children from the "humid" areas, the skin prick test was positive to Dermatophagoides farinae in 31% and D. pteronyssinus in 40%, whereas in those children from "dry" areas, tests were positive in 3% and 2%, respectively, (p less than 0.001). There was also a marked difference in the degree of sensitivity. In those children with a positive RAST (more than 12% of binding relative to allergen-specific pooled reference sera), the mean level of binding was 51% +/- 3.5% for D. farinae and 62% +/- 4.4% for D. pteronyssinus in children from "humid" areas but never exceeded 14% for either species in those children from "dry" areas (p less than 0.001). Sensitivity to D. farinae and D. pteronyssinus is frequent in "humid" areas and seldom, if it is ever, occurs in areas that are "dry," either as a result of a semiarid climate or a prolonged heating season. These findings have implications for the etiologic diagnosis and specific treatment of atopic patients living in different climatic regions.

Child↗
PubMed1985

Incidence, morphology, and ultrastructure of spontaneous thymoma--the most common neoplasm in W/Nhg rats.

Spontaneous thymoma was observed with an incidence of 97 and 36% in female and male rats, respectively, from an inbred Wistar/Neuherberg strain (W/Nhg). The thymomas often caused dyspnea and were occasionally the direct cause of death. The neoplasms resembled human thymomas and showed a variable cell composition, ranging from mainly lymphocytic to mainly epithelial. The detailed ultrastructural findings are described and compared with those in other rat thymomas and in human thymomas. A characteristic feature of all dividing lymphocytes was the presence of often multilayered, confronting cisternae. As in more than 50% of human thymomas, W/Nhg rat thymomas were not associated with myopathies or any other possibly autoimmune diseases. They may thus offer a useful model for the study of thymoma without associated parathymic syndromes.

Age Factors↗
PubMed1983

The frequency and severity of cat allergy vs. dog allergy in atopic children.

Questions were put to parents accompanying 1238 children, 1 to 17 yr old, who had symptoms of respiratory tract allergy. Skin prick tests were then performed. Symptoms after exposure to cats and positive skin test results from cat hair extract were significantly more frequent than symptoms after exposure to dogs or reactions to dog hair extract. The prevalence of symptoms and positive skin test reactions to cat allergens increased with age, significantly more so than the reaction or symptoms after exposure to dog allergens. The greater frequency of sensitivity to cats was not caused by exposure to cats in more homes, since dogs significantly outnumbered cats as the household pet in both atopic and nonatopic families. However, greater intimacy of exposure to cats when they were present may have been a factor because cats, significantly more often than dogs, were inside the house and in the child's bedroom. Two subgroups were examined to determine whether those with cat sensitivity who owned cats had more severe symptoms than those with dog sensitivity who owned dogs. Numbers were small and differences not statistically significant, but those in the cat subgroup more frequently had persistent allergic nasal symptoms and abnormally low spirometric measurements than did those in the dog subgroup. Our findings indicate that children are more often allergic to cats than to dogs and suggest that the greater frequency of sensitization to cats may be due to increased intimacy of exposure to cats.

Adolescent↗
PubMed1983

Diagnosis of house dust mite allergy in asthmatic children: what constitutes a positive history?

Standardized questions were put to the parents of 530 children, referred consecutively for evaluation of asthma, to determine which features in the history were associated with house-dust mite allergy. Bronchial challenge tests performed on 19 of the children confirmed that there is a highly significant association between a positive skin prick test and a positive bronchial challenge test to Dermatophagoides farinae mite antigen. One hundred and eighteen (23%) of the children had positive prick tests to the mite. There is a highly significant association between a positive prick test to mite and a history that the subject's respiratory symptoms become worse when there is exposure to domestic activity that stirs up house dust (vacuuming, dusting, sweeping, making the bed, or shaking out blankets) or that the symptoms improve when out of doors. Seasonal variation and other features in the history are of little value in distinguishing mite-sensitive from mite-insensitive asthmatics. Although the 4% whose only positive prick test reaction was to mite had significant worsening of asthma during the colder months compared with the remainder, most mite-positive subjects had multiple allergies and had no characteristic seasonal pattern. The presence of a positive prick test to mite was not associated with aggravation of asthma either at night in bed or in the morning on awakening. A history similar to that of mite-sensitive subjects was elicited in those with a positive prick test to house dust. A positive history of house dust or house-dust mite allergy in asthmatics is one in which respiratory symptoms become worse during domestic activity that stirs up house dust or improve when outdoors.

Adolescent↗
PubMed1983

Differences in the physiological response and ultrastructure of human and guinea pig vas deferens. Effects of prostaglandins, irradiation, and temperature.

Marked differences were observed in the mechanical reactions of human and guinea pig vas deferens to prostaglandins, irradiation, and cooling. In human preparations prostaglandin E1 (0.1-1 ng/ml) had an augmentory effect on the contractile response after electrical neurostimulation (10 Hz, 0.3 ms, 3 s), but no visible influence (at concentrations ranging from 1 ng to 10 micrograms/ml) on the contractile response after electrical muscle stimulation (10 Hz, 40 ms, 3 s). In contrast, in guinea pig preparations (PGE1 (0.1-1 ng/ml) had an inhibitory effect on the contractile response after electrical neurostimulation and an augmentory effect (0.1-1 micrograms/ml) on the contractile response after electrical muscular stimulation. Human vas deferens showed higher radiosensitivity than guinea pig preparations. The neurotransmitters acetylcholine and catecholamines increased the radiosensitivity of guinea pig preparations, but not of human ones. Vas deferens reacted to short-time (15-120 s) cooling with an immediate temporary contraction, at 25 degrees C of short (seconds), at 5 degrees C of long (minutes) duration; after rewarming (5-37 degrees C) a second contraction appeared in guinea pig preparations, but not in human ones. Whereas the contraction to electrical neurostimulation (10 Hz, 0.3 ms, 3 s) was abolished in human preparations by cooling, it was only inhibited in guinea pig vas deferens. Electron microscopy showed differences in the ultrastructure of human and guinea pig vas deferens. Muscle cells were more widely separated in human vas deferens (generally 400 nm or more) than in guinea pig (approximately 100-200 nm), and the intracellular space in human preparations contained more collagen. The axons in human preparations contained predominantly large granular and agranular vesicles, those in guinea pig preparations small granular and agranular vesicles. The possible correlation between the physiological response of human and guinea pig vas deferens and the ultrastructural differences is discussed. The results indicate the possibility that other pharmacophysiological and toxicological phenomena could be essentially different in human and guinea pig material.

Alprostadil↗
PubMed1983

Dust-free bedrooms in the treatment of asthmatic children with house dust or house dust mite allergy: a controlled trial.

Twenty asthmatic children with prick tests positive for house dust or house dust mites were allocated to two groups that were matched for severity. One group was provided with zippered vinyl covers for pillows, mattresses, and box springs, and instructions for making the bedroom as easy to keep clean as a hospital ward; the other group was not. At the end of a 1-month study period, there was a marked and statistically significant difference in symptoms and signs of asthma between the two groups. Those with a dust-free bedroom had fewer days on which wheezing was observed, medication was given, or an abnormally low peak expiratory flow rate was recorded. Bronchial tolerance to aerosolized histamine significantly improved in the group whose bedrooms had been modified. A dust-free bedroom diminishes bronchial irritability and is a practical and effective method for decreasing asthma in children with house dust or house dust mite allergy.

Asthma↗
PubMed1982

Short stature and delayed skeletal maturation in children with allergic disease.

The frequency of short stature was assessed in 598 children (66% boys, 34% girls) referred consecutively because of asthma or allergic rhinitis. Six percent were of small stature, with heights of less than the third percentile for age. A total of 66 children with small stature were subsequently studied, 36 of whom had asthma. None had received steroids. Children with short stature were predominantly boys (83%, p less than 0.005) and had delayed bone age (less than 2 SD of mean, 34/45), correspondence of bone age with height age (r = 0.93), normal serum thyroxine but increased tri-iodothyronine levels (11/24), and normal insulin-induced growth hormone secretion (12/12). Their heights corresponded only in part to midparental height. The results were the same for those with and without asthma, and the severity of asthma was not related to the degree of growth retardation. The findings suggest that short stature is more common than expected in children with allergic respiratory disease, both asthmatic and nonasthmatic, that their growth potential is good, and that impaired linear growth is not necessarily a result only of asthma but of a more fundamental abnormality possibly associated with the atopic state. They emphasize the importance of considering allergic respiratory disease in the clinical evaluation of children with small stature.

Adolescent↗