Search PubMed⌕ Search

Biomedical subjects

D W Cockcroft

Publications and source records attributed to D W Cockcroft.

At least 163 records · Page 9Linked to original sources
PubMed1978

Effect of Sch1000 in allergen-induced asthma.

Carefully controlled allergen inhalation tests were carried out in twelve subjects to provoke early asthmatic responses with a mean maximum FEV1 fall of 30.7 +/- 5.2% (mean +/- s.d.). Four subjects had additional late asthmatic responses with a maximum mean FEV1 fall of 21.0 +/- 5.9%. The tests were repeated at intervals of 7 days in an identical way, following inhalation of Sch1000 (80 microgram) and placebo, each given 45 min before the onset of the early asthmatic response. This dose of Sch1000 produced a marked and uniform inhibition of methacholine-induced bronchoconstriction in the same subjects. The allergen-induced responses were reproducible in eleven out of the twelve subjects; the coefficient of variation for the decrease in FEV1 in the early responses being +/- 7% and in the late response +/- 43%. Sch1000 produced a slight and variable inhibition of early asthmatic responses (P less than 0.02) and no inhibition of late asthmatic responses. We examined the relationship between the degree of inhibition of the early asthmatic response by Sch1000 and : (a) the degree of inhibition produced by Sch1000 on histamine- and methacholine-induced bronchoconstriction; (b) the level of non-specific bronchial reactivity measured by inhaled histamine and methacholine; and (c) the degree of bronchodilatation produced by Sch1000. No relationship was found.

Administration, Intranasal↗
PubMed1978

Reproducibility and comparison of responses to inhaled histamine and methacholine.

The efficiency of a standardised inhalation test procedure was studied by examining the reproducibility of responses to histamine and methacholine. In addition, the responses to the two agents were compared. Each set of duplicate tests was carried out on a separate day within one week, and all factors known or presumed to influence responses were carefully controlled. The results were expressed as the provocative concentration of the agent causing a 20% fall in forced expired volume in one second (PC20). Responses to histamine and methacholine were highly reproducible (coefficients of determination [r2] = 0.994 and 0.990 respectively). Responsiveness to histamine correlated closely with responsiveness to methacholine (r2 = 0.85). There was a small but significant cumulative dose effect with methacholine (P less than 0.01) but not with histamine. Side effects of throat irritation, flushing, and headache were more frequent with histamine than methacholine, and were dose-related. The high level of reproducibility indicates the efficiency of the test procedure. The similar severity of effects by agents with different mechanisms of action suggests that the primary cause of non-specific bronchial hyperreactivity lies at the level of bronchial smooth muscle.

Adult↗
PubMed1977

Subsittution of inhaled beclomethasone dipropionate for ingested prednisone in steroid-dependent asthmatics.

The effect of inhaled beclomethasone dipropionate (dose, 400 mug daily) was investigated in 31 prednisone-dependent asthmatics. In a double-blind noncrossover study of 25 patients dependent on a daily prednisone dose of 17.5 mg or less, the dose of ingested prednisone was significantly diminished through the use of beclomethasone as compared with placebo (P < 0.001). In a subsequent single-blind study of the 12 patients who had received placebo, a similar decrease in prednisone dose was possible when these patients received beclomethasone. In all 25 patients the effect of beclomethasone was maintained for 2 years; 9 came to require less beclomethasone and 1 required more. In an additional single-blind study of six patients with severe asthma, dependent on prednisone in a dose of 20 to 25 mg/d, the response to beclomethasone was more variable and less significant (P < 0.01). However, at 2 years there was no significant benefit (P > 0.05) and there were two treatment failures.In patients in whom reduction of dose or discontinuation of prednisone was possible plasma cortisol values before and after corticotropin administration increased significantly (P < 0.001). Prednisone reduction was associated with the appearance of mild musculoskeletal steroid-withdrawal symptoms of short duration in 15 patients, and recurrence of symptoms of rhinitis in 15 patients. Side effects of beclomethasone included episodes of hoarseness in 6 and easily treated oropharyngeal Candida albicans infection in 14.

Administration, Oral↗
PubMed1977

Beclomethasone dipropionate aerosol in perennial rhinitis.

Beclomethasone dipropionate aerosol (BDA), 50 mug four times daily sprayed into each nostril, was compared with placebo in a double-blind crossover trial in 26 patients with perennial rhinitis. Patients received BDA for 3 weeks and placebo for 3 weeks; the order of administration was randomized. Response was assessed with daily symptom score cards and twice weekly measurements of nasal airway inspiratory resistance at a standard flow rate of 0.4 L/sec. Symptom score and nasal resistance during BDA treatment were significantly lower than those duirng placebo treatment (p less than 0.02 and p less than 0.05, respectively) in the third week. Eighteen of the patients expressed a preference for BDA, 6 for placebo, and 2 for neither (p less than 0.05). Acceptable symptomatic improvement (moderate or marked) was achieved by 54%. Mild side effects were noted by 5 patients; these included nasal irritation and bleeding in 2, aerosol-induced sneezing in 2, and headache in 1. These side effects occurred in 3 patients who used BDA, 1 who used placebo, and 1 who used both. After a 6-mo follow-up period, in which the dose of BDA was adjusted and concurrent initial oral prednisone was administered to patients who were treatment failures, 73% of the patients obtained moderate or marked symptomatic improvement. No further side effects were noted during this time. Results in those in whom a possible allergic component could be identified were not different from those of the whole group. We conclude that BDA is a useful addition to the therapy of perennial rhinitis.

Administration, Intranasal↗
PubMed1977

Bronchial reactivity to inhaled histamine: a method and clinical survey.

An easy and safe dose-response histamine-inhalation test is described, to measure the level of non-specific bronchial reactivity. The test was performed in 307 subject. Non-specific bronchial reactivity was increased in 3% of presumed normal subjects, in 100% of active asthmatics and in 69% of asymptomatic asthmatics with previous symptoms only at times of exposure to clinically relevant allergens. It was also increased in 47% of patients with cough and no other chest symptoms, in 40% of patients with rhinitis and vague chest symptoms not by themselves diagnostic of asthma, and in 22% of patients with rhinitis and no chest symptoms. The patients with asthma were studied when their asthma was well controlled and when their minimum drug requirements had been established. The mean level of bronchial reactivity increased with increasing minimum drug requirements. The level of bronchial reactivity also showed a strong negative correlation with the forced expiratory volume in 1 sec (FEV1). Atopic subjects, with or without asthma, showed a significant positive correlation between the level of bronchial reactivity and atopic status as indicated by the number of positive allergy skin tests.

Adult↗
PubMed1977

Allergen-induced increase in non-allergic bronchial reactivity.

Non-allergic bronchial hyper-reactivity is a feature of most patients with asthma. We have measured non-allergic bronchial reactivity to inhaled histamine and methacholine in thirteen asthmatic subjects before and after allergen inhalation in the laboratory. The allergen inhalation produced mild early asthmatic responses (19-40% FEV1 fall) in all thirteen, additional definite late asthmatic responses (17-29% FEV1 fall) in four, and equivocal late asthmatic responses (5-11% FEV1 fall) in five. Following allergen inhalation, non-allergic bronchial reactivity increased in seven for up to 7 days. The seven included all four with definite late asthmatic responses and three of the five with equivocal late asthmatic responses. We conclude that allergens make asthma worse, partly through non-allergic mechanisms, and that avoidance of allergens is important in reducing non-allergic bronchial hyper-reactivity.

Allergens↗
PubMed1977

Protective effect of drugs on histamine-induced asthma.

Controlled standardised histamine inhalation tests were carried out in 21 asthmatics to determine the degree of non-specific bronchial hyperreactivity with and without prior treatment with several anti-asthmatic drugs. A significant protective effect was produced by inhaled salbutamol, 200 microgram, ingested salbutamol, 4 mg, inhaled Sch1000, 40 microgram inhaled atropine sulphate, 290 microgram, and ingested choline theophylinate (200 or 400 mg) producing serum theophylline levels over 10 mg/l. Inhaled salbutamol was consistently the most effective and was significantly better than the other drugs. The protective effect between the other four was not significantly different. Drug side-effects occurred only with the ingested drugs. No significant protection was detected after ingested choline theophyllinate producing serum theophylline levels of less than 10 mg/l, inhaled sodium cromoglycate, 20 mg given once or six-hourly for one week, or ingested ascorbic acid, 1 gram.

Albuterol↗
PubMed1977

Dimethyl ethanolamine-induced asthma.

Progressively severe sneezing, rhinorrhea, cough, wheezing, and dyspnea developed in a spray-painter, apparently in relation to exposure to a particular spray paint. A monitoring of exposure at work revealed the development of symptoms and a decrease in peak flow rates. Subsequent challenges in the laboratory performed under conditions resembling occupational exposure resulted in dual asthmatic responses on exposure to the whole paint (98 per cent methyl methacrylate emulsion and 2 per cent dimethyl ethanolamine solution) and to dimethyl ethanolamine solution (2 per cent) alone. Water, methyl methacrylate emulsion, and 1,4 dioxane (0.6 per cent) used as a thinner in the dimethyl ethanolamine did not produce a response in the airways. Allergy skin tests with dimethyl ethanolamine and a mixture of dimethyl ethanolamine and human serum albumin were negative. To our knowledge, this is the first report of asthma and/or rhinitis induced specifically by dimethyl ethanolamine. The mechanism of the specific reactivity is not known.

Adult↗
PubMed1976

Miliary tuberculosis presenting with hyponatremia and thrombocytopenia.

A 74-year-old woman with miliary tuberculosis had moderately severe hyponatremia due to inappropriate secretion of antidiuretic hormone (SIADH) and very severe thrombocytopenia without other hematologic abnormalities. She was treated with isoniazid, rifampin, ethambutol, prednisone, vincristine and fluid restriction and recovered completely. The SIADH may have been a response by the posterior pituitary to a decrease in intravascular volume resulting from the extensive pulmonary disease or associated hypoxia, or the tuberculous lung may have released ADH or an ADH-like substance. The thrombocytopenia may have resulted from a direct or indirect toxic effect of infection or, less likely, the tuberculosis may have activated latent idiopathic thrombocytopenic purpura.

Aged↗
PubMed1976

Beclomethasone dipropionate aerosol in allergic rhinitis.

Treatment with beclomethasone dipropionate aerosol (BDA), 50 mug four times daily in each nostril, was compared with placebo therapy in a double-blind non-crossover trial of 30 matched patients with allergic rhinitis induced by ragweed pollen. The trial was started at the beginning of the ragweed season and continued for 42 days. Response to treatment was assessed from information on daily diary cards, weekly objective measurements of nasal patency and measurement of total eosinophil count (TEC) before treatment and at week 4. Patients in the BDA group had significantly less (P less than 0.05) sneezing, rhinorrhea and nasal stuffiness at 36 days, cough at 10 days and antihistamine consumption at 17 days. There was no significant difference between the groups in eye symptoms, nasal airway inspiratory resistance, maximum inspiratory nasal flow or TEC. Overall comparison with previous pollen seasons by the patients indicated moderate to great improvement in 86% of the BDA group and in 13% of the placebo group (P less than 0.01). Minor side effects were noted by two patients in each group.

Adult↗
PubMed1976

Endobronchial lipoma: two cases and review of the literature.

Endobronchial lipoma is a benign tumour of the large bronchi occurring in middle-aged men. To the 38 successfully treated cases in the English literature a further 2 are added. The symptoms are those of obstructive pneumonitis mimicking bronchogenic carcinoma, and the result of delayed therapy may be bronchiectasis. Treatment includes local resection through a bronchoscope or a bronchotomy incision, or removal, if necessary, of the obstructed lobe or lung at thoracotomy. Smoking may be important in the pathogenesis of this tumour.

Adult↗
PubMed1976

Factors in allergen-induced asthma: relevance of the intensity of the airways allergic reaction and non-specific bronchial reactivity.

Early asthmatic responses (EAR) of similar severity were produced by allergen inhalation challenges in nine asthmatic subjects. The severity of the airways allergic reaction was estimated by measuring the skin test weal size produced by the same dilution of allergen which caused the EAR. The non-specific bronchial reactivity was assessed by inhalation of incresing concentrations of histamine acid phosphate. Possible relationships between the severtiy of the airways allergic reaction, the level of non-specific bronchial hyper-reactivity and the pattern of asthmatic response were examined. There was a marked inverse correlation between the required severity of the airways allergic reaction and the non-specific bronchial reactivity (log10) of the individual (r = -0-96, P less than 0-001). The EAR was followed by a late asthmatic response (LAR) in five subjects. There was no evident correlation between the magnitude of the EAR and that of the LAR. In addition, no correlation was obtained between the pattern of response interms of EAR or LAR and the severity of the allergic reaction, or the level of non-specific bronchial reactivity. These results indicate that the allergic reaction and the non-specific bronchial reactivity are interrelated in the production of allergen-induced asthma. Thus a mild allergic reaction will induce and EAR in patients with markedly increased non-specific bronchial reactivity, whereas a severe allergic reaction is required to produce an EAR in those with only slightly increased non-specific reactivity. The lack of correlation between the occurrence of the LAR and the intensity of the airways allergic reaction, the non-specific bronchial reactivity and the intensity of the EAR indicates that other factors are involved in the development of LAR.

Adolescent↗
PubMed1976

Prediction of creatinine clearance from serum creatinine.

A formula has been developed to predict creatinine clearance (Ccr) from serum creatinine (Scr) in adult males: (see article)(15% less in females). Derivation included the relationship found between age and 24-hour creatinine excretion/kg in 249 patients aged 18-92. Values for Ccr were predicted by this formula and four other methods and the results compared with the means of two 24-hour Ccr's measured in 236 patients. The above formula gave a correlation coefficient between predicted and mean measured Ccr's of 0.83; on average, the difference predicted and mean measured values was no greater than that between paired clearances. Factors for age and body weight must be included for reasonable prediction.

Adolescent↗
PubMed1967

Calcitonin from ultimobranchial glands of dogfish and chickens.

Acid extracts of thyroid glands from a small shark Squalus suckleyi and domestic fowl Gallus domestica contained no detectable calcitonin activity, while very potent hypocalcemic responses were obtained in rats with similar extracts from the ultimobranchial glands of these two species. The calcitonin concentration was 4 to 40 times that present in hog thyroid, which, as in most other mammals, contains ultimobranchial tissue. The evidence suggests that calcitonin is a fundamental calcium-regulating hormone present in all higher vertebrates and that it is an ultimobranchial rather than a thyroid hormone. It also indicates an important and hitherto unrecognized function for the ultimobranchial glands.

Animals↗