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Biomedical subjects

K Knol

Publications and source records attributed to K Knol.

At least 55 records · Page 3Linked to original sources
PubMed1989

The reproducibility and agreement of three indices of airway responsiveness to histamine in asthmatic children.

In 12 asthmatic children, aged 8-14 years, we investigated the possibility of using a provocation concentration of histamine (PC) causing a 10% or 15% fall in baseline forced expiratory volume in 1 sec (FEV1), instead of a PC20 histamine, in the assessment of bronchial hyperreactivity. Inhalation challenge tests were performed on days 6 and 7 after withdrawal of medication. PC10, PC15, and PC20 were calculated from the dose-response curves. Reproducibilities for PC10, PC15, and PC20 values for both days, determined by Student's t-test, were not significantly different. Correlation coefficients between PC20 and PC15 values on days 6 and 7 and between PC10 values on days 6 and 7 were 0.82 and 0.76, respectively; between PC20 values on day 6 and PC15 values on day 7; and between PC20 values on day 6 and PC10 values on day 7 they were 0.84 and 0.82, respectively. (P less than 0.01 for all r values). The predictive value of PC20 for PC10 and PC15 was determined by a least-squares regression line with 95% confidence intervals. Variances between PC10, PC15, and PC20 were not significantly different on either day 6 or 7. Our data show that a PC10, as well as a PC15, can be used in the assessment of the degree of bronchial hyperreactivity in children with asthma.

Adolescent↗
PubMed1989

Hypercalcaemia in a child with miliary tuberculosis.

Hypercalcaemia and hypercalciuria were diagnosed in a 21-week-old boy with miliary tuberculosis. The tuberculosis was treated with isoniazid, rifampin and streptomycin. After 2 months, streptomycin was replaced by ethambutol. The hypercalcaemia was treated initially with prednisone, which decreased the serum 1.25 (OH)2 cholecalciferol level but the serum calcium level remained unaltered. After calcium and vitamin D restriction, the serum calcium level normalized within 1 day. The patient's tuberculosis was treated and he remains well.

Calcium↗
PubMed1989

Survival and clinical outcome in patients with cystic fibrosis, with or without neonatal screening.

After an experimental neonatal screening program for cystic fibrosis had been carried out in the Netherlands during 1973 to 1979, a follow-up study to evaluate the effects of neonatal screening was started in 1980. Although before 1980 the management of patients with cystic fibrosis was partly left to local hospitals, from the start of the follow-up program all patients in the study received similar treatment. A cumulative survival rate, calculated with exclusion of the patients with meconium ileus, showed at the age of 11 years a significantly better survival rate (p less than 0.05) for the 19 patients from the screened population (88%) than for the 25 patients from the nonscreened population (60%). Clinical condition was assessed on entry and at the age of 9 years in 16 screened and 20 nonscreened patients. On entry, comparison showed significantly better chest radiograph scores for the screened patients but no other significant differences. At the age of 9 years, after several years of similar treatment for all patients in the study, significantly better clinical (p less than 0.02) and chest radiograph scores (p less than 0.01), lower IgG levels (p less than 0.05), and higher vitamin A levels (p less than 0.01) were observed in the screened patients. Our study results suggest that early diagnosis and appropriate treatment may prevent serious deterioration and death at a young age, and may reduce the extent of early irreversible lung damage in patients with cystic fibrosis.

Albumins↗
PubMed1989

Circadian change in bronchial responsiveness and airflow obstruction in asthmatic children.

To throw light on the question of whether the increase in bronchial responsiveness seen during the night is due to increased airflow obstruction, nine asthmatic children with increased airflow obstruction at night (group 1) were compared with nine without (group 2). The mean fall in forced expiratory volume in one second (FEV1) between 16.00 and 04.00 hours was 21.9% in group 1 and 2.3% in group 2. Selection of patients was based on the amplitude of change in peak expiratory flow (PEF) measured every four hours for three consecutive days at home. The study was performed in hospital on four consecutive days. Medication was withheld for three days before and during the measurements at home and in hospital. On the first day in hospital (day 4) FEV1 was measured every four hours for 24 hours. On day 6 inhaled histamine provocation tests were performed at the same times as the FEV1 measurements on day 4. Both groups showed a nocturnal fall in the provocative dose of histamine causing a 20% fall in FEV1 (PC20). The mean change in histamine PC20 from 16.00 to 04.00 hours was 1.1 doubling doses of histamine in group 1 and 1.5 doubling doses in group 2. The results indicate that the increase in nocturnal bronchial responsiveness that occurs at night is not due to an increase in airflow obstruction.

Adolescent↗
PubMed1989

Prognosis of asthma from childhood to adulthood.

The outcome of childhood asthma was studied in 101 adults who came from a group of 119 asthmatic children (85%) 6 to 14 yr of age who had originally been investigated between 1966 and 1969. Changes in respiratory symptoms, spirometry, and airway responsiveness to histamine in childhood and adult life were analyzed. It was found that 43 of the 101 adults (43%) had current symptoms; 29 of the 43 (67%) were receiving maintenance therapy. In the first study, 83 of the 101 children (82%) showed a response on inhalation of histamine (PC10-histamine less than or equal to 16 mg/ml). The number of subjects in the second study who still had a PC10-histamine less than or equal to 16 mg/ml fell to 29, suggesting that airway responsiveness decreases from childhood to adulthood. During the second survey (in adults), 25 of the 43 (59%) subjects with current symptoms and four of the 58 (7%) without respiratory symptoms responded to histamine. Adults with current symptoms had a significantly lower %FEV1 in both childhood and adulthood than did adults without current symptoms; %FEV1 was not different in females and males or in smokers and nonsmokers in either the first or the second survey. The outcome of childhood asthma is primarily predicted by the initial degree of bronchial obstruction (p = 0.041) and airway responsiveness to histamine (p = 0.050), and does not appear to be related to sex, smoking habits, or age of onset of respiratory symptoms.

Adolescent↗
PubMed1988

The effect of reduction of maintenance treatment on circadian variation in peak expiratory flow rate values in asthmatic children.

We investigated in well controlled asthmatic children whether it is possible to predict by measuring daytime forced expiratory volume in one second, the decline in nocturnal peak expiratory flow rate values after withdrawal of maintenance medication. Forced expiratory volume in one second and peak expiratory flow rate were measured in the outpatient clinic, on the last day with medication. Peak expiratory flow rates were then measured every four hours on days 4, 5 and 6 without medication. Seventeen children showed an amplitude in circadian peak expiratory flow rate values of more than 20% (group I) and nine children showed an amplitude of 20% or less on the three study days (group II). Mean values +/- SEM were 34.7 +/- 2.1% and 10.5 +/- 1.5%, respectively. Forced expiratory volume in one second values were comparable in both groups. Daytime peak expiratory flow rate values before and after withdrawal, remained on the same level in both groups. In group I peak expiratory flow rate values of 24.00 and 08.00 hours on day 6 were significantly lower (p less than 0.05) than on day 4. The results indicate that history and daytime pulmonary function measurements alone, are insufficient to assess the clinical situation and suggest that a decrease in early morning peak expiratory flow rate value (08.00 hours) is an early sign of deterioration of the disease state, after reduction of medication.

Adolescent↗
PubMed1988

Propranolol inhalation challenge in relation to histamine response in children with asthma.

The relation between airway responsiveness to propranolol and histamine was studied in 32 asthmatic children. Propranolol and histamine were given by nebuliser to a maximum dose of 16 mg/ml and 32 mg/ml respectively and the response was measured as the provocative concentration of agonist causing a 20% fall in FEV1 (PC20). A PC20 histamine value of less than 32 mg/ml was obtained in 24 of the 32 children, of whom 15 had a measurable PC20 propranolol (less than 16 mg/ml). In these 24 children the geometric mean PC20 histamine was 4.5 mg/ml and 14.4 mg/ml respectively in those with and without a measurable PC20 propranolol (p = 0.023). There was a linear relationship between histamine and propranolol PC20 values (r = 0.60), and between PC20 histamine and FEV1 % predicted (r = 0.43), but not between PC20 propranolol and FEV1 % predicted (r = 0.38). In an open time course study in 12 children with asthma recovery of FEV1 after inhaled propranolol was incomplete in seven of the children after 90 minutes. When inhaled propranolol was followed by inhaled ipratropium bromide in a further 11 children FEV1 had returned to baseline in all children after 60 minutes. Thus propranolol inhalation can be used in children with asthma to assess the contribution of the beta adrenergic system to the regulation of bronchial smooth muscle tone. The test has several disadvantages in comparison with histamine provocation-long duration, the prolonged action of propranolol, and the fact that only the children with substantial hyperreactivity to histamine react to propranolol.

Adolescent↗
PubMed1987

Fulminant hepatitis during treatment with rifampicin, pyrazinamid and ethambutol.

A 10-year-old girl with cervical tuberculosis was treated with Isoniazid, Rimfampicin and Ethambutol. After 2 weeks of treatment a hepatotoxic reaction developed. Withdrawal of therapy resulted in complete clinical improvement and in normalization of all laboratory measurements. Treatment was restarted with Rifampicin, Pyrazinamid and Ethambutol. Liver enzyme levels were monitored weekly. Seven weeks after this three-drug regiment was started, all therapy was discontinued because of elevated liver enzyme levels. However, the patient died 2 weeks later of progressive fulminant hepatitis.

Cervical Vertebrae↗
PubMed1987

Recovery of FEV1 after histamine challenge in asthmatic children.

Factors that influence the time necessary for complete recovery of FEV1 after inhaling histamine were analysed in forty-five children with asthma. These included the initial bronchial obstruction (baseline FEV1), the provocation dose of histamine producing a 20% fall in FEV1 (PD20) and the fall in FEV1 after the histamine challenge. In addition it was also investigated whether a second challenge carried out after complete recovery of FEV1 would produce a reproducible PD20-histamine value. The time for complete recovery varied widely from 15 to more than 75 min. The time needed for complete recovery of FEV1 after the histamine challenge seems to be mainly determined by the PD20 value. The other factors such as initial bronchial obstruction and the fall in FEV1 after the challenge showed no significant relationship with the recovery time. A second challenge with histamine resulted in a highly reproducible PD20 value. The clinical implication of this study is that other tests can only be performed when FEV1 has returned to 95% of baseline.

Adolescent↗
PubMed1987

Effect of screening for cystic fibrosis on the influence of genetic counseling.

We studied the influence of genetic counseling for cystic fibrosis on family planning, using neonatal screening, family size at time of diagnosis, and maternal age as possible determinants for reproductive behaviour. The expected number of children born to mothers of equal age and parity in the same period was approximated on the basis of population statistics. These numbers were compared to the numbers of children born in the study group after a CF diagnosis and information on the 25% recurrence risk were given. A 50.8% reduction in childbirth was found in the study group, although 77% of families had decided against further high-risk pregnancies. No statistically significant influence of neonatal screening could be demonstrated, but this may be due to the small number of families involved.

Adult↗
PubMed1987

Screening for cystic fibrosis. A comparative study.

A neonatal screening program for CF by determination of albumin in meconium was performed in the north eastern part of the Netherlands from 1973 to 1979. In this period 94,043 newborns were screened and 116,953 were not. A follow-up study of CF patients in the above cohorts was started in 1980. The purposes of this study were to evaluate the effects of early diagnosis and treatment in CF patients by comparing the outcome in the two groups of patients. Although the results indicate that very early diagnosis and treatment have a beneficial effect on outcome, more studies are needed before a definite answer can be given as to whether or not mass neonatal screening should be started.

Albumins↗