Biomedical subjects

P K Knudsen

Publications and source records attributed to P K Knudsen.

4 recordsLinked to original sources

PubMed2005

Acid suppression does not change respiratory symptoms in children with asthma and gastro-oesophageal reflux disease.

BACKGROUND: Epidemiological studies have shown an association between gastro-oesophageal reflux disease (GORD) and asthma, and oesophageal acid perfusion may cause bronchial constriction. However, no causative relation has been proven. AIM: To assess whether acid suppression would lead to reduced asthma symptoms in children with concomitant asthma and GORD. METHODS: Thirty eight children (mean age 10.8 years, range 7.2-16.8; 29 males) with asthma and a reflux index > or =5.0 assessed by 24 hour oesophageal pH monitoring were randomised to 12 weeks of treatment with omeprazole 20 mg daily or placebo. The groups were similar in age, gender, mean reflux index, and asthma severity. Primary endpoints were asthma symptoms (daytime wheeze, symptoms at night, in the morning, and during exercise) and quality of life (PAQLQ). Secondary endpoints were changes in lung function and the use of short acting bronchodilators. At the end of the study a repeated pH study was performed to confirm the efficacy of acid suppression. RESULTS: The change in total symptom score did not differ significantly between the omeprazole and the placebo group, and decreased by 1.28 (95% CI -0.1 to 2.65) and 1.28 (95% CI -0.72 to 3.27) respectively. The PAQLQ score increased by 0.62 (95% CI 0.29 to 0.95) in the omeprazole group compared to 0.50 (95% CI 0.29 to 0.70) in the placebo group. Change in lung function and use of short acting bronchodilators were similar in the groups. The acid suppression was adequate (reflux index <5.0) under omeprazole treatment. CONCLUSION: Omeprazole treatment did not improve asthma symptoms or lung function in children with asthma and GORD.

Adolescent↗

PubMed1998

Copper exposure impairs intra- and extracellular acid-base regulation during hypercapnia in the fresh water rainbow trout (Oncorhynchus mykiss).

In order to evaluate the impact of water-borne copper on acid-base regulation in fresh water rainbow trout, chronically cannulated fish were exposed to copper (0.6 mg 1(-1)), hypercapnia (water PCO2 of 6 mmHg) or a combination of copper and hypercapnia, while a fourth untreated group served as the control. Blood samples obtained at 0 h, 4 h and 24 h were analysed for acid-base status, ion concentrations and respiratory parameters. Tissue samples from caudal skeletal muscle, liver and gill filaments were examined for intracellular acid-base status, ion- and water contents, and copper concentration. Exposure to copper alone elicited a small extracellular metabolic alkalosis, no changes in arterial PO2, and a minor decrease in plasma ion concentrations. Hypercapnia alone increased arterial PCO2 from approximately 2 mmHg to 7.2 mmHg, but the extracellular respiratory acidosis present at 4 h was almost completely compensated at 24 h due to an increase in plasma bicarbonate concentration [HCO3-] from 8.1 mM to 24.4 mM. Combined exposure to hypercapnia and copper resulted in a slightly larger acidosis at 4 h, and the fish failed to restore extracellular pH at 24 h, because plasma [HCO3-] only increased to 16.3 mM. Fish exposed to hypercapnia and copper also showed a delayed recovery of intracellular pH in skeletal muscle, compared to fish exposure to hypercapnia only. Thus, copper exposure impaired both extracellular and intracellular acid-base regulation during hypercapnia. When seen in connection with only minor effects of copper on osmoregulatory and respiratory parameters, the reduced ability to regulate acid-base suggests that acid-base regulation may be one of the most copper-sensitive branchial functions.

Acid-Base Equilibrium↗

PubMed1998

Effects of exhausting exercise and catecholamines on K+ balance, acid-base status and blood respiratory properties in carp.

The potential role of adrenergic mechanisms in the recovery of potassium balance and acid-base status following 5 min of exhausting exercise was studied in carp. The extracellular metabolic H+ load after exercise matched the lactate load, suggesting similar release rates of H+ and lactate from white muscle. Blockage of alpha-adrenoceptors by phentolamine or beta-adrenoceptors by propranolol neither influenced absolute magnitudes nor recovery kinetics of extracellular H+ and lactate loads. The arterial oxygen tension increased following exercise, but blood oxygen transport was not improved via a red cell beta-adrenergic response or modulation of the red cell nucleoside triphosphate content. Exercise induced an increase in extracellular [K+] which was corrected within 30-60 min of recovery. The recovery of K+ balance was not influenced by blockage of adrenergic receptors. Red cell [K+] changed only insignificantly following exercise, whereby a possible function of the red cells as a temporary depository for K+ during the extracellular hyperkalaemia could not be established. The minimal influence of catecholamines on the measured parameters during recovery from exercise was supported by an absence of change in these parameters upon adrenaline injection in resting carp.

Acid-Base Equilibrium↗

PubMed1987

Diet and dialysis.

Personal experience shows that subjective and objective improvements can be achieved in chronic renal failure treated with dialysis. These aims were achieved by limiting energy intake to 8 MJ a day and by substituting cassava for bread and potatoes, thereby reducing the intake of protein, sodium, potassium, and phosphorus. Water soluble vitamins were added to the diet. With this regimen blood urea concentrations vary between 2.5 and 12 mmol/l for most of the week and the packed cell volume between 0.30 and 0.37.

Anecdotes as Topic↗