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Biomedical subjects

T K Hansen

Publications and source records attributed to T K Hansen.

43 records · Page 3Linked to original sources
PubMed1998

The efficacy of DDAVP is related to the circadian rhythm of urine output in patients with persisting nocturnal enuresis.

OBJECTIVE: Desmopressin may be a useful treatment in some, but not all, patients with nocturnal enuresis. We have evaluated a relation between nocturnal urine output in patients with primary monosymptomatic nocturnal enuresis and the treatment response to synthetic vasopressin. DESIGN: Adolescent or adult enuretics and normal subjects were enrolled in the study and admitted to hospital for a 24 hour investigation of the diurnal variation in urine output, plasma vasopressin (AVP) and plasma atrial natriuretic peptide (ANP). The enuretics were characterized prior to investigation as either 1-desamino-8-D-arginine vasopressin (DDAVP) responders or non-responders. During admission the fluid intake was restricted to 25 ml/kg per day. PATIENTS: Twenty-four patients (15-37 years) with primary monosymptomatic nocturnal enuresis and 9 normal subjects (24-31 years). MEASUREMENTS: Circulating levels of AVP, ANP, plasma electrolytes and plasma osmolality were measured (1400, 2000, 2300, 0200, 0500 and 0800 hours) together with urine volume, urine osmolality and urine electrolytes during daytime and nighttime. Tubular reabsorptive capacity for water, osmoles and creatinine were assessed as well as urinary and fractional excretion rates of sodium and potassium. RESULTS: Controls and DDAVP non-responders had a significant decrease in urine output at night concomitant with a significant plasma AVP amplitude in peak/nadir values although both groups lacked a significant nocturnal increase in AVP. In contrast, in DDAVP responders there was no circadian variation in urine output and thus a nocturnal polyuria together with no oscillation in plasma AVP. The DDAVP responding group had a nocturnal urine production significantly larger than the two other groups. However, the mean 24 hour AVP levels were similar in all groups. The excessive urine production at night in DDAVP responders was accompanied by nocturnal natriuresis due to an increased fractional excretion of sodium. In contrast, nocturnal antidiuresis in controls and DDAVP non-responding enuretics coincided with diminished sodium excretion. Average ANP levels were elevated in both enuretic groups compared to normals, whereas a circadian variation was detected only in the latter. CONCLUSION: It is concluded that DDAVP responsiveness is linked to the nocturnal urine production and that no pathophysiological role can be ascribed to AVP or ANP in DDAVP refractory adolescent and adult enuretics. Moreover, it is suggested that an abnormal tubular handling of sodium may contribute to the nocturnal polyuria seen in DDAVP responders.

Adolescent↗
PubMed1997

Codfish allergy in adults: IgE cross-reactivity among fish species.

BACKGROUND: Fish is reported to be one of the most common causes of food allergic reactions. Species specificity and patterns of cross-reactivity are still to be defined. OBJECTIVE: To demonstrate the immunologic reactivity of clinically codfish-allergic adults to four species of fish: cod, mackerel, herring, and plaice. METHODS: IgE reactivity was measured in eight clinically codfish-allergic adult patients, confirmed by double-blind, placebo-controlled challenges with fresh raw codfish, and in 30 codfish-tolerant control subjects, by means of skin prick test, histamine release test, specific IgE tests, SDS-PAGE, and immunoblotting. RESULTS: All eight patients had positive skin prick tests to plaice and herring, seven of eight to mackerel, whereas fish-induced histamine release from basophil leukocytes was positive in five, four, and six of six patients, respectively. Elevated specific IgE to the fish species was found in all eight, and reactions among the control subjects using an in-house method, the Maxisorp RAST, with freshly prepared fish extracts, were fewer (n = 8) than found with Phadebas RAST (n = 12) and Pharmacia CAP System (n = 11). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting revealed individual and common antigenic proteins in freshly prepared extracts. Sera from all eight patients recognized a protein in the area of 11 to 14 kD in all fish species. This is believed to be a protein fraction analogous to Gad cl. Inhibition of the codfish Maxisorp RAST was obtained with mackerel, herring, and plaice. No cross-reactivity to shrimp or milk was shown. CONCLUSION: This study suggests that serologic cross-reactivity to different fish species in clinically codfish-allergic adults exists, and that cod, mackerel, herring, and plaice share a common antigenic structure.

Adolescent↗
PubMed1996

Codfish allergy in adults. Specific tests for IgE and histamine release vs double-blind, placebo-controlled challenges.

BACKGROUND: At present, several in vitro tests for immunoglobulin E (IgE)-mediated food allergy are available. An estimation of the diagnostic accuracy of the various tests used in predicting clinical sensitivity to codfish in a well-characterized allergic material is necessary. OBJECTIVES: To compare the diagnostic value of four specific IgE tests, and histamine release from basophils (HR) in identifying clinical type I allergy to codfish. As a true diagnosis, double-blind, placebo-controlled food challenges (DBPCFC) were employed. METHODS: Eight clinically codfish-allergic adult patients were investigated together with 30 codfish-tolerant control subjects for evidence of codfish-specific reactivity by Phadebas RAST (PHA), Pharmacia CAP System RAST (CAP), Magic Lite (ML) and HR. To characterize the diagnostic properties of a freshly prepared raw codfish extract, experiments were conducted employing an in-house radioallergosorbent test (RAST), the Maxisorp RAST (MAXI) and HR. Finally, protein profile and IgE-reacting allergens were detected by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. RESULTS: The sensitivities of HR with commercial extract and the three commercially available specific IgE analyses were 0.83 and 1.00 respectively. Specificities were 1.00 (HR) and 0.87-1.00 (specific IgE tests). Freshly prepared codfish extracts improved the sensitivity of HR. SDS-PAGE revealed approximately 29 bands (< 14.3-200 kDa) including a band of 12-13 kDa, and in immunoblotting 18 sera identified 17 IgE-binding bands. The protein migrating at 12-13 kDa was identified in the fresh codfish extract tested with sera from all clinical codfish allergics, while no significant reaction was seen in the control subjects. CONCLUSION: Based on the small number of adult patients included in our study, the in vitro assays with commercial and fresh extracts have high sensitivity and are acceptable for screening for codfish allergy. Specificity of Phadebas, CAP, and our in-house RAST was less than unity, whereas ML and strong binding of IgE to a 12-13 kDa protein completely matches DBPCFC results, and thus seems sufficient for establishing the diagnosis.

Adult↗
PubMed1995

The influence of dietary ethoxyquin on the vitamin E status in broilers.

In a feeding experiment with 48 male broiler chickens was the effect of dietary ethoxyquin and dl-alpha-tocopherol acetate on vitamin E status of chickens investigated. The experimental diets were offered the chickens from the first day of age until the end of the experiment at 42 days. Chickens were fed on diets containing 0, 75, or 150 mg ethoxyquin/kg feed, with (30 mg/kg feed) or without added dl-alpha-tocopherol acetate. The concentration of alpha-tocopherol in plasma of chickens on dl-alpha-tocopherol acetate supplemented diets were significantly higher than those of chickens fed on the nonsupplemented diets. Supplementation with alpha-tocopherol acetate reduced the haemolysis in vitro. Ethoxyquin seemed to have an increasing effect on the concentration of alpha-tocopherol in plasma, but not in the liver. Addition of ethoxyquin to diets without dl-tocopherol acetate reduced the concentration of gamma-tocopherol in plasma. Significant interactions between the addition of ethoxyquin and the addition of dl-alpha-tocopherol acetate to the feed were observed on the haemolysis in vitro and the activity of glutathione peroxidase in plasma. The results indicate that incorporation of ethoxyquin in the diets of chickens exert an improving effect on the vitamin E status of the organism.

Analysis of Variance↗
PubMed1992

Codfish allergy in adults. Identification and diagnosis.

Ten adult patients with a medical history of immediate allergic reactions following ingestion of minute amounts of codfish were examined together with 27 control subjects (8 nonatopics, 7 pollen allergics, and 12 suffering from atopic dermatitis) all regularly ingesting codfish without experiencing reactions. All 37 subjects were evaluated by skin prick test, RAST, and histamine release test in order to determine the value of these commonly used diagnostic tests. The results were compared to titrated, oral, double-blind, placebo-controlled food challenges (DBPCFCs) with fresh codfish undertaken in the 10 patients, whereas all control subjects were classified as challenge-negative according to their questionnaires. Totally, 7 of 10 medical histories were confirmed by DBPCFC, and in these most of the reported symptoms proved reproducible. Oropharyngeal itching and swelling occurred as the first symptom, always preceding the onset of any accompanying symptom. For identification of DBPCFC-positive subjects, skin prick test and RAST proved to be the most sensitive tests (7/7), and all tests showed specificities of 90-97%. The skin prick test still seems reliable but does not, however, exclude the need for DBPCFC.

Adult↗