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Biomedical subjects

L Knudsen

Publications and source records attributed to L Knudsen.

At least 109 records · Page 6Linked to original sources

Local blood pressure in chronic leg ulcers.

The local arterial blood supply was evaluated according to clinical criteria in 30 consecutive patients with chronic leg ulcers. Separately, the blood pressure was measured at the ankle level with both strain gauge plethysmography and a Doppler ultrasonic method. In patients with clinical signs of arterial obliterative disease the systolic ankle pressure and the ankle/arm systolic pressure ratio were lower than in patients without such signs. In none of the patients was the local pressure decreased to such a degree that ischemia was the main cause of the ulcer, nor was gangrene imminent. Hence, success or failure of skin grafting or conservative treatment depends primarily on factors other than the nutritive flow, when the perfusion pressure is above 70 mmHg, as in the present study.

Adult↗

Cromones in atopic dermatitis.

Three new cromones have been studied that are supposed to be better absorbed and to have a wider spectrum of anti-allergic activity than disodium cromoglycate. Pretreatment with i.d. injection of 10 microgram FPL 52758 significantly reduced the weal and flare reaction induced by specific antigen in 11 patients with atopic dermatitis. The weal and flare reaction was not reduced in the same patients when 1.5 mg of FPL 52758 was applied topically under occlusion for a 24-h period prior to challenge with antigen. The itch and slight pain caused by antigen injection was not experienced in the FPL 52758 pretreated areas. Preliminary clinical results were obtained with the cromone FPL 52757, but due to possible hepatotoxicity this trial was not completed. Another similar cromone without hepatotoxicity was used in a double blind within-patient study. Nine patients with mild to moderate atopic dermatitis were treated with FPL 57787 (5%) ointment and matching placebo ointment. No significant improvement was observed after 4 weeks of treatment with the cromone containing ointment.

Chromones↗

65Zinc absorption in patients suffering from acrodermatitis enteropathica and in normal adults assessed by whole-body counting technique.

65Zinc absorption was studied in five acrodermatitis enteropathica (AE) patients and in eight normal adults by means of a whole-body counting assay. The absorption was calculated from retention values recorded in the time interval 8-30 days after oral administration of the isotope. Two AE patients (7 and 13 years old) had a low absorption, 3.3 and 1.8% respectively, corroborating their high need for additional elemental zinc (about 2 mg/kg/day). Three adult AE patients, all in their twenties, had a considerably lower need for extra zinc (about 0.2 mg/kg/day). Their zinc absorption ranged from 28 to 36% (mean 34%). In the controls the range was 27 - 65% (mean 43%). Turnover of retained 65Zn from day 8 - 30 was about 0.7% in the patient as well as in the control groups. Oral zinc therapy was withdrawn prior to the study. During the zinc-free period (3-7) a marked decrease in serum zinc and serum alkaline phosphatase values was noted in the two children with AE and they showed clinical evidence of zinc deficiency (angular stomatitis, scaling around finger nails, and irritability). None of the adult patients showed such evidence of impending zinc deficiency. One complained of exacerbation of facial acne, and another of pain in her feet. All symptoms disappeared promptly when oral zinc therapy was resumed.

Acrodermatitis↗

Effects of tetracycline on the absorption of 65zinc in rats.

The effects of tetracycline on the absorption of orally ingested 65Zn was studied on rats by whole body counting assay. 65Zn was given as a single dose to groups of rats, five in each, which were started on tetracycline. Tetracycline was given in daily doses of 25 mg, 50 mg, 100 mg, and 200 mg for 10 days. From the 6th day of the study, 65Zn retention when plotted against time in a semilog plot, approximated linearity. The net absorption of 65Zn in the various groups was determined by extrapolating to zero time the linear curve segment of individual retention curves. Except for the lowest tetracycline dosage, tetracycline significantly impaired 65Zn absorption. The elimination rate of retained 65Zn from the 6th day was significantly higher in the group receiving 200 mg tetracycline as compared with the control group.

Animals↗

Effects of penicillamine and hydroxyquinoline on absorption of orally ingested 65zinc in the rat.

The influence of high doses of 2 chelating agents, D-penicillamine and iodochlorohydroxyquin, on the metabolism of orally ingested 65 Zn was studied on rats by means of whole body counting assay technique. Both drugs were found to increase zinc absorption in a dose-dependent way to values significantly above those of the untreated control group. At identical doses D-penicillamine had a significantly stronger enhancing effect than the 8-hydroxyquinoline derivate, except for the highest dosage which was 100 mg daily. The turnover of the absorbed 65Zn fraction was followed during the time of observation which was 11 days. The elimination rate was practically identical in all experimental groups, except for the 100 mg D-penicillamine group in which the biological half-life of 65Zn was significantly decreased as compared to the control group.

Animals↗

Phenytoin increases 65zinc absorption in the rat.

A single oral dose of 65Zn was given to groups of rats, 6 or 7 in each, which were started on phenytoin. The drug was given in daily doses of 10, 50, and 100 mg for 10 days. The retention of 65Zn was followed by a whole body counter, and the net absorption of 65Zn was calculated. All phenytoin doses studied were found to increase zinc absorption significantly.

Animals↗

Taste dysfunction and changes in zinc and copper metabolism during penicillamine therapy for generalized scleroderma.

The taste function and the zinc and copper levels in serum and urine were followed for up tp 16 weeks in ten patients who were started on penicillamine therapy for generalized scleroderma (9 patients) and rheumatoid arthritis (one patient). During therapy the serum zinc concentration remained unchanged, whereas the serum copper concentration increased significantly during the first 4--5 weeks and then tended to decrease. Urinary copper rose significantly and remained considerably above the upper normal limit throughout the study. Six of the patients complained after about 4--5 weeks of a decreased taste function, which was gradually restored whether the medication was stopped or continued. The alterations in the taste acuity for sweet, salt, sour, and bitter significantly paralleled the variations in urinary copper before as well as during therapy. Thus, the patients who showed the most pronounced loss of taste, had a lower urinary copper output than those whose taste acuity was less disturbed.

Adult↗

Urolithiasis in chronic inflammatory bowel disease.

In a selected material of 228 patients with chronic inflammatory bowel disease (CIBD) the incidence of urolithiasis was 15% (95% confidence limit 11-21). The tendency to urolithiasis is significantly correlated to small-bowel resection and its extent and to obstruction in the urinary tract. On the other hand, there is no definite correlation to the duration or extent of the bowel disease. The significant correlation between urolithiasis and ileal resection is in agreement with the hyperabsorption of oxalate as an important cause of stone formation demonstrated by others. That local factors too play an essential role in the formation of urinary calculi is apparent from the increased incidence of urolithiasis in obstruction of the urinary tract. The incidence of urolithiasis was particularly high (22-25%) among patients with ileostomies. The few and negligible symptoms of and sequelae to, urolithiasis in CIBD encourage a conservative attitude.

Adolescent↗

Acquired zinc deficiency dermatosis in man.

We encountered two cases of acquired zinc deficiency. In one of the patients the state was due to alcoholism with liver cirrhosis and pancreatitis, and in the other patient it was attributed to a small intestine bypass operation for obesity. The skin symptoms included hair loss, acrodermatitis, and widespread eczema craquelé (asteatosis). The cutaneous manifestations of zinc deficiency seem to constitute a characteristic syndrome that might be helpful in recognizing manifest zinc-deficient states in man.

Acrodermatitis↗

Obstructive uropathy in chronic inflammatory bowel disease.

On the basis of intravenous pyelography the frequency of ureteral obstruction was elucidated in retrospect in 140 patients with Crohn's disease and 88 patients with ulcerative colitis. The findings were related to X-ray examination of the gastrointestinal tract and to the clinical condition at the time of examination. 19% of the Crohn patients had ureteral obstruction, typically affecting the right ureter on a level with the linea terminalis. There was a close topographic relationship between radiologically demonstrated intestinal changes and a mass in the homolateral iliac fossa. There was no relation to duration or activity of the disease, urinary tract infections, surgery, or steroid medication. 14% of the patients with ulcerative colitis had ureteral obstruction of varying localization and nearly always arising after colectomy. Renal calculi were found in 13% of the patients with Crohn's disease and in 18% of those with ulcerative colitis. I.v. pyelography is recommended before and after intestinal resection in chronic inflammatory bowel disease to demonstrate the relatively common and often fairly silent urinary tract complications.

Adolescent↗

[Diagnosis and therapy of the zinc deficiency syndrome during total parenteral feeding. Review with report of a case].

A 47-year-old man with ulcerative colitis developed severe zinc deficiency during longterm intravenous feeding. Early symptoms included seborrhoeic lesions in the face and scalp. Later on his general condition deteriorated, and erythema and bullae erupted in the fingers, together with an erosive area with a marked border in the perianeal and scrotal regions. The symptomatology was suggestive of zinc depletion syndrome, a recently recognised acrodermatitis-enteropathica-like disorder in patients receiving longterm total intravenous feeding. A significantly lowered serum zinc level and a prompt beneficial response to intravenous zinc therapy (20 mg Zn2+ daily for one week) substantiate the provisional clinical diagnosis. As zinc depletion is caused by a zinc free parenteral alimentation this serious complication should be avoided by adding zinc to the infusions. Serum zinc determinations should be carried out as a control of the prophylactic zinc supply. Possibly, zinc plays a role in the symptomatology of various disorders with skin and bowel symptoms.

Acrodermatitis↗