Search PubMed⌕ Search

Biomedical subjects

E Larsen

Publications and source records attributed to E Larsen.

At least 127 records · Page 7Linked to original sources
PubMed1981

Pharmacokinetic comparison of seven 8-methoxypsoralen brands.

The pharmacokinetics of seven 8-MOP brands were evaluated in 7 volunteers using an incomplete bloc design. After a single oral dose the 8-MOP plasma level was followed for 3 hours. The plasma concentration was measured with a gas chromatographic - mass spectrometric method, using an isotopic dilution technique. The different brands could be divided into three groups. Two gave a high maximum concentration, four a medium, and one a low concentration. The large interbrand variation observed in this study can explain the variations in the results of the treatment and the differing numbers of joules required to clear the patients in various PUVA centers.

Adult↗
PubMed1980

N-Nitrosodiethanolamine revisited.

N-nitrosodiethanolamine is believed to be a weakly carcinogenic chemical, and as it occurs widely--in consumer products for example--it may constitute a significant hazard to humans. However, the chemical evidence concerning the identity, purity and properties of N-nitrosodiethanolamine is incomplete, and this casts some doubt on the basis of the current interest in this substance. In the present paper a purification procedure of synthetic N-nitrosodiethanolamine based on high-performance liquid chromatography is given. Other fractionation procedures such as gas liquid chromatography, ambient pressure column chromatography and distillation are shown to be inadequate. The purity and identity of purified N-nitrosodiethanolamine is established by means of electron impact and field ionization mass spectrometry, including metastable defocusing and collision induced decomposition techniques. Furthermore, 1H and 13C nuclear magnetic resonance and, to a lesser extent, infrared and ultraviolet spectroscopy are used. Deuterium labelled analogues of N-nitrosodiethanolamine and the parent diethanolamine are employed in rationalizing the results obtained.

Carcinogens↗
PubMed1980

Pharmacokinetic and clinical comparison of two 8-methoxypsoralen brands.

We compared the Danish 8-MOP brand Meladinine with the Austrial brand Oxsoralen because of our discouraging result with PUVA in treating psoriasis. Nine healthy volunteers participated in the investigation. The plasma level of 8-MOP was measured by a gas chromatogrpahic-mass spectrometric method using isotopic dilution technique. The level obtained with Oxsoralen was on the average 5.8 times higher than that with Meladinine.

Fasting↗
PubMed1978

Thallium intoxication treated with long-term hemodialysis, forced diuresis and Prussian blue.

A 56-year-old woman, who ingested 2 g of thallium sulfate, was successfully treated with long-term hemodialysis for 200 hours during ten days, combined with forced diuresis and Prussian blue. The effect of the artificial kidney dialysis was determined by repeated analysis of the thallium concentration in the dialysis bath and in blood samples. During the first 120 hours of hemodialysis, 143 mg of thallium was eliminated via the artificial kidney and 110 mg via the urinary tract. The present case of acute thallium intoxication is the first in which long-term hemodialysis has been used in the acute phase together with forced diuresis and Prussian blue. The data obtained are compared to those obtained from cases treated with hemodialysis in the past. It is concluded that treatment with hemodialysis should be considered as an important supplement to treatment with forced diuresis and Prussian blue in cases of thallium intoxication.

Antidotes↗
PubMed1977

Determination of mass spectrometric sensitivity of different metalloporphyrin esters relative to porphyrin ester.

Quantitative determination of metalloporphyrin contamination in preparations of biologically important porphyrins was achieved mass spectrometrically by application of the integrated ion current technique. For this purpose, the relative molecular ion sensitivities of the contaminating metal complexes were determined from the ratios of the integrated molecular ion currents of a series of calibration samples containing a porphyrin ester and one of its metal complexes in known molar ratio. Complexes formed with divalent ions of Cu, Zn, Fe, Co and Ni of copro- as well as uro-porphyrin permethylester were all found to have the same molecular ion sensitivities as their metal-free porphyrin ester. The relative metalloporphyrin ester content in a sample of porphyrin ester was thus obtained directly as the integrated ion current ratios of the normalized molecular ions. The preparation of calibration samples, including complex formation and the mass spectrometric methodology, is described and discussed.

Chemical Phenomena↗
PubMed1976

Mucociliary function of the eustachian tube: assessment by saccharin test in patients with dry perforations of the tympanic membrane.

The mucociliary function of the Eustachian tube was assess in 44 patients with dry perforations of the lympanic membrane by means of the saccharin test. A saccharin crystal was placed on the mucous membrane of the middle ear as close to the orifice of the Eustachian tube as possible, and the time taken for the patient to taste the saccharin was measured. The function of the Eustachian tube was also assessed by means of the aspiration test and by the Valsalva maneuver. No relationship was found between the results of the saccharin test, aspiration test, and the Valsalva maneuver. However, a correlation seems to exist between the hearing improvement obtained as determined by the postoperative air-bone gap, the positive or negative results of the saccharin test, and (in cases with positive saccharin test) the saccharin perception time.

Adolescent↗