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Biomedical subjects

S Eksborg

Publications and source records attributed to S Eksborg.

At least 109 records · Page 6Linked to original sources
PubMed1982

Protein binding of anthraquinone glycosides, with special reference to adriamycin.

The binding of anthraquinone glycosides (adriamycin, adriamycinol, daunorubicin, daunorubicinol, and 4'epiadriamycin) to human serum albumin and human plasma has been studied by equilibrium dialysis. About 62% of adriamycin was bound to human serum albumin (45 g/l). Only minor variations in the degree of binding were observed between the anthraquinone glycosides. The binding degree of adriamycin in plasma from cancer patients was not significantly different from that observed in healthy volunteers, the fraction of free adriamycin being 24.56% +/- 4.51%, and 27.67% +/- 2.78%, respectively. The plasma albumin concentration was significantly lower in cancer patients than in the healthy volunteers (26.90% +/- 5.88% and 39.24% +/- 1.74%, respectively). In cancer patients the fraction of free adriamycin decreased with increasing plasma albumin concentration.

Adsorption↗
PubMed1981

Toxic epidermal injury following intraarterial adriamycin treatment.

Toxic epidermal injury was induced in the right forearm and thumb of a 74-year-old woman following two courses of 28 mg/m2 Adriamycin infused in the brachial artery with a three-week interval. The toxic epidermal injury was treated with a wet dressing solution and a neomycin cream without corticoids; it healed in one month. Afterwards the woman received 22 courses of Adriamycin intravenously or intraarterially in 5.5 or 11 mg/m2 doses, but the toxic epidermal injury did not occur.

Brachial Artery↗
PubMed1981

Pharmacokinetics of daunorubicin after administration as free drug or as DNA complex in leukemic patients.

An earlier whole-body autoradiographic study in mice revealed large differences between the tissue distribution of daunorubicin (D) after administration as free drug as as DNA-linked D. Therefore, the pharmacokinetics of D administered as free drug or linked to DNA was studied in 15 adult patients with acute non-lymphoblastic leukemia. The data obtained following infusion of free drug over either 45 or 240 min could be fitted to a two-compartment open-body model. With the D-DNA infusion considerably higher plasma concentrations were achieved, with a slower distribution and elimination from plasma than seen after the administration of free drug. this confirmed earlier animal data indicating a different pharmacokinetic behavior of D when it was administered linked to DNA. Furthermore, different pharmacokinetic parameters were obtained for D during infusion and in the post-infusion phase after administration of DNA-linked D (P less than 0.005). This finding strongly indicates that the D-DNA acts as a slow-release preparation in humans, which might modify tissue distribution and toxic side-effects of the drug.

DNA↗
PubMed1980

Determination of chlorambucil in plasma by GLC with selected-ion monitoring.

A GLC technique with selected-ion monitoring is described for chlorambucil determination in plasma using [2H]chlorambucil as the internal standard. Chlorambucil is extracted from plasma with methylene chloride at pH 3 and converted to a thiazane derivative by reaction with 0.1 M sodium sulfide at 80 degrees. The carboxylic group of the chlorambucil derivative is derivatized with allyl bromide using extractive alkylation. Analysis by selected-ion monitoring was performed by focusing at m/e 305 (M) and 313. The relative standard deviation was +/- 5% (n = 5) at the 10-ng/ml level.

Alkylation↗
PubMed1980

Degradation of chlorambucil in aqueous solution.

The stability of chlorambucil and its degradation product 4-[p-(2-chloroethyl-2-hydroxyethylamino)phenyl]butyric acid (I) was studied using reversed-phase high-pressure liquid chromatography. The degradation rate of chlorambucil was unaffected by pH between pH 5 and 10 but decreased at lower pH. The degradation rates of chlorambucil and I differed only slightly (pH < 6). The proteolytic properties of the compounds were studied using spectrophotometric and partition techniques.

Chemical Phenomena↗
PubMed1980

Intravesical instillation of Adriamycin. A model for standardization of the chemotherapy.

Intravesical instillation of Adriamycin has successfully been used in the treatment of bladder tumours. The Adriamycin concentration in the bladder has been monitored and the area under the bladder concentration-time curve, AUC, is proposed to be considered rather than the amount of instilled drug when optimizing the treatment schedules. pH effects which may arise in the bladder when instilling protolytic drugs like Adriamycin are discussed.

Doxorubicin↗
PubMed1979

Liquid chromatographic determination of tetracycline in plasma and urine.

Tetracycline is extracted from plasma (0.50 ml) as an ion pair with tetrabutylammonium into chloroform-1-heptanol (9:1). After re-extraction into an acidic aqueous phase the separation is performed by reversed-phase liquid chromatography using LiChrosorb RP-2 as the support and acetonitrile-water-phosphoric acid as the mobile phase. The chromatographic system shows a high selectivity for the separation of tetracycline analogues. A high detection selectivity is obtained by the use of photometric detection at 357 nm. Analysis of urine is performed by direct injection of the sample into the liquid chromatograph. The precision in the determination of tetracycline in plasma was about 10% (relative standard deviation) at drug levels of 200 ng/ml and 200 microgram. Urine samples containing 20 and 200 microgram/ml of tetracycline were determined with a precision of 3%.

Chromatography, Liquid↗
PubMed1979

Reversed-phase liquid chromatographic determination of plasma levels of adriamycin and adriamycinol.

A method is given for the determination of adriamycin and its main metabolite, adriamycinol in plasma from cancer patients after administration of adriamycin as the free drug or as a complex with DNA. Adriamycin and adriamycinol are extracted in a column from 1 ml of plasma (pH 8.6) using a mixture of chloroform--1-heptanol (8:2). After re-extraction into phosphate buffer pH 2.2, the separation is performed as reversed-phase liquid chromatography on a LiChrosorb RP-2 (5 micron) column with a mobile phase of acetonitrile-water, acidified with phosphoric acid. The precision by quantitation with photometric detection was better than 5% within the range 50-300 ng/ml. Plasma levels of adriamycin and adriamycinol in a cancer patient are presented in this paper.

Chromatography, Liquid↗
PubMed1979

Liquid chromatographic monitoring of daunorubicin and daunorubicinol in plasma from leukemic patients treated with daunorubicin or the daunorubicin-DNA complex.

Fifteen patients with acute nonlymphocytic leukemia have been randomized for treatment with daunorubicin (1.0--1.5 mg/kg) either as the free drug (for 45 min or 4 h) or as the drug bound to a DNA carrier (for 5--6 h). The correlation between plasma kinetics of daunorubicin and its main metabolite daunorubicinol and the different administration schedules of daunorubicin has been studied by reversed-phase liquid chromatography. Plasma concentration kinetics of daunorubicin as well as the daunorubicin-DNA complex was biphasic in character. Maximum plasma level of daunorubicin was found during the infusion period. Its concentration decreased rapidly when the infusion stopped and was below the detection limit of the analytical method 2--4 h later. The data suggests a slower disposition of the duanorubicin-DNA complex compared with the free drug.

Animals↗
PubMed1979

Uptake and distribution of daunorubicin and daunorubicin-DNA complex in mice as studied by whole-body autoradiography and liquid chromatography.

The tissue distribution of daunorubicin (D) and daunorubicin-DNA complex (D-DNA) was studied in mice by means of whole-body autoradiography (WBA) and high-performance liquid chromatography (HPLC). A higher accumulation of radioactivity in the blood after 1 min and a lower initial accumulation in the cardiac muscle were found after administration of 3H-D-DNA than after the infection of free drug. Comparative studies of plasma levels of daunorubicin and daunorubicinol (DOH) in D- and D-DNA-treated animals by HPLC showed that the initial differences were negligible from 2 h onward. A rapid accumulation of D in bone marrow occurred in both D- and D-DNA-treated mice. D reached its maximum level after 1 h and was almost constant for 12 h. A new WBA finding was a rapid and specific accumulation of radioactivity in the pituitary gland, in the thyroid, and in the pancreatic islets, which might be of some interest in consideration of possible late endocrine side effects of anthraquinone glycoside therapy.

Animals↗
PubMed1978

Liquid chromatographic determination of daunorubicin and daunorubicinol in plasma from leukemic patients.

A method is given for the determination of daunorubicin and its main metabolite, daunorubicinol, in plasma from leukemic patients after administration of daunorubicin as the free drug or as a complex with DNA. Daunorubicin and daunorubicinol are extracted from 2 ml of plasma (pH 8.1) using a mixture of chloroform and 1-heptanol (9:1). After re-extraction into phosphoric acid (0.1 M), the separation is performed as reversed phase liquid chromatography on a LiChrosorb RP-2 (5 micrometer) column with a mobile phase of acetonitrile-water, acidified with phosphoric acid. The precision, by quantitation with a photometric detector, was better than 2% within the range 20 ng/ml to 200 ng/ml. Some determinations of plasma levels of daunorubicin and daunorubicinol are presented.

Chromatography, Gas↗
PubMed1978

Reversed-phase liquid chromatography of adriamycin and daunorubicin and their hydroxyl metabolites adriamycinol and daunorubicinol.

Adriamycin and daunorubicin and their metabolites adriamycinol and daunorubicinol were separated by reversed-phase liquid chromatography using LiChrosorb RP-2, RP-8 and RP-18 as supports and acetone, acetonitrile and alcohols as organic modifiers in the mobile phase. The highest separation selectivity was obtained using a mobile phase containing low concentrations (less than 20%) of acetonitrile. The length of the hydrocarbon chains of the surface-modified silica supports had no significant influence on the selectivity. The lowest capacity factor was obtained with 40-60% of organic solvent in the mobile phase. Increasing the length of the hydrocarbon chains of the supports increased the retention of the solutes.

Chromatography, Liquid↗
PubMed1978

A selective method for determination of methylguanidine in biological fluids. Its application in normal subjects and uremic patients.

A selective analytical method for the determination of methylguanidine in plasma in biological fluids has been developed. Methylguanidine is extracted in a column to dichloromethane as an ion pair with hexanitrodiphenylamine (dipicrylamine). It is isolated from coextracted compounds by partition chromatography as the picrate ion-pair. The methylguanidine fraction is collected and after reextraction to a buffer solution the methylguanidine content is quantitatively determined photometrically as picrate. An absolute recovery of 95 +/- 5% was obtained in the concentration range 1.5-10 microgram/ml plasma. The concentration of methylguanidine in plasma was higher in uremic patients, (44.4 +/- 5.71 mumol/l in conservatively-treated and 42.4 +/- 7.87 mumol/l in dialysis-treated patients) than in normal subjects, (4.0 mumol/l), but still lower than reported by other investigators using non-specific methods and also lower than the concentrations found to be toxic in experimental animals. There was a significant correlation between methylguanidine and creatinine concentration but no correlation between methylguanidine and urea concentration in plasma. No obvious relation was found between plasma methylguanidine concentration and various uremic symptoms, mode of treatment or protein intake.

Creatinine↗