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Biomedical subjects

S Lundgren

Publications and source records attributed to S Lundgren.

At least 73 records · Page 4Linked to original sources

Distribution of 4-hydroxy-N-desmethyltamoxifen and other tamoxifen metabolites in human biological fluids during tamoxifen treatment.

Several metabolites of tamoxifen, including 4-hydroxy-N-desmethyltamoxifen (metabolite BX), 4-hydroxytamoxifen (metabolite B), N-desmethyltamoxifen (metabolite X), the primary alcohol (metabolite Y), and N-desdimethyltamoxifen (metabolite Z) were identified and their concentrations determined in fluids and feces from patients receiving chronic tamoxifen treatment. The biological samples investigated were serum, pleural, pericardial and peritoneal effusions, cerebrospinal fluid, saliva, bile, feces, and urine. In serum, tamoxifen itself, and the metabolites X and Z were the prevailing species, but significant amounts of the metabolites Y, B, and BX were also detected. About 3 h after drug intake tamoxifen as well as Y, B, BX, X, and Z showed a peak in serum. This may be explained by efficient metabolism of the metabolite precursor before being distributed to peripheral compartments. Upon drug withdrawal all metabolites showed first-order elimination curves which paralleled that of tamoxifen suggesting that their rate of elimination exceeded that of tamoxifen and that the serum levels are production rate limited. The protein binding of tamoxifen and its major serum metabolites (Y, X, Z) was determined and found to be higher than 98%. Albumin was the predominant carrier for tamoxifen in human plasma. The concentrations of tamoxifen and its metabolites in pleural, pericardial, and peritoneal effusions equalled those detected in serum, corresponding to an effusion/serum ratio between 0.2 and 1. Only trace amounts of tamoxifen and metabolite X were detected in cerebrospinal fluid (CSF/serum ratio less than 0.02). In saliva, concentrations of tamoxifen and X exceeded the amounts of free drug in serum, suggesting active transport or trapping of these compounds in the salivary gland. Bile and urine were rich in the hydroxylated, conjugated metabolites (Y, B, and BX), whereas in feces unconjugated metabolite B and tamoxifen were the predominating species.

Adult↗

Megestrol acetate versus aminoglutethimide for metastatic breast cancer.

In this prospective, randomized study the clinical response and toxicity of megestrol acetate (MA) and aminoglutethimide (AG) as second-line treatment in patients with metastatic breast cancer was compared. 176 patients were included, and 150 received treatment greater than 8 weeks and are evaluable for treatment response. The two groups did not differ with regard to prognostic factors. Response rate for the AG and MA groups were 34% and 31% respectively, with duration of response of 13.1 and 13.0 months. Stable disease was obtained in 33% and 35% respectively. No difference was observed in survival. Side effects occurred more frequently in the AG group (42%) than in the MA group (18%).

Aged↗

Oral high-dose progestins as treatment for advanced breast cancer.

Fifty-two postmenopausal, previously treated advanced breast cancer patients who received oral high-dose progestins (medroxyprogesterone acetate [MPA] and/or megestrol acetate [MA]) were retrospectively reviewed. MPA was given to 45 patients and MA to 17 (10 earlier treated with MPA); 48 were evaluable for clinical response to progestin treatment, 43 for MPA and 5 for MA. Two complete responses and 10 partial responses (25%) with median duration of 9.5 months were seen. Forty percent of the patients obtained stable disease greater than or equal to 6 months with a median duration of 8.0 months. In patients with estradiol receptor positive (n = 31) and estradiol and progesterone receptor positive (n = 19) tumors the response rates were 35% and 37% respectively. No differences in serum levels of MPA or MA were observed in the different responding groups. The serum levels of MA were twice as high as MPA in spite of a dose of 160 mg/day of MA compared to 1,000 mg/day of MPA. A long disease-free interval, and positive receptor status of primary or metastatic lesions seemed to predict response to endocrine therapy even late in a therapeutic sequence. Side effects occurred in 11/45 (24%) of MPA treated patients and in 1/15 (7%) of MA treated patients. No difference in serum levels of MPA was found between patients with side effects and patients without side effects.

Administration, Oral↗

[Which hormone therapy should be used in advanced breast carcinoma in males?].

A 76-year-old man with advanced carcinoma of the breast who had not been orchiectomized underwent sequential hormonal treatment. The tumour progressed during monotherapy with dexamethasone. Objective regression of the tumour followed sequential administration of tamoxifen (twice) and the two aromatase inhibitors, aminoglutethimide and testololactone. In addition, his condition remained stable on two progestogens in high doses, medroxyprogesterone acetate and megestrol acetate.

Adenocarcinoma↗

Pharmacokinetics and metabolism of medroxyprogesterone acetate in patients with advanced breast cancer.

The pharmacokinetics and metabolism of medroxyprogesterone acetate (MPA) were studied in patients with advanced breast cancer after i.v. injection and oral administration of [3H]MPA. MPA was distributed very rapidly into three compartments after i.v. injections, revealing half-lives of 4-7 h. Using a nonlinear model fitting metabolic clearance rates (MCR) were found to be 652 1/day before and 601 1/day during MPA treatment, and distribution volumes (V0) 5.9 and 3.41 respectively. The major metabolite of MPA following i.v. injection was a glucuronide of MPA, presumably of the 3-enol form. After oral administration the radioactivity in serum increased rapidly and reached a plateau of about 1% of the dose per litre serum after approx 2 h. About 80-90% of the radioactivity was found in the water phase after hexane extraction, persumably as glucuronides of metabolites more polar than MPA. Radioimmunoassay (RIA) of MPA in untreated serum samples showed 3-8-fold greater MPA values as compared to measurements in hexane extracts of serum. Ethanol extraction did not remove these interfering substances. Extraction of serum with a low polar solvent before RIA of MPA is essential in order to prevent great overestimation, as the glucuronidated polar metabolites most likely will crossreact in an assay with an antiserum raised against a MPA-3-O-carboximethyloxime coupled to bovine serum albumin.

Administration, Oral↗

Sedation as an alternative to general anaesthesia.

Dental patients are generally in good health, the procedures are often short, and it is fear and anxiety about pain rather than the nature of the procedure that dictates the use of sedation or general anaesthesia. Indications and contra-indications for sedation, appropriate agents and techniques, and facilities and personnel needed for managing and monitoring patients are discussed. Safe and effective use of sedation in combination with local anaesthesia is a realistic alternative to general anaesthesia for many outpatient procedures.

Anesthesia, Dental↗

Intravenous or rectal administration of sedatives in outpatient oral surgery.

A number of cross-over studies on sedation in outpatient oral surgery investigated the quality of sedation produced by intravenous or rectal administration of diazepam. The sedation methods were equally efficient with a mean dose of 0.24 mg/kg (range 0.1-0.4) for i.v. administration and 0.53 mg/kg (range 0.5-0.6) for rectal administration. Eighty-five per cent of the patients preferred surgery under sedation and local anaesthesia to local anaesthesia alone. The patients preferred the session in which they experienced stronger sedation, regardless of the route of administration.

Administration, Rectal↗

Effect of oral high-dose progestins on the disposition of antipyrine, digitoxin, and warfarin in patients with advanced breast cancer.

The influence of two progestins, medroxyprogesterone acetate (MPA) and megestrol acetate (MA), given orally in high doses, on the pharmacokinetics of antipyrine, digitoxin, and warfarin were studied in patients with advanced breast cancer. Antipyrine and warfarin were given as a single test dose before and after 5 weeks of progestin treatment. The pharmacokinetics of digitoxin was investigated at steady state in patients receiving this drug therapeutically before and during treatment with progestins. Small changes in clearance rates for antipyrine, warfarin, and digitoxin were found. A minor decrease observed in warfarin clearance however may be of clinical importance. Half-lives decreased by 13% for antipyrine and increased by 71% for warfarin. High-dose progestins given orally do not seem to have a major influence on drug metabolism, probably reflecting a minor effect on drug and steroid-metabolizing microsomal mono-oxygenases in the liver.

Administration, Oral↗

Intravenous or rectal diazepam for outpatient sedation in minor oral surgery.

In a randomized cross-over study on sedation in outpatient oral surgery, intravenous and rectal administration of diazepam were compared. The mean dose for intravenous diazepam was 0.22 mg X kg-1 (range 0.15-0.38) and for rectal diazepam 0.58 mg X kg-1 (range 0.50-0.71). The determining factors for the patients' preference for sedation method, apprehension, effect produced by the sedative, recovery from sedation and the postoperative course were studied. The patients preferred the session in which they experienced stronger effect, regardless of the route of administration. Patient preference for sedation method did not differ when optimal dose regimens were used, and a preset dose of 10 mg rectal diazepam did not produce the desired effect. Apprehension was significantly higher prior to and during the first operation than the second operation, and all patients recovered from sedation within 2 1/2 hours after the administration.

Adolescent↗

Comparison of rectal diazepam and subcutaneous morphine-scopolamine administration for outpatient sedation in minor oral surgery.

In a randomized cross-over study on sedation in outpatient oral surgery, subcutaneous administration of morphine-scopolamine was compared with rectal administration of diazepam. The mean dose of morphine was 0.13 mg kg-1 (range 0.13-0.24) and of diazepam 0.57 mg kg-1 (range 0.50-0.71). Apprehension, the determining factor for patients' preference for sedation method, the recovery from sedation and the postoperative course were studied. Both methods produced the desired effects. For diazepam, the effect was scored higher by the patient than the nurse observer and for morphine-scopolamine the opposite was found. Postoperative pain and patients' preference for sedation did not differ between the methods and the determining factor for the patients' preference for sedation method was the experience of stronger tranquilization. Side-effects such as prolonged recovery, nausea, dizziness, and dysphoria were frequent during the postoperative course after the morphine-scopolamine sedation but were not seen during diazepam sedation. Thus, rectal administration of diazepam should be preferred to morphine and scopolamine for sedation in minor oral surgery performed under local anesthesia.

Adolescent↗

Sequence of an epidermal growth factor-binding protein.

A cDNA clone has been isolated that corresponds to the entire translated region of the mRNA coding for the epidermal growth factor-binding protein type B. The complete nucleotide sequence and the predicted amino acid sequence of the protein were elucidated. The protein sequence was compared to some related serine proteases. This comparison supports the notion that several serine proteases suggested to be involved in the processing of precursors to polypeptide hormones and growth factors are closely related to each other. It appears that these proteases are descendants of a common ancestral gene and thus form a distinct subfamily among the serine proteases.

Amino Acid Sequence↗

Comparison of sedation, amnesia, and patient comfort produced by intravenous and rectal diazepam.

In a cross-over study, intravenous diazepam was compared with rectal diazepam for sedation in outpatient oral surgery. Fifty-four operations were performed on 27 patients. Recovery from sedation, experience during the postoperative course, amnesia, estimation of the sedative effect, and patient preference of method of sedation were studied. The recovery times of the sedation methods did not differ. Sedative effects after the first operation were estimated as good by 87% of patients given intravenous sedation and by 75% of those given rectal sedation. However, there was a significant relationship between the subjective experience of stronger sedative effect and preference of sedation method that favored the intravenous technique. The degree of amnesia was significantly higher during intravenous sedation, but a high degree of amnesia was not related to patients' preference for a sedation method. Neither sedation method produced any local side effects.

Adolescent↗

Spontaneous periodic hypothermia.

We studied a patient with spontaneous periodic hypothermia, agenesis of corpus callosum (Shapiro's syndrome), polydipsia polyuria, and hyponatremia. Endocrine evaluation of hypothalamic-pituitary unit, thyroid, adrenals and gonads was normal. Results of a water deprivation test implied primary polydipsia. Four of 10 reported cases of Shapiro's syndrome had abnormalities in water metabolism. In view of the known effects of arginine vasopressin in thermoregulation, the recurrent hypothermia of this syndrome and the abnormalities of water metabolism may have a common pathogenetic mechanism.

Adult↗

Growth factor-binding proteases in the murine submaxillary gland: isolation of a cDNA clone.

The submaxillary gland of the adult male mouse contains a number of serine proteases, several of which are involved in the proteolytic processing of precursors to growth factors and other biologically active polypeptides. Here we report the isolation and identification of a cDNA clone corresponding to one of the proteases, the type B of the epidermal growth factor-binding protein. A pronounced sequence homology was found between the predicted activation peptide of this protease and the NH2-terminal extension of the nerve growth factor alpha subunit, suggesting that the latter protein has an uncleaved activation peptide attached to its NH2 terminus.

Amino Acid Sequence↗

Amnesia, pain experience, and patient satisfaction after sedation with intravenous diazepam.

Recovery time, the effect of sedation or amnesia on postoperative pain, and patients' opinions of the sedation were studied. Forty operations were performed on 20 patients. Each patient had four impacted third molars removed in two sessions, one in which a new emulsion form of diazepam (Diazemuls) was used, and one in which no sedation was used. The recovery from sedation was found to be very individual and not related to the dose administered, as assessed by a simple, easy-to-use method. There was no difference in postoperative pain between the sedated and unsedated groups, and we found no correlation between postoperative pain and amnesia. Eighty-five per cent of the patients preferred sedation during surgery, even though none of them had a preoperative indication for sedation.

Adolescent↗