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Biomedical subjects

B Lindström

Publications and source records attributed to B Lindström.

At least 145 records · Page 8Linked to original sources
PubMed1980

Determination of methimazole in plasma using gas chromatography--mass spectrometry after extractive alkylation.

A gas chromatography--mass spectrometry method for quantitation of the thyreostatic agent methimazole in plasma is described. The drug was transferred from the plasma sample and derivatized in one step by extractive alkylation. Either of two alkylating agents benzyl-chloride or pentafluorobenzyl bromide were used. Deuterium-labelled methimazole was used as internal standard. The precision of the method at the level of 5 ng methimazole per ml plasma was 6%.

Alkylation↗
PubMed1980

[Pelvic pain syndrome in women--a psychiatric-gynaecological study (author's transl)].

77 selected patients suffering from dyspareunia and pelvic pain on moving, with normal findings on gynaecological palpation were submitted to laparoscopy or laparotomy, as well as to a psychiatric investigation. In 25% of the cases no pathological changes were seen--group I; in a further 40% signs of slight--group II--and in the remaining 35% of cases signs of serious pelvic congestion were present--group III. Serious pelvic congestion occurred most frequently between 26 and 35 years of age and seemed to be connected with more than one delivery. Furthermore, in the total material, 65% of patients showed psychologically inadequate personalities whereby nearly 90% of the women in group I, but only a little over 40% in group III, displayed psychological inadequacy, with the women in group II occupying an intermediate position. On the basis of this observation and other investigated personality variables, pelvic pain without pathological findings seems to be caused by neuromuscular spasm in psychologically vulnerable persons. Pelvic pain with different degrees of pelvic congestion cannot be entirely dissociated from the possibility of psychological overlay, which may, however, be of a secondary nature.

Adult↗
PubMed1980

Pharmacokinetics and oral bioavailability of pyridostigmine in man.

The pharmacokinetics of pyridostigmine was evaluated after intravenous injection in two healthy male volunteers and after oral administration to five subjects. Plasma concentrations of pyridostigmine were determined after ion pair extraction from plasma and analysis by gas chromatography - mass spectrometry with chemical ionization, using d6-pyridostigmine as internal standard. Degradation of pyridostigmine in vitro was compensated for by use of the deuterated internal standard and by rapid cooling and separation of plasma after blood sampling. After intravenous administration of pyridostigmine 2.5 mg the plasma elimination half-life was 1.52 h, the volume of distribution was 1.43 l/kg and the plasma clearance 0.65 l/kg x h. The pharmacokinetic constants were very similar after oral administration of pyridostigmine 120 mg; the elimination half-life was 1.78 +/- 0.24 h, the volume of distribution 1.64 +/- 0.29 l/kg and the plasma clearance was 0.66 +/- 0.22 l/kg x h. The bioavailability was calculated to be 7.6 +/- 2.4%. When pyridostigmine was taken together with food, the time to reach the peak plasma concentration was prolonged from 1.7 to 3.2 h. Bioavailability, however, was not influenced by concomitant food intake. "Steady-state" plasma concentrations of pyridostigmine were measured in myasthenic patients on their ordinary dose schedule of cholinesterase inhibitor drugs. More than a seven-fold difference in steady-state plasma concentration was found between patients taking approximately the same daily dose of pyridostigmine.

Administration, Oral↗
PubMed1980

Longitudinal study of oral hygiene and dietary habits among immigrant children in Sweden.

Families immigrating to Sweden from Finland and Southern Europe (Greece, Yugoslavia, and Turkey), as well as Swedish control families of the same social class, were interviewed twice on their children's oral hygiene and dietary habits and on the parents' knowledge of oral health. The first interview was made on the immigrants' arrival in Sweden and the second one 30 months later. The material comprised 35 Finnish, 23 South-European and 54 Swedish families. During the observation period more immigrant than control children had complained about toothache. The frequency of toothbrushing was lower among the immigrants than among the Swedes at both interviews. The frequency of sweets consumption was significantly higher among the immigrants. Fewer immigrant than Swedish children had been examined or treated by a dentist before the first interview. There was no difference between the immigrants and the controls in channels of information about oral hygiene, the schools and the dentists being the foremost source of information for both groups. The Swedish parents had a more competent knowledge of oral hygiene than the parents of the immigrant children. It was concluded that Finnish and South-European immigrant children definitely have a great need of preventive dentistry.

Adolescent↗
PubMed1980

Placental transfer of hydrochlorothiazide.

The concentrations of hydrochlorothiazide (HCT) in maternal and umbilical cord plasma and in amniotic fluid were determined at partus in 10 pregnancies. The levels of HCT in umbilical cord plasma were 0.1--0.8 of that in maternal plasma. The concentrations of the diuretic in amniotic fluid were up to 5 and 19 times higher than in maternal and umbilical cord plasma, respectively.

Amniotic Fluid↗
PubMed1980

On the use of click-evoked electric brainstem responses in audiological diagnosis. II. The influence of sex and age upon the normal response.

Brain stem electric responses (BSER) to clicks at 80, 60 and 40 dB SL (rate 22.5/sec) were recorded from 62 normally hearing subjects grouped according to sex and age. There were four groups: young females (mean age 26.8 years), old females (56.1 years), young males (29.6 years), and old males (59.3 years). The BSERs were measured in respect to peak latencies (I, III, V) and interpeak intervals (I-III, III-V, I-V). Wave replicability was seen to deteriorate with age. Concerning peak, latencies, highly significant differences were established between the group of young females on the one hand, and the other three groups on the other, young females exhibiting shorter latencies (of the order of 0.2 msec); differences between the other three groups were less significant or not significant at all. Concerning interpeak intervals, the differences between groups showed little or no significance. Furthermore, in old subjects--but not in young ones--the individual III-V interval exhibited a significant increase with reduction of click intensity from 80 to 60 dB SL of the order of 0.1 msec. Variances of peak latency and interpeak interval measures were not seen to differ significantly between groups.

Adult↗
PubMed1980

Quantitation of a bisacodyl metabolite in urine for the diagnosis of laxative abuse.

A 2 year history of severe diarrhea, tiredness, and weight loss in a female patient could not be diagnosed satisfactorily despite repeated and extensive clinical investigations of various kinds. The final diagnosis of laxative abuse was arrived at after identification and quantitation of a bisacodyl metabolite in the urine from the patient. The metabolite was bisacodyl disphenol. The analytical method developed was based on liquid chromatographic determination after hydrolysis of the conjugated metabolite of bisacodyl and selective isolation from the urine. The precision of the method was 5% at the 2.3 microgram/ml level (n = 9) of bisacodyl diphenol, and the absolute recovery was estimated at 80%. The method allowed detection of 0.5 migrogram/ml of the metabolite in urine. After a single dose (10 mg) of bisacodyl to volunteers, urinary concentrations of the metabolite in the range of 1--5 microgram/ml were found. The bisacodyl diphenol recovered in the urine corresponded to 20--30% of the original dose. The urinary concentration of the diphenol derivative in the patient was estimated at 17 microgram/ml.

Adult↗
PubMed1979

Extractive alkylation of sulphonamide diuretics and their determination by electron-capture gas chromatography.

The extractive alkylation of 11 sulphonamide diuretics has been evaluated using tetrabutylammonium, tetrapentylammonium or tetrahexylammonium as counter ion at different pH values and methyl iodide in methylene chloride as the organic phase. The sulphonamides are methylated within 20 min with tetrahexylammonium as counter ion in 0.2 M sodium hydroxide at 50 degrees. The derivatives have been identified by mass spectral and nuclear magnetic resonance analysis. Relative retentions of the derivatives are given using 1% SE-30 as the stationary phase. A contaminant, dimethylsulphuric acid, occurs in methyl iodide and seriously disturbs the gas chromatographic analysis. The application of the extrative alkylation to biological samples is demonstrated by the direct analysis of acetazolamide in serum. 0.1 M tetrapentylammonium in 0.5 M sodium hydroxide is suitable as the aqueous phase with 1.6 M methyl iodide as alkylating reagent in methylene chloride. The trimethyl derivative of acetazolamide formed has been determined by electron-capture gas chromatography down to 0.5 microgram/ml in a 0.1-ml serum sample. The relative standard deviation at the 10 microgram/ml level is 6.6% (n = 10).

Acetazolamide↗