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Biomedical subjects

L Larsson

Publications and source records attributed to L Larsson.

At least 253 records · Page 14Linked to original sources
PubMed1988

Analgesic treatment in acute myocardial infarction. A double-blind comparison of ketobemidone + the spasmolytic A29 (Ketogan) and morphine.

The analgesic effect of ketobemidone hydrochloride + the spasmolytic component A29 (Ketogan) and morphine hydrochloride was compared double-blindly in patients with suspect acute myocardial infarction. The test drugs were administered i.v. in an initial dose of 0.5 ml (2.5 mg Ketogan, 5 mg morphine) followed, if necessary, by additional injections of 0.25 ml. Altogether, 309 patients participated in the trial. The total consumption of the test drugs showed that 5 mg Ketogan was equipotent with 10 mg of morphine. Treatment with Ketogan resulted in a significantly higher proportion of patients who were completely free of pain 15 and 30 min after the initial injection: 16% and 15% more, respectively, compared to morphine. Within 2 hours after the initial injection, approximately 15% of the patients in both treatment groups had reported nausea and about 7% had vomited (patients who vomited or were nauseated before treatment were not included in this analysis). The frequency of other side-effects was low, with no differences between the two treatment groups. Morphine caused a greater reduction of the systolic blood pressure than Ketogan. The effect of both drugs on pulse rate and respiration was the same.

Adult↗
PubMed1988

Correlation between single nephron glomerular filtration rate and filtration area in superficial glomeruli of developing rats.

Single nephron glomerular filtration rate (SNGFR) was correlated to the area of the glomerular basement membrane (GBM) determined by stereological techniques in rats between 20 and 40 days of age. Single nephron glomerular filtration rate increased 8.4 times in parallel with a twofold increase in GBM area. The much greater postnatal increase in SNGFR than in GBM area demonstrates that the increase in GBM area cannot account for the entire increase in SNGFR. Instead a combination of other factors influencing SNGFR most likely determines the largest part of the increase in SNGFR during this period. Thus, the drop in vascular resistance known to occur during maturation will increase the renal blood flow and may cause the filtration process to turn from a state of filtration equilibrium to or close to disequilibrium, thereby increasing GFR. Additional increase in GFR may be due to an increased net driving force for filtration and/or changed hydraulic permeability.

Age Factors↗
PubMed1988

Effects of chronic nicotine exposure on contractile enzyme-histochemical and biochemical properties of fast- and slow-twitch skeletal muscles in the rat.

Nicotine-exposed and control rats were compared with respect to contractile, enzyme-histochemical and biochemical properties of fast- and slow-twitch skeletal muscles in order to elucidate the mechanisms underlying previously observed effects of tobacco smoking on skeletal muscle. The nicotine was administered in drinking water, since this approach has been shown to result in a plasma nicotine pattern similar to that seen in tobacco smokers. In a pilot study, fibre-type proportions and mitochondrial enzyme activities tended to change in the slow-twitch soleus muscle after 9 weeks of nicotine exposure in a way similar to that previously reported in tobacco smokers. In the present study, the duration of nicotine exposure was more prolonged (18 weeks) and the number of studied animals was increased. In this series neither contractile, enzyme-histochemical nor biochemical properties were affected by the nicotine exposure. It is thus concluded that prolonged nicotine exposure has no significant effect on the skeletal muscle characteristics studied, and that other aetiological agent(s) for the observed differences in such characteristics between smokers and non-smokers should be searched for.

Animals↗
PubMed1988

Fatty and mycolic acids of Mycobacterium malmoense.

The fatty acids and mycolic acids of 16 clinical isolates of Mycobacterium malmoense were studied by gas chromatography and thin-layer chromatography. All strains contained 2-methyleicosanoic and 2,4,6-trimethyltetracosanoic acids and alpha-, alpha'-, and keto-mycolic acids. The reported findings suggest that lipid analysis is a very useful approach in the species identification of M. malmoense.

Chromatography, Gas↗
PubMed1988

Hemiacidrin: a useful component in the treatment of infectious renal stones.

Experimental irrigation of 15 infectious renal stones with hemiacidrin resulted in complete dissolution of 11 stones within 5 days. Three of the undissolved stones had a calcium oxalate (CaOx) content of more than 10%. Stones containing calcium phosphate (CaP) and magnesium ammonium phosphate (MAP) and weighing less than 500 mg were most easily dissolved. Twenty-five stones placed in 10 ml of hemiacidrin resulted in complete dissolution of 13 and partial dissolution of 11. Even this experiment showed that the CaOx content was of importance for the outcome of hemiacidrin treatment. After treatment the MAP and CaP fractions had decreased and CaOx increased. In 36 clinical irrigations of residual concrements of known chemical composition, 5 resulted in total stone dissolution and 21 in a reduced stone volume, whereas the result was inconclusive in 3. Seven stones were not affected by the treatment, these stones were usually composed of CaP and CaOx. There was a good correlation between the dissolution test and the clinical response to hemiacidrin treatment. Based on these findings it is suggested that hemiacidrin might be a useful complement to the modern techniques of stone fragmentation such as extracorporeal shock wave lithotripsy and percutaneous surgery, at least for infectious stones with a CaOx content of less than 10%.

Calcium Oxalate↗
PubMed1987

Determination of endotoxins by gas chromatography: evaluation of electron-capture and negative-ion chemical-ionization mass spectrometric detection of halogenated derivatives of beta-hydroxymyristic acid.

The sensitivity and selectivity of gas chromatography for analysing several halogenated ester derivatives of beta-hydroxymyristic acid were studied using both selected-ion monitoring detection with negative-ion chemical-ionization mass spectrometry and electron-capture detection. Six different derivatization methods were compared with respect to yield, chemical stability and formation of by-products. Procedures for removal of excess reagents using disposable silica columns and thin-layer chromatography were elaborated. The 3-O-pentafluorobenzoyl-methyl ester was the preferred derivative since it provided high sensitivity and had the molecular ion as the base peak in the mass spectrum. The detection limit was 0.5 pg with electron-capture detection and 0.3 pg with the mass spectrometric system. Using beta-hydroxymyristic acid as a chemical marker it was possible to detect Escherichia coli endotoxin in aqueous solution at a level of 1 ng/ml.

Chromatography, Gas↗
PubMed1987

Gas chromatographic comparison of peptone yeast glucose and gas liquid chromatography growth media for anaerobic bacteria.

The growth media peptone yeast extract glucose broth and gas liquid chromatography broth were compared with respect to their suitability for anaerobic bacteria, using 63 strains belonging to 12 species. After incubation for 24 and 48 h the broth cultures were subjected to viable counts and gas chromatographic analysis of short-chain alcohols and fatty acids in head-space vapours and ether extracts. Head-space analysis was superior to the ether extraction method for detecting the rapidly eluting short-chain alcohols. The gas liquid chromatography medium provided superior growth and contained fewer compounds that interfered with the chromatographic analyses. Whereas incubation in gas liquid chromatography medium for 24 h gave characteristic chromatograms for all but one of the studied species, most species required 48 h of incubation in peptone yeast extract glucose medium. Gas liquid chromatography broth is the preferred substrate for use in gas chromatographic identification of anaerobic bacteria.

Alcohols↗
PubMed1987

Ultrasensitive analysis of microbial fatty acids using gas chromatography with electron capture detection.

Pentafluorobenzyl and pentafluoropropionyl/pentafluorobenzyl esters of bacterial fatty acids were analysed by capillary gas chromatography using both flame ionization and electron capture detection. No differences between the relative peak areas of the various fatty acids were observed as regards the two detectors used except that response of the electron capture dectector to the hydroxy acid derivatives exceeded that to the non-hydroxy acid derivatives by 20%. Use of the described derivatives in combination with electron capture detection yields chromatograms comparable with those obtained by analysis of methyl esters using flame ionization detection but with superior sensitivity.

Bacteria↗
PubMed1987

Corynebacterium diphtheriae in the environment of carriers and patients.

A total of 533 throat and nasopharyngeal cultures were obtained from 328 staff who nursed cases of diphtheria and carriers of Corynebacterium diphtheriae; none yielded C. diphtheriae. Only one out of 189 environmental samples relating to 22 patients and carriers was positive. In addition, one carrier with chronic skin disease was found to have widespread colonization with C. diphtheriae. Several samples both from his hospital room and home yielded C. diphtheriae, indicating that he was a 'disperser.'

Carrier State↗
PubMed1987

Neonatal reference values for ionized calcium, phosphate and magnesium. Selection of reference population by optimality criteria.

Thirty-one full-term newborn babies were investigated in order to establish reference values for ionized calcium. Only children fulfilling certain optimality criteria (with best possible maternal and infant conditions and uncomplicated pregnancy and delivery) were included. All infants were breast fed. Capillary blood for analysis of ionized calcium was collected by heel puncture on day 1 (6-36 h post partum, p.p.), day 3 (60-84 h p.p.) and day 5 (108-132 h p.p.). Ionized calcium was measured with a semi-automatic electrode system ICA 1 (Radiometer A/S, Copenhagen, Denmark). The reference ranges (mean +/- 2 SD) for days 1, 3 and 5 were 1.05-1.37, 1.10-1.42 and 1.20-1.48 mmol/l, respectively. The mean ionized calcium concentration on day 1 was significantly lower than on days 3 and 5. Reference values are also given for total calcium, magnesium and phosphate. We emphasize that it is impossible to calculate ionized calcium from total calcium or vice versa.

Calcium↗
PubMed1987

Biochemical characteristics and fatty acid compositions of some armadillo-derived mycobacteria and their relation to Mycobacterium gordonae.

The long-chain components of 75 strains of mycobacteria, cultivated from Mycobacterium leprae-infected or non-infected armadillos, and of eight clinical and 15 environmental isolates of M. gordonae, were compared. Four major groups could be distinguished based on the presence of 10-methyloctadecanoic (tuberculostearic) and 2-methyl 3-hydroxyeicosanoic acids and secondary alcohols (2-octadecanol and 2-eicosanol). Some heterogeneity was found in strains assigned to M. gordonae: the characteristic absence of tuberculostearic acid and secondary alcohols and the presence of the branched C14 and the hydroxylated C20 acids were seen in only 34 of the 49 strains studied. Three strains were identified as M. malmoense, one as M. kansasii, ten as belonging to the M. avium-M. intracellulare-M. scrofulaceum complex and eight as belonging to new groups of armadillo-derived mycobacteria (ADM 1, ADM 2 and ADM 3) by conventional bacteriological tests and fatty acid compositions, though M. malmoense was heterogeneous in its fatty acids composition. Four strains, identified as M. avium by conventional tests, differed from this species by their fatty acid compositions. Thirteen strains showed some similarity to M. simiae and ten strains differed from all other known mycobacteria.

Animals↗
PubMed1987

The composition of four-hour urine samples from patients with calcium oxalate stone disease.

Urine collected during a 24-h period between 06.00 and 10.00 h from 25 patients with recurrent CaOx stone disease was analysed with respect to calcium, oxalate, magnesium, citrate and creatinine. Urinary excretion of oxalate in relation to creatinine was slightly higher in 24-h urine but the correlation between 24-h and 4-h values was good. Good correlations were also recorded for calcium and citrate, whereas a more variable result was obtained for magnesium. In terms of the risk of forming a supersaturated urine (CaOx risk index), a good correlation was observed between 24-h and 4-h urine samples, although the highest values were found in 24-h urine. As a result of a low mean urine flow between 06.00 and 10.00 h, the highest supersaturation in terms of the AP (CaOx) index was observed in these samples. When the risk of calcium oxalate crystallisation (CaOx-CR) was determined by means of the increment in oxalate concentration required for precipitation of CaOx, 7 of 11 samples had the highest values in the 4-h urine. Samples collected during a 4-h period might thus be useful in the evaluation and follow-up of CaOx stone formers and further studies will show to what extent they can replace 24-h urine collections.

Calcium↗