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Biomedical subjects

S Gustafsson

Publications and source records attributed to S Gustafsson.

At least 19 recordsLinked to original sources
PubMed2005

Lack of insulin-like growth factor binding protein-3 protease activation by venous cannulation.

Disruption of the endothelium activates thrombogenic and fibrinolytic enzymes that cleave insulin-like growth factor binding protein-3 (IGFBP-3) in vitro. The aim of the present human study was to determine whether blood sampling, i.e., venous stasis and cannulation increase IGFBP-3 proteolysis before and/or after surgery by activating these enzymes. Serum samples obtained immediately after cannulation were compared with samples obtained from a previously inserted venous catheter. Cannulation did not increase serum IGFBP-3 proteolytic activity pre- and post-operatively, as determined by in vitro degradation of 125I-IGFBP-3. Furthermore, there was no effect on in vivo IGFBP-3 fragmentation assessed by western immunoblot. In addition, a standardized venous stasis did not affect IGFBP-3 proteolytic activity or fragmentation. Comparison of IGFBP-3 proteolytic activity before and after surgery demonstrated a significant post-operative increase. However, this could not be demonstrated immediately after the initial cannulation, due to a large individual variation at this time-point before surgery.

Abdomen↗
PubMed2004

A new mathematical model for chemotactic bacterial colony growth.

A new continuum model for the growth of a single species biofilm is proposed. The geometry of the biofilm is described by the interface between the biomass and the surrounding liquid. Nutrient transport is given by the solution of a semi-linear Poisson equation. In this model we study the morphology of a chemotactic bacterial colony, which grows in the direction of increasing nutrient concentration. Numerical simulations using the level set method and finite difference schemes are presented. The results show rich heterogeneous morphology.

Bacteria↗
PubMed2003

Genetic differentiation and habitat preference of flowering-time variants within Gymnadenia conopsea.

Using fast-evolving microsatellites, more slowly evolving ITS markers and performing habitat analyses, we demonstrated a drastic genetic divergence and significant habitat differentiation between early- and late-flowering variants of plants morphologically belonging to Gymnadenia conopsea ssp conopsea. The two phenological variants can either be found in separate or in mixed populations. Information from microsatellite markers and ITS sequences indicated the occurrence of an early historical split between the two flowering-time variants, a split that has been maintained until the present time even within sympatric populations. Early-flowering variants were also far more genetically diverse, had more alleles per microsatellite locus and a wider habitat amplitude than late-flowering variants. As a comparison, we included G. odoratissima in the sequencing study. We found G. odoratissima to be most closely related to the early-flowering type. This indicates a more ancient divergence event between the two flowering-time variants within G. conopsea ssp conopsea than between the two different species G. odoratissima and the early-flowering variant of G. conopsea. Possible explanations to the results arrived at and possible mechanisms maintaining the genetic separation are discussed.

DNA, Plant↗
PubMed2000

Demineralization of the vertebral skeleton in Atlantic salmon Salmo salar L. during spawning migration.

In Atlantic salmon, Salmo salar, the mineral rate of vertebrae in a given fish varies according to the position of the vertebra along the rachidian axis. Indeed, the mean rate goes from 49% in the anterior vertebrae and raises to 51% in post-truncal vertebrae. Although no significant difference in the mineral rate was noticed between males and females either in the lower river basin or after spawning, the mineral rate of vertebral bone decreased significantly (1-2%) during spawning migration. Vertebrae, like scales, are an important reservoir of calcium from which fasting salmon draws the minerals and organic materials necessary for the substantial remodeling of cranial bones in males and for sexual maturation. We hypothesize that mineral decrease in vertebrae may be the result of a halastasic demineralization of the vertebral tissues.

Animals↗
PubMed2000

Patterns of genetic variation in Gymnadenia conopsea, the fragrant orchid.

Gymnadenia conopsea (L.) R. Br., or the fragrant orchid, is one of many plant species negatively influenced by new practices in agriculture and forestry during the last decades. This study describes the level of microsatellite variation within and among 10 Swedish populations of this species. It was not possible to detect strong effects of small population size or fragmentation. In general, the species had high genetic variation within and low genetic divergence among populations, although the correlation between population size and number of alleles was close to significance at the 95% level. Also, a significant isolation by distance effect was observed, indicating the presence of modest restrictions in gene dispersal between the investigated populations.

DNA, Plant↗
PubMed1999

13C-urea breath test results in pigs challenged with Helicobacter pylori or other urease producing bacteria.

The gastric bacterial flora and its influence on the 13C-urea breath test (UBT) for detection of Helicobacter pylori infection was studied in a pig model. Seven SPF minipigs were used. H. pylori or a mix of other urease positive bacteria were administered orally. UBT, serum and biopsies for histology and culture were collected. Our results show that UBT is not specific for H. pylori in pigs as the gastric bacterial flora is responsible for the high UBT values observed. Furthermore, the Ellegaard Göttingen SPF minipigs are not useful in an animal model for H. pylori studies.

Animals↗
PubMed1998

Humoral immune responses to Mycoplasma hyopneumoniae in sows and offspring following an outbreak of mycoplasmosis.

Previously healthy sows, seropositive to Mycoplasma hyopneumoniae, developed clinical signs of mycoplasmosis, as well as increasing amounts of antibodies to M. hyopneumoniae during an outbreak of the disease in a herd. During the early phase of the outbreak, young piglets (2 weeks) with maternal antibodies remained healthy while older seronegative piglets (4-7 weeks) developed the disease. The duration of the maternal antibodies to M. hyopneumoniae varied between litters and was related to the amount of antibodies in the serum of the dam. In sows, the level of serum antibodies decreased continuously from 4 weeks ante partum to partus, and the level of antibodies in the whey of colostrum was comparable to that in serum 4 weeks ante partum. After loss of maternal antibodies to M. hyopneumoniae, seropositive animals were not found among piglets younger than 9 weeks. Therefore peripheral blood mononuclear cells (PBMC) were collected from various age categories of piglets in order to measure the ability to produce antibodies to M. hyopneumoniae in vitro. PBMC obtained from piglets aged 1 and 3 weeks produced few antibodies to M. hyopneumoniae. Significantly higher levels of antibodies to M. hyopneumoniae were produced by PBMC obtained from pigs aged 5-9 weeks. Thus, the ability of PBMC to produce antibodies to M. hyopneumoniae in vitro seemed to be age-dependent.

Animals↗
PubMed1996

Dihydrotestosterone and testosterone levels in men screened for prostate cancer: a study of a randomized population.

OBJECTIVE: To investigate the possible relationship between serum levels of prostate specific antigen (PSA), dihydrotestosterone (DHT), testosterone, sexual-hormone binding globulin (SHBG) and tumour stage, grade and ploidy in 65 cases of prostate cancer diagnosed in a screening study compared to 130 controls from the same population. PATIENTS, SUBJECTS AND METHODS: From a population of 26,602 men between the ages of 55 and 70 years, 2400 were selected randomly and invited to undergo screening for prostate cancer using a digital rectal examination, transrectal ultrasonography and PSA analysis. Among the 1782 attendees, 65 cases of prostate cancer were diagnosed. Each case was matched with two control subjects of similar age and prostate volume from the screening population. Frozen serum samples were analysed for PSA, DHT, testosterone and SHBG, and compared to the diagnosis and tumour stage, grade and ploidy. Comparisons between these variables, and multivariate and regression analyses were performed. RESULTS: There were significant differences in PSA level with all variables except tumour ploidy. DHT levels were slightly lower in patients with prostate cancer but the difference was not statistically significant. There was a trend towards lower DHT values in more advanced tumours and the difference for T-stages was close to statistical significance (P = 0.059). Testosterone levels were lower in patients with cancer than in the control group, but the differences were not significant. There was no correlation between testosterone levels, tumour stage and ploidy, but the differences in testosterone level in tumours of a low grade of differentiation compared to those with intermediate and high grade was nearly significant (P = 0.058). The testosterone/DHT ratio tended to be higher in patients with more advanced tumours. SHBG levels were lower in patients with cancer than in controls but the differences were not statistically significant. There were no systematic variations of tumour stage, grade and ploidy. Multivariate analysis showed that if the PSA level was known, then DHT, testosterone or SHBG added no further information concerning diagnosis, stage, grade or ploidy. Regression analysis on T-stage, PSA level and DHT showed an inverse linear relationship between PSA and DHT for stage T-3 (P = 0.035), but there was no relationship between PSA and testosterone. CONCLUSION: PSA was of value in discriminating between cases and controls and between various tumour stages and grades, but no statistically significant correlation was found for ploidy. If PSA level was known, no other variable added information in individual cases. Within a group, DHT levels tended to be lower among cases and in those with more advanced tumours. There was an inverse relationship between tumour volume, as defined by PSA level, and 5 alpha-reductase activity, as defined by DHT level, and the testosterone/DHT ratio. This trend was most obvious with T-stage. No systematic variation were found in the levels of testosterone or SHBG.

Aged↗
PubMed1992

Separate taxation and married women's labor supply: a comparison of West Germany and Sweden.

"The focus of this paper is an empirical analysis of the effects of taxation on women's incentives to contribute to family income. Data on earnings and individual characteristics in 1984 for married or cohabiting Swedish couples...are used together with similar data on German couples.... The main features of the personal income taxation of the two countries have been programmed, and are used for simulating after tax incomes using both tax systems for both countries.... The difference between the Swedish and German tax systems is an important factor in explaining why Swedish women participate more than German women in the labor market, although paid parental leaves and subsidized childcare are other important explanations for the Swedish situation."

Developed Countries↗
PubMed1991

Effects of diltiazem and metoprolol on blood pressure, adverse symptoms and general well-being. The Swedish Diltiazem-Metoprolol Multi-Centre Study Group.

General well-being, adverse effects and anti-hypertensive efficacy have been investigated in a double blind, parallel-group, dose-response multicentre study of diltiazem and metoprolol monotherapy for hypertension. 128 patients with primary hypertension were included from 10 participating centres. The patients were randomized to receive oral diltiazem 120-240-360 mg/day or metoprolol 50-100-200 mg/day. Each dose was given for a 4-week period as a forced titration regime. In all 119 patients, 59 and 60, respectively, on diltiazem and metoprolol completed the study protocol. There were dose-dependent reductions in supine and standing blood pressures (BP) after both diltiazem and metoprolol therapy. In the diltiazem group, supine BP was reduced by 10 (11)/10 (6) mmHg (SBP/DBP) at the highest dose level, and the corresponding values for the metoprolol group were 7 (16)/8 (9) mmHg (SBP/DBP). Target pressures (DBP less than or equal to 90 mmHg and/or a reduction in DBP of greater than or equal to 10%) were reached in 63% and 48% of the patients, respectively. The incidence and severity of dose-dependent adverse effects, as evaluated by spontaneous reports or open and direct questioning, did not differ between treatments. Subjective well-being, evaluated by a self-administered questionnaire, the MSE-profile, did not differ significantly between diltiazem and metoprolol therapy. However, after an initial slight deterioration, contentment and vitality tended to improve with increasing doses of diltiazem, while a dose-related deterioration in these variables was observed on metoprolol therapy. At the highest dose levels, contentment and vitality tended to be better in the diltiazem than the metoprolol group. Thus, diltiazem and metoprolol in daily doses of 120-360 mg and 50-200 mg, respectively, produce comparable and parallel reductions in supine and standing BP. However, while subjective well-being tended to improve with increasing doses of diltiazem, there was a negative trend for metoprolol. It is concluded that diltiazem, given as monotherapy to hypertensive patients, does not impair subjective well-being.

Adult↗
PubMed1991

Diltiazem compared with metoprolol as add-on-therapies to diuretics in hypertension. Swedish Diltiazem-Metoprolol Multicentre Study Group.

In a randomized, double-blind, parallel group study, diltiazem was compared with metoprolol as add-on therapy to diuretic treatment in 115 patients with hypertension. Following a placebo and diuretic period of four weeks, patients were randomized to either slow release diltiazem 90 mg twice daily or metoprolol 100 mg once daily using a double dummy technique. If after four weeks a target supine diastolic blood pressure (DBP) less than or equal to 90 mmHg pressure was not reached, the doses of diltiazem and metoprolol were doubled. Supine inclusion systolic/diastolic blood pressures (SBP/DBP) at randomization were 158 +/- 13 (mean +/- SD)/102 +/- 5 mmHg in the diltiazem group and 158 +/- 17/101 +/- 6 mmHg in the metoprolol group. Active therapy significantly lowered SBP and DBP in both groups by 7-10%. Heart rate was significantly lowered in both groups, although the effect of metoprolol was more pronounced. Response rates (supine DBP less than or equal to 90 mmHg and/or decreased by greater than or equal to 10%) were 43% on diltiazem 90 mg twice daily and 52% on metoprolol 100 mg once daily, increasing to 82% and 62%, respectively, after dose escalations. No serious side effects were seen, but three patients, two on diltiazem and one on metoprolol, were withdrawn from the study due to severe headache, nausea and bradycardia respectively. of mild to moderate adverse reactions, tiredness was most frequent, occurring in 14.5% and 15.8% on active diltiazem and metoprolol therapy, respectively. We conclude that both diltiazem and metoprolol lower BP when added to diuretics in hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Cis-trans isomerization of an angiotensin I-converting enzyme inhibitor. An enzyme kinetic and nuclear magnetic resonance study.

The angiotensin I-converting enzyme (peptidyl-dipeptide hydrolase, EC 3.4.15.1) inhibitor, ramiprilat (2-[N-[(S)-1-ethoxycarbonyl-3-phenylpropyl]-L-Ala]-(1S,3S,5S)-2- azabicyclo[3.3.0]octane-3-carboxylic acid), is shown to exist in tow conformational isomers, cis and trans, which interconvert around the amide bond. The two conformers were separated by reversed-phase high-performance liquid chromatography. The conformers were identified by nuclear Overhauser effect measurements. From line shape analysis the isomerization rate constants were determined to be kcis----trans = 15 s-1 and ktrans----cis = 5 s-1 at 368 K in [2H]phosphate buffer (p2H 7.5). By enzyme kinetic studies using 3-(2-furylacryloyl)-L-Phe-Gly-Gly as substrate, the trans conformer was found to be the most potent enzyme inhibitor, whereas the cis conformer had a very low inhibitory effect. A new inhibition mechanism is presented for this type of slow, tight-binding inhibitors that contain an amide bond. This mechanism involves an equilibrium between the two conformers and the enzyme-bound inhibitor complex.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1990

A comparison of diltiazem and metoprolol in hypertension. Swedish Diltiazem-Metoprolol Multicentre Study Group.

A double-blind, parallel-group multicentre study has been done to compare the antihypertensive properties, effects on serum lipoproteins and adverse effect profiles of diltiazem and metoprolol given as monotherapy to primary hypertensive patients. 128 patients were included from 10 participating centers. Following a placebo wash-out period of 5 weeks, patients were randomized either to diltiazem or metoprolol treatment according to a forced titration regimen. Each dose was given for a 4-week period in a stepwise regimen. A total of 119 patients, 59 and 60 in the two groups, completed the study. Supine and standing BPs were reduced in a similar, dose-dependent fashion by diltiazem and metoprolol. In the former supine BP fell from 161/101 to 151/91 mmHg at the highest dose level. In the latter patients, supine BP at the highest dose level was reduced from 161/102 to 155/94 mmHg. Target pressures (DBP less than or equal to 90 mmHg and/or DBP reduction of greater than or equal to 10%) were reached in 63% and 48% of the patients, respectively. HDL-cholesterol was increased in diltiazem-treated patients and decreased in those on metoprolol. Otherwise, serum lipoproteins did not differ significantly between treatments. The incidence and severity of dose-dependent adverse effects did not differ significantly between treatments, although moderate to distressing side effects were reported more commonly by metoprolol-treated patients. Ankle oedema and breathlessness tended to be more common on diltiazem therapy, while tiredness, increased sweating and sleep disturbances appeared to be experienced more frequently by metoprolol-treated patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗