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Biomedical subjects

B Larsson

Publications and source records attributed to B Larsson.

At least 289 records · Page 16Linked to original sources
PubMed1987

Is the fibrinolytic activity involved in the mechanism of fetal membrane rupture? A clinical study of term and prematurely ruptured membranes.

The fibrinolytic activity (FA) was determined in fetal membrane specimens obtained in 15 cases of premature rupture of the membranes (PROM) and from 15 control women who gave birth spontaneously at term. In each case two membrane specimens were obtained, one from the rupture margin and the other from the membranes close to the placental margin. No significant difference in FA was demonstrated between the two groups of patients. Nor could any significant difference be found on comparing the FA within the paired membrane specimens of each group. Furthermore, no obvious change in FA was demonstrated in relation to clinical signs of chorioamnionitis or microbiological findings. However, although the FAs observed in prematurely ruptured membranes were comparable to those found in term specimens, this does not exclude the possibility of an involvement of FA in the mechanism of membrane rupture.

Adolescent↗
PubMed1987

Pad test with fixed bladder volume in urinary stress incontinence.

A pad-weighing test of urinary stress incontinence during a set program of physical exercises is presented. The test was begun at a fixed bladder volume (75% of maximum capacity) and was repeated once. The duration of the exercises was approx. 15 min. Leakage was greater in the second test, but statistical analysis showed highly significant intraindividual correlation between the two amounts. Degree of leakage was not correlated to subjective assessment of incontinence. The test can be done as part of a routine urodynamic investigation.

Adult↗
PubMed1987

The mortality in an age cohort followed from birth to age 70.

The Study of Men Born in 1913 is a prospective population study of cardiovascular diseases in Gothenburg, Sweden, that started in 1963. To describe survival curves and mortality pattern, all boy-children born alive in 1913 in the city of Gothenburg, were identified. This birth cohort was followed from birth to age 70 for residence, vital status and cause of death. At the age of 50 years, 25% of the birth cohort were dead and at age 70, 43% had died. The high infant mortality and the great impact of infectious diseases in the beginning of this century is illustrated. The death rate for the cohort was almost identical to national figures for men in the same age group. Men who migrated from Gothenburg had a death rate very similar to those who stayed. It can therefore be concluded that the men in the Study of Men Born in 1913 is a representative sample not only of men in Gothenburg but also of men in Sweden as far as mortality is concerned. Special attention was paid to death from otitis media complications, congestive heart failure, and diabetes. Few persons died from these diseases before age 50 when the prospective study started and therefore did not influence the study of the natural history for these conditions to any great extent. Otitis media infections might be studied retrospectively from this age.

Aged↗
PubMed1987

Equipment for radiation surgery using narrow 185 MeV proton beams. Dosimetry and design.

The purpose of the present work was to optimize and standardize irradiation conditions and dosimetry methods in order to investigate the prerequisites for the routine use of narrow high energy proton beams for cerebral radiation surgery. Particular importance was laid on the design of the arrangements for defining and controlling the path of the beam in the laboratory in view of the desirability of working with well-defined parallel beams containing a minimal contribution of scattered and secondary radiation. At the same time it was intended that this apparatus should be used to adjust the beam reproducibly onto an ideal beam path prior to each irradiation session. It was also considered desirable to be able to supervise the centering and the structure of the beam during the irradiations in view of the variations which can arise due to varying running conditions in the synchrocyclotron. The beam was collimated and led to the place where the irradiations were to be performed, 25 metres from the synchrocyclotron, with a system of focusing quadrupole magnets and bending magnets. Final collimation of the beam penetrating the object was arranged with a system of accurately aligned cylindrical and plane-parallel metal apertures. The energy of the protons in the beam was 185 +/- 0.2 MeV and the maximum total fluence was 5 X 10(10) protons/s. A method of 11C activation dosimetry was developed with which an absolute determination of the fluence and the dose in the proton beam could be made with good accuracy. These determinations were performed by irradiating small polystyrene cylinders placed along the beam axis at the isocentre. The activity induced in the cylinders by the protons was measured in a well-type crystal detector. The efficiency of the detector for the detection of annihilation photons was determined before each measurement by means of calibration with standardized activities of 22Na and 60Co. The overall uncertainty in the dose determinations using 11C activation dosimetry was +/- 8 per cent. Monitoring of the dose during irradiation was performed with an ionization chamber. Since it was most important to minimize the scattering of the protons, this chamber was designed as a 'free air chamber' with the electrodes parallel to the beam. The chamber could not be used for absolute measurements, however, since there was a contribution to the ionization in the chamber from scattered protons and secondary radiation from the walls of the collimator defining the cross section of the ionization volume.(ABSTRACT TRUNCATED AT 400 WORDS)

Energy Transfer↗
PubMed1987

The growth of polio virus in human diploid fibroblasts grown with cellulose microcarriers in suspension cultures.

Human diploid fibroblasts have been successfully grown with cellulose fiber microcarriers in suspension giving values of between 1 to 2 X 10(6) cells/ml. When infected with polio virus type 1 titers were obtained which were at least as good or better than those obtained with monkey kidney cells and similar to that obtained with Vero cells. Good results were also obtained using conventional microcarriers such as Cytodex, Biosilon and Gelibeads. Our results suggest that many of the technical difficulties in growing human diploid fibroblasts on microcarriers can be overcome allowing these cells to be a favourable alternative to heteroploid cells as a substrate for viral vaccine production.

Biotechnology↗
PubMed1986

Release of both urokinase and tissue plasminogen activator from veins in vitro.

Specimens of human veins were incubated in culture media, in which the concentrations of urokinase (UK) and tissue plasminogen activator (t-PA) were determined by radioimmunoassay and immunoradiometric assay. Both UK and t-PA were released to the media, in which the concentration of plasminogen activators was correlated to the weight of the specimens. The release of t-PA was maximal on the first day, after which it rapidly decreased, and t-PA was not demonstrable after the third day of incubation. By contrast, UK was continuously liberated to the media during the study period of 5 days. The present results indicate that both UK and t-PA are present in the vein wall and probably released by different cells.

Culture Media↗
PubMed1986

Estrogen regulation of tissue plasminogen activator in a human melanoma cell line.

The influence of ethinylestradiol and the three natural estrogens, i.e. estrone, 17-beta-estradiol and estriol, was studied in a melanoma cell line producing a tissue-type plasminogen activator (t-PA). The cell cultures were exposed to the four estrogens by addition of the steroids dissolved in a weak alcoholic solution to the culture media, in which the released t-PA was assayed by an immunoradiometric method. Ethanol (0.76% w/v) stimulated the t-PA production, while no significant effect of the estrogens in the concentration of 1.7 X 10(-7) M was seen. By tenfold increase in estrogen concentration a highly significant reduction of t-PA levels was recorded in the cultures exposed to ethinylestradiol and 17-beta-estradiol. Estriol differed from these two estrogens in having rather weak inhibitory effect; whereas estrone in this concentration had toxic effect on melanoma cells. It was concluded that the present estrogens, in particular ethinylestradiol and 17-beta-estradiol, had a dose-dependent inhibitory effect on the production of t-PA in melanoma cell culture.

Cell Line↗
PubMed1986

Thermogenic effect of food in physically well-trained elderly men.

Basal metabolic rate (BMR) and the thermogenic effect of food (TEF) after a liquid mixed meal of 2092 kJ (500 kcal) were examined in physically well-trained, elderly men in comparison with sedentary weight- and age-matched controls. BMR tended to be higher and TEF was significantly higher in the physically well-trained men than in the controls. No certain differences were found in plasma thyroid hormones or catecholamines. BMR correlated with whole body potassium while TEF did not. The tendency to elevated BMR in the well-trained men might therefore be due to their greater muscle mass. The elevated TEF, however, probably has other causes and might be associated with the elevated catecholamine sensitivity associated with the physically trained condition.

Aged↗
PubMed1986

Fasting blood glucose and risk of coronary heart disease, stroke, and all-cause mortality: a 17-year follow-up study of men born in 1913.

This report concerns the relationship between baseline levels of fasting blood glucose (FBG) in non-diabetics and the subsequent 17-year incidence of coronary heart disease (CHD), stroke and all-cause mortality. In 1963, 973 men aged 50 years were recruited from a general Swedish urban population for a prospective study of risk factors for CHD. Eight hundred and fifty-five (88%) men agreed to participate and have been observed for 17 years. The 832 men who had no history of myocardial infarction, stroke, diabetes mellitus or who had a fasting blood glucose below 7.0 mmol/l at baseline were selected for this analysis. CHD occurred in 106 men, 35 developed a stroke and 137 died during follow-up. When quintiles and deciles of the FBG distribution were considered, no trend of 17-year incidence of CHD, stroke or death was apparent. However, for men with an FBG above the 95th percentile (greater than 5.7 mmol/l) a non-significant trend towards increasing risk was indicated.

Aged↗
PubMed1986

Regional distribution of alpha-adrenoceptor subtypes in the female rabbit urethra.

The aim of the present investigation was to study the regional distribution of alpha-adrenoceptor subtypes in the female rabbit bladder base and urethra, using radioligand binding and mechanical activity studies. The binding studies performed on membranes prepared from the bladder base, and the proximal and distal part of the urethra, revealed that the number of alpha 1-adrenoceptors did not significantly differ between the three regions, whereas the number of alpha 2-adrenoceptors increased distally. The mechanical activity studies showed that noradrenaline and clonidine, but not phenylephrine, were more potent in the distal than the proximal part of the urethra. It is suggested that in the female rabbit urethra the lower EC50-value found for noradrenaline and clonidine in the distal as compared to the proximal part of the urethra, at least in part, is attributable to a higher number of postjunctional alpha 2-adrenoceptors in the distal than in the proximal urethra.

Adrenergic alpha-Agonists↗
PubMed1986

Long-term treatment with combined oral contraceptives and cigarette smoking associated with impaired activity of tissue plasminogen activator.

The fibrinolytic activity in vein walls (FAV) was determined by a semi-quantitative fibrin slide technique in a group of 68 healthy middle-aged women consisting of 22 healthy controls, 19 non-smoking contraceptive pill users and 27 cigarette-smoking non-users. Significantly decreased FAV was demonstrated in pill users because of high frequency of low values among women using combined oral contraceptives (OC) for more than 5 years. Significantly lower FAV was also recorded in smoking non-users, among whom low FAV values were found mainly in heavy smokers. However, no effect of OC usage for less than 5 years was observed, neither did smoking of less than 10 cigarettes daily influence FAV. Thus, the two well-known risk groups with respect to circulatory diseases, long-term contraceptive users and heavy smokers, included the vast majority of middle-aged women with impaired plasminogen activator activity.

Adult↗
PubMed1986

Does the hygroscopic property of the laminaria tent imply a risk for ascending infection in legal abortions? A microbiological study.

In 53 women admitted for first-trimester abortion, the cervical canal was dilated with laminaria tents prior to vacuum aspiration. Before insertion of the tents, endocervical specimens were taken for microbiological investigations, including Chlamydia trachomatis, and both aerobic and anaerobic microorganisms. The laminaria tents, widened by their hygroscopic properties, were removed just before the vacuum aspiration and sent for cultivation of aerobic and anaerobic microorganisms. The Gram-positive aerobic cocci, Staph. epidermidis, Strept. faecalis and Strept. agalactiae as well as Escherichia coli and Klebsiella/Enterobacter were the most frequent microorganism among the aerobic isolates from the endocervices as well as from the laminaria tents. These microorganisms were identified on the tents in greater numbers than in the cervices. Staph. aureus was isolated from three laminaria tents, but only one of these 3 women was proved to be primarily colonized endocervically. Among the anaerobes, Bacteroidaceae followed by peptococci and peptostreptococci were the predominant genera found in the cervix as well as on the removed laminaria tents. These three groups of anaerobic microorganisms were found markedly less frequently on the laminaria tents than in the endocervix. On the other hand, Strept. intermedius, another anaerobe of possible enteric origin, was recovered from 9 laminaria tents but not in the cervices. Since no cases of clinically verified endometritis/salpingitis were registered in the present study it is concluded that the risk of a pelvic inflammatory disease (PID) due to the laminaria tent is negligible as long as the laminaria treatment does not exceed 24 hours.

Abortion, Induced↗
PubMed1986

Fibrinolytic activity in amniotic fluid during late pregnancy.

Fibrinolytic activity (FA) was assessed by the fibrin plate technique in 47 amniotic fluid samples obtained at 35 to 39 weeks' gestation. In amniotic fluid the FA (63.1 +/- 2.5 mm2) was considerably elevated when compared with previously reported serum levels of pregnant women. After centrifugation of the amniotic fluid samples a highly significant reduction of FA in the supernatant was recorded (42.9 +/- 1.3 mm2), suggesting that the cells of fetal origin are the main source of the high plasminogen activator activity demonstrated in amniotic fluid. A significant rise in amniotic fluid FA was demonstrated beyond the 37th gestational week. Furthermore, significantly greater FA was recorded in amniotic fluid samples from women with spontaneous onset of labor within a week. However, a single FA determination in amniotic fluid obtained by routine amniocentesis was found to be of little value for prediction of the time interval to delivery.

Amniotic Fluid↗
PubMed1986

Simultaneous recording of uterine and tubal motility during utero-tubal insufflation in monkeys.

One main cause of female infertility is the tubal factor, and interest in the role and function of the Fallopian tube has increased our knowledge about tubal infertility. In this study in monkeys, Cynomolgus (Macaca fascicularis), the tubal and uterine motility was recorded with a Millar microtransducer. The recordings were made during uterotubal, uterine as well as tubal insufflation with gas. Tubal activity patterns varied with the phase of the menstrual cycle. The kymograms made during gas insufflation did not reflect tubal or uterine activity, as registered by the Millar microtransducer, but rather the resistance to pressure of the intra-uterine part of the tube. An intra-uterine pressure up to 200 mmHg, has previously been regarded as being free from risk of uncontrolled escape of gas outside the uterus and the oviducts. This was not confirmed in the present study.

Animals↗
PubMed1986

The contraceptive efficacy of a Cu-IUD: size of the device and the uterine cavity.

This investigation deals with a small Cu-7 IUD (Cu-7-P), originally designed for women with uterine cavities less than 7 cm in sound measures. The accidental pregnancy rate was almost doubled when this small IUD was used in women with normal-sized uterine cavities (sound measures 7-8 cm), when compared to that in women with small-sized uteri. It was assumed that this difference in efficacy might be at least partly caused by the distribution of the increased fibrinolytic activity of the endometrium in the 2 groups of women.

Blood↗
PubMed1986

The possible advantage of keeping the uterine and intestinal serosa irrigated with saline to prevent intraabdominal adhesions in operations for fertility. An experimental study in rats.

In an attempt to find out whether a constant irrigation of the abdominal cavity with saline, as advocated in operations for fertility, is an adjuvant in the prevention of postoperative adhesions or not an experimental study was performed in 52 rats. The influence of a constant drying and irrigation with saline, respectively, on the exudation of an intact and of an injured serosa of the uterus and of the caecum was assessed after intravenous administration of fluoreisothiocyanate-dextran (FITC-dextran) in 12 rats. The influence of constant drying and constant irrigation with saline, respectively, on the postoperative adhesion formation on an intact and on an injured serosa was evaluated in all 52 animals. The results of this study imply that there was no significant difference in exudation of the intact serosa of the uterus and the caecum irrespective of constant drying or irrigation with saline. Subsequent to a certain trauma, however, the exudation increased with approximately 80 per cent in the uterus and 70 percent in the caecum. Moreover, constant irrigation of the abdominal serosa did not inhibit the increase of the exudation. The adhesion formation on the injured and intact abdominal serosa, respectively, was furthermore not influenced by irrigation with saline or drying, but seemed solely associated with a trauma to the serosa.

Animals↗