Search PubMed⌕ Search

Biomedical subjects

B Persson

Publications and source records attributed to B Persson.

At least 469 records · Page 26Linked to original sources
PubMed1982

Uteroplacental blood flow in diabetic pregnancy: measurements with indium 113m and a computer-linked gamma camera.

The uteroplacental blood flow index in the last trimester of pregnancy in 26 women with diabetes mellitus was compared to that in 41 healthy control subjects. After an intravenous injection of 1 mCi of indium 113m, the radiation over the placenta was recorded with a computer-linked gamma camera. From time-activity analysis of the isotope accumulation curve, a uteroplacental blood flow index could be calculated. In the diabetic pregnant women, the maternal-placental blood flow index was reduced 35% to 45% compared to that in healthy women. The blood flow index tended to be further impaired in those diabetic women who had higher blood glucose values.

Adolescent↗
PubMed1982

A scintillation camera technique for measurements of the reticuloendothelial function - comparison of different methods for measuring RES function.

A highly standardized 99mTc-sulphur colloid was used to evaluate reticuloendothelial system (RES)-function in the normal rat and after RE blockade by gelatin (Haemaccel). Activity distribution in the animals was measured with a scintillation camera technique. Total uptake of activity in the liver was estimated. From the time-activity curves over the liver, the phagocytic index (kphag) was evaluated. Estimation of the uptake rate of the labelled colloid into the liver and into other parts of the RES was also performed using a two-compartment model. Different methods of evaluation of RE function were compared. It was shown that for a proper estimation of the RE function, the whole uptake curve must be considered. Gelatin (Haemaccel) significantly reduced the total colloid uptake by the liver. The colloid uptake rate into the liver was also significantly reduced. Liver specimens after colloid injection were examined by light and electron microscopy showing vacuolation of hepatocytes and sinusoidal cells probably due to pinocytosis. The technique described enables functional studies of the RES. It has the advantage of noninvasive registrations and is based on the same technical facilities as used for routine liver scintigraphy.

Animals↗
PubMed1982

Computed tomography in suspected osteoid osteomas of tubular bones.

Six cases of suspected osteoid osteoma of tubular bones were evaluated by computed tomography (CT). In all cases a radiolucent nidus was clearly demonstrated. In two cases a radiodense center of the nidus was visualized. It is suggested that CT may replace conventional tomography in the evaluation of these lesions. Due to its ability to locate the lesion in the transverse plane, CT is superior for the exact planning of surgery to avoid unnecessary large or misdirected resections. Adequate window settings are essential in the evaluation of these lesions.

Adolescent↗
PubMed1982

Dihydralazine inhibits tyrosine hydroxylase in vivo in the rat.

The effect of dihydralazine on monoamine metabolism in the rat was investigated. Dihydralazine, 5 mg/kg i.v., reduced noradrenaline (NA) in the heart. After pretreatment with phenoxybenzamine an NA depletion was evident also in the brain. Dihydralazine did not affect the utilization of NA or dopamine in the brain as judged by the disappearance rates of these amines following synthesis inhibition by alpha-methyl-p-tyrosine. However, dihydralazine reduced the synthesis of monoamines as evidenced by a decreased accumulation of the monamine precursor dihydroxyphenylalanine (and 5-hydroxytryptamine) subsequent to treatment with NSD 1015. It is concluded that dihydralazine inhibits central tyrosine hydroxylase (and tryptophan hydroxylase) in the rat.

Animals↗
PubMed1982

Experimental set-up for studies of microwave-induced hyperthermia in rats.

A low-cost microprocessor-based temperature controller for hyperthermia experiments on rats is described. The system directs a microwave generator, used for heating, by feedback power regulating signals in accordance with the temperature in the animal. The microwave power is pulsed for short on-and-off periods and the temperature recordings are carried out during the off periods. More than 300 hyperthermia runs have been carried out on rats using this fully automated unit. The controller can direct the hyperthermia to the predetermined level with a deviation of +/- 0.1 degree C for systemic hyperthermia. For local hyperthermia in the liver, individual recorded mean temperatures were up to -0.5 degree C from the preset temperature.

Adenocarcinoma↗
PubMed1982

Labetalol, a combined alpha- and beta-blocker, in hypertension of pregnancy.

Labetalol was given to women with hypertension of pregnancy in their last trimester to study its acute effect on circulation and metabolism. Seven women were given 50 mg labetalol i v. There was a significant decrease of blood pressure from a mean of 143/101 +/- 4/2 (SEM) to 127/88 +/- 5/2 mm Hg. Maternal heart rate fell significantly from 77 +/- 5 to 68 +/- 3 beats per min. These changes persisted during a three-hour observation period. The hypotensive response was accompanied by a significant increase in plasma noradrenaline from 1.54 +/- 0.16 to 2.37 +/- 0.41 nmol/l, suggesting sympathetic activation. Plasma cyclic AMP, which is increased by beta 2-adrenoceptor stimulation, was significantly elevated after labetalol. This supports the hypothesis of partial beta-agonist activity of labetalol. Lipid metabolism, as judged from measurements of plasma FFA, glycerol and 3-hydroxybuturic acid, showed little change. The acute effect of labetalol on uteroplacental blood flow was determined in eight women with pregnancy hypertension using a gammacamera on line with a computer. 0.5 mCi indium-113m was given i v before and 30 min after labetalol was administered i v in a dose of 1 mg per kg body weight. After the injections of indium-113m, serial scintigrams were recorded during 10 s periods for 240 s. By computerized summation of the scintigrams, an image was obtained in which the placenta could be outlined for time-activity analysis of the isotope accumulation curve. From this curve a uteroplacental blood flow index could be calculated. Labetalol induced a significant drop of mean arterial blood pressure from 114 +/- mm Hg to 100 +/- 3 mm Hg after 30 min in this group of women. However, the uteroplacental blood flow index did not change. As we have earlier shown with this technique that uteroplacental blood flow can be severely impaired in hypertension of pregnancy, the finding of substained uteroplacental blood flow simultaneously with a decrease in blood pressure should be of clinical importance. Taken together with other studies of clinical effects, these results indicate that labetalol is useful in the treatment of hypertension of pregnancy.

Adult↗
PubMed1982

Amniotic fluid volumes and concentrations of C-peptide in diabetic pregnancies.

Amniotic fluid (AF) volumes were determined by sodium p-aminohippurate (PAH) dilution in a consecutive series of 24 diabetic women at 34-35 weeks gestation. AF and maternal venous blood samples were analysed for C-peptide immunoreactivity (CPR). When the patients were subgrouped according to the presence (n = 17) or absence (n = 8) of neonatal morbidity, AF volumes (1340 +/- 236 ml vs 807 4/- 130 ml; mean +/- SEM), AF concentrations of CPR (1.38 +/- 0.54 nmol/l vs 0.61 +/- 0.14 nmol/l) and maternal blood glucose levels (5.3 +/- 0.2 nmol/l vs 4.8 +/- 0.3 nmol/l) during the last trimester of pregnancy were not different. The total content of CPR was significantly (P less than 0.05) greater in pregnancies with neonatal complications (1.25 +/- 0.31 nmol/ compared with that in pregnancies without neonatal complications (0.54 +/- 0.18 nmol). AF volumes were significantly (P less than 0.02) larger in pregnancies where feeding problems occurred (1546 +/- 307 ml, n = 9) compared with that in pregnancies without such problems (957 +/- 188 ml, n = 16). These findings indicate an impact of fetal hyperinsulinism on the functional maturation of the fetus. When the patients were subgrouped according to the presence or absence of detectable maternal plasma CPR, i.e. greater than 0.05 nmol/l, and to insulin dependent and gestational diabetes no differences of AF volumes, AF concentrations of CPR or total AF contents of CPR were found.

Amniotic Fluid↗
PubMed1982

Circulatory adaptation in newborn infants of strictly controlled diabetic mothers.

Possible relations between neonatal circulatory function and maternal diabetic control were investigated in 22 infants of strictly controlled diabetic mothers during the first 2 days after birth. Eleven infants were delivered vaginally (V) and 11 infants by elective cesarean section (S). Maternal diabetes was more severe in the latter group. Half of the infants had one or more episodes of neonatal morbidity although none presented symptomatic hypoglycemia. Plasma glucose FFA and C-peptide were measured at birth and 3-6 hours later together with skinfold thickness; heart size was determined by X-ray at 24-28 hours; stroke volume and cardiac output were repeatedly determined by transthoracic impedance and ECG. C-peptide at birth was higher in group S than in V. C-peptide in both groups were neither related to glucose or FFA nor to birthweight or skinfold thickness. Infants with neonatal complications including cardiomegaly had the highest C-peptide values. Skinfold was positively correlated to maternal pregnancy glucose level, birthweight percentile and infant heart volume. Mean values for stroke volume and cardiac output were similar in both groups and not different from normal controls when related to body weight. Heart volume and stroke volume were significantly related. ECG abnormalities were seen in 6 infants who showed cardiomegaly on X-ray. We suggest that the present finding of an association between elevated C-peptide concentration at birth and the occurrence of neonatal complications including cardiomegaly and ECG abnormalities could be the consequence of functional hyperinsulinism and that the cardiomegaly is of adaptive type.

Blood Glucose↗
PubMed1982

Cardiovascular effects in the rat of ketanserin, a novel 5-hydroxytryptamine receptor blocking agent.

Following intravenous administration of ketanserin (0.3-10 mg kg-1) to conscious or anaesthetized normotensive and spontaneously hypertensive rats there were dose-dependent blood pressure reductions but no compensatory tachycardia. Intracerebroventricular administration of ketanserin (25-500 microgram) had inconsistent and largely insignificant cardiovascular effects. In a dose range where it produces hypotension ketanserin antagonized the pressor responses to adrenaline and noradrenaline as well as to 5-hydroxytryptamine in monoamine depleted and spinalized rats. It is suggested that the hypotensive action of ketanserin in the rat does not involve a central mechanism but a peripheral alpha-adrenolytic action is implicated.

Animals↗
PubMed1982

Metabolic and circulatory effects of intravenous and oral salbutamol in late pregnancy in diabetic and non-diabetic women.

The present study investigated the cardiovascular and metabolic "side-effects" of the beta 2-adrenoceptor stimulating drug salbutamol in the third trimester of pregnancy in diabetic and non-diabetic women. Salbutamol was administered either orally or as an intravenous infusion. Blood samples were collected for analyses of plasma cyclic AMP, insulin, C-peptide, and carbohydrate and lipid metabolites. Fetal heart rate, maternal heart rate, and blood pressure were registered simultaneously. After both intravenous and oral salbutamol, there was a statistically significant decrease in diastolic blood pressure, increase in maternal heart rate, plasma levels of cyclic AMP, insulin, and carbohydrate and lipid metabolites showing stimulation of glycogenolysis, lipolysis, and insulin secretion. The increase in fetal heart rate was slight. In diabetic women, the glycogenolytic and lipolytic effects of salbutamol were significantly more pronounced than in non-diabetics. The acute maternal circulatory and metabolic effects after salbutamol are probably too slight to have any clinical significance in healthy women. However, in diabetics, due to their impaired insulin function, a serious metabolic deterioration after salbutamol might occur.

Administration, Oral↗
PubMed1982

Technique for microwave-induced hyperthermia in superficial human tumours.

In order to induce local hyperthermia in superficial tumours a computer system using a 2,450 MHz microwave generator connected to a circular (diameter 90 mm) direct contact applicator was constructed based on invasive temperature control. Small thermistor probes with a diameter of 0.6 mm are inserted in the tumour and surrounding tissues. Eight thermistors can be used simultaneously and one of them is chosen as the "master'. The automatic control system used a pulsed irradiation technique to avoid the problem with interactions between the metallic wires of the temperature probe and the electromagnetic field. With the system it was possible to control the temperature at the master thermistor within +/- 0.5 degrees C from the preset value.

Computers↗
PubMed1982

Microwave-induced hyperthermia and ionizing radiation. Preliminary clinical results.

The combination of microwave-induced (2450 MHz) hyperthermia and ionizing radiation was used in 7 patients with superficial malignant tumours, which were considered refractory to other therapy. A newly developed heating system was used, allowing for a maintained temperature at the master probe of 42.5 degrees C +/- 0.5 degrees C during 45 min, but temperature measurements at multiple sites showed a marked variation. This preliminary series indicates that the combination of hyperthermia and ionizing radiation may be useful, the response rate (complete or partial) being 8 of 8 evaluable lesions. Even previously heavily irradiated sites responded. Technical improvements are highly needed to allow for controlled heating of any tissue volume.

Adenocarcinoma↗
PubMed1982

Cerebral blood flow and cerebral metabolism in children following cardiac surgery with deep hypothermia and circulatory arrest. Clinical course and follow-up of psychomotor development.

Between November 1975 and June 1977, 49 children underwent repair of complicated cardiac defects with the aid of deep hypothermia. Circulatory arrest was used in 28 cases. Nine children died (18%) due to early postoperative heart failure. A decisive cause of death in terms of important cardiovascular defects, which were either unknown or not correctable at the time of repair, was found in 6 patients. Children with complicated forms of congenital heart disease requiring an extensive repair were overrepresented among those who died. Hence, there was an excess in the duration of bypass among nonsurvivors (p less than 0.01) whereas the patient's age at operation, the use of circulatory arrest and the duration of aortic occlusion had no bearing on operative mortality. Cerebral blood flow (CBF) and cerebral metabolism were studied in 9 survivors. A negative correlation (r = -0.67) was found between the duration of circulatory arrest and CBF measured directly after surgery. CBF was reduced to values below 0.2 ml . g-1 . min-1 in 3 children with long periods of circulatory arrest. The cerebral uptake of oxygen and glucose was normal both before and after surgery. Two separate interviews with the parents were performed, the first one 3-22 months and the second one about 3 years after surgery. No serious neurological symptoms or psychomotor disturbances were reported. However, in 3 children operated with circulatory arrest, difficulties in performing more delicate motor activities were noted by the parents. The findings indicate that circulatory arrest should be used with caution and total arrest periods exceeding 60 min avoided.

3-Hydroxybutyric Acid↗
PubMed1982

Amniotic fluid volumes in pregnant diabetics during the last trimester. A comparative study using ultrasound and PAH dilution.

Amniotic fluid was measured by ultrasound and PAH dilution technique in 15 insulin-dependent diabetics during the last trimester of pregnancy. Total uterine volume and fetal volume were estimated by ultrasound. The amniotic fluid volume was obtained by subtracting fetal volume and approximated values for placental volume obtained from the literature from the total uterine volume. The mean amniotic fluid volume determined by ultrasound was 1261 ml (range 278-3563). The mean amniotic fluid volume determined by PAH dilution was 1264 ml (range 344-3852). The values for amniotic fluid determined by these two methods were closely correlated (r = 0.96).

Aminohippuric Acids↗