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Biomedical subjects

J Kuikka

Publications and source records attributed to J Kuikka.

At least 73 records · Page 4Linked to original sources
PubMed1980

Evaluation of cerebral infarctions of the carotid area by an intravenous 133Xenon and 99mTechnetium method.

Quantitative determinations of regional cerebral blood flow (rCBFf, rCBFm) and volume (rCBV), transfer time (rCTT) and fast compartmental weight (Wf) were performed in 34 patients with infarctions of the carotid area by a 133Xe and 99mTc intravenous injection method. The results were compared with clinical signs and electroencephalographic (EEG) findings. A significant difference was found between the lesion side and the control side in all the parameters except rCBV. This difference increased with the severity of the infarction and age of the patients. The difference between the two sides was especially great in the patients with totally occluded internal carotid artery. A slight diaschisis could be observed in the present infarction group. An almost significant reduction on the "normal side" was seen in Wf. In order to assess the reciprocal influence of all the different blood flow parameters, the difference index (DI): Formula: (see text) was calculated, where delta i = the difference between the two sides in one parameter expressed in percent. This proved to be abnormal in 80% of the patients. The atraumatic isotope technique employed offers a good opportunity for the quantitative evaluation of hemodynamics in cerebral infarction and serves as an aid in the diagnosis of infarction.

Adult↗
PubMed1980

Transcapillary exchange and distribution of carbon-11 labelled ethanol in the isolated perfused rat liver.

The distribution kinetics of ethanol in the isolated perfused rat liver at various flow rates and ethanol concentrations were studied by the indicator diffusion technique using 11C-labelled ethanol. A double tracer solution with 99mTc-labelled red blood cells as the vascular reference and 11C-ethanol as the test substance was injected into the catheter connected to the portal vein. Time-activity curves were monitored by a NaI(Tl) scintillation detector above the outflow catheter. The following values were obtained: 0.95 +/- 0.01 for the maximal extraction (Emax), 3.0 +/- 0.1 x flow (r = 0.98) for the capillary permeability surface area product (PScap), 18.7 +/- 2.5% for the vascular volume (V1) and 56.2 +/- 9.0% for the ethanol distribution volume (V2). The volumes were calculated from the products of mean transit time (MTT) and flow (f), and PScap was calculated from the equation PScap = -f x ln(1-Emax). The results show that the ethanol distribution in the liver is flow limited since Emax was constant at various flow rates (0.67-2.55 ml/g x min-1). The distribution volumes obtained agree well with the values for liver vascular volume and water distribution volume reported in the literature.

Animals↗
PubMed1980

Intervillous blood flow in normal and complicated late pregnancy measured by means of an intravenous 133Xe method.

Intervillous blood flow (IVBF) was measured intravenously with a new quantitative 133Xe method in 50 normal and 74 complicated late pregnancies between the 35th and 42nd weeks. The distribution of individual flow rates seemed to be fairly wide in both the normal and the pathological groups. The mean rate of IVBF in normal pregnancies was 140 ml/100 ml of intervillous space/min. The lowest mean flow values were observed in pregnancies complicated by diabetes mellitus (class B-E), cholestasis of pregnancy and severe pre-eclampsia, a highly significant difference (p less than 0.001) from the mean IVBF observed in normal pregnancies. The significance of the results in the different groups has been discussed in detail. This method may open up a new diagnostic area in the management of high-risk pregnancies.

Cholestasis↗
PubMed1980

Decreased intervillous and unchanged myometrial blood flow in supine recumbency.

The supine position in late pregnancy is associated with many hemodynamic changes caused by compression of the inferior vena cava and a resulting fall in cardiac output. To investigate the effect of this position on uteroplacental blood flow, 22 women with normal (N = 12) or hypertensive (N = 10) pregnancy were investigated using the intravenous 133Xe washout method, in both the supine and left-tilted (45-degree) lateral positions. The intervillous blood flow (113 +/- 48 ml/min/dl) was lower in the supine position than in the left-tilted position (141 +/- 48 ml/min/dl) (P less than 0.01), while the myometrial blood flow was similar in both (9.0 +/- 3.3 ml/min/100 g in supine and 8.7 +/- 2.7 ml/min/100 g in left-tilted position). The results suggest that the autoregulation system for uteroplacental circulation is operative only in the nonplacental component of the pregnant uterus.

Adolescent↗
PubMed1980

Effect of smoking on the central circulation at rest and during exercise as studied by radiocardiography.

The pulmonary vessels are the first target of tobacco smoke in the circulatory system, but the functional changes occurring in the pulmonary circulation are poorly understood. Hence 46 volunteers were studied by radiocardiography under the following conditions: 1. At rest before and after smoking 2 cigarettes (15 men); 2. After repeated ergometer exercise (5 min, 100 W) with and without smoking (13 men); and 3. Control experiments under the corresponding conditions without smoking (18 subjects). A significant increase occurred in heart rate, cardiac output and systolic arterial blood pressure after smoking when at rest, but an almost significant decrease in pulmonary dispersion volume , whereas the heart rate and pulmonary capillary pressure attained significantly higher values after than before smoking in the exercise tests, with a significant decrease observed in stroke volume, pulmonary blood volume and pulmonary dispersion volume. It is concluded that smoking impairs physical performance, increases pulmonary capillary pressure and reduces pulmonary blood volume and probably the number of open capillaries.

Adult↗
PubMed1979

Effect of induction of general anesthesia for cesarean section on intervillous blood flow.

Intervillous blood flow was measured by a new intravenous 133Xe method before and during induction of general anesthesia for cesarean section in 10 healthy mothers. The flow values showed a highly significant decrease (p less than 0.001) (35 per cent on an average) at the time of anesthesia compared with the control values. The impairment was observed in all the cases. The role of the maternal changes in hemodynamic parameters and acid-base balance as a background of this decrease is discussed.

Acid-Base Equilibrium↗
PubMed1979

Quantitative radiocardiographic evaluation of cardiac dynamics in man at rest and during exercise.

113Inm radiocardiography in conjunction with a gamma camera and a digital computer is applied to measurements of cardiac output, stroke volume, ejection fraction, end-diastolic volume, pulmonary blood volume, pulmonary transfer time and dispersion both at rest and during muscular exercise. A modified gamma function is used in calculations of radiocardiographic curves. In twelve supine male subjects the maximal increase of cardiac output was 220%, stroke volume 30%, ejection fraction 15%, and pulmonary blood volume 30%. The present method provides a non-invasive tool for cardiovascular examinations during exercise.

Adult↗
PubMed1979

[Pulmonary capillary pressure and the exercise test].

In the present work with radiocardiography the change of pulmonary capillary pressure as well as cross correlations of stroke index, cardiac index, pulmonary blood volume, pulmonary arterial pressure and pulmonary dispersion volume which reflects pulmonary capillary volume have been studied during muscular exercise. With increase in cardiac output the mathematical estimation showed decrease in pulmonary capillary pressure while stroke index, pulmonary blood volume and pulmonary dispersion volume increased. The pulmonary arterial pressure also rose but this increase was insignificant. The estimated decrease in pulmonary capillary pressure might be due to decreased resistance, a consequence of recruitment of new capillaries and of increase of cross sectional area of pulmonary vasculature. The radiocardiographic method used here appears to be suitable in exercise studies, and it may further be applicable in clinical studies, e.g. in evaluation of left ventricular failure.

Adult↗
PubMed1978

Radionuclide diagnosis of venous angioma.

Venous angioma is a rare vascular anomaly of the central nervous system. Pathologically, it resembles arteriovenous malformation, but the vascular changes are seen only in the veins. In the present case, the lesion was seen better with dynamic rather than static radionuclide examination. In a computerized dynamic study, the circulation time in the lesion was significantly prolonged compared with the circulation time in the symmetrical area of the contralateral hemisphere. The peak of the time-activity curve also appeared later in the lesion area than in the symmetrical contralateral area. Thus the use of the computerized gamma camera is useful in the diagnosis of venous angioma and the method seems to have some differential diagnostic possibilities.

Adult↗
PubMed1978

Placental blood flow during caesarean section under lumbar extradural analgesia.

The effect on intervillous blood flow of lumbar extradural analgesia for Caesarean section was studied in nine healthy women using xenon-133. Extradural anaesthesia was performed with lignocaine 1 1/2% 16--20 ml with adrenaline 5 microgram ml-1. Impairment of placental blood flow during the block was observed in seven patients, but the mean decrease (13% from the control value) was not statistically significant. The most notable decrease in intervillous blood flow occurred in two patients with simulateous arterial hypotension.

Anesthesia, Epidural↗
PubMed1978

Effect of segmental extradural analgesia on placental blood flow during normal labour.

Placental blood flow was measured during the first stage of normal labour using a xenon-133 clearance technique before and after segmental extradural analgesia. Analgesia was produced with 0.5% plain bupivacaine in eight patients and with 0.5% bupivacaine--adrenaline in 10 patients. Segmental extradural analgesia with a small dose (20 mg) of bupivacaine did not change placental blood flow significantly. The addition of adrenaline 20 microgram produced no effect.

Adolescent↗
PubMed1978

An intravenous 133Xe method for measuring regional distribution of placental blood flow.

A new method for measuring regional distribution of placental blood flow is presented. After 2-5 mCi of 133Xe saline has been injected intravenously, the counts over the placenta are registered with a scintillation camera interfaced with a digital data storage and television readout system. Using "area of interest" technique, time activity curves are obtained for different regions. Analysis of the curves is based on two-exponential curve fitting. In normal pregnancy the mean intervillous flow in 16 healthy women was 125 ml/min/100 ml and myometrial flow 17 ml/min/100 g. The intervillous flow in the central part of the placenta was 55% higher than in the marginal parts. The myometrial flow in the placental area was nearly the same as outside the placenta.

Adolescent↗
PubMed1978

Effect of fenoterol and isoxsuprine on myometrial and intervillous blood flow during late pregnancy.

The use of beta-adrenergic agonists in high-risk pregnancies has shown evidence of favorable effects on the fetus. Intravenous injections of 133Xe were given to evaluate the effects of short-term administration of fenoterol (3 microgram/min) and isoxsuprine (150 migrogram/min) on the intervillous and myometrial blood flow in a series of 48 women during the last trimester of pregnancy. Both fenoterol and isoxsuprine treatment increased the maternal heart rate significantly. There was a significant rise in myometrial blood flow when fenoterol was given, but the intervillous blood flow did not change significantly during the administration of either isoxsuprine or fenoterol. Previous oral isoxsuprine treatment did not diminish the cardiac effect of intravenous fenoterol, but the improvement in myometrial blood flow was eliminated. This result indicates that beta-adrenergic agonists may have a specific dilatational effect on the myometrial blood vessels. From the hemodynamic point of view, the beta-adrenergic agonists have a limited value in the treatment of chronic fetal asphyxia or intrauterine fetal growth retardation.

Ethanolamines↗
PubMed1977

Hemodynamic effects of oral contraceptives during exercise.

The effects of a combined oral contraceptive pill on female hemodynamics during exercise were studied in 14 young, healthy women. The increase in blood volume, stroke volume, and cardiac output during exercise was significantly greater during combined oral contraceptive therapy than when the patients were not taking the pill. The use of combined oral contraceptive pills may be advantageous to the physical fitness of female athletes.

Adult↗