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Biomedical subjects

L Eriksson

Publications and source records attributed to L Eriksson.

At least 289 records · Page 16Linked to original sources
PubMed1980

Cardiovascular and behavioural changes after i.c.v. infusions of histamine and agonists in conscious goat.

Histamine (3 and 10 mumoles) raised the blood pressure in the conscious goat when given i.c.v. but lowered it when given intravenously. The results with 2-PEA support the view that central H1-stimulation raises the blood pressure. However, the results with dimaprit do not exclude the participation of central H2-receptors in the effect of histamine on the blood pressure. It appears that in the goat the stimulation of central H1- and H2-receptors mediates opposite actions on behavour. H1-agonist increased and H2-agonist decreased the general activity of the animal.

Animals↗
PubMed1980

Positron emission tomography in the evaluation of subdural hematomas.

Fifteen patients with 21 subdural effusions were investigated both with transmission computer assisted tomography (CAT) and positron emission tomography (PET). The tracer in the emission studies was 68Ga-EDTA. Twelve lesions were visualized both with CAT and PET. Five lesions that were negative or doubtful on CAT were visualized with PET, whereas four lesions negative or doubtful on PET were demonstrated by CAT. The two methods complement each other due to the fact that they are based on different mechanisms: CAT mainly on attenuation of the fluid collection. PET on isotope accumulation, particularly in the hematoma membranes.

Adolescent↗
PubMed1980

The clinical impact of long-term ECG recording. A retrospective study of 150 patients.

One-hundred and fifty patients referred for long-term ECG (LECG) recording at a university hospital were monitored for 12 hours or more. The referring physicians' patient records were studied 12 months or more after monitoring in an attempt to establish if and how LECG had affected patient management. Seventeen patients were treated with permanent pacemakers and 13 with antiarrhythmic drugs as a direct result of LECG. Thirteen patients who experienced symptoms with concomitant cardiac arrhythmia at the time of recording were considered not to require treatment. In 17 patients who experienced symptoms without concomitant arrhythmia during monitoring, cardiac arrhythmia could be ruled out as the cause of the symptoms. In 9 more patients, LECG was considered to have contributed "valuable clinical information" (which could not be obtained by other diagnostic methods) to the referring physician. Thus, LECG was considered to have affected the referring physician's management of the patients in 69 cases (46%).

Arrhythmias, Cardiac↗
PubMed1979

Antidiuresis induced by infusions of histamine into the brain ventricles of conscious hydrated goats.

Histamine was infused into the third or lateral ventricle of conscious hydrated goats, and urine samples were analyzed for volume, osmolality and electrolytes. Doses of 10--1000 microgram of histamine induced dose-dependent antidiuretic responses both as to the maximum osmolality and the duration of the osmolality increase. Urine osmolality began to rise within a few minutes, reached its maximum within 0.5--2 h and was elevated for 1.5--4 h, depending on the dose. Thereafter a second increase in osmolality often occurred, which lengthened the effect of histamine dose-dependently up to about 10 h with the largest dose of histamine. Histamine (50--300 microgram) and the control solution given into the lateral ventricle increased the excretion of Na+ into the urine. After the largest dose of histamine (1000 microgram), however, the excretion of Na+ was significantly lower than in the control experiments. After the larger doses of histamine, effects on motor or autonomic functions were seen. These included decreased spontaneous motor activity, increased respiratory rate, defecation and miosis. It is suggested that the site of action of histamine is central, and that the release of vasopressin through the activation of the neurosecretory system is probably involved. In addition the changes in electrolytes may suggest an involvement of the release of other factors such as prolactin.

Animals↗
PubMed1979

Unilateral fracture of the pterygoid process. Report of a case.

An unusual case of an isolated unilateral fracture of the pterygoid process is presented. The symptoms include a primary malocclusion as well as paresthesia of the major part of the maxillary nerve, indicating maxillary and/or mandibular fracture with dislocation of the fragments. The symptoms related to the regional anatomy as well as the mechanism of origin of the fracture are discussed.

Adult↗
PubMed1979

Plasma vasopressin in conscious goats after cerebroventricular infusions of angiotensins, sodium chloride, and fructose.

Using a sensitive RIA, the levels of plasma arginine vasopressin (pAVP) were determined from jugular venous blood of conscious goats given cerebroventricular (c.v.) infusions of angiotensins, saralasin, NaCl, and fructose. In hydrated goats, c.v. angiotensin II (0.1--1.0 microgram) caused a dose-dependent rise of pAVP, drinking, and antidiuresis. The same responses were obtained after angiotensin III (1.8 microgram) and hypertonic NaCl (0.5 M), but the effect on water intake was less striking. [des1,2]Angiotensin II hexapeptide and isotonic NaCl (0.15 M) failed to affect these variables. In nonhydrated goats, there were no changes in drinking, diuresis, or pAVP after c.v. infusions of saralasin (5.0 microgram) and isotonic NaCl (0.15 M). Fructose (0.3 M) infusions lowered the pAVP, apparently by reducing the cerebrospinal fluid (CSF) Na+ concentration, while the renal free water clearance turned positive. Angiotensin III thus carries the minimal structural requirements for pAVP release via central nervous receptors in the goat. Lack of a saralasin effect suggests that, in the nonhydrated goat, angiotensin II may not regulate pAVP via receptors accessible to the CSF. Sodium-sensitive cells monitoring the Na+ concentration of the CSF seem to control the pAVP.

Angiotensin II↗
PubMed1978

A ring detector positron camera system: its merits: clinical experience.

A ring detector positron camera system for CT of the brain is described. The system uses 95 NaI (Tl) detectors, arranged with cylindrical geometry, for the simultaneous detection of coincidences from 1,900 detector combinations. With a new sampling technique an experimental system resolution of 7 mm FWHM has been obtained. The sensitivity was found to be 5,300 c/s with a 100-keV energy threshold and using a 19.2-cm-diameter cylindrical phantom with a homogeneous specific activity of 1 muCi/cm3. A clinical study of blood-brain barrier damage using 68Ga-EDTA is reported.

Brain↗
PubMed1978

Lack of behavioural effects following intraventricular infusion of somatostatin in the conscious goat.

The effect of IV or intracerebroventricular (ICV) administration of somatostatin was studied on the behaviour of conscious goats. The doses of somatostatin infused IV were 100 and 300 microgram for 30 min and 600 microgram for 6 min. The doses infused ICV were 10 and 100 microgram for 30 min and 600 microgram for 6 min. In contrast to earlier reports on experiments with rats ,no behavioral effects whatsoever were seen in goat. IV infusion of 100 to 600 microgram and ICV infusion of 600 microgram of somatostatin caused a difinite reduction in the secretion of insulin and growth hormone, but had no effect on the concentration of blood glucose. The reason why neither IV nor ICV administration of somatostatin had any behavioural effects in the conscious goat, in contrast to the effects in rat, cannot be explained with certainty. This may be due to species specificity, to the amount of somatostatin reaching the central nervous system, or to some metabolic changes in rat but not in goat.

Animals↗
PubMed1978

Inhibition of vasopressin-release during developing hypernatremia and plasma hyperosmolality: an effect of intracerebroventricular glycerol.

In non-hydrated goats prolonged (3 h, 0.02 ml/min) intracerebroventricular (IVT) infusion of 0.35 M glycerol depressed the plasma vasopressin level during the entire infusion period which resulted in a conspicuous water diuresis outlasting the infusion by about 20 min. Since no compensatory drinking occurred during this sustained water diuresis it gradually induced pronounced dehydration (loss of greater than 1 liter of total body water causing 5% increase in plasma [Na+] and osmolality). The same degree of dehydration was in other experiments induced by water deprivation. It then caused a 5-fold increase in plasma vasopressin level. Corresponding IVT infusions of 0.35 M d-glucose depressed plasma vasopressin level only during the first half of the 3 h infusion period. Consequently, the resulting water diuresis was transient and subsided before the glucose infusion was finished. Plasma renin activity increased during the IVT glycerol infusion and during water deprivation, but was largely unaffected by IVT glucose. Both IVT glycerol and glucose decreased renal sodium excretion. The possibility is discussed that the pronounced ability of IVT glycerol to depress the vasopressin release and thirst is not only due to dilution induced reduction of CSF [Na+], but also to an influence of glycerol on choroidal and/or transependymal Na+-transporting mechanisms.

Animals↗
PubMed1977

Responses of reindeer to water loading, water restriction and ADH.

Two female reindeer were hydrated by administration of (10% of b.wt.) water into the rumen. The diuretic response was very fast and strong but the urea and electrolyte excretion were little affected. Dehydration was carried out by not giving the reindeer water for 48 h. This water deprivation caused a loss of up to 20% of their body weight. The urine osmolality did not exceed 840 mosm/kg H2O, although the plasma osmolality rose from 300 to 346 and 368 mosm/kg H2O respectively. The plasma and urine urea concentrations were elevated during dehydration, while the urine urea excretion did not increase. Urine sodium concentration did not increase. When the urine flow rate, after two days of water deprivation, decreased to half of the original, the urine Na+ concentrations, instead of increasing, went down to half of the original. So did the potassium excretion. When ADH was injected intravenously into hydrated animals a dose of 30 mU of ADH was needed to induce antidiuresis or increased excretion of potassium. The resistance to ADH and the low relative thickness of the medulla confirm the limited capacity of reindeer kidney to concentrate urine or to excrete a solute load. On the other hand, reindeer is able rapidly to excrete surplus water without affecting the electrolyte or nitrogen balance.

Animals↗
PubMed1976

Plasma renin activity following central infusion of angiotensin II and altered CSF sodium concentration in the conscious goat.

To study central influences on the renal release of renin, angiotensin II was infused into the lateral cerebral ventricle of conscious hydrated goats. CSF sodium concentrations was increased or lowered by similar infusions of hypertonic NaCl or of isotonic fructose solution. Infusion of angiotensin II in doses from 0.5 to 1 mug caused a drop in plasma renin activity (PRA) and elicited a rise in blood pressure, antidiuresis, natriuresis, and thirst. Intraventricular infusion of hypertonic NaCl also supressed PRA, induced antidiuresis, natriuresis, and an inconsistent rise in blood pressure. Lowering of CSF [Na+] by infusion of isotonic fructose caused a rise in PRA and was followed by a water diuresis in the non-hydrated animal. The fructose infusions caused some decrease in renal K+ excretion but no consistent change in renal Na+ excretion. The results indicate that angiotensin II and changes in sodium balance modulate renal renin release also via the central nervous system.

Angiotensin II↗