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Biomedical subjects

E B Pedersen

Publications and source records attributed to E B Pedersen.

At least 289 records · Page 16Linked to original sources

Calcium, parathyroid hormone and calcitonin in normal pregnancy and preeclampsia.

Calcium, parathyroid hormone (PTH) and calcitonin (CT) in serum, and the fractional renal excretion of calcium (FECa) were determined in (1) normal pregnant women, (2) patients with preeclampsia, and (3) normal nonpregnant control subjects. Serum calcium, corrected for individual variation in serum protein, was reduced and FECa increased in the normal pregnant group when compared to the nonpregnant control group. In preeclampsia serum calcium did not differ significantly from the normal pregnant group, but FECa was considerably lower and also reduced below the level in the nonpregnant control group. PTH was slightly lower during normal pregnancy than after delivery, but did not deviate significantly from the nonpregnant control group; in preeclampsia PTH did not deviate significantly from the levels in normal pregnancy. CT was the same in the third trimester of pregnancy in both groups. Changes in serum calcium and FECa were not correlated to PTH or CT. It is concluded that both normal pregnancy and preeclampsia are accompanied by considerable alterations in calcium metabolism, that PTH and CT in both groups are mainly unchanged and at nonpregnant level, and that the increase and decrease in renal calcium excretion in normal pregnancy and preeclampsia, respectively, may be attributed to changes in kidney function.

Adolescent↗

Circulating immune complexes and hypertension in pregnancy.

Eighteen patients with pre-eclampsia, 10 patients with essential and 9 with transient hypertension during pregnancy, were investigated regarding circulating immune complexes by a Clq-binding assay and a PEG precipitation assay. The women were studied during pregnancy, 2 and 5 days after childbirth, and also 3 and 6 months afterwards. The frequency of circulating immune complexes was not significantly increased in any of the groups when compared with that in 18 normotensive pregnant control subjects and 19 non-pregnant controls. Thus Clq-binding and PEG-precipitable immune complexes are a feature neither of normal pregnancy, nor of pregnancy complicated by hypertension or pre-eclampsia.

Antigen-Antibody Complex↗

Renin-angiotensin-aldosterone system in exaggerated natriuresis of chronic glomerulonephritis.

Angiotensin II (AII) and aldosterone (Aldo) in plasma, blood pressure (BP) and urinary excretion of sodium were studied before, during and in two periods after intravenous sodium loading with 500 ml of sodium chloride solution (50 g/l) in 11 normotensive and 10 hypertensive patients with histologically verified chronic glomerulonephritis and creatinine clearance in the range from 11 to 167 ml/min, and in 10 normotensive control subjects. The absolute increase of sodium excretion during loading was higher in the patients grouped together and in the hypertensives alone, but not in the normotensive patients when compared with the control subjects. No correlation was found between sodium excretion and control mean BP or change in mean BP during loading. AII and Aldo were suppressed during loading in both patients and control subjects. In the patients but not in the control subjects the increase of sodium excretion correlated positively with pre-infusion value of AII and negatively with change in AII during the sodium loading. No correlation was found between sodium excretion and Aldo and changes of Aldo. In conclusion, the results might suggest that the renin-angiotensin system is involved in the regulation of exaggerated natriuresis in chronic glomerulonephritis.

Adult↗

Urine and plasma propranolol.

Eight hypertensive patients who had been followed in an outpatient clinic during long-term therapy with propranolol (40 to 160 mg twice daily) were studied during a 24-hr stay in the ward. The usual oral dose was given and the total and free plasma concentrations were determined during the 24 hr and the urinary excretion of unchanged drug was measured. Average free plasma concentration of propranolol (y free) was calculated from: y free = Excreted propranolol (ng/24 hr)/Creatinine clearance (ml/24 hr). There was a significant relationship between log y free and average free plasma concentration (means free) determined from the directly measured plasma concentration curve: log y free = 0.0743 means free - 0.0466 (r = 0.98, P less than 0.001). In another group of propranolol-treated hypertensive patients there was a significant positive relationship between orosomucoid concentration and reciprocal of the free propranolol fraction in plasma. From this relationship the average total drug concentration (y total) was calculated from y free; there was a significant correlation with directly measured total plasma level: log y total = 0.0038 . means total + 1.0895 (r = 0.91, P less than 0.001). It is suggested that individually determined values of y free below 30 ng/ml and y total below 400 ng/ml (the concentration range studied) can be used to calculate the average mean 24-hr free and total plasma concentrations.

Adult↗

Effects of exercise on plasma renin, aldosterone and catecholamines before and after surgery for aortic coarctation.

The pre- and postoperative values of blood pressure, pulse rate, plasma renin activity, plasma aldosterone concentration and circulating catecholamines were studied in a group of 12 patients with uncomplicated aortic coarctation before and after exercise. Mean age of patients studied was 21.5 years. Postoperative studies were carried out on average 204 days after surgery. Following operation, both resting and exercising upper extremity pressures decreased. Six out of the 11 patients still had an abnormally high exercising blood pressure when compared with a normal control group of six persons. Postoperative pulse rates during exercise were significantly higher than pre-operatively (P less than 0.01). No statistically significant differences between pre- and postoperative values, and between patients and normal controls were found in the hormonal studies. This study suggests that the renin-aldosterone-system does not have a major role in the maintenance of the hypertension associated with coarctation of the aorta.

Adolescent↗

Prostaglandins, renin, aldosterone, and catecholamines in preeclampsia.

Urinary excretion of prostaglandin E2 (PGE2) and F2 alpha (PGF2 alpha), plasma concentrations of renin (PRC), aldosterone (PAC), noradrenaline (PNA) and adrenaline (PA) were determined in the third trimester of pregnancy, 5 days and 3 months after delivery in preeclampsia and normotensive pregnant and non-pregnant control subjects. PGE2 was higher in pregnant control subjects than in non-pregnant subjects, but reduced to non-pregnant level in preeclampsia. PGF2 alpha was the same in preeclampsia and normotensive pregnancy but higher than in the non-pregnant group. PRC and PAC were increased during pregnancy, but considerably lesser in preeclampsia than during normotensive pregnancy. PNA and PA were the same in all three groups. All parameters were normal 3 months after delivery. There were no correlations between any of the hormones and blood pressure in any of the groups. PGE2 was positively correlated to PRC. The lack of renal PGE2 in preeclampsia might be responsible for the decrease in renal blood flow and sodium excretion, and the changes in PRC and PAC are supposed to be secondary to changes in PGE2. It is hypothesised that preeclampsia is a state of prostaglandin deficiency.

Aldosterone↗

X-linked resistance of mice to high doses of herpes simplex virus type 2 correlates with early interferon production.

Mice inoculated intraperitoneally with herpes simplex virus type 2 develop focal necrotizing hepatitis and eventually die from ascending myelitis and encephalitis. The genetics of resistance to the infection were analyzed in crosses between resistant C57BL/10 mice and susceptible BALB/c mice. It was shown that the resistance of C57BL/10 mice to hepatitis induction was influenced by an X-linked dominant gene as previously shown for the GR mouse strain. The course of infection in the liver pointed to early, natural defense mechanisms as being responsible for the difference between the mouse strains, whereas the clearance of virus from the liver, probably mediated by specific immunity, was exerted at the same time and with equal efficiency for all groups of mice. In mortality experiments, resistance was shown to be an autointerference phenomenon in that a considerable number of C57BL/10 mice survived an intraperitoneal injection of 10(6) PFU, whereas all mice were killed by 10(5) PFU. This resistance of C57BL/10 mice to high doses of HSV-2 was retrieved in all groups of F1 mice in crosses between C57BL/10 and BALB/c mice except the (BALB/c female X C57 male) male group, in which the mice receive the X chromosome from the susceptible BALB/c female. Thus, the autointerference phenomenon also seems to be influenced by loci on the X chromosome. A similar pattern of inheritance was observed when early interferon induction (4 to 5 h after infection) in response to HSV-2 was measured. The possible relevance of this early interferon response in conjunction with other potential natural defense mechanisms is discussed.

Animals↗

Aggression-provoked huge release of submaxillary mouse renin to saliva.

In a normal male mouse, which had been kept isolated for some time, confrontation with another male mouse, resulted in aggressive behaviour, including fighting. The aggressive behaviour resulted in secretion of a few microlitre of saliva with vast renin concentration. The renin concentration in saliva reached values of 6000 Goldblatt units X ml-1, corresponding to 15 mg/ml of renin. This concentration is 6 orders of magnitude higher than normal plasma renin concentrations. The secretory pattern could be mimicked by ip injection of pharmacological doses (2-18 mg/kg) of the alpha-adrenergic agonist phenylephrine. This is probably the first demonstration of a physiological secretion of renin to saliva which may be of importance since renin most likely is injected into the opponent or prey through bites.

Aggression↗

The influence of normotensive pregnancy and pre-eclampsia on angiotensin-converting enzyme.

Serum angiotensin-converting enzyme (SACE) levels were determined in normotensive pregnant subjects and patients with pre-eclampsia in the third trimester of pregnancy and 5 days, 3 and 6 months after parturition, and also in the first and second trimester in the normotensive group. SACE levels were reduced during pregnancy and 5 days after delivery in the normotensive subjects compared with the levels 3 and 6 months after delivery and to the non-pregnant control subjects. After correction for plasma volume expansion, SACE was reduced in first and second trimester only. In pre-eclampsia both SACE and corrected SACE were significantly lower in third trimester and 5 days after parturition than 3 and 6 months after delivery and in non-pregnant control subjects. The reason for the reduced level of SACE in first and second trimester during normal pregnancy is not known. The low SACE levels in pre-eclampsia may be a secondary phenomenon due to a decreased placental synthesis without primary importance for the blood pressure regulation.

Adolescent↗

Phenotypical, functional and chromosomal studies of lymphocytes from patients with infectious mononucleosis.

The present study describes the T lymphocytosis in infectious mononucleosis (IM), using rosette techniques, lymphocyte transformation tests, Con A suppressor tests, and chromosomal analysis. Blood was drawn from twelve patients with IM during acute illness and during convalescence. We found a T lymphocytosis with a normal sheep erythrocyte receptor affinity of T cells, using three different E-rosette techniques. The percentage of T cells with Fc receptors for IgM (T mu) was reduced during acute illness, but normal in convalescence. The percentage of T cells with Fc receptors for IgC (T gamma) was normal during illness and slightly reduced afterwards. Owing to the T lymphocytosis the total number of T gamma lymphocytes was significantly increased during IM. The lymphocyte reactivity in vitro after mitogen stimulation (PHA, Con A, PWM) was in the lower end of the normal range. We found no evidence of increased suppressor-cell activity activity during IM, using a Con A suppressor cell assay. No chromosomaL defects were observed in lymphocytes from blood.

Adolescent↗

Urinary excretion of albumin and beta-2-microglobulin, glomerular filtration rate and immune complexes in serum during infectious mononucleosis.

Immune complexes in serum, urinary excretion of albumin and beta-2-microglobulin were determined in patients with infectious mononucleosis, both during the acute stage of the disease and one month later. At the first examination immune complexes were detected in 8 out of 12 patients, using both the ClqBA and the PP-Lc methods, but had disappeared in all after one month. Urinary excretion was initially increased for albumin in one of 9 and for beta-2-microglobulin in 5 of 9 patients. A significant fall in excretion was noted for beta-2-microglobulin during the acute phase (0.486 to 0.190 ng/min (medians), p less than 0.01) whereas albumin excretion did not change significantly (9.0 to 4.0 micrograms/min). Excretions were normal in all patients after one month. The magnitude of proteinuria was not correlated to the serum level of immune complexes. Serum beta-2-microglobulin was initially increased in 8 of 9 patients, but normal after one month (3.8 to 2.2 mg/l, p less than 0.01). There was a significant correlation between levels of beta-2-microglobulin in serum and urine (rho = 0.833, n = 9, p less than 0.01). 51Cr-EDTA clearance was the same during the acute illness and one month later. It is concluded that the abnormalities in urinary protein excretion do not seem to be related to the presence of circulating immune complexes in infectious mononucleosis and that the elevated urinary beta-2-microglobulin excretion is most likely due to increase production.

Acute Disease↗

Plasma arginine-vasopressin, renal-concentrating ability and lithium excretion in a group of patients on long-term lithium treatment.

Plasma arginine-vasopressin (AVP) was measured before and after 24 h of a 26-hour renal concentration test in 47 patients treated with lithium for 6-180 months (mean 70 months). In 34 of the patients, plasma AVP was also measured before and after a 2- to 4-hour period of water loading, and in 31 of the patients, creatinine, 125iothalamate, 131I-hippuran and lithium clearances were measured. Plasma AVP values were compared to those obtained in 8 healthy controls. Baseline AVP levels were significantly higher in the lithium-treated patients than in healthy controls. During the period of water deprivation AVP values increased significantly and during oral water loading a significant decrease took place, AVP values still being significantly higher in the lithium-treated patients than in the healthy controls. During oral water loading a slight increase in lithium clearance as well as fractional lithium excretion was seen as compared to values obtained during the last 2 h of a renal concentration test. This study demonstrates that antidiuretic hormone production is neither blocked nor inhibited during lithium treatment. The hypothalamic system reacts on water deprivation as well as on water loading. This study supports the notion that the main lithium-induced renal affection is a vasopressin-resistant impairment of renal concentrating ability.

Adult↗

Plasma noradrenaline and adrenaline in pre-eclampsia, essential hypertension in pregnancy and normotensive pregnant control subjects.

Noradrenaline and adrenaline in plasma were determined in 15 patients with pre-eclampsia, 10 pregnant patients with essential hypertension, 2 patients with transient hypertension in pregnancy, 11 normotensive pregnant control subjects, and 16 non-pregnant normotensive control subjects. Measurements were performed in the second and third trimester, 5 days, and 3 months after delivery. Comparison within groups showed no significant differences in plasma noradrenaline or adrenaline between levels in pregnancy, 5 days after delivery, and 3 months after delivery in neither pre-eclampsia, essential hypertension nor normotensive pregnant control subjects. Comparison between groups showed no significant differences between the levels in pre-eclampsia, essential hypertension and normotensive pregnant control subjects, neither in pregnancy nor after delivery. Plasma noradrenaline and adrenaline in pregnancy were the same as in normotensive non-pregnant control subjects. Plasma noradrenaline and blood pressure were not correlated in any of the groups. It is concluded that the sympathetic adrenergic activity evaluated by plasma catecholamines is normal in patients with pre-eclampsia and pregnant patients with essential hypertension.

Adolescent↗

Vast release of submaxillary mouse renin to saliva after stimulation with cholinergic, beta-adrenergic but especially alpha-adrenergic agonists.

alpha-adrenergic stimulation with phenylephrine causes release of vast amounts of mouse submaxillary gland renin to saliva. The amount released is about 100-fold higher than that released after beta-adrenergic stimulation with isoproterenol and about 1000-fold higher than the amount released after cholinergic stimulation with pilocarpine. alpha-blockade with phenoxybenzamine before phenylephrine stimulation strongly inhibits the renin release. However, phenoxybenzamine or beta-blockade with propranolol before isoproterenol stimulation have no effect on the amount of renin released. Thus, the release of submaxillary mouse renin to saliva is triggered mainly by activation of alpha-adrenergic receptors. Renin in cholinergic and alpha- and beta-adrenergic stimulated saliva has the same molecular weight and the same specific enzymatic activity as renin in the submaxillary gland. This indicates that renin is secreted to saliva, and probably also to the blood, in its fully enzymically active 40000 mol.wt. form regardless of the stimulus used. The vast amounts of renin released to saliva (up to 600 Goldblatt Units) demonstrate that submaxillary mouse renin is secreted predominantly to saliva and much less to the blood. The mouse submaxillary gland therefore seems to have an exocrine rather than an endocrine role for release of renin.

Adrenergic alpha-Agonists↗