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Biomedical subjects

F Fyhrquist

Publications and source records attributed to F Fyhrquist.

At least 37 records · Page 2Linked to original sources
PubMed1993

Anaesthesia affects plasma concentrations of vasopressin, von Willebrand factor and coagulation factor VIII in cardiac surgical patients.

Operative stress may affect haemostatic mechanisms through hormonal systems. As the endocrine stress response to surgery may be modulated by anaesthesia, we have altered stress hormone concentrations by using either opioid or inhalation based anaesthesia to study haemostatic mechanisms in cardiac surgical patients. Thirty patients undergoing coronary artery surgery were allocated randomly to receive fentanyl (non-stress group) or enflurane (stress group) as the main anaesthetic agent. After cardiopulmonary bypass (CPB), plasma arginine vasopressin (AVP) concentrations were significantly (P < 0.001) greater in the stress group (81.8 (46.9-142.9) pg ml-1, mean with 95% confidence limits) than in the non-stress group (5.8 (3.3-10.2) pg ml-1). Plasma noradrenaline and adrenaline concentrations increased similarly in both groups after CPB. Plasma concentrations of both von Willebrand factor (stress: 1.56 (1.33-1.79) IU ml-1; non-stress: 1.00 (0.76-1.25) IU ml-1) and coagulation factor VIII: C (stress 1.15 (0.87-1.44) IU ml-1; non-stress: 0.69 (0.55-0.80) IU ml-1) were significantly (P < 0.01) greater in the stress group than in the non-stress group after CPB. The results indicate that there is a temporal relationship between the increased plasma concentrations of AVP and von Willebrand factor and factor VIII: C. It is not clear if this indicates a causal relationship. However, variable stress control by anaesthesia may modify haemostasis in cardiac surgical patients.

Adult↗
PubMed1993

Endothelin antiserum decreases volume-stimulated and basal plasma concentration of atrial natriuretic peptide.

BACKGROUND: Endothelin-1 (ET-1) is the most powerful factor known to release atrial natriuretic peptide (ANP) in vivo and in cultured cardiac myocytes or preparations of atrium. We tested the role of endogenous ET-1 in the regulation of ANP release by passive immunization in anesthetized rats. METHODS AND RESULTS: Intravenous injection of antiserum against ET-1 was shown to decrease basal and volume-stimulated plasma concentrations of ANP, whereas control serum was without effect. Antiserum generated in rabbits cross-reacted 100% with endothelin-2 and -3. In pentobarbital-anesthetized Wistar rats treated with ET-1 antiserum, plasma ANP concentration measured by radioimmunoassay was reduced by 37% from starting level after 10 minutes and by 30% after 60 minutes. Control rat serum had no effect on plasma ANP. Rapid intravenous infusion of 8 mL of 0.9% NaCl caused a sixfold increase of plasma ANP concentration in control rats but only twofold in rats pretreated with ET-1 antiserum (P < .01). This effect of ET-1 antiserum was dose dependent. ET-1 antiserum changed neither blood pressure nor heart rate significantly in anesthetized rats. Pretreatment with ET-1 antiserum did not affect the initial hypotensive response to intravenous ET-1 0.5 nmol/kg but significantly attenuated the subsequent hypertensive response to endothelin. CONCLUSIONS: Endothelin may be a physiological modulator of both basal and stimulated ANP release.

Animals↗
PubMed1993

Recurrent fever associated with progesterone action and persistently elevated serum levels of immunoreactive tumor necrosis factor-alpha and interleukin-6.

We describe two women who suffer from recurrent fever up to 40 C in association with progesterone action and who have continuously elevated serum levels of immunoreactive tumor necrosis factor-alpha (TNF alpha) and interleukin-6 (IL-6). In patient 1, recurrent fever began at age 17 yr and has now continued for 11 yr. The patient has had three early pregnancy terminations because of continuous fever and, thereafter, three early pregnancy losses associated with fever. In patient 2, fever first appeared at age 18 yr, and the attacks have now continued for 3 yr. The association between fever and progesterone action is supported by the following facts. 1) The episodes of fever appear in the midluteal phase of the menstrual cycle concomitantly with the highest concentration of serum progesterone. 2) Fever is further exaggerated in early pregnancy. 3) Synthetic progestins induce fever regardless of the day of the menstrual cycle. 4) The progesterone antagonist RU 486 and an agonist of GnRH, nafarelin, are capable of preventing the fever, with no effect on serum cytokine levels. Although the underlying mechanism of elevated TNF alpha and IL-6 levels in our patients remains unknown, the data suggest that these cytokines cooperate with progesterone in exerting a pyrogenic response in the hypothalamic thermoregulatory center.

Acute-Phase Proteins↗
PubMed1993

Successful treatment of the anemia of rheumatoid arthritis with subcutaneously administered recombinant human erythropoietin. Slower response in patients with more severe inflammation.

We performed a 24-week open clinical study in which 12 patients with rheumatoid arthritis (RA) and anemia (mean hemoglobin (Hb) value 102 g/l, range 90-109 g/l) were treated with recombinant human erythropoietin (rHuEPO). rHuEPO was given as a subcutaneous injection twice weekly with an initial dose of 300 U/kg/week. Nine of the 11 patients who completed the study responded with an increase in Hb value of 15 g/l or more within 3 to 17 weeks. Three months after treatment the Hb levels were significantly lower than the highest Hb levels (p < 0.0001). There was an inverse correlation between the response rate and the mean serum concentrations of C-reactive protein and serum amyloid A protein (p < 0.001 and p < 0.003, respectively). We conclude that rHuEPO can correct anemia in patients with RA, but the response seems to be adversely influenced by the inflammatory activity of the disease.

Adult↗
PubMed1993

Raised plasma endothelin-1 concentration in patients with nephropathia epidemica.

Nephropathia epidemica (NE) with renal syndrome, caused by the Puumala-virus, is manifested clinically by the triad of fever, hemorrhage and renal failure. We observed raised plasma concentrations of endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) in 23 patients during the acute phase of NE. They all developed transient renal failure and all displayed characteristics of NE, also verified by a rapid IgG antibody test. Blood pressure was normal or low in all subjects during the acute phase of the disease. Plasma ET-1 and ANP levels returned to normal following recovery one month later. The cause of increased ET-1 synthesis in NE remains unknown. It may be related to vascular damage or extravasation of blood. ET-1 may participate in the pathogenesis of acute renal failure of NE. Raised plasma ANP levels were most likely caused by fluid retention during the acute phase of NE. However, high levels of circulating ET-1 might have contributed to increased release of ANP.

Acute Kidney Injury↗
PubMed1993

Effects of psychological stress on plasma interleukins-1 beta and 6, C-reactive protein, tumour necrosis factor alpha, anti-diuretic hormone and serum cortisol.

The study was undertaken to determine whether psychological stress influences immunobiological functions and is an important preanalytical factor to be considered in connection with blood specimen collection. Two kinds of stress were applied, the Stroop colour conflict test and the thrill of a novice about to make the first jump with a parachute. In both test situations, the level of the stress indicators cortisol or anti-diuretic hormone rose significantly. The concentrations of the cytokines studied did not change significantly. However, in the parachute test significant positive correlations were found, e.g. between the changes of cortisol and C-reactive protein and between anti-diuretic hormone and interleukin-1 beta. This suggests that there is an interaction between the endocrine and the immune systems in the response to a psychological stress.

Adolescent↗
PubMed1992

Endothelin-1 stimulates its own synthesis in human endothelial cells.

We studied whether endothelin-1 (ET-1) would affect its own synthesis. Human umbilical cord vein endothelial cells in methionine-poor culture medium containing [35S] methionine were treated with synthetic ET-1 or ET-3. Immunoprecipitation of 35 S-labeled ET-1 was performed with rabbit ET-1 antiserum. ET-1 caused an 40 +/- 4% (mean +/- SEM) increase of immunoprecipitable 35 S-labeled ET-1 as confirmed by its elution point in reversed phase high power liquid chromatography (HPLC). ET-3 caused a 23 +/- 2% increase in ET-1 concentration. Amplification of cDNA by PCR showed both ET-1 and ETB receptor mRNAs in human cord vein endothelial cells. We conclude that ET-1 increases its own synthesis in endothelial cells. This suggests a positive autocrine feed-back action of ET-1 on its own synthesis, an effect which is probably mediated by non-specific ETB receptors.

Cells, Cultured↗
PubMed1992

Pharmacokinetics and effects of atrial natriuretic factor during hypothermic cardiopulmonary bypass.

The pharmacokinetics of a bolus dose of synthetic atrial natriuretic factor (ANF) 50 micrograms and its effects on urine output, blood pressure and plasma renin activity have been studied in 5 patients undergoing hypothermic cardiopulmonary bypass for cardiac surgery. The half-lives of the fast and slow components were 2.4 min and 14.2 min, respectively. The volume of the central compartment was 16.7 l and the volume of distribution at steady-state was 38.9 l. The total plasma clearance was 3.8 l.min-1. ANF significantly increased urine output and decreased blood pressure, but it did not affect plasma renin activity.

Atrial Natriuretic Factor↗
PubMed1992

Human endometrial adenocarcinoma cells express endothelin-1.

The expression of endothelin-1 (ET-1) in five human endometrial adenocarcinoma cell lines was studied. Using specific radioimmunoassay, immunoreactive ET-1 was detected in conditioned medium from two of the cell lines (RL 952 and HEC 1A). In reverse-phase high-performance liquid chromatography (HPLC), synthetic ET-1 and immunoreactive ET-1 from conditioned media revealed the same elution profile. By amplification of cDNA using the polymerase chain reaction, normal human endometrium as well as cell lines RL 952 and HEC 1A were shown to express ET-1 mRNA. In addition, cell line HEC 1B and KLE, which did not produce measurable amounts of immunoreactive ET-1, contained ET-1 specific mRNA whereas cell line AN3CA had no detectable ET-1 mRNA and did not secrete immunoreactive ET-1.

Adenocarcinoma↗
PubMed1992

Cytokine and acute-phase reactant levels in serum of children with cancer admitted for fever and neutropenia.

Serum concentrations of tumor necrosis factor-alpha (TNF alpha), interleukin (IL)-1 beta, IL-6, and the acute-phase reactants C-reactive protein (CRP) and serum amyloid A (SAA) were measured on admission in 46 neutropenic children with cancer in 81 episodes of fever. The aim was to find out whether any of these variables would differentiate true bacteremia from fever due to other causes. In most episodes serum concentrations of TNF alpha and IL-1 beta were elevated. IL-6 was detectable in 68%, but the serum concentration was elevated in only 15%. SAA proved to be more sensitive than CRP for the early detection of bacteremia. However, not even SAA was sufficiently accurate at the individual level. We conclude that the cytokine and acute-phase protein levels found were related to the febrile response but did not correlate with documented bacterial etiology.

Acute-Phase Proteins↗
PubMed1992

Hormonal changes in patients with severe chronic congestive heart failure treated by ultrafiltration.

Plasma atrial natriuretic peptide (ANP), antidiuretic hormone (ADH), plasma renin activity (PRA), and circulatory haemodynamics were studied in five patients with chronic congestive heart failure undergoing ultrafiltration on two consecutive days. The patients were in the New York Heart Association class IV, and were considered candidates for heart transplantation. A mean of 3.3 +/- 0.5 litres of fluid was removed during each ultrafiltration. Plasma ANP concentration remained unchanged during ultrafiltration: 369 +/- 151 pg/ml at start and 316 +/- 116 pg/ml at the end, while plasma ADH concentration and PRA increased from 5.1 +/- 2.1 to 7.5 +/- 3.4 pg/ml (P less than 0.02), and 5.9 +/- 3.0 to 7.7 +/- 3.2 ng/ml (P less than 0.03) respectively (n = 10). After treatment, plasma ADH and PRA declined to baseline values within 1 h. Pulmonary artery, pulmonary capillary wedge, and right atrial pressures decreased significantly, while blood pressure and heart rate remained constant during ultrafiltration. A volume of 3.3 +/- 0.5 litres of fluid was removed, and caused an increase in colloid osmotic pressure from 22.0 +/- 3.0 to 33.7 +/- 3.9 mmHg (P less than 0.02). It was unexpected that plasma ANP concentration did not decline. Due to long-standing severe heart failure the atrial wall may have lost some of its elastic properties, resulting in less ability to adapt to reduced filling pressures. Accordingly, atrial wall stretch remained unchanged, explaining the constant ANP levels. Ultrafiltration treatment caused an increased responsiveness to diuretic therapy, and four patients survived long enough to receive heart transplants.

Adult↗
PubMed1992

Immunoreactive interleukin-6 in serum of patients with B-lymphoproliferative diseases.

Serum immunoreactive interleukin-6 (ir-IL-6) concentration was measured by radioimmunoassay in nine patients with chronic lymphocytic leukaemia (CLL), 16 patients with multiple myeloma (MM), 12 patients with monoclonal gammapathy of undetermined significance (MGUS), 22 patients with primary Sjögren's syndrome (SS), and in 32 control subjects. Measurable quantities of ir-IL-6 were detected in every sample studied. Patients with MGUS and SS had significantly higher serum ir-IL-6 (mean +/- SD) concentrations (337 +/- 92 ng l-1 and 299 +/- 100 ng l-1, respectively) than controls (92 +/- 77 ng l-1) and patients with CLL and MM (120 +/- 32 ng l-1 and 113 +/- 58 ng l-1, respectively). Longitudinal studies of ir-IL-6 concentration in a few patients with MM showed a decrease before remission and an increase prior to relapse, but no consistent pattern was detected. In conclusion, we found that serum ir-IL-6 levels are higher in patients with benign hypergammaglobulinaemic states than in patients with malignant neoplastic B-cell disorders.

Adult↗
PubMed1992

Secondary polycythaemia associated with nocturnal apnoea--a relationship not mediated by erythropoietin?

A polysomnographic study was undertaken in nine patients with unexplained polycythaemia and nine age- and sex-matched controls. Circulating plasma levels of immunoreactive erythropoietin (IrEPO) were analysed before and after sleep. Seven out of nine polycythaemia patients were found to have sleep-disordered breathing and fulfilled the criteria for the sleep apnoea syndrome. Erythrocyte volume fraction was by definition higher among polycythaemia patients, and showed a weak positive correlation with minimum oxygen saturation during sleep (P less than 0.05). However, plasma IrEPO did not differ between the two groups or between morning and evening samples within the respective groups. In a separate study, IrEPO was repeatedly analysed during sleep in a group of six patients with severe obstructive sleep apnoea and six matched controls. No correlation with severity of sleep-disordered breathing was found. None of these patients had polycythaemia, and there was no obvious diurnal variation in IrEPO levels. A nocturnal sleep study may be warranted in patients with unexplained polycythaemia. Obstructive sleep apnoea does not appear to be related to increased IrEPO levels, although polycythaemia has been reported as a relatively common finding in this disease.

Circadian Rhythm↗
PubMed1992

Raised plasma endothelin during acute migraine attack.

Endothelins are the most potent vasoconstrictor peptides known. Plasma endothelin (ET-1) concentrations were measured in eight migraine patients (mean age 44.5 years), two during an acute migraine attack with aura and six during an attack without aura. The mean ET-1 values were elevated in all migraine patients above the range of normal subjects, and were 10.6 (range 6.0-16.0) pg/ml in migraine patients and 3.8 (range 0.7-5.8) pg/ml in controls. We hypothesize that ET-1 may constrict cerebral vessels during the initial stage of the migraine attack.

Adult↗
PubMed1992

Fuel and fluid homeostasis during long-term exercise in healthy subjects and type I diabetic patients.

OBJECTIVE: This study was designed to examine metabolic and hormonal effects of long-term exercise in healthy subjects and insulin-dependent (type I) diabetic patients. RESEARCH DESIGN AND METHODS: Two studies were performed. First, 16 healthy males (32 +/- 3 yr) were studied during a semitriathlon competition (2 km swimming, 90 km biking, and 21 km running). Second, 9 type I diabetic males (41 +/- 2 yr) and 17 healthy matched control subjects were studied during a 75 km cross-country skiing race. Blood samples were taken before and immediately after exercise, and also during the ski race. RESULTS: During the semitriathlon race, serum insulin, C-peptide, glucagon cortisol, growth hormone ACTH, prolactin, and plasma renin activity increased two- to ninefold, whereas serum testosterone fell. Apart from a fall in magnesium, serum electrolyte concentrations remained unchanged. Before long-term skiing, patients reduced their insulin dose by 30-40%. They were hyperglycemic during the initial part of the race, but near normoglycemic thereafter. There were large interindividual variations in the increments of counterregulatory hormones, whereas serum testosterone and luteinizing hormone fell quite uniformly. Plasma renin activity and aldosterone concentrations rose similarly in diabetic and healthy subjects, whereas the rise in antidiuretic hormone was slightly greater in diabetic patients. During the initial part of the race, serum atrial natriuretic peptide fell in both groups. CONCLUSIONS: Severalfold increments in hormone concentrations contribute to the maintenance of fuel and fluid homeostasis during long-term exercise. With an appropriate adjustment of insulin dose and diet, also type I diabetic patients can participate in competitive long-term exercise.

Adult↗
PubMed1992

Raised plasma concentrations of endothelin-1 and -3 in marmosets with acute aortic stenosis: no relation to the renin-angiotensin system.

Plasma levels of endothelin (ET), plasma renin activity (PRA) and angiotensin II (Ang II) were measured in anaesthetized marmosets exposed to acute aortic stenosis proximal to the renal arteries. In vehicle experiments, ET rose from 5 +/- 2 to 38 +/- 4 pg ml-1, PRA from 5 +/- 2 to 99 +/- 21 ng ml-1 h-1 and Ang II from 21 +/- 4 to 213 +/- 76 pg ml-1. Administration of renin inhibitor and angiotensin converting enzyme inhibitor reduced PRA and Ang II to control levels, while the plasma levels of ET increased further (51 +/- 10 and 71 +/- 16 pg ml-1, respectively). During aortic stenosis the two isoforms ET-1 and ET-3 appeared in the circulation, while in conscious control animals only ET-1 was found. It is concluded that the increased plasma levels of ET in our primate model could not be ascribed to the increased circulating levels of PRA and Ang II.

Acute Disease↗