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Biomedical subjects

P Toft

Publications and source records attributed to P Toft.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Hyperthyroidism and heart disease. Is thyrotoxic cardiomyopathy a disease entity?].

Cardiac symptoms have a prominent position in hyperthyroidism. The basic haemodynamic change is an increased cardiac output due to an increased stroke volume and an increased heart rate. Dyspnoea and palpitations are frequent symptoms. ECG-changes such as atrial fibrillation, sinus tachycardia, prolonged atrioventricular conduction and ST-segment changes are seen, but such changes are unspecific. Chest X-ray and echocardiographic studies are often normal, but cardiomegaly and ventricular hypertrophy are seen. The cardiac and non-cardiac symptoms of hyperthyroidism may in part be related to an increased sympathoadrenal activity. The thyroid hormones also exert a direct effect on the heart. Treatment includes specific anti-thyroid medication, beta-blocking agents, digoxin, diuretics and possibly anticoagulant therapy. Congestive heart failure, ventricular hypertrophy and arrhythmia are most commonly seen if other cardiac abnormalities are already present. The existence of thyrotoxic cardiomyopathy as an independent disease is illustrated by two case histories, which also demonstrate the reversibility of this condition.

Adult↗
PubMed1993

The concentration of N-acetyl aspartate, creatine + phosphocreatine, and choline in different parts of the brain in adulthood and senium.

The fully relaxed water signal was used as an internal standard in a STEAM experiment to calculate the concentrations of the metabolites: N-acetyl aspartate (NAA), creatine + phosphocreatine (Cr + PCr), and choline (Cho) containing compounds in four different parts of the brain in two age groups of healthy volunteers (20-30 yr, n = 8) and (60-80 yr, n = 8). Furthermore, T1 and T2 relaxation time of the metabolites and signal ratios: NAA/Cho, NAA/Cr + PCr, and Cho/Cr + PCr at TE = 272 msec were calculated. The experiments were carried out using a Siemens Helicon SP 63/84 wholebody MR-scanner at 1.5 T. In the younger age group, the concentration of NAA was significantly higher in the occipital part than in the other three parts of the brain. No significant regional variation was found for any other metabolite concentration. There was a significantly higher concentration of NAA in the occipital part of the brain in the younger age group compared to the older one. No significant regional or age dependent variation was found concerning the T1 and T2 relaxation times.

Adult↗
PubMed1993

Redistribution of lymphocytes following E. coli sepsis.

Infusion of endotoxin elicits lymphopenia and a transient granulocytopenia followed by granulocytosis in peripheral blood. The purpose of this study was to investigate which tissues the lymphocytes are redistributed to in response to endotoxaemia. Lymphocytes were isolated from the peripheral blood of 20 rabbits, labelled with 111Indium-tropolene and reinjected intravenously into the rabbits. Ten rabbits received an infusion of Escherichia coli endotoxin 2 micrograms/kg-1, while 10 rabbits received isotonic saline and served as a control group. The redistribution of lymphocytes was imaged with a gamma camera, and calculated with an interfaced computer before, and 2, 4 and 6 h after infusion of endotoxin or saline. Interleukin-1 beta and serum cortisol were measured. Following endotoxaemia the lymphocytes in peripheral blood decreased from 1.95 10(9)/l to 0.83 6 h later. Interleukin-1 beta and serum cortisol increased significantly. The radioactivity of labelled cells in the spleen and in the heart and lungs decreased to 83.3% and 87.8% of initial values respectively, 6 h after infusion of endotoxin. The radioactivity of the lymphatic tissue in and around the intestine increased to 128.8% of initial values. The results indicate that endotoxaemia induces redistribution of lymphocytes from peripheral blood and spleen to lymphatic tissue.

Animals↗
PubMed1993

Redistribution of lymphocytes after major surgical stress.

Major surgery evokes an endocrine stress response, characterized by increased serum cortisol, plasma adrenaline and noradrenaline. Furthermore, surgical stress is accompanied by lymphopenia and granulocytosis in peripheral blood. The changes in peripheral white blood cells have been demonstrated after surgery as well as after cortisol infusion. The aim of the present study was to investigate to which tissues/organs peripheral blood lymphocytes are redistributed after major surgery. From 20 rabbits lymphocytes were isolated from peripheral blood, labelled with indium-111-tropolene and reinjected intravenously into the rabbits. Ten of the rabbits underwent major surgery (upper laparatomy) during general anaesthesia, while the control group (n = 10) was anaesthetized without surgery. The endocrine stress response to surgery was measured as serum cortisol, plasma adrenaline and noradrenaline. The redistribution of lymphocytes was imaged with a gamma camera and calculated with a connected computer before, 2, 4, and 7 h after the skin incision. Compared to preoperative values, laparotomy resulted in an increase in serum cortisol from 116.6 to 461.9 nmol/l (mean) and a decrease in the fraction/percentage of lymphocytes in peripheral blood from 43.8% to 14.7% 7 h after surgery. Simultaneously, the activity of the heart and lungs together decreased to 76.1% of initial values, while the spleen activity was unaffected. The radioactivity of the lymphatic tissue increased to 137.8% and 134.7%, respectively, 4 and 7 h after the start of surgery. The results indicate that major surgery induces a redistribution of lymphocytes from peripheral blood to lymphatic tissue. It is suggested that the endocrine stress response may be of major importance.

Animals↗
PubMed1993

Effect of methylprednisolone on the cytokine response in patients undergoing lung surgery.

Tumour necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha) and IL-6, when released in excess, have been suggested to be important host mediators of the immunoinflammatory response to injury and infections. Corticosteroids suppress this response in vitro. This study was undertaken to investigate if a single dose of methylprednisolone (MP) could modify the cytokine response in patients undergoing lung surgery. Twenty-one patients with lung cancer were allocated randomly to treatment with MP 30 mg/kg i.v. (MP group) or isotonic saline (control group). Patients were anaesthetized with a balanced anaesthesia combined with thoracic epidural anaesthesia. MP or saline was administered immediately before induction of anaesthesia. The cytokines in plasma were measured by ELISA, and blood samples were collected preoperatively, at the end of surgery, 4 h later, and 1 and 5 days postoperatively. All patients had detectable IL-6 in plasma. Compared to preoperative values, plasma IL-6 levels in the MP group increased from 114 pg/ml (12-350 pg/ml) (mean, range) to peak value 146 pg/ml (15-580 pg/ml) on the first postoperative day. In the control group, IL-6 levels increased from 99 pg/ml (17-350 pg/ml) preoperatively to 125 pg/ml (10-300 pg/ml) on the first postoperative day. The increases were not significant. TNF alpha was detectable in only two patients, one from each group. Low levels of IL-1 alpha were demonstrated in three patients in the MP group and in four patients in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Cytokines in plasma and ultrafiltrate during continuous arteriovenous haemofiltration.

Cytokines are considered to be important mediators in the pathophysiology of sepsis and septic shock. We investigated if continuous arteriovenous haemofiltration (CAVH) could be used to remove excessive amounts of the cytokines tumour necrosis factor-alpha (TNF alpha), interleukin (IL)-1 alpha and IL-6 from peripheral blood in critically ill patients. Nine septic patients with renal failure were treated with CAVH. Ultrafiltrate and plasma were tested for cytokines by ELISA. All patients had detectable TNF alpha and IL-6 plasma levels, ranging from 10-750 pg/ml and 50-4,575 pg/ml, respectively. TNF alpha was removed by the ultrafiltrate with concentrations ranging from 10-1,000 pg/ml. The TNF alpha levels were significantly higher in the ultrafiltrate samples than in the corresponding plasma samples (P < 0.003). IL-6 was undetectable in the ultrafiltrate from five of the patients despite concomitant high plasma levels. IL-1 alpha was detectable in both plasma and ultrafiltrate in four patients. All patients developed multi-organ failure and septic shock and seven died. It is concluded that TNF alpha and IL-1 alpha but not IL-6 can be removed by CAVH in patients with sepsis.

Acute Kidney Injury↗
PubMed1993

Functional MR imaging at 1.5 T. Initial results using photic and motoric stimulation.

A preliminary investigation of the effects of stimulation of the visual and the motor cortex was made on a conventional 1.5 T MR imaging scanner. Both types of activation gave a detectable change in the signal between rest and stimulation using a gradient echo sequence with an echo time of 60 ms. The observed effects were assumed to be caused by variation in the amount of paramagnetic deoxyhemoglobin between stimulation and rest due to local increase of capillary blood flow in the human brain during stimulation.

Brain↗
PubMed1992

Redistribution of lymphocytes after cortisol administration.

Major surgical procedures awake an endocrine metabolic stress response characterized by increased secretion of cortisol and lymphopenia. The purpose of this study was to clarify to which tissues the lymphocytes are redistributed after cortisol administration. Lymphocytes were isolated from 16 rabbits, labelled with indium-111-tropolone and reinjected into the rabbits. Eight of the rabbits received 25 mg of cortisol intravenously (group I), while eight received isotonic saline (group II). The redistribution of lymphocytes was imaged with a gamma camera and calculated by a connected computer before and two, four, and seven h after cortisol or saline administration. The radioactivity of cells from the spleen and bone marrow decreased to 84% and 56% of the initial values seven h after cortisol administration. The activity of the lymphatic tissues increased to 121% of initial values. It is concluded that during cortisol-induced lymphopenia the lymphocytes are redistributed from peripheral blood, spleen and bone marrow to lymphatic tissue.

Animals↗
PubMed1992

The influence of tourniquet ischaemia on post-operative degranulation of polymorphonuclear granulocytes.

Degranulation of polymorphonuclear granulocytes following minor surgery and the contributory role of temporary tissue ischaemia in a limb were examined in 22 otherwise healthy patients undergoing elective arthroscopy under general anaesthesia with and without tourniquet. Apart from an increase in lactate levels following tourniquet release there was no difference in complement split product C3d, cortisol, leukocyte or creatinine kinase levels between the two groups. There was a post-operative increase in the plasma E alpha 1-proteinase inhibitor concentration, whereas lactoferrin values decreased 4 h following tourniquet deflation. Anaesthesia and minor surgery are followed by post-operative release of polymorphonuclear neutrophil elastase. This release is not related to complement activation and is apparently unaffected by 50 min of lower limb ischaemia. Anaesthesia and minor surgery do not cause lactoferrin release.

Adolescent↗
PubMed1992

Hypothermic patients admitted to an intensive care unit: a fifteen year survey.

In the period 1975-1989, 620 (4.5%) of 13,645 patients admitted to the intensive care unit of a Danish university hospital were diagnosed as suffering from hypothermia. The aim of the retrospective survey carried out is to describe this group of patients and to evaluate the methods used for rewarming. The degree of hypothermia was mild in 554 of the patients, moderate in 60, and severe in six. The rewarming method used was passive rewarming with the use of endogenous heat production. Rewarming was established with a median temperature increment of 0.1 to 2.5 degrees centigrade. The mortality rate showed no relationship to the hypothermia. With the exception of extracorporal circulation, the rewarming and mortality rates did not differ from the results shown in studies carried out using active and invasive rewarming procedures. In conclusion, with the exception of extracorporal circulation, rewarming of hypothermic patients by preservation of the endogenous heat production seems as effective as active and invasive rewarming methods.

Adolescent↗
PubMed1992

The redistribution of lymphocytes during adrenaline infusion. An in vivo study with radiolabelled cells.

Adrenergic activation is known to occur in sepsis and after major surgery or trauma. An elevated serum concentration of adrenaline is followed by lymphocytosis in peripheral blood even in splenectomized patients. The purpose of the present study was to clarify the redistribution of lymphocytes in the tissues during adrenaline infusion. Lymphocytes were isolated from 24 rabbits, labelled with indium-111-tropolone and reinjected into the rabbits. The next day the rabbits were anaesthetized. Eight rabbits received 3 micrograms of adrenaline i.v. followed by 0.2 micrograms/min, eight received 300 micrograms of adrenaline i.v. followed by 20 micrograms/min, while eight received a saline infusion and served as a control group. The activity of labelled cells was imaged with a gamma camera and computer before, during and after adrenaline infusion. The activity of the spleen decreased to 90% and 94% of initial values during low and high doses of adrenaline. The activity of the bone marrow decreased to 91% and 96%, respectively, while the activity of the heart/lung and the liver increased to 107% and 106% with the high dose of adrenaline. In peripheral blood the lymphocytes increased 10%. It is concluded that lymphocytes are redistributed from spleen and bone marrow to peripheral blood, lungs and liver during adrenaline infusion in this animal model.

Animals↗
PubMed1991

[Prevention of the TURP syndrome by using the Swan-Ganz catheter in a patient with severe aortic stenosis].

A patient with a severe valvular aortic stenosis, who required transurethral resection of the prostate, was monitored with a Swan-Ganz catheter. Overloading of the patient due to absorption of irrigating fluid was quickly reflected by elevation of pulmonary artery pressure PAP and pulmonary capillary wedge pressure PCWP, while the central venous pressure CVP was unchanged. Monitoring of PAP and PCWP may prevent the development of the TURP-syndrome in patients with compromised left sided cardiac function.

Aged↗
PubMed1991

Digitalis enhances exercise-induced hyperkalaemia.

In 9 patients with atrial fibrillation the effect of zero, low and high levels of serum digoxin on exercise-induced hyperkalemia was assessed by bicycle exercise tests. Exercise at each level of serum digoxin was associated with a significant (up to 20%) rise in plasma potassium. At a work load of 75 W the highest level of serum digoxin was associated with a significantly higher maximum plasma potassium concentration as compared to the maximum valueatazero serum digoxin. The enhancement of exercise-induced hyperkalemia may add to the arrhythmogenic effect of digitalis.

Adult↗
PubMed1991

Theophylline and ethylenediamine pharmacokinetics following administration of aminophylline to septic patients with multiorgan failure.

The pharmacokinetics of theophylline and ethylenediamine were examined in 6 patients with septicaemia and multiorgan failure (MOF). The patients received a bolus injection of 4 mg/kg aminophylline. Aminophylline is the ethylenediamine salt of theophylline. The clearance of theophylline was reduced in all our patients ranging from 10-66% of the value obtained in healthy volunteers. The median t 1/2 beta was 18.8 h (range 5.8-25.5) compared to a normal value of 6 h. The median clearance of ethylenediamine was 54% of the normal value, while the peripheral volume of distribution was increased to 650%. Due to this t 1/2 beta was 2.3 (2.0-2.7) h, which is 5 times the normal value of 0.55 h. There was no correlation between clearance of theophylline and ethylenediamine. As theophylline has a narrow therapeutic range, routine monitoring with measurements of serum theophylline is mandatory in patients with MOF.

Adult↗
PubMed1991

Influence of physical exercise on serum digoxin concentration and heart rate in patients with atrial fibrillation.

Heart rate and serum digoxin concentration in eight patients with atrial fibrillation were studied at rest and during exercise when initial serum digoxin concentrations were zero and at low and high therapeutic values. Eight patients with ischemic heart disease and in sinus rhythm were studied for comparison. Though the serum digoxin concentration decreased significantly during exercise, the absolute reduction in heart rate was the same at rest and during exercise in patients with atrial fibrillation. Compared with the control patients in sinus rhythm, the heart rate in patients with atrial fibrillation was not adequately controlled during exercise by any serum digoxin concentration tested despite a reduction in heart rate with increasing digoxin concentration. The effects of digoxin on heart rate regulation in atrial fibrillation are complex and include direct effects on the myocardium as well as indirect effects mediated by modulation of the autonomic nervous system; the present results indicate that the drug is not displaced from the target organs by decreasing serum concentrations during exercise. In atrial fibrillation, because the demands on the filter function of the atrioventricular node are highly unphysiological, the effect of digoxin on heart rate during exercise is not adequate.

Adult↗
PubMed1991

Attenuation of intra-operative surgical stress response has no influence on post-operative degranulation of polymorphonuclear granulocytes.

Degranulation of polymorphonuclear (PMN) granulocytes, complement activation, and the endocrine metabolic response to hysterectomy were compared in two groups of patients receiving either general anaesthesia (GA group) or combined epidural analgesia and general anaesthesia (GAE group). The B-leucocyte and the cortisol responses were attenuated in the GAE group. There was no sign of complement activation. The post-operative rise in elastase-alpha-1-proteinase levels 4 h post-operatively on the first, second and third post-operative days was similar in the two groups. Plasma lactoferrin values were significantly elevated 4 h post-operatively and reached pre-operative values on Day 1 in both groups. Attenuation of the surgical stress response during uncomplicated hysterectomy did not influence the post-operative increase in proteinase activity. Mediators generated at the site of surgical trauma may account for the PMN degranulation observed after major surgery.

Adult↗
PubMed1990

[Mortality of severe asthma in Danish intensive care units in 1988. A questionnaire study].

The mortality due to asthma is gradually increasing in Denmark. In 1988, 209 patients died from asthma. Of these patients, 108 were under 70 years. Information about patients who died from asthma in Danish intensive care units (ICU) in 1988 was obtained retrospectively by questionnaires. 99% of all the ICU's replied. Eleven of the abovementioned patients died in an ICU because of inadequate oxygenation or ventilation. In cases where an anaesthesiologist was called to a patient with acute severe asthma, who subsequently died from the disease, the majority had developed cardiac arrest, when the anaesthesiologist arrived. The use of objective monitoring of the degree of pulmonary obstruction by use of peak flow measurements and series of arterial blood gas values is recommended. Hypoxemia, the main risk factor, might be revealed in time by measurements of pulseoximetry. If the arterial PCO2 is increasing, the patient should be monitored in an ICU in view of oxygenation and ventilation, and possibly mechanical ventilation.

Asthma↗