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Biomedical subjects

J A Dahlström

Publications and source records attributed to J A Dahlström.

At least 19 recordsLinked to original sources
PubMed2000

Changes in transfer factor of the lung in response to bronchodilatation.

Measurement of the transfer factor for carbon monoxide (TLCO) is a widely used clinical lung function test. Although it is frequently applied in patients with bronchial obstruction, there is little information on the effects of bronchodilatation on the test. We therefore measured TLCO in 40 patients before and after inhalation of terbutaline. TLCO was measured with the single-breath technique in 20 patients and with the intra-breath technique in 20 patients. TLCO was also measured in 20 healthy subjects with the single-breath technique. Forced expiratory volume (FEV1) increased from 2.9 +/- 1. 1 to 3.2 +/- 1.2 l in patients with bronchial obstruction in response to terbutaline inhalation. TLCO increased from 8.2 +/- 2.6 to 8.6 +/- 2.7 mmol min-1 kPa-1 (P< 0.001) and alveolar volume (VA) from 5.74 +/- 1.21 to 5.90 +/- 1.21 l (P<0.001). There was no difference between the single-breath and the intra-breath techniques. There was little change in FEV1 in the healthy subjects in response to terbutaline. TLCO increased from 10.2 +/- 2.1 to 10.5 +/- 2.2 mmol min-1 kPa-1 (P< 0.01), but there was no change in VA. The increase in TLCO in patients may partly be explained by improved distribution of the inhaled gas. In healthy subjects, terbutaline may increase pulmonary capillary volume. We conclude that bronchodilatation results in a small increase in TLCO in patients with light to moderate bronchoconstriction as well as in healthy subjects. The effect is small and should in most cases be simple to account for in the interpretation of pulmonary function tests, provided the patient's treatment is known.

Adult↗
PubMed1997

Venous thrombectomy for iliofemoral vein thrombosis--10-year results of a prospective randomised study.

OBJECTIVES: To study if venous thrombectomy prevents late post-thrombotic sequelae, venous obstruction reflux, and improves venous physiology following an acute iliofemoral venous thrombosis. DESIGN: Prospective randomised controlled study. MATERIAL: Thirty patients returned for follow-up 10 years after an acute iliofemoral venous thrombosis initially treated with conventional anticoagulation treatment (medical group, n = 17) or with thrombectomy combined with a temporary arteriovenous fistula and anticoagulation (surgical group, n = 13). Clinical assessment, radionuclide angiography, duplex ultrasound and venous physiology tests were performed. RESULTS: Leg swelling was recorded in 12 (71%) and leg ulcers in three (18%) of the medical patients and in, respectively, six (46%) and one (8%) of the surgical patients. The surgical patients had less severe sequelae (class 0-2). Radionuclide angiography demonstrated that the iliac vein was more commonly occluded following medical (59%) than following surgical (17%) treatment (p < 0.05). Duplex examination demonstrated slightly (n.s.) more reflux in the femoral and popliteal veins in the medical group. Venous physiology (occlusion plethysmography, foot volumetry, and foot vein pressures) did not show any significant differences, although the medical group tended to have a more severe pathology. CONCLUSION: Venous thrombectomy improves venous patency and possibly reduces venous reflux and post-thrombotic sequelae as compared to anticoagulation treatment.

Acute Disease↗
PubMed1992

Maximum anal sphincter strength measured by the solid sphere test and anal pressure profiles.

OBJECTIVE: To evaluate two methods of quantifying external anal sphincter function. DESIGN: Open study. SETTING: Helsingborg Hospital, Sweden. SUBJECTS: 73 patients (63 women and 10 men), of whom 25 were incontinent of gas and liquid or solid stool. INTERVENTIONS: Anal pressure profiles and the "solid sphere" test. OUTCOME MEASURE: Correlation between results of tests and presence of incontinence. RESULTS: Continent patients were younger than incontinent ones. The correlation between the maximum force the patient could retain and the maximum anal squeeze pressure was good (r = 0.67, p < 0.001). Younger continent patients (n = 48) and significantly higher pressures than incontinent patients (n = 25), but the range and overlap were wide. The reproducibility of both methods was good. CONCLUSIONS: Although the solid sphere test is easier and quicker to do, anal pressure profiles yield more information that is important in the evaluation of incontinence.

Adult↗
PubMed1991

Anal sphincter competence in healthy women: clinical implications of age and other factors.

Normal variation in anal sphincter competence was examined with anal pressure profilometry, using a low compliant recording system and a perfused catheter, in 49 healthy women with a mean age of 51 years (range 20-79). Maximum resting anal pressure and maximum squeeze pressure declined with age (r = -0.61; P less than .001 for both), more rapidly so after menopause. Rectal pressure increased with body mass index (r = 0.60, P less than .001). Closing pressure (ie, the difference between maximum resting anal pressure and rectal pressure), an important determinant of anal continence, was more markedly reduced with age (r = -0.69, P less than .001) than was maximum resting anal pressure. Age-related changes were found for the length of the anal canal (r = -0.36, P less than .05). Parity and anal pressures were unrelated. Women are more frequently affected by anal incontinence than are men. Anal pressure profilometry is a useful diagnostic aid, though age-related changes must be taken into consideration when evaluating the results. The more rapid decline of anal pressures after menopause might imply that anal sphincter tissue is a target for estrogen.

Adult↗
PubMed1990

Anal sphincter function after delivery: a prospective study in women with sphincter rupture and controls.

Twenty-one consecutive women with anal sphincter muscle rupture during delivery (0.79%) and 15 controls were examined. The anal sphincter was immediately repaired in the study group and the function determined with anal profilometry at 3 days and 3 months after delivery, and in ten of the patients after 12 months. Anal sphincter strength was reduced soon after delivery in the controls but regained normal strength within 3 months. In the anal sphincter rupture group, an improvement was found over the first 3 months after delivery, but afterwards no further change occurred. The anal sphincter strength was significantly reduced compared to the control group, both soon after delivery and after 3 months. Their voluntary anal pressure increased from 1.7 kPa immediately after delivery to 3.2 kPa at 3 months in the study group and the corresponding values in the control group were 4.0 and 6.5 kPa, respectively. For the closing pressure, that is the resting pressure minus the rectal pressure, the values in the study group were 4.2 and 6.7 kPa, and in the control group 7.2 and 9.4 kPa, respectively. In the women with anal sphincter rupture, however, a significantly increased frequency of gas incontinence was found.

Adult↗
PubMed1990

Venous function assessed during a 5 year period after acute ilio-femoral venous thrombosis treated with anticoagulation.

To determine the chronological changes of venous physiology following major thromboses, 20 patients were repeatedly examined for over 5 years after an acute ilio-femoral thrombosis which was treated with conventional anticoagulation. Radionuclide angiography showed that 70% of the patients had obstructive lesions of the iliac vein with only minor changes occurring from 6 months to 5 years. In spite of this, the plethysmographic maximum venous outflow increased from 31 to 45 ml/min/100 ml (P less than 0.001). The foot volumetric reflux did not change with time and about half of the patients had abnormal values. Venous reflux assessed by the refill time of foot vein pressure, deteriorated with time (P less than 0.05), and at 5 years all but one patient had a refill time less than 20 s. The muscle pump function, examined by foot volumetry, was abnormally low in about half of the patients throughout the study. The ambulatory foot vein pressure was constantly pathological (greater than 60 mmHg) in half of the patients and only two of 18 patients had normal values (less than 45 mmHg) at 5 years. Five patients with thromboses involving only the proximal veins had better physiological results than 15 patients with thromboses that extended to the peripheral veins. Three patients who developed venous claudication had iliac vein obstruction and an impaired venous outflow and three patients who developed venous ulcers had venous reflux and severe venous hypertension. Although venous outflow continuously improves following ilio-femoral thromboses, valvular competence and muscle pump function are constantly pathological, creating severe venous hypertension with a risk of post-thrombotic sequelae.

Anticoagulants↗
PubMed1988

Non-invasive recognition of arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia causes ventricular arrhythmias and sometimes heart failure. The condition is easily overlooked, but once suspected, it may be diagnosed non-invasively. This is illustrated by the case reported. The clinical features of this syndrome are discussed, with special emphasis on the non-invasive findings.

Adult↗
PubMed1988

Diagnosis of deep vein thrombosis with a new radionuclide method--99Tcm-albumin test.

The diagnostic efficiency of 99Tcm-albumin test (AT), a new radionuclide method, was evaluated in 90 consecutive patients with suspected deep vein thrombosis (DVT) admitted to the medical emergency ward. Phlebography was used as reference method. The sensitivity of the AT test was 92% and the specificity was 61%. As the method is objective, rapid and convenient for the patients, it can be recommended as an initial examination method to be followed by phlebography, in cases with a positive test result. Criteria with high specificity, 98%, have also been defined but these criteria should be further investigated.

Adult↗
PubMed1984

Haemodynamic assessment of fetal heart arrhythmias.

The effects of fetal heart arrhythmias were examined serially in two pregnancies by three non-invasive methods: fetal ECG, fetal phonocardiography and ultrasonic measurement of fetal blood flow. In a case of supraventricular arrhythmia, there was evidence suggesting that the stroke volume varied with ventricular filling according to the Frank-Starling law. In a case of total atrioventricular block the mean blood flow in the fetal descending aorta and in the umbilical vein was within the normal range. Blood flow velocity in the inferior vena cava of the fetus reflected atrial contractions. In the phonocardiogram, a phenomenon similar to 'bruit de canon' was found. Both pregnancies had good outcomes and subsequent development of the infants was normal except for the persisting dysrhythmias. The two cases exemplify how fetal heart function can be assessed in utero.

Adult↗
PubMed1984

Comparison between 99Tcm-porcine plasmin and 99Tcm-labelled erythrocytes in diagnosis of deep vein thrombosis.

In 20 patients with suspect deep venous thrombosis (DVT), scintillation detector measurements were performed over each leg during the first 60 min after intravenous injection of 99Tcm-porcine plasmin. Thereafter, 99Tcm-labelled autologous erythrocytes were injected i.v. and repeat measurements were performed. Finally, scintillation camera images of both legs were obtained. Phlebography was used as a reference method. A close relationship (P less than 0.01) was found between the scintillation detector measurements, both in patients with DVT (n = 11) and in patients without DVT (n = 9). Thus, 99Tcm-plasmin is not specifically bound to the thrombus. Rather the clinical utility of the test depends mainly on circulatory changes secondary to the thrombus. Scintillation camera images of 99Tcm-erythrocytes in the legs were not useful for diagnosis of DVT in the calves but showed a high specificity for DVT in the popliteal and femoral veins.

Adult↗
PubMed1984

Ectopic bone after hip replacement. Excision and free fat transplants in four cases.

In four patients ectopic bone formed after total hip replacement was replaced with free fat transplants. One year later the patients were free from pain, and hip flexion had increased by 60 degrees on average. Ectopic bone was completely absent in one patient, and markedly reduced in the remaining three patients. Bone scintigraphy was found to be a sensitive technique to reveal early ectopic bone formation. Fat transplantation seems to be a satisfactory complement in the treatment of ectopic bone.

Adipose Tissue↗
PubMed1983

Simultaneous assessment of right ventricular ejection fraction and central haemodynamics at rest and during exercise in patients with pulmonary hypertension.

In 10 patients, aged 55-73, with pulmonary hypertension, right ventricular ejection fraction (RVEF) was measured simultaneously with central haemodynamics twice, at rest and during exercise. In the first investigation, RVEF was measured with first pass (FP) radionuclide angiocardiography using 133Xe and 99Tcm as tracers. In the second investigation after 1 h's rest, RVEF was measured with equilibrium (EQ) radionuclide angiocardiography. Significant correlations were found between RVEF and pulmonary artery pressure (r = -0.76 to -0.88) and between RVEF and right arterial pressure (r = -0.76 to -0.84) at rest and during exercise. RVEF was low or decreased during exercise in all patients with haemodynamic signs of right ventricular failure. Good correlations were found between the FP and EQ techniques for measuring RVEF both at rest, r = 0.86, and during exercise, r = 0.91. RVEF, measured with the FP technique, showed better reproducibility and better correlation to haemodynamic variables and to history of right ventricular failure than the EQ technique. Thus, the FP technique seemed to be the method of choice for assessment of RVEF.

Aged↗
PubMed1982

Left ventricular function after myocardial infarction.

We assessed simultaneously left ventricular filling pressure and stroke index with left ventricular ejection fraction in 22 patients who had had their first transmural myocardial infarction about 11 days before the examination. Eleven were classified as anterior myocardial infarctions and 11 as inferior. Left ventricular ejection fraction was determined by equilibrium radionuclide angiocardiography. Significant correlations between left ventricular ejection fraction and left ventricular filling pressure or stroke index were obtained both at rest and during exercise. Left ventricular dysfunction was more severe in patients with anterior myocardial infarction whose left ventricular ejection fraction at rest was 34.9+/-3.4% as compared to 52.6+/-2.1% in inferior myocardial infarction. We conclude that the radionuclide method is as sensitive as catheterization for detecting left ventricular dysfunction at rest and during exercise in patients with myocardial infarction.

Aged↗
PubMed1982

Radionuclide assessment of right ventricular ejection fraction: a comparison of first pass studies with 133Xe and 99Tcm.

Right ventricular ejection fraction (RVEF) was determine in 26 patients using the first pass radionuclide angiocardiography with 133Xe and 99Tcm as tracers. A good correlation (r = 0.88) was found. Duplicate determinations in 13 patients with 133Xe showed good reproducibility, the absolute value for the standard error of a single determination being 2.6% and the coefficient of variation 5.7%. In a reference group of 17 individuals RVEF was 49 +/- 5% (range 42-61%). It is concluded that 133Xe can be used for RVEF determinations. Due to the rapid elimination and the low radiation dose 133Xe is preferable when repeated determinations of RVEF are desired.

Adult↗
PubMed1982

Left ventricular function at rest and during exercise in coronary insufficiency--a simultaneous evaluation by means of radionuclide angiocardiography and catheterization.

Left ventricular function was assessed simultaneously with heart catheterization and equilibrium radionuclide angiocardiography at rest and during supine exercise in ten patients with effort angina. At rest all had normal haemodynamics. During exercise all developed angina with signs of left ventricular dysfunction in the form of high left ventricular filling pressure, 31 +/- 2 mm Hg (mean +/- SEM) and pathological decreases in left ventricular ejection fraction (11 +/- 1% units). Left ventricular end-systolic volume increased significantly (43 +/- 7%), but the increase in left ventricular end-diastolic volume (13 +/- 7%) was not significant. The discordance between the changes in left ventricular filling pressure and the changes in left ventricular end-diastolic volume is discussed. Radionuclide angiocardiography revealed left ventricular dysfunction as frequently as did heart catheterization.

Aged↗
PubMed1979

Adjustments of circulation including blood pressure to orthostatic reaction and physical exercise during application of a low estrogen dose steroid oral contraceptive.

The orthostatic circulatory reaction, the physical working capacity on a bicycle ergometer, the blood pressure reactions at rest both during and after the ergometer test, the total hemoglobin content and the heart volume in the supine position were all determined on four separate occasions in 34 nulligravidae who were taking a low estrogen dose steroid oral contraceptive consisting of 30 micrograms of ethinyl estradiol and 150 micrograms of levonorgestrel (known as Neovletta, Schering AG). These examinations were performed once prior to the commencement of this medication, and 6, 12 and 24 months thereafter. The orthostatic pulse and blood pressure reactions taken on these subjects standing upright for a period of eight minutes were pronounced up to and including the 12 month control, but decreased thereafter. Physical working capacity at a pulse rate of 170 beats per minute on the different test occasions decreased up to and including the 12 month control, but thereafter seemed to increase almost to their initial levels. Blood pressure, heart volume and total amount of hemoglobin increased up to and including the 12 month control but thereafter seemed to return to the pre-treatment level. These circulatory changes during the first year of the application of this contraceptive may be as the result of a marked sympathicotonic reaction induced by the steroids. Possibly because of some form of adaptive mechanism, this reaction seems to decrease (and almost to "normalize") during the second year of use.

Adolescent↗
PubMed1979

Cardiac blood pool imaging--a clinical comparison between red blood cells labeled with 99mTc in vivo and in vitro and 99mTc-labeled human serum albumin.

In 25 patients undergoing radiocardiographic determination of ventricular function, three methods for blood pool imaging were compared. 99mTc was used to label human serum albumin (HSA) and red blood cells (RBC) in vivo or in vitro. The activity concentration of 99mTc in blood was measured during 2 hrs after injection and a significantly higher concentration was found with RBC compared to HSA already after 15 min. The left ventricular to background count rate ratio was significantly lower for HSA after 90 min compared to RBC. There was no statistical difference in 99mTc activity concentration in blood or in left ventricular to background count rate ratio during the two hrs when the two RBC-labeling procedures were compared. 99mTc-labeled RBC are superior to 99mTc-labeled HSA for gated blood pool studies and especially for repeated determinations of ventricular function. Because the in vivo labeling is the most convenient method it has been adopted as the clinical routine at our hospital.

Erythrocytes↗