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Biomedical subjects

F Hansen

Publications and source records attributed to F Hansen.

At least 55 records · Page 3Linked to original sources
PubMed1994

Differences in mechanical properties of the common carotid artery and abdominal aorta in healthy males.

PURPOSE: Vascular disease is differentiated throughout the vascular regions, with central arteries more prone to dilation and with peripheral arteries more prone to occlusive disease. In this study we investigated the diameter and compliance in the common carotid artery and abdominal aorta in healthy males at varying ages to assess potential differences in the aging process. METHODS: An ultrasound phase-locked echo-tracking system was used to determine differences in diameter and pulsatile diameter changes of the common carotid artery and abdominal aorta in 56 healthy Caucasian males ages 10 to 74 years. Pressure strain elastic modulus (Ep) and stiffness (beta) were calculated from diameter, pulsatile diameter change, and blood pressure obtained by the auscultatory method. Compliance was defined as the inverse of Ep and stiffness. RESULTS: The diameter of both common carotid artery and abdominal aorta increases not only when a person is a child, but also when they are between 25 and 70 years old. The dilation in adults seems to be more accentuated in the abdominal aorta (27%) than in the common carotid artery (17%). Ep and stiffness (beta) are higher in the common carotid artery when a person is 10 years of age (p < 0.01 and 0.05). However, during aging, Ep and stiffness (beta) increase to a higher extent in the aorta than in the common carotid artery, with a significantly higher Ep and stiffness (beta) in the aorta when a person is 45 years and older (45 years: p < 0.05 and p = NS; 60 years: p < 0.001 and p < 0.001; 70 years: p < 0.01 and p < 0.01). CONCLUSIONS: This investigation demonstrates regional differences in diameter change and compliance in the common carotid artery and abdominal aorta and implies that the abdominal aorta is more prone to degenerative changes than the common carotid artery. This may be one etiologic factor for the regional differences in vascular disease.

Adolescent↗
PubMed1994

Sex difference in the mechanical properties of the abdominal aorta in human beings.

PURPOSE: A previous study has shown age- and sex-related differences in abdominal aortic compliance. In that study blood pressure determined by auscultation in the brachial artery was assumed to be equal to blood pressure in the abdominal aorta. To validate our findings we investigated the pressure-diameter (P-D) relationship of the abdominal aorta. METHODS: Diameter and pulsatile diameter change of the abdominal aorta were determined noninvasively by an ultrasound phase-locked echo-tracking system with simultaneous measurement of aortic pressure resulting in P-D curves in 27 healthy male and female volunteers 23 to 72 years of age. The degree of error in aortic compliance as calculated from blood pressure determined by auscultation of the brachial artery rather than from direct measurement of aortic pressure was evaluated. Compliance was defined as the inverse of pressure strain elastic modulus (Ep) or of stiffness (beta). RESULTS: There was no significant difference in the systolic pressure at the two sites, but the diastolic pressure was systematically overestimated by approximately 10 mm Hg when determined by the auscultatory method (p < 0.01) leading to a 15% to 20% underestimation of Ep and stiffness (beta). The individual P-D curves exhibited hysteresis, were nonlinear, and revealed that the aorta is more distensible at lower than at higher pressures. The steepness of the P-D curve decreased with increasing age and this occurred at an earlier age in men than in women. CONCLUSION: This investigation demonstrates a decrease in abdominal aortic wall distensibility with age, which occurs at an earlier age in men, and confirms earlier results by use of the indexes Ep and stiffness (beta). This implies that the abdominal aorta in men is more prone to degenerative changes, which may be one of the factors responsible for the sex difference in aortic vascular disease.

Adult↗
PubMed1994

Infrarenal aortic diameter in the healthy person.

In order to determine the relevance of abdominal aortic dilatation, knowledge of the normal aortic diameter and its relation to age, sex and body size (height, weight, body surface area) is essential. The diameter of the infrarenal aorta was measured in 146 healthy males and females 4-74 years old with ultrasonography and the influence of the aforesaid factors on aortic diameter was analysed by means of a multiple stepwise regression model. The infrarenal aorta was found to increase steadily in diameter throughout life. From about 25 years the diameter was larger in males than in females (p < 0.01) though this difference vanished if corrected for differences in body surface area. Significant correlations were found between aortic diameter and weight (r = 0.84, p < 0.001), height (r = 0.77, p < 0.001) and body surface area (r = 0.83, p < 0.001). Age followed by body surface area were the factors most influencing aortic diameter in both males (r = 0.92, p < 0.001) and females (r = 0.94, p < 0.001). Nomograms predicting aortic diameters in relation to age, sex, and body surface area are presented.

Adolescent↗
PubMed1994

Abnormal mechanical properties of the aorta in Marfan's syndrome.

OBJECTIVES: Aortic dilatation, dissection and rupture are among the major causes of death in subjects with Marfan's syndrome. The aim of the study was to investigate the mechanical properties or compliance of the aorta in these subjects and compare them with a healthy age- and sex-matched reference population. MATERIALS AND METHODS: An ultrasound phase-locked echo-tracking system was used to determine diameter and pulsatile diameter change of the infrarenal aorta in nine subjects with Marfan's syndrome which were then compared with the values for 165 healthy individuals. Compliance, defined as the inverse of Ep (pressure strain elastic modulus) or stiffness (beta), was calculated from pulsatile diameter change and blood pressure obtained by the auscultatory method with a sphygmomanometer. For statistical analysis confidence intervals (95%) obtained from the healthy controls were used for comparison. Analysis of covariance (ANCOVA) was performed for the female patients. The sample size for males (n = 2) was too small for the latter analysis. RESULTS: Compared with normal subjects and their confidence intervals, subjects with Marfan's syndrome had an increased Ep and stiffness (beta) and decreased strain (fractional diameter change) in the infrarenal aorta. Furthermore, ANCOVA in the female patients showed increased beta (p < 0.01) and Ep (p < 0.01) and a decreased strain (p < 0.001). Aortic diameters, MAP, as well as the pulse pressure, were similar in the two groups. CONCLUSION: This investigation demonstrates alterations in the mechanical properties of the aorta in Marfan's syndrome in the form of increased stiffness of the aortic wall. This may be of importance in the pathogenesis of aortic dissection and rupture.

Adolescent↗
PubMed1993

Infections in patients treated with high-dose chemotherapy for germ cell tumours.

25 patients with disseminated germ cell tumours were treated with high-dose cisplatin and etoposide (40 mg/m2 and 200 mg/m2 daily x five, respectively) leading to severe myelosuppression. A comprehensive study was undertaken in order to identify and describe the bacterial, viral and fungal infections in this group of patients. Fever (> 38.5 degrees C) and leucopenia (white blood cell count < 1.0 x 10(9)/l) were observed in 61 of 90 treatment cycles (68%). A microbiological aetiology compatible with the clinical manifestations of infection could be identified in 33 of the 61 febrile episodes (54%). Bacteraemia occurred in 14 episodes in 12 patients. Eight episodes (57%) involved gram-positive aerobic bacteria.

Adult↗
PubMed1993

Can recurrent stenosis after carotid endarterectomy be prevented by low-dose acetylsalicylic acid? A double-blind, randomised and placebo-controlled study.

Recurrent stenosis (> 50%) after carotid endarterectomy is reported with a frequency ranging from 7-20%. 232 patients undergoing carotid endarterectomy were randomised to low-dose acetylsalicylic acid (ASA, 75 mg daily) or placebo (identical tablets). The treatment was started the day before surgery and continued for 6 months. All patients were followed clinically for 1 year. Doppler examination was performed preoperatively (n = 230) and postoperatively (n = 228) and at follow-up at 2 (n = 220) and at 6 months (n = 174) after surgery. The degree of stenosis was estimated from the maximum Doppler frequency shift in the internal carotid artery. Recurrent stenosis of 30% or more was detected in 85 of the 220 patients (38.6%) at 2 months, and at 6 months in 73 of the 174 examined patients (42.0%). Stenosis > 50% was seen in 16 patients (9.2%) and occlusion was found in four patients (1.8%) at 6 months. No difference between the low-dose ASA-treated group (n = 112) compared to the placebo group (n = 108) was seen regarding recurrent stenosis. Women had an increased risk of recurrent stenosis (p < 0.001), whereas other factors such as age, hyperlipidaemia, diabetes and smoking were not associated with increased risk. Importantly, the number of neurological events did not differ between those with or without restenosis. Therefore, the indications for surgery of asymptomatic recurrent stenosis are questionable. The progress of arteriosclerosis in the contralateral carotid artery did not differ between the treatment groups.

Adult↗
PubMed1993

Compliance and diameter in the human abdominal aorta--the influence of age and sex.

OBJECTIVES: Females develop cardiovascular diseases and abdominal aortic aneurysms later in life than males. In this study we investigated the diameter and compliance of the distal abdominal aorta in healthy females of varying ages. The results were compared with those obtained previously from healthy males in order to assess potential sex-related differences in the aging process of the abdominal aorta. METHODS: An ultrasound phase-locked echo-tracking system was used to determine differences in diameter and pulsatile diameter change of the distal abdominal aorta in 69 Caucasian females from 4 to 74 years. Pressure strain elastic modulus (Ep) and stiffness (beta) were calculated from diameter, pulsatile diameter change and blood pressure obtained by the auscultatory method. Compliance was defined as the inverse of Ep and beta. The pressure dependence of Ep and beta was evaluated in 10 females with intraarterial blood pressure measurement at rest and during isometric exercise. RESULTS: The diameter of the distal abdominal aorta increased not only in the period between the ages of 5 and 25 years, but also by about 24% between 25 and 70 years (p < 0.0001). From about the age of 25 years the diameter was smaller in females than in males (p < 0.01). Ep and beta increased nearly linearly with advancing age in females from 0.18 x 10(5) to 1.17 x 10(5) N/m2 (Ep) and from 1.85 to 8.51 (beta). In males the increase in Ep and beta was greater and exponential in nature (p < 0.001). Ep but not beta increased significantly during blood pressure increase (p < 0.05). Stiffness (beta) may therefore be a more useful index of arterial compliance than Ep. CONCLUSIONS: This investigation demonstrates age and sex-related differences in diameter and compliance in the normal human abdominal aorta and implies that degenerative changes appear later in females than in males.

Adolescent↗
PubMed1993

Non-invasive measurement of pulsatile vessel diameter change and elastic properties in human arteries: a methodological study.

A recently developed ultrasound phase-locked echo-tracking system makes it possible to measure non-invasive pulsatile vessel diameter changes, and, in combination with blood-pressure measurement, to calculate pressure strain elastic modulus (Ep) and stiffness (beta). The reproducibility in measurements of pulsatile diameter changes with this system was evaluated. Also the precision of indirect blood-pressure measurements, as compared to the simultaneously measured intra-arterial blood pressure was tested. The resulting reproducibility in pressure strain elastic modulus (Ep) and stiffness (beta) was evaluated. Intra-observer variabilities in measuring pulsatile diameter changes were 16% for the abdominal aorta, 10% for the common carotid artery, and 15% for the common femoral artery, respectively. Intra-observer variabilities for Ep and beta were 21% for both in the abdominal aorta, 17% for both in the common carotid artery, and 18% for both in the common femoral artery, respectively. There were only small differences in indirect and direct measurement of systolic blood pressure, whereas indirect blood pressure measurement systematically overestimated the diastolic blood pressure, on average by 20%. The variabilities in indirect blood pressure measurements were 2% for the systolic and 3% for the diastolic blood pressure, respectively. Inter-observer variability in the investigation of the common carotid artery was 10% for the pulsatile diameter changes, and 21% and 23% for Ep and beta, respectively. Thus, the echo-tracking system represents a reliable system for estimation of pressure strain elastic modulus and stiffness. However, Ep and beta are systematically underestimated by 25-30%, when used in combination with indirect blood pressure measurements.

Adult↗
PubMed1992

Cardiovascular disease in male patients with carotid transient ischemic attacks or minor strokes.

The authors tested the hypothesis that coronary heart disease and lower extremity atherosclerosis occur more frequently in patients with transient ischemic attacks (TIA) than in patients with minor stroke. Thirty-three consecutive male patients with TIA and 36 with minor stroke from the carotid artery territory were examined with ultrasonography of the cardiac, iliac, and femoral arteries; echocardiography (UCG); electrocardiogram (ECG); thallium scintigraphy (TS) of the myocardium; and assessment of the ankle/arm index (A/AI). TS showed myocardial infarctions to be more common among TIA patients than among minor stroke patients, 54% vs 19%, p = 0.019. UCG showed the frequency of left ventricular and atrial dilatation to be higher in the TIA group than in the minor stroke group, 64% vs 27%, p = 0.0084. Significant artery stenosis (greater than or equal to 50%) was not, however, more frequent in the TIA group than in the minor stroke group, nor was there any significant difference between the groups in A/AI. The frequency of TS-verified myocardial infarction (MI) was higher in the subgroup with greater than or equal to 50% carotid artery stenosis than in that with less than 50% stenosis, 61% vs 25%, p = 0.022, and also higher in the pathological UCG subgroup than in the normal UCG subgroup, 50% vs 15%, p = 0.025. Thus, there was a greater incidence both of TS-verified MI and of UCG-verified cardiac dilatation in the TIA group than in the minor stroke group but no difference between the groups in the degree of atherosclerosis either in the carotid or lower extremity regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Phase II clinical trial of VP-16-213 (etoposide) administered orally in advanced ovarian cancer.

Antitumor effect and toxicity of single-drug treatment with per oral VP-16-213 (etoposide) were evaluated in a phase II trial which included 22 patients with recurrence or progression of ovarian carcinoma. Two of these patients were evaluable only for toxicity. All patients had previously been treated with a combination chemotherapy involving at least three different drugs. The median age was 59 years (range 21-76). VP-16-213 was administered orally at a daily dose of 200 mg/m2 for 4 consecutive days every third week with systematic dose escalation. Fourteen patients were treated to grade 3-4 hematologic toxicity (WHO) and 8 to grade 0-2. Eleven experienced nausea and vomiting and 4 partial alopecia. One patient achieved a CR and another a PR with a duration of 3 months and 5 + months, respectively.

Administration, Oral↗
PubMed1990

Eighty-year-old men without cardiovascular disease in the community of Malmö. Part I. Social and medical factors, with special reference to the lipoprotein pattern.

A total of 1280 80-year-old men were invited to a medical examination to study common risk indicators for cardiovascular disease (CVD) in the elderly. From the pool of 811 responders (63.3%), all 122 individuals who fulfilled our inclusion criteria were assigned to one of four groups: (1) no CVD, non-smokers; (2) no CVD, smokers; (3) CVD, smokers; (4) CVD, non-smokers. A telephone interview with 75 non-responders suggested that this group contained more institutionalized subjects, but otherwise did not differ from the group of participants. Subjects with CVD had higher levels of plasma cholesterol and LDL cholesterol than those without CVD, whereas plasma HDL cholesterol and plasma triglyceride concentrations did not differ between the groups; thus the LDL/HDL ratio was higher in the CVD group. Lipoprotein concentrations did not differ between smokers and non-smokers. However, the mean cholesterol levels were low (5.19 +/- 1.01 mmol l-1), suggesting selective mortality. No differences between the groups were found with regard to Lp(a). The mean blood pressure for the whole group was 149/79 mmHg, and there were no differences between subgroups. Our study suggests that mechanisms such as selective mortality modify the risk factor pattern in the elderly. In 80-year-old individuals, elevated LDL cholesterol levels can still be identified as a risk indicator for CVD, whereas there does not appear to be any association between CVD or low HDL levels or elevated blood pressure in this age group.

Aged↗
PubMed1990

Eighty-year-old men without cardiovascular disease in the community of Malmö. Part II. Smoking characteristics and ultrasound findings, with special reference to glutathione transferase and pyridoxal-5-phosphate.

A total of 1280 80-year-old men in the community of Malmö were questioned about smoking habits and the occurrence of cardiovascular disease (CVD). After a careful medical and duplex ultrasound examination, four groups were selected for further studies: (1) no CVD, non-smokers: (2) no CVD, smokers: (3) CVD, smokers: (4) CVD, non-smokers. In total 122 individuals participated. The average tobacco consumption by smokers was 13 g d-1 for 59 years. In the CVD group 45% of subjects had atherosclerotic symptoms at more than one site. Smoking was found to be correlated with lower extremity atherosclerosis, cholesterol and LDL cholesterol were correlated with carotid artery lesions and pathological ankle/arm index, and blood pressure was correlated with lower extremity lesions. In contrast with middle-aged populations, individuals with an increasing degree of lesions in the lower extremities had a larger percentage of high glutathione transferase activity than subjects without CVD. Smokers had significantly lower pyridoxal-5-phosphate levels than non-smokers. It is concluded that some heavy smokers might reach an advanced age in good health. Smoking was also operative as a risk indicator for lower extremity atherosclerosis in 80-year-old individuals.

Aged↗
PubMed1990

Anxiety disorders during acute bereavement: risk and risk factors.

Forty-four percent of bereaved spouses reported at least one type of anxiety disorder during the first year of bereavement in a survey of a representative sample composed of a subgroup (N = 48) assessed 6 months after bereavement and another subgroup (N = 54) assessed 12 months after bereavement. The bereaved spouses experienced 6-month prevalence rates for panic disorder and generalized anxiety disorders that were higher than community prevalence rates for the same metropolitan area (p less than .01). Past personal history of anxiety disorder was an independent risk factor (p less than .05), and anxiety disorders were associated with severe grief (p less than .01) and depression (p less than .05). The large overlap of anxiety disorders with major depression observed in this study indicates that the estimated rates of anxiety disorder are not independent of major depression in most cases and raises questions about whether the anxiety disorders of bereavement are prodromal, concomitant, or residual with respect to major depression.

Adult↗
PubMed1989

Evaluation of ulceration in the extracranial carotid artery with ultrasonography: a comparison with arteriography.

The accuracy of duplex-scanning and angiography in detecting ulceration in the carotid arteries was evaluated. Sixty-nine patients underwent duplex-scanning and carotid arteriography, and the findings were blindly compared to the operative specimens. Duplex-scanning had a significantly higher sensitivity (90 vs 48%, P less than 0.001) and accuracy (88 vs 59%, P less than 0.001) than angiography. There was no difference in specificity (84 vs 89%, P = 0.28). Comparison was also made between conventional arch angiography and selective carotid angiography in detecting ulceration. There was no significant difference between the methods (sensitivity 47 vs 50%, specificity 82 vs 100%). Finally, interobserver variability in detecting ulceration with duplex-scanning was evaluated in double-blind evaluation of the duplex-scans. The interobserver agreement was 84%. Duplex-scanning seems to be superior to angiography in detecting ulcerations in the extracranial carotid artery.

Adult↗
PubMed1987

Phase II study of 1,2,4-triglycidylurazol (TGU) in previously untreated and treated patients with small cell lung cancer.

Six previously untreated poor prognosis patients and eight previously treated patients with small cell lung cancer (SCC) were treated with 1,2,4-triglycidylurazol (TGU, NSC-332488) 800 and 650 mg/m2 every 4 weeks, respectively. No responses were observed. The survival time of the previously untreated patients was short, a median of 7 weeks (range 5-10 weeks). Myelosuppression was severe and prolonged with white blood count, WHO grade 3-4, in four previously untreated patients and in two previously patients, and with platelets, WHO grade 3-4, in both four previously untreated and in four previously treated patients. Gastrointestinal toxicity was mild to moderate. It is concluded that TGU is inactive in SCC.

Aged↗
PubMed1987

Regional lung function in long-term survivors after chemotherapy for small cell lung cancer.

In order to evaluate the regional lung function in patients with small cell lung cancer with long-term survival, we measured the regional lung function in 17 patients. We studied the patients with 81m-krypton ventilation scans and 99m-technetium perfusion scans, as well as measurements of static lung volumes (VC, RV, TLC), flow volume indices (FEV1, FVC, MEF50), and carbon monoxide diffusing capacity (DLCO). We found both the ventilation and the perfusion of the affected lung to be slightly but significantly lower (P less than 0.05), while no obvious ventilation or perfusion defects could be identified at the former tumor site. The static volumes of the lungs, the FVC and the FEV1 were within predicted normal values, while a significant decrease was seen in the PEF, MEF50, and DLCO. It is concluded that patients with small cell lung cancer who obtain complete remission with normalization of the chest X-ray and long-term survival after 18 months of intensive chemotherapy also have a nearly normal lung function.

Aged↗
PubMed1985

beta-Granins: 21 kDa co-secreted peptides of the insulin granule closely related to adrenal medullary chromogranin A.

Three closely related forms of a 21 kDa protein which is co-secreted with insulin have been purified and analysed. These differed in behaviour on ion-exchange chromatography but were indistinguishable by their susceptibility to staphylococcal V8 proteinase digestion, amino acid composition or N-terminal amino acid sequence. Their amino acid composition and N-terminal sequences were remarkably similar to adrenal medullary chromogranin A, a much larger protein (72 kDa). Antibodies to chromogranin A also reacted strongly with the 21 kDa protein in isolated insulin granules. It is concluded that the 21 kDa proteins either represent a repeated domain within the chromogranin molecule or a closely related gene product. The name beta-granin is proposed for these proteins.

Adrenal Medulla↗