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Biomedical subjects

F Hansen

Publications and source records attributed to F Hansen.

At least 19 recordsLinked to original sources
PubMed1997

Pressure-flow studies: an evaluation of within-testing reproducibility--validity of the measured parameters.

The within-examination variation in selected test parameters in repeated pressure-flow studies was determined in a retrospective study of consecutive pressure-flow examinations in 105 patients. It was further evaluated to see whether there was a systematic change in the measured parameters during retesting. To see if variation and reproducibility were influenced by the procedure of investigation, i.e., transurethral or suprapubic, patients were grouped according to the method employed. Finally, the effect of detrusor instability on the measurements was evaluated. Using the Abrams-Griffiths nomogram, patients were classified as obstructed, equivocal, or unobstructed. The test-retest variations in classification were evaluated. We found a systematic variation in Pdet.Qmax' Pdet.Open' and Qmax during testing, indicating a physiological effect of repeated pressure-flow studies resulting in a less obstructed second voiding. Accordingly, 69% of the patients who shifted group of classification during retesting shifted to a group of lesser obstruction at the second voiding. Still, 88% of patients remained in the same group of classification of bladder outlet obstruction. Within- and between-patient variations and reproducibility of the test results were not influenced by the procedure of investigation, i.e., the transurethral or suprapubic method. However, we found variations suggesting a decrease in urethral resistance and bladder contractility from test to test in the transurethral group, whereas variations suggesting an isolated decrease in bladder contractility were seen in the suprapubic group. Detrusor instability per se does not seem to cause any systematic changes during repeated testing.

Adult↗
PubMed1997

Stiffness and diameter of the common carotid artery and abdominal aorta in women.

Vascular disease is differentiated throughout the vascular regions with aorta more prone to dilatation and with peripheral arteries more prone to occlusive disease. In this study, we investigated the diameter and distensibility in the common carotid artery (CCA) and abdominal aorta (AO) in healthy females of varying ages to assess potential differences in the aging process. The diameter and pulsatile diameter change of the CCA and AO in 66 healthy Caucasian females aged 8 to 79 y were examined using an ultrasound phase-locked echo-tracking technique. Blood pressure was obtained by the auscultatory method. Arterial stiffness (beta) was calculated. The diameter of both CCA and AO increases, not only in childhood, but also in adult women. The dilatation in adults (25 to 75 y) seems to be more pronounced in the AO (23%) than in the CCA (11%). Stiffness (beta) is higher in the CCA than AO before 20 y of age (p < 0.05). Stiffness increases with aging in both arterial regions, but the increase is initially somewhat higher in the AO, which means that no differences between the CCA and AO are seen from 25 y onward. In conclusion, this study demonstrates regional differences in diameter change and stiffness in the CCA and AO, and implies that the AO is more prone to age-related changes of the arterial wall than the CCA. These differences, however, are not as marked as previously reported in males.

Adolescent↗
PubMed1997

Abdominal aortic aneurysm: a general defect in the vasculature with focal manifestations in the abdominal aorta?

PURPOSE: It has been suggested that abdominal aortic aneurysms (AAA) develop as a result of an alteration in the systemic connective tissue metabolism. This might change wall mechanics and diameter, not only in the AAA but also in the rest of the vascular system. This hypothesis was tested by studying the mechanical properties of AAAs as well as the common carotid artery (CCA) in the same patient population. METHODS: AAA and carotid artery stiffness (beta) was studied in 121 individuals (101 men, 20 women) who were admitted for elective repair of AAA. Stiffness (beta) was calculated from diameter and pulsatile diameter change determined noninvasively from an ultrasonic echo-tracking system and blood pressure obtained by the auscultatory method. The results were compared with those of healthy individuals of corresponding age and gender published elsewhere. RESULTS: The stiffness of the AAA was increased in both men and women (p = 0.0001). The increase was more pronounced in women compared with men (p = 0.0003) to a mean of 435% and 189% of the normal predicted values, respectively. In the CCA, the stiffness was increased in men (p = 0.027) and in women (p = 0.0001) to a mean of 131% and 149% of the normal predicted values, respectively. A significant correlation between stiffness in the aneurysm and in the carotid artery was seen (p = 0.0031). The carotid diameter was unchanged in men (p = 0.924) and in women (p = 0.070) if adjusted for the difference in blood pressure between the individuals with AAAs and control subjects. There was no correlation between stiffness and diameter of the aneurysm in men (r = 0.16, p = 0.119) nor in women (r = 0.12, p = 0.598). CONCLUSIONS: This investigation demonstrated altered mechanical properties of the aneurysmal wall as well as in the CCA in individuals with AAAs. The normal age- and gender-related differences seen in the healthy aorta and CCA vanished. The results suggest that AAA is a generalized process of the vasculature with focal manifestation in the abdominal aorta.

Aged↗
PubMed1997

Improved reliability of ultrasonic surveillance of abdominal aortic aneurysms.

OBJECTIVES: Small abdominal aortic aneurysms (AAA) are usually managed conservatively by serial ultrasound examinations to assess size. The development of the size of the AAA will determine whether the patient is a candidate for surgery. The precision of measurement is therefore of considerable importance. The aim of this study was to evaluate the accuracy and the reproducibility of a newly developed echo-tracking ultrasonic system in the size evaluation of AAA. DESIGN: Prospective study at a University Hospital. MATERIAL AND METHODS: An echo-tracking ultrasound system with a 3.5 MHz transducer was used in 54 patients with AAA. Thirty-six patients had repeated measurements by one technician to evaluate the intra-observer variability. In another 18 patients with aortic dilatation/AAA, the measurements were repeated by a second technician in a blinded fashion with calculation of inter-observer variability. The reproducibility was evaluated both using linear regression and plots according to the method described by Bland and Altman. RESULTS: The mean diameter of the aorta was 37 mm (range 21-51 mm). The coefficient of correlation of repetitive measurements with one observer was r = 0.99 and with two observers r = 0.99. The intra-observer variability was 0.78 mm (S.D.) and the inter-observer variability 0.93 mm (S.D.). The intra- and inter-observer coefficient of variation (CV) was 2-3%. CONCLUSIONS: The newly developed echo-tracking ultrasonography seems at present to be the most accurate and reliable method to follow the diameter of an abdominal aortic aneurysm detecting relevant changes in the diameter exceeding 2 mm (2 S.D.). Thus it fulfils the requirements both for follow-up of conservatively managed AAAs and endovascularly treated aneurysms.

Adult↗
PubMed1997

The mechanical properties of elastic arteries in Ehlers-Danlos syndrome.

OBJECTIVE: To study whether measurements of wall mechanics can be used as an indicator of disturbed vessel wall integrity and predictor of vessel fragility in Ehlers-Danlos Syndrome (EDS). METHODS: The wall mechanics of the abdominal aorta (AO) and common carotid artery (CCA) were estimated from the indices Ep (pressure strain elastic modulus) and stiffness (beta) in twelve individuals with EDS of different subtypes and compared with the results of a healthy reference population. Ep and beta were calculated from diameter and pulsatile diameter change determined non-invasively with the aid of an ultrasonic echo-tracking system and blood pressure obtained by the auscultatory method. RESULTS: Compared with normal individuals and their confidence intervals, subjects with EDS had unaltered diameter, Ep and beta in the AO, as well as in the CCA. Analysis of covariance (ANCOVA) also showed unaltered results. AO: diameter (males p = 0.66, females p = 0.27), Ep (males p = 0.81, females p = 0.27) and beta (males p = 0.95, females p = 0.12). CCA: diameter (males p = 0.36, females p = 0.46), Ep (males p = 0.93, females p = 0.48) and beta (males p = 0.86, females p = 0.47). CONCLUSIONS: This investigation could not demonstrate any alteration in wall mechanics as a sign of disturbed vessel wall integrity of elastic arteries in EDS. This might indicate that the structural defect in the arterial wall collagen, and thus the tendency to vessel fragility, cannot be revealed under normal physiological pressure conditions.

Adolescent↗
PubMed1997

Influence of sympathetic stimulation on the mechanical properties of the aorta in humans.

The mechanical properties of the aorta play a major role in the regulation of blood pressure and cardiac performance. The effect of sympathetic stimulation on the mechanical properties of the human abdominal aorta was studied in 19 healthy volunteers, divided into young (25 +/- 2 years) and elderly individuals (69 +/- 2 years) of both sexes. A non-invasive ultrasonic echo-tracking system for measurement of systolic/diastolic variation of aortic diameter in combination with intra-aortic pressure measurements was used to determine wall mechanics. The pressure-diameter (P-D) relationship and the distensibility indices, stiffness (beta) and pressure strain elastic modulus (Ep) of the abdominal aorta were obtained. Measurements were made at rest and during sympathetic stimulation induced by lower body negative pressure (LBNP). As a sign of sympathetic activation, the peripheral resistance increased by 74-96% (P < 0.001) during LBNP. However, the mechanical properties of the abdominal aorta remained unaltered, as estimated either from the P-D relationship or from the indices Ep and beta, both in the young (rest: Ep = 0.53 +/- 0.18, beta = 4.5 +/- 1.5; LBNP: Ep = 0.51 +/- 0.15, beta = 4.5 +/- 1.2, NS) and in the elderly (rest: Ep = 2.17 +/- 0.70, beta = 17.6 +/- 5.8; LBNP: Ep = 2.11 +/- 0.60, beta = 16.9 +/- 3.9, NS). In conclusion, this investigation shows that LBNP-induced sympathetic activation does not change aortic wall mechanics. Thus, sympathetic modulation of the aortic smooth muscle contractile activity seems to be unimportant in the blood pressure regulation.

Adult↗
PubMed1997

Expression of complement receptors and regulatory proteins on alveolar CD4+ lymphocytes from human immunodeficiency virus-1 infected individuals.

Several lines of evidence suggest a dysregulation of the complement system in human immunodeficiency virus-1 (HIV-1) infected patients. The aim of this study was to elucidate whether CD4+ alveolar lymphocytes from HIV-1 infected patients show a loss of complement regulatory proteins that would render these cells susceptible to antibody-dependent complement-mediated cytotoxicity. We investigated the expression of complement regulatory (CD46, CD55, CD59) and complement receptor (CR1, CR2, CR3, CR4) proteins on alveolar cells by flow cytometry. Cells were obtained by bronchoalveolar lavage from 17 HIV-1 infected and 12 HIV-1 negative individuals. Expression of adhesion molecules (leucocyte functional associated antigen-1 (LFA-1), intercellular adhesion molecule-1 (ICAM-1)) and CD30 were evaluated in patient subgroups. In addition, interleukin (IL)-1beta, tumour necrosis factor alpha (TNF-alpha), IL-4 and interferon gamma (IFN-gamma) concentrations were measured in supernatants of alveolar cells. We found a significantly reduced expression of CD46 and CD59 on CD4+ alveolar lymphocytes from HIV-1 infected individuals, whereas the expression of CR3, CR4, ICAM-1 and CD30 was increased. IL-1beta and TNF-alpha concentration in supernatants of alveolar cells was augmented in HIV-1 infected patients, but did not correlate with the expression of surface molecules. IFN-gamma concentration was also increased and showed an inverse relationship to the surface expression of CD30 on CD4+. Our data suggest that in human immunodeficiency virus-1 infection an increased level of activation is associated with a diminished expression of complement regulatory proteins on CD4+ alveolar lymphocytes. This phenomenon might contribute to the depletion of CD4+ lymphocytes and the local immunodeficiency in the pulmonary compartment.

Adult↗
PubMed1996

[Anderson-Hynes pyeloplasty in hydronephrosis].

The purpose of the study was to evaluate pyeloplasty a.m. Anderson-Hynes in the treatment of hydronephrosis in a large series of patients. In 175 patients, consecutively operated for ureteropelvic junction obstruction, we found 24 (14%) with minor postoperative complications, mostly urinary tract infection. Six patients (3%) were reoperated because of continued pain and obstructed drainage postoperatively. There was a small, but statistically significant increase in renal functional share on the operated side. We found a highly significant correlation between postoperative changes in total GFR and single kidney GFR on the operated side, which suggests a real improvement in renal function, rather than a simple reallocation of function between the two kidneys. We conclude that newer treatment modalities known as "minimally invasive surgery" must give comparably good results in order to be an acceptable alternative to traditional dismembered pyeloplasty.

Adolescent↗
PubMed1996

Phase II study of second-line treatment with high-dose cyclophosphamide in recurrent metastatic breast cancer.

A total of 78 patients with second recurrence or progression of histologically verified breast cancer were treated with single-agent cyclophosphamide given at 2.5 g/m2 by i.v. infusion every 3 weeks along with mesna support. All had previously been treated with epirubicin and cisplatin or epirubicin alone. Toxicity was predominantly hematologic: WHO grade III+IV toxicity was found in 95% of cases. The overall response rate was 26.7% (95% confidence limits, 15.8-41.4%), with 7% of patients achieving a complete response (CR) and 19.7%, a partial response (PR). The median duration of CRs and PRs was 11 and 5 moths, respectively. The response rate observed for patients previously treated with epirubicin alone was 30.5% in contrast to the 8.3% recorded for patients previously treated with cisplatin plus epirubicin. Thus, an indication of cross-resistance was absent between cyclophosphamide and epirubicin but possible between cyclophosphamide and cisplatin.

Adult↗
PubMed1996

Regional differences in mechanical properties between major arteries--an experimental study in sheep.

PURPOSE: To study possible differences in mechanical properties between central (abdominal aorta) and more peripheral (common carotid and common femoral) arteries validating an earlier non-invasive study in children showing that central arteries are more distensible than peripheral ones. As invasive blood pressure was needed, but ethically impossible to obtain in children in an experimental setting, an animal model was chosen. DESIGN: Open experimental study. SETTING: Animal laboratory at university hospital. MATERIAL AND METHODS: The pulsatile vessel wall movements of the abdominal aorta (AA), common femoral (CFA) and common carotid (CCA) artery of nine sheep were examined using an ultrasound phase-locked echo-tracking technique. Intra-arterial blood pressure was measured and pressure-diameter relations, pressure strain elastic modulus (Ep) and stiffness (beta) calculated. Distensibility was defined as the inverse of Ep and stiffness. RESULTS: The AA showed lower values for Ep and stiffness (beta) than the CFA (p = 0.002) and CCA (p = 0.006), i.e. the latter two vessels were stiffer. The pressure-diameter relations confirmed these differences and showed a non-linearity for all three vessels with increased stiffness above 70-90 mm Hg. CONCLUSION: This study on young animals supports earlier findings of differences in mechanical properties between central and more peripheral arteries seen in healthy children. As pathologies between these vessels differ, with dilatation of the abdominal aorta and occlusive disease in the more peripheral vessels, part of the explanation might be found in the mechanical properties of the healthy vessels, characterised here with the echo-tracking technique.

Animals↗
PubMed1996

Accuracy of duplex sonography before carotid endarterectomy--a comparison with angiography.

OBJECTIVES: The aim of this prospective study was to contribute to the evaluation of the reliability of Duplex sonography (DS) before carotid endarterectomy (CEA). DESIGN: The study was performed prospectively in a university hospital setting. METHODS: Eighty-one consecutive patients aged 49-83 years were examined with DS and carotid angiography (CAG) before CEA. The results of the DS were judged as either confident, or CAG was assessed to be necessary preoperatively. The results from the DS and the CAG were then compared. RESULTS: DS was judged as confident in 148 of the 162 arteries examined. In none of these 148 arteries did CAG change patient management in any way, and the agreement between DS and CAG was good. In the remaining 14 arteries CAG was judged necessary, in 11 arteries because DS assessed the internal carotid artery (ICA) as occluded, which was confirmed by CAG in 10 arteries. In three arteries the reason was poor quality of the DS, however these three arteries were correctly assessed as severely diseased. CONCLUSIONS: This study confirms that DS alone is sufficient in the preoperative evaluation before CEA, provided that CAG is performed whenever DS shows occlusion of the ICA, or when the quality of the DS is poor.

Aged↗
PubMed1996

Prostatic specific antigen and benign prostatic hyperplasia.

The aim of this study on patients (n = 51) with urodynamically proven obstruction was to search for correlations between serological levels of prostatic specific antigen (PSA) and age of patients, volume of prostate and prostatic morphology as evaluated on transurethral resection specimens. No correlations could be found between PSA levels and morphological parameters such as degree of inflammation and relative degree of stromal or epithelial hyperplasia. Significant correlations were demonstrated between PSA levels and age of patients and prostatic volume.

Age Factors↗
PubMed1996

Benign prostatic hyperplasia. Does a correlation exist between prostatic morphology and irritative symptoms?

Fifty-two consecutive patients with prostatism who underwent a prostatectomy were investigated with regard to irritative symptom score, age, prostate volume, urine culture results, degree of detrusor instability, inflammation in the prostate, and stromal, glandular or mixed prostatic histopathology. We did not find any statistical correlations between irritative symptom score and the mentioned parameters. This indicates that irritative symptoms should rather be attributed to extraprostatic factors such as e.g. bladder reaction.

Age Factors↗
PubMed1995

Increased arterial stiffness in women, but not in men, with IDDM.

For unknown reasons, there is a greater increase in the risk for cardiovascular complications in diabetic women than in diabetic men. Our aim was to study gender-related differences in the mechanical properties of the great arteries in patients with insulin-dependent diabetes mellitus (IDDM) but free from known cardiovascular and cerebrovascular complications. We measured arterial stiffness (beta, inversely related to arterial compliance) in the abdominal aorta and the common carotid artery non-invasively using echo-tracking sonography in 30 women (mean age 34 years, range 20-61) and 26 men (mean age 38 years, range 22-56) with IDDM. The results were compared with those of healthy individuals of corresponding age and gender. The results showed a marked gender-difference in changes of arterial stiffness. Arterial stiffness was increased in both the abdominal aorta and the common carotid artery in diabetic women compared to control women (p = 0.0001 and p = 0.0076, respectively). In contrast, there was no significant difference in stiffness of the abdominal aorta or the common carotid artery between the diabetic men and the control men (p = 0.69 and p = 0.39, respectively). In conclusion, this study has shown that stiffness of the aorta and the common carotid artery is increased in diabetic women but not in diabetic men. Increased arterial stiffness in diabetic women may be a pathogenic factor which could help to explain the gender-related differences in the risk for cardiovascular and cerebrovascular complications in diabetic subjects.

Adult↗
PubMed1995

Diameter and compliance in the human common carotid artery--variations with age and sex.

In this study, age and sex differences in diameter and compliance of the common carotid artery (CCA) were evaluated in 119 healthy subjects with a phase-locked echo-tracking system. The diameter and pulsatile diameter changes were measured, and pressure strain elastic modulus (Ep) and stiffness (beta) were calculated and used as the inverse estimate of compliance. The carotid diameter increased more rapidly in males and was larger than in females from 25 years of age. The relative diameter change was equal in both sexes, and decreased from 12% to 14% in younger subjects to approximately 5% in elderly subjects. Compliance decreased almost linearly and in parallel in males and females up to 45 years of age. Between 45 and 60 years the decrease was more marked in females than in males, whereas it was by far more marked in males between 60 and 70 years of age.

Adolescent↗
PubMed1995

Femoropopliteal-crural graft patency is improved by an intensive surveillance program: a prospective randomized study.

PURPOSE: The purpose of this study was to evaluate whether intensive surveillance compared with routine follow-up examinations improves femoropopliteal/crural graft patency. METHODS: After operation the patients were randomized to intensive (n = 79) or routine surveillance (n = 77). The groups were matched with regard to sex, diabetes, indication for surgical procedure, surgical procedure, and graft material. Intensive surveillance was clinical examination, ankle/brachial index measurements, and duplex scans 1, 3, 6, 9, 12, 15, 18, 21, 24, and 36 months after operation. Routine surveillance was clinical examination and ankle/brachial index measurements without duplex scanning 1, 12, 24, and 36 months after operation. Grafts with a decrease in ankle/brachial index of more than 0.15 compared with the initial postoperative ankle/brachial index or a duplex scan showing a graft or anastomotic stenosis of more than 50% underwent angiography and if necessary, a revision or repeat procedure. Occluded grafts were reopened with thrombectomy or thrombolysis or were replaced with a new graft. RESULTS: Assisted primary cumulative vein graft patency in the intensive group (n = 56) compared with that in the routine surveillance group (n = 50) after 3 years was 78% versus 53% (chi square analysis, 4.51; one degree of freedom; p < 0.05). Secondary patency was 82% versus 56% (chi square analysis, 5.62; one degree of freedom; p < 0.05). Assisted primary cumulative e-polytetrafluoroethylene and composite graft patency after 1 year in the intensive group (n = 23) compared with that of the routine surveillance group (n = 20) was 57% vs 50% (chi square analysis, 2.17; one degree of freedom; p > 0.1). Secondary patency was 67% vs 54% (chi square analysis, 1.85; one degree of freedom; p > 0.1). Revisions were made on 14 patent and 10 thrombosed grafts in the intensive group and on four patent and 15 thrombosed grafts in the routine surveillance group. All except eight were made during the first postoperative year. CONCLUSIONS: Intensive surveillance identified failing vein grafts leading to a significantly higher cumulative assisted primary and secondary patency compared with cumulative assisted primary and secondary patency after routine follow-up examination. The patency of e-polytetrafluoroethylene and composite grafts was not influenced by intensive surveillance.

Aged↗