Search PubMed⌕ Search

Biomedical subjects

U Baandrup

Publications and source records attributed to U Baandrup.

At least 37 records · Page 2Linked to original sources
PubMed1998

Animal experimental implantation of an atrial septal defect occluder system.

OBJECTIVE: To establish the implantation technique for the atrial septal defect occluder system (ASDOS) device in an experimental animal model and to determine long term mechanical stability of the device and its in vivo properties in terms of biocompatibility and tissue reaction. MATERIALS AND METHODS: An atrial septal defect was created and the device implanted in 17 pigs (mean weight 30 kg). The implantation technique was refined and modified because of initial technical and anatomical complications during nine acute pilot studies. The technique proved to be feasible in eight subsequent survival studies. Four pigs were electively killed three months after implantation (group 1). The remaining four pigs were killed six months after implantation (group 2). RESULTS: Necropsy showed all devices were embedded in soft tissue three months after implantation. Microscopic examination of atrial septal tissue showed an acute granulomatous inflammatory reaction in group 1 and fibrosis in group 2. The intensity of the inflammatory reaction around the device was clearly milder in group 2, indicating a decline in the inflammatory response with time. Clinical and biochemical investigations indicated acceptable biocompatibility of the device. CONCLUSION: The implantation technique for the ASDOS device in a chronic pig model has been established. Biocompatibility of the device was acceptable.

Animals↗
PubMed1998

Latissimus dorsi cardiomyoplasty: a chronic experimental porcine model. Feasibility study of cardiomyoplasty in Danish Landrace pigs and Göttingen minipigs.

Cardiomyoplasty is an experimental treatment for end-stage heart failure. We hypothesized that the porcine latissimus dorsi muscle (LDM) in an experimental porcine model is a suitable surrogate for a clinically relevant evaluation of this concept. Fourteen Danish Landrace (DL) pigs and six Göttingen minipigs (GM) were studied. The LDM was evaluated immediately after surgical dissection and in various phases: phase 1 (n = 4)--outcome of a partial vascular isolation (vascular delay), 2 to 3 weeks prior to heart wrapping in DL pigs; phase 2 (n = 6)--long-term flap survival of nonstimulated LDM cardiomyoplasty in DL pigs; phase 3 (n = 6)--outcome of nonstimulated cardiomyoplasty in GM; phase 4--one DL pig had dynamic cardiomyoplasty performed and was subjected to low-intensity LDM stimulation for 8 months. Isolation of the LDM of DL pigs and GM as a pedicled graft had no acute deleterious impact on the global blood supply. In phase 1a, partial vascular isolation and in situ recovery of the LDM resulted in a muscle encapsulated in fibrotic tissue, which hampered a later heart wrap. In phase 1b, a less extensive dissection diminished fibrosis and allowed subsequent wrapping. In phase 2, after 6 weeks of nonstimulated LDM cardiomyoplasty, the LDM of DL pigs was viable, with excellent heart-muscle integration. In phase 3, the same procedure applied in GM yielded the same result as that in DL pigs, but with a higher success rate owing to the learning phase.

Animals↗
PubMed1997

Ischemia and reperfusion of the porcine myocardium: effect on collagen.

We studied the effect of acute myocardial infarction and late reperfusion on myocardial collagen in a closed chest porcine model, to investigate if any collagen degradation could be detected in blood samples and myocardium. Sixteen 60-80 kg pigs were used with six animals serving as controls and 10 submitted to ischemia-reperfusion. In the ischemia-reperfusion group the left anterior descending coronary artery was occluded for 6 h by inflation of a percutaneous transluminal coronary angioplasty balloon followed by reperfusion for 3 h. Blood samples were taken from the aorta and the coronary sinus and analyzed for creatine kinase and collagen degradation products, i.e. the N-terminal propeptide of procollagen type III (PIIINP) and C-terminal pyridinoline cross-linked telopeptide of collagen type I (ICTP). Myocardial tissue samples were analyzed for content of hydroxyproline, collagen volume fraction and amount of extractable PIIINP/dry weight. Transmission electron microscopy of biopsies was performed to evaluate myocytes and collagen structure outside and within the infarct zone. Creatine kinase showed a statistically significant increase during ischemia and reperfusion but we found no evidence of release of collagen degradation products either during ischemia or reperfusion compared with control. Myocardial content of hydroxyproline, collagen volume fraction and extractable PIIINP/dry weight did not differ between groups. Transmission electron microscopy of biopsies from the infarct zone showed myocyte damage but no visible evidence of collagen degradation when photos were evaluated blindly. In this porcine model of acute myocardial infarction and late reperfusion no release of collagen degradation products from the myocardium or any decrease in or damage to myocardial collagen was detected.

Analysis of Variance↗
PubMed1997

Impaired human coronary artery distensibility by atherosclerotic lesions: a mechanical and histological investigation.

The objective of this study was to evaluate the relationship between human coronary artery distensibility and vessel wall morphology assessed by histomorphometry. Coronary artery pressure-cross-sectional area relations and distensibility were studied in excised autopsy hearts by means of a balloon-based impedance planimetric technique 2 cm from the aortic orifice of the arteries. Later the hearts were perfusion fixed at 100 mm Hg and cross-sectioned 17, 20 and 23 mm distal to the aortic orifice. The areas of lumen, intima and media were measured. Nineteen left anterior descending coronary arteries (LAD) and 15 right coronary arteries (RCA) from 25 hearts (12 women and 13 men) were investigated. The age of the subjects was 48-97 years (mean 73.8 years). Non-linear relations were found between balloon pressure and coronary cross-sectional area (according with the function y = a + bx0.5) and between balloon pressure and coronary distensibility, but there were no differences in these relations between the LAD and RCA. Subjects' age was positively correlated with wall thickness (r = 0.44, P < 0.05), intima area (r = 0.46, P < 0.01) and media area (r = 0.44, P < 0.05) of the coronary arteries. Additionally, the distensibility at low pressures was inversely correlated with arterial wall thickness (r = -0.37, P < 0.05). When focusing only on arteries with concentric atherosclerotic lesions, distensibility at low pressures was inversely correlated with arterial wall thickness (r = -0.57, P = 0.01) and intima area (r = -0.53, P < 0.05). Arteries with concentric lesions were less distensible at low pressures compared with arteries having eccentric lesions (5.4 +/- 0.8.10(-2) vs. 3.6 +/- 0.7.10(-2) kPa-1, P < 0.05) but this difference was absent at higher pressures. No difference in coronary artery distensibility was found between men and women. Age and distensibility were not correlated. These findings may have in vivo implications for complications to angioplasty procedures such as recoil and restenosis.

Aged↗
PubMed1997

Endogenous TGF-beta 1 and TGF-beta 2 are not essential for epithelialization and neovascularization in the hairless mouse ear wound model.

BACKGROUND AND AIMS: TGF-beta stimulates neovascularization and epithelialization in healing wounds, yet relatively little is known about the mechanisms involved. Using the hairless mouse ear wound model, we studied the effects endogenous TGF-beta 1 and TGF-beta 2 have on epithelialization and neovascularization following the application of neutralizing antibodies. MATERIAL AND METHODS: Forty-three adult male hairless mice had an excisional wound made on the dorsum of each ear. Using vital microscopy, epithelialization and neovascularization were measured every third day until completion. TGF-beta 1 and TGF-beta 2 antibody, control-IgG, or phosphate buffered saline (PBS) were applied to the wounds. RESULTS AND CONCLUSIONS: Excisional wounds treated with anti-TGF-beta 1 and anti-TGF-beta 2, IgGcontrol IgG, and PBS epithelialized in 11.2 +/- 0.5 days (N = 22), 10.9 +/- 0.6 days (N = 17), and 10.6 +/- 0.6 days (N = 15), respectively and neovascularized in 27.9 +/- 0.5 days (N = 17), 27.1 +/- 0.8 days (N = 14), and 26.1 +/- 0.8 days (N = 10), respectively (mean +/- SEM). There were no significant differences in time to epithelialization and neovascularization between the three groups. Furthermore, there were no differences in the average time course of epithelialization and neovascularization between the three groups throughout the healing process. We conclude that endogenous TGF-beta 1 and TGF-beta 2 are not essential for epithelialization and neovascularization in the hairless mouse ear wound model.

Animals↗
PubMed1996

An increase in sudden unexpected cardiac deaths among young Swedish orienteers during 1979-1992.

BACKGROUND: Sixteen cases of sudden unexpected cardiac death, 15 males and one female, are known to have occurred among young Swedish orienteers from 1979 to 1992, of which seven cases occurred between 1989 and 1992. This is considered to be indicative of an increased death rate. RESULTS: Histopathological evaluation showed myocarditis in a higher than expected proportion of cases. In one such case, which we studied before the sudden unexpected death occurred, the victim had suffered a Chlamydia pneumoniae infection verified by serology, and a nucleotide sequence was found in the heart and lung by means of the polymerase chain reaction (PCR) that hybridized with a probe specific for that organism. Male Swedish orienteers do not, however, seem to have an increased rate of exposure to this agent. No further sudden unexpected deaths among young orienteers have occurred over the past 3.5 years. At the beginning of that period, attempts were made to modify training habits and attitudes.

Adolescent↗
PubMed1995

Perivalvular cavities in endocarditis: abscesses versus pseudoaneurysms? A transesophageal Doppler echocardiographic study in 118 patients with endocarditis.

The appearance of perivalvular cavities (PCs) in patients with infectious endocarditis (IE) was studied by transesophageal echocardiography (TEE) color Doppler examinations to determine whether the color Doppler TEE presentation was in keeping with the current concept of PCs representing abscesses. Two heart centers participated in the study. Videotape recordings of TEE examinations in patients with IE were analyzed retrospectively for 18 months in both centers, and one center included patients prospectively for an additional 18 months. A total of 118 patients with a diagnosis of IE based on TEE and clinical and laboratory findings were seen during the study period. TEE showed PCs in 34 patients. In 3 patients who died, no autopsy was performed; the PCs were proved at autopsy or surgery in the remaining 31 patients, who constituted the study population. All PCs were echo free at TEE. Apart from one technically inadequate examination, all PCs contained color Doppler signals indicating intracavitary blood flow; the PCs communicated through a narrow channel with high-pressure regions (the left ventricle or the ascending aorta). At surgery or autopsy, only 2 of the 31 patients had pus accumulations besides the blood-filled PCs. At TEE the pus accumulations presented as echo-rich, shaggy tissue thickening. It is concluded that well-delineated, echo-free PCs with intracavitary color Doppler signals at TEE appear to be pseudoaneurysms, and therefore the term abscess should not be used in these cases. Although further studies are needed, our findings suggest that PCs more likely occur by infectious tissue weakening and subsequent dissection rather than as a result of primary abscess formation with secondary rupture.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1993

Leucocyte depletion attenuates the early increase in myocardial capillary permeability to small hydrophilic solutes following ischaemia and reperfusion.

OBJECTIVE: The aim was to assess the significance of polymorphonuclear leucocytes on the myocardial capillary permeability to a small hydrophilic indicator, on the vascular tone of the resistance vessels, and on contractile function following ischaemia and reperfusion. METHODS: Open chest, anaesthetised dogs were randomised to treatment with polyclonal antibody against polymorphonuclear leucocytes (anti-PMN group) or non-specific antibody (control group), and subjected to 40 min of coronary occlusion followed by 3 h of reperfusion. The capillary extraction fraction and the myocardial plasma flow rate were quantitated in vivo by intracoronary indicator bolus injection and external registration of the washout, and the capillary permeability-surface area product was calculated. Postischaemic vasodilator tone in the myocardial resistance vessels was measured by the local 133xenon washout method. RESULTS: 20 dogs were included (10 in each group), and 13 dogs completed the ischaemia-reperfusion protocol (anti-PMN group, n = 7; control group, n = 6). In the anti-PMN group, blood polymorphonuclear leucocyte counts were reduced to a minimum of 15% of pretreatment values. After ischaemia and 5 min reperfusion, the capillary extraction increased by 17% in the control group but decreased by 22% in the anti-PMN group (p < 0.05). The corresponding capillary permeability-surface area product increased by 22% in the control group, but decreased by 16% in the anti-PMN group (p < 0.05). Neither maximum myocardial plasma flow during reactive hyperaemia nor contractile function were influenced by anti-PMN treatment. CONCLUSIONS: Polymorphonuclear leucocytes appear to participate in the increase in myocardial capillary permeability observed early after reperfusion following a 40 min period of ischaemia, but do not influence postischaemic vascular tone or postischaemic contractile function. During normal physiological conditions reduction of the circulating polymorphonuclear leucocyte counts did not induce significant changes in myocardial capillary permeability.

Animals↗
PubMed1993

Heart transplantation in a case of juvenile hereditary haemochromatosis followed up by MRI and endomyocardial biopsies.

Cardiac involvement in hereditary haemochromatosis (HH) is a poor prognostic sign and is the main cause of death in the juvenile form. The treatment of choice is iron removal therapy by phlebotomy, but treatment by iron chelation (desferrioxamine) has been recommended in cases with severe cardiac symptoms. We describe here the first case of juvenile HH undergoing heart transplantation, which became necessary despite intensive iron removal therapy by phlebotomy and treatment by desferrioxamine. Throughout the course the myocardial iron content was monitored by endomyocardial biopsies and by magnetic resonance imaging (MRI). At the last follow-up, 18 months after transplantation, the myocardial iron content in the transplanted heart was still within reference ranges by biochemical determination and MRI and the patient's condition was completely satisfactory. In conclusion, heart transplantation should be considered in cases of severe juvenile HH. In the follow-up of these patients MRI may be a useful supplement.

Adult↗
PubMed1992

Peripheral low-grade mucoepidermoid carcinoma of the lung--needle aspiration cytodiagnosis and histology.

Mucoepidermoid carcinoma of the lung is a rare tumour, and is not usually considered in the differential diagnosis of a peripheral lung mass. The cytological and histological features of an intimate admixture of polygonal intermediate cells, well differentiated mucinous and squamous cells, as illustrated in this case report, serve to differentiate a well differentiated mucoepidermoid carcinoma from adenosquamous carcinoma, low grade adenocarcinoma, bronchioloalveolar carcinoma, and benign reactive changes.

Aged↗
PubMed1992

Influence of pre-existing ischemia on recovery from chemical cardioplegia. A study on pig hearts in an isolated blood-perfused model.

The impact of prior cardiac ischemia on recovery from chemical cardioplegia was investigated in pig hearts. Group I hearts were subjected to 9-min normothermic ischemia before the start of chemical cardioplegia. After 180 min of induced cardiac arrest, all hearts were reperfused and monitored for 120 min in a blood-perfused Langendorff model. Consistent with left ventricular performance, myocardial oxygen uptake was significantly lower in group I than in the other hearts during the first 60 min of reperfusion. Lactate elimination was significantly higher in group I at the start of reperfusion, but showed no intergroup difference after 25 min. Nor was intergroup difference found in left ventricular end-diastolic pressure, total myocardial flow or glucose extraction fraction during reperfusion. The mitochondrial ultrastructure was identical in the two groups before chemical cardioplegia. During cardioplegia it deteriorated in group I but normalized in group II. During reperfusion these circumstances were reversed. Although precardioplegic ischemia thus significantly impaired left ventricular performance during early recovery, with corresponding effects on metabolism and ultrastructure, stable performance during reperfusion indicated that the ischemic injury did not worsen.

Animals↗
PubMed1990

The concentration of the Na,K-pump in skeletal and heart muscle in congestive heart failure.

Na,K-ATPase (or the Na,K-pump) is essential for excitability and contractility of muscle tissue. Previous studies have shown a decrease in the concentration of this pump in endomyocardial biopsies from patients with dilated cardiomyopathy. The effect of congestive heart failure on the concentration of Na,K-ATPase in skeletal muscle was assessed in 16 patients by measurement of binding of 3H-ouabain to biopsies of the vastus lateralis muscle. Ten patients had impaired left ventricular function with an ejection fraction of 0.32 +/- 0.03 and a concentration of the Na,K-pump of 229 +/- 15 pmol/g wet weight in the skeletal muscle, whereas 6 patients had an ejection fraction of 0.66 +/- 0.05 (P less than 0.001) and a concentration of 307 +/- 17 pmol/g wet weight (P less than 0.01). In endomyocardial biopsies, the concentration of Na,K-ATPase was 340 +/- 37 and 500 +/- 39 pmol/g wet weight (P less than 0.025) in patients with impaired and normal ventricular function, respectively. There was a significant correlation between the concentration of the Na,K-pump in the biopsies of the skeletal muscle and ejection fraction, as well as between its concentration in the endomyocardial and skeletal muscular biopsies (r = 0.56, P less than 0.025 and r = 0.72, P less than 0.005, respectively). The decrease in concentration of the pump in skeletal muscle may contribute to the limitation of exercise capacity in congestive heart failure.

Adult↗
PubMed1990

Importance of abstention from alcohol in alcoholic heart disease.

A case of alcohol-associated heart disease, presenting with congestive heart failure, was followed for 36 months. After abstinence from alcohol, fractional shortening rose from 13 to 60%. After 1 1/2 years of abstinence and normal physical capacity, the alcoholic abuse was resumed. Eleven months later, the patient was again in overt heart failure. Withdrawal of alcohol was again associated with significant clinical improvement, but despite being in functional NYHA class I, fractional shortening only increased from 14 to 29%. Endomyocardial morphology was unrelated to the severity of the disease. Alcoholic heart disease is partially reversible, but total abstinence is necessary to preserve cardiac function.

Adult↗
PubMed1990

Recovery after cold cardioplegic arrest of isolated blood-perfused hearts excised from non-anesthetized pigs.

An isolated blood-perfused pig heart model has been established in order to evaluate the recovery of hearts obtained from slaughterhouse domestic pigs avoiding anesthesia and direct experiments on animals. Eleven hearts subjected to 9 min of normothermic ischemia were infused with cold modified Bretschneider solution. After 180 min of cardioplegic-induced global ischemia (including 9 min of normothermic ischemia) 8 hearts were reperfused for 120 min. Left ventricular function (measured isovolumetrically by means of a balloon, and expressed as developed left ventricular pressure, positive and negative dP/dt) was stable during the whole reperfusion period. Lactate production was abolished after 25 min of reperfusion, while there was a small glucose extraction during the whole reperfusion period. Slight deterioration of the mitochondria was found during the induced cardiac arrest, however, reversing during the reperfusion. Thus, due to the stability of left ventricular function, improved metabolism and ultrastructure during the reperfusion period, the model with no use of laboratory animals, and without any influence of anesthesia, seems to be suitable for testing the pure effect on the performance of the left ventricle of drugs and substrates added to the reperfusate during the reperfusion period.

Animals↗
PubMed1989

Antitrophic properties of antihypertensive drugs may depend solely on their blood pressure-lowering capability. A comparative study of isradipine, hydralazine, and metoprolol.

The objective of this study was to examine the effect of antihypertensive treatment on the structure of intramyocardial resistance vessels in spontaneously hypertensive rats. The rats were divided into four groups: one was used as control and the other three were treated from the age of four to 24 weeks with isradipine, hydralazine, and metoprolol, respectively. Half of the animals in each group were examined at the end of active treatment and the rest were examined three weeks later. The rats were anesthetized and killed during constant flow perfusion with 1 percent glutaraldehyde. The media index was determined by point counting. The media indices of rats treated with isradipine and hydralazine were significantly smaller than those of age-matched spontaneously hypertensive rat controls, whereas the media indices of rats in the metoprolol group did not differ significantly. Three weeks after treatment withdrawal, the media index tended to increase in all three groups, but the values for the isradipine and hydralazine groups were still significantly reduced. Non-invasive blood pressure measurements taken at the same time demonstrated a significant blood pressure reduction in all groups, although differences within each treatment group were evident. All pressures had stabilized on the level of spontaneously hypertensive rats three weeks after withdrawal. Thus, it is evident that both isradipine and hydralazine were able to prevent hypertrophy of intramyocardial vascular structure and continue to do so even after treatment withdrawal. This finding is consistent with previous findings, suggesting a close relationship between the extent of blood pressure reduction and the degree of prevention of vascular hypertrophy.

Animals↗