Biomedical subjects

Odd Geiran

Publications and source records attributed to Odd Geiran.

11 recordsLinked to original sources

PubMed2005

Detection of Actinobacillus actinomycetemcomitans but not bacteria of the red complex in aortic aneurysms by multiplex polymerase chain reaction.

BACKGROUND: Aortic aneurysms affect an increasing number of elderly patients and cause considerable morbidity and mortality. The understanding of the mechanisms involved in the pathogenesis of aortic aneurysms is unclear and little is known about the role of microorganisms in the development of the condition. The aim of the present study was to examine aortic aneurysm samples for the presence of four putative periodontal pathogens: Actinobacillus actinomycetemcomitans, Treponema denticola, Tannerella forsythensis, and Porphyromonas gingivalis. METHODS: Fifty-six samples from the aneurysm wall were obtained from patients undergoing aneurysm repair. DNA was extracted from tissue by conventional methods. Universal eubacterial primers for general detection of bacteria and species specific primers for detection of the periodontal pathogens were used to amplify part of the 16S rRNA gene by polymerase chain reaction (PCR). RESULTS: Bacterial DNA was detected in 50 of the 56 aneurysm samples (89.2%). A. actinomycetemcomitans was found in four samples (7.1%). None of the samples was positive for T. denticola, T. forsythensis, or P. gingivalis. CONCLUSION: Bacteria are commonly present in aortic aneurysms and may play a role in the development of the condition. Periodontal pathogens are also present.

Adult↗

PubMed2004

Functional serotonin 5-HT4 receptors in porcine and human ventricular myocardium with increased 5-HT4 mRNA in heart failure.

Serotonin (5-hydroxytryptamine, 5-HT) increases contractile force and elicits arrhythmias through 5-HT(4) receptors in porcine and human atrium, but its ventricular effects are unknown. We now report functional 5-HT(4) receptors in porcine and human ventricle. 5-HT(4) mRNA levels were determined in porcine and human ventricles and contractility studied in ventricular trabeculae. Cyclic AMP-dependent protein kinase (PKA) activity was measured in porcine ventricle. Porcine and human ventricles expressed 5-HT(4) receptor mRNA. Ventricular 5-HT(4(b)) mRNA was increased by four times in 20 failing human hearts compared with five donor hearts. 5-HT increased contractile force maximally by 16% (EC(50)=890 nM) and PKA activity by 20% of the effects of (-)-isoproterenol (200 microM) in ventricular trabeculae from new-born piglets in the presence of the phosphodiesterase-inhibitor 3-isobutyl-1-methylxanthine. In ventricular trabeculae from adult pigs (3-isobutyl-1-methylxanthine present) 5-HT increased force by 32% (EC(50)=60 nM) and PKA activity by 39% of (-)-isoproterenol. In right and left ventricular trabeculae from failing hearts, exposed to modified Krebs solution, 5-HT produced variable increases in contractile force in right ventricular trabeculae from 4 out of 6 hearts and in left ventricular trabeculae from 3 out of 3 hearts- range 1-39% of (-)-isoproterenol, average 8%. In 11 left ventricular trabeculae from the failing hearts of four beta-blocker-treated patients, pre-exposed to a relaxant solution with 0.5 mM Ca(2+) and 1.2 mM Mg(2+) followed by a switch to 2.5 mM Ca(2+) and 1 mM Mg(2+), 5-HT (1-100 microM, 3-isobutyl-1-methylxanthine present) consistently increased contractile force and hastened relaxation by 46% and 25% of (-)-isoproterenol respectively. 5-HT caused arrhythmias in three trabeculae from 3 out of 11 patients. In the absence of phosphodiesterase inhibitor, 5-HT increased force in two trabeculae, but not in another six trabeculae from 4 patients. All 5-HT responses were blocked by 5-HT(4) receptor antagonists. We conclude that phosphodiesterase inhibition uncovers functional ventricular 5-HT(4) receptors, coupled to a PKA pathway, through which 5-HT enhances contractility, hastens relaxation and can potentially cause arrhythmias.

1-Methyl-3-isobutylxanthine↗

PubMed2004

Predictors of exercise capacity and the impact of angiographic coronary artery disease in heart transplant recipients.

BACKGROUND: Maximal exercise capacity is limited in patients after heart transplantation. The extent to which transplant coronary artery disease contributes to exercise intolerance in these patients has not been well defined. METHODS: This prospective study examined exercise capacity among 174 heart transplant recipients who underwent 358 exercise tests 0.3 to 13 years after surgery. Data were collected as part of routine posttransplantation treatment that each year consist of clinical and hemodynamic measurements (including ejection fraction, cardiac index, pulmonary capillary wedge pressure, and the presence of coronary artery disease) and cardiopulmonary exercise test (including measures of peak VO2). The mean follow-up was 3.5 +/- 0.2 years after transplantation. Serial exercise test data were available in 102 patients RESULTS: Peak VO2 was 19.4 +/- 0.4 mL/kg per minute, representing 70% +/- 1.3% of the age-predicted value. Exercise capacity increased significantly after transplantation and then remained stable throughout long-term follow-up. Only age, maximal systolic blood pressure, pulmonary vascular resistance, and body mass index were independent determinants of exercise capacity (R2 = 0.51), whereas specific transplant factors such as denervation, hemodynamic variables, donor characteristics, immunosuppressive drugs, biochemical parameters, and transplant coronary artery disease (TxCAD) did not contribute to the explanation of reduced exercise capacity. Although TxCAD was not related to exercise capacity in the multivariate analysis, exercise capacity declined by 17.1% (P <.05) among those in whom CAD developed during follow-up. CONCLUSIONS: Exercise capacity is reduced among heart transplant recipients, and age is the strongest determinant of aerobic performance. Specific transplant-related factors, including TxCAD, do not contribute significantly to the explanation of exercise capacity. However, the occurrence of TxCAD may contribute to reduced exercise capacity during follow-up, since peak VO2 appears to decline only among those who have TxCAD.

Coronary Angiography↗

PubMed2004

Improvement of coronary artery fistula surgery by intraoperative imaging.

Complete surgical closure of coronary artery fistulas may be difficult because of complex anatomy and often multiple sites of origin. This study therefore assessed whether intraoperative fistula imaging would contribute to and improve the final surgical result. Seven adult patients underwent operation for coronary arteriovenous fistula during a 10-year period. In all 4 patients who had image guidance, the operation was guided by immediate imaging to achieve complete and persistent closure. In contrast, 2 of 3 patients who underwent operation without image guidance had residual left-to-right shunts at follow-up. Image guidance was helpful and increased the success rate of surgical closure of coronary artery fistulas.

Adult↗

PubMed2004

Coronary artery aneurysms mimicking cardiac tumor.

AIMS: To discuss the diagnosis of giant coronary aneurysms. METHODS AND RESULTS: We describe three patients in whom initial echocardiographic findings suggested cardiac tumors in the right atrium. Additional examination proved the tumor-like structures to be giant atherosclerotic coronary aneurysms of either the right coronary artery or its saphenous vein coronary bypass graft. CONCLUSION: Giant coronary aneurysms are an important differential diagnosis for cardiac tumors.

Aged↗

PubMed2003

[Pulmonary arterial hypertension treated with prostacyclin or calcium blockers].

BACKGROUND: Until recently, medical treatment of pulmonary arterial hypertension in Norway has included diuretics, anticoagulation and calcium channel blockers. We describe our experience with prostacyclin (epoprostenol) in the treatment of this disease. MATERIALS AND METHODS: After diagnostic procedures, 11 patients with pulmonary arterial hypertension in functional class III or IV were treated with oral calcium channel blockade or intravenous epoprostenol. Choice of medical agent was based on right heart catheterisation with acute vasodilator testing. Functional capacity and haemodynamics were assessed at referral and after three months of therapy. RESULTS: Acute vasodilator testing revealed a much greater improvement in haemodynamics in the two patients subsequently treated with nifedipine than in the nine patients found to be candidates for epoprostenol. In the latter group, a significant median reduction in pulmonary arterial pressure of 23% and pulmonary vascular resistance of 59% together with a significant increase in cardiac index of 90% and mixed venous oxygen saturation of 17% was found after three months of treatment. All 10 survivors significantly improved their functional class to I or II and peak exercise oxygen consumption by 60%. INTERPRETATION: Epoprostenol is a valuable agent in severe pulmonary arterial hypertension for non-responders to acute vasodilator testing. The treatment is complex and demands considerable patient involvement.

Administration, Oral↗

PubMed2003

[Lung transplantation--established treatment, uncovered need].

BACKGROUND: Lung transplantation has been a therapeutic option for end-stage pulmonary disease in Norway since 1990 and there has been an increasing shortage of donor lungs. MATERIAL AND METHODS: The present study evaluates the assessment of a total of 409 patients (212 men and 197 women) referred in the period between 1990 and 2001. RESULTS: The most frequent diagnoses were chronic obstructive pulmonary disease (45%), a1-antitrypsin deficiency with emphysema (15%), idiopathic pulmonary fibrosis (14%), cystic fibrosis (7%) and sarcoidosis (6%). Among patients with chronic obstructive pulmonary disease, 53% were female. Numbers of referred and transplanted patients per 100 000 inhabitants did not differ significantly between the five health regions of Norway. The number of transplantations has been stable, 10-15 per year, while the number of patients on the waiting list has gradually increased to 30-40. Mean waiting time has increased to 500-600 days. Total mortality rate during assessment and on the waiting list was 41%. Patients with idiopathic pulmonary fibrosis and cystic fibrosis had significantly higher mortality than patients with chronic obstructive pulmonary disease and a1-antitrypsin deficiency with emphysema (63%, 72%, 26%, 21% respectively). Patients with idiopathic pulmonary fibrosis died after a median of 188 days on the waiting list, while patients with cystic fibrosis died after a median of 729 days. INTERPRETATION: Patients with idiopathic pulmonary fibrosis should be referred earlier and patients with idiopathic pulmonary fibrosis and cystic fibrosis should be given higher priority on the waiting list.

Adolescent↗

PubMed2003

Myocardial gene expression of inflammatory cytokines after heart transplantation in relation to the development of transplant coronary artery disease.

Long-term success of cardiac transplantation is mainly limited by the development of transplant coronary artery disease (CAD); it is generally accepted that it is immune mediated, involving cytokines and growth factors. We show that development of transplant CAD is associated with a particular cytokine profile in myocardial biopsies characterized by a late (i.e., 1 year) increase in tumor necrosis factor-alpha and interferon-gamma gene expression, which precede and potentially contribute to the development of allograft vasculopathy, further supporting a role for inflammation and the pathogenesis of transplant CAD in humans.

Adult↗

PubMed2003

Plasma C-reactive protein as a marker of cardiac allograft vasculopathy in heart transplant recipients.

OBJECTIVES: This study was initiated to determine whether heart transplant recipients (HTRs) with cardiac allograft vasculopathy (CAV) have increased levels of high-sensitivity C-reactive protein (hsCRP) and to examine whether an increase in hsCRP after heart transplantation predicts the development of CAV. Furthermore, the effect of pravastatin on plasma levels of hsCRP in HTRs was investigated. BACKGROUND: The relationship between CAV and hsCRP, as well as the effect of statins on hsCRP in HTRs, has not been well established. METHODS: On referral for their annual angiographic control study, 150 consecutive HTRs (mean 6.5 years since transplantation) were included. Plasma levels of hsCRP were measured before angiography and compared with patients with (n = 52) and without (n = 98) CAV. In 49 of these patients, we additionally analyzed hsCRP in blood samples stored from their six-month visit after the transplantation procedure. Furthermore, in a randomized, crossover study, hsCRP was analyzed in 17 male HTRs before and after six weeks of treatment with 20 mg pravastatin. RESULTS: Median levels of CRP were elevated among patients with CAV compared with those with normal angiograms [3.86 (1.78 to 7.00) vs. 1.08 (0.72 to 2.13) mg/l, p < 0.001]. Prospectively evaluated hsCRP levels from six months to follow-up were significantly higher among those who developed CAV compared with those with normal angiograms [+2.76 (1.56 to 5.00) vs. +0.07 (-0.57 to 0.41) mg/l, p < 0.001]. On multivariate analysis, the increase in hsCRP was the only significant predictor of CAV. Six weeks of treatment with pravastatin significantly reduced hsCRP levels by 25%, without any relation to changes in lipid values. CONCLUSIONS: Elevated plasma levels of CRP are associated with angiographic evidence of CAV, and the increase in hsCRP is a strong predictor of development of CAV. Statin treatment reduces levels of hsCRP and should be used in HTRs, regardless of their lipid levels.

Adult↗

PubMed2003

Multiple bacteria in aortic aneurysms.

OBJECTIVE: The purpose of the present study was to reexamine the possibility that bacteria, particularly anaerobes, are present in aortic aneurysms. METHODS: From December 2000 to November 2001, 53 samples from aneurysm walls were collected from 49 patients during reconstructive surgery. The tissue specimens were sectioned and cultured under anaerobic conditions. Twenty-eight specimens were also subjected to scanning or transmission electron microscopy. RESULTS: Anaerobic cultivation yielded bacteria in 14 of the 53 samples (26.4%). All bacteria were gram-positive cocci or rods from nine genera and 12 species. Five cultures (35%) were mixed, containing two bacterial species. Mixed aerobic and anaerobic species were found in four samples (28.5%). Anaerobic bacteria were recovered from 10 of 14 positive cultures (71%). Among anaerobes found were Propionibacterium acnes, Propionibacterium granulosum, Actinomyces viscosus, Actinomyces naeslundii, and Eggerthella lenta. Coaggregating bacteria of different sizes and structure were found on the aneurysm walls and inside the intravascular plaque at electron microscopy. Bacteria were found in 20 of the 28 samples (71%) examined with scanning or transmission electron microscopy. CONCLUSION: Multiple bacteria, many of which did not belong to the indigenous skin microflora, colonize aortic aneurysms. It is not clear whether the bacteria contribute to weakening of the aortic wall by eliciting inflammation or whether they are secondary colonizers of aneurysms.

Actinomyces↗

PubMed2003

Clinical and exercise test determinants of survival after cardiac transplantation.

BACKGROUND: Cardiac transplantation (CTX) is now a viable option for patients with end-stage heart failure, but there remains a paucity of available donor hearts relative to the demand for them. Establishing prognosis after CTX can help direct this resource to patients most likely to benefit, as well as to help guide therapy for CTX recipients. Clinical, exercise, and hemodynamic factors associated with survival after CTX have not been well established. METHODS: One hundred seventy-four randomly selected patients who underwent heart transplantation between 1983 and 1999 at Rikshospitalet University Hospital were included in the study. Data were collected as a part of routine posttransplantation management a mean of 3.5 +/- 2.1 years (+/- SD) after CTX. Clinical, cardiopulmonary exercise testing, and hemodynamic measures were performed, including measures of peak oxygen uptake (O(2)), ejection fraction, cardiac index, pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure, creatinine, and the presence of coronary artery disease. Patients were followed up for a mean of 7.1 +/- 2.1 years; all-cause mortality was used as the end point for survival analysis. RESULTS: During the follow-up period, 39 patients died; the average annual mortality was 3.6%. Peak O(2) was 19.6 +/- 5.6 mL/kg/min, representing 70.5 +/- 6.7% of the age-predicted value. Only right atrial pressure and PCWP differed between those who survived and those who died; both were slightly higher among those who died. By Cox proportional hazard analysis, there were no age-adjusted univariate or multivariate predictors of survival among continuous variables. Exploring various cut points revealed that serum creatinine > 118 micromol/L, PCWP > 12 mm Hg, and mean pulmonary artery pressure > 25 mm Hg were significant univariate predictors of mortality. These cut points for PCWP and pulmonary artery pressure generated hazard ratios of 2.3 and 2.9, respectively. CONCLUSION: Long-term survival after CTX was comparatively high in our cohort, with 5-year survival > 80%. Standard clinical, hemodynamic, and cardiopulmonary exercise test variables were not strong predictors of mortality in CTX patients a mean of 7 years after CTX. The association between elevated hemodynamic pressures and mortality, although weak, suggests that ventricular compliance, pulmonary vascular resistance, or both, may predict long-term survival after CTX.

Blood Pressure↗