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Biomedical subjects

G Nielsen

Publications and source records attributed to G Nielsen.

At least 19 recordsLinked to original sources
PubMed2001

Sustained postinfarction myocardial oedema in humans visualised by magnetic resonance imaging.

OBJECTIVE: To demonstrate postinfarction myocardial oedema in humans with particular reference to the longitudinal course, using magnetic resonance imaging (MRI). DESIGN: Prospective observational study. Subjects were studied one week, one month, three months, six months, and one year after presenting with a myocardial infarct. SETTING: Cardiology and magnetic resonance departments in a Danish university hospital. PATIENTS: 10 patients (three women, seven men), mean (SEM) age 58.2 (3.20) years, with a first transmural myocardial infarct. MAIN OUTCOME MEASURES: Location and duration of postinfarction myocardial oedema. RESULTS: All patients had signs of postinfarction myocardial oedema. The magnetic resonance images were evaluated by two blinded procedures, employing two MRI and two ECG observers: (1) MRI determined oedema location was compared with the ECG determined site of infarction and almost complete agreement was found; (2) the time course of postinfarction myocardial oedema was explored semiquantitatively, using an image ranking procedure. Myocardial oedema was greatest at the initial examination one week after the infarction, with a gradual decline during the following months (Spearman's rank correlation analysis: rho(observer 1) = 0.94 (p < 0.0001) and rho(observer 2) = 0.97 (p < 0.0001)). The median duration of oedema was six months. CONCLUSIONS: Postinfarction myocardial oedema seems surprisingly long lasting. This observation is of potential clinical interest because the oedema may have prognostic significance.

Aged↗
PubMed2000

Relationship between methylmalonic acid and cobalamin in uremia.

UNLABELLED: Relationship between methylmalonic acid and cobalamin in uremia. BACKGROUND: To evaluate the requirement for routine supplementation with vitamin B12 and to study the effect of a change from injection to oral B12 supplementation, we examined the relationship between cobalamin and methylmalonic acid in plasma from 67 patients on chronic hemodialysis, all in regular therapy with intramuscular cobalamin injections (1 mg) every third month. METHODS: Starting just before one cobalamin injection, blood samples were collected once a month during a nine-month withdrawal from regular cobalamin substitution to a final three-month period with cyanocobalamin tablets (1 mg) administered once daily. RESULTS: Plasma cobalamin was above the lower reference limit in all subjects, and from a peak value one month after the regular injection, the cobalamin concentration during the withdrawal period decreased to a level below the point of origin, followed by a significant rise after cyanocobalamin tablets. The methylmalonic acid concentrations were above the reference interval. In the withdrawal period, the concentrations significantly increased further, followed by a significant decrease after oral cyanocobalamin substitution. CONCLUSION: We demonstrated a within-patient inverse relationship between the concentrations of methylmalonic acid and cobalamin in plasma from these uremic patients. Despite the fact that only two of the patients developed subnormal plasma cobalamin values, we demonstrated a B12 depletion during the withdrawal period. Treatment with cyanocobalamin tablets once daily was found efficient, but the oral doses should possibly be increased.

Adult↗
PubMed2000

Screening for pulmonary arteriovenous malformations: contrast echocardiography versus pulse oximetry.

Pulmonary arteriovenous malformations (PAVM) cause right-to-left shunt and imply risk of paradoxical embolism and cerebral abscess. These complications can be prevented by appropriate treatment. Detection of PAVMs is therefore important, so simple and reliable screening methods are needed for this purpose. The aim of this investigation was to compare pulse oximetry and contrast echocardiography as screening tools for detection of pulmonary arteriovenous malformations. Eighty-five hereditary haemorrhagic telangiectasia (HHT) patients and first-degree relatives identified in a comprehensive study of HHT-families in the county of Funen, Denmark, were investigated. Standing and supine pulse oximetry in room air was performed in all subjects, and in subjects with symptoms and/or abnormal pulse oximetry in room air, supine pulse oximetry breathing 100% oxygen was also performed. Transthoracic echocardiography with intravenous injection of echo contrast was performed in all subjects. Outcome measures were oxygen saturation change >2% units on changing body position and echo contrast observed in the left-sided heart chambers. Positive contrast echocardiography indicating the presence of PAVM was found in 47 subjects, whereas pulse oximetry was abnormal in only 16. The results strongly suggest that contrast echocardiography is a more sensitive screening tool for PAVMs than pulse oximetry.

Adolescent↗
PubMed2000

Comparison of the factor VII:C clot analysis and a modified activated factor VII analysis for monitoring factor VII activity in patients treated with recombinant activated factor VII (NovoSeven).

Bleeding episodes in haemophilia A and B inhibitor patients are now frequently treated with recombinant activated factor VII (NovoSeven, Novo Nordisk A/S, Bagsvaerd, Denmark). Until now, the FVII:C coagulation assay has been used to monitor NovoSeven-mediated coagulation. However, a new assay (Staclot VIIa-rTF, Diagnostica Stago, France) has been designed to specifically detect activated factor (F)VII. Replacement of the buffer supplied by the manufacturer with a PIPES buffer containing BSA (modified FVIIa assay), resulted in a linear standard curve, greater sample stability and a reduced coefficient of variation. The FVII:C assay and the modified FVIIa assay were compared in a recovery experiment using the International FVIIa standard No 89/688(IS). Recovery of FVIIa was 93-97% for the modified FVIIa assay and 91-115% for the FVII:C assay. However, because samples in the FVII:C assay were not parallel to the standard curve, confidence limits for recovery were as wide as 67-130% compared with 92-106% for the FVIIa assay. In conclusion, a modified version of the Staclot VIIa-rTF assay, suitable for monitoring treatment with NovoSeven, even at low concentrations, has been developed. It provides an alternative to the FVII:C assay, which is not suitable for monitoring FVIIa at low concentrations.

Biological Assay↗
PubMed2000

Quality counts.

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Cost Savings↗
PubMed1999

Tetralogy of Fallot. A population-based study of epidemiology, associated malformations and survival in western Denmark 1984-1992.

The study describes the epidemiology and mortality of tetralogy of Fallot (TOF) in a population-based study in Western Denmark. Ninety-two infants with TOF were born during 1984-1992. Prevalence was 3.01 per 10,000 livebirths. Karyotype anomalies were present in 12 (13%) and extracardiac malformations in 16 (17%) of the infants. Down syndrome, cleft palate, cleft lip and palate and combined skeletal, gastrointestinal and renal lesions (VACTERL association) were prevalent. Twenty-four infants died (26% of total), 13 (54%) of the deaths occurring during the first year of life. Mortality was significantly increased in infants with extracardiac malformations (50% vs 19%, p < 0.05). Eighteen deaths (75% of total deaths) occurred before corrective surgery and 7 of these deaths were sudden. Extracardiac malformation(s) in infants with TOF is a significant risk factor for death. The study stresses the importance of population-based studies for the assessment of mortality from congenital heart malformations. Overall mortality may be very different from mortality related to cardiac surgery.

Chi-Square Distribution↗
PubMed1998

Tumor induction of VEGF promoter activity in stromal cells.

We have established a line of transgenic mice expressing the A. victoria green fluorescent protein (GFP) under the control of the promoter for vascular endothelial growth factor (VEGF). Mice bearing the transgene show green cellular fluorescence around the healing margins and throughout the granulation tissue of superficial ulcerative wounds. Implantation of solid tumors in the transgenic mice leads to an accumulation of green fluorescence resulting from tumor induction of host VEGF promoter activity. With time, the fluorescent cells invade the tumor and can be seen throughout the tumor mass. Spontaneous mammary tumors induced by oncogene expression in the VEGF-GFP mouse show strong stromal, but not tumor, expression of GFP. In both wound and tumor models the predominant GFP-positive cells are fibroblasts. The finding that the VEGF promoter of nontransformed cells is strongly activated by the tumor microenvironment points to a need to analyze and understand stromal cell collaboration in tumor angiogenesis.

Animals↗
PubMed1997

[Prehospital emergency treatment in the county of Northern Jutland 1993].

As part of the community planning of prehospital treatment in Northern Jutland, a mixed rural and urban region with a population of 500,000 people, we estimated the prehospital treatment in connection with 1617 emergency ambulance services. The investigation included data collected by the ambulance staff, the hospital doctors and review of medical records. The frequency of use of the emergency ambulance per 1000 population was 41 annually, and rapid emergency transport using signals constitutes 65% of call-outs. In the rural region the time from ambulance call until the ambulance reached the patients was longer than in the urban region. The ambulance staff as well as the doctor at the hospital considered a minor number of the patients as seriously ill. In 60% of the emergency ambulance transports the ambulance staff performed therapeutic efforts, frequently oxygen treatment (34%). In 305 transports the staff would have liked to carry out other forms of prehospital service, most often electrocardiographic-monitoring and treatment of pain. Only a few patients had need of advanced prehospital services but political consideration should be given to the possibility of advanced prehospital service in both rural and urban regions.

Ambulances↗
PubMed1997

[Paraneoplastic opsoclonus].

Opsoclonus occurs in a number of clinical settings, but its association with carcinomas in adult patients is rare. We present a case of paraneoplastic opsoclonus in a 63 year-old male who had a small-cell lung cancer. Even though paraneoplastic opsoclonus may be associated with an immunological response, there was no elevation of blood parameters associated with inflammation. The patient was treated with prednisolon without any clinical effect, and died only a few months after opsoclonus was diagnosed.

Carcinoma, Small Cell↗
PubMed1997

Metabolic cobalamin deficiency in patients with low to low-normal plasma cobalamins.

Over a 2-year period, we examined 48 patients with P-cobalamin levels in the difficult "grey zone" at the lower reference limit detected by a competitive protein binding assay using intrinsic factor as binder. In 21 of 30 patients (70%) with low P-cobalamins we could not establish the diagnosis of metabolic cobalamin deficiency, but 1 of 18 patients (6%) with low-normal P-cobalamin values was confirmed metabolically cobalamin-deficient. Half of these 30 patients with low P-cobalamins had neuropsychiatric disorders, but only one-third of the latter patients had metabolic cobalamin deficiency. Ten of the remaining 15 patients (67%) were characterized as non-deficient. In patients with low-normal P-cobalamin level, we found neuropsychiatric disorders in 5 of the 18 (28%), but none of these had metabolic cobalamin deficiency. We conclude that P-cobalamins below the reference interval combined with typical neuropsychiatric symptoms or findings are not diagnostic of cobalamin deficiency and that further analyses are necessary.

Adult↗
PubMed1995

Endocarditis caused by Aerococcus urinae, a newly recognized pathogen.

Aerococcus urinae is a newly described pathogen. A case of Aerococcus urinae endocarditis is presented, the primary focus being a urinary tract infection. The diagnosis of endocarditis was supported by isolation of Aerococcus urinae from blood as well as from heart vegetations.

Aged↗
PubMed1995

The prognostic value of exercise testing early after myocardial infarction in patients treated with thrombolytics.

Exercise testing early post AMI was evaluated as a predictor of reinfarction in patients treated with thrombolytics. AMI patients exercise-tested prior to discharge were included in the study (n = 178). The patients were followed for 2.9 +/- 0.9 years (mean +/- 1 SD) for the development of new cardiac events defined as cardiac death or reinfarction. Cox regression analysis of clinical and exercise test variables showed that there was significant predictive value of treating heart failure with drugs from two or more therapeutic groups (P < 0.001; hazard ratio 9.4 (3.1-28.2) (estimate and 95% confidence interval)), such as those with a previous history of myocardial infarction (P = 0.001; hazard ratio 4.0 (1.7-9.6)) and of significant ST depression (P = 0.029; hazard ratio 2.5 (1.1-5.7)). Significant ST depression could be substituted by the delta ST/delta HR index (P = 0.042; hazard ratio 2.8 (1.2-6.8)). The exercise test had independent but limited prognostic value in AMI patients treated with thrombolytics. The delta ST/delta HR index did not improve the predictive value of the exercise test.

Aged↗
PubMed1995

Proatrial natriuretic polypeptide (31-67) in healthy individuals: day-to-day variation and influence of sex and age.

N-terminal parts of proatrial natriuretic polypeptide have been proposed to be sensitive and specific markers of congestive heart failure (CHF). A prerequisite for use of a clinical marker is knowledge of day-to-day variation and dependence on age and sex. Immunoreactive N-terminal proatrial natriuretic polypeptide (31-67) (ir-N-ANP(31-67)) was measured in a clinically relevant population of healthy individuals. A total of 21 females (mean age 52 years, range 42-76) and 26 males (mean age 54 years, range 42-73), without cardiovascular disease, were included in the study. No correlation was found between ir-N-ANP(31-67) and sex. A statistically significant positive linear correlation (ir-N-ANP pmol 1(-1) = 182+ (8.2 x age in years) (p = 0.004) was found between age and ir-N-ANP(31-67). For the youngest subjects (42 years) the expected mean ir-N-ANP(31-67) was 530 pmol 1(-1), and for the oldest subjects (76 years) it was 800 pmol 1(-1). For all the subjects, the median ir-N-ANP(31-67) was found to be 626 pmol 1(-1) (range 300-1151). The day-to-day variation was studied and no significant difference was found in the plasma concentration of two samples taken 2-5 days apart. Of the individual day-to-day variation, 95% would be expected to be in the interval from -244 to 188 pmol 1(-1) (mean +/- 2 x SD). We conclude that ir-N-ANP(31-67) rises with age. The age-dependent rise in ir-N-ANP(31-67) is modest, but should be taken into consideration in order to use ir-N-ANP(31-67) as a diagnostic marker of CHF. The day-to-day variation is found to be rather high and cannot be neglected if N-ANP(31-67) is to be used as a marker of asymptomatic heart failure.

Adult↗
PubMed1994

[The role of social factors in the place of death of cancer patients in the county of Nordjylland].

The purpose of this study was to evaluate the importance of social factors on whether cancer deaths occurred at home or in hospitals. The study was based on questionnaires to the patient's general practitioner and to the home nursing service. The study included 241 patients with terminal cancer who were all identified by death certificates via the Department of Public Health in the period of the 1st February, 1992 to the 31st April, 1992. The study demonstrated that significantly more patients died in their own homes when a contact to the home nursing service had been established. The same tendency could be observed for patients with relatives being reimbursed for loss of income while providing care in the home. Significantly more patients died at home in municipalities where 24-hour nursing facilities could be offered. No association between age, sex, or whether the patient lived alone or lived cohabitantly were observed. The study suggest that an intensification of the home nursing facilities would give a greater number of terminal cancer patients the option of dying in their own homes. The possibility of relatives being reimbursed for loss of income while providing care in the home has a positive influence on the development of the number of cases home nursing.

Adult↗
PubMed1994

Antithrombotic effect of recombinant truncated tissue factor pathway inhibitor (TFPI1-161) in experimental venous thrombosis--a comparison with low molecular weight heparin.

The aim was to investigate whether a truncated recombinant Tissue Factor Pathway Inhibitor (TFPI1-161), which lacked the third Kunitz-type domain and the basic c-terminal region, had an antithrombotic effect comparable to LMWH in a randomised double-dummy study. The experimental thrombosis was induced in jugular veins, in a total of 40 rabbits by a combination of destruction of the endothelium and restricted blood flow. Group 1: placebo, gr 2: LMWH 60 anti-FXa IU/kg, gr 3-5: 0.1, 1.0 and 10.0 mg/kg TFPI1-161. TFPI1-161 reduced the thrombus weights in all treated groups, significantly in doses of 1.0 and 10.0 mg/kg compared to placebo. The frequency of thrombosis and occlusive thrombosis were also significantly reduced in those doses. The antithrombotic properties of TFPI1-161 (1.0-10.0 mg/kg) measured as thrombus weight, frequency of thrombosis and frequency of occlusive thrombosis was equivalent to the anti-thrombotic properties of LMWH. In the anti-FXa, APTT and PT-assays TFPI1-161 displayed a dose dependent increase of activity. Recombinant-TFPI1-161 did not influence the anti-FIIa-assay. No haemorrhagic side effects were noted.

Animals↗
PubMed1993

Antithrombotic properties of a truncated recombinant tissue factor pathway inhibitor in an experimental venous thrombosis model.

The aim of this study was to investigate whether a truncated recombinant tissue factor pathway inhibitor (rTFPI1-161) had an antithrombotic effect comparable to low-molecular-weight (LMW) heparin. A randomized double-dummy study was conducted with 40 rabbits in 6 groups. An experimental thrombosis was induced in the jugular veins by a combination of destroyed endothelium and restricted blood flow. Group 1 was given placebo; group 2, LMW heparin 60 anti-factor Xa units/kg; group 3, rTFPI1-161 0.1 mg/kg; group 4, rTFPI1-161 1.0 mg/kg and group 5, rTFPI1-161 10.0 mg/kg. rTFPI1-161 reduced the thrombus weights in all treated groups, with a significant effect in doses between 1.0 and 10.0 mg/kg compared to placebo. The frequency of thrombosis was significantly reduced in all treated groups. No hemorrhagic side effects were noted. In conclusion, rTFPI1-161 (1.0-10.0 mg/kg) has an antithrombotic effect comparable to that of LMW heparin.

Animals↗