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Liselotte Højgaard

Publications and source records attributed to Liselotte Højgaard.

At least 19 recordsLinked to original sources

Self-reported fatigue common among optimally treated HIV patients: no correlation with cerebral FDG-PET scanning abnormalities.

OBJECTIVE: It was the aim of this study to determine the prevalence and severity of fatigue among optimally treated HIV patients and to investigate the potential association with systemic inflammation and abnormalities of the distribution of cerebral glucose metabolism. METHODS: A cohort of HIV patients (n = 95), known to be HIV positive for 5 years, on anti-retroviral therapy for a minimum of 3 years and with CD4 counts above 0.2 x 10(9) cells/l, completed a validated fatigue inventory, and plasma was analysed for pro-inflammatory markers including tumour necrosis factor-alpha, interleukin 6 and soluble urokinase receptor (suPAR) levels. The distribution of the regional cerebral metabolic rate of glucose was measured in a sub-group of patients suffering from severe fatigue (n = 9) and a group with no fatigue (n = 7) using fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) scanning. RESULTS: Fifteen percent suffered from severe fatigue, but no association with pro-inflammatory markers was found. About 50% of the FDG-PET-scanned patients showed minor abnormalities in the relative cerebral metabolic rate of glucose. These abnormalities were not associated with fatigue but tended to correlate with a short HIV history (p = 0.058), a low CD4 nadir (p = 0.082) and elevated tumour necrosis factor-alpha levels (p = 0.074). CONCLUSION: Fatigue is common among optimally treated HIV patients. FDG-PET-described signs of imminent neurodegeneration among HIV patients who had a low CD4 nadir may illustrate an aspect of HIV neuropathogenicity.

AIDS Dementia Complex↗

How few cancer cells can be detected by positron emission tomography? A frequent question addressed by an in vitro study.

PURPOSE: Positron emission tomography (PET) has gained widespread use in cancer diagnosis and treatment, but how many malignant cells are required for a tumour to be detected by PET? METHODS: Three human cancer cell lines [glioblastoma and two subtypes of small cell lung cancer (SCLC)] in concentrations from 10(4) to 10(7) were seeded on six-well plates or plastic tubes and treated with [(18)F]fluorodeoxy-glucose (FDG) in vitro. FDG retention was measured in a PET/CT scanner and in a calibrated well counter. The clinical situation was simulated using a cylinder phantom with a background concentration of FDG. RESULTS: The theoretical detection limit was found to be around 10(5) malignant cells. In a cylinder phantom the detection limit was increased by a factor of 10. The FDG retention by the glioblastoma cell line was significantly higher than the activity of the SCLC cell line. FDG retention measured by PET and a gamma counter was closely correlated to the number of cells and a linear relationship was found. DISCUSSION: The detection limit of PET is in the magnitude of 10(5) to 10(6) malignant cells. The experimental set-up was robust and well suited as a platform for further investigations of factors influencing the detection limit of PET.

Carcinoma, Small Cell↗

[The importance of centralized treatment: research and development].

Biomedical research in Denmark enjoys a strong position at present but will be challenged by a new organization for all hospitals in Denmark beginning in 2007. It will be very important to recognize the importance of medical research as the cornerstone of optimal patient treatment in the new hospital organizations. Centralization with a focus on efficiency and low cost, as well as decentralization combined with the loss of university hospital functions, will further challenge the conditions of clinical research already seen worldwide and also experienced in Denmark.

Biomedical Research↗

[Centralised diagnostic].

Diagnostic examinations with complicated and expensive equipment should be centralised in departments of radiology, clinical physiology and nuclear medicine, clinical biochemistry etc. For the future reorganisation of hospitals in Denmark, focus on centralisation in larger university hospitals is recommended with close collaboration between diagnostic specialities and clinical specialities, and with research and advanced competence as main assets.

Centralized Hospital Services↗

[New research councils in Denmark and the European Union].

Research is on the political agenda in Denmark and the other EU countries. In January 2004, a new structure for the Danish Research Council was launched, including the Danish Councils for Independent Research and the the Danish Council for Strategic Research. The Danish Political Research Council gives independent advice to the government and the Parliament. ESFRI, the European Strategy Forum on Research Infrastructure, is an organisation giving advice to the European Union on questions of research infrastructure. Also in Denmark, a research infrastructure programme has been initiated. For researchers it is important to be informed about the research council structures in order to be able to secure optimal research funding.

Denmark↗

Increased fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) uptake in childhood CNS tumors is correlated with malignancy grade: a study with FDG positron emission tomography/magnetic resonance imaging coregistration and image fusion.

PURPOSE Positron emission tomography (PET) has been used in grading of CNS tumors in adults, whereas studies of children have been limited. PATIENTS AND METHODS Nineteen boys and 19 girls (median age, 8 years) with primary CNS tumors were studied prospectively by fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) PET with (n = 16) or without (n = 22) H(2)(15)O-PET before therapy. Image processing included coregistration to magnetic resonance imaging (MRI) in all patients. The FDG uptake in tumors was semiquantitatively calculated by a region-of-interest-based tumor hotspot/brain index. Eight tumors without histologic confirmation were classified as WHO grade 1 based on location, MRI, and clinical course (22 to 42 months). Results Four grade 4 tumors had a mean index of 4.27 +/- 0.5, four grade 3 tumors had a mean index of 2.47 +/- 1.07, 10 grade 2 tumors had a mean index of 1.34 +/- 0.73, and eight of 12 grade 1 tumors had a mean index of -0.31 +/- 0.59. Eight patients with no histologic confirmation had a mean index of 1.04. For these 34 tumors, FDG uptake was positively correlated with malignancy grading (n = 34; r = 0.72; P < .01), as for the 26 histologically classified tumors (n = 26; r = 0.89; P < .01). The choroid plexus papilloma (n = 1) and the pilocytic astrocytomas (n = 3) had a mean index of 3.26 (n = 38; r = 0.57; P < .01). H(2)(15)O-uptake showed no correlation with malignancy. Digitally performed PET/MRI coregistration increased information on tumor characterization in 90% of cases. CONCLUSION FDG PET of the brain with MRI coregistration can be used to obtain a more specific diagnosis with respect to malignancy grading. Improved PET/MRI imaging of the benign hypermetabolic tumors is needed to optimize clinical use.

Adolescent↗

The importance of dietary composition for efficacy of iron absorption measured in a whole diet that includes rye bread fortified with ferrous fumerate: a radioisotope study in young women.

Fe absorption is affected by many dietary factors. The objective of the present study was to measure the effects of high v. low content of vitamin C, meat and phytic acid in whole diets with Fe-fortified bread on the efficacy of Fe absorption. Thirty-two healthy women with low Fe stores were randomised to three groups, each of which was given two of six test diets containing either low/high amounts of vitamin C, meat or phytic acid, respectively, in a cross-over design. Each diet was served throughout a 5 d period. Fe-fortified rye bread, extrinsically labelled with (59)Fe, was given with all main meals. Fe absorption was determined from whole-body counter measurements of (59)Fe retention. The fractional non-haem Fe absorption (corrected to a 40 % standard absorption by measurements from the reference dose) was 1.9 % v. 3.4 % (P=0.04) for the low/high vitamin C diets, 3.0 % v. 3.5 % (P=0.58) on the low/high meat diets and 4.9 % v. 3.8 % (P=0.24) on the low/high phytic acid diet, respectively. The total Fe absorbed (geometric mean with standard error) varied from 0.43 (se 0.11) mg from the diet with lowest bioavailability to 1.09 (se 0.18) mg from the diet with highest bioavailability (P<0.001). The present whole-diet study indicates that diet composition is a strong predictor of Fe absorption. In the diet with a low content of enhancers and a high content of inhibitors, vitamin C improved non-haem Fe absorption. The total Fe absorption varied 2.5-fold after small alterations of the content of enhancers and inhibitors in the diet.

Absorption↗

Early clinical experience and impact of 18F-FDG PET.

PURPOSE: To determine the influence and impact of [F]- fluorodeoxyglucose positron emission tomography (FDG PET) in Denmark. METHODS: A standardized questionnaire was sent to the referring physicians of 743 consecutive cases between January 2000 and December 2001. The questionnaire was designed to determine whether and how the results of the FDG PET imaging changed patient management. RESULTS: The response rate was 71% (524 responded). The distribution of all responding physicians included 26 different specialities. The majority were from haematology (23%), oncology (20%), plastic surgery (17%) and neurology (10%). The primary diagnoses at referral was in the field of oncology (94%), with lymphoma (24%), melanomas (20%), unknown primary neoplasms (13%), nervous system neoplasms (9%), lung cancer (6%) and cancer of the digestive system (4%). FDG PET imaging resulted in a change in the patients' management in 224 cases (43%). Of these, surgery was affected in 88 cases. Chemotherapy was affected in 71 cases and radiation therapy in 54 cases. In patients where the intended plan of management was not changed, 78% of the physicians stated that FDG PET was nevertheless clinically helpful; for example confirmed the diagnosis, helped staging, changed treatment plan or confirmed treatment of choice. Physicians indicated a general satisfaction with FDG PET imaging in 86% of the cases. CONCLUSION: This survey-based study indicates that FDG PET imaging has a major impact on patient management, contributing to changes in management in 43% of cases. The present study also demonstrates that referring physicians are generally satisfied with FDG PET imaging in 86% of the cases.

Data Collection↗

Fever of unknown origin: prospective comparison of diagnostic value of 18F-FDG PET and 111In-granulocyte scintigraphy.

The diagnostic work-up in patients with fever of unknown origin (FUO) is often challenging and frequently includes nuclear medicine procedures. Whereas a role for leucocyte or granulocyte scintigraphy in FUO is generally accepted, a possible role of fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in these patients remains to be established. To study this, we compared prospectively, on a head-to-head basis, the diagnostic value of FDG-PET and indium-111 granulocyte scintigraphy in patients with FUO. Nineteen patients with FUO underwent both FDG-PET and (111)In-granulocyte scintigraphy within 1 week. FDG-PET scans and granulocyte scintigrams were reviewed by different doctors who were blinded to the result of the other investigation. The diagnostic values of FDG-PET and granulocyte scintigraphy were evaluated with regard to identification of a focal infectious/inflammatory or malignant cause of FUO. The sensitivity of granulocyte scintigraphy and FDG-PET were 71% [95% confidence interval (CI): 37-85%] and 50% (CI: 16-84%), respectively. The specificity of granulocyte scintigraphy was 92% (71-100%), which was significantly higher than that of FDG-PET, at 46% (34-62%). Positive and negative predictive values for granulocyte scintigraphy were both 85%. Positive and negative predictive values for FDG-PET were 30% and 67%, respectively. (111)In-granulocyte scintigraphy has a superior diagnostic performance compared to FDG-PET for detection of a localised infectious/inflammatory or neoplastic cause of FUO. The poorer performance of FDG-PET is in particular attributable to a high percentage of false positive scans, leading to low specificity.

Adult↗

Calcium from milk or calcium-fortified foods does not inhibit nonheme-iron absorption from a whole diet consumed over a 4-d period.

BACKGROUND: Single-meal studies have indicated that calcium inhibits iron absorption in humans. However, numerous dietary factors influence iron absorption, and the effect of calcium may not be as pronounced when calcium is served as part of a whole diet. OBJECTIVE: We investigated the effect of 3 sources of calcium served with the 3 main meals on nonheme-iron absorption from a 4-d diet. DESIGN: (59)Fe absorption was estimated from whole-body retention measurements in 14 women aged 21-34 y, each of whom consumed four 4-d diets in a randomized crossover design. The diets differed in the source of calcium as follows: a basic diet (BD) with a low content of calcium (224 mg Ca/d), a BD with a glass of milk served at each meal (826 mg Ca/d), a BD with calcium lactate (802 mg Ca/d), and a BD with a milk mineral isolate containing calcium (801 mg Ca/d). The 2 latter calcium sources were added to selected foods of the BD (rye bread, white bread, chocolate cake, and orange juice), and these foods were consumed with the 3 meals. All diets provided 13.2 mg Fe/d. RESULTS: No significant differences in nonheme-iron absorption were found between the BD and the BD supplemented with milk, calcium lactate, or the milk mineral isolate [7.4% (95% CI: 5.3%, 10.5%), 5.2% (3.5%, 7.9%), 6.7% (5.0%, 8.9%), and 5.1% (3.2%, 7.9%), respectively; P = 0.34]. CONCLUSION: Consumption of a glass of milk with the 3 main meals or of an equivalent amount of calcium from fortified foods does not decrease nonheme-iron absorption from a 4-d diet.

Adult↗

Practical use and implementation of PET in children in a hospital PET centre.

Children are not just small adults-they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine.

Adolescent↗