Biomedical subjects

H Jacobsson

Publications and source records attributed to H Jacobsson.

At least 73 records · Page 4Linked to original sources

PubMed1997

Somatostatin in neuroblastoma and ganglioneuroma.

Neuroblastoma, a childhood tumour of the sympathetic nervous system, may in some cases differentiate to a benign ganglioneuroma or regress due to apoptosis. Somatostatin may inhibit neuroblastoma growth and induce apoptosis in vitro and was therefore investigated. Using a radioimmunoassay, we found that all ganglioneuromas contained high somatostatin concentrations (> 16 pmol/g), significantly higher than neuroblastomas (n = 117, median 2.8 pmol/g), healthy adrenals, Wilms' tumours, phaeochromocytomas and other neuroendocrine tumours (P < 0.001). Neuroblastomas contained more somatostatin than control tumours (P < 0.001-0.05). Neuroblastomas amplified for the MYCN oncogene contained less somatostatin than non-amplified tumours (1.2 pmol/g versus 4.0 pmol/g, respectively; P = 0.026). In a clinically unfavourable neuroblastoma subset (age > 12 months, stage 3 or 4) 16 children with high concentrations of somatostatin in primary tumours had a better prognosis than 23 with low somatostatin (46.7% versus 0% survival at 5 years, P < 0.005). Scintigraphy using 111In-pentetreotide identified tumours expressing high-affinity somatostatin receptors in vivo. However, no significant correlation was found between somatostatin receptor expression and peptide content in 15 tumours. Similarly, human SH-SY5Y neuroblastoma xenografts grown in nude rats showed low somatostatin concentrations, but were positive for somatostatin receptor scintigraphy. Treatment of these rats with the somatostatin analogue octreotide seemed to upregulate in vivo receptor expression of somatostatin and vasoactive intestinal peptide more effectively than 13-cis retinoic acid. In conclusion, somatostatin in neuroblastoma is associated with differentiation to benign ganglioneuromas in vivo and favourable outcome in advanced tumours. Furthermore, somatostatin receptor scintigraphy may identify tumours with high-affinity receptors in children that might benefit from targeted therapy using synthetic somatostatin analogues.

Animals↗

PubMed1997

Effect of food intake on liver and spleen volume: assessment with single photon emission computed tomography.

RATIONALE AND OBJECTIVES: The authors evaluated the influence of food intake on liver and spleen size. The rationale was that since a meal induces a marked increase in splanchnic blood flow, organ volume might also be affected. This could influence conclusions made at clinical examination. METHODS: Single photon emission computed tomography (SPECT) was performed in 20 healthy volunteers after administration of technetium-99m albumin colloid before and after ingestion of a standardized meal. A semiautomatic technique was used to determine liver and spleen size. RESULTS: There was a nonsignificant reduction in liver volume of 1.5% (P = .063) and a significant reduction in spleen volume of 3.2% (P = .00033) after food intake. CONCLUSION: Liver and spleen volume are marginally affected by food intake, and the changes are within the methodologic error of radiologic modalities.

Eating↗

PubMed1997

Gastrointestinal hormones and gastric emptying 20 years after jejunoileal bypass for massive obesity.

OBJECTIVE: Some studies have shown a more rapid gastric emptying in obese subjects. Six to twelve months after jejunoileal bypass (JIB) neurotensin (NT) and enteroglucagon have been shown to be elevated after food intake. These hormones, together with peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) have been implicated in the reduction of upper gastrointestinal motility seen after infusion of nutrients into the ileum. AIM: To study if the postprandial gut hormone pattern and gastric emptying is altered 20 y after JIB. SUBJECTS: Seven subjects operated with JIB a mean (s.d.) 20 +/- 3 y ago, with a BMI of 44 +/- 4 kg/m2 at the time of surgery and 31 +/- 4 at present. For comparison seven sex-matched non-operated obese controls (BMI 43 +/- 3) were studied. METHODS: Serial blood samples were obtained every 10 min after intake of a 280 kcal meal. Radioimmunoassays for motilin, cholecystokinin (CCK), NT, PYY and GLP-1 were performed. Gastric emptying of a solid meal was studied using a radioactively labelled omelette (of 310 kcal) for 120 min). RESULTS: After JIB postprandial motilin, CCK, NT, PYY and GLP-1 were elevated compared to non-operated obese subjects. Similarly, basal levels of CCK, motilin, GLP-1 and PYY were elevated in the operated group. No difference was observed in the rate of gastric emptying between the two groups. CONCLUSION: Both fasting and postprandial gut hormone levels are elevated 20 y after JIB. The impact of long-term rapid stimulation of the ileum and subsequent raised gut hormone levels on gastric emptying is not clear.

Cholecystokinin↗

PubMed1997

Reduced food intake after jejunoileal bypass: a possible association with prolonged gastric emptying and altered gut hormone patterns.

The object of this study was to examine whether eating behavior, food preference, gastric emptying, and gut hormone patterns are altered after jejunoileal bypass (JIB) in patients with severe obesity. Eight obese [mean (+/- SD) body mass index (BMI; in kg/m2) 42.9 +/- 4] subjects were studied prospectively before and 9 mo after JIB with eight age- and sex-matched normal-weight control subjects. Total energy intake, data from the universal eating monitor (VIKTOR), eating motivation measured by visual analog scales, a food-preference checklist, a forced-choice list, solid-phase gastric emptying, and postprandial concentrations of cholecystokinin, motilin, and neurotensin were studied. BMI was reduced by 29% after JIB. Compared with normal subjects, the JIB patients showed a reduced desire to eat, decreased hunger, and reduced prospective consumption before a test meal. After surgery, obese subjects selected fewer food items and showed a reduced preference for high-carbohydrate and high-fat items before a test meal. There was a trend from an accelerated toward a decelerated eating pattern in obese subjects after JIB. After JIB, gastric emptying of obese subjects was slowed and similar to that in control subjects. Obese subjects had lower postprandial cholecystokinin concentrations that were lower than those of control subjects both before and after JIB. Postprandial concentrations of neurotensin were higher after JIB. We conclude that after JIB, the desire to eat and preference for high-carbohydrate and high-fat items is reduced, resulting in decreased energy intake. That gastric emptying is prolonged and gut hormone patterns are altered with low postprandial plasma cholecystokinin and high neurotensin plasma concentrations may at least partly account for these observations.

Adult↗

PubMed1997

Hydration does not influence the image quality in bone scintigraphy: an investigation using 99Tcm-HDP.

We investigated the possibility that the increased diuresis caused by hydration leads to enhanced renal excretion of radiotracer and thereby increases the target-to-background activity ratio and improves the image quality in bone scintigraphy. The study was carried out using paired comparisons in 10 healthy volunteers. Whole-body antero-posterior and postero-anterior acquisitions were obtained for 4 h after the administration of 99Tcm-hydroxymethylene diphosphonate with and without hydration. The bone-to-soft tissue activity ratio was semi-quantified by comparing regions of interest acquired from geometrical means of the acquisitions. Hydration was performed by slowly drinking 1.5 litres of water after administration of the tracer. Hydration induced a slight enhancement of excretion of the activity, but it had no effect on the bone-to-soft tissue activity ratio, nor did it influence image quality. We conclude that hydration could be avoided when it is cumbersome for the patient. However, as hydration reduces the radiation dose to the urinary bladder wall, which is the critical organ, hydration should be maintained in younger patients.

Adult↗

PubMed1997

Treatment of high-grade, high-stage prostate cancer with estramustine phosphate or diethylstilbestrol. A double-blind study. The SPCG-1 Study Group. Scandinavian Prostate Cancer Group.

Between 1984 and 1989, 197 patients with T1-4, NX, M1, G2-3 or G3 prostate cancer were randomized to treatment with 560 mg estramustine phosphate (EMP, Estracyt, Emcyt) or 3 mg diethylstilbestrol (DES) per day in a double blind study with stratification on presence or absence of cancer pain at start. A total of 194 patients were evaluated for efficacy of therapy. Time to progression (p = 0.054), to treatment failure (p = 0.036), cancer-specific survival (p = 0.068) as well as overall survival (p = 0.021) were longer in the DES group. There were more patients with prognostic parameters indicating bad prognosis in the EMP group. This trial was designed to study whether EMP had better effect than DES as the primary treatment of high-grade, disseminated prostate cancer. The results did not confirm this hypothesis. On the contrary, treatment with DES had relatively good effect on this very aggressive form of prostate cancer.

Antineoplastic Agents, Hormonal↗

PubMed1997

Comparison of technetium-99m-MIBI and technetium-99m-tetrofosmin uptake by musculoskeletal sarcomas.

UNLABELLED: Technetium-99m-MIBI was initially developed for heart studies but it can also be used to depict tumors, predict multidrug resistance and evaluate chemotherapy. Recently, 99mTc-tetrofosmin, which exhibits similar physical properties, has been launched for heart studies. Tumor uptake and prediction of multidrug resistance have also been reported regarding the latter tracer. A comparison of these two tracers regarding the detectability of musculoskeletal sarcoma has been made. METHODS: Twenty patients with musculoskeletal sarcoma of the extremities or pelvis underwent planar examination after the administration of 99mTc-MIBI and 99mTc-tetrofosmin with an interval of 2-7 days. The tumor activity was compared with one ipsilateral and one contralateral background region. RESULTS: There was a small, but not significant, difference in favor of 99mTc-MIBI with regard to both background regions. CONCLUSION: Technetium-99m-MIBI and 99mTc-tetrofosmin can both be used to visualize musculoskeletal sarcomas. The choice may depend on which agent is used routinely for myocardial studies in the laboratory.

Adolescent↗

PubMed1997

Detection of extrathoracic manifestations in sarcoidosis with somatostatin analogue scintigraphy.

BACKGROUND AND AIM OF WORK: Scintigraphy using a long lived radiolabelled somatostatin analogue [111In-DTPA-D-Phe1]-octreotide (OctreoScan) has previously been shown to be useful in the detection and management of neuroendocrine tumours, as well as in the imaging of various other malignant tumours. It was recently reported that the radiopharmaceutical accumulates also in the granulomatous lesions in Wegener's disease and in sarcoidosis. The present study was undertaken in order to evaluate the usefulness of the technique in detection of extrathoracic manifestations. METHODS: OctreoScan scintigraphy was performed in 5 patients with biopsy-proven sarcoidosis. A patient with a familial history of multiple endocrine neoplasia served as control. RESULTS: In 4/5 patients previously unknown granulomas were registered, and in the remaining subject the findings at the physical examination were confirmed. CONCLUSIONS: We conclude that somatostatin analogue scintigraphy may be helpful in finding extrathoracic granulomatous lesions in sarcoidosis, thus providing good prerequisites for focused biopsy attempts.

Adult↗

PubMed1996

[MIBI-scintigraphy. A simple and reliable method for localization of pathological parathyroid glands].

99Tcm-sestamibi scintigraphy was used to localise enlarged parathyroid glands in 25 patients with primary hyperparathyroidism previously operated in the neck, 20 of whom had recurrent disease and five had previously undergone surgery for thyroid disorders. Of the 18 patients for whom positive scans were obtained, nine were operated on the scan findings being confirmed. Crucial information was provided in two cases of intrathyroidal and one case of intramediastinal localisation of the pathological gland were not operated on as the hypercalcaemia was only marginal or the symptoms were vague. Though preoperative localisation of pathological parathyroid glands is a prerequisite for neck exploration in patients with persistent or recurrent hypercalcaemia due to primary (or secondary) hyperparathyroidism, the procedure is not cost-effective before the initial operation.

Adult↗

PubMed1996

Gastric emptying of solids in humans: improved evaluation by Kaplan-Meier plots, with special reference to obesity and gender.

It has been suggested that obesity is associated with an altered rate of gastric emptying, and that there are also sex differences in gastric emptying. The results of earlier studies examining gastric emptying rates in obesity and in males and females have proved inconsistent. The aim of this study was to investigate the influence of obesity and gender on gastric emptying, by extending conventional evaluation methods with Kaplan-Meier plots, in order to assess whether these factors have to be accounted for when interpreting results of scintigraphic gastric emptying tests. Twenty-one normal-weight volunteers and nine obese subjects were fed a standardised technetium-99m labelled albumin omelette. Imaging data were acquired at 5- and 10-min intervals in both posterior and anterior projections with the subjects in the sitting position. The half-emptying time, analysed by Kaplan-Meier plot (log-rank test), were shorter in obese subjects compared to normal-weight subjects and later in females compared to males. Also, the lag-phase and half-emptying time were shorter in obese females than in normal females. This study shows an association between different gastric emptying rates and obesity and gender. Therefore, body mass index and gender have to be accounted for when interpreting results of scintigraphic gastric emptying studies.

Adult↗

PubMed1996

Accumulation of 99mTc-MIBI in bone marrow.

99mTc-MIBI (Sestamibi) was originally developed for myocardial perfusion studies. The agent also may be used for the depiction and characterization of tumors. Performing such examinations has shown uptake in skeletal structures in several patients suggesting bone engagement of the disease which later was excluded. Retrospective evaluation of 44 examinations with 99mTc-MIBI performed in order to localize diseased parathyroid in patients with suspected hyperparathyroidism showed skeletal activity in 21 (48%) patients. Although these patients represent a selected group, the observation indicates a mechanism for skeletal accumulation of this radiopharmaceutical. Evaluation of another 13 normocalcemic patients undergoing whole-body registration for malignancy staging or to assess lower extremity ischemia with 99mTc-MIBI showed skeletal activity in 6 (46%) patients. Complementary mouse experiments confirmed skeletal uptake of 99mTc-MIBI, where most of the activity is taken up by the red bone marrow. It is concluded that homogeneous, diffuse weak skeletal activity at examination with 99mTc-MIBI is a normal finding and does not indicate malignancy.

Adult↗

PubMed1996

Diagnosing sternal wound infections with 99mTc-labeled monoclonal granulocyte antibody scintigraphy.

BACKGROUND: Postoperative mediastinitis is a serious complication of thoracic operations. The diagnosis can sometimes be difficult, especially in cases with subacute clinical presentation. The aim of this study was to assess the clinical use of granulocyte scintigraphy and tomography in the diagnosis of postoperative wound infection and mediastinitis. METHODS: Twenty-nine patients after cardiothoracic operations were included, of whom 5 patients with a normal postoperative course formed the control group. We injected technetium 99m-monoclonal antigranulocyte antibodies and performed single-photon emission computed tomography after 4 and 20 hours. RESULTS: Twenty-three patients had both the early and the later scan; the remaining 6 had only the early scan. Seven scans indicated infection: 3 cases of mediastinitis, 2 cases of superficial wound infection, 1 case of infection in a synthetic aortic graft, and 1 case of osteitis. All were verified by bacterial culture. There was one false-negative scan; this patient had only the early registration and then was explored. CONCLUSIONS: This method when combined with the tomographic scan option is able to distinguish between deep and superficial infections. Two registrations must be made for optimal results.

Adult↗

PubMed1996

Sweat glands accumulate Tc-99m MIBI.

Tc-99m MIBI, which was originally developed for myocardial perfusion studies, may also be used for depiction and characterization of tumors. Forty-one patients with suspected hyperparathyroidism were examined with Tc-99m MIBI to localize a parathyroid adenoma or hyperplasia. In 19 of these patients (46%), bilateral symmetrical activity corresponding to the large deep apocrine sweat glands of the axillae was present. Sweat gland activity was not correlated with serum calcium levels. Although these patients may represent a selected group, the observation is clinically relevant regardless of its reason or mechanism. It is important also to be aware of this cause for activity in the axilla when assessing lymph node involvement in breast cancer patients using Tc-99m MIBI.

Adenoma↗

PubMed1996

MR imaging, CT and CEA scintigraphy in the diagnosis of local recurrence of rectal carcinoma.

PURPOSE: To compare advanced imaging techniques in the diagnosis of recurrent rectal cancer. MATERIAL AND METHODS: Twenty-five consecutive patients with either suspected or verified recurrence were examined by CT (n = 25), MR with phased-array capabilities (n = 24) and CEA scintigraphy (n = 16). Three experienced radiologists (who were blinded to results obtained at surgery and histopathology) independently evaluated the films, one observer for each modality. RESULTS: The MR radiologist arrived at a correct diagnosis in 87.5% of the examinations, the CT radiologist in 76% and the CEA radiologist in 75%. The MR radiologist's results correlated more often with reported pathology than did those of the CT radiologist with regard to the relation of recurrent tumor to surrounding structures in the pelvis. CONCLUSION: MR imaging is the most effective of the 3 modalities in the diagnosis of recurrent rectal cancer.

Aged↗

PubMed1996

Activity in the gastrointestinal tract after administration of bone-seeking radiopharmaceuticals. Experimental studies in mice.

PURPOSE: To test the possibility that (radio)activity of non-pertechnetate nature is excreted into the gastrointestinal tract at bone scintigraphy. MATERIAL AND METHODS: The distribution of a bone-seeking radiopharmaceutical (99mTc-HDP) was studied in an experimental mouse system by dissecting different organs and assessing their activity with a gamma-counter. RESULTS: A comparison of the activity of the submandibular glands, which are assumed to accumulate only pertechnetate, and the gastrointestinal tract showed that a significant fraction of the activity excreted into the gastrointestinal tract did not consist of pertechnetate. Part of the excretion took place in the stomach. It was not connected to a specific bone-seeking agent or 99Mo/99mTc generator. Nor did it increase with time between make-up and injection. The excretion of the non-pertechnetate activity was reduced by cimetidine and omeprazole. These gastric-secretion blocking drugs did not reduce excretion of pertechnetate or significantly affect the general distribution of the radiopharmaceutical. CONCLUSION: There is a significant excretion of non-pertechnetate activity in the gastrointestinal tract. Part of this may be caused by excretion of the undegraded radiopharmaceutical by the stomach mucosa.

Animals↗

PubMed1996

Comparison between scintigraphy with polyclonal immunoglobulin (99Tcm-HIG) and physical examination in polyarthritic disease.

99Tcm-labelled polyclonal human immunoglobulin 99Tcm-HIG scintigraphy has been suggested as a technique to detect joint inflammation in arthritic disorders. Scintigraphy was performed in fifteen patients with active polyarthritis. All joints except the hips were scored clinically for swelling and pain by a rheumatologist and scintigraphic images were obtained at 30 minutes and four hours after injection of 350MBq 99Tcm-HIG. The images were assessed by a nuclear medicine physician according to a four grade scale. The images were easy to assess. There was a highly significant correlation between swelling and scan score, but no correlation between pain and scan score. The mechanism for the accumulation of activity to inflamed synovial tissue remains unclear. The mean values of the scan score however increased significantly between 30 minutes and 4 hours, indicating an active binding mechanism. The method has a potential as an objective tool in monitoring rheumatic diseases.

Adult↗

PubMed1996

Collimator design for improved spatial resolution in SPECT and planar scintigraphy.

UNLABELLED: This paper evaluates the design of a new planar-concave collimator with nonuniform response that better matches the body shape than conventional collimators. METHODS: The collimator properties are evaluated and assessed by means of both a stimulation program and an experimental test using a prototype planar-concave collimator. RESULTS: The results, for points located 150 mm from the axis of rotation, demonstrate that the ratio of radial and tangential spatial resolution in SPECT with the new collimator decreased by 40%, as compared to SPECT with a standard collimator. In planar scintigraphy, the spatial resolution improved correspondingly from 10.9 mm (FWHM) to 7.8 mm in lateral areas of the body. CONCLUSION: The new collimator reduces nonisotropic blurring in SPECT in addition to improving spatial resolution in both planar scintigraphy and in SPECT.

Aged↗

PubMed1995

Preoperative gastric emptying. Effects of anxiety and oral carbohydrate administration.

BACKGROUND: Overnight fasting is routine before elective surgery. This may not be the optimal way to prepare for surgical stress, however, because intravenous carbohydrate supplementation instead of fasting has recently been shown to reduce postoperative insulin resistance. In the current study, gastric emptying of a carbohydrate-rich drink was investigated before elective surgery and in a control situation. METHODS: Twelve patients scheduled for elective surgery were randomly given 400 mL of either a carbohydrate-rich drink (285 mOsm/kg, 12.0% carbohydrates, n = 6) or water 4 hours before being anesthetized. Gastric emptying was measured (gamma camera, 99Tcm). Each patient repeated the protocol postoperatively as a control. All values were presented as the mean +/- SEM by means of a nonparametric statistical evaluation. RESULTS: Despite the increased anxiety experienced by patients before surgery (p < 0.005), gastric emptying did not differ between the experimental and control situations. Initially, water emptied more rapidly than carbohydrate. However, after 90 minutes, the stomach was emptied regardless of the solution administered (3.2 +/- 1.1% [mean +/- SEM] remaining in the stomach in the carbohydrate group versus 2.3 +/- 1.2% remaining in the stomach in the water group). CONCLUSIONS: Preoperative anxiety does not prolong gastric emptying. The stomach had been emptied 90 minutes after ingestion of both the carbohydrate-rick drink and water, thereby indicating the possibility of allowing an intake of iso-osmolar carbohydrate-rich fluids before surgery.

Adult↗