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Biomedical subjects

K Bergström

Publications and source records attributed to K Bergström.

At least 109 records · Page 6Linked to original sources
PubMed1988

Malignant prolactinoma with multiple intracranial metastases studied with positron emission tomography.

A rare case of a patient with multiple intracranial metastases from a prolactin-secreting pituitary neoplasm is described. At the age of 14 years, the patient had been operated on for a sellar tumor; he presented 12 years later with severe headache, at which time computed tomographic and magnetic resonance imaging scans revealed multiple intracranial metastases. Histopathology examination showed pituitary neoplastic cells with positive immunostaining for prolactin. The patient was investigated with positron emission tomography (PET) and dopamine D2-receptor binding, and the amino acid metabolism of the tumor was characterized in vivo. High dopamine D2-receptor binding and high amino acid metabolism were found in the tumor. The patient was subsequently treated with bromocriptine injections that resulted in a decrease in serum prolactin levels, decreased dopamine D2-receptor binding, reduced amino acid metabolism, and a reduction in tumor volume. This case demonstrates a beneficial effect of bromocriptine treatment in a patient with prolactinoma with multiple intracranial metastases. It also illustrates the great potential of PET in the in vivo characterization of the D2-binding and the high sensitivity of 11C-labeled L-methionine in the follow-up of treatment in patients with pituitary adenomas.

Adenoma↗
PubMed1987

Granulocyte elastase-alpha 1-antiproteinase complex in cystic fibrosis: sensitive plasma assay for monitoring pulmonary infections.

Elastase in plasma was determined as a complex of granulocyte elastase and alpha 1-antiproteinase (GEC) by an enzyme-linked immunosorbent assay in 67 patients with cystic fibrosis. The patients were observed for 1 years, when clinically infected and noninfected. Although noninfected patients had GEC levels within the normal range, the mean value was significantly higher than the mean values in patients in an optimal noninfectious state (P less than 0.01) and in healthy controls (P less than 0.001). Clinical signs of (in most cases) low-grade infection were paralleled by significant increases in GEC levels (P less than 0.001). There was no correlation with different types of bacteria or age of patients. No cross reaction to Pseudomonas elastase could be found in vitro or in vivo. Significant decreases of GEC values were seen after intravenously administered antimicrobial therapy (P less than 0.001), and although the white blood cell count and erythrocyte sedimentation rate were rarely increased above the normal range, they decreased congruently (P less than 0.001), and lung function improved (P less than 0.001). The sensitivity of GEC was significantly higher than that for erythrocyte sedimentation rate (P less than 0.01) and white blood cell count (P less than 0.05). Determination of GEC values seems to be a simple and sensitive measurement for monitoring treatment in cystic fibrosis, especially of low-grade infections in patients with normal standard blood tests.

Adolescent↗
PubMed1987

In vivo evaluation of striatal dopamine reuptake sites using 11C-nomifensine and positron emission tomography.

In vitro nomifensine demonstrates high affinity and specificity for dopamine reuptake sites in the brain. In the present study 11C-nomifensine was administered i.v. in trace amounts (10-50 micrograms) to ketamine anaesthetized Rhesus monkeys (6-10 kg b.w.) and the time-course of radioactivity within different brain regions was measured by positron emission tomography (PET). Six base-line experiments lasting for 60-80 min were performed. The procedure was repeated after pretreatment with nomifensine (2-6 mg/kg i.v.), another reuptake inhibitor, mazindol (0.3 mg/kg i.v.), desipramine (0.5 mg/kg i.v) or spiperone (0.3 mg/kg i.v.) before the administration of a second 11C-nomifensine dose. The highest radioactivity uptake was found in the dopamine innervated striatum and the lowest in a region containing the cerebellum, known to be almost devoid of dopaminergic neurons. The difference between striatal and cerebellar uptake of 11C-nomifensine derived radioactivity was markedly reduced after nomifensine and mazindol but not after desipramine and spiperone. These results indicate that in vivo the striatal uptake of 11C-nomifensine, as measured with PET, involves specific binding with the dopamine reuptake sites. In the first human applications of 11C-nomifensine and PET in a healthy volunteer, the regional uptake of radioactivity was similar to that in base-line experiments with Rhesus monkeys. In the healthy subject the striatal/cerebellar ratio was 1.6, 50 min after the injection of 11C-nomifensine. In a hemi-parkinsonian patient this ratio was 1.1 contralaterally and 1.3 ipsilaterally to the affected side. 11C-nomifensine and PET seems to be an auspicious method to measure the striatal dopaminergic nerve terminals of man in vivo.

Aged↗
PubMed1987

Magnetic resonance images related to clinical outcome after psychosurgical intervention in severe anxiety disorder.

Postoperative verification of radiosurgical lesions in white matter has been difficult to obtain with CT. With magnetic resonance (MR) imaging, however, lesions could be demonstrated in patients undergoing a psychosurgical procedure, gamma capsulotomy, for anxiety disorder. The appearance and location of the lesions were related to the irradiation dose and to the long-term clinical outcome studied prospectively by two independent evaluators who had not been involved in the selection or the treatment of the patients. Seven consecutive cases were examined. CT was also included for comparison reasons. Lesions were clearly visible with MR in patients who improved after surgery. Conversely, lesions were inadequate in cases who did not benefit. MR proved to be more accurate than CT both in detecting the lesions and in defining their configuration. The observations argue for the use of MR for post-operative verification of radiosurgical lesions. MR may facilitate the determination of a clinically effective radiation threshold estimate for radiosurgical lesions, which should be of value for the planning of studies of this type of limbic system surgery.

Adult↗
PubMed1987

Transsphenoidal therapeutic puncture of a cystic pituitary adenoma.

Transsphenoidal diagnostic puncture of skull base tumours has been a routine procedure in Uppsala for a decade. Bromocriptine is the treatment of choice for patients with prolactin secreting pituitary adenomas. Here we report on a patient with a pituitary adenoma who instead developed an increase in tumour size after bromocriptine treatment. Magnetic resonance imaging showed the tumor to be cystic. A transsphenoidal puncture was used therapeutically instead of surgery with excellent result.

Adenoma↗
PubMed1987

Positron emission tomography: an animal model of spinal distribution of drugs after intrathecal administration.

An animal model has been developed in the Rhesus monkey for noninvasive monitoring of CSF transport of drugs by external detectors i.e. positron emission tomography. The model compromises the cannulation of the subarachnoid space (with a spinal needle), and has been used without any damage to the monkey. With the method it was shown that injection rate had a major influence on the transport rate of 68GaCl3 in the CSF. Injection of 0.5 ml over 60 sec gave the highest radioactivity near the injection site, whereas an injection rate of this volume over 10 sec resulted in high radioactivity more rostrally shortly after injection. This method have been of value for the determination of drug kinetics after spinal administration.

Animals↗
PubMed1987

Cerebral damage during open-heart surgery. Clinical, psychometric, biochemical and CT data.

The incidence and extent of cerebral damage following open-heart surgery were prospectively investigated in 103 patients, using clinical assessment, psychometry, adenylate kinase analysis in cerebrospinal fluid (CSF-AK) and computed tomography (CT) of the brain. The surgical mortality was 1.9%. Clinically there was obvious cerebral dysfunction in four cases, subtle evidence of brain damage (mainly undue fatigue) in 16 and no evidence in 81 cases. In the 16 patients the mean CSF-AK was substantially increased (0.122 U/l) and the psychometric performance distinctly impaired (-12 points) postoperatively; in the 81 patients the figures were 0.55 U/l and -3.4. Psychometrically, 60% of the patients showed cerebral dysfunction, which was pronounced in 16%. CSF-AK analysis indicated cerebral damage as absent or trival in 45%, moderate in 33% and marked in 22%. CT revealed postoperative cerebral infarction in two cases. Results from the various methods showed reasonable correlation, but also considerable overlap. Open-heart surgery thus can cause brain damage additional to that neurologically discernible. Fatigue is an important sign in this context. In research on postoperative brain damage, the relative insensitivity of routine neurologic investigation calls for supplementary, refined methods.

Adenylate Kinase↗
PubMed1986

Distribution of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in experimental animals studied by postiron emission tomography and whole body autoradiography.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a selective potent neurotoxin which has induced a syndrome similar to parkinsonism both in man and in monkeys. At autopsy degeneration of pigmented nerve cells in the pars compacta of the substantia nigra has been confirmed. The regional distribution of intravenously administered 1-(11C-methyl)-4-phenyl-1,2,3,6-tetrahydropyridine (11C-MPTP) in the brain of Rhesus monkeys was studied by positron emission tomography and the whole body distribution in mice was documented by autoradiography and by impulse counting of selected tissues. A very rapid and high uptake of 11C-MPTP derived radioactivity was seen in areas corresponding to striatum and midbrain, including the substantia nigra area. No elimination from these regions was seen during the study period of 2 h. The uptake was in the order of 7-8 times the homogenous distribution of the radioactivity in the monkey. The uptake was generally high also in other regions of the brain, but there some elimination could be distinguished. Pretreatment of the monkey with spiperone, a selective dopamine receptor antagonist, did not alter uptake nor the kinetics of the 11C-MPTP derived radioactivity. Thus 11C-MPTP does not have a high affinity for postsynaptic dopamine receptors. A remarkably high uptake of 11C-MPTP derived radioactivity was seen in the eye of the monkey. The selective uptake of radioactivity in the eye was also confirmed in pigmented but not in albino mice. The melanin affinity of MPTP may cause high intracellular concentrations of the compound or its metabolites in the melanin containing nerve cells in substantia nigra, which may explain the serious vulnerability of these neurons to MPTP.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1986

Carbohydrates--purity assessment.

In this brief review a superficial introduction is given to the important area of biologically active carbohydrates. The complexity of carbohydrate chemistry is considered and the possible uses of carbohydrates as drugs and diagnostic agents are outlined. The analytical tools and methods that are especially useful for purity assessment of carbohydrates are examined with particular emphasis on liquid chromatography.

Journal Article↗
PubMed1986

Influence of plasma components on luminol-enhanced chemiluminescence from peripheral granulocytes in juvenile periodontitis.

The generation rate of free oxygen radicals as measured by maximal light intensity of luminol-enhanced chemiluminescence from peripheral blood granulocytes (PMN) stimulated with differently opsonized Staphylococcus aureus was studied in 13 patients with juvenile periodontitis (JP) and pair-matched, healthy controls. Plasma proteins related to inflammation were also assayed. When stimulated with bacteria opsonized with autologous serum, the PMN from the JP patients showed a more intensive chemiluminescence than did their pair-matched controls (p less than or equal to 0.0005). The difference was consistent but slightly reduced when using heat-treated serum (p less than or equal to 0.006) or heterologous gammaglobulin (p less than or equal to 0.19) for opsonization. When testing freeze preserved sera from 11 of the compared pairs, the sera from JP patients induced a slightly higher chemiluminescence in PMN from a healthy donor (p less than or equal to 0.031). Protein analysis of the patient sera revealed a slightly higher concentration of complement 4 (p less than or equal to 0.032) and IgM (p less than or equal to 0.030) when compared with their respective pair-matched healthy controls. The influence of other blood components contaminating our assay system was checked on healthy PMN cells. Lymphocytes, platelets, relevant amounts of ADP and serum had no effect on the chemiluminescence. In conclusion, the increased chemiluminescence of peripheral blood granulocytes from patients with juvenile periodontitis seems to be related mainly to the cells. The association with free oxygen radicals and their tissue-damaging potency might be a contributing factor in the pathogenesis of periodontal disease.

Adolescent↗
PubMed1986

Tumour delineation with magnetic resonance imaging in gliomas. A comparison with positron emission tomography and computed tomography.

In ten patients with histopathologically confirmed low-grade (n = 4) and high-grade (n = 6) cerebral gliomas, the ability of magnetic resonance imaging (MRI) to delineate these tumours was examined. Spin echo (SE) technique with dual and multiple echoes and subtraction of images recorded with multiple echo sequences was applied. Computed tomography (CT) and positron emission tomography (PET) with 11C-L-methionine were used as reference methods. In high-grade gliomas multiple echo sequences and subtractions delineated the tumours better than ordinary SE sequences and equally well as CT, but slightly less well than PET. In low-grade tumours, the tumour delineation was better than with CT and comparable to that obtained with the present PET method. Multiple echo sequences and subtraction increase the reliability of MRI in delineating cerebral gliomas as compared with standard SE sequences.

Adolescent↗
PubMed1986

Magnetic resonance imaging of tumours of the sellar region. Evaluation of treatment with bromocriptine retard.

Magnetic resonance imaging (MRI) with a superconductive 0.5 T magnet has been used in 10 patients with pituitary adenomas to evaluate the effect of bromocriptine treatment. Seven patients had prolactinomas, one a growth hormone (GH) producing adenoma and two patients null cell adenomas with slight hyperprolactinaemia. A single dose of 50 mg bromocriptine was given intramuscularly in a slow release preparation, followed after 6 weeks by 5 mg/day orally. Significant reduction of serum prolactin was noticed in all patients. Visual field defects disappeared rapidly. In all prolactinoma patients and in the patient with the GH producing adenoma MRI showed a decrease in tumour size. In 5 of these 8 patients MR signal analysis, aided by the use of a subtraction technique, clearly visualized the development of large intratumour cysts. In one further patient with a null cell adenoma there was also a rapid development of an intratumour cyst and an increase in tumour size. This patient was treated with transsphenoidal needle aspiration. In all tumour cases an increase in intensity quotients based on T1 and T2 relaxation times was calculated.

Adenoma↗
PubMed1986

Magnetic resonance imaging of brain tissue displacement and brain tissue water contents during progressive brain compression. An experimental study in dogs.

Continuous recording of vital physiologic parameters and magnetic resonance imaging (MRI) was performed during continuous expansion of extradural rubber balloons in spontaneously ventilated anesthetized dogs. Initial physiologic changes appeared when the pontine cistern was compressed while respiratory arrest was regularly paralleled by marked tentorial and tonsillar herniation. Local increase in brain tissue water progressed during brain compression and was most marked in white matter of the brain. This was related to the regional decrease in cerebral perfusion pressure. The correlation between the morphologic and physiologic course of events during brain compression has a predictive value.

Animals↗
PubMed1986

Magnetic resonance imaging of water intoxication. An experimental study in dogs.

Sequential magnetic resonance imaging (MRI) was performed to correlate signs of herniation and increase in local brain tissue water content with continuous changes in vital physiologic parameters during progressive water intoxication in anaesthetized dogs. The intracranial pressure increase ultimately resulted in respiratory and cardiac arrest. MRI concomitantly showed an increase in local brain water content starting and dominating in the cerebral cortex but progressing to all parts of the central nervous system. The late appearance of transtentorial pressure gradients and of brain herniation suggests that development of cerebral edema occurs in at least two stages, an intracellular osmotic edema appearing first, being followed by an ischemic edema related to a progressive decrease in local perfusion pressure.

Animals↗