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A Lilja

Publications and source records attributed to A Lilja.

At least 19 recordsLinked to original sources
PubMed1995

Kinetic analysis of regional (S)(-)11C-nicotine binding in normal and Alzheimer brains--in vivo assessment using positron emission tomography.

A compartment model has been developed and validated for the kinetic analysis of (S)(-)11C-nicotine binding in the brain including a compensation for the influence of regional cerebral blood flow (rCBF). The model was applied to eight patients with Alzheimer disease (AD) and three age-matched healthy volunteers who received intravenous injections of (S)(-)11C-nicotine and 11C-butanol. The uptake and time course of radioactivity in different brain regions were assessed by positron emission tomography (PET). The rate constant k2* was formulated by dividing the K2 rate constant for 11C-nicotine with the K1 rate constant for 11C-butanol and thereby minimizing the influence of CBF on the quantitated binding of 11C-nicotine. The rate constant k2* for 11C-nicotine giving a quantitative measure of binding in the brain tissue was significantly higher in the temporal and frontal cortices as well as in the hippocampus of AD brains as compared with controls, indicating deficits in specific nicotinic binding in these brain areas of AD patients. A significant and negative correlation was obtained between cognitive function (Mini-Mental State Examination) and k2* of 11C-nicotine in the temporal and frontal cortices as well as in the hippocampus. The described kinetic model allowed in vivo quantification of nicotinic receptor binding in brain, which will be of importance in the future for evaluation of diagnosis, progress of disease, as well as the therapeutic effects in the treatment of AD.

Aged↗
PubMed1995

Positron emission tomography with [11C]deuterium-deprenyl in temporal lobe epilepsy.

We performed positron emission tomography (PET) with [11C]deuterium-deprenyl in 9 patients with temporal lobe epilepsy (TLE) undergoing evaluation for possible epilepsy surgery. Seven patients had unilateral and 2 had bilateral mesiotemporal epileptic foci based on the preoperative investigation including ictal EEG discharges and PET with 2-[18F]fluoro-2-deoxyglucose (FDG). Deprenyl is an irreversible inhibitor of monoamine oxidase type B (MAO-B) with a very high affinity for the enzyme. In the brain, MAO-B is preferentially located in astrocytes, and a previous in vitro study showed increased binding of the ligand in sclerotic hippocampi. Dynamically acquired N-[methyl-11C]-a,a-di-deutero-L-deprenyl distribution in PET images were analyzed graphically, and the focus regions were assessed visually on the PET images. In addition, the accumulation rate and distribution volume of the tracer relative to the cerebellar cortex were measured in standardized homologous temporal regions by semiquantitative methods. Uptake of [11C]deuterium-deprenyl was significantly increased in the epileptogenic temporal lobes, both apparently and semiquantitatively. By calculating mean interlobar ratios, we identified the temporal lobe containing the epileptic focus in six unilateral cases. One case was ambiguous but was not falsely localized. The two bilateral cases were correctly identified as such. Our results suggest that PET with [11C]deuterium-deprenyl might be a useful method for identification of epileptogenic temporal lobes.

Adult↗
PubMed1995

Positron emission tomography studies in patients with locally advanced and/or metastatic breast cancer: a method for early therapy evaluation?

PURPOSE: To investigate if sequential positron emission tomographic (PET) scans with the glucose analog 18F-2-fluoro-2-deoxy-D-glucose (18FDG) and/or L-methyl-11C-methionine (11C-methionine) in patients with breast cancer could provide early information on the efficacy of polychemotherapy. PATIENTS AND METHODS: Sixteen patients with breast cancer (11 with locally advanced tumors, three with recurrent disease in the contralateral breast, two of them with distant and regional metastases, and two with distant metastases) underwent a baseline and two follow-up PET scans after the first and third/fourth polychemotherapy course. Tumor response was determined clinically/radiographically after three/four polychemotherapy courses. RESULTS: Five patients were investigated with 18FDG, seven with both 11C-methionine and 18FDG, and four with only 11C-methionine before polychemotherapy. 11C-methionine presented a more distinct visualization of primary/contralateral breast cancers in five of seven patients when compared with 18FDG. Twelve of 16 patients demonstrated a response using conventional methods after the third/fourth course of polychemotherapy. Eight of these 12 clinical responders had a significant decrease in tracer uptake at the first PET scan performed 6 to 13 days after the first polychemotherapy course, and these reductions were further augmented after the third/fourth course and corresponded to the conventional therapy evaluation (clinical examination, computed tomography [CT], ultrasonography, and mammography). CONCLUSION: Our data indicate that PET may be of clinical value in predicting response to chemotherapy in patients with locally advanced breast cancer and/or metastatic disease earlier than any other method used.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Non-synchronous behavior of neuronal activity, oxidative metabolism and blood supply during mental tasks in man.

In near-infrared spectroscopic studies during mental tasks such as problem solving and mental arithmetic, we found that 9 of 33 healthy volunteers showed decreases in both the regional cerebral blood flow (r-CBF) and oxygen consumption rate (CMRO2) in the frontal region of the dominant hemisphere. To confirm these unexpected observations, we performed simultaneous measurements by positron emission tomography (PET) and near-infrared spectroscopy (NIRS) in two such subjects. PET images also showed that CBF decreased within the presumptive area illuminated by near-infrared light during mental task. However, CBF decreased in almost all regions while the subject gave a correct answer. Thus, the questions arose: Are mental tasks always associated with increases in r-CBF and/or CMRO2?

Adult↗
PubMed1994

Patient positioning for fractionated precision radiation treatment of targets in the head using fiducial markers.

When irradiating targets in the brain, an accurately localised dose is often needed. One crucial moment to achieve this is the positioning of the patient. We have developed a positioning method where the patient is immobilised with a bite block and a head mould, and where the position of the target is determined by X-ray imaging of fiducial markers that are placed in the patient's skull. A method for computing the transformation needed to move the target from the observed to the prescribed position and orientation is described. This method uses the information from two orthogonal X-ray images and takes measurement errors and data from three or more markers into account. Results from using the method clinically in proton beam therapy are given.

Algorithms↗
PubMed1994

MR imaging in cerebral gliomas. Tissue component analysis in correlation with histopathology of whole-brain specimens.

A comparative analysis between MR examinations and histopathologic whole-brain sections regarding tumour components was performed in 5 brain specimens from patients with malignant glial brain tumours. All cases were examined with MR imaging in vitro and in 2 cases a close comparison with the MR examinations in vivo was also possible. The most homogeneous hypercellular area in malignant gliomas, giving the highest tumour grade, was not visualised on MR imaging as an isolated entity, either in vitro or in vivo. The most conspicuous tumour component, reflecting the heterogeneity of malignant gliomas, was necrosis. This feature was best depicted in the T2WI. In 4 of 5 cases, distant tumour spread of benign-looking tumour cells was found in areas visualised as normal on T2WI, outside the margins of the peritumoural oedema. In 2 cases, estimation of water content was performed immunohistochemically and a close correlation was found in each case between peritumoural and periventricular hyperintensity on T2WI and areas of pallor on the haematoxylin-eosin-stained whole-brain sections. These areas corresponded to microscopical oedema. MR imaging reflects underlying heterogeneous histopathology in malignant gliomas. The degree of malignancy of the lesion as a whole can thus be assessed by MR imaging. However, the method does not allow malignant gliomas to be correctly delineated.

Adult↗
PubMed1993

Intracranial infusion of purified nerve growth factor to an Alzheimer patient: the first attempt of a possible future treatment strategy.

We report on the clinical outcome of a first case of intracranial infusion of nerve growth factor (NGF) to an Alzheimer patient. The therapeutic attempt is based on animal research showing that NGF stimulates central cholinergic neurons of the type known to be lost during the development of Alzheimer's disease (AD). Furthermore, our own previous clinical experience of infusing NGF to support the survival of intracranially transplanted adrenal chromaffin cells to Parkinsonian patients indicate this approach to be technically possible and safe and clinically of significant potential. Our first case was a 69-year-old woman, with symptoms of dementia since 8 years. Intraventricular infusion of 6.6 mg NGF over three months resulted in a marked transient increase in uptake and binding of [11C]nicotine in frontal and temporal cortex and a persistent increase in cortical blood flow as measured by PET as well as progressive decreases of slow wave EEG activity. After one month of NGF infusion, tests of verbal episodic memory were improved whereas other cognitive tests were not. No adverse effects of the NGF infusion were found. The results of this single case indicate that NGF may counteract cholinergic deficits in AD, and suggest that further clinical trials of NGF infusion in AD are warranted.

Aged↗
PubMed1993

Positron emission tomography (PET) in neuroendocrine gastrointestinal tumors.

Positron emission tomography (PET) makes it possible to study effects of medical treatment in vivo. Carcinoid tumors with liver metastases, especially those of midgut origin, produce serotonin via the precursors tryptophan and 5-hydroxytryptophan (5-HTP) and this overproduction contributes to the clinical symptoms of the carcinoid syndrome. Seven patients with histopathologically verified neuroendocrine tumors and liver metastases, five of whom with ileal carcinoids, one a lung carcinoid and one an endocrine pancreatic tumor, were included in the study. All patients had elevation of urinary 5-HIAA with the exception of one patient with a solitary liver metastasis of midgut origin. After an intravenous injection of 11C-5-HTP, PET was performed and the uptake of radioactivity in tumor tissue, normal liver and plasma were compared. All patients with elevated urinary 5-HIAA and also the patient with a solitary liver metastasis and normal urinary 5-HIAA had high accumulation and signs of a high rate of binding of 5-HTP in the liver metastases. The uptake was relatively homogeneous in midgut carcinoid liver metastases but in large necrotic metastases the radioactivity was localized to the periphery. In three patients PET examination was repeated after 3 months of interferon treatment and in agreement with circulating tumor markers and ultrasonography the uptake of 5-HTP was unchanged. Another patient who received the somatostatin analog somatuline progressed on treatment and accordingly the uptake of 5-HTP also increased. The experience with PET in neuroendocrine gastrointestinal tumors is very limited. Our results so far indicate that 5-HTP can be used to visualize serotonin-producing neuroendocrine tumors and furthermore it might prove to be of value to monitor the effects of treatment, possibly also as an early predictive test of the outcome of treatment.

5-Hydroxytryptophan↗
PubMed1992

Binswanger's disease in the absence of chronic arterial hypertension. A case report with clinical, radiological and immunohistochemical observations on intracerebral blood vessels.

The cerebral changes are described in a woman of 54 who suffered from Binswanger's encephalopathy: there were no signs or symptoms of chronic arterial hypertension. The disease presented as dementia of about 3 years duration. Computed tomography of the brain 2.5 years before her death showed bilateral widespread hypodense lesions in the cerebral white matter. She died of an asthmatic attack. Autopsy disclosed extensive bilateral degeneration of the central white matter, lacunes and gliosis. Severe obliterative arteriolosclerosis occurred in the meningeal vessels and those supplying the affected parts of the brain. Light microscopy showed that the most severe lesions occurred in the arterioles. Immunohistochemistry demonstrated profound extravasation of plasma proteins chiefly albumin, indicating dysfunction of the blood-brain barrier. Thus, the lesions characteristic of Binswanger's encephalopathy may develop in the absence of chronic arterial hypertension. Additional pathogenic factors, possibly genetic predisposition to vascular injury may play a role in the development of this condition.

Blood Proteins↗
PubMed1992

Nerve growth factor affects 11C-nicotine binding, blood flow, EEG, and verbal episodic memory in an Alzheimer patient (case report).

Based on animal research suggesting that nerve growth factor (NGF) can stimulate central cholinergic neurons, the known losses of cholinergic innervation of the cortices in Alzheimer's disease (AD), and our experience of infusing NGF to support adrenal grafts in parkinsonian patients, we have initiated clinical trials of NGF infusions into the brain of patients with AD. Here we report a follow-up of our first case, a 69-year-old woman, with symptoms of dementia since 8 years. Intraventricular infusion of 6.6 mg NGF during three months resulted in a marked transient increase in uptake and binding of 11C-nicotine in frontal and temporal cortex and a persistent increase in cortical blood flow as measured by PET as well as progressive decreases of slow wave EEG activity. After one month of NGF, tests of verbal episodic memory were improved whereas other cognitive tests were not. No adverse effects could be ascribed to the NGF infusion. Taken together, the results of this case study indicate that NGF may counteract cholinergic deficits in AD, and suggest that further clinical trials of NGF infusion in AD are warranted.

Aged↗
PubMed1992

Microprocesses in perception and personality.

This paper utilizes an ontogenetically validated personality test, the Meta-Contrast Technique (MCT). The instrument focuses on the microdevelopment of perception (percept genesis) reflecting the process of individual adaptation to and construction of reality. Empirical evidence for the adequacy of the MCT paradigm in neuropsychological personality research is presented. In all, 45 patients were tested; thirty-three patients with various forms of supratentorial brain tumors were examined and compared with a group of 12 cerebrovascular disease (CVD) patients. Without the examiner's knowledge of degree of tumor malignancy, the MCT results allowed differentiation among tumors of various histological types. Uninformed of the final diagnosis, patients with highly malignant gliomas showed panic-related anxiety and schizoid-like regressions, in contrast both to patients with low and nonmalignant brain tumors and to the group of CVD patients.

Adult↗
PubMed1992

Differentiation of pituitary adenoma and meningioma: visualization with positron emission tomography and [11C]-L-deprenyl.

Seven patients with clinically nonsecreting pituitary adenoma and 5 patients with meningioma were examined with positron emission tomography using [11C]-LL-deprenyl and [11C]-LL-methionine. The dynamics of the uptake of [11C]-L-deprenyl in the pituitary adenomas demonstrated a rapid and high uptake immediately after the injection, and, later, an almost constant level was observed that was equal to or higher than that observed in normal brain tissue. In the meningiomas, however, the initially high uptake was followed by a marked decrease with time, reaching a level that was approximately half that observed in brain tissue. The study demonstrated high binding of [11C]-L-deprenyl to monoamine oxidase B in pituitary adenomas, whereas the binding in meningiomas was very low. This fact can be used in the differential diagnosis of pituitary adenoma and parasellar meningioma. Operative samples from 10 patients with meningioma and from 5 patients with pituitary adenoma were analyzed biochemically for activity of monoamine oxidase B, using [14C]-phenyl-ethylamine as substrate. The nonsecreting pituitary adenomas demonstrated high enzyme activity, the secreting adenomas about one-tenth of that of the nonsecreting, and the meningiomas one-thirtieth of that of nonsecreting adenomas.

Adenoma↗
PubMed1991

Maternal blood volume in placenta of the rhesus monkey measured in vivo by positron emission tomography.

The relative volume of the intervillous space of the placenta of the rhesus monkey was measured in vivo using positron emission tomography (PET), a noninvasive tracer technique. 11CO-Hb and 68GaCl3 were both used in three experiments and 68Ga-EDTA in two. The tracers were administered intravenously as bolus doses to 6 pregnant monkeys during 7 different pregnancies. Measurements with 11CO-Hb gave a volume of 48.0% of the total placental volume. Transplacental transfer of 11CO to the fetal circulation is probably a minor problem due to the small fetal blood volume and the prolonged time before the same concentration is reached in the maternal and fetal blood. Measurements with 68GaCl3, which binds to transferrin, gave an intervillous space volume of 55.6% of the placental volume. The concentration of radioactivity in the placenta did not attain a steady state, indicating a clearance of the tracer from the blood only to a small extent. Measurements with 68Ga-EDTA displayed a volume of 60.4% of the placental volume. Transplacental transfer and the additional distribution of radioactivity to fetal and maternal extracellular spaces, including the placenta, when 68Ga-EDTA was used will make this tracer unsuitable in measurements of the blood volume of the placenta with PET.

Animals↗
PubMed1990

Decreased uptake and binding of 11C-nicotine in brain of Alzheimer patients as visualized by positron emission tomography.

Positron emission tomography of the brain following intravenous injection of (+) (R) and (-) (S) N-[11C-methyl]nicotine showed a marked reduced uptake of both isomers, especially the (R) form, in Alzheimer patients as compared to age-matched controls. The significantly larger difference between the uptake values of the (S)- and (R)-enantiomers of 11C-nicotine in Azheimer brains may be of diagnostic value.

Aged↗