Biomedical subjects

K Ericson

Publications and source records attributed to K Ericson.

At least 55 records · Page 3Linked to original sources

PubMed1993

Low dose cyclophosphamide, alpha-interferon and continuous infusions of interleukin-2 in advanced renal cell carcinoma.

Pretreatment with a low dose of cyclophosphamide (CY) has been claimed to inhibit suppressor functions and augment various immune functions. A combination of a low dose of CY, alpha-interferon (IFN-alpha) and continuous infusion of interleukin-2 (IL-2) was used to treat patients with advanced renal cell cancer (RCC) (stage IV). Sixteen patients received four cycles consisting of CY (500 mg m-2) three days prior to daily i.m. injections of alpha-IFN (3 x 10(6) U), and continuous infusion of 18 x 10(6) IU rIL-2 for five days. The cycle interval was three weeks. Two patients had partial response (13%) (26+ and 12+ months), two had a minor response (9+ and 4 months), and three patients achieved stable disease (19+, 14+ and 8+ months). No patients required intensive care. Side effects were mainly fever, malaise, capillary leak syndrome and diarrhoea. Non-responders showed significantly higher eosinophil and platelet counts compared to responders. Serum concentration of IL-2 was significantly higher in responders. 5/11 patients had abnormally low values of serum thyroxine after therapy. Two patients needed thyroid hormone substitution. The difference between the initial and the lowest thyroxine values correlated significantly to survival (p < 0.03). The addition of CY to rIL-2 and IFN-alpha in the present protocol did not contribute to an increased major response rate.

Adolescent↗

PubMed1993

A functional cerebral response to frightening visual stimulation.

The defense reaction, a fundamental reflex in the human behavioral response to threat, is characterized by anxiety and increased activity of the sympathetic nervous system. To study changes in regional cerebral blood flow (rCBF) related to the defense reaction, volunteers with snake phobia were investigated with positron emission tomography. The relative rCBF during phobogenic visual stimulation was increased in the secondary visual cortex but reduced in the hippocampus, orbitofrontal, prefrontal, temporopolar, and posterior cingulate cortex compared with that observed during neutral visual stimulation. The relative rCBF under aversive stimulation was intermediate between phobic and neutral stimulation. The rCBF patterns observed are suggested to represent a functional cerebral correlate to the visually elicited defense reaction and its associated emotions.

Adult↗

PubMed1993

Regional cerebral blood flow during experimental phobic fear.

Positron emission tomographic measurements of regional cerebral blood flow (rCBF) were used to investigate central nervous system correlates of fear and anxiety. Volunteers with symptomatic snake phobia were studied while exposed to visual phobogenic, aversive, and neutral stimuli. Anxiety ratings and the number of nonspecific electrodermal fluctuations increased as a function of phobic stimulation. Phobic, compared to neutral and aversive, stimulation elevated rCBF in the visual associative cortex. The basal ganglia were not activated more by phobic than aversive or neutral stimulation. However, cortical and thalamic rCBF were always correlated during phobic but not aversive or neutral stimulation. This indicates that the thalamus could be a relay station for phobic stimulus processing and affect.

Adult↗

PubMed1993

Combined embolization and gamma knife radiosurgery for cerebral arteriovenous malformations.

In a study of 46 patients with cerebral arteriovenous malformations (AVMs) the value of combining embolization and gamma knife radiosurgery was assessed. In 35 patients with large grade III to V AVMs (Spetzler-Martin system) staged combined treatment was planned. In 11 patients, radiosurgery complemented embolization for a residual AVM. The number of embolization sessions ranged from 1 to 7 (median 2). Twenty-six patients needed multiple embolization sessions. In 28 patients the grade of AVMs decreased as a result of embolization. In 16 patients collateral feeding vessels developed after embolization which made delineation of the residual nidus difficult. The time lag between the last embolization and radiosurgery ranged from 1 to 24 months (median 4). Nineteen of 35 large grade III to V AVMs were possible to treat by radiosurgery following embolization. In the 46 patients complications occurred in 9 from embolization and in 2 from radiosurgery. Two patients had transient and 9 had permanent neurologic deficits. It is concluded that embolization facilitates radiosurgery for some large AVMs and therefore this combined treatment has a role in the management of AVMs.

Adolescent↗

PubMed1993

Target delineation in radiosurgery for cerebral arteriovenous malformations. Assessment of the value of stereotaxic MR imaging and MR angiography.

A study of 6 selected arteriovenous malformation (AVM) patients was performed to investigate the feasibility of delineating an AVM on MR images and to compare the AVM volume outlined on different images. Conventional stereotaxic angiograms, stereotaxic MR images and MR angiograms using several different pulse sequences were obtained prior to radiosurgery. Treatment plans were made from the conventional stereotaxic angiograms. These plans were then transferred to a separate dose planning computer which displayed the MR images with the superimposed isodose lines. The radiated volumes of AVM and brain tissue were measured from these MR images. Last, an assessment was made of the radiation volume needed for an appropriate treatment of the AVM if the treatment plan was made from the MR images rather than from the conventional stereotaxic angiogram. It was possible to delineate medium and large size AVM nidi on stereotaxic MR images based on an integration of information obtained from various pulse sequences. The estimated volumes of the AVM nidi were found to be larger on the conventional stereotaxic angiograms than on the stereotaxic MR images. Consequently, a dose plan based on a conventional stereotaxic angiogram would result in a higher integral dose to the brain with the same target dose. By using reliable MR information it is expected that the volume of brain exposed to radiation could be decreased and the adverse effects of stereotactic radiosurgery for AVM thereby minimized.

Adult↗

PubMed1992

In vivo distribution of [11C]-busulfan in cynomolgus monkey and in the brain of a human patient.

The in vivo distribution of the antileukemic agent busulfan labeled with the positron-emitting radionuclide carbon 11 was investigated in cynomolgus monkeys and in a human patient using positron emission tomography. After i.v. injection of the radiotracer, its regional uptake was monitored for about 1 h in the monkey's body and, in a separate experiment, in the monkey's brain. The concentration of radioactivity in the liver, which showed the highest levels of all the organs scanned, increased throughout the experiment and was 9-fold that in the brain at the end of the experiment. [11C]-Busulfan rapidly crossed the blood-brain barrier. The radioactivity peaked in both the cortex and the white matter showing a ratio of 1.25, at 3 min but declined quickly to yield a ratio of approximately 1 after 30 min. In the human brain, radioactivity in the cerebellum, cortex, and white matter reached a maximum within 5 min showing a cortex:white matter ratio of 1.6. The activity in the cortex declined to yield a ratio of 1 within 30 min. Of the delivered dose, 20% penetrated into the brain.

Adult↗

PubMed1992

SUNCT may be another manifestation of orbital venous vasculitis.

A patient with more than 20 years of SUNCT, i.e., long lasting periods with frequent attacks of intense orbital pain with a duration of about one minute, associated with ipsilateral conjunctival injection, lacrimation, rhinorrhea and facial sweating is described. Some attacks were possibly related to increased cerebral blood flow but could also be triggered from the oral area. Orbital phlebography showed pathologic changes on the side of the pain, changes which were normalized when these attacks ceased to appear. Due to these findings in conjunction with serum evidence of inflammation, associated systemic symptoms and susceptibility to steroids and azathioprine, venous vasculitis is suggested to be the cause of SUNCT in this patient. Carbamazepine and sumatriptan decreased the frequency, intensity and duration of attacks, although not completely.

Headache↗

PubMed1992

Orbital phlebography: a comparison between cluster headache and other headaches.

Orbital phlebography has previously been found to be pathologic in 8 of 13 patients with episodic cluster headache. To compare the frequency and pattern of the pathologic findings in cluster headache with those in other headache categories, orbital phlebographies were carried out in patients with cluster headache, cervicogenic headache, migraine and tension-type headache (tension headache). The investigations were evaluated independently by two radiologists, one of whom had no knowledge of the diagnoses. The frequencies of pathologic findings were at maximal 2/12 in the cluster headache group, 2/11 in the cervicogenic headache group, 5/12 in the migraine group and 5/15 in the tension-type headache group. The investigators agreed completely in the evaluation of 39/50 phlebograms, with lesser disagreements in 7. In conclusion, the frequency of pathologic findings at orbital phlebography in cluster headache was not higher than in the other diagnostic categories investigated, and the pattern of the pathology was generally the same.

Adult↗

PubMed1990

Blood as tracer for CSF circulation after subarachnoidal hemorrhage.

The amount and distribution of blood in the cerebrospinal fluid following subarachnoid hemorrhage can be monitored with CT. An investigation of 110 patients was performed retrospectively in 100 patients with a total of 132 CT examinations, and prospectively in 10 patients with 40 CT examinations. During the days following the hemorrhage, the blood was redistributed within the subarachnoid space and eventually reabsorbed. The blood in the basal cisterns was cleared first, whereas the amount of blood in the cortical sulci appeared to increase after a few days, later to be cleared. It is concluded that the redistribution of the blood reflects the circulation of the cerebrospinal fluid, and that the erythrocytes thus act as tracers of this circulation. The amount of blood within the ventricular system was correlated to the size of the ventricles; patients with large amounts of blood within the subarachnoid space had hydrocephalus more often than other patients.

Blood Physiological Phenomena↗

PubMed1989

Histochemical evaluation of the glycosaminoglycans in vasoconstricted human cerebral arteries after subarachnoid haemorrhage.

Sixteen patients dying after subarachnoid haemorrhage (SAH) were investigated with regard to the presence of angiographic vasoconstriction and of glycosaminoglycans in samples from the main cerebral arteries. All patients had a statistically significant (p less than 0.001) vasoconstriction at angiography performed before death. At morphological examination, the vessels of all patients showed signs of intimal thickening, necrosis of the media and leucocyte infiltration of the adventita. The presence of glycosaminoglycans was determined semiquantitatively and did not differ from the values obtained from presumably normal controls. It is suggested that the angiographically verified vasoconstriction found after SAH as well as the morphological changes of the cerebral arteries are not related to a concentration increase of glycosaminoglycans.

Adult↗

PubMed1989

Positron emission tomography with 68-Ga-EDTA and computed tomography in patients with subarachnoid haemorrhage.

26 patients with subarachnoid haemorrhage (SAH) were investigated with 68-Ga-EDTA and positron emission tomography (PET) in order to evaluate the presence of a blood brain barrier (BBB) disturbance. Only one patient showed a BBB disruption. It is suggested that increased levels of substances with higher molecular weight than 68-Ga-EDTA in the cerebrospinal fluid (CSF) are the result of a change in the metabolism of the CSF and the brain tissue caused by a SAH.

Adult↗

PubMed1988

Bilateral angiographic vasoconstriction of the middle cerebral and internal carotid arteries after subarachnoid haemorrhage in patients with and without aneurysms. A retrospective study.

A retrospective study of cerebral angiographies from 173 patients with subarachnoid haemorrhage (SAH) were investigated and divided into three groups. The diameters of the middle cerebral artery and the internal carotid artery were measured and correlated with time elapsing between the onset of SAH and the angiographic study. A significant (p less than 0.001) reduction in vascular diameter was found at all levels of intra- as well as extradural parts of the internal carotid artery in patients with aneurysms (group I). Also, bilateral angiographic investigation from 70 patients showed a significant (p less than 0.001) reduction at all levels on both sides, regardless of whether aneurysms were present (group II) or not (group III). Moreover, the reduction in vascular diameter was more pronounced in patients with than in patients without aneurysms. The most pronounced reduction in vascular diameter was found in one of the extradural parts of the internal carotid artery in both group II and III. However, reduction in vascular diameter did not correlate significantly with the cerebral circulation time despite a tendency towards it. On the other hand, layering of the contrast medium along the posterior wall of the internal carotid artery was more often found in patients with prolongation in cerebral circulation time suggesting a reduced cerebral blood flow in these patients. It is suggested that the significant reduction in vascular diameter of intra- as well as extradural parts of the internal carotid artery, might reflect an adaptation to altered cerebral metabolism after SAH.

Blood Circulation Time↗

PubMed1988

Angiographic investigation of cerebral vasospasm in subarachnoid haemorrhage due to arteriovenous malformation.

Fifty (50) selected patients with arteriovenous malformation (AVM) with and without subarachnoid haemorrhage (SAH) were investigated, in respect of occurrence and course of the vasospasm. The diameters of the carotid siphon and its main branches were measured and plotted against the time elapsing between the haemorrhage and the angiographic study. Patients without SAH were used as a reference group. The results suggest intracranial arterial spasm to occur between the third and eleventh day after the onset of SAH. Patients with intracerebral haematoma may show vasospasm from the first day onwards. It seems that the radiologically demonstrated spasm in AVM had no impact on the clinical outcome in this series.

Adolescent↗

PubMed1987

The normal pituitary examined with positron emission tomography and (methyl-11C)-L-methionine and (methyl-11C)-D-methionine.

Four patients with radiologically normal pituitary gland were examined with positron emission tomography after the administration of (methyl-11C)-L-methionine. On a following day the examination was repeated with (methyl-11C)-D-methionine. The accumulation rate of L-methionine in the pituitary was measured, giving a value that was about twice that of normal brain tissue. The accumulation rate of D-methionine in the pituitary was almost a factor of 10 lower than that of L-methionine. In the normal brain tissue that ratio was 2.3. The study clearly indicates that the methionine uptake in the pituitary is stereospecific. 11C-D-methionine is freely distributed in the tissue without entrapment, whereas 11C-L-methionine is irreversibly bound. It is concluded that PET with 11C-L-methionine can be used to study amino acid utilization in the pituitary.

Adult↗

PubMed1987

11C-labelled glycine: synthesis and preliminary report on its use in the investigation of intracranial tumours using positron emission tomography.

Carbon-11-labelled glycine has been prepared by a Bücherer-Strecker synthesis using [11C]cyanide, formaldehyde and ammonium carbonate. Total synthesis time, including chromatographic purification, was 30-35 min from end-of-bombardment. Radiochemical yield was 35%, based on [11C]cyanide and radiochemical purity was shown to be greater than 98% by analytical HPLC. The 11C-labelled glycine thus prepared was used along with [68Ga]EDTA and L-[methyl-11C]methionine in the visualization of an anaplastic astrocytoma by positron emission tomography.

Astrocytoma↗

PubMed1987

Effect of adenosine on human cerebral blood flow as determined by positron emission tomography.

The effect of intravenous infusion of adenosine on CBF was studied in seven patients with cerebral arteriovenous malformation. The patients were examined with positron emission tomography with controlled ventilation using [15O] water and [11C] fluoromethane as tracers. Total and regional CBF were determined before and during infusion of adenosine at rates producing a reduction of the MABP by approximately 10-40%. Six patients were normoventilated, and one was hyperventilated. Mean CBF in areas with normal brain tissue was 54 ml/100 g/min before adenosine infusion under normoventilation. Adenosine infusion increased mean CBF with 23-85%. Mean CVR was decreased with 43-65% and exceeded the percentage reduction of MABP in all normoventilated subjects. In the hyperventilated patient, the reduction of CVR was similar to the reduction of MABP, and CBF was unaffected, except for the 30% increase in the thalamus. It is concluded that intravenous administration of adenosine produces marked cerebral vasodilation in normoventilated subjects and that this response can be counteracted by hyperventilation.

Adenosine↗

PubMed1987

Chronic paroxysmal hemicrania: orbital phlebography and steroid treatment. A case report.

A 62-year-old man with ankylosing spondylitis and with a 3-year history of chronic paroxysmal hemicrania is presented. Because of his ankylosing spondylitis naproxen was prescribed; this decreased the attacks of headache to about 50%. However, treatment with indomethacin and steroids eliminated the attacks completely, the former drug in 24 h but only when the drug was taken; the latter drug was completely effective after a week but with an effect that lasted half a year after the medication was stopped. Orbital phlebography showed changes similar to those previously observed in patients with Tolosa-Hunt syndrome and cluster headache. Venous vasculitis thus seems to be associated with all three disorders and may be a factor of etiologic significance.

Chronic Disease↗

PubMed1987

Orbital phlebography in patients with cluster headache.

Thirteen patients with cluster headache in an active stage were investigated with orbital phlebography. About 60% of the patients showed pathologic changes on the phlebograms, such as changes in the appearance of the superior ophthalmic vein. Five patients had pathologic changes on both sides and three patients on one side only. All patients with unilateral pathologic findings on orbital phlebography had the attacks on the same side. The phlebographic findings in these patients with cluster headache were very similar to those of patients with the Tolosa-Hunt syndrome. There is also some similarity in the symptoms in the two disorders. It has previously been suggested that the Tolosa-Hunt syndrome is caused by venous vasculitis, and the present findings to some extent support the idea that cluster headache may have the same etiology.

Adult↗