Masahito Fujimoto

Estrogen receptors in brain tumors.

We examined the cytosolic estrogen receptor (ER) level in tumor tissue from 77 patients: 36 meningiomas, 20 gliomas (12 glioblastomas, 2 cerebellar astrocytomas, 2 ependymomas, and 4 medulloblastomas), 8 neurinomas, 7 pituitary adenomas (2 prolactin-producing adenomas, 1 growth hormone-producing adenoma, and 4 nonfunctioning adenomas), and 6 metastatic brain tumors (1 from breast cancer, 4 from lung cancers, and 1 from colon cancer). Nuclear ER levels were assayed in 11 meningiomas and 2 glioblastomas. ER was determined by the dextran-coated charcoal method and calculated by Scatchard analysis, Cytosolic ER was detected in 100% of the pituitary adenomas, 50% of the meningiomas, 50% of the metastatic brain tumors, 25% of the neurinomas, and 15% of the gliomas. In gliomas, only medulloblastomas had ER activity. Nuclear ER was found in three premenopausal women with meningioma. The dissociation constant of the ER complex was, in each case, less than 10−9M. These observations suggest that some brain tumors may be responsive to estrogen via the cellular ER.

Value of Repeat Angiography in Patients With Spontaneous Subcortical Hemorrhage

BACKGROUND AND PURPOSE Neuroradiological investigations do not disclose a source of bleeding in some patients with spontaneous subcortical hemorrhage. These patients may harbor undetected vascular malformations and may be at risk of rebleeding in the future. We investigated patients with subcortical hemorrhage with use of repeat angiography and MRI to determine the incidence of occult vascular malformations and the risk of bleeding during follow-up. METHODS We reviewed a consecutive series of 137 patients with subcortical hemorrhage during a 10-year period (June 1987 through June 1997). If the patient was <65 years old and the first angiogram and/or MRI did not show a source of bleeding, repeat angiography was recommended. All angiographic and MRI studies were reviewed. The relationship between the identified bleeding source and clinical variables such as patient age, sex, and history of hypertension and the size and location of the hematoma were examined. RESULTS One hundred seven patients (78%) underwent angiography on admission, 10 (7%) had immediate surgery for hematoma without angiography, and 20 (15%) had neither angiography nor surgery. Overall, an etiology for the hemorrhage was found in 55 cases (40%). Vascular malformations were common in young patients without preexisting hypertension. A second angiogram was obtained in 22 patients, and 4 arteriovenous malformations were demonstrated. Rebleeding at the site of the initial hemorrhage was not observed after a mean follow-up of 68 months. CONCLUSIONS Angiography performed acutely after hemorrhage may not demonstrate vascular malformations. Consideration should be given to repeat angiography in patients who do not have a specific cause for hemorrhage.

Chronological Positron Emission Tomographic Study of Severe Diffuse Brain Injury in the Chronic Stage

Cerebral blood flow and metabolism were investigated in five patients with severe diffuse brain injury in the chronic stage, using positron emission tomography (PET). Regional cerebral blood flow, regional oxygen extraction fraction, regional cerebral blood volume, regional cerebral metabolic rate for oxygen, and regional cerebral metabolic rate for glucose were measured bilaterally in the frontal, temporal, occipital, and parietal gray matter, as well as the white matter of the centrum semiovale. In 4 of 5 patients, a follow-up PET study was also performed. In three cases, below-normal regional cerebral blood flow and regional cerebral metabolic rate for oxygen values accompanied by above-normal regional oxygen extraction fraction values, as well as low metabolism, were demonstrated in the initial PET studies. In two of three cases, clinical improvements were observed, and follow-up PET data also improved. These findings suggest that chronological PET studies may be able to assess quantitatively clinical improvements in patients with diffuse brain injury.

Kissing aneurysms of distal anterior cerebral arteries demonstrated by magnetic resonance angiography

BACKGROUND Multiple aneurysms, associated with distal anterior cerebral artery (ACA) aneurysm, are not rare; therefore, it is important to examine multiplicity of the aneurysms preoperatively. CASE REPORT A case of ruptured distal ACA aneurysm, associated with another one in a mirror position, is reported. A 43-year-old woman suffered subarachnoid hemorrhage. Conventional angiography demonstrated a saccular aneurysm on the bifurcation of the right or left distal ACA; however, magnetic resonance angiography (MRA) revealed two mirror-image aneurysms on both bifurcations. CONCLUSION MRA was useful for preoperative diagnosis of kissing aneurysms on distal ACAs.

An adult case of recurrent arteriovenous malformation after “complete” surgical excision: a case report

BACKGROUND Complete surgical excision of arteriovenous malformations (AVM) documented by postoperative angiography is considered a cure. However, recent reports have shown that AVMs in children may recur after negative postoperative angiograms, and some suggest that it may reflect the immaturity of their cerebrovasculature. This case report demonstrates that AVM in adults may also recur, despite postoperative angiograms confirming complete removal. CASE DESCRIPTION This 28-year-old man presented in 1994 with a focal motor seizure and was found to have an AVM in the right frontal lobe. He underwent surgical excision of the AVM; postoperative angiograms taken immediately after surgery and 15 days later showed no residual AVM. He remained free of symptoms after surgery and it was considered that a complete removal had been achieved. In 1998 he developed a subarachnoid hemorrhage, and subsequent angiograms revealed a small AVM in an adjacent location. CONCLUSION This is the oldest patient reported in the literature with a recurrence of AVM, despite postoperative angiograms confirming complete removal. Angiographically invisible immature vessels, which might have been left in the surgical field, might have formed a new malformation later. We still believe that such recurrence must be very rare after AVM surgery, but we now recommend follow-up angiography at yearly intervals to our patients.

Studies on estrogen induced pituitary tumor in the rat with special reference to the relationship of the tuberoinfundibular dopamine neuron system

Pituitary tumors were experimentally induced in female Wistar rats by repeated injections of estradiol dipropionate. The hypothalamus and pituitary tumors were studied simultaneously by fluorescence histochemistry and immunohistochemistry. The pituitary gland became larger with a concomitant increase of serum prolactin in proportion to the dose of estrogen. Estrogen-induced pituitary tumor exhibited a proliferating prolactin cells by the peroxidase immunohistochemical method. Ultramicroscopical findings showed that these tumor cells were in an extremely hyperfunctional state.The dopamine neuronal perikarya in the hypothalamic arcuate nucleus and their terminals in the external layer of the median eminence were examined by fluorescence histochemistry in the rats bearing estrogen induced pituitary tumor and it was concluded that in our experimental conditions, estrogen effected directly on pituitary rather than on the hypothalamus and consequently dopamine synthesis in the arcuate neurons and its release into portal capillaries were accerelated simultaneously in order to inhibit prolactin secretion from tumor cells.

Chromosomal translocation, t(1;11)(q12;p15), in an extragonadal immature teratoma

A case of immature teratoma arising from the base of the skull is reported. The cytogenetic analysis revealed t(1;11)(q12;p15) as a sole chromosomal abnormality, suggesting that the breakpoint on chromosome 11 plays an important role in the early oncogenesis of human germ cell tumors (GCTs).

Chromosomes and Clinical Features in 6 Cases of Gliomas

Several characteristic and specific chromosomal changes have been observed in human solid tumors [1]. It has been assumed that these aberrations are involved in the processes of initiation and progression of the tumor. In glioblastoma, numerical and structural chromosomal abnormalities have been reported, such as gains of chromosome 7, losses of chromosome 10, structural abnormalities of chromosome 9, and double minute chromosomes (dmin) [2]. Cytogenetic analysis of the initial and recurrent tumor tissues of malignant gliomas has provided information regarding the specific and multistep chromosomal changes during initiation and progression of the lesions [3].

Imaging Techniques in the Evaluation of Behavior After Traffic Accidents

Imaging techniques of the brain are briefly described but are considered limited in the evaluation of behavioural state rather than of anatomical or functional disturbance. For the covering abstract see ITRD E110301.

Cerebral Hemodynamics and Metabolism in Severe Diffuse Brain Injury in Chronic Stage: Positron Emission Tomography

The authors measured the cerebral hemodynamics and metabolism in patients with severe diffuse brain injury (SDBI) in the chronic stage using positron emission tomography (PET). In this study, regional cerebral blood flow (rCBF), oxygen extraction fraction (rOEF), cerebral blood volume (rCBV), cerebral metabolic rate for oxygen (rCMRO2), cerebral metabolic rate for glucose (rCMRGlu), and cerebral metabolic rate were measured in three patients with SDBI in the chronic stage. The patients were all male, and aged 17, 19 and 25 years. The Glasgow Coma Scale score on admission was 3,4 and 3, respectively. In all patients, the cause of injury had been a traffic accident, computed tomography and magnetic resonance imaging revealed findings of so-called diffuse axonal injury (DAI), and the clinical course was also typical of that of DAI. The PET studies were performed 2 to 16 months after injury. The clinical condition of the patients at that time was vegetative state in two and severely disabled in one. PET revealed misery perfusion and low metabolism in two and matched low perfusion and low metabolism in one. It is interesting that any slight difference in clinical state was correlated with a slight difference in PET findings in every patients. The authors stress the usefulness of PET study in the investigation of SDBI in the chronic stage and in the assessment of its prognosis.