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Biomedical subjects

E Yoshino

Publications and source records attributed to E Yoshino.

At least 19 recordsLinked to original sources

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.

Adult

Tumor cell proliferation and apoptosis associated with the Gamma Knife effect.

In this study, the expression of proliferating-cell nuclear antigen (PCNA) and Bcl-2 protein was examined in neurinomas, meningiomas, pituitary adenomas, and malignant lymphomas before treatment with Gamma Knife radiosurgery. Tumor volume was rapidly reduced by radiosurgery in all malignant lymphomas and in some benign tumors. The latter had been characterized by strong positive immunohistochemical staining for PCNA and Bcl-2. Radiation-induced apoptosis is thought to contribute to the low-dose effects of Gamma Knife radiosurgery. A population with a large proportion of proliferating cells may be susceptible to the induction of apoptosis, and the presence of Bcl-2 may not suppress this Gamma Knife effect.

Apoptosis

Irradiation effects on the metabolism of metastatic brain tumors: analysis by positron emission tomography and 1H-magnetic resonance spectroscopy.

To evaluate irradiation effects on the metabolism of metastatic brain tumors treated by Gamma Knife radiosurgery, positron emission tomography (PET) and 1H-magnetic resonance spectroscopy (MRS) studies were performed on five patients. The tumor origins were lung cancer in three patients and breast cancer in two. Treatment volume was 0.4-10.1 cm3 (mean: 5.5 cm3). The marginal dose to the tumor was 24-30 Gy (mean: 26.2 Gy). The follow-up period was 5-19 months (mean: 13.4 months). No patients had conventional whole-brain radiation therapy. 18F-fluoroboronophenylalanine (18FBPA) or 18F-fluorodeoxyglucose (18FDG) were used as tracers for the PET study. Using 1H-MRS, several metabolites were simultaneously measured in metastatic brain tumor and adjacent brain. In the PET study of the representative case, the uptake rate of 18FBPA that is actively transported to the tumor decreased markedly 15 days after radiosurgery and continued to decrease thereafter. In the 1H-MRS study, choline, which is characteristically high in metastatic brain tumors, also decreased over time. In two cases with suspected radiation injury, the enhanced region, which was decreased in size in early follow-up, enlarged progressively and was accompanied by edema. However, 18FBPA and 18FDG were not transported to the enhanced region. The peak of free lipid, which might show destruction of the cell membrane, was recognized in the enhanced region and adjacent brain in these cases. This study revealed that radiation effects on the metabolism of metastatic brain tumors occur at an early stage after radiosurgery and continue over several months. In particular, in the case of radiation injury, PET and 1H-MRS studies made it possible to distinguish between regrowth of the tumor and radiation injury.

Aged

Spontaneous regression of intracranial arteriovenous malformation on PET.

We report a case of spontaneous regression of intracranial arteriovenous malformation (AVM) detected by PET in a 57-yr-old woman who had suffered repeated ruptures of the AVM at 28, 30 and 31 yr of age associated with pregnancy. The rupture at this hospitalization was the most critical, and after repeated ruptures for 1 mo, the AVM regressed spontaneously. The decreased cerebral blood volume (CBV) in the AVM indicated regression. The flow-to-volume (CBF/ CBV) ratios surrounding the AVM increased. The metabolic rate for oxygen (CMRO2) did not correlate with her improved neurological status, and an imbalance between CBF and CMRO2 was recognized.

Cerebrovascular Circulation

Cerebral hemodynamics and metabolism of severe diffuse brain injury measured by PET.

Cerebral hemodynamics and metabolism in three patients with severe diffuse brain injury were measured 10 days after onset using 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 (rCMRglc) and cerebral metabolic ratio (rCMRO2/rCMRglc) were measured. The Glasgow Coma Scale scores on admission were 4, 5 and 5, respectively, and CT on admission showed typical findings of diffuse brain injury. As a result, PET revealed misery perfusion and hyperglycolysis in Patient 1 and matching low perfusion and low glucose metabolism in Patients 2 and 3. Although Patient 1 died, Patients 2 and 3 had good recoveries. We speculate that a long-lasting anaerobic state, indicated by a high OEF value and low metabolic ratio, is an important undesirable factor related to the outcome.

Adolescent

A novel action of epidermal growth factor in rat granulosa cells: its potentiation of gonadotrophin action.

It is well known that epidermal growth factor (EGF) induces down-regulation of LH receptors and desensitization to gonadotrophin stimulation in gonadal cells, including granulosa cells. In a previous study we showed that EGF receptor levels in rat granulosa cells were increased up to fourfold after 96 h of culture with human GH in the presence of FSH, and the present study has evaluated the action of EGF on these cells. The induced EGF receptors were identical in size to the pre-existing receptors as assessed by affinity labelling with 125I-EGF. After 48 h in culture, various amounts of EGF (0.5-10 ng) were added and the cells were cultured for a further 48 h. The addition of EGF caused down-regulation of LH receptors in cells expressing high levels of EGF receptors. However, this down-regulation was less than that in control cells. After the cells were washed, cAMP synthesis in response to human chorionic gonadotrophin (hCG) increased by two to three times the control value and this increase was closely correlated with an increase in EGF receptor content. However, stimulation with cholera toxin or forskolin showed no such augmentation, indicating that it may not be due to quantitative alterations in G proteins and their effector systems. Induction of EGF potentiation required long-term exposure to EGF, for at least more than 24 h. In addition, progesterone synthesis was sensitive to stimulation with lower doses of hCG. These findings indicate that the activation of hGH-induced EGF receptors may potentiate gonadotrophin action in granulosa cells.

Animals

["Disproportionately large, communicating fourth ventricle" due to membranous obstruction of Magendie's foramen].

A case of disproportionately large, communicating fourth ventricle (DLCFV) with the entire ventricular system dilated symmetrically due to membranous obstruction of Magendie's foramen is reported. A 20-year-old female complained of headache and nausea. Slight papilledema was found in both eyes. CT scan and MRI showed that the entire ventricular system was dilated symmetrically, but we could not locate the cause of this disease, for example, tumor, arachnoid cyst, cerebellar malformation and so on. Although cinemode-MRI showed CSF pulsation as if CSF flowed through Magendie's foramen, we were not convinced that CSF flowed through it. We speculated that something obstructed CSF flow at Magendie's or Luschka's foramen, so surgery was performed by suboccipital craniectomy. As expected, a membranous obstruction was found at Magendie's foramen. After excision of the membrane, all symptoms improved. Postoperative cinemode-MRI clearly demonstrated CSF flow through Magendie's foramen. Ventriculoperitoneal shunting is generally effective for DLCFV, but we do not consider it the optimal treatment. The cause of DLCFV must be confirmed by suboccipital craniectomy if evidence of NPH, mass lesion or cerebellar malformation cannot be found anywhere especially around Magendie's foramen.

Adult

Basic fibroblast growth factor messenger RNA is expressed strongly at the acute stage of cerebral contusion.

Basic fibroblast growth factor (bFGF) has a neurotrophic effect both in vitro and in vivo, and is considered to play an important role in the maintenance of neuronal functions in the normal brain. Neural damage in brain contusion progresses after the primary injury of trauma because of cerebral hemodynamic and metabolic impairment including intracranial hemorrhage and/or brain swelling. Northern blot analysis of bFGF mRNA was performed in rats after cerebral contusion produced by our modified fluid percussion device. Expression of bFGF mRNA increased significantly on the second day after trauma. A possible role of bFGF is functioning to protect the critical neurons from secondary neural damage in cerebral contusion.

Actins

A modified fluid percussion device.

This report examines a modified fluid percussion device with specific improvements made to address deficiencies found in previously reported devices. These improvements include the use of a cylindrical saline reservoir made of stainless steel, placement of the reservoir in a 15-degree head-up position for the easy release of air bubbles, placement of the fluid flushing outlet and the pressure transducer close to the piston on the same plane, with both perpendicular to the direction of the piston, and adjustable reservoir volume to vary the waveform of the pressure pulse, and a metallic central injury screw secured to the animal's skull over the exposed dura. Using this device, midline fluid percussion (MFP) and lateral fluid percussion (LFP) injuries were performed in 70 rats. Histopathologic findings included diffuse axonal injury in the MFP model and cortical contusion in the LFP model. Survival rate was 41.4% in MFP animals and 100% in LFM animals when the device settings were 178 mm3 of the cylindrical reservoir and 50 degrees-60 degrees in height of the pendulum. Our results suggest that this modified fluid percussion device may offer significant improvements over previously reported fluid percussion models for use in experimental head injury.

Animals

Human growth hormone augmentation of epidermal growth factor binding sites on rat granulosa cells.

The effect of human GH (hGH) on the regulation of epidermal growth factor (EGF) receptor was investigated during differentiation of FSH-treated rat granulosa cells, which has been reported to be mediated by a cAMP-dependent mechanism. By measuring the binding of [125I]iodo-EGF to the intact cells, FSH was shown to cause increases in the number of EGF binding sites after culture for 72 h. When granulosa cells were cultured with hGH, the number of FSH-induced EGF binding sites was augmented, with a half-maximal effect at about 10 micrograms hGH/l and a maximal stimulatory concentration of 100 micrograms/l. The stimulatory effect of hGH was absolutely dependent on insulin which by itself showed stimulatory effects on EGF binding sites. Scatchard analysis of EGF binding sites indicated that treatment with hGH increased the number of EGF binding sites (17,200 sites/cell after treatment with FSH; 31,700 sites/cell after FSH plus hGH), but did not alter the binding affinity. The augmentation was observed after culturing for 48 h and increased progressively with time, reaching 280% of the level after FSH treatment by 120 h. Although progesterone synthesis was increased by hGH, the markers of cell differentiation such as cAMP synthesis and LH binding sites were suppressed, indicating hGH inhibition of the cAMP-mediated signal. The action of hGH on the EGF binding sites was not accompanied by cell proliferation. These findings indicate that hGH has a novel action on the regulation of rat granulosa cell EGF binding sites and that the granulosa cell may possess both cAMP-dependent and -independent mechanisms for expression of EGF binding sites.

Animals

Spontaneous epidural hematoma from a hepatocellular carcinoma metastasis to the skull--case report.

A rare case of acute epidural hematoma originating from a hepatocellular carcinoma metastasis to the skull in a 52-year-old male is reported. The skull metastasis and epidural hematoma were completely removed, but he died of large liver tumor. Histological examination of the removed tumor showed many sinusoid-like blood vessels, which probably lead to hemorrhage and formation of epidural hematoma.

Carcinoma, Hepatocellular

[Positron emission tomographic evaluations on hemodynamics and glucose metabolism of brain tumors and perifocal edematous tissues].

Blood flow and glucose metabolism of the tumors and perifocal edematous tissues were evaluated using positron emission tomography (PET). Thirty-one brain tumor cases were investigated 12 non glial tumors (9 meningiomas and 3 metastatic tumors) and 19 gliomas (these were classified in 5 astrocytomas, 7 anaplastic astrocytomas and 7 glioblastomas, according to the malignancy). The diagnosis were confirmed pathologically in 30 cases. Cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), oxygen extraction fraction (OEF) and cerebral blood volume (CBV) were measured by O-15 labeled gases inhalation methods. Cerebral metabolic rate for glucose (CMFglu) were measured by F-18 Deoxyglucose intravenous injection method and calculated by Hutchins's formula. The rate constant (ks) and lumped constant (LC) used in this study were the same as those published by Phelps et al. in 1979. The blood flow and glucose metabolic rates of tumors were measured by the same methods. The results were as follows: 1) Meningiomas showed very high blood flow and blood volume with a wide range. The OEF and metabolic rate for glucose (MRglu) values were very low. 2) Metastatic tumors showed the low values of blood flow, metabolic rate for oxygen (MRO2) and OEF. 3) The blood flow and MRglu values on gliomas were varied with no significant differences between the three subgroups. On the other hands, as the malignancy of the glioma increased, a statistically significant increase in blood volume and a decrease in OEF were noted. 4) The OEF values from the various types of tumors studied were significantly lower than those obtained from the normal tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

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 accelerated simultaneously in order to inhibit prolactin secretion from tumor cells.

Adenoma

[Traumatic posterior fossa hematoma].

The traumatic posterior fossa hematoma was regarded as relatively rare thing, but recently, as the result of the prevalence of CT scanners, the number of reported cases is increasing. We report nine cases of traumatic posterior fossa hematoma. We divided into two categories: one was the acute epidural hematoma, the other was the acute subdural hematoma with cerebellar contusion. Five were cases of the acute epidural hematoma, three were cases of the acute subdural hematoma with cerebellar contusion and a case had both an epidural and a subdural hematoma. All the cases had struck the occipital region and had the occipital bone fracture. The prognosis of the five cases of the acute epidural hematoma was excellent, but that of the four cases of the acute subdural hematoma with cerebellar contusion was poor and they all died inspite of the removal of the hematoma executed in three cases. We estimated that the hitting forth was extremely strong in cases of the subdural hematoma with cerebellar contusion, and that the momentary deformity of the occipital bone might injure the cerebellum directly. Once a hematoma was produced in the posterior fossa, it oppresses the brainstem and causes the acute hydrocephalus, so the state of consciousness and respiration deteriorate suddenly. In cases of the acute epidural hematoma, appropriate surgical intervention could save the patients and resulted in good outcome. But in some cases of the fulminant type acute epidural hematoma of the posterior fossa caused by tearing the sinuses, though we have not experienced, patients die before the diagnosis and treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Rapidly growing aneurysm.

A rare case of rapidly growing intracranial aneurysm is reported. The enlarged aneurysmal wall was extirpated and studied histologically. The cause of the rapid growth of the aneurysm is discussed.

Humans

Value of high-resolution computed tomography in diagnosis of petrous bone fracture.

High-resolution computed tomography (CT) was performed on 31 patients clinically suspected of having petrous bone fracture. The location of the fracture was demonstrated accurately in 28 patients (90.3%), whereas it could be diagnosed by plain skull film in only 17 patients (54.8%). The anatomic location of fractures demonstrated by high-resolution CT clearly corresponded to the clinical symptoms and signs. We have classified petrous bone fracture into five types according to the anatomic levels demonstrated on CT images. The findings indicate that high-resolution CT is extremely useful for diagnosing petrous bone fracture.

Humans