A rare type of false negative three-dimensional CT angiography of a cerebral aneurysm.
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Aged↗
Biomedical subjects
T Yamaki
Publications and source records attributed to T Yamaki.
Changes in cerebral blood flow velocity in healthy young men during overnight sleep and while awake.
Using transcranial Doppler ultrasonography, we measured in 6 healthy young men cerebral blood flow velocity (CBFV) in the middle cerebral artery as well as oxygen saturation by a non-invasive method. Continuous recordings were taken starting from a point before the onset of sleep, throughout the duration of normal nighttime sleep, ending after awakening. During stages 2, 3 and 4, CBFV was approximately 15% lower than during the waking period preceding sleep. CBFV during rapid eye movement sleep did not differ from the presleep waking value, whereas the postsleep waking value was 6.6% lower. In 5 subjects CBFV showed a transient rise after sleep onset. Oxygen saturation was lower during sleep than during waking.
Adult↗
Deletion of complex gangliosides of human glioma cells during mitotic cell division.
Glycolipid compositions of the human glioma cell line T98G were studied during each phase of the cell cycle to see if those cell surface molecules are concerned with cell proliferation. In vitro cultured non-synchronized T98G cells are composed of ceramidemonohexoside (CMH), ceramidedihexoside (CDH), ceramidetrihexoside (CTH) and neolactotetraosylceramide (nLc4Cer) as neutral glycolipids, and of sulfatide (CS), gangliosides GM3, GM2, GD1a and several other gangliosides as acidic ones. While total glycolipid content per cellular weight was shown to be increased during the M phase, deletion of complex gangliosides particularly b-series gangliosides was recognized (p < 0.05). The glycolipid profile in other phases was fairly consistent, and there was no glycolipid molecule specific to a certain phase of the cell cycle. Relative enhancement of simple gangliosides with a decrease of complex ones during mitotic division may imply the functional involvement of complex gangliosides in cell-cell or cell-matrix attachment, which may have to be abandoned during the process of detachment from the matrix or cellular cleavage.
Cell Division↗
The salmon SmaI family of short interspersed repetitive elements (SINEs): interspecific and intraspecific variation of the insertion of SINEs in the genomes of chum and pink salmon.
The genomes of chum salmon and pink salmon contain a family of short interspersed repetitive elements (SINEs), designated the salmon SmaI family. It is restricted to these two species, a distribution that suggests that this SINE family might have been generated in their common ancestor. When insertions of the SmaI SINEs at 10 orthologous loci of these species were analyzed, however, it was found that there were no shared insertion sites between chum and pink salmon. Furthermore, at six loci where SmaI SINEs have been species-specifically inserted in chum salmon, insertions of SINEs were polymorphic among populations of chum salmon. By contrast, at four loci where SmaI SINEs had been species-specifically inserted in pink salmon, the SINEs were fixed among all populations of pink salmon. The interspecific and intraspecific variation of the SmaI SINEs cannot be explained by the assumption that the SmaI family was amplified in a common ancestor of these two species. To interpret these observations, we propose several possible models, including introgression and the horizontal transfer of SINEs from pink salmon to chum salmon during evolution.
Animals↗
Investigation of morphological change of lateral and midline fluid percussion injury in rats, using magnetic resonance imaging.
OBJECTIVE: Investigating the time course of morphological changes in experimental traumatic brain injury (TBI) in vivo helps to clarify the mechanism of TBI and develop new therapeutic modalities. We examined the morphological changes in experimental TBI, using magnetic resonance imaging (MRI) in a rat model. METHODS: We produced lateral fluid percussion injury (LFP) and midline fluid percussion injury (MFP) in rats, using the Yamaki fluid percussion device. The rats were divided into four groups: LFP, MFP, sham LFP, and sham MFP. MRI was performed with a 4.7-T magnetic resonance apparatus 2 days and 90 days after the induction of injury. T1-, T2-, and T2- weighted images were obtained using a surface coil. RESULTS: Hemorrhage, contusion, and brain edema in LFP models were detected on the 2nd day after injury, and the necrotic tissue was absorbed and replaced by cerebrospinal fluid on the 90th day. In MFP animals, we detected a small hemorrhage in the corpus callosum with minimal brain edema around the hemorrhage on the 2nd day after injury, and on the 90th day, enlarged ventricles and cisterns were observed, indicating brain atrophy. CONCLUSION: MRI, therefore, is useful for plotting morphological changes in experimental TBI in vivo. We report the novel and clinically important finding of brain atrophy after experimental TBI.
Animals↗
Mucinous adenocarcinoma arising in a giant urachal cyst associated with pseudomyxoma peritonei and stromal osseous metaplasia.
An unusual urachal lesion, which is a mucinous adenocarcinoma arising in a giant urachal cyst and is associated with pseudomyxoma peritonei and stromal osseous metaplasia of the cyst wall, was examined in a 45-year-old male. The cyst was encapsulated, measured 22 x 20 x 20 cm and weighed 3800 g. The unilocular cavity was filled with mucin. Most of the cystic cavity was lined with tall, simple or stratified columnar epithelium with a focus of papillary projection into the cavity. These findings suggest that this cystic lesion represents cystadenoma rather than a simple cyst. Foci of invasive moderately differentiated mucinous adenocarcinoma were detected in the area of macroscopic papillary fronds. Carcinoembryonic antigen and CA19-9 were immunohistochemically positive for tumor cells and their serum levels were also elevated. Stromal dystrophic calcification was extensively observed in the cyst wall with foci of osseous metaplasia. Mucinous implants, which histologically demonstrated adherent mucinous masses without epithelial components on the surface, were observed in the pelvic and abdominal cavity, indicating pseudomyxoma peritonei.
Adenocarcinoma, Mucinous↗
Supratentorial glioma manifesting as acute onset of pure motor hemiparesis--case report.
A 68-year-old male presented with an anaplastic astrocytoma deep in the sensorimotor cortex manifesting as acute pure motor hemiparesis suggestive of a vascular mechanism rather than tumor mass effect. Perfusion-weighted magnetic resonance (MR) imaging showed a significant decrease of blood flow in the sensorimotor area, where fluid-attenuated inversion recovery imaging demonstrated a prominently edematous area. Angiography also suggested ischemia with poor visualization of the precentral and central arteries. Diffusion-weighted MR imaging failed to identify the edema as cytotoxic or vasogenic due to technical problems. Brain tumors may manifest through impairment of peritumoral blood supply, which can be clarified by recent MR methods.
Aged↗
Lymphoplasmacyte-rich meningioma with clinical resemblance to inflammatory pseudotumor. Report of two cases.
Two cases of lymphoplasmacyte-rich meningioma manifesting clinical and radiological characteristics unusual for a meningioma are reported. The patient in Case 1 was a 22-year-old man with a 9-year history of bilateral visual disturbances and recent dyspnea. An en plaque skull base mass, which was partially resected, was found at surgery to extend down from the planum sphenoidale into the spinal canal to C-5. Seven years later most of the residual mass in the spinal canal had disappeared, although a localized round tumor recurred at C2-3. The patient in Case 2 was a 24-year-old woman with an original diagnosis of clival meningioma, which recurred as multiple skull base lesions that spontaneously regressed in 10 months. These two cases and others reported in the literature indicate that lymphoplasmacyte-rich meningiomas may manifest peculiar biological behavior more typical of intracranial granulomas than of meningiomas.
Adult↗
[An anaphylactic shock case after hepatic arterial infusion of zinostatin stimalamer suspension improved by anti-histaminics].
A 47-year-old man with hepatocellular carcinoma (HCC) at anterior and medical segment in the liver was treated with hepatic arterial infusion of Zinostatin Stimalamer-lipiodol suspension (SMANCS). After the 2nd infusion of SMANCS, the accumulation of lipiodol in the tumor was not good (Grade II), so additional administration was undertaken at five-weeks intervals. His systolic blood pressure immediately decreased from 120 to 60 mmHg, and he had numbness of hands, shaking chills, sweating, chest pain and numerous urticaria-like red exanthema. In spite of treatment by anti-shock agents such as steroid and catecholamines, these symptoms did not disappear, but antihistaminics greatly improved them without any serious side effects. Because of the remarkable effects of the antihistaminics and possibility of antibody production (IgE) after repeated infusions of high molecular SMANCS, this patient may have suffered anaphylactic shock caused by massive histamine release from mast cells.
Anaphylaxis↗
Familial presumed cerebral cavernous angiomas diagnosed by MRI: three generations.
Familial cerebral cavernous angiomas are rare, with an autosomal dominant pattern of inheritance. To our knowledge, 25 families with this disorder have been described. We report three family members in a direct line of descent, who all brain had lesions typical of cavernous angiomas on MRI.
Adult↗
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↗
Functional nerve growth factor receptor in von Recklinghausen neurofibromatosis: an immunocytochemical and short-term culture study.
Immunocytochemistry reveals 75 kDa low affinity type nerve growth factor receptor (NGFR) on the cell membrane of human neurofibroma cells of von Recklinghausen disease in vivo and in vitro. NGF-immunoreactivity is detected in the primary and cultured tumor cells. Growth augmentation of cultured neurofibroma cells by exogenous NGF is also confirmed. Phosphotyrosine-immunoreactivity is demonstrated by immunocytochemistry in the in vivo and in vitro neurofibroma cells suggesting possible phosphorylation of tyrosine residue in the NGFR or a cellular protein downstream of signal transduction through the ligand receptor system. These results indicate human neurofibroma cells possess functional NGFR and the growth is potentiated through the NGF-NGFR system in the paracrine and/or autocrine fashion.
Adult↗
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↗
Traumatic acute subdural hematoma localized on the superior surface of the tentorium cerebelli--two case reports.
An 8-year-old boy, who fell downstairs and struck his head, and a 62-year-old female, who hit her head in the automobile accident, presented with unusual traumatic acute subdural hematoma localized on the superior surface of the tentorium cerebelli. Magnetic resonance imaging was useful for determination of the anatomical location of the hematoma, and confirmation of absence of significant parenchymal contusion. Injury of the variant bridging vein possibly caused subdural hematoma over the tentorium.
Child↗
Cerebral venous sinus thrombosis associated with systemic multiple hemangiomas manifesting as chronic subdural hematoma--case report.
A 35-year-old male was admitted with headache, nausea, and vomiting persisting for 2 days. Computed tomography (CT) revealed a left chronic subdural hematoma. Cerebral angiography demonstrated cerebral venous sinus thrombosis (CVST). He had presented with a subcutaneous mass involving the neck at age 2 years, which was shown to be a cavernous angioma, and thereafter shown signs of consumptive coagulopathy with systemic multiple hemangiomas. Burr hole aspiration of the hematoma was performed. Seventy-two-hours later, he developed clouding of consciousness and right hemiparesis. CT revealed a fresh hematoma in the operated subdural cavity and hemorrhagic diathesis manifested. A frontotemporoparietal large craniotomy was performed to remove the hematoma. Extensive electrocauterization was required. He had a satisfactory postoperative course. Collateral venous pathways, resulting from the CVST due to systemic multiple hemangiomas, may have caused hemodynamic stress in the bridging veins which subsequently induced chronic subdural hematoma.
Adult↗
Multiple dermoid cysts on the forehead. Case report.
A 41-year-old man presented with multiple tumours on the forehead which had developed over a 20-year period. Preoperative computed tomography of the brain showed multiple subcutaneous lesions in the frontal region with no intracranial extension. Histological examination of a biopsy specimen from one of the tumours showed a dermoid cyst. The patient underwent excision of the tumours, and the resulting skin defect was covered with a full-thickness skin graft. His postoperative course was uneventful. Dermoid cysts of the head and neck are relatively rare, and usually occur in childhood as solitary lesions.
Adult↗
A case of calcification of the cervical ligamentum flavum.
We report a case of cervical myelopathy caused by the calcification of the cervical ligamentum flavum. A 42-year-old woman with gait disturbance and an episode of dysuria was transferred to our hospital on June 30, 1994. Neurological examination revealed only a mild right hemiparesis. A plain neck X-ray and a tomogram revealed a nodular calcification in the posterior part of the spinal canal at the level of C5/6. Three dimensional computed tomography clearly demonstrated that the mass consisted of three nodular structures on the vertebral lamina. Magnetic resonance images demonstrated severe compression of the spinal cord by the mass whose intensity was low. The mass was removed en bloc together with the ligamentum flavum and C5 and C6 lamina. The mass showed no continuity to the dura mater. The calcification was confined within the ligament. The patient's neurological deficits were resolved two weeks after the surgery. X-ray diffraction study demonstrated the component of the mass was found to be pure hydroxyapatite. Clinical features of calcification of the ligamentum flavum are reviewed from 85 reported cases including ours, and the difference between this calcification and the ossification of the ligament is emphasized. Calcification of the ligamentum flaum is a distinct clinical entity.
Adult↗
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↗