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Katsuyoshi Mineura

Publications and source records attributed to Katsuyoshi Mineura.

14 recordsLinked to original sources
PubMed2006

Surgical decision for adult optic glioma based on [18F]fluorodeoxyglucose positron emission tomography study.

A 51-year-old male presented with a 5-year history of progressive right exophthalmos and visual loss. Magnetic resonance imaging showed a right intraorbital lesion. [(18)F]fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET) revealed high uptake in the tumor. No FDG was accumulated in the remaining optic tract. He underwent removal of the tumor. The histological diagnosis was optic glioma. Six months after the operation, the tumor recurred, and a second operation was performed to spare the visual acuity of the other eye, which remained stable for 1.5 years after the first operation. However, the patient died 2 years after the first operation of liver dysfunction. Adult optic glioma tends to rapidly extend into the surrounding tissue and to affect the contralateral visual pathway. Early diagnosis and surgical intervention are imperative. In the present case, [(18)F]FDG-PET was valuable for evaluating malignancy to determine whether radical surgery was indicated to preserve the remaining visual acuity.

Fluorodeoxyglucose F18↗
PubMed2006

[Orbital schwannoma developing from the superior branch of the oculomotor nerve--case report].

Orbital schwannoma accounts for 1-6% of all orbital tumors and it is not easy to identify the origin of the tumor because of the anatomy of the orbit. A case of orbital schwannoma developing from the superior branch of the oculomotor nerve is reported. A 74-year-old female was admitted to our hospital with the chief complaint of left exophthalmus. MR imaging revealed a space-occupying lesion in the left orbit. Operation was performed through the transcranial approach. It was noticed that the tumor was developing from the nerve that runs into the superior rectus muscle or the levator palpebrae superioris muscle, and it was diagnosed as a schwannoma on frozen section histology during surgery. The tumor was successfully removed and, postoperatively, no additional defects occurred. Careful consideration of microsurgical anatomy is essential for surgery of orbital schwannoma especially when it's necessary to cut the nerves.

Aged↗
PubMed2005

Tractography for arteriovenous malformations near the sensorimotor cortices.

We sought to use diffusion-tensor imaging-based tractography to assess the relationship between the arteriovenous malformations (AVM) and the sensorimotor cortices/tracts. Three patients who had an AVM closely situated to the sensorimotor tracts were studied. The relationship between the sensorimotor tracts and the AVM was well demonstrated in all patients. Tractography was also helpful in identifying the location of the motor cortex in some of the cases.

Adult↗
PubMed2005

Positron emission tomography elucidates transport system and tumor proliferation in meningiomas.

To test the in vivo transport system and tumor proliferation of meningiomas, in comparison with gliomas, 25 patients with meningiomas and 8 gliomas underwent quantitative kinetic analysis of ([18F])fluoro-2-deoxy-D-glucose (FDG) - positron emission tomography (PET) imaging and immunohistochemical study. Kinetic analysis was obtained by calculation of the rate constants: K1 (ml/g/min), which represents the transport of FDG from plasma to tissue; k2 (min(-1)), which demonstrates the transport back from tissue to plasma; and k3 (min(-1)), an indicator of glucose metabolism, using Gjedde's plot methods in a three-compartment model. Surgical specimens were evaluated by means of three different methods: i) immunoreactivity to vascular endothelial growth factor (VEGF) and glucose transporter-1 (Glut-1), representing the permeability of tumor vessels; ii) immunostaining for von Willebrand Factor (vWF), reflecting vascular surface areas of arterioles; and iii) the MIB-1 labeling index (MIB-1 LI), representing the proliferative potential. K1 was higher in meningiomas than in gliomas and was higher in atypical than in benign meningiomas. k3 was correlated with MIB-1 LI in meningiomas, but not in gliomas. Immunohistochemically, meningiomas were less reactive to VEGF or Glut-1 than gliomas but atypical meningiomas stained more intensely than benign meningiomas. The vascular surface area was significantly larger in meningiomas than in gliomas and atypical meningiomas had high values for both permeability and surface area than benign meningiomas. High values for K1 and k3 indicate the aggressive proliferation of meningiomas and, in atypical meningiomas, the synergistic interaction of the high permeability and the large surface area yielded conditions conducive to glucose metabolism and tumor proliferation. Evaluation of K1 and k3 facilitates to predict the tumor aggressiveness and to optimize the surgical management.

Adult↗
PubMed2003

Prognostic and therapeutic indicator of fluoroboronophenylalanine positron emission tomography in patients with gliomas.

PURPOSE: Boron neutron capture therapy (BNCT) for the treatment of brain tumors has attracted attention recently, and its clinical application has been progressing. We have focused on the use of BNCT with 10B-boronophenylalanine, which preferentially delivers boron-10 atoms to malignant cells through the amino acid transport system. In the present study, we evaluated the long-term outcomes of treatments using 18F-10B-fluoroboronophenylalanine (FBPA), which is an analogue of 10B-boronophenylalanine, by investigating the prognostic significance of the metabolic values and ratios of FBPA as determined by positron emission tomography (PET) in patients with gliomas. EXPERIMENTAL DESIGN: Our subjects were 22 patients who underwent an FBPA-PET study and were followed for at least 4 months thereafter. PET parameters, such as the rate constants K1, k2, k3, and k4, were measured before treatment. Data regarding the tumors, the contralateral normal region, and the uptake ratio of FBPA between the tumor and normal tissue 40 min after injection of the tracer were compared with survival rates after the PET treatment. The survival time and the prognostic factors were tested using a Kaplan-Meier survival curve and Cox regression analysis, respectively. RESULTS: Among the clinical parameters, the histological grade of a tumor influences survival significantly. When the survival of patients with PET parameters or ratios above the median was compared with that of patients with parameters or ratios below the median, the most significant PET parameter was the K1 value of the tumor. Median survival in patients with a tumor K1 value of 0.033 ml/min (median value) or higher was 11 months, which was significantly shorter than the 77 months in patients with a K1 value below the median (P=0.0006 by generalized Wilcoxon test). CONCLUSIONS: The kinetic constants of FBPA metabolism as determined by PET can be of ancillary significance in predicting the prognosis and indicating the feasibility of BNCT in patients with gliomas. The mean survival time was significantly shorter in patients with high uptakes of FBPA. A contributing factor is the K1 value, which reflects amino acid transport activity. FBPA-PET images can allow clinicians to develop treatment plans that are better tailored to the clinical features of their patients.

Adult↗
PubMed2003

Correlation between genetic alteration and long-term clinical outcome of patients with oligodendroglial tumors, with identification of a consistent region of deletion on chromosome arm 1p.

BACKGROUND: In oligodendroglial tumors, allelic losses on chromosome arms 1p and 19q are not only diagnostic molecular markers but also statistically significant predictors of both chemosensitivity and longer recurrence-free survival. In the current study, the authors attempted to analyze 21 patients genetically and clinically, with special emphasis on the correlation between genetic alterations and long-term therapeutic results. METHODS: The authors reviewed the clinical cases of 21 patients who had undergone surgery for oligodendroglial tumors (13 oligodendrogliomas, World Health Organization [WHO] Grade II; 3 anaplastic oligodendrogliomas, WHO Grade III; 3 oligoastrocytomas, WHO Grade II; and 2 anaplastic oligoastrocytomas, WHO Grade III). Genetic testing for 1p deletions was performed using fluorescence in situ hybridization, and testing for 1p, 17p, and 19q deletions was carried out by microsatellite analysis. Survival was analyzed with univariate and multivariate Cox regression models. In addition, a high-resolution deletion map of 1p, which led to the discovery of a new deleted region on 1p, was obtained. RESULTS: Statistical analysis revealed that both loss of 1p and loss of 19q independently and significantly predicted overall survival. A high-resolution deletion map, which displayed unusually narrow deletions, revealed a new region of deletion between D1S513 and D1S458 (1p34.3-36.11). CONCLUSIONS: One of the putative tumor suppressor loci exists more proximally than ever reported. Based on the observation that 1p and 19q deletions predicted survival, the authors suggest further use of diagnostic and prognostic genetic testing in the clinical setting.

Adolescent↗
PubMed2003

A consistent region of deletion on 1p36 in meningiomas: identification and relation to malignant progression.

We analyzed the genetic aberrations on chromosome arms 1p, 10q, and 14q, which are thought to be loci that include putative tumor suppressor genes in meningiomas. We initially conducted molecular genetic testing on a total of 72 tumors including 15 atypical and 8 anaplastic meningiomas using double-target fluorescence in situ hybridization. An incidence of deletion of 1p was observed in 16.3% of histologically benign, 86.7% of atypical, and 87.5% of anaplastic meningiomas. Microsatellite analysis for loss of heterozygosity on 1p, 10q, and 14q was performed in 15 tumors (6 benign, 6 atypical, and 3 anaplastic meningiomas). We detected alimited deleted region on 1p36 in two tumors and suggest a new consistent region of deletion at 1p36.21 approximately p23 distal to D1S507 and proximal to D1S214, which spans 8.21 megabases. In addition, loss of 10q was detected in two of three secondary atypical meningiomas, and loss of 14q in two of three primary anaplastic meningiomas. We suggest that one of the putative suppressor genes is located at 1p36.21 approximately p23, and that 10q loss may contribute to the malignant progression from benign to atypical meningiomas.

Adult↗
PubMed2003

Brain fiber tracking with clinically feasible diffusion-tensor MR imaging: initial experience.

Two technical challenges must be overcome before brain fiber tracking with diffusion-tensor magnetic resonance (MR) imaging can be applied to clinical practice: Imaging time must be shortened, and image distortion must be minimized. Single-shot echo-planar MR imaging with parallel imaging technique enabled both objectives to be accomplished. Twenty-three consecutive patients with brain tumors underwent MR imaging with a 1.5-T whole-body MR system. Fiber tracts on the lesion side in the brain had varying degrees of displacement or disruption as a result of the tumor. Tract disruption resulted from direct tumor involvement, compression on the tract, and vasogenic edema surrounding the tumor. This diffusion-tensor MR imaging method with the parallel imaging technique allows clinically feasible brain fiber tracking.

Adolescent↗
PubMed2003

Spinal intramedullary tuberculoma requiring surgical treatment--case report.

A 71-year-old male presented with multiple central nervous system tuberculomas including spinal intramedullary tuberculoma manifesting as occipitalgia and left hemiparesis. He had received medical treatment for lung and testis tuberculosis. Magnetic resonance imaging revealed an intramedullary lesion at the C-2 level as well as multiple small extramedullary and intracranial lesions. His neurological symptoms gradually worsened despite intensive antituberculous therapy. The C-2 intramedullary lesion responsible for left hemiparesis was surgically extirpated. Postoperatively, his neurological symptoms improved gradually, and no recurrence was evident at the resected site. Surgical intervention is mandatory in patients with intramedullary tuberculoma if neurological symptoms deteriorate or lesions enlarge despite continuous antituberculous therapy.

Aged↗
PubMed2002

Positron emission tomography: measurement of the activity of second messenger systems.

Phosphoinositide turnover is closely connected to modulation of synaptic function and is part of an important second messenger-producing system. New radioligands for imaging second messenger systems by positron emission tomography have been developed: carbon-11-labeled 1,2-diacylglycerols. The theoretical background of second messenger imaging is described in detail and the relation between the biologically active compounds and potential tracers for imaging second messenger systems is discussed. We report informative findings on postsynaptic biological responses in the living human brain of healthy normal subjects and with various diseases.

Adult↗
PubMed2002

[Endoscopic findings in chronic subdural hematoma].

On the genesis of chronic subdural hematoma (CSH), it is one of the possible explanations that a head injury triggers uncertain cause off for the formation of the hematoma membrane, where the bleeding occurs to form and enlarge the hematoma. Although some reports on the staging classification based on computed tomography (CT) findings are available the natural course or history of the hematoma formation is not yet known. As previously reported, we have been using an endoscopically guided method in which a drainage tube is placed in the most frontal area of the cavity so as to evacuate the residual air efficiently. In this study, we analyzed the endoscopic findings in hematoma cavities and compared them with the clinical data, focusing on the post-trauma interval and recurrence of the hematoma. Between January 1999 and October 2000, we had an opportunity to observe the inner aspect of 60 hematomas in 48 patients. A trabecular structure was found in 39 hematoma cavities (65%), whereas apparent clot formation was observed in 18 cavities (30%). Septum formation leading to a multi-loculated hematoma was observed in 10 cavities (17%). Twenty-six patients with 32 hematomas with the obvious history of head injury were classified into 4 groups according to the post-traumatic interval to the surgery, which are stage I; less than 30 days, stage II; 31 to 60 days, stage III; 61 to 90 days and stage IV; more than 91 days. Clot formation and a trabecular structure were frequently seen in stages II and III. Clot formation was statistically and significantly seen in the recurrent group. The results suggest that CSHs increase in size in stages II and III, when clot formation and a trabecular structure are frequently observed. Endoscopic observation of hematomas may assist to know hematomas, and clot formation may be a warning of hematoma recurrence.

Aged↗
PubMed2002

[Relationship of direction of drainage tube and recurrence in chronic subdural hematoma].

The favorable effect of burr hole irrigation and closed drainage system has been reported in the treatment of chronic subdural hematoma (CSH). After analyzing the relationship of the direction of the drainage tube and recurrence, we have suggested that the residual air after surgery night be important as one of the factors causing recurrence. The present study included 128 chronic subdural hematomas in 102 patients who had been treated in our institute between January, 1996 and October, 2000. We attempted to place the tip of the external drain at the occipital side within the hematoma cavity between January, 1996 and December, 1998 (occipital drainage group), while we tried to insert the tip of the external drain at the frontal side using an endoscope between January, 1999 and October, 2000 (frontal drainage group). We focused on the residual air on CT, the direction of the drainage, recurrence of the hematoma and the size of the hematoma. Some statistical analyses were conducted using these factors. The recurrence rate was slightly lower in the frontal drainage group than that in occipital drainage group. There was no difference in the residual rate of air immediately after the surgery on CT and the recurrence rate between the 2 groups. However, the interval preceding the recurrence was statistically significantly longer in the frontal drainage group. A higher rate of recurrence was noted for cases in which the volume of hematoma was more than 70 ml. The residual rate of air 1 week after surgery was significantly higher in the recurrent group than in non-recurrent group. In this study, it is demonstrated that a long-standing residual of air after surgery is one of the causes of the recurrence of CSH. We must contrive to reduce the residual air after surgery for the treatment of CSH.

Adult↗
PubMed2002

[Short time bacterial endotoxins test for positron emission tomography by means of positively charged filters].

Positron emission tomography (PET) radiotracers have very short physical half-lives. It is hard to complete a bacterial endotoxins test prior to release from medical institutes. For endotoxin quantitative determination, limulus amebocyte lysate (LAL) reagent and kinetic-turbidimetry system were previously developed. We investigated the possibility of a short time test by means of positively charged filters. As a result of this study, the effects of positively charged filters on endotoin removal were over 99.5% for [18F]FDG and [18F]NaF, which were contaminated with the indicated concentration of endotoxin. Combining this filter and the kinetic-turbidimetric method, it was possible to complete a bacterial endotoxins test in 5 min prior to the patient's administration. This test should be required prior to release for PET radiopharmaceutical quality control. It has been suggested that this combination is a good method for this purpose.

Drug Contamination↗