Biomedical subjects

Y Kyuma

Publications and source records attributed to Y Kyuma.

At least 19 recordsLinked to original sources

PubMed1996

Cosmetic reconstruction after mastoidectomy for the transpetrosal-presigmoid approach: technical note.

OBJECTIVE: We describe the technique of cosmetic reconstruction after mastoidectomy in the transpetrosal-presigmoid approach for petroclival lesions. TECHNIQUES: This technique involves raising a single temporo-occipital bone flap and cosmetic mastoidectomy, removing the mastoid bone fragments (by means of a rongeur instead of an air drill) for later reconstruction. Replacement of the bone fragments mixed with fibrin glue enables tamponade against the dura to be achieved without a fat graft. RESULTS: Computed tomographic scans and plain cranial films taken a few years later showed successful reconstruction of the mastoid bone with a good appearance of the retromastoid area in seven patients who underwent this procedure. The only complication was infection in one patient from cerebrospinal fluid leakage from the wound. CONCLUSION: We have developed a simple and easy technique of cosmetic reconstruction after the transpetrosal-presigmoid approach.

Bone Transplantation↗

PubMed1993

Urinary epidermal growth factor in patients with gliomas: significance of the factor as a glial tumor marker.

Epidermal growth factor (EGF) content in urine from patients with glial tumors was examined by radioimmunoassay techniques with labeled human EGF and its rabbit EGF polyclonal antibody. There was no cross-reaction with transforming growth factor-alpha, which has a common receptor with EGF. Forty glial tumors were divided into three groups according to the clinical stage: Samples from Group A patients were obtained before therapy and/or after biopsy; in these patients a large volume of tumor was apparent on computerized tomography (CT). Group B samples were obtained after gross total removal of the tumor and/or chemo- and radiation therapy; these patients showed a small volume of residual tumor on CT. Samples from Group C patients were obtained after gross tumor total removal and/or chemo- and radiation therapy; no tumor was detected on CT scans in these patients. Urinary EGF levels in Group A samples were statistically significantly higher than in samples from healthy individuals (p < 0.001), Group B patients (p < 0.10), and Group C patients (p < 0.02). In addition, high-grade glial tumors in Group A cases showed a significantly higher level of urinary EGF than low-grade tumors in Group A patients (p < 0.05), or patients with meningioma (p < 0.02), metastatic brain tumor (p < 0.05), and cerebral infarction (p < 0.001). Longitudinal changes of urinary EGF levels in glioma patients mostly synchronized with the clinical course and therapeutic interventions. Therefore, urinary EGF, as a glial tumor marker, may be of practical value for diagnosing a malignant glioma and evaluating for the efficacy of chemo- and radiation therapy.

Adolescent↗

PubMed1993

[Treatment results of intra-arterial ACNU infusion chemotherapy for primary cerebral malignant lymphoma].

From May, 1987 to January, 1991, eight patients harboring primary cerebral malignant lymphoma (primary, six cases; recurrent, two cases) were treated by intra-arterial ACNU infusion chemotherapy. All but two cases also had hyperosmotic blood brain barrier (BBB) modification. Six primary cases had conventional teletherapy of 46-58.7 Gy (average 54.1 Gy) and one recurrent case had been irradiated again by 18 Gy. The follow-up period was 3 to 67.5 months (average 21.4 months). In six cases demonstrating measurable tumors on diagnostic images, all showed a complete response. The 1- and 2-year survival time was 50.0% and 37.5%, respectively, with a median survival time of 13.0 months. These were somewhat better than our previous results, but not better than those in the literature. Although intra-arterial ACNU infusion chemotherapy with BBB modification was not considered superior to other chemotherapy regimens, it yielded some long-surviving cases. Hence this chemotherapy is still worth using for treatment of primary cerebral malignant lymphoma.

Adult↗

PubMed1992

Stereotactic radiosurgery using a linear accelerator.

A basic and clinical study of radiosurgery using the linear accelerator (Linac) system for unremovable deep-seated brain tumors is reported. A Komai stereotactic ring was used to locate the target coordinates. The patient was laid on the Linac treatment table and held in the head fixation system. Irradiation was given in five positions. The dose profile by film dosimetry and Rando phantom was satisfactory. Seventeen tumors in 14 patients were treated. Clinical or histological diagnoses were nine metastases, one benign and two malignant gliomas, one meningioma, and one craniopharyngioma. Tumor sizes were between 8 and 30 mm. Doses were between 12 and 30 Gy. Computed tomographic evaluation after 3 months of 12 tumors in 11 survivors showed one complete remission, three partial remission, six no change, and two partial deterioration. For progressive tumors, Linac radiosurgery results are excellent.

Adult↗

PubMed1991

Subarachnoid dissemination of pineal germinoma 9 years after radiation therapy without local relapse--case report.

A 22-year-old female developed intracranial and spinal subarachnoid metastases 9 years after radiation therapy for a pineal germinoma. Computed tomographic scans showed no evidence of local recurrence. Cerebrospinal axis irradiation achieved total remission. Delayed subarachnoid dissemination may be caused by germinoma cells remaining dormant in the subarachnoid space, outside the radiation field.

Brain Neoplasms↗

PubMed1990

[Intra-arterial infusion of high dose methotrexate therapy in recurrent gliomas].

Intra-arterial high dose methotrexate (MTX) infusion therapy for ACNU resistant recurrent gliomas was reported. MTX was administered 16 times to 6 patients. In all cases, 20% mannitol was infused to produce a reversible osmotic blood brain barrier disruption. Dosage of infused MTX was 1,000-2,000 mg per an artery. One case revealed a complete response on CT. Another case showed an intratumoral necrosis. Intra-arterial high dose MTX infusion yielded high arterial and cerebrospinal fluid concentration of MTX. No critical complications were experienced. Dosage of MTX, an interval between the therapies and proper timing to start leucovorin rescue will be discussed.

Adult↗

PubMed1990

[Management results of primary intracranial malignant lymphoma].

Nineteen cases of primary malignant lymphoma of the central nervous system were reported. The clinical characteristics, diagnostic procedure and therapeutic method, especially concerning chemotherapy, were analysed. The following conclusions were obtained: 1) histological classifications and surgical procedures were not factors involved in prognosis. 2) radiotherapy was regarded as an effective but a palliative treatment. 3) combined chemotherapy for systemic malignant lymphoma, such as VEMP, VEP, COPP, seemed to be of little use for intracranial malignant lymphoma. 4) intra-arterial administration of high-dose methotrexate, ACNU and intravenous administration of high-dose cytosine arabinoside can be expected to be a useful chemotherapeutic approach.

Adolescent↗

PubMed1989

[Basic study on MRI guided stereotaxic surgery].

In 1987, we started MRI guided stereotaxic surgery using BRW-MRI apparatus. As distortion of image had been noted around the periphery of MRI due to the characteristic static magnetic field, we examined accuracy of data before clinical application. The MRI machine was a MRT-15A, 0.15 Tesla resistive type made by Toshiba. The stereotaxic apparatus consisted of a head ring, which was fixed to the patient's head, a cubical localizer frame which was attached to the head ring for the scanning phase, and a programmed computer. The localizer frame had multitubular channels, which could be fixed and drained easily with whatever paramagnetic fluid was desired. Since the beginning of our use of the instrument, we have used petroleum jelly. This material produced sufficient localizer image for us to fully determine any MRI scan plane. Once the MRI scan target had been identified, it could be approached stereotaxically in a same way as was done in the CT-related one. In the examination, at first, we studied the MRI image of a grid phantom, or the localizer frame placed on the center of the magnetic field. In the MRI, distortion of the image was seen only at the periphery of the Z axis. Secondly, we calculated the three-dimensional coordinates of the center of tumors in axial, coronal and sagittal images for correlation. But, the target values did not differ by over 5.1 mm. Therefore we concluded that the distortion of the image had minimum effect on surgery. Thirteen surgical operations were performed for brain tumors. Among these surgical interventions biopsy alone was performed in 8 cases, and biopsy combined with brachytherapy was performed in 5 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Brachytherapy↗

PubMed1986

[Controlling precocious puberty--surgical excision of hypothalamic hamartoma causing precocious puberty].

Among the causes of precocious puberty, hypothalamic hamartoma comprises a small percentage. However, the frequency of precocious puberty in the presence of hypothalamic hamartoma is quite high. Recently, results of surgery in 14 cases of hypothalamic hamartoma were reported. Precocious puberty completely subsided in three cases and slight improvement was achieved in another three cases. We performed surgery in four patients with hypothalamic hamartomas, with the goal of decreasing the symptoms of precocious puberty. The patients were two females (aged 1 yr, 3 mo and 6 mo) and two males (aged 3 yr, 7 mo and 1 yr, 9 mo). The main symptoms were precocious puberty and mental retardation of varying degrees. The males had excessive growth of body and external genitalia, while the females had genital bleeding and premature breast development. In each case, computed tomographic scans disclosed a round, isodense mass in the interpeduncular cistern, attached to the base of the hypothalamus. Contrast enhancement was negative. Endocrinologically, in case 1, testosterone was 92.6 ng/ml, FSH was 16 mIU/ml, and LH was 2.2 mIU/ml. Although LH was within normal limits, it overresponded to LH-RH stimulation. In case 2, estrogen was 13.5 ng/day, LH was 5.2 mIU/ml, FSH was 5.3 mIU/ml, and LH showed an exaggerated response to LH-RH stimulation. In case 3, testosterone was 362 ng/ml, LH was 8.8 mIU/ml, FSH was 4.8 mIU/ml, and LH showed an abnormally high response to LH-RH stimulation. In case 4, LH was 18.4 mIU/ml, FSH was 12.0 mIU/ml, and both hormones were stimulated abnormally strongly by LH-RH.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗

PubMed1985

Hypothalamic hamartoma successfully treated by operation. Case report.

An 18-month-old boy was diagnosed as having a hypothalamic hamartoma. When he was 1 year old, he developed precocious puberty, and at 18 months old, endocrinological tests revealed abnormally high follicle-stimulating hormone, luteinizing hormone, and testosterone levels. The center of the hamartoma was subtotally excised, as confirmed on the postoperative computerized tomography scan. Precocious puberty subsided after the operation.

Brain Neoplasms↗

PubMed1984

CT findings in patients with gliomas, surviving more than 10 years.

After reviewing the latest CT scans of 23 mostly low grade glioma patients who survived more than 10 years after treatment, it was suggested that loss of the original tumour bulk and frequently the presence of porencephalic cavity replacing the original tumour, with a smooth lining which is not contrast-enhanced is essential to assume a clinical "cure" in the case of intrinsic cerebral gliomas. In the case of gliomas growing within the ventricle or subarachnoid space, tissue with calcium deposit but without contrast-enhancement was noted, although the number of cases was limited.

Adolescent↗

PubMed1984

[Treatment of recurrent gliomas].

In operation for gliomas, it is our principle to remove extensively by sucker dissection technique. But, in many cases, we cannot achieve total removal because of invasion of tumor cells into the deep or vital structure. Postoperatively we apply irradiation, chemotherapy and immunotherapy in every cases. Even after multimodality treatment, recurrence may be inevitable. In order to check the recurrence as early as possible, we took follow-up CT scan regularly. When the recurrence appeared on CT scan, we actively performed reoperation. In this paper, we present characteristics of follow-up CT scan and result of the reoperation. Since introduction of CT scan in 1977, we have followed 30 supratentorial malignant gliomas and 16 supratentorial low grade gliomas postoperatively. CT scan was taken in every three months to check the course of contrast enhancement. After removal of the tumor, round low density area appeared on CT scan showing residual cavity. By contrast enhancement, various shape of high density area were seen. We divide the postoperative CT scan in 4 types by mode of contrast enhancement. In the type 1, enhanced area was persistent around the low density area. In the type 2, enhanced area was present around the low density area just after operation, but gradually disappeared. In the type 3, no enhanced area was present. In the type 4, dissemination occurring late after operation. Among the malignant gliomas, 12 cases belonged to the type 1, 6 cases to the type 2, 10 cases to the type 3, and 2 cases to the type 4. Among the low grade gliomas, 3 cases belonged to the type 1, 2 cases to the type 2, and 9 cases to the type 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1984

[Chemotherapy for experimental subarachnoid dissemination model of brain tumor].

Chemotherapy was applied for experimental subarachnoid dissemination model of brain tumor which was established in male Wister-SPF (SLC) rats inoculated intracisternally with 2 X 10(5) C6 rat glioma cells. Nontreated animals died about 24 days after inoculation. Autopsy findings of the animals showed localized or multifocal invasion of the tumor on leptomeninges in cisterna magna, and partially infiltration into the parenchyma of the cerebellum and medulla oblongata. Three days after inoculation, the tumor deposition and proliferation already occurred. Several tumor cell layers were found in the subarachnoid space over the cerebellomedullary surface. Tumor bearing animals were at first treated by single agent. These are ACNU administered intraperitoneally, methotrexate administered intracisternally, and OK-432 administered intraperitoneally. In the next stage, combination of these drugs was applied. ACNU, 3 mg/kg i. p., on Day 3, was effective in elongation of median survival time by 23.6%, statistically significant (P less than 0.02). Methotrexate, 0.25 mg/kg i.th., on Day 3, was also effective in elongation of median survival time by 8.4%, statistically significant (P less than 0.05). OK-432, 0.1 KE/kg i. p., daily, 14 times, from Day 3 to Day 16, was ineffective in elongation of median survival time. Combination of ACNU, methotrexate and OK-432, in the same schedule as described above, produced the longest median survival time of 42.4%, statistically significant (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1981