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T Nagashima

Publications and source records attributed to T Nagashima.

At least 235 records · Page 13Linked to original sources
PubMed1988

[Brain necrosis following intraoperative radiation therapy or interstitial brachytherapy].

We have experienced 8 cases of radiation necrosis which occurred following radiation therapy of malignant brain tumors. In all 8 cases, necrosis developed in the brain tissue adjacent to the tumor after intraoperative radiation or interstitial radiation therapy. Considering that the extent of necrosis usually coincides with the extent of the radiation therapy, this type of necrosis is thought to be the expected result of radiation therapy. A differential diagnosis between radiation necrosis and the recurrence of a brain tumor has been thought to be difficult to achieve. Yet with the use of a dynamic CT or an Xe-enhanced CT, differential diagnosis between these two lesions was clearly accomplished.

Adult↗
PubMed1988

[Changes in capillary permeability in experimental brain tumor].

It is still controversial whether edema fluid around a malignant brain tumor is derived from capillaries inside the tumor itself or not only from tumor vessels but also from peritumoral tissue. The purpose of this study is to clarify the region where the capillary permeability is increased using double autoradiographic method. A suspension of 1 X 10(4) rat glioma cells (RG-12) was stereotactically implanted into the right basal ganglia of C-D Fisher rats. In this model, all animals are dead 20 +/- 1 days after the implantation. Two kinds of tracers, 14C-alpha-aminoisobutyric acid (AIB) and 131I-human serum albumin (HSA), were administered 14 to 17 days after the tumor implantation. In all rats, 14C-AIB was intravenously injected 10 min before decapitation. 131I-HSA was given 10 min before decapitation in five animals (group 1), one hour before in four animals (group 2), and six hours before in three animals (group 3). Autoradiograms for 131I-HSA were exposed for initial one to two days after the decapitation, while the exposure for 14C-AIB was delayed until 4 months later. Autoradiograms of these two tracers were compared with the corresponding sections with H-E stain for neuropathological examination. In group 1, the distribution of HSA as well as AIB was quite similar to tumor itself. In group 2 and group 3, the distributions of AIB were similar to the tumor. However, the distributions of HSA were 1.4 fold larger (group 2) and 3.6 fold larger (group 3) than the tumor and expanded into the peritumoral region.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminoisobutyric Acids↗
PubMed1987

Proliferative potential of vascular components in human glioblastoma multiforme.

Sixteen patients with glioblastoma multiforme received a 1-h intravenous infusion of 5-bromo-deoxyuridine (BrdU), 150-200 mg/m2 at the start of surgery, to label S-phase cells in tumor tissue. Labeled cells of vascular components and of tumor parenchyma were detected in excised tumor specimens by indirect immunoperoxidase staining using anti-BrdU monoclonal antibodies followed by periodic acid-Schiff staining. The BrdU labeling index (LI, defined as the percentage of labeled cells in relation to the total number of cells scored) was calculated separately for vascular components and tumor parenchyma in each specimen. The BrdU LI of vascular components of glioblastoma multiforme was remarkably higher than that of normal brain (1.1%-8.7% vs. less than 0.05%). The mean BrdU LIs of vascular components and tumor cells in eight primary glioblastomas were 4.5 +/- 0.8% (mean +/- SE) and 9.9 +/- 1.1%, respectively, while the corresponding BrdU LIs in eight recurrent tumors were 2.7 +/- 0.5% and 9.3 +/- 0.7%. The differences in the BrdU LIs of primary and recurrent tumors were not statistically significant, but the BrdU LI of vascular components was consistently much lower than that of tumor cells. BrdU labeling of vascular components was inconsistent and occurred mostly in glomerular-shaped vessels, but only about 20% of them contained labeled cells. These results suggest that unusual vascular proliferation, such as the formation of glomerular-shaped vessels and endothelial or adventitial proliferation, in glioblastoma multiforme may have been programmed to slow down or even to cease at a certain stage, and is not likely to be the result of neoplastic transformation.

Adolescent↗
PubMed1987

A high prevalence of chlamydial cervicitis in postmenopausal women.

One hundred eighty-one healthy women were examined for Chlamydia trachomatis of the cervix. The results revealed a high prevalence of chlamydia-positive cases concentrated in postmenopausal ages. We would like to suggest that the primary infections occurred when the subjects were younger and that the organisms have survived for decades.

Adolescent↗
PubMed1987

Cytotoxic effect and induction of sister chromatid exchange in exponentially growing rat 9L gliosarcoma cells after brief exposure to BrdU.

The magnitude of DNA modulation in rat 9L gliosarcoma cells after a brief exposure to bromodeoxyuridine (BrdU) was studied by assaying colony-forming efficiency (CFE) and the number of sister chromatid exchanges (SCEs) per metaphase. The CFE assay showed that a 1-hr exposure to BrdU, at concentrations ranging from 10 to 1000 microM, produced a maximum cell kill of 5%. After a 2-hr exposure to 20 microM BrdU, the surviving fraction was 0.99, and even at a BrdU concentration of 1000 microM, 77% of the 9L cells survived. Compared with control cultures, the relative number of SCEs per metaphase in treated cultures was increased after a 1-hr exposure to BrdU at concentrations of 100 microM or more and after a 2-hr exposure to concentrations of 20 microM or more; no increase was observed in cells treated for 30 min with BrdU at concentrations up to 1000 microM. When the treated cells were allowed to grow in BrdU-free growth medium, the number of SCEs per metaphase returned to the control level within 24 hr, even after exposure to BrdU at concentrations as high as 1000 microM. These results demonstrate that exposure to BrdU at concentrations of up to 1000 microM for 30 min, 100 microM for 1 hr, and 20 microM for 2 hr causes little modulation of DNA.

Animals↗
PubMed1987

Biomechanics of hydrocephalus: a new theoretical model.

The finite element method (FEM), an advanced method of computer simulation, is used to examine biomechanical studies of hydrocephalus. Biot's theory of consolidation, which describes the mechanical behavior of a porous medium containing viscous fluid, is applied to represent the coupled behavior of tissue and fluid in the hydrocephalic brain. A computer simulation of the hydrocephalic process is carried out by FEM to evaluate the mathematical model. A two-dimensional finite element model is constructed using a horizontal computed tomographic (CT) slice of the brain. Specifying the material properties of the brain parenchyma, the loading characteristics, and the boundary conditions, the change of interstitial pressure, intracerebral stress distribution, and ventricular configuration are computed and graphically represented. The results of the computer simulation are compared with the findings of CT and magnetic resonance imaging of hydrocephalic patients. The progress of periventricular cerebrospinal fluid edema and ventricular enlargement is well represented by the mathematical model. The model demonstrated that stress concentration in the brain tissue and increased parenchymal hydraulic conductivity play an important role in the generation of periventricular cerebrospinal fluid edema.

Brain↗
PubMed1987

[Surgical resection of adrenal carcinoma extending into the vena cava, right atrium and ventricle: case report and review of the literature].

A case of adrenal carcinoma with the tumor thrombus extending into the right atrium and right ventricle is reported. A 46-year-old man was admitted because of abdominal distention and back pain. Angiogram, venacavography, dynamic CT, cardio-echogram and determinations of blood concentration of hormones disclosed a huge non-functional right adrenal tumor and its thrombus having extended into the right atrium and ventricle via the right adrenal vein. Right adrenalectomy and nephrectomy were followed by simultaneous removal of the tumor thrombus. The resected tumor was 14 X 11 X 7 cm in size and 880 g. The thrombus was 90 g. Pathohistological diagnosis of sarcomatoid adrenocortical carcinoma was made. The patient was discharged three weeks after operation and had been remained asymptomatic for 5 months. He died of the recurrence of the tumor on the 206th postoperative day. In the review of English and Japanese literature, 61 cases of malignant tumors extending into the right atrium were analyzed, among which only one case was an adrenal tumor. From this survey, it seems that aggressive resection would provide better survival, and a surgical excision with a use of cardiopulmonary bypass is worth trying for such conditions.

Adrenal Cortex Neoplasms↗
PubMed1986

Proliferative potential of human meningiomas of the brain. A cell kinetics study with bromodeoxyuridine.

Twenty patients with intracranial meningiomas were given a 1-hour intravenous infusion of bromodeoxyuridine (BrdU), 200 mg/m2, at the time of surgery to label tumor cells in the DNA synthesis phase (S phase). The excised tumor specimens were fixed with 70% ethanol, embedded in paraffin, sectioned, and stained by an indirect immunoperoxidase method using anti-BrdU monoclonal antibody as the first antibody. The BrdU labeling index (LI), or S-phase fraction, was determined by counting the number of BrdU-labeled cells in the tissue sections. The average LIs for nonmalignant (11 cases) and histologically malignant meningiomas (seven cases) were 0.45% and 3.9% respectively (P less than 0.05). Two hemangiopericytic variants showed average LIs of 0.53% and 4.1%. Four of seven malignant meningiomas and both hemangiopericytomas were recurrent tumors. Nine of 20 meningiomas had an LI greater than 1%, and six of those nine (67%) were recurrent. Thus, meningiomas with an LI greater than 1% appear to grow faster and recur more frequently than those with LIs less than 1%; the higher LI may indicate biological malignancy. The measurement of BrdU LI in meningioma may prove valuable in establishing the diagnosis of "malignant meningioma."

Adult↗
PubMed1986

S-phase fraction of human brain tumors in situ measured by uptake of bromodeoxyuridine.

One hundred fifty-four patients with brain tumors of various types were given an intravenous infusion of the thymidine analogue bromodeoxyuridine (BUdR), 200 mg/m2, at the time of surgery but before biopsy of the tumor to label S-phase cells. Excised tumor specimens were fixed, sectioned, and stained by immunoperoxidase methods to detect BUdR. The labelling index (LI), or percentage of BUdR-labelled cells, was calculated for each tumor specimen. The LIs of glioblastomas, medulloblastomas, and most highly anaplastic astrocytomas were 5% to 20%. The majority of moderately anaplastic astrocytomas showed LIs of less than 1%, but 30% of them had LIs similar to those of highly malignant gliomas. Most pituitary adenomas and neurinomas showed LIs of less than 1%. Nonmalignant meningiomas had LIs of less than 1%, whereas malignant meningiomas had LIs higher than 2.7%. This is an important observation, because malignant meningiomas are not well-defined histopathologically and their growth rate and rate of recurrence cannot be predicted by current diagnostic procedures. By estimating the proliferative potential of individual tumors more precisely, the BUdR LI supplements histopathological diagnosis, allowing a more accurate estimate of prognosis and facilitating the design of treatment regimens for individual patients.

Adult↗