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Biomedical subjects

T Nagashima

Publications and source records attributed to T Nagashima.

At least 199 records · Page 11Linked to original sources
PubMed1990

Hydrocephalic oedema in normal-pressure hydrocephalus.

The hydrocephalic oedema in normal-pressure hydrocephalus (NPH) was evaluated by measurement of the relaxation time of protons of the water molecules of brain tissue. Patients with NPH were divided into two groups: shunt responders and shunt non-responders. In the group of shunt responders both T1 and T2 of periventricular white matter were significantly prolonged compared to those of controls, and shortened after shunting. Both T1 and T2 of white matter were significantly longer than of gray matter, while a reversed relationship was seen in normal controls. However, in the group of shunt non-responders, T1 of white matter was significantly prolonged, while T2 of the same area not. There was no change in either T1 or T2 of this region after shunting. Both T1 and T2 were almost the same in white and gray matter in shunt non-responders. It is suggested that periventricular abnormalities seen in various diseases may be distinguished on the basis of the relaxation behavior of protons of tissue water.

Body Water↗
PubMed1990

Changes in free water content and energy metabolism of the brain in experimental hydrocephalus.

In acute and subacute hydrocephalus periventricular oedema is most prominent. At these stages of hydrocephalus, the free water content is increased and the bound water content, to the contrary, significantly decreased in the periventricular white matter. The bioenergetic state is also altered. In the chronic stage the ratio of free-to-bound water content returns to a level near the control value, leading to a decrease of periventricular oedema by formation of alternative pathways of CSF absorption. The bioenergetic state was slightly altered at this stage.

Acute Disease↗
PubMed1990

The finite element analysis of brain oedema associated with intracranial meningiomas.

The mathematical model of vasogenic brain oedema, which was presented at the previous meeting in 1987, was applied to the analysis of peritumoural brain oedema associated with meningiomas. Magnetic resonance images of 90 patients with intracranial meningiomas were reviewed to analyze the spatial extension of peritumoural brain oedema. It is assumed that the heterogeneous pattern of distribution of peritumoural oedema reflects the variability of the compact density of the fibers in the white matter. A two dimensional finite element model was constructed with 786 triangular elements from a horizontal section of the human brain. The development of oedema, the change of interstitial pressure, the deformation of the brain and the absorption of oedema fluid could be simulated by the finite element method. The result of computer simulation represented interactive behaviour of the brain tissue, extracellular fluid, and cerebrospinal fluid in the clinical situation. The finite element method (FEM) may provide a new experimental tool to analyze the pathophysiology of vasogenic brain oedema.

Brain↗
PubMed1990

A two-dimensional, finite element analysis of vasogenic brain edema.

The authors constructed a two-dimensional model of vasogenic brain edema, using the finite element method (FEM). The model incorporates the following physical parameters: cerebrovascular hydraulic conductivity, metabolic water production, tissue hydraulic conductivity and compliance, tissue and plasma osmotic and hydrostatic pressures, cerebrospinal fluid hydrostatic pressure and absorption, intracerebral stress, and shift of brain tissue. These parameters, related by partial differential equations, were approximated numerically in time and space by the FEM. The results of computer simulation of brain edema by the FEM were compared with experimental data obtained in a feline cold injury brain edema model. Computer simulation predicted the changes observed in interstitial pressure, extent of edema, intracerebral stress distribution, and shift of brain tissue. The results indicate that the FEM, applied to a model of vasogenic brain edema, can be used to predict the time course and regional distribution of fluid accumulation and the accompanying regional stress and deformation of brain tissue.

Animals↗
PubMed1990

Changes in the components and content of biological water in the brain of experimental hydrocephalic rabbits.

Changes in biological water components and their respective content in the cortical gray matter and periventricular white matter were studied in rabbits rendered hydrocephalic by intracisternal kaolin injection. There was no change in either total water content or free or bound water content in the cortical gray matter at the various stages of hydrocephalus development. While there was no significant change in total water content in the periventricular white matter at any stage of hydrocephalus, free water content was significantly elevated and bound water content was decreased at the acute and subacute stages, with a return to relatively normal levels at the chronic stage. It is concluded that in the periventricular white matter, free water enters the brain across the ependymal lining during the acute and subacute stages of experimental hydrocephalus with a simultaneous reduction in the bound water and that there is some recovery at the chronic stage. It is suggested that alternative drainage pathways may develop in chronic hydrocephalus allowing drainage of free water in the periventricular white matter, which in turn permits bound water to return to relatively normal levels.

Animals↗
PubMed1990

[Establishment and characterization of human cholaginocarcinoma, MEC, producing carbohydrate antigen 19-9].

A new tumor cell line MEC was established from pleural effusion of a patient of cholaginocarcinoma. In tissue culture, the cell line grew in the sheet of variant cells and showed the epithelial-like pattern. Histologically, the cell line almost showed the same pattern as those in bile and preural effusion from the patient. Electron microscopic observation of this cell line showed the irregular microvilli on the surface of the cell and the desmosome between cells. The doubling time of the cell line was 40.8 hours. Chromosome counts ranged from 61 to 86. The cell line had 9 marker chromosomes and some variant chromosomes. The cell line was transplanted into the subcutaneous of nude mice and formed the tumor. It showed the moderately differentiated tubular adenocarcinoma the same pattern as the primary tumor. We have recognized the producing and releasing of CA19-9 in the serum from the tumor bearing nude mouse and supernate of the medium as the serum from the patient. The presentation of CA19-9 in the cytosol of the cell line and the tumor cells of nude mouse was recognized in Avidin-Biotin-Peroxidase Complex in immunoloperoxidase techniques. The cell line can grow in serum-free medium. On September, 1990, the cell line has been maintained from 70 passages during about 800 days.

Adenoma, Bile Duct↗
PubMed1990

[Clinical diagnosis of gliomatosis cerebri by radioimages].

Gliomatosis cerebri (GC) is a rare clinical entity characterized by diffuse and infiltrative overgrowth of the tumor cells. Most of the previously reported cases of GC were autopsy cases because the clinical diagnosis of GC has been difficult. The authors report four cases diagnosed clinically as GC. Cases 1 and 2 are females aged 19 and 69. Cases 3 and 4 are males aged 47 and 50. In the first three cases, CT findings were almost normal. MRI study, especially on its T2 weighted image (T2W1), clearly demonstrated the wide extent of the infiltration of the tumor cells along the white matter. The last case occurred in the pre-MRI era, but contrast enhanced CT showed a bilateral periventricular high density area accompanied by diffuse low density white matter. Three of them underwent echo-guided needle biopsy, and one underwent partial excision of the lesion. Histological diagnosis was glioblastoma in Cases 1 and 4, and anaplastic astrocytoma in Cases 2 and 3. Difficulty in the clinical diagnosis of GC has been based on the fact that traditional imaging studies, including CT, can not clearly show the extent of tumor cell infiltration. MRI study is a very sensitive imaging technique which can easily demonstrate the area infiltrated by glioma cells. So we may be able to make clinical diagnosis of GC, coupling the data from MRI study and brain biopsy. The authors expect that accumulation of clinical experiences of GC may give useful information for the investigation of "invasion", which is one of the major problems in the treatment of malignant gliomas.

Adult↗
PubMed1990

[Pindolol-induced rhabdomyolysis in sarcoid myopathy].

A 72-year-old man suddenly developed severe muscle weakness following the treatment with pindolol (Calvisken) for three days. Neurological examination on admission disclosed marked proximal muscle weakness with absent deep tendon reflexes. Laboratory data showed significant increase of serum CK, aldolase and myoglobin. Electromyography revealed both neurogenic and myogenic changes in all muscle tested. Skeletal muscle CT showed patchy low density areas in muscles of thigh and leg, especially in the hamstrings. Femoral muscle biopsy demonstrated a granulomatous nodule with multinucleated giant cells in the degenerated muscle fibers showing small-grouped atrophy. By Mb-PAP staining, Mb-negative fibers were randomly distributed among normally stained ones. Leu 1, 3a, 4, HLA-DR positive cells were found adjacent to the granuloma by immunoperoxidase staining. After immediate withdrawal of pindolol and treatment with steroid, he recovered muscle strength and enzyme activities were normalized in a week. Beta blockers have been known to induce muscle cramps or pain and moderate elevation of serum muscle enzymes. However, severe muscle weakness with highly elevated enzyme activities leading to rhabdomyolysis as noticed in the present case was rarely reported in the literature. Underlying sarcoid myopathy might be suspected to exaggerate this unusual case of pindolol-induced rhabdomyolysis. A careful use of pindolol is emphasized.

Aged↗
PubMed1990

[Postpolio late progressive muscular atrophy--clinical and epidemiologic analyses in 4 Japanese cases].

Four Japanese cases of postpolio progressive muscular atrophy (PPMA) of late onset were clinically studied to characterize their clinical features and discussed upon the epidemiologic viewpoint. Four male patients were included with mean age of 43.5 (30-59) years on examination, diagnosed as PPMA after the criteria by Alter (1982) and Dalakas (1986). All suffered from polio at age 10 month to 8 years (mean: 3y) between 1931 and 1957 with residual motor paresis in one limb or two. Twenty-eight to 55 (mean: 40.3) years later, subsequent muscle weakness and atrophy appeared in the limb seemingly unaffected by the initial polio attack. Marked fasciculations and occasional myalgias were noticed without sensory disturbance and bulbar as well as upper motor neuron signs. Laboratory examinations revealed moderate elevations of serum CK and protein content in SCF. No significant elevation of polio virus antibody titers was found in both serum and CSF. Electromyography showed neurogenic changes of various degrees by muscle tested. Muscle CT disclosed patchy distribution of atrophied muscles with fatty replacement in all extremities. Spinal cord MRI images were unremarkable. Scatters of small grouped atrophy and fiber type grouping were noticed on muscle biopsy specimens. These findings summarized in our cases are generally compatible with those of hereby reported PPMA cases. On reviewing the western literature and the great epidemic of polio around 1960 in Japan, an increasing number of patients with PPMA can be anticipated in near future; possibly in 10 years.

Adult↗
PubMed1990

A mathematical model for vasogenic brain edema.

A two-dimensional model of vasogenic brain edema was constructed using the FEM. The model incorporates the following physical parameters: cerebrovascular hydraulic conductivity, metabolic water production, tissue hydraulic conductivity and compliance, tissue and plasma osmotic and hydrostatic pressures, CSF hydrostatic pressure and absorption, intracerebral stress, and shift of brain tissue. These parameters, related by partial differential equations, were approximated numerically in time and space by the FEM. The results of computer simulation of brain edema by the FEM were compared with experimental data of cold injury brain edema in cats. Computer simulation predicted the observed changes in interstitial pressure, extension of edema, intracerebral stress distribution, and displacement.

Animals↗
PubMed1989

[The study on radiotherapy for hepatocellular carcinoma].

The effects of radiotherapy on hepatocellular carcinoma (HCC) were studied clinically. Involved-field radiotherapy was employed in the treatment of 27 cases with HCC (irradiation of primary tumor in 12 cases and tumor embolism in 15 cases). Adverse effects of radiation on hepatic functions were minimum, as fluctuations in choline-esterase, prothrombin time and T-bilirubin were insignificant. Changes in ICGR-15 were assessed from the aspects of radiation dose and treatment field. Aggravation was minimum when Time-Dose-Fractionation factor (TDF) was 80 and the involved filed was not more than 8 x 8 cm, but moderate pathologic changes were noted when these levels were exceeded. Clinical effect of the radiotherapy was monitored by medical imagings was remarkable, as tumor regression was evident in 82% of the primary tumors and in 92% of the tumor emboli irradiated. Histologically, improvement of at least clinical stage IIA as described by Ohboshi and Shimosato were observed in 88% of the primary tumors and 80% of tumor emboli treated. When TDF exceeded 80, improvements observed were at least IIA in all cases treated. From these results, it is clear that a TDF80 or higher dose is required for the effective radiation treatment of HCC, and that a treatment field of not more than 8 x 8 cm is safe for the TDF80 dose. As for prognosis of the cases treated with radiotherapy, significant prolongation of the survival period was achieved in the cases with nonresected HCC involved tumor emboli. Thus, radiotherapy for HCC is effective not only for the primary tumor but for tumor embolism as well, and this is a particularly useful modality for the latter.

Carcinoma, Hepatocellular↗
PubMed1989

Effect of erythropoietin on the micronucleus test.

The micronucleus test is used widely as an in vivo short-term assay for potential carcinogens. In the present study, results of the micronucleus test were affected by the rate of erythropoiesis in the bone marrow erythropoietin, a growth factor for the erythroblast, which was used to induce erythropoiesis. The highest frequency of micronucleated polychromatic erythrocytes (MPCE) and a dose-response relationship between erythropoietin doses and MPCE frequency were seen 30 hr after injection of 1,1-dimethylhydrazine (DMH) to mice administered 24 hr previously with erythropoietin. The effect of erythropoietin was maximal when erythropoietin was given 24 hr before DMH, indicating that accelerating the multiplication of erythroblasts will increase the frequency of micronuclei induced by mutagens. Induction of MPCE in the bone marrow by four other compounds--benzo(a)pyrene, 2-naphthylamine, mitomycin C, and vincristine--was also increased by pretreatment with erythropoietin.

1,2-Dimethylhydrazine↗
PubMed1989

Variability in the proliferative potential of human gliomas.

One hundred forty-three patients with gliomas of astrocytic origin (61 with glioblastomas multiforme (GM) and 82 with astrocytomas) received an intravenous infusion of bromodeoxyuridine (BUdR), 150-200 mg/m2 at the time of surgery, to label tumor cells undergoing DNA synthesis. BUdR-labeled cells were identified by the indirect immunoperoxidase method using anti-BUdR monoclonal antibodies. The percentage of BUdR-labeled cells, or BUdR labeling index (LI), was calculated by microscopic examination of selected viable areas of the tissue sections. The GMs had a median LI of 7.5%, and three quarters of these tumors had LIs greater than 5%. Highly anaplastic astrocytomas (HAAs) and moderately anaplastic astrocytomas (MoAAs) had median LIs of 2.3% and less than 1%, respectively. Among the HAAs, the LI was 1% to 5% in 56% of tumors, greater than 5% in 26%, and less than 1% in 18%. More than 60% of MoAAs had LIs less than 1%, which agrees with the slow clinical progression of this type of tumor, and the remainder had LIs of 1.4% to 9.3%. These results show that histopathologically similar tumors may have different proliferative potentials. Measuring the proliferative potential of individual gliomas is therefore crucial for predicting the prognosis more accurately and for devising more tumor-specific treatment regimens for individual patients.

Astrocytoma↗
PubMed1989

Sensory components facilitating jaw-closing muscle activities in the rabbit.

The role of oral and facial sensory receptors in the control of masticatory muscle activities was assessed from the effect of acute deafferentiation on cortically induced rhythmic jaw movements (CRJMs) in anesthetized rabbits. When a thin polyurethane-foam strip (1.5, 2.5 or 3.5 mm thick) was placed between opposing molars during CRJMs, masseteric activities were facilitated in association with an increase in the medial excursion of the mandible during the power phase. The effects varied with the pattern of CRJMs, and the rate of facilitation was greater for small circular movements than for the crescent-shaped movements. Furthermore, the response of the masseter muscle was greater in the anterior half of the muscle, where muscle spindles are most dense, than in its posterior half. It was also demonstrated that the response increased with an increase in the thickness of the test strip. In contrast, the activities of the jaw-opening muscle were not affected significantly. The duration of masseteric bursts increased during application of the test strip and the chewing rhythm tended to slow down. However, the latter effect was not significant. After locally anesthetizing the maxillary and inferior alveolar nerves, the facilitative responses of the masseter muscle to the test strip was greatly reduced but not completely abolished. Lesioning of the mesencephalic trigeminal nucleus (Mes V) where the primary ganglion cells of muscle spindle afferents from jaw-closing muscles and some periodontal afferents are located, also reduced the facilitative effects. Similar results were obtained in the animals with the kainic acid injections into the Mes V 1 week before electrical lesioning of this nucleus. In these animals the effects of electrical lesioning of the Mes V could be attributed to the loss of muscle receptor afferents since the neurons in the vicinity of the Mes V were destroyed and replaced by glial cells, whereas the Mes V neurons are resistant to kainic acid. When electrical lesioning of the Mes V and sectioning of the maxillary and inferior alveolar nerves were combined in animals with a kainic acid injection into the Mes V, the response of the masseter muscle to application of the strip was almost completely abolished. From these findings, we conclude that both periodontal receptors and muscle spindles are primarily responsible for the facilitation of jaw-closing muscle activities.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

The proliferative activity of neurilemomas.

Twenty-one patients with neurilemomas (15 intracranial and 6 intraspinal) received a 1-hour intravenous infusion of 5-bromodeoxyuridine (BrdU), 200 mg/m2 before tumor removal, to label S-phase tumor cells. Excised tumor specimens were stained by the indirect immunoperoxidase method with anti-BrdU monoclonal antibodies to determine the BrdU labeling index, or percentage of S-phase cells. The BrdU labeling index ranged from 0.1% to 3.1% (mean, 0.9%). The BrdU labeling index was greater than 1.5% in four of the 21 tumors (three trigeminal and one spinal). One acoustic tumor in a patient with neurofibromatosis type 1 had a labeling index of 1.3%, which was the highest among the acoustic tumors. The BrdU labeling indices did not correlate with the patient's age, tumor size, or the duration of signs and symptoms. There was no significant difference between the BrdU labeling indices of Antoni type A and Antoni type B tissue. The low BrdU labeling index of most of the intracranial neurilemomas coincides well with the slow growth of these tumors. As the BrdU labeling index may reflect growth potential of individual tumors, it could be used to guide the follow-up patients with incompletely resected tumor.

Adult↗
PubMed1989

Quantitation and distribution analysis of glial fibrillary acidic protein in human glioma cells in culture.

The amount and distribution of glial fibrillary acidic protein (GFAP) were determined by flow cytometry (FCM) and an enzyme-linked immunosorbent assay (ELISA) in five human glioma cell lines stained by the indirect immunofluorescence method using anti-GFAP monoclonal antibody. Standard reference beads containing a known amount of fluorescein were used to calibrate the flow cytometer; however, the intensity of fluorescence from these beads was too weak to allow direct comparison with the fluorescence from the stained cells. Therefore, the flow cytometer was recalibrated using reference beads with a fluorescence intensity similar to that of the glioma cells. By comparing the fluorescence intensities of the two types of reference beads, it was possible to determine the fluorescein content of the stained cells directly from the relative fluorescence intensity (channel number). Glioma cell lines 343 MGA, SF 126, SF 188, U 251, and U 87 had fluorescein concentrations of 72.0 +/- 6.8, 8.1 +/- 0.3, 52.6 +/- 3.1, 86.4 +/- 4.0, and 56.2 +/- 2.9 x 10(5) (mean +/- standard error) Eq Sol Mol (equivalent solution of mole), respectively. The GFAP content of these cell lines, determined by ELISA, was 15.7 +/- 5.2, 0.5 +/- 0.1, 11.1 +/- 2.0, 20.8 +/- 4.6, and 9.5 +/- 2.7 pg GFAP/cell, respectively, and correlated closely with the results of FCM (R = 0.983, p less than 0.0028). A linear regression analysis yielded the following equation: pg GFAP/cell = -2.3376 + 0.2518 x FCM integrated mean channel number (fluorescein concentration: 10(5) Eq Sol Mol).(ABSTRACT TRUNCATED AT 250 WORDS)

Enzyme-Linked Immunosorbent Assay↗