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Biomedical subjects

J Okada

Publications and source records attributed to J Okada.

At least 145 records · Page 8Linked to original sources
PubMed1990

Marked latency change of auditory brainstem response in preterm infants in the early postnatal period.

In order to evaluate the influence of extrauterine life on auditory brainstem response in neonates, we performed serial ABR recordings twice a week in 10 preterm infants. A marked decrease of I-III interpeak latency was observed in 7 infants during the first 2 or 3 weeks after birth. Wave I latency also remarkably reduced during this period in 5. These findings were related not to the conceptional age but to the extrauterine age. In 2 infants III-V interpeak latency increased during the first 1 or 2 weeks after birth, and the rate of latency increase seemed to be inversely proportional to that of decrease of I-III interpeak latency.

Aging↗
PubMed1990

Increased activity on radiocolloid scintigraphy in splenic hamartoma.

A higher uptake of radiocolloid in a splenic tumor than in the rest of the spleen was observed in a 17-year-old boy. The pathologic diagnosis of the surgically resected tumor was hamartoma composed of anomalous mixtures of splenic elements, and radiocolloid was considered to be distributed to reticuloendothelial cells in the tumor. Radiocolloid scintigraphy, which can demonstrate the function of the reticuloendothelial system, is helpful in the diagnosis of splenic hamartoma.

Adolescent↗
PubMed1990

Analysis of premovement components of movement-related cortical potentials in patients with Parkinson's disease or brain tumors.

We have recorded movement-related cortical potentials (MRCPs) preceding voluntary finger extension in patients with Parkinson's disease and in patients with brain tumors that may involve the motor system. Three components of potential shifts preceding the voluntary movement were identified in all subjects. There were no differences between the healthy subjects and those with Parkinson's disease, or between pre- and postoperative recordings from the same parkinsonian patients in terms of onset latencies and gradients of these potential shifts. There was no evidence of MRCPs from the depth electroencephalogram recorded from the thalamic ventrolateral (VL) nucleus. After removal of the cerebellar dentate nucleus along with a tumor, MRCPs were still identified. After removal of tumors from the supplementary motor cortex and frontal association cortex, a part of the MRCPs preceding the voluntary movement was absent. The generation of MRCPs was considered not to be greatly affected by the cerebellar system because: (1) no MRCPs were detected from the thalamic VL nucleus, which is the relay nucleus of the dentato-rubro-thalamic pathway, believed to be related to voluntary movement; (2) destruction of the VL nucleus did not cause any changes in the MRCPs recorded at other sites, and (3) the MRCPs did not disappear when the dentate nucleus, an output system, was excised.

Adult↗
PubMed1990

[An autopsy case of primary intracranial squamous cell carcinoma].

An autopsied case of primary intracranial squamous cell carcinoma (PISCC) is reported, and 25 previously reported cases of PISCC, followed by the Garcia's criteria, are reviewed. A 72-year-old female was admitted to our service with chief complaints of headache and nausea on March 30, 1988. She had no neurological deficits on admission. However, CT examination revealed a round mass lesion in the left hypothalamus with dislocation of the brain stem. The cerebrospinal fluid (CSF) examination showed squamous cell carcinoma cytologically, and slightly higher levels of beta-HCG (13.0 ng/ml) and CEA (14.2 ng/ml). Because of progressive worsening in the level of her consciousness, total removal of a suprasellar tumor was performed on April 19, 1988. Gross appearance of the tumor was yellowish, soft and encapsulated. Histologically, it was squamous cell carcinoma. She did well for several days after the operation, then deteriorated. Finally she expired because of dissemination of the carcinoma on May 14, 1988. Postmortem examination revealed a large mass of squamous cell carcinoma in her right cerebellopontine angle. Except for that in the brain, no cancer was found in her body. Immunohistological study of the tumor specimen demonstrated positive for HCG in some of the large-sized neoplastic cells. Twenty-six cases of PISCC have been reported previously, so far. However, 21 cases out of the 26 PISCC were thought to have originated from intracranial epidermoid, one from the dermoid and the other one from craniopharyngioma. In the other three cases of PISCC, including the present case, the origin of the tumor was not able to be identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[A case of subacute cerebral infarction demonstrating hyperemia and crossed cerebellar diaschisis in I-123 IMP SPECT].

SPECT with N-isopropyl-p-[I-123]iodoamphetamine were performed in a 81-year-old man with cerebral infarction. In the subacute phase, the radioactivity was increased in the infarct area where fogging effect and remarkable contrast enhancement was demonstrated in X-ray CT. The contralateral cerebellar hemisphere showed reduced activity due to crossed cerebellar diaschisis (CCD). In the chronic phase, the decrement of the activity in the infarct was observed. Increased activity in the subacute phase was thought to reflect the hyperemia in the infarct, while CCD suggested the decreased metabolic activity in the lesion. The coexistence of the hyperemia and the CCD indicates flow and metabolic uncoupling, which means "luxury perfusion". This case was also thought to demonstrate atypical findings of CCD in SPECT imaging.

Aged↗
PubMed1990

[A case of pulmonary embolism diagnosed by 111In labeled platelet scintigraphy].

Although the role of 111In platelet scintigraphy is established in the diagnosis of deep vein thrombosis, its indication in pulmonary embolism remains uncertain. We performed platelet scintigraphy in a patient with recurrent pulmonary thromboembolism, which revealed abnormal accumulation in the left hilar region. Pulmonary perfusion scintigraphy performed at the same time did not show perfusion defect. However, pulmonary angiography and thromboembolectomy demonstrated recurrent embolus in the hilus. This suggested that platelet aggregation in the left hilus shown by platelet scintigraphy was indeed related with recurrence of pulmonary embolism, and platelet scintigraphy is useful in detecting new development of thrombus in patient with recurrent pulmonary thromboembolism.

Blood Platelets↗
PubMed1990

[Evaluation of pontine visualization with single photon emission computed tomography using N-isopropyl-p-(I-123)iodoamphetamine in normal and pathological cases].

Pontine visualization with single photon emission computed tomography (SPECT) using N-isopropyl-p-[I-123]iodoamphetamine (I-123 IMP) was evaluated in 99 cases including 46 cases of brain infarction, 25 of other cerebrovascular disorders and 28 of brain tumor and in 19 normal subjects. In each case, SPECT using a rotating gamma camera was started at 30 minutes after intravenous administration of 111 MBq of I-123 IMP. Transverse images were reconstructed parallel to the cantho-meatal line and displayed on films. Pontine visualization was visually classified into three grades: high radioactive accumulation confined to the pons with clear contour (Grade 3), faint accumulation with indistinct contour in the pontine region (Grade 1), the pontine accumulation was identified but its activity was less significant (Grade 2). The results showed that grade of the pontine accumulation was lower in pathological cases compared to normal subjects. Six cases with brain stem lesion demonstrated pontine accumulation of grade 1 in 4 case and of grade 2 in 2 cases. Lower grade was also revealed in 29 cases with crossed cerebellar diaschisis (CCD). No significant correlation was observed between classified grade of pontine accumulation and maximum counts of reconstructed images. We concluded that SPECT could detect brain stem lesions and that lower accumulation in pons with CCD positive cases was thought to partially reflect the reduced blood flow and metabolism in the pontine nuclei.

Adolescent↗
PubMed1989

[Comparison study of positron emission tomography, X-ray CT and MRI in parkinsonism with dementia].

In cases of Parkinson's disease, a high incidence of dementia and simultaneous pathologic changes of Alzheimer's type have been reported. X-ray CT and MRI have such good spatial resolution that they can be expected to be useful for evaluation of brain atrophy. Positron emission tomography (PET) used with 18F-2-deoxy-2-fluoro-D-glucose is considered to reflect regional function. By these techniques, brain atrophy and local cerebral metabolic rate of glucose (LCMR-glc) in patients with Parkinsonism with dementia was studied, and also compared with age-matched normal controls and senile dementia of Alzheimer type. In seven cases of Parkinson's disease with dementia, LCMRs-glc were statistically decreased in all regions in comparison with ten normal controls. LCMRs-glc in six Parkinson's disease without dementia were higher than those of demented Parkinson's disease, but significantly lower than normal controls in all regions except basal ganglia. Some aged normal controls presented cortical atrophy and a significant difference could not be seen in evaluation by MRI among these three groups. There was also no correlation between LCMR-glc and cortical atrophy. There was no significant difference of LCMR-glc between six Guamnian cases of Parkinsonism-Dementia complex (PD complex) without ALS and four cases of PD complex with ALS, and these values were significantly lower than five Guamanian and ten Caucasian normal controls. In PD complex with and without ALS, remarkable cortical atrophy and ventricular dilatation were recorded in comparison with normal controls, and correlation between decrement of LCMR-glc and cortical atrophy was indicated in frontal, parietal and temporal lobe. In Parkinson's disease with dementia and PD complex in Guam, LCMRs-glc in all regions of brain were generally lower than normal controls. These findings were different from Alzheimer's disease in which LCMR-glc have been reported to be low especially in cerebral cortex. On the other hand, cortical atrophy and ventricular dilatation evaluated by MRI and CT was apparent in PD complex, but these changes were not remarkable in Parkinson's disease. Cortical atrophy did not always correlate with the decrease of LCMR-glc and changes of LCMR-glc could reflect clinical signs such as Parkinsonism and dementia. Both PET as a functional imaging method and MRI, CT as an anatomical imaging method are useful to access the study of these diseases.

Aged↗
PubMed1989

Positron emission tomography in manganese intoxication.

We employed 6-fluorodopa to study the integrity of the nigrostriatal dopaminergic projection by positron emission tomography in 4 subjects with clinical features of mild parkinsonism caused by exposure to manganese. The 6-fluorodopa scans were normal. This finding suggests that in early manganism sufficient to cause parkinsonian deficits, damage may occur in pathways postsynaptic to the nigrostriatal system, probably involving striatal or pallidal neurons. Fluorodeoxyglucose scans showed decreased cortical glucose metabolism, the significance of which is discussed.

Adult↗
PubMed1989

Circulating activated suppressor T lymphocytes in hepatitis-associated aplastic anaemia.

Lymphocyte subpopulations were measured in the blood of 21 children with severe aplastic anaemia (SAA). Five children with hepatitis-associated AA appeared to constitute a unique group. Compared with children with idiopathic AA, four of five children had a striking increase in percentage of activated suppressor T lymphocytes, which were defined by binding of both anti-Leu 2a and anti-HLA DR monoclonal antibodies (children with hepatitis-associated AA, 21.8 +/- 19.9% [mean +/- SD], children with idiopathic AA, 2.9 +/- 1.2%). However, there was no difference in the mean absolute number of the activated suppressor T lymphocytes between the two groups, because the mean number of lymphocytes was markedly less in children with hepatitis-associated AA (0.28 +/- 0.06 x 10(9)/l) than in those with idiopathic AA (1.64 +/- 0.74 x 10(9)/l). The mean helper: suppressor T lymphocyte ratio was significantly lower in children with hepatitis-associated AA (0.58 +/- 0.74) than in those with idiopathic AA (1.22 +/- 0.44). On the other hand, we did not find such a remarkable alteration of lymphocyte subpopulations in children with non-A non-B hepatitis who did not develop AA. These findings suggested that an imbalance of lymphocyte subpopulations and T lymphocyte activation may have pathogenetic relevance in some of the children with hepatitis-associated AA.

Adolescent↗
PubMed1989

[A case of mucinous carcinoma of the skin].

We were consulted by an 81-year-old man who had been complaining of a slow-growing tumor on his abdomen for 20 years. Histologically, small islets of the tumor cells were floating in mucinous lake separated by fibrous septa, so we diagnosed this tumor as mucinous carcinoma of the skin (Mendoza). Electron-microscopically, nuclei of the tumor cells were slightly folded. There were a few secretory granules and many secretory vacuoles in cytoplasm, but no findings of decapitation secretion. Like some other authors' reports, our data suggest that this tumor has an eccrine gland origin. To our knowledge, this is the 12th case of mucinous carcinoma of the skin in the Japanese literature.

Adenocarcinoma, Mucinous↗
PubMed1989

[Effects of tooth surface treatment with the acid solutions containing metal chloride on the bond strength of a self-curing resin].

We evaluated the use of aqueous solutions containing an acid and metal chloride as a tooth surface pretreating agent. Nineteen solutions containing 10% acetic (AA), citric (CA), lactic (LA) or phosphoric acid (PA) and/or 0.11 M aluminum (Al), cupric (Cu) or ferric chloride (Fe) were prepared. The tensile bond strengths of the TBB-O initiated MENTA resin to tooth surfaces treated with the respective aqueous solutions were measured. The amount of dissolved Ca by each of the solutions was determined. The demineralization of tooth surface was mainly dependent on the pH of the aqueous solutions. There was no specific relationship between the bond strength and amount of dissolved Ca. This suggests that a high bond strength can be obtained without serious demineralization. Pretreatment with the CA-Cu, CA-Fe or LA-Cu solution markedly enhanced the bond strengths to both enamel and dentin, although these solutions demineralized tooth surface less than the solutions containing 10% PA.

Acid Etching, Dental↗
PubMed1988

Abnormalities in DNA rearrangements of immunoglobulin gene loci in precursor B cells derived from X-linked agammaglobulinemia patient and a severe combined immunodeficiency patient.

In an attempt to characterize the genes that cause immunodeficiencies such as X-linked agammaglobulinemia (XLA) and severe combined immunodeficiency (SCID) we established precursor B-cell lines by transforming the patients' bone marrow cells with Epstein-Barr viruses. DNA rearrangements of immunoglobulin JH gene loci were observed on both chromosomes in pre-B cells derived from an XLA patient. We cloned and characterized both rearranged bands from one cell line. Both of the rearrangements occurred between DH and JH gene loci without the VH-DH structure. On the other hand, JH gene loci retained the germline configuration on both chromosomes in almost all the transformants derived from a SCID patient that had been determined according to their surface markers, to be in an early precursor B-cell stage. The implications of the observations are discussed.

Agammaglobulinemia↗
PubMed1988

Assignment of a gene coding for a human T-cell antigen with a molecular weight of 40,000 daltons to chromosome 17.

Hybrid human-mouse T-cell clones reactive with Tp40 antibody, which detects cluster of differentiation (CD)7 antigen on human T lymphocytes, were established. Karyotype analysis showed that human chromosome 17 was essential for the expression of CD7 antigen. The presence of this chromosome was confirmed by enzyme analysis of galactokinase, which is coded by a gene on human chromosome 17.

Animals↗