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Biomedical subjects

S Takashima

Publications and source records attributed to S Takashima.

At least 163 records · Page 9Linked to original sources

A profound hemispheric hypoperfusion with relatively small infarcts indicates a progressing stroke.

We determined clinical features of patients who had a profound hemispheric hypoperfusion with relatively small, acute cerebral infarcts. One hundred and thirty-five patients with acute cerebral infarction underwent both magnetic resonance imaging (MRI) and cerebral blood flow (CBF) measurement in the acute phase of stroke. Eleven (8.1%) had a profound hemispheric hypoperfusion with relatively small infarcts. In these patients, magnetic resonance angiography or conventional angiography was performed, demonstrating the internal carotid artery (ICA) stenosis or occlusion on the ipsilateral side of the infarcts. MRI and CBF measurement were repeated one month later. All of 11 patients suffered from a mild consciousness disturbance, and showed a progress of neurological symptoms during a few days, indicative of a progressing stroke. Five patients of 11 concomitantly had atherosclerotic lesions in the arteries distal to the circle of Willis. The remaining six patients had only the ICA lesions. The prognosis of the former was poor and the hemispheric hypoperfusion pattern did not improved. On the other hand, the prognosis of the latter was good and the hemispheric hypoperfusion was recovered soon. In conclusion, if the collateral flow through the circle of Willis could compensate the misery perfusion, the prognosis of low-flow infarctions with ipsilateral ICA lesions might be good.

Acute Disease↗

[Brain lesion in congenital myotonic dystrophy].

Congenital myotonic dystrophy (CMyD) affects the brain, causing mental changes and psychomotor retardation. However, the pathophysiology of the brain dysfunctions in CMyD remain to be clarified. We described two cases of CMyD with brain abnormalities. Case 1 was diagnosed as having ventricular dilation at 17 days after birth, and died at 3 years and 6 months. Case 2 was diagnosed as having ventricular dilation at birth, and died at 1 year and 3 months. Pathologically, both cases showed remote hypoxic ischemic brain damage and leptomeningeal glioneuronal heterotopia (LGH). In our patients, the white matter changes may have been caused by perinatal asphyxia, and LGH by embryological abnormalities. Taken our data and those of previous reports together, it is suggested that cerebral abnormalities in CMyD are ascribed to both hypoxic ischemic changes and histogenetic abnormalities.

Asphyxia Neonatorum↗

Fukutin protein is expressed in neurons of the normal developing human brain but is reduced in Fukuyama-type congenital muscular dystrophy brain.

Fukuyama-type congenital muscular dystrophy (FCMD) results from a mutation in a gene on chromosome 9q31, fukutin, and is characterized pathologically by micropolygyria of the cerebral and cerebellar cortices. To elucidate the physiological function of fukutin as well as its pathological role in FCMD, we raised antisera against fukutin protein and observed its expression in developing human brains with or without FCMD. Western blotting using these antibodies demonstrated a 60-kd band in the fetal but not in postnatal cerebral cortex of the controls. This band appeared negligible in the brains of FCMD fetuses. Immunohistochemistry revealed the localization of fukutin in Cajal-Retzius cells, the subpial granular layer, the neuropil of the marginal zone, the cortical plate neurons, and the ventricular neuroepithelium of the fetal cerebrum. In the fetal cerebellum, fukutin immunoreactivity was localized to the external granule cell layer, molecular layer, Purkinje cells, and some internal granular cells. The immunoreactivity in these structures was reduced markedly in postnatal normal brains, as well as in an FCMD cerebrum at 23 gestational weeks. The spatial and temporal pattern of fukutin expression is compatible with its predicted role: the regulation of neuronal migration in the fetal cerebrum and cerebellum.

Adolescent↗

[Improvement of obstructive sleep apnea by uvulopalatopharyngoplasty and tonsillectomy in a case of Duchenne muscular dystrophy].

A 10-year-old boy with Duchenne muscular dystrophy (DMD) underwent uvulopalatopharyngoplasty and tonsillectomy for obstructive sleep apnea (OSA). He has snored loudly during nocturnal sleep since infancy, and OSA developed one and a half years after he was wheel chair-bound at 8 years. Magnetic resonance imaging (MRI), conventional spirometry and overnight polysomnography were performed before and after the surgery. MRI before surgery revealed moderate tonsillar hypertrophy and a long uvula which narrowed the upper airway. After the surgery, his vital capacity (VC) was not changed (% VC; from 77 to 78%), but forced expiratory volume (FEV) was improved (FEV 1.0%; from 75 to 86%). A preoperative apnea index of 32.8/hour decreased to 0.8/hour postoperatively. REM-related falls in HbSaO2 improved remarkably. The present case suggests that subjects with DMD with tonsillar hypertrophy and a redundant uvula tend to develop noctrurnal OSA earlier than DMD cases with a normal tonsil and uvula. Assessment of respiratory function, particularly FEV 1.0%, is important for determining surgical indication of OSA in patients with DMD.

Child↗

[Combination chemotherapy with vinorelbine and other cytotoxic agents for advanced breast cancer patients--a protocol of vinorelbine plus AC regimens used by the Japan Vinorelbin Study Group].

A new generation type of vinca alkaloid, vinorelbine (VNR), is a promising agent for the treatment of breast cancer patients. As a first line treatment for metastatic breast cancer, combination chemotherapy including anthracyclines plus VNR has demonstrated a high response rate and tolerability. In addition, other VNR containing regimens, such as 5-fluorouracil plus VNR, produced a 64% response rate. This evidence suggests VNR-containing combination chemotherapy may be a promising first-line treatment for breast cancer patients. In Japan, VNR is not registered, but a late phase II study has been completed. An approximately 30% response rate was obtained with its use as a monotherapy. In addition, a phase I/II study of combination VNR plus AC (adriamycin + cyclophosphamide) has been conducted. At the present time, the results are being analyzed.

Antineoplastic Agents, Phytogenic↗

[Evidence for Taxotere treatment with solid tumors].

Evidence based medicine is essential to further develop the state of the art for cancer treatments. We introduce the levels of evidence for Taxotere treatment against various solid tumors. Most evidence for Taxotere therapy was produced in other countries. However, in Japan we have some data from phase II clinical trials for the approval of Taxotere. We review these domestic results, which reveal its usefulness and toxicity in Japanese patients. In addition, we analyze the evidence from the data of clinical trials of Taxotere conducted by investigators in the USA/Europe. Japanese physicians or academies must build a consensus for the application of Taxotere to Japanese patients with solid tumors.

Antineoplastic Agents, Phytogenic↗

[Ulegyria].

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Brain↗

[A combined effect of fadrozole and tamoxifen in postmenopausal patients with recurrent breast cancer: a preliminary report: Japanese Cooperative Study Group of Fadrozole and Tamoxifen].

To elucidate the combined effects of fadrozole (nonsteroidal aromatase inhibitor) and tamoxifen, 11 postmenopausal patients with recurrent breast cancer were examined between October 1996 and June 1998. One patient, 49 years old, was ineligible due to the short period after castration. The patients were aged 53-71 years (mean 63.5). PS was 0-1. Six patients were pre-treated with tamoxifen and 6 with oral 5-FU derivatives. One had no previous treatment. The target lesions were soft tissues in 5, bone in 4, lungs in 6 and liver in 1. The response was CR in 2, PR in 2, SD (longer than 24 weeks) in 2, NC in 1 and PD in 3. Consequently, the response rate was 60% (6 out of 10 eligible cases). Hormonal concentration was measured before and after administration of two drugs in weeks 2, 4, 6, 8 and at the end of the treatment, and significant decreases in estrogens in peripheral blood were observed. Adverse effects (4 cases of low grade headache, dizziness and elevation of GOT, GPT, gamma-GTP) did not influence the continuous administration of the drugs. We conclude that combined administration of fadrozole (2nd generation aromatase inhibitor) and tamoxifen produces a good response in postmenopausal recurrent breast cancer patients, and can be a useful treatment for patients with breast cancer.

Aged↗

Localization of Estrone Sulfatase in Human Breast Carcinomas.

We generated anti-human E1-STS monoclonal antibodies to localize estrone sulfatase (E1-STS) in human breast carcinomas. In particular, we examined the MCF-7 clone E3, ZR-75-1, MDA-MB 231, and MDA-MB-468 breast cancer cell lines and 25 breast carcinomas by either immunohistochemistry or Western blotting analysis. Simultaneously, we analyzed histological data, estrogen receptor (ER) status, progesterone receptor (PgR) status and epidermal growth factor receptor (EGFR) in breast tissue. All were surgical specimens from female patients. Nine of 25 carcinomas were obtained from premenopausal women, and 16 carcinomas were obtained frompostmenopausal women. All cell lines demonstrated positive staining for E1-STS.Interestingly, fine granulated staining of E1-STS on the cell membrane was observed. In addition, Western blotting analysis detected a 65 kD protein with an E1-STS specific band in all breast cancer cell lines regardless of the presence orabsence of E2. Twenty-two of 25 (88.0%) carcinomas showed positive staining forE1-STS, whereas negative staining was observed in the interstitial tissue surrounding tumors. In the premenopausal patients, 8 of 10 carcinomas (80.0%) showed positive staining for E1-STS, whereas 14 of 15 carcinomas (93.3%) revealed positive staining in the postmenopausal patients. The frequency of E1-STS expression was relatively higher in postmenopausal patients than in premenopausal patients but not statistically significant. The intensity of immunostaining for E1-STS depended upon the size of the tumor (NS). There was no correlation between E1-STS expression and other parameters. This evidence suggests E1-STS expression may beinvolved in the development of breast cancer. Further studies are necessary to clarify the relationship between E1-STS expression and prognostic factors. Immunoreactive E1-STS may be localized in cancer cells but not in surrounding tissuesin breast cancer.

Journal Article↗

Developmental and age-related changes of dopamine transporter, and dopamine D1 and D2 receptors in human basal ganglia.

The developmental and age-related changes of the dopamine transporter (DAT), and the dopamine D1 and D2 receptor (D1R and D2R) subtypes were investigated in basal ganglia (BG) of human brain. DAT immunostaining was mainly observed in the neuropil, neurons, and glia of the striatum. The DAT-positive neuropil was detectable at 32 GW, a peak being reached at 9-10 years of age, with a decrease to 50-63 years of age. The developmental pattern of DAT immunoreactivity in neuron was similar to that of the neuropil. DAT-positive glia were observed in the BG at 32 GW, which increased slightly at 38-40 GW, and then did not obviously change until 6-8 months after birth. D2R-positive neurons were clearly observed at 19 GW, a peak being reached at 32 GW and 1-3 months of age in the globus pallidus and striatum, respectively, with a decrease after 9-10 years of age. D1R was expressed as early as D2R, but decreased after 6-8 months. Our results suggest that D1R and D2R expression is an intrinsic property of striatal neurons and is independent of dopaminergic innervation. D1R may play a more important role in neuronal maturation of the BG than D2R. D2R may be closely correlated with late neuronal development. The higher expression of DAT during adolescence may be related to function of the BG which learns complex behavioral patterns. The significance of the age-related decreases in DAT, D1R and D2R in the BG remains to be further investigated.

Adolescent↗

The electric dipole moment of DNA-binding HU protein calculated by the use of an NMR database.

Electric birefringence measurements indicated the presence of a large permanent dipole moment in HU protein-DNA complex. In order to substantiate this observation, numerical computation of the dipole moment of HU protein homodimer was carried out by using NMR protein databases. The dipole moments of globular proteins have hitherto been calculated with X-ray databases and NMR data have never been used before. The advantages of NMR databases are: (a) NMR data are obtained, unlike X-ray databases, using protein solutions. Accordingly, this method eliminates the bothersome question as to the possible alteration of the protein structure due to the transition from the crystalline state to the solution state. This question is particularly important for proteins such as HU protein which has some degree of internal flexibility; (b) the three-dimensional coordinates of hydrogen atoms in protein molecules can be determined with a sufficient resolution and this enables the N-H as well as C = O bond moments to be calculated. Since the NMR database of HU protein from Bacillus stearothermophilus consists of 25 models, the surface charge as well as the core dipole moments were computed for each of these structures. The results of these calculations show that the net permanent dipole moments of HU protein homodimer is approximately 500-530 D (1 D = 3.33 x 10(-30) Cm) at pH 7.5 and 600-630 D at the isoelectric point (pH 10.5). These permanent dipole moments are unusually large for a small protein of the size of 19.5 kDa. Nevertheless, the result of numerical calculations is compatible with the electro-optical observation, confirming a very large dipole moment in this protein.

Bacterial Proteins↗

Development of telencephalin in the human cerebrum.

Telencephalin (TLN) is a 130kDa, type 1 integral membrane glycoprotein of the immunoglobulin superfamily found in the mammalian central nervous system. TLN shows a molecular structure resembling intercellular adhesion molecules-1 and -3, and binds to the CD11a/CD18 leukocyte integrin. TLN was localized to neuronal dendrites in the telencephalic gray matter: cerebral cortex and basal ganglia. We studied immunohistochemically the expression of TLN in the developing human brain. In the hippocampus, TLN immunoreactivity appeared at 29 gestational weeks (GW), intensified subsequently, and persisted into adulthood. In the temporal cortex, labeling was weak and restricted to the cytoplasm of pyramidal neurons from 35 to 39 GW, but thereafter became diffuse and intense in the cortical layers, especially the molecular layer, by 5 months of postnatal age. The development of TLN was late compared to synaptophysin and microtubule-associated protein 2, suggesting its involvement in the functional maturation of neuronal dendrites and synapses.

Adolescent↗

Quantitative analysis of expression of mouse sialyltransferase genes by competitive PCR.

The present paper describes a rapid and systematic method for semi-quantitative analysis of the expression of sialyltransferase genes. So far, fifteen sialyltransferase cDNAs have been cloned from mice. Most of these genes are expressed in developmental stage-dependent and/or tissue-specific manners, and the expression levels of some of them are too low to detect on Northern blot analysis. To resolve how each sialyltransferase contribute to synthesize sialylglycoconjugates, it is necessary to establish the method for quantification of gene expression levels of these fifteen sialyltransferases. Therefore, we developed a competitive PCR-based method for analyzing the quantitative relationship of the gene expression of fifteen sialyltransferases. Using this method, we can investigate the levels of gene expression of sialyltransferases in various cell lines and various tissues of mice, and can accurately determine their expression levels.

Animals↗

A novel peroxisomal enzyme, D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein: its expression in the developing human brain.

D-bifunctional protein, which is a newly recognized peroxisomal enzyme (D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase), demonstrates a characteristic development of pattern in the human brain. At 13 gestational weeks (GW), D-bifunctional protein immunoreactivity first appeared in the brain. Each neuron exhibited increased immunoreactivity along with growth in size as age increased and size with age. Glial cells in the white matter showed immunoreactivity after 30 GW. On the other hand, the L-bifunctional protein immunoreactivity was reported in neurons from 23 or 25 GW and in the white matter from 12 or 14 GW. Because of polymicrogyria in conditions such as infantile Refsum disease and infantile adrenoleukodystrophy, peroxisomal enzymes are thought to play an important role in neuronal migration and possibly myelination. D-bifunctional protein may be relevant to neuronal migration and L-bifunctional protein may be involved in axonal growth and synaptic development. This study is designed to access the ontogeny of D-bifunctional protein in the human brain.

17-Hydroxysteroid Dehydrogenases↗