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T Ohshima

Publications and source records attributed to T Ohshima.

At least 289 records · Page 16Linked to original sources
PubMed1991

[Roles of tumor suppressor genes in human osteosarcoma cells].

Inactivation of two tumor suppressor genes, RB and p53, is associated with tumor formation. To elucidate the molecular basis of the tumorigenesis of human osteosarcoma, structural and expressional alterations of these two genes were examined in five human osteosarcoma cell lines, two of which were from Japanese patients. In addition, I analyzed two adenovirus E1A-binding proteins, p107 and p300, putative "tumor suppressor gene products", which share similar properties with the RB protein in binding to the E1A oncoprotein. Detailed analyses of DNA, mRNA, and protein showed that (1) 3 lines including both Japanese lines lost the expression of the RB protein due to either the absence or the alteration of mRNA caused by DNA rearrangement, (2) abnormality of p53 gene was detected in all cell lines : 4 lines lost p53 expression due to either gene loss or the absence of mRNA, and one line expressed an abnormal form of the protein without detectable DNA and mRNA alterations and (3) no significant alteration of p107 or p300 was detected in all cell lines. These results further confirm that inactivating mutations of p53 and RB genes are deeply involved in the carcinogenesis of human osteosarcoma and suggest that p107 and p300 may not play a role in the tumorigenesis.

Adenovirus Early Proteins↗
PubMed1991

Histopathological study on the changes of pulmonary arteries of guinea-pigs in strangulation.

The pulmonary artery in asphyxia was observed with both light and scanning electron microscopes. The media of this vessel showed the repetition of the partially thickening of the circular muscle layers. Our observations indicate that the bead-like contraction of the pulmonary artery in asphyxia is mainly induced by contraction of the localized sphincter muscle layers.

Animals↗
PubMed1991

[A case report of adjacent tumor of sphenoid ridge meningioma and GH producing pituitary adenoma].

A case of sphenoid ridge meningioma and pituitary adenoma adjacent in the brain is reported. A 70-year-old female was admitted to our hospital with headache. She had no neurological deficit but did have acromegalic change. Hormonal examination showed elevation of plasma levels of HGH (19.0 ng/ml), with normal levels of the other hormones. CT examination revealed a tumor with calcification in the inner third of the sphenoid ridge and another in the pituitary fossa with suprasellar expansion. MRI showed flow void of ICA between these tumors. Intensity of the T1-weighted image of the tumor in the sphenoid ridge was homogeneously iso intensity, and low intensity in the pituitary fossa. The diagnosis of adjacent tumors in the sphenoid ridge meningioma and pituitary adenoma had been made preoperatively. Left front-temporal craniotomy and removal of these tumors were performed. These tumors were close to each other, but were separated by the internal carotid artery and anterior cerebral artery. Pathological examination demonstrated meningotheliomatous meningioma in the sphenoid ridge and sparsely granulated somatotroph adenoma in the pituitary fossa. Fourteen cases showing association of meningioma and pituitary adenoma, which had no history of radiation and trauma, have been reported previously. Although GH producing pituitary adenoma may stimulate adjacent dura and arachnoid cells resulting in the formation of meningioma, the possibility of coincidental occurrence of the two tumors cannot be ignored.

Adenoma↗
PubMed1991

Treatment of myelodysplastic syndromes with orally administered N-(2S, 3R)-3-amino-2-hydroxy-4-phenylbutyryl-L-leucine (ubenimex).

N-(2S, 3R)-3-amino-2-hydroxy-4-phenylbutyryl-L-leucine (ubenimex) was administered orally, to patients with myelodysplastic syndromes (MDS) and acute leukemia derived from MDS, in a multi-institute study. Out of 77 patients evaluated, one achieved a complete remission, three a good response and two a partial response while 71 failed to respond to a daily oral administration of 30 mg ubenimex. The overall response rate was 7.8% (95% confidence limits; 3.6-16.0%); 7.0% (3.0-15.4%) in 71 MDS and 16.6% (3.0-56.3%) in acute six leukemias derived from MDS. Responses continued for six to 24 (median 10.5) weeks. No serious hematologic, biochemical or clinical toxicity was encountered, except for gastro-intestinal (GI) toxicity in one patient. The present study demonstrated ubenimex not to be generally beneficial for patients with MDS, and not to be recommended as a standard treatment for the disease.

Acute Disease↗
PubMed1991

[Determining aging changes of melanin granules of human scalp hairs by image analyser].

Using electron micrographs of human hairs, we measured the minor axis and density of hair melanin granules in a 0 year old infant, 20-30 year old adult and 60-70 year old adult by an image analyser for the purpose of determining the aging changes of melanin granules of human scalp hairs. The melanin density of the outer hair cortex was higher than that of the inner hair cortex. There were no differences between the 0 year old infant and the 20-30 year old adult in the minor axis and density of melanin granules, but significant differences were evident in the minor axis between the 60-70 year old adult and the other generations. Significant differences were noted in the density of melanin granules of the inner hair cortex between the 60-70 year old adult and the other generations. As a result of the quantitative analyses, it was proved that the melanin granules of human scalp hair increase in size and decrease in number by age.

Adult↗
PubMed1990

Thermostable alanine dehydrogenase from thermophilic Bacillus sphaericus DSM 462. Purification, characterization and kinetic mechanism.

Alanine dehydrogenase (L-alanine: NAD+ oxidoreductase, deaminating) was simply purified to homogeneity from a thermophile, Bacillus sphaericus DSM 462, by ammonium sulfate fractionation, red-Sepharose 4B chromatography and preparative slab gel electrophoresis. The enzyme had a molecular mass of about 230 kDa and consisted of six subunits with an identical molecular mass of 38 kDa. The enzyme was much more thermostable than that from a mesophile, B. sphaericus, and retained its full activity upon heating at 75 degrees C for at least 60 min and with incubation in pH 5.5-9.5 at 75 degrees C for 10 min. The enzyme can be stored without loss of its activity in a frozen state (-20 degrees C, at pH 7.2) for over 5 months. The optimum pH for the L-alanine deamination and pyruvate amination were around 10.5 and 8.2, respectively. The enzyme exclusively catalyzed the oxidative deamination of L-alanine in the presence of NAD+, but showed low amino acceptor specificity; hydroxypyruvate, oxaloacetate, 2-oxobutyrate and 3-fluoropyruvate are also aminated as well as pyruvate in the presence of NADH and ammonia. Initial velocity and product inhibition studies showed that the reductive amination proceeded through a sequential mechanism containing partially random binding. NADH binds first to the enzyme, and then pyruvate and ammonia bind in a random fashion. The products are sequentially released from the enzyme in the order L-alanine then NAD+. A dead-end inhibition by the formation of an abortive ternary complex which consists of the enzyme, NAD+ and pyruvate was included in the reaction. A possible role of the dead-end inhibition is to prevent the enzyme from functioning in the L-alanine synthesis. The Michaelis constants for the substrates were as follows: NADH, 0.10 mM; pyruvate, 0.50 mM; ammonia, 38.0 mM; L-alanine, 10.5 mM and NAD+, 0.26 mM.

Alanine Dehydrogenase↗
PubMed1990

Direct determination of protein binding of phenytoin in serum by high-performance liquid chromatography.

A reliable, routine method has been developed which speeds and simplifies the determination of free phenytoin levels in serum. The free fraction of the drug was determined by a single direct injection of serum (350 microL) into a high-performance liquid chromatography (HPLC) system. The mobile phase was a mixture of isopropanol (0.5%) and pH 7.4 phosphate buffer. An internal surface reversed-phase silica column, the Pinkerton column, was used with a flow rate of 1.0 mL/min at ambient temperature, and the wavelength was set at 254 nm. The resolution of free and bound phenytoin peaks was affected by the percentage of isopropanol, the serum volume injected, and the protein concentration in the sample. The concentrations of free and bound drug agreed well with those determined by the conventional ultrafiltration method (MPS-1). The determination of protein binding by HPLC appears to be a satisfactory method for routine therapeutic drug monitoring. The factors affecting the binding and chromatographic separation and the application of this method for clinical use are discussed.

1-Propanol↗
PubMed1990

Biochemistry and biotechnology of amino acid dehydrogenases.

Over the last decade, amino acid dehydrogenases such as alanine dehydrogenase (Ala DH), leucine dehydrogenase (Leu DH), and phenylalanine dehydrogenase (Phe DH) have been applied to the enantiomer-specific synthesis and analysis of various amino acids. In perticular, amino acid dehydrogenases from thermophiles have received much attention because of their high stability. Their productivity was enhanced and the purification facilitated by the gene cloning. The advances in biotechnological applications of these enzymes are based on fundamental studies concerning characteristics of the enzymes and reaction mechanism as described in this chapter. Further elucidation of the structure and function of these enzymes based on genetic engineering and protein engineering may enable their properties to be improved for their future uses in biotechnology.

Amino Acid Oxidoreductases↗
PubMed1990

Spinal sensory and motor tract activation after epidural electrical stimulation in the cat.

Somatosensory evoked potentials (SEPs) after peripheral nerve stimulation and motor evoked potentials (MEPs) after transcranial stimulation have been routinely used as monitors of the viability of pathways in the posterior and anterior spinal cord, respectively, in patients undergoing spinal cord surgery. To assess total spinal cord function, both of these procedures must be performed simultaneously, which is both cumbersome and technically difficult. The objectives of this study were to demonstrate both sensory and motor spinal tract activation after epidural electrical stimulation of the cat spinal cord. Thirty-seven adult mongrel cats were anesthetized with ketamine, intubated, and maintained with Ethrane and nitrous oxide. Stimulating electrodes were placed over the right dorsolateral spinal cord epidurally at T7 after a laminectomy. Recording electrodes were placed over the right L3 spinal cord epidurally, on the right L7 dorsal and ventral nerve roots, on the right and left sciatic nerves in the popliteal fossa, and in the right gastrocnemius muscle. After epidural stimulation of the spinal cord at T11, distinct reproducible potentials were recorded at each site. Activity in the L7 dorsal root implicated activation of spinal sensory tracts. Activity in the L7 ventral root and in the gastrocnemius implicated activation of spinal motoneurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Synchronized discharge of taste neurons recorded simultaneously in rat parabrachial nucleus.

1. Cross-correlation analysis was made in the taste-sensitive neuron pairs recorded simultaneously from the parabrachial nucleus (PBN) of rats. Three indexes were adopted to evaluate the activities of the taste neurons; namely, 1) spike response density (RD value), which is the net spike density to stimulation with the four basic tastes; 2) the frequency of correlated discharges (FC value in spikes per second), which was determined by measuring the area of the peak appearing in the cross-correlogram (CC) during application of the test fluids; and 3) the weight of correlated discharge (WC = FC/RD), which shows the relative importance of correlated discharges in the taste signals delivered by a component neuron of a given pair. 2. In 11 of 23 pairs, the CCs exhibited peaks during stimulation with tastants. These 11 pairs, which were recorded in the pontine taste area, were composed of 18 NaCl-best (most sensitive to NaCl) and 4 HCl-best neurons. In eight pairs, the best-stimulus of both of the component neurons was NaCl, and it was HCl in one pair (homo-type pairs). The remaining two pairs were composed of an NaCl-best and an HCl-best neuron (hetero-type pairs). 3. In eight homo-type pairs (7 NaCl-best pairs and 1 HCl-best pair), each pair exhibited the maximal FC value during stimulation with the best-stimulus of the component neurons (2.3 less than or equal to maximal FC less than or equal to 26.6 Hz). In the remaining three pairs, the maximal FC values were low (0.8-1.9 Hz).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Cerebral amyloid angiopathy as a cause of subarachnoid hemorrhage.

Cerebral amyloid angiopathy is a pathologic condition characterized by the deposition of amyloid in the walls of small vessels in the cerebral cortex and meninges. Intracerebral hemorrhage is common in persons with this condition, but pure subarachnoid or subdural hemorrhage is rarely seen. Recently, the existence of two types of amyloid proteins related to cerebral amyloid angiopathy, beta protein and cystatin C, has been reported, and immunohistochemical methods using antisera to these proteins have become available. We describe a patient with fatal subarachnoid hemorrhage presumably caused by beta protein-type cerebral amyloid angiopathy, which was demonstrated immunohistochemically by using a monoclonal antibody to a synthetic peptide corresponding to residues 8-17 of beta protein. We suggest that beta protein-type cerebral amyloid angiopathy is a possible etiologic factor in subarachnoid hemorrhage of unknown cause.

Aged↗
PubMed1990

The influence of the supernatant obtained from a culture of IL-2-activated lymphocytes on human hematopoietic progenitors.

A supernatant obtained from the culture of recombinant human interleukin 2-activated lymphocytes was added to granulocyte (G)-, macrophage (M)-, and granulocyte-macrophage (GM)-progenitor assays using a plasma clot culture method. The supernatant was found to exert a suppressive influence on the colony and cluster formations of the G progenitors. This suppressive influence of the supernatant was almost completely neutralized by the addition of a combination of anti-human tumor necrosis factor alpha (HuTNF-alpha) and anti-human interferon gamma (HuIFN-gamma) antibodies, and it has been speculated that this suppressive influence of the supernatant is probably due to TNF-alpha and IFN-gamma. The numbers of M and GM progenitors increased remarkably in the assays in which the supernatant was added when compared to assays without the supernatant; this suggests that these progenitors were resistant to TNF-alpha and IFN-gamma. Among the bone marrow mononuclear cells (BMNC) excluding erythroid-rosette-forming (ERFC) or adherent cells, the influence of the supernatant on these progenitors was not significantly different. The results of our study have shown that ERFC and the adherent cells in BMNC hardly affected the appearance of the suppressive influence.

Cells, Cultured↗
PubMed1990

[Impairment of neuromuscular transmission in fatigued canine diaphragm].

The role of impairment of neuromuscular transmission in fatigued canine diaphragm was investigated by comparing the function of fatigued diaphragm with that of neuromuscular junction (NMJ)-blocked diaphragm. Diaphragmatic fatigue was produced by intermittent supramaximal stimulation of bilateral phrenic nerves. Partial NMJ blockade was obtained by vecuronium bromide administered intravenously. During control study, no fade was observed either in integrated diaphragmatic electric activity (Edi) or transdiaphragmatic pressure (Pdi). In fatigued diaphragm, Edi generated by 100 Hz showed a remarkable fade. The fade was prominent in high frequency fatigue. In NMJ-blocked diaphragm, fade was observed in Pdi as well as in Edi produced by 100 Hz. The fade of Edi by 100 Hz was prominent. In low frequency fatigue, both Pdi and Edi produced by 20 Hz test stimulation were significantly lower than control values. These results show that in addition to impairment of excitation-contraction coupling, neuromuscular blockade is involved, at least in part, in low frequency diaphragmatic fatigue.

Animals↗
PubMed1990

[Successful high-dose methylprednisolone therapy in a patient with primary myelofibrosis].

We are presenting a patient with primary myelofibrosis who responded to the High-Dose methylprednisolone therapy (1 g/day for 3 days). Three and a half years ago, a 55-year-old male was admitted to our hospital because of severe erythroblastic anemia, thrombocytopenia, splenomegaly and "dry tap" of bone marrow aspiration. Bone marrow biopsy revealed a marked fibrosis without any blastoid cell proliferations. Since a thrombocytopenia was progressive and refractory to the ordinary therapy, high-dose methylprednisolone therapy was performed which was followed by an administration of activated vitamin D3. After the therapy, hematologic improvements were achieved within a month (RBC: 284 x 10(4)/microliters----413 x 10(4)/microliters, WBC: 3,000/microliters----11,500/microliters, Plat.: 7,000/microliters----20,000/microliters). Three months after the therapy, the bone marrow biopsy and 113In scintigraphy were performed. These tests also proved marked improvement of histological features of the bone marrow and a decrease of uptake of 113In to the spleen, respectively. The patient continues to be in good condition and he is free from any medications at present time.

Bone Marrow↗
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↗