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Biomedical subjects

S Hidaka

Publications and source records attributed to S Hidaka.

At least 109 records · Page 6Linked to original sources
PubMed1995

The occurrence of silicon-containing particles in calcified lesions of DBA/2NCrj mice.

The crystalline structure in calcified deposits of DBA/2 mice was analysed, because understanding this is essential in assessing the significance of this species as an animal model for spontaneous soft-tissue mineralization. In order to remove the thin soft tissue which covers the lesion, the samples were bombarded with an argon beam. The uncoated samples were analysed with an electron-probe microanalyser. The deposits were composed of a calcium phosphate material. At a higher magnification, smaller particles surrounding these large deposits were found. There were three types of particles: rod-shaped (calcium phosphate), polygonal (silicate) and round (about 1 microns dia).

Animals↗
PubMed1995

Protective effect of N-benzyl-D-glucamine dithiocarbamate against renal toxicity in rats during repeated cis-diamminedichloroplatinum administrations.

The protective effects of N-benzyl-D-glucamine dithiocarbamate (BGD) against the renal toxicity caused by repeated injections of cis-diamminedichloroplatinum (DDP) were studied in rats. The rats were injected i.p. with BGD (2.0 mmol/kg) immediately after i.v. injection of DDP (20 mumol/kg), and after 10 and 20 days they received repeated treatments with the same doses of DDP and BGD. Treatment with BGD prevented nephrotoxicity after repeated DDP administrations. Repeated DDP injections increased lipid peroxidation in the kidney and decreased GSH concentration in the kidney at 5 days after the third injection of DDP. BGD treatment prevented the increase in lipid peroxidation and the decrease in the GSH concentration caused by repeated administration of DDP. The determination of activities of antioxidant enzymes in the kidney showed that catalase activity decreased after repeated DDP administrations and that superoxide dismutase activity tended to decrease. Changes in activities of these enzymes were prevented by BGD treatment. The platinum concentrations in kidney and liver were decreased by BGD treatment. These results indicate that BGD treatment prevents the accumulation of platinum in the kidney after repeated administrations of DDP, resulting in protection against the DDP-induced renal toxicity.

Animals↗
PubMed1995

[Successful adjuvant therapy of M-CSF with chemotherapy of two cases of chemotherapy resistant acute promyelocytic leukemia].

We demonstrate two conventional chemotherapy-resistant cases of acute promyelocytic leukemia (APL) who were successfully treated with macrophage-colony stimulating factor (M-CSF). Case no 1 was a 40-year-old woman who was made diagnosis of APL on June, 1992, and treated repeatedly with a conventional chemotherapy, BHAC-DMP regimen, resulting in complete remission on October, 1992. After a couple of years, she had relapse with marked growth of APL cells in bone marrow. She was treated with BHAC-AMP and modified B-triple V but could not obtain remission. Case no 2 was a 36-year-old-man with APL who was treated with BHAC-DMP and BHAC-AMP and modified B-triple V therapy. These three conventional chemotherapy regimen were not effective for him. Eight million units of human native M-CSF was administered intravenously for 14 days after the last BHAC-AMP therapy in case no 1, and for 5 days after the last modified B-triple V therapy in case no 2. After the therapy, APL cells in peripheral blood or bone marrow of both patients disappeared completely and normal hemopoietic cells increased, obtaining in complete remission in both cases. These successful cases treated with M-CSF combining chemotherapy may suggest a new therapeutic strategy for APL in addition to all-trans retinoic acid.

Aclarubicin↗
PubMed1994

Structural features unique to a new 405-nucleotide satellite RNA of cucumber mosaic virus inducing tomato necrosis.

The complete nucleotide sequence of a new satellite RNA (KN-satRNA) of cucumber mosaic virus (CMV) strain KN, isolated from tomato plants showing severe necrosis, has been determined by the analysis of a full-length cDNA clone from which biologically active transcript was produced. KN-satRNA was 405 nucleotides and is the largest among the known CMV-satRNAs. Comparison of the sequence with D-CARNA5 (335 nucleotides) revealed three extensive homologous regions, which were the 5' region (position 1-80), the 3' half (position 213-405), and a middle section (position 116-177) of the molecule. The total length of the three regions covers almost the entire molecule of D-CARNA5. Thus, it is apparent that insertions would occur at two sites of D-CARNA5, positions 81-86 and 146, to evolve the larger size satRNA. These insertions did not alter the proposed secondary structure model of Q-satRNA. The in vitro transcript of the cDNA clone of KN-satRNA induced necrosis on tomato which was identical to that of native KN-satRNA. The 3'half of the RNA contained the "necrogenic consensus" sequence reported for other satRNAs, to which the pathogenicity of KN-satRNA may be attributed.

Base Sequence↗
PubMed1994

Structural analysis of the chloroplastic and cytoplasmic aldolase-encoding genes implicated the occurrence of multiple loci in rice.

The genes AldP and AldC-a, encoding the rice chloroplastic (cp) and cytoplasmic (ct) types of aldolase, respectively, were isolated and sequenced, and their transcription start points (tsp) were determined. Organization of the two genes was found to differ greatly; AldP consisted of six exons while AldC-a consisted of two exons. The deduced amino acid (aa) sequence of AldP contained a cp stromal targeting signal, followed by a sequence that matches the experimentally determined N-terminal sequence of mature AldP. The two enzymes share only 55% aa identity. However, rice AldP had about 73% homology with the cp aldolase of spinach. Also, the homology of AldC-a with maize, spinach and Arabidopsis thaliana cytoplasmic aldolases ranged from 70 to 90%. Southern blot analyses indicated that AldP is encoded at a single locus, whereas the gene encoding the ct counterpart is distributed at three loci on the genome. This feature is quite different from those of maize and spinach, in which only one locus was found for the ct aldolase.

Amino Acid Sequence↗
PubMed1994

CD8-positive adult T-cell leukemia cells with an integrated defective HTLV-I genome show a paracrine growth to IL-2.

We describe a 50-year-old man with adult T-cell leukemia complicated by laryngeal tuberculosis whose tumor cells proliferate in response to IL-2 in a paracrine manner. On admission, the patient's white blood cell count was 17,900/mm3; 73% were abnormal lymphocytes with convoluted nuclei. FACS analysis showed that the tumor cells were CD4-negative, CD8-positive T cells. Southern blot analysis of tumor cells revealed integration of a defective HTLV-I genome lacking gag and pol genes. He was diagnosed with chronic ATL complicated by laryngeal tuberculosis. The primary leukemic cells expressed IL-2R alpha and IL-2R beta detected by FACS and Northern blot analysis and showed marked growth in response to exogenously added recombinant IL-2 in short-term cultures. Northern blot analysis did not show any IL-2 mRNA. We have previously demonstrated that primary leukemic cells from some ATL patients grow in response to IL-2 in an autocrine or paracrine manner. These results suggest that in CD8 ATL, IL-2 may be involved in a paracrine manner.

Blotting, Northern↗
PubMed1994

Elutions of metal ions from dental casting alloys and their effect on calcium phosphate precipitation and transformation.

The elution characteristics of metal ions from dental casting alloys were studied in vitro. Large amounts of nickel (0.12-4.94 mg/cm2) and chromium (< 0.01-0.63 mg/cm2) were solubilized from the surface of seven brands of nickel-chromium alloy in either 1% lactic acid or 0.05% hydrochloric acid solutions. The elution of chromium from two brands of cobalt-chromium alloys in both eluents was below the detection limit or less than 0.01 mg/cm2. The elution of tin, copper, and zinc from a gold-palladium-silver alloy in both eluents was below the detection limit or less than 0.01 and 0.04 mg/cm2. Some amounts of tin (0.19-1.92 mg/cm2) and zinc (0.56-1.73 mg/cm2) were eluted from a silver alloy in both eluents. The effects of five eluting metal ions, i.e., nickel, chromium, tin, copper, and zinc, on the conversion of amorphous calcium phosphate (ACP) to hydroxyapatite (HAP) in vitro also were studied by a pH drop method. All divalent cations except for chromium decreased the rate of HAP transformation and elongated the induction time. Nickel had an inhibitory effect comparable to 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) on the rate of HAP transformation. Tin, copper, and zinc inhibited similarly, but the inhibition was weaker than that by nickel. Chromium did not inhibit these reactions.

Calcium Phosphates↗
PubMed1994

Studies on calcium phosphate precipitation: effects of metal ions used in dental materials.

The effects of 26 metal ions, of which 23 are used in dental materials, on the conversion of amorphous calcium phosphate (ACP) to hydroxyapatite (HAP) in vitro were studied. From the effects on both the rate of HAP transformation and induction time, effects of metal ions were classified into three types; inhibitory (in the order: nickel, tin, cobalt, manganese, copper, zinc, gallium, thallium, molybdenum, cadmium, antimony, magnesium, and mercury); ineffective (cesium, titanium, chromium, iron [ferrous], iridium, palladium, platinum, silver, gold, aluminum, and lead); and stimulatory (iron [ferric] and indium). These results suggest that metal ions used in dental materials may modify the precipitation of oral calcium phosphate.

Calcium↗
PubMed1994

Localized silicon distribution in supragingival calculus from Japanese monkeys (Macaca fuscata).

Using an electron-probe microanalyser, the distribution of silicon and other elements in supragingival dental calculus in domestic Japanese monkeys (Macaca fuscata) was studied. In two out of four monkeys kept in animals centres, a localized silicon distribution was found in both fracture and oral surfaces of the calculi. The silicon-rich area consisting of silicon alone resembled opal, but the areas containing silicon and other metal ions such as magnesium, aluminium, potassium and iron resembled clay minerals. In eight domestic monkeys, including the four animals described above, abundant calculus deposits were found. However, in four captured wild monkeys and in one which had been kept for less than a year at an animal centre, no dental calculus was found. There was almost no dental plaque accumulation in captured wild monkeys. It is suggested that calculus formation in Japanese monkeys is dependent on length of exposure to a commercial diet.

Animal Feed↗
PubMed1994

Protective effects of dithiocarbamates against renal toxicity of cis-diamminedichloroplatinum in rats.

Sodium diethyldithiocarbamate (DDTC), sodium N-benzyl-D-glucamine dithiocarbamate (BGD), sodium N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), and sodium N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD) were evaluated for efficacy as inhibitors of cis-diamminedichloroplatinum (DDP)-induced nephrotoxicity in a rat model. Treatments with 2.0 mmol/kg of BGD, HBGD, and CBGD immediately after DDP (20 mumol/kg) injection effectively prevented the nephrotoxic effects of DDP, but administration of DDTC immediately after DDP injection afforded a small protection. Concurrent treatment with 0.5 or 1.0 mmol/kg of HBGD, or 1.0 mmol/kg of CBGD could prevent DDP-induced renal damage. A significant decrease in weight loss was also observed in these dithiocarbamate-rescued rats. The platinum concentrations in liver and kidney were significantly decreased by BGD, HBGD, and CBGD treatments, respectively. The antitumor efficacy of DDP in the Walker 256 carcinoma-bearing rats was not affected by administration of HBGD (1.0 mmol/kg) or CBGD (1.0 mmol/kg). The results of this study indicated that the injection of HBGD or CBGD to rats treated with DDP can protect against DDP-induced nephrotoxicity more effectively than DDTC or BGD.

Animals↗
PubMed1994

[Anoxic spell in an adult case for intracardiac repair].

We report a 51-year-old male patient with tetralogy of Fallot who had an anoxic spell during pre-bypass period before intracardiac repair. Immediately after starting sternotomy, SpO2 decreased suddenly from 83% to 30% with PaO2 of 26 mmHg. Heart rate showed an increase to 120-140 bpm with little change in blood pressure. We considered that the causes of this spell were 1) light level of anesthesia, 2) hypoxemia and 3) lack of intravascular blood volume. This case warns us that we should take care to avoid an anoxic spell in an adult case for intracardiac repair.

Anesthesia↗
PubMed1994

[Non-Hodgkin's lymphoma; initially presenting cardiac symptoms].

Two long surviving cases of cardiac lymphoma are reported. The first case was an 83-year old man with complete A-V block, congestive heart failure, and pleural effusion. Echocardiography revealed a widespread tumor from the right ventricular wall to the inner space. Cytological examination of pleural effusion showed B-cell type lymphoma. He was treated with systemic chemotherapy and achieved partial remission, continuing for more than 12 months. The second case was a 50-year old man with superior vena cava syndrome caused by a cardiac tumor occupying the whole right atrium. He was treated with partial resection of the tumor and pathological examination showed B-cell type lymphoma. Then he was treated with systemic chemotherapy for massively residual lymphoma, and achieved partial remission, continuing for more than 20 months. Both cases are in good condition under maintenance chemotherapy. In general, malignant lymphoma which is initially presenting cardiac symptoms (so called "cardiac lymphoma") is not so frequent to diagnose premortally, and its prognosis is poor because of delay of diagnosis due to the location of tumor. In addition, insufficient chemotherapy to avoid cardiac rupture or embolism of the pulmonary artery also tend to make the prognosis poor. Recently, several successful cases of cardiac lymphoma treated with systemic chemotherapy have been reported owing to the progress an diagnostic techniques, including echocardiography, CT scan, Ca-scintigraphy and MR imaging. Our experience also indicated that early diagnosis and intensive systemic chemotherapy can obtain long survival in cases of cardiac lymphoma.

Aged↗
PubMed1993

Lateral gap junction connections between retinal amacrine cells summating sustained responses.

Vertebrate retinal amacrine cells produce transient or sustained responses. Sustained depolarizing amacrine cells in the dace retina were identified by their intracellularly recorded responses to light flashes. The response amplitude produced a notable spatial summation which exceeded that of individual dendritic arbors. When sustained type amacrine cells were intracellularly injected with Lucifer Yellow and biocytin, there was extensive transfer of biocytin, but not Lucifer Yellow, to surrounding cells with similar cellular morphology. Ultrastructural analysis of the interconnections by electron microscopy revealed the presence of gap junctions at the contact area, which did not include conventional synapses. Present results demonstrate that sustained response amacrine cells make direct electrical connections between the cells of the same type and electrical coupling may contribute to extension of their receptive fields.

Animals↗
PubMed1993

Identification of three Wx proteins in wheat (Triticum aestivum L.).

Nullisomic analysis of waxy (Wx) protein of hexaploid wheat (Triticum aestivum L.) cv. "Chinese Spring" using two-dimensional polyacrylamide gel electrophoresis revealed that three Wx loci, Wx-A1, Wx-B1, and Wx-D1, located on chromosome arms 7AS, 4AL, and 7DS, produce three distinct Wx subunit groups, subunit group-A (SGA), SGB, and SGD, respectively. SGA has a higher molecular weight and a more basic isoelectric point (pI) than the other two. SGB and SGD have the same molecular weight but a slightly different pI range. Owing to the detection of these three subunit groups, we were able to identify the expression of three waxy genes in wheat endosperm and to find two types of mutants among Japanese wheat cultivars, one lacking SGA and the others SGB. These results suggest the possibility of breeding a waxy wheat.

Electrophoresis, Polyacrylamide Gel↗
PubMed1993

In vitro and in vivo evaluations of Chinese traditional (kampo) medicines as anticalculus agents in the rat.

Inhibitory effects of two Chinese traditional (Kampo) medicines, Shigyaku-san and Shikunshi-to, on the in vitro formation of calcium phosphate precipitates and the in vivo deposition of supragingival dental calculus were studied. Both had inhibitory effects on hydroxyapatite transformation and induction; effects of Shigyaku-san and Shikunshi-to were 1/100 and 1/400 of that of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP). When used topically (in drinking water) for 4 weeks, 20-40 mg/ml of Shigyaku-san or Shikunshi-to reduced the formation of dental calculus by 40-60%, while 0.03% (w/v) HEBP decreased it by 70-98%. However, when these drugs were given by gastric intubation for 2 weeks, they were all ineffective, suggesting that the observed anticalculus effects were of topical rather than of systemic origin.

Administration, Topical↗