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I Nishida

Publications and source records attributed to I Nishida.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Twenty-six-week intravenous toxicity study of montirelin hydrate (NS-3) in rats followed by 9-week recovery test].

A repeated dose toxicity study of montirelin hydrate (NS-3), a new drug for the treatment of disturbance of consciousness, was conducted in Sprague-Dawley rats. Male and female rats were given the drug intravenously for 26 weeks at doses of 0 (control), 0.0004, 0.02, 1 and 50 mg/kg. After discontinuation of the treatment, a 9-week recovery test was also conducted in the 0, 1 and 50 mg/kg groups. No deaths related to the treatment were observed. Tremor and polyuria were seen in the 50 mg/kg group. There were decrease in body weight gain, and increase in water consumption in the 1 and 50 mg/kg groups. In those dose groups of males, decrease in food consumption was observed. Ophthalmoscopic examination failed to show any abnormalities attributable to the treatment. Blood chemical examination disclosed decrease in total cholesterol in the 50 mg/kg group. There were also decreases in phospholipid in the 50 mg/kg group of females, and in triglyceride in the 1 and 50 mg/kg groups of males. Urinalysis and hematologic examination failed to show any abnormalities attributable to the treatment. In pathological examination, serous cell hypertrophy and increase in organ weight of the submandibular gland were observed in the 1 and 50 mg/kg groups, and increase in organ weight of thyroid was revealed in the 0.02 mg/kg group and over. The changes mentioned above were satisfactorily reversible except for the decrease in food consumption in the 50 mg/kg group of males. Increased thyroid weight in the 0.02 mg/kg group was considered to be of no toxicological significance. These results show that the NOAEL of montirelin hydrate is 0.02 mg/kg for 26-week repeated dose toxicity in rats.

Animals↗
PubMed1994

delta 9 Acyl-lipid desaturases of cyanobacteria. Molecular cloning and substrate specificities in terms of fatty acids, sn-positions, and polar head groups.

In cyanobacteria, the biosynthesis of unsaturated fatty acids is initiated by delta 9 acyl-lipid desaturase which introduces the first double bond at the delta 9 position of a saturated fatty acid that has been esterified to a glycerolipid. We have cloned genes, designated desC, for delta 9 acyl-lipid desaturases from two cyanobacteria, namely Anabaena variabilis and Synechocystis sp. PCC 6803. These desaturases, when expressed in Escherichia coli, desaturated stearic acid to yield oleic acid at the C-1 positions of phosphatidylethanolamine and phosphatidylglycerol, but did not desaturate palmitic acid, palmitoleic acid, and cis-vaccenic acid. These results indicate that the delta 9 acyl-lipid desaturases are specific to stearic acid esterified at the C-1 position of a glycerolipid and are nonspecific with respect to the polar head group of the glycerolipid. The deduced amino acid sequences of the delta 9 acyl-lipid desaturases are similar in part to those of stearoyl-CoA desaturases of the rat, the mouse, and Saccharomyces cerevisiae, but not to those of acyl-(acyl-carrier-protein) desaturases of higher plants.

Amino Acid Sequence↗
PubMed1994

Identification of conserved domains in the delta 12 desaturases of cyanobacteria.

Cyanobacterial genes for enzymes that desaturate fatty acids at the delta 12 position, designated desA, were isolated from Synechocystis PCC6714, Synechococcus PCC7002 and Anabaena variabilis by cross-hybridization with a DNA probe derived from the desA gene of Synechocystis PCC6803. The genes of Synechocystis PCC6714, Synechococcus PCC7002 and A. variabilis encode proteins of 349, 347 and 350 amino acid residues, respectively. The transformation of Synechococcus PCC7942 with the desA genes from Synechocystis PCC6714, Synechococcus PCC7002 and A. variabilis was associated with the ability to introduce a second double bond at the delta 12 position of fatty acids. The amino acid sequence of the products of the desA genes revealed the presence of four conserved domains. Since one of the conserved domains was also found in the amino acid sequences of omega 3 desaturases of Brassica napus and mung bean, this domain may play an essential role in the introduction of a double bond into fatty acids bound to membrane lipids.

Amino Acid Sequence↗
PubMed1994

Expression of mRNA and steady-state levels of protein isoforms of enoyl-ACP reductase from Brassica napus.

The expression of mRNA and the steady-state levels of two-component enzymes of plant fatty acid synthetase (FAS) were studied. Northern analysis of enoyl-ACP reductase (ER) and stearoyl-ACP desaturase (SD) gene expression showed that steady-state levels of both transcripts increase during lipid deposition in the seed reaching a maximum at 29 days after flowering (DAF). The steady-state level of ER message falls very quickly after reaching its maximum, whereas the SD message is longer-lived. The levels of these specific mRNAs in seed are 15-30 times greater than in leaf. Optimum mRNA expression precedes the maximum levels of synthesis of the two proteins, which in turn precede the maximum level of oil. The expression of isoenzymes of ER were examined by two-dimensional western blotting in both leaf and seed tissue. Four enzymes are expressed in both of these tissues; the two most abundant isoforms in seed material are also the most abundant in leaf tissue.

Brassica↗
PubMed1994

Cloning of omega 3 desaturase from cyanobacteria and its use in altering the degree of membrane-lipid unsaturation.

Cyanobacteria respond to a decrease in temperature by desaturating fatty acids of membrane lipids to compensate for the decrease in membrane fluidity. Among various desaturation reactions in cyanobacteria, the desaturation of the omega 3 position of fatty acids is the most sensitive to the change in temperature. In the present study, we isolated a gene, designated desB, for the omega 3 desaturase from the cyanobacterium, Synechocystis sp. PCC 6803. The desB gene encodes a protein a 359 amino-acid residues with molecular mass of 41.9 kDa. The desB gene is transcribed as a monocistronic operon that produced a single transcript of 1.4 kb. The level of the desB transcript in cells grown at 22 degrees C was 10 times higher than that in cells grown at 34 degrees C. In order to manipulate the fatty-acid unsaturation of membrane lipids, the desB gene in Synechocystis sp. PCC 6803 was mutated by insertion of a kanamycin-resistance gene cartridge. The resultant mutant was unable to desaturate fatty acids at the omega 3 position. The desA gene, which encodes the delta 12 desaturase of Synechocystis sp. PCC 6803, and the desB gene were introduced into Synechococcus sp. PCC 7942. Whilst the parent cyanobacterium can only desaturate membrane lipids at the delta 9 position of fatty acids, the resultant transformant was able to desaturate fatty acids of membrane lipids at the delta 9, delta 12 and omega 3 positions. These results confirm the function of the desB gene and demonstrate that it is possible to genetically manipulate the fatty-acid unsaturation of membrane lipids in cyanobacteria.

Amino Acid Sequence↗
PubMed1994

Clinical evaluation of a light-cured glass ionomer lining cement.

This study was a clinical evaluation of a light-cured glass ionomer lining material (Fuji Lining LC) applied to prepared cavities in 45 primary teeth of children aged 3-5 years. The overall assessment, based on clinical and radiographic findings, was 'good' in 42 cases and 'fair' in the other three cases. The material had no effect on the shade of the composite resin restorative material that was used. The findings indicate that Fuji Lining LC has significant value in clinical practice.

Child, Preschool↗
PubMed1993

The gene and the RNA for the precursor to the plastid-located glycerol-3-phosphate acyltransferase of Arabidopsis thaliana.

The gene and the RNA from Arabidopsis thaliana for the plastid-located glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15) and their encoded product have been studied. The gene (designated ATS1) was isolated by screening a lambda DASH genomic library for cross-hybridization with a radiolabeled probe prepared from cDNA for GPAT from squash. cDNA clones representing the mRNA were isolated by screening a lambda ZAPII cDNA library for hybridization with a radiolabeled probe prepared from a DNA fragment of ATS1. The nucleotide sequences of the gene and the cDNA were determined, and the 5' end of the RNA was mapped by primer extension. Sequences similar to the TATA box, polyadenylation sequences and intron-splicing sequences were found at the expected locations. The pre-mRNA was 3288 nucleotides long and contained 5' and 3'-untranslated sequences of 57 and 442 nucleotides, respectively. The coding sequence of 1377 nucleotides was interrupted by 11 introns of 1412 nucleotides in total and the 3'-untranslated sequence contained another intron of 94 nucleotides. The open-reading frame encoded a polypeptide of 459 amino acid residues, the amino acid sequence of which was highly homologous to those of precursors to plastid-located GPATs from squash and pea. The enzymatic activity of a gene product that was over-produced in Escherichia coli confirmed the identity of the gene.

Amino Acid Sequence↗
PubMed1992

Molecular cloning of higher-plant 3-oxoacyl-(acyl carrier protein) reductase. Sequence identities with the nodG-gene product of the nitrogen-fixing soil bacterium Rhizobium meliloti.

cDNA clones encoding the fatty-acid- biosynthetic enzyme NADPH-linked 3-oxoacyl-(acyl carrier protein) (ACP) reductase were isolated from a Brassica napus (rape) developing seed library and from an Arabidopsis thaliana (thale cress) leaf library. The N-terminal end of the coding region shows features typical of a stromal-targeting plastid-transit peptide. The deduced amino acid sequences have 41% and 55% identity respectively with the nodG-gene product of Rhizobium meliloti, one of the host-specific genes that restrict infectivity of this bacterium to a small range of host plants. The probability that the nodG-gene product is a oxoreductase strengthens the hypothesis that some of the host-specific nod-gene products are enzymes which synthesize polyketides that uniquely modify the Rhizobium nodulation signal molecule.

3-Oxoacyl-(Acyl-Carrier-Protein) Reductase↗
PubMed1992

Acyl-(acyl-carrier protein) hydrolase from squash cotyledons specific to long-chain fatty acids: purification and characterization.

Acyl-(acyl-carrier-protein) hydrolase (EC 3.1.2.14) releases fatty acids from the end-product of fatty acid synthesis in plastids for the subsequent synthesis of glycerolipids in the cytoplasm. Isoelectric focusing of chloroplast stroma proteins from squash cotyledons suggested that there were at least three isomeric forms of acyl-(acyl-carrier-protein) hydrolase having pI values of 4.5, 5.3 and 7.8. The pI 4.5 and pI 5.3 forms showed maximum activity at pH 9.8 whereas the activity of the pI 7.8 form increased within the range 6.2 to 10.2 but no optimum was seen. The pI 4.5 form was purified 100,000-fold from squash cotyledons. The highly purified fraction contained two polypeptides, whose molecular masses were estimated to be 35 kDa and 33 kDa by SDS-PAGE. It is suggested that the 33 kDa polypeptide was a degradation product of the 35 kDa polypeptide. Oleoyl-(acyl-carrier protein) was the preferred substrate of this enzyme over palmitoyl- and stearoyl-(acyl-carrier protein), whereas lauroyl-(acyl-carrier protein) was nearly inactive. These results indicate the enzyme is specific for long-chain acyl-(acyl-carrier protein).

Acyl Carrier Protein↗
PubMed1992

[A clinical observation of cases which was suspected of congenital cholesteatoma].

Four cases which was suspected of congenital cholesteatoma were treated in the past 15 years. The age of the patients ranged from 4 to 17 years. In all cases, the cholesteatoma arose in the middle ear. In one case the cholesteatoma extended into the mastoid cavity. Tympanoplasty of colummella type III was indicated. Postoperative hearing gain was from 20 to 30dB. Although the incidence is low, otolaryngologists must be aware of congenital cholesteatoma when treating conductive hearing loss with a normal ear drum.

Adolescent↗
PubMed1991

Cochlear fistula found in a naturally healed tympanic cavity.

A cochlear fistula found in a naturally healed mastoid cavity is reported. The patient is a 53-year-old Japanese woman who was complaining of unsteadiness. She had a long history of otorrhoea in childhood. Her tympanic and mastoid cavities were widely open and were covered by thin epithelium. The posterior wall of the ear canal was missing. She had no hearing in the ear but responded to electrical promontory testing. Exploratory surgery was indicated at which fistulae of the basal turn of the cochlea and the horizontal semicircular canal were found. These fistulae were sealed by pieces of bone and muscle.

Cochlea↗
PubMed1990

Concentrations of long-chain acyl-acyl carrier proteins during fatty acid synthesis by chloroplasts isolated from pea (Pisum sativum), safflower (Carthamus tinctoris), and amaranthus (Amaranthus lividus) leaves.

Fatty acid synthesis from [1-14C]acetate by chloroplasts isolated from peas and amaranthus was linear for at least 15 min, whereas incorporation of the tracer into long-chain acyl-acyl carrier protein (ACP) did not increase after 2-3 min. When reactions were transferred to the dark after 3-5 min, long-chain acyl-ACPs lost about 90% of their radioactivity and total fatty acids retained all of theirs. Half-lives of the long-chain acyl-ACPs were estimated to be 10-15 s. Concentrations of palmitoyl-, stearoyl-, and oleoyl-ACP as indicated by equilibrium labeling during steady-state fatty acid synthesis, ranged from 0.6-1.1, 0.2-0.7, and 0.4-1.6 microM, respectively, for peas and from 1.6-1.9, 1.3-2.6, and 0.6-1.4 microM, respectively, for amaranthus. These values are based on a chloroplast volume of 47 microliters/mg chlorophyll and varied according to the mode of the incubation. A slow increase in activity of the fatty acid synthetase in safflower chloroplasts resulted in long-chain acyl-ACPs continuing to incorporate labeled acetate for 10 min. Upon re-illumination following a dark break, however, both fatty acid synthetase activity and acyl-ACP concentrations increased very rapidly. Palmitoyl-ACP was present at concentrations up to 2.5 microM in safflower chloroplasts, whereas those of stearoyl- and oleoyl-ACPs were in the lower ranges measured for peas. Acyl-ACPs were routinely separated from extracts of chloroplasts that had been synthesising long-chain fatty acids from labeled acetate by a minor modification of the method of Mancha et al. (Anal. Biochem., 1975, 68, 600-608). The results compared favorably with those obtained using alternative analytical methods such as adsorption to filter paper and partition chromatography on silicic acid columns. The acyl-ACP which coprecipitated with ammonium sulfate was not affected by treatments with neutral hydroxylamine or borohydride, whereas that eluted from silicic acid was relatively easily derivatized. A single radioactive polypeptide of Mr 11,500 from pea and amaranthus chloroplasts was revealed by autoradiography of gels from sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the silicic acid eluates.

Acetates↗
PubMed1990

Effect of dosing schedule on aminoglycoside ototoxicity: comparative cochlear ototoxicity of amikacin and isepamicin.

The effect of the dosing schedule on aminoglycoside ototoxicity was investigated in the guinea pig. The animals were given amikacin or isepamicin either by once-daily intramuscular injection of 200 mg/kg or by twice-daily injections of 100 mg/kg for 28 days. The once-daily treatment induced a lesser degree of ototoxicity than the twice-daily injections, which may indicate that the once-daily treatment therapy has a potential value in the clinical use of aminoglycoside antibiotics. Isepamicin sulfate is a new aminoglycoside antibiotic currently undergoing clinical investigation. This study revealed that isepamicin also has ototoxic properties as has been observed in all other aminoglycosides. The degree of ototoxicity, however, was markedly less than that of amikacin.

Amikacin↗
PubMed1990

[An experimental study of the effect of food on osteoporosis especially on the mandible].

Three-week-old male rats of the Wistar strain given standard formed food (MF formed food) were grouped as controls. Those given calcium-deficient food for three weeks and then standard formed food after experimental osteoporosis induced in the rats were grouped as the experimental group. Experimental periods were for 4 and 6 weeks and the effect of the food on osteoporosis was investigated. The results were as follows: 1. Bone density of the alveolar bone showed significantly lower values for the experimental group than for the controls. 2. In comparison of relative Ca ratios (Ca/[Ca]c) and of P ratios (P/[P]c) on an X-ray microanalyzer, the controls showed higher values each week than the experimental group. 3. Compressive strength of the mandible in the experimental group decreased compared with the controls.

Animals↗
PubMed1989

Spin-label ESR studies of lipid-protein interactions in thylakoid membranes.

Lipid-protein interactions in thylakoid membranes, and in the subthylakoid membrane fractions containing either photosystem 1 or photosystem 2, have been studied by using spin-labeled analogues of the thylakoid membrane lipid components, monogalactosyldiacylglycerol, phosphatidylglycerol, and phosphatidylcholine. The electron spin resonance spectra of the spin-labeled lipids all consist of two components, one corresponding to the fluid lipid environment in the membranes and the other to the motionally restricted membrane lipids interacting directly with the integral membrane proteins. Spectral subtraction has been used to quantitate the fraction of the membrane lipids in contact with the membrane proteins and to determine the selectivity between the different lipid classes for the lipid-protein interaction. The fractions of motionally restricted lipid in the thylakoid membrane are 0.36, 0.39, and 0.53, for the spin-labeled monogalactosyldiacylglycerol, phosphatidylcholine, the phosphatidylglycerol, respectively. Spin-labeled monogalactosyldiacylglycerol exhibits very little preferential interaction over phosphatidylchline, which suggests that part of the role of monogalactosyldiacylglycerol in thylakoid membranes is structural, as is the case for phosphatidylcholine in mammalian membranes. Spin-labeled phosphatidylglycerol shows a preferential interaction over the corresponding monogalactosyldiacylglycerol and phosphatidylcholine analogues, in contrast to the common behavior of this lipid in mammalian systems. This pattern of lipid selectivity is preserved in both the photosystem 1 and photosystem 2 enriched subthylakoid membrane fractions.

Chemical Phenomena↗
PubMed1988

Cloning and nucleotide sequence of cDNA for the plastid glycerol-3-phosphate acyltransferase from squash.

The partial amino acid sequence and amino acid composition of acyl-(acyl-carrier-protein):glycerol-3-phosphate acyltransferase purified from squash cotyledons were determined. cDNAs encoding this enzyme were isolated from lambda gt 11 cDNA libraries made from poly(A)+ RNA of squash cotyledons by immunological selection and cross-hybridization. One of the resultant clones contained a cDNA insert of 1426 base pairs and an open reading frame of 1188 base pairs. The amino acid sequence deduced from the nucleotide sequence matched the partial amino acid sequence determined for the enzyme. The results suggest that a precursor protein of 396 amino acid residues is processed to the mature enzyme of 368 amino acid residues, losing a leader peptide of 28 amino acid residues. Relative molecular masses of the precursor and mature proteins were calculated to be 43,838 and 40,929 Da, respectively.

Acyltransferases↗