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Kenji Hara

Publications and source records attributed to Kenji Hara.

At least 19 recordsLinked to original sources
PubMed2006

Rapid GC-MS analysis of methamphetamine and its metabolites in urine--application of a short narrow-bore capillary column to GC-MS.

A rapid analysis of methamphetamine and its metabolites in urine was performed by gas chromatography-mass spectrometry (GC-MS) using a short narrow-bore capillary column (NBC) (5 m x 0.1 mm I.D.). For detection, selected ion monitoring (SIM) was performed for the characteristic ions of each of the compounds. The analytes were independently detected within 2 min. Linearity was demonstrated over a range from 25-2500 ng/ml. As an application of this study, a urine sample from a drug-abuse suspect was analyzed. The analytes from the actual sample were detected with reasonable reproducibility. The results indicate the possibility of rapid analysis using a conventional GC-MS with a short NBC at a relatively low inlet pressure.

Female↗
PubMed2006

Toxicological and histopathological analysis of a patient who died nine days after a single intravenous dose of methamphetamine: a case report.

A man in his late twenties collapsed shortly after intravenously injecting himself with methamphetamine (MA). He slipped into a deep coma and remained in this condition for 9 days, until his death. Autopsy revealed severe brain edema and localized subarachnoid hemorrhages in the cerebrum and cerebellum. Histopathological examination revealed myocardial necrosis in the left ventricle, rhabdomyolysis and bronchopneumonia. Blood derived from the cadaver was found to have high levels of blood urea nitrogen and creatinine, suggesting he experienced acute renal failure probably due to rhabdomyolysis. Most of the postmortem findings were consistent with MA poisoning. The patient's bronchopneumonia may have represented a hypostatic pneumonia that developed as a result of his deep coma. While the patient's brain edema, myocardial necrosis and rhabdomyolysis were diagnosed soon after admission, his bronchopneumonia and acute renal failure only occurred 6 and 8 days later, respectively. Although MA was not detected in the cadaver's blood, urine or liver, analysis of the decedent's hair using gas chromatography-mass spectrometry confirmed its presence at a concentration of 1.1 ng/mg. Based on these findings, we concluded that the patient's cause of death was multiorganopathy resulting from MA poisoning. This case suggests that the postmortem diagnosis of MA poisoning in patients who survive for relatively longer periods after drug injection should include toxicological hair analysis in combination with histopathological and postmortem physiochemical examination.

Adult↗
PubMed2006

Characterization of hydrophilic polymer fine particles by steady-state fluorescence spectroscopy.

We synthesized hydrophilic polymer particles based on acrylamide, and their chemical properties are investigated by fluorescence spectroscopy. The morphology of the synthesized polymers was monitored by scanning electron microscopy (SEM) and a dynamic light-scattering analyzer, and it was observed that the synthesized polymers are spherical with a median diameter of approximately 500 nm. A fluorescent probe molecule (C153) was introduced into the polymer/water solution, and the steady-state fluorescence spectrum was observed. In the C153/polymer/water solution, strong fluorescence inHtensity from the C153 molecules was observed with a maximum intensity at 515 nm, whereas the C153/water solution only gave very weak fluorescence with a maximum at 540 nm. Since C153 is hardly soluble in water, it was concluded that the C153 molecules existed selectively around the particle surfaces. Because of the difference between the fluorescence spectra, it was found that the chemical properties around the polymer surface were very different from that of the bulk water.

Microscopy, Electron, Scanning↗
PubMed2005

Concentration-dependent suppressive effect of shrimp head protein hydrolysate on dehydration-induced denaturation of lizardfish myofibrils.

To utilize fishery waste products as functional food material, the shrimp head protein hydrolysate (SHPH) was produced from three species of shrimp wastes, Northern pink shrimp, Endeavour shrimp and black tiger shrimp, by enzymatic hydrolysis. The SHPH was used as a natural food preservative by adding to lizardfish myofibrils at concentrations ranging from 2.5% to 10%. Their effects on the state of water and the denaturation of myofibrils during dehydration were evaluated. The amount of monolayer and multilayer water in myofibrils containing SHPH were higher than those without SHPH (control). DSC analyses revealed that the amount of unfrozen water increased significantly after addition of SHPH. The Ca-ATPase inactivation rate of myofibrils containing SHPH decreased during dehydration while 5-7.5% concentrations of SHPH exhibited optimum effect regardless of the species. The results implicated that SHPH can be used as an alternative food preservative for suppressive the dehydration-induced denaturation of myofibrils.

Animals↗
PubMed2005

Further characterization of a sarcoplasmic serine proteinase from the skeletal muscle of white croaker (Argyrosomus argentatus).

A trypsin-type serine proteinase (WSP) was purified previously from the sarcoplasmic fraction of skeletal muscle of white croaker (Argyrosomus argentatus) by Yanagihara et al. ((1991) Nippon Suisan Gakaishi, 57, 133-142). However, further research on WSP was not carried out. In the present study, we determined the N-terminal amino acid sequence of this enzyme (27 amino acid residues), which revealed relatively high identity in the conserved region to other trypsin-type serine proteinases. Degradation action of WSP on neuropeptides is also reported in this manuscript. The results show that WSP only cleaves at the carboxyl side of Arg or Lys residue of the peptides, especially between dibasic amino acid residues such as Arg-Arg and Arg-Lys.

Amino Acid Sequence↗
PubMed2005

A novel type of myofibril-bound serine protease from white croaker (Argyrosomus argentatus).

Myofibril-bound serine protease (MBSP) was purified from the myofibril fraction of white croaker (Argyrosomus argentatus) muscle and its enzymatic properties were compared with other fish MBSPs. White croaker MBSP was extracted by the heat treatment of myofibrils and then purified by a series of column chromatographies on Q-Sepharose, Sephacryl S-300, hydroxyapatite and Benzamidine Sepharose. The purified MBSP migrated as a single protein band at 67 kDa in SDS-PAGE under both reducing and non-reducing conditions. It was inhibited by Pefabloc SC, soybean trypsin inhibitor (STI), aprotinin and benzamidine, and was not affected by E-64, pepstatin A and EDTA. The enzyme was most active against Boc-Phe-Ser-Arg-MCA at pH 7.0 and 50 degrees C, and preferentially hydrolyzed Boc-Val-Pro-Arg-MCA and Boc-Asp-Pro-Arg-MCA. Unlike other marine fish MBSPs, white croaker MBSP considerably hydrolyzed Boc-Val-Leu-Lys-MCA and Boc-Glu-Lys-Lys-MCA. Some enzymatic characteristics including the molecular structure and the substrate specificity for a lysine residue at the P(1) position are quite different not only from other fish MBSPs but also from soluble serine protease obtained from white croaker muscle (MSSP). White croaker MBSP could be therefore classified into a novel type of fish muscle MBSP.

Animals↗
PubMed2005

Postembryonic development of the mushroom bodies in the ant, Camponotus japonicus.

Mushroom bodies (MB) are insect brain centers involved in learning and other complex behaviors and they are particularly large in ants. We describe the larval and pupal development of the MB in the carpenter ant, Camponotus japonicus. Based on morphological cues, we characterized the stages of preimaginal development of worker ants. We then describe morphological changes and neurogenesis underlying the MB development. Kenyon cells are produced in a proliferation cluster formed by symmetrical division of MB neuroblasts. While the duration of larval instars shows great individual variation, MB neuroblasts increase in number in each successive larval instar. The number of neuroblasts increases further during prepupal stages and peaks during early pupal stages. It decreases rapidly, and then neurogenesis generally ceases during the mid pupal stage (P4). In contrast to the larval period, the MB development of individuals is highly synchronized with physical time throughout metamorphosis. We show that carpenter ants (C. japonicus) have approximately half as many MB neuroblasts than are found in the honey bee Apis mellifera. Mature MBs of carpenter ants and honey bees reportedly comprise almost the same number of neurons. We therefore suggest that the MB neuroblasts in C. japonicus divide more often in order to produce a final number of MB neurons similar to that of honey bees.

Animals↗
PubMed2005

Successful DNA typing of urine stains using a DNA purification kit following dialfiltration.

To evaluate the utility of DNA polymorphism typing of urine stains in forensic investigations, the amplifiable amount of DNA was estimated in 20 urine specimens obtained from 10 male and 10 female volunteers using a DNA purification kit following dialfiltration. DNA obtained from both urine and urine stains was amplified with the AmpflSTR Profiler PCR Amplification Kit, and was analyzed by capillary electrophoresis using the Genetic Analyzer. The amount of male and female urine necessary for obtaining a complete DNA profile was 0.2 mL and 0.08 mL, respectively. When 0.2 mL of male urine were used to create urine stains, complete DNA profiles could be obtained from just some of the stains. However, when only 0.1 mL of female urine was used, complete profiles could be successfully obtained from all of the stains. DNA on bleached cotton remained amplifiable for 3-6 weeks. This method using a DNA purification kit following dialfiltration can be recommended for the genotyping of urine stains.

DNA↗
PubMed2004

Sequential coupling of zincated hydrazone, alkenylboronate, and electrophile that creates several contiguous stereogenic centers.

A zincated N,N-dimethylhydrazone of a ketone undergoes stereospecific syn addition to E- or Z-alkenylboronate to generate a gamma-Zn/B dimetallic intermediate, which reacts with a carbon electrophile to give a gamma-borylhydrazone in good yield with excellent diastereoselectivity, creating two to four contiguous stereogenic centers in a one-pot reaction.

Journal Article↗
PubMed2004

Mono- and bis(tetrathiafulvaleno)hexadehydro[12]annulenes.

Hexadehydro[12]annulenes annelated with one or two TTF units have been synthesized to investigate their pi-amphoteric properties based on the TTF and [12]annulene moieties; these compounds show multi-redox potentials, solvatochromism and the formation of large sandwich complexes.

Journal Article↗
PubMed2004

Molecular characterization of cathepsin L from hepatopancreas of the carp Cyprinus carpio.

Purified cathepsin L from carp, Cyprinus carpio, consists of a 28 kDa single-chain form that is different from the 24 and 5 kDa mammalian two-chain form. We cloned cathepsin L from carp hepatopancreas. The sequence consisted of a 1490 bp cDNA and a 1014 bp open reading frame, encoding a deduced protein of 337 amino acids that is likely processed to an active enzyme (single-chain form) with 222 amino acids. Its similarity to other types of vertebrate cathepsin L is less than 69%. Mammalian cathepsin L is further processed to a two-chain form, but possibly this is not the case with carp cathepsin L: the P1 site where cleavage occurred in the two-chain form of mammalian cathepsin L contains a serine, while carp cathepsin L processes a valine. Therefore, carp cathepsin L may have a different mechanism of action from mammalian cathepsin L.

Amino Acid Sequence↗
PubMed2004

Purification and characterization of myofibril-bound serine protease from lizard fish (Saurida undosquamis) muscle.

Myofibril-bound serine protease (MBSP) from lizard fish (SAURIDA UNDOSQUAMIS: Synodontidae) skeletal muscle was purified to homogeneity with higher purification (1260-fold) and higher recovery (7%) than our previous report in lizard fish (Saurida wanieso). The new purification method combines a heat-treatment for dissociation from washed myofibrils, acid-treatment at pH 5.0 before and after lyophilization, and alcohol-treatment, followed by two column chromatographies. The molecular mass of the enzyme was estimated to be 50 kDa under non-reducing conditions and 28 kDa under reducing conditions by SDS-PAGE. The N-terminal amino acid sequence of the MBSP was determined to be 22 residues (IVGGYEXEAYSKPYQVSINLGY) and the sequence showed high homology to carp and other fish trypsins (64-77%), but did not show high homology to carp MBSP (41%). The enzyme activity was inhibited by serine protease inhibitors such as Pefabloc SC, leupeptin, TLCK and native protein inhibitors (soybean trypsin inhibitor, alpha(1)-antitrypsin and aprotinin). The purified enzyme specifically hydrolyzed at the carboxyl side of the arginine residue of synthetic 4-methyl-coumaryl-7-amide substrate. When purified MBSP was stored at -35 degrees C in the presence of 50% ethylene glycol (V/V), the enzyme activity was entirely preserved over 6 months and stable against freezing and thawing. Activities for both casein and the synthetic substrate were most active at pH 9.0, and the enzyme was most active approximately 55 degrees C with casein and between 35 and 45 degrees C for synthetic substrate. When myofibrils were incubated with purified MBSP, myosin heavy chain was mostly degraded approximately 55 degrees C, but the degradation of actin was very slow.

Animals↗
PubMed2004

A novel serine protease complexed with alpha2-macroglobulin from skeletal muscle of lizard fish (Saurida undosquamis).

A novel fish muscle serine protease named muscle soluble serine protease (MSSP) was purified from the soluble fraction of lizard fish (Saurida undosquamis: Synodontidae) muscle by ammonium sulfate fractionation followed by four steps of column chromatographies. In native-PAGE, the purified enzyme appeared as a single band with an estimated mol. mass of approximately 380 kDa by gel filtration. In SDS-PAGE under reducing conditions, the purified enzyme migrated as two protein bands at 110 and 100 kDa, named subunits A and B, respectively. The 20 residues of N-terminal amino acid sequence of subunit B showed 70% of homology to beta-chain of carp alpha(2)-macroglobulin-1. Moreover, both subunits A and B showed immunoreactivity with anti carp alpha(2)-macroglobulin antibody. Purified MSSP was inactivated by Pefabloc SC, aprotinin, benzamidine and TLCK, but not by alpha(1)-antitrypsin. After acid treatment (pH 2, 24 h), however, the enzyme activity eluted at 14 kDa from Sephacryl S-200 carried out under acidic conditions was inhibited by alpha(1)-antitrypsin. Lizard fish MSSP most rapidly hydrolyzed Boc-Val-Pro-Arg-MCA and Boc-Gln-Arg-Arg-MCA, but did not hydrolyzed Suc-Leu-Leu-Val-Tyr-MCA and Suc-Ala-Ala-Pro-Phe-MCA, and was not suppressed either by E-64, pepstatin A and ethylenediaminetetraacetic acid (EDTA). These results indicate that the purified MSSP is a serine protease complexed with alpha(2)-macroglobulin, and the entrapped protease was dissociated by the acid treatment. Purified and free MSSPs were most active at pH 10.0 and 9.0, respectively. Purified MSSP degraded myofibrillar proteins and casein but time courses of degradation of these substrates by the enzyme differed.

Amino Acid Sequence↗
PubMed2003

Effect of proteolytic squid protein hydrolysate on the state of water and dehydration-induced denaturation of lizard fish myofibrillar protein.

With the goal of preparing low-cost functional food, squid protein hydrolysate (SPH) was extracted from four squid species by protease treatment. Peptides are the major components (approximately 84-88%) of the SPH. The stabilization effects of 5% SPH (dried weight/wet weight) on the state of water and the denaturation of frozen lizard fish Saurida wanieso myofibrillar protein (Mf) were evaluated on the basis of desorption isotherm curves with respect to Ca2+-ATPase inactivation and the presence of unfrozen water, which was determined using differential scanning calorimetry during dehydration, and the effects were compared with those of sodium glutamate. The Mf with SPH was found to contain higher levels of monolayer and multilayer sorption water, resulting in decreased water activity and Ca2+-ATPase inactivation. The amount of unfrozen water in Mf with SPH increased significantly, suggesting that the peptides of SPH stabilized water molecules on the hydration sphere of Mf, which maintained the structural stability of Mf, and therefore suppressed dehydration-induced denaturation. The effect by SPH was less than that by sodium glutamate.

Animals↗
PubMed2003

Nonvolatile Me(3)P-like P-donor ligand: synthesis and properties of 4-phenyl-1-phospha-4-silabicyclo[2.2.2]octane.

[reaction: see text] A new trialkylphosphine ligand with Me(3)P-like steric and electronic properties, 4-phenyl-1-phospha-4-silabicyclo[2.2.2]octane (Ph-SMAP), was synthesized. Given a phenyl group at the silicon atom, the Ph-SMAP ligand displayed nonvolatility with retention of Me(3)P-like properties. The new ligand was air-stable, crystalline, and easy to handle.

Journal Article↗
PubMed2003

Enantioselective synthesis of alpha-substituted ketones by asymmetric addition of chiral zinc enamides to 1-alkenes.

A zinc enamide of a chiral imine derived from a ketone and (S)-valinol or (S)-t-leucinol undergoes addition to 1-alkene to generate a gamma-zincioimine intermediate, which reacts with a carbon electrophile to give upon hydrolysis an optically active alpha-substituted ketone in good yield. The stereoselectivity of the addition reaction may reach 99% for the reaction of a cyclohexanone imine with ethylene.

Journal Article↗
PubMed2003

Queen discrimination ability of ant workers (Camponotus japonicus) coincides with brain maturation.

Discrimination behavior is a fundamental feature of social insects, and the discrimination ability allows the individual to be integrated into the colony. To address the brain functions associated with this task, which underlies intraspecific communication, I examined the ability to discriminate queens in young workers of the ant Camponotus japonicus together with a histological analysis of their brains. Workers raised in a foster colony were tested with respect to their ability to discriminate the foster queen from an unfamiliar queen. During the first 3 days after eclosing, some young workers made erroneous decisions whereas after 3-4 days the decisions were always correct. To assess brain maturation, mitotic activity in the brains of workers was individually analyzed using BrdU injection immediately after the behavioral test. Neurogenesis appeared to be complete at eclosion, but in 3 of 8 young workers that showed incorrect behavioral decisions, mitotic activity was observed in the antennal lobe. In contrast, no mitotic activity was observed in the brains of young workers who correctly discriminated their foster queens from alien queens. These results suggest that in newly emerged ant workers the ability to discriminate queens coincides with the completion of cell proliferation in the brain.

Animals↗