Biomedical subjects

T Kanno

Publications and source records attributed to T Kanno.

At least 91 records · Page 5Linked to original sources

PubMed2000

Genetic diversity of RNA segments 5, 7 and 9 of the Palyam serogroup orbiviruses from Japan, Australia and Zimbabwe.

Reverse transcriptase-polymerase chain reaction (RT-PCR) methods, based on the sequences of RNA segments 5, 7 and 9 of Chuzan virus, were established for specific detection and molecular characterization of the Palyam serogroup orbiviruses. Nucleotide sequences obtained from the amplified cDNA fragments of these three genes of 24 isolates were analyzed and compared individually to determine the intra-serogroup phylogenetic relationship of Japanese, Australian and Zimbabwean isolates. It seems that Chuzan virus isolates in Japan are genetically stable. Interestingly, mutations have occurred almost simultaneously on these three genes of Chuzan virus. In all cases, isolates from the same geographical area were closely related to each other at the molecular level, irrespective of serotype. The data suggested that the Palyam serogroup viruses can be differentiated into geographically distinct groups and that the viruses evolve independently in the different gene pools. A strain KY-115 was considered to be produced by reassortment of genome segments between different groups. Restriction fragment length polymorphism (RFLP) analysis of these PCR products is useful for rapid discrimination of isolates and for detection of genetic mutations.

Animals↗

PubMed2000

Involvement of phosphorylation of beta-subunit in cAMP-dependent activation of L-type Ca2+ channel in aortic smooth muscle-derived A7r5 cells.

We investigated the effect of intracellular cAMP on the gating kinetics of L-type Ca2+ channel in an A7r5 smooth muscle-derived cell line using the whole-cell patch-clamp technique. Application of dibutyryl cyclic AMP (db-cAMP) to the cell increased the magnitude of Ca2+ currents through L-type Ca2+ channels (I(Ca)), and shifted the current-voltage relationship (I-V curve) for I(Ca) to the left. The magnitudes of maximum I(Ca) were 14.1 +/- 0.7 before and 16.0 +/- 1.1 pA/pF after application of 1 mM db-cAMP (P < 0.05). The values of the half-activation potential (V(1/2)) of I(Ca), estimated from activation curves, were -7.0 +/- 0.8 mV before and -10.8 +/- 1.0 mV after application of db-cAMP (P < 0.05). In cells pretreated with 10 microM Rp-cAMPS (a specific inhibitor of PKA), db-cAMP affected neither the I-V curve nor the activation curve for I(Ca). In cells pretreated with the antisense oligonucleotide for the beta-subunit of L-type Ca2+ channel, db-cAMP failed to enhance I(Ca) or alter the activation curve. On the other hand, in the cells pretreated with the nonsense oligonucleotide, application of db-cAMP caused an increase in magnitude of I(Ca) and shifted the activation curve to the left. Western blot analysis revealed that the pretreatment of cells with antisense oligonucleotide but nonsense oligonucleotide reduced the expression of the beta-subunit of the L-type Ca2+ channel. We conclude that the cAMP-dependent phosphorylation of the beta-subunit potentiates the voltage dependency of the activation kinetics of the L-type Ca2+ channel in A7r5 cells.

Animals↗

PubMed2000

Effects of a magnetic fields on the various functions of subcellular organelles and cells.

Magnetic fields (MF) are widely distributed in environment and their effects are increasing by the development of electrical machines. Several investigators reported that the MF might affect various functions of cells. However, an acceptable hypothesis has not yet been proposed. Thus, we studied the effects of weak MFs on various biological functions of cells, such as mitochondrial functions, stimulation dependent signal transduction of neutrophils, cell growth and transformation of HL-60 cells, H(2)O(2)-induced apoptosis and the expression of apoptotic genes in HL-60 cells. As a result of the study, a weak MF has scarcely any effects on various biological functions of cells. We also studied the direct effect of a static strong MF (SSMF, 600-2000 G) on the functions of cells or on Fe(2+)-induced lipid peroxidation and on reactive oxygen species (ROS) generation in oral polymorphonuclear leukocytes (OPMN) without stimulation using Ferrite magnets. The generation of ROS from OPMN was slightly inhibited but Fe(2+)-induced lipid peroxidation of biological membrane was slightly stimulated by exposure to the SSMF. At present, however, conclusive results have been neither obtained experimentally nor any acceptable idea proposed.

Journal Article↗

PubMed2000

Effective onion vinegar production by a two-step fermentation system.

A two-step fermentation system combining a repeated batch process using a flocculating yeast with a charcoal pellet bioreactor was developed for onion vinegar production. Juice from the red onion R-3, which contained 67.3 g/l total sugar, was smoothly converted to onion alcohol containing 30.6 g/l ethanol by repeated batch operation using the flocculating yeast Saccharomyces cerevisiae strain IR-2. Stable operation was possible and the maximum productivity was about 8.0 g/l/h. A packed bed bioreactor containing charcoal pellets produced from waste mushroom medium was then applied to continuous onion vinegar production from the onion alcohol. Onion vinegar was successfully produced, with a maximum productivity and acetic acid concentration of about 3.3 g/l/h and 37.9 g/l, respectively. The total acetic acid yield calculated from the amount of sugar consumed was 0.86. The two-step system was operated for 50 d and proved to be competitive with other systems in terms of its high productivity, high acetic acid yield, operational stability and low production costs.

Journal Article↗

PubMed2000

Continuous acetic acid production by a packed bed bioreactor employing charcoal pellets derived from waste mushroom medium.

A packed bed bioreactor using charcoal pellets produced from waste mushroom medium by thermal carbonization was developed and applied to continuous acetic acid production. The pellets were characterized by their high specific surface area (200 m2/g) with numerous micropores (2-10 microm). The continuous acetic acid fermentation started up smoothly after seeding and was successfully operated for about 180 d under various retention times. The maximum acetic acid productivity was about 3.9 g/l/h using normal aeration and 6.5 g/l/h using air enriched with 40% O2. The pellets are expected to prove useful as a new packing material for bioreactor in terms of their bacterial affinity, high specific surface area with appropriate pore sizes for bacteria, as well as the operational stability of the system and the low production cost.

Journal Article↗

PubMed2000

MET-88, a gamma-butyrobetaine hydroxylase inhibitor, improves cardiac SR Ca2+ uptake activity in rats with congestive heart failure following myocardial infarction.

We previously reported that MET-88, 3-(2,2,2-trimethylhydrazinium) propionate, improved left ventricular diastolic dysfunction induced by congestive heart failure (CHF) in rats. The present study was designed to investigate the mechanism by which MET-88 improved the cardiac relaxation impaired in CHF rats. The left coronary artery of the animals was ligated, and the rats were then orally administered vehicle (control), MET-88 at 50 or 100 mg/kg or captopril at 20 mg/kg for 20 days. Myocytes were isolated from the non-infarcted region in the left ventricle, and cell shortening and [Ca2+]i transients were measured with a video-edge detector and by fluorescence analysis, respectively. In CHF control rats, the diastolic phase of cell shortening was prolonged compared with that of the sham-operated (sham) rats. This prolongation was prevented by treatment with MET-88 at 100 mg/kg or captopril at 20 mg/kg. CHF control rats also showed an increase in the decay time of [Ca2+]i transients compared with sham rats. MET-88 at 100 mg/kg and captopril at 20 mg/kg attenuated the increase in decay time of [Ca2+]i transients. Ca2+ uptake activity of the sarcoplasmic reticulum (SR) isolated from the non-infarcted region in the left ventricle was measured, and Lineweaver-Burk plot analysis of the activity was performed. CHF control rats revealed a decrease in the Vmax for SR Ca2+ uptake activity without alteration in Kd. MET-88 at 100 mg/kg significantly prevented the decrease in Vmax, but had no effect on Kd. Also, treatment with MET-88 at 100 mg/kg improved myocardial high-energy phosphate levels impaired in CHF rats. These results suggest that one of the mechanisms by which MET-88 improved cardiac relaxation in CHF rats is based on the amelioration of [Ca2+]i transients through increase of SR Ca2+ uptake activity.

Adenine Nucleotides↗

PubMed2000

Human peptidylarginine deiminase type III: molecular cloning and nucleotide sequence of the cDNA, properties of the recombinant enzyme, and immunohistochemical localization in human skin.

Peptidylarginine deiminase catalyzes the post-translational modification of proteins through the conversion of arginine to citrulline in the presence of calcium ions. In rodents, peptidylarginine deiminase has been classified into four isoforms, types I, II, III, and IV, which are distinct in their molecular weights, substrate specificities, and tissue localization. Of these isoforms, only type III was detected in epidermis and hair follicles. Although the role of this enzyme in these tissues is not yet clear, indirect data have shown that several structural proteins such as filaggrin, trichohyalin, and keratin are substrates for peptidylarginine deiminase. In this study, we cloned the full-length cDNA of human peptidylarginine deiminase type III (3142 bp) from cultured human keratinocytes by reverse transcription-polymerase chain reaction and by rapid amplification of cDNA ends methods. This cDNA contained a 1995 bp open reading frame encoding 664 amino acids (Mr = 74 770). To explore the physicochemical and enzymatic properties of human peptidylarginine deiminase type III, we constructed a plasmid for producing a recombinant human peptidylarginine deiminase type III in bacteria. The enzymatic characteristics of the recombinant enzyme were very similar to those of the rodent peptidylarginine deiminase type III. The recombinant enzyme showed the catalytic activities toward structural proteins of epidermis and hair follicle, filaggrin and trichohyalin, in which the deiminations maxima of about 60% and 13% arginine residues were observed in filaggrin and trichohyalin, respectively. An immunohistochemical study of human scalp skin with a monospecific anti-peptidyl-arginine deiminase type III antibody revealed that the type III enzyme was localized to the inner root sheath and outer root sheath of hair follicles. Peptidylarginine deiminase type III in the inner root sheath was notable between supramatrix and keratogenous zone and was scarcely detected in cornified hair zone. The enzyme was also expressed in the cuticle layer of hair. On the other hand, expression of the enzyme in the epidermis was very low. These data imply that human peptidylarginine deiminase type III is the predominant isoform in hair follicles and may function as a modulator of hair structural proteins, including trichohyalin during hair and hair follicle formation.

Amino Acid Sequence↗

PubMed2000

Strategy for the treatment of arteriovenous malformations.

The treatment of arteriovenous malformations (AVMs) is still a challenging problem in the neurosurgical field. The deep-seated AVMs are a definite indication for radiosurgery for the small AVMs and with pre-embolisation for the large AVMs. The superficial AVMs are a good indication for surgery. In the case of small AVMs, surgery alone is a viable option; however, in the case of large AVMs, pre-operative embolisation is essential for prevention of NPPB (normal perfusion pressure breakthrough). Embolisation alone cannot be used, except for a small AVM in the non-eloquent cortex. Preoperative embolisation makes surgery easy; however, it causes the surrounding cortex to infarct. Hyperperfusion may occur after the direct removal of high-flow large AVMs, therefore postoperative management will be difficult in these cases. In eloquent cortex minimally invasive surgery is more reliable with respect to the morbidity produced. Therefore in cases of small AVMs in the functional cortex, direct surgery is the only choice. In cases of high-flow large AVMs, surgery and postoperative management are risky because of NPPB. Therefore pre-operative embolisation followed by surgery is a better choice. In high-flow AVMs, local blood circulation is not decreased by temporary clipping of the feeding arteries. So we recommend temporary clipping of all feeding arteries, even away from the nidus where it is easier to control bleeding.

Adolescent↗

PubMed2000

Endoscope-assisted microsurgery for cerebral aneurysms.

We performed endoscope-assisted microsurgery for 64 patients with cerebral aneurysms from June 1998 to January 1999. Two patients were treated under picture-in-picture imaging using a surgical microscope connected with an endoscopic-image display system. The study included 34 patients with incidental discovery: 3 IC oph, aneurysm, 1 from cavernous (C3) portion, 8 at ICPC, 1 from infundibular dilatation, 2 at IC bifurcation, 6 at AcoA, 1 at A1A2, 8 at MCA, 1 at P1, 1 from basilar tip, 1 at AICA, 1 at VA and 1 from PICA. The study also included 30 patients with subarachnoid hemorrhage: 5 ICPC, 2 from anterior choroidal, 1 from IC infundibular dilatation, 10 from AcoA, 2 from A2A3, 7 from MCA, 2 from basilar tip and 1 from PICA. They were classified into gr. 1 for 2, gr. 2 for 8, gr. 3 for 10, gr. 4 for 7, and gr. 5 for 3 cases.

Carotid Artery Diseases↗

PubMed2000

Neurosurgery at Fujita Health University, Japan.

Neurosurgery at the Fujita Health University began in 1972 with Dr. Tetsuo Kanno. In 1973, he was joined by Dr. Kazuhiro Katada and in the year 1976, an independent neurosurgery department was established with Dr. Kanno as the Chief of Neurosurgery. Under his guidance the department continued to grow and by 1978, a neurosurgical residency program recognised by the Japanese Board of Neurosurgery was established. Integration of laboratory research and clinical experience is the hallmark of this program. The current philosophy is directed towards subspecialization and academic training. This article provides a brief overview of the rapid development of a Neurosurgical Centre to reach international acclaim under the guidance of Prof. Tetsuo Kanno.

Hospitals, University↗

PubMed2000

Neuroendoscopy in microvascular decompression for trigeminal neuralgia and hemifacial spasm: technical note.

Miocrovascular decompression is an effective treatment for trigeminal neuralgia (TN) and hemifacial spasm (HFS). A complete cure cannot be obtained, and additional adjuncts for extended use of endoscopy are needed. The use of an endoscope combined with the operating microscope can enhance the surgeon's ability to view deep structures during operation. We study the application of combined microsurgical and endoscopic techniques in 21 cases of HFS and 12 cases of TN. With these techniques the surgeon can explore the ventral aspect of the brainstem and cranial nerves without further retraction, can see the groove caused by compression of the offending artery, and can confirm the proper position of the prosthesis after attachment to the dura by fibrin glue. In HFS the most common offending vessels in 75% of cases were the posterior inferior cerebellar artery (PICA) and anterior inferior cerebellar artery (AICA) and in 25% of cases the vertebral artery (VA). In trigeminal neuralgia the offending vessel in 60% of cases was the superior cerebellar artery (SCA), and in 40% of cases the AICA. The overall success rate was 97% with minimal morbidity 3% (facial palsy) and no mortality. The aim of this work is to study advantages and disadvantages of using endoscopy during microvascular decompression for TN and HFS.

Brain Stem↗

PubMed2000

Mechanism and prevention of enlargement or new development of aneurysm following treatment by clipping or coiling.

The mechanisms of cerebral aneurysm recurrence and enlargement were investigated in 11 patients: two with dissecting aneurysms, six with fully grown aneurysms after neck clipping, one with enlarged aneurysm after dome clipping, and two with enlarged aneurysm due to recanalization after GDC coil embolization. We concluded that it is fundamentally important to ensure complete attachment of the internal elastic lamina around the aneurysm neck by precise neck clipping and effective embolization, with accurate positioning of remaining internal elastic lamina.

Endothelium, Vascular↗

PubMed2000

Mechanism of alpha-tocopheryl succinate-induced apoptosis of promyelocytic leukemia cells.

Selective induction of apoptosis in tumor cells is important for treating patients with cancer. Because oxidative stress plays an important role in the process of apoptosis, we studied the effect of alpha-tocopheryl succinate (VES) on the fate of cultured human promyelocytic leukemia cells (HL-60). The presence of fairly low concentrations of VES inhibited the growth and DNA synthesis of HL-60 cells, and also induced their apoptosis via a mechanism that was inhibited by z-VAD-fluoromethylketone (z-VAD-fmk), an inhibitor of pan-caspases. VES activated various types of caspases, including caspase-3, 6, 8, and 9, but not caspase-1. VES triggered the reaction leading to the cleavage of Bid, a member of the death agonist Bcl-2 family, and released cytochrome c (Cyt.c) from the mitochondria into the cytosol by a z-VAD-fmk-inhibitable mechanism. VES transiently increased the intracellular calcium level [Ca2+]i and stimulated the release of Cyt.c in the presence of inorganic phosphate (Pi). However, high concentrations of VES (approximately 100 microM) hardly induced swelling of isolated mitochondria but depolarized the mitochondrial membrane potential by a cyclosporin A (CsA)-insensitive mechanism. These results indicate that VES-induced apoptosis of HL-60 cells might be caused by activation of the caspase cascade coupled with modulation of mitochondrial membrane function.

Amino Acid Chloromethyl Ketones↗

PubMed2000

Post-transcriptional gene silencing in cultured rice cells.

Post-transcriptional gene silencing (PTGS) has been shown to occur in many transgenic dicotyledonous plants. Although transgene silencing has been documented in transgenic monocots, PTGS has been only recently described in monocotyledonous plants. To study PTGS in rice, we generated 25 transgenic rice cell lines in which the 35S-gus gene was stably integrated. In one transgenic cell line, lack of gus expression was shown to be caused by PTGS based on the results of run-on transcription assays. Furthermore, to examine whether reintroduction of the same plasmid DNA into cells in which the gus gene was highly expressed causes the suppression of the gus expression, the gus plasmid was introduced into protoplasts isolated from a high gus-expressing line. Results of the kinetic analysis of the GUS activities in transfected protoplasts indicated that the gus expression in transfected protoplasts was suppressed by the gus plasmid but not by the luc plasmid harboring the 35S-luciferase gene, suggesting that suppression of the gus expression by introduced plasmid DNA was homology-dependent. These results suggest that the transgenic protoplasts may be a useful experimental system to study PTGS in rice and other species.

Cells, Cultured↗

PubMed2000

VIP- and PACAP-induced salivary chromogranin A secretion in the isolated perfused submandibular gland of rats.

In the study reported in this paper, sensitive ELISA for rat CgA was developed using synthetic rat CgA(359-389) as antigen, N alpha-biotinylated glycylglycyl rat CgA(359-389), and antirat CgA(359-389) serum for the measurement of CgA-LI in rat saliva. CgA-LI in rat submandibular tissues and saliva was characterized by both immunohistochemical and immunochemical methods. Using isolated perfused rat submandibular gland. VIP at 0.1-1.0 nM in the presence of 0.1 microM ACh was found to cause CgA-LI secretion, whereas neither PACAP-27 nor PACAP-38 showed any effect on CgA secretion.

Amino Acid Sequence↗

PubMed2000

Effects of chlorine, iodine, and quaternary ammonium compound disinfectants on several exotic disease viruses.

The effects of three representative disinfectants, chlorine (sodium hypochlorite), iodine (potassium tetraglicine triiodide), and quaternary ammonium compound (didecyldimethylammonium chloride), on several exotic disease viruses were examined. The viruses used were four enveloped viruses (vesicular stomatitis virus, African swine fever virus, equine viral arteritis virus, and porcine reproductive and respiratory syndrome virus) and two non-enveloped viruses (swine vesicular disease virus (SVDV) and African horse sickness virus (AHSV)). Chlorine was effective against all viruses except SVDV at concentrations of 0.03% to 0.0075%, and a dose response was observed. Iodine was very effective against all viruses at concentrations of 0.015% to 0.0075%, but a dose response was not observed. Quaternary ammonium compound was very effective in low concentration of 0.003% against four enveloped viruses and AHSV, but it was only effective against SVDV with 0.05% NaOH. Electron microscopic observation revealed the probable mechanism of each disinfectant. Chlorine caused complete degeneration of the viral particles and also destroyed the nucleic acid of the viruses. Iodine destroyed mainly the inner components including nucleic acid of the viruses. Quaternary ammonium compound induced detachment of the envelope of the enveloped viruses and formation of micelle in non-enveloped viruses. According to these results, chlorine and iodine disinfectants were quite effective against most of the viruses used at adequately high concentration. The effective concentration of quaternary ammonium compound was the lowest among the disinfectants examined.

African Horse Sickness↗

PubMed2000

Molecular cloning of equine chromogranin A and its expression in endocrine and exocrine tissues.

Chromogranin A (CGA) is a member of a family of highly acidic proteins co-stored and co-released with catecholamines in the adrenal medullary cells as well as in other neurons and paraneurons. The nucleotide sequence encoding equine CGA was determined using RT-PCR and rapid amplification of complementary DNA (cDNA) ends (RACE) techniques. A total 1,828 bp of the nucleotide sequence reveals that equine CGA is a 448-residue protein preceded by an 18-residue signal peptide. Comparison of the amino acid sequence of equine CGA with those of human, porcine, bovine, mouse, rat and frog CGA showed high conservation at the NH2-terminal 1-77 amino acids regions (94.8%, 93.5%, 92.2%, 81.8%, 83.1% and 66.2%, respectively) and COOH-terminal 314-430 amino acids regions (90.6%, 81.4%, 90.6%, 80.5%, 83.3% and 39.0%, respectively), as well as a potential dibasic cleavage site, whereas the middle portion showed marked sequence variation (52.5%, 49.1%, 38.9%, 26.6%, 27.9% and 6.2%, respectively). Northern blot analysis and RT-PCR elucidated the tissue distribution of equine CGA mRNA. Its expression was confirmed not only in the adrenal medullary cells but also in other organs (cerebrum, cerebellum, pituitary gland, spinal cord, liver, thyroid gland, striated muscle, lung, spleen, kidney, parotid gland and sublingual gland). Further, in adrenal chromaffin cells and pituitary cells of the anterior-intermediate lobe, the expression was confirmed by in situ hybridization with anti-sense CGA cRNA probe.

Amino Acid Sequence↗

PubMed2000

Hypertriglyceridemia characterized by low-density lipoprotein phenotype and lipoprotein lipase gene mutation.

A high serum triglyceride (TG) concentration is associated with an increased serum concentration of small, dense low-density lipoprotein (LDL). To further characterize the hypertriglyceridemic condition, we examined sera from 240 subjects for small, dense LDL using non-denaturing polyacrylamide gradient gel electrophoresis. We focused on determining the frequency of the pattern B, which is characterized by a higher proportion of small, dense LDL, among hypertriglyceridemic individuals. The subjects were divided into four groups: a control group (TG < or = 1.65 mmol/l, high-density lipoprotein cholesterol (HDL-C) > or =1.17 mmol/l; n = 71), a high TG group (TG > 1.65 mmol/l, HDL-C > or = 1.17 mmol/l; n = 36), a group with high TG and low HDL-C (TG > 1.65 mmol/l, HDL-C < or = 0.91 mmol/l; n = 106), and a low HDL-C group (TG < or = 1.65 mmol/l, HDL-C < or = 0.91 mmol/l; n = 27). We found that pattern B occurs at a high frequency mainly in individuals with high TG and low HDL-C levels. We also observed an increased percentage of LDL within the 20.0 nm to 25.5 nm particle diameter range in this group. Analysis of the lipoprotein lipase gene in this group showed that some mutations seem to be associated with small, dense LDL, resulting in LDL pattern B.

Densitometry↗