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Biomedical subjects

M Kishi

Publications and source records attributed to M Kishi.

At least 73 records · Page 4Linked to original sources
PubMed1998

[A case of eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis with unique brain MRI findings].

A 17-year-old Japanese girl was admitted to our hospital because of meningeal irritation, hyperesthesia of extremities, and disturbance of consciousness after having traveled to Okinawa in February, 1996. Examination on admission revealed pleocytosis of CSF with many eosinophils (65%) and increased eosinophils (25%) in the peripheral blood. The history and clinical symptoms were suggestive of a parasitic infection. We diagnosed the patient as having eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis, which was confirmed by immunological tests of double diffusion, counterimmuno-electrophoresis, and ELISA. Magnetic resonance imaging (MRI) of the brain demonstrated multiple small high intensity areas on Gd-DTPA-enhanced T1-weighted images. MRI findings suggested tissue reactions to dead or dying worms, and local vasodilatation associated with minimal thrombus formation.

Adolescent↗
PubMed1998

Two-dimensional finite element analysis of the influence of bridge design on stress distribution in bone tissues surrounding fixtures of osseointegrated implants in the lower molar region.

This study is a comparison and examination of the stress distribution of the bone tissues surrounding the fixture under a static vertical load condition with regard to an osseointegrated implant bridge (OIB) applied to the lower molar region. It was performed by constructing more than one of two-dimensional finite element models that differ in design conditions. In the case of the bounded type OIB design to the fixture placed in a straight line, a decrease in the maximum stress value of the compact bone surrounding the fixture was recognized with a decrease in the total inter-fixture distance and an increase in the number of placed fixtures. On the other hand, in the case of the free-end type OIB design, there is an increase in the maximum stress value compared with the bounded type OIB design and, in particular, a marked increase with the decrease in the total inter-fixture distance and the extension of the free-end pontic. However, the effect of the number of fixtures placed on the maximum stress value of the surrounding bone tissues was considered to be comparatively small.

Alveolar Process↗
PubMed1997

Structure and expression of the mouse S10 gene.

We previously reported the cloning of a human S10 cDNA which encodes a small GTP-binding protein belonging to the Rab subfamily. Here we describe a mouse S10 cDNA and its genomic structure. Mouse S10 is 92.3% homologous at the nucleotide level and 98.3% identical at the amino acid level compared to human S10. The mouse S10 gene is comprised of two exons and a single intron. Northern blotting of tissue RNAs indicates that the S10 gene is predominantly expressed in brain.

Amino Acid Sequence↗
PubMed1997

Developmental capacity of bovine oocytes following inhibition of meiotic resumption by cycloheximide or 6-dimethylaminopurine.

This study was conducted to assess the fertilizability and developmental capacity of bovine oocytes which had been maintained in meiotic arrest by either a protein synthesis inhibitor, cycloheximide (CHX), or an inhibitor of serine/threonine protein kinases, 6-dimethylaminopurine (6-DMAP). Both CHX and 6-DMAP reversibly prevented nuclear maturation of nearly all oocytes for 24 h. After the reversal of arrest, CHX-treated oocytes could be successfully matured and fertilized. They developed to the blastocyst stage at slightly lower rates than oocytes cultured without inhibition for 22 h prior to sperm addition but at higher rates than those incubated in a medium containing no inhibitors for 46 h prior to fertilization. Oocytes inhibited by CHX for 48 h matured and fertilized normally but failed to develop into blastocysts. Even though 6-DMAP-treated oocytes completed meiosis I after removal from the drug, the rates of fertilization and blastocyst formation were lower than for untreated oocytes or CHX-treated oocytes. Effects of adding FSH and/or estradiol-17 beta (E(2)) during CHX-inhibition for 24 h were also examined. Embryos from oocytes treated with CHX and E(2) or with CHX and FSH + E(2) developed into blastocysts at similar rates as the controls. Further development of inhibited oocytes was examined by transferring blastocysts derived from oocytes inhibited by CHX with FSH and E(2) for 24 h to recipient heifers. Two calves were obtained following transfer. These results indicate that CHX-inhibited oocytes retain developmental competence, while 6-DMAP-inhibited oocytes after the reversal of arrest have reduced capacities for fertilization and further development. The addition of FSH and E(2) during CHX-inhibition improves development to the blastocyst stage of the oocytes that are capable of initiating and maintaining pregnancy after embryo transfer to recipient animals.

Journal Article↗
PubMed1997

CT, MR imaging and muscle biopsy in severe crush injury.

PURPOSE: We reviewed CT and MR findings in crush injuries in muscles and compared them with findings at muscle biopsy. MATERIAL AND METHODS: CT and MR examinations were made of the lower extremities in 6 adult patients whose muscles were crushed in the big earthquake in Kobe, Japan, on 17 January 1995. All CT examinations were performed twice and within 60 days of the earthquake. In 5 of the 6 patients, biopsies were taken of the injured muscle after the CT and MR examinations. RESULTS: At CT investigation, the images in 5 patients showed calcification in the muscles, and the crushed muscle appeared atrophic. In 3 of these 5, the degree of calcification decreased with time. At MR investigation, T1-weighted images of the crushed muscle showed isointensity in 4 of the 6 patients and high intensity in the remaining 2. T2-weighted images of the crushed muscle showed inhomogeneous high intensity in all patients. After Gd injection, all the crushed muscles were enhanced, either slightly or markedly. At muscle biopsy, in 5 of the 6 cases, the findings showed calcification in the muscle cells and the total destruction of the normal muscle structure. CONCLUSION: CT and MR findings in crush injury correlated well with the findings at histopathology.

Acute Disease↗
PubMed1997

Fluid resuscitation and systemic complications in crush syndrome: 14 Hanshin-Awaji earthquake patients.

BACKGROUND: Crush syndrome is a form of traumatic rhabdomyolysis characterized by systemic involvement, in which acute renal failure is potentially life-threatening. METHODS: Clinical and laboratory data of 14 crush-syndrome patients transferred to a tertiary emergency department after the Hanshin-Awaji earthquake were analyzed. The patients were buried under collapsed houses for the average of 6.7 +/- 5.7 (SD) hours (range, 1 to 24 hours). They were referred to us 6 to 250 hours after the earthquake. RESULTS: Of those who arrived at our institution within 40 hours, 25% (two of eight) developed renal failure, whereas all six patients who arrived after 40 hours developed renal failure. Peak serum creatine kinase ranged from 6,677 to 134,200 U/L (51,674 +/- 41,776). Renal failure was highly associated with massive muscle damage (serum creatine kinase above 25,000 U/L) and insufficient initial fluid resuscitation (below 10,000 mL/2 days). CONCLUSIONS: Prompt and adequate, if not massive, fluid resuscitation is the key to preventing renal failure after such injury.

Creatine Kinase↗
PubMed1997

Analysis of 2,702 traumatized patients in the 1995 Hanshin-Awaji earthquake.

BACKGROUND: This study was undertaken to define the factors that affected the final outcome of trauma patients in the Hanshin-Awaji earthquake. METHODS: Medical records of patients admitted to 95 hospitals within or surrounding the affected area during the first 15 days after the quake were reviewed. RESULTS: There were 2,702 traumatized patients. One-third of the patients were transported to hospitals in the surrounding area and had a mortality rate of 3%. The remainder, who were treated in the affected hospitals, showed a significantly higher mortality rate (8%; p < 0.05). Intensive care was provided for 513 patients, most of whom suffered from crush syndrome or from injuries to vital organs; these patients had a high mortality rate. Patients with other types of injuries had a lower mortality rate. CONCLUSION: Crush syndrome and injuries to vital organs were potentially life-threatening. We believe that early transportation of such patients to undamaged hospitals with the ability to provide intensive care would have improved the survival rate.

Abbreviated Injury Scale↗
PubMed1997

Insertions, duplications and substitutions in restricted gp90 regions of equine infectious anaemia virus during febrile episodes in an experimentally infected horse.

We have studied a horse which exhibited typical clinical signs of disease when experimentally infected with a non-adapted virulent strain of equine infectious anaemia virus (EIAV), designated V70. Five viruses (F1V, F2V, F3V, F4V and F5V) were recovered during periodic febrile episodes. Cross-neutralization tests revealed that all of these variants and the parental V70 were antigenically distinct. Sequencing of their full-length env gp90 genes and gp45 5' sequences revealed novel mutations at a limited number of nucleotide positions, consisting of insertions and duplications in the gp90 principal neutralizing domain (PND) in F1V, F3V and F5V. Parts or all of small units (6, 9 and 12 nucleotides) located just before the insertion site were used for the duplications. Furthermore, amino acid substitutions in the env PND and hypervariable region were also observed in all five viruses. These mutations may contribute to the generation of serial variants. Consequently, the full-length gp90 sequences showed close relationships between V70, F2V and F4V, and between F1V, F3V and F5V. In addition to the two domains (PND and hypervariable region), a comparison of these viruses with the reported env gp90 sequences revealed four additional variable domains, although these four domains were highly conserved among the five variants.

Amino Acid Sequence↗
PubMed1997

Amplification of a full-length Borna disease virus (BDV) cDNA from total RNA of cells persistently infected with BDV.

We have developed a novel reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify the full-length 8.9 kilobase (kbp) cDNA of the Borna disease virus (BDV) RNA genome from the total cellular RNA of MDCK cells persistently infected with BDV (MDCK/BDV). Antigenomic BDV cDNA was reverse transcribed using a 53-mer oligonucleotide primer, corresponding to the 5'-terminus of a putative 3'-leader sequence of the BDV RNA genome, for 2 hr at 42 C followed by 30 min at 55 C. PCR was performed in the presence of this 53-mer antigenomic primer and a 25-mer primer, corresponding to the 3'-terminus of the BDV antigenomic cDNA, by use of an rTth DNA polymerase with proof-reading activity. The amplified full-length BDV cDNA was detected in as little as 20 ng of total cellular RNA of MDCK/BDV. This RT-PCR method should be a useful technique to study the molecular quasispecies of BDV.

Animals↗
PubMed1997

Nonadrenergic, noncholinergic relaxation in longitudinal muscle of rat jejunum.

The mediators of nonadrenergic, noncholinergic (NANC) relaxation in the longitudinal muscle of rat jejunum were studied in vitro. Electrical field stimulation (EFS) of segments of rat jejunum induced a rapid transient relaxation followed by a subsequent contraction in the presence of atropine and guanethidine. NG-Nitro-L-arginine (L-NOARG, 10 microM) inhibited the EFS-induced NANC relaxation by about 25%, and L-arginine (1 mM) completely reversed this inhibition. Exogenously added nitric oxide (0.1-10 microM) induced relaxation of the segment. Treatment of the segment with alpha-chymotrypsin resulted in about 50% inhibition of the EFS-induced relaxation. Several peptide candidates for the mediator of NANC relaxation were examined by using selective antagonists of their receptors or by a receptor-desensitization method. Results indicated that vasoactive intestinal peptide, pituitary adenylate cyclase activating peptide, peptide histidine isoleucine, atrial natriuretic peptide and neurotensin are not associated with NANC relaxation of the segments. On the other hand, apamin at 1 microM inhibited the EFS-induced relaxation by 74%. Inhibitory effects of L-NOARG and, apamin or alpha-chymotrypsin treatment on the EFS-induced relaxation were additive and almost complete. Exogenous nitric oxide-induced relaxation was not affected by apamin. Inhibitory junction potentials (i.j.p.'s) were recorded from longitudinal muscle cells of rat jejunum. Apamin at 200 nM abolished i.j.p.'s induced by two pulses of EFS. These results suggest that NANC relaxation in longitudinal muscle of rat jejunum involves two independent components: one is a nitric oxide-mediated minor component, and the other is an unknown substance-mediated apamin-sensitive major component that is inhibited by alpha-chymotrypsin treatment.

Adrenergic Fibers↗
PubMed1997

A study on the evaluation of masticatory ability in osseointegrated implants applied to lower molar region.

Masticatory function was investigated in 7 subjects (5 women and 2 men) with unilateral OIB in their lower molar region. Masticatory movement and myoelectric discharge were analyzed. To examine occlusal contact, the closely occlusal contact area and occluding forces were investigated. The results from the OIB side were compared with the ones from the opposite side. In all subjects, there were no significant differences in the parameters of mandibular movement between chewing the test foods on the OIB side and chewing them on the opposite side. In 6 out of 7 subjects, the closely occlusal area of the interocclusal space differed by less than 1.0 mm between the OIB side and the opposite side in the molar region, and the occluding forces between them were similar. In 6 out of 7 subjects, the masticatory sensations were also similar between the two sides. There were no significant differences between the OIB side and the opposite side in the parameters of mandibular movement, the condition of occlusal contact and the sensation of mastication in patients who were treated with unilateral OIB in the lower molar region. The data seem to suggest that there is little difference between the masticatory ability of OIB and that of natural dentition.

Adult↗
PubMed1996

High susceptibility of U937-derived subclones to human immunodeficiency virus type 1 infection correlates with accumulation of unintegrated circular viral DNA.

Our previous report showed that U937-derived subclones were differentiated into at least three types (high, middle, and low types), even in the subclones expressing similar levels of surface CD4, in terms of the kinetics of the appearance of viral antigens and virus production after infection with human immunodeficiency virus type 1 (HIV-1). Here we showed the evidence that high susceptibility to HIV-1 infection, which was confirmed by the profound expression of viral messages and antigens, was exclusively associated with a high number of the unintegrated extrachromosomal form of viral DNA, but not with the amounts of adsorbed virus RNA nor those of integrated DNA form. The difference in the amounts of extrachromosomal form of viral DNA was also observed in the culture with 3'-azido-3'-deoxythymidine (AZT), indicating that the susceptibility is essentially unrelated to multiple infection events. Thus, the susceptibility of U937-derived subclones to HIV-1 infection seems to be affected by the occurrence of specific events involved in the accumulation of unintegrated viral DNA after viral adsorption.

DNA, Circular↗
PubMed1996

Serial passage of human immunodeficiency virus type 1 generates misalignment deletions in non-essential accessory genes.

Human immunodeficiency virus type 1 (HIV-1) derived from an infectious molecular clone pNL432 was extensively passaged in tissue culture by repeated rounds of acute infection. We previously showed the natural occurrence of a nonsense mutation in the vpr gene during continued passage of this virus. In this report, we show that two forms of large deletions (561 and 518 base pairs containing short direct repeats at the deletion junctions) occur after passage 50 in the region that spans the vif and vpr open reading frames. One model to explain the occurrence of these deletion regions is that such mutations result from misalignment of the growing point at a limited number of nucleotide positions. Infection of CD4+ T-cells with a recombinant HIV-1 construct containing the same vif to vpr deletion showed virtually no cytopathogenic phenotype. Thus, misalignment deletions at non-essential accessory genes of HIV-1 might be induced during replication, which result in the generation of virus with a low cytopathogenic potential.

Base Sequence↗
PubMed1996

Interspecies diversity of the occludin sequence: cDNA cloning of human, mouse, dog, and rat-kangaroo homologues.

Occludin has been identified from chick liver as a novel integral membrane protein localizing at tight junctions (Furuse, M., T. Hirase, M. Itoh, A. Nagafuchi, S. Yonemura, Sa. Tsukita, and Sh. Tsukita. 1993. J. Cell Biol. 123:1777-1788). To analyze and modulate the functions of tight junctions, it would be advantageous to know the mammalian homologues of occludin and their genes. Here we describe the nucleotide sequences of full length cDNAs encoding occludin of rat-kangaroo (potoroo), human, mouse, and dog. Rat-kangaroo occludin cDNA was prepared from RNA isolated from PtK2 cell culture, using a mAb against chicken occludin, whereas the others were amplified by polymerase chain reaction based on the sequence found around the human neuronal apoptosis inhibitory protein gene. The amino acid sequences of the three mammalian (human, murine, and canine) occludins were very closely related to each other (approximately 90% identity), whereas they diverged considerably from those of chicken and rat-kangaroo (approximately 50% identity). Implications of these data and novel experimental options in cell biological research are discussed.

Amino Acid Sequence↗
PubMed1996

VIP- and PACAP-mediated nonadrenergic, noncholinergic inhibition in longitudinal muscle of rat distal colon: involvement of activation of charybdotoxin- and apamin-sensitive K+ channels.

1. The mediators of nonadrenergic, noncholinergic (NANC) inhibitory responses in longitudinal muscle of rat distal colon were studied. 2. An antagonist of pituitary adenylate cyclase activating peptide (PACAP) receptors, PACAP6-38, concentration-dependently inhibited the rapid relaxation of the longitudinal muscle induced by electrical field stimulation (EFS), resulting in a maximal inhibition of 47% at 3 microM. 3. PACAP6-38 inhibited the relaxation by 75% in the presence of the vasoactive intestinal peptide (VIP) receptor antagonist, VIP10-28 at 3 microM, which inhibited the relaxation by 44%. 4. An antagonist of large conductance Ca(2+)-activated K+ channels, charybdotoxin, concentration-dependently inhibited the rapid relaxation of the longitudinal muscle, resulting in a maximal inhibition of 58% at 100 nM. 5. An antagonist of small conductance Ca(2+)-activated K+ channels, apamin, concentration-dependently inhibited the relaxation (58% at 1 microM). 6. Treatment with both K+ channel antagonists resulted in 84% inhibition of the EFS-induced relaxation, which is comparable to the extent of inhibition induced by PACAP6-38 plus VIP10-28. 7. The inhibitory effect of VIP10-28 and of apamin, but not of charybdotoxin was additive: the same applied to PACAP6-38 and charybdotoxin, but not apamin. 8. Exogenously added VIP (100 nM 1 microM) induced a slow gradual relaxation of the longitudinal muscle. Charybdotoxin, but not apamin significantly inhibited the VIP-induced relaxation VIP10-28, but not PACAP6-38 selectively inhibited the VIP-induced relaxation. 9. Exogenously added PACAP (10-100 nM) also induced slow relaxation. Apamin and to a lesser extent, charybdotoxin, inhibited the PACAP-induced relaxation. PACAP6-38, but not VIP10-28 selectively inhibited the PACAP-induced relaxation. 10. Apamin at 100 nM inhibited inhibitory junction potentials (i.j.ps) induced by a single pulse of EFS Apamin also inhibited a rapid phase, but not a delayed phase of i.j.ps induced by two pulses at 10 Hz. VIP10-28 did not inhibit i.j.ps induced by a single pulse, but significantly inhibited the delayed phase at two pulses. A combination of apamin and VIP10-28 abolished the i.j.ps induced by two pulses. 11. Both VIP and PACAP induced slow hyperpolarization of the cell membrane of the longitudinal muscle. Apamin inhibited the PACAP-, but not VIP-induced hyperpolarization. 12. From these findings it is suggested that VIP and PACAP are involved in NANC inhibitory responses of longitudinal muscle of the rat distal colon via activation of charybdotoxin- and apamin-sensitive K+ channels, respectively.

Animals↗
PubMed1996

Nitric oxide-mediated relaxation without concomitant changes in cyclic GMP content of rat proximal colon.

1. We studied the relation of nitric oxide-mediated relaxation of longitudinal muscle to changes in cyclic GMP content of the tissue in the proximal colon of rats. 2. Dimethylphenylpiperazinium (DMPP) and electrical field stimulation (EFS) induced nitric oxide-mediated relaxation of the segments with a concomitant increase in cyclic GMP content. 3. LY 83583 and methylene blue, soluble guanylyl cyclase inhibitors, significantly inhibited the stimulatory effects of DMPP and EFS on the cyclic GMP content, but did not affect the relaxant responses of the segments to DMPP and EFS. 4. Rp-8 bromo cyclic GMPS, an inhibitor of cyclic GMP-dependent protein kinase had no effect on DMPP- and EFS-induced relaxation. 5. These data strongly suggested that nitric oxide-mediated relaxation of the rat proximal colon is not associated with change in cyclic GMP content of the tissue.

Aminoquinolines↗