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Biomedical subjects

Y Kataoka

Publications and source records attributed to Y Kataoka.

At least 163 records · Page 9Linked to original sources
PubMed1993

An occurrence of equine transport pneumonia caused by mixed infection with Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus.

An acute death occurred in a racehorse with pneumonia after long-distance transportation in December, 1990. Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus were isolated from the lung at high rate. Specific antigens of these bacteria were also demonstrated immunohistologically in the pneumonic lesion. These findings indicated that the disease is equine transport pneumonia caused by a mixed infection of the three bacterial species. This is the first report on the isolation of P. caballi and S. suis from a racehorse in Japan.

Animals↗
PubMed1993

The epidemiological studies of Streptococcus suis infections in Japan from 1987 to 1991.

The epidemiological studies of S. suis infections in Japan were carried out between 1987 to 1991. A total of 380 S. suis strains isolated from pigs, cattle and a horse were serotyped by using antisera against S. suis types 1 to 22. A total of 318 (83.7%) of S. suis isolates were serologically typable. Serotype 2 was the most prevalent with 28.2%, followed by type 7 (10.8%), 1/2 (8.4%), 3 (7.4%) and 4 (5.5%). Of twenty S. suis strains isolated from cattle, eight were type 9, one was type 10, five were type 18, one was type 20 and five were untypable. One out of all the strains was also isolated from a racing horse with pneumonia. The majority of the isolates were originated from meningitis (38.2%), followed by from pneumonia (33.4%) and endocarditis (9.2%). Of all of the S. suis isolates, 333 isolates (87.6%) were identified correctly by API STREP 20 system.

Animals↗
PubMed1993

The effect of hyperbaric oxygenation on bone in spontaneously hypertensive rats.

We investigated whether hyperbaric oxygenation treatment can enhance osteogenesis in spontaneously hypertensive rats (SHRs). 8-week-old SHRs were exposed to hyperbaric oxygen for 6 weeks and were killed at 17 weeks of age. Wistar-Kyoto normal rats and untreated SHRs of the same age were used as controls. Radiographic measurements of cortical thickness and length of femora showed that these parameters increased in oxygen-treated SHRs; they became almost normal. Ash weight and ash, Ca and P content of L5 vertebras showed similar results. We conclude that high partial pressure oxygen has an effect on osteogenesis in SHRs.

Animals↗
PubMed1993

[Detection by PCR of genomic markers in canine parvovirus and feline panleukopenia virus].

The NS1 and VP1/VP2 genes of canine parvovirus and feline panleukopenia virus were amplified by the polymerase chain reaction (PCR). The restriction cleavage patterns of the amplified DNA fragments were compared among these parvoviruses including vaccine strains. Differences of the restriction site in the NS1 portions were observed between the vaccine strain and the wild type strain as well as between canine parvoviruses and feline panleukopenia viruses. The restriction patterns of feline panleukopenia viruses were distinct from those of canine parvoviruses, and showed differences between the vaccine strain and its wild type strain. This PCR-based restriction cleavage can be used for ecological study of such viruses.

Feline Panleukopenia Virus↗
PubMed1993

Waldenström's macroglobulinemia associated with amyloidosis and membranous nephropathy.

A 61-year-old man with massive proteinuria and hyper gamma-globulinemia was admitted to hospital because of massive edema and pulmonary infection. He showed significantly high level of serum IgM (3244 mg/dl) with lambda-type M-protein and Bence Jones protein detected by immunoelectrophoresis. Renal biopsy specimen showed not only the diffuse amorphous amyloid deposition in mesangial area but global thickening of capillary wall with spike formation by silver staining which was similar to the spicular formation. Immunofluorescence disclosed find granular deposition of IgG and C3 along the capillary wall and the electromicroscopic findings clearly showed both massive amyloid fibril at mesangial area and diffuse epimembranous electron dense deposits. lambda-type Bence Jones protein in macroglobulinemia was suggested not only the cause of renal amyloidosis but also the antigenic origin of membranous nephropathy in this case.

Amyloidosis↗
PubMed1993

Induction of hprt mutations in mice after exposure to fission-spectrum neutrons or 60Co gamma rays.

The effects of exposure to fission-spectrum neutrons and 60Co gamma rays on mutation induction in B6CF1 mice were investigated. Mutation induction was measured at the hypoxanthine-phosphoribosyl-transferase (hprt) locus in splenic lymphocytes at 56 days after whole-body irradiation. Lymphocytes were cultured 12-16 days in round-bottomed, 96-microwell plates in the presence of 5 x 10(4) feeder cells (syngeneic lymphocytes irradiated with 50 Gy gamma rays). The selective agent used as 6-thioguanine at a concentration of 2.5 micrograms/ml. Animals were exposed to either single doses of neutrons (1.5 Gy) or photons (7.5 Gy) or fractionated doses delivered over 2 weeks of neutrons (0.25 Gy x 6, total 1.5 Gy) or photons (1.5 Gy x 6, total 9.0 Gy). The frequency of hprt mutant induction by fission-spectrum neutrons delivered in a 1.5-Gy single dose compared to a 7.5-Gy single dose of 60Co photons was approximately the same, i.e., 5.98 x 10(-5) +/- 1.51 x 10(-5) (SE) vs. 5.56 x 10(-5) +/- 3.09 x 10(-5) (SE), respectively (Student's two-tailed t test, P = 0.8997). Multiple doses of neutrons gave rise to slightly higher mutant frequencies compared to photons even though the ratio of total doses of neutrons to photons was increased from 5 to 6, i.e., 8.71 x 10(-5) +/- 5.39 x 10(-5) (SE), total dose 1.5 Gy, vs 2.30 x 10(-5) +/- 9.07 x 10(-6) (SE), total dose 9.0 Gy, respectively (Student's two-tailed t test, P = 0.3330). These results suggest that the relative differences in magnitude in radiation-induced genotoxic effects between fission-spectrum neutrons and 60Co gamma rays increase when the comparisons are made between fractionated rather than single-dose exposure regimens.

Animals↗
PubMed1993

[Effect of deliberate hypotension with PGE1 on PaO2 in pediatric patients].

We compared the effect of deliberate hypotension with PGE1 on PaO2 between pediatric and adult patients. Seven children, aged 3-9 yrs and 10 adults, aged 35-65 yrs who were scheduled for elective head and neck surgeries were studied. Anesthesia was maintained with enflurane, 50% N2O in oxygen and supplemental infusion of fentanyl. Ventilation was controlled to maintain PaCO2 at 35-40 mmHg. Hypotension was induced with continuous infusion of PGE1 and the systolic blood pressure was maintained at 70% of the presurgical value. Blood gases were measured three times, i.e. before, during, and after hypotension. The hypotension in adults caused a significant reduction in PaO2. In children, on the contrary, PaO2 was not affected by the hypotension. The results suggest that intrapulmonary shunting is smaller in children than in adults during PGE1-induced hypotension.

Adult↗
PubMed1993

[Intensive chemotherapy for alveolar soft part sarcoma with lung metastasis in a child].

Alveolar soft part sarcoma (ASPS) is one of the soft tissue sarcomas characterized by metastasis early in the course of the disease, regardless of slow tumor growth. The ultimate clinical outcome is, therefore, very poor. To date, the efficacy of combination chemotherapy for this tumor has not been confirmed. We present a case of ASPS in an 8-year-old boy with bilateral pulmonary metastasis who received systemic combination chemotherapy (CPM/IFO/ACD/ADR/CD DP/VP-16 as induction, and VCR/ACD as maintenance therapy) for eleven months. The result showed that despite the prevention of tumor progression, such intensive chemotherapy could not cure the disease. Besides refinement of chemotherapy regimens, immunotherapy might be considered for ASPS.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Indications and results of vascularized pedicle iliac bone graft in avascular necrosis of the femoral head.

Several reports describe methods of treatment for avascular necrosis of the femoral head (ANFH) involving 0 to 2 mm of collapse. Some cases of ANFH have good prognoses, requiring only non-weight-bearing treatment. Other cases rapidly progress to collapse and complete destruction with enlargement of the necrotic area. The progression of the necrotic area is related to the activity of the original disease, steroid treatment, and the size and location of the necrotic area in the early stages of the disorder. In this report, a vascularized pedicle bone graft was used to treat ANFH, particularly those cases identified as Stage II on the system established by the Japanese Investigation Committee. Surgery involved curettage of necrotic bone, implantation of spongy bone, and application of a vascularized pedicle bone graft. Grafts were taken from the ilium and included the superficial circumflex iliac artery (SCIA). A bony canal was made in the anterior femoral neck, from which the necrotic bone was curetted and to which the bone graft was applied. The deep circumflex iliac artery (DCIA) was also used in combination with the SCIA. The postoperative weight-bearing period was six months. Follow-up periods lasted one to six years. Seventeen of 23 Stage II joints (19 cases) achieved satisfactory results at a mean of three years after surgery. Three Stage II joints and three Stage III joints continue to have significant problems. One of these six has been converted to a dual-bearing type endoprosthesis. The unsuccessful results generally occurred in patients who were treated with steroids.

Adult↗
PubMed1992

In vitro quantitative autoradiography of [125I]alpha-bungarotoxin binding at the motor end-plates of experimental autoimmune myasthenia gravis.

A quantitative evaluation was made of nicotinic acetylcholine receptors (AChR) at the motor end-plates in experimental autoimmune myasthenia gravis (EAMG). Female Lewis rats were immunized with AChR protein purified from electric organs of Narke japonica. The forelimb digit extensor muscle obtained in the chronic stage of the controls and EAMG were studied using [125I]alpha-bungarotoxin, in vitro and autoradiographically. The maximum binding capacity (Bmax) values of the controls and EAMG were calculated to be 237.7 +/- 13.0 fmol/mg (n = 4) and 42.0 +/- 4.1 fmol/mg (n = 4), respectively (P less than 0.001), and the dissociation constant (Kd) values were 11.7 +/- 1.6 nM and 7.6 +/- 0.9 nM, respectively. This in vitro autoradiographic method revealed a quantitative reduction of AChR at the motor end-plates in EAMG.

Animals↗
PubMed1992

C-type natriuretic peptide-22 differentiates between natriuretic peptide receptors in rat choroid plexus and subfornical organ.

Atrial natriuretic peptide (ANP) receptors in the rat choroid plexus and subfornical organ were characterized with C-type natriuretic peptide-22 (CNP-22) and 125I-Tyr0-CNP-22. The receptor autoradiographic method we used revealed that 125I-Tyr0-CNP-22 specifically bound to the choroid plexus, but only slightly to the subfornical organ, areas densely labeled with 125I-alpha-rat ANP (125I-rANP). CNP-22 significantly inhibited 125I-rANP binding to the choroid plexus; however, the peptide did not affect 125I-rANP binding to the subfornical organ. Thus, the characteristics of ANP receptors in the rat choroid plexus and subfornical organ are probably different.

Amino Acid Sequence↗
PubMed1992

Specific binding sites for 125I-endothelin-1 in the porcine and human spinal cord.

Specific binding sites for 125I-endothelin-1 (125I-ET-1) in the spinal cord were investigated using quantitative receptor autoradiographic and chemical cross-linking methods. The binding sites were highly concentrated in porcine and human spinal cord areas corresponding anatomically to the dorsal horn (Rexed's laminae I-III), an area around the central canal (lamina X) and the principal part of the intermediolateral nucleus (IMLp). The localization of the binding sites differed from those of 125I-omega-conotoxin GVIA (125I-CgTx) and 125I-Bolton-Hunter substance P (125I-BH-SP), with the exception that the IMLp shared 125I-ET-1 with 125I-CgTx and 125I-BH-SP binding sites. Specific 125I-ET-1 binding sites in the areas examined were characteristically single and of high affinity. There were no differences between the potencies of unlabeled ET family peptides, ET-1, ET-2, ET-3 and sarafotoxin S6b at inhibiting 125I-ET-1 binding to the areas. Chemical cross-linking studies showed that 125I-ET-1 and 125I-ET-3 mainly bound to a protein with molecular mass of 43 kDa in the porcine and human thoracic spinal cord membranes. The present finding shows the neuronal significance of this newly discovered peptide in the spinal cord.

Aged↗
PubMed1992

Endothelin-3 stimulates the release of catecholamine from cortical and striatal slices of the rat.

Endothelin-3 (ET-3) evoked the release of dopamine/noradrenaline from cortical slices and dopamine from striatal slices in a concentration-dependent manner. This action peaked slowly and was long-lasting in real-time monitoring, being different from the high K(+)-evoked response. The striatal response to 10 microM of ET-3 was reduced by extracellular Ca2+ depletion to 40% of control and by Ca2+ antagonists, especially nifedipine and flunarizine, to 40% of control. Our findings suggest that ET has a physiological significance in the brain as a neuromodulator for catecholaminergic transmission.

Animals↗
PubMed1992

Antimutagenic effects of radioprotector WR-2721 against fission-spectrum neurons and 60Co gamma-rays in mice.

The antimutagenic effects of the radiation protective agent, S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721), were studied against fission-spectrum-neutron- and 60Co-gamma-ray-induced mutagenesis in mice. Mutagenesis at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus was measured 56 days following whole-body irradiation with JANUS neutrons (single doses, 50-150 cGy) or 60Co photons (single doses, 250-750 cGy). Splenic T lymphocytes from B6CF1 mice were grown in round-bottomed 96-microwell culture plates with or without the selective agent 6-thioguanine (6-TG). The mutant frequency, as a result of exposure to neutrons or 60Co photons, increased 100-fold with dose. Doses of 150 cGy neutrons and 750 cGy 60Co photons were equally mutagenic. When animals were injected with WR-2721 at a dose of 400 mg/kg body weight, i.p., 30 min before whole-body irradiation with JANUS neutrons or 60Co photons, mutant frequencies were significantly reduced at all radiation doses (i.e. protection factors of 1.4 and 2.4, respectively). Thus, the aminothiols are effective antimutagens. A novel clinical application of these compounds could be in their use to protect against radiation- and/or chemotherapy-induced genotoxic damage to normal cells.

Amifostine↗
PubMed1992

The radioprotector WR-2721 reduces neutron-induced mutations at the hypoxanthine-guanine phosphoribosyl transferase locus in mouse splenocytes when administered prior to or following irradiation.

An in vitro T-lymphocyte cloning technique has been applied to study the effects of JANUS fission-spectrum neutron irradiation and the radioprotector S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR-2721) on the subsequent development of somatic mutations at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus in hybrid B6CF1 male mice. In control studies performed to establish an in vitro cloning technique, the mutant frequencies of splenic T-lymphocytes, as a result of exposure to a 100 cGy dose of neutrons, increased with time from a control level of 9 x 10(-7) to a maximum value of 1.7 x 10(-5) at 56 days following irradiation. Between 56 and 150 days after irradiation, mutant frequencies were observed to plateau and remain stable. All subsequent determinations were performed at 56 days following the experimental treatment of animals. WR-2721 at a dose of 400 mg/kg was effective in protecting against the induction of hprt mutants (i.e. a mutant frequency reduction factor, MFRF) following the largest dose of neutrons used (i.e. 150 cGy), whether it was administered i.p. 30 min before, 5 min after, 3 h after, or three times at 3, 24, and 48 h after, as evidenced by MFRFs of 6.0, 6.6, 4.8 and 5.8 respectively. The antimutagenic effectiveness of WR-2721 administered 30 min prior to irradiation was unaffected, even when the dose was reduced to 200 mg/kg, MFRF = 7.0; 100 mg/kg, MFRF = 3.8; and 50 mg/kg, MFRF = 8.9. These findings confirm our earlier report using the radioprotector N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065) under in vitro conditions, and demonstrate that these agents can be used as effective antimutagens even when they are administered up to 3 h following radiation exposure.

Amifostine↗
PubMed1992

CD7 expression in malignant pleural mesothelioma.

CD7 antigen was found to be expressed on malignant mesothelioma arising from the right pleura in a 15-year-old girl not only by immunostaining using monoclonal antibodies, but also by Northern blot analysis. The level of expression in this tumor was comparable to those in T-cell lines, Jurkat and CCRF-CEM. Cytogenetic analysis of the tumor showed hypodiploidy (n = 43). CD7 has been regarded as one of the hematopoietic cell markers selectively expressed on the majority of T cells and multipotential stem cells. To our knowledge, this is the first report of a non-hematopoietic tumor expressing CD7.

Adolescent↗
PubMed1992

Activation of protein kinase C suppresses the gamma-aminobutyric acidB receptor-mediated inhibition of the vesicular release of noradrenaline and acetylcholine.

Modulation of the gamma-aminobutyric acidB (GABAB) receptor-mediated response by protein kinase C (PKC) was examined with regard to inhibition by stimulation of the GABAB receptor of stimulation-evoked release of noradrenaline (NA) from slices of cerebellar cortex and of acetylcholine (ACh) from strips of ileum. 12-O-Tetradecanoylphorbol 13-acetate (TPA) potentiated the high K(+)-evoked Ca2+-dependent release of NA and ACh, but not the ouabain-evoked release, even in the presence of external Ca2+. The potentiating effect was antagonized by sphingosine, thereby suggesting that PKC participates in the exocytotic-vesicular release of neurotransmitters, but does not do so in case of a nonvesicular release. GABA inhibited the high K(+)-evoked release of NA and ACh, but not the ouabain-evoked Ca(2+)-independent release. The effect of GABA was mimicked by baclofen and was antagonized by phaclofen, thereby suggesting that stimulation of the GABAB receptor inhibits the vesicular but not the nonvesicular release of neurotransmitters. TPA suppressed the GABAB receptor-mediated inhibition of high K(+)-evoked release of NA and ACh. The effect of TPA was antagonized by sphingosine. These results indicate that stimulation of the GABAB receptor inhibits the stimulation-evoked Ca(2+)-dependent release of neurotransmitters and that activation of PKC suppresses the GABAB receptor-mediated response.

Acetylcholine↗