Biomedical subjects

Koichi Ohno

Publications and source records attributed to Koichi Ohno.

At least 19 recordsLinked to original sources

PubMed2004

Identification of CpG oligodeoxynucleotide sequences that induce IFN-gamma production in canine peripheral blood mononuclear cells.

Oligodeoxynucleotides containing the cytosine-phosphate-guanine (CpG) motif (CpG-ODNs) have been shown to induce T(H)1 immune responses in animals. Since the sequences of CpG-ODNs that induce T(H)1 responses are considered to vary among animal species, it is necessary to identify effective CpG-ODNs in each animal. In order to identify the sequences of CpG-ODNs that induce T(H)1 responses in dogs, mRNA expression and protein production of IFN-gamma were examined in peripheral blood mononuclear cells (PBMCs) from healthy dogs treated with 11 kinds of synthetic CpG-ODNs. One of the 11 CpG-ODNs (No. 2 CpG-ODN, 5'-GGTGCATCGATGCAGGGGGG-3') was shown to significantly increase mRNA expression and protein production of IFN-gamma in canine PBMCs in a manner dependent on the sequence of the CpG motif. This CpG-ODN also enhanced the expression of IL-12 p40 mRNA in canine PBMCs, whereas expression of IL-12 p35, IL-18, and IL-4 mRNAs was not induced by this CpG-ODN. These results indicate that this CpG-ODN was able to produce IFN-gamma by induction of T(H)1-skewed immune response in dogs. CpG-ODNs may be useful for inducing prophylactic and therapeutic immunity against allergic diseases, viral infection, and tumors in dogs.

Animals↗

PubMed2004

Characterization of a newly established nonproducer lymphoma cell line for feline leukemia virus.

A feline lymphoblastoid cell line (KO-1) was established from a 5-year-old neutered female cat with naturally occurring thymic lymphoma. KO-1 cells had a rearrangement of T-cell receptor beta-chain gene and a germ-line configuration of immunoglobulin heavy chain gene, however, they were devoid of T-cell-specific surface phenotype. Cytogenetically, KO-1 cells showed a hyperploidy (2n = 41) due to the trisomy of B2, F2 and X chromosomes. Although KO-1 cells were shown to be clonally expanded cells integrated with feline leukemia virus (FeLV) proviruses and expressed its structural proteins in their cytoplasm, they did not produce virus particles as shown by transmission electron microscopy and the absence of the viral protein and reverse transcriptase activity in the culture supernatant. The present study showed that the KO-1 cell line established here was a feline T-cell lymphoma cell line having a unique characteristic as an FeLV nonproducer.

Animals↗

PubMed2004

Multiple photofragmentation pathways with different recoil anisotropy from a metal-ion-ligand complex.

Spatial recoil anisotropy that is dependent upon the fragment-ion species is reported for the first time for a metal-ion-ligand complex after a single photoexcitation process by linearly polarized light. Upon excitation to the lowest three excited states of Mg+-ICH3, originating from the Mg+2P states, fragment ions of MgI+ and ICH+3 are found to have clear and different angular dependences, which are also characteristic of the excited states. These are explained from the results of theoretical work in that the calculated ground-state complex has a bent structure and further in that each transition dipole moment vector of the complex almost coincides with the Mg+ 3p orbital lobe direction in each case. The fragment ions are concluded to be formed along dissociative potential surfaces which are crossed by the initially excited states, in a much faster process than the rotational period of the complex.

Journal Article↗

PubMed2004

Collision-energy-resolved Penning ionization electron spectroscopy of bromomethanes (CH3Br, CH2Br2, and CHBr3) by collision with He*(2(3)S) metastable atoms.

Ionization of bromomethanes (CH3Br, CH2Br2, and CHBr3) upon collision with metastable He*(2(3)S) atoms has been studied by means of collision-energy-resolved Penning ionization electron spectroscopy. Lone-pair (nBr) orbitals of Br4p characters have larger ionization cross sections than sigma(C-Br) orbitals. The collision-energy dependence of the partial ionization cross sections shows that the interaction potential between the molecule and the He*(2(3)S) atom is highly anisotropic around CH3Br or CH2Br2, while isotropic attractive interactions are found for CHBr3. Bands observed at electron energies of approximately 2 eV in the He*(2(3)S) Penning ionization electron spectra (PIES) of CH2Br2 and CHBr3 have no counterpart in ultraviolet (He I) photoionization spectra and theoretical (third-order algebraic diagrammatic construction) one-electron and shake-up ionization spectra. Energy analysis of the processes involved demonstrates that these bands and further bands overlapping with sigma(C-Br) or piCH2 levels are related to autoionization of dissociating (He+ - Br-) pairs. Similarly, a band at an electron energy of approximately 1 eV in the He*(2(3)S) PIES spectra of CH3Br has been ascribed to autoionizing Br** atoms released by dissociation of (unidentified) excited states of the target molecule. A further autoionization (S) band can be discerned at approximately 1 eV below the lone-pair nBr bands in the He*(2(3)S) PIES spectrum of CHBr3. This band has been ascribed to the decay of autoionizing Rydberg states of the target molecule (M**) into vibrationally excited states of the molecular ion. It was found that for this transition, the interaction potential that prevails in the entrance channel is merely attractive.

Journal Article↗

PubMed2004

Collision-energy-resolved Penning ionization electron spectroscopy of p-benzoquinone: study of electronic structure and anisotropic interaction with He(*)(2 (3)S) metastable atoms.

Collision energy dependence of partial ionization cross sections (CEDPICS) of p-benzoquinone with He(*)(2 (3)S) metastable atoms indicates that interaction potentials between p-benzoquinone and He(*)(2 (3)S) are highly anisotropic in the studied collision energy range (100-250 meV). Attractive interactions were found around the C==O groups for in-plane and out-of-plane directions, while repulsive interactions were found around CH bonds and the benzenoid ring. Assignment of the first four ionic states of p-benzoquinone and an analogous methyl-substituted compound was examined with CEDPICS and anisotropic distributions of the corresponding two nonbonding oxygen orbitals (n(O) (+),n(O) (-)) and two pi(CC) orbitals (pi(CC) (+),pi(CC) (-)). An extra band that shows negative CEDPICS was observed at ca. 7.2 eV in Penning ionization electron spectrum.

Journal Article↗

PubMed2004

An overlap expansion method for improving ab initio model potentials: anisotropic intermolecular potentials of N2, CO, and C2H2 with He*(2(3)S).

An overlap expansion method is proposed for improving ab initio model potentials. Correction terms are expanded in terms of overlap integrals between orbitals of the interacting system. The method is used to improve ab initio model potentials for N2+He*(2(3)S), CO+He*(2(3)S), and C2H2+He*(2(3)S). Physical meanings of the optimization are elucidated in terms of target orbitals. Correction terms are found to be dominated by the components of HOMO, LUMO, next-HOMO, and next-LUMO on the target molecule. The present overlap expansion method using a limited number of correction terms related to frontier orbitals provides an efficient and intuitive approach for construction of highly anisotropic intermolecular interaction potentials.

Journal Article↗

PubMed2004

Peptic ulcer-induced acute aortogastric fistula occurring 7 years after a pharyngogastrostomy following a resection for carcinoma of the esophagus: report of a case.

A 46-year-old woman underwent a pharyngogastrostomy, following a laryngoesophagectomy for esophageal carcinoma. Although she had been disease-free for 7 years, she subsequently was admitted to undergo a workup due to fever along with chest and back pain. A few days after admission, the patient suddenly vomited a large volume of blood and went into shock. Bleeding was stopped with a Sengstaken-Blakemore tube, and an emergency thoracotomy was performed. A fistula between the thoracic aorta and an ulcer of the gastric tube was identified. We decided to close the aortic lesion directly because the adhesions were extremely dense and her blood circulation was poor. One week later, we resected the thoracic part of the gastric tube, debrided the fistula, and wrapped the aortic lesion with a patch. However, on the 18th postoperative day, she developed massive hematemesis due to rupture of an infected pseudoaneurysm in the thoracic aorta and died.

Acute Disease↗

PubMed2004

Effects of chlorine on the decrease of estrogenic chemicals.

The effects of chlorination on the elimination of three estrogenic chemicals such as 17beta-estradiol, nonylphenol and bis-phenol A were investigated using yeast two-hybrid assay (YTA), estrogen receptor (ER) competition assay (ER-CA), and high-performance liquid chromatography/mass spectrometry (LC/MS). The results of YTA, ER-CA and the analysis of LC/MS indicated that the estrogenic activity of the above-mentioned three endocrine disruptors were significantly reduced as a result of chlorination. The decrease in estrogenic activity paralleled a decrease in estrogenic chemicals under the influence of free chlorine. One common characteristic of estrogenic chemicals is the presence of a phenolic ring. Considering that a phenolic ring is likely to undergo some sort of transformation in an aqueous chlorination solution, the above-mentioned results may be applied to the rest of the estrogenic chemicals in natural waters.

Benzhydryl Compounds↗

PubMed2004

Immunological findings in 3 dogs clinically diagnosed with allergic rhinitis.

Three dogs clinically diagnosed with allergic rhinitis (AR) were examined for their immunological findings. House dust mites (HDM) such as Dermatophagoides farinae (DF) and D. pteronyssinus (DP) were identified as positive allergens in the 3 dogs with both intradermal skin test and serum antigen-specific IgE test. Lymphocyte blastogenic response of peripheral blood mononuclear cells (PBMCs) under stimulation with DF antigen in dogs with AR was higher than that in 4 healthy control dogs. Expression level of IL-4 mRNA in PBMCs obtained from the 3 AR dogs was higher than that in PBMCs obtained from 4 healthy control dogs before and after stimulation with DF antigen. Expression level of IFN-gamma mRNA in PBMCs was not different between the AR and control dogs before and after stimulation with DF antigen. These results suggested that allergic reaction to HDM antigen and T(H)2-type immune response were associated with the development of AR in 3 dogs examined in this study.

Animals↗

PubMed2004

Expression of LacZ gene in canine muscle by intramuscular inoculation of a plasmid DNA.

DNA immunization induces systemic humoral and cellular immune responses to the antigen encoded by cDNA in a plasmid DNA. In the present study, a plasmid DNA encoding cDNA of beta-galactosidase (beta-gal), pCAGGS-lacZ, was inoculated intramuscularly to a healthy dog in order to evaluate location and duration of the gene expression. On day 7, the plasmid DNA was found by PCR in the muscle where the plasmid was injected. Furthermore, beta-gal expression was detected in the same muscle sample by beta-gal staining. However, the plasmid DNA was not detected in any samples collected on days 14, 21 and 28. The present results suggest that duration of the gene expression of beta-gal by the plasmid DNA is limited in the muscle in dogs and an efficacy for a gene expression should be evaluated depending on the gene inserted in the plasmid DNA for immunotherapy.

Animals↗

PubMed2004

CTLA-4 recombinant protein genetically fused to canine Fcepsilon receptor Ialpha enhances allergen specific lymphocyte responses in experimentally sensitized dogs.

Vaccination with a recombinant antigen fused to a targeting molecule is a potential strategy for inducing efficient immune responses. For the therapeutic purpose of allergic diseases in dogs, a DNA construct which expresses recombinant fusion protein with two functional domains, cytotoxic T lymphocyte antigen (CTLA-4) and Fcepsilon receptor Ialpha, was developed to bridge antigen-presenting cells and IgE-allergen complex. The recombinant fusion protein expressed by the DNA construct was demonstrated to retain the ability to bind monocytes in PBMC and dog IgE, respectively. Additionally, the recombinant protein induced enhancement of allergen-induced lymphoproliferation in experimentally sensitized dogs under conditions of suboptimal allergen stimulation. These results indicated that the DNA construct could enhance allergen-induced immune responses in vivo, implying its usefulness for perspective application in immunotherapy in dogs.

Abatacept↗

PubMed2004

Molecular cloning of canine activation-induced cytidine deaminase (AID) cDNA and its expression in normal tissues.

Activation-induced cytidine deaminase (AID) is essential for class switch recombination, somatic hypermutation, and gene conversion of immunoglobulin gene. In the present study, canine AID cDNA was cloned from the lymph node of a healthy dog by RT-PCR with rapid amplification of cDNA ends (RACE) method. The canine AID cDNA was 1,377 bp in length, and contained the entire open reading frame encoding 198 amino acids which had 94.9%, 94.4%, and 89.9% homology with human, mouse, and chicken homologues, respectively. Canine AID mRNA was expressed in thymus, lung, spleen, kidney, small intestine, lymph node, and tonsil of a healthy dog, similar to humans.

Amino Acid Sequence↗

PubMed2003

Cytokine profiles of peripheral blood mononuclear cells from dogs experimentally sensitized to Japanese cedar pollen.

Japanese cedar (Cryptomeria japonica, CJ) pollinosis is mediated by type-I hypersensitivity and induces seasonal rhinitis and conjunctivitis in humans. Previous studies showed that dogs could be experimentally sensitized with CJ pollen. In this study, we carried out quantitative analysis of mRNA levels of various cytokines in the peripheral blood mononuclear cells (PBMC) of 12 dogs experimentally sensitized to Japanese cedar pollen. Experimental sensitization was carried out by injection of crude CJ pollen extract with aluminium hydroxide gel. The expression levels of interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, interferon (IFN)-gamma, transforming growth factor (TGF)-beta(1), and tumor necrosis factor (TNF)-alpha mRNAs in the PBMC were quantified using a real-time sequence detection system. In the PBMC tested without culture, the expression levels of IL-8 and TNF-alpha mRNAs in experimentally sensitized dogs were significantly higher than those in control dogs. The expression level of IFN-gamma mRNA in the sensitized group was significantly lower than that in the control group. When the PBMCs were cultured in the presence of CJ pollen extract, the level of IL-4 mRNA expression was markedly increased in the PBMC from the experimentally sensitized dogs. In the PBMC stimulated with the CJ pollen extract, the expression level of IL-2 mRNA in the sensitized group was also significantly higher than that in the control group. Our data indicated that a Th2 response and proliferation of PBMC occur in response to the sensitizing antigen in dogs experimentally sensitized with CJ pollen, and revealed the presence of antigen-specific Th2 cells in this canine model. In addition, the expression levels of the mRNAs encoding proinflammatory cytokines were shown to be elevated after CJ pollen sensitization, indicating the activation of monocytes and macrophages.

Animals↗

PubMed2003

Malignant pheochromocytoma associated with pseudo-obstruction of the colon.

Effective treatment has not yet been established for intestinal pseudo-obstruction, a rare complication of malignant pheochromocytoma. We report the case of a 41-year-old man who presented with malignant pheochromocytoma associated with pseudo-obstruction of the colon. His serum catecholamine level was markedly elevated, and his large intestine was distended with gas and lodged stool. Laxatives and enemas were not effective in relieving his symptoms. We subsequently performed an ileostomy, after which the patient had good bowel movement and was able to resume oral food intake.

Adrenal Gland Neoplasms↗

PubMed2003

Indications for surgical repair of funnel chest based on indices of chest wall deformity and psychological state.

PURPOSE: We examined the surgical indications for funnel chest, taking psychological factors into consideration. METHODS: We assessed 36 young people with funnel chest who were seen as outpatients, including 31 boys and 5 girls aged from 1 to 22 years old. Respondents were asked whether they suffered psychological distress, and if they wanted surgery. The severity of the deformity was evaluated using the Vertebral Index (VI) and the Frontosagittal Index (FSI) calculated from chest roentgenograms. RESULTS: The VI in 11 patients without distress (23.7 +/- 4.1) was lower than that in 25 patients with distress (32.8 +/- 8.2), and the FSI in the patients without distress (33.5 +/- 5.3) was higher than that in the patients with distress (23.6 +/- 8.6). The VI in 19 patients who did not want surgery (26.9 +/- 7.9) was lower than that in 17 patients who did (33.5 +/- 7.5), and the FSI in the patients who did not want surgery (30.4 +/- 8.1) was higher than that in the patients who did (22.4 +/- 8.1). The distressed patients suffered many psychological problems, such as being the object of bullying. CONCLUSION: The severity of the deformity affected the patient's psychological state. We consider that a VI >28 or an FSI <28 are indications for surgery, based on the mean VI + SD and the mean FSI-SD of patients not suffering distress.

Adolescent↗

PubMed2003

Hand-assisted endoscopic esophagectomy for esophageal cancer.

Radical esophagectomy is a highly invasive operation for esophageal cancer, and improved techniques are being sought to reduce the invasiveness of this procedure. We devised a method in which an assistant inserts their left hand into the thoracic cavity, and the operator inserts their left hand into the abdominal cavity through a small incision in the upper quadrant during an endoscopic procedure. Between 1996 and 1999, we performed endoscopic esophagectomy on 18 patients. The median number of mediastinal lymph nodes removed by thoracoscopic surgery was 20.1 +/- 9.4 and the median number of abdominal lymph nodes removed by laparoscopic surgery was 11.1 +/- 5.6. The number of nodes dissected by endoscopic surgery did not differ significantly from the number of nodes dissected by conventional thoracotomy with laparotomy. Our experience shows that endoscopic esophagectomy with reconstruction of the esophagus assisted by inserting the hand into the thoracic and abdominal cavity, for safety and certainty, is an effective technique that is much less invasive than radical esophagectomy performed by conventional thoracotomy with laparotomy.

Endoscopy↗

PubMed2003

Molecular cloning of the feline thymus and activation-regulated chemokine cDNA and its expression in lesional skin of cats with eosinophilic plaque.

Thymus and activation-regulated chemokine (TARC) is a member of CC chemokine and plays an essential role in recruitment of CC chemokine receptor 4 positive Th2 cells to allergic lesion. To investigate the association of TARC in allergic inflammation of cats, a TARC cDNA was cloned from feline thymus by RT-PCR with 3' rapid amplification of cDNA ends (RACE) method. The feline TARC clone contained a full length open reading frame encoding 99 amino acids which shared 80.8%, 72.5%, 65.6% and 67.8% homology with dog, human, mouse and rat homologues, respectively. Expression of TARC mRNA was detected not only in thymus but also in spleen, lung, lymph node, kidney, small intestine, colon and skin of the normal cat tissues examined. Furthermore, it was found that TARC mRNA was strongly expressed in lesional skin of cats with eosinophilic plaque. The present results demonstrated that TARC might be involved in the pathogenesis of eosinophilic plaque in cats.

Amino Acid Sequence↗

PubMed2003

Antigen-specific enhancements of CD80 mRNA expression in experimentally sensitized dogs with Japanese cedar pollen.

CD80, CD86, CD28 and Cytotoxic T lymphocyte antigen-4 (CTLA-4) are well-known co-stimulatory molecules that form the major co-stimulatory pathway essential for full activation of T cells. To investigate their role in pathogenesis of immune-mediated diseases, 12 dogs were sensitized experimentally to Japanese cedar pollen antigen (CPAg) as models of allergic diseases in dogs. After sensitization, lymphocyte stimulation test (LST) was carried out to evaluate reactivity to CPAg, and semi-quantitative real-time RT-PCR analysis of CPAg-stimulated peripheral blood mononuclear cells (PBMCs) to evaluate the expression of co-stimulatory molecules. As a result, CPAg-specific enhancements of CD80 expression were detected in all sensitized dogs. Furthermore, two different kinetics of its enhancements according to the blastgenic responses to CPAg were also observed. Expression of CD28, CTLA-4 and CD86 were suppressed following CPAg-stimulation. The result of the present study indicated the potential role of the CD28-CD80 co-stimulation pathway in pathogenesis of allergic diseases in dogs.

Animals↗