Biomedical subjects

Koichi Ohno

Publications and source records attributed to Koichi Ohno.

At least 55 records · Page 3Linked to original sources

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↗

PubMed2003

Antigen-specific histamine release in dogs with food hypersensitivity.

An in vitro evidence of IgE-mediated hypersensitivity to food allergens was detected by positive results of antigen-specific histamine release in dogs with food hypersensitivity. Eight dogs were diagnosed to have food hypersensitivity based on identification of offending food allergens with food elimination followed by oral food provocation. The percentages of histamine release against the stimulation of offending food allergens in the cases ranged from 2.1% to 70.9%. Six of the 8 cases showed histamine release higher than those of healthy control dogs. Four dogs showed relatively high histamine release at the percentage beyond 10% that was compatible with a positive value of histamine release in humans with food hypersensitivity. These findings would suggest that IgE-mediated hypersensitivity against food allergens could be involved in canine food hypersensitivity.

Animals↗

PubMed2003

Molecular cloning of the feline telomerase reverse transcriptase (TERT) gene and its expression in cell lines and normal tissues.

Telomerase is a kind of reverse transcriptase which synthesizes and elongates telomeres. Telomerase activity is detected in many naturally occurring tumors and its expression appears to play an important role in the immortalization of tumor cells. In this study, cDNA encoding the feline telomerase reverse transcriptase (TERT) gene was cloned partially from a feline lymphoma cell line. The clone obtained in this study was 237 bp long including a reverse transcriptase motif 2, and was shown to have amino acid sequence similarity of 81.0% and 58.2% with human and mouse TERT cDNAs, respectively. TERT mRNA expression was detected in telomerase-positive cells (FL74, FT-1, 3201, FKNp, FONp, and FYMp), and was not detected in telomerase-negative cells (normal fibroblasts and CRFK). TERT mRNA was detected in various normal tissues including the spleen, pancreas, stomach, cerebrum, testis, bone marrow, lymph node and thymus, and relatively high-level expression was observed in the small bowel and large bowel. No expression of TERT mRNA was detected in the liver, adrenal gland, urinary bladder and lung. The TERT cDNA clone and the results obtained in this study will be useful for further investigation of feline tumors.

Amino Acid Sequence↗

PubMed2003

Molecular cloning of the canine telomerase reverse transcriptase gene and its expression in neoplastic and non-neoplastic cells.

OBJECTIVE: To perform molecular cloning of the canine telomerase reverse transcriptase (TERT) gene and determine its expression in neoplastic and non-neoplastic cells. SAMPLE POPULATION: 9 canine tumor cell lines derived from various neoplasms, 16 primary canine tumors, and tissues from 15 normal canine organs. PROCEDURE: Tumor cell lines were derived from canine tumors that included osteosarcoma, mammary gland adenocarcinoma, melanoma, acute lymphoblastic leukemia, lymphoma, and mastocytoma and a canine primary fibroblast culture. Canine TERT complementary DNA (cDNA) was amplified by use of polymerase chain reaction (PCR) and sequenced. Expression of TERT mRNA was examined by reverse transcription (RT)-PCR assay. Telomerase activity was measured by use of the telomeric repeat amplification protocol assay. RESULTS: The canine TERT cDNA clone was 237 base pairs in length and contained a central region encoding the reverse transcriptase motif 2. Expression of TERT mRNA was detected in canine tumor cell lines that had telomerase activity but not in telomerase-negative canine primary fibroblasts. The TERT mRNA was detected in 13 of 16 canine tumor tissues and several normal tissues such as liver, ovary, lymph node, and thymus. A significant correlation between TERT expression level and telomerase activity was noted. CONCLUSIONS AND CLINICAL RELEVANCE: Expression of TERT mRNA was closely associated with telomerase activity in neoplastic cells as well as some non-neoplastic cells from dogs. In addition to telomerase activity, expression of TERT mRNA can be used as a marker of tumor cells.

Animals↗

PubMed2003

Effect of an adenoviral vector that expresses the canine p53 gene on cell growth of canine osteosarcoma and mammary adenocarcinoma cell lines.

OBJECTIVE: To generate an adenoviral vector that expressed the canine p53 gene and investigate its growth-inhibiting effect on canine osteosarcoma and mammary adenocarcinoma cell lines. SAMPLE POPULATION: 2 canine osteosarcoma cell lines (HOS, OOS) and 3 canine mammary adenocarcinoma cell lines (CHMp, CIPm, and CNMm). PROCEDURE: An adenoviral vector that expressed the canine p53 gene (AxCA-cp53) was generated. p53 gene expression was examined by use of reverse transcription (RT)-polymerase chain reaction (PCR) assay and immunohistochemistry. Susceptibility of cell lines to the adenoviral vector was determined by infection with an adenoviral vector that expresses beta-galactosidase (AxCA-LacZ) and 3-indolyl-beta-D-galactopyranoside staining. Growth inhibitory effects were examined by monitoring the numbers of cells after infection with mock (PBS) solution, AxCA-LacZ, or AxCA-cp53. The DNA contents per cell were measured by flow cytometry analysis. Apoptotic DNA fragmentation was detected by use of a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. RESULTS: AxCA-cp53-derived p53 gene mRNA and P53 protein were detected by RT-PCR analysis and immunohistochemistry, respectively. Multiplicity of infection at which 50% of cells had positive 3-indolyl-beta-D-galactopyranoside staining results ranged from 10 to 50. AxCA-cp53 induced growth inhibition in a dose-dependent manner. Arrest of the G1-phase population and apoptotic DNA fragmentation were observed in cells infected with AxCA-cp53. CONCLUSIONS AND CLINICAL RELEVANCE: AxCA-cp53 inhibits cell growth via induction of cell cycle arrest and apoptosis in canine osteosarcoma and mammary adenocarcinoma cell lines that lack a functional p53 gene. AxCA-cp53 may be useful to target the p53 gene in the treatment of dogs with tumors.

Adenocarcinoma↗

PubMed2003

Comparison of the Nuss procedure for pectus excavatum by age and uncommon complications.

BACKGROUND: We summarized our experience of the Nuss procedure for pectus excavatum with comparison by age and uncommon complications. METHODS: Twenty-three patients underwent the Nuss procedure. Their age ranged from 3 to 19 years old. The outcome was compared between two groups divided by age: teenagers (> or = 13 yrs old, n = 5, Group 1) and younger patients (n = 18, Group 2). RESULTS: Cosmetic results were significantly better, and the operating time and postoperative hospital stay in Group 2 were significantly shorter than in Group 1. Complications were more frequently seen in Group 1 than in Group 2. In all three younger patients whose bars were removed after 2 years, the ribs holding the bar were deformed. Uncommon complications occurred in two cases. In one case, pneumothorax occurred due to laceration by a fragment of wire after 12 months, and the fragment fell into the thoracic cavity. In another case, pneumothorax occurred due to injury by the port of a thin thoracoscope. CONCLUSION: The teenaged patients had more complications and poorer cosmetic results. Therefore, this operation should be performed before the teenage years. In younger patients with rapid growth, the bar should be removed less than 2 years to prevent restriction of costal growth.

Adolescent↗

PubMed2002

Lesional expression of thymus and activation-regulated chemokine in canine atopic dermatitis.

In this study, we investigated the mRNA expression of a chemokine, thymus and activation-regulated chemokine (TARC), and cytokines including IL-1beta, IL-4, IFN-gamma and TNF-alpha in skin samples obtained from both dogs with atopic dermatitis (AD) and healthy dogs. TARC mRNA was found to be selectively expressed in lesional skin of the dogs with AD, but not in non-lesional skin of the dogs with AD or the normal skin of the healthy dogs. The expression levels of IL-1beta, IFN-gamma and TNF-alpha in the lesional skin were also significantly higher than those in the non-lesional skin of the dogs with AD. However, IL-4 mRNA was not detected in any of the skin samples in this study. The present results suggest that TARC and inflammatory cytokines such as IL-1beta, IFN-gamma and TNF-alpha may play roles in the pathogenesis of canine AD as well as that of human AD.

Animals↗

PubMed2002

Analysis of the 18S rRNA gene sequence of a Hepatozoon detected in two Japanese dogs.

Partial sequences of the 18S rRNA gene (625 bp) from a Hepatozoon detected in two canine hepatozoonosis cases, one clinical and one subclinical, in Japan were analyzed. Both sequences were identical to each other and they were closely related to the Hepatozoon canis strain found in Israel with 99% (617/625) nucleotide identity. Both Hepatozoon americanum and Hepatozoon catasbianae were distantly related to the Japanese Hepatozoon with 94% (586/625) and 91% (566/625) identities, respectively. In a phylogenetic tree, the Japanese Hepatozoon was most closely related to H. canis from Israel but was significantly different than H. americanum and H. catasbianae. These results suggest that the Hepatozoon detected in the Japanese dogs might be a strain variant of H. canis, but is apparently a different species than H. americanum.

Animals↗

PubMed2002

Expression of CC chemokine receptor 4 (CCR4) mRNA in canine atopic skin lesion.

CC chemokine receptor 4 (CCR4) is a G protein-coupled seven transmembrane receptor that is selectively expressed on Th2 cells and plays an important role in the trafficking of Th2 cells into inflammatory sites. In this study, a full-length canine CCR4 cDNA was cloned and characterized in order to examine the potential role of CCR4 in allergic responses that produce skin lesions in canine atopic dermatitis (AD). The canine CCR4 cDNA reported in this study contained an open reading frame of 1083 nucleotides encoding 360 amino acids. The predicted amino acid sequence of canine CCR4 showed 91.9, 85.3 and 84.5% similarity with those of the human, mouse and guinea pig counterparts, respectively. Expression of CCR4 mRNA was detected in various tissues including thymus, spleen, heart, small intestine and lymph node. Furthermore, it was found that CCR4 mRNA was preferentially expressed in lesional skin of dogs with AD, together with the mRNA of thymus and activation-regulated chemokine (TARC), which is a ligand for CCR4. The present study demonstrates that CCR4 contributes strongly to the immunopathogenesis of canine AD.

Amino Acid Sequence↗