Biomedical subjects

K Ohshima

Publications and source records attributed to K Ohshima.

At least 289 records · Page 16Linked to original sources

PubMed1993

Involvement of CD8+ T cells in delayed-type hypersensitivity responses against bovine leukemia virus (BLV) induced in sheep vaccinated with recombinant vaccinia virus expressing BLV envelope glycoprotein.

Delayed-type hypersensitivity responses against bovine leukemia virus (BLV) envelope glycoprotein (gp60) were induced in the skin of sheep vaccinated with recombinant vaccinia virus (RVV) expressing BLV glycoprotein. The lesions were characterized by marked infiltration of lymphocytes, slight migration of neutrophils, eosinophils, and macrophages in the dermis to hypodermis, and partial intercellular edema in the reticular layer. Immunohistochemical analysis with monoclonal antibodies demonstrated that the lymphocytic infiltrates consisted mainly of CD8+ T cells (53.7-55.8% at 48 hours post-challenge of BLV), CD4+ T cells (24.7-26.7%), and B cells (11.5-16.9%). The role of CD4+ and CD8+ T cells in suppressing BLV growth in RVV-vaccinated animals is discussed.

Animals↗

PubMed1993

Effect of human galanin on growth hormone prolactin, and antidiuretic hormone secretion in normal men.

Galanin is a brain-gut peptide occurring widely in the central and peripheral nervous system. Effects of iv administration of synthetic human galanin on pituitary GH, PRL, and antidiuretic hormone secretion were studied. Intravenous infusion of the peptide resulted in a significant increase in plasma GH levels whereas PRL and antidiuretic hormone did not significantly change. These findings suggest that galanin might play a role in modulating GH secretion in humans.

Adult↗

PubMed1993

Scirrhous adenocarcinoma of the rectum in a cow.

Clinical and pathological examinations were performed on a 3-year-old Holstein-Friesian cow with scirrhous adenocarcinoma of the rectum. Hemorrhagic diarrhea causing rectal stenosis was a principal clinical manifestation. Microscopically, cancerous transformation of the intestinal epithelium was observed in the rectal crypts. Irregular glandular arrangements containing PAS positive and eosinophilic mucus were observed in the lumen, which were surrounded by scirrhous collagenous fibers. The neoplastic epithelial cell had round or ovoid nucleus and slightly eosinophilic cytoplasm. Metastatic lesions were localized in the marginal and medullary sinuses of the anorectal lymph nodes.

Adenocarcinoma, Scirrhous↗

PubMed1993

A case of neonatal calf with meningitis associated with Klebsiella oxytoca infection.

A 16-days-old calf exhibited pyrexia, difficulty to stand and walk, cloudiness of the ocular aqueous humor, and swelling of the shoulder joints. The primary pathological lesion was fibrinopurulent meningitis with Gram-negative small bacilli, and which was concurrently accompanied with endophthalmitis, polyarthritis, and purulent inflammation in several visceral organs. Klebsiella oxytoca was isolated from the brain and spinal cord. These results suggest that this is a rare case of meningitis with septicemic K. oxytoca infection in neonatal calf.

Animals↗

PubMed1993

Morphogenesis of compound melanosomes in melanoma cells of a gray horse.

A thoroughbred horse, gelding, gray color, aged 19 years old had cutaneous melanomas from the root to the middle of the tail, and throughout the connective tissues of the whole body. Histologically, the tumors were diagnosed as mature melanotic melanomas characteristically deposited with abundant melanin pigment. Examined with an electron microscope, melanosomes were electron opaque without internal structure (stage IV), or as mature granular and lamellar types. Most of them were fused with each other, and formed compound melanosomes, which was similar to internal melanin aggregates in shape. The internal melanin aggregates gradually disintegrated, and compound melanosomes grew spherical. The compound melanosomes changed into autophagosomes.

Animals↗

PubMed1993

Ultrastructural study of post-hatching development in the pineal gland of the Japanese quail.

The pineal gland of the Japanese quail (Coturnix coturnix japonica) retained numerous follicular structures, each of which was composed mostly of pinealocytes and supporting cells radially arranged around the follicular lumen during the first 6 weeks of age. In the pinealocytes, paraboloids and regular stacks of lamellar disks, which were demonstrated at 1 day of age in a previous study [14], rapidly decreased in number after 1 week of age. From 1 to 6 weeks of age, the pinealocytes had more developed lamellar whorls in the follicular lumen with the increased numbers of mitochondria in their apical protrusions and synaptic ribbons in their basal processes. In addition to these photosensory elements, pigment-containing cells occasionally accumulated in the basal side of the follicular structure. Their pigment granules, which were considered as melanin, gradually became larger and more roundish in shape after 1 week of age. The histological elements associated with the secretory function of the quail pineal were dense-cored vesicles and lysosomes in the pinealocytes and dense bodies in the supporting cells. The synaptic ribbons and the dense-cored vesicles in the pinealocytes rapidly increased in number at 1 week of age, scarcely exhibiting distinct changes thereafter. Thus, it is clarified that the foregoing photosensory and secretory elements change during the post-hatching development. Furthermore, it is suggested that, in respect of these elements, the pineal gland of the quail assumes more active appearances than that of the chicken.

Aging↗

PubMed1993

Bone marrow findings in malignant histiocytosis and/or malignant lymphoma with concurrent hemophagocytic syndrome.

We examined bone marrow specimens from 19 patients with malignant histiocytosis (MH) and/or malignant lymphoma (ML) with concurrent hemophagocytic syndrome (HS) who suffered from high fever, hepatosplenomegaly, liver dysfunction, profound cytopenia, and erythrophagocytosis. There was little lymph-node enlargement or no tumor formation. The neoplastic cells in 3 patients exhibited histiocytes/macrophages phenotype with positive reactions for fluoride-sensitive nonspecific esterase, lysozyme and CD68 (KP1). Twelve other patients showed a T-cell (CD3) phenotype, in which 5 patients expressed CD30 (BerH2) as well. B-cell characteristics with CD20 (L26), CIg. nu lambda and gamma kappa were manifest in 2 patients, but indeterminate markers were found in the 2 remaining patients. Eighteen patients showed an infiltration of large neoplastic cells mainly with noncohesive interstitial growth pattern, ranging from 1.7% to 74.2% of the nucleated cells in the bone marrow. A large number of histiocytes/macrophages and dendritic cells was diffusely observed in 15 patients. Severely decreased hematopoiesis in all three series of hematopoietic cells was found in 16 patients. Bone marrow infiltration by the neoplastic cells and numerous reactive cells with erythrophagocytosis appears to be an important factor of profound cytopenia in patients of MH and/or ML with HS. The infiltrating pattern of the neoplastic and reactive cells in the bone marrow of MH and/or ML with HS was different from that of other types of peripheral T-cell ML, B-cell ML in high grade malignancy, and Hodgkin's disease. Cell characteristics and lineage of the neoplastic cells in MH and/or ML with HS are also discussed in this study.

Adolescent↗

PubMed1993

Rapid and severe proteinuria induced in rats by antibody against cultured rat glomerular epithelial cells.

The aim of this study was to investigate the role of glomerular visceral epithelial cell (GEC) antigens in the induction of proteinuria. An antibody (anti-GECIg) was produced by rabbit immunization with membrane extracts prepared from a clonal GEC line, SGE1, from the isolated rat renal glomeruli. A one-shot intraperitoneal injection of anti-GECIg (day 0) induced rapid and severe proteinuria in rats, reaching a peak on day 2 (mean value, 425 mg/24h), then gradually decreased to normal levels by day 10. By direct immunofluorescence, fine granular binding of anti-GECIg along the glomerular capillary walls was observed within 24 h. Electron microscopy and immunoelectron microscopy revealed GEC alterations consisting of extensive retraction of the foot processes, vacuolar changes in the cytoplasm, microvillous transformation of the cell surface, and binding of anti-GECIg to the surface of the foot process, mainly to its soles. Two major components with Mr of 108,000 and 39,000 were identified by immunoblotting assay using SGE1 cell membrane extracts and anti-GECIg. This model of rat nephropathy induced by anti-GECIg hopefully will lead to a greater understanding of the mechanism by which proteinuria is induced and developed.

Animals↗

PubMed1992

Production and characteristics of strain common antibodies against a synthetic polypeptide corresponding to the C-terminal region of potato virus Y coat protein.

Comparing the predicted amino acid sequence between two Japanese potato virus Y (PVY) strains, necrotic strain and ordinary strain, it was found that the C-terminal regions (H2N-HTTEDVSPSMHTLLGVKNM-COOH) of the coat proteins in the two strains were completely conserved. The conserved amino acid sequence was also found in the C-terminal region coat protein of PVY-36, a strain which did not react with monoclonal antibodies specific to the necrotic and the ordinary strain respectively. Antibodies were produced against a synthetic polypeptide PVY-C19 consisting of 19 amino acids, which correspond to the C-terminal region of the coat protein, using 4 coupling combinations of polypeptide PVY-C19 to protein carriers. Carrier-free polypeptides and those coupled to ovalbumin with ECDI (ethyl-dimethylaminopropyl carbodiimide) produced high titer of antibodies and detected PVY strains from PVY-infected plants by Western blot analysis and by ELISA.

Amino Acid Sequence↗

PubMed1992

[Structure-function studies of galanin].

Galanin is widely distributed in the central and peripheral nervous system and exerts a variety of physiological effects. This review briefly describes the chemical structure, tissue distribution, physiological effects, receptors and structure-function relationships of galanin. It is worth noting that the inhibitory effect of newly synthesized galanin (1-15)-ol on guinea pig ileum contractions was of the same magnitude as that of galanin. This observation gives us an important clue as to the discovery of antagonists of galanin for neural systems.

Amino Acid Sequence↗

PubMed1992

Cardiovascular and respiratory actions of pituitary adenylate cyclase-activating polypeptides.

Effects of pituitary adenylate cyclase-activating polypeptide (PACAP38) and PACAP27 on the cardiovascular and respiratory systems were examined and compared to those of vasoactive intestinal polypeptide (VIP) in anesthetized beagle dogs. Intravenous PACAP27 and PACAP38 produced a decrease in mean arterial blood pressure (MBP), and an increase in both femoral arterial blood flow (ABF) and in frequency of respiration (FR) with a dose-dependent relationship between 10 and 300 pmol/kg. PACAP27 produced a dose-dependent increase in heart rate (HR) between 10 and 300 pmol/kg while PACAP38 induced tachycardia which was not dose-dependent. Administration of 300 pmol/kg PACAP38 and PACAP27 produced extreme hypertension after transient hypotension. PACAP38 produced severe bradycardia after transient tachycardia. The cardiovascular actions of PACAP38 were persistent compared to those of PACAP27. Intravenous injection of 10-300 pmol/kg VIP brought about hypotension, tachycardia and an increase in ABF and FR with a dose-dependent relationship. VIP, at 2000 pmol/kg, did not produce the biphasic response obtained by a large dose of PACAP38. The present studies demonstrate that PACAP partially possesses VIP-like cardiovascular and respiratory actions and that the C-terminal 11 amino acid residues of PACAP38 are presumably responsible for a prolongation of its actions.

Adenylyl Cyclases↗

PubMed1992

[Mechanism of suppressed prolactin secretion due to medium hyperosmolarity--the importance of Ca2+ influx].

It is still unknown how extracellular hyperosmolarity suppresses exocytosis. To evaluate the possibility that extracellular hyperosmolarity affects one of the most important second messenger system, Ca2+ signal, we evaluated the effect of hyperosmolarity on the thyrotropin releasing hormone (TRH)-induced changes in both intracellular Ca2+ concentration ([Ca2+]i) and prolactin (PRL) secretion in GH4C1 cells. TRH caused two phases of [Ca2+]i: an initial high-amplitude phase (first phase), which was not inhibited by Ca2+ free medium, and a sustained low-amplitude phase (second phase), which was abolished by Ca2+ free medium. Medium hyperosmolarity (isotonic = 300mOsm, hypertonic = 338, 375, 450, and 600mOsm) suppressed both TRH-induced phases of [Ca2+]i in a dose dependent manner, however, the suppressive effect was clearly stronger in the second phase of [Ca2+]i than in the first phase of [Ca2+]i. Low doses of medium hyperosmolarity (338 and 375mOsm) suppressed PRL secretion, which was dependent on Ca2+ influx. However, high doses of medium hyperosmolarity (450 and 600mOsm) also blocked PRL secretion, which was dependent on Ca2+ mobilized from cytosolic Ca2+ pools. These data indicate that in GH4C1 cells medium hyperosmolarity may inhibit PRL secretion by both blocking Ca2+ influx and a mechanism unrelated to Ca2+.

Calcium↗

PubMed1992

Human T-cell leukemia virus type I associated lymphadenitis.

Histopathologic changes in lymph nodes were examined from ten patients with mild lymphadenopathy, a few atypical lymphocytes in their peripheral blood, skin lesions, and proviral DNA of human T-cell leukemia virus type I (HTLV-I) in their nodes. The proviral DNA of HTLV-I was detected by southern blot analysis, in situ hybridization, and/or polymerase chain reaction techniques. The lymph nodes showed preserved nodal architecture with diffuse infiltration of small to intermediate-sized lymphocytes in association with scattered transformed lymphocytes and a few immunoblast-like cells in the enlarged paracortex. The infiltrating lymphocytes were positive for CD4, but neither rearrangement nor deletion of T-cell receptors and immunoglobulin heavy chain genes was detected. Eight of ten patients received no therapy, and all patients were alive and healthy more than 5 months after the biopsies. The histologic findings resembled those of a viral infection and could be distinguished from HTLV-I associated lymphomas.

Adult↗

PubMed1992

A case of histiocytic necrotizing lymphadenitis with bone marrow and skin involvement.

We report a case of histiocytic necrotizing lymphadenitis (HNL) with bone marrow extension in a 29-year-old male in which many large mononuclear cells infiltrated the bone marrow and mimicked malignant lymphoma. A lymph node biopsy confirmed the diagnosis of HNL. Immunohistologically, the infiltrating cells in the bone marrow were positive for lysozyme, LeuM1, Kp-1 and T-cell markers. The cells did not show haemophagocytosis. A skin biopsy from an accompanying facial skin rash revealed a proliferation of large cells similar to those observed in affected foci of the lymph node in subcutaneous tissue. The infiltrating cells were mainly lysozyme and Kp-1-positive histiocytes, some with phagocytosis of nuclear debris but none characteristic of haemophagocytosis. Transformed T-cells were also infiltrating.

Adult↗

PubMed1992

Immunohistological study of skin involvement in Kikuchi's disease.

Five patients with histiocytic necrotizing lymphadenitis (Kikuchi's disease) with erythematous or popular skin lesions were studied. All patients healed naturally within a few months like the patients with no skin involvement. Histological findings for the skin lesions mimicked cutaneous malignant lymphoma. The infiltrated mononuclear cells usually demonstrated positive reactions for Ki-M1p (20-63%), lysozymes (13-54%), MT-1 (18-64%), UCHL-1 (22-39%) and LN2 (17-36%). OPD-4 and L26 positive cells were few in number. These results suggest that the infiltrated cells in a Kikuchi's disease skin lesion are composed of the same components as the affected lesion in the lymph node.

Adolescent↗

PubMed1992

A pathological study of bovine alimentary mycosis.

A 10-year study showed that 45 of 692 cattle aged > 6 months had systemic mycosis and, of these, 38 had alimentary mycosis. The percentages of these 38 cattle with lesions in various sites were: rumen (73.7), omasum (71.1), abomasum (34.2), reticulum (21.1), intestine (15.8), omasoabomasal orifice (7.9) and tongue (2.6). Infections in both the forestomachs and abomasum occurred in 31.6 per cent; mucormycosis was found in 94.7 per cent and aspergillosis in 31.6 per cent; 26.3 per cent (10 cattle) had complicated infections with both Mucorales and Aspergillus and eight of these animals had mixed lesions of both mucormycosis and aspergillosis. Macroscopically, focal haemorrhagic necrosis was seen in all 38 cattle. Histologically, thrombosis, coagulative necrosis and hyphae typical of the order Mucorales or of Aspergillus spp. were found. Many of the cattle were also affected by ruminal acidosis-inducing factors (ruminal atony 81.6 per cent, mastitis 63.2 per cent, "downer cow syndrome" 57.9 per cent and parturition 50.0 per cent), which may have predisposed to alimentary mycosis.

Animals↗

PubMed1992

Augmentation of bovine leukemia virus (BLV)-specific lymphocyte proliferation responses in ruminants by inoculation with BLV env-recombinant vaccinia virus: their role in the suppression of BLV replication.

Lymphocyte proliferation responses were investigated in sheep and cattle, in which the replication of bovine leukemia virus (BLV) had been known to be suppressed by inoculation with recombinant vaccinia virus (rVV) expressing BLV envelope glycoprotein (gp60). Enhanced lymphocyte proliferation responses were observed in animals inoculated with rVV, regardless of whether they were naive or BLV carriers. These responses were roughly inversely correlated to the growth of BLV in the peripheral blood leukocytes. In contrast, there was no apparent correlation between humoral immune response and BLV growth. Based on these results, it was suggested that rVV rendered its suppressive effect of BLV replication primarily via augmentation of cell-mediated immunity.

Animals↗

PubMed1992

Linear antigenic regions of the structural proteins of human T-cell lymphotropic virus type I detected by enzyme-linked immunosorbent assays using synthetic peptides as antigens.

We synthesized 46 sequential peptides 21 to 39 amino acids long over the structural protein of human T-cell leukemia virus type I (HTLV-I; the p19 and p24 gag protein and the gp46 and p20E env proteins) and tested their reactivities against antibodies in sera from HTLV-I healthy carriers and patients diagnosed as having human T-cell leukemia-lymphoma (ATLL) and myelopathy (HAM) by using an enzyme-linked immunosorbent assay. Of the 46 synthetic peptides, 18 peptides (2 corresponding to the p19 gag protein, 2 corresponding to the p24 gag protein, 8 corresponding to the gp46 env protein, and 6 corresponding to the p20E env protein) reacted with antibodies in the sera from HTLV-I healthy carriers. In particular, the peptides comprising amino acids 100 to 119 and 119 to 130 of the gag and 175 to 199, 213 to 236, 253 to 282, and 288 to 317 of the env proteins reacted with antibodies in sera from more than 30% of HTLV-I healthy carriers. These peptides also showed high reactivities to the antibodies in the sera from patients with ATLL and HAM. The results indicate that the predominant antigenic regions of the structural protein of HTLV-I were located at the C-terminal end of the p19 gag protein and the C-terminal half of the gp46 env protein, and the corresponding peptides proved to be useful antigens in detecting antibodies in the sera from individuals infected with HTLV-I.

Amino Acid Sequence↗