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Biomedical subjects

Y Ueyama

Publications and source records attributed to Y Ueyama.

At least 109 records · Page 6Linked to original sources
PubMed1997

Primary human immunodeficiency virus type 1 viremia and central nervous system invasion in a novel hu-PBL-immunodeficient mouse strain.

We established four new mouse strains with defective T and B cells as well as defects in innate immunological reactions using an NK cell depletion antibody and showed that all mutant mouse strains efficiently received human peripheral blood leukocyte (PBL) engraftment (hu-PBL-scid mice). Higher levels of human immunodeficiency virus type 1 (HIV-1) replication were observed in these new hu-PBL-scid mice than in conventional hu-PBL-C.B-17-scid mice. In one particular strain, hu-PBL-NOD-scid mice, high levels of HIV-1 viremia (more than 10(6) 50% infectious doses per ml) were detected after infection with HIV-1. The plasma viral load was about 100 to 1,000 times higher than that observed in other hu-PBL-scid mice infected with HIV-1. Although high-level viremia did not correlate with the total amount of HIV-1 RNA in cells from infected mice, high levels of free virions were detected only in hu-PBL-NOD-scid mice. HIV-1 viremia induced systemic HIV-1 infection involving the liver, lungs, and brain. PCR in situ hybridization confirmed that HIV-1-infected cells invaded the brain tissue of the hu-PBL-NOD-scid mice. Our results suggest that the genetic background, including innate immunity, is critical in the development of primary HIV-1 viremia and subsequent central nervous system invasion with HIV-1. The hu-PBL-NOD-scid mouse represents a useful model for the study of the pathogenesis of HIV-1 in vivo, especially brain involvement, and therapy of primary HIV-1 viremia.

Animals↗
PubMed1997

Practical role of genetic profiling and preservation stock of human tumour xenograft lines as a tool in animal experiments for antitumour drug evaluation.

Human tumour xenografts (HTXs) are a useful tool for animal experiments especially for evaluation of new antitumour drugs. We have been establishing HTXs, and have developed tumour chemosensitivity panels for new drug evaluation using them. With regard to quality control (problems in changes into mouse-type tumours and/or artificial cross-contamination among tumour lines), we studied genetic profiling, and effects of long-term passaging on tumour properties such as growth and chemosensitivities, and we discuss the use of cryopreservation stock of HTXs and periodic replacement in order to maintain reproducibility of the experimental results. We examined isozyme markers and DNA fingerprinting to identify species and individuality of the tumours, respectively. Growth curves and sensitivities to antitumour drugs were examined using HTXs with different passaging in nude mice. Among the tumours we maintained, five human tumours were found to have changed to mouse origin from their isozyme markers and were excluded. We identified the individuality of tumours which we used for the chemosensitivity panels by DNA fingerprinting, and their properties were stable for long-term passaging in nude mice. However, growth speed and chemosensitivities to drugs were altered with long-term passaging, although DNA fingerprint analysis did not show any obvious changes with passaging. Genetic profiling, such as isozyme markers and DNA fingerprinting, is useful to identify individuality of experimental HTXs, and tumours should be renewed periodically even when there are no signs of artificial contamination when they are used in experiments which require continuous reproducibility of experimental results.

Animals↗
PubMed1997

Chemotherapeutic profiles of human tumors implanted in SCID mice showing appreciable inconsistencies with those in nude mice.

Sensitivities to antitumor drugs of human tumor xenografts (HTXs) implanted in C.B-17-scid and in BALB/cA-nu were compared to examine whether genetic backgrounds of immune deficiency of the host mice influenced the chemotherapeutic profiles of implanted tumors. In a total of 25 pairs of corresponding experiments with each host mouse strain (5 HTXs x 5 drug treatment groups), we obtained consistent results in 23 (92.0%) experiments consisting of 10 which were both significantly effective and 13 which were both ineffective, although the remaining two (8.0%) experiments showed inconsistent results. A human T-cell lymphoma cell line, LM-2-JCK, implanted in nude mice, was resistant to treatment with 65 mg/kg of cyclophosphamide, but this tumor showed sensitivity to the same treatment when implanted in either SCID mice or mice with a recombination activating gene 2 defect [BALB/cA-TgH (Rag2)], suggesting that the genetic immune background of the host mouse should not be overlooked as a factor affecting tumors.

Animals↗
PubMed1997

Quarantine for contaminated pathogens in transplantable human tumors or infections in tumor bearing mice.

To quarantine human tumor samples for transplantation into immune deficient mice or tumor xenograft lines established and introduced from other institutions, we performed isolated implantation and passaging of tumors in a vinyl isolator, and microbiological examinations of sentinel mice kept together with tumor bearing mice. We examined 105 pairs of sentinel mice used to quarantine 907 tumors, and found six cases of contamination or infection with Staphylococcus aureus, 20 cases with Pseudomonas aeruginosa and one case with mouse hepatitis virus (MHV). It was, however, possible that Mycoplasma pulmonis contamination was overlooked because the microbe had been isolated from tumors passaged after quarantine, even though the results of the quarantine of these tumors showed no sign of pathogens. Direct culture of tumors for the microbe was recommended to improve the quarantine system.

Animals↗
PubMed1997

High levels of viremia in hu-PBL-NOD-scid mice with HIV-1 infection.

We studied the compatibility of human lymphocyte engraftment and susceptibility to HIV-1 infection in 2 new immunodeficient mice. NOD/Shi-scid mice were generated by backcrossing of the scid mutation into NOD mice while C57BL/6-RAG2(0/0) were generated by knocking out the RAG-2 gene. Human T lymphocytes were reconstituted in new immunodeficient mouse strains. We found that the new immunodeficient mouse strains accepted human PBL engraftment and HIV-1 infection more efficiently than conventional C.B-17-scid mice. Especially in the hu-PBL-NOD/Shi-scid strain, we reproduced the high levels of HIV-1 viremia comparable to or at significantly higher levels than after HIV-1 primary infection. These results indicate that our hu-PBL-NOD-scid animal is useful for investigations of the activation mechanism in HIV-1 replication in vivo and after primary infection.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Cell adhesion via murine alpha4 human beta1 integrin chimera on transfected K562 cells to endothelial cells.

To evaluate the property of binding activity of alpha4beta1 integrin in cell-cell interaction, we newly established a cell line, alpha4mK562, by transfecting cDNA of murine integrin alpha4 subunit into human erythroleukemic K562 cells. alpha4mK562 transfectant expressed both murine alpha4 and human beta1 subunit, which generated a functional heterodimer. alpha4mK562 cells more efficiently bound to murine endothelial cell lines and recombinant human TNFalpha (rhTNF)-treated human umbilical vein endothelial cells (HUVEC) than the parental K562 cells. These adhesion resulted from the interaction between alpha4beta1 and VCAM-1. Interestingly, treatment with mAb against human beta1 (4B4 clone), which has been known as inhibitory mAb, enhanced binding of alpha4mK562 cells to rhTNF-treated HUVEC but not to murine endothelial cells. This increase in binding induced by 4B4 mAb was completely inhibited by another mAb against human beta1 (mAb13), but only partially by anti-alpha4 mAb (PSsolidus2). The increase in binding induced by 4B4 mAb was also abolished by metabolic inhibitors, indicating that the increased binding is energy dependent. These observations suggest that the binding of 4B4 mAb to the chimeric alpha4beta1 induces an unique outside-in signaling and enhances the specific binding of alpha4mK562 cells to rhTNF-treated HUVEC.

Animals↗
PubMed1996

Establishment and characterization of transgenic mice expressing human platelet glycoprotein Ib alpha.

The platelet glycoprotein (GP) Ib/IX/V is a hetero-oligomeric receptor complex for von Willebrand factor (vWF) and mediates platelet adhesion and aggregation under high shear stress conditions. It is composed of alpha and beta chain of GP Ib, GP IX, AND and GP V. To establish transgenic mice carrying human GP Ib alpha, we injected into mouse zygotes a 6 kb DNA fragment containing human GP Ib alpha gene that included entire coding sequence and putative promoter region. One hundred and thirteen offsprings were screened, and only one was found to express human GP Ib alpha protein and has passed the human GP Ib alpha gene as well as the expression of the gene to next generation. The expression of human GP Ib alpha in transgenic mice was limited to platelets and megakaryocytes. Glycocalicin, a proteolytic fragment of human GP Ib alpha found in normal human plasma, was not detected in transgenic mouse plasma. Human vWF in the presence of ristocetin supported agglutination of transgenic mouse platelets, but not of control mouse platelets.

Animals↗
PubMed1996

A new approach to analysis of human sweating.

In human skin transplanted to the back of 3 strains of immuno-deficient mice the function of the eccrine sweat glands of the human transplant was tested by topical intradermal application of pilocarpine, adrenaline and atropine + pilocarpine. Sweat responses were observed in pre-selected fields of observation by means of video macroscope. The iodine starch reaction served as an indicator for the appearance of sweat sport and permitted the evaluation of areas wetted by sweat in the field of observation. Among 9 animals tested, the hybrids between the CB-17-scid mouse and the BALB/cA-nu mouse (BALB/cA-nu,scid) seemed to exhibit the most consistent sweating response to local pharmacological stimulation. According to histological examination, eccrine sweat glands were preserved in human skin transplanted into the back skin of the BALB/cA-nu,scid mouse strain. The heterologous, human skin graft provides a novel model permitting, independent of the normal sweat gland innervation, the analysis of molecular receptors of sweat gland cells by which the actions of natural transmitters and pharmacological agents are transduced.

Animals↗
PubMed1996

Analysis of reconstruction of mandibular defects using single stainless steel A-O reconstruction plates.

PURPOSE: This report reviews the results and complications of immediate reconstruction using a single stainless steel A-O plate after resection of mandibles invaded by malignant tumors. PATIENTS AND METHODS: Thirty-four patients were retrospectively evaluated. According to the extent of the tumor, hemimandibulectomy or segmental resection were performed in 4 and 30 cases, respectively. Five of 34 cases required a myocutaneous flap to close soft tissue defects. RESULTS: Nine of the 34 patients died during the follow-up period. Complications occurred in 7 of these patients: plate exposure was caused by local tumor recurrence (4 cases), screw loosening (1 case), and temporomandibular joint pain (2 cases). Twenty-five of the 34 patients (73.5%) were alive, with a mean follow-up of 47.4 months (range 6 to 115 months). Eighteen of the 25 surviving patients with the single A-O plate reconstruction did not show any complications. Thirteen of these (52%) patients had not undergone secondary reconstruction. Five of the 25 patients received secondary reconstruction for cosmetic or masticatory function reasons. Postoperative complications occurred in 7 of the 25 surviving patients (28%): extraoral plate exposure (2 cases), fracture of the plate (1 case), mandibular fracture (1 case), screw loosening (3 cases), and screw fracture (1 case). CONCLUSIONS: On the basis of the findings, it was concluded that a single A-O reconstruction plate can be used for temporary, or sometimes even permanent, reconstruction after mandibular resection.

Bone Plates↗
PubMed1996

In vitro and in vivo anti-tumour effects of a humanised monoclonal antibody against c-erbB-2 product.

The c-erbB-2 product is thought to be a unique and useful target for antibody therapy of cancers overexpressing the c-erbB-2 gene. In vitro and in vivo anti-tumour effects of a humanised antibody against the extracellular domain of the c-erbB-2 gene product, rhu4D5, were examined. Rhu4D5 was less effective than its murine counterpart, mu4D5, for the direct antiproliferative activity against the c-erbB-2-overexpressing SK-BR-3 cell line. In vivo treatment of severe combined immunodeficient (SCID) mice carrying the c-erbB-2-overexpressing 4-1ST human gastric carcinoma xenograft with 4hu4D5 revealed that the recombinant protein had potent anti-tumour activity. Furthermore, cytotoxicity of human peripheral blood mononuclear cells against 4-1ST was significantly augmented with rhu4D5, but not with mu4D5. These results indicate that rhu4D5 might perform better in patients than predicted from preclinical studies.

Animals↗
PubMed1996

Establishment of human granulocyte-macrophage colony stimulating factor producing transgenic SCID mice.

Previous work has shown the usefulness of severe combined immunodeficient (SCID) mice as in vivo models for the growth of normal human haemopoietic cells and leukaemic cells. Many approaches have been made to improve the engraftment of human haemopoietic cells in SCID mice. We established transgenic mice producing human granulocyte-macrophage colony stimulating factor (hGM-CSF) with the homozygote of the scid gene. Endogenous serum hGM-CSF levels were detected by ELISA [mean 9585 pg/ml (line A, n = 4); mean 1610 pg/ml (line B, n = 4)]. Expression of hGM-CSF was observed in all organs tested including the heart, lung, liver, kidney, spleen, thymus, bone marrow and brain of hGM-CSF transgenic (hGMTg) mice. Morphological analysis of organs and peripheral blood cell counts showed no differences between hGMTg mice and their littermates. Murine Ba/F3 cells expressing functional hGM-CSF alpha beta receptor (BAF/alpha beta cells) could be successfully engrafted in hGMTg SCID mice. The cells invaded multiple organs and caused death within a few weeks of transplantation, although they infiltrated only the spleen of their littermates. These results showed that these hGM-CSF-producing SCID mice are useful as an in vivo assay system for investigating leukaemogenesis.

Animals↗
PubMed1996

A compound heterozygote for familial hypercholesterolaemia with a homozygous mother.

Homozygous familial hypercholesterolaemia (FH) is a rare disorder in which the patients develop severe hypercholesterolaemia and premature coronary atherosclerosis from childhood. Here we report a unique family with clustering of homozygous FH. The proband was a 25-year-old man, who showed marked hypercholesterolaemia, multiple xanthomas and severe coronary atherosclerosis. His mother also showed the typical characteristics of homozygous FH. Sequencing analysis of the low-density lipoprotein receptor gene revealed that he was a compound heterozygote, carrying two different point mutations. One was a novel mutation, FH Wakayama (Cys-->Ser at 317), derived from his mother, and the other was a recurrent mutation, FH Niigata (T-->C at 1845 + 2, 5' splice signal in intron 12), derived from his father. The proband we report seems to be a very rare case of an FH homozygote born from a homozygous mother.

Adult↗
PubMed1995

In vivo evidence for progressive activation of parathyroid hormone-related peptide gene transcription with tumor growth and stimulation of osteoblastic bone formation at an early stage of humoral hypercalcemia of cancer.

The present study was undertaken to clarify in vivo the temporal profile of parathyroid hormone-related peptide (PTHRP) gene expression as well as bone histomorphometric features as a function of tumor growth, using an athymic rat model associated with humoral hypercalcemia of malignancy (HHM). Tumor-bearing animals exhibited hypercalcemia, hypophosphatemia, and increased circulating levels of PTHRP, and died within 3 weeks. Steady-state PTHRP mRNA levels and the transcription rate of PTHRP gene in the tumors were markedly increased with tumor growth. RNAse mapping analysis revealed that both upstream and downstream promoters of the human PTHRP gene were utilized in the tumors and became progressively activated with time. Bone histomorphometric analysis showed that osteoclastic bone resorption was progressively increased throughout the course, whereas osteoblastic bone formation was stimulated more than 2-fold at a very early stage (day 6 after tumor implantation) and then markedly suppressed thereafter on day 12 and day 18 compared with age-matched control animals. These results provide in vivo evidence that PTHRP gene transcription is progressively activated with tumor growth and that activation of osteoblasts does occur at a very early phase of HHM syndrome in contrast to the marked suppression of bone formation at later stages.

Analysis of Variance↗
PubMed1995

Effects of fibroblasts of different origin on long term maintenance of xenotransplanted human epidermal keratinocytes in immunodeficient mice.

We examined effects of fibroblasts of different origin on long-term maintenance of xenotransplanted human epidermal keratinocytes. A suspension of cultured epidermal cells, originating from adult human trunk skin, was injected into double mutant immunodeficient (BALB/c nu/scid) mice subcutaneously, with or without cultured fibroblastic cells of different origin. At one week after transplantation, the epidermal cells generated epidermoid cysts consisting of human epidermis-like tissue. When the epidermal cells were injected alone or together with fibroblastic cells derived from human bone marrow, muscle fascia, or murine dermis, organized epidermoid cysts regressed within 6 weeks. In contrast, when the epidermal cells were injected together with human dermal fibroblasts, generated epidermoid cysts were maintained in vivo for more than 24 weeks. Histological examination showed that the reorganized epidermis, after injection of both epidermal keratinocytes and dermal fibroblasts, retained normal structures of the original epidermis during 6 to 24 weeks after transplantation. The results indicate that human dermal fibroblasts facilitate the long-term maintenance of the reorganized epidermis after xenotransplantation of cultured human epidermal keratinocytes by supporting self renewal of the human epidermal tissue in vivo.

Animals↗
PubMed1995

Engraftment of precursor lesions of human cutaneous neoplasms onto C.B-17 SCID mice: a useful in vivo experimental model of carcinogenesis in human skin.

Using a full-thickness skin grafting technique, lesional skin from various human neoplastic and preneoplastic skin diseases was transplanted onto SCID (severe combined immunodeficiency) mice. Of 27 grafted lesions, 21 were successfully accepted by the mice and maintained in good condition. All these accepted grafts were finally excised 10-101 days after transplantation for histological examination. In most grafts, the characteristic histological configurations of each disease were well preserved. Immunohistochemical study using monoclonal antibodies to human blood group antigens ABH revealed that some elements of the grafts such as sweat glands were clearly positive, confirming that the tissue was from human skin. Neoplastic (atypical) cells were detected in 9 of 17 accepted grafts containing neoplastic cells from the beginning. The detection rates for neoplastic cells were very high (90%) in grafts from precursor lesions of squamous cell carcinomas such as Bowen's disease (5/5 specimens) and thermal keratosis (2/3). In contrast, no definite neoplastic cells were found in two grafts from extramammary Paget's disease and five grafts from the radial growth component of malignant melanoma. In most of the grafts from latter two diseases, characteristic histological configurations such as elongation of the rete ridges were maintained, suggesting that the neoplastic cells were selectively eliminated from the grafts. Split-thickness grafts of normal human skin were accepted and remained in a good condition for as long as 6 months. Engraftment of human lesional and non-lesional skin onto SCID mice therefore may well provide a useful in vivo experimental model of human skin diseases.

ABO Blood-Group System↗
PubMed1995

Gigantic ameloblastoma of the mandible complicating hypoproteinemia: case report.

A case of gigantic ameloblastoma of the mandible complicating hypoproteinemia is reported. The patient, a 73-year-old male, had refused a surgical procedure on an ameloblastoma for 13 years. By the time the tumor had increased in size and fistulas from it had formed, hypoproteinemia and generalized edema had occurred. The tumor was removed when the serum total protein level had recovered to about 5 g/dl following the administration of a plasma protein preparation. After the operation, hypoproteinemia and edema clearly improved. Hypoproteinemia is thought to be caused by leakage of plasma or occasional bleeding through the oral fistulas of ameloblastoma, and in this patient's case, poor nutrition because of his masticatory and swallowing difficulties.

Aged↗