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Biomedical subjects

H Kaneshima

Publications and source records attributed to H Kaneshima.

At least 55 records · Page 3Linked to original sources

Human neural xenografts: progress in developing an in-vivo model to study human immunodeficiency virus (HIV) and human cytomegalovirus (HCMV) infection.

Human immunodeficiency virus type 1 (HIV-1) infection is highly specific for its human host. In order to study HIV-1 infection of the human nervous system, we have established a small animal model in which second-trimester (11-17.5 weeks) human fetal brain or neural retina is transplanted into the anterior chamber of the eye of immunosuppressed adult rats (Epstein et al., 1992; Cvetkovich et al., 1992), and more recently in immunodeficient (SCID) mice. The human xenografts survive for many months, vascularize and form a blood-brain barrier. Immunohistochemistry with PGP 9.5 identified neuronal cell bodies and neuritic processes. Electron microscopy revealed axonal growth cones and synaptic junctions. Infection of these xenografts with cell-free HIV-1 proved difficult, however co-engraftment with HIV-1-infected human monocytes resulted in characteristic pathological changes, including the formation of syncytial giant cells, neuronal loss, and astroglial proliferation, supporting the hypothesis that these cells can mediate neurotoxicity. In other studies, xenografts of human fetal retinal tissue were readily infected with cell-free human cytomegalovirus (HCMV) strain AD169. These grafts contained cells with intracytoplasmic and intranuclear inclusions typical of HCMV infection. Productive infection within these grafts was demonstrated by the presence of immediate early, and late (capsid) HCMV antigens, by recovery of HCMV on human fibroblast cultures, and by serial passage of virus to additional retinal xenografts (DiLoreto et al., 1994).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Rapid-high, syncytium-inducing isolates of human immunodeficiency virus type 1 induce cytopathicity in the human thymus of the SCID-hu mouse.

Clinical deterioration in human immunodeficiency virus type 1 (HIV-1) disease is associated with an increased viral burden in the peripheral blood and a loss of circulating CD4+ T cells. HIV-1 isolates obtained prior to this stage of disease often have a "slow-low," non-syncytium-inducing (NSI) phenotype, whereas those obtained afterwards are often characterized as "rapid-high" and syncytium inducing (SI). Paired NSI and SI isolates from two different patients were inoculated into the human thymus implants of SCID-hu mice. The two slow-low, NSI isolates replicated to minimal levels in the grafts and did not induce thymocyte depletion. In contrast, the two SI isolates from the same patients showed high levels of viral replication and induced a marked degree of thymocyte depletion, accompanied by evidence of programmed cell death. These observations reveal a correlation between the replicative and cytopathic patterns of HIV-1 isolates in vitro and in the SCID-hu mouse in vivo and provide direct evidence that the biological phenotype of HIV-1 switch may be a causal and not a derivative correlate of HIV-1 disease progression.

Acquired Immunodeficiency Syndrome↗

TNF alpha mRNA, but not IL-1 beta, is differentially expressed in lung macrophages of patients with active pulmonary sarcoidosis.

In pulmonary sarcoidosis or experimental granuloma formation, interleukin-1 beta (IL-1 beta) or tumor necrosis factor alpha (TNF alpha) seem to play important roles during the inflammatory process. In order to examine whether IL-1 beta or TNF alpha mRNA expression in lung macrophages relates to disease activity or clinical course, ten cases with pulmonary sarcoidosis were divided into two groups: five cases with disease duration of more than 10 years (14.6 +/- 4.4 yrs; group A), and 5 cases with a duration of less than 3 years (1.7 +/- 1.1 yrs; group B). All cases showed both abnormal chest X-rays and elevated serum angiotensin converting enzyme activities. We compared these ten cases with 12 healthy subjects (6 nonsmokers: NS and 6 current smokers: S), and 5 cases with idiopathic pulmonary fibrosis (IPF) as disease control. Lavage macrophages were purified using the rosette forming method followed by plastic adhesion for one hour. Thereafter, RNA was extracted according to the AGPC method and amplified by the reverse transcription-polymerase chain reaction (RT-PCR). The results showed that IL-1 beta mRNA was detected in all samples studied, but TNF alpha mRNA expression was different among the groups: 5/5 (100%) in group A, 1/5 (20%) in group B, 5/5 (100%) in IPF, and 12/12 (100%) in healthy subjects. A constitutive expression was seen in healthy controls. On the other hand, no detection of TNF alpha mRNA was shown in pulmonary sarcoidosis. This fact may relate to a spontaneous regression of inflammation in sarcoidosis, as a substantial number of cases in group B may in time regress spontaneously.

Adult↗

[Pulmonary nocardiosis concurrent with Pneumocystis carinii pneumonia in a case of smoldering adult T-cell leukemia].

A 76-year-old man, with concomitant pulmonary nocardiosis and Pneumocystis carinii (PC) pneumonia, is described. He suffered from smoldering type adult T-cell leukemia and strongyloidiasis. Chest X-rays showed bilateral infiltrative shadows. Nocardia asteroides was isolated from sputum and bronchofiberscopic aspirates. PC was not detected, however, despite the chest X-ray raising the suspicion of PC pneumonia. Since PC antigen was detected by immunoelectrophoresis in the absence of other clinical or histologic data, we diagnosed a latent PC infection. He improved with the use of cefuzonam and ST compounds, but experienced recurrence five months after discharge. N. asteroides and PC were detected from sputum on the second admission. As multiple concurrent infections with opportunistic organisms are not uncommon in immunocompromised hosts, we must maintain a high index of suspicion for opportunistic infection in cases such as this one.

Aged↗

Human immunodeficiency virus infection of the human thymus and disruption of the thymic microenvironment in the SCID-hu mouse.

Infection with the human immunodeficiency virus (HIV) results in immunosuppression and depletion of circulating CD4+ T cells. Since the thymus is the primary organ in which T cells mature it is of interest to examine the effects of HIV infection in this tissue. HIV infection has been demonstrated in the thymuses of infected individuals and thymocytes have been previously demonstrated to be susceptible to HIV infection both in vivo, using the SCID-hu mouse, and in vitro. The present study sought to determine which subsets of thymocytes were infected in the SCID-hu mouse model and to evaluate HIV-related alterations in the thymic microenvironment. Using two different primary HIV isolates, infection was found in CD4+/CD8+ double positive thymocytes as well as in both the CD4+ and CD8+ single positive subsets of thymocytes. The kinetics of infection and resulting viral burden differed among the three thymocyte subsets and depended on which HIV isolate was used for infection. Thymic epithelial (TE) cells were also shown to endocytose virus and to often contain copious amounts of viral RNA in the cytoplasm by in situ hybridization, although productive infection of these cells could not be definitively shown. Furthermore, degenerating TE cells were observed even without detection of HIV in the degenerating cells. Two striking morphologic patterns of infection were seen, involving either predominantly thymocyte infection and depletion, or TE cell involvement with detectable cytoplasmic viral RNA and/or TE cell toxicity. Thus, a variety of cells in the human thymus is susceptible to HIV infection, and infection with HIV results in a marked disruption of the thymic microenvironment leading to depletion of thymocytes and degeneration of TE cells.

Animals↗

HIV induces thymus depletion in vivo.

Human immunodeficiency virus (HIV) disease is typified by declining CD4+ T lymphocyte counts in the peripheral circulation, a loss which may be secondary to accelerated destruction, to suppressed differentiation, and/or to sequestration of circulating cells into tissue spaces. As it is hard to distinguish between these possibilities in human subjects, the pathogenic mechanisms associated with HIV infection are unclear. In particular, little is known about the events that occur within infected lymphoid organs in which most CD4 T lymphocytes mature and function. To obtain a better description of HIV pathogenesis in vivo, we have implanted human haematolymphoid organs into the immunodeficient SCID mouse to create the SCID-hu mouse. We have previously shown that these organ systems promote long-term multilineage human haematopoiesis and are permissive for infection with HIV. Here we report that human thymopoiesis is suppressed by HIV infection, thereby precluding regeneration of the peripheral T-cell compartment.

Animals↗

Human cytomegalovirus in a SCID-hu mouse: thymic epithelial cells are prominent targets of viral replication.

Animal models of human cytomegalovirus (CMV) infections have not been available to study pathogenesis or to evaluate antiviral drugs. Severe combined immunodeficient mice implanted with human fetal tissues (SCID-hu) were found to support CMV replication and may provide a model for this species-specific virus. When conjoint implants of human fetal thymus and liver were inoculated with a low-passage-number isolate of CMV, strain Toledo, consistent high-level viral replication was detected 5, 12, 15, 28, and 35 days after inoculation and virus replication continued for up to 9 months. Other human tissue implants, including lung and colon, were also found to support viral growth but with greater variability in levels and for a shorter duration. As expected, the species specificity of human CMV was preserved in this model such that virus was detected in the human conjoint thymus/liver implant but not in surrounding mouse tissues. The majority of virus-infected cells were localized in the thymic medulla rather than cortical region of the implant and immunofluorescence analysis identified epithelial cells rather than any hematopoietic cell population as the principal hosts for viral replication. Finally, treatment of infected animals with ganciclovir reduced viral replication, thereby demonstrating the value of this system for evaluating antiviral therapies. This animal model opens the way for a range of investigations not previously possible with human CMV.

Animals↗

[A case of acetaminophen-induced pneumonitis].

A case of acetaminophen-induced pneumonitis is described. A 63-year-old woman took 2350 mg of acetaminophen for fever. She subsequently developed a non-productive cough and dyspnea. Chest X-ray revealed diffuse reticulonodular shadows in bilateral lung field and she was admitted to our hospital. PaO2 was 45.0 Torr and PaCO2 35.7 Torr while breathing room air. Bronchoalveolar lavage examination showed an increase in the percentage of lymphocytes and a decrease of CD4/CD8 ratio. Microscopic examination of a transbronchial lung biopsy specimen showed alveolar septal thickening. The lymphocyte stimulation test was positive for acetaminophen, with a stimulation index of 237%, while other drugs used were negative. Because drug-induced pneumonitis was suspected, all drugs were stopped and she was administered methylprednisolone. Consequently her symptoms, laboratory data and chest X-ray findings improved. Based on these findings, we diagnosed this case as acetaminophen-induced pneumonitis. To our knowledge, there has been only one previously reported case of acetaminophen-induced pneumonitis.

Acetaminophen↗

[Differential detection of IL-1 beta and TNF-alpha mRNA on lung macrophages from patients with pulmonary sarcoidosis].

In pulmonary sarcoidosis or experimental granuloma formation, interleukin-1 beta (IL-1 beta) or tumor necrosis factor alpha (TNF-alpha) are considered to play important roles during inflammatory evolution. In order to examine whether IL-1 beta or TNF-alpha mRNA expression on lung macrophages relates to the disease activity or clinical course, ten cases with pulmonary sarcoidosis were divided into two groups: five cases who had a disease duration of more than 10 years (14.6 +/- 4.4 years; group A), and 5 cases with duration of less than 3 years (1.7 +/- 1.1 years; group B). All cases showed both abnormal radiographs and elevated serum angiotensin converting enzyme activities. We compared the 10 cases with 12 healthy individuals as normal control (6 nonsmokers: NS and 6 current smokers: S), and 5 cases with idiopathic pulmonary fibrosis (IPF) as disease control. Lavage macrophages were purified by rosette forming method and plastic adhesion was then performed for 1 hour. Thereafter mRNA was extracted by AGPC method and amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) (20 cycles). The results showed that IL-1 beta mRNA was detected in all materials studied, but TNF-alpha mRNA expression was different among the groups: 5/5 (100%) in group A, 1/5 (25%) in group B, 5/5 (100%) in IPF, and 12/12 (100%) in normal controls. The absence of detection of TNF-alpha mRNA (rapid down regulation) in pulmonary sarcoidosis may relate to spontaneous regression, because a substantial number of cases in group B showed spontaneous regression in their natural course.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Density of phenotypic markers on BAL T-lymphocytes in hypersensitivity pneumonitis, pulmonary sarcoidosis and bronchiolitis obliterans with organizing pneumonia.

In vitro studies have shown that the density of surface antigens reflects the degree of activation of T-cells. We therefore studied the density of surface antigens on T-cells from bronchoalveolar lavage fluid (BALF) and blood in patients with sarcoidosis, hypersensitivity pneumonitis (HP) and bronchiolitis obliterans with organizing pneumonia (BOOP). BALF cells were stained with anti-CD3, anti-CD4, anti-CD8 and anti-human leucocyte antigen-DR(HLA-DR) monoclonal antibodies, and were analysed by cytoflowmetry. The density was evaluated by measuring the Mean Channel fluorescence intensity of the stained cells. The results demonstrated a significant increase in the CD3 density in patients with hypersensitivity pneumonitis (108.2 +/- 20.2 MC), compared with those with pulmonary sarcoidosis (51.2 +/- 12.6), BOOP (74.5 +/- 29.3), and healthy controls (57.1 +/- 11.5). Similar results were obtained for the CD4 and CD8 density in patients with HP. Although the number of HLA-DR positive cells was increased, the density was lower in patients with sarcoidosis (57.4 +/- 11.6) and hypersensitivity pneumonitis (57.4 +/- 14.8), than in healthy controls (72.2 +/- 15.1). Comparable changes were not observed in the peripheral blood. These results suggest that T-cell activation in hypersensitivity pneumonitis may be associated with an increase in the CD3, CD4, and CD8 density on BALF T-cells.

Adult↗

Implantation and maintenance of functional human bone marrow in SCID-hu mice.

Human fetal bone fragments implanted in the immunodeficient C.B-17 scid/scid (SCID) mouse were shown to sustain active human hematopoiesis in vivo. Human progenitor cell activity was maintained for as long as 20 weeks after implantation and was associated with multilineage differentiation in the engrafted bone. Thus, the bone implants provided stem cells as well as the microenvironment requisite for their long-term maintenance and multilineage differentiation. Administration of human erythropoietin (Epo) stimulated human erythropoiesis in human bone implants. This animal model may facilitate direct analysis of a wide variety of physiologic and pathologic conditions of human bone marrow (BM) in vivo.

Animals↗

Acute toxicity, percutaneous absorption and effects on hepatic mixed function oxidase activities of 2,4,4'-trichloro-2'-hydroxydiphenyl ether (Irgasan DP300) and its chlorinated derivatives.

Acute toxicity of 2,4,4'-trichloro-2'-hydroxydiphenyl ether (Irgasan DP300) (I) and its three chlorinated derivatives, 2',3,4,4'-tetrachloro-2-hydroxydiphenyl ether (II), 2',4,4',5-tetrachloro-2-hydroxydiphenyl ether (III) and 2',3,4,4',5-pentachloro-2-hydroxydiphenyl ether (IV), in mice were examined by intraperitoneal injection. The LD50 values of Irgasan DP300, II, III and IV were 1,090, 710, 650 and 430 mg/kg, respectively. The percutaneous absorptions of these tritiated compounds were also examined by the application on the backs of mice. The radioactivities in most tissues reached to the maximal levels at 12 h or 18 h after dosing, which corresponded to 11-76% of the maximal levels given by the oral administration (Kanetoshi et al. 1988a). These results show the high percutaneous absorbability of Irgasan DP300 and its chlorinated derivatives. The intraperitoneal administrations of III and IV to rats induced hepatic microsomal aminopyrine N-demethylase and aniline 4-hydroxylase activities similarly to phenobarbital. These chlorinated derivatives also increased cytochrome P-450 content, and the activities of aminopyrine N-demethylase and N-methylaniline N-demethylase in hepatic microsomes from mice. The extents of the increases were similar to those by phenobarbital and 3-methylcholanthrene.

Animals↗

Characterization of IL-1 inhibitory factor released from human alveolar macrophages as IL-1 receptor antagonist.

IL-1 possesses pleiotropic properties on various cells and its activity may be stringently regulated in several ways. We have previously reported that both IL-1 and its inhibitory factor are concomitantly released from alveolar macrophages in both healthy subjects and patients with chronic inflammatory lung diseases. An increase in IL-1 activities and a decrease in inhibitory activities are characteristics found in both healthy smokers and patients with interstitial lung diseases. In this study, we further examined the biological properties of IL-1 inhibitory factor. The inhibitor exhibited a dose-dependent specific inhibition of an augmentation by IL-1 of PHA-induced murine thymocyte proliferation, while no inhibition of the augmentation by IL-2, IL-4, IL-6, or tumour necrosis factor (TNF) was found. 125I-labelled IL-1 alpha binding on PHA-stimulated murine thymocytes revealed two types of IL-1 binding sites, 44 sites/cell with a Kd of 2.7 x 10(-10) M and 230 sites/cell with a Kd of 2.5 x 10(-9) M. Alveolar macrophage culture supernatants blocked the binding of labelled IL-1 to the IL-1 receptor in a dose-dependent fashion. Scatchard plot analysis revealed that the inhibitory factor in the supernatants blocked the binding competitively. These results indicate that alveolar macrophages produce a specific IL-1 inhibitory factor, functioning as an IL-1 receptor antagonist.

Cells, Cultured↗

Human T cells in the SCID-hu mouse are phenotypically normal and functionally competent.

SCID-hu mice are heterochimeric animals that are constructed by transplanting human fetal thymus (Thy), liver (Liv), and/or lymph nodes into congenitally immunodeficient C.B-17 scid/scid (SCID) mice. Sensitive and specific two-color flow cytometric assays were used to evaluate human lymphocytes from peripheral blood of SCID-hu mice. Kinetic studies presented in this report show long term T lymphopoiesis in SCID-hu mice. Approximately one-half of SCID-hu mice constructed with Thy and Liv tissue develop detectable levels of circulating human T cells by 4 mo after transplantation. The average level of circulating human cells in SCID-hu mice is generally less than 2% of the total lymphoid cells in the peripheral blood of these mice. Some SCID-hu mice with as high as 13% human lymphocytes, however, have been detected. Nearly all human cells in the peripheral blood of SCID-hu mice are CD3+ cells that express TCR-alpha beta. The percentages of gamma delta+, CD4+, CD8+, CD25+, CD69+, and Leu-8+ cells among CD45+ cells in SCID-hu blood are similar to the levels found in adult peripheral blood. On average, 74% of SCID-hu T cells express CD45RA and 18% express CD29. Functional studies demonstrate that cells from SCID-hu Thy/Liv grafts or human T cells from SCID-hu peripheral blood are functionally competent to respond to mitogens or allogeneic human cells in vitro. They are similar to fetal thymocytes or adult T cells, respectively, in these responses. These studies demonstrate that the SCID-hu mouse is a useful model for the analysis of human immune differentiation and function in vivo.

Animals↗

Human immunodeficiency virus infection of human lymph nodes in the SCID-hu mouse.

The SCID-hu mouse is a small animal in which human hematolymphoid organs can be engrafted and maintained in vivo. In this study, parameters are described for reproducible infection of SCID-hu mice after i.v. inoculation. Infection was found to be dependent upon the time after inoculation, the virus isolate, the titer of virus, and the human target organ implanted into the mouse. Ten to 14 days after the i.v. administration of HIV isolates derived freshly from patients (e.g., JR-CSF, JR-FL, SM), 100% of engrafted human lymph nodes in SCID-hu mice were infected; greater than 95% of these animals were also viremic. Implants of human thymus or connective tissue, as well as the endogenous murine hematolymphoid organs, were not infected. As demonstrated by a combination of in situ hybridization and immunohistochemistry, both T-lymphoid and myelomonocytic lineage cells were infected in this system. HIV isolates that have been adapted to growth in vitro (e.g., HTLV-IIIb) were not infectious. When either 3'-azido-3'-deoxythymidine (AZT) or 2',3'-dideoxyinosine (ddIno) was administered to SCID-hu mice before HIV infection, the animals were protected in dose ranges similar to those used in man. This animal model may now be used as an efficient intermediate step between the lab and the clinic to study the infectious process in vivo and to best select efficacious antiviral compounds against HIV.

Animals↗

Identification of a 107-kD glycoprotein that mediates adhesion between stromal cells and hematolymphoid cells.

The mechanism of cell complex formation between lymphocytes and stromal cells was investigated. We found that lymphoid lines of both T and B lineages could form cell complexes with stromal cells from the thymus as well as bone marrow but not with macrophages or typical fibroblast lines. Formation of these cell complexes is temperature dependent and requires the presence of Mg2+, active cellular metabolism, and microfilament assembly of cytoskeleton. We raised an antiserum against a thymic stromal cell clone (BATE-2) in rats and found that, after absorption, this serum could effectively block cell complex formation between lymphocytes and stromal cells from both thymus and bone marrow. An efficient blocking was obtained only when the antiserum was added at the initial stage of cell interaction. From the blocking experiments and the SDS-PAGE analysis of immunoprecipitated materials from the stromal cell surface, we identified a unique 107-kD glycoprotein on the stromal cells as a molecule for mediating stromal cell-lymphocyte interaction. This is further supported by the findings that an antiserum raised in hamsters against the excised gel band corresponding to 107 kD, which specifically immunoprecipitated the 107-kD molecule, effectively blocked the lymphocyte-stromal cell interaction. The possible function of this molecule in hematolymphoid development is discussed.

Animals↗

Postexposure prophylaxis with zidovudine suppresses human immunodeficiency virus type 1 infection in SCID-hu mice in a time-dependent manner.

Occupational exposure to the human immunodeficiency virus (HIV) has led to a low but finite incidence of infection among health care providers. In such circumstances, postexposure administration of 3'-azido-3'-deoxythymidine (zidovudine; AZT) might be beneficial. To test this possibility, the SCID-hu mouse (the immunodeficient C.B-17 scid/scid mouse engrafted with human hematolymphoid organs) was treated with AZT at different times after intravenous infection with a standard dose of HIV (known to infect 100% of animals). If given within 2 h, AZT suppressed infection in all animals; if given after 2 days, no suppression was observed. At least in some animals, an AZT-sensitive phase lasted for as long as 36 h. These data support the hypothesis that prompt administration of AZT might be efficacious in suppressing acute HIV infection in humans. Further studies in the SCID-hu mouse might provide insight into treatment protocols of even greater efficacy.

Animals↗

The SCID-hu mouse: a small animal model for HIV infection and pathogenesis.

The SCID-hu mouse is a heterochimeric small animal model designed to support hematopoietic differentiation and function in vivo. Multiple organs of the human hematolymphoid system have been successfully engrafted into the immunodeficient C.B-17 scid scid mouse, including fetal liver, thymus, lymph node, and skin. Co-implantation of human fetal liver and human fetal thymus results in long-term, multilineage human hematopoiesis in vivo. Mature human lymphocytes within the SCID-hu mouse are phenotypically and functionally normal. HIV infection of the SCID-hu mouse reflects a tropism similar to that found in humans: only human organs with CD4+ cells are infected. Viral replication can thereafter be monitored with assays that are safe, reproducible, and quantitative. Given this small animal model, it is now possible to study systematically the infective process of HIV and to address questions about the efficacy of novel antiviral compounds or vaccines in vivo.

Animals↗