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Biomedical subjects

H Katano

Publications and source records attributed to H Katano.

At least 55 records · Page 3Linked to original sources
PubMed1999

Expression of PDGF-beta receptor, EGF receptor, and receptor adaptor protein Shc in rat osteoblasts during spaceflight.

A number of studies have indicated that microgravity induces osteopenia and modulates functions of mammalian cells. However, the molecular mechanisms underlying these effects of microgravity are still unknown. Rat osteoblasts were cultured for 4 and 5 days during Shuttle-Spacelab flight, and fixed by guanidine isothiocyanate solution on board after treatment with 1alpha, 25 (OH)2 vitamin D3. The mRNA levels for platelet-derived growth factor (PDGF)-beta receptor, epidermal growth factor (EGF) receptor, the growth factor receptor adaptor protein Shc, and c-fos were determined using the method of quantitative reverse transcription-polymerase chain reaction. The mRNA levels for EGF receptor were not altered by microgravity. However, the mRNA levels for PDGF-beta receptor, Shc, and c-fos were decreased to 62, 55 and 25% on the 4th day of flight, and 47, 40, and 43% on the 5th day, respectively, as compared to the corresponding ground controls. Expression of the growth factor receptor and the receptor adaptor protein was modulated in rat osteoblasts during spaceflight. Data suggest that signal transduction via growth factor receptors in rat osteoblasts is impaired by microgravity. Dysfunction of osteoblasts might be involved in spaceflight-induced osteopenia.

Animals↗
PubMed1999

Human herpesvirus type 8 and epstein-barr virus-associated cutaneous lymphoma taking anaplastic large cell morphology in a man with HIV infection.

Human herpesvirus type 8 (HHV-8, Kaposi's sarcoma-associated herpesvirus)-positive lymphoma taking anaplastic large cell morphology in the skin is described in a 46-year-old man with AIDS. Multiple erythematous nodules appeared on the trunk and extremities during the treatment of AIDS. Histological examination of cutaneous nodules showed dense infiltration of CD30 + atypical lymphoid cells in the deep dermis. Immunoglobulin JH gene rearrangement was detected in these lymphoma cells. Both Epstein-Barr virus-encoded small RNA and HHV-8 mRNA (T1.1/nut-1) were detected in these lymphoma cells by in situ hybridization. Remarkable retention of the pericardial fluid was observed at the same time that cutaneous lesions grew, and lymphoma cells in the pericardial fluid showed the same phenotype as the cutaneous lymphoma. Chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone effectively reduced both the cutaneous nodules and pericardial fluid. However, the patient died 4 months after diagnosis because of cytomegalovirus infection. As far as we know, this is the first report of an HHV-8-positive cutaneous lymphoma taking anaplastic large cell morphology. This case suggests the association of AIDS-related anaplastic large cell lymphoma with HHV-8.

Herpesvirus 4, Human↗
PubMed1999

Detection of Toxoplasma gondii, Epstein-Barr virus, and JC virus DNAs in the cerebrospinal fluid in acquired immunodeficiency syndrome patients with focal central nervous system complications.

OBJECT: Toxoplasmic encephalitis (TE), primary central nervous system lymphoma (PCNSL) and progressive multifocal leukoencephalopathy (PML) are major central nervous system (CNS) diseases in patients with acquired immunodeficiency syndrome (AIDS). We assessed the diagnostic value of polymerase chain reaction (PCR) in the detection of DNAs of Toxoplasma gondii (T. gondii), Epstein-Barr virus (EBV) and JC virus (JCV) in the cerebrospinal fluid (CSF). METHODS: We compared the PCR results with those of pathological findings at autopsy. PATIENTS OR MATERIALS: The present study included 23 autopsies representing those in whom CSF samples were obtained before death while the patient was hospitalized or at autopsy. RESULTS: The threshold levels for PCR detection were 4 tachyzoites of T. gondii, 5-15 genomes of EBV and 10 genomes of JCV. We identified T. gondii DNA in 4 out of 5 autopsy-defined cases of TE, EBV DNA in 5 out of 5 cases with PCNSL, and JCV DNA in 2 out of 2 cases with PML. The specificity of PCR was 100% in TE, 78% in PCNSL, and 100% in PML. CONCLUSION: Although the number of cases was relatively small in this study, PCR correctly identified T. gondii DNA in those cases in which PML or PCNSL was the sole clinical diagnosis. Our results indicate that PCR examination of CSF is a clinically useful tool for the diagnosis of focal brain lesions in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Establishing and characterizing a CD30-positive cell line harboring HHV-8 from a primary effusion lymphoma.

Primary effusion lymphoma (PEL, or body-cavity-based lymphoma [BCBL]) is a new subtype of non-Hodgkin's lymphoma in which tumor cells locate in the body cavity exclusively. PEL/BCBL is widely accepted as one of the neoplastic complications of AIDS, associated mostly with human herpesvirus 8 (HHV-8/Kaposi's sarcoma-associated herpesvirus [KSHV]) and Epstein-Barr virus (EBV). We established and characterized a PEL cell line named TY-1 from a 47-year-old patient with AIDS. TY-1 exhibits indeterminate immunophenotype, expressing CD45 and CD30 cell surface antigens but not expressing B- or T-cell markers. Cytogenetic analysis revealed the representative karyotype of 50,XYq-,+7,+8,+11,+15. Southern blot analysis demonstrated HHV-8 and EBV genomes in the original tumor cells obtained from the pericardial effusion, while HHV-8 but not EBV was detected in TY-1 using PCR or Southern blot analysis. Tetradecanylphorbol acetate treatment induced some TY-1 cells to proceed to the reproductive phase. This cell line may be an useful tool for research on PEL and HHV-8.

Fatal Outcome↗
PubMed1998

Differential induction of immediate early gene mRNAs following cryogenic and impact trauma with/without craniotomy in rats.

Expression of immediate early gene (IEG) mRNAs following traumatic brain injury in 3 different models-cryogenic injury, impact injury with craniotomy and impact injury without craniotomy-was investigated using in situ hybridization. Cryogenic brain injury resulted in c-fos and c-jun mRNA expression throughout the ipsilateral cortex, piriform cortex and dentate gyrus on the injured side, with peak at 30 min to 1 h post-injury. Impact injury with craniotomy was associated with hybridization signals in the same areas and also in the subcortical white matter or ependyma underlying the impact site at 30 min post-injury. The expression was rather more prolonged than with cryogenic injury. Impact injury without craniotomy induced the expression of both mRNAs throughout the ipsilateral cortex, piriform cortex and dentate gyrus at 30 min post-injury, but this was promptly attenuated by 1 h post-injury, except for bilateral elevation in the dentate gyrus. The present study, thus, demonstrated that regional and temporal expression of IEG mRNAs is influenced by the intensity, quality and manner of application of the insult. Differences in the expression of IEGs may alter the late response gene expression and affect the succeeding events.

Animals↗
PubMed1998

Body-cavity-based lymphoma in an elderly AIDS-unrelated male.

Body-cavity-based lymphoma (BCBL) is a recently described subtype of human non-Hodgkin's lymphoma characterized by the localization of neoplastic cells exclusively in the body cavities. BCBL is found most commonly in AIDS patients, and is known to be highly associated with Kaposi's sarcoma-associated herpes virus (KSHV). We describe here a case of BCBL that occurred in a 101-year-old man. He was successively treated with etoposide, but died 8 months after the diagnosis of BCBL. No lymphoma masses were noted at pre- and postmortem examinations. KSHV was demonstrated in large numbers in the neoplastic cells using semiquantitative PCR analysis. Although there have been four brief reports of HIV negative BCBL, the present case is the first for which the detailed clinical course and response to chemotherapy have been recorded.

Aged↗
PubMed1998

Immunochemical and biochemical characteristics of enamel proteins in hypocalcified amelogenesis imperfecta.

Amelogenesis imperfecta is a hereditary disease of the enamel that is unassociated with generalized defects. Cases of the condition are clinically classified into three groups: hypoplastic, hypomaturation, and hypocalcified. In this study, soluble protein fractions of the enamel from three patients with hypocalcified amelogenesis imperfecta were examined through the use of immunochemical and biochemical techniques. In immunochemical analyses done with a polyclonal anti-amelogenin antibody, all samples from enamel in which there was amelogenesis imperfecta were found to contain considerable amounts of amelogenin peptides. When an enamel sample from one patient was examined by Western-blot transfer and immunobinding analysis, the amelogenin fraction was found to consist of a 26-kDa molecule thought to be normally present in the outer layer of secretory-stage enamel. This enamel was also found to contain albumin as one of the major constituents of the protein fraction. These results suggest that hypocalcified amelogenesis imperfecta may in part be caused by a disturbance in matrix protein degradation during the maturation phase.

Adolescent↗
PubMed1998

Simple delineation of misery perfusion areas by superimposition of PET on PET images.

Oxygen extraction fraction images were superimposed on cerebral blood flow images of positron emission tomography (PET) to depict the so-called misery perfusion area in two patients with moyamoya disease. The superimposed image following extra-intracranial bypass surgery was obtained in one case, which convincingly disclosed attenuation as compared with the preoperative image. This simple PET on PET approach should find an application in the evaluation of misery perfusion and in assessing operative indications for cerebral ischaemic diseases.

Adult↗
PubMed1998

Spaceflight modulates insulin-like growth factor binding proteins and glucocorticoid receptor in osteoblasts.

Rat osteoblasts were cultured for 4 or 5 days during a Space Shuttle mission. After 20-h treatment with 1alpha,25-dihydroxyvitamin D3, conditioned media were harvested and cellular DNA and/or RNA were fixed on board. The insulin-like growth factor binding protein (IGF BP)-3 levels in the media were three- and tenfold higher than in ground controls on the fourth and fifth flight days, as quantitated by Western ligand blotting and radioimmunoassay, respectively. The increased IGF BP-3 protein levels correlated with two- to threefold elevation of IGF BP-3 mRNA levels, obtained by reverse transcription-polymerase chain reaction. The IGF BP-5 mRNA levels in flight cultures were 33-69% lower than in ground controls. The IGF BP-4 mRNA levels in flight cultures were 75% lower than in ground controls on the fifth day but were not different on the fourth day. The glucocorticoid receptor mRNA levels in flight cultures were increased by three- to eightfold on the fourth and fifth days compared with levels in ground controls. These data suggest potential mechanisms underlying spaceflight-induced osteopenia.

Animals↗
PubMed1998

Visual disturbance by lymphocytic hypophysitis in a non-pregnant woman with systemic lupus erythematosus.

The authors present the case of a patient with systemic lupus erythematosus who developed visual disturbance and amenorrhea. Though the clinical and radiological findings resembled those of pituitary adenoma, the patient was finally diagnosed as having lymphocytic hypophysitis after the operation. We briefly describe this relatively rare entity in relation to its autoimmune pathogenesis.

Adenoma↗
PubMed1998

Clinical-pathological varieties of gliosarcoma: report of two cases.

The authors present two tumour cases, in both of which the diagnosis of gliosarcoma was made. The two cases differ histologically, one being a tumour clearly consisting of two different parts, the other being a tumour seemingly composed of cells with multipotential differentiation. Pathological and radiological studies are shown as well as the clinical course of the cases.

Adult↗
PubMed1997

Follicular dendritic cell sarcoma complicated by hyaline-vascular type Castleman's disease in a schizophrenic patient.

Follicular dendritic cell (FDC) sarcoma is an exceedingly rare neoplasm of unknown pathogenesis. A case of FDC sarcoma complicated by the hyaline-vascular type Castleman's disease occurring in a schizophrenic male is presented. Swelling of the left cervical lymph node appeared in a 44-year-old male schizophrenic who had been medicated with major tranquilizers for 20 years. He had had a history of cervical lymphadenopathy 14 years before, for which a diagnosis of hyaline-vascular type Castleman's disease had been made. The present specimen, obtained from the same site, was an enlarged lymph node heavily infiltrated with oval to spindle-shaped atypical cells but was uninvolved at the periphery. The infiltrating cells showed nodular or sheet-like growth, occasionally taking fascicular or storiform patterns. Follicular involvement was also common. Peculiarly, various amounts of small lymphocytes were intermingled with the neoplastic cells. The atypical cells expressed two FDC-specific antigens, DRC-1 and Ki-M4 antigen, together with a few other markers that are shared by FDC, including CD21 and HLA-DR. These findings clearly show the tumor to be FDC sarcoma. In addition, a peculiar fibro-hyalinous change in the lymph follicle, which is compatible with hyaline-vascular type Castleman's disease, was noted at the periphery of the lymph node where neoplastic cells had not infiltrated. Surprisingly, similar hyaline-vascular changes were observed in the previous biopsy taken 14 years ago. Meanwhile, Kaposi's sarcoma-associated herpesvirus, which is often identified from generalized Castleman's disease, was not identified in the present case by polymerase chain reaction study. Thus, this case is unique in two aspects: (i) the overlap of FDC sarcoma with hyaline-vascular type follicular changes; and (ii) its occurrence in a schizophrenic patient.

Adult↗
PubMed1997

[EBV-associated lymphoma].

Several subtypes of human malignant lymphomas are known to be highly associated with the Epstein-Barr virus. These include the Burkitt's lymphoma, opportunistic (immune deficiency-associated) lymphoma, nasal T/NK lymphoma, Hodgkin's disease pyothorax-associated lymphoma, cutaneous panniculitis-type lymphoma, and mediastinal large B-cell lymphoma. Improvement of histopathological technology, the demonstration of EBV-encoded small RNAs(EBERs), as well as the molecular virological methods, contributed much in the progression of such EBV-associated lymphomas.

Herpesvirus 4, Human↗
PubMed1997

[Opportunistic lymphoma].

Malignant lymphoma is one of the most common complications in patients under immunodeficiency. Such lymphomas, termed as opportunistic lymphoma, are growing in these days because of the high prevalence of AIDS and the wide introduction of organ/bone marrow transplantation. The Epstein-Barr virus has been regarded as the sole causative agent of this condition. Recent studies, however, added another new virus, the Kaposi's sarcoma-associated herpesvirus (KSHV) as the second pathogen of this condition. Insufficient immunological surveillance on these patients seems to permit the virus-transformed host cells to proliferate, which finally lead to the tumor formation.

AIDS-Related Opportunistic Infections↗
PubMed1996

An improved quantitative RT-PCR fluorescent method for analysis of gene transcripts in the STS-65 space shuttle experiment.

We describe a reverse transcription polymerase chain reaction (RT-PCR) technique using fluorescent dUTP to examine changes in mRNA level in samples. In this procedure, the amplified product is identified by the fluorescent detection system in an automated DNA sequencer, and if the MW of the DNA/RNA or the fluorescent dye is different, several samples can be analyzed in a single lane. The basis for this technique is similar to that of radiolabeled methods, and we applied this technique for the comparison of the expression level of the rat c-myc gene in osteoblasts exposed to microgravity and unit gravity conditions. Using the fluorescent- and radiolabeled methods, the level of rat c-myc mRNA were compared quantitatively and the results demonstrated that the c-myc expression level was not altered by microgravity. Therefore, this fluorescent RT-PCR technique is useful for gene expression analysis particularly when the samples are limited, such as in space flight experiments. The method also allows for rapid assessment of mRNA changes in many samples simultaneously.

Animals↗
PubMed1996

Microgravity induces prostaglandin E2 and interleukin-6 production in normal rat osteoblasts: role in bone demineralization.

It has been suggested that microgravity alters bone metabolism. Evidence for this phenomenon includes the negative calcium balance and decreased bone density in astronauts, as well as, inhibition of bone formation in rats flown for 2 to 3 weeks. However, the specific mechanisms that modulate these changes in microgravity are unknown. The purpose of this study was to clarify the mechanism of microgravity-induced bone demineralization using normal rat osteoblasts obtained from femur marrow cultures. The osteoblasts were cultured for 5 days during a Shuttle-Spacelab flight (STS-65). After collection of the culture medium, the cellular DNA and RNA were fixed on board. Enzyme-immunoassay of the culture medium for prostaglandin E2 (PGE2) indicated that microgravity induced a 4.5- to 136-fold increase in flight samples as compared to the ground control cultures. This increase of PGE2 production was consistent with a 3.3- to 9.5-fold elevation of inducible prostaglandin G/H synthase-2 (PGHS-2) mRNA, quantitated by reverse transcription-polymerase chain reaction (RT-PCR). The mRNA induction for the constitutive isozyme PGHS-1 was less than that for PGHS-2. The interleukin-6 (IL-6) mRNA was also increased (6.4- to 9.3-fold) in microgravity as compared to the ground controls. Since PGE2 and IL-6 are both known to play a role in osteoclast formation and bone resorption, these data provide molecular mechanisms that contribute to our understanding of microgravity-induced alterations in the bone resorption process.

Animals↗
PubMed1996

Expression of latent membrane protein 1 in clinically isolated cases and animal models of AIDS-associated non-Hodgkin's lymphomas.

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is known to be expressed in non-Hodgkin's lymphomas (NHL) occurring in immunocompromised hosts, playing crucial roles in lymphomagenesis. LMP1 expression at the microscopic level, however, was reported to be limited to some, not all, neoplastic cells in each specimen studied. In order to determine whether LMP1 expression of NHL really is limited to some cells, five clinically isolated acquired immunodeficiency syndrome (AIDS)-associated and six experimental NHL were studied immunohistochemically, immuno-electron microscopically and flow cytometrically. The experimental models were the lymphocytic tumors produced in severe combined immune deficiency (SCID) mice after engrafting EBV-infected B cells. Light microscopy revealed intense LMP1-immunostaining in less than 5% of neoplastic cells in the NHL, weak staining in less than 50% and apparently unstained cells in over 50%. Immuno-electron microscopy revealed that the intensely stained cells were those undergoing degeneration, whereas a proportion of the remainder demonstrated patchy reactions on their cell membranes. The weakly stained cells were found to correspond to cells with several patches on their cell membranes. Flow-cytometric analysis demonstrated that a large proportion of the neoplastic cells expressed LMP1 to some extent. Taken together, the results suggest that most of the neoplastic cells expressed LMP1 molecules at quantitatively different levels, some of which were below the level detectable by light microscopy. The intensely stained cells were shown to be those undergoing degeneration.

Acquired Immunodeficiency Syndrome↗