Biomedical subjects

T Akagi

Publications and source records attributed to T Akagi.

At least 217 records · Page 12Linked to original sources

PubMed1993

Spindle cell hemangioendothelioma: a report of two cases.

Two cases of spindle cell hemangioendothelioma (SCH) are reported. One of the patients was a 16 year old Japanese female, who had been suffering from Ollier's disease (multiple enchondromatosis) since 3 years of age and had developed multiple SCH in the right leg at the age of 11 years. Spindle cell hemangioendothelioma lesions coincided with the site of enchondromatosis and increased in number thereafter. This is the first report of Ollier's disease complicated with multiple SCH. Another patient, a 33 year old Japanese female, who was a carrier of hepatitis B virus (HBV), developed solitary SCH in the lateral aspect of the right ankle where a lipoma was extirpated 10 years previously. Tumor cells of both cases were composed of four cell types: (i) spindle cells; (ii) epithelioid cells; (iii) vacuolated endothelial cells; and (iv) usual endothelial cells. Endothelia in the cavernous area and vacuolated cells reacted to Ulex europaeus agglutin 1 (UEA-I), factor VIII-related antigen and vimentin. Spindle cells and epithelioid cells reacted only to vimentin.

Adolescent↗

PubMed1993

Current issues in Kawasaki disease.

The most important clinical aspect of Kawasaki disease is the cardiovascular problems. This article reports on the cardiovascular spectrum in acute Kawasaki disease, analysis of myocardial infarction and fatal cases, a follow-up study on the natural history of coronary artery lesions, long-term cardiovascular problems including premature atherosclerosis, problems in the adult cardiology and the treatment of acute Kawasaki disease. The etiology and pathogenesis of this disease are still unknown. Current hypotheses and leading studies on the etiology and the pathogenesis of Kawasaki disease are also reviewed.

Adult↗

PubMed1993

Proliferative response of Tax1-transduced primary human T cells to anti-CD3 antibody stimulation by an interleukin-2-independent pathway.

The growth properties of human T-cell leukemia virus Tax1-transduced primary human T cells derived from peripheral blood lymphocytes were compared with those of the same subset of T cells transduced with a control vector. Tax1-transduced T cells exhibited slightly elevated responsiveness to externally added interleukin-2 (IL-2) and a markedly higher proliferative response to stimulation with anti-CD3 antibody. The proliferation after anti-CD3 antibody stimulation was mainly via an IL-2-independent pathway. Therefore, some other mechanism than the previously proposed IL-2 autocrine model seems to be involved in the process of deregulation of T-cell proliferation by Tax1. Moreover, Tax1-transduced T cells have continued to proliferate in medium containing IL-2 long after control T cells ceased to grow, and so they are considered to be immortalized.

CD3 Complex↗

PubMed1993

Two distinct proteinase activities required for the processing of a putative nonstructural precursor protein of hepatitis C virus.

Gene products of hepatitis C virus (HCV), a possible major causative agent of posttransfusion non-A, non-B hepatitis, are considered to be produced from a precursor polyprotein via proteolytic processing mediated by either host cell or viral proteinases. The presence of HCV serine proteinase has been proposed from analyses of amino acid sequence homology. To examine the processing mechanism of the HCV precursor polyprotein, the amino-terminal region of the putative nonstructural protein region of the HCV genome, containing the serine proteinase motif, was expressed and analyzed by using an in vitro transcription/translation system and a transient expression system in cultured cells. Two distinct proteinase activities which function in the production of a 70-kDa protein (p70) from the precursor polyprotein were detected. One of these proteinase activities, which cleaved the carboxyl (C)-terminal side of p70, required the presence of the serine proteinase motif, which is located in the amino (N)-terminal region of p70. That suggested that the predicted HCV serine proteinase was functional. The other activity, which was responsible for the cleavage of the N-terminal side of p70, required the expression of the region upstream and downstream of that cleavage site, including the p70 serine proteinase domain. From the results of pulse-chase analysis, using proteinase inhibitors coupled with a point mutation analysis, the latter activity was proposed to be a novel zinc-dependent metalloproteinase.

Amino Acid Sequence↗

PubMed1993

Bauhinia purpurea lectin (BPA) binding spectra in hyperplastic human tonsil and in peripheral blood: immunohistochemical, immunoelectron microscopic, and flow cytometric analyses.

We studied the binding of Bauhinia purpurea lectin (BPA) to human tonsils and peripheral blood mononuclear cells by immunohistochemical, immunoelectron microscopic, and flow cytometric techniques. The effect of several fixatives (acetone, ethanol, buffered and non-buffered formalin, B5, Bodian 11, Bouin's, Carnoy's, Zenker's, and glutaraldehyde) was also examined. BPA was reactive with germinal center lymphocytes, macrophages/histiocytes, follicular dendritic cells, squamous epithelial cells, and a subset of endothelial cells. Mantle zone and paracortical lymphocytes were non-reactive with BPA. The profile of the specific binding characteristic of BPA lectin was found to be influenced by the fixatives. Most significantly, formalin fixation greatly reduced overall binding intensity, particularly making germinal center lymphocytes totally non-reactive. The reaction intensity was most prominent in frozen sections or those fixed in Carnoy's or ethanol solution. The combination of heavy metal salt-containing fixatives with acetic acid usually did not enhance BPA binding. Glutaraldehyde solution used for immunoelectron microscopic study also preserved BPA receptors fairly well, and BPA was confined to the membrane in lymphocytes and to both the membrane and cytoplasm in macrophages/histiocytes and follicular dendritic cells. Neuraminidase treatment of tissues resulted in binding of BPA to lymphocytes that were non-reactive before treatment. Double-staining studies on cell suspensions from tonsils with FITC-BPA and PE-conjugated anti-CD3 or SIg reagents revealed that 28.4% of CD3+ cells and 61.3% or SIg+ cells were BPA reactive. In PBL, 65.6% and 81.4% of CD3+ and SIg+ cells, respectively, were BPA reactive. Neuraminidase treatment also increased the percentage of BPA-reactive lymphocytes. In conclusion, BPA is a marker for macrophages/histiocytes and germinal center lymphocytes, provided that the tissues are unfixed or fixed with suitable fixatives such as ethanol or Carnoy's solution.

Adolescent↗

PubMed1993

Expression of a lymphocyte adhesion molecule (CD44) in malignant lymphomas: relevance to primary site, histological subtype and clinical stage.

Lymphocyte adhesion molecules defined by anti-CD44 antibody (Hermes-3) may be involved in lymphocyte binding to high endothelial venules at sites where lymphocytes exist the blood. CD44 expression was immunohistochemically examined in 167 well characterized cases of malignant lymphomas (MLs). None of 12 nodal follicular lymphomas (FLs) were CD44+, whereas 3 of 4 extranodal ones showed distinct CD44 expression. In contrast to nodal FLs, 28 of the 38 (74%) nodal diffuse B-cell lymphomas were CD44+ (p < 0.0001). T-cell lymphomas showed a significantly higher expression of CD44 antigen than diffuse B-cell lymphomas in the nodal cases (p < 0.04), but not in the extranodal ones. In nodal diffuse lymphomas, 3 of 5 stage I lymphomas (60%) were CD44+ in contrast to 53 of 63 stage II-IV lymphomas (84%), but the difference was not statistically significant. Of 14 Hodgkin's diseases, 9 cases were CD44+ with no significant correlation with clinical stage. The data of flow cytometric analysis confirmed the results of immunohistochemical analysis. In conclusion, CD44 expression is relevant to primary sites of distinctive MLs originating in the mucosal regions (MALToma) and some histological subtypes, but the relation with clinical stage was not defined. Some other adhesion molecules or different mechanisms must also be taken into account concerning the genesis and the expansion of MLs.

Humans↗

PubMed1993

Distribution of lectin receptors in the human hyperplastic tonsil: histochemical and flow cytometric analyses.

The distribution of lectin receptors in the human tonsil was studied using 16 biotinylated lectins. The avidin-biotin-peroxidase complex (ABC) method was used on frozen and paraffin-embedded tissue sections. Cell suspensions were also analysed by dual flow cytometry using respective fluorescein isothiocyanate-conjugated lectins and phycoerythrin-labeled anti-CD3 and anti-human immunoglobulin. Frozen sections fixed with acetone and paraffin-embedded materials fixed in three solutions were compared for lectin affinity; ethanol-fixed sections gave best results followed by frozen and buffered formalin-fixed ones, then nonbuffered formalin. Con-A, RCA-1, LcH, WGA, MPA, PHA, PSA, PNA, SJA and GSA-1 reacted with all tissue components of the tonsil in immunohistochemical studies, but binding intensity was fixative dependent. Binding of Lotus and BPA to lymphocytes was limited to germinal center lymphocytes. Other tissue components were also reactive but staining intensity was weaker in Lotus compared with BPA. SBA and DBA did not react with lymphocytes, but reacted with macrophages/histiocytes, vascular endothelia, and epithelial cells. LBA and LPA were constantly negative with all tissue components irrespective of fixatives. Flow cytometric analyses showed that all but three (DBA, LBA and LPA) partially or totally stained lymphocyte surfaces. Lotus receptors were expressed exclusively on B-lymphocytes.

Acetone↗

PubMed1993

Brief induction chemotherapy followed by involved-field irradiation for the treatment of localized intermediate- and high-grade non-Hodgkin's lymphoma.

In an attempt to assess the effects and toxicity of brief induction chemotherapy plus involved-field irradiation for localized intermediate- and high-grade non-Hodgkin's lymphoma, we conducted a single-arm prospective trial between May 1987 and July 1991. Patients received four cycles of a five-drug chemotherapy regimen consisting of cyclophosphamide, doxorubicin, vincristine, prednisolone, and bleomycin (CHOP-Bleo) followed by involved-field irradiation of 30 Gy. Of 32 patients consecutively enrolled, 30 patients had measurable and/or evaluable disease, while two had no evaluable disease, as their major tumors had been surgically removed. All the patients were in complete remission at the conclusion of all treatment. Four patients have relapsed so far and one died of the disease at 17 months. With a median follow-up time of 33 months (range, 8 to 58), the actuarial disease-free survival rate was 82% and the overall survival rate was 96%. The toxicity was generally mild and all the patients received the planned treatment course. This treatment modality appeared to be safe and effective for localized intermediate- and high-grade non-Hodgkin's lymphoma.

Adult↗

PubMed1993

[Clinicopathological significance of immune complex (IC) along the tubular basement membrane (TBM) in lupus nephritis].

This paper reports on the clinicopathological significance of IC along the TBM in lupus nephritis. Renal biopsies were performed on 60 patients with SLE. All of the patients demonstrated immunoglobulin deposits in the glomeruli, and 16 of them also showed immune deposits along the TBM. The IgG in the glomeruli or along the TBM completely disappeared after incubation with human IgG, IgG Fc fragments, but not with human F(ab')2, rabbit or rat IgG. These results suggest that IgG along the TBM are similar in nature to IC in the glomeruli and that the IC are composed of IgG rheumatoid factor. The square of tubulointerstitial lesions was more severe in the group with IgG along the TBM than in the group with no IgG along the TBM (5.85 +/- 9.88% vs 1.29 +/- 3.72%). In addition of this, the group with IgG deposits along the TBM frequently demonstrated type IV lupus nephritis. Although the renal function was not significantly different in the both groups, the serum complement level was lower in the cases with IC deposits in the TBM. From these results, it is suggested that IC deposits along the TBM as one of the important inflammatory agents lead to the severe forms of tubulointerstitial injury and show the active stage of the disease in SLE patients.

Antigen-Antibody Complex↗

PubMed1992

Primary non-Hodgkin malignant lymphoma of the breast. An immunohistochemical study of seven patients and literature review of 152 patients with breast lymphoma in Japan.

BACKGROUND: The breast is rarely a primary site for extranodal malignant lymphoma. Most reported primary non-Hodgkin malignant lymphomas of the breast (PBL) are of B-cell phenotype. METHODS: Histologic and immunohistochemical analyses of seven patients with PBL and a statistical analysis of 152 patients with PBL reported in the Japanese literature were performed. RESULTS: Malignant lymphoma could not be predicted preoperatively with clinical and radiologic findings; breast carcinoma, fibroadenoma, and phyllodes tumor were the preoperative diagnoses. All patients were women; they ranged in age from 31 to 80 years (mean, 57.6 years). The right breast was involved initially in five patients. In four, only the breast was involved (Stage I), whereas in three, the ipsilateral axillary lymph nodes (Stage II) were involved at diagnosis. According to the Working Formulation, all patients belonged to the intermediate grade and were classified as having diffuse large cell (five patients) or mixed (two patients) lymphoma. Immunophenotypic analysis revealed that all patients had B-cell lymphoma. No patients had lymphoepithelial lesions, which is the characteristic feature in categorizing a lymphoma as a mucosa-associated lymphoid tissue (MALT) lymphoma. A statistical analysis of the patient reported in the Japanese literature has divided PBL into two types: a bilateral type that affects younger women and a unilateral type that has a broad age distribution, but preponderantly occurs in older women. The age and stage at diagnosis were significant prognostic factors in predicting the survival time, but the location and size of the tumor at initial presentation, histopathologic type, terminal leukemic manifestation, and treatment modality were not. CONCLUSIONS: This study indicates that most PBL are diffuse large cell lymphoma of B-cell phenotype and that the age and stage at diagnosis are significant prognostic factors.

Adult↗

PubMed1992

Infectivity of human T-lymphotropic virus type I to human nervous tissue cells in vitro.

Infectivity of human T-lymphotropic virus type I (HTLV-I) to human nervous tissue cells was explored using co-cultivation with X-irradiated, HTLV-I-producing MT2 cells. Examined cells included normal cerebellar cells, brain tumor cells (astrocytoma, medulloblastoma, meningioma, hemangioblastoma, and schwannoma), and various cell lines (astrocytoma, ependymoma, oligodendroglioma, medulloblastoma, and neuroblastoma). Successful HTLV-I infection was confirmed immunohistochemically using monoclonal antibodies to HTLV-I p19, p24, and pX product. All cell lines and primary cultures from normal cerebellar tissues and brain tumors could be infected with HTLV-I. Double immunostaining showed that glial fibrillary acidic protein-, S-100 protein- or vimentin-positive cells were susceptible to infection. Neurofilament- or neuron-specific enolase-positive cells in medulloblastoma could also be infected. Reverse-transcriptase assay revealed the productive infection in U251-MG (astrocytoma) and KG-IC (oligodendroglioma) lines. Co-cultivated U251-MG cells formed syncytial polykaryons after serial passages, and polymerase chain reaction assay detected HTLV-I genome in U251-MG syncytial polykaryons and p19+ mononuclear cells. HTLV-I viral RNA was also detected in infected U251-MG cells by in situ hybridization. These data show that HTLV-I may have a wide spectrum of infectivity in human nervous tissues.

Base Sequence↗

PubMed1992

An immunohistochemical study on HLA-DR expression in human meningiomas.

The expression of HLA-DR was examined in 38 cases of meningiomas with the streptavidin-biotin immunoperoxidase method using two monoclonal antibodies to HLA-DR (LN-3 and TAL-IB5) on formalin-fixed, paraffin-embedded specimens. Similar immunoreactivity was obtained with these two monoclonal antibodies. In addition to infiltrated lymphoid cells and perivascular macrophages, tumor cells themselves showed HLA-DR expression in 16 cases (42%) of meningiomas. The rate of HLA-DR-positive cases in the transitional and fibrous subtypes (64% and 67%, respectively) was higher than that in the meningotheliomatous subtype (8%). Spindle-shaped tumor cells were frequently positive for HLA-DR, whereas few of meningotheliomatous cells with plump cytoplasm were positive. Most of HLA-DR-positive cases showed no or scanty lymphoid cell infiltration, and a few cases with marked infiltration of lymphoid cells were variable for HLA-DR expression. These findings suggest little correlation between HLA-DR expression of tumor cells and the degree of lymphoid cell infiltration, but indicate an aberrant HLA-DR expression of tumor cells themselves.

Adult↗

PubMed1992

HTLV-II-specific antisera raised in rabbits immunized with a synthetic peptide of HTLV-II envelope protein.

In order to discriminate HTLV-II from HTLV-I, HTLV-II-specific polyclonal antibodies against a synthetic peptide of HTLV-II envelope sequence were raised in rabbits. We immunized two adult rabbits with a KLH-conjugated synthetic peptide corresponding to the amino acid sequence 171-196 of the HTLV-II envelope sequence, which is a specific region for HTLV-II as evaluated with an ELISA method. The resulting rabbit antisera to the synthetic peptide reacted with gp46 of HTLV-II lysates in Western blot analysis but not with that of HTLV-I. Flow cytometric analysis and immunohistochemical study revealed that these affinity purified antisera recognized some HTLV-II-producing cell lines examined, but not HTLV-I-producing cell lines or other cell lines uninfected by HTLV. These findings indicate that these antisera specifically recognized the envelope glycoprotein (gp46) of HTLV-II and suggest the specificity of this region in the immune response to HTLV-II. Such antisera are useful in distinguishing between HTLV-I and HTLV-II infection and in determining the presence of individual HTLV-II-infected cells both in vivo and in vitro, including non-lymphoid cells. They may also assist in the elucidation of the pathogenesis of HTLV-II.

Amino Acid Sequence↗

PubMed1992

Induction of interdigitating reticulum cell-like differentiation in human monocytic leukemia cells by conditioned medium from IL-2-stimulated helper T-cells.

Monocytic leukemia (MoL) cells were obtained from the peripheral blood of a patient in whom the leukemic cells infiltrating various lymphoreticular organs exhibited features intermediate between interdigitating reticulum cells (IDC) and ordinary phagocytic macrophages, whereas the leukemic cells in the peripheral blood were essentially monocytic and lacked such features. Peripheral blood CD4+ T-cells were established as an interleukin-2-dependent T-cell line. When the MoL cells were exposed for a few days to conditioned medium from the T-cell line, they extended several dendritic cytoplasmic projections and became intensely positive for HLA-DR antigen, cytoplasmic S-100 beta protein, and CD1 antigen. Functionally, the conditioned medium significantly down-regulated Fc-mediated and Fc-independent phagocytic activities, and the levels of lysosomal enzymes such as lysozyme and nonspecific esterase in the MoL cells. Moreover, the conditioned medium significantly up-regulated the accessory cell function of the MoL cells as measured by the primary allogenic mixed leukocyte reaction (MLR). Furthermore, the conditioned medium significantly down-regulated the expression of CD14 antigen. Biochemical analysis indicated that the factor responsible for these changes is a protein which is distinct from known human cytokines and whose molecular weight is approximately 31 kDa. These findings suggest that IDC are closely related the monocytic lineage and that helper T-cells play an important role in constructing the microenvironment of T-lymphoid tissues which is necessary for the differentiation and maturation of IDC.

Adult↗

PubMed1992

Cutaneous T-cell lymphoma associated with granular lymphocytic leukemia in its terminal stage.

A 79-year-old woman had cutaneous T cell lymphoma. After a long clinical course, numerous tumors and an enormous increase in peripheral granular lymphocytes without lymphadenopathy developed suddenly. Surface markers and DNA analysis of the tumor cells from her skin and peripheral blood and electron microscopic examination suggested that granular lymphocytic leukemia had developed in the terminal stage of cutaneous T cell lymphoma. To our knowledge this association has not been reported previously.

Acute Disease↗

PubMed1992

Ventricular performance before and after Fontan repair for univentricular atrioventricular connection: angiographic and radionuclide assessment.

OBJECTIVES: This study was designed to evaluate changes in ventricular volume, mass and cardiac function before and after creation of an atrial to pulmonary connection in patients with a univentricular atrioventricular connection. BACKGROUND: Intact systolic and diastolic performance is critical for successful establishment of an atrial dependent circulation, and few studies are available comparing cardiac performance before and after creation. METHODS: With the use of radionuclide blood pool imaging and ventricular cineangiography, 54 patients (mean age 6.4 +/- 3.4 years) were studied. Twenty-eight patients were investigated preoperatively and 36 greater than 1 year after repair and compared with a control population. RESULTS: Before operation, end-diastolic volume and wall mass were significantly increased compared with those of control subjects; however, the mass/volume ratio was normal (1.08 +/- 0.31 g/ml for the preoperative group; 0.97 +/- 0.19 for control subjects). Although end-diastolic volume returned to normal after the procedure, wall mass remained elevated and contributed to an elevated mass/volume ratio (1.20 +/- 0.38 g/ml). After the procedure, systemic vascular resistance index was significantly elevated compared with that before surgery or with that of control subjects (1,199 +/- 373, 2,120 +/- 645, 1,556 +/- 275 dynes.s.cm-5.m2: pre- and postrepair and control subjects, respectively). Radionuclide studies demonstrated that preoperative ejection fraction (52 +/- 9, 50 +/- 9, 60 +/- 8%), peak ejection (2.58 +/- 0.66, 2.95 +/- 0.81, 3.73 +/- 0.70 EDV/s) and peak filling rates (2.84 +/- 0.75, 2.75 +/- 0.79, 3.84 +/- 0.51 end-diastolic volumes [EDV/s]) were significantly reduced compared with those of control subjects and remained so after surgery. CONCLUSIONS: These data suggest that systolic and diastolic function is depressed preoperatively in these patients, remains unchanged after the creation of an atrial-dependent circulation and is associated with an increased systemic vascular resistance. Long-term issues addressing preservation of cardiac function need to be prospectively studied.

Child↗

PubMed1992

Outcome of coronary artery aneurysms after Kawasaki disease.

From 1974 through 1991, a total of 583 children with Kawasaki disease were seen at the Hospital for Sick Children, in Toronto, of whom 80 (13.7%) had coronary artery involvement. There were 55 boys and 25 girls, whose mean age at onset was 2.9 +/- 2.5 years, followed for a mean period of 4.0 +/- 3.6 years. Giant aneurysms (maximum diameter > or = 8 mm) were found in 22 children, moderate-sized aneurysms (> or = 4 to < 8 mm) in 44, and dilation lesions (< 4 mm) in 14. Myocardial infarction occurred in 9 (1.5%), all of whom had giant aneurysms. The persistence rate for aneurysms was 72% at 1 year and 41% at 5 years of follow-up. In multivariate analysis, the regression of an aneurysm was significantly related to the severity of coronary artery lesions, initial treatment, and gender. Although > 80% of small or moderate-sized aneurysms regressed within 5 years, giant aneurysms did not regress during the follow-up period. In patients who received immune globulin therapy, coronary lesions tended to resolve more rapidly than in those treated with salicylate therapy alone, because 91% of the lesions in the former were small or moderate. These findings suggest that the severity of coronary artery involvement during the initial stages of Kawasaki disease influences the regression of these lesions, and that immune globulin treatment may improve outcome by reducing the incidence of severe lesions.

Adolescent↗

PubMed1992

Ultrastructure of Warthin-Starry stain-positive bacteria in abscess-forming reticular lymphadenitis.

This study describes the ultrastructure of Warthin-Starry (WS) stain-positive bacteria in abscess-forming reticular lymphadenitis (ARL) compatible with cat scratch disease (CSD). Sections containing WS-positive bacteria were re-embedded in Epon, and semithin sections were examined by electron microscopy. Silver particles were aggregated on the outer surfaces of the bacteria. Stereoscopic observations clearly showed that the bacteria were pleomorphic, rod-shaped, arranged in a row or at an angle, and frequently showed septal formation. Electron microscopy of ultrathin sections revealed that the cell wall possessed an outer membrane characteristic of gram-negative bacteria. The results indicate that rod-shaped bacteria with the WS-positive, gram-negative staining cause ARL histopathologically consistent with CSD.

Abscess↗