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Biomedical subjects

R Abe

Publications and source records attributed to R Abe.

At least 73 records · Page 4Linked to original sources
PubMed2000

CD28 knockout mice as a useful clue to examine the pathogenesis of chronic graft-versus-host reaction.

BACKGROUND: Injection of BALB/c or DBA/2 spleen cells into F1 C57BL/6 (B6) hybrids induces a graft-versus-host reaction (GVHR) of a chronic stimulatory type that results in clinical and pathologic manifestations that resemble the human systemic lupus erythematosus (SLE). The aim of the present study was to examine the role of a major T-cell costimulatory signal receptor, CD28, in the production of autoantibody and the development of an immune complex glomerulonephritis, which are common in SLE pathology. METHODS: For this purpose, CD28-deficient (CD28KO) mice were used for the source of donor lymphocytes. Chronic GVHR was induced by an injection of BALB/c or BALB. CD28KO donor cells into normal BCF1 mice. Serum titers of anti-dsDNA antibodies were assessed by enzyme-linked immunosorbent assay (ELISA) and major histocompatibility complex (MHC) class II antigen expression on B cells were tested by flow cytometry. In addition, depositions of immunoglobulin (Ig) were examined by direct immunofluorescence staining on frozen kidney sections. RESULTS: When (BALB/c x B6)F1 mice were injected with parental BALB/c lymphocytes, serum anti-dsDNA titer was significantly increased in association with nonspecific B-cell activation and IgG deposition in the glomerular basement membrane. In sharp contrast, none of these signs were observed in F1 mice, which were injected with CD28KO spleen cells. CONCLUSION: The CD28-mediated T-cell costimulatory pathway plays a pivotal role in the development of polyclonal B-cell activation, autoantibody production, and an immune complex glomerulonephritis. We propose that CD28KO mice are useful clues in examining the pathogenesis of experimental lupus nephritis.

Animals↗
PubMed2000

[The evaluation of pamidronate therapy for bone metastases from breast cancer].

We devised a method to evaluate comprehensively the therapy to alleviate the pain of bone metastases from breast cancer according to the three items of bone pain and effects of analgesia and radiology. In 12 patients, we evaluated the therapeutic effect of pamidronate as an alleviative treatment for the pain of bone metastases from breast cancer. Bone pain was evaluated on a 6-grade scale, as was use of analgesics. Improvement in bone pain, in addition to improvement in use of analgesia, was evaluated as markedly improved, improved, unchanged, aggravated, no pain or undeterminable. Radiological improvement in bone lesions was evaluated as markedly improved, improved, unchanged, aggravated or undeterminable. An overall evaluation was made by combining the above two. In this evaluation method, pamidronate therapy resulted in an evaluation of markedly improved in 2 patients, improved in 5, unchanged in 4 and aggravated in 1, demonstrating that the therapy was very useful as an alleviative treatment for the pain of bone metastases from breast cancer. The evaluation method, in which pain, a subjective complaint, is combined with use of analgesics, an objective factor, and to which radiological evaluation is added for further objectively, may in the future to be applicable for evaluation of various alleviative treatments of pain of bone metastases.

Adult↗
PubMed1999

High expression of macrophage migration inhibitory factor in human melanoma cells and its role in tumor cell growth and angiogenesis.

Macrophage migration inhibitory factor (MIF) is known to function as a cytokine, hormone, and glucocorticoid-induced immunoregulator. In this study, we reported for the first time that human melanocytes and melanoma cells express MIF mRNA and produce MIF protein. Immunohistochemical analysis demonstrated that MIF was mostly localized in the cytoplasm of melanocytes and G361 cells, a widely available human melanoma cell line. In particular, strong positive staining was observed at the dendrites of these cells. Expression of MIF mRNA and production of MIF protein were much higher in human melanoma cells such as G361, A375, and L32 than in normal cultured melanocytes. To assess the role of MIF overexpression in melanoma cells, G361 cells were transfected with an antisense human MIF plasmid. The results demonstrated that the cell growth rate of the transfected cells was markedly suppressed, suggesting that MIF participates in the mechanism of proliferation of melanoma cells. To further evaluate the function of MIF, we employed the Boyden chamber method to examine the effect on tumor cell migration and found that MIF enhanced the migration of G361 cells in a dose-dependent manner. Furthermore, we administered anti-MIF antibody into tumor (G361 cells in a Millipore chamber)-bearing mice to assess the effect on tumor-associated angiogenesis. The anti-MIF antibody significantly suppressed tumor-induced angiogenesis. Taken together, these results indicated that it is likely that MIF may function as a novel growth factor that stimulates incessant growth and invasion of melanoma concomitant with neovascularization.

Animals↗
PubMed1999

Cytotoxic T lymphocyte antigen 4 (CTLA-4) engagement delivers an inhibitory signal through the membrane-proximal region in the absence of the tyrosine motif in the cytoplasmic tail.

Cytotoxic T lymphocyte antigen 4 (CTLA-4) is a T cell costimulation receptor that delivers inhibitory signals upon activation. Although the tyrosine-based motif ((165)YVKM) within its cytoplasmic tail has been shown to associate in vitro with Src homology 2 domain-containing tyrosine phosphatase (SHP-2) and phosphatidylinositol 3 kinase upon phosphorylation, the mechanism of negative signaling remains unclear. Here, we report a new mechanism of negative signaling based on the analysis of murine T cell clones transfected with various mutants of CTLA-4. Upon T cell activation by cross-linking with anti-CD3 and anti-CD28 antibodies, CTLA-4 engagement inhibited both proliferation and interleukin 2 production in tyrosine mutants as well as in wild-type CTLA-4 transfectants. Furthermore, the mutant CTLA-4 lacking most of the cytoplasmic region strongly suppressed interleukin 2 production as well. These data suggest that negative signals by CTLA-4 could be mediated through the membrane-proximal region of CTLA-4 but not through the YVKM motif and that the association of CTLA-4 with SHP-2 is not required for CTLA-4-mediated suppression of T cell activation.

Abatacept↗
PubMed1999

CD28 costimulation accelerates IL-4 receptor sensitivity and IL-4-mediated Th2 differentiation.

The development of Th1 and Th2 cells is determined by the type of antigenic stimulation involved in the initial cell activation step. Evidence indicates that costimulatory signals, such as those delivered by CD28, play an important role in Th2 development, but little is known about how CD28 costimulation contributes to Th2 development. In this study, TCR cross-linking was insufficient for Th2 development, while the addition of CD28 costimulation drastically increased Th2 generation through the IL-4-mediated pathway. Th2 generation following CD28 costimulation was not simply explained by the enhancement of IL-4 production in naive T cells. To generate Th2 cells after TCR cross-linking only, it was necessary to add a 20- to 200-fold excess of IL-4 generated after TCR and CD28 stimulation. TCR cross-linking increased the expression level and binding property of the IL-4R, but enhanced the sensitivity to IL-4 only slightly. In contrast, as evidenced by the enhanced phosphorylation of Jak3, the IL-4Ralpha-chain, and STAT6 following IL-4 stimulation, CD28 costimulation increased IL-4R sensitivity without affecting its expression and binding property. This evidence of the enhancement of IL-4R sensitivity increases our understanding of how CD28 costimulation accelerates Th2 development.

Adjuvants, Immunologic↗
PubMed1999

Histopathological Predictors of Axillary Lymph Node Metastases in Patients with Breast Cancer.

BACKGROUND: A tumor 30 mm or less in diameter is a standard candidate for breast conserving surgery (BCS) in Japan. Axillary lymph node metastases (ALNM) is the most important prognostic factor for survival in patients with breast cancer, but the role of axillary node dissection has been controversial. Histopathological predictive factors of axillary lymph node involvement have not been established. The purpose of this study was to determine the association between the incidence of ALNM and histopathological factors by univariate and multivariate analysis METHODS: Sixty-five patients with noninvasive ductal carcinoma, and 993 patients with tumors 30 mm or less in diameter who underwent axillary dissection between 1988 and 1997 at our institute were reviewed. The association between ALNM and 13 histopathological factors (size, age, histological subtype, histological invasiveness, lymphatic invasion, vascular invasion, macroscopic classification, histological daughter mass, ductal spread, ER, PgR, p-53, and c-erbB-2) were analyzed by univariate and, when significant, by multivariate analysis. RESULTS: Only one patient with noninvasive ductal carcinoma had ALNM, and 33.1% of 993 patients with a tumor 30 mm or less in size had ALNM. Multivariate analysis identified six factors as independent predictors for ALNM: lymphatic invasion, size, histological invasiveness, macroscopic classification, age and histological daughter mass. CONCLUSION: Axillary lymph node dissection can be omitted in patients with noninvasive ductal carcinoma. Histopathological features of tumors 30 mm or less in diameter can be used to estimate the risk of ALNM, and routine axillary node dissection might be spared in selected patients at minimal risk of ALNM, if the treatment decision is not influenced by lymph node status, such as in elderly patients.

Journal Article↗
PubMed1999

A Case of Breast Cancer Metastatic to the Head of the Pancrea.

A case of breast cancer that metastasized to the head of the pancreas 6 yearsand 8 months after mastectomy is reported. The pancreas head metastasis was associated with general fatigue and obstructive jaundice. The serum levels of CEA, CA15-3 and NCC-ST-439, tumor markers of breast cancer, were within normal limits, but CA15-3 was immunohistochemically demonstrated in the resected metastatic lesion, in a manner similar to lobular carcinoma of the breast.

Journal Article↗
PubMed1999

Cooperative interaction of NF-kappaB and C/EBP binding sites is necessary for manganese superoxide dismutase gene transcription mediated by lipopolysaccharide and interferon-gamma.

Expression of the manganese superoxide dismutase (Mn-SOD) is induced by pro-inflammatory cytokines. We investigated the cis-acting elements within a tumor necrosis factor-responsive element (TNFRE) which was identified in the second intron of the murine Mn-SOD gene. Site-directed mutagenesis, reporter plasmid transfection studies and electrophoretic mobility shift assays demonstrated that inducible transcription factors enhanced the transcriptional activity of the Mn-SOD gene through the TNFRE. The cooperation between proteins binding to the newly identified NF-kappaB and C/EBP sites led to synergistic gene transcription. This report provides the first evidence that cooperation between two distinct cis-acting elements may be required for induction of Mn-SOD gene expression mediated by lipopolysaccharide and interferon-gamma.

3T3 Cells↗
PubMed1999

ZAP-70 protein promotes tyrosine phosphorylation of T cell receptor signaling motifs (ITAMs) in immature CD4(+)8(+) thymocytes with limiting p56(lck).

As a result of interaction with epithelial cells in the thymic cortex, immature CD4(+)8(+) (double positive, DP) thymocytes express relatively few T cell receptors (TCRs) and contain diminished numbers of coreceptor-associated p56(lck) (lck) PTK molecules. As a result, TCR signal transduction in DP thymocytes is significantly impaired, despite its importance for repertoire selection. We report here that, in DP thymocytes, tyrosine phosphorylation of TCR signaling motifs (ITAMs) by lck, an early event in TCR signal transduction, is dependent upon ZAP-70 protein independent of ZAP-70's kinase activity. Furthermore, the dependence on ZAP-70 protein for ITAM phosphorylation diminishes as available lck increases. Importantly, ZAP-70's role in ITAM phosphorylation in DP thymocytes is not limited to protecting phosphorylated ITAMs from dephosphorylation. Rather, this study indicates that ZAP-70 protein augments ITAM phosphorylation in DP thymocytes and so compensates in part for the relative deficiency of coreceptor-associated lck.

Animals↗
PubMed1999

Endosalpingiosis of nonmetastatic lymph nodes along the stomach in a patient with early gastric cancer: report of a case.

We report herein the case of a 32-year-old woman who underwent distal gastrectomy with D2 lymph node dissection for gastric cancer. Microscopic examination of the resected specimen revealed signet-ring cell carcinoma of the stomach with lymph node metastases, and endosalpingiosis in the normal lymph nodes. There was no evidence of malignancy in the peritoneal cavity. To our knowledge, no other case of endosalpingiosis in the lymph nodes along the stomach has ever been reported. The possible significance of endosalpingiosis is discussed following this case report.

Adult↗
PubMed1999

Stomal recurrence invading the cervicothoracic esophagus and upper mediastinum: resectability and the creation of a safe anterior mediastinal tracheostoma.

Surgical salvage for stomal recurrence is a for midable problem for head and neck surgeons. The two factors of considerable significance are resectability and establishment of a safe anterior mediastinal tracheostoma. A case of stomal recurrence invading the cervicothoracic esophagus and upper mediastinum is presented. Total esophagectomy and upper mediastinal dissection was performed. The esophagus was reconstructed immediately with a pedicled gastric flap. The omentum on the gastric pedicle was wrapped around the trachea to reduce the likelihood of erosion into the great vessels and to supplement the lateral blood supply to the trachea. No serious postoperative complications were observed. We believe that the total esophagectomy improved the resectability, and that the bulk of the gastric pedicle and the use of the omentum prevented significant postoperative complications associated with an anterior mediastinal tracheostoma.

Anastomosis, Surgical↗
PubMed1999

Increased production of macrophage migration inhibitory factor by PBMCs of atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disorder. The underlying cause of AD is multifactorial, and several cytokines are considered to be involved in this severe inflammatory skin disease. Macrophage migration inhibitory factor (MIF) is an immunoregulatory cytokine essential for T-cell activation and delayed-type hypersensitivity. Recently we demonstrated that serum MIF content was significantly elevated in patients with AD. Consistent with this, expression of MIF messenger RNA in keratinocytes of the eczematous skin lesion was up-regulated. OBJECTIVE AND METHOD: Although keratinocytes are considered to be a potential source of increased serum MIF content in AD, precise evaluation has not been carried out in other tissues. MIF is ubiquitously expressed in various cells, including T cells and macrophages. In this study we examined MIF production and its messenger RNA level of PBMCs from patients with AD to investigate the contribution of these cells to elevated serum MIF content and to its pathologic characteristics. RESULTS: Consistent with our previous findings, the serum MIF content of patients with AD was significantly elevated compared with nonatopic healthy control subjects and patients with chronic urticaria without eczema. As for the MIF productivity of unstimulated PBMCs, the MIF content in the culture medium of PBMCs obtained from patients with AD (40.4 +/- 8.4 ng/mL) (mean +/- SEM) was significantly increased compared with that from healthy control subjects (6.6 +/- 1.1 ng/mL) and patients with chronic urticaria (8.5 +/- 1.4 ng/ml) (P <.0001). When PBMCs were stimulated by concanavalin A, MIF production by PBMCs of patients with AD was more enhanced than in control subjects or patients with chronic urticaria. The increased ratio of MIF production by PBMCs in response to concanavalin A was significantly correlated with the severity of clinical features of AD. Supporting these results, the level of MIF mRNA in PMBCs of patients with AD was significantly higher than in nonatopic healthy control subjects. CONCLUSIONS: The current results showed that PBMCs should be an important source of increased serum MIF in AD. Because MIF has the potential to induce local and systemic inflammatory and immune responses, it is conceivable that MIF produced by PBMCs may affect local and systemic pathologic features in AD.

Adolescent↗
PubMed1999

Distribution of sialic acid-dependent carbohydrate epitope in thyroid tumors: immunoreactivity of FB21 in paraffin-embedded tissue sections.

The reactivity of monoclonal antibody FB21, which recognizes a sialic acid-dependent carbohydrate epitope, was tested with 94 non-neoplastic and neoplastic thyroid tissue specimens using immunohistochemical methods on formalin-fixed, paraffin-embedded tissue sections. These specimens included 11 cases of adenomatous goiter, three cases of Basedow's disease, 30 cases of follicular adenoma, 20 cases of papillary carcinoma, 15 cases of follicular carcinoma, six cases of medullary carcinoma, and nine cases of anaplastic carcinoma. FB21 reacted with 14 of 15 cases of follicular carcinoma that showed a microfollicular or trabecular pattern, and with nine of 20 cases of papillary carcinoma. A positive reaction was found on the cell surface membranes or apical parts of neoplastic follicles. FB21 also reacted with five of 30 cases of follicular adenoma. These cases showed a follicular pattern and positive staining pattern similar to that in follicular carcinoma. Adenomatous goiters, Basedow's disease, medullary carcinomas, and anaplastic carcinomas were negative for FB21 reactivity. Although the different reactivities of FB21 with papillary carcinoma and follicular carcinoma remain to be investigated, the high frequency of reactivity with FB21 suggests that it may be useful as a complement to morphological diagnosis in follicular carcinoma.

Adenoma↗
PubMed1999

Ultraviolet B radiation upregulates the production of macrophage migration inhibitory factor (MIF) in human epidermal keratinocytes.

Human epidermal cells are capable of secreting various cytokines with immunologic, inflammatory, and proliferative properties. In a previous study, by reverse transcription-polymerase chain reaction and immunohistochemical analysis, we have shown that human epidermal keratinocytes express macrophage migration inhibitory factor and identified its presence in the cytoplasm. In this study, we detected an increased serum macrophage migration inhibitory factor level by enzyme-linked immunosorbent assay after a single total-body ultraviolet B exposure in vivo, indicating that human keratinocytes respond and release this cytokine in response to ultraviolet B irradiation. Moreover, we evaluated the effect of ultraviolet B on migration inhibitory factor production in cultured human epidermal keratinocytes and epidermal sheets. The results of enzyme-linked immunosorbent assay and northern blot analyses showed that migration inhibitory factor production of cultured keratinocytes was increased by ultraviolet B exposure. During the past few years, migration inhibitory factor was found to have a variety of biologic functions, such as being essential for T cell activation and induction of inflammatory cytokines. In this context, these results should encourage further investigation on the pathophysiologic role of migration inhibitory factor in cutaneous inflammatory reactions and immune responses.

Cell Survival↗
PubMed1999

Ictal catatonia as a manifestation of de novo absence status epilepticus following benzodiazepine withdrawal.

To describe ictal catatonia as a manifestation of de novo absence status epilepticus following benzodiazepine withdrawal. Ictal catatonia was documented by concurrent EEG recordings. A catatonic syndrome, first diagnosed as a psychogenic reaction, was found to be an ictal event by EEG recording. De novo absence status and benzodiazepine withdrawal should be considered when a catatonic syndrome suddenly occurs in elderly patients.

Aged↗
PubMed1999

A randomized controlled comparative study of oral medroxyprogesterone acetate 1,200 and 600 mg in patients with advanced or recurrent breast cancer.

A randomized controlled comparative study of oral medroxyprogesterone acetate (MPA) 1,200 mg (arm I) and 600 mg (arm II) was conducted in 80 patients with advanced or recurrent breast cancer. There were no significant differences between arm I and arm II in terms of response rate, duration of response and survival, or in terms of incidence and severity of adverse reactions. The lowest serum MPA concentration in responders tended to be higher than that in nonresponders. In the cohort of this study, the lowest concentration in partial response was 17.4 ng/ml, suggesting that this level may be the required minimum serum concentration.

Antineoplastic Agents, Hormonal↗
PubMed1999

Characterization of chimeric enzymes constructed between two distinct alpha-amylase cDNAs from cultured rice cells.

Cultured cells of rice (Oryza sativa cv Sasanishiki) produce two alpha-amylase isozymes, AMY-I and AMY-III. Using a bacterial expression system, eight chimeric genes constructed with various combination of AMY-I and AMY-III cDNA fragments were expressed, and each recombinant chimeric protein was characterized. Four of the eight recombinant enzymes having region c (one of the four regions having unconserved base sequences between AMY-I and AMY-III cDNAs) of AMY-I showed the same enzyme characteristics as that of native AMY-I, which had high temperature optimum at 50 degrees C. The other four chimeric proteins carrying region c of AMY-III showed the AMY-III type characteristics, which were a low temperature optimum at 25 degrees C and susceptibility to a higher maltooligosaccharide (G17) substrate. The unconserved region c is involved in the decision of the characteristic of AMY-I or AMY-III.

Amino Acid Sequence↗