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Biomedical subjects

S Suehiro

Publications and source records attributed to S Suehiro.

At least 91 records · Page 5Linked to original sources
PubMed1993

Lysosomal glycosphingolipid storage in chloroquine-induced alpha-galactosidase-deficient human endothelial cells with transformation by simian virus 40: in vitro model of Fabry disease.

Human umbilical venous endothelial cells were transformed with a temperature-sensitive mutant of simian virus 40, tsA640, and a cell line, subcultured for over 20 serial passages, was established at a temperature permissive for the virus. Treatment of transformed endothelium with 3 micrograms/ml chloroquine caused a specific reduction of alpha-galactosidase activity, without cell injury, and revealed several electron-dense materials surrounded by single unit membranes. Crystalline lamellae in lysosomes with a periodicity of 6.5 nm, which are typically seen in various tissues in Fabry disease, were produced in the presence of a glycosphingolipid mixture. These cells should be useful for in vitro pathophysiological studies on Fabry endothelium.

Cell Transformation, Viral↗
PubMed1993

2-Buten-4-olide (2-B4O) inhibits type II collagen-induced arthritis in Lewis rats.

2-Buten-4-olide (2-B4O) is an endogenous substance which suppresses appetite and/or food intake. We studied its effect on type II collagen-induced arthritis (CIA) in Lewis rats, an animal model for human rheumatoid arthritis. Bovine type II collagen with incomplete Freund's adjuvant was injected intradermally into Lewis rats to induce CIA. 2-B4O (50 or 100 mg/kg) significantly inhibited the expression of the clinical symptoms when administered i.p. daily from day 1 to 21 after immunization. Furthermore, administration of 2-B4O daily from day 15 to 21 significantly reduced the severity of symptoms in established CIA. In addition, the progression of soft tissue swelling and articular bone erosions were suppressed by daily administration of 2-B4O. 2-B4O also significantly suppressed the delayed-type hypersensitivity (DTH) response to type II collagen at doses of 50 and 100 mg/kg. Finally 2-B4O significantly inhibited the formation of anti-type II collagen antibody at a dose of 100 mg/kg, but not at 50 mg/kg. These results suggest that 2-B4O has the strong inhibitory effects and therapeutic usefulness effects on CIA through the suppression of immune responses to type II collagen.

4-Butyrolactone↗
PubMed1993

[Pathologic changes at the coronary artery-bypass graft anastomosis--an immunocytochemical study].

We have performed immunocytochemical investigations on proliferative tissues observed in anastomotic sites of the saphenous vein aortocoronary bypass grafts to the coronary arteries. Nine anastomotic sites were obtained from 5 necropsy patients who had died after bypass grafting. Interval between the operation and death in these patients varied from 5 days to 9 months. The anastomotic sites were fixed in methanol-Carnoy's fixative, and embedded in paraffin. Six monoclonal antibodies specific for muscle cell actin (HHF35), smooth muscle cell actin (CGA7), vimentin, desmin, macrophages (HAM56) and endothelial cells were used for the immunocytochemical study. Of the 9 anastomotic sites, 4 were totally occluded, while the remaining 5 were patent. The occluded sites were characterized by a presence of fresh or organized thrombus. Immunocytochemically, the latter was composed of macrophages, smooth muscle cells and neovascularization. In contrast, a patent site at 5 days after grafting showed an early stage of intimal proliferation composed of macrophages and spindle-shaped cells. Two patent sites at 33 days after grafting revealed a distinct intimal thickening consisting almost entirely of smooth muscle cells. At this stage, smooth muscle cells at a deeper intima were stained positive with both HHF35 and CGA7, whereas the cells at the luminal site were stained positive with HHF35 but negative with CGA7. In older lesion at 9 months after grafting, almost all smooth muscle cells within intimal thickening showed positive with HHF35 and CGA7. Moreover, these smooth muscle cells were stained positive with vimentin but were negative with desmin, irrespective of the lesion's age.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[A case of thymic cyst & thymolipoma with ocular myasthenia gravis].

A 65-year-old woman with ocular myasthenia gravis (MG) and thymic tumor underwent expanded thymectomy. Histologically the tumor was thymic cyst and thymolipoma. To our knowledge, there has been no case reported in medical literatures, which is thymic cyst & thymolipoma with ocular MG. This case suggests some effect of steroid therapy.

Aged↗
PubMed1992

Effect of Neurotropin on the activation of the plasma kallikrein-kinin system.

Bradykinin (BK), an important mediator of allergic reactions and pain induction, is released by the activation of the plasma kallikrein-kinin (K-K) cascade. Neurotropin is a biological material obtained from inflamed rabbit skin inoculated with vaccinia virus and is widely used clinically in Japan as an effective agent for these disorders. Since its mechanism of action is not clearly known, we have investigated the effects of Neurotropin on the human plasma K-K system. In dextran sulfate-activated plasma, Neurotropin inhibited the formation of BK, the cleavage of high molecular weight kininogen (HK) and the formation of kallikrein-C1 inhibitor and activated coagulation factor XII (FXIIa)-C1 inhibitor complexes. Experiments using purified enzyme of the K-K cascade indicated that Neurotropin inhibited surface-mediated activation of coagulation factor XII (FXII) and the activation of prekallikrein by FXIIa. Neurotropin also inhibited the binding of FXII and HK to the activating surface. These data suggest that the ameliorating effects of Neurotropin in allergic disorders and pain syndromes may be related to this ability to inhibit activation of the K-K cascade and consequently the formation of BK.

Animals↗
PubMed1992

Changes in thrombomodulin level in plasma of endotoxin-infused rabbits.

Changes in the plasma thrombomodulin (TM) level were examined in endotoxin-infused rabbits. The plasma TM level in normal rabbits was 143.8 +/- 8.4 ng/ml (n = 67) and the molecular weight of the major TM was about 55 kd. Endotoxin (lipopolysaccharide, LPS, E. Coli B8:0127) was intravenously infused. LPS infusion increased the plasma TM level dose-dependently between 0.2 mg/kg and 5 mg/kg. When 5 mg/kg LPS was infused, the plasma TM level started to increase immediately and was 2.3 times higher than the control value within 1 hr. The molecular weight of the major TM was about 75 kd. This rapid increase in TM occurred before the decrease in fibrinogen content and the prolongation of prothrombin time. To examine the effect of circulating leukocytes on the TM increase in endotoxin-infused rabbits, 5 mg/kg LPS was infused into rabbits with leukocytopenia induced by X-ray irradiation. The maximum plasma level of TM was significantly lower than in the untreated rabbits given LPS. These data suggest that the increase in plasma TM is caused by LPS-stimulated leukocyte's prior to hemostaseological changes. It is well known that endothelial cells can be injured by stimulated leukocytes, so this increase in plasma TM probably reflects the deterioration of endothelial cells. This deterioration decreases the ability of endothelial cells to inhibit thrombosis, which would, in turn, contribute to the development of disseminated intravascular coagulation in endotoxin-infused rabbits.

Animals↗
PubMed1992

A simple assay to detect endothelial cell injury; measurement of released thrombomodulin from cells.

A simple assay to determine the degree of endothelial cell injury has been developed using released thrombomodulin as the index. Thrombomodulin is a cell surface protein on endothelial cells which is released from the cell upon injury. In this assay, bovine arterial endothelial cells were cultured in serum free medium with the test substances and the amount of thrombomodulin released into the culture medium was measured by enzyme immunoassay. Substances which are known to injure cells such as H2O2, prostaglandin A2, lipopolysaccharide, and elastase released significant amounts of thrombomodulin. The sensitivity of this assay for mild injury was superior or at least equal to the traditional 51Cr release method. Since this method does not require the use of radioisotopes, it seems to be advantageous and suitable for the detection of endothelial cell injury during routine examination.

Animals↗
PubMed1992

Detection of HIV-1 RNA in heparinized plasma of HIV-1 seropositive individuals.

The interference of reverse transcription by heparin was removed by heparinase. When the HIV-1 RNA in the presence of heparin was detected by a combination of reverse transcription and the polymerase chain reaction (PCR), heparinase treatment followed by removal of Ca2+ before the reverse transcription step permitted the efficient detection of HIV-1 RNA. Prior treatment with heparinase revealed HIV-1 RNA in 68% (13/19) of heparinized plasma samples from HIV-1 carriers, whereas only 26% (5/19) of the same specimens were positive without the heparinase step. Heparinase removed the inhibition of reverse transcription by heparin and is highly recommended when detecting low levels of viral RNA in heparinized plasma.

HIV Reverse Transcriptase↗
PubMed1992

Stress and murine NK cell function: the role of blood loss.

It has been previously reported that NK cell function decreases following surgery in mice. To explore the basis of this observation, we compared the relative influence of anesthesia, surgical amputation and bleeding on NK cell cytotoxicity in C57BL/6 mice. After hind limb amputation, including with blood loss, there was a statistically significant decrease in NK cell cytotoxicity and the appearance of splenomegaly on the 4th day postoperative day. The increase in spleen size appeared to be due to either the surgical stress-induced expansion of splenic erythroblasts or erythroblast generation following blood loss. In contrast, if blood loss was minimal there was no suppression of NK cell cytotoxicity following hind limb amputation. Moreover, there was a statistically significant correlation of NK cell activity and the quantitation of total blood loss. Interestingly, the decrement in NK cell activity was not observed if blood transfusion was made, even in the presence of surgical amputation. These observations are important for defining the immune suppression reported following surgery and suggest that in human, chronic blood loss may also be associated with immune suppression.

Anesthesia↗
PubMed1992

Characterization of monoclonal IgG antibodies produced by hybridomas derived from rheumatoid synovial cells.

IgM rheumatoid factors (RF) are the predominant autoantibody found in rheumatoid arthritis. They are polyclonal, fix complement, and are directed against epitopes in the Fc portion of IgG. One hypothesis regarding the induction and persistence of RF production in rheumatoid arthritis is that the Fc of IgG is somehow altered, rendering it antigenic. In this study, to better understand the derivation and pathogenicity of RF in rheumatoid arthritis, monoclonal IgG (mIgG) constitutively secreting hybridomas were established by fusing rheumatoid synovial mononuclear cells (RSC) from patients with a mouse/human heteromyeloma cell line, F3B6. To clarify the primary structure of IgG Fc constant regions produced locally by RSC, we amplified the cDNA corresponding to the CH2 and CH3 domains of an IgG1-, IgG2-, and an IgG3-producing hybridoma derived from RSC. The amplified DNA segments were cloned in M13 vectors and sequenced. Interestingly, very few differences in the nucleotide sequences were observed, and the deduced amino acid sequences were identical, except for the allotype, with those encoded by the human germline genes GEA and CL. Thus, the primary structure of the IgG1, IgG2, and IgG3 Fc regions produced by RSC were not altered when compared with those encoded by the unmutated human germline gene. These results suggest that factors other than altered IgG induce and sustain high avidity RF production in rheumatoid arthritis.

Amino Acid Sequence↗
PubMed1991

Suppression of acute experimental allergic encephalomyelitis by neurotropin: clinical, histopathologic, immunologic and immunohistochemical studies.

The effect of neurotropin, an extract isolated from the inflamed skin of rabbits inoculated with Vaccinia virus was examined on acute experimental allergic encephalomyelitis (EAE) in Lewis rats. A dose of 40 mg per kg body weight of neurotropin was administered intraperitoneally for 7 days post-inoculation. The severity of clinical signs of acute EAE was decreased by the administration of neurotropin. Histopathologic evaluation showed that lesion severity of EAE in neurotropin-treated rats was less than that seen in untreated rats. Blood lymphocyte subset analysis revealed that in comparison to untreated EAE rats, in neurotropin-treated rats, the percentage of OX6+ (Ia antigen) cells was lower and the W3/25+ (helper T cell): OX8+ (suppressor/cytotoxic T cell) cell ratio was greater during the period of peak inflammation. Immunohistochemical examination of neurotropin-treated rats demonstrated that OX6+ and W3/25+ cells within EAE lesions were fewer and that OX8+ cells in lesions occurred in greater numbers than those in untreated rats. These findings suggest that the OX8+ cells in the inflammatory lesions may have been induced by neurotropin treatment and that the suppressive effects on the disease may have been causally related to their presence.

Acute Disease↗
PubMed1991

Restorative effect of neurotropin on maturation of bone marrow cells to IL-2-producing T-cells in aging BALB/c mice.

In a previous paper, we have demonstrated that Neurotropin, a non-protein extract isolated from the inflamed skin of rabbits inoculated with vaccinia virus, restores decreasing immune responses through the recovery of interleukin-2 (IL-2) production in aging BALB/c mice. To clarify the mechanism by which Neurotropin restores IL-2 production, its effect on the recruitment of IL-2-producing T-cells from bone marrow cells was examined using syngenic radiation bone marrow chimeras. Two fundamental lesions in recruiting IL-2-producing T-cells in aging BALB/c mice were demonstrated: (1) a drastic decline of the maturation of bone marrow cells to IL-2-producing T-cells as demonstrated by old----young chimeras; and (2) an environment unable to support bone marrow cell differentiation to IL-2-producing T-cells by young----old chimeras. Neurotropin clearly restored the maturation of bone marrow cells to IL-2-producing T-cells when administered from 13 to 16 month-old mice, whereas the non-complementing environment was not normalized with Neurotropin administration. These results suggest that Neurotropin administration restores IL-2 production through the recovery of the maturation of bone marrow cells to IL-2-producing T-cells, resulting in restoration of in vivo T-cell immune response in aging BALB/c mice.

Adjuvants, Immunologic↗
PubMed1991

Neurotropin inhibits experimental allergic encephalomyelitis (EAE) in Lewis rats.

The effects of Neurotropin, a substance extracted from the inflammatory dermis of rabbits inoculated with Vaccinia virus, for experimental allergic encephalomyelitis (EAE) in Lewis rats, a model for human multiple sclerosis (MS), was studied. The peptide defined by residues 68-84 (MB 68-84) which corresponds to the encephalitogenic portion of the guinea pig myelin basic protein (MBP) in complete adjuvant H37Ra (CFA) was injected into the hind foot pad of each rat. Neurotropin significantly suppressed the clinical and histological expression of actively induced EAE when administered i.p. daily from day 0 to day 6 after immunization. In addition, passive EAE induced by precultured spleen cells from rats immunized with MB 68-84 in CFA was also suppressed by daily administration of Neurotropin after cell transfer. Neurotropin treatment significantly suppressed the delayed-type hypersensitivity (DTH) response to MB 68-84. Furthermore, the ability of spleen cells from Neurotropin-treated rats to transfer EAE was significantly lower than that of saline-treated rats. It seemed that the suppression may be due to the inhibition of the activation by MB 68-84 of sensitized spleen cells, as demonstrated by proliferative response to MB 68-84. However, no difference was observed in Con A-induced proliferative response of the spleen cells between Neurotropin- and saline-treated rats. These findings indicate that Neurotropin inhibits EAE by suppressing the immune responses to encephalitogenic MBP with little non-specific suppression.

Animals↗
PubMed1990

Nuclear DNA content in breast carcinoma with special reference to the parameters of malignant potentiality.

Nuclear DNA ploidy pattern was examined in 22 breast carcinomas with a tumor mass of up to 2.2 cm and compared with the clinical and histological parameters of the malignant potentiality of breast carcinomas. The 22 carcinomas were divided into 11 aneuploid and 11 near-diploid carcinomas. It was found that the histological type, histological grade, nuclear grade, mitotic index and lymphatic invasion were either only slightly, or not correlated at all with the DNA ploidy pattern. Nevertheless, lymph node metastasis and negative estrogen receptor status was more frequently seen in the patients with aneuploid carcinoma than in those with near-diploid carcinoma.

Breast Neoplasms↗
PubMed1990

Study on pruritus in hemodialysis patients and the antipruritic effect of neurotropin: plasma levels of substance P, somatostatin, IgE, PTH and histamine.

It has been reported that Neurotropin can markedly improve pruritus in patients undergoing hemodialysis (HD). In order to elucidate the probable causes of pruritus and the antipruritic effect of Neurotropin, various biochemical parameters in the plasma of patients before and during HD were investigated. Forty-three patients undergoing HD were divided into three groups. Eighteen patients had suffered no episode of pruritus (group A), 17 patients had on-going pruritus (group B) and the remaining 8 patients had experienced improvement of pruritus following Neurotropin treatment (group C). The mean concentration of substance P was in only B group significantly increased with HD only in B group, indicating that substance P could be one of the causes of pruritus in patients undergoing HD. Neurotropin appears to exert its antipruritic effect by lowering the level of substance P. The change in parathyroid hormone (PTH) level during HD was not significant in any of the groups, but the mean concentration of PTH in group B was higher than that of group A, indicating that PTH may also be one of the causes of pruritus.

Adjuvants, Immunologic↗
PubMed1989

Immunocytochemical and biochemical analysis of epidermal growth factor receptor expression in human breast cancer tissues: relationship to estrogen receptor and lymphatic invasion.

Expression of epidermal growth factor receptor (EGFR) and estrogen receptor (ER) was examined by an immunocytochemical assay (ICA) using serial cross-sections of human breast cancer tissues. Immunocytochemical results were compared with those obtained by biochemical competitive binding assay and with histological lymphatic invasion. EGFR was evaluated as positive in 17 (34.0%) out of 50 primary tumors by ICA. A significant inverse relationship of the proportion of stained cells between EGFR and ER was demonstrated. In more than one-half of the tumors that were positive for both EGFR and ER, these 2 receptors were inversely stained in relation to the distribution. In ER-negative cells, EGFR expression was more marked than in ER-positive cells. Biochemical data confirmed the immunocytochemical results, pointing to an inverse relationship between EGFR and ER content. EGFR status correlated well with the degree of lymphatic invasion but not with the number of lymph nodes with metastases.

Breast Neoplasms↗