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Biomedical subjects

S Haraguchi

Publications and source records attributed to S Haraguchi.

At least 19 recordsLinked to original sources
PubMed2001

Involvement of a herbimycin A-sensitive protein tyrosine kinase in extracellular action of HIV-1 Nef.

Extracellular Nef which has been implicated in disease progression and development of AIDS induces IL-10, a potent immunosuppressive cytokine, in vitro. The present study was designed to examine whether the action of extracellular Nef is a protein tyrosine kinase (PTK)-dependent event. Anti-phosphotyrosine immunoblotting reveals that recombinant HIV-1 Nef induces rapid tyrosyl phosphorylation of several cellular proteins in human peripheral blood mononuclear cells. Pre-treatment of cells with herbimycin A, but not with genistein, significantly abolishes the Nef-induced tyrosine phosphorylation of cellular proteins. Furthermore, ELISA and RNase protection assays show that herbimycin A significantly blocks Nef-induced production of IL-10 at both the protein and the mRNA level. Genistein and aminogenistein have a much less blocking effect on the ability of Nef to induce IL-10. These results provide evidence for the involvement of a herbimycin A-sensitive PTK in the signal transduction pathway for exogenous HIV-1 Nef.

Benzoquinones↗
PubMed2000

Monocytes are target cells for IL-10 induction by HIV-1 Nef protein.

IL-10 plays a pivotal role in the pathogenesis of several diseases and is elevated in sera of HIV-infected patients. Recently, we demonstrated that HIV Nef induces IL-10 mRNA expression as well as IL-10 production using PBMCs, H9 or U937 cells. This induction of IL-10 is inhibited by a calmodulin antagonist, W-7. In the present study, T or B lymphocytes or monocytes were isolated from PBMCs of healthy HIV-negative donors. Production of IL-10 and mRNA gene expression were analyzed on each isolated cell population after treatment with Nef or SEA for 3-24 h. The results show that Nef induces IL-10 production as well as mRNA expression significantly using monocytes but not with T or B lymphocytes. By contrast, SEA induced IL-10 production as well as mRNA expression using T lymphocytes but not with monocytes or B lymphocytes.

Avian Proteins↗
PubMed2000

Effectiveness of prostaglandin E1 on pulmonary hypertension and right cardiac function induced by single-lung ventilation and hypoventilation.

It is known that prostaglandin E1 (PGE1) is a potent vasodilator and improves red cell deformability. Single lung-ventilation sometimes occurs under lung transplantation, lung cancer surgery and traumatic pneumonectomy, and may result in increased pulmonary resistance, right heart failure and severe hypoxemia. The present experimental study was undertaken to examine the effects of PGE1 on these states induced by single-lung ventilation and hypoventilation. Fourteen pigs weighing 32-33 kg were anesthetized, intubated and ventilated using a respirator and then randomly assigned to two groups, the control group and the PGE1 treated group, 7 pigs each. After median sternotomy to induce severe hypoxemia hypoventilation was induced and then the right hilus pulmonis was cross clamped. Mean blood pressure, mean pulmonary arterial pressure (PAP), pulmonary vessel resistance (PVR), right ventricular stroke work (RVSW) and arterial blood gases (PaO2 and SatO2) were measured at baseline, in the hypoventilation state, and 15 min, 1 hour, and 2 hours after the right hilus pulmonis clamping with hypoventilation. PGE1 (250 microg/20 ml saline) was administered via the central vein starting 15 min after right hilus cross clamping for 1 hour and 45 min in the PGE1 group. PGE1 significantly reduced PAP and PVR, normalized RVSW, and improved PaO2. PGE1 may be useful for the condition of increased pulmonary hypertension during single-lung ventilation and hypoventilation.

Alprostadil↗
PubMed1999

Phosphate exposure during the late 1-cell and early 2-cell stages induces a time-specific decrease in cyclin B and cdc25B mRNAs in AKR/N mouse embryos in vitro.

Phosphate induces 2-cell block in AKR/N mouse embryos in vitro. In an attempt to define the mechanism responsible for the inhibitory effect of phosphate, the critical period for this effect was determined. Then the amounts of the mRNAs for cyclin B and cdc25B, factors related to activation of M-phase promoting factor (MPF), were measured by quantitative reverse transcription-polymerase chain reaction. Exposure to phosphate during the late 1-cell (10-20 h after insemination) and early 2-cell stages (0-12 h after first cleavage) was found to induce 2-cell block in AKR/N mouse embryos. This period corresponds to the initiation of zygotic gene activation (ZGA). The presence of phosphate during second cleavage had no effect on 2-cell block of the embryos. The relative levels of cyclin B and cdc25B mRNAs did not change significantly during the 1-cell stage and decreased during the early 2-cell stage to almost half of the initial levels. When the amounts of mRNA in embryos cultured with and without phosphate were compared they were found to be almost identical even in the 2-cell block embryos, and a significant decrease in mRNA was observed only 33 h after insemination in embryos about to undergo phosphate block at the 2-cell stage. These results show that phosphate does not directly inhibit MPF activity and confirm the presence of cyclin B and cdc25B even in 2-cell block embryos. Furthermore, the fact that the decrease in mRNA levels corresponded to the critical period for the inhibitory effect of phosphate suggests that suppression of initial ZGA induction is involved in the 2-cell block of mouse embryos in vitro.

Animals↗
PubMed1999

Pulmonary carcinosarcoma: immunohistochemical and ultrastructural studies.

A case of pulmonary carcinosarcoma in a 68-year-old male patient is reported. The tumor in the resected left upper lobe extended mainly endobronchially, invading the normal bronchial lumina and mucosa. The carcinomatous component consisted of poorly differentiated squamous cell carcinoma and was mainly located in the periphery of the tumor nests. The sarcomatous component consisted of chondrosarcoma and was mainly located in the center of the tumor nests. Tumor cells in the sarcomatous component reacted with anti-S-100 protein antibody and were surrounded with abundant homogeneous extracellular matrix staining positively with Alcian blue. The transition from the carcinomatous component to the sarcomatous component appeared to be very smooth. The tumor cells in both the carcinomatous and sarcomatous components reacted with anti-epithelial membrane antigen antibody. Ultrastructurally, the tumor cells with tonofibrils in the carcinomatous component were apposed and connected to each other by desmosomes. By contrast, in the sarcomatous component, the tumor cells had well-developed and dilated rough endoplasmic reticulum and were arranged loosely in a myxomatous matrix. Some tumor cells in the sarcomatous component had occasional tonofibrils, and were apposed and connected to each other by desmosome-like structures. It is shown for the first time, ultrastructurally and immunohistochemically, that the tumor cells in the sarcomatous component of pulmonary carcinosarcomas have features of both epithelial and mesenchymal cells. It is suggested that the sarcomatous component in the present case is derived from the carcinomatous component.

Aged↗
PubMed1998

Interleukin 12 deficiency associated with recurrent infections.

A 3-yr-old female patient exhibited interleukin 12 (IL-12) deficiency that was associated with recurrent episodes of pneumococcal pneumonia with sepsis and other infections in the absence of fevers. The patient's peripheral blood mononuclear cells (PBMCs) exhibited normal proliferative responses to antigens. Immune responses, including in vivo production of antibodies to diphtheria, tetanus, or pneumococcal antigens, were normal. Ig levels and B cell and T cell phenotypes were also normal. In contrast, IL-12 p70 heterodimer production was undetectable by using supernatants of the patient's stimulated PBMCs when compared with control cells treated similarly. Although present, interferon gamma (IFN-gamma) was reduced. The addition of recombinant IFN-gamma to control cells enhanced the production of IL-12 by up to sixfold. By contrast, IL-12 was undetectable in supernatants of the patient's cells in the presence of recombinant IFN-gamma. IL-12 p40 subunit mRNA by using the patient's PBMCs after stimulation with Staphylococcus aureus Cowan strain 1 or lipopolysaccharide was also undetectable by reverse transcription-PCR when compared with control cells. Production of IL-2, IL-6, tumor necrosis factor alpha, or IFN-gamma of the patient's PBMCs after appropriate stimulation was observed. This patient has either a defect in Staphylococcus aureus Cowan strain 1-lipopolysaccharide- or staphylococcal enterotoxin A-induced signaling pathways for the activation of IL-12 p40 gene expression, or an abnormality in the IL-12 p40 gene itself.

Adolescent↗
PubMed1998

MAP kinase cascade, but not ERKs, activated during early cleavage of mouse embryos.

Mitosis in early embryos is independent of exogenous mitogens, although mitogen stimulations and subsequent activation of a mitogen-activated protein (MAP) kinase cascade are essential for the proliferation of somatic cells. The activation state of the MAP kinase cascade during early cleavage has never been reported. In the present study, factors involved in the MAP kinase cascade--Ras, Raf-1, 14-3-3, MEK, and ERKs--and their activation states were detected by immunoblotting during early cleavage of mouse embryos. We found the constant presence of these molecules in mouse early embryos and the activation of Raf-1 exclusively at the M-phase. An immunoprecipitation study revealed that active Raf-1 in the M-phase was dissociated from 14-3-3, as in somatic cells, whereas inactive Raf-1 was associated with 14-3-3. Surprisingly, the ERKs (MAP kinases) were not activated throughout early cleavage, although M-phase-specific activation of the MAP kinase kinase, MEK was observed. Myelin basic protein kinase activity was, however, significantly higher in the M-phase than in the interphase. These results indicate that the MAP kinase cascade is activated at the M-phase and that some MAP kinases other than ERKs are activated during early cleavage of mouse embryos.

14-3-3 Proteins↗
PubMed1998

Lobectomy by video-assisted thoracic surgery for primary lung cancer: experiences based on provisional indications.

A retrospective study on compromised patients who underwent a lobectomy by a standard thoracotomy for stage I non-small cell lung cancer revealed them to show a poor prognosis and quality of life due to their deteriorated physical conditions. Therefore, a lobectomy by video-assisted thoracic surgery (VATS lobectomy) was performed on some of these patients according to the provisional indications based on our retrospective study which indicated that it may be beneficial. Fourteen patients underwent VATS lobectomies (VATS group). Sixteen patients who underwent lobectomy by standard thoracotomy (ST group) were compared with those of the VATS group as historical controls. Although the mean operating time for the VATS group was longer than that for the ST group, there was no significant difference. The mean amount of blood loss for the VATS group was significantly less than that for the ST group. The mean maximal postoperative serum CPK level of the VATS group was slightly less than that of the ST group. A significant difference was observed regarding the changes in performance status both before and after operation between the VATS group and the ST group. We thus considered a VATS lobectomy to be beneficial for aged patients, especially in those with restricted physical conditions.

Aged↗
PubMed1998

Video-assisted thoracoscopic excision of a benign cystic mesothelioma of pleura.

We are reporting on the case of a 44-year-old woman upon which video-assisted thoracoscopic excision of a benign cystic mesothelioma of the pleura was performed. To our knowledge, this is the second report on a case of a benign cystic mesothelioma of the pleura. The cyst in our case was solitary and was easily excised. Microscopic examination revealed that the cyst was lined by a single layer of flattened and cuboidal cells. Immunohistochemical analysis revealed that the cells lining the cyst stained positively for keratin and negatively for factor VIII-related antigen. Benign cystic mesothelioma of the pleura was diagnosed based on histological findings. For seven months her condition has been monitored at our out-patient clinic with no signs of recurrence. However, continued careful observation is required because benign cystic mesothelioma often recurs locally. Local recurrence is thought to be related to incomplete resection of the tumor. Therefore, careful observations and techniques to ensure complete resection of the cyst, are important during video-assisted thoracoscopic surgery.

Adult↗
PubMed1998

Thoracoscopic enucleation of a submucosal bronchogenic cyst of the esophagus: report of two cases.

Thoracoscopic enucleation of a bronchogenic cyst of the esophagus was successfully performed in two cases. The first patient was a 26-year-old female complaining of dysphagia and retrosternal discomfort. The second patient was a 56-year-old female complaining of retrosternal discomfort. A close examination revealed a cystic lesion compressing the esophagus in both cases. Three trocars were employed under general anesthesia. Thoracoscopy offering excellent visualization allowed us to perform a precise anatomical dissection between the muscle layer and the mucosa. Both patients recovered uneventfully and the symptoms disappeared postoperatively. Thoracoscopic surgery is thus considered to be beneficial for the treatment of a benign esophageal tumor because of the small chest wall entry, which might positively contribute to a favorable postoperative course.

Adult↗
PubMed1997

Prolactin, epidermal growth factor or transforming growth factor-alpha activate a mammary cell-specific enhancer in mouse mammary tumor virus-long terminal repeat.

Mammary specific expression of elevated levels of mouse mammary tumor virus (MMTV) contributes to mammary carcinogenesis. Mechanisms which regulate provirus expression have not been completely defined. Using a MMTV-long repeat terminal (MMTV-LRT) directed chloramphenicol-acetyltransferase (CAT) reporter gene system and a human breast cancer cell line T47D, we demonstrate that prolactin (PRL), epidermal growth factor (EGF), or transforming growth factor-alpha (TGF-alpha) act on a mammary cell-specific enhancer at the extreme 5' end of the MMTV-LTR involving sequences -1094 through -858. PRL and either EGF or TGF-alpha exert concerted roles in this activation of these sequences. In contrast, using a plasmid construct lacking this mammary cell-specific enhancer, EGF or TGF-alpha, but not PRL, act synergistically with progesterone to induce CAT activity, indicating that the action of PRL on regulatory elements of the MMTV-LTR is restricted to this mammary cell-specific enhancer involving sequences -1094 through -858. A mobility shift assay was used to demonstrate that PRL, EGF or TGF-alpha induce nuclear factors (MP4, MAF, and MGF) which bind directly to this mammary cell-specific enhancer element.

Binding Sites↗
PubMed1997

Interleukin 10 is induced by recombinant HIV-1 Nef protein involving the calcium/calmodulin-dependent phosphodiesterase signal transduction pathway.

HIV-1 Nef protein shares a significant homology with the immunosuppressive and highly conserved retroviral transmembrane protein p15E. In the present study, extracellular Nef protein is shown to induce interleukin (IL)-10 mRNA expression in human peripheral blood mononuclear cells as well as in cells of H9 T and U937 promonocytic human cell lines. Release of IL-10 protein into supernatants of peripheral blood mononuclear cells stimulated with Nef is dose-dependent. Expression of cytokines IL-2, IL-4, IL-5, IL-12 p40, IL-13, and interferon gamma is not affected by Nef stimulation. IL-10 protein production induced by Nef is inhibited by the calcium/calmodulin phosphodiesterase inhibitor W-7 but not by the protein kinase A inhibitor H-89 nor the protein kinase C inhibitors staurosporine and calphostin C. The calcium chelating agent EGTA also inhibits the IL-10 production induced by Nef, and this inhibition is reversed by the addition of calcium along with Nef. These findings indicate that extracellular Nef may contribute to the immunopathogenesis of HIV infection by inducing IL-10.

Cell Line↗
PubMed1997

Immunosuppressive retroviral peptides: immunopathological implications for immunosuppressive influences of retroviral infections.

Studies of the effects of retroviruses on the immune system, which date back through thirty years of investigations, are reviewed. In the earliest published studies in the 1960s, it was demonstrated that mice infected with oncogenic viruses were immunosuppressed. Since then, numerous articles have been published describing profound immunodeficiencies observed in vivo in humans infected with human immunodeficiency virus and in animals such as cats infected with the feline immunodeficiency virus. In vitro investigations have shown that inactivated retroviruses or transmembrane envelope protein p15E as well as a synthetic 17-amino acid peptide (CKS-17) impressively conserved within the transmembrane envelope protein of several animal or human retroviruses are highly immunosuppressive. More recently, dysfunction of cytokines produced by CKS-17 at both a cellular and molecular level have been found to mimic influences observed in vivo in patients infected with the human immunodeficiency virus. CKS-17 has also been shown to induce cAMP in vitro. The significance of these observations to understanding the immunological disturbances observed in malignancy, cytokine biosynthesis, and modulations of immune functions through cAMP is discussed.

Amino Acid Sequence↗
PubMed1997

HIV-1 recombinant gp41 induces IL-10 expression and production in peripheral blood monocytes but not in T-lymphocytes.

The effects of recombinant gp41 (rgp41) protein of the human immunodeficiency virus type 1 (HIV-1) on interleukin 10 (IL-10) expression and production using human peripheral blood mononuclear cells was investigated. Expression of IL-10 mRNA was demonstrated within 3 h of cell exposure to endotoxin-free rgp41 by RT-PCR and Northern blot analyses in a time- and dose-dependent manner. IL-10 protein was detected in the supernatants of peripheral blood mononuclear cells following stimulation with rgp41 also in a dose dependent manner. Fractionation of peripheral blood mononuclear cells showed that purified monocytes but not purified T-lymphocytes induced expression of IL-10 mRNA by rgp41. Recombinant HIV-1 gp120 exhibits similar influences on the induction of IL-10. These results indicate that both of these components of envelope proteins may play an important role in HIV related immunomodulation by influencing regulatory functions of monocytes and macrophages.

Chemical Fractionation↗