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Biomedical subjects

S Haraguchi

Publications and source records attributed to S Haraguchi.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1996

Effects of phosphate on in vitro 2-cell block of AKR/N mouse embryos based on changes in cdc2 kinase activity and phosphorylation states.

This study demonstrated the effects of phosphate on the 2-cell block of AKR/N mouse embryos at the molecular level and focused on changes in the kinase activity and the phosphorylation state of cdc2, which is shown to regulate the cell division cycle. Removal of phosphate from the culture medium dramatically increased developmental rates to the 4-cell (91.8%) and blastocyst (42.6%) stages compared with those of embryos cultured in 1.17 mM phosphate (3.3% and 0%, respectively). The rate of development to the 4-cell stage was significantly inhibited by 0.001 mM phosphate (p < 0.05), and no morula formation was observed at 1.0 mM. The patterns of cdc2 kinase activity during the first cell cycle in AKR/N embryos were similar to those of control MCH embryos, showing the highest activity at M phase and low activity during the interphase. The phosphorylated form of cdc2 increased during the interphase, indicating that the synthesis of cyclin B and accumulation of inactive pre-maturation-promoting factor (pre-MPF) as well as abrupt dephosphorylation of cdc2 at the first cleavage correlated with the activation of cdc2 kinase. When phosphate was absent, the activation pattern of cdc2 kinase during the second cell cycle in AKR/N embryos was similar to that in the first cell cycle. On the other hand, no dephosphorylation of cdc2 was observed and the kinase activity remained at a low level until 56 h after insemination in the presence of phosphate, although an increase in phosphorylated cdc2 was observed as in the phosphate-free group. Treatment of AKR/N embryos arrested at the 2-cell stage with okadaic acid resulted in the dephosphorylation and activation of cdc2, confirming the presence of a sufficient amount of pre-MPF. These results show that phosphate has a deteriorative effect on the in vitro development of AKR/N embryos and suggest that this effect was not on the synthesis of cyclin B but on the dephosphorylation of phosphorylated cdc2.

Animals↗
PubMed1996

Meiotic abnormalities of c-mos knockout mouse oocytes: activation after first meiosis or entrance into third meiotic metaphase.

In Xenopus oocytes, Mos activates the mitogen-activated protein kinase (MAPK) signal transduction cascade and regulates meiosis. In mammalian oocytes, however, the functions of Mos are still unclear. In the present study, we used c-mos knockout mouse oocytes and examined the roles of Mos in mouse oocyte maturation and fertilization, including whether Mos controls MAPK and maturation promoting factor (MPF) activity. The kinetics of germinal vesicle breakdown (GVBD) and the first polar body emission were similar in wild-type, heterozygous mutant, and homozygous mutant mice. Activities of MPF were also not significantly different among the three genotypes until the first polar body emission. In contrast, MAPK activity in c-mos knockout oocytes did not significantly fluctuate throughout maturation, and the oocytes had abnormal diffused spindles and loosely condensed chromosomes, although a clear increase in MAPK activities was observed after GVBD in wild-type and heterozygous mutant oocytes that had normal spindles and chromosomes. After the first polar body emission, 38% of c-mos knockout oocytes formed a pronucleus instead of undergoing second meiosis, indicating the crucial role of Mos in MPF reactivation after first meiosis. When oocytes that reached second metaphase were fertilized or stimulated by ethanol, many c-mos knockout oocytes emitted a second polar body and progressed into third meiotic metaphase instead of interphase, although all fertilized or activated oocytes in the heterozygote progressed to interphase, indicating that Mos deletion leads to compensatory factors that might not be degraded after fertilization or parthenogenetic activation. These results suggest that Mos is located upstream of MAPK in mouse oocytes as in Xenopus oocytes but is independent of MPF activity, and that Mos/MAPK is not necessary go GVBD and first polar body emission. Our results also suggest that Mos plays a crucial role in normal spindle and chromosome morphology and the reactivation of MPF after first meiosis.

Animals↗
PubMed1996

[Evaluation of the prognosis of patients with stage I non-small cell lung cancer with respect to predicted postoperative lung function].

One hundred and forty patients underwent absolute curative resction for stage I non-small lung cancer from 1982 to 1993 at our department. For these, prognosis and changes in quality of life (QOL) were evaluated retrospectively with respect to the predicted postoperative lung function. The average age of the patients was 62 years (range 31 to 84 years), and 103 males and 37 females were included. Seventy-five of the patients had adenocarcinoma, 61 squamous cell carcinoma, and 4 large cell carcinoma. These 140 patients were classified into two groups, H and N, according to the predicted postoperative %FEV1.0 and %VC. Group H patients (n = 39) had a predicted %FEV1.0 and/or %VC of 55% or less for postoperative respiratory disease. Group N patients (n = 101) had a predicted %FEV1.0 and %VC of 56% or more for expected normal respiratory conditions postoperatively. Group N patients showed a 98% one-year survival rate, and 72% five-year survival rate and good QOL postoperatively. On the other hand, group H patients showed 86% and 45% one- and five-year survival rates respectively, the same as those predicted for patients with stage II non-small cell lung cancer. Furthermore, group H patients more than 70 years old showed 80% and 17% one- and five-year survival rates, the same as those predicted for patients with stage IIIA non-small cell lung cancer, and poor prognosis in comparison with that of the group N patients more than 70 years old. Then, QOL was investigated one year postoperatively. The group H patients showed deterioration of performance status in comparison with the group N patients. Since there was a high incidence of postoperative respiratory disease in the patients with a predicted %FEV1.0 and/or %VC of 55% or less, physicians should avoid extended lung resection, which might cause deterioration of the cardiopulmonary reserve volume, in patients in whom respiratory disease is predicted to occur, particularly for patients more than 70 years old. In conclusion, physicians should consider limiting surgical intervention to preserve lung volume and QOL of patients more than 70 years old with restricted cardiopulmonary function.

Adult↗
PubMed1996

[Analysis of risk factors for development of bronchopleural fistula after pneumonectomy for lung cancer].

Bronchopleural fistulas (BPF) developed in six (7.9%) of 76 patients who underwent a pneumonectomy for treatment of lung cancer. Five patients (18.2%) underwent a right pneumonectomy and one (3.7%) a left pneumonectomy. All patients were male, had squamous cell carcinoma, and were diagnosed as having BPF within one month after pneumonectomy. Their average age was 60.2 years. Univariate analyses related to development of BPF showed that significant risk factors were preoperative infection (Chi-square test; p < 0.001), right pneumonectomy (Chi-square test; p < 0.05), and metastasis to a subcarinal lymph node (Chi-square test; p < 0.05). However, sex, age, operating time, amount of blood loss during surgery, amount of blood transfused during surgery, history of smoking, degree of lymph node dissection, degree of curability, performance of combined resection, histologic type of tumor, tumor size, presence of residual tumor at the bronchial stump, and suturing method were not significant risk factors for development of BPF. Our stepwise regression analysis related to development of BPF showed that preoperative infection, metastasis to a subcarinal lymph node, right pneumonectomy, and combined resection were significant risk factors. Sometimes it is difficult to preserve the bronchial arteries upon the dissection of metastatic subcarinal lymph nodes which tightly adhere to the bronchial sheath. Moreover, after a conventional right pneumonectomy, the bronchial stump protrudes into the pleural cavity and is not covered by any tissue. Ligation of the bronchial arteries or protrusion of the bronchial stump into the right pleural cavity reduces the blood supply to the bronchial stump to a very low level and causes development of BPF. Therefore, we suggest that control of preoperative infection, wrapping of the bronchial stump, and preservation of the bronchial arteries during mediastinal lymph node dissection are important to prevent development of BPF.

Bronchial Fistula↗
PubMed1995

Induction of intracellular cAMP by a synthetic retroviral envelope peptide: a possible mechanism of immunopathogenesis in retroviral infections.

A synthetic heptadecapeptide, CKS-17, represents the highly conserved amino acid sequences occurring within the transmembrane envelope protein of many animal and human retroviruses. CKS-17 has been demonstrated to exhibit suppressive properties for numerous immune functions. We have recently shown that CKS-17 acts as an immunomodulatory epitope causing an imbalance of human type 1 and type 2 cytokine production and suppression of cell-mediated immunities. cAMP, an intracellular second messenger, plays an important role in regulation of cytokine biosynthesis--i.e., elevation of intracellular cAMP levels selectively inhibits type 1 cytokine production but has no effect or enhances type 2 cytokine production. Here, we demonstrate that CKS-17 induces dramatic rises in the intracellular cAMP levels of a human monocyte cell line and of human peripheral blood mononuclear cells in a time- and dose-dependent manner. A peptide corresponding to the reverse sequence of CKS-17, used as control, has no effect on intracellular cAMP levels. The cAMP-inducing ability of CKS-17 is significantly blocked by SQ-22536, an inhibitor of adenylate cyclase. These results indicate that CKS-17, a highly conserved component of the transmembrane proteins of immunosuppressive retroviruses, induces increased intracellular levels of cAMP via activation of adenylate cyclase and suggest that this retroviral envelope peptide may differentially modulate type 1 and type 2 cytokine production through elevation of intracellular cAMP levels.

Adenylyl Cyclases↗
PubMed1995

Differential modulation of Th1- and Th2-related cytokine mRNA expression by a synthetic peptide homologous to a conserved domain within retroviral envelope protein.

The influence of a synthetic retroviral peptide, CKS-17, on T helper type 1 (Th1)- or Th2-related cytokines was investigated in human blood mononuclear cells. Cells were stimulated with staphylococcal enterotoxin A, anti-CD3 plus anti-CD28 monoclonal antibodies, or lipopolysaccharide to induce cytokine mRNA. mRNA was detected by a reverse transcription-polymerase chain reaction or Northern blot analysis. CKS-17 down-regulated stimulant-induced mRNA accumulation for interferon gamma (IFN-gamma), interleukin (IL)-2, and p40 heavy and p35 light chains of IL-12, a cytokine that mediates development of Th1 response. CKS-17 up-regulated stimulant-induced mRNA accumulation of IL-10 and did not suppress Th2-related cytokine (IL-4, IL-5, IL-6, or IL-13) mRNA expression. A reverse sequence of CKS-17 peptide, used as a control, showed no such action. Anti-human IL-10 monoclonal antibody blocked ability of CKS-17 to inhibit mRNA accumulation for IFN-gamma but not the CKS-17 suppressive activity of IL-12 p40 heavy chain mRNA. Thus, CKS-17-mediated suppression of IFN-gamma mRNA expression is dependent upon augmentation of IL-10 production by CKS-17. This conserved component of several retroviral envelope proteins, CKS-17, may act as an immunomodulatory epitope responsible for cytokine dysregulation that leads to suppression of cellular immunity.

Amino Acid Sequence↗
PubMed1995

Immunosuppressive retroviral peptides: cAMP and cytokine patterns.

The mechanism(s) by which retroviral proteins exert immunosuppressive influences has remained enigmatic. Here, Soichi Haraguchi, Robert Good and Noorbibi Day propose that induction of intracellular cAMP by a synthetic, immunosuppressive, retroviral envelope peptide causes a shift in the cytokine balance, leading to suppression of cell-mediated immunity by upregulation of interleukin 10 (IL-10) and downregulation of IL-2, IL-12 and tumor necrosis factor alpha production. This may be a crucial step towards generation of immune dysfunction.

Amino Acid Sequence↗
PubMed1995

[Pulmonary infarct hardly differentiated from lung cancer--a case report].

A 64-year-old woman experienced high grade fever, chest pain, and hemosputum. She was admitted to a hospital for evaluation of the infiltrate on an chest X-ray. She was diagnosed as having lung cancer by sputum cytology and transferred to our hospital for operation. The tumor was obscure on palpation during thoractomy, but malignancy could not be ruled out based on analysis of frozen sections. Therefore, a right lower lobectomy and mediastinal lymph node dissection were performed. Pulmonary infarct was not suspected until thrombi were observed in the dissected pulmonary artery. Urokinase and heparin were intravenously administered soon after the operation, but the patient died of pulmonary thromboembolism of the sixth postoperative day. Examination of the operative specimen revealed pulmonary thromboembolism with infarction and no evidence of malignancy. Atypical cells observed in sputum cytology seemed to be derived from basal cell hyperplasia in the area of infarction. Type II alveolar epithelial cell hyperplasia was observed in the periphery of the infarction. These findings seemed to make accurate analysis of frozen sections difficult. An increasing number of cases of pulmonary thromboembolism is being reported in Japan. Therefore, pulmonary infarct with false positive cytology may be encountered more frequently in the future.

Diagnosis, Differential↗