113 research outputs found

    Crystal structure of a family I.3 lipase from Pseudomonas sp. MIS38 in a closed conformation

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    AbstractThe crystal structure of a family I.3 lipase from Pseudomonas sp. MIS38 in a closed conformation was determined at 1.5Å resolution. This structure highly resembles that of Serratia marcescens LipA in an open conformation, except for the structures of two lids. Lid1 is anchored by a Ca2+ ion (Ca1) in an open conformation, but lacks this Ca1 site and greatly changes its structure and position in a closed conformation. Lid2 forms a helical hairpin in an open conformation, but does not form it and covers the active site in a closed conformation. Based on these results, we discuss on the lid-opening mechanism

    Approach for growth of high-quality and large protein crystals

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    Three crystallization methods, including crystallization in the presence of a semi-solid agarose gel, top-seeded solution growth (TSSG) and a large-scale hanging-drop method, have previously been presented. In this study, crystallization has been further evaluated in the presence of a semi-solid agarose gel by crystallizing additional proteins. A novel crystallization method combining TSSG and the large-scale hanging-drop method has also been developed

    Malignant Lymphoma in the Parasellar Region

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    The entity of pituitary (sellar or parasellar) lymphoma includes primary pituitary lymphoma (PPL) and secondary pituitary lymphoma (SPL). The latter has an involvement of systemic lymphoma. Both of these lymphomas are extremely rare. We describe a patient with SPL showing a good prognosis. A 78-year-old woman presented with diplopia, left ptosis, and back pain. Magnetic resonance (MR) imaging revealed a parasellar mass lesion extending to the upper clivus and another mass lesion with compression fracture of the Th3 vertebral body. Transsphenoidal exploration was performed, and it showed diffuse large B-cell lymphoma. Based on the positive tumor cells in the following bone marrow aspiration and hepatosplenomegaly in computed tomography (CT) findings, this patient was diagnosed as having a pituitary involvement of systemic lymphoma. After chemotherapy, she achieved complete remission for 4 years. The entity of pituitary lymphoma is extremely rare. Nineteen cases of PPL and 16 cases of SPL have been reported. Generally, clinical and radiological diagnosis was difficult because there are no specific findings. Therefore, biopsy was necessary in all of the cases. T2 hypointensity of a lesion in MR imaging in addition to an elevated serum level of soluble interleukin-2 receptor (sIL-2R) in a patient with a sellar lesion can be useful clues for the differential diagnosis of this rare disease

    Development and External Validation of a Nomogram Predicting the Probability of Significant Gleason Sum Upgrading among Japanese Patients with Localized Prostate Cancer

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    Objective. The aim of this study is to develop a prognostic model capable of predicting the probability of significant upgrading among Japanese patients. Methods. The study cohort comprised 508 men treated with RP, with available prostate-specific antigen levels, biopsy, and RP Gleason sum values. Clinical and pathological data from 258 patients were obtained from another Japanese institution for validation. Results. Significant Gleason sum upgrading was recorded in 92 patients (18.1%) at RP. The accuracy of the nomogram predicting the probability of significant Gleason sum upgrading between biopsy and RP specimens was 88.9%. Overall AUC was 0.872 when applied to the validation data set. Nomogram predictions of significant upgrading were within 7.5% of an ideal nomogram. Conclusions. Nearly one-fifth of Japanese patients with prostate cancer will be significantly upgraded. Our nomogram seems to provide considerably accurate predictions regardless of minor variations in pathological assessment when applied to Japanese patient populations

    Correlations of Vascular Architecture and Angiogenesis with Pituitary Adenoma Histotype

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    Vascular endothelial growth factor (VEGF) is a potent angiogenic factor in solid tumors. However, its role in angiogenesis in pituitary adenoma is controversial. Angiogenesis in solid tumors including pituitary adenoma is commonly evaluated by microvascular density (MVD). Here, we evaluated MVD and the role of VEGF in vascular architecture in 51 pituitary adenomas (24 nonfunctioning, 13 prolactin-secreting, 10 growth hormone-secreting, 3 adrenocorticotropic hormone-secreting, and 1 thyroid-stimulating hormone-secreting). Paraffin sections were stained with CD34 and VEGF. MVD and vascular architecture parameters (vessel area, diameter, perimeter, and roundness) were evaluated in CD34-stained sections. Immunohistochemistry showed 27/51 tumors (53%) were VEGF-positive. There were no significant differences in MVD, any vascular parameter, or adenoma volume between VEGF-positive and VEGF-negative tumors. VEGF mRNA expression was significantly higher in VEGF-positive tumors. There were no significant correlations between VEGF mRNA expression and MVD or vascular parameters. However, vessel diameter and perimeter were significantly larger in prolactin-secreting than nonfunctioning and growth hormone-secreting macroadenomas. The difference in vessel diameter was observed among both VEGF-positive and all adenomas (micro- and macroadenoma). Thus, VEGF may have limited roles in the development of vascular architecture and tumor angiogenesis in pituitary adenomas, but the differences in vessel architecture by histotype (i.e., larger vessel diameter and perimeter in prolactin-secreting adenomas) suggest the hormonal regulation of vessel architecture rather than angiogenesi

    バッシゴ シュッケツ オ ケイキ ニ シンダン サレタ コウレイシャ ニオケル センテンセイ ケツユウビョウ A ノ 1レイ

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    Hemophilia A is often diagnosed by gingival change, traumatic injuries, or bleeding after extraction in childhood, but rarely in senior age. We experienced that a 66 year-old man was diagnosed as hemophilia A by bleeding after tooth extraction. He was referred to our hospital for control the bleeding after tooth extraction. Although we tried to stop bleeding by local hemostasis, we repeated to bleed several times. Then we examined the level of hemorrhage factors. As a result, the patient was diagnosed as moderate hemophilia A, and he received recombinant factor VIII intravenously. After that, the bleeding had been stopped completely

    Relationship between the Immunohistochemical Expressions of Cathepsin B, Laminin and Tenascin and Clinicopathologic Features in Gallbladder Carcinomas

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    In the present study, the expression of protease indicated by cathepsin B (CB) and the expression of extracellular matrix indicated by laminin (LN) and tenascin (TN) was immunohistochemically examined in 25 gallbladder carcinomas. The incidence of expression of .CB and TN in normal epithelium was 1/25 (4%) and 0/25 (0%), respectively, and significantly increased in carcinomas (14/25 : 56% and 21/25 : 84%, respectively) (p<0.01). The LN expression was detected in the basement membrane of all normal epithelium, and the incidence of LN expression was significantly decreased in the carcinomas (7/25: 28%) (p<0.01). The incidence of CB expression in poorly differentiated adenocarcinomas (1/8: 13%) was significantly lower than that in papillary, welland moderately differentiated adenocarcinomas (11/15: 74%) (p<0.01). However, these responses were not significantly related with other histologic features or nuclear DNA ploidy pattern. The LN expression of the hepatic metastasis group (4/6 :67%) was significantly greater than that in the non-metastatic group (3/19 :16%) (p<0.05). The expressions of CB, LN and TN were not associated with the postoperative prognosis. In conclusion, the increased expressions of CB and TN, and the decreased expression of LN were cancerassociated alterations. The expression of CB was correlated with the histological grade of differentiation, and the expression of LN was correlated with the hepatic metastasis

    Efficacy of bevacizumab therapy in recurrent malignant gliomas in relation to the prior recurrence pattern or tumor location

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    Although promising preliminary results have been widely observed with bevacizumab for recurrent malignant gliomas, many unanswered questions remain to be resolved to achieve an optimal outcome. No predictive biomarkers of a survival benefit from bevacizumab have been established, and no consensus exists about the response or survival benefit regarding the prior recurrence pattern or tumor location. Here we retrospectively analyzed the clinical benefit from bevacizumab for recurrent malignant gliomas in relation to the prior recurrence pattern or tumor location. Thirty-one consecutive patients with recurrent malignant gliomas who were treated with bevacizumab were investigated. The treatment response and survival benefit from bevacizumab were analyzed in association with age, sex, Karnofsky performance status, prior pathological diagnosis, prior recurrence pattern, primary location of tumor, recurrence status, and expression of angiogenic and hypoxic markers. The group with leptomeningeal dissemination had a significantly shorter median overall survival with bevacizumab (OSBev) (6.0 months, 95% confidence interval (CI) 1.4–10.7) compared to those in the local/distant group (11.8 months, 95% CI 6.1–17.4). The median OSBev of the infratentorial tumor group and supratentorial tumor group were 9.2 months (95% CI 5.0–13.4) and 10.4 months (95% CI 6.6–14.3), respectively. With multivariate analysis, the prior recurrence pattern was the only independent prognostic factor of OSBev. Patients with leptomeningeal dissemination of recurrent malignant glioma experienced minimal benefit from bevacizumab. Therefore, in the context of cost effectiveness, bevacizumab is not recommended for patients with leptomeningeal dissemination

    Conformational plasticity of RNA for target recognition as revealed by the 2.15 Å crystal structure of a human IgG–aptamer complex

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    Aptamers are short single-stranded nucleic acids with high affinity to target molecules and are applicable to therapeutics and diagnostics. Regardless of an increasing number of reported aptamers, the structural basis of the interaction of RNA aptamer with proteins is poorly understood. Here, we determined the 2.15 Å crystal structure of the Fc fragment of human IgG1 (hFc1) complexed with an anti-Fc RNA aptamer. The aptamer adopts a characteristic structure fit to hFc1 that is stabilized by a calcium ion, and the binding activity of the aptamer can be controlled many times by calcium chelation and addition. Importantly, the aptamer–hFc1 interaction involves mainly van der Waals contacts and hydrogen bonds rather than electrostatic forces, in contrast to other known aptamer–protein complexes. Moreover, the aptamer–hFc1 interaction involves human IgG-specific amino acids, rendering the aptamer specific to human IgGs, and not crossreactive to other species IgGs. Hence, the aptamer is a potent alternative for protein A affinity purification of Fc-fusion proteins and therapeutic antibodies. These results demonstrate, from a structural viewpoint, that conformational plasticity and selectivity of an RNA aptamer is achieved by multiple interactions other than electrostatic forces, which is applicable to many protein targets of low or no affinity to nucleic acids
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