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71.
ESCs are a potential cell source for cell therapy. However, there is no evidence that cell transplantation using ESC-derived hepatocytes is therapeutically effective. The main objective of this study was to assess the therapeutic efficacy of the transplantation of ESC-derived endodermal cells into a liver injury model. The beta-galactosidase-labeled mouse ESCs were differentiated into alpha-fetoprotein (AFP)-producing endodermal cells. AFP-producing cells or ESCs were transplanted into transgenic mice that expressed diphtheria toxin (DT) receptors under the control of an albumin enhancer/promoter. Selective damage was induced in the recipient hepatocytes by the administration of DT. Although the transplanted AFP-producing cells had repopulated only 3.4% of the total liver mass 7 days after cell transplantation, they replaced 32.8% of the liver by day 35. However, these engrafted cells decreased (18.3% at day 40 and 7.9% at day 50) after the cessation of DT administration, and few donor cells were observed by days 60-90. The survival rate of the AFP-producing cell-transplanted group (66.7%) was significantly higher in comparison with that of the sham-operated group (17.6%). No tumors were detected by day 50 in the AFP-producing cell-transplanted group; however, splenic teratomas did form 60 days or more after transplantation. ESC transplantation had no effect on survival rates; furthermore, there was a high frequency of tumors in the ESC-transplanted group 35 days after transplantation. In conclusion, this study demonstrates, for the first time, that ESC-derived endodermal cells improve the survival rates after transplantation into mice with induced hepatocellular injury. Disclosure of potential conflicts of interest is found at the end of this article.  相似文献   
72.
Gestational trophoblastic disease (GTD) is a unique spectrum of diseases ranging from complete hydatidiform mole (CHM), partial hydatidiform mole (PHM), and invasive mole (IM) to choriocarcinoma (CC). Placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT) have been classified as related disorders. Mesenchymal dysplasia (MD) may be misdiagnosed as PHM; however, it is said to have a quite different histogenesis from PHM. P57kip2 is the protein product of a paternally imprinted or maternal gene that inhibits cyclin-dependent kinases (CDK), thus serving to inhibit cell proliferation and to suppress tumor growth. Its lack of expression in trophoblastic disease plays a role in its abnormal proliferation and differentiation. In this study, P57kip2 immunostaining was absent in the trophoblastic layers of CHM and was positive in the trophoblast layer of nonmolar villi and MD. Ultrastructure of complete molar cystic villi showed tree-like branching of microvillous processes and intracytoplasmic lacunae without capillaries in the stroma, whereas MD contained many newly formed blood vessels and collagen. Also, large lacunae with microvilli and polymorphic nuclei of syncytiotrophoblast cells with well-developed organelles were observed in IM. Lung ETT following CHM and normal deliveries showed two types of large mononuclear cells and binuclear cells with abundant organelles and bundles of intermediate-type filaments in the stroma.  相似文献   
73.
74.
BackgroundNeoadjuvant chemotherapy (NAC) has been conducted for patients with non-resectable colorectal cancer; however, few reports of a systematic approach to NAC exist. At our hospital, bevacizumab with capecitabine and oxaliplatin (B-mab XELOX) has been used as chemotherapy for Stage IV colorectal cancer since 2014. We aimed to evaluate the efficacy and safety of NAC with a molecular-targeting agent for Stage IV colorectal cancer.MethodsA retrospective, single-institute analysis was performed including 27 patients with advanced recurrent cancer following primary tumor resection and 43 patients with non-resectable tumors and remote metastasis. At the time of resection, 17 were receiving chemotherapy. All 70 patients received at least 3 cycles of B-mab XELOX (total: 920 cycles). We determined the 1-year progression-free survival (1Y-PFS), 1-year overall survival (1Y-OS), 3Y-PFS, 3Y-OS, and number of treatment cycles. The objective response rate, clinical benefit rate, and adverse events were assessed. The number of chemotherapy cycles, survival time, and R0 surgery rate were determined for patients who underwent RO conversion surgery.ResultsThe 1Y-PFS was 28.5% [median survival time (MST): 7.4 months], 1Y-OS was 76.6% (MST not reached), 3Y-PFS was 5.5% (MST: 7.4 months), and 3Y-OS was 26.4% (MST: 25.2 months). The mean and median number of cycles of B-mab XELOX was 13.1 and 10.5, respectively. The objective response rate was 28.6%, and the clinical benefit rate was 58.6%. Grade 1 or Grade 2 adverse events occurred in 60 patients (85.7%); however, they all resolved without intervention. A single Grade 4 event (perforation of the primary tumor) occurred in 1 patient (1.4%). RO conversion surgery was performed in 7 patients (10.0%; primary + liver in 2 patients, primary + lung in 1 patient, liver in 3 patients, and primary in 1 patient). These patients received 3 to 10 cycles preoperatively (mean: 7.3; median: 6.5). R0 surgery was achieved in 5 of the 7 patients (71.4%). Postoperative survival ranged from 1 to 26 months (MST: 8 months).ConclusionsThis modified regimen was safe and effective in Japanese patients, and a high quality of life/quality-adjusted life-year was achieved. To further evaluate PFS and OS, more patients are being investigated.  相似文献   
75.
The development of new drugs and limitations of clinical trials have increased the likelihood of adverse drug events. Pharmacovigilance is essential to detect and evaluate adverse drug events, thereby reducing risks and avoiding excessive public health costs. This study focused on the pharmacovigilance programs in the pharmaceutical industry in S?o Paulo State, Brazil. Data were collected through questionnaires sent electronically to 105 companies, 41.9% of which responded. The main reason for implementing pharmacovigilance programs was to comply with legal requirements, while the main justification for its absence was production limited to herbal remedies, officinal products, and supplements. The article discusses the obstacles to program implementation, resources used, and characteristics of several such programs. Conclusions: (a) standardization is the reason for the increasing number of programs and reports, but more specific guidelines are needed; (b) results depend on multi-sector involvement; (c) customer service centers are an important source of reports; and (d) operation of the service requires only modest human and material resources.  相似文献   
76.
The neurohypophyseal peptide [Arg(8)]-vasopressin (AVP) exerts major physiological actions through three distinct receptor isoforms designated V1a, V1b, and V2. Among these three subtypes, the vasopressin V1b receptor is specifically expressed in pituitary corticotrophs and mediates the stimulatory effect of vasopressin on ACTH release. To investigate the functional roles of V1b receptor subtypes in vivo, gene targeting was used to create a mouse model lacking the V1b receptor gene (V1bR-/-). Under resting conditions, circulating concentrations of ACTH and corticosterone were lower in V1bR-/- mice compared with WT mice (V1bR+/+). The normal increase in circulating ACTH levels in response to exogenous administration of AVP was impaired in V1bR-/- mice, while corticotropin-releasing hormone-stimulated ACTH release in the V1bR-/- mice was not significantly different from that in the V1bR+/+ mice. AVP-induced ACTH release from primary cultured pituitary cells in V1bR-/- mice was also blunted. Furthermore, the increase in ACTH after a forced swim stress was significantly suppressed in V1bR-/- mice. Our results clearly demonstrate that the V1b receptor plays a crucial role in regulating hypothalamic-pituitary-adrenal axis activity. It does this by maintaining ACTH and corticosterone levels, not only under stress but also under basal conditions.  相似文献   
77.
It is very important to examine the influence of inhibition of in situ estrogen production on the pathobiology of human sex steroid-dependent tumors in order to understand the clinical effects of aromatase inhibitors. We have examined the biological changes before and after aromatase inhibitor treatment in vitro (endometrial and ovarian cancer) and in vivo (breast cancer). First, we analyzed these changes using histoculture of 15 human endometrial cancers and 9 ovarian cancers. Five of the fifteen endometrial cancers and four of the nine ovarian cancers demonstrated decreased [3H]thymidine uptake or Ki67 labeling index after 14alpha-hydroxy-4-androstene-3,6,17-trione (NKS01) treatment. In ovarian cancer cases, the responsive cases tended to be associated with higher aromatase and estrogen receptor alpha (ER) expression compared with the other cases but this was not seen in the endometrial cancer cases. There were no changes in ER and aromatase expression before and after NKS01 treatment in either ovarian or endometrial cancer cases. We then studied the same primary human breast tumors before and after aminoglutethimide (AMG, n=3) and 4-hydroxyandrostenedione (4-OHA, n=3) treatment. Tumor aromatase activity increased in 3 cases and decreased or was unchanged in 3 cases but aromatase immunoreactivity in stroma and adipocytes was unaltered in 5 cases. There were no changes in the ER labeling index before or after treatment. Five of the six cases including the responsive cases tended to be associated with decreased cell proliferation or Ki67 expression and increased apoptosis when examined by the TUNEL method. These results indicate that aromatase inhibitors may exert their effects on human breast and other cancers through decreasing proliferation and increasing apoptosis, possibly without altering ER status.  相似文献   
78.
To investigate the role of the neck domain of kinesin, we used optical trapping nanometry to perform high-resolution measurements of the movements and forces produced by recombinant kinesin fragments in which the neck domains were shortened or replaced by an artificial random coil. Truncated kinesin fragments (K351) that contain a motor domain consisting of ≈340 aa and a short neck domain consisting of ≈11 aa showed fast movement (800 nm/s) and 8-nm steps. Such behavior was similar to that of recombinant fragments containing the full-length neck domain (K411) and to that of native kinesin. Kinesin fragments lacking the short neck domain (K340), however, showed very slow movement (<50 nm/s), as previously reported. Joining an artificial 11-aa sequence that was expected to form a flexible random chain to the motor domain (K340–chain) produced normal fast (≈700 nm/s) and stepwise movement. The results suggest that the neck domain does not act as a rigid lever arm to magnify the structural change at the catalytic domain as has been believed for myosin, but it does act as a flexible joint to guarantee the mobility of the motor domain.  相似文献   
79.
80.
Type I IFNs have broad activity in tissue inflammation and malignant progression that depends on the expression of IFN-stimulated genes (ISGs). ISG15, one such ISG, can form covalent conjugates to many cellular proteins, a process termed “protein ISGylation.” Although type I IFNs are involved in multiple inflammatory disorders, the role of protein ISGylation during inflammation has not been evaluated. Here we report that protein ISGylation exacerbates intestinal inflammation and colitis-associated colon cancer in mice. Mechanistically, we demonstrate that protein ISGylation negatively regulates the ubiquitin–proteasome system, leading to increased production of IFN-induced reactive oxygen species (ROS). The increased cellular ROS then enhances LPS-induced activation of p38 MAP kinase and the expression of inflammation-related cytokines in macrophages. Thus our studies reveal a regulatory role for protein ISGylation in colonic inflammation and its related malignant progression, indicating that targeting ubiquitin-activating enzyme E1 homolog has therapeutic potential in treating inflammatory diseases.Chronic inflammation is a major pathologic basis for a number of malignancies, such as esophageal, gastric, hepatic, and colorectal cancer (CRC) (1). Specifically, ulcerative colitis (UC), a form of human inflammatory bowel disease (IBD), is associated with an increased risk for the development of CRC. Extensive experimental and clinical studies strongly suggest that the initiation and progression of human IBD involve complicated interactions among genetic, environmental, and immune factors, which result in aberrant immune responses in the intestinal mucosa (2, 3). IFNs are crucial regulators of cell proliferation, differentiation, survival, and death. They are categorized further as type I (IFN-α, -β, -ω, or -τ), type II (IFN-γ), and type III (IFN-λ) based on their structure (4). Type I IFNs are associated with multiple autoimmune and inflammatory disorders, including IBD (5). Early studies demonstrated beneficial effects of type I IFNs in regulating intestinal homeostasis in experimental colitis models (6); however, most later studies failed to demonstrate a beneficial therapeutic effect of type I IFNs in patients who have IBD (7, 8). Interestingly, recent studies also uncovered a proinflammatory role for type I IFNs in an experimental colitis model (9). In clinical practice, some patients who were treated with type I IFN for hepatitis C infection or multiple sclerosis either experienced an exacerbation of existing UC or developed UC (5, 10). These studies in animal models and clinical observations indicate a complicated role for type I IFNs during intestinal inflammation. However, the role of specific IFN-stimulated genes (ISGs) in colonic inflammation is poorly understood.ISG15 is strongly up-regulated by type I IFN (11). As a ubiquitin-like modifier, ISG15 can form covalent conjugates to many cellular proteins, a process termed “protein ISGylation” (12, 13). A series of distinct enzymes are involved in the process of protein ISGylation, including ubiquitin-activating enzyme E1 homolog (UBE1L) (14, 15), a conjugating enzyme, ubiquitin carrier protein L6 (UBCH8) (E2) (16, 17), protein ligases (E3) (1821), and an ISG15-specific protease USP18 (22, 23), as well as some viral proteins (24). Interestingly, ISG15 and the majority of its modification enzymes are encoded by ISGs (25), indicating that protein ISGylation is a tightly regulated process and plays important roles in immune responses (26). Protein ISGylation is strongly enhanced upon pathogen infection and cellular stress related o IFN induction (25). Several in vitro studies using cell lines and human cancer samples have begun to reveal anti- and protumorigenic roles of ISGylation (2729). However, in vivo studies of protein ISGylation in tumorigenesis are relatively rare and have become a pressing need for understanding the role of ISG15 in malignant progression. In this report we demonstrate, for the first time to our knowledge, that protein ISGylation is linked to intestinal inflammation and colitis-associated CRC in mouse models.  相似文献   
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